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| J Mol Biol, 2004 Jul 16, 340(4), 753 - 66 Stepwise dissection of the Hin-catalyzed recombination reaction from synapsis to resolution; Sanders ER et al.; The Hin DNA invertase promotes a site-specific DNA recombination reaction in the Salmonella chromosome . The native Hin reaction exhibits overwhelming selectivity for promoting inversions between appropriately oriented recombination sites and requires the Fis regulatory protein, a recombinational enhancer, and a supercoiled DNA substrate . Here, we report a robust recombination reaction employing oligonucleotide substrates and a hyperactive mutant form of Hin . Synaptic complex intermediates purified by gel electrophoresis were found to contain four Hin protomers bound to two recombination sites . Each Hin protomer is associated covalently with a cleaved DNA end . The cleaved complexes can be ligated into both parental and recombinant orientations at equivalent frequencies, provided the core residues can base-pair, and are readily disassembled into separated DNA fragments bound by Hin dimers . Kinetic analyses reveal that synapsis occurs rapidly, followed by comparatively slow Hin-catalyzed DNA cleavage . Subsequent steps of the reaction, including DNA exchange and ligation, are fast . Thus, post-synaptic step(s) required for DNA cleavage limit the overall rate of the recombination reaction. J Food Prot, 2004 Jun, 67(6), 1257 - 60 Heat treatments to enhance the safety of mung bean seeds; Hu H et al.; Salmonella enterica serovars and Escherichia coli O157:H7 have been associated with contaminated seed sprout outbreaks . The majority of these outbreaks have been traced to sprout seeds contaminated with low levels of pathogens . E . coli O157:H7 strains can grow an average of 2.3 log CFU/g over 2 days during seed germination, and Salmonella can achieve an average growth of 3.7 log CFU/g . Therefore, it is important to find an effective method to reduce possible pathogenic bacterial populations on the seeds prior to sprouting . Our objective was to assess the effectiveness of various dry heat treatments on reducing E . coli O157:H7 and Salmonella populations on mung beans intended for sprout production and to determine the effect of these treatments on seed germination . Mung beans were inoculated with five-strain cocktails of E . coli O157:H7 and of Salmonella serovars harboring the green fluorescent protein gene and then air dried overnight . Heat treatments were performed by incubating the seeds at 55 degrees C for various periods of time . Heat-treated seeds were then assessed for the efficacy of the heat treatment and the effects of heat treatment on germination rates . After inoculation and drying, 6 log CFU/g E . coli O157:H7 and 4 log CFU/g Salmonella were detected on the seeds . Following heat treatment, pathogenic bacterial populations on the seeds were below detectable levels (<1 log CFU/g), but the germination rate of the seed was not affected . Thus, the risk of contamination and the presence of pathogens in the finished sprouts were greatly reduced via the seed heat treatment process. J Food Prot, 2004 Jun, 67(6), 1201 - 8 Simulation model for enumeration of Salmonella on chicken as a function of PCR detection time score and sample size: implications for risk assessment; Oscar TP; A data gap commonly identified in risk assessments is the lack of quantitative information on the contamination of food with pathogens . A simulation model that predicts the incidence and distribution of Salmonella contamination on chicken as a function of PCR detection time score and sample size was developed with data from challenge studies with preenrichment samples that were composed of 25 g of chicken and 225 ml of buffered peptone water inoculated with 10(0.7) to 10(6) Salmonella and incubated at 37 degrees C . At 0, 2, 4, 6, 8, 10, 12, and 24 h of incubation, subsamples were collected and tested for Salmonella by PCR, and a PCR detection time score based on the widths of the bands in the electrophoresis gel was obtained for each preenrichment sample . Standard curves relating PCR detection time score to initial density of Salmonella inoculated were developed for sterile and nonsterile preenrichment samples . Presence of other microorganisms in the preenrichment sample decreased the PCR detection time score at low (<10(2) per 25 g) but not at high (>10(2) per 25 g) initial densities of Salmonella and resulted in a nonlinear standard curve rather than the linear standard curve obtained for sterile samples . The predicted incidence and distribution of Salmonella contamination on chicken increased in a nonlinear manner as sample size increased from 25 to 500 g . The new method reduced the time and cost of Salmonella enumeration by eliminating the selective enrichment, selective plating, and confirmation steps of the traditional most-probable-number method . Results are useful for risk assessment because they consider the uncertainty of the standard curve predictions and because they provide distributions of Salmonella contamination for different size samples of chicken that can be directly used in risk assessment. J Food Prot, 2004 Jun, 67(6), 1177 - 83 Reduction of Salmonella by two commercial egg white pasteurization methods; Robertson WR et al.; The effect of pH, processing temperatures, and preheating steps in two commercial egg white pasteurization procedures (Armour and Standard Brands methods) were evaluated using a five-strain cocktail of Salmonella . We devised a benchtop pasteurization system that would more closely resemble the two commercial processes than could the traditional capillary tube method . The pasteurization methods both require hydrogen peroxide to be metered into the egg white stream between a required initial preheat step and the main heating regimen . Both processes were evaluated at three pH levels (pH 8.2, 8.6, 9.0), at four temperatures (51.7 degrees C/125 degrees F, 53.1 degrees C/127.5 degrees F, 54.4 degrees C/130 degrees F, 55.8 degrees C/132.5 degrees F), and over four residence times to allow calculation of D-values at each temperature . When compared at the minimum allowable time and temperatures for each process, our results showed at least a 1-log greater log reduction (P < 0.05) for the Standard Brands method than the Armour method in 10 of 12 of the pH and temperature combinations tested . Almost all runs at any given temperature showed more reduction at pH 9.0 than at pH 8.2 except for the Standard Brands method at 54.4 degrees C and 55.8 degrees C, which showed the most consistent reduction across all three pH levels tested . Analysis of the preheat portion of the two methods showed that there was no contribution (P > 0.05) toward Salmonella reduction when compared with the identical process without the preheating step . We generally observed a greater reduction of Salmonella with egg white at pH 9.0 that is typical of older, off-line processing than with low pH egg white (i.e., 8.2) that is typical of modern in-line processing facilities . This difference was as much as 3.5 log cycles depending on the processing conditions . The data has been used to make recommendations for minimum processing conditions for hydrogen peroxide-based egg white pasteurization. J Food Prot, 2004 Jun, 67(6), 1157 - 62 Radiosensitization of Escherichia coli and Salmonella Typhi in ground beef; Chiasson F et al.; The radiosensitization of two pathogenic bacteria, Escherichia coli and Salmonella Typhi, was evaluated in the presence of thyme and its principal essential oil constituents (carvacrol and thymol) in ground beef . Ground beef was inoculated with E . coli or Salmonella Typhi (10(5) CFU/g), and each compound was added separately at various concentrations (0 to 3.5%, wt/wt) . The antimicrobial potential of carvacrol, thymol, and thyme was evaluated in unirradiated meat by determining the MIC in percentage (wt/wt) after 24 h of storage at 4 +/- 1 degree C . Results showed a MIC of 0.88 +/- 0.12%, 1.14 +/- 0.05%, and 2.33 +/- 0.32% for E . coli in the presence of carvacrol, thymol, and thyme, respectively . MICs of 1.15 +/- 0.02%, 1.60 +/- 0.01%, and 2.75 +/- 0.17% were observed for Salmonella Typhi in the presence of the same compounds, respectively . The best antimicrobial compound (i.e., carvacrol) was selected and added to the sterilized ground beef along with ascorbic acid (0.5%, wt/wt) and tetrasodium pyrophosphate (0.1%, wt/wt) . Meat samples (10 g) were packed in air and then irradiated in a 60Co irradiator at doses of 0 to 0.7 kGy for the determination of E . coli radiation D10 and 0 to 2.25 kGy for the determination of Salmonella Typhi radiation D10 . Addition of carvacrol increased the relative sensitivity of both bacteria 2.2 times . The radiation D10 was reduced from 0.126 +/- 0.0039 to 0.057 +/- 0.0015 kGy for E . coli and from 0.519 +/- 0.0308 to 0.235 +/- 0.0158 kGy for Salmonella Typhi . The addition of tetrasodium pyrophosphate did not affect significantly (P > 0.05) the radiosensitization of either bacterium . However, the presence of ascorbic acid in the media reduced significantly (P < or = 0.05) the radiosensitivity of both bacteria . An additive effect of carvacrol addition and packaging under modified atmosphere conditions (60% O2-30% CO2-10% N2) was also observed on bacterial radiosensitization at 4 degrees C . Compared with the control packed under air, modified atmosphere packaging conditions in the presence of carvacrol and tetrasodium pyrophosphate improved the relative sensitivity of E . coli by 2.7 times and Salmonella Typhi by 9.9 times. J Food Prot, 2004 Jun, 67(6), 1111 - 5 Frozen chicken nuggets and strips--a newly identified risk factor for Salmonella Heidelberg infection in British Columbia, Canada; MacDougall L et al.; Salmonella enterica var . Heidelberg was isolated from an unusual food source during routine case follow-up, prompting a case control investigation of frozen chicken nuggets and strips . Most frozen nuggets and strips are raw; however, par-frying lends a cooked appearance . As such, suitable food preparation precautions might not be undertaken by consumers . Cases were confirmed in the laboratory between 1 January and 1 April 2003 . Controls were generated through forward-digit dialing and individually matched by age category . Telephone interviews were conducted, and limited sampling of unopened product was performed . Eighteen matched pairs were interviewed . The odds of infection were 11 times higher in individuals who had consumed frozen processed chicken nuggets and strips (95% confidence interval, 1.42 < odds ratio < 85.20) . One-third of cases and controls considered frozen nuggets and strips to be precooked, and one quarter used the microwave, an ill-advised cooking method . Consumer misconceptions contributed to the risk of infection . Clear labels identifying nuggets and strips as raw poultry are needed. J Food Prot, 2004 Jun, 67(6), 1092 - 103 Survival and recovery of Escherichia coli O157:H7, Salmonella, and Listeria monocytogenes on lettuce and parsley as affected by method of inoculation, time between inoculation and analysis, and treatment with chlorinated water; Lang MM et al.; The effects of method for applying inoculum and of drying time after inoculation on survival and recovery of foodborne pathogens on iceberg lettuce and parsley were studied . Five-strain mixtures of Escherichia coli O157:H7, Salmonella, or Listeria monocytogenes were applied to lettuce and parsley by dip, spot, or spray inoculation methods . Inocula were dried for 2 h at 22 degrees C or for 2 h at 22 degrees C and then 22 h at 4 degrees C before being treated with water (control) or chlorine (200 microg/ml) . Significantly higher populations (CFU per lettuce or parsley sample) of E . coli O157:H7 and Salmonella (alpha = 0.05) were recovered from dip-inoculated produce than from spot- or spray-inoculated produce . This difference was attributed to larger numbers of cells adhering to lettuce and parsley subjected to dip inoculation . Populations of E . coli O157:H7 and Salmonella recovered from lettuce inoculated by spot and spray methods were not significantly different, but populations recovered from spot-inoculated parsley were significantly higher than those recovered from spray-inoculated parsley, even though the number of cells applied was the same . Significantly different numbers of L . monocytogenes were recovered from inoculated lettuce (dip > spray > spot); populations recovered from dip-inoculated parsley were significantly higher than those recovered from spot- or spray-inoculated parsley, which were not significantly different from each other . Populations of pathogens recovered from lettuce and parsley after drying inoculum for 2 h at 22 degrees C were significantly higher than or equal to populations recovered after drying for 2 h at 22 degrees C and then for 22 h at 4 degrees C . Significant differences (water > chlorine) were observed in populations of all pathogens recovered from treated lettuce and parsley, regardless of inoculation method and drying time . It is recommended that spot inoculation with a drying time of 2 h at 22 degrees C followed by 22 h at 4 degrees C be used to determine the efficacy of chlorine and other sanitizers in killing foodborne pathogens on lettuce and parsley. Biometals, 2004 Jun, 17(3), 337 - 42 Recombinant human lactoferrin treatment for global health issues: iron deficiency and acute diarrhea; Bethell DR et al.; Iron deficiency and diarrhea are two of the most significant issues for global health . Iron deficiency anemia is the most common nutritional deficiency in the world, affecting nearly 25% of the world population (UNICEF/WHO 1999) . The prevalence of iron deficiency in developing countries is illustrated by comparison with other deficiencies: iron deficiency affects 3.5 billion people, while vitamin A and iodine deficiency affect 0.3 billion people and 0.8 billion people, respectively . The prevalence is highest among young children and women of childbearing age (particularly pregnant women) . It is estimated that national productivity levels could be raised as much as 20% by correcting iron deficiency in developing countries . Recombinant human lactoferrin (rhLF), expressed and extracted from rice seed, is being evaluated by Ventria Bioscience for use as a dietary supplement to treat iron deficiency and/or iron deficiency anemia . Diarrhea is also a major world health issue . Sixty percent of children who die under age five die of pneumonia, diarrhea or measles . World Health Organization oral rehydration solution (WHO-ORS) is one of the major medical advances in the past 50 years, saving the lives of 1 to 2 million children annually . Many studies have demonstrated similar efficacy of rice-based ORS . There are studies documenting the reduced frequency of diarrhea in breast-fed children and this health improvement is attributed to the antimicrobial action of the human milk proteins lactoferrin and lysozyme . In vitro data document the growth inhibition of the diarrheal associated organisms: rotavirus, ETEC, cholera, salmonella, and shigella by human lactoferrin (hLF) and human lysozyme . Using Ventria's ExpressTec system, we have expressed human lactoferrin and human lysozyme in rice . In a rice-based ORS formulation, these proteins have the potential to provide not only the benefits of reduced stool volume and improved weight gain, but also shorten the course of diarrheal episodes via antimicrobial activity against the causative agent. Prev Vet Med, 2004 Jun 10, 64(1), 1 - 14 Estimation of infection prevalence from correlated binomial samples; Condon J et al.; Infection prevalence in a population often is estimated from grouped binary data expressed as proportions . The groups can be families, herds, flocks, farms, etc . The observed number of cases generally is assumed to have a Binomial distribution and the estimate of prevalence is then the sample proportion of cases . However, the individual binary observations might not be independent--leading to overdispersion . The goal of this paper was to demonstrate random-effects models for the estimation of infection prevalence from data which are correlated and in particular, to illustrate a nonparametric random-effects model for this purpose . The nonparametric approach is a relatively recent addition to the random-effects class of models and does not appear to have been discussed previously in the veterinary epidemiology literature . The assumptions for a logistic-regression model with a nonparametric random effect were outlined . In a demonstration of the method on data relating to Salmonella infection in Irish pig herds, the nonparametric method resulted in the classification of herds into a small number of distinct prevalence groups (i.e . low, medium and high prevalence) and also estimated the relative frequency of each prevalence category in the population . We compared the estimates from a logistic model with a nonparametric distribution for the random effects with four alternative models: a logistic-regression model with no random effects, a marginal model using a generalised estimating equation (GEE) and two methods of fitting a Normally distributed random effect (the GLIMMIX macro and the NLMIXED procedure both in SAS) . Parameter estimates from random-effects models are not readily interpretable in terms of prevalences . Therefore, we outlined two methods for calculating population-averaged estimates of prevalence from random-effects models: one using numerical integration and the other using Monte Carlo simulation. Public Health Rep, 2004 Jul-Aug, 119(4), 435 - 42 A review of outbreaks of waterborne disease associated with ships: evidence for risk management; Rooney RM et al.; OBJECTIVE: The organization of water supply to and on ships differs considerably from that of water supply on land . Risks of contamination can arise from source water at the port or during loading, storage, or distribution on the ship . The purpose of this article is to review documented outbreaks of waterborne diseases associated with passenger, cargo, fishing, and naval ships to identify contributing factors so that similar outbreaks can be prevented in the future . METHODS: The authors reviewed 21 reported outbreaks of waterborne diseases associated with ships . For each outbreak, data on pathogens/toxins, type of ship, factors contributing to outbreaks, mortality and morbidity, and remedial action are presented . RESULTS: The findings of this review show that the majority of reported outbreaks were associated with passenger ships and that more than 6,400 people were affected . Waterborne outbreaks due to Enterotoxigenic Escherichia coli, noroviruses, Salmonella spp, Shigella sp, Cryptosporidium sp, and Giardia lamblia occurred on ships . Enterotoxigenic E . coli was the pathogen most frequently associated with outbreaks . One outbreak of chemical water poisoning also occurred on a ship . Risk factors included contaminated port water, inadequate treatment, improper loading techniques, poor design and maintenance of storage tanks, ingress of contamination during repair and maintenance, cross-connections, back siphonage, and insufficient residual disinfectant . CONCLUSIONS: Waterborne disease outbreaks on ships can be prevented . The factors contributing to outbreaks emphasize the need for hygienic handling of water along the supply chain from source to consumption . A comprehensive approach to water safety on ships is essential . This may be achieved by the adoption of Water Safety Plans that cover design, construction, operation, and routine inspection and maintenance. Przegl Epidemiol, 2004, 58(1), 213 - 8 {Typhoid fever in a child--a case report}; Kuchar E et al.; We report a case of typhoid fever in an 8 years old boy . The child was initially admitted to a local hospital where pneumonia, myocarditis with heart failure, pyelonephritis, liver and pancreatic failure as well as cholelithiasis were suspected . Zinaceff and Amikin were administered and after 8 days the child was referred to the cardiology department of a regional reference hospital due to heart failure symptoms . There the diagnosis of sepsis was established, and the antibiotics changed to Pipril and Amikin . The child however did not improve and after two days he was transferred to an intensive care unit . The previous anti-microbial therapy was continued for another 7 days until the results of stool culture revealing Salmonella sp . were available . Subsequently the boy was admitted to our clinic . Based on the clinical course, Widal test and isolating of the Salmonella typhi from the stool samples typhoid fever was diagnosed. Przegl Epidemiol, 2004, 58(1), 85 - 101 {Foodborne infections and intoxications in Poland in 2002}; Przybylska A; A total of 26,734 bacterial foodborne infections and intoxications were registered in 2002 (incidence 69.9/100,000 population) . S . Enteritidis was found in 94.8% of collective outbreaks (in Poland 4 sick people and more) and 90.4% cases in outbreaks caused by Salmonella of animal's source . The main vehicle of foodborne and waterborne outbreaks in 2002 was food prepared from various raw materials (3 and more) of animal's source (35.6% cases in outbreaks) and the next--from eggs (20.9% cases in outbreaks) . Private homes prevailed (47.1% outbreaks, 66.2% outbreaks caused by Salmonella) among the places of the ready made food production . Ten epidemics with 100 and more cases each, were registered . Six deaths were noted in outbreaks in 2002 (2--in the result of salmonellosis of the animal's source, 1--in the result of staphylococcal infection and 3--after chemical poisoning). Przegl Epidemiol, 2004, 58(1), 67 - 76 {Salmonellosis in Poland in 2002}; Gonera E et al.; Total number of salmonellosis cases slightly increased . In 2002, 20,688 cases were reported (19,881 in previous year), incidence rate = 54.1 per 100,000 population . 68% of patients were hospitalized, but percentage of hospitalized cases with extraintestinal manifestations was much higher--above 91% . The seasonal peak was observed as in previous year in July and August . Since 1995 (when Salmonella strains were isolated in 91% patients) decreasing trend in confirmation of clinical diagnosis is observed . The most frequent isolated type remained Salmonella Enteritidis--above 86% of cases . Only four other serotypes (Typhimurium, Hadar, Virchow and Infantis) were detected in all of 16 voivodeships of Poland . The age, sex, urban/rural distribution of salmonellosis cases remains stable; the highest incidence was registered among children aged 2 (474.0/100,000) . Extraintestinal manifestations of salmonellosis (septicaemia, meningitis, pneumonia peritonitis and other) were observed in 113 patients (the highest number since 1994). J Vasc Surg, 2004 Jul, 40(1), 30 - 5 Infected aortic aneurysms: clinical outcome and risk factor analysis; Hsu RB et al.; PURPOSE: Infected aortic aneurysms are difficult to treat, and are associated with significant mortality . Hospital survival is poor in patients with severe aortic infection, Salmonella species infection, Staphylococcus aureus infection, aneurysm rupture, and suprarenal aneurysm location . We reviewed the clinical outcome in 46 patients with primary infected aortic aneurysms and identified clinical variables associated with prognosis . METHODS: Data were collected by means of retrospective chart review . Univariate and multivariate logistic regression models were used for risk factor analysis . RESULTS: Between August 1995 and March 2003, 48 patients with primary infected aortic aneurysms were treated at our hospitals . Two patients with negative culture results were excluded . Of the remaining 46 patients, 35 patients had aortic aneurysms infected with Salmonella species and 11 patients had aortic aneurysms infected with microorganisms other than Salmonella species . There were 20 suprarenal infections and 26 infrarenal infections . Surgical debridement and in situ graft replacement were performed in 35 patients, with an early mortality rate of 11% . The incidence of late prosthetic graft infection was 10% . The 90-day mortality rate in patients operated on was 0% for elective operation and 36% for nonelective operation (P =.006, Fisher exact test) . Independent predictors of aneurysm-related death were advanced age, non-Salmonella infection, and no operation . CONCLUSION: With timely surgical intervention and prolonged antibiotic treatment, in situ graft replacement provides an excellent outcome in patients with primary infected aortic aneurysms and elective operation . Mortality is still high in patients undergoing urgent operation . Advanced age, non-Salmonella infection, and no operation are major determinants of mortality. J Med Assoc Thai, 2004 Apr, 87(4), 400 - 4 Percutaneous ultrasound-guided fine needle aspiration of abdominal lymphadenopathy in AIDS patients; Veerapand P et al.; OBJECTIVE: To analyse the causes of abdominal lymphadenopathy in AIDS patients and evaluate the performance success rate, diagnostic yielding rate and safety of ultrasound (US)-guided fine needle aspiration (FNA) . MATERIAL AND METHOD: Medical records of HIV seropositive with abdominal lymphadenopathy who underwent percutaenous US-guided FNA from August 1997 to January 2002 were retrospectively reviewed . Records of clinical and ultrasonographic findings, numbers of FNA performed, numbers of obtained specimen, laboratory results and postoperative problems were analysed . Performance success is defined as obtaining a specimen while diagnostic yielding is performance success with laboratory result . RESULTS: FNA was done 72 times in 71 patients obtaining specimens in 68 cases (performance success rate = 94.4%) with positive laboratory result in 63 cases (diagnostic yielding rate = 87.5%) . The culture gave results in 56 cases; M . tuberculosis (TB) = 36, TB with other organisms = 5, Mycobacterium avium complex = 2, Nontuberculous mycobacterium = 10, C . neoformans = 1, Salmonella with positive fungal stain = 1, E . coli with P . mirabilis = 1 . Five cases had positive AFB without culture specimen and one revealed positive AFB stain but negative culture . Lymphoma was found in only one case . No postoperative hemorrhage, peritonitis or perforated bowel in patient or needle stick injury to medical staff was reported . CONCLUSION: Abdominal lymphadenopathy at Bamrasnaradura Hospital is mostly caused by TB and the second most common is nontuberculous mycobacterium . Percutaneous FNA under US guidance could yield definite diagnosis with a high performance success rate, high diagnostic yielding rate and was safe. J Chemother, 2004 Apr, 16(2), 128 - 33 Effects of acetyl salicylate and ibuprofen on fluoroquinolone MICs on Salmonella enterica serovar typhimurium in vitro; Coban AY et al.; In this study, the effects of acetylsalicylate and ibuprofen at 2, 4 and 8 mM concentration were investigated on ofloxacin, ciprofloxacin, levofloxacin and pefloxacin minimum inhibitory concentrations (MICs) for 14 Salmonella enterica serovar typhimurium clinical isolates, one standard strain (SZH KUEN 557), SH7616 (acr mutant), SH5014 (parent strain of acr mutant) and PP120 (soxRS mutant) strains . All isolates were susceptible to the 4 fluoroquinolones . In the presence of 2, 4 and 8 mM acetylsalicylate and ibuprofen, 2- to 8-fold increases were observed in fluoroquinolone MICs . This rise was higher, especially in the presence of acetylsalicylate . In spite of this rise, none of the MICs were in the range of resistance limits in vitro . Except for a 2-fold increase in levofloxacin MICs, we did not observe any difference in MICs of ofloxacin, ciprofloxacin, and pefloxacin in the presence of 2, 4 and 8 mM acetylsalicylate and ibuprofen for SH7616 and PP120 strains . According to the in vitro results of this study, it can be suggested that use of acetylsalicylate or ibuprofen together with clinical treatment of bacteria, especially bacteria which show intermediate resistance, will cause resistance . However, since clinical data are insufficient, further studies are needed. Rozhl Chir, 2004 May, 83(5), 209 - 16 {Bacterial aortitis}; Sebesta P et al.; A cohort of 14 patients with bacterial destruction of various segments of the aortic wall is presented . The Salmonella enteritidis strain was predominantly responsible . Most patients had typical history of symptomatic trias of sepsis, abdominal and/or back pain and positive blood cultures . CT scan showed pseudoaneurysm within the thoracic, subphrenic or subrenal aorta as well as acute hemorrhage in three patients . One of these was excluded from invasive treatment due to hopeless prognosis . In one patient primary aortoduodenal phistula was responsible for GI bleeding . Five patients were operated and prosthetic replacement of subrenal or iuxtarenal aortic portion together with aortorenal bypass in a couple of cases was performed . In eight patients stentgrafts (SG) of various types were deployed completed with femorofemoral crossover bypass when necessary . All patients were subject to long-standing antibiotic therapy . Two patients expired following SG insertion, all operated patients survived . Average follow-up has been 1 year (1-22 months) so far . A groin abscess was later drained in one patient . Neither CT nor isotope scanning showed persistent or recurrent infectious or hemorrhagic foci in any survivors whatsoever . The authors review and consider the doubtful indication of aortic SG deployment into the septic terrain in selected cases . Midterm results might justify its use in overly debilitated patients otherwise not eligible for radical operation due to its prohibitive risk. Virus Genes, 2004 Aug, 29(1), 87 - 98 Homology between two different Salmonella phages: Salmonella enterica serovar Typhimurium phage P22 and Salmonella enterica serovar Anatum var . 15 + phageepsilon34; Salgado CJ et al.; A distinguishing feature of many microorganisms, belonging to the Gram negative group of bacteria, is the presence of the lipopolysaccharide on their cell surface . Salmonella is a prominent member of this group of bacteria . Many Salmonella phages use the LPS as the initial receptor in the infection process and they can distinguish subtle changes in the LPS molecules . The phage protein that is responsible for recognition of these cells is the tail or tailspike protein (TSP) . Those TSPs, which use LPS as a receptor, are prokaryotic LPS-binding proteins . As an initial step in using phage TSPs as model systems for a detailed molecular genetic analysis of protein-LPS interactions, a comparison of two phages and their TSPs from two different Salmonella bacterial viruses (phages), Salmonella enterica serovar Typhimurium phage P22 and Salmonella enterica serovar Anatum var . 15 + phage epsilon34, is being carried out . This present study shows significant viral protein homology between many viral structural proteins from these two phages including their TSPs . Significantly this report suggests a general structural motif for part of the TSP of phages and suggests that a more detailed comparative analysis of these TSPs is warranted. J Biol Chem, 2004 Aug 27, 279(35), 36470 - 80 Epub 2004 Jun 23. Investigation of the structural requirements in the lipopolysaccharide core acceptor for ligation of O antigens in the genus Salmonella: WaaL "ligase" is not the sole determinant of acceptor specificity; Kaniuk NA et al.; The ligation of O antigen polysaccharide to lipid A-core oligosaccharide is a late step in the formation of the complex glycolipid known as lipopolysaccharide . Although the process has been localized to the periplasmic face of the inner membrane, details of the ligation mechanism have not been resolved . To date, there is only one gene product (WaaL, often referred to as "ligase") known to be required . There exists a requirement for a specific lipid A-core oligosaccharide acceptor structure for ligation activity, and it has been proposed that the WaaL protein imparts this acceptor specificity . Here the structural requirements in the core oligosaccharide acceptor for O antigen ligation are investigated in prototype serovars of Salmonella enterica . Complementation experiments in mutants with defined core oligosaccharide structure indicate that the specificity of the ligation reaction for a particular core oligosaccharide structure is not dependent on the WaaL protein alone . The data provide the first indication of a more complicated recognition process involving additional cellular components. Antimicrob Agents Chemother, 2004 Jul, 48(7), 2712 - 5 Incidence of the recently described sulfonamide resistance gene sul3 among German Salmonella enterica strains isolated from livestock and food; Guerra B et al.; The sul3 gene recently described in Escherichia coli was found in 22 of 512 (4.3%) German Salmonella isolates from different regions and sources and of different serotypes, antimicrobial resistance phenotypes, and genomic groups . This is the first report on the prevalence of sul3 among Salmonella strains, and the findings support the strong potential of this determinant to spread within bacterial populations. Antimicrob Agents Chemother, 2004 Jul, 48(7), 2510 - 7 Salmonella genomic island 1 multidrug resistance gene clusters in Salmonella enterica serovar Agona isolated in Belgium in 1992 to 2002; Doublet B et al.; Salmonella genomic island 1 (SGI1) harbors a multidrug resistance (MDR) gene cluster which is a complex class 1 integron . Variant SGI1 MDR gene clusters conferring different MDR profiles have also been identified in several Salmonella enterica serovars and classified as SGI1-A to -F . A retrospective study was undertaken to characterize MDR regions from serovar Agona strains harboring SGI1 isolated from poultry in Belgium between 1992 and 2002 . A total of 171 serovar Agona strains, displaying resistance to at least one antibiotic, were studied for the presence of SGI1 . SGI1 was detected in 94 serovar Agona strains . The most prevalent variant was SGI1-A (85%), which harbors within the SGI1 complex class 1 integron a common region (CR1) containing orf513, a putative transposase gene, adjacent to the dfrA10 trimethoprim resistance gene . A new variant SGI1 named SGI1-G was identified in two strains . It consisted of the pse-1 gene cassette, as in SGI1-B, but with additional insertion of the orf513/dfrA10 region structure . Seven strains displaying the typical SGI1 MDR profile (Ap Cm Ff Sm Sp Su Tc) showed genetic variation at the 3' end of SGI1 . These strains harbored the insertion of the CR1 containing orf513 as in SGI1-A, -D, and -G . However, downstream the right end of CR1, they presented different 7.4- to 8.5-kb deletions of the SGI1 3' end that extended to the chromosomal genes yieE and yieF . These results suggest a possible role of CR1 in deletion formation, as has been reported for some insertion sequences . Pulsed-field gel electrophoresis analysis showed that all the serovar Agona SGI1-carrying strains belonged to a single clone . Thus, SGI1 is largely encountered in serovar Agona strains isolated from poultry in Belgium, the most prevalent variant being SGI1-A . SGI1 MDR region undergoes recombinational events resulting in a diversity of MDR gene clusters. Antimicrob Agents Chemother, 2004 Jul, 48(7), 2364 - 9 Antibiotic resistance conferred by a class I integron and SXT constin in Vibrio cholerae O1 strains isolated in Laos; Iwanaga M et al.; Changes in the drug susceptibility pattern were observed in Vibrio cholerae O1 isolated in the Lao People's Democratic Republic during 1993 to 2000 . In this study, 50 V . cholerae O1 strains were selected during this period for studying the presence of class I integron and SXT constin . Twenty-four streptomycin-resistant strains out of 26 isolated before 1997 contained a class I integron harboring the aadA1 gene cassette . Twenty-four strains isolated after 1997 contained an SXT constin (a large conjugative element) . Twenty of the strains were resistant to chloramphenicol, tetracycline, streptomycin, and trimethoprim-sulfamethoxazole, while four strains were susceptible to the antibiotic tested . The resistance genes included in the SXT constins were floR, tetA, strAB, and sulII, which encode resistance to chloramphenicol, tetracycline, streptomycin, and sulfamethoxazole, respectively . The antibiotic resistance gene cluster was found to be deleted in the four susceptible strains . SXT(LAOS) did not contain dfrA1 or dfr18, which confer resistance to trimethoprim in SXT(ET) and SXT(MO10), respectively . A hot spot region of SXT(LAOS) was sequenced, and we identified two novel open reading frames showing homology to sO24 (exonuclease) and sO23 (helicase) of the genomic island associated with the multidrug resistance region of Salmonella enterica serovar Typhimurium DT104 . Analysis of SXT(LAOS) showed that there is a continuous flux of genes among V . cholerae SXT constins which should be carefully monitored. Antimicrob Agents Chemother, 2004 Jul, 48(7), 2355 - 63 Single-nucleotide polymorphism mutation spectra and resistance to quinolones in Salmonella enterica serovar Enteritidis with a mutator phenotype; Levy DD et al.; Resistance to quinolone antibiotics has been associated with single-nucleotide polymorphisms (SNPs) in the quinolone resistance-determining region (QRDR) of gyrA . Mutations in the gyrA gene were compared by using mutant populations derived from wild-type Salmonella enterica serovar Enteritidis and its isogenic mutS::Tn10 mutator counterpart . Spontaneous mutants arising during nonselective growth were isolated by selection with either nalidixic acid, enrofloxacin, or ciprofloxacin . QRDR SNPs were identified in approximately 70% (512 of 695) of the isolates via colony hybridization with radiolabeled oligonucleotide probes . Notably, transition base substitution SNPs in the QRDR were dramatically increased in mutants derived from the mutS strain . Some, but not all, antibiotic-resistant mutants lacking QRDR SNPs were resistant to tetracycline and chloramphenicol, consistent with alterations in nonspecific efflux pumps or other membrane transport mechanisms . Changing the selection conditions shifted the mutation spectrum . Selection with ciprofloxacin was least likely to yield a mutant harboring either a QRDR SNP or chloramphenicol resistance . Selection with enrofloxacin was more likely to yield mutants containing Ser83-->Phe mutations, whereas selection with ciprofloxacin or nalidixic acid favored recovery of Asp87-->Gly mutants . Fluoroquinolone-resistant Salmonella strains isolated from veterinary or clinical settings frequently display a mutational spectrum with a preponderance of transition SNPs in the QRDR, the pattern found in vitro among mutS mutator mutants reported here . Both the preponderance of transition mutations and the varied mutation spectra reported for veterinary and clinical isolates suggest that bacterial mutators defective in methyl-directed mismatch repair may play a role in the emergence of quinolone and fluoroquinolone resistance in feral settings. Clin Microbiol Infect, 2004 Jul, 10(7), 595 - 7 Rhabdomyolysis induced by Salmonella enterica serovar Typhi bacteraemia; Fisk DT et al.; Rhabdomyolysis has been reported infrequently with salmonella infection . Since 1964, there have been at least 22 reports associated with gastroenteritis or bacteraemia . Twenty cases have been associated with non-typhoidal strains of Salmonella, with single reports of Salmonella enterica serovars Paratyphi and Typhi . A second case of typhoid fever associated with rhabdomyolysis was recently diagnosed in Ann Arbor, USA in a traveller returning from an endemic area . Prompt diagnosis and treatment resulted in a good outcome . Salmonella infection should be considered by clinicians as a possibility in the differential diagnosis of rhabdomyolysis. Lett Appl Microbiol, 2004, 38(4), 265 - 70 Cloth-based hybridization array system for the detection of multiple antibiotic resistance genes in Salmonella enterica subsp . enterica serotype Typhimurium DT104; Gauthier M et al.; AIMS: A simple DNA macroarray system was developed for detection of antibiotic resistance and other marker genes associated with the multidrug-resistant food pathogen Salmonella enterica subsp . enterica serotype Typhimurium DT104 . METHODS AND RESULTS: A multiplex polymerase chain reaction (PCR) incorporating digoxigenin-dUTP was used to simultaneously amplify seven marker sequences, with subsequent rapid detection of the amplicons by hybridization with an array of probes immobilized on polyester cloth and immunoenzymatic assay of the bound label . This system provided sensitive detection of the different genetic markers in the S . Typhimurium DT104 genome, giving positive reactions with as few as 10 CFU, and the hybridizations were highly specific, with no reactions of amplicons with heterologous probes on the array . CONCLUSIONS: This cloth-based hybridization array system (CHAS) provides a simple, cost-effective tool for monitoring S . Typhimurium DT104 in foods and their production environment . SIGNIFICANCE AND IMPACT OF THE STUDY: The CHAS is a simple and cost-effective tool for the simultaneous detection of amplicons generated in a multiplex PCR, and the concept is broadly applicable to the detection and characterization of food pathogens. Infect Immun, 2004 Jul, 72(7), 4297 - 301 Oral immunization with an rfaH mutant elicits protection against salmonellosis in mice; Nagy G et al.; Loss of the transcriptional antiterminator RfaH results in virulence attenuation (>10(4)-fold increase in 50% lethal dose) of the archetypal Salmonella enterica serovar Typhimurium strain SL1344 by both orogastric and intraperitoneal routes of infection in BALB/c mice . Oral immunization with the mutant efficiently protects mice against a subsequent oral infection with the wild-type strain . Interestingly, in vitro immunoreactivity is not confined to strain SL1344; rather, it is directed also towards other serovars of S . enterica and even Salmonella bongori strains. Infect Immun, 2004 Jul, 72(7), 4138 - 50 Flagella and chemotaxis are required for efficient induction of Salmonella enterica serovar Typhimurium colitis in streptomycin-pretreated mice; Stecher B et al.; Salmonella enterica subspecies 1 serovar Typhimurium is a common cause of gastrointestinal infections . The host's innate immune system and a complex set of Salmonella virulence factors are thought to contribute to enteric disease . The serovar Typhimurium virulence factors have been studied extensively by using tissue culture assays, and bovine infection models have been used to verify the role of these factors in enterocolitis . Streptomycin-pretreated mice provide an alternative animal model to study enteric salmonellosis . In this model, the Salmonella pathogenicity island 1 type III secretion system has a key virulence function . Nothing is known about the role of other virulence factors . We investigated the role of flagella in murine serovar Typhimurium colitis . A nonflagellated serovar Typhimurium mutant (fliGHI) efficiently colonized the intestine but caused little colitis during the early phase of infection (10 and 24 h postinfection) . In competition assays with differentially labeled strains, the fliGHI mutant had a reduced capacity to get near the intestinal epithelium, as determined by fluorescence microscopy . A flagellated but nonchemotactic cheY mutant had the same virulence defects as the fliGHI mutant for causing colitis . In competitive infections, both mutants colonized the intestine of streptomycin-pretreated mice by day 1 postinfection but were outcompeted by the wild-type strain by day 3 postinfection . Together, these data demonstrate that flagella are required for efficient colonization and induction of colitis in streptomycin-pretreated mice . This effect is mostly attributable to chemotaxis . Recognition of flagellar subunits (i.e., flagellin) by innate immune receptors (i.e., Toll-like receptor 5) may be less important. Infect Immun, 2004 Jul, 72(7), 3987 - 4003 The two murein lipoproteins of Salmonella enterica serovar Typhimurium contribute to the virulence of the organism; Sha J et al.; Septic shock due to Salmonella and other gram-negative enteric pathogens is a leading cause of death worldwide . The role of lipopolysaccharide in sepsis is well studied; however, the contribution of other bacterial outer membrane components, such as Braun (murein) lipoprotein (Lpp), is not well defined . The genome of Salmonella enterica serovar Typhimurium harbors two copies of the lipoprotein (lpp) gene . We constructed a serovar Typhimurium strain with deletions in both copies of the lpp gene (lpp1 and lpp2) by marker exchange mutagenesis . The integrity of the cell membrane and the secretion of the effector proteins through the type III secretion system were not affected in the lpp double-knockout mutant . Subsequently, the virulence potential of this mutant was examined in a cell culture system using T84 intestinal epithelial and RAW264.7 macrophage cell lines and a mouse model of salmonellosis . The lpp double-knockout mutant was defective in invading and inducing cytotoxic effects in T84 and RAW264.7 cells, although binding of the mutant to the host cell was not affected when compared to the wild-type (WT) serovar Typhimurium . The motility of the mutant was impaired, despite the finding that the number of flagella was similar in the lpp double knockout mutant and the WT serovar Typhimurium . Deletion in the lpp genes did not affect the intracellular survival and replication of Salmonella in macrophages and T84 cells . Induction of the proinflammatory cytokines tumor necrosis factor alpha and interleukin-8 (IL-8) was significantly reduced in macrophages and T84 cells infected with the lpp double-knockout mutant . The levels of IL-8 remained unaffected in T84 cells when infected with either live or heat-killed WT and lpp mutant, indicating that invasion was not required for IL-8 production and that Toll-like receptor 2 signaling might be affected in the Lpp double-knockout mutant . These effects of the Lpp protein could be restored by complementation of the isogenic mutant . The lpp double-knockout mutant was avirulent in mice, and animals infected with this mutant were protected from a lethal challenge dose of WT serovar Typhimurium . The severe combined immunodeficient