Int Immunol, 2002 Feb, 14(2), 111 - 9 A quantitative model for neutrophil response and delayed-type hypersensitivity reaction in rats orally inoculated with various doses of Salmonella Enteritidis; Takumi K et al.; Our aim was to investigate the quantitative relationship between inoculation doses and physiological responses to infection by Salmonella enterica serovar Enteritidis . Rats were orally inoculated with 10-10(9) c.f.u . of S . Enteritidis and monitored for 6 days . Neutrophil and delayed-type hypersensitivity (DTH) responses were assessed, and the spleens were analyzed for the pathogen . The experimental data were analyzed by a mathematical model for the host response to salmonella infection, which is based on the assumptions that: (i) the number of pathogens in the inoculum is Poisson distributed, (ii) any cell that is inoculated can multiply and form a clone to infect the animal, (iii) the probability of infection by any cell of the pathogen is independent of the number of cells ingested, and (iv) the magnitude of the immune response increases with dose, but eventually saturates to a maximum level . The probability of infection assessed by the DTH response is 7.5 x 10(-3)/c.f.u . of the inoculum (confidence interval 5.1 x 10(-5), 1.2 x 10(-2)) . When five S . Enteritidis independently initiated the infection, the DTH response to the resulting clones of the salmonellae saturated to the maximum level . The probability of infection assessed by the neutrophil response is 3.4 x 10(-4)/c.f.u . (1.0 x 10(-4), 6.8 x 10(-4)) . The response saturated when six S . Enteritidis independently initiated the infection . The probability of infection assessed by the analysis of spleens is 1.2 x 10(-3)/c.f.u . (4.1 x 10(-4), 2.6 x 10(-3)) . We conclude that at low inocula, infections are initiated by very small numbers of bacteria . The magnitude of the immune responses is similar whether only a few or a larger number of bacteria initiated the infection. J Food Prot, 2002 Jan, 65(1), 53 - 60 Thermal inactivation D- and z-values of Salmonella serotypes and listeria innocua in chicken patties, chicken tenders, franks, beef patties, and blended beef and turkey patties; Murphy RY et al.; Commercially formulated meat products, including chicken patties, chicken tenders, franks, beef patties, and blended beef and turkey patties, were obtained from processors . Each product was inoculated with 7 to 8 logs of Salmonella (Senftenberg, Typhimurium, Heidelberg, Mission, Montevideo, and California) or Listeria innocua . The inoculated meat samples were heat treated at 55 to 70 degrees C . At each temperature, the decimal reduction time (D) was obtained by linear regression of survival curves . Values of D and the temperature difference required for the thermal inactivation curve to drop a logarithmic cycle (z) were determined for the Salmonella serotypes and L . innocua in each product . At 55 to 70 degrees C . for the five tested products, the D-values for the Salmonella serotypes and L . innocua were 26.97 to 0.25 min and 191.94 to 0.18 min, respectively, and their z-values were 7.60 to 9.83 degrees C and 4.86 to 8.67 degrees C, respectively . Significant differences were found for the D- and z-values among the five products . This study will better enable processors to determine the process lethality of pathogens in commercial meat products. J Food Prot, 2002 Jan, 65(1), 100 - 5 Inactivation of Escherichia coli O157:H7, Salmonella enteritidis, and Listeria monocytogenes on apples, oranges, and tomatoes by lactic acid with hydrogen peroxide; Venkitanarayanan KS et al.; The objective of this study was to develop a practical and effective method for inactivating or substantially reducing Escherichia coli O157:H7, Salmonella Enteritidis, and Listeria monocytogenes on apples, oranges, and tomatoes . Apples, oranges, and tomatoes were spot-inoculated with five-strain mixtures of E . coli O157:H7, Salmonella Enteritidis, and L . monocytogenes near the stem end and were submerged in sterile deionized water containing 1.5% lactic acid plus 1.5% hydrogen peroxide for 15 min at 40 degrees C . Inoculated samples treated with sterile deionized water at the same temperature and for the same duration served as controls . The bacterial pathogens on fruits subjected to the chemical treatment were reduced by >5.0 log10 CFU per fruit, whereas washing in deionized water decreased the pathogens by only 1.5 to 2.0 log10 CFU per fruit . Furthermore, substantial populations of the pathogens survived in the control wash water, whereas no E . coli O157:H7, Salmonella Enteritidis, or L . monocytogenes cells were detected in the chemical treatment solution . The sensory and qualitative characteristics of apples treated with the chemical wash solution were not adversely affected by the treatment . It was found that the treatment developed in this study could effectively be used to kill E . coli O157:H7, Salmonella Enteritidis, and L . monocytogenes on apples, oranges, and tomatoes at the processing or packaging level. Acta Crystallogr D Biol Crystallogr, 2002 Feb, 58(Pt 2), 306 - 9 Epub 2002 Jan 24. Pentaerythritol propoxylate: a new crystallization agent and cryoprotectant induces crystal growth of 2-methylcitrate dehydratase; Gulick AM et al.; In the search for macromolecular crystallization conditions, the precipitant is probably the most important variable, such that when problematic crystals are encountered there is always the question of whether an alternative precipitant might resolve the problem . During an effort to obtain high-quality crystals of several problematic proteins, two new agents, pentaerythritol propoxylate and pentaerythritol ethoxylate, yielded well ordered quality crystals where more traditional precipitants were unsuccessful . Pentaerythritol propoxylate and pentaerythritol ethoxylate contain a pentaerythritol backbone to which organic polymers are bound, forming a branched polymer . As such, they are larger than small organic precipitants such as low molecular-weight alcohols or 2-methyl-2,4-pentanediol, but behave differently to polyethylene glycols . These compounds have been used to crystallize an enzyme encoded by the Salmonella enterica prpD gene that catalyzes the dehydration of 2-methylcitrate to form 2-methyl-cis-aconitate . While the PrpD protein has crystallized readily under a number of conditions, the resultant crystals were unsuitable for a crystal structure determination . The new crystals obtained with 25-40% pentaerythritol propoxylate belong to the orthorhombic space group C222(1), with unit-cell parameters a = 73.2, b = 216.4, c = 214.3 A, and diffract beyond 2.0 A with synchrotron radiation . A further benefit of this precipitant for crystallization is its ability to function as a cryoprotectant, allowing the crystals to be transferred directly from the mother liquor to the nitrogen stream at 113 K. J Bacteriol, 2002 Feb, 184(4), 1209 - 13 FimZ is a molecular link between sticking and swimming in Salmonella enterica serovar Typhimurium; Clegg S et al.; Salmonella enterica serovar Typhimurium produces two types of filamentous appendages on its surface . Fimbriae mediate adherence to tissues and cells via receptor-specific interactions, and flagella are the organelles of motility . These appendages play a role in colonization and dissemination, respectively, from infected surfaces and may be important components of bacterial survival . Increased expression of FimZ in serovar Typhimurium resulted in bacteria which were hyperfimbriated but were nonmotile in soft agar . This lack of motility was associated with down regulation of the flhDC master flagellar operon . Therefore, FimZ represents a molecular connection between flagella and fimbrial formation in serovar Typhimurium, indicating that the synthesis of flagella and fimbriae are oppositely controlled. J Bacteriol, 2002 Feb, 184(4), 992 - 1002 Transposable element ISHp608 of Helicobacter pylori: nonrandom geographic distribution, functional organization, and insertion specificity; Kersulyte D et al.; A new member of the IS605 transposable element family, designated ISHp608, was found by subtractive hybridization in Helicobacter pylori . Like the three other insertion sequences (ISs) known in this gastric pathogen, it contains two open reading frames (orfA and orfB), each related to putative transposase genes of simpler (one-gene) elements in other prokaryotes; orfB is also related to the Salmonella virulence gene gipA . PCR and hybridization tests showed that ISHp608 is nonrandomly distributed geographically: it was found in 21% of 194 European and African strains, 14% of 175 Bengali strains, 43% of 131 strains from native Peruvians and Alaska natives, but just 1% of 223 East Asian strains . ISHp608 also seemed more abundant in Peruvian gastric cancer strains than gastritis strains (9 of 14 versus 15 of 45, respectively; P = 0.04) . Two ISHp608 types differing by approximately 11% in DNA sequence were identified: one was widely distributed geographically, and the other was found only in Peruvian and Alaskan strains . Isolates of a given type differed by < or = 2% in DNA sequence, but several recombinant elements were also found . ISHp608 marked with a resistance gene was found to (i) transpose in Escherichia coli; (ii) generate simple insertions during transposition, not cointegrates; (iii) insert downstream of the motif 5"-TTAC without duplicating target sequences; and (iv) require orfA but not orfB for its transposition . ISHp608 represents a widespread family of novel chimeric mobile DNA elements whose further analysis should provide new insights into transposition mechanisms and into microbial population genetic structure and genome evolution. Zentralbl Chir, 2001 Dec, 126(12), 982 - 8 {Mycotic aneurysms--A retrospective analysis}; Klein F et al.; 12 patients (10 males and 2 females, average age 53 years) were operated upon in our hospital between 1994 and 1999 for mycotic aneurysms . The aneurysms were located in 7 patients in the aorto-iliac segment, 5 patients were treated for peripheral or visceral aneurysms . Two of these patients suffered from multiple aneurysms . When peripheral arteries were affected, a pulsatile tumour was felt . Most of these tumours developed in a relatively short period of time and sometimes a perivascular inflammation occurred . This was not the case when central arteries were attacked . A septic process or an infection, for example salmonella-enteritis, often preceded shortly the development of a mycotic aneurysm . In the case of an aneurysm of the aorto-iliac section we consider an in situ reconstruction with alloplastic material in combination with a perivascular debridement, lavage and omentum majus plastic as the treatment of choice . In peripheral arteries reconstruction should be performed with autologous vessels . Depending on the local findings, a perivascular debridement should also be performed in these cases . The reconstruction always should be combined with a calculated antibiotic therapy . Two of our patients died perioperatively . During follow up, 8 patients showed patent reconstructions and no signs of infection . The urgency of surgery depends on the level of inflammation and the existence of any secondary complications. J Agric Food Chem, 2002 Jan 30, 50(3), 610 - 7 Antioxidant and antimutagenic properties of aqueous extract of date fruit (Phoenix dactylifera L . Arecaceae); Vayalil PK; Fruits of the date palm (Phoenix dactylifera L . Arecaceae) are very commonly consumed in many parts of the world and are a vital component of the diet in most of the Arabian countries . This preliminary study documents for the first time its antioxidant and antimutagenic properties in vitro . There was a dose-dependent inhibition of superoxide and hydroxyl radicals by an aqueous extract of date fruit . The amount of fresh extract required to scavenge 50% of superoxide radicals was equivalent to 0.8 mg/mL of date fruit in the riboflavin photoreduction method . An extract of 2.2 mg/mL of date fruit was needed for 50% hydroxyl-radical-scavenging activity in the deoxyribose degradation method . Concentrations of 1.5 and 4.0 mg/mL completely inhibited superoxide and hydroxyl radicals, respectively . Aqueous date extract was also found to inhibit significantly the lipid peroxidation and protein oxidation in a dose-dependent manner . In an Fe(2+)/ascorbate system, an extract of 1.9 mg/mL of date fruit was needed for 50% inhibition of lipid peroxides . In a time course inhibition study of lipid peroxide, at a 2.0 mg/mL concentration of date extract, there was a complete inhibition of TBARS formation in the early stages of the incubation period that increased during later stages of the incubation . Similarly, in the high Fe(2+)/ascorbate induction system a concentration of 2.3 mg/mL inhibited carbonyl formation measured by DNPH reaction by 50% . Moreover, a concentration of 4.0 mg/mL completely inhibited lipid peroxide and protein carbonyl formation . Date fruit extract also produced a dose-dependent inhibition of benzo(a)pyrene-induced mutagenecity on Salmonella tester strains TA-98 and TA-100 with metabolic activation . Extract from 3.6 mg/plate and 4.3 mg/plate was found required for 50% inhibition of His+ revertant formation in TA-98 and TA-100, respectively . These results indicate that antioxidant and antimutagenic activity in date fruit is quite potent and implicates the presence of compounds with potent free-radical-scavenging activity. Water Sci Technol, 2001, 44(11-12), 345 - 52 Residential subsurface flow treatment wetlands in northern Minnesota; Axler R et al.; Approximately 30% of Minnesotans use on-site systems (approximately 500,000 residences) and >50% are failing or non-compliant with regulations due to restrictive soils and site conditions . Many sites occur near lakes and streams creating health hazards