mice, on the other hand, were susceptible to infection by the lpp double-knockout mutant . The serovar Typhimurium mutants from which only one of the lpp (lpp1 or lpp2) genes was deleted were also avirulent in mice . Taken together, our data indicated that Lpp specifically contributed to the virulence of the organism. Infect Immun, 2004 Jul, 72(7), 3803 - 11 Oral tolerance in T cells is accompanied by induction of effector function in lymphoid organs after systemic immunization; Parameswaran N et al.; The physiological ramifications of oral tolerance remain poorly understood . We report here that mice fed ovalbumin (OVA) exhibit oral tolerance to subsequent systemic immunization with OVA in adjuvant, and yet they clear systemic infection with a recombinant OVA-expressing strain of Salmonella enterica serovar Typhimurium better than unfed mice do . Mice fed a sonicated extract of S . enterica serovar Typhimurium are also protected against systemic bacterial challenge, and the protection is Th1 mediated, as feeding enhances clearance in interleukin-4-null (IL-4(-/-)) and IL-10(-/-) mice but not in gamma interferon-null (IFN-gamma(-/-)) mice . When T-cell priming in vivo is tracked temporally in T-cell receptor-transgenic mice fed a single low dose of OVA, CD4 T-cell activation and expansion are restricted largely to mucosal lymphoid organs . However, T cells from spleens and peripheral lymph nodes of fed mice proliferate and secrete IFN-gamma when restimulated with OVA in vitro, indicating the presence of primed T cells in systemic tissues following oral exposure to antigen . Nonetheless, oral tolerance can be observed in the fed mice as reduced recall responses following subsequent systemic immunization with OVA in adjuvant . Soluble OVA administered systemically has similar effects in vivo, and the "tolerance" seen in both cases can be partially reversed if the initial priming is made more immunogenic . Together, the results indicate that antigen exposure under poor adjuvantic conditions, whether oral or systemic, may lead to T-cell commitment to effector rather than proliferative capabilities, necessitating a reassessment of therapeutic modalities for induction of oral tolerance in allergic or autoimmune states. FEMS Microbiol Lett, 2004 Jul 1, 236(1), 103 - 7 Inhibition of Salmonella enterica serovars by microcin J25; Vincent PA et al.; Escherichia coli microcin J25 (MccJ25) is a 2107-Da peptide antibiotic whose uptake into E . coli is mediated by the outer-membrane receptor FhuA and the inner membrane proteins TonB, ExbB, ExbD, and SbmA . A survey of the sensitivity of several Salmonella enterica serovars showed that the antibiotic was highly active against some serovars, while S . Typhimurium, S . Derby, and some S . Enteritidis strains were completely resistant . Resistant strains became hypersensitive to MccJ25 when given the fhuA gene of E . coli, indicating that insensitivity is due to the inability of the FhuA protein to mediate penetration of MccJ25 . Whereas in E . coli MccJ25 targets RNA polymerase, in S . Typhimurium it inhibits not only RNA synthesis but also cell respiration . Fluorescence viability staining showed that S . Typhimurium cells exposed to MccJ25 remain viable but are unable to form colonies. FEMS Microbiol Lett, 2004 Jul 1, 236(1), 65 - 72 The steady-state orgA specific mRNA levels in Salmonella enterica serovar Typhimurium are repressed by oxygen during logarithmic growth phase but not early-stationary phase; Russell DA et al.; The orgA gene from Salmonella enterica serovar Typhimurium is involved in promoting cellular invasion of the pathogen . Its exact role in virulence is still unclear mainly due to difficulties in understanding its complex regulation . In this study a novel competitive RT-PCR (cRT-PCR) system was developed to measure the steady-state orgA specific mRNA levels in cells under various growth parameters . Previous studies have been inconsistent regarding oxygen regulation of orgA . Using our system we found that oxygen repressed the copy levels 3.5-fold in cells grown only to logarithmic phase . Oxygen repression was not observed in cells grown to early-stationary phase, a parameter that has previously been demonstrated to be the most invasive stage of growth . The importance of NaCl in orgA gene regulation is also illustrated . Significant increases in copy numbers were observed after growth in high NaCl conditions . Measuring the steady-state mRNA levels using cRT-PCR provides an accurate insight into prokaryotic gene regulation prior to translation. Tohoku J Exp Med, 2004 Jun, 203(2), 129 - 32 Cerebrospinal fluid cytokines in Salmonella urbana encephalopathy; Minami K et al.; We present a case report of encephalopathy associated with Salmonella urbana infection in a child . A 5-year-old boy was admitted to our clinic with convulsions and coma . Cerebrospinal fluid (CSF) interleukin-6 (IL-6) and IL-8 were elevated at onset and were decreased within normal limit on the fifth day . Residual neurological deficits included severe mental deficits and spastic tetraplegia . High levels of CSF proinflammatory cytokines might be related to central nervous system (CNS) disease activity . Although encephalopathy is a rare complication of non-typhi Salmonella infection, it should be borne in mind as an occasionally serious and potentially lethal disease. Wei Sheng Yan Jiu, 2004 May, 33(3), 284 - 7 {Toxicological effects of copper on human intestinal Caco-2 cells}; Liu Z et al.; OBJECTIVE: To study the toxicological effects of copper on human intestinal Caco-2 cells . METHODS: The effects of copper on human intestinal Caco-2 cells were evaluated by MTT conversion, intra-cellular production of reactive oxygen species (ROS), cloning efficiency and changes of P-glycoprotein (P-gp) activities in Caco-2 cells . In addition, Caco-2 cells and Salmonella enteritidis served as the models to examine the effect of copper on the host-parasite interaction . RESULTS: Copper induced a dose-dependent decrease of cell viability measured by MTT assay; by using the fluorescent probe 2, 7-dichlorofluorescin diacetate, a significant increase of ROS production in Cu-treated cells was detected; the significant time- and dose-dependent decrease of P-gp activities in Cu-treated cells was demonstrated by increased accumulation of rhodamine 123 in cells . Copper treatment also increased the efficiency of the bacterial invasion, but decreased the number of bacteria surviving in the intracellular environment . CONCLUSION: Copper induced a variety of toxicological endpoints which might be caused by oxidative damage, but the effect of copper on cell-bacteria interaction needs to be further investigated. J Appl Toxicol, 2004 May-Jun, 24(3), 177 - 81 Determination of the rat tissue partitioning of endotoxin in vitro for physiologically-based pharmacokinetic (PBPK) modeling; Ross IA et al.; The biosynthetically double-labeled lipopolysaccharide (LPS), containing (3)H-labeled on the fatty acyl-chains and (14)C-labeled on the glucosamine of Salmonella enterica serotype typhimurium, was isolated from bacteria grown in proteose peptone-beef extract (PPBE) medium in the presence of labeled precursors; 133 micro Ci/ml of {2-(3)H} acetate sodium salt and 0.167 micro Ci/ml of N-acetyl{D-1-(14)C}glucosamine . The LPS was extracted from the bacteria with 90% phenol/chloroform/petroleum ether, purified and stored in 0.1% (v/v) triethylamine/10 mM Tris HCl at -70 degrees C . Tissue slices and portions of the meninges were prepared and incubated in artificial cerebrospinal fluid (CSF) or Krebs phosphate buffer (Krebs) containing 150 ng/ml LPS with {(3)H} LPS (0.004 micro Ci/ml, sp . act . 28 micro Ci/mg LPS) . The tissues were incubated under 95% oxygen/5% carbon dioxide at 37 degrees C with constant agitation until steady-state uptake was reached (60 min) . At the end of the incubation period, tissues were processed for radioactivity measurement . The rat tissue partitioning of LPS in artificial CSF for brain and Krebs for other organs was measured by using the ratio of tissue to medium at the steady state in vitro . The following results were obtained from the study: Heart, 0.15; liver, 0.19; spleen, 0.12; kidney, 0.18; stomach, 0.17; small intestine, 0.18; brain stem, 0.10; cerebellum, 0.11; meninges, 0.77; hippocampus, 0.12; hypothalamus, 0.12; frontal cortex, 0.09 and caudate nucleus, 0.10 . This information, along with plasma or blood/buffer partition coefficients, is a requisite for constructing a physiologically-based pharmacokinetic (PBPK) model of endotoxins for quantitative risk assessment . Chemotherapy, 2004 Jun, 50(2), 88 - 91 Antimicrobial susceptibility of 128 Salmonella enterica serovar typhi and paratyphi A isolates from northern India; Safdar A et al.; Most systemic Salmonella enterica serovar typhi and paratyphi A infections diagnosed in the United States (up to 70%) are acquired during travel to regions of high endemicity . Increasing resistance to agents commonly used for the treatment of such infections (including multidrug resistant isolates) is being reported from several areas of the world (Southeast Asia, Africa, Latin America) . Since regional differences in susceptibility patterns may exist, we sought to determine the frequency of antimicrobial resistance among blood and stool isolates (n = 128) from patients in Northwestern India . Salmonella enterica serotype typhi (n = 101) isolates from 14 patients were susceptible to all agents tested . Among 55 isolates with single drug resistance, 44 (81%) were resistant to chloramphenicol . Multidrug resistant (>/=3 drugs) Salmonella enterica was more common in pediatric patients (10 of 30) compared to adults (10 of 71 patients; p = 0.05) . All isolates (S . enterica serovar typhi and serovar paratyphi A) were susceptible to ciprofloxacin and ceftriaxone . Travelers to Northwestern India may still receive trimethoprim-sulfamethoxazole, or ciprofloxacin for effective chemoprophylaxis if indicated . Ceftriaxone and ciprofloxacin remain favorable choices for treatment of patients with enteric fever in this region . Am J Trop Med Hyg, 2004 Jun, 70(6), 670 - 5 The etiology of febrile illness in adults presenting to Patan hospital in Kathmandu, Nepal; Murdoch DR et al.; In Nepal, many infections remain poorly characterized, partly due to limited diagnostic facilities . We studied consecutive febrile adults presenting to a general hospital in Kathmandu, Nepal . Of the 876 patients enrolled, enteric fever and pneumonia were the most common clinical diagnoses . Putative pathogens were identified in 323 (37%) patients, the most common being Salmonella enterica serotype Typhi and S . enterica serotype Paratyphi A (117), Rickettsia typhi (97), Streptococcus pneumoniae (53), Leptospira spp . (36), and Orientia tsutsugamushi (28) . Approximately half of the Salmonella isolates were resistant to nalidixic acid . No clinical predictors were identified to reliably distinguish between the different infections . These findings confirm the heavy burden of enteric fever and pneumonia in Kathmandu, and highlight the importance of murine typhus, scrub typhus, and leptospirosis . Given the lack of reliable clinical predictors, the development of cheap and accurate diagnostic tests are likely to be of great clinical utility in this setting. Vet Res, 2004 May-Jun, 35(3), 291 - 8 Humoral immune response in hens naturally infected with Salmonella Enteritidis against outer membrane proteins and other surface structural antigens; Ochoa-Reparaz J et al.; A simple procedure for obtaining surface exposed antigens of Salmonella Enteritidis is described . A heat treatment of whole bacteria in saline solution induced the release of small membrane vesicles containing outer membrane components as well as surface appendage components, such as fimbriae and flagellin . The characterization of the structural components of this extract, called HE, was established by SDS-PAGE and immunoblotting using polyclonal and monoclonal specific antibodies . Five major groups of proteins were identified: flagellin, porins, OmpA, SEF21 and SEF14 fimbriae . The immunogenicity of these proteins was studied by immunoblotting with serum samples from naturally infected hens . Flagellin, porins, OmpA, SEF14 and SEF21 fimbriae were immunogenic in the S . Enteritidis infected hens (frequency of reactants: 47.3, 97.3, 64.7, 50.0 and 60.8%, respectively); porins also reacted with sera from non infected hens (66.7%) . The immunogenicity of these antigens in infected birds provide promise that they may serve as components of an effective subcellular vaccine for poultry salmonellosis . J Biol Chem, 2004 Sep 10, 279(37), 38618 - 25 Epub 2004 Jun 18. Transcriptional control of the antimicrobial peptide resistance ugtL gene by the Salmonella PhoP and SlyA regulatory proteins; Shi Y et al.; The PhoP/PhoQ two-component system is a master regulator that governs the ability of Salmonella to cause a lethal infection in mice, the adaptation to low Mg(2+) environments, and resistance to a variety of antimicrobial peptides . We have recently established that the PhoP-activated ugtL gene is required for resistance to the antimicrobial peptides magainin 2 and polymyxin B . Here we report that ugtL transcription requires not only the PhoP protein but also the virulence regulatory protein SlyA . The PhoP protein footprinted two regions of the ugtL promoter, mutation of either one of which was sufficient to abolish ugtL transcription . Although the SlyA protein is a transcriptional activator of the ugtL gene, it footprinted the ugtL promoter at a region located downstream of the transcription start site . The PhoP protein footprinted the slyA promoter, indicating that it controls slyA transcription directly . The slyA mutant was hypersensitive to magainin 2 and polymyxin B, suggesting that the virulence attenuation exhibited by slyA mutants may be caused by hypersensitivity to antimicrobial peptides . We propose that the PhoP and SlyA proteins control ugtL transcription using a feed-forward loop design. Vet Immunol Immunopathol, 2004 Aug, 100(3-4), 151 - 64 Age at primary infection with Salmonella enterica serovar Typhimurium in the chicken influences persistence of infection and subsequent immunity to re-challenge; Beal RK et al.; Salmonella enterica remains one of the most important food-borne pathogens of humans and is often acquired through consumption of infected poultry meat or eggs . Control of Salmonella infections in chicken is therefore an important public health issue . Infection with S . enterica serovar Typhimurium results in a persistent enteric infection without clinical disease in chickens of more than 3 days of age, and represents a source for contamination of carcass at slaughter and entry into the human food chain . Data presented indicate a profound effect of age at initial exposure on the persistence of infection and a lesser effect on the development of effective immunity to re-challenge . The percentage of birds positive for Salmonella was high until 8-9 weeks of age, regardless of the age at which the birds were infected (1, 3 or 6 weeks) . The birds infected at 3 and 6 weeks of age produced a more rapid and higher antibody response (IgY and IgA) than those infected at 1 week of age, but in all cases infection persisted for a considerable period despite the presence of high antibody levels . Following a re-challenge infection with S . Typhimurium, all three previously-infected groups had fewer bacteria in the gut, spleen and liver compared with age-matched birds receiving a parallel primary infection . However, the birds primary infected at 3 and 6 weeks of age cleared infection more rapidly than those infected at a younger age . Interestingly older-primed birds had higher specific T lymphocyte proliferative responses and specific circulating levels of IgY antibody at time of re-challenge . Although birds initially infected at 1 week of age and those that were previously uninfected produced a stronger antibody response following re-challenge, they were slower to clear Salmonella from the gut than the older-primed groups which expressed a stronger T lymphocyte response . The data presented indicate that clearance of Salmonella from the gut is age-dependent and we propose that this relates to the increased competence of the enteric T cell response . The findings that Salmonella persists beyond 8-9 weeks, irrespective of age at exposure, has implications for the broiler sector and indicates the need to remain Salmonella free throughout the rearing period . Moreover, the re-challenge data demonstrates that infection at a young age is less effective in producing protective immunity than in older chickens . This feature of the development of protective immunity needs to be considered when developing vaccines for the broiler sector of the poultry industry. Cytokine, 2004 Jul 7, 27(1), 15 - 24 Interleukin-8 production by THP-1 cells stimulated by Salmonella enterica serovar Typhimurium porins is mediated by AP-1, NF-kappaB and MAPK pathways; Vitiello M et al.; Interleukin-8 (IL-8) is released in response to inflammatory stimuli, such as bacterial products . Either porins or lipopolysaccharide (LPS) stimulated THP-1 cells to release IL-8 after 24 h . We have previously reported that stimulation of monocytic cells with Salmonella enterica serovar Typhimurium porins led to the activation of mitogen-activated protein kinase cascades and of protein tyrosine kinases (PTKs) . In this report, we demonstrate, using two potent and selective inhibitors of MEK activation by Raf-1 (PD-098059) and p38 (SB-203580), that both ERK1/2 and p38 pathways play a key role in the production of IL-8 by porins and LPS . Porin-stimulated expression of activating protein 1 (AP-1) and correlated IL-8 release is also inhibited by PD-098059 or SB-203580 indicating that the Raf-1/MEK1-MEK2/MAPK cascade is required for their activation . Also PTKs modulate the pathway that control IL-8 gene expression, in fact its expression is abolished by tyrphostin . By using N-acetyl-leucinyl-leucinyl-norleucinal-H (ALLN) an inhibitor of nuclear factor-kappaB (NF-kappaB) activity, we also observed IL-8 release modulation . Our results elucidate some of the molecular mechanisms by which AP-1 and NF-kappaB regulate IL-8 release and open new strategies for the design of specific molecules that will modulate IL-8 effects in various infectious diseases. Emerg Infect Dis, 2004 Jun, 10(6), 985 - 7 Salmonella-based rodenticides and public health; Painter JA et al.; Several countries still permit strains of Salmonella enterica serotype Enteritidis, a leading cause of gastrointestinal illness in humans, to be used in rat baits . To assess the human health risk associated with such rat bait, we first reviewed historic data on health hazards associated with Ratin, a rodenticide that was used in Europe until the early 1960s . Ratin caused outbreaks of human illness, including several deaths . We then compared S . Enteritidis isolated from a current commercial product, Biorat, with S . Enteritidis from Ratin and found that the strains were both phage type 6a . Based on the similarity of the strains, currently available Salmonella-based rodenticides likely are as great a threat to public health as past strains were . Health officials should be aware that the continued use of Salmonella-based rodenticides is a risk to public health and should take appropriate measures to prevent use in their jurisdictions. Poult Sci, 2004 Jun, 83(6), 997 - 1002 Ovarian cell-mediated immune response to Salmonella enteritidis infection in laying hens (Gallus domesticus); Barua A et al.; The aim of this study was to examine the response of cell-mediated ovarian immunity against Salmonella infection in hens . Laying hens were injected intraperitoneally with PBS (control) or Salmonella enteritidis (SE) . Ovarian stroma containing stromal follicles, small white follicles (SWF), and third largest (F3) and the largest (F1) follicles were collected 12 or 24 h after inoculation and fixed in periodate-lysine-paraformaldehyde . Frozen sections were stained first for CD3+, CD4+, or CD8+ T cells and then for SE by a double immunostaining method . Immunoreaction products for SE were detected in the ovarian stroma, theca of stromal follicles, SWF, F3, and F1 at 12 and 24 h after inoculation . Immunopositive T-cell subsets were localized in the stroma and theca of follicles in birds inoculated with or without SE . The populations of CD3+, CD4+, and CD8+ T cells were significantly greater in the stroma and the theca of follicles 12 h after SE inoculation than in those of control birds (P < 0.01) . Their frequencies were further increased in those tissues 24 h after inoculation (P < 0.01) . Injection of SE did not cause significant differences in the CD4+:CD8+ T-cell ratio as both subsets increased proportionately . The current results indicate that the population of T-cell subsets increases in the ovarian stroma and the follicular tissues in response to SE invasion within 12 h of inoculation . Thus, cell-mediated immune response against SE, their products, or both may be induced in the hen ovary. Clin Infect Dis, 2004 Jul 1, 39(1), 61 - 7 Epub 2004 Jun 14. A clinical, microbiological, and pathological study of intestinal perforation associated with typhoid fever; Nguyen QC et al.; One of the most serious complications of typhoid fever is intestinal perforation . Of 27 patients admitted to a provincial hospital in the Mekong Delta region of Vietnam who had gastrointestinal perforation secondary to suspected typhoid fever, 67% were male, with a median age of 23 years and a median duration of illness of 10 days . Salmonella enterica subspecies enterica serotype Typhi (S . Typhi) was isolated from 11 (41%) of 27 patients; of 27 patients, only 4 (15%) had positive cultures from gut biopsies . S . Typhi DNA was detected by polymerase chain reaction for all perforation biopsy samples . Detailed histological examination of the gastrointestinal mucosa at the site of perforation in all cases showed a combination of discrete acute and chronic inflammation . Acute inflammation at the serosal surface indicated additional tissue damage after perforation . Immunohistochemical results showed that the predominant infiltrating cell types at the site of perforation were CD68+ leukocytes (macrophages) or CD3+ leukocytes (T lymphocytes). Science, 2004 Jun 18, 304(5678), 1805 - 7 Salmonella modulates vesicular traffic by altering phosphoinositide metabolism; Hernandez LD et al.; Salmonella enterica, the cause of food poisoning and typhoid fever, induces actin cytoskeleton rearrangements and membrane ruffling to gain access into nonphagocytic cells, where it can replicate and avoid innate immune defenses . Here, we found that SopB, a phosphoinositide phosphatase that is delivered into host cells by a type III secretion system, was essential for the establishment of Salmonella's intracellular replicative niche . SopB mediated the formation of spacious phagosomes following bacterial entry and was responsible for maintaining high levels of phosphatidylinositol-three-phosphate {PtdIns(3)P} in the membrane of the bacteria-containing vacuoles . Absence of SopB caused a significant defect in the maturation of the Salmonella-containing vacuole and impaired bacterial intracellular growth. J Bacteriol, 2004 Jul, 186(13), 4124 - 33 The PmrA-regulated pmrC gene mediates phosphoethanolamine modification of lipid A and polymyxin resistance in Salmonella enterica; Lee H et al.; The PmrA/PmrB regulatory system of Salmonella enterica controls the modification of lipid A with aminoarabinose and phosphoethanolamine . The aminoarabinose modification is required for resistance to the antibiotic polymyxin B, as mutations of the PmrA-activated pbg operon or ugd gene result in strains that lack aminoarabinose in their lipid A molecules and are more susceptible to polymyxin B . Additional PmrA-regulated genes appear to participate in polymyxin B resistance, as pbgP and ugd mutants are not as sensitive to polymyxin B as a pmrA mutant . Moreover, the role that the phosphoethanolamine modification of lipid A plays in the resistance to polymyxin B has remained unknown . Here we address both of these questions by establishing that the PmrA-activated pmrC gene encodes an inner membrane protein that is required for the incorporation of phosphoethanolamine into lipid A and for polymyxin B resistance . The PmrC protein consists of an N-terminal region with five transmembrane domains followed by a large periplasmic region harboring the putative enzymatic domain . A pbgP pmrC double mutant resembled a pmrA mutant both in its lipid A profile and in its susceptibility to polymyxin B, indicating that the PmrA-dependent modification of lipid A with aminoarabinose and phosphoethanolamine is responsible for PmrA-regulated polymyxin B resistance. J Bacteriol, 2004 Jul, 186(13), 4056 - 66 Regulation of the Ysa type III secretion system of Yersinia enterocolitica by YsaE/SycB and YsrS/YsrR; Walker KA et al.; Yersinia enterocolitica biovar 1B contains two type III secretion systems (TTSSs), the plasmid-encoded Ysc-Yop system and the chromosomally encoded Ysa-Ysp system . Proteins secreted from the Ysa TTSS (Ysps) have only been detected in vitro when cells are cultured at 26 degrees C in a high-NaCl medium . However, the exact role of the Ysa TTSS is unclear . Thus, investigations into the regulation of this system may help elucidate the role of the Ysps during the life cycle of Y . enterocolitica . Here we present evidence that the AraC-like regulator YsaE acts together with the chaperone SycB to regulate transcription of the sycByspBCDA operon, a phenomenon similar to that seen in the closely related Salmonella SPI-1 and Shigella flexneri Mxi-Spa-Ipa TTSSs . Deletion of either sycB or ysaE results in a twofold reduction in the activity of a sycB-lacZ fusion compared to the wild type . In a reconstituted Escherichia coli system, transcription of sycB was activated sixfold only when both YsaE and SycB were present, demonstrating that they are necessary for activation . ysrR and ysrS are located near the ysa genes and encode a putative two-component regulatory system . Mutations in either gene indicated that both YsrR and YsrS were required for secretion of Ysps . In addition, transcription from sycB-lacZ and ysaE-lacZ fusions was decreased 6.5- and 25-fold, respectively, in the ysrS mutant compared to the wild type . Furthermore, in the absence of NaCl, the activity of ysaE-lacZ was reduced 25-fold in the wild-type and DeltaysrS strains, indicating that YsrS is probably required for the salt-dependent expression of the ysa locus . These results suggest that the putative two-component system YsrRS may be a key element in the regulatory cascade for the Ysa TTSS. J Drug Target, 2003, 11(8-10), 481 - 8 Attenuated salmonella and Shigella as carriers for DNA vaccines; Xu F et al.; The discovery that genes can be functionally transferred from bacteria to mammalian cells has suggested the possible use of bacterial vectors as gene delivery vehicles for vaccines . Attenuated invasive human intestinal bacteria, such as Salmonella and Shigella, have been used as plasmid DNA vaccine carriers and their potency has been evaluated in several animal models . This delivery system allows the administration of DNA vaccines together with associated bacterial immunostimulators directly to professional antigen presenting cells via human mucosal surfaces . Various strategies have been taken to improve the use of this delivery system to achieve robust immune responses at both mucosal and systemic sites of the immunized animals. J Drug Target, 2003, 11(8-10), 471 - 9 The use of live attenuated bacteria as a delivery system for heterologous antigens; Garmory HS et al.; Live attenuated mutants of several pathogenic bacteria have been exploited as potential vaccine vectors for heterologous antigen delivery by the mucosal route . Such live vectors offer the advantage of potential delivery in a single oral, intranasal or inhalational dose, stimulating both systemic and mucosal immune responses . Over the years, a range of strategies have been developed to allow controlled and stable delivery of antigens and improved immunogenicity where required . Most of these approaches have been evaluated in Salmonella vaccine vectors and, as a result, several live attenuated recombinant Salmonella vaccines are now in human clinical trials . In this review, these strategies and their use in the development of a delivery system for the Yersinia pestis V antigen are described. Rev Esp Quimioter, 2004 Mar, 17(1), 37 - 43 {Change in resistance to quinolones and betalactams in different serogroups of Salmonella during the last decade in a Madrid hospital}; Guerri Santos ML et al.; The prevalence of antibiotic resistance was studied in 3230 strains of Salmonella enterica isolated in the Hospital Universitario La Paz in Madrid, Spain, from 1991 to 2001 . Betalactam antibiotic resistance has been notorious in serogroup B4; the highest prevalence of ampicillin resistance (84%) was reached in 2000 and that of amoxicillin-clavulanic acid (45%) in 1996 . Resistance to cephalosporins has been controlled, although in 2000 cefazolin resistance reached 37% in serogroup C2-8 . An increase in first generation quinolone resistance was detected in every serogroup, especially in D9 and C2-8, which showed an increase from 6% and 15% in 1991, respectively, to 40% and 85% in 2001 . Although important resistance to ciprofloxacin has not yet been detected, the activity of fluoroquinolones against Salmonella must be closely monitored. Rev Esp Quimioter, 2004 Mar, 17(1), 29 - 36 {Antimicrobial drug resistance in non-typhi Salmonellae in Castilla y Leon}; Delgado Ronda M et al.; We studied the antibiotic susceptibility of 309 Salmonella isolates obtained from three hospitals serving the provinces of Salamanca, Avila and Zamora in the region of Castilla y Leon (mid-west Spain) . The susceptibility to 18 antibiotics was studied using the agar dilution method, according to NCCLS guidelines, and the most common multiresistance phenotypes were determined for each province . We observed clear susceptibility differences between the two main serotypes found, S . enteritidis and S . typhimurium . Seventy percent of S . typhimurium were resistant to amoxicillin . In 44% of these isolates, amoxicillin resistance was associated with resistance to streptomycin, sulfonamides, tetracyclines and chloramphenicol . S . enteritidis was susceptible to most antibiotics tested; amoxicillin resistance was observed in 23.3%, and nalidixic acid resistance in 49.6% . Resistance to nalidixic acid was higher in S . enteritidis than in any other serotypes . According to NCCLS breakpoints, no strain was resistant to fluoroquinolones . However, according to MENSURA criteria, 9% of S . typhimurium isolates were resistant to ciprofloxacin . Resistance to cotrimazole and gentamicin was less than 10% for all the serotypes tested . The results indicate that S . typhimurium showed greater resistance and a high multidrug resistance rate . Conversely, S . enteritidis showed high resistance only to amoxicillin and nalidixic acid, though in most cases there was no correlation between this resistance and reduced susceptibility to fluoroquinolones. Eur J Cardiothorac Surg, 2004 Jul, 26(1), 225 - 7 Endovascular stent-graft for thoracic aorta aneurysm caused by Salmonella; Nikos K et al.; We describe the placement of an endovascular stent-graft in a patient with mycotic aneurysm of the descending thoracic aorta caused by Salmonella . Endovascular grafting combined with antibiotic therapy in thoracic mycotic aneurysms might represent an alternative to conventional surgery in patients with high operative risk. Eur J Cardiothorac Surg, 2004 Jul, 26(1), 221 - 4 Endovascular repair for multiple Salmonella mycotic aneurysms of the thoracic aorta presenting with Cardiovocal syndrome; Ting AC et al.; Salmonella mycotic thoracic aortic aneurysm is a rare but life-threatening condition . We report a 59-year-old man with two Salmonella mycotic thoracic aortic aneurysms, presented with fever and chills associated with hoarseness due to left vocal cord palsy (Cardiovocal syndrome) . Successful endovascular repair was performed using two Talent thoracic stent-graft devices deployed separately to cover the two mycotic aneurysms . Subsequent computed tomography at 12 months after the operation confirmed exclusion of the two pseudoaneurysms with no endoleak . With potent antibiotics and careful surveillance program, endovascular repair is a possible alternative to conventional open surgery in the management of mycotic thoracic aortic aneurysms, especially in high-risk patients. Emerg Infect Dis, 2004 May, 10(5), 795 - 801 Multidrug-resistant strains of Salmonella enterica Typhimurium, United States, 1997-1998; Rabatsky-Ehr T et al.; To evaluate multidrug-resistant strains of Salmonella enterica serotype Typhimurium, including definitive type 104 (DT104) in the United States, we reviewed data from the National Antimicrobial Resistance Monitoring System (NARMS) . In 1997 to 1998, 703 (25%) of 2,767 serotyped Salmonella isolates received at NARMS were S . Typhimurium; antimicrobial susceptibility testing and phage typing were completed for 697 . Fifty-eight percent (402) were resistant to > or = 1 antimicrobial agent . Three multidrug-resistant (> or = 5 drugs) strains accounted for (74%) 296 of all resistant isolates . Ceftriaxone resistance was present in 8 (3%), and nalidixic acid resistance in 4 (1%), of these multidrug-resistant strains . By phage typing, 259 (37%) of S . Typhimurium isolates were DT104, 209 (30%) were of undefined type and 103 (15%) were untypable . Fifty percent (202) of resistant (> or = 1 drug) isolates were DT104 . Multidrug-resistant S . Typhimurium isolates, particularly DT104, account for a substantial proportion of S . Typhimurium isolates; ceftriaxone resistance is exhibited by some of these strains. Nucleic Acids Res . 2004 Jun 15;32(10):e82. The recognition and modification sites for the bacterial type I restriction systems KpnAI, StySEAI, StySENI and StySGI; Kasarjian JK et al.; Using an in vivo plasmid transformation method, we have determined the DNA sequences recognized by the KpnAI, StySEAI, StySENI and StySGI R-M systems from Klebsiella oxytoca strain M5a1, Salmonella eastbourne, Salmonella enteritidis and Salmonella gelsenkirchen, respectively . These type I restriction-modification systems were originally identified using traditional phage assay, and described here is the plasmid transformation test and computer program used to determine their DNA recognition sequences . For this test, we constructed two sets of plasmids, pL and pE, that contain phage lambda and Escherichia coli K-12 chromosomal DNA fragments, respectively . Further, using the methylation sensitivities of various known type II restriction enzymes, we identified the target adenines for methylation (listed in bold italics below as A or T in case of the complementary strand) . The recognition sequence and methylation sites are GAA(6N)TGCC (KpnAI), ACA(6N)TYCA (StySEAI), CGA(6N)TACC (StySENI) and TAAC(7N)RTCG (StySGI) . These DNA recognition sequences all have a typical type I bipartite pattern and represent three novel specificities and one isoschizomer (StySENI) . For confirmation, oligonucleotides containing each of the predicted sequences were synthesized, cloned into plasmid pMECA and transformed into each strain, resulting in a large reduction in efficiency of transformation (EOT). J Biotechnol, 2004 Jul 1, 111(1), 1 - 8 Surface plasmon resonance immunosensor using self-assembled protein G for the detection of Salmonella paratyphi; Oh BK et al.; A surface plasmon resonance (SPR) based immunosensor using self-assembled protein G was developed for the detection of Salmonella paratyphi . In order to endow a solid substrate binding affinity to protein G, the free amine (-NH2) of protein G was substituted into thiol (-SH) using 2-iminothiolane . Thus, self-assembled protein G was fabricated on gold (Au) substrate . The formation of protein G layer on Au surface, and the binding of antibody and antigen in series were confirmed by SPR spectroscopy . The surface morphology analysis of the protein G layer on Au surface was performed by atomic force microscope (AFM) . Consequently, an immunosensor based on SPR for the detection of S . paratyphi using self-assembled protein G was developed with a detection range of 10(2)-10(7) CFU/ml . The current fabrication technique of a SPR immunosensor for the detection of S . paratyphi could be applied to construct other immnosensors or protein chips. Microb Pathog, 2004 Jul, 37(1), 11 - 9 Lipid raft microdomains mediate class A scavenger receptor-dependent infection of Brucella abortus; Kim S et al.; Brucella abortus is a facultative intracellular bacterium that can survive inside macrophages . Intracellular replication of B . abortus requires the VirB complex, which is highly similar to the conjugative DNA transfer system . In this study, we showed that a class A scavenger receptor (SR-A) of macrophages is required to internalize B . abortus and contributes to the establishment of bacterial infection in mice . Macrophages from SR-A-deficient mice inhibited internalization and intracellular replication of both wild type strain and the virB4 mutant, and that bacterial proliferation was inhibited in SR-A-deficient mice . Adding lipopolysaccharide from B . abortus and Salmonella enterica serovar Typhimurium, but not from Escherichia coli, to macrophages inhibited bacterial internalization . VirB-dependent bacterial internalization induced localization of SR-A into detergent-resistant membrane lipid rafts . These results indicate that B . abortus internalizes into macrophages by using SR-A as a receptor and that the VirB type IV secretion system of B . abortus regulates signal transduction dependent on SR-A to form replicative phagosomes, and which is mediated by lipid rafts. Mol Ther, 2004 Jun, 9(6), 895 - 901 Retroviral-mediated gene transfer restores IL-12 and IL-23 signaling pathways in T cells from IL-12 receptor beta1-deficient patients; Bosticardo M et al.; Genetic deficiency of human IL-12 receptor beta1 chain (IL-12Rbeta1) results in increased vulnerability to weakly pathogenic strains of Mycobacteria and Salmonella . This phenotype results from the combined lack of IL-12 and IL-23 signaling as both cytokine receptors share IL-12Rbeta1 . Such infections can be treated by administration of antibiotics and IFN-gamma; however, patients can succumb to infections despite these treatments . Reversion of patients' susceptibility by corrective gene transfer could prevent the infectious episodes, thus providing a beneficial alternative . We therefore evaluated the feasibility of retroviral-mediated gene correction of T cells obtained from patients carrying "null" mutations of IL-12Rbeta1 . Transduction of the IL-12Rbeta1 cDNA restored the expression of IL-12Rbeta1 and resulted in the reconstitution of a functional IL-12 signaling pathway, as demonstrated by STAT4 phosphorylation and IFN-gamma production . IFN-gamma production in response to IL-23 was also corrected after gene transfer . These results indicate that the biological defects of T cells from patients carrying IL-12Rbeta1 deficiency can be corrected by gene transfer and form the basis for further development of gene therapy for this disease. Vaccine, 2004 Jun 30, 22(20), 2524 - 32 A Salmonella enterica serovar Typhi vaccine expressing Yersinia pestis F1 antigen on its surface provides protection against plague in mice; Morton M et al.; A recombinant strain of attenuated Salmonella enterica serovar Typhi surface-expressing Yersinia pestis F1 antigen was generated by transforming strain BRD1116 (aroA aroC htrA) with plasmid pAH34L encoding the Y . pestis caf operon . BRD1116/pAH34L was stable in vitro and in vivo . An immunisation regimen of two intranasal doses of {Formula: see text} cfu of BRD1116/pAH34L given intranasally to mice 7 days apart induced the strongest immune response compared to other regimens and protected 13 out of 20 mice from lethal challenge with Y . pestis . Intranasal immunisation of mice constitutes a model for oral immunisation with Salmonella vaccines in humans . Thus, the results demonstrate that attenuated strains of S . enterica serovar Typhi which express Y . pestis F1 antigen may be developed to provide an oral vaccine against plague suitable for use in humans. J Zoo Wildl Med, 2004 Mar, 35(1), 60 - 4 Survey for Haemoproteus spp., Trichomonas gallinae, Chlamydophila psittaci, and Salmonella spp . in Galapagos Islands columbiformes; Padilla LR et al.; Endemic free-ranging Galapagos doves (Zenaida galapagoensis) and introduced rock doves (Columba livia) were surveyed in several islands of the Galapagos archipelago to establish sample prevalence of hemoparasites, Trichomonas gallinae, Chlamydophila psittaci, and Salmonella species . A Haemoproteus sp., the only hemoparasite identified, was found in 89% of the Galapagos doves sampled but not in the rock doves . Trichomonas gallinae was detected by polymerase chain reaction in 44% of rock doves from San Cristobal but in none of the Galapagos doves . Chlamydophila psittaci was detected from cloacal swabs in 6% of the Galapagos doves but in none of the rock doves sampled . All positive cases of C . psittaci occurred on Espanola, where the crude sample prevalence was 24% . A polymerase chain reaction-based Salmonella test failed to show evidence of this organism from any birds sampled. MMWR Morb Mortal Wkly Rep, 2004 Jun 11, 53(22), 484 - 7 Outbreak of Salmonella serotype Enteritidis infections associated with raw almonds--United States and Canada, 2003-2004; Centers for Disease Control and Prevention (CDC); On May 12, 2004, the Oregon State Public Health Laboratory identified a cluster of five patients infected with Salmonella enterica serotype Enteritidis (SE) isolates that were matched by using two-enzyme pulsed-field gel electrophoresis (PFGE) . The five patients were from four Oregon counties; their onsets of illness occurred during February-April 2004 . A subsequent investigation, still ongoing, has identified a total of 29 patients in 12 states and Canada with matching SE isolates, since at least September 2003 . Seven patients have been hospitalized; no one has died . Raw almonds distributed throughout the United States and internationally have been implicated as the source of the SE infections . As of May 21, approximately 13 million pounds of raw almonds had been recalled by the producer. Epidemiol Infect, 2004 Jun, 132(3), 443 - 53 The effect of temperature on food poisoning: a time-series analysis of salmonellosis in ten European countries; Kovats RS et al.; We investigated the relationship between environmental temperature and reported Salmonella infections in 10 European populations . Poisson regression adapted for time-series data was used to estimate the percentage change in the number of cases associated with a 1 degree C increase in average temperature above an identified threshold value . We found, on average, a linear association between temperature and the number of reported cases of salmonellosis above a threshold of 6 degrees C . The relationships were very similar in The Netherlands, England and Wales, Switzerland, Spain and the Czech Republic . The greatest effect was apparent for temperature 1 week before the onset of illness . The strongest associations were observed in adults in the 15-64 years age group and infection with Salmonella Enteritidis (a serotype of Salmonella) . Our findings indicate that higher temperatures around the time of consumption are important and reinforce the need for further education on food-handling behaviour. Zh Mikrobiol Epidemiol Immunobiol, 2004 Mar-Apr, (2), 85 - 7 {Adhesiveness and antibiotic resistance of the causative agents of salmonella infection in Gomel' region}; Tapal'skii DV et al.; The adhesive capacity, resistance to antibiotics and biological properties of Salmonella strains of different serogroups, circulating in the Gomel region, were under study . Resistance to antibiotics and changes in biological properties were accompanied by an increased adhesiveness of these strains . A high degree of adhesiveness was noted in S . hadar, a new for Belarus strains. Tohoku J Exp Med, 2004 May, 203(1), 47 - 52 Phenoxazine compounds produced by the reactions with bovine hemoglobin show antimicrobial activity against non-tuberculosis mycobacteria; Shimizu S et al.; We studied the anti-microbial effects of phenoxazines produced by the reaction of o-aminophenol or its derivatives with bovine hemoglobin, on seven species of mycobacteria such as Mycobacterium tuberculosis, Mycobacterium marinum, Mycobacterium intracellulare, Mycobacterium scrofulaceum, Mycobacterium fortuitum, Mycobacterium kansasii and Mycobacterium smegmatis and some bacteria such as Escherichia coli, Pseudomonas aeruginosa, Salmonella enterica serovar Typhimurium, Staphylococcus aureus, Listeria monocytogeneses . These phenoxazines, including 2-amino-4, 4alpha-dihydro-4alpha, 7-dimethyl-3H-phenoxzine-3-one (Phx-1), 3-amino-1, 4alpha-dihydro-4alpha, 8-dimethyl-2H-phenoxazine-2-one (Phx-2), and 2-aminophenoxazine-3-one (Phx-3), prevented the proliferation of four non-tuberculosis mycobacteria including M . scrofulaceum, M . kansasii, M . marinum, and M . intracellulare dose-dependently, though the inhibitory effects of these phenoxazines differed according to the species of mycobacteria . However these phenoxazines failed to prevent the proliferation of M . tuberculosis, M . fortuitum, and M . smegmatis, and the concerned bacteria other than mycobacteria . The present results may contribute to development of novel antibiotics against non-tuberculolsis mycobacteria. Epidemiol Mikrobiol Imunol, 2004, 53(2), 70 - 3 {Occurrence of phage types of non-typhoid Salmonella serovar in the Slovak Republic 2000-2003}; Majtanova L; Salmonellae of non-typhoidal serovars are the most important pathogens involved in foodborne diseases in humans all over the world . The incidence rates of two major Salmonella serovars, i.e . S . enterica serovar Enteritidis (S . Enteritidis) and S . enterica serovar Typhimurium (S . Typhimurium), in the Slovak Republic in 2000-2003 are given . Over the period studied, 829 S . Enteritidis strains and 258 S . Typhimurium strains isolated from patients with salmonellosis were investigated in the National Reference Centre for Salmonella Phage Typing . The S . Enteritidis strains were differentiated into 16 phage types, with phage type 8 being dominant since found in 73.6%, 53.8%, 62.8% and 45.6% of strains in 2000, 2001, 2002 and 2003, respectively . The following most frequent phage types were 4 and 13a . New phage types, i.e . 