and deteriorating water quality . SSF CWs have been evaluated year-round at two northern sites since 1995 . The NERCC CWs simulate single homes and the Grand Lake demonstration CW treats STE from a cluster of 9 lakeshore homes . Systems were generally able to achieve design criteria of 25 mg TSS/L and 30 mg BOD5/L and the NERCC CWs required only 0.3 m of unsaturated soil to achieve consistent disinfection to <200 fecals/100 mL year round . Seeding experiments with Salmonella indicated removal efficiencies of 99.8% in summer and 95% in winter . High strength (approximately 300 mg BOD/L, 95 mg TN/L) influent at NERCC probably limited system performance, particularly N-removal (mass) which was approximately 42% in summer and 20% in winter . The data indicate CW's are a viable, year-round treatment option for homeowners in terms of performance, ease of operation, and cost but require additional maintenance related to inconsistent vegetation growth, winter insulation, and meeting concentration-based regulatory standards since they were seasonally and annually variable due to rain events, partial freezing, spring snowmelt, and summer evapotranspiration. J Med Microbiol, 2002 Jan, 51(1), 13 - 9 Elimination of Salmonella enterica serotype enteritidis in intestinal epithelial cells by mechanisms other than nitric oxide; Saarinen M et al.; Production of nitric oxide (NO) by intestinal epithelial cells is induced after infection with Salmonella spp . or some other enteroinvasive bacteria . However, direct evidence of the role of NO in the elimination of intracellular pathogens in intestinal mucosa has not been established . This study investigated whether NO mediates killing of Salmonella enterica serovar Enteritidis in human intestinal epithelial cells by using parent Henle-407 cell line and a transfected cell line not capable of induced NO production (Henle-NO(def)) . NO synthesis was studied as combined accumulation of nitrite and nitrate, as inducible nitric oxide synthase (iNOS) protein determined by Western blotting and as iNOS mRNA detected by reverse transcription (RT)-PCR . Although parent and Henle-NO(def) cells differed markedly in their ability to produce NO after infection, they eliminated S . Enteritidis equally, as determined by cfu counts . The presence of aminoguanidine, a selective iNOS inhibitor, during the infection blocked the production of NO but did not affect the elimination of the bacteria . These data suggest that NO does not have a direct role in the elimination of intracellular Salmonellae by human intestinal epithelial cells. Res Vet Sci, 2001 Dec, 71(3), 155 - 9 Antibacterial activity of raspberry cordial in vitro; Ryan T et al.; Raspberry juice cordial has a long anecdotal use in Australia for the prophylaxis and treatment of gastroenteritis in livestock, cage birds and humans . The antimicrobial properties of raspberry juice cordial, raspberry juice, raspberry leaf extract and a commercial brand of raspberry leaf tea were investigated against five human pathogenic bacteria and two fungi . Raspberry cordial and juice were found to significantly reduce the growth of several species of bacteria, including Salmonella, Shigella and E . coli, but demonstrated no antifungal activity . No antimicrobial activity was detected in the leaf extract or tea . J Infect, 2001 Oct, 43(3), 169 - 72 Epidemiological analysis of Salmonella enteritidis isolates in Singapore; Ling ML et al.; OBJECTIVES: Salmonella enteritidis is the most common non-typhoidal Salmonella species isolated in Singapore causing gastroenteritis and occasional bacteremia with secondary complications . The number of S . enteritidis isolates rose in 1993 and since then, it was the commonest Salmonella sp . isolated . In 1997, a total of 139 S . enteritidis was isolated and this comprised 19.2% of all non-typhoidal Salmonella sp . isolated . METHODS: We studied the antimicrobial susceptibilities, phage types and molecular epidemiology of 89 of these S . enteritidis strains . Fifty per cent were stool isolates whilst 33.3% were isolated from blood samples . RESULTS: All the isolates were susceptible to cephalothin, ceftriaxone, ciprofloxacin, aztreonam, gentamicin, amikacin, kanamycin, neomycin, streptomycin and nalidixic acid; whilst 75.3% were resistant to sulphonamide, 15.7% to tetracycline, 7.9% to co-trimoxazole, 6.7% to trimethoprim, 2.2% to ampicillin and 2.2% to chloramphenicol . The most frequent phage types were phage type 4 (64%), followed by phage type 1 (12.4%) and phage type 8 (2.2%) . Seventy four of the 89 (83.1%) S . enteritidis isolates analysed by pulsed-field gel electrophoresis showed an indistinguishable pattern A when digested by restriction enzyme Xba I suggesting the presence of a predominant clone of S . enteritidis circulating in Singapore in 1997 . Nature, 2002 Jan 17, 415(6869), 287 - 94 X-ray structure of a ClC chloride channel at 3.0 A reveals the molecular basis of anion selectivity; Dutzler R et al.; The ClC chloride channels catalyse the selective flow of Cl- ions across cell membranes, thereby regulating electrical excitation in skeletal muscle and the flow of salt and water across epithelial barriers . Genetic defects in ClC Cl- channels underlie several familial muscle and kidney diseases . Here we present the X-ray structures of two prokaryotic ClC Cl- channels from Salmonella enterica serovar typhimurium and Escherichia coli at 3.0 and 3.5 A, respectively . Both structures reveal two identical pores, each pore being formed by a separate subunit contained within a homodimeric membrane protein . Individual subunits are composed of two roughly repeated halves that span the membrane with opposite orientations . This antiparallel architecture defines a selectivity filter in which a Cl- ion is stabilized by electrostatic interactions with alpha-helix dipoles and by chemical coordination with nitrogen atoms and hydroxyl groups . These findings provide a structural basis for further understanding the function of ClC Cl- channels, and establish the physical and chemical basis of their anion selectivity. Infect Immun, 2002 Feb, 70(2), 1027 - 31 Urease of enterohemorrhagic Escherichia coli: evidence for regulation by fur and a trans-acting factor; Heimer SR et al.; Recent genomic analyses of Escherichia coli O157:H7 strain EDL933 revealed two loci encoding urease gene homologues (ureDABCEFG), which are absent in nonpathogenic E . coli strain K-12 . This report demonstrates that the cloned EDL933 ure gene cluster is capable of synthesizing urease in an E . coli DH5alpha background . However, when the gene fragment is transformed back into the native EDL933 background, the enzymatic activity of the cloned determinants is undetectable . We speculate that an unidentified trans-acting factor in enterohemorrhagic E . coli (EHEC) is responsible for this regulation of ure expression . In addition, Fur-like recognition sites are present in three independent O157:H7 isolates upstream of ureD and ureA . Enzymatic assays confirmed a difference in urease expression of cloned EHEC ure clusters in E . coli MC3100Deltafur . Likewise, interruption of fur in O157:H7 isolate IN1 significantly diminished urease activity . We propose that, similar to the function of Fur in regulating the acid response of Salmonella enterica serovar Typhimurium, it modulates urease expression in EHEC, perhaps contributing to the acid tolerance of the organism. Infect Immun, 2002 Feb, 70(2), 964 - 9 Nitric oxide and apoptosis induced in Peyer's patches by attenuated strains of Salmonella enterica serovar Enteritidis; Cerquetti MC et al.; Nitric oxide (NO) is a toxic molecule of the immune system which contributes to the control of microbial pathogens . Additional functions of NO in innate and adaptive immunity have recently been described; these functions include the modulation of the cytokine response of lymphocytes and the regulation of immune cell apoptosis . In addition to direct microbicidal actions, NO has immunoregulatory effects relevant to the control of infections . In turn, infected macrophages and macrophage-regulating lymphocytes may undergo apoptosis during infection by Salmonella spp . In this work we investigated the ability of attenuated strains of Salmonella enterica serovar Enteritidis with different protective capacities to induce intestinal inducible nitric oxide synthase (iNOS) and apoptosis in Peyer's patches (PP) in mice . Results showed that the intestinal iNOS activity correlated with increased apoptosis in PP . Furthermore, the ability to induce intestinal NO production and apoptosis within the first few hours after immunization seemed to correlate with the protective capacity of mutant E/1/3 of S . enterica serovar Enteritidis . It was found that nonprotective mutant C/2/2, which was unable to induce intestinal NO production, also failed to induce apoptosis in PP . Moreover, aminoguanidine treatment at the time of immunization resulted in inhibition of the NO production and apoptosis induced by protective mutant E/1/3 and completely abolished protection against challenge . These results suggest that the induction of iNOS in the intestinal mucosa by attenuated mutant E/1/3 of S . enterica serovar Enteritidis at the time of immunization is necessary to generate a protective immune response. Infect Immun, 2002 Feb, 70(2), 953 - 63 Cell differentiation is a key determinant of cathelicidin LL-37/human cationic antimicrobial protein 18 expression by human colon epithelium; Hase K et al.; Antimicrobial peptides are highly conserved evolutionarily and are thought to play an important role in innate immunity at intestinal mucosal surfaces . To better understand the role of the antimicrobial peptide human cathelicidin LL-37/human cationic antimicrobial protein 18 (hCAP18) in intestinal mucosal defense, we characterized the regulated expression and production of this peptide by human intestinal epithelium . LL-37/hCAP18 is shown to be expressed within epithelial cells located at the surface and upper crypts of normal human colon . Little or no expression was seen within the deeper colon crypts or within epithelial cells of the small intestine . Paralleling its expression in more differentiated epithelial cells in vivo, LL-37/hCAP18 mRNA and protein expression was upregulated in spontaneously differentiating Caco-2 human colon epithelial cells and in HCA-7 human colon epithelial cells treated with the cell differentiation-inducing agent sodium butyrate . LL-37/hCAP18 expression by colon epithelium does not require commensal bacteria, since LL-37/hCAP18 is produced with a similar expression pattern by epithelial cells in human colon xenografts that lack a luminal microflora . LL-37/hCAP18 mRNA was not upregulated in response to tumor necrosis factor alpha, interleukin 1alpha (IL-1alpha), gamma interferon, lipopolysaccharide, or IL-6, nor did the expression patterns and levels of LL-37/hCAP18 in the epithelium of the normal and inflamed colon differ . On the other hand, infection of HCA-7 cells with Salmonella enterica serovar Dublin or enteroinvasive Escherichia coli modestly upregulated LL-37/hCAP18 mRNA expression . We conclude that differentiated human colon epithelium expresses LL-37/hCAP18 as part of its repertoire of innate defense molecules and that the distribution and regulated expression of LL-37/hCAP18 in the colon differs markedly from that of other enteric antimicrobial peptides, such as defensins. Infect Immun, 2002 Feb, 70(2), 606 - 11 The Helicobacter pylori homologue of the ferric uptake regulator is involved in acid resistance; Bijlsma JJ et al.; The only known niche of the human pathogen Helicobacter pylori is the gastric mucosa, where large fluctuations of pH occur, indicating that the bacterial response and resistance to acid are important for successful colonization . One of the few regulatory proteins in the H . pylori genome is a homologue of the ferric uptake regulator (Fur) . In most bacteria, the main function of Fur is the regulation of iron homeostasis . However, in Salmonella enterica serovar Typhimurium, Fur also plays an important role in acid resistance . In this study, we determined the role of the H . pylori Fur homologue in acid resistance . Isogenic fur mutants were generated in three H . pylori strains (1061, 26695, and NCTC 11638) . At pH 7 there was no difference between the growth rates of mutants and the parent strains . Under acidic conditions, growth of the fur mutants was severely impaired . No differences were observed between the survival of the fur mutant and parent strain 1061 after acid shock . Addition of extra iron or removal of iron from the growth medium did not improve the growth of the fur mutant at acidic pH . This indicates that the phenotype of the fur mutant at low pH was not due to increased iron sensitivity . Transcription of fur was repressed in response to low pH . From this we conclude that Fur is involved in the growth at acidic pH of H . pylori; as such, it is the first regulatory protein implicated in the acid resistance of this important human pathogen. Infect Immun, 2002 Feb, 70(2), 558 - 68 Porins from Salmonella enterica serovar Typhimurium activate the transcription factors activating protein 1 and NF-kappaB through the Raf-1-mitogen-activated protein kinase cascade; Galdiero M et al.; In this study we examined the ability of Salmonella enterica serovar Typhimurium porins to activate activating protein 1 (AP-1) and nuclear factor kappaB (NF-kappaB) through the mitogen-activated protein kinase (MAPK) cascade, and we identified the AP-1-induced protein subunits . Our results demonstrate that these enzymes may participate in cell signaling pathways leading to AP-1 and NF-kappaB activation following porin stimulation of cells . Raf-1 was phosphorylated in response to the treatment of U937 cells with porins; moreover, the porin-mediated increase in Raf-1 