15, 5, 25 and 14b, were identified from salmonellosis outbreaks in 2003 . The S . Typhimurium strains were also differentiated into 16 phage types with phage type DT104 strains being prevalent and showing an increase from 7.4% in 2000 to 44.6% in 2003; 54.2% of them were resistant and of R type ACSSut . The second most frequent phage type in 2000-2001 was 2b in 2003 DT41 . The frequency of the other phage types was not epidemiologically significant. J Med Microbiol, 2004 Jul, 53(Pt 7), 705 - 9 Protection in a mouse peritonitis model mediated by iron-regulated outer-membrane protein of Salmonella typhi coupled to its Vi antigen; Chibber S et al.; Vi polysaccharide and iron-regulated outer-membrane proteins (IROMPs) were extracted and purified from the standard strain of Salmonella typhi, Ty2 . These were then conjugated by chemical coupling using the carbodimide method . Vi-IROMP conjugate was tested for its ability to protect against colonization by S . typhi in different organs . Mice immunized with 2.5 microg Vi-IROMP conjugate showed the most protection, as the least bacterial colonization of spleen, liver and Peyer's patches was observed . Peritoneal macrophages obtained from conjugate-treated mice phagocytosed bacteria efficiently . Circulating antibodies and the delayed type hypersensitivity response elucidated by mouse foot-pad swelling was significantly higher in conjugate-treated animals . These results clearly demonstrate that an IROMP and polysaccharide conjugate of S . typhi prepared from the same strain has the potential to protect animals against challenge. J Clin Microbiol, 2004 Jun, 42(6), 2581 - 6 Multiplex PCR for distinguishing the most common phase-1 flagellar antigens of Salmonella spp; Herrera-Leon S et al.; Most Salmonella serotypes alternatively express either phase-1 or phase-2 flagellar antigens, encoded by the fliC and fljB genes, respectively . Flagellar phase reversal for the identification of both flagellar antigens is not necessary at the genetic level . Variable internal regions of the fliC genes encoding the H:i, H:r, H:l,v, H:e,h, H:z(10), H:b, and H:d antigens have been sequenced; and the specific sites for each antigen in selected Salmonella serotypes have been determined . These results, together with flagellar G-complex variable internal sequences obtained by the Foodborne and Diarrheal Diseases Branch at the Centers for Disease Control and Prevention in Atlanta, GA, have been used to design a multiplex PCR to identify the G-complex antigens as well as the H:i, H:r, H:l,v, H:e,h, Hz(10), H:b, and H:d first-phase antigens . These antigens are part of the most common Salmonella serotypes possessing first-phase flagellar antigens . Salmonella enterica serotype Enteritidis is identified by adding a specific primer pair published previously . This multiplex PCR includes 13 primers . A total of 161 Salmonella strains associated with 72 different serotypes were tested . Each strain generated one first-phase-specific antigen fragment ranging from 100 to 500 bp; Salmonella serotype Enteritidis, however, generated two amplicons of 500 bp that corresponded to the G complex and a 333-bp serotype-specific amplicon, respectively . Twenty-three strains representing 19 serotypes with flagellar genes different from those targeted in this work did not generate any fragments . The method is quick, specific, and reproducible and is independent of the phase expressed by the bacteria when they are tested. J Clin Microbiol, 2004 Jun, 42(6), 2432 - 7 SHV-12-like extended-spectrum-beta-lactamase-producing strains of Salmonella enterica serotypes Babelsberg and Enteritidis isolated in France among infants adopted from Mali; Weill FX et al.; From December 2002 to June 2003, 14 cultures of Salmonella enterica serotype Babelsberg and 6 cultures of serotype Enteritidis, isolated in France from internationally adopted children, were identified at the French National Reference Center for Salmonella . All serotype Babelsberg isolates were related, as determined by pulsed-field gel electrophoresis, and all serotype Enteritidis strains displayed the same phage type . All serotype Enteritidis and seven serotype Babelsberg isolates produced an SHV-12-like extended-spectrum beta-lactamase as determined by sequencing of PCR products and by isoelectrofocusing . Some serotype Enteritidis isolates exhibited additional antimicrobial resistance (aminoglycosides, tetracycline, chloramphenicol, sulfonamides, and trimethoprim) . Our investigation indicated that these Salmonella isolates were certainly acquired in the same orphanage in Bamako, Mali, before the children were adopted by French families . An inappropriate use of ceftriaxone was probably the cause of the emergence of such strains . There is an urgent need to determine the origin of the contamination and to introduce adequate antibiotic protocols into this orphanage to prevent further transmission and dissemination . Screening for infections and follow-up, adapted to the origin of the internationally adopted children, should be recommended. Appl Environ Microbiol, 2004 Jun, 70(6), 3706 - 14 Uptake and replication of Salmonella enterica in Acanthamoeba rhysodes; Tezcan-Merdol D et al.; The ability of salmonellae to become internalized and to survive and replicate in amoebae was evaluated by using three separate serovars of Salmonella enterica and five different isolates of axenic Acanthamoeba spp . In gentamicin protection assays, Salmonella enterica serovar Dublin was internalized more efficiently than Salmonella enterica serovar Enteritidis or Salmonella enterica serovar Typhimurium in all of the amoeba isolates tested . The bacteria appeared to be most efficiently internalized by Acanthamoeba rhysodes . Variations in bacterial growth conditions affected internalization efficiency, but this effect was not altered by inactivation of hilA, a key regulator in the expression of the invasion-associated Salmonella pathogenicity island 1 . Microscopy of infected A . rhysodes revealed that S . enterica resided within vacuoles . Prolonged incubation resulted in a loss of intracellular bacteria associated with morphological changes and loss of amoebae . In part, these alterations were associated with hilA and the Salmonella virulence plasmid . The data show that Acanthamoeba spp . can differentiate between different serovars of salmonellae and that internalization is associated with cytotoxic effects mediated by defined Salmonella virulence loci. Appl Environ Microbiol, 2004 Jun, 70(6), 3618 - 23 Establishment of a real-time PCR-based approach for accurate quantification of bacterial RNA targets in water, using Salmonella as a model organism; Fey A et al.; Quantitative PCR (Q-PCR) is a fast and efficient tool to quantify target genes . In eukaryotic cells, quantitative reverse transcription-PCR (Q-RT-PCR) is also used to quantify gene expression, with stably expressed housekeeping genes as standards . In bacteria, such stable expression of housekeeping genes does not occur, and the use of DNA standards leads to a broad underestimation . Therefore, an accurate quantification of RNA is feasible only by using appropriate RNA standards . We established and validated a Q-PCR method which enables the quantification of not only the number of copies of target genes (i.e., the number of bacterial cells) but also the number of RNA copies . The genes coding for InvA and the 16S rRNA of Salmonella enterica serovar Typhimurium were selected for the evaluation of the method . As DNA standards, amplified fragments of the target genes were used, whereas the same DNA standards were transcribed in vitro for the development of appropriate RNA standards . Salmonella cultures and environmental water samples inoculated with bacteria were then employed for the final testing . Both experimental approaches led to a sensitive, accurate, and reproducible quantification of the selected target genes and RNA molecules by Q-PCR and Q-RT-PCR . It is the first time that RNA standards have been successfully used for a precise quantification of the number of RNA molecules in prokaryotes . This demonstrates the potential of this approach for determining the presence and metabolic activity of pathogenic bacteria in environmental samples. Appl Environ Microbiol, 2004 Jun, 70(6), 3582 - 7 Medium-chain fatty acids decrease colonization and invasion through hilA suppression shortly after infection of chickens with Salmonella enterica serovar Enteritidis; Van Immerseel F et al.; The most common source of Salmonella infections in humans is food of poultry origin . Salmonella enterica serovar Enteritidis has a particular affinity for the contamination of the egg supply . In this study, the medium-chain fatty acids (MCFA), caproic, caprylic, and capric acid, were evaluated for the control of Salmonella serovar Enteritidis in chickens . All MCFA were growth inhibiting at low concentrations in vitro, with caproic acid being the most potent . Contact of Salmonella serovar Enteritidis with low concentrations of MCFA decreased invasion in the intestinal epithelial cell line T84 . By using transcriptional fusions between the promoter of the regulatory gene of the Salmonella pathogenicity island I, hilA, and luxCDABE genes, it was shown that all MCFA decreased the expression of hilA, a key regulator related to the invasive capacity of Salmonella . The addition of caproic acid (3 g/kg of feed) to the feed of chicks led to a significant decrease in the level of colonization of ceca and internal organs by Salmonella serovar Enteritidis at 3 days after infection of 5-day-old chicks . These results suggest that MCFA have a synergistic ability to suppress the expression of the genes required for invasion and to reduce the numbers of bacteria in vivo . Thus, MCFA are potentially useful products for reducing the level of colonization of chicks and could ultimately aid in the reduction of the number of contaminated eggs in the food supply. Appl Environ Microbiol, 2004 Jun, 70(6), 3485 - 92 Effects of physical properties of feed on microbial ecology and survival of Salmonella enterica serovar Typhimurium in the pig gastrointestinal tract; Mikkelsen LL et al.; A two-by-two factorial experiment with pigs was conducted to study the effect of feed grinding (fine and coarse) and feed processing (pelleted and nonpelleted) on physicochemical properties, microbial populations, and survival of Salmonella enterica serovar Typhimurium DT12 in the gastrointestinal tracts of pigs . Results demonstrated a strong effect of diet on parameters measured in the stomachs of the pigs, whereas the effect was less in the other parts of the gastrointestinal tract . Pigs fed the coarse nonpelleted (C-NP) diet showed more solid gastric content with higher dry matter content than pigs fed the fine nonpelleted (F-NP), coarse pelleted (C-P), or fine pelleted (F-P) diet . Pigs fed the C-NP diet also showed significantly increased number of anaerobic bacteria (P < 0.05), increased concentrations of organic acids, and reduced pH in the stomach . In addition, pigs fed the C-NP diet showed increased in vitro death rate of S . enterica serovar Typhimurium DT12 in content from the stomach (P < 0.001) . Pigs fed the C-NP diet had a significantly higher concentration of undissociated lactic acid in gastric content than pigs fed the other diets (P < 0.001) . A strong correlation between the concentration of undissociated lactic acid and the death rate of S . enterica serovar Typhimurium DT12 was found . In the distal small intestine, cecum, and midcolon, significantly lower numbers of coliform bacteria were observed in pigs fed the coarse diets than in pigs fed the fine diets (P < 0.01) . Pigs fed the C-NP diet showed the lowest number of coliform bacteria in these segments of the gastrointestinal tract . Pigs fed the coarse diets showed increased concentration of butyric acid in the cecum (P < 0.05) and colon (P < 0.10) compared with pigs fed the fine diets . It was concluded that feeding a coarsely ground meal feed to pigs changes the physicochemical and microbial properties of content in the stomach, which decreases the survival of Salmonella during passage through the stomach . In this way the stomach acts as a barrier preventing harmful bacteria from entering and proliferating in the lower part of the gastrointestinal tract. Biochem Biophys Res Commun, 2004 Jul 2, 319(3), 1001 - 9 Cloning of IP15, a pancreatitis-induced gene whose expression inhibits cell growth; Ropolo A et al.; We describe the cloning and expression of the mouse gene interferon-inducible-protein 15 (IP15), whose activation is related to the acute phase of experimental pancreatitis . Analysis of its structure indicates that it encodes a putative transmembrane protein of 137 amino acids . This gene contains a predicted IFN-stimulable-response element . In vivo studies showed that IP15 is strongly activated in pancreas early during caerulein-induced pancreatitis . In situ hybridization of IP15 mRNA showed that its expression is restricted to acinar cells . IP15 was also induced in pancreas under systemic-lipopolysaccharide treatment and in intestine under Salmonella infection . In vitro studies using NIH3T3 fibroblasts showed that IP15 is induced by IFN-alpha . Growth rate was significantly lower in cells transfected with pcDNA4/IP15 plasmid . In addition, cells expressing IP15 showed less capacity to develop colonies after antibiotic selection . In conclusion, we identified a new interferon-inducible gene that is activated early in pancreas with pancreatitis and whose expression inhibits cell growth. Vet Immunol Immunopathol, 2004 Jul, 100(1-2), 81 - 97 Effects of furazolidone pretreatment of Salmonella enteritidis PT4 at sub- and suprainhibitory concentrations on phagocytosis and intracellular survival in chicken macrophages; Chadfield MS et al.; The antimicrobial effect of the nitrofuran derivative furazolidone at sub- and suprainhibitory concentrations on Salmonella enteritidis PT4 and the influence with regard to interaction with avian macrophages was investigated in this study . Phagocytosis of furazolidone-sensitive (FzS) S . enteritidis with chicken macrophages in the presence of furazolidone at concentrations of 1/8, 1/4, 1/2 and 8x MIC resulted in an increase in the rate of phagocytic killing of approximately 3-, 6-, 6.5- and 9-fold, respectively, with 1/2 and 8x MIC concentrations producing statistically significant (P<0.05) increases in phagocytosis . Treatment of the FzS Salmonella with furazolidone at concentrations of 4x and 10x MIC, for 15 min prior to phagocytosis, also significantly (P<0.005) increased phagocytic uptake when compared with untreated bacteria . The rate of phagocytosis monitored over 90 min was highest between 30 and 60 min with the furazolidone pretreated salmonella, compared with the delayed rate of the control between 60 and 90 min . Exposure of FzS and FzR strains with suprainhibitory concentrations of furazolidone at 4x, 8x and 10x MIC for 30 min prior to phagocytosis demonstrated an increase in bacterial killing . Exposure of strains to sub-inhibitory concentrations of furazolidone led to an increase in chemiluminescence during phagocytosis with macrophages, suggesting an increase in oxidative metabolism in the macrophages as a result of an increase in activation and phagocytosis . Pretreatment of the strains with suprainhibitory concentrations of furazolidone for 30 min prior to phagocytosis demonstrated a similar increase in oxidative metabolism in the macrophages . Measurement of the amount of 14C-furazolidone associated with chicken macrophages was determined over 20 h incubation . The level of radioactivity of 14C-furazolidone alone was used to estimate the amount of cell-associated nitrofuran when incubated with the macrophages by means of regression analysis . Incubation with concentrations of 16, 32 and 64 microg/ml for 20 h resulted in the cell association of >or=1 microg/ml of furazolidone, which is the concentration required for the agent to exhibit bactericidal activity on furazolidone-sensitive Salmonella strains . Furazolidone was able to reduce intracellular salmonella viability at all concentrations, but total killing was achieved only with concentrations of >or=8 microg/ml, which supports the results for furazolidone association with the macrophages . This substantiates that the bioactivity of the nitrofuran was not inhibited or diminished in the intracellular environment of the macrophage and that exposure of salmonella to nitrofurans enhances phagocytosis. Curr Biol, 2004 Jun 8, 14(11), 1018 - 24 Caenorhabditis elegans-based screen identifies Salmonella virulence factors required for conserved host-pathogen interactions; Tenor JL et al.; A Caenorhabditis elegans-Salmonella enterica host-pathogen model was used to identify both novel and previously known S . enterica virulence factors (HilA, HilD, InvH, SptP, RhuM, Spi4-F, PipA, VsdA, RepC, Sb25, RfaL, GmhA, LeuO, CstA, and RecC), including several related to the type III secretion system (TTSS) encoded in Salmonella pathogenicity island 1 (SPI-1) . Mutants corresponding to presumptive novel virulence-related genes exhibited diminished ability to invade epithelial cells and/or to induce polymorphonuclear leukocyte migration in a tissue culture model of mammalian enteropathogenesis . When expressed in C . elegans intestinal cells, the S . enterica TTSS-exported effector protein SptP inhibited a conserved p38 MAPK signaling pathway and suppressed the diminished pathogenicity phenotype of an S . enterica sptP mutant . These results show that C . elegans is an attractive model to study the interaction between Salmonella effector proteins and components of the innate immune response, in part because there is a remarkable overlap between Salmonella virulence factors required for human and nematode pathogenesis . J Microbiol Immunol Infect, 2004 Apr, 37(2), 109 - 14 Changing characteristics of typhoid fever in Taiwan; Su CP et al.; Typhoid fever, a systemic disease caused by Salmonella typhi, is classically characterized by fever and abdominal symptoms . Although now considered uncommon, it seems to have re-emerged in Taiwan in recent years . We conducted a retrospective study of the clinical characteristics and microbiologic findings in 24 confirmed cases of typhoid fever treated over a 7-year period at a medical center in northern Taiwan . There were 11 males and 13 females, including 15 adults (over 18 years in age) and 9 children . Their mean age was 24.7 years (range, 9 months to 58 years) . Twelve patients had recently returned from abroad, mostly from Southeast Asia . The most common complaints were fever (24/24), diarrhea (18/24), abdominal pain (10/24), and cough (10/24) . The average duration of fever before diagnosis was 14.1 days, with a maximum of 30 days . Relative bradycardia was noted in 6 patients . Leukopenia was noted in 2 patients . S . typhi was isolated from blood culture in 20 cases, from stool culture in 3 cases, and from bone marrow culture in 1 case . Widal test was only positive initially in 7/18 cases . Fever of unknown origin was the most common initial diagnosis . Typhoid or enteric fever was impressed initially in only 2 cases . Almost all isolates of S . typhi were susceptible to antibiotics currently used for typhoid fever, with only 1 isolate resistant to chloramphenicol . All patients survived after antibiotic treatment . Only 1 patient developed recurrence after a 10-day course of ceftriaxone . In conclusion, the diagnosis of typhoid fever is often challenging due to non-specific symptoms and lack of an immediate confirmatory test . It is important to include this disease in the differential diagnosis of febrile patients with abdominal symptoms. Comp Immunol Microbiol Infect Dis, 2004 Jul, 27(4), 255 - 72 Cell-mediated immune responses to a killed Salmonella enteritidis vaccine: lymphocyte proliferation, T-cell changes and interleukin-6 (IL-6), IL-1, IL-2, and IFN-gamma production; Okamura M et al.; Two experimental approaches were used to investigate the immunological responses of chickens to a commercial killed Salmonella enteritidis (SE) vaccine . In the first, the effects of host age on antigen-specific proliferative responses and cytokine production were examined . Compared with non-vaccinated controls, 4-wk-old vaccinated chickens showed higher proliferation to SE LPS and flagella . The lymphoproliferation responses to these antigens of 8-mo-old vaccinated chickens were not different compared to the non-vaccinated controls . Increased production of interferon-gamma (IFN-gamma) and interleukin-2 (IL-2) by antigen-stimulated splenocytes following vaccination were, in general, more often observed in 4-wk-old compared with 8-mo-old chickens, whereas serum levels of these cytokines were consistently higher in the vaccinated birds compared with controls regardless of age . The second set of experiments were designed to determine the effects of SE vaccination on mitogen- or antigen-induced splenocyte proliferation and serum nitric oxide (NO) and cytokine levels . Splenocytes from vaccinated chickens stimulated with SE flagella showed significantly increased numbers of TCRgammadelta+ cells at 7 days post-vaccination compared with non-vaccinated birds . In contrast, no differences were noted with CD4+, CD8+, or TCRalphabeta+ cells at any time points examined . Higher levels of NO production were observed following stimulation with SE flagella at 4, 7, 11, and 14 days after SE vaccination while serum levels of IFN-gamma, IL-1, IL-6, and IL-8 were elevated only at day 7 post-vaccination . In conclusion, younger chickens mounted a more robust antigen-specific immune response to the SE vaccine compared with older birds and vaccination induced not only T-cell-mediated responses but also host innate and pro-inflammatory responses. J Microbiol Methods, 2004 Jul, 58(1), 131 - 4 Rapid detection of quinolone-resistant Salmonella by real time SNP genotyping; Esaki H et al.; A total of 63 isolates were screened for the gyrA mutation (87Asp-Tyr) in Salmonella enterica serovars using real time PCR . All of the isolates were successfully identified as resistant or susceptible, consistent with the MIC result of the agar dilution method and gyrA sequencing . J Microbiol Methods, 2004 Jul, 58(1), 67 - 78 A protocol for quantifying the birth, death and emigration rates of produce-associated bacteria, illustrated by its application to Salmonella enterica serovar Typhimurium on cultivated mushrooms; Ercolani GL; Colony counts, counts of immunostained cells, fluorescent assays for cell viability and titration of a superinfecting bacteriophage were incorporated into a protocol for studying the growth kinetics of produce-associated bacteria in vivo . A set of equations was assembled for measuring the true rates of birth, death and emigration of the bacteria within the frame of a "transit growth" model, thus allowing the independent measurement of the carrying capacity of the substrate and of the overall productivity of the system . Implementation of the protocol on two species of cultivated mushrooms inoculated with Salmonella enterica serovar Typhimurium showed that large bacterial populations developed on Agaricus bisporus A15 but emigration was not detected, whereas resident populations on Agrocybe aegerita FAR142 amounted to 79.7%, 65.1% and 80.7% of the cultivable, dead and total bacterial cells produced, owing to emigration . J Microbiol Methods, 2004 Jul, 58(1), 49 - 57 Method for assessment of functional affinity of antibodies for live bacteria; Brovko L et al.; A rapid and convenient method for assessment of functional affinity of antibodies against live bacteria is described . When a combination of immunomagnetic separation (IMS) with bioluminescent or fluorescent genetic labelling of the cells was employed, the method showed good correlation with plate count . However, the use of reporter bacteria allowed results to be obtained within 1 h compared with days using conventional methods . Due to its lower detection limit, the bioluminescent assay performed better than the fluorescent assay . Antibody affinities for Escherichia coli O157:H7 and Salmonella enteritidis were examined at different environmental conditions such as pH 3-7, temperature 4-25 degrees C, and sodium chloride concentrations 0-5% and compared with sensitivities of ELISA . J Bacteriol, 2004 Jun, 186(12), 4038 - 41 Resuscitation of a defective prophage in Salmonella cocultures; Figueroa-Bossi N et al.; Widely studied Salmonella enterica serovar Typhimurium strains ATCC 14028s and SL1344 harbor a cryptic ST64B prophage unable to produce infectious virions . We found that coculturing either strain with an isogenic sibling lacking the prophage leads to the appearance of active forms of the virus . Active phage originates from reversion of a +1 frameshift mutation at a monotonous G:C run in a presumptive tail assembly pseudogene. J Bacteriol, 2004 Jun, 186(12), 4034 - 7 A mutant allele of rpoD results in increased conversion of aminoimidazole ribotide to hydroxymethyl pyrimidine in Salmonella enterica; Dougherty MJ et al.; An allele of rpoD (rpoD1181) that results in increased synthesis of the pyrimidine moiety of thiamine in Salmonella enterica was identified . The S508Y substitution caused by rpoD1181 is analogous to the S506F derivative of the Escherichia coli protein . The properties of this E . coli mutant protein have been well characterized in vitro . Identification of a metabolic phenotype caused by the rpoD1181 allele of S . enterica allows past in vitro results to be incorporated in continuing efforts to understand cellular processes that are integrated with the thiamine biosynthetic pathway. J Bacteriol, 2004 Jun, 186(12), 4019 - 24 The Escherichia coli tppB (ydgR) gene represents a new class of OmpR-regulated genes; Goh EB et al.; The EnvZ/OmpR two-component regulatory system plays a critical role in the Escherichia coli stress response . In this study, we examined the expression of a new OmpR-regulated gene, ydgR . Our results indicate that ydgR is equivalent to the Salmonella enterica serovar Typhimurium tppB gene and represents a new class of OmpR-regulated genes. Am J Physiol Cell Physiol, 2004 Oct, 287(4), C939 - 48 Epub 2004 Jun 02. Modulation of chloride secretory responses and barrier function of intestinal epithelial cells by the Salmonella effector protein SigD; Bertelsen LS et al.; The Salmonella effector protein SigD is an inositol phosphate phosphatase that inhibits phosphatidylinositol 3-kinase-dependent signaling . Because epidermal growth factor (EGF) inhibits chloride secretion via phosphatidylinositol 3-kinase, we explored whether Salmonella infection might modify the inhibitory effect of EGF . As expected, EGF inhibited chloride secretion induced by carbachol in T(84) epithelial cells . Infection with wild-type (WT) but not sigD(-) mutant S . typhimurium SL1344 decreased CCh-stimulated chloride secretion . Moreover, WT but not sigD(-) Salmonella reduced the inhibitory effect of EGF on carbachol-stimulated chloride secretion . Complementation of sigD restored the ability of mutant Salmonella to reverse the inhibitory effect of EGF . EGF-induced EGF receptor phosphorylation was similar in cells infected with either WT or mutant Salmonella, and neither WT nor sigD(-) Salmonella altered recruitment of the p85 subunit of phosphatidylinositol 3-kinase to EGF receptor, implying that SigD acts downstream of these signaling events . Furthermore, transepithelial resistance fell more rapidly in cells infected with WT vs . sigD(-) Salmonella, indicating an early role for SigD in reducing barrier function, perhaps via activation of protein kinase C . We conclude that the Salmonella bacterial effector protein SigD may play critical roles in the pathogenesis of disease caused by this microorganism. Environ Health Perspect, 2004 Jun, 112(8), 814 - 9 Bioassay-directed fractionation and salmonella mutagenicity of automobile and forklift diesel exhaust particles; DeMarini DM et al.; Many pulmonary toxicity studies of diesel exhaust particles (DEPs) have used an automobile-generated sample (A-DEPs) whose mutagenicity has not been reported . In contrast, many mutagenicity studies of DEPs have used a forklift-generated sample (SRM 2975) that has been evaluated in only a few pulmonary toxicity studies . Therefore, we evaluated the mutagenicity of both DEPs in Salmonella coupled to a bioassay-directed fractionation . The percentage of extractable organic material (EOM) was 26.3% for A-DEPs and 2% for SRM 2975 . Most of the A-EOM (~55%) eluted in the hexane fraction, reflecting the presence of alkanes and alkenes, typical of uncombusted fuel . In contrast, most of the SRM 2975 EOM (~58%) eluted in the polar methanol fraction, indicative of oxygenated and/or nitrated organics derived from combustion . Most of the direct-acting, base-substitution activity of the A-EOM eluted in the hexane/dichloromethane (DCM) fraction, but this activity eluted in the polar methanol fraction for the SRM 2975 EOM . The direct-acting frameshift mutagenicity eluted across fractions of A-EOM, whereas > 80% eluted only in the DCM fraction of SRM 2975 EOM . The A-DEPs were more mutagenic than SRM 2975 per mass of particle, having 227 times more polycyclic aromatic hydrocarbon-type and 8-45 more nitroarene-type mutagenic activity . These differences were associated with the different conditions under which the two DEP samples were generated and collected . A comprehensive understanding of the mechanisms responsible for the health effects of DEPs requires the evaluation of DEP standards for a variety of end points, and our results highlight the need for multidisciplinary studies on a variety of representative samples of DEPs. Environ Health Perspect, 2004 Jun, 112(8), 812 - 3 A tale of two diesels; Arey J; Two different samples of diesel exhaust particles (DEP) have been used by toxicologists interested primarily in cancer/genotoxicity or noncancer--such as pulmonary inflammation and asthma exacerbation--health end points . These are, respectively, a standard reference material, SRM 2975, from a heavy-duty diesel engine, and a sample collected by researchers at the Japanese National Institute for Environmental Studies from an automobile diesel engine . In this issue of Environmental Health Perspectives companion papers appear, by David DeMarini and co-workers and by Pramila Singh and co-workers, characterizing these samples and contrasting their Salmonella mutagenicity and pulmonary toxicity in mice . This commentary is a plea from an atmospheric chemist for more cooperation among toxicologists, analytical chemists, atmospheric chemists, and automotive and combustion engineers to provide a comprehensive assessment of health risks to humans exposed to contemporary diesel emissions and for greater quantities and more diverse types of DEP and ambient samples (i.e., SRMs) that can be shared and exhaustively characterized . This needs to be a continuing process as diesel engines, fuels, and exhaust components evolve in response to control regulations. Proc Natl Acad Sci U S A, 2004 Jun 8, 101(23), 8739 - 44 Epub 2004 Jun 01. Antigen selection based on expression levels during infection facilitates vaccine development for an intracellular pathogen; Rollenhagen C et al.; Vaccines effective against intracellular pathogens could save the lives of millions of people every year, but vaccine development has been hampered by the slow largely empirical search for protective antigens . In vivo highly expressed antigens might represent a small attractive antigen subset that could be rapidly evaluated, but experimental evidence supporting this rationale, as well as practical strategies for its application, is largely lacking because of technical difficulties . Here, we used Salmonella strains expressing differential amounts of a fluorescent model antigen during infection to show that, in a mouse typhoid fever model, CD4 T cells preferentially recognize abundant Salmonella antigens . To identify a large number of natural Salmonella antigens with high expression levels during infection, we used a quantitative in vivo screening strategy . Immunization studies with five particularly attractive candidates revealed two highly protective antigens that might permit the development of an improved typhoid fever vaccine . In conclusion, we have established a rationale and an experimental strategy that will substantially facilitate vaccine development for Salmonella and possibly other intracellular pathogens. Vet Microbiol, 2004 Jun 21, 101(2), 131 - 41 The correlation between Salmonella serology and isolation of Salmonella in Danish pigs at slaughter; Sorensen LL et al.; In Denmark, a serological Salmonella surveillance programme in finishing pig herds has been in place since 1995 . The programme was founded on data from experimental studies, which demonstrated a strong association between Salmonella serology and the prevalence of these bacteria . The current study was carried out in three Danish abattoirs to evaluate the correlation under field conditions . A total of 160 Danish finishing pig herds were included . Seven out of these were examined twice, yielding a total of 167 observations . The herds were selected according to their herd serology based on data from the national surveillance . From each herd, samples were taken from 10 finishers at slaughter . The prevalence of Salmonella bacteria was measured at four sites: (1) caecal-content; (2) carcass surface; (3) pharynx; and (4) caecal lymph nodes . A logistic regression model was constructed for each sampling site . Abattoir, sanitary slaughter and herd seroprevalence were used as explanatory variables . The results demonstrated that there was a strong association between herd serology and the prevalence of Salmonella bacteria measured at three of the sampling sites: caecal-content, pharynx, and carcass surface . For these sites, the odds for being culture-positive for Salmonella varied from 1.3 to 1.5 for each increase of 10% in herd serology (P < 0.0001) . For caecal lymph nodes, however, no linear association was found . Prostaglandins Leukot Essent Fatty Acids, 2004 Jul, 71(1), 1 - 5 The role of cyclooxygenase inhibition in the effect of alpha-melanocyte-stimulating hormone on reactive oxygen species production by rat peritoneal neutrophils; Oktar BK et al.; The effect of alpha-MSH on reactive oxygen species (ROS) production by rat peritoneal neutrophils and the effect of cyclooxygenase (COX) inhibition were investigated using the chemiluminescence (CL) technique . Cells were obtained by peritoneal lavage 4h after administration of oyster glycogen to rats and were stimulated with lipopolysaccharide (LPS) from Salmonella enderitidis and phorbol 12-myristate 13-acetate (PMA) . The increasing concentrations of alpha-MSH (10(-12)-10(-6) M) were added to stimulated cells alone or along with the COX inhibitors indomethacin, ketorolac or nimesulide (10(-8)-10(-5) M) . Luminol and lucigenin CL levels were significantly increased in cells stimulated with LPS and PMA compared to unstimulated ones . alpha-MSH significantly reduced lucigenin CL values and this effect was completely reversed in the presence of indomethacin (10(-8) and 10(-7) M) . In conclusion, alpha-MSH inhibits the production of superoxide radicals by activated rat peritoneal neutrophils and COX contributes to this effect . J Biol Chem, 2004 Aug 13, 279(33), 34631 - 42 Epub 2004 May 28. Two periplasmic disulfide oxidoreductases, DsbA and SrgA, target outer membrane protein SpiA, a component of the Salmonella pathogenicity island 2 type III secretion system; Miki T et al.; The formation of disulfide is essential for the folding, activity, and stability of many proteins secreted by Gram-negative bacteria . The disulfide oxidoreductase, DsbA, introduces disulfide bonds into proteins exported from the cytoplasm to periplasm . In pathogenic bacteria, DsbA is required to process virulence determinants for their folding and assembly . In this study, we examined the role of the Dsb enzymes in Salmonella pathogenesis, and we demonstrated that DsbA, but not DsbC, is required for the full expression of virulence in a mouse infection model of Salmonella enterica serovar Typhimurium . Salmonella strains carrying a dsbA mutation showed reduced function mediated by type III secretion systems (TTSSs) encoded on Salmonella pathogenicity islands 1 and 2 (SPI-1 and SPI-2) . To obtain a more detailed understanding of the contribution of DsbA to both SPI-1 and SPI-2 TTSS function, we identified a protein component of the SPI-2 TTSS apparatus affected by DsbA . Although we found no substrate protein for DsbA in the SPI-1 TTSS apparatus, we identified SpiA (SsaC), an outer membrane protein of SPI-2 TTSS, as a DsbA substrate . Site-directed mutagenesis of the two cysteine residues present in the SpiA protein resulted in the loss of SPI-2 function in vitro and in vivo . Furthermore, we provided evidence that a second disulfide oxidoreductase, SrgA, also oxidizes SpiA . Analysis of in vivo mixed infections demonstrated that a Salmonella dsbA srgA double mutant strain was more attenuated than either single mutant, suggesting that DsbA acts in concert with SrgA in vivo. Acta Vet Hung, 2004, 52(2), 219 - 26 Health status of free-living pigeons (Columba livia domestica) in the city of Ljubljana; Dovc A et al.; In the year 2000 an epidemiological research was undertaken on the health status of free-living pigeons in the city of Ljubljana, Slovenia . A total of 139 pigeons were captured and examined for the most common bacterial, viral, and parasitic diseases . Serum samples, oropharyngeal and cloacal swabs as well as samples of droppings and feathers were taken from the captured birds . Antibodies to paramyxovirus type 1 were found in 84.2% of the sera examined, and 23.7% of birds were serologically positive to Chlamydophila psittaci . Antibodies to avian influenza virus were not detected . Salmonella spp . were isolated from 5.7% of the cloacal swabs . Trichomonas gallinae was clinically suspected and then microscopically confirmed using oropharyngeal swabs in 7.9% of examined birds . Eimeria spp . was identified in 71.9%, Capillaria sp . in 26.6% and Ascaridia columbae in 4.3% of droppings samples examined . Of the ectoparasites, Columbicola columbae and Campanulotes bidentatus compar were found. Pediatr Surg Int . 2004 May 28; {Epub ahead of print} Mesenteric cyst infected with non-typhoidal salmonella infection; Okumus M et al.; Although extra-intestinal non-typhoidal Salmonella infections are common in developing countries, infection of the mesenteric cyst with Salmonella enteritidis is an extremely rare occurrence . Review of the English literature has revealed one report up to this date . The case of a 4-year-old boy with a mesenteric cyst infected with Salmonella enteritidis is presented. J AOAC Int, 2004 Mar-Apr, 87(2), 390 - 4 Evaluation of VIDAS Immuno-Concentration Salmonella (ICS)/VIDAS Salmonella (SLM) immunoassay method for detection of Salmonella in selected foods (Method Modification 2001.09): collaborative study; McMahon WA et al.; A new method for detection of Salmonella in foods in a minimum of 24 h was adopted as an AOAC Official First Action Method for selected foods (2001.09) using both the VIDAS Immuno-Concentration Salmonella (ICS) and VIDAS Salmonella (SLM) methods. J AOAC Int, 2004 Mar-Apr, 87(2), 385 - 9 Evaluation of VIDAS Immuno-Concentration Salmonella (ICS) plus selective plate method (Hektoen enteric, bismuth sulfite, xylose lysine desoxycholate) for detection of Salmonella in selected foods (Method Modification 2001.08): collaborative study; McMahon WA et al.; A new method for detection of Salmonella in foods in 48 h has been granted AOAC First Action approval in selected foods (Official Method 2001.08) using both the VIDAS Immuno-Concentration Salmonella (ICS) method and a combination of 3 selective plates: Hektoen enteric (HE), bismuth sulfite (BS), and xylose lysine desoxycholate (XLD). J AOAC Int, 2004 Mar-Apr, 87(2), 380 - 4 Evaluation of VIDAS Immuno-Concentration Salmonella (ICS) plus selective plate method (Hektoen enteric, bismuth sulfite, Salmonella identification) for detection of Salmonella in selected foods (Method Modification 2001.07): collaborative study; McMahon WA et al.; A new method for detection of Salmonella in foods in 48 h has been granted AOAC First Action approval in selected foods (Official Method 2001.07) using both the VIDAS Immuno-Concentration Salmonella (ICS) method and a combination of 3 selective plates: Hektoen enteric (HE), bismuth sulfite (BS), and Salmonella Identification (SMID). J AOAC Int, 2004 Mar-Apr, 87(2), 374 - 9 Validation study to demonstrate the equivalence of a minor modification (TECRA ULTIMA protocol) to AOAC Method 998.09 (TECRA Salmonella Visual Immunoassay) with the cultural reference method; Briggs J et al.; The TECRA Salmonella Visual Immunoassay (VIA) using Rappaport-Vassiliadis RV{R10} as a single selective enrichment broth has Final Action approval (AOAC Method 998.09) . TECRA has recently developed a protocol (TECRA ULTIMA), which involves the addition of a new additive to a 1 mL aliquot of the RV{R10} broth, prior to the heat-killing step, thereby allowing the RV{R10} broth to be tested directly in the kit and thus eliminating the need for the 2 h post-enrichment in M broth . An in-house validation study was conducted to compare the modified AOAC Method 998.09 to the reference culture method . Three foods were used in the study: Naturally contaminated raw ground poultry at high (10-50 cells/25 g), and low (1-5 cells/25 g) levels; and milk powder and peanut butter, artificially inoculated at low and high levels with Salmonella bovismorbificans and S . enterica Mbandaka, respectively . Twenty test portions were analyzed for each level with 10 uninoculated control samples per food . Overall, no significant differences (p <0.05) were observed when the proportion of positive test portions for the modified VIA were compared with that for the reference method . This minor modification, which employs the additive (provided in the TECRA ULTIMA SALMONELLA Test Kit) to permit the direct analysis of RV{R10} broth has demonstrated the utility of the TECRA ULTIMA SALMONELLA protocol . It is recommended that the minor modification to Method 998.09 be approved First Action as an additional option within the method. Trop Gastroenterol, 2003 Oct-Dec, 24(4), 198 - 9 Unusual presentation of enteric fever: three cases of splenic and liver abscesses due to Salmonella typhi and Salmonella paratyphi A; Chaudhry R et al.; Enteric fever is a multisystem disorder caused mainly by Salmonella typhi and Salmonella paratyphi A . It continues to be a major public health problem, especially in developing countries . Unusual presentations of Salmonellosis are rare . We report 3 such cases of young adult males, one of splenic abscess due to Salmonella typhi and one each of liver abscess due to Salmonella typhi and Salmonella paratyphi A . A brief review of the literature pertaining to the cases is also given. Indian J Pediatr, 2004 May, 71(5), 413 - 5 Cefpodoxime - utility in respiratory tract infections and typhoid fever; Aggarwal A et al.; Cefpodoxime is a oral third generation cephalosporin active against most of gram positive and gram negative bacteria except Pseudomonas, B . fragilis and Entrococcous . Clinical studies have confirmed efficacy of cefpodoxime in acute otitis media, sinusitis and tosillopharyngitis . Twice daily administration and safety profile increases compliance and decreases failure rate . It has a role as switch over therapy from intravenous ceftriaxone in serious respiratory tract infections (RTIs) . In areas where common respiratory pathogens show decreased sensitivity to penicillins and macrolides cefpodoxime can be used as empirical first line therapy in respiratory tract infections . It seems to be a promising molecule in pediatric typhoid fever because of its excellent activity against Salmonella species but clinical trials are limited. J Neurosci, 2004 May 26, 24(21), 4928 - 34 Long-term alterations in neuroimmune responses after neonatal exposure to lipopolysaccharide; Boisse L et al.; Fever is an integral part of the host's defense to infection that is orchestrated by the brain . A reduced febrile response is associated with reduced survival . Consequently, we have asked if early life immune exposure will alter febrile and neurochemical responses to immune stress in adulthood . Fourteen-day-old neonatal male rats were given Escherichia coli lipopolysaccharide (LPS) that caused either fever or hypothermia depending on ambient temperature . Control rats were given pyrogen-free saline . Regardless of the presence of neonatal fever, adult animals that had been neonatally exposed to LPS displayed attenuated fevers in response to intraperitoneal LPS but unaltered responses to intraperitoneal interleukin 1beta or intracerebroventricular prostaglandin E(2) . The characteristic reduction in activity that accompanies fever was unaltered, however, as a function of neonatal LPS exposure . Treatment of neonates with an antigenically dissimilar LPS (Salmonella enteritidis) was equally effective in reducing adult responses to E . coli LPS, indicating an alteration in the innate immune response . In adults treated as neonates with LPS, basal levels of hypothalamic cyclooxygenase 2 (COX-2), determined by semiquantitative Western blot analysis, were significantly elevated compared with controls . In addition, whereas adult controls responded to LPS with the expected induction of COX-2, adults pretreated neonatally with LPS responded to LPS with a reduction in COX-2 . Thus, neonatal LPS can alter CNS-mediated inflammatory responses in adult rats. J Biol Chem, 2004 Aug 13, 279(33), 34183 - 90 Epub 2004 May 25. ppGpp-dependent stationary phase induction of genes on Salmonella pathogenicity island 