phosphorylation is accompanied by the phosphorylation of MAPK kinase 1/2 (MEK1/2), p38, extracellular-signal-regulated kinase 1/2, and c-Jun N-terminal kinase . We used three different inhibitors of phosphorylation pathways: 2'-amino-3'-methoxyflavone (PD-098059), a selective inhibitor of MEK1 activator and the MAPK cascade; 4-(4-fluorophenyl)-2-(4-methylsulfinylphenyl)-5-(4-pyridyl)1H-imidazole (SB203580), a specific inhibitor of the p38 pathway; and 7beta-acetoxy-1alpha,6beta,9alpha-trihydroxy-8,13-epoxy-labd-14-en-11-one (forskolin), an inhibitor at the level of Raf-1 kinase . PD-098059 pretreatment of cells decreases AP-1 and NF-kappaB activation by lipopolysaccharide (LPS) but not by porins, and SB203580 pretreatment of cells decreases mainly AP-1 and NF-kappaB activation by porins; in contrast, forskolin pretreatment of cells does not affect AP-1 and NF-kappaB activation following either porin or LPS stimulation . Our data suggest that the p38 signaling pathway mainly regulates AP-1 and NF-kappaB activation in cells treated with S . enterica serovar Typhimurium porins . Antibody electrophoretic mobility shift assays showed that JunD and c-Fos binding is found in cells treated with porins, in cells treated with LPS, and in unstimulated cells . However, by 30 to 60 min of stimulation, a different complex including c-Jun appears in cells treated with porins or LPS, while the Fra-2 subunit is present only after porin stimulation . These data suggest different molecular mechanisms of activation induced by porins or by LPS. Infect Immun, 2002 Feb, 70(2), 551 - 7 Increased susceptibility of C1q-deficient mice to Salmonella enterica serovar Typhimurium infection; Warren J et al.; The role of the complement system in host defense against Salmonella infection is poorly defined . Bacterial cell wall O-antigen polysaccharide can activate the alternative pathway in vitro . No studies, however, have elucidated the role of the classical pathway in immunity to Salmonella spp . in vivo . C1q-deficient mice (C1qa(-/-)) on a 129/Sv genetic background and strain-matched controls were infected intraperitoneally and intravenously with Salmonella enterica serovar Typhimurium and monitored over a 14-day period . After inoculation by either route, the C1qa(-/-) mice were found to be significantly more susceptible to Salmonella infection . Hepatic and splenic bacterial counts, performed at various time points, showed increased numbers of colonies in complement-deficient mice compared to controls . Analysis of blood clearance showed no difference between the two experimental groups during the first 15 min . However, after 20 min and until 6 h postinfection, numbers of circulating bacteria were significantly higher in complement-deficient mice . In vitro experiments using either resident or thioglycolate-elicited peritoneal macrophages showed a significant increase in the number of bacteria inside C1q-deficient macrophages compared to controls irrespective of the serum used for opsonizing the bacteria . These findings could not be explained either by an increased bacterial uptake, analyzed in vitro and in vivo using green fluorescent protein-tagged salmonellae, or by a defect in the respiratory burst or in NO production . The data presented here suggest the possibility of novel pathways by which C1q may modulate the pathogenesis of infectious diseases caused by intracellular pathogens. Infect Immun, 2002 Feb, 70(2), 451 - 61 The global regulator ArcA controls resistance to reactive nitrogen and oxygen intermediates in Salmonella enterica serovar Enteritidis; Lu S et al.; Salmonella enterica serovar Enteritidis is a major cause of food-borne diseases associated with consumption of shell eggs . Clinical isolates of S . enterica serovar Enteritidis exhibit a wide spectrum of virulence in mice . A highly virulent isolate (SE2472) was previously shown to be more resistant in vitro than other clinical isolates to acidified sodium nitrite (ASN), a generator of reactive nitrogen and oxygen intermediates (RNI/ROI) . SE2472 is also more resistant to S-nitrosoglutathione (GSNO) and hydrogen peroxide (H(2)O(2)) than an ASN-susceptible isolate of S . enterica serovar Enteritidis (SE8743) . To investigate the molecular basis for the RNI/ROI resistance of S . enterica serovar Enteritidis, we transformed a genomic DNA library of SE2472 into SE8743 . A plasmid clone conferred upon SE8743 enhanced resistance to ASN, GSNO, and H(2)O(2) . The DNA insert in the clone encoded ArcA, a global regulator . An arcA mutant of SE2472 was constructed and was found to be more susceptible to GSNO and hydrogen peroxide but not more susceptible to ASN than wild-type SE2472 . The susceptibility of the arcA mutant to GSNO and H(2)O(2) was complemented by a plasmid harboring arcA . The coding sequence of the arcA gene in SE2472 and the coding sequence of the arcA gene in SE8743 were identical, suggesting that the difference in resistance to RNI/ROI maybe due to the activity of genes regulated by ArcA . No significant difference in virulence between the wild type and the arcA mutant of SE2472 was observed in mice . These observations show that arcA is essential for resistance of S . enterica serovar Enteritidis to nitrosative and oxidative stress . However, additional genetic loci may contribute to the resistance to RNI/ROI and unusually high virulence for mice of SE2472. Antimicrob Agents Chemother, 2002 Feb, 46(2), 360 - 6 Molecular cloning and characterization of the Salmonella enterica Serovar Paratyphi B rma Gene, which confers multiple drug resistance in Escherichia coli; Yassien MA et al.; A genomic library from a strain of Salmonella enterica serovar Paratyphi B that exhibits multiple drug resistance (MDR) was constructed in Escherichia coli . Two of the recombinant plasmids, pNOR5 and pNOR5, conferred resistance only to fluoroquinolones in E . coli, whereas the third, pNCTR4, conferred the MDR phenotype . Sequence and subcloning analysis showed that it is the presence of RecA on the first two plasmids which confers resistance to fluoroquinolones in E . coli . A similar analysis established that the MDR phenotype conferred by pNCTR4 is due to a gene, rma (resistance to multiple antibiotics), which encodes a 13.5-kDa polypeptide . The derived sequence for Rma exhibits a high degree of similarity to those of a group of MarA-like activators that confer MDR in E . coli . A MalE-Rma fusion protein was purified to near homogeneity and was shown to interact with a DNA fragment carrying a MarA operator sequence . Furthermore, overexpression of rma in E . coli caused changes in the outer membrane protein profile that were similar to those reported for MarA . These results suggest that Rma might act as a transcriptional activator of the marA regulon. Protein Sci, 2002 Feb, 11(2), 401 - 8 Crystal structure of the Yersinia pestis GTPase activator YopE; Evdokimov AG et al.; Yersinia pestis, the causative agent of bubonic plague, evades the immune response of the infected organism by using a type III (contact-dependent) secretion system to deliver effector proteins into the cytosol of mammalian cells, where they interfere with signaling pathways that regulate inflammation and cytoskeleton dynamics . The cytotoxic effector YopE functions as a potent GTPase-activating protein (GAP) for Rho family GTP-binding proteins, including RhoA, Rac1, and Cdc42 . Down-regulation of these molecular switches results in the loss of cell motility and inhibition of phagocytosis, enabling Y . pestis to thrive on the surface of macrophages . We have determined the crystal structure of the GAP domain of YopE (YopE(GAP); residues 90-219) at 2.2-A resolution . Apart from the fact that it is composed almost entirely of alpha-helices, YopE(GAP) shows no obvious structural similarity with eukaryotic RhoGAP domains . Moreover, unlike the catalytically equivalent arginine fingers of the eukaryotic GAPs, which are invariably contained within flexible loops, the critical arginine in YopE(GAP) (Arg144) is part of an alpha-helix . The structure of YopE(GAP) is strikingly similar to the GAP domains from Pseudomonas aeruginosa (ExoS(GAP)) and Salmonella enterica (SptP(GAP)), despite the fact that the three amino acid sequences are not highly conserved . A comparison of the YopE(GAP) structure with those of the Rac1-ExoS(GAP) and Rac1-SptP complexes indicates that few, if any, significant conformational changes occur in YopE(GAP) when it interacts with its G protein targets . The structure of YopE(GAP) may provide an avenue for the development of novel therapeutic agents to combat plague. J Bacteriol, 2002 Feb, 184(3), 771 - 6 Effects of lipoprotein biogenesis mutations on flagellar assembly in Salmonella; Dailey FE et al.; Flagellar assembly requires the expression of a large number of flagellum-specific genes . However, mutations in a number of other genes in Salmonella and Escherichia coli have been shown to have pleiotropic effects that affect flagellar assembly . FlgH (the L-ring subunit of the flagellar basal body) is a lipoprotein whose modification is important for L-ring assembly . We therefore tested whether the lack of motility of Salmonella mutants defective in lipoprotein biogenesis is a result of inability to modify FlgH . Our results show that temperature-sensitive apolipoprotein N-acyltransferase {lnt(Ts)} mutants are nonflagellate at 42 degrees C . However, the flagellar assembly defect occurs at a much earlier step in the pathway than L-ring assembly . These mutants failed to assemble even an MS ring, presumably because of the observed decrease in transcription of fliF . In contrast, temperature-sensitive diacylglycerol transferase {lgt(Ts)} mutants were motile at 42 degrees C, provided the strains carried an lpp (Braun lipoprotein) mutation to permit growth . We have isolated second-site mutants from an lgt(Ts) lpp(+) strain that grow but are nonflagellate at 42 degrees C . Thus, lipoprotein biogenesis is a factor that is important for flagellar assembly. J Bacteriol, 2002 Feb, 184(3), 706 - 17 Identification of the periplasmic cobalamin-binding protein BtuF of Escherichia coli; Cadieux N et al.; Cells of Escherichia coli take up vitamin B(12) (cyano-cobalamin {CN-Cbl}) and iron chelates by use of sequential active transport processes . Transport of CN-Cbl across the outer membrane and its accumulation in the periplasm is mediated by the TonB-dependent transporter BtuB . Transport across the cytoplasmic membrane (CM) requires the BtuC and BtuD proteins, which are most related in sequence to the transmembrane and ATP-binding cassette proteins of periplasmic permeases for iron-siderophore transport . Unlike the genetic organization of most periplasmic permeases, a candidate gene for a periplasmic Cbl-binding protein is not linked to the btuCED operon . The open reading frame termed yadT in the E . coli genomic sequence is related in sequence to the periplasmic binding proteins for iron-siderophore complexes and was previously implicated in CN-Cbl uptake in SALMONELLA: The E . coli yadT product, renamed BtuF, is shown here to participate in CN-Cbl uptake . BtuF protein, expressed with a C-terminal His(6) tag, was shown to be translocated to the periplasm concomitant with removal of a signal sequence . CN-Cbl-binding assays using radiolabeled substrate or isothermal titration calorimetry showed that purified BtuF binds CN-Cbl with a binding constant of around 15 nM . A null mutation in btuF, but not in the flanking genes pfs and yadS, strongly decreased CN-Cbl utilization and transport into the cytoplasm . The growth response to CN-Cbl of the btuF mutant was much stronger than the slight impairment previously described for btuC, btuD, or btuF mutants . Hence, null mutations in btuC and btuD were constructed and revealed that the btuC mutant had a strong impairment similar to that of the btuF mutant, whereas the btuD defect was less pronounced . All mutants with defective transport across the CM gave rise to frequent suppressor variants which were able to respond at lower levels of CN-Cbl but were still defective in transport across the CM . These results finally establish the identity of the periplasmic binding protein for Cbl uptake, which is one of few cases where the components of a periplasmic permease are genetically separated. J Bacteriol, 2002 Feb, 184(3), 645 - 53 The ClpXP ATP-dependent protease regulates flagellum synthesis in Salmonella enterica serovar typhimurium; Tomoyasu T et al.; The ClpXP protease is a member of the ATP-dependent protease family and plays a dynamic role in the control of availability of regulatory proteins and the breakdown of abnormal and misfolded proteins . The proteolytic activity is rendered by the ClpP component, while the substrate specificity is determined by the ClpX component that has ATPase activity . We describe here a new role of the ClpXP protease in Salmonella enterica serovar Typhimurium in which ClpXP is involved in the regulation of flagellum synthesis . Cells deleted for ClpXP show "hyperflagellate phenotype," exhibit overproduction of the flagellar protein, and show a fourfold increase in the rate of transcription of the fliC encoding flagellar filament . The assay for promoter activity of the genes responsible for expression of the fliC showed that the depletion of ClpXP results in dramatic enhancement of the expression of the fliA encoding sigma factor final sigma(28), leaving the expression level of the flhD master operon lying at the top of the transcription hierarchy of flagellar regulon almost normal . These results suggest that the ClpXP may be responsible for repressing the expression of flagellar regulon through the control of the FlhD/FlhC master regulators at the posttranscriptional and/or posttranslational levels . Proteome analysis of proteins secreted from the mutant cells deficient for flhDC and clpXP genes demonstrated