1; Song M et al.; We have examined expression of the genes on Salmonella pathogenicity island 1 (SPI1) during growth under the physiologically well defined standard growth condition of Luria-Bertani medium with aeration . We found that the central regulator hilA and the genes under its control are expressed at the onset of stationary phase . Interestingly, the two-component regulatory genes hilC/hilD, sirA/barA, and ompR, which are known to modulate expression from the hilA promoter (hilAp) under so-called "inducing conditions" (Luria-Bertani medium containing 0.3 m NaCl without aeration), acted under standard conditions at the stationary phase induction level . The induction of hilAp depended not on RpoS, the stationary phase sigma factor, but on the stringent signal molecule ppGpp . In the ppGpp null mutant background, hilAp showed absolutely no activity . The stationary phase induction of hilAp required spoT but not relA . Consistent with this requirement, hilAp was also induced by carbon source deprivation, which is known to transiently elevate ppGpp mediated by spoT function . The observation that amino acid starvation elicited by the addition of serine hydroxamate did not induce hilAp in a RelA(+) SpoT(+) strain suggested that, in addition to ppGpp, some other alteration accompanying entry into the stationary phase might be necessary for induction . It is speculated that during the course of infection Salmonella encounters various stressful environments that are sensed and translated to the intracellular signal, ppGpp, which allows expression of Salmonella virulence genes, including SPI1 genes. J Agric Food Chem, 2004 Jun 2, 52(11), 3329 - 32 Antibacterial activity of coriander volatile compounds against Salmonella choleraesuis; Kubo I et al.; Aliphatic (2E)-alkenals and alkanals characterized from the fresh leaves of the coriander Coriandrum sativum L . (Umbelliferae) were found to possess bactericidal activity against Salmonella choleraesuis ssp . choleraesuis ATCC 35640 . (2E)-Dodecenal (C(12)) was the most effective against this food-borne bacterium with the minimum bactericidal concentration (MBC) of 6.25 microg/mL (34 microM), followed by (2E)-undecenal (C(11)) with an MBC of 12.5 microg/mL (74 microM) . The time-kill curve study showed that these alpha,beta-unsaturated aldehydes are bactericidal against S . choleraesuis at any growth stage and that their bactericidal action comes in part from the ability to act as nonionic surfactants. J Biol Chem, 2004 Jul 23, 279(30), 31599 - 605 Epub 2004 May 24. NMR structure of a type IVb pilin from Salmonella typhi and its assembly into pilus; Xu XF et al.; The structure of the N-terminal-truncated Type IVb structural pilin (t-PilS) from Salmonella typhi was determined by NMR . Although topologically similar to the recently determined x-ray structure of pilin from Vibrio cholerae toxin-coregulated pilus, the only Type IVb pilin with known structure, t-PilS contains many distinct structural features . The protein contains an extra pair of beta-strands in the N-terminal alphabeta loop that align with the major beta-strands to form a continuous 7-stranded antiparallel beta-sheet . The C-terminal disulfide-bonded region of t-PilS is only half the length of that of toxin-coregulated pilus pilin . A model of S . typhi pilus has been proposed and mutagenesis studies suggested that residues on both the alphabeta loop and the C-terminal disulfide-bonded region of PilS might be involved in binding specificity of the pilus . This model structure reveals an exposed surface between adjacent subunits of PilS that could be a potential binding site for the cystic fibrosis transmembrane conductance regulator. Immunol Lett, 2004 May 15, 93(2-3), 115 - 22 Induction of cellular immune response and anti-Salmonella enterica serovar typhi bactericidal antibodies in healthy volunteers by immunization with a vaccine candidate against typhoid fever; Salazar-Gonzalez RM et al.; Typhoid fever remains a serious public health problem . We have developed a vaccine from Salmonella enterica serovar typhi (S . typhi) outer-membrane proteins (OMPs) known as porins . A single subcutaneous dose of 10 microg of porins induced a five-fold (P = 0.05) seroconversion index consisting of IgM and IgG at 7 and 15 days after vaccination as well as the production of IgG1 and IgG2 isotypes . The porins-based vaccine induced a two-fold increase (P = 0.05) in bactericidal titres in volunteers, whom also developed a T-cell response characterized by the production of interferon-gamma (INF-gamma) . Side effects after vaccination were mild and transient . The data showed that our S . typhi porins-based candidate vaccine is safe and immunogenic in healthy humans. Prev Vet Med, 2004 May 14, 63(3-4), 151 - 61 Risk factors for Salmonella enterica subsp . enterica infection in senegalese broiler-chicken flocks; Cardinale E et al.; Our objective was to assess the association of managerial practices, general hygiene and Salmonella infection in Senegalese broiler flocks . Seventy broilers farms were studied from January 2000 to December 2001 around Dakar . A questionnaire was submitted to the farmers and samples of fresh broiler droppings were taken . A 28.6% of the flocks were infected by Salmonella (mainly Hadar and Brancaster serovars) . Salmonella infection of the previous flock (OR = 6.82) and of day-old chicks (OR = 3.73), frequent poultry farmers' visits (OR = 5.38) and keeping sick birds inside the farm (OR = 5.32) increased the risk of Salmonella infection . But, using antibiotics on day-old chicks (OR = 0.17) and a detergent for cleaning (OR = 0.16) decreased the risk. Methods Mol Biol, 2004, 268, 225 - 33 Purification of antilisterial bacteriocins; Berjeaud JM et al.; In recent years, numerous contamination outbreaks, involving various pathogens (i.e., Listeria and Salmonella), have increased concern over food preservation . Research efforts have focused on the discovery of new molecules targeting such foodborne pathogens and therefore able to inhibit and or kill them . Lactic acid bacteria (LAB) extensively used in fermented foods for thousands of years not only improve their flavor and texture but also inhibit pathogenic and spoilage microorganisms . LAB inhibitory activity is primarily owing to pH decrease and competition for substrates . Antagonistic activity of LAB also depends on secreted antimicrobial compounds with a poor selectivity, such as metabolic compounds (i.e., hydrogen peroxide, acetoin, and others) or more specific ones like bacteriocins . The latter are proteinaceous compounds, ribosomally synthesized and subsequently secreted by Gram-positive as well as Gram-negative bacteria . Their antimicrobial activity is generally restricted to strains phylogenetically related to the producers.A classification of bacteriocins produced by LAB was first proposed by Klaenhammer in 1993 and was modified by Nes et al . in 1996; class I and class II bacteriocins are the most abundant and thoroughly studied . Bacteriocins from both classes exhibit antilisterial activity . Class I bacteriocins, namely, lantibiotics, have been widely studied, and among them, nisin is used in many countries as a preservative in food products . These bacteriocins are characterized by the presence, in their primary structure, of post-translationally modified amino acid residues (i.e., lanthionine and methylanthionine) that are formed . Class II bacteriocins, containing three subclasses, consist of small peptides that do not bear any modified amino acid residue . The most studied subclass corresponds to class IIa, also termed anti-Listeria bacteriocins . These peptides share strong structural homologies in their N-terminal domain, with the presence of one disulfide bond and a net positive charge . Their C-terminal domain is more variable but appears quite hydrophobic . Moreover, some of these bacteriocins, namely, sakacin G, pediocin PA-1, enterocin A, coagulin, and divercin V41, are characterized by the presence of a second disulfide bond in the C-terminal region. Methods Mol Biol, 2004, 268, 49 - 58 Molecular genotyping methods and computerized analysis for the study of Salmonella enterica; Vivanco AB et al.; Salmonella enterica is widely recognized as a major cause of foodborne diseases in humans and animals and has been isolated from environmental sources in increasing numbers worldwide . Conventional typing methods such as serotyping and phage typing have been and still are the mainstay in descriptive epidemiology of this microorganism . Nevertheless, limitations on the availability of phage reagents circumscribes the performance of such technique in reference laboratories.The resolving power of epidemiological typing has been expanded during recent years through the molecular analysis of microbial DNA . The broader availability of the reagents and equipment is accelerating their generalized use in clinical and public health laboratories . Important differences in the performance criteria of the genotyping techniques (typability, reproducibility, stability, and discriminatory power) and the convenience criteria (flexibility, accessibility, and ease of use) exist between them, and there is no ideal typing system for universal use . Most of these powerful strain-discriminative techniques are based on comparison of electrophoretic patterns or fingerprints, for which computer-assisted strategies and software packages have been developed to help in construction and analysis of microbial databases . Several initiatives, such as PulseNet or Harmony , have arisen during recent years for international construction of such fingerprinting databases, which will allow the rapid detection of new strains and the spread of pathogenic clones of bacteria through different regions or countries . Nevertheless, complete consensus has not yet been achieved on the techniques to use or the criteria for interpretation of the results, but these goals may be reached soon. Methods Mol Biol, 2004, 268, 15 - 32 Integron analysis and genetic mapping of antimicrobial resistance genes in Salmonella enterica serotype Typhimurium; Daly M et al.; Antimicrobial resistance determinants may be transferred among bacteria via mobile genetic elements including plasmids, transposons, and the more recently explored integrons . Integrons are naturally occurring genetic elements found as part of the Tn21 transposon family or located on various broad host-range plasmids . The fundamental integron structure consists of a 5'-conserved segment (5'-CS) of 1.4-kbp and a 2-kbp 3'-CS . Between these conserved regions are DNA sequences of variable length and molecular complexity . These intervening sequences are known as gene cassettes, and several have now been characterized . Acquisition and dissemination of these genes located within the integron structure, results in an increase in antimicrobial resistance.Three classes of integron structure have been described . Class 1 integrons are of principal importance in clinical isolates . The 5'-CS of class 1 integrons includes an intI 1 gene of 1358 bp, which encodes a specific recombinase, a member of the DNA integrase family . This gene contains the att1 recombination site, required for specifically integrating gene cassettes . Classes 2 and 3 also contain integrase genes (intI 2 and intI 3), with the former showing 40% sequence identity to those of class 1, and the latter showing 61% . All three classes of integrons contain similar gene cassettes from the same families, which suggests the existence of a common pool of gene cassette with cross-specificity between the classes.When the 3'-CS region is examined in detail, it contains several open reading frames (ORFs) . These include qacEDelta1, which confers resistance to quaternary ammonium compounds, often associated with antiseptics, along with a sul1 gene expressing resistance to sulphonamide antimicrobial agents . The sul1 gene encodes the enzyme hydopteroate synthase . Transcription of the sul1 gene begins at a promoter located in the 5'-CS . The latter is also responsible for the transcription of the inserted gene cassette(s) . Two additional ORFs, ORF-5 and -6, are located toward the distal end of the 3'-CS . The gene product of ORF 5 appears to share some sequence similarity with puromycin acetyltransferase, and this feature suggests a possible role in antimicrobial resistance . A biological function has yet to be ascribed to ORF-6. Infect Immun, 2004 Jun, 72(6), 3638 - 42 Delivery of the immunosuppressive antigen Salp15 to antigen-presenting cells by Salmonella enterica serovar Typhimurium aroA mutants; Motameni AR et al.; A Salmonella enterica serovar Typhimurium aroA-deficient delivery system was used to target the immunosuppressive protein Salp15 to antigen-presenting cells . In vitro and in vivo infections with Salp15-containing Salmonella resulted in an impaired CD4(+)-T-cell activation, suggesting that the protein was produced by antigen-presenting cells in a physiologically active form. Infect Immun, 2004 Jun, 72(6), 3577 - 83 The Vibrio cholerae ToxR-regulated porin OmpU confers resistance to antimicrobial peptides; Mathur J et al.; BPI (bactericidal/permeability-increasing) is a potent antimicrobial protein that was recently reported to be expressed as a surface protein on human gastrointestinal tract epithelial cells . In this study, we investigated the resistance of Vibrio cholerae, a small-bowel pathogen that causes cholera, to a BPI-derived peptide, P2 . Unlike in Escherichia coli and Salmonella enterica serovar Typhimurium, resistance to P2 in V . cholerae was not dependent on the BipA GTPase . Instead, we found that ToxR, the master regulator of V . cholerae pathogenicity, controlled resistance to P2 by regulating the production of the outer membrane protein OmpU . Both toxR and ompU mutants were at least 100-fold more sensitive to P2 than were wild-type cells . OmpU also conferred resistance to polymyxin B sulfate, suggesting that this porin may impart resistance to cationic antibacterial proteins via a common mechanism . Studies of stationary-phase cells revealed that the ToxR-repressed porin OmpT may also contribute to P2 resistance . Finally, although the mechanism of porin-mediated resistance to antimicrobial peptides remains elusive, our data suggest that the BPI peptide sensitivity of OmpU-deficient V . cholerae is not attributable to a generally defective outer membrane. Infect Immun, 2004 Jun, 72(6), 3310 - 4 Cystathionine beta-lyase is important for virulence of Salmonella enterica serovar Typhimurium; Ejim LJ et al.; The biosynthesis of methionine in bacteria requires the mobilization of sulfur from Cys by the formation and degradation of cystathionine . Cystathionine beta-lyase, encoded by metC in bacteria and STR3 in Schizosaccharomyces pombe, catalyzes the breakdown of cystathionine to homocysteine, the penultimate step in methionine biosynthesis . This enzyme has been suggested to be the target for pyridinamine antimicrobial agents . We have demonstrated, by using purified enzymes from bacteria and yeast, that cystathionine beta-lyase is not the likely target of these agents . Nonetheless, an insertional inactivation of metC in Salmonella enterica serovar Typhimurium resulted in the attenuation of virulence in a mouse model of systemic infection . This result confirms a previous chemical validation of the Met biosynthetic pathway as a target for the development of antibacterial agents and demonstrates that cystathionine beta-lyase is important for bacterial virulence. Antimicrob Agents Chemother, 2004 Jun, 48(6), 2292 - 4 Salmonella gene rma (ramA) and multiple-drug-resistant Salmonella enterica serovar typhimurium; van der Straaten T et al.; MarA and its homologue, RamA, have been implicated in multidrug resistance (MDR) . RamA overexpression in Salmonella enterica serovar Typhimurium and Escherichia coli conferred MDR independently of marA . Inactivation of ramA did not affect the antibiotic susceptibilities of wild-type S . enterica serovar Typhimurium or 15 unrelated clinical MDR isolates . Thus, ramA overexpression is not a common MDR mechanism in Salmonella. J Immunol, 2004 Jun 1, 172(11), 6884 - 93 Massive number of antigen-specific CD4 T cells during vaccination with live attenuated Salmonella causes interclonal competition; Srinivasan A et al.; The clonal burst size of CD4 T cells is predicted to be less than that of CD8 T cells . In this study, we demonstrate that massive numbers of Ag-specific CD4 T cells respond during vaccination of mice with live attenuated Salmonella, reaching a peak frequency of approximately 50% of CD4 T cells . Salmonella-specific T cells persisted at high frequency for several weeks and could be detected in the memory population for months after infection . Surprisingly, the expansion of endogenous Salmonella-specific CD4 T cells prevented the persistence of adoptively transferred Salmonella-specific T cells in vivo, demonstrating interclonal competition for access to the memory compartment. J Immunol, 2004 Jun 1, 172(11), 6828 - 37 Infection-induced expansion of a MHC Class Ib-dependent intestinal intraepithelial gammadelta T cell subset; Davies A et al.; Salmonella species invade the host via the intestinal epithelium . Hence, intestinal intraepithelial lymphocytes (iIELs) are potentially the first element of the immune system to encounter Salmonella during infection . In this study, we demonstrate, in a mouse model, the expansion of a CD8alphabeta(+)CD94(-)TCRgammadelta(+) T cell subset within the iIEL population in response to oral infection with virulent or avirulent Salmonella . This population can be detected 3 days following infection, represents up to 15% of the TCRgammadelta(+) iIELs, and is dependent on the MHC class Ib molecule T23 (Qa-1) . Qa-1 is expressed by intestinal epithelial cells and thus accessible for iIEL recognition . Such cells may play a role in the early immune response to Salmonella. APMIS, 2004 Mar, 112(3), 165 - 71 Geographically dependent distribution of gyrA gene mutations at codons 83 and 87 in Salmonella Hadar, and a novel codon 81 Gly to His mutation in Salmonella Enteritidis; Lindstedt BA et al.; In all, 90 nalidixic acid-resistant clinical strains of Salmonella Hadar and Salmonella Enteritidis isolated in Norway but of predominantly foreign origin were subjected to sequencing of the gyrA, gyrB, parC and parE genes . All the isolates contained at least one mutation in gyrA codon 83 or codon 87 . A highly significant correlation between mutations in gyrA codon 83 and strains originating from Southeast Asia was found in S . Hadar but not in S . Enteritidis . A novel gyrA codon 81 Gly to His mutation was discovered in one S . Enteritidis isolate . One amino-acid (aa) changing mutation was found outside the quinolone resistance-determining region (QRDR) of S . Hadar parC at codon 57, which has previously only been observed once in Salmonellae. J Vet Diagn Invest, 2004 May, 16(3), 212 - 8 Age-stratified validation of an indirect Salmonella Dublin serum enzyme-linked immunosorbent assay for individual diagnosis in cattle; Nielsen LR et al.; Enzyme-linked immunosorbent assays (ELISAs) are routinely used for cattle herd diagnosis of Salmonella Dublin infection in many countries . It is also possible to use such tests for individual diagnosis . Passively transferred immunoglobulins may cause false-positive test results in young calves . Also, false-positive test results may be seen in recovered animals several months after infection . False-negative results are seen in acutely infected animals, especially immature animals that are unable to produce a humoral antibody response to infection . To be able to interpret the individual animal test results, it is necessary to take age into account when validating the ELISA . In the present study an age-stratified validation of an indirect Salmonella Dublin serum ELISA as predictor of bacterial excretion was performed using receiver-operating characteristic (ROC) analysis . Three age groups were formed according to the results of an exploratory analysis of the age effect on area under curve (AUC) of ROC curves . The AUC for the youngest age group (0-99 days) was 0.816 (SE = 0.033), which was significantly (z = 4.23, P < 0.0001) smaller than the 0.977 (SE = 0.019) estimated for the next age group (100-300 days) . The oldest age group (> 300 days) had an AUC of 0.905 (SE = 0.023), which was significantly different from the AUC of both the other age groups (z = 2.21, P = 0.027 when compared with the youngest age groups and z = 2.41, P = 0.016 when compared with the age group of 100-300 days) . The results showed that the indirect Salmonella Dublin serum ELISA is most valid for detection of infection in individual cattle from the age of 100 days . Purpose-related test sensitivities and specificities were evaluated at different cutoff values. J Food Prot, 2004 May, 67(5), 999 - 1004 Method of applying sanitizers and sample preparation affects recovery of native microflora and Salmonella on whole cantaloupe surfaces; Ukuku DO et al.; Standardized methods for applying sanitizer treatments to cantaloupes and for recovering surviving native microflora or Salmonella on inoculated cantaloupe after sanitizing are lacking . Accordingly, the objectives of this study were to compare four methods for applying sanitizers (dipping, dipping with rotation, dipping with agitation, and dipping with rubbing) using 200 ppm of chlorine or 5% H2O2, two recovery methods (homogenization of rind plugs in a stomacher or blender), and five selective recovery media for Salmonella . Whole cantaloupes were submerged in a cocktail of five strains of Salmonella (each at approximately 2 x 10(8) CFU/ml) for 10 min and allowed to dry for 1 h inside a biosafety cabinet and stored at 20 degrees C for approximately 23 h before sanitizing . The recovery of Salmonella from whole cantaloupe without sanitizing averaged 5.09 log CFU/cm2 by blending and 4.30 log CFU/cm2 by homogenization in a stomacher for the five selective agar media . Microbial populations (Salmonella or the indigenous aerobic mesophilic bacteria, gram-negative bacteria, lactic acid bacteria, Pseudomonas spp., and yeast and mold) were not significantly (P > 0.05) reduced by treating with water regardless of the treatment method used . Sanitizing with chlorine or H2O2 by dipping, with or without rotation for 2 min, also did not reduce microbial populations . However, populations of all classes of native microflora and Salmonella were significantly (P < 0.05) reduced by sanitizer treatments (2 min) applied with agitation or by rubbing . In general, sanitizer treatments applied by rubbing resulted in greater log reductions (by up to 1.7 log unit) than for treatments applied with agitation . Populations of native microflora and Salmonella recovered from cantaloupe were higher (by up to 1.8 log unit) by blending compared to homogenization in a stomacher . In most instances, selective media used did not differ significantly (P > 0.05) for recovery of Salmonella after washing treatments. J Food Prot, 2004 May, 67(5), 908 - 14 Polyphenol oxidase activity as a potential intrinsic index of adequate thermal pasteurization of apple cider; Chen L et al.; In response to increasing concerns about microbial safety of apple cider, the U.S . Food and Drug Administration has mandated treatment of cider sufficient for a 5-log reduction of the target pathogen . Pasteurization has been suggested as the treatment most likely to achieve a 5-log reduction, with Escherichia coli O157:H7 as the target pathogen . Regulators and processors need a reliable method for verifying pasteurization, and apple cider polyphenol oxidase (PPO) activity was studied as a potential intrinsic index for thermal pasteurization . The effect of pasteurization conditions and apple cider properties on PPO activity and survival of three pathogens (E . coli O157:H7, Salmonella, and Listeria monocytogenes) was studied using a Box-Behnken response surface design . Factors considered in the design were pasteurization conditions, i.e., hold temperature (60, 68, and 76 degrees C), preheat time (10, 20, 30 s), and hold time (0, 15, 30 s), pH, and sugar content ((o)Brix) of apple cider . Response surface contour plots were constructed to illustrate the effect of these factors on PPO activity and pathogen survival . Reduction in PPO activity of at least 50% was equivalent to a 5-log reduction in E . coli O157:H7 or L . monocytogenes for cider at pH 3.7 and 12.5 (o)Brix . Further studies, however, are needed to verify the relationship between PPO activity and pathogen reduction in cider with various pH and (o)Brix values. J Food Prot, 2004 May, 67(5), 894 - 900 Preharvest evaluation of coliforms, Escherichia coli, Salmonella, and Escherichia coli O157:H7 in organic and conventional produce grown by Minnesota farmers; Mukherjee A et al.; Microbiological analyses of fresh fruits and vegetables produced by organic and conventional farmers in Minnesota were conducted to determine the coliform count and the prevalence of Escherichia coli, Salmonella, and E . coli O157:H7 . A total of 476 and 129 produce samples were collected from 32 organic and 8 conventional farms, respectively . The samples included tomatoes, leafy greens, lettuce, green peppers, cabbage, cucumbers, broccoli, strawberries, apples, and seven other types of produce . The numbers of fruits and vegetables was influenced by their availability at participating farms and varied from 11 strawberry samples to 108 tomato samples . Among the organic farms, eight were certified by accredited agencies and the rest reported the use of organic practices . All organic farms used aged or composted animal manure as fertilizer . The average coliform counts in both organic and conventional produce were 2.9 log most probable number per g . The percentages of E . coli-positive samples in conventional and organic produce were 1.6 and 9.7%, respectively . However, the E . coli prevalence in certified organic produce was 4.3%, a level not statistically different from that in conventional samples . Organic lettuce had the largest prevalence of E . coli (22.4%) compared with other produce types . Organic samples from farms that used manure or compost aged less than 12 months had a prevalence of E . coli 19 times greater than that of farms that used older materials . Serotype O157:H7 was not detected in any produce samples, but Salmonella was isolated from one organic lettuce and one organic green pepper . These results provide the first microbiological assessment of organic fruits and vegetables at the farm level. J Food Prot, 2004 May, 67(5), 870 - 7 Relative effectiveness of the Bacteriological Analytical Manual method for the recovery of Salmonella from whole cantaloupes and cantaloupe rinses with selected preenrichment media and rapid methods; Hammack TS et al.; Soak and rinse methods were compared for the recovery of Salmonella from whole cantaloupes . Cantaloupes were surface inoculated with Salmonella cell suspensions and stored for 4 days at 2 to 6 degrees C . Cantaloupes were placed in sterile plastic bags with a nonselective preenrichment broth at a 1:1.5 cantaloupe weight-to-broth volume ratio . The cantaloupe broths were shaken for 5 min at 100 rpm after which 25-ml aliquots (rinse) were removed from the bags . The 25-ml rinses were preenriched in 225-ml portions of the same uninoculated broth type at 35 degrees C for 24 h (rinse method) . The remaining cantaloupe broths were incubated at 35 degrees C for 24 h (soak method) . The preenrichment broths used were buffered peptone water (BPW), modified BPW, lactose (LAC) broth, and Universal Preenrichment (UP) broth . The Bacteriological Analytical Manual Salmonella culture method was compared with the following rapid methods: the TECRA Unique Salmonella method, the VIDAS ICS/SLM method, and the VIDAS SLM method . The soak method detected significantly more Salmonella-positive cantaloupes (P < 0.05) than did the rinse method: 367 Salmonella-positive cantaloupes of 540 test cantaloupes by the soak method and 24 Salmonella-positive cantaloupes of 540 test cantaloupes by the rinse method . Overall, BPW, LAC, and UP broths were equivalent for the recovery of Salmonella from cantaloupes . Both the VIDAS ICS/SLM and TECRA Unique Salmonella methods detected significantly fewer Salmonella-positive cantaloupes than did the culture method: the VIDAS ICS/SLM method detected 23 of 50 Salmonella-positive cantaloupes (60 tested) and the TECRA Unique Salmonella method detected 16 of 29 Salmonella-positive cantaloupes (60 tested) . The VIDAS SLM and culture methods were equivalent: both methods detected 37 of 37 Salmonella-positive cantaloupes (60 tested). J Food Prot, 2004 May, 67(5), 864 - 9 Rapid, specific detection of Salmonella Enteritidis in pooled eggs by real-time PCR; Seo KH et al.; An assay was developed for the specific detection of Salmonella Enteritidis in eggs with the use of an application of the fluorogenic 5' nuclease assay (TaqMan) . In this assay, a segment of the gene sefA specific to Salmonella group D strains such as Salmonella Enteritidis was used . The amplification of the target gene products was monitored in real-time by incorporating a fluorescent dye-labeled gene-specific probe in the PCR reaction . This method correctly detected and distinguished Salmonella Enteritidis from nearly 50 of non-group D Salmonella and other non-Salmonella strains . Detection of the sefA gene was linear for DNA extracted from approximately 10(2) to 10(9) CFU/ml in phosphate-buffered saline and 10(3) to 10(8) CFU/ml in raw egg . In two trials, when applied to detection of Salmonella Enteritidis in homogenized egg pools and compared with conventional culture methods, the newly developed PCR method yielded a 100% correlation with results obtained by a conventional culture method . However, the PCR method required only 2 days, compared to the 5 days required by the culture method . The sensitivity of this assay was approximately less than 1 CFU/600 g of egg pool . The real-time PCR assay proved to be a rapid, highly sensitive test for detection and quantification of low concentrations of Salmonella Enteritidis in egg samples. J Med Microbiol, 2004 Jun, 53(Pt 6), 539 - 43 Frequency and polymorphism of sopE in isolates of Salmonella enterica belonging to the ten most prevalent serotypes in England and Wales; Hopkins KL et al.; Translocated effector protein, SopE, leads to actin cytoskeletal rearrangements and membrane ruffling . Only a subset of Salmonella enterica serotypes possess sopE, with the majority of sopE-carrying S . enterica serotype Typhimurium associated with epidemics . Using real-time PCR and sequencing, sopE was investigated in the ten most prevalent serotypes of S . enterica in England and Wales in 2001 . sopE was identified in S . Typhimurium definitive phage types 29, 44, 49, 204b and 204c, all of which either have been involved in major epidemics or are precursors of epidemic strains . The presence of sopE varied in the remaining nine serotypes, but was more common in the top four (Enteritidis, Virchow, Hadar and Newport) . Nucleotide changes were detected throughout sopE and may result in altered specificity for certain signal transduction pathways . Since acquisition of sopE may play a key role in emergence of epidemic strains, detection of sopE could aid identification of those Salmonella strains with the potential for epidemic spread. J Bacteriol, 2004 Jun, 186(11), 3547 - 60 The ETT2 gene cluster, encoding a second type III secretion system from Escherichia coli, is present in the majority of strains but has undergone widespread mutational attrition; Ren CP et al.; ETT2 is a second cryptic type III secretion system in Escherichia coli which was first discovered through the analysis of genome sequences of enterohemorrhagic E . coli O157:H7 . Comparative analyses of Escherichia and Shigella genome sequences revealed that the ETT2 gene cluster is larger than was previously thought, encompassing homologues of genes from the Spi-1, Spi-2, and Spi-3 Salmonella pathogenicity islands . ETT2-associated genes, including regulators and chaperones, were found at the same chromosomal location in the majority of genome-sequenced strains, including the laboratory strain K-12 . Using a PCR-based approach, we constructed a complete tiling path through the ETT2 gene cluster for 79 strains, including the well-characterized E . coli reference collection supplemented with additional pathotypes . The ETT2 gene cluster was found to be present in whole or in part in the majority of E . coli strains, whether pathogenic or commensal, with patterns of distribution and deletion mirroring the known phylogenetic structure of the species . In almost all strains, including enterohemorrhagic E . coli O157:H7, ETT2 has been subjected to varying degrees of mutational attrition that render it unable to encode a functioning secretion system . A second type III secretion system-associated locus that likely encodes the ETT2 translocation apparatus was found in some E . coli strains . Intact versions of both ETT2-related clusters are apparently present in enteroaggregative E . coli strain O42. Vaccine, 2004 Jun 2, 22(17-18), 2273 - 7 Impact of vector-priming on the immunogenicity of a live recombinant Salmonella enterica serovar typhi Ty21a vaccine expressing urease A and B from Helicobacter pylori in human volunteers; Metzger WG et al.; Orally administered recombinant Salmonella vaccines represent an attractive option for mass vaccination programmes against various infectious diseases . Therefore, it is crucial to gather knowledge about the possible impact of preexisiting immunity to carrier antigens on the immunogenicity of recombinant vaccines . Thirteen volunteers were preimmunized with Salmonella typhi Ty21a in order to evaluate the effects of prior immunization with the carrier strain . Then, they received three doses of 1-2 x 10(10) viable organisms of either the vaccine strain S . typhi Ty21a (pDB1) expressing subunits A and B of recombinant Helicobacter pylori urease (n = 9), or placebo strain S . typhi Ty21a (n = 4) . Four volunteers were preimmunized and boosted with the vaccine strain S . typhi Ty21a (pDB1) . No serious adverse effects were observed in any of the volunteers . Whereas none of the volunteers primed and boosted with the vaccine strain responded to the recombinant antigen, five of the nine volunteers preimmunized with the carrier strain showed cellular immune responses to H . pylori urease (56%) . This supports the results of a previous study in non-preimmunized volunteers where 56% (five of nine) of the volunteers showed a cellular immune response to urease after immunisation with S . typhi Ty21a (pDB1). Int J Med Microbiol, 2004 Apr, 293(7-8), 565 - 9 Inverted pathogenicity: the use of pathogen-specific molecular mechanisms for prevention or therapy of disease; Russmann H; The term "inverted pathogenicity" stands for the exploitation of microbial toxins, virulence factors and cellular mechanisms for preventive or therapeutic purposes . This mini-review will focus on the major pathogenicity concept of Salmonella and Yersinia and how to use its underlying molecular principle for the development of a novel vaccination strategy . Both bacterial species employ a type III secretion system which mediates secretion and direct delivery (translocation) of antihost factors into the cytosol of eukaryotic cells . One of the best studied type III effector proteins is the 25-kDa Yersinia outer protein E (YopE) . During the interaction of Yersinia with professional phagocytes, YopE translocation disturbs eukaryotic cytoskeleton dynamics and inhibits phagocytosis . YopE is a GTPase-activating protein that is active towards G proteins from the Rho family . Fusion of the N-terminal 138 amino acids of YopE comprising the translocation domain of the type III molecule to listeriolysin O (LLO) or p60 of Listeria monocytogenes results in hybrid proteins that are engaged and translocated by both Yersinia and Salmonella type III secretion systems . Oral immunization of mice with attenuated Yersinia or Salmonella vaccine strains expressing translocated chimeric YopE leads to pronounced LLO- or p60-peptide-specific CD8 T-cell responses that confer protective immunity . Surprisingly, cytosolic delivery of YopE/LLO by Yersinia also results in LLO-specific CD4 T-cell priming. Vet Microbiol, 2004 Jun 3, 100(3-4), 255 - 68 Efficacy of vaccines against bacterial diseases in swine: what can we expect? Haesebrouck F, Pasmans F, Chiers K, Maes D, Ducatelle R, Decostere A. This paper discusses what can be expected with regard to efficacy of antibacterial vaccines used in swine, based on the present knowledge of pathogen-host interactions . First, vaccination against bacteria that mainly cause disease by production of exotoxins is considered . Vaccines containing the inactivated toxin or a non-toxic but antigenic recombinant protein derived from the exotoxin can be expected to provide protection against disease . The degree of protection induced by such vaccines varies, however, depending amongst other things on the pathogenesis of the disease . Vaccination against clostridial infections, Actinobacillus pleuropneumoniae infections, progressive atrophic rhinitis and enterotoxigenic Escherichia coli, is considered . The second part of the article deals with vaccination against extracellular bacteria . Protection against these bacteria is generally mediated by antibodies against their surface antigens and certain secreted antigens, but cellular immunity may also play a role . Efficacy of vaccines against swine erysipelas, Streptococcus suis infections, Mycoplasma hyopneumoniae infections and swine dysentery is discussed . Finally, vaccination against facultatively intracellular bacteria is considered . For protection against these bacteria cell-mediated immunity plays an important role, but antibodies may also be involved . It is generally accepted that live-attenuated vaccines are more suitable for induction of cell-mediated immunity than inactivated vaccines, although this also depends on the adjuvant used in the vaccine . As an example, vaccination against Salmonella enterica serotype Typhimurium is discussed. Vet Microbiol, 2004 Jun 3, 100(3-4), 247 - 54 Detection of mutations in the gyrA gene and class I integron from quinolone-resistant Salmonella enterica serovar Choleraesuis isolates in Taiwan; Huang TM et al.; The quinolone resistance-determining regions (QRDRs) of the gyrA gene of quinolone-resistant Salmonella enterica serovar Choleraesuis isolates were sequenced . Four types of point mutation, Ser-83-to-Phe (TCC --> TTc), Ser-83-to-Tyr (TCC --> TAC), Asp-87-to-Gly (GAC --> GGC), and Asp-87-to-Asn (GAC --> AAC), were found . PCR-RFLP and MAS-touch down PCR were performed on fifty swine clinical isolates of S . enterica serovar Choleraesuis (NalR) collected during 1997-2002 . The analysis indicated seven isolates with point mutations in codon 83, 13 with point mutations in codon 87, and 30 with double mutations in both codons 83 and 87 . The MICs of enrofloxacin of the isolates with a single mutation in codon 83 or 87 were <2microg/ml, while the MICs of the isolates with double mutations in both codon 83 and 87 ranged from 2 to 64microg/ml . A class I integron comprised of dhfr, orfF and aad2 was also identified in both human and swine S . enterica serovar Choleraesuis isolates . These results indicate that PCR-RFLP and MAS-touchdown PCR assays can be used for surveillance of gyrA gene mutations, which are important for fluoroquinolone resistance in Salmonella . Isolates with double mutations in gyrA codons 83 and 87 are the major type of quinolone-resistant Salmonella isolated from swine in Taiwan . A surveillance system may be applied to the swine industry to monitor the emergence of fluoroquinolone and/or multi-drug-resistant S . enterica serovar Choleraesuis in Taiwan. Vet Microbiol, 2004 Jun 3, 100(3-4), 205 - 17 Comparison of pulsed field gel electrophoresis and repetitive sequence polymerase chain reaction as genotyping methods for detection of genetic diversity and inferring transmission of Salmonella; Weigel RM et al.; Pulsed field gel electrophoresis (PFGE) using restriction enzymes AvrII, SpeI, and XbaI, and repetitive sequence polymerase chain reaction (Rep-PCR) using BOX, ERIC, and REP primers, were compared with respect to their ability to detect genetic differences among 68 Salmonella isolates from nine Illinois swine farms . Both genotyping methods had high reproducibility of fragment numbers (reliability>0.9) and sizes (reliability>0.85), and sizes {Formula: see text}, and produced approximately the same number of DNA fragments, but Rep-PCR fragment profiles had considerably greater variation . Genetic distances between isolates were calculated from fragment size matching . There was good agreement between the genetic distance matrices for the composite (3-enzyme and 3-primer) methods (Mantel's r=0.83) . PFGE detected slightly greater variation in genetic distances among isolates, but failed to differentiate seven pairs of isolates, three of which were sampled at least 1 month apart and therefore unlikely to be truly identical genetically . In contrast, Rep-PCR identified no isolates as genetically identical . In cluster analyses based on genetic distances, there were moderate differences between PFGE and Rep-PCR (about 2/3 agreement in tight cluster membership) . Both PFGE and Rep-PCR were able to differentiate isolates of the same serotype . However, some serotypes (Agona, Anatum, Derby, Infantis, Worthington) were distributed across clusters . There was less agreement between individual primer/enzyme and composite results for Rep-PCR than for PFGE . This greater independence of results for individual primers for Rep-PCR accounted in part for the greater discriminative ability of the composite method . Both composite methods indicated that most Salmonella transmission occurred within a farm and that there was no preference for transmission between specific ecological compartments . Given the equally high reliability of both genotyping methods, the greater discriminative ability of Rep-PCR recommends it as the preferred method for precise detection of transmission links. Vet Microbiol, 2004 Jun 3, 100(3-4), 189 - 95 Multiple genetic typing of Salmonella Enteritidis phage-types 4, 6, 7, 8 and 13a isolates from animals and humans in the UK; Liebana E et al.; Salmonella enterica serovar Enteritidis is a common cause of salmonellosis in people in the UK . This study aimed to assess the degree of genetic diversity among animal and human isolates from UK, Wales and northern Ireland . A total of 250 isolates from humans (n = 59) and animals or their environment (n = 191), belonging to the most common phage-types, were fingerprinted by a combination of PFGE, PS ribotyping and plasmid profiling . The different techniques identified different degrees of polymorphism (PS ribotyping (52 types) > PFGE (22 types) > plasmid profiling (17 types)) . A prevalent genomic clone, as well as a variety of less frequent clones are present for each of the phage-types . In most cases, the prevalent clones appeared within isolates from several animal species and from several geographical locations . The percentage of sporadic clones found in animal and human populations were very similar . There was not clear evidence of a higher degree of diversity for human or animal isolates . Some clones were found to be present in both human and animal. FEMS Immunol Med Microbiol, 2004 Jun 1, 41(2), 177 - 85 Transcriptional regulation of Salmonella enterica serovar Typhimurium genes by bile; Prouty AM et al.; DNA microarrays and two-dimensional (2-D) gel electrophoresis were utilized to analyze the global effect of bile on transcription and protein synthesis in Salmonella enterica serovar Typhimurium . Two bile-regulated proteins, YciF and PagC, were identified by 2-D gel electrophoresis and mass spectrometry fingerprinting . The operon yciGFE-katN demonstrated increased transcriptional activity in the presence of bile . While this operon has previously been shown to be RpoS-regulated, data from this study suggested that yciGFE-katN is regulated by bile independent of RpoS . The PhoP-PhoQ-regulated PagC is decreased in the presence of bile . Characterization of the untranslated leader of pagC demonstrated that a 97-bp region is necessary for the bile-mediated repression of this promoter . Analysis of data from the DNA microarray revealed an effect of bile on important global mechanistic pathways in S . enterica serovar Typhimurium . Genes involved in type III secretion-mediated invasion of epithelial cells demonstrated an overall repression of transcription in the presence of bile, corroborating previously reported data from this laboratory {Infect . Immun . 68 (2000) 6763} . In addition, bile-mediated transcriptional repression of genes involved in flagellar biosynthesis and motility was observed . These data further demonstrate that bile is an important environmental signal sensed by Salmonella spp . and that bile plays a role in regulating bacterial gene expression in multiple virulence-associated pathways. Clin Exp Rheumatol, 2004 May-Jun, 22(3), 278 - 84 Yersinia enterocolitica leads to transient induction of TNF-alpha and activates NF-kappaB in synovial fibroblasts; Meyer-Bahlburg A et al.; OBJECTIVE: The importance of the presence of bacterial antigen or even living bacteria for the pathogenesis of reactive arthritis has been discussed increasingly ever since bacterial antigen was found in inflamed joints . Bacteria may persist in the body and drive the local immune response, maintaining arthritis . Cytokines, in particular tumor necrosis factor-alpha (TNF-alpha) are essential for bacterial elimination . In reactive arthritis, the course of the disease is influenced by several cytokines, including TNF-alpha . TNF-alpha expression can be mediated by transcription factor nuclear factor-kappa B (NF-kappaB) . Moreover, TNF-alpha is also one of the strongest activators of NF-kappaB . METHODS: In vitro expression of TNF-alpha and activation of NF-kappaB in synovial fibroblasts after infection with Yersinia enterocolitica or Salmonella enteritidis was analysed by electrophoretic mobility shift assay, Western blot assay and real-time PCR . RESULTS: We found that infection of synovial fibroblasts with yersinia and salmonellae lead to the transient expression of TNF-alpha mRNA and induction of NF-kappaB . CONCLUSION: Induction of TNF-alpha in synovial fibroblasts after infection with yersiniae or salmonellae might be insufficient to eliminate bacteria, and this could allow the intracellular persistence of these bacteria . Our results therefore support the hypothesis that a permissive cytokine pattern might contribute to the pathogenesis of reactive arthritis. Am J Vet Res, 2004 May, 65(5), 538 - 43 Comparison of methods for differentiation of Salmonella enterica serovar Enteritidis phage type 4 isolates; Lopes VC et al.; OBJECTIVE: To compare molecular typing methods for the differentiation of Salmonella enterica serovar Enteritidis phage type (PT) 4 isolates that allowed for the determination of their genetic relatedness . SAMPLE POPULATION: 27 Salmonella Enteritidis PT 4 strains isolated in the United States and Europe . PROCEDURE: Several molecular typing methods were performed to assess their ability to genetically differentiate among Salmonella Enteritidis PT 4 isolates . Results of pulse-field gel electrophoresis (PFGE), repetitive polymerase chain reaction (PCR) assay, 16S rRNA gene sequencing, random amplification of polymorphic DNA (RAPD), PCR-restriction fragment length polymorphism of 16S rRNA, and antimicrobial susceptibility were evaluated . RESULTS: Compared with results for other techniques, results for the RAPD typing method with the RAPD1 primer reveal that it was the most discriminatory fingerprinting technique, and it allowed us to cluster Salmonella Enteritidis PT 4 isolates on the basis of their genetic similarity . CONCLUSIONS AND CLINICAL RELEVANCE: This study revealed the value of RAPD with the RAPD1 primer as a tool for epidemiologic investigations of Salmonella Enteritidis PT 4 . It can be used in conjunction with PFGE and phage typing to determine the genetic relatedness of Salmonella Enteritidis isolates involved in outbreaks of disease . A reliable and highly discriminatory method for epidemiologic investigations is critical to allow investigators to identify the source of infections and consequently prevent the spread of Salmonella Enteritidis PT 4. Environ Mol Mutagen, 2004, 43(4), 217 - 25 Bacterial and mammalian-cell genotoxicity of mixtures of chlorohydroxyfuranones, by-products of water chlorination; Maki-Paakkanen J et al.; The genotoxic responses of mixtures of four chlorohydroxyfuranones (CHFs), 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX), 3,4-dichloro-5-hydroxy-2(5H)-furanone (MCA), 3-chloro- 4-(chloromethyl)-5-hydroxy-2(5H)-furanone (CMCF) and 3-chloro-4-methyl-5-hydroxy-2(5H)-furanone (MCF), were compared with the genotoxicity of the individual compounds . Genotoxicity was evaluated in the Salmonella reversion assay (Ames test), the in vitro Chinese hamster ovary (CHO) cell Hprt mutation assay, and in the CHO chromosome aberration test . When tested individually, the concentrations of the chemicals that were chosen for the mixtures induced no or only a modest increase in the genotoxic effects, and caused little or no cytotoxicity . In the Ames test, the genotoxic responses caused by the mixtures of CHFs did not follow simple additivity . Synergism was observed with strains TA97 and TA98, and antagonism with strain TA100 . In the CHO/Hprt mutation assay, the mutagenic response of the mixtures was inconsistent, with near additivity seen with a mixture of CHFs that resulted in 12% cell survival . In contrast, the four CHFs together consistently caused more structural chromosome damage (mainly chromatid-type breaks and exchanges) compared to the sum of net effects of the four CHFs tested alone . Also, a potentiating effect was consistently seen for the cytotoxicity of the CHF mixtures both in the CHO/Hprt mutation assay and the chromosome aberration test . The present results indicate that the genotoxic effects of CHF mixtures can be greater than additive . Such effects may be worth considering in the cancer risk assessment of chlorinated drinking water . Rev Inst Med Trop Sao Paulo, 2004 Mar-Apr, 46(2), 115 - 7 Epub 2004 May 05. "Multiplex PCR" identification of the atypical and monophasic Salmonella enterica subsp . enterica serotype 1,4,{5},12:i:- in São Paulo State, Brazil: frequency and antibiotic resistance patterns; Tavechio AT et al.; Salmonella spp . are the etiologic agents of salmonellosis, a worldwide spread zoonoses causing foodborne outbreaks and clinical diseases . By serological identification, Salmonella enterica subsp . enterica serotype 1,4,{5},12:i:- accounted for 8.8% of human and 1.6% of nonhuman Salmonella strains isolated in Sao Paulo State, during 1991-2000 . A total of 28.6% of them amplified a fragment corresponding to H:1,2 (flagellar phase two) through PCR analysis and were further assigned as S . Typhimurium . Antimicrobial resistance was detected in 36.3% of the 369 PCR-negative strains tested, including the multiresistance to ampicillin, chloramphenicol, sulfonamides, tetracycline, and streptomycin. Microb Drug Resist, 2004 Spring, 10(1), 1 - 9 Characterization of beta-lactamases responsible for resistance to extended-spectrum cephalosporins in Escherichia coli and Salmonella enterica strains from food-producing animals in the United Kingdom; Liebana E et al.; Nine epidemiologically unrelated isolates {1 Salmonella Bredeney from turkeys, and 8 Escherichia coli {3 environmental isolates (2 from chickens, 1 from pigs), and 5 isolates from cattle with neonatal diarrhea}} were examined both pheno- and genotypically for extended-spectrum beta-lactam (ESBL) resistance . Resistance phenotypes (ampicillin, aztreonam, cefotaxime, cefpodoxime, ceftazidime, and ceftriaxone) suggested the presence of an ESBL enzyme, but cefoxitin MICs (>/= 32 mg/L) suggested the presence of an AmpC-like enzyme . Synergism experiments with benzo(b)thiophene-2-boronic acid (BZBTH2B) and isoelectric focusing (IEF) revealed the presence of an AmpC beta-lactamase with a pI >/= 9 . amp C multiplex PCR, sequence, and Southern analyses indicated that only the Salmonella isolate had a plasmid-encoded AmpC beta-lactamase CMY-2 on a nonconjugative 60-MDa plasmid . PCR and sequence analysis of the E . coli ampC promoter identified mutations at positions -88(T), -82(G), -42(T), -18(A), -1(T) and +58(T) in all the isolates . In addition one strain had two extra-mutations at positions +23(A) and +49(G), and another strain had one extra-mutation at position +32(A) . DNA fingerprinting revealed that all the E . coli isolates were different clones . It also showed that the U.K . Salmonella isolate was indistinguisable from a Canadian Salmonella isolate from turkeys; both had identical resistance phenotypes and produced CMY-2 . This is the first report of a CMY-2 Salmonella isolate in the United Kingdom . These data imply that beta-lactam resistance in animal isolates can be generated de novo as evidenced by the E . coli strains, or in the case of the Salmonella strains be the result of intercontinental transmission due to an acquired resistance mechanism. Trans R Soc Trop Med Hyg, 2004 Jul, 98(7), 423 - 30 The emergence of multidrug resistance to antimicrobial agents for the treatment of typhoid fever; Wain J et al.; Resistance to chloramphenicol was reported in Salmonella Typhi in 1950 but it was not until 22 years later that the first outbreaks of chloramphenicol-resistant typhoid fever occurred . Multidrug-resistant (MDR) Salmonella Typhi emerged in the 1980s and today has an almost worldwide distribution . Genome analysis of Salmonella Typhi strain CT18, an MDR isolate from a patient admitted to The Centre for Tropical Diseases, Ho Chi Minh City, Viet Nam, in December 1993 revealed that the resistance plasmid pHCM1 is very closely related to plasmid R27 which was first isolated in 1961 . There is a core region shared by the two plasmids with five regions of variation . Two of these regions contain the genes encoding resistance . The largest region is 34.955 kbp in length, is bordered by two almost identical IS10 elements and contains several integron-like structures including a truncated Tn10 element . The second region is 14.75I kbp and encodes a trimethoprim-resistance gene, dfrA14, associated with a class one integrase . Restriction enzyme analysis has shown that the variation in Salmonella Typhi plasmids, collected during the emergence of resistant Salmonella Typhi in Viet Nam, maps to five variable regions . These regions appear to be hot spots for DNA acquisition in IncHI1 plasmids. J Mol Biol, 2004 May 28, 339(2), 423 - 35 In vitro characterization of FlgB, FlgC, FlgF, FlgG, and FliE, flagellar basal body proteins of Salmonella; Saijo-Hamano Y et al.; The bacterial flagellar basal body is a rotary motor . It spans the cytoplasmic and outer membranes and drives rapid rotation of a long helical filament in the cell exterior . The flagellar rod at its central axis is a drive shaft that transmits torque through the hook to the filament to propel the bacterial locomotion . To study the structure of the rod in detail, we have established purification procedures for Salmonella rod proteins, FlgB, FlgC, FlgF, FlgG, and also for FliE, a rod adapter protein, from an Escherichia coli expression system . While FlgF was highly soluble, FlgB, FlgC, FlgG and FliE tended to self or cross-aggregate into fibrils in solutions at neutral pH or below, at high ionic strength, or at high protein concentration . These aggregates were characterized to be beta-amyloid fibrils, unrelated to the rod structure formed in vivo . Under non-aggregative conditions, no protein-protein interactions were detected between any pairs of these five proteins, suggesting that their spontaneous, template-free polymerization is strongly suppressed . Limited proteolyses showed that FlgF and FlgG have natively unfolded N and C-terminal regions of about 100 residues in total just as flagellin does, whereas FlgB, FlgC and FliE, which are little over 100 residues long, are unfolded in their entire peptide chains . These results together with other data indicate that all of the ten flagellar axial proteins share structural characteristics and folding dynamics in relation to the mechanism of their self-assembly into the flagellar axial structure. J Mol Biol, 2004 May 28, 339(2), 279 - 300 The role of prophage-like elements in the diversity of Salmonella enterica serovars; Thomson N et al.; The Salmonella enterica serovar Typhi CT18 (S.Typhi) chromosome harbours seven distinct prophage-like elements, some of which may encode functional bacteriophages . In silico analyses were used to investigate these regions in S.Typhi CT18, and ultimately compare these integrated bacteriophages against 40 other Salmonella isolates using DNA microarray technology . S.Typhi CT18 contains prophages that show similarity to the lambda, Mu, P2 and P4 bacteriophage families . When compared to other S.Typhi isolates, these elements were generally conserved, supporting a clonal origin of this serovar . However, distinct variation was detected within a broad range of Salmonella serovars; many of the prophage regions are predicted to be specific to S.Typhi . Some of the P2 family prophage analysed have the potential to carry non-essential "cargo" genes within the hyper-variable tail region, an observation that suggests that these bacteriophage may confer a level of specialisation on their host . Lysogenic bacteriophages therefore play a crucial role in the generation of genetic diversity within S.enterica. Vet Immunol Immunopathol, 2004 Jun, 99(3-4), 169 - 77 In utero infection with PRRS virus modulates cellular functions of blood monocytes and alveolar lung macrophages in piglets; Riber U et al.; The putative immunosuppressive effect of PRRS virus (PRRSV) on innate immune responses was studied in piglets infected in utero with PRRSV . Phagocytosis and oxidative burst capacities in 2-, 4- and 6-week-old in utero infected piglets were investigated and compared with age-matched control piglets . Phagocytic capacity of blood monocytes against Salmonella bacteria was investigated by flow cytometry . Oxidative burst in blood monocytes and in alveolar lung macrophages was investigated by luminol- and lucigenin-enhanced chemiluminescence, respectively . Decreased phagocytosis against Salmonella was found in blood monocytes from 4- and 6-week-old infected piglets compared to controls . In contrast, 2-week-old infected piglets showed phagocytic responses comparable to age matched control piglets . While oxidative burst capacity was increased in blood (PBMC) from in utero PRRSV infected piglets, the oxidative burst capacity of alveolar lung macrophages was decreased, especially in 2- and 4-week-old piglets, compared to age-matched control piglets . The present results indicate that in utero infection with PRRSV inhibits phagocytosis against Salmonella in blood monocytes as well as the oxidative burst capacity of alveolar macrophages . These observations indicate that PRRSV in utero infection induces at state of immunosuppression in piglets paving the way for enhanced secondary infections . Int J Food Microbiol, 2004 Jun 1, 93(2), 231 - 47 A quantitative risk assessment model for Salmonella and whole chickens; Oscar TP; Existing data and predictive models were used to define the input settings of a previously developed but modified quantitative risk assessment model (QRAM) for Salmonella and whole chickens . The QRAM was constructed in an Excel spreadsheet and was simulated using @Risk . The retail-to-table pathway was modeled as a series of unit operations and associated pathogen events that included initial contamination at retail, growth during consumer transport, thermal inactivation during cooking, cross-contamination during serving, and dose response after consumption . Published data as well as predictive models for growth and thermal inactivation of Salmonella were used to establish input settings . Noncontaminated chickens were simulated so that the QRAM could predict changes in the incidence of Salmonella contamination . The incidence of Salmonella contamination changed from 30% at retail to 0.16% after cooking to 4% at consumption . Salmonella growth on chickens during consumer transport was the only pathogen event that did not impact the risk of salmonellosis . For the scenario simulated, the QRAM predicted 0.44 cases of salmonellosis per 100,000 consumers, which was consistent with recent epidemiological data that indicate a rate of 0.66-0.88 cases of salmonellosis per 100,000 consumers of chicken . Although the QRAM was in agreement with the epidemiological data, surrogate data and models were used, assumptions were made, and potentially important unit operations and pathogen events were not included because of data gaps and thus, further refinement of the QRAM is needed. Int J Food Microbiol, 2004 Jun 1, 93(2), 175 - 83 Effects of a lactoperoxidase-thiocyanate-hydrogen peroxide system on Salmonella enteritidis in animal or vegetable foods; Touch V et al.; Lactoperoxidase (LPO) from skim milk was purified by ion-exchange chromatography . The purified protein was used to catalyze the oxidation of thiocyanate by H2O2 in an antibacterial system (LPO system) . The LPO system was used to inactivate or inhibit Salmonella enteritidis in tomato juice, carrot juice, milk, liquid whole egg, and chicken skin extract under various conditions . The system was found to be more effective against the organism in vegetable juices than in animal products, at low pH than at neutral pH, and at higher temperatures than at lower temperatures . Acid-adapted S . enteritidis cells were more susceptible than nonadapted cells . The system reduced numbers of S . enteritidis in vegetable products by up to 5.4 log units and inhibited growth of the organism in animal-derived foods during 4 h incubation at 30 degrees C . Sodium chloride (>100 mM) and polyphosphate (0.01-0.5%) enhanced the antibacterial effects of the system in tomato juice and chicken skin extract, respectively . The findings indicate that the LPO system could probably be used to prevent the growth and survival of salmonellae in minimally processed fruit and vegetable products, but combination of the system with other preservatives or treatments would be needed to effectively inhibit growth and survival of salmonellae in animal products . FEMS Microbiol Lett, 2004 May 15, 234(2), 239 - 46 Cloning and characterization of the gene encoding the z66 antigen of Salmonella enterica serovar Typhi; Huang X et al.; Z66 antigen-positive strains of Salmonella enterica serovar Typhi change flagellin expression in only one direction from the z66 antigen to the d or j antigen, which is different from the phase variation of S . enterica serovar Typhimurium . In the present study, we identified a new flagellin gene in z66 antigen-positive strains of S . enterica serovar Typhi . The genomic structure of the region containing this new flagellin gene was similar to that of fljBA operon of biphasic S . enterica serovars . A fljA-like gene was present downstream of the new flagellin gene . A rho-independent terminator was located between the new flagellin gene and the fljA-like gene . Hin-like gene was not present upstream of the new flagellin gene . We generated a mutant strain of S . enterica serovar Typhi, which carries a deletion of the new flagellin gene . Western blotting revealed that the 51-kDa z66 antigen protein was absent from the population of proteins secreted by the mutant strain . Southern hybridization demonstrated that the z66 antigen-positive strains of S . enterica serovar Typhi carried the new flagellin gene and fliC on two different genomic EcoRI fragments . When z66 antigen-positive strains were incubated with anti-z66 antiserum, the flagellin expression by S . enterica serovar Typhi changed from z66 antigen to j antigen . The new flagellin gene and the fljA-like gene were absent in the strain with altered flagellin expression . These results suggested that the new flagellin gene is a fljB-like gene, which encodes the z66 antigen of S . enterica serovar Typhi, and that deletion of fljBA-like operon may explain why S . enterica serovar Typhi alters the flagellin expression in only one direction from the z66 antigen to the d or j antigen . Vet Microbiol, 2004 May 20, 100(1-2), 91 - 105 Evaluation of three serum i-ELISAs using monoclonal antibodies and protein G as peroxidase conjugate for the diagnosis of bovine brucellosis; Saegerman C et al.; Three i-ELISAs using LPS, the immunodominant component of Brucella abortus, were developed with three different conjugates: monoclonal antibodies 1C8 (anti-bovine IgG(1)) and 3H3 (mainly specific for bovine IgG(2) but also reacting with IgG(1)) and protein G (reacts with both bovine IgG subclasses) . Using a cut-off value of 2.5U/ml, the i-ELISA with 3H3 as conjugate had a specificity (95% CI: 98.32-99.63%) that was significantly higher than the same assay with 1C8 (95% CI: 96.08-98.26%) or PG (95% CI: 95.83-98.09%) . In areas where false positive serological reactions (FPSR) were common, the specificity of the i-ELISAs decreased significantly . The specificity of the i-ELISAs increased with the age of the animals tested, irrespective of the conjugate . The specificity of the i-ELISAs and traditional tests was also examined using sera from animals infected per os with bacteria bearing LPS similar to the Brucella LPS . It appeared that Yersinia enterocolitica O:9, Xanthomonas maltophilia and Salmonella urbana infections induced FPSR both in the i-ELISAs and in the traditional tests, but the 3H3 assay was significantly less prone to produce false positive reactions than the 1C8 and PG assays . The i-ELISAs were more sensitive, allowed earlier detection, and were more persistent than the traditional serological tests both in experimentally and naturally Brucella-infected animals . Weekly i-ELISA monitoring of experimentally infected pregnant heifers (previously vaccinated or not) allowed a prediction of abortion . Furthermore, the 1C8 assay showed significantly higher titres irrespective of day post-infection and vaccination status . The accuracy of the assay could be improved by making use of additional information (e.g . animal age or conjugate) and by selecting appropriate cut-off points on the basis of the prevailing epidemiological situation . The i-ELISAs appear an appropriate choice in order to maintain an official brucellosis-free status because of their sensitivity, early detection and long persistence and, for the same reasons, seem especially valuable for the detection of latent carriers (i.e . animals classified negative by classical serological tests) among imported animals. Diagn Microbiol Infect Dis, 2004 May, 49(1), 1 - 3 Treatment failure in typhoid fever with ciprofloxacin susceptible Salmonella enterica serotype Typhi; Rupali P et al.; Fluoroquinolones are considered the most effective drugs for the treatment of typhoid fever and hence are widely used in the empiric treatment of acute undifferentiated febrile illnesses in India . Recent reports of Salmonella enterica serotype Typhi (S . Typhi) strains with increasing minimum inhibitory concentration (MIC) of ciprofloxacin have raised the fear of potential treatment failures . In this case series of 109 consecutive patients hospitalized with typhoid fever (S . Typhi grown from blood), we documented clinical failure (fever persisting >6 days) in 25 of 46 (54.3%) adults who could be evaluated . Among these, eight (17.4%) had microbiological failure (S . Typhi recovered from blood after 6 days of ciprofloxacin therapy) despite adequate serum ciprofloxacin levels, and all required alternative drugs for treatment . These 8 S . Typhi strains, although susceptible to ciprofloxacin (MIC < 1 microg/mL) (NCCLS 2000), had MICs (median MIC 0.5 microg/mL) that were increased 15-fold compared to S . Typhi strains from patients with typhoid fever seen at our center in 1995 (median MIC 0.032 microg/mL), and were nalidixic acid resistant S . Typhi (NARST) (MIC > or =32 microg/mL) . The poor treatment outcomes with ciprofloxacin therapy in patients infected with NARST strains that exhibit an increased ciprofloxacin MIC call for a need to revise the ciprofloxacin breakpoints for S . Typhi. Biochim Biophys Acta, 2004 May 6, 1698(2), 219 - 26 Structural analysis of Salmonella enterica effector protein SopD; Wood MW et al.; Salmonella outer protein D (SopD) is a type III secreted virulence effector protein from Salmonella enterica . Full-length SopD and SopD lacking 16 amino acids at the N-terminus (SopDDeltaN) have been expressed as fusions with GST in Escherichia coli, purified with a typical yield of 20-30 mg per litre of cell culture and crystallized . Biophysical characterization has been carried out mainly on SopDDeltaN . Analytical size exclusion chromatography shows that SopDDeltaN is monomeric and probably globular in aqueous solution . The secondary structure composition, calculated from the CD spectrum, is mixed (38% alpha-helix and 26% beta-strand) . Sequence analysis indicates that SopD contains a coiled coil motif, as found in numerous other type III secretion system-associated proteins . This suggests that SopD has the potential for one or more heterotypic protein-protein interactions . Limited trypsin digestion of SopDDeltaN, monitored by both one-dimensional proton NMR spectroscopy and SDS-PAGE, shows that the protein has a large, protease-resistant core domain of 286 amino acid residues . This single-domain architecture suggests that SopD lacks a cognate chaperone . In crystallization trials, SopDDeltaN produced better crystals than either full-length SopD or trypsin-digested SopDDeltaN . Diffraction to 3.0 A resolution has so far been obtained from crystals of SopDDeltaN. Anim Health Res Rev, 2003 Dec, 4(2), 143 - 55 A review of porcine tonsils in immunity and disease; Horter DC et al.; The porcine tonsils are a group of lymphoepithelial tissues located at the common openings of the gastrointestinal and respiratory tracts . The tonsils participate in a variety of functions involving innate, cellular and humoral immunity at the local and systemic levels . Among these immunological functions is the continuous surveillance for the presence of foreign antigens at the openings of the gastrointestinal and respiratory tracts . Within the pig, the movement of lymphocytes, cytokines and chemotactic molecules from the tonsils to other lymphoid organs confers immunity to other portals of pathogen entry and facilitates an efficient and rapid systemic immune response . In spite of the immunological nature of the tonsils, some microorganisms have acquired adaptations that allow them to circumvent the tonsillar immune defenses and utilize the tonsils as a site of entry, replication and colonization . Several bacterial and viral pathogens persist asymptomatically within the tonsils, making identification of asymptomatic carrier animals difficult in disease control and/or pathogen elimination . This paper reviews the current information on the anatomy, immunology and pathobiology of porcine tonsils and discusses the tonsils as a site of pathogen entry, replication and colonization using Salmonella spp., classical swine fever virus and porcine reproductive and respiratory syndrome virus as examples. Microbiology, 2004 May, 150(Pt 5), 1385 - 95 The last step in coenzyme B(12) synthesis is localized to the cell membrane in bacteria and archaea; Maggio-Hall LA et al.; In Salmonella enterica, the last step of the synthesis of adenosylcobamide is catalysed by the cobalamin synthase enzyme encoded by the cobS gene of this bacterium . Overexpression of the S . enterica cobS gene in Escherichia coli elicited the accumulation of the phage shock protein PspA, a protein whose expression has been linked to membrane stress . Resolution of inner and outer membranes of S . enterica by isopycnic density ultracentrifugation showed CobS activity associated with the inner membrane, a result that was confirmed using antibodies against CobS . Computer analysis of the predicted amino acid sequence of CobS suggested it was an integral membrane protein . Results of experiments performed with strains carrying plasmids encoding CobS-alkaline phosphatase or CobS-beta-galactosidase protein fusions were consistent with the membrane localization of the CobS protein . Modifications to the predicted model were made based on data obtained from experiments using protein fusions . The function encoded by the cobS orthologue in the methanogenic archaeon Methanobacterium thermoautotrophicum strain deltaH compensated for the lack of CobS during cobalamin synthesis in cobS strains of S . enterica . Cobalamin synthase activity was also detected in a membrane preparation of M . thermoautotrophicum . It was concluded that the assembly of the nucleotide loop of adenosylcobamides in archaea and bacteria is a membrane-associated process . Possible reasons for the association of adenosylcobamide biosynthetic enzymes with the cell membrane are discussed. J Clin Microbiol, 2004 May, 42(5), 2314 - 6 Characterization of Salmonella enterica serotype Typhimurium isolates from human, food, and animal sources in the Republic of Ireland; Gorman R et al.; A potential epidemic clone of Salmonella enterica serotype Typhimurium DT104, and the possible emergence of S . enterica serotype Typhimurium DT104b, has been identified from the characterization of 67 S . enterica serotype Typhimurium strains from three sources, human gastroenteritis isolates, isolates from food samples, and veterinary isolates, by antimicrobial resistance profiling, phage typing, and pulsed-field gel electrophoresis . Resistance to ampicillin, chloramphenicol, streptomycin, sulfonamides, and tetracycline was found in 77.6% of these strains. J Clin Microbiol, 2004 May, 42(5), 1923 - 32 Sequencing and comparative analysis of flagellin genes fliC, fljB, and flpA from Salmonella; McQuiston JR et al.; Salmonella isolates have traditionally been classified by serotyping, the serologic identification of two surface antigens, O-polysaccharide and flagellin protein . Serotyping has been of great value in understanding the epidemiology of Salmonella and investigating disease outbreaks; however, production and quality control of the hundreds of antisera required for serotyping is difficult and time-consuming . To circumvent the problems associated with antiserum production, we began the development of a system for determination of serotype in Salmonella based on DNA markers . To identify flagellar antigen-specific sequences, we sequenced 280 alleles of the three genes that are known to encode flagellin in Salmonella, fliC, fljB, and flpA, representing 67 flagellar antigen types . Analysis of the data indicated that the sequences from fliC, fljB, and flpA clustered by the antigen(s) they encode not by locus . The sequences grouped into four clusters based on their conserved regions . Three of the four clusters included multiple flagellar antigen types and were designated the G complex, the Z4 complex, and the alpha cluster . The fourth cluster contained a single antigen type, H:z(29) . The amino acid sequences of the conserved regions within each cluster have greater than 95% amino acid identity, whereas the conserved regions differ substantially between clusters (75 to 85% identity) . Substantial sequence heterogeneity existed between alleles encoding different flagellar antigens while alleles encoding the same flagellar antigen were homologous, suggesting that flagellin genes may be useful targets for the molecular determination of flagellar antigen type. J Clin Microbiol, 2004 May, 42(5), 1885 - 9 Evaluation of rapid diagnostic tests for typhoid fever; Olsen SJ et al.; Laboratory diagnosis of typhoid fever requires isolation and identification of Salmonella enterica serotype Typhi . In many areas where this disease is endemic, laboratory capability is limited . Recent advances in molecular immunology have led to the identification of sensitive and specific markers for typhoid fever and technology to manufacture practical and inexpensive kits for their rapid detection . We evaluated three commercial kits for serologic diagnosis of typhoid fever . Patients presenting with > or = 4 days of fever were enrolled at two hospitals in Southern Vietnam . Cases were patients with serotype Typhi isolated from blood samples, and controls were patients with other laboratory-confirmed illnesses . Serotype Typhi isolates were confirmed and tested for antimicrobial susceptibility at the Pasteur Institute in Ho Chi Minh City . The Widal test was run at the hospitals and the Pasteur Institute . Sera were shipped frozen to the Centers for Disease Control and Prevention and tested by using Multi-Test Dip-S-Ticks, TyphiDot, and TUBEX to detect immunoglobulin G (IgG), IgG and IgM, and IgM, respectively . Package insert protocol instructions were followed . We enrolled 59 patients and 21 controls . The sensitivity and specificity findings were as follows: 89 and 53% for Multi-Test Dip-S-Ticks, 79 and 89% for TyphiDot, 78 and 89% for TUBEX, and 64 and 76% for Widal testing in hospitals and 61% and 100% for Widal testing at the Pasteur Institute . For all assays, the sensitivity was highest in the second week of illness . The Widal test was insensitive and displayed interoperator variability . Two rapid kits, TyphiDot and TUBEX, demonstrated promising results. Comput Biol Chem, 2004 Apr, 28(2), 109 - 18 The difficult interpretation of transcriptome data: the case of the GATC regulatory network; Riva A et al.; Genomic analyses on part of Escherichia coli's chromosome had suggested the existence of a GATC regulated network . This has recently been confirmed through a transcriptome analysis . Two hypotheses about the molecular control mechanism have been proposed-(i) the GATC network regulation is caused by the presence of GATC clusters within the coding sequences; the regulation is the direct consequence of the clusters' hemi-methylation and therefore their elevated melting temperature, (ii) the regulation is caused by the presence of GATCs in the non-coding 500 bp upstream regions of the affected genes; it is the consequence of an interaction with a regulatory protein like Fnr or CAP . An analysis of the transcriptome data has not allowed us to decide between the two hypotheses . We have therefore taken a classic genomic approach, analyzing the statistical distribution of GATC along the chromosome, using a realistic model of the chromosome as theoretical reference . We observe no particular distribution of GATC in the non-coding upstream regions; however, we confirm the presence of GATC clusters within the genes . In order to verify that the particular distribution observed in E . coli is not a statistical artefact, but has a physiological role, we have carried out the same analysis on Salmonella, making the hypothesis that the genes containing a GATC clusters should be largely the same in the two bacteria . This has been indeed observed, showing that the genes containing a GATC cluster are part of a regulation network . The present is a case study, which demonstrates that the analysis of transcriptome data does not always permit to identify the primary cause of a phenomenon observed; on the other hand, a classic genomic approach linked with a comparative study of related genomes may allow this identification. J Immunol, 2004 May 15, 172(10), 6202 - 8 Toll-like receptor 4 dependence of innate and adaptive immunity to Salmonella: importance of the Kupffer cell network; Vazquez-Torres A et al.; Mammalian cells recognize LPS from Gram-negative bacteria via the Toll-like receptor 4 (TLR4) complex . During experimental Salmonella infection, C3H/HeJ mice carrying a dominant-negative mutation in TLR4 exhibited delayed chemokine production, impaired NO generation, and attenuated cellular immune responses . However, dramatically enhanced bacterial growth within the Kupffer cell network before the recruitment of inflammatory cells appeared to be primarily responsible for the early demise of Salmonella-infected TLR4-deficient mice . LPS-TLR4 signaling plays an essential role in the generation of both innate and adaptive immune responses throughout the course of infection with Gram-negative bacteria . Alternative pattern-recognition receptors cannot completely compensate for the loss of TLR4, and compensation occurs at the expense of an increased microbial burden. J Bacteriol, 2004 May, 186(10), 3249 - 53 Contribution of the RpoA C-terminal domain to stimulation of the Salmonella enterica hilA promoter by HilC and HilD; Olekhnovich IN et al.; Expression of invasion genes in Salmonella pathogenicity island 1 (SPI-1) is mainly driven by the transcriptional activator HilA . Transcription of hilA is subject to complex control and is stimulated by the SPI-1-encoded HilC and HilD proteins . The C-terminal domain of RpoA contributes to hilA activation by HilC/D under certain inducing conditions. J Bacteriol, 2004 May, 186(10), 3214 - 23 Salmonella enterica serovar Typhi strains from which SPI7, a 134-kilobase island with genes for Vi exopolysaccharide and other functions, has been deleted; Nair S et al.; Salmonella enterica serovar Typhi has a 134-kb island of DNA identified as salmonella pathogenicity island 7 (SPI7), inserted between pheU and 'pheU (truncated), two genes for tRNA(Phe) . SPI7 has genes for Vi exopolysaccharide, for type IVB pili, for putative conjugal transfer, and for sopE bacteriophage . Pulsed-field gel electrophoresis following digestion with the endonuclease I-CeuI, using DNA from a set of 120 wild-type strains of serovar Typhi assembled from several sources, identified eight strains in which the I-CeuI G fragment, which contains SPI7, had a large deletion . In addition, agglutination tests with Vi antiserum and phage typing with Vi phages show that all eight strains are Vi negative . We therefore tested these strains for deletion of SPI7 by multiplex PCR, by microarray analysis, and by sequencing of PCR amplicons . Data show that seven of the eight strains are precise deletions of SPI7: a primer pair flanking SPI7 results in a PCR amplicon containing a single pheU gene; microarrays show that all SPI7 genes are deleted . Two of the strains produce amplicons which have A derived from pheU at bp 27, while five have C derived from 'pheU at this position; thus, the position of the crossover which results in the deletion can be inferred . The deletion in the eighth strain, TYT1669, removes 175 kb with junction points in genes STY4465 and STY4664; the left junction of SPI7 and adjacent genes, as well as part of SPI7 including the viaB operon for Vi exopolysaccharide, was removed, while the right junction of SPI7 was retained . We propose that these deletions occurred during storage following isolation. J Bacteriol, 2004 May, 186(10), 3202 - 13 Precise excision of the large pathogenicity island, SPI7, in Salmonella enterica serovar Typhi; Bueno SM et al.; The large pathogenicity island (SPI7) of Salmonella enterica serovar Typhi is a 133,477-bp segment of DNA flanked by two 52-bp direct repeats overlapping the pheU (phenylalanyl-tRNA) gene, contains 151 potential open reading frames, and includes the viaB operon involved in the synthesis of Vi antigen . Some clinical isolates of S . enterica serovar Typhi are missing the entire SPI7, due to its precise excision; these strains have lost the ability to produce Vi antigen, are resistant to phage Vi-II, and invade a human epithelial cell line more rapidly . Excision of SPI7 occurs spontaneously in a clinical isolate of S . enterica serovar Typhi when it is grown in the laboratory, leaves an intact copy of the pheU gene at its novel join point, and results in the same three phenotypic consequences . SPI7 is an unstable genetic element, probably an intermediate in the pathway of lateral transfer of such pathogenicity islands among enteric gram-negative bacteria. J Bacteriol, 2004 May, 186(10), 2909 - 20 OmpR and LeuO positively regulate the Salmonella enterica serovar Typhi ompS2 porin gene; Fernandez-Mora M et al.; The Salmonella enterica serovar Typhi ompS2 gene codes for a 362-amino-acid outer membrane protein that contains motifs common to the porin superfamily . It is expressed at very low levels compared to the major OmpC and OmpF porins, as observed for S . enterica serovar Typhi OmpS1, Escherichia coli OmpN, and Klebsiella pneumoniae OmpK37 quiescent porins . A region of 316 bp, between nucleotides -413 and -97 upstream of the transcriptional start point, is involved in negative regulation, as its removal resulted in a 10-fold increase in ompS2 expression in an S . enterica serovar Typhi wild-type strain . This enhancement in expression was not observed in isogenic mutant strains, which had specific deletions of the regulatory ompB (ompR envZ) operon . Furthermore, ompS2 expression was substantially reduced in the presence of the OmpR D55A mutant, altered in the major phosphorylation site . Upon random mutagenesis, a mutant where the transposon had inserted into the upstream regulatory region of the gene coding for the LeuO regulator, showed an increased level of ompS2 expression . Augmented expression of ompS2 was also obtained upon addition of cloned leuO to the wild-type strain, but not in an ompR isogenic derivative, consistent with the notion that the transposon insertion had increased the cellular levels of LeuO and with the observed dependence on OmpR . Moreover, LeuO and OmpR bound in close proximity, but independently, to the 5' upstream regulatory region . Thus, the OmpR and LeuO regulators positively regulate ompS2. Arch Latinoam Nutr, 2003 Dec, 53(4), 389 - 92 {Presence of Escherichia coli O157:H7, Listeria monocytogenes and Salmonella spp . in food from animal origin in Costa Rica}; Reuben A et al.; The presence of Escherichia coli O157:H7, Listeria monocytogenes and Salmonella spp was analyzed in two kinds of food from animal origin in Costa Rica . 100 samples of non pasteurized milk, from the principal producing zones of the country, and 100 samples of chicken giblets, purchased in retail markets, were analyzed according to the methodology described by Food and Drug Administration, 1995 . Escherichia coli O157:H7 was analyzed in both kinds of food, while L . monocytogenes was evaluated in raw milk and Salmonella spp . in chicken giblets . Five strains of E . coli O157:H7 were isolated, three of them coming from chicken giblets and the other two from raw milk . 15% positivity for Salmonella spp . was found in chicken giblet samples and 3% positivity for L . monocytogenes in raw milk samples . The results obtained show the importance of the adequate processing of food from animal origin in order to decrease the potential transmission of pathogenic agents . The introduction of Hazard Analysis Critical Control Points system (HACCP) and Good Manufacturing practices in food industry keep on being the principal control measures and inocuity warranty. J Clin Invest, 2004 May, 113(9), 1296 - 306 Bacterial flagellin is a dominant antigen in Crohn disease; Lodes MJ et al.; Chronic intestinal inflammation, as seen in inflammatory bowel disease (IBD), results from an aberrant and poorly understood mucosal immune response to the microbiota of the gastrointestinal tract in genetically susceptible individuals . Here we used serological expression cloning to identify commensal bacterial proteins that could contribute to the pathogenesis of IBD . The dominant antigens identified were flagellins, molecules known to activate innate immunity via Toll-like receptor 5 (TLR5), and critical targets of the acquired immune system in host defense . Multiple strains of colitic mice had elevated serum anti-flagellin IgG2a responses and Th1 T cell responses to flagellin . In addition, flagellin-specific CD4(+) T cells induced severe colitis when adoptively transferred into naive SCID mice . Serum IgG to these flagellins, but not to the dissimilar Salmonella muenchen flagellin, was elevated in patients with Crohn disease, but not in patients with ulcerative colitis or in controls . These results identify flagellins as a class of immunodominant antigens that stimulate pathogenic intestinal immune reactions in genetically diverse hosts and suggest new avenues for the diagnosis and antigen-directed therapy of patients with IBD. Indian Pediatr, 2004 Apr, 41(4), 395 - 6 Acute renal tubular dysfunction in association with Salmonella enteritidis; Deshpande PV et al.; A thirteen-year-old boy presented with acute renal tubular dysfunction after an infection with salmonella enteritidis . The child recovered following treatment with ciprofloxacin for a week. Chem Biol, 2004 Apr, 11(4), 565 - 73 A bacterial acetyltransferase capable of regioselective N-acetylation of antibiotics and histones; Vetting MW et al.; The Salmonella enterica chromosomally encoded AAC(6')-Iy has been shown to confer broad aminoglycoside resistance in strains in which the structural gene is expressed . The three-dimensional structures reported place the enzyme in the large Gcn5-related N-acetyltransferase (GNAT) superfamily . The structure of the CoA-ribostamycin ternary complex allows us to propose a chemical mechanism for the reaction, and comparison with the Mycobacterium tuberculosis AAC(2')-CoA-ribostamycin complex allows us to define how regioselectivity of acetylation is achieved . The AAC(6')-Iy dimer is most structurally similar to the Saccharomyces cerevisiae Hpa2-encoded histone acetyltransferase . We demonstrate that AAC(6')-Iy catalyzes both acetyl-CoA-dependent self-alpha-N-acetylation and acetylation of eukaryotic histone proteins and the human histone H3 N-terminal peptide . These structural and catalytic similarities lead us to propose that chromosomally encoded bacterial acetyltransferases, including those functionally identified as aminoglycoside acetyltransferases, are the evolutionary progenitors of the eukaryotic histone acetyltransferases. Indian J Med Sci, 2004 Apr, 58(4), 141 - 9 Comparison of the immunogenicity and safety of two different brands of Salmonella typhi Vi capsular polysaccharide vaccine; Sabitha P et al.; BACKGROUND: The recent emergence of multi-drug-resistant Salmonella strains highlights the need for better preventive measures, including vaccination . Safe and immunologic vaccines have been developed based on purified Vi polysaccharide . OBJECTIVE: To compare the immune response elicited by two different brands of Salmonella Vi capsular polysaccharide vaccine (ViCPS) . SETTING AND DESIGN: Double blind, randomized (3:1), controlled, parallel, phase III study was conducted at two centres in India to compare the safety and immunogenicity of Typbar, the investigational vaccine with an already marketed vaccine "X", in healthy subjects aged between 12 -25 years . MATERIAL AND METHODS: A sample size of 184 subjects was calculated . Subjects were randomly distributed in two groups, immunized with single dose of Typbar or Vaccine "X" . Serum samples were taken before 7 days and 4 weeks after immunization for the determination of antibodies to Vi polysaccharide, by ELISA method . Safety was assessed by physical examination, laboratory parameters before and after vaccination and by monitoring adverse events . Statistics: The geometric mean antibody titre (GMT) 4 weeks after vaccination was compared from respective pre-vaccination values by Wilcoxon signed rank test . Geometric mean of antibody levels before and after immunization and the ratio between them (Mann-Whitney test), the Seroconversion rates (Z test of proportions) and the adverse events (Fisher's exact test and Chi square test), were compared between two groups . P value < 0.05 was considered statistically significant . P values and 95% confidence intervals were estimated in two-tailed fashion . RESULTS: 153 subjects (Typbar =116 and Vaccine "X" =37) were studied . 