that the DeltaflhD mutation abolished the enhanced effect by DeltaclpXP mutation on the production of flagellar proteins, suggesting that the ClpXP possibly defines a regulatory pathway affecting the expression of flagellar regulon that is dependent on FlhD/FlhC master regulators. Curr Biol, 2002 Jan 8, 12(1), R15 - 7 Microbial pathogenesis: new niches for salmonella; Brumell JH et al.; Salmonella occupies a vacuolar compartment inside cells of its host . Recent studies have shown that the fate of this vacuole is different in various cell types, and that the outcome of colonization is determined by both the infecting bacterium and defense mechanisms of the host cell. J Environ Qual, 2001 Nov-Dec, 30(6), 2134 - 40 Viral and chemical tracer movement through contrasting soils; McLeod M et al.; Land treatment of animal or human waste can result in chemical and microbial contamination of shallow ground water and/or water-ways . We investigated the fate of a host-specific Salmonella bacteriophage and a nonreactive chemical (Br-) tracer when applied to large intact lysimeter soil cores (500 mm diam . by 700 mm high) . The soils included a poorly drained Gley Soil and well-drained Pumice, Allophanic, and Recent Soils . A depth of 30 mm of water containing the bacteriophage and Br- was applied to the soil at a rate of 5 mm h(-1) followed by up to about 1.8 pore volumes of simulated rainfall . Resulting leachates, collected continuously over at least one pore volume were analyzed for the bacteriophage and bromide (Br-) tracers . Bromide moved uniformly through the Pumice and Allophanic Soils with peak concentrations at about 1 pore volume, while the bacteriophage was detected only at trace levels or not at all . In contrast, both Br- and bacteriophage tracers moved rapidly through Gley and Recent Soils, appearing early in the leachate and then tailing off . Such flow patterns in the Gley and Recent Soils are indicative of bypass flow . Coarse soil structure in the Gley Soil, and finger-flow due to water repellency in the sandy Recent Soil are considered responsible for the observed bypass flow in these two soils . Allophanic and Pumice Soils have finer, more porous soil structure leading to a predominance of matrix flow over bypass flow . This study suggests vertical movement of viruses varies significantly with soil type. Int J Food Microbiol, 2001 Dec 30, 71(2-3), 263 - 6 Salmonella serotypes isolated from chicken meat in Albania; Beli E et al.; A total of 31 salmonellae, belonging to four different serogroups and nine serotypes, were isolated from 30 out of 461 (6.5%) chicken meat samples, taken during a 3-year period, from 1996 to 1998 . There were no significant differences among years in Salmonella positive samples, ranging from 5.1% to 8% . The most frequently encountered serotype was Salmonella enteritidis, isolated in 16 out of 30 Salmonella positive samples (53.3%), but its predomination was clearly evident only in 1996 . The other isolated serotypes were S . senftenberg (three isolates), S . newport (two isolates), and S . abony, S . agona, S . banana, S . brancaster, S . infantis and S . oslo with only one isolate each . Four other Salmonella strains were not fully serotyped. Avian Dis, 2001 Oct-Dec, 45(4), 875 - 86 Determination of close genetic relatedness of the major Salmonella enteritidis phage types by pulsed-field gel electrophoresis and DNA sequence analysis of several Salmonella virulence genes; Hudson CR et al.; Salmonella enteritidis (SE) is an important cause of egg-associated outbreaks in both Europe and the United States . Phage typing has become an important epidemiologic tool in identifying the source of outbreaks . Limitations of phage typing have become apparent with wholesale egg distributors that have multiple suppliers in an area where a particular phage type is endemic . Several different molecular typing methods were evaluated for their discriminatory power to identify genetic differences among different SE phage types isolated in Europe and the United States . Pulsed-field gel electrophoresis (PFGE) identified a single DNA pattern among the different SE phage types . Comparison of the nucleotide sequence for several Salmonella virulence genes failed to identify a single nucleotide change in the gene sequences from most SE isolates, regardless of phage type . On the basis of these results, the different SE phage types appear to be genetically related or clonal . However, with primers 1283 and Opa4, it was possible to differentiate not only SE isolates from different geographic locations but those within a specific geographic locale as well by random amplified polymorphic DNA polymerase chain reaction . Any chance for discerning genetic differences among isolates will need to rely on molecular techniques other than PFGE. Avian Dis, 2001 Oct-Dec, 45(4), 797 - 806 Induction of humoral immune response and protective immunity in chickens against Salmonella enteritidis after a single dose of killed bacterium-loaded microspheres; Liu W et al.; Formalin-inactivated Salmonella enteritidis phage type 4 strain 119/95 (SE) was encapsulated in biodegradable poly (DL-lactide co-glycolic acid) PLGA; (65:35) microspheres by a modified water-in-oil-in-water (w/o/w) double-emulsion solvent extraction/evaporation technique . These SE-loaded microspheres (SE-MS) were porous and spherical in shape with diameters of 0.4-10 microm and 20-80 microm in two preparations . SE-MS were subsequently used to vaccinate specific-pathogen-free chickens in a single dose in order to investigate the potency of a single-dose vaccination in inducing immune responses and protective immunity . In Experiment 1, 4-wk-old chickens that were vaccinated intramuscularly with 20-80-microm SE-MS generated long lasting (over 6 mo) and persistently high serum anti-SE immunoglobulin (Ig)G antibody response . In Experiment 2, 2-wk-old chickens were vaccinated orally with 0.4-10-microm or intramuscularly with 20-80-microm SE-MS and challenged with 10(9) colony-forming units of homologous SE strain at 6 wk postvaccination . When challenged intramuscularly, one each of the orally vaccinated (n = 10) and the intramuscularly vaccinated birds (n = 10) showed clinical signs and death, whereas all of the nonvaccinated control birds (n = 12) were sick and 11 of them were killed . When challenge was via oral route, 26.1% of cloacal swabs and 24.0% of organs (liver, spleen, and cecum) collected from orally vaccinated birds (n = 35) were positive for SE, comparable to 27.9% of feces and 18.7% of organs from the intramuscularly vaccinated birds (n = 35) . These figures were significantly lower than those for nonvaccinated birds (n = 30) from which 59.3% of feces and 44.0% of organs tested SE positive (P < 0.05) . The humoral immune response was also determined after vaccination with a single dose . The intramuscular vaccination elicited higher serum IgG response than oral administration, but