71.6% (95% CI=63.4%-79.8%) and 75.7% (95% CI=64.9% - 89.5%) were the seroconversion rates with Typbar and vaccine "X" respectively . The GMT values for Vi antibodies induced after Typbar and vaccine "X" were 10.23 Typbar and 13.46 mg/mL respectively and these values showed high significance when compared to their respective pre-immunization GMT values (P<0.0001) at 95% CI (-10.49 to -7.19 mg/mL for Typbar and -14.69 to -8.86 mg/mL for Vaccine "X") . The induction of antibody response appeared to be slightly stronger (P=0.032) with vaccine "X" when compared to that of Typbar . This is justifiable as the same group also had high pre-immunization GMT values (P=0.021) . CONCLUSION: The immunogenicity and safety of the investigational vaccine Typbar was found to be similar to that of already marketed brand of Vi CPS, Vaccine "X" . The availability of a single dose of vaccine that is safe and effective enhances the prospective for control of typhoid fever. Mol Biol Cell, 2004 Jul, 15(7), 3146 - 54 Epub 2004 Apr 30. Salmonella impairs RILP recruitment to Rab7 during maturation of invasion vacuoles; Harrison RE et al.; After invasion of epithelial cells, Salmonella enterica Typhimurium resides within membrane-bound vacuoles where it survives and replicates . Like endocytic vesicles, the Salmonella-containing vacuoles (SCVs) undergo a maturation process that involves sequential acquisition of Rab5 and Rab7 and displacement toward the microtubule-organizing center . However, SCVs fail to merge with lysosomes and instead develop subsequently into a filamentous network that extends toward the cell periphery . We found that the initial centripetal displacement of the SCV is due to recruitment by Rab7 of Rab7-interacting lysosomal protein (RILP), an effector protein that can simultaneously associate with the dynein motor complex . Unlike the early SCVs, the Salmonella-induced filaments (Sifs) formed later are devoid of RILP and dynein, despite the presence of active Rab7 on their membranes . Kinesin seems to be involved in the elongation of Sifs . SifA, a secreted effector of Salmonella, was found to be at least partly responsible for uncoupling Rab7 from RILP in Sifs and in vitro experiments suggest that SifA may exert this effect by interacting with Rab7 . We propose that, by disengaging RILP from Rab7, SifA enables the centrifugal extension of tubules from the Salmonella-containing vacuoles, thereby providing additional protected space for bacterial replication. Microb Pathog, 2004 Jun, 36(6), 337 - 47 Differences in the carriage and the ability to utilize the serotype associated virulence plasmid in strains of Salmonella enterica serotype Typhimurium investigated by use of a self-transferable virulence plasmid, pOG669; Olsen JE et al.; Most strains of Salmonella enterica subspecies enterica serotype typhimurium (S . typhimurium) naturally harbour a virulence plasmid which carries the salmonella plasmid virulence (spv) genes . However, isolates belonging to certain phage types are generally found without the plasmid . We have utilized a self-transferable virulence plasmid, pOG669 to investigate the effect of introduction of spv genes into strains of such phage types . The use of the co-integrate plasmid, pOG669, was validated on a diverse collection of strains . pOG669 was transferred into strains of serotypes that are normally associated with the possession of virulence plasmids . All strains maintained the wild type level of virulence in a mouse model, except that introduction of pOG669 restored normal virulence levels in an avirulent, plasmid free strain of S . dublin and resulted in a decrease in virulence in a strain of S . dublin from clonal line Du3 . S . gallinarum did not become virulent in mice, but pOG669 was functionally interchangeable with the wild type plasmid when strains were tested in a chicken model . Strains of serotypes not normally associated with the carriage of a virulence plasmid did not increase in virulence upon the introduction of pOG669 . An IncX plasmid pOG670 that was included as control was incompatible with the virulence plasmid in a strain of S . dublin, demonstrating that the common virulence plasmid of this serotype is of a different incompatibility group than other virulence plasmids . Strains of S . typhimurium from phage types that do not normally carry a virulence plasmid responded differently to attempts to introduce pOG669 . No transconjugants were observed with the strains of DT5 and DT21 . The introduction of pOG669 did not alter the virulence of JEO3942(DT10), DT35 and JEO3949(DT66) significantly, while DT1 and DT27 became more virulent . DT27 became as virulent as wild type C5, while logVC(10) of DT1 only increased from 4.1 to 5.7 . The ability to express spv-genes was measured by use of an spvRAB'-cat fusion . Expression in S . enteritidis was found to be higher than in other serotypes tested . Only serotypes that naturally carry a virulence plasmid expressed spv-genes . The strain of DT1 expressed spv at a very low level, while expression in the strains of DT10 and DT35 was approximately 2-fold lower than in a control strain of S . typhimurium, while the level in the DT66 strain corresponded to the control strain . The plasmid pSTF9, which carried the fusion gene could not be introduced into the strains of DT5, DT21 and DT27 . The RpoS level in the strains was measured indirectly by use of a katE-lacZ fusion . In the DT5 strain the level of expression was low, while the strains JEO3942(DT10), DT21, DT27 and DT35 expressed 4-5 fold the level in this strain . An internal fragment of the rpoS gene was sequenced in three strains . These all showed an identical sequence to a published S . typhimurium rpoS gene. J Antimicrob Chemother, 2004 Jun, 53(6), 1004 - 9 Epub 2004 Apr 29. Class 1 integrons in various Salmonella enterica serovars isolated from animals and identification of genomic island SGI1 in Salmonella enterica var . Meleagridis; Ebner P et al.; OBJECTIVES: To determine the prevalence of integron-mediated antibiotic resistance in a diverse sample set of Salmonella enterica isolated from animals . MATERIALS AND METHODS: Multiplex PCR was used to detect class 1 integron gene sequences, and integron gene cassettes were identified by PCR mapping . Susceptibility to 18 antibiotics or antibiotic combinations commonly used in either human or veterinary medicine was measured using a microdilution method, and statistical comparisons of the frequency of resistance between groups were made using Fisher's two-sided probability test . Genotypic comparisons of isolates were made following pulsed-field gel electrophoresis of genomic DNA . RESULTS: Thirty-two (30.8%) of 104 isolates contained class 1 integron sequences . Integron-positive isolates represented 15 different S . enterica serovars, were obtained from nine different animal species and had a higher frequency of non-integron-mediated antibiotic resistance (P < 0.05) compared with integron-negative isolates . One non-Typhimurium isolate (S . enterica Meleagridis) contained an SGI1 genomic island, including the antibiotic resistance gene cluster . CONCLUSIONS: These data demonstrate that integron-mediated antibiotic resistance is common among diverse Salmonella serovars, many of them rare . In addition, SGI1 is not limited to Salmonella enterica Typhimurium DT104 or other commonly isolated serovars. J Med Food, 2004 Spring, 7(1), 90 - 4 An in vitro study on antimicrobial activity of propolis from Mugla province of Turkey; Ugur A et al.; Antibacterial and antifungal activities of acetone and dimethyl sulfoxide (DMSO) extracts of 45 different propolis samples from the Mugla province of Turkey were investigated . Antimicrobial activity of propolis varied depending on propolis sample, dosage of propolis, and the extraction solvents for all test microorganisms . Antimicrobial activity of all propolis samples increased with increasing dosage without reaching a plateau at the highest dosage tested . Except for Brucella melitensis, the DMSO extracts of all propolis samples were more active than the acetone extracts of the same samples . For B . melitensis, the acetone extracts of all propolis samples showed greater activity . The most sensitive microorganism to propolis was Shigella sonnei in the gram-negative group and Streptococcus mutans in the gram-positive group . The least sensitive microorganism was Candida albicans . A control test run with standard antibiotics revealed that propolis samples from the Mugla province of Turkey has a similar or greater inhibitory effect on S . mutans, Salmonella typhi, Pseudomonas aeruginosa, S . sonnei, and C . albicans growth. Protein J, 2004 Jan, 23(1), 71 - 7 Complete amino acid sequence and location of Omp-28, an important immunogenic protein from Salmonella enterica serovar typhi; Neves-Ferreira AG et al.; Omp-28 isolated from Salmonella enterica serovar typhi presented a subunit molecular mass of 9,632 Da by MALDI-TOF MS . It was denatured, S-alkylated, and 1) directly submitted to Edman sequencing, 2) cleaved with CNBr, and 3) hydrolyzed either with endoproteinase Glu-C or Asp-N . The major CNBr peptide containing the C-terminal portion of Omp-28 was isolated by tricine-SDS-PAGE and electroblotted whereas Omp-28 enzymatic peptides were isolated by C18-RP-HPLC . All peptides were sequenced . This approach allowed the elucidation of the complete primary structure of Omp-28 . Its amino acid sequence is identical to that deduced from part of the DNA of the "putative periplasmic transport protein" of either S . enterica serovar typhimurium and a multiple drug resistant S . enterica serovar typhi . Omp-28 homologous protein sequences were also deduced from Escherichia coli and Yersinia pestis genomic DNA . All proteins had their secondary structures predicted . Immunogold cytochemistry indicated that Omp-28 is found on the bacterium outer membrane. Southeast Asian J Trop Med Public Health, 2003 Dec, 34(4), 839 - 44 Characterization and utilization of monoclonal antibodies reactive to Yersinia pseudotuberculosis; Jain R et al.; The 3 murine monoclonal antibodies, Yps1, Yps2 and Yps3 reactive to Y . pseudotuberculosis can be stabilized and all were found to be of IgG type . Monoclonal antibody, Yps1, recognized a glycoprotein antigen of the organism with reactivity at the 55-75 kDa region, while Yps2 and Yps3 recognized protein antigens of Y . pseudotuberculosis 65 kDa and 26-28 kDa molecular weight regions, respectively . The specificity of monoclonal antibodies was tested using dot ELISA and Western blotting with whole cell organisms or whole cell sonicated soluble antigens of different Yersinia species, Salmonella typhi, Klebsiella pnemoniae, Streptococcus abortus-equi and Escherichia coli . Monoclonal antibody, Yps1 exhibited cross-reactivity with soluble antigens and whole cell preparations of Y . pestis . Yps2 cross-reacted to soluble antigens of all the tested bacteria . Reactivity of monoclonal antibody, Yps3 was restricted to Y . pseudotuberculosis and Y . pestis with soluble antigen preparations . No reaction was observed with Yps2 and Yps3 to whole cell organism preparations from tested bacteria including Y . pseudotuberculosis . The co-agglutination reagent prepared by sensitizing staphylococcal cells with Yps1 monoclonal antibody produced a positive agglutination with all the 4 Y . pseudotuberculosis isolates and the 3 Y . pestis strains tested . Sandwich dot ELISA using monospecific antisera as a capture antibody and a monoclonal antibody, and Yps3 as a revealing antibody had a high level of specificity in detecting Y . pseudotuberculosis antigens. Minerva Chir, 2004 Feb, 59(1), 75 - 8 {Systemic Salmonella Arizona infection: description of a rare surgical case}; Catani M et al.; Salmonella arizona enteritis has been described in patients resident in the southern states of the USA and in Mexico, whereas in Europe it is rarer . The virulence of this bacillus is, however, still little known and we have few descriptions of severe systemic infections, which are all present in patients with immune system impairment . Only two cases have been reported in Italy where the infection has occurred as severe sepsis with the pathogenic agent being isolated in the blood . Here we report what is, on the basis of our knowledge, the third case in Italy of a systemic Salmonella arizona infection. Food Chem Toxicol, 2004 Jun, 42(6), 969 - 73 Genotoxic evaluation of a vinifera skin extract that present pharmacological activities; Aiub C et al.; Toxicity of an alcohol-free hydro-alcoholic grape skin extract (GSE) obtained from red grapes Vitis labrusca (Isabel varietal) that present antihypertensive, vasodilator and antioxidant effects was estimated by different bioassays . Using the Salmonella/microsome assay for strains TA97, TA98, TA100 and TA102 no mutagenicity was detected for all tested concentrations (0.1-100 microg/ml), even with metabolization . Nevertheless, cytotoxicity was observed for TA97 and TA102 with and without metabolization and for TA100 with metabolization . The measurement of beta-galactosidase induction in the SOS-chromotest was positive only for Escherichia coli PQ37 when metabolization enzymes were present . Using Balb/c 3T3 fibroblasts, DNA strand breaks induction by GSE was also investigated by the comet assay and no significative difference was detected for treated and no treated DNA for 60 min . Our data suggest that GSE although no mutagenic presents cytotoxic activity. Int J Food Microbiol, 2004 Apr 15, 92(2), 199 - 205 Have changes to meat and poultry food safety regulation in Australia affected the prevalence of Salmonella or of salmonellosis? Sumner J, Raven G, Givney R. During the 1990s, there was radical change in regulation of meat and poultry hygiene in Australia, and Australian Standards were developed for each sector of the meat industry . Systems for industry/government co-regulation and company-employed meat inspection were introduced based on company HACCP programs approved and audited by the Controlling Authority . However, in the 5 years since regulatory changes took full effect, rates of salmonellosis have not decreased (surveillance and reporting systems have remained unchanged) . Using statistics gathered by the National Enteric Pathogens Surveillance Scheme, an attempt was made to link Salmonella serovars isolated from meat and poultry with those causing salmonellosis . Two periods were studied, 1993/1994, before regulations were introduced, and 2000/2001, when regulations should be having an effect . For red meat, the same serovars were prominent among the top 10 isolates both before and after regulation, and there was little linkage with salmonelloses . For poultry, frequently isolated serovars differed pre- and post-regulation, however, in both periods there was some linkage between serovars isolated from poultry and those causing salmonelloses . Using published and unpublished survey data, it was concluded that there had been improvements in microbiological quality of red meat and poultry over the same timeframe as regulatory changes . That these improvements apparently have not carried through to reduced case-rates for salmonellosis may be due to numerous causes, including lack of control in the food processing, food service and home sectors . The present paper illustrates difficulties faced by governments in measuring public health outcomes of changes to food hygiene regulation. Poult Sci, 2004 Apr, 83(4), 611 - 23 Recent progress on the cytokine regulation of intestinal immune responses to Eimeria; Lillehoj HS et al.; A variety of methods are available to combat avian diseases in the commercial setting, including improved farm management practices, use of antibiotic drugs, selection of disease resistant chicken strains, and manipulation of the chicken immune system . In the latter category, development of vaccines against the major avian diseases has become a priority for the poultry industry . With increasing demands for developing alternative control programs for many poultry diseases, it is important to understand the basic immunobiology of host-pathogen interactions in order to develop novel vaccination strategies . From studies carried out in many mammalian species, it is evident that host immune responses to intracellular pathogens are complex and involve many components of the host immune system . For enteric pathogens such as Eimeria and Salmonella, understanding cell-mediated immunity is most important because antibodies, although abundantly produced locally, can not access and act on these intracellular pathogens . In poultry, slow but increasing understanding of various components of host immune system mediating cellular immunity is opening new opportunities for thorough investigation of the role of thymus-derived lymphocyte subpopulations and cytokines in normal and disease states . This paper will review recent progress with chicken cytokines that have been characterized, and discuss various experimental strategies to enhance host immunity to pathogens using chicken cytokines. Poult Sci, 2004 Apr, 83(4), 544 - 9 Analysis of chicken TLR4, CD28, MIF, MD-2, and LITAF genes in a Salmonella enteritidis resource population; Malek M et al.; Salmonella enteritidis is a foodborne pathogen that negatively affects both animal and human health . Genetic variations in response to pathogenic SE colonization or to SE vaccination were measured in a chicken resource population . Outbred broiler sires and 3 diverse, highly inbred dam lines produced 508 F1 progeny that were evaluated for either bacterial colonization after pathogenic SE inoculation or circulating antibody level after SE vaccination . Five candidate genes were selected for study, based on their biological function as possibly affecting response to SE: toll-like receptor 4 (TLR4), T-cell specific surface protein (CD28), macrophage migration inhibitory factor (MIF), MD-2, and lipopolysaccharide-induced tumor necrosis factor (TNF)-alpha factor (LITAF) . Gene fragments were sequenced from the founder lines of the resource population . The LITAF and MIF genes were homozygous for all sires . Single nucleotide polymorphisms (SNP) were identified in 3 genes (TLR4, CD28, and MD-2) and were used to test for associations of sire SNP with SE response . Linear mixed models were used for statistical analyses . The CD28 broiler sire SNP was associated with both bacterial load in the cecum (P < 0.003) and vaccine antibody response (P < 0.05) . The MD-2 SNP was associated (P < 0.04) with the bacterial load in the spleen . The use of these SNP in these genes in marker-assisted selection may result in enhancement of disease resistance. Infect Dis Obstet Gynecol, 2003, 11(4), 217 - 9 Unilateral ovarian abscess caused by Salmonella; Tohya T et al.; BACKGROUND: Patients with unilateral ovarian abscesses due to Salmonella are rare . CASE REPORT: A 48-year-old woman with a left ovarian abscess caused by Salmonella group 07 is reported . CONCLUSION: In our patient, the ovary may have been seeded hematogenously by salmonellae and may have evolved into a local infection. ScientificWorldJournal, 2004 Mar 15, 4, 193 - 9 Toward molecular level of the "Salmonella-victim" ecology, genetics, and evolution; Rumyantsev SN; Bacteria of the Salmonella genus are polypathogenic agents that can affect both men and animals, causing devastating and fatal illness . Despite considerable immunological, epidemiological, and genetic efforts, and increased understanding of how the Salmonella infection develops, many key questions concerning Salmonella infection remain unanswered . Salmonella can be carried as harmless commensals in some sectors of the population . In some individuals, however, the same microbes cause illness while others display immunity to primary Salmonella infection . Nothing is known about the molecular base of the Salmonella pathogenicity . Even the ability of Salmonella to destroy the victim's cells has been the subject of century-long discussions . In this article, some key findings concerning ecology, molecular ecology, and cell level of the Salmonella infection genetics are summarized and interpreted from the viewpoint of evolutionary theory with certitude that this approach can help to decipher the undiscovered secrets of Salmonella infection's epidemiology and pathogenesis, as well as the clinical course and severity, and to select ways for fighting against Salmonella. Antimicrob Agents Chemother, 2004 May, 48(5), 1593 - 9 Biophysical characterization of endotoxin inactivation by NK-2, an antimicrobial peptide derived from mammalian NK-lysin; Andra J et al.; NK-2, a membrane-acting antimicrobial peptide, was derived from the cationic core region of porcine NK-lysin and consists of 27 amino acid residues . It adopts an amphipathic, alpha-helical secondary structure and has been shown to interact specifically with membranes of negatively charged lipids . We therefore investigated the interaction of NK-2 with lipopolysaccharide (LPS), the main, highly anionic component of the outer leaflet of the outer membrane of gram-negative bacteria, by means of biophysical and biological assays . As model organisms and a source of LPS, we used Salmonella enterica strains with various lengths of the LPS carbohydrate moiety, including smooth LPS, rough LPS, and deep rough LPS (LPS Re) mutant strains . NK-2 binds to LPS Re with a high affinity and induces a change in the endotoxin-lipid A aggregate structure from a cubic or unilamellar structure to a multilamellar one . This structural change, in concert with a significant overcompensation of the negative charges of LPS, is thought to result in the neutralization of the endotoxic LPS activity in a cell culture system . Neutralization of LPS activity by NK-2 as well as its antibacterial activity against the various Salmonella strains strongly depends on the length of the sugar chains of LPS, with LPS Re being the most sensitive . This suggests that a hydrophobic peptide-LPS interaction is necessary for efficient neutralization of the biological activity of LPS and that the long carbohydrate chains, besides their function as a barrier for hydrophobic drugs, also serve as a trap for polycationic substances. Infect Immun, 2004 May, 72(5), 3059 - 62 Two Salmonella OmpC K(b)-restricted epitopes for CD8+-T-cell recognition; Diaz-Quinonez A et al.; We report the identification of two peptides from Salmonella OmpC porin that can bind to major histocompatibility complex class I K(b) molecules and are targets of cytotoxic T lymphocytes from Salmonella-infected mice . These peptides are conserved in gram-negative bacterial porins and are the first Salmonella porin-specific epitopes described for possible CD8(+)-T-cell elimination of infected cells. Infect Immun, 2004 May, 72(5), 2879 - 88 Functional transfer of Salmonella pathogenicity island 2 to Salmonella bongori and Escherichia coli; Hansen-Wester I et al.; The type III secretion system (T3SS) encoded by the Salmonella pathogenicity island 2 (SPI2) has a central role in systemic infections by Salmonella enterica and for the intracellular phenotype . Intracellular S . enterica uses the SPI2-encoded T3SS to translocate a set of effector proteins into the host cell, which modify host cell functions, enabling intracellular survival and replication of the bacteria . We sought to determine whether specific functions of the SPI2-encoded T3SS can be transferred to heterologous hosts Salmonella bongori and Escherichia coli Mutaflor, species that lack the SPI2 locus and loci encoding effector proteins . The SPI2 virulence locus was cloned and functionally expressed in S . bongori and E . coli . Here, we demonstrate that S . bongori harboring the SPI2 locus is capable of secretion of SPI2 substrate proteins under culture conditions, as well as of translocation of effector proteins under intracellular conditions . An SPI2-mediated cellular phenotype was induced by S . bongori harboring the SPI2 if the sifA locus was cotransferred . An interference with the host cell microtubule cytoskeleton, a novel SPI2-dependent phenotype, was observed in epithelial cells infected with S . bongori harboring SPI2 without additional effector genes . S . bongori harboring SPI2 showed increased intracellular persistence in a cell culture model, but SPI2 transfer was not sufficient to confer to S . bongori systemic pathogenicity in a murine model . Transfer of SPI2 to heterologous hosts offers a new tool for the study of SPI2 functions and the phenotypes of individual effectors. Infect Immun, 2004 May, 72(5), 2843 - 9 Bacterial and host factors involved in the major histocompatibility complex class Ib-restricted presentation of Salmonella Hsp 60: novel pathway; Lo WF et al.; Previously, a peptide epitope derived from the Hsp 60 molecule of Salmonella that is presented by the major histocompatibility complex (MHC) class Ib molecule Qa-1 to CD8(+) cytotoxic T cells (CTLs) was described . In the present study we investigated the Salmonella-induced processing and presentation pathway for generating this Qa-1-restricted epitope . Live bacteria and, to a lesser extent, opsonized heat-killed bacteria are able to sensitize target cells for lysis by Salmonella-specific CTL . In contrast, heat-killed bacteria cannot sensitize target cells . Presentation of the Hsp 60 epitope appears independent of bacterial internalization, because cytochalasin D does not affect presentation . Moreover, Salmonella strains defective in the InvA or InvE operon, two critical components of the type III secretion pathway, are as efficient as wild-type Salmonella enterica serovar Typhimurium in sensitizing infected targets to lysis . Collectively, these results suggest the existence of a novel antigen-processing pathway in which exogenous antigens gain access to the cytosolic MHC class I processing machinery . Considering the abundant nature of bacterial Hsp 60 and the upregulation of this protein after Salmonella infection of eukaryotic cells, this mode of antigen presentation may be particularly relevant to understanding the host defense mechanisms against gram-negative bacteria. Infect Immun, 2004 May, 72(5), 2546 - 55 Host and bacterial factors affecting induction of immune responses to flagellin expressed by attenuated Salmonella vaccine strains; Sbrogio-Almeida ME et al.; Previous observations demonstrated that the delivery of recombinant Salmonella enterica serovar Dublin strains to mice via mucosal routes did not efficiently activate systemic and secreted antibody responses to either type d flagellin or genetically fused heterologous B-cell epitopes, thus reducing the usefulness of the protein as a carrier of epitopes for vaccine purposes . In this work, we investigated murine systemic and mucosal flagellin immunogenicity after oral immunization with attenuated Salmonella strains . The reduced anti-type d flagellin antibody responses in mice immunized via mucosal routes with three doses of flagellated S . enterica serovar Dublin strains were not caused by oral tolerance and could not be restored by coadministration of a mucosal adjuvant . The induction of antibody responses to Salmonella flagellins was shown to differ according to the genetic background, but not the haplotype, of the mouse lineage . Moreover, BALB/c mice orally immunized with S . enterica serovar Typhimurium strains developed anti-type i flagellin sera and secreted antibody responses, which indicated that the serovar of the Salmonella vaccine strain also affected flagellin immunogenicity . Analyses of cytokine responses of BALB/c mice immunized with three oral doses of flagellated S . enterica serovar Dublin vaccine strains showed that, in spite of the lack of antibody responses, elevated type d flagellin-specific CD4-cell-activation-dependent gamma interferon (IFN-gamma) and interleukin-10 responses were elicited after the administration of the vaccine strains via either parenteral or mucosal routes . Similar cytokine production patterns were detected to a T-cell heterologous epitope, derived from the CFA/I fimbriae of enterotoxigenic Escherichia coli (ETEC), in mice orally immunized with a Salmonella vaccine strain expressing hybrid flagella . These results indicate that the immunogenicities of Salmonella flagellins can differ significantly, depending on the murine host and on the bacterial vector used, and demonstrate that the induction of CD4-cell-activation-dependent IFN-gamma production represents a major immune response triggered by flagellin and in-frame fused heterologous T-cell epitopes after the oral administration of recombinant S . enterica serovar Dublin vaccine strains. J Med Primatol, 2004 Jun, 33(3), 127 - 33 Use of florfenicol in non-human primates; Cook AL et al.; Studies were undertaken to determine if florfenicol, an antimicrobial agent structurally similar to chloramphenicol, could be used as an effective broad spectrum antibiotic for the treatment of bacterial infections in primates . Florfenicol was developed as an injectable antibiotic for use in cattle on an every other day dosing schedule . Its broad spectrum activity, long duration of action following i.m . administration, and its safety as compared with chloramphenicol made it an attractive antibiotic for use in non-human primates . Previous studies had shown that florfenicol is effective against common primate pathogens such as Salmonella, Klebsiella, Escherichia coli, Bordetella bronchiseptica, Streptococcus pneumoniae, Staphylococcus spp., and Yersinia pseudotuberculosis . We performed experiments on a total of 15 macaques . The animals were given florfenicol at 50 mg/kg i.m . and blood samples taken at various time points . Serum was evaluated for florfenicol absorption . Necropsies were also performed to determine if major organs were affected and to determine the effects of i.m . injection of florfenicol . We determined that florfenicol given every 48 hours in rhesus macaques results in blood levels that were acceptable for therapeutic use . The effect on muscle tissue of i.m . injection was similar to ketamine and normal saline . There were no gross lesions observed and no changes with tissues submitted for histology . Our work shows that with further studies, florfenicol may be useful when injectable antibiotic therapy is required in non-human primates. Microbes Infect, 2004 Apr, 6(4), 398 - 405 Salmonella infections in the mouse model: host resistance factors and in vivo dynamics of bacterial spread and distribution in the tissues; Mastroeni P et al.; The mouse model is widely used to study the mechanisms of the pathogenesis of, and immunity to, systemic salmonellosis . During infection, Salmonella grows in phagocytic cells that reside in well-defined pathological lesions, are activated by cytokines and control the growth of intracellular bacteria using oxygen and nitrogen derivatives . Salmonella growth in the tissues results in the spatial segregation of bacterial populations and in their continuous distribution to new phagocytes . High bacterial numbers within infected phagocytes are uncommon in vivo. Int Immunopharmacol, 2004 Apr, 4(4), 527 - 37 A synthetic peptide derived from bactericidal/permeability-increasing protein neutralizes endotoxin in vitro and in vivo; Jiang Z et al.; Lipopolysaccharide (LPS {endotoxin}), a structural component of gram-negative bacteria, is implicated in the pathogenesis of septic shock . Lipid A is an evolutionarily conserved region of LPS that has been identified as the toxic component of LPS . Therapeutic strategies for the treatment of septic shock in humans are currently focused on neutralization of LPS . Here, the anti-endotoxin activity of BNEP, a synthetic peptide derived from the human bactericidal/permeability-increasing protein (BPI; aa 148-161) was investigated in vitro and in experimental animal endotoxemia models in vivo . The ability of BNEP to bind LPS from Escherichia coli O55:B5 and lipid A from Salmonella Re 595 was tested using an affinity sensor assay, and its ability to neutralize LPS was tested using a sensitive Limulus amebocyte lysate (LAL) assay . Polymyxin B (PMB) was used as the positive control in the in vitro experiments and in mouse experiments . We found that BNEP and PMB bound LPS with a similar affinity (Kd values of 25.4 and 25.8 nM, respectively) . In contrast, BNEP bound lipid A with a slightly lower affinity than that of PMB (Kd values of 8 and 5.6 nM, respectively) . The exact capacity of BNEP binding to LPS was approximately 0.53 microg peptide per 1 ng of LPS, as shown by affinity sensor assay . The LAL test showed that 256 microg of BNEP almost completely neutralized 2 ng LPS . In vivo, mice were randomized, intravenously injected with BNEP (0.5-10 mg/kg) or 1 mg/kg PMB, and then lethally challenged with 20 mg/kg LPS . We found that 5 mg/kg BNEP significantly protected mice from LPS challenge . In an endotoxemia rat model, animals were co-treated with 5 or 10 mg/kg BNEP and 10 mg/kg LPS via cardiac catheter . BNEP treatment resulted in significant reduction of tumor necrosis factor alpha (TNF-alpha) and IL-6, compared with LPS-only control animals . In addition, 10 mg/kg BNEP-treated animals showed a significant decrease in plasma endotoxin levels in comparison to animals treated with LPS alone . These results provide evidence that BNEP effectively neutralizes LPS in vitro and in vivo, and could protect animals from the lethal effects of LPS via decreasing plasma endotoxin and proinflammatory cytokines . Our work suggests that this peptide is worthy of further investigation as a possible novel treatment for septic shock . Wei Sheng Yan Jiu, 2004 Jan, 33(1), 49 - 54 {Study on national active monitoring for food borne pathogens and antimicrobial resistance in China 2001}; Wang M et al.; OBJECTIVE: To survey food borne pathogens and antimicrobial resistance in China . METHODS: A total of 4034 samples of foods (raw meats, raw milk, cooked meats, ice cream, yoghurt, aquatic product and vegetable) were examined for the presence of Escherichia coli O157:H7 Salmonella spp and Listeria monocytogens by national active foodborne pathogens surveillance system . The samples were obtained from 11 provinces in 2001 . RESULTS: Approximate 5.50% of the all samples yielded 3 pathogenes, whereas Escherichia coli O157:H7 (0.82%), Salmonella servoars (3.32%) and Listeria monocytogens (1.29%) . The most heavy contamination by three food borne pathogens are in raw meat (12.96%) . Top seven serotype of the 137 Salmonella isolates are S . derby, S . agona, S . enteritidis, S . reading, S . anatum . S . muenster, S . typhimurium . CONCLUSION: Serotypes and antibiotic resistance patterns of Salmonella isolates are different in 11 provinces . E . coli O157:H7 strains that are isolated from raw meat and cooked meat have VT2, eae, Hly genes . Salmonella and E . coli strains of multidrug resistance were isolated and identified. J Pediatr Gastroenterol Nutr, 2004 May, 38(5), 518 - 23 Nontyphoid salmonellosis in taiwan children: clinical manifestations, outcome and antibiotic resistance; Huang IF et al.; OBJECTIVES: The purposes of this study were to investigate the epidemiologic, clinical, and microbiologic features of patients with nontyphoid salmonellosis and to elucidate the impact of resistance on the outcome of nontyphoid salmonellosis in Taiwan . The authors also sought to develop a severity score to derive an objective guideline for antibiotic use in nontyphoid salmonellosis in the era of increasing antibiotic resistance . METHODS: The authors prospectively monitored 311 children with nontyphoid salmonellosis in Kaohsiung, Taiwan . The demographic, clinical, and microbiologic features, underlying diseases, treatment regimen, complications, and outcome were analyzed . In vitro susceptibility testing of the isolates was performed . RESULTS: The median age of affected patients was 15 months . Salmonella enteritidis B caused 68.5% of episodes, followed by S . enteritidis C1 (11.9%), D (7.7%), C2 (7.1%), E (2.6%), S . choleraesuis (1.6%), and S . paratyphi (0.6%) . Sixty percent of isolates were resistant to ampicillin . Patients with bacteremia could not be differentiated from patients without bacteremia on clinical grounds . Patients receiving antibiotics that were inactive in vitro (discordant therapy) had more days of fever and longer hospital stay compared with patients receiving antibiotics that were active in vitro (concordant therapy) . Patients receiving no antibiotic treatment had the fewest days of fever and shortest hospital stays, especially among patients with mild illness (severity score, 0-1) . CONCLUSION: Blood culture should be obtained in patients with nontyphoid salmonellosis to detect bacteremia . In treating antibiotic-resistant nontyphoid salmonellosis, antibiotics are still not mandatory for patients who present with primarily gastrointestinal symptoms and limited signs of systemic inflammation reflected by a low severity score (low C-reactive protein, fewer band cells in peripheral blood, and fewer days of fever before admission) . Susceptibility data should be promptly obtained because use of discordant antibiotics appears to prolong illness. Clin Infect Dis, 2004 Apr 15, 38 Suppl 3, S262 - 70 Breast-feeding decreases the risk of sporadic salmonellosis among infants in FoodNet sites; Rowe SY et al.; Among the population of the Foodborne Diseases Active Surveillance Network (FoodNet) surveillance areas ("FoodNet sites") in 1996, children under 12 months of age had the highest incidence of sporadic salmonellosis . We conducted a case-control study in 5 FoodNet sites to identify risk factors for sporadic infant salmonellosis . A case patient was a child under 12 months of age with a laboratory-confirmed, nontyphoidal serogroup B or D Salmonella infection . Twenty-two case patients were matched with 39 control subjects by age and either telephone exchange or vital record birth list . In a multivariate analysis, case patients were more likely to have a liquid diet containing no breast milk than a liquid diet containing only breast milk (matched odds ratio, 44.5; P=.04) . Case-patients were more likely to reside in a household where a member had diarrhea (matched odds ratio, 13.2; P=.01) . To decrease their infants' risk of salmonellosis, mothers should be encouraged to breast-feed their infants . Caretakers of infants should learn about salmonellosis, hand washing, and safe preparation of formula and solid food. Clin Infect Dis, 2004 Apr 15, 38 Suppl 3, S253 - 61 Reptiles, amphibians, and human Salmonella infection: a population-based, case-control study; Mermin J et al.; To estimate the burden of reptile- and amphibian-associated Salmonella infections, we conducted 2 case-control studies of human salmonellosis occurring during 1996-1997 . The studies took place at 5 Foodborne Diseases Active Surveillance Network (FoodNet) surveillance areas: all of Minnesota and Oregon and selected counties in California, Connecticut, and Georgia . The first study included 463 patients with serogroup B or D Salmonella infection and 7618 population-based controls . The second study involved 38 patients with non-serogroup B or D Salmonella infection and 1429 controls from California only . Patients and controls were interviewed about contact with reptiles and amphibians . Reptile and amphibian contact was associated both with infection with serogroup B or D Salmonella (multivariable odds ratio {OR}, 1.6; 95% confidence interval {CI}, 1.1-2.2; P<.009) and with infection with non-serogroup B or D Salmonella (OR, 4.2; CI, 1.8-9.7; P<.001) . The population attributable fraction for reptile or amphibian contact was 6% for all sporadic Salmonella infections and 11% among persons <21 years old . These data suggest that reptile and amphibian exposure is associated with approximately 74,000 Salmonella infections annually in the United States. Clin Infect Dis, 2004 Apr 15, 38 Suppl 3, S244 - 52 Chicken consumption is a newly identified risk factor for sporadic Salmonella enterica serotype Enteritidis infections in the United States: a case-control study in FoodNet sites; Kimura AC et al.; The sources of sporadic Salmonella enterica serotype Enteritidis (SE) infections in the United States are unclear . To determine risk factors for sporadic SE infection, we conducted a population-based case-control study in 5 Foodborne Disease Active Surveillance Network surveillance areas . During the 12-month study, 396 cases of SE infection were ascertained . Among the 182 case patients and 345 controls, SE infection was univariately associated with international travel (matched odds ratio {MOR}, 61; 95% confidence interval {CI}, 8-447), eating undercooked eggs (MOR, 2.2; 95%CI, 1-5), and eating chicken prepared outside of the home (MOR, 2.2; 95% CI, 1.3-3.4) . Multivariate analysis revealed that eating chicken outside of the home remained the only significant risk factor for illness (MOR, 2.0; 95% CI, 1.1-3.6) . Chicken consumption has not previously been identified in the United States as a risk factor for SE infection . Measures to prevent SE infections include educating consumers and food handlers about food safety and interventions to decrease contamination of eggs and poultry. Clin Infect Dis, 2004 Apr 15, 38 Suppl 3, S237 - 43 Egg consumption is the principal risk factor for sporadic Salmonella serotype Heidelberg infections: a case-control study in FoodNet sites; Hennessy TW et al.; To determine risk factors for sporadic Salmonella serotype Heidelberg diarrheal disease, we conducted a population-based case-control study in 5 Foodborne Diseases Active Surveillance Network (FoodNet) surveillance areas in 1996-1997 . Forty-four case patients and 83 control subjects matched by age and telephone exchange were asked about exposures during the 5-day period before onset of illness in the case patient . Risk factors for infection were evaluated using conditional logistic regression analysis . Eating eggs prepared outside the home remained the only significant risk factor for illness (matched odds ratio {MOR}, 6.0; 95% confidence interval {CI}, 1.2-29.6) . The population-attributable fraction of S . Heidelberg infections associated with eating eggs prepared outside the home was 37% . Eliminating the risk associated with out-of-home egg consumption could substantially reduce the incidence of S . Heidelberg infections . Control measures to prevent S . Heidelberg infection should include advising consumers to avoid eating undercooked eggs and educating food handlers about proper egg handling and cooking. Clin Infect Dis, 2004 Apr 15, 38 Suppl 3, S227 - 36 Prior antimicrobial agent use increases the risk of sporadic infections with multidrug-resistant Salmonella enterica serotype Typhimurium: a FoodNet case-control study, 1996-1997; Glynn MK et al.; Several strains of multidrug-resistant (MDR) Salmonella serotype Typhimurium, including MDR S . Typhimurium definitive type 104, cause almost 10% of Salmonella infections among humans in the United States . To determine the risk factors for acquiring sporadic MDR S . Typhimurium infection, we conducted a population-based, case-control study using data from the Foodborne Diseases Active Surveillance Network (FoodNet) during 1996-1997 . S . Typhimurium isolates from 5 FoodNet surveillance areas (California, Connecticut, Georgia, Minnesota, and Oregon) were tested for antimicrobial resistance and phage typing . Telephone interviews were conducted with ill persons and matched control subjects . Compared with both control subjects and patients infected with pansensitive strains of S . Typhimurium, patients with MDR S . Typhimurium infection were significantly more likely to have received an antimicrobial agent, particularly an agent to which the Salmonella isolate was resistant, during the 4 weeks preceding illness onset . Prudent antimicrobial agent use among humans and among veterinarians and food-animal producers is necessary to reduce the burden of drug-resistant salmonellosis in humans. Clin Infect Dis, 2004 Apr 15, 38 Suppl 3, S149 - 56 Invasive Salmonella infections in the United States, FoodNet, 1996-1999: incidence, serotype distribution, and outcome; Vugia DJ et al.; Invasive Salmonella infections are severe and can be life threatening . We analyzed population-based data collected during 1996-1999 by the Foodborne Diseases Active Surveillance Network (FoodNet), to determine the incidences, infecting serotypes, and outcomes of invasive Salmonella infection . We found that the mean annual incidence of invasive salmonellosis was 0.9 cases/100,000 population and was highest among infants (7.8 cases/100,000) . The incidence was higher among men than women (1.2 vs . 0.7 cases/100,000; P<.001) and higher among blacks, Asians, and Hispanics than among whites (2.5, 2.0, and 1.3 cases/100,000 population, respectively, vs . 0.4 cases/100,000; all P<.001) . Seventy-four percent of cases were caused by 8 Salmonella serotypes: Typhimurium, Typhi, Enteritidis, Heidelberg, Dublin, Paratyphi A, Choleraesuis, and Schwarzengrund . Of 540 persons with invasive infection, 386 (71%) were hospitalized and 29 (5%) died; 13 (45%) of the deaths were among persons aged > or =60 years . Invasive Salmonella infections are a substantial health problem in the United States and contribute to hospitalizations and deaths. Clin Infect Dis, 2004 Apr 15, 38 Suppl 3, S142 - 8 Hospitalizations and deaths due to Salmonella infections, FoodNet, 1996-1999; Kennedy M et al.; Nontyphoidal Salmonella causes a higher proportion of food-related deaths annually than any other bacterial pathogen in the United States . We reviewed 4 years (1996-1999) of population-based active surveillance data on laboratory-confirmed Salmonella infections from the Emerging Infections Program's Foodborne Diseases Active Surveillance Network (FoodNet), to determine the rates of hospitalization and death associated with Salmonella infection . Overall, 22% of infected persons were hospitalized, with the highest rate (47%) among persons aged >60 years . Fifty-eight deaths occurred, for an estimated annual incidence of 0.08 deaths/100,000 population . These deaths accounted for 38% of all deaths reported through FoodNet from 1996 through 1999, and they occurred primarily among adults with serious underlying disease . Although Salmonella infection was seldom listed as a cause of death on hospital charts and death certificates, our chart review suggests that Salmonella infection contributed to these deaths. Clin Infect Dis, 2004 Apr 15, 38 Suppl 3, S135 - 41 Dramatic decrease in the incidence of Salmonella serotype Enteritidis infections in 5 FoodNet sites: 1996-1999; Marcus R et al.; Salmonella serotype Enteritidis (SE) emerged as the most common Salmonella serotype among infected persons in the United States during the 1980s and 1990s, with infections reaching a peak in 1995 . During the past decade, farm-to-table control measures have been instituted in the United States, particularly in regions with the highest incidence of SE infection . We report trends in the incidence of SE in the 5 original surveillance areas of the Foodborne Diseases Active Surveillance Network during 1996-1999: Minnesota, Oregon, and selected counties in California, Connecticut, and Georgia . Overall, the incidence of SE decreased 46% from 1996 to 1999 . The greatest decrease was in Connecticut (71%), followed by northern California (50%), Minnesota (46%), and Oregon (13%) . Although SE infection remains an important public health concern, there has been a remarkable decrease in its incidence . This decrease may be a result of targeted interventions, including on-farm control measures, refrigeration, and education efforts. Clin Infect Dis, 2004 Apr 15, 38 Suppl 3, S127 - 34 FoodNet estimate of the burden of illness caused by nontyphoidal Salmonella infections in the United States; Voetsch AC et al.; To determine the burden of Salmonella infections in the United States, Foodborne Diseases Active Surveillance Network (FoodNet) investigators conducted population-based active surveillance for culture-confirmed Salmonella infections during 1996-1999 at FoodNet laboratories . In addition, all clinical microbiology FoodNet laboratories were surveyed to determine their practices for isolating Salmonella . Telephone interviews were also conducted among residents of the FoodNet sites to determine the proportion of persons with diarrheal illness who sought medical care and the proportion who submitted stool specimens for bacterial culture . Using our model, we estimated that there were 1.4 million nontyphoidal Salmonella infections in the United States, resulting in 168,000 physician office visits per year during 1996-1999 . Including both culture-confirmed infections and those not confirmed by culture, we estimated that Salmonella infections resulted in 15,000 hospitalizations and 400 deaths annually . These estimates indicate that salmonellosis presents a major ongoing burden to public health. Rev Soc Bras Med Trop, 2004 Mar-Apr, 37(2), 143 - 7 Epub 2004 Apr 13. Optimization of randomly amplified polymorphic DNA-polymerase chain reaction for molecular typing of Salmonella enterica serovar Typhi; Quintaes BR et al.; Optimization of the RAPD reaction for characterizing Salmonella enterica serovar Typhi strains was studied in order to ensure the reproducibility and the discriminatory power of this technique . Eight Salmonella serovar Typhi strains isolated from various regions in Brazil were examined for the fragment patterns produced using different concentrations of DNA template, primer, MgCl2 and Taq DNA polymerase . Using two different low stringency thermal cycle profiles, the RAPD fingerprints obtained were compared . A set of sixteen primers was evaluated for their ability to produce a high number of distinct fragments . We found that variations associated to all of the tested parameters modified the fingerprinting patterns . For the strains of Salmonella enterica serovar Typhi used in this experiment, we have defined a set of conditions for RAPD-PCR reaction, which result in a simple, fast and reproducible typing method. Lancet, 2004 Apr 17, 363(9417), 1285 - 6 Isolation of Salmonella enterica serotype choleraesuis resistant to ceftriaxone and ciprofloxacin; Chiu CH et al.; Salmonella enterica serotype choleraesuis (S choleraesuis) usually causes systemic infections in man that need antimicrobial treatment . We isolated a strain of S choleraesuis that was resistant to ceftriaxone and ciprofloxacin from a patient with sepsis . Ciprofloxacin resistance was associated with mutations in gyrA and parC, whereas the ampC gene (bla(CMY-2)), responsible for ceftriaxone resistance, was carried by a transposon-like mobile element . This element was found inserted into finQ of a potentially transmissible 140 kb plasmid, with an 8 bp direct repeat flanking the junction regions . The appearance of this resistant S choleraesuis is a serious threat to public health, and thus constant surveillance is warranted. FEMS Immunol Med Microbiol, 2004 May 1, 41(1), 1 - 8 Subtracted restriction fingerprinting--a new typing technique using magnetic capture of tagged restriction fragments; Terletski V et al.; Molecular typing of bacterial pathogens is an important issue in the epidemiological analysis of emerging infections in humans and animals . Numerous methods have been developed for and applied to a wide variety of bacteria of medical, veterinary and zoonotic importance . The present minireview provides a description of a new typing approach designated subtracted restriction fingerprinting (SRF), its use for typing of Salmonella isolates and a comparison with the most widely used typing techniques for these bacteria . SRF is based on double restriction endonuclease digestion of whole cell DNA, followed by a fill-in reaction with specifically tagged nucleotides and subtractive capture of selected restriction fragments . This results in a reduced number of fragments optimal for separation in standard agarose gels. Environ Pollut, 1997, 96(2), 195 - 205 Use of semi-permeable membrane devices to monitor pollutants in water and assess their effects: A laboratory test and field verification; Sabaliunas D et al.; Uptake of eight pesticides of different classes (organochlorines, synthetic pyrethroids, dinitroanilines, amides) by semi-permeable membrane devices (SPMDs) was studied in a laboratory continuous-flow system . After 20 days of exposure, membrane concentration factors were in the range of 50 000-120 000 for all the analytes except for the amide herbicides propachlor and alachlor, which were not detected in any of the SPMDs . The kinetic data and mathematical models were used to calculate analyte uptake rate constants, SPMD lipid/water partition coefficients, average sampling rates and concentrations of the pesticides in water . To assess the effects of concentrated pesticides, standard bioassays (Salmonella/histidine reversion assay and bioluminescence inhibition in Vibrio fischeri test) were incorporated in the SPMD technique . To test the method in an environmental situation, SPMDs were deployed in polluted sites in Lithuania . Polynuclear aromatic hydrocarbons were the major pollutants detected in the SPMDs deployed in the field . All the SPMD dialysates were highly toxic in the bioluminescence inhibition test but no mutagenic activity was observed in the Salmonella/histidine reversion assay. Environ Pollut, 1997, 97(1-2), 71 - 8 Mercury and organomercurial resistance in bacteria isolated from freshwater fish of wetland fisheries around Calcutta; Sadhukhan PC et al.; Mercury-resistant bacteria belonging to the genera Bacillus, Escherichia, Klebsiella, Micrococcus, Pseudomonas, Salmonella, Sarcina, Shigella, Staphylococcus and Streptococcus were isolated from gills and guts of fresh water fish collected from wetland fisheries around Calcutta, India, contaminated with mercury compounds . The total number of bacteria, as well as Hg-resistant bacteria, were always higher in guts than gills . Bottom-dwelling fish contained higher number of bacteria, including Hg-resistant bacteria, than surface and middle water dwelling fish . They belonged either to narrow-spectrum or to broad-spectrum Hg-resistant groups and they also possessed other heavy metal and antibiotic resistant properties . In the presence of toxic levels of HgCl(2), phenylmercuric acetate (PMA) and methylmercuric chloride (MMC), the lag in growth of the bacterial strains gradually increased with increasing concentration of Hg-compounds . Narrow-spectrum Hg-resistant bacterial strains volatilized only HgCl(2) from the liquid medium in the range of 64-89%, whereas the broad-spectrum group exhibited a high level of HgCl(2) (80-94%), PMA (72-84%) and MMC (64-80%) volatilizing capacity with inducible mercuric reductase and organomercurial lyase enzyme activities in their cell-free extracts . Cell-free extracts prepared from narrow-spectrum Hg-resistant bacterial strains induced by HgCl(2) exhibited Hg(+2)-dependent NADPH oxidation, indicating the presence of only mercuric reductase enzyme. Environ Pollut, 1998, 99(3), 329 - 37 Composting of spent pig litter in turned and forced-aerated piles; Tiquia SM et al.; A study was carried out to compare the compositing efficiency of spent litter (a mixture of partially decomposed pig manure and sawdust) in turned and forced-aerated piles . Duplicate piles were built with manual turning (every 4 days) during composting, and duplicate piles were set up with forced aeration using an air pump . The present study demonstrated that the efficiency of composting in the turned and forced-aerated piles was similar . Spent litter in these piles reached maturity at the same time (60 days) . The forced-aerated piles went through similar physical, chemical, and microbial changes with the turned piles during composting . The forced-aerated composting system was also as effective as the turned system in eliminating Salmonella sp . in the spent litter . These results suggest that a forced-aerated composting system could be used as an alternative method in composting spent litter . The similarities in temporal changes in temperature, chemical, and microbiological properties of the forced-aerated piles, compared with the turned piles, indicate that addition of a bulking agent under forced aerated composting of spent litter is not necessary . The partially decomposed sawdust in the spent litter provided enough free air space, allowing the delivery of oxygen for the microorganisms in the spent litter piles. Environ Pollut, 1987, 45(4), 305 - 14 Pyrolysing insecticidal coils: air pollution by polycyclic aromatic hydrocarbons and other mutagens detected by the Salmonella/microsome test; Lazaridis G et al.; Pyrolysing insecticidal coils, which are used commonly for their evaporative release of insecticidal amounts of pyrethrins, have been investigated with respect to the emission of airborne particles, their mutagenic activity in the Salmonella/microsome mutagenicity test and their polycyclic aromatic hydrocarbons (PAH) content . Emitted particles contain compounds that are mutagenic in the absence of exogenous activation, as well as components that require mammalian activation . The particles also contain a range of PAH, but their concentration cannot account for the mutagenic response with mammalian activation . The use of pyrolysing insecticidal coils in semi-enclosed spaces may cause air pollution by releasing mutagenic and carcinogenic compounds that are of a magnitude similar to that found in other air pollution situations. Environ Pollut, 1990, 68(1-2), 147 - 59 The influence of application rate on the bacterial mutagenicity of soil amended with municipal sewage sludge; Donnelly KC et al.; The mutagenic potential of two soils amended with a municipal sewage sludge at two application rates was monitored over a 2-year period using Salmonella/microsome mutagenicity assay . Samples were collected from undisturbed monolith lysimeters of Weswood sandy clay (Fluventic Ustochrept) and Padina sandy loam (Grossarenic Paleustalf) amended with dried sewage sludge at 50 and 100 Mg/ha . Soil samples were collected and sequentially extracted with methylene chloride and methanol . The residues from these extracts were tested for mutagenicity at five doses with and without metabolic activation in Salmonella strain TA98 . In general, the mutagenic potential of the amended soils of both application rates for the first 8 weeks following sludge application increased and then slowly decreased . The maximum mutagenic response observed in the soil extracts was 222 revertants at a dose of 10 mg of residue . This response was induced by the methanol extract from the Weswood soil collected 56 days after the application of 50 Mg/ha sewage sludge as compared to the 100 Mg/ha application which induced 202 revertants/mg . The mutagenicity of all fractions extracted from the sludge-amended soil at both application rates collected 717 days after application were not appreciably different from extracts from the unamended soils . The data indicate that chemicals that were mutagenic in bacteria persist in the soil and that at the higher application rates, as much as 2 years may be required for the mutagenic potential of the soil to return to background levels. Environ Pollut, 1995, 89(2), 131 - 5 Assessment of the toxic potential of hydrocarbon containing sludges; Morelli IS et al.; A short-time period microbial toxicity test-battery was used for the investigation of acute toxicity and genotoxicity of five hydrocarbon containing sludges . Four sludges were obtained from a petrochemical industry and the fifth from a petroleum refinery . Some of the sludges had been stored for long periods . Bioremediation potential assays for soils polluted with each of the sludges were also considered . The sludges did not show acute toxicity in any of the microbial tests performed . However, when the diethylether soluble fractions of these sludges were analyzed some of them showed acute toxicity, for which the clearest results were obtained with the resazurin reduction method . The greatest toxicity detected with the Resazurin based method was found in the diethylether extracts of the freshly collected (not stored) sludges . On the other hand, the diethylether soluble fraction of those sludges that had been stored showed genotoxicity when analyzed with the Salmonella/microsome assay . After the incorporation of the sludges into the soil, increased bacterial counts were noted and substantial hydrocarbon elimination was achieved in 30 days, showing that bioremediation may be a possible technology for cleaning soils polluted with these sludges. J Bacteriol, 2004 May, 186(9), 2829 - 40 Highly divergent RfaH orthologs from pathogenic proteobacteria can substitute for Escherichia coli RfaH both in vivo and in vitro; Carter HD et al.; The transcriptional enhancer protein RfaH positively regulates production of virulence factors in Escherichia coli and Salmonella enterica serovar Typhimurium via a cis element, ops . Genes coding for RfaH orthologs were identified in conceptually translated genomes of bacterial pathogens, including Vibrio and Yersinia spp . We cloned the rfaH genes from Vibrio cholerae, Yersinia enterocolitica, S . enterica serovar Typhimurium, and Klebsiella pneumoniae into E . coli expression vectors . Purified RfaH orthologs, including the most divergent one from V . cholerae, were readily recruited to the E . coli transcription elongation complex . Postrecruitment stimulation of transcript elongation appeared to vary with the degree of similarity to E . coli RfaH . V . cholerae RfaH was particularly defective in reducing downstream pausing and termination; this defect was substantially alleviated by an increase in its concentration . When overexpressed episomally, all of the rfaH genes complemented the disruption of the chromosomal copy of the E . coli gene . Thus, despite the apparently accelerated divergent evolution of the RfaH proteins, the mechanism of their action is conserved well enough to make them transcriptionally active in the E . coli system. J Bacteriol, 2004 May, 186(9), 2619 - 28 Host restriction of Salmonella enterica serotype Typhimurium pigeon isolates does not correlate with loss of discrete genes; Andrews-Polymenis HL et al.; The definitive phage types (DT) 2 and 99 of Salmonella enterica serotype Typhimurium are epidemiologically correlated with a host range restricted to pigeons, in contrast to phage types with broader host ranges such as epidemic cattle isolates (DT104 and DT204) . To determine whether phage types with broad host range possess genetic islands absent from host-restricted phage types, we compared the genomes of four pigeon isolates to serotype Typhimurium strain LT2 using a DNA microarray . Three of the four isolates tested caused fluid accumulation in bovine ligated ileal loops, but they had reduced colonization of liver and spleen in susceptible BALB/c mice and were defective for intestinal persistence in Salmonella-resistant CBA mice . The genomes of the DT99 and DT2 isolates were extremely similar to the LT2 genome, with few notable differences on the level of complete individual genes . Two large groups of genes representing the Fels-1 and Fels-2 prophages were missing from the DT2 and DT99 phage types we analyzed . One of the DT99 isolates examined was lacking a third cluster of five chromosomal genes (STM1555 to -1559) . Results of the microarray analysis were extended using Southern analysis to a collection of 75 serotype Typhimurium clinical isolates of 24 different phage types . This analysis revealed no correlation between the presence of Fels-1, Fels-2, or STM1555 to -1559 and the association of phage types with different host reservoirs . We conclude that serotype Typhimurium phage types with broad host range do not possess genetic islands influencing host restriction, which are absent from the host-restricted pigeon isolates. Biometals, 2004 Apr, 17(2), 135 - 9 Hemochromatosis and the enigma of misplaced iron: implications for infectious disease and survival; Moalem S et al.; The mystery surrounding the apparent lack of iron within the macrophages of individuals with hereditary hemochromatosis, a condition of excessive uptake of dietary iron, has yet to be fully explained . We have suggested that iron deficiency of macrophages in people with hereditary hemochromatosis mutations is associated with increased resistance to infection by Yersinia and other intracellular pathogens, a selection pressure resulting in unusually high current population frequencies of hereditary hemochromatosis mutations . Such selection pressure has been called Epidemic Pathogenic Selection (EPS) . In support of the theory of EPS, a considerable number of virulent species of bacteria multiply mainly in iron-rich macrophages of their mammalian hosts . Among these fastidious pathogens are strains of Chlamydia, Coxiella, Francisella, Legionella, Mycobacterium, Salmonella and Yersinia . Iron deficiency of macrophages of persons with hereditary hemochromatosis gene mutations may result in increased resistance to members of these bacterial pathogens . People with genes that result in hereditary hemochromatosis may be protected against coronary artery disease associated with Chlamydia and Coxiella infection in the absence of iron overload . In the clinical setting, when a patient appears to be iron deficient, the reason for this should be carefully evaluated . Iron supplementation may adversely affect the health of individuals who have mounted an acute phase response to infection, injury or stress, or who carry genes predisposing them to iron overload disorders. Traffic, 2004 May, 5(5), 356 - 70 Effector proteins encoded by Salmonella pathogenicity island 2 interfere with the microtubule cytoskeleton after translocation into host cells; Kuhle V et al.; The facultative intracellular pathogen Salmonella enterica has evolved strategies to modify its fate inside host cells . One key virulence factor for the intracellular pathogenesis is the type III secretion system encoded by Salmonella Pathogenicity Island 2 (SPI2) . We have previously described SPI2-encoded SseF and SseG as effector proteins that are translocated by intracellular Salmonella . Detailed analysis of the subcellular localization of SseF and SseG within the host cell indicated that these effector proteins are associated with endosomal membranes as well as with microtubules . Specific association with microtubules was observed after translocation by intracellular Salmonella as well as after expression by transfection vectors . In epithelial cells infected with Salmonella, both SseF and SseG are required for the aggregation of endosomal compartments along microtubules and to induce the formation of massive bundles of microtubules . These observations demonstrate that SPI2 effectors interfere with the microtubule cytoskeleton and suggest that microtubule-dependent host cell functions such as vesicle transport or organelle positioning are altered by intracellular Salmonella. Clin Exp Immunol, 2004 May, 136(2), 297 - 303 Development of an anti-Salmonella typhi Vi ELISA: assessment of immunocompetence in healthy donors; Ferry BL et al.; We have developed a solid-phase enzyme-linked immunosorbent assay (ELISA) to study the vaccination responses to Vi capsular polysaccharide of Salmonella typhi (S . typhi Vi) vaccine . Purified S . typhi Vi polysaccharide was biotinylated and bound to streptavidin coated microtitre plates . Reproducibility was determined across a range of IgG antibody levels: mean interassay coefficients of variation (CVs) were <11.9% for non-vaccinated sera with low levels and <11.1% for sera with very high levels of anti-S . typhi Vi IgG . Specificity was assessed by inhibition studies using salmonella antigen . We have developed the ELISA based on normal adult serum responses to test immunization with S . typhi Vi vaccine . We also report here anti-S . typhi Vi IgG levels in a group of healthy preschool children . In non-vaccinated adult sera (n = 104), the median value of anti-S . typhi Vi IgG, expressed in S . typhi Vi arbitrary units (AU/ml), was 5.3 AU/ml and in non-vaccinated sera from children (n = 44) the median value was 1.4 AU/ml . The data from immunization of healthy volunteers (n = 23) show that geometric mean levels of anti-S . typhi Vi IgG were significantly higher (P < 0.0001) for post-vaccination subjects (39.2 AU/ml) compared to paired prevaccination (3.9 AU/ml) values . A total of 21/23 vaccine recipients had <8 AU/ml S . typhi Vi IgG in their sera prior to vaccination and of these 20/21 (95%) exhibited threefold increases and 14/21 (67%) fourfold increases in their S . typhi Vi IgG following vaccination . Based on the data in this study, we propose a threefold increase in anti-S . typhi Vi IgG post-vaccination to be considered a positive vaccination response . The ability to demonstrate clearly an antibody rise in response to immunization with S . typhi Vi capsular polysaccharide vaccine suggests that this is likely to be a useful vaccine for the assessment of B cell function in patients with suspected immune deficiency. Clin Microbiol Rev, 2004 Apr, 17(2), 323 - 47 Invasion of the central nervous system by intracellular bacteria; Drevets DA et al.; Infection of the central nervous system (CNS) is a severe and frequently fatal event during the course of many diseases caused by microbes with predominantly intracellular life cycles . Examples of these include the facultative intracellular bacteria Listeria monocytogenes, Mycobacterium tuberculosis, and Brucella and Salmonella spp . and obligate intracellular microbes of the Rickettsiaceae family and Tropheryma whipplei . Unfortunately, the mechanisms used by intracellular bacterial pathogens to enter the CNS are less well known than those used by bacterial pathogens with an extracellular life cycle . The goal of this review is to elaborate on the means by which intracellular bacterial pathogens establish infection within the CNS . This review encompasses the clinical and pathological findings that pertain to the CNS infection in humans and includes experimental data from animal models that illuminate how these microbes enter the CNS . Recent experimental data showing that L . monocytogenes can invade the CNS by more than one mechanism make it a useful model for discussing the various routes for neuroinvasion used by intracellular bacterial pathogens. Clin Microbiol Rev, 2004 Apr, 17(2), 311 - 22 Salmonella enterica serotype Choleraesuis: epidemiology, pathogenesis, clinical disease, and treatment; Chiu CH et al.; Nontyphoid Salmonella strains are important causes of reportable food-borne infection . Among more than 2,000 serotypes, Salmonella enterica serotype Choleraesuis shows the highest predilection to cause systemic infections in humans . The most feared complication of serotype Cholearesuis bacteremia in adults is the development of mycotic aneurysm, which previously was almost uniformally fatal . The advances in diagnostic techniques, surgical care, and antimicrobial therapy have greatly improved the survival of these patients . However, the recent emergence of serotype Choleraesuis that is resistant to ampicillin, chloramphenicol, trimethoprim-sulfamethoxazole, and, notably, fluoroquinolone antibiotics has aroused concern about the use of these agents for the empirical treatment of systemic infection caused by this organism . In view of the serious implications of the situation, the chain of transmission and mechanism of resistance should be carefully studied to reduce the spread of infection and threat to human health . To date, there are no vaccines available to prevent serotype Choleraesuis infections in humans . The availability, in the near future, of the genome sequence of serotype Cholearesuis will facilitate the development of effective vaccines as well as the discovery of new targets for novel antimicrobial agents. J Food Prot, 2004 Apr, 67(4), 813 - 7 Effect of alfalfa seed washing on the organic carbon concentration in chlorinated and ozonated water; Rajkowski KT et al.; The bioassays assimilable organic carbon (AOC) and coliform growth response are better indexes than biological oxygen demand to determine water quality and water's ability to support the growth of bacteria . Ozonated (5 mg/liter) and chlorinated tap water were used to wash alfalfa seeds for 30 min . After washing in the ozonated tap water, the AOC concentration increased 25-fold, whereas the dissolved ozone decreased to undetectable levels . The AOC levels for the chlorinated water after washing the seeds also increased . These increases are due to ozone's strong oxidizing ability to break down refractory, large-molecular-weight compounds, forming smaller ones, which are readily used as nutrient sources for microorganisms . This same phenomenon was observed when using ozone in the treatment of drinking water . The AOC value increased from 1,176 to 1,758 micrograms C-eq/liter after the reconditioned wastewater was ozonated . When the ozonated wastewater was inoculated with Salmonella serotypes, the cells survived and increased generation times were observed . The increased nutrients would now become more readily available to any pathogenic microorganisms located on alfalfa seed surface as seen with the increase in the inoculated levels of Salmonella in the ozonated wastewater . If the washing process using ozonated water is not followed by the recommended hypochlorite treatment or continually purged with ozone, pathogen growth is still possible. J Food Prot, 2004 Apr, 67(4), 758 - 65 Analysis of published sprout seed sanitization studies shows treatments are highly variable; Montville R et al.; Consumption of raw sprouts has caused many foodborne illness outbreaks in the last decade, and most outbreaks have been linked to contaminated seeds . Many seed sanitization treatments have been studied as a means to reduce the risk of illness associated with sprouts . Published data on seed sanitization were analyzed collectively to identify factors that influenced the efficacy of seed sanitization and to determine the variability associated with various sanitization processes . Temperature and duration of the sanitization treatment were found to produce a negligible effect on log microbial reductions . Salmonella, Escherichia coli O157:H7, and total aerobic microorganisms were all inactivated at similar rates . Data were fit to triangular or uniform distributions for 16 different chemical treatments . Among the most effective treatments were 8% hydrogen peroxide (uniform distribution {2.5, 4.5}), 20,000 ppm of chlorine (triangular distribution {1, 2.5, 6.5}), and 1% Ca(OH)2 (triangular distribution {0.5, 4, 5}) . Chemical treatments where more published data were available showed more variability. J Food Prot, 2004 Apr, 67(4), 732 - 41 Evaluation of inoculation method and inoculum drying time for their effects on survival and efficiency of recovery of Escherichia coli O157:H7, Salmonella, and Listeria monocytogenes inoculated on the surface of tomatoes; Lang MM et al.; A study was undertaken to evaluate methods for applying inoculum and to examine the effect of inoculum drying time on survival and recovery of foodborne pathogens inoculated onto the surface of raw, ripe tomatoes . Five-strain mixtures of Escherichia coli O157:H7, Salmonella, or Listeria monocytogenes were applied to tomatoes by dip, spot, or spray inoculation methods . Inocula were dried for 1 or 24 h at 22 degrees C before tomatoes were treated with water (control) or chlorine (200 micrograms/ml) . Significantly (alpha = 0.05) larger populations (CFU per tomato) of E . coli O157:H7 and Salmonella were recovered from dipinoculated tomatoes than from spot- or spray-inoculated tomatoes . This difference was attributed to larger numbers of cells adhering to tomatoes subjected to dip inoculation . Populations of E . coli O157:H7 and Salmonella recovered from spot- and spray-inoculated tomatoes containing the same initial number of cells were not significantly different . Significantly different L . monocytogenes population sizes were recovered from inoculated tomatoes (dip > spot > spray) . Populations of pathogens recovered from tomatoes were significantly larger when inocula were dried for 1 h compared with 24 h . Significant differences (water > chlorine) were observed in the sizes of populations for all pathogens recovered from tomatoes treated with chlorine, regardless of inoculation method or drying time . Results indicate that inoculation method, drying time, and treatment affect survival and/or recovery of foodborne pathogens inoculated onto the surface of tomatoes . We recommend that spot inoculation with a drying time of 24 h at 22 degrees C be used with standard methods to determine the efficacy of chlorine and other sanitizers for killing foodborne pathogens on tomatoes. J Food Prot, 2004 Apr, 67(4), 713 - 20 Salmonella contamination during production of cantaloupe: a binational study; Castillo A et al.; Six cantaloupe farms and packing plants in South Texas (950 cantaloupe, 140 water, and 45 environmental samples), including the Rio Grande Valley area, and three farms in Colima State, Mexico (300 cantaloupe, 45 water, and 15 environmental samples), were sampled to evaluate cantaloupe contamination with Salmonella and Escherichia coli during production and processing . Samples collected from external surfaces of cantaloupes, water, and the environments of packing sheds on cantaloupe farms were examined for the presence of Salmonella and E . coli . Of a total of 1,735 samples collected, 31 (1.8%) tested positive for Salmonella . Fifteen Salmonella serotypes were isolated from samples collected in Texas, and nine from samples collected in Colima . Two serotypes (Poona and Oranienburg) that have been associated with three large Salmonella outbreaks in the United States and Canada linked to the consumption of contaminated cantaloupe were found in water samples collected at four farms (three from the United States) . Susceptibility of Salmonella isolates to 10 antimicrobials was evaluated by disk diffusion . Eighty-eight percent of the isolates from the United States and Mexico were pansusceptible to the antimicrobials tested; eight isolates from the United States demonstrated an intermediate susceptibility to streptomycin and only two isolates were resistant to the same antimicrobial . From Mexico, four isolates showed an intermediate susceptibility to streptomycin and one isolate was resistant to nalidixic acid and streptomycin . Repetitive sequence-based PCR analysis of Salmonella isolates helped to trace potential sources of Salmonella contamination in source water and in subsequent water samples obtained after the filtration systems of U.S . and Mexican cantaloupe farms . No differences could be seen between the levels of Salmonella contamination in melons from both countries. J Food Prot, 2004 Apr, 67(4), 706 - 12 Efficacy of egg cleaning compounds on eggshells contaminated with Salmonella enterica serovar Enteritidis; Soljour G et al.; Salmonella Enteritidis infections of egg contents can be related to external contamination of the shell . In this study, the efficacy of three commercial cleaning and/or sanitizing compounds (sodium carbonate, sodium hypochlorite, and potassium hydroxide) was evaluated for bactericidal activity at pH values of 10, 11, and 12 against various concentrations (10(2), 10(4), or 10(6) CFU/ml) of Salmonella Enteritidis inoculated onto the eggshell surface . Efficacy of these chemical agents was also assessed against Salmonella Enteritidis in aqueous suspension . Our results indicated that none of the chemicals applied at the recommended manufacturer's concentrations (sodium carbonate, 36 ppm; other treatments, 200 ppm) could eliminate Salmonella Enteritidis from eggshells artificially contaminated with the highest bacterial concentrations (10(4) or 10(6) CFU/ml) . Higher concentrations of each product, at least 5 to 20 times greater than recommended doses, were needed to destroy the bacteria on egg surfaces . However, at or slightly above the manufacturer's recommended use concentrations, all three formulations were effective against Salmonella Enteritidis in aqueous suspension (10(8) CFU/ml) or on eggshells contaminated with 10(2) CFU/ml . For both shell and suspension assays, inactivation of Salmonella Enteritidis occurred at lower concentrations at pH 12 than at pH 11 and 10 . Contact time between chemicals and Salmonella apparently influenced bacterial inactivation . Extended contact times (2 to 10 min) reduced minimum chemical concentrations necessary to inactivate the bacteria . However, neither pH nor contact time influenced Salmonella Enteritidis inactivation when the initial bacterial numbers on eggshells were high. J Food Prot, 2004 Apr, 67(4), 691 - 7 Salmonella enterica serovars from pigs on farms and after slaughter and validity of using bacteriologic data to define herd Salmonella status; Gebreyes WA et al.; The primary objective of this study was to evaluate the validity of using data obtained from slaughtered pigs for farm-level epidemiologic studies of Salmonella . The study involved groups of pigs from five farms . Salmonella isolates were obtained from on-farm samples, and a total of 370 on-farm and an additional 486 isolates from samples collected after commercial slaughter were subsequently tested . Preharvest samples included feces of individual animals from defined groups of nursery and finishing pigs on commercial farms and swabs from trucks . Postslaughter samples were cecal contents and mesenteric lymph node samples . The concordance between Salmonella serovars isolated from on-farm samples and those serovars isolated after slaughter varied widely among farms . Results of paired lymph node and cecal cultures were strongly associated (odds ratio, 7.0), but the agreement between on-farm and postslaughter results at the pig level was poor (kappa = 0.34) . The results support recent findings that risk of exposure to Salmonella during transport and lairage remains a concern under contemporary industry conditions . The findings further imply that slaughter plant studies based on phenotyping of Salmonella alone (such as serovars) may not reliably indicate the Salmonella status of commercial swine farms. J Food Prot, 2004 Apr, 67(4), 685 - 90 Reduction of Escherichia coli O157:H7 and Salmonella enterica serovar Enteritidis in chicken manure by larvae of the black soldier fly; Erickson MC et al.; Green fluorescent protein-labeled Escherichia coli O157:H7 and Salmonella enterica serovar Enteritidis were inoculated at 10(7) CFU/g into cow, hog, or chicken manure . Ten- or 11-day-old soldier fly larvae (Hermetia illucens L.) (7 to 10 g) were added to the manure and held at 23, 27, or 32 degrees C for 3 to 6 days . Soldier fly larvae accelerated inactivation of E . coli O157:H7 in chicken manure but had no effect in cow manure and enhanced survival in hog manure . The initial pH values of the hog and chicken manure were 6.0 to 6.2 and 7.4 to 8.2, respectively, and it is surmised that these conditions affected the stability of the larval antimicrobial system . Reductions of E . coli O157:H7 populations in chicken manure by larvae were affected by storage temperature, with greater reductions in samples held for 3 days at 27 or 32 degrees C than at 23 degrees C . Pathogen inactivation in chicken manure by larvae was not affected by the indigenous microflora of chicken manure, because Salmonella Enteritidis populations in larvae-treated samples were approximately 2.5 log lower than control samples without larvae when either autoclaved or nonautoclaved chicken manure was used as the contaminated medium during 3 days of storage . Extending the storage time to 6 days, larvae again accelerated the reduction in Salmonella Enteritidis populations in chicken manure during the first 4 days of storage; however, larvae became contaminated with the pathogen . After 2 days of feeding on contaminated manure, Salmonella Enteritidis populations in larvae averaged 3.3 log CFU/g . Populations decreased to 1.9 log CFU/g after 6 days of exposure to contaminated chicken manure; however, the absence of feeding activity by the maggots in later stages of storage may be responsible for the continued presence of Salmonella Enteritidis in larvae . Transfer of contaminated larvae to fresh chicken manure restored feeding activity but led to cross-contamination of the fresh manure. J Mol Biol, 2004 Apr 30, 338(3), 463 - 7 Evidence against reciprocal recombination as the basis for tuf gene conversion in Salmonella enterica serovar Typhimurium; Arwidsson O et al.; The duplicate tuf genes on the Salmonella enterica serovar Typhimurium chromosome co-evolve by a RecA-, RecB-dependent gene conversion mechanism . Gene conversion is defined as a non-reciprocal transfer of genetic information . However, in a replicating bacterial chromosome there is a possibility that a reciprocal genetic exchange between different tuf genes sitting on sister chromosomes could result in "apparent" gene conversion . We asked whether the major mechanism of tuf gene conversion was classical or apparent . We devised a genetic selection that allowed us to isolate and examine both expected products from a reciprocal recombination event between the tuf genes . Using this selection we tested within individual cultures for a correlation in the frequency of jackpots as expected if recombination were reciprocal . We found no correlation, either in the frequency of each type of recombinant product, or in the DNA sequences of the products resulting from each recombination event . We conclude that the evidence argues in favor of a non-reciprocal gene conversion mechanism as the basis for tuf gene co-evolution. Sci Total Environ, 2004 May 25, 324(1-3), 79 - 90 The Salmonella mutagenicity of urban airborne particulate matter (PM2.5) from eight sites of the Emilia-Romagna regional monitoring network (Italy); Cassoni F et al.; ARPA Emilia Romagna created, in 1997, a regional network for the continuous monitoring of the mutagenicity of PM(2.5) by short-term mutagenicity bioassays to guarantee a constant surveillance on the entire regional territory . The continuous monitoring of the PM mutagenicity provides essential information for a better understanding of the impact of air pollution on the health of the population, and allows one to better judge the efficiency of national and local efforts for urban air quality improvement (use of "green" petrol and ecodiesel, days during which traffic is prohibited, etc.) . This article presents the results relating to the Network's activity between September 2000 and December 2002, on PM(2.5) fraction . The organic extracts of PM(2.5) were tested for mutagenicity using Salmonella tester strains TA98 and TA100 with and without metabolic activation (S9) . The data obtained on the genotoxicity of air particulate extracts have revealed a constant presence of mutagenic substances adsorbed on particulate matter-with a prevalence of direct-acting mutagens than of promutagens-in a typical seasonal trend featuring higher levels in autumn-winter and lower in warmer periods of the year . In this work the evolution of PM(2.5) mutagenicity was compared with the particles, carbon monoxide (CO) and nitrogen dioxide (NO(2)) concentrations (monthly average); these comparisons revealed a quite good level of agreement on a local basis. Int J Antimicrob Agents, 2004 Apr, 23(4), 332 - 6 Predictive value of nalidixic acid resistance for detecting salmonellae with decreased ciprofloxacin susceptibility; Albayrak F et al.; Seventy-three Salmonella isolates classified as ciprofloxacin susceptible when using the criteria of the National Committee for Clinical Laboratory Standards were studied for nalidixic acid (NA) resistance . The aim of the study was to determine the predictive value of nalidixic acid resistance in screening for decreased ciprofloxacin susceptibility . We observed that isolates with decreased ciprofloxacin susceptibility were all resistant to nalidixic acid . Identification of nalidixic acid resistance by the disk diffusion method provided 100% sensitivity and a specificity of 98.4% in strains with minimum inhibitory concentrations (MICs) >0.008 mg/l. Emerg Infect Dis, 2004 Jan, 10(1), 131 - 6 Salmonella serovars from humans and other sources in Thailand, 1993-2002; Bangtrakulnonth A et al.; We serotyped 44,087 Salmonella isolates from humans and 26,148 from other sources from 1993 through 2002 . The most common serovar causing human salmonellosis in Thailand was Salmonella enterica Weltevreden . Serovars causing human infections in Thailand differ from those in other countries and seem to be related to Salmonella serovars in different food products and reservoirs. Emerg Infect Dis, 2004 Jan, 10(1), 60 - 8 Ciprofloxacin-resistant Salmonella enterica Typhimurium and Choleraesuis from pigs to humans, Taiwan; Hsueh PR et al.; We evaluated the disk susceptibility data of 671 nontyphoid Salmonella isolates collected from different parts of Taiwan from March 2001 to August 2001 and 1,261 nontyphoid Salmonella isolates from the National Taiwan University Hospital from 1996 to 2001 . Overall, ciprofloxacin resistance was found in 2.7% (18/671) of all nontyphoid Salmonella isolates, in 1.4% (5/347) of Salmonella enterica serotype Typhimurium and in 7.5% (8/107) in S . enterica serotype Choleraesuis nationwide . MICs of six newer fluoroquinolones were determined for the following isolates: 37 isolates of ciprofloxacin-resistant (human) S . Typhimurium (N = 26) and Choleraesuis (N = 11), 10 isolates of ciprofloxacin-susceptible (MIC <1 mg/mL) (human) isolates of these two serotypes, and 15 swine isolates from S . Choleraesuis (N = 13) and Typhmurium (N = 2) with reduced susceptibility to ciprofloxacin (MIC >0.12 microg/mL) . Sequence analysis of the gryA, gyrB, parC, parE, and acrR genes, ciprofloxacin accumulation, and genotypes generated by pulsed-field gel electrophoresis with three restriction enzymes (SpeI, XbaI, and BlnI) were performed . All 26 S . Typhimurium isolates from humans and pigs belonged to genotype I . For S . Choleraesuis isolates, 91% (10/11) of human isolates and 54% (7/13) of swine isolates belonged to genotype B . These two genotypes isolates from humans all exhibited a high-level of resistance to ciprofloxacin (MIC 16-64 mg/mL) . They had two-base substitutions in the gyrA gene at codons 83 (Ser83Phe) and 87 (Asp87Gly or Asp87Asn) and in the parC gene at codon 80 (Ser80Arg, Ser80Ile, or Ser84Lys) . Our investigation documented that not only did these two S . enterica isolates have a high prevalence of ciprofloxacin resistance nationwide but also that some closely related ciprofloxacin-resistant strains are disseminated from pigs to humans. Emerg Infect Dis, 2004 Jan, 10(1), 1 - 7 Salmonella enteritidis infections, United States, 1985-1999; Patrick ME et al.; Salmonella enterica serotype Enteritidis emerged as an important illness during the 1980s . Investigations showed that consumption of undercooked eggs was the major risk factor for disease, and a variety of prevention and control efforts were initiated during the 1990s . We describe sporadic infections and outbreaks of S . Enteritidis in the United States from 1985 through 1999 and discuss prevention and control efforts . After reaching a high of 3.9 per 100,000 population in 1995, S . Enteritidis infections declined to 1.98 per 100,000 in 1999 . While the total number of outbreaks decreased by half, those in the western states tripled . Outbreaks of S . Enteritidis phage type 4 infections accounted for 49% of outbreaks in 1999 . Outbreak-associated deaths in health facilities decreased from 14 in 1987 to 0 in 1999 . Overall, rates of sporadic S . Enteritidis infection, outbreaks, and deaths have declined dramatically . For further reductions, control measures should continue to be applied along the entire farm-to-table continuum. J Appl Microbiol, 2004, 96(5), 1002 - 12 In vitro activity of nitrofuran derivatives on growth and morphology of Salmonella enterica serotype Enteritidis; Chadfield MS et al.; AIMS: To evaluate the effect of nitrofuran derivatives furazolidone (Fz) and nitrofurantoin (Nf) on Salmonella enterica serovar Enteritidis PT4 in vitro, with regard to cell growth, morphology and ultrastructure . METHODS AND RESULTS: The effects of Fz on the growth rates of Fz resistant (FzR) and sensitive (FzS) strains were assessed by viable counts . Over 24 h incubation, concentrations of <1 microg ml(-1) of Fz were bacteriostatic to the FzS strain . The FzR strain tolerated concentrations up to 16 microg ml(-1) before cell numbers diminished over the same time period . The effect on the growth rate of the FzS strain after 1 h exposure to supra-inhibitory concentrations of Fz, gave a maximum response at 32X minimum inhibitory concentration (MIC) of 4.5 h . Effects on the ultrastructure of bacterial cells by scanning electron and transmission microscopy, and DNA-specific staining with DAPI of the FzS strain exposed to nitrofurans were studied . Abnormalities such as extensive filamentation with sparse, sporadic nucleotide distribution and evidence of extrusions in the cell envelope in the form of blebs were evident . CONCLUSIONS: Nitrofurans exert their bactericidal effect on Salmonella by inducing extensive structural alteration after exposure at sub- or suprainhibitory concentrations, involving inhibition of cell division because of the activated drug causing an intercalating type of binding in DNA . SIGNIFICANCE AND IMPACT OF THE STUDY: These results demonstrate the in vitro activity of the nitrofuran derivatives, furazolidone and nitrofurantoin on Salmonella, defining the pharmacodynamics and physical nature of their action as therapeutic agents. Avian Dis, 2004 Jan-Mar, 48(1), 183 - 8 The effect of killed Salmonella enteritidis vaccine prior to induced molting on the shedding of s . enteritidis in laying hens; Nakamura M et al.; Effects of administering killed Salmonella enterica serovar enteritidis (SE) vaccines to laying hens prior to induced molting on egg production and on shedding of SE were investigated . Forty hens were vaccinated with one of two SE vaccines available commercially in the United States and Japan . Twenty-five days after vaccination, feed was withdrawn for 2 wk from 20 vaccinated plus 10 unvaccinated hens to induce molt . Four days after molt induction, all hens were challenged with a dose of 2.4 X 10(9) of SE . For the 25 days following administration of the SE bacterins, egg production in vaccinated hens showed approximately a 15% decrease . After molt induction, egg production in molted hens ceased and then returned to normal levels 8 or 9 wk postvaccination . Through the 3-mo experimental period, the decreases in numbers of eggs laid in the unvaccinated/molted group and two vaccinated/molted groups were 225 (26.2%), 245 (28.4%), and 274 (31.9%), respectively, compared with 860 in the unvaccinated/unmolted group . There was no significant difference in egg lay at the P < 0.05 level among the former three groups . Hens in the vaccinated/molted groups shed about two logs less SE than hens in the unvaccinated/molted group 3 14 days postchallenge (P < 0.05 or 0.01) . These results indicate that vaccination prior to induced molting might be effective in preventing the exacerbation of SE problems within flocks in which the potential for SE contamination may exist. Avian Dis, 2004 Jan-Mar, 48(1), 160 - 6 Effects of prior coinfection with different Salmonella serovars on the progression of a Salmonella enterica serovar enteritidis infection in hens undergoing induced molt; Holt PS et al.; Four trials were conducted to evaluate whether prior infection with Salmonella enterica serovar typhimurium (S . typhimurium) or Salmonella enterica serovar muenchen (S . muenchen) would modify the severity or the transmission of Salmonella enterica serovar enteritidis (S . enteritidis) challenge in hens undergoing molt via feed withdrawal . Hens were separated into two groups where one group received a prior S . typhimurium or S . muenchen infection, whereas the other group remained untreated until S . enteritidis challenge . In trials 1 and 2, one group of hens was infected with S . typhimurium 5 days prior to feed withdrawal . Both groups of hens were then challenged with S . enteritidis on day 4 post feed withdrawal . In trials 3 and 4, one group of hens received S . typhimurium or S . muenchen, respectively, 1 day after feed was withdrawn . Transmission of S . enteritidis was evaluated by challenging the center hen in rows of 11 hens per row with S . enteritidis at 4 days post feed withdrawal and following the progression of the S . enteritidis down the row of hens over time . In trials 1 and 2, where hens received S . typhimurium 5 days prior to feed withdrawal, shedding of the S . enteritidis challenge was significantly reduced in hens on day 10 postchallenge in trial 1 and on days 3 and 10 postchallenge in trial 2 compared with the hens subjected only to the molt procedure . Significantly fewer S . enteritidis were recovered in livers and spleens at day 9 postchallenge in trial 2 from hens receiving the prior S . typhimurium infection . In trial 3, where hens received S . typhimurium 1 day after feed withdrawal, S . enteritidis transmission was significantly reduced in these hens on days 3, 10, and 24 postchallenge . In trial 4, similar in methodology to trial 3 except that, rather than S . typhimurium, hens received S . muenchen, a Salmonella organism totally lacking any antigen cross-reactive with S . enteritidis, S . enteritidis transmission was significantly reduced on days 3, 10, 17, and 24 postchallenge, suggesting that factors other than specific immunity were involved in the observed resistance to S . enteritidis infection . These results indicate that prior infection of a flock with a non-S . enteritidis paratyphoid Salmonella can reduce S . enteritidis problems that may occur during a molt. Avian Dis, 2004 Jan-Mar, 48(1), 148 - 54 Detection of airborne Salmonella enteritidis in the environment of experimentally infected laying hens by an electrostatic sampling device; Gast RK et al.; Bacteriologic culturing of environmental samples taken from sources such as manure pits and egg belts has been the principal screening tool in programs for identifying commercial laying flocks that have been exposed to Salmonella enteritidis and are thus at risk to produce contaminated eggs . Because airborne dust and aerosols can carry bacteria, air sampling offers a potentially efficient and inexpensive alternative for detecting S . enteritidis in poultry house environments . In the present study, an electrostatic air sampling device was applied to detect S . enteritidis in a room containing experimentally infected, caged laying hens . After oral inoculation of hens with a phage type 13a S . enteritidis strain, air samples were collected onto agar plates with the electrostatic sampling device, an impaction air sampler, and by passive exposure to the settling of aerosols and dust . Even though the floor of the room was cleaned once per week (removing most manure, dust, and feathers), air samples were positive for S . enteritidis for up to 4 wk postinoculation . On the basis of both the number of S . enteritidis colonies observed on incubated agar plates and the frequency of positive results, the efficiency of the electrostatic device was significantly greater than that of the passive exposure plates (especially at short collection intervals) and was similar to that of the far more expensive impaction sampler . The electrostatic device, used for a 3-hr sampling interval, detected airborne S . enteritidis on 75% of agar plates over the 4 wk of the study. Euro Surveill . 2004 Mar 1;9(3) {Epub ahead of print} Foodborne outbreaks in northern Portugal, 2002; Correia AM et al.; In October 2001, foodborne outbreaks (FBO) were included in the Portuguese alert and response surveillance system . Accordingly, the northern regional health authority (Delegado Regional de Saude do Norte - DRSN) began a surveillance programme of foodborne outbreaks . This report is a brief description of data generated from this programme in 2002 . For each foodborne outbreak the local health authority (Delegado de Saude Concelhio - DSC) produced a written report . Fifty-nine percent of the 27 FBOs studied by DSCs during 2002 were reported within 72 hours after the date of onset . Five hundred and seventy seven people became ill, 9.6% of the patients were admitted to hospital, and no deaths were reported . The aetiological agent was identified from patients in 63% of FBOs, and in food items in 18.5% of the situations . Salmonella enterica was responsible for 73.7% of the outbreaks in which the agent was laboratory confirmed . Meals implicated in the outbreak were mainly prepared in restaurants and private homes (75.0% of FBO) . Inadequate processing, preparing or handling of foods were the contributing factors more often reported by the DSC . We believe that epidemiological surveillance and control of FBO must be reinforced in Portugal as part of a wider strategy to promote food safety. Vet Res Commun, 2004 Apr, 28(3), 179 - 89 Effect of drinking-water administration of experimental chlorate ion preparations on Salmonella enterica serovar Typhimurium colonization in weaned and finished pigs; Anderson RC et al.; Foodborne disease caused by Salmonella is of public health and economic significance . In order to assess the practical effectiveness of a new intervention strategy, experimental chlorate preparations (ECP) were administered via the drinking water to weaned and finished pigs that had been orally challenged the previous day with 10(9)-10(10) colony-forming units of Salmonella serovar Typhimurium . After 24 or 36 h ad libitum access to 0X, 1X or 2X ECP treatment (where X is the concentration estimated to deliver a minimal daily effective dose), the pigs were euthanized and gut contents and lymph tissue collected at necropsy were cultured for the challenge Salmonella . Drinking water administration of ECP effectively reduced (p < 0.05) caecal Salmonella concentrations and, with the weaned pigs, tended (p < or = 0.10) to reduce rectal Salmonella concentrations . No negative effects of ECP treatment on water intake and animal wellbeing were observed and only marginal effects on gut fermentation characteristics occurred . The bactericidal effect of administering ECP in drinking water was relatively rapid, with reductions in caecal Salmonella concentrations occurring within 24 h . These results suggest that ECP administered to pigs just days before slaughter may reduce gut concentrations of Salmonella; however, the impacts of such reductions on slaughter hygiene have yet to be determined. Acta Vet Scand, 2003, 44(3-4), 181 - 97 Salmonella isolated from animals and feed production in Sweden between 1993 and 1997; Boqvist S et al.; This paper presents Salmonella data from animals, feedstuffs and feed mills in Sweden between 1993 and 1997 . During that period, 555 isolates were recorded from animals, representing 87 serotypes . Ofthose, 30 serotypes were found in animals in Sweden for the first time . The majority of all isolates from animals were S . Typhimurium (n = 91), followed by S . Dublin (n = 82) . There were 115 isolates from cattle, 21 from broilers, 56 from layers and 18 from swine . The majority of these isolates were from outbreaks, although some were isolated at the surveillance at slaughterhouses . The number of isolates from the feed industry was similar to that of the previous 5-year period . Most of those findings were from dust and scrapings from feed mills, in accordance with the HACCP programme in the feed control programme . It can be concluded that the occurrence of Salmonella in animals and in the feed production in Sweden remained favourable during 1993-97. Microbiology, 2004 Apr, 150(Pt 4), 1073 - 8 A DNA adenine methylase mutant of Shigella flexneri shows no significant attenuation of virulence; Honma Y et al.; Mutants of Salmonella defective in DNA adenine methylase (dam) have been reported to be attenuated for virulence and to provide protective immunity when used as vaccine strains . To determine whether these observations could be extended to Shigella, a dam mutant of Shigella flexneri 2a was characterized and examined for the role of dam in pathogenesis . The Shigella dam mutant showed some unique characteristics; however, it retained virulence in vivo as well as in vitro . The mutant invaded cultured L2 monolayer cells as efficiently as the wild-type parent, but its intracellular growth was suppressed up to 7 h post-invasion . Furthermore, the invading dam mutant formed smaller plaques in cell monolayers compared to the parent strain . However, the mutant produced keratoconjunctivitis in the Sereny test in guinea pigs only slightly more slowly than the wild-type . While the effect of the dam mutation on virulence was modest, the rate of spontaneous mutation in the dam mutant was 1000-fold greater compared with the wild-type . The virulence and high mutability displayed by the dam mutant of Sh . flexneri suggest that a general anti-bacterial pathogen vaccine strategy based on mutations in dam needs to be re-evaluated. Microbiology, 2004 Apr, 150(Pt 4), 1063 - 71 Flagella and curli fimbriae are important for the growth of Salmonella enterica serovars in hen eggs; Cogan TA et al.; Salmonella enterica serovar Enteritidis is unable to multiply in the albumen of fresh eggs and must gain access to the yolk contents in order to multiply to a high level (>10(6) c.f.u . per ml egg contents) . As human Salmonella infections resulting from the consumption of infected eggs more frequently involve serovar Enteritidis phage type (PT) 4 than other serovars or PTs, a number of isolates of various S . enterica serovars were examined for their ability to multiply to a high level in eggs over a period of 8 days storage at 20 degrees C . Their behaviour was compared to that of a range of defined fimbrial and flagella mutants of S . Enteritidis . Strains that did not express flagella were unable to multiply in eggs, and those deficient for curli fimbriae, including strains of S . Enteritidis PT6, displayed high-level growth in significantly fewer eggs than those able to express curli . Most S . Enteritidis strains multiplied to a high level in between 5 and 10 % of eggs during 8 days storage . One PT4 strain, though, showed high levels of growth in more than 25 % of eggs over this period, significantly higher than the other PTs or the two other isolates of PT4 tested . This ability may be important for the association of PT4 infection with the consumption of eggs. Arch Inst Pasteur Tunis, 2002, 79(1-4), 35 - 41 {Salmonella identification after incubation in the soil}; Bakhrouf A et al.; We have tried to study the fate of Salmonella strains in soil . We have looked at their biochemical modifications during their evolution to dormant state and during their reviviscence . The beta galactosidase which is negative in the parent strain became positive after two weeks of cells starvation in soil . Stressed cells became able to produce acetoin . Some stressed cells did not produce the lysine decarboxylase, which is positive in parent cells . These modifications are reversible and depend on cultural conditions . Incubation of stressed cells in nutrient broth for more than four weeks helped them to reverse to normal forms . Simultaneous search for atypical Salmonella was done in dissect sludge of a domestic wastewater treatment plant and in soil irrigated with treated water . Atypical strains of Salmonella are found . We have seen that, after incubation in nutrient broth for more than four weeks, atypical strains characters evolved generally to their parental characters . All modifications of Salmonella in soil samples can make their identification very difficult and perhaps impossible. Proc Natl Acad Sci U S A, 2004 Apr 20, 101(16), 6110 - 5 Epub 2004 Apr 07. Intestinal villous M cells: an antigen entry site in the mucosal epithelium; Jang MH et al.; M cells located in the follicle-associated epithelium of Peyer's patches (PP) are shown to be the principal sites for the sampling of gut luminal antigens . Thus, PP have long been considered the gatekeepers of the mucosal immune system . Here, we report a distinct gateway for the uptake of gut bacteria: clusters of non-follicle-associated epithelium-associated Ulex europaeus agglutinin (UEA)-1(+) cells, which we have designated intestinal villous M cells . Interestingly, villous M cells are developed in various PP {or gut-associated lymphoid tissue (GALT)}-null mice, such as in utero lymphotoxin beta receptor (LTbetaR)-Ig-treated, lymphotoxin alpha (LTalpha)(-/-), tumor necrosis factor/LTalpha(-/-), and inhibition of differentiation 2 (Id2)(-/-) mice . Intestinal villous M cells have been observed to take up GFP-expressing Salmonella, Yersinia, and Escherichia coli-expressing invasin, as well as gut bacterial antigen for subsequent induction of antigen-specific immune responses . Thus, the identified villous M cells could be an alternative and PP-independent gateway for the induction of antigen-specific immune responses by means of the mucosal compartment. J Clin Microbiol, 2004 Apr, 42(4), 1807 - 12 Molecular characterization of a prophage of Salmonella enterica serotype Typhimurium DT104; Tanaka K et al.; Isolates of the Salmonella enterica serotype Typhimurium definitive phage type (DT104) were found to contain the same prophage (designated phage ST104) . The complete sequence of the DNA genome of prophage ST104 was determined . The entire DNA sequence consisted of 41,391 bp, including 64 open reading frames, and exhibited high similarity to P22 and to phage type conversion phage ST64T. J Clin Microbiol, 2004 Apr, 42(4), 1734 - 8 Development of a multiplex PCR technique for detection and epidemiological typing of salmonella in human clinical samples; Alvarez J et al.; We have developed a multiplex PCR assay for Salmonella detection and epidemiological typing . Six sets of primers were designed to detect the major Salmonella serotypes and phage types in Spain . An internal amplification control was designed in order to detect PCR inhibition . The different amplification profiles obtained allowed us to detect Salmonella bacteria and to distinguish the clinically prevalent Salmonella enterica serotypes Enteritidis, Typhimurium and subspecies I serotype 4,5,12:i:- . Using this method, we could detect a specific band for DT104 and U302 phage types in Salmonella serotype Typhimurium . Salmonella enterica serotype Hadar and other C2 serogroup strains showed two specific band profiles . In the validation stage, the assay was reproducible for all serotypes studied, apart from some C2 serogroup strains . When the technique was applied to clinical stool specimens, the prevalent serotypes Enteritidis and Typhimurium were detected with a sensitivity of 93%, specificity of 100%, and efficiency of 98% . Also, a low PCR inhibition rate (8%) was obtained . The overall agreement of the multiplex PCR with conventional culture-based techniques was 95% for Salmonella typing using Cohen's kappa index. J Clin Microbiol, 2004 Apr, 42(4), 1477 - 82 Characterization of multidrug-resistant typhoid outbreaks in Kenya; Kariuki S et al.; We characterized by antibiotic susceptibility, plasmid analysis, incompatibility grouping, and pulsed-field gel electrophoresis (PFGE) of XbaI- and SpeI-digested DNA 102 Salmonella enterica serovar Typhi (serovar Typhi) isolated from recent outbreaks of typhoid in three different parts of Kenya . Only 13.7% were fully susceptible, whereas another 82.4% were resistant to each of the five commonly available drugs: ampicillin, chloramphenicol, and tetracycline (MICs of >256 microg/ml); streptomycin (MIC, >1,024 microg/ml); and cotrimoxazole (MIC of >32 microg/ml) . Resistance to these antibiotics was encoded on a 110-kb self-transferable plasmid of IncHI1 incompatibility group . The MICs of nalidixic acid (MIC, 8 to 16 micro g/ml) and ciprofloxacin (MIC of 0.25 to 0.38 micro g/ml) for 41.7% of the 102 serovar Typhi isolates were 5- and 10-fold higher, respectively, than for sensitive strains . Amplification by PCR and sequencing of the genes coding for gyrase (gyrA and gyrB) and topoisomerase IV (parE and parC) within the quinolone resistance-determining region revealed that the increase in the MICs of the quinolones had not resulted from any significant mutation . Analysis of genomic DNA from both antimicrobial agent-sensitive and multidrug-resistant serovar Typhi by PFGE identified two distinct subtypes that were in circulation in the three different parts of Kenya . As the prevalence of multidrug-resistant serovar Typhi increases, newer, more expensive, and less readily available antimicrobial agents will be required for the treatment of typhoid in Kenya. Proc Natl Acad Sci U S A, 2004 Mar 30, 101(13), 4614 - 9 Salmonella typhi encodes a functional cytolethal distending toxin that is delivered into host cells by a bacterial-internalization pathway; Haghjoo E et al.; Many bacterial pathogens encode the cytolethal distending toxin (CDT), which causes host cells to arrest during their cell cycle by inflicting DNA damage . CDT is composed of three proteins, CdtA, CdtB, and CdtC . CdtB is the enzymatically active or A subunit, which possesses DNase I-like activity, whereas CdtA and CdtC function as heteromeric B subunits that mediate the delivery of CdtB into host cells . We show here that Salmonella enterica serovar Typhi encodes CDT activity, which depends on the function of a CdtB homologous protein . Remarkably, S . enterica serovar Typhi does not encode apparent homologs of CdtA or CdtC . Instead, we found that toxicity, as well as cdtB expression, requires bacterial internalization into host cells . We propose a pathway of toxin delivery in which bacterial internalization relieves the requirement for the functional equivalent of the B subunit of the CDT toxin. J Basic Microbiol, 2004, 44(2), 137 - 46 Adaptive acid tolerance response in Salmonella enterica serovar Typhimurium and Salmonella enterica serovar Typhi; Tiwari RP et al.; The survival of bacteria in various environments depends on a number of protective responses including acid tolerance response (ATR) . In this study, ATR phenomenon was compared in Salmonella enterica serovar Typhi 6 and Salmonella enterica serovar Typhimurium 98 under different culture conditions . Survival of the adapted culture (pre-acid shocked to pH 5.5) was significantly better (p < 0.05) as compared to control, unadapted culture after acid shock at pH 3.3 . However, the ATR varied with the serovar, incubation temperature and the growth medium used (all p-values < 0.05) . S . Typhi 6 failed to grow in pH 3.3 at 45 degrees C . The addition of tetracycline or chloramphenicol (1.0 microg ml(-1)) to adapted cultures during or after acid shock (pH 3.3) had no effect on ATR expression . In S . Typhimurium 98, growth was increased by 10% or greater in adapted culture (when grown at pH 3.3) as compared to growth observed with an unadapted culture (when grown at pH 7.3) on transfer to fresh growth medium at pH 7.3 . A poor ATR observed in non-growing S . Typhimurium 98 suspensions clearly showed that ATR is an energy-consuming process . Storage of S . Typhimurium 98 cultures in pH 4.5 nutrient broth at 4 degrees C demonstrated that prolonged exposure to acidic conditions is more detrimental in comparison to the cultures stored at pH 7.3 at this temperature . Prev Vet Med, 2004 Apr 16, 62(4), 253 - 66 Herd-level risk factors for subclinical Salmonella infection in European finishing-pig herds; Lo Fo Wong DM et al.; Our objective was to find herd factors associated with pigs testing seropositive for Salmonella . Data were collected from 359 finishing-pig herds in Germany, Denmark, Greece, The Netherlands and Sweden, between 1996 and 1998 . Pigs fed non-pelleted feed (dry or wet) had 2- and 2.5-times lower odds of seropositivity, compared to pigs fed pelleted feed . The protective effect of non-pelleted feed over pelleted feed may be ascribed to the structure and composition . Also, pigs that were given whey (to drink or as the liquid part of the diet) had 2.6-times lower odds to test seropositive than pigs not getting whey . Pigs produced in batches in herds with hygienic-lock facilities had >3-times lower odds for testing seropositive compared to pigs in herds where only one or neither factor was present . In herds where the caretaker(s) washed hands consistently before tending to the animals, pigs had 1.5-times lower odds of seropositivity than pigs in herds where the caretaker did not . Pigs which were able to have snout contact with pigs in neighbouring pens (because pen separations were either open or too low) had 1.7-times higher odds to test seropositive compared to pigs for which such contact was prevented . Pigs in herds recruiting from more than three supplier herds had three-times higher odds to test seropositive than pigs in herds which breed their own replacement stock or recruit from a maximum of three supplier herds. J Immunol, 2004 Apr 15, 172(8), 5056 - 62 Human intestinal microvascular endothelial cells express Toll-like receptor 5: a binding partner for bacterial flagellin; Maaser C et al.; Bacterial flagellin has recently been identified as a ligand for Toll-like receptor 5 (TLR5) . Human sites known to specifically express TLR5 include macrophages and gastric and intestinal epithelium . Because infection of intestinal epithelial cells with Salmonella leads to an active transport of flagellin to the subepithelial compartment in proximity to microvessels, we hypothesized that human intestinal endothelial cells functionally express TLR5, thus enabling an active inflammatory response upon binding of translocated flagellin . Endothelial expression of TLR5 in human macro- and microvascular endothelial cells was examined by RT-PCR, immunoblot analysis, and immunofluorescence . Endothelial expression of TLR5 in vivo was verified by immunohistochemistry . Endothelial modulation of ICAM-1 expression was quantitated using flow cytometry, and leukocyte transmigration in vitro was assessed by an endothelial transmigration assay . Epithelial-endothelial cellular interactions upon infection with viable Salmonella were investigated using a coculture system in vitro . We found that Salmonella-infected intestinal epithelial cells induce endothelial ICAM-1 expression in cocultured human endothelial cells . Both macro- (HUVEC) and microvascular endothelial cells derived from human skin (human dermal microvascular endothelial cell 1) and human colon (human intestinal microvascular endothelial cells) were found to express high constitutive amounts of TLR5 mRNA and protein . These findings were paralleled by strong immunoreactivity for TLR5 of normal human colonic microvessels in vivo . Furthermore, incubation of human dermal microvascular endothelial cells with flagellin from clinical isolates of Escherichia and Salmonella strains led to a marked up-regulation of ICAM-1, as well as to an enhanced leukocyte transendothelial cell migration . These results suggest that endothelially expressed TLR5 might play a previously unrecognized role in the innate immune response toward bacterial Ags. Appl Environ Microbiol, 2004 Apr, 70(4), 2497 - 502 Fate of Salmonella enterica serovar Typhimurium on carrots and radishes grown in fields treated with contaminated manure composts or irrigation water; Islam M et al.; Three different types of compost, PM-5 (poultry manure compost), 338 (dairy cattle manure compost), and NVIRO-4 (alkaline-pH-stabilized dairy cattle manure compost), and irrigation water were inoculated with an avirulent strain of Salmonella enterica serovar Typhimurium at 10(7) CFU g(-1) and 10(5) CFU ml(-1), respectively, to determine the persistence of salmonellae in soils containing these composts, in irrigation water, and also on carrots and radishes grown in these contaminated soils . A split-plot block design plan was used for each crop, with five treatments (one without compost, three with each of the three composts, and one without compost but with contaminated water applied) and five replicates for a total of 25 plots for each crop, with each plot measuring 1.8 x 4.6 m . Salmonellae persisted for an extended period of time, with the bacteria surviving in soil samples for 203 to 231 days, and were detected after seeds were sown for 84 and 203 days on radishes and carrots, respectively . Salmonella survival was greatest in soil amended with poultry compost and least in soil containing alkaline-pH-stabilized dairy cattle manure compost . Survival profiles of Salmonella on vegetables and soil samples contaminated by irrigation water were similar to those observed when contamination occurred through compost . Hence, both contaminated manure compost and irrigation water can play an important role in contaminating soil and root vegetables with salmonellae for several months. Appl Environ Microbiol, 2004 Apr, 70(4), 2089 - 97 Influence of environmental factors and human activity on the presence of Salmonella serovars in a marine environment; Martinez-Urtaza J et al.; The temporal and spatial distribution of Salmonella contamination in the coastal waters of Galicia (northwestern Spain) relative to contamination events with different environmental factors (temperature, wind, hours of sunlight, rainfall, and river flow) were investigated over a 4-year period . Salmonellae were isolated from 127 of 5,384 samples of molluscs and seawater (2.4%), and no significant differences (P < 0.05) between isolates obtained in different years were observed . The incidence of salmonellae was significantly higher in water column samples (2.9%) than in those taken from the marine benthos (0.7%) . Of the 127 strains of Salmonella isolated, 20 different serovars were identified . Salmonella enterica serovar Senftenberg was the predominant serovar, being represented by 54 isolates (42.5%), followed by serovar Typhimurium (19 isolates {15%}) and serovar Agona (12 isolates {9.4%}) . Serovar Senftenberg was detected at specific points on the coast and could not be related to any of the environmental parameters analyzed . All serovars except Salmonella serovar Senftenberg were found principally in the southern coastal areas close to the mouths of rivers, and their incidence was associated with high southwestern wind and rainfall . Using multiple logistic regression analysis models, the prevalence of salmonellae was best explained by environmental parameters on the day prior to sampling . Understanding this relationship may be useful for the control of molluscan shellfish harvests, with wind and rainfall serving as triggers for closure. Mol Microbiol, 2004 Apr, 52(2), 345 - 55 The ShdA adhesin binds to the cationic cradle of the fibronectin 13FnIII repeat module: evidence for molecular mimicry of heparin binding; Kingsley RA et al.; Introduction of Salmonella enterica serotype Typhimurium into food products results from its ability to persist in the intestine of healthy livestock by mechanisms that are poorly understood . The non-fimbrial adhesin ShdA is a fibronectin binding protein required for persistent intestinal carriage of S . Typhimurium . We further investigated the molecular mechanism of ShdA-mediated intestinal persistence by determining the binding-site of this receptor in fibronectin . Analysis of ShdA binding to fibronectin proteolytic fragments and to recombinant fibronectin fusion proteins identified the (13)FnIII repeat module of the Hep-2 domain as the primary binding site for this adhesin . The (13)FnIII repeat module of fibronectin contains a cationic cradle formed by six basic residues (R6, R7, R9, R23, K25 and R54) that is a high affinity heparin-binding site conserved among fibronectin sequences from frogs to man . Binding of ShdA to the (13)FnIII repeat module of fibronectin and to a second extracellular matrix protein, Collagen I, could be inhibited by heparin . Furthermore, binding of ShdA to the Hep-2 domain was sensitive to the ionic buffer strength, suggesting that binding involved ionic interactions . We therefore determined whether amino acid substitutions of basic residues in the cationic cradle of the Hep-2 domain that inhibit heparin binding also abrogate binding of ShdA . Combined substitution of R6S and R7S strongly reduced ShdA binding to (13)FnIII . These data suggest that ShdA binds the Hep-2 domain of fibronectin by a mechanism that may mimic binding of the host polysaccharide heparin. Mol Microbiol, 2004 Apr, 52(2), 329 - 44 Unequal access of chromosomal regions to each other in Salmonella: probing chromosome structure with phage lambda integrase-mediated long-range rearrangements; Garcia-Russell N et al.; We have investigated the fluidity of the Salmonella chromosome architecture using the phage lambda site-specific recombination system as a probe . We determined how chromosome position affects the extent of integrase-mediated recombination between pairs of inversely oriented att sites at various loci . We also investigated the accessibility of each chromosomal att site to an extrachromosomal partner carried on a low-copy plasmid . Recombination events were assayed by semi-quantitative polymerase chain reaction of the attP product . The extent of recombination between the chromosome and the plasmid was generally higher than intrachromosomal recombination except for two loci, araA::attL and galT::attL, which gave no detectable recombination with any other locus . Based on 20 intervals, we found that chromosomal locations are not equally accessible to each other . Although multiple factors probably affect accessibility, the most important is the specific combination of the end-points used . Neither the size of the intervals nor the accessibility of individual end-points to extrachromosomal sequences is as important . These results suggest that the chromosome is not completely fluid but rather organized in some way, with barriers that limit the movement of DNA within the cell . The nature of the barriers involved in chromosomal organization remains to be determined. Environ Mol Mutagen, 2004, 43(3), 186 - 95 DNA adducts and mutagenic specificity of the ubiquitous environmental pollutant 3-nitrobenzanthrone in Muta Mouse; Arlt VM et al.; 3-nitrobenzanthrone (3-NBA) is an extremely potent mutagen in the Salmonella reversion assay and a suspected human carcinogen identified in diesel exhaust and in ambient airborne particulate matter . To evaluate the in vivo mutagenicity of 3-NBA, we analyzed the mutant frequency (MF) in the cII gene of various organs (lung, liver, kidney, bladder, colon, spleen, and testis) in lambda/lacZ transgenic mice (Muta Mouse) after intraperitoneal treatment with 3-NBA (25 mg/kg body weight injected once a week for 4 weeks) . Increases in MF were found in colon, liver, and bladder, with 7.0-, 4.8-, and 4.1-fold increases above the control value, respectively, whereas no increase in MF was found in lung, kidney, spleen, and testis . Simultaneously, induction of micronuclei in peripheral blood reticulocytes was observed . The sequence alterations in the cII gene recovered from 41 liver mutants from 3-NBA-treated mice were compared with 32 spontaneous mutants from untreated mice . Base substitution mutations predominated for both the 3-NBA-treated (80%) and the untreated (81%) groups . However, the proportion of G:C-->T:A transversions in the mutants from 3-NBA-treated mice was higher (49% vs . 6%) and the proportion of G:C-->A:T transitions was lower than those from untreated mice (10% vs . 66%) . The increase in MF in the liver was associated with strong DNA binding by 3-NBA, whereas in lung, in which there was no increase in MF, a low level of DNA binding was observed (268.0-282.7 vs . 8.8-15.9 adducts per 10(8) nucleotides) . DNA adduct patterns with multiple adduct spots, qualitatively similar to those formed in vitro after activation of 3-NBA with nitroreductases and in vivo in rats, were observed in all tissues examined . Using high-pressure liquid cochromatographic analysis, we confirmed that all major 3-NBA-DNA adducts produced in vivo in mice are derived from reductive metabolites bound to purine bases (70-80% with deoxyguanosine and 20-30% with deoxyadenosine in liver) . These results suggest that G:C-->T:A transversions induced by 3-NBA are caused by misreplication of adducted guanine residues through incorporation of adenine opposite the adduct (A-rule) . Environ Mol Mutagen, 2004, 43(3), 143 - 58 Assessment of the sensitivity of the computational programs DEREK, TOPKAT, and MCASE in the prediction of the genotoxicity of pharmaceutical molecules; Snyder RD et al.; Computational models are currently being used by regulatory agencies and within the pharmaceutical industry to predict the mutagenic potential of new chemical entities . These models rely heavily, although not exclusively, on bacterial mutagenicity data of nonpharmaceutical-type molecules as the primary knowledge base . To what extent, if any, this has limited the ability of these programs to predict genotoxicity of pharmaceuticals is not clear . In order to address this question, a panel of 394 marketed pharmaceuticals with Ames Salmonella reversion assay and other genetic toxicology findings was extracted from the 2000-2002 Physicians' Desk Reference and evaluated using MCASE, TOPKAT, and DEREK, the three most commonly used computational databases . These evaluations indicate a generally poor sensitivity of all systems for predicting Ames positivity (43.4-51.9% sensitivity) and even poorer sensitivity in prediction of other genotoxicities (e.g., in vitro cytogenetics positive; 21.3-31.9%) . As might be expected, all three programs were more highly predictive for molecules containing carcinogenicity structural alerts (i.e., the so-called Ashby alerts; 61% +/- 14% sensitivity) than for those without such alerts (12% +/- 6% sensitivity) . Taking all genotoxicity assay findings into consideration, there were 84 instances in which positive genotoxicity results could not be explained in terms of structural alerts, suggesting the possibility of alternative mechanisms of genotoxicity not relating to covalent drug-DNA interaction . These observations suggest that the current computational systems when applied in a traditional global sense do not provide sufficient predictivity of bacterial mutagenicity (and are even less accurate at predicting genotoxicity in tests other than the Salmonella reversion assay) to be of significant value in routine drug safety applications . This relative inability of all three programs to predict the genotoxicity of drugs not carrying obvious DNA-reactive moieties is discussed with respect to the nature of the drugs whose positive responses were not predicted and to expectations of improving the predictivity of these programs . Limitations are primarily a consequence of incomplete understanding of the fundamental genotoxic mechanisms of nonstructurally alerting drugs rather than inherent deficiencies in the computational programs . Irrespective of their predictive power, however, these programs are valuable repositories of structure-activity relationship mutagenicity data that can be useful in directing chemical synthesis in early drug discovery . FEMS Microbiol Lett, 2004 Apr 15, 233(2), 301 - 5 Plasmid-mediated florfenicol and ceftriaxone resistance encoded by the floR and bla(CMY-2) genes in Salmonella enterica serovars Typhimurium and Newport isolated in the United States; Doublet B et al.; Multidrug resistance plasmids carrying the bla(CMY-2) gene have been identified in Salmonella enterica serovars Typhimurium and Newport from the United States . This gene confers decreased susceptibility to ceftriaxone, and is most often found in strains with concomitant resistance to ampicillin, chloramphenicol, streptomycin, sulfamethoxazole and tetracycline . The bla(CMY-2)-carrying plasmids studied here were shown to also carry the florfenicol resistance gene, floR, on a genetic structure previously identified in Escherichia coli plasmids in Europe . These data indicate that the use of different antimicrobial agents, including phenicols, may serve to maintain multidrug resistance plasmids on which extended-spectrum cephalosporin resistance determinants co-exist with other resistance genes in Salmonella. Epidemiol Infect, 2004 Apr, 132(2), 273 - 81 Salmonella enterica serotype Javiana infections associated with amphibian contact, Mississippi, 2001; Srikantiah P et al.; Salmonella Javiana is a Salmonella serotype that is restricted geographically in the United States to the Southeast . During the summer of 2001, the number of reported S . Javiana infections in Mississippi increased sevenfold . To identify sources of infection, we conducted a case-control study, defining a case as an infection with S . Javiana between August and September in a Mississippi resident . We enrolled 55 cases and 109 controls . Thirty (55%) case patients reported exposure to amphibians, defined as owning, touching, or seeing an amphibian on one's property, compared with 30 (29%) controls (matched odds ratio 2.8, P=0.006) . Contact with amphibians and their environments may be a risk factor for human infection with S . Javiana . The geographic pattern of S . Javiana infections in the United States mimics the distribution of certain amphibian species in the Southeast . Public health officials should consider amphibians as potential sources of salmonellosis, and promote hand washing after contact with amphibians. Epidemiol Infect, 2004 Apr, 132(2), 253 - 61 Molecular epidemiology and population genetics of Salmonella subspecies diarizonae in sheep in Norway and Sweden; Alvseike O et al.; Fifty-four isolates of Salmonella enterica subsp . diarizonae (IIIb) in Norway, Sweden, England, the United States, France and Australia were characterized by pulsed-field gel electrophoresis (PFGE) . This study focuses on serovar 61:k:1,5,(7) {S . IIIb 61:k:1,5,(7)} isolated from sheep . Digestion of the bacterial DNA with restriction enzyme XhaI yielded 15 distinct PFGE profiles comprising 12-16 fragments in the range 48.5-630.5 kbp . Four different profiles were identified in Norwegian sheep isolates and a single profile in Swedish isolates . The spatial and temporal distribution of profiles is discussed. Epidemiol Infect, 2004 Apr, 132(2), 245 - 51 Antibiotic resistance in Salmonella enterica serotypes Typhimurium, Enteritidis and Infantis from human infections, foodstuffs and farm animals in Italy; Busani L et al.; The antimicrobial susceptibility of isolates of Salmonella enterica serotypes Typhimurium, Enteritidis, and Infantis isolated from humans, foodstuffs and farm animals in Italy between 1999 and 2001 was examined . All the isolates were susceptible to cefotaxime and ciprofloxacin, but high rates of resistance were observed for several other drugs, especially for S . Typhimurium . The rates of resistance and multiresistance were generally higher among animal and food isolates than in human strains; conversely, no significant difference was observed between animal and food isolates . Among S . Typhimurium, multiresistance was more common in bovine, poultry and rabbit strains than in swine isolates, and was rare in strains from pigeon . Resistance to trimethoprim sulphamethoxazole was mainly found in isolates of swine and human origin . This study confirms the role of livestock as a reservoir of drug-resistant Salmonella spp . and underlines the need for integrated surveillance systems of antibiotic resistance that consider isolates not only from human disease but also from the animal reservoirs and the food vehicles. Epidemiol Infect, 2004 Apr, 132(2), 239 - 43 Bacteria-host interactions of Salmonella Paratyphi B dT+ in poultry; Van Immerseel F et al.; In recent years, a dramatic increase in incidence of the dextro-rotatory tartrate-positive variant (dT+) of Salmonella enterica subspecies enterica serovar Paratyphi B has been observed in poultry and poultry products . In the present study the interactions of this bacterium with the host were studied in vivo and in vitro in an attempt to explain the preferential association of this serotype with poultry . The ability of this organism to invade and multiply in chicken intestinal epithelial cells and the intracellular behaviour in chicken macrophages was studied in vitro using chicken cell lines . In vivo challenge experiments in specific pathogen-free chickens were carried out to determine the level of colonization of caeca and internal organs early after experimental infection . An in vivo trial with commercial broiler chickens, using a seeder model, was performed to determine whether S . Paratyphi B dT+ could persist and spread in broilers until slaughter . S . Paratyphi B dT+ invaded and multiplied in the chicken epithelial cell line and survived in a chicken macrophage cell line . The strain used colonized caeca and internal organs of chickens to a high extent 1 week after infection with a low-dose inoculum . Moreover, the strain was efficiently transmitted within a group of broilers and persisted until slaughter . It was concluded that S . Paratyphi B dT+ was well adapted to poultry and therefore it is suggested that specific control measures against this serotype should be considered. Pol J Vet Sci, 2004, 7(1), 33 - 7 The detection and determination of potential virulence of Salmonella spp . using PCR method; Skwark M et al.; The aim of this study was to prove that PCR is a very useful method to identify Salmonella strains and to determine their virulence factors by amplification of characteristic genetic markers . Investigations included 5 strains of Salmonella which were obtained from pure cultures and 1 Salmonella strain from the mixed culture . Genotypic analysis of 6 examined strains revealed the 163-bp fragment of chromosomal DNA, which is the DNA rep . ori . gene, encoding the particular genus . In all of these strains 215-bp, 203-bp and 204-bp chromosomal DNA fragments were identified as representing the stn, stpA and spaO genes that confirmed their virulence . These amplification products were identified in both pure and mixed culture from pork . Sensitive and rapid PCR method may be used not only for identification of Salmonella strains and for determination of their virulence factors but also for routine microbiological diagnostic of food pathogens. J Microbiol Immunol Infect, 2004 Feb, 37(1), 39 - 44 Splenic abscess in southern Taiwan; Lee CH et al.; The clinical characteristics and isolated pathogens from 49 cases of splenic abscess treated at a medical center in southern Taiwan between 1981 and 2001 were retrospectively analyzed . Male patients were predominant (63%) . Mean age at presentation was 55 years (range, 19 to 78 years) . The most common presentations were fever (95.9%, 47/49), abdominal pain confined to the left upper quadrant (67.3%, 33/49), left pleural effusion (55.1%, 27/49) and splenomegaly (55.1%, 27/49) . Leukocytosis occurred in 39 patients (79.6%), and leucopenia in 3 (6.1%) . Blood cultures were positive in 32 patients (65.3%) . The most common pathogen was Klebsiella pneumoniae (16.3%, 8/54), a well-known Gram-negative bacillus causing liver abscess in Taiwan, followed by Escherichia coli and Salmonella spp . (each 11.1%, 6/54) . Multiple splenic abscesses occurred predominantly in patients with underlying malignancies . Due to the rarity of splenic abscess and the increasing number of immunocompromised patients, multicenter study is needed to determine the epidemiological features and optimal management of this disease.
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