the latter elicited a significant intestinal mucosal IgA antibody response . This is the first evidence that chickens vaccinated with killed SE-loaded PLGA microspheres, intramuscularly and orally in a single dose, developed systematic and local immune responses, thereby conferring protective immunity. Avian Dis, 2001 Oct-Dec, 45(4), 1044 - 9 Dynamics of Salmonella contamination in a commercial quail operation; Sander J et al.; Control of carcass contamination requires knowledge of the source and dynamics of spread of Salmonella in commercial poultry production . We examined Salmonella contamination at a U.S . commercial quail operation . Pulsed-field gel electrophoresis (PFGE) was used to type isolates in order to trace Salmonella throughout this production environment . During a 6-mo survey, Salmonella serotypes hadar, typhimurium, typhimurium variant Copenhagen, and paratyphi were encountered within this poultry operation . Ninety-four percent of the Salmonella isolated from breeder and production houses and from carcass rinses belonged to Salmonella serotypes typhimurium variant Copenhagen and hadar . There were six distinct S . typhimurium variant Copenhagen genetic types, as identified by PFGE, present within this particular poultry operation . Seventy-nine percent of S . typhimurium variant Copenhagen identified from the environment of the breeder and production houses produced the same PFGE pattern . Thirty-eight percent of S . typhimurium Copenhagen isolated from carcass rinses and the breeder house shared the same PFGE DNA pattern . This study demonstrates the transmission of salmonellae throughout this production environment, from the breeders to their progeny and to the birds ultimately processed for human consumption. Microbiology, 2002 Jan, 148(Pt 1), 113 - 22 The starvation-stress response of Salmonella enterica serovar Typhimurium requires sigma(E)-, but not CpxR-regulated extracytoplasmic functions; Kenyon WJ et al.; Starvation of Salmonella enterica serovar Typhimurium (S . Typhimurium) for an exogenous source of carbon and energy (C-starvation) induces the starvation-stress response (SSR) . The SSR functions to (i) maintain viability during long-term C-starvation and (ii) generate cross-resistance to other environmental stresses . The SSR is, at least partially, under the control of the alternative sigma factor, sigma(S) . It is hypothesized that C-starvation causes cell envelope stresses that could induce the sigma(E) and/or Cpx regulons, both of which control extracytoplasmic functions and, thus, may play a role in the regulation of the SSR . In support of this hypothesis, Western blot analysis showed that the relative levels of sigma(E) increased during C-starvation, peaking after approximately 72 h of C-starvation; in contrast, CpxR levels remained relatively constant from exponential phase up to 72 h of C-starvation . To determine if sigma(E), and thus the regulon it controls, is an essential component of the SSR, several mutant strains were compared for their abilities to survive long-term C-starvation and to develop C-starvation-induced (CSI) cross-resistances . An rpoE mutant strain was significantly impaired in both long-term C-starvation survival (LT-CSS) and in CSI cross-resistance to challenges with 20 mM H(2)O(2) for 40 min, 55 degrees C for 16 min, pH 3.1 for 60 min and 870.2 USP U polymyxin B ml(-1) (PmB) for 60 min, to varying degrees . These results suggest that C-starvation can generate signals that induce the rpoE regulon and that one or more members of the sigma(E) regulon are required for maximal SSR function . Furthermore, evidence suggests that the sigma(E) and sigma(S) regulons function through separate mechanisms in the SSR . In contrast, C-starvation does not appear to generate signals required for Cpx regulon induction which support the findings that it is not required for LT-CSS or cross-resistance to H(2)O(2), pH 3.1 or PmB challenges . However, it was required to achieve maximal cross-resistance to 55 degrees C . Therefore, sigma(E) is a key regulatory component of the SSR and represents an additional sigma factor required for the SSR of SALMONELLA: Microb Pathog, 2002 Jan, 32(1), 15 - 25 Excess production of interleukin-12 subunit p40 stimulated by the virulence plasmid of Salmonella enterica serovar Typhimurium in the early phase of infection in the mouse; Chang CC et al.; The production of interleukin-12 (IL-12) and its subunits in response to Salmonella enterica serovar Typhimurium infection in the BALB/c mouse was examined . Unlike wild-type Typhimurium, a plasmidless strain, isolated by curing of the virulence plasmid (pSTV), did not stimulate excess IL-12p40 production . When a Tn 5 tagged pSTV was transferred back to the plasmidless strain, the ability to stimulate IL-12p40 production was restored . However, a strain harbouring another Tn50pSTV failed to stimulate excess IL-12p40 production . This Tn 5 insertion area, located on fragment H3 of pSTV, was designated spf (stimulation of protein forty) . The ability to stimulate IL-12p40 production was restored in a partial diploid that carried a wild-type fragment covering the spf site . There is one known gene, repA, a locus, rsk, and two putative ORFs, in the vicinity of the Tn 5 insertion site; however, these are not spf . The precise location of the spf locus is still unknown . Genetics, 2001 Dec, 159(4), 1405 - 14 Growth-dependent DNA breakage and cell death in a gyrase mutant of Salmonella; Gari E et al.; A class of gyrase mutants of Salmonella enterica mimics the properties of bacteria exposed to quinolones . These mutants suffer spontaneous DNA breakage during normal growth and depend on recombinational repair for viability . Unlike quinolone-treated bacteria, however, they do not show accumulation of cleavable gyrase-DNA complexes . In recA or recB mutant backgrounds, the temperature-sensitive (ts) allele gyrA208 causes rapid cell death at 43 degrees . Here, we isolated "suppressor-of-death" mutations, that is, secondary changes that allow a gyrA208 recB double mutant to survive a prolonged exposure to 43 degrees and subsequently to form colonies at 28 degrees . In most isolates, the secondary change was itself a ts mutation . Three ts alleles were mapped in genes coding for amino acyl tRNA synthetases (alaS, glnS, and lysS) . Allele alaS216 completely abolished DNA breakage in a gyrA208 recA double mutant . Likewise, treating this mutant with chloramphenicol prevented death and DNA damage at 43 degrees . Additional suppressors of gyrA208 lethality include rpoB mutations and, surprisingly, icd mutations inactivating isocitrate dehydrogenase . We postulate that the primary effect of the gyrase alteration is to hamper replication fork movement . Inhibiting DNA replication under conditions of continuing macromolecular synthesis ("unbalanced growth") activates a mechanism that causes DNA breakage and cell death, reminiscent of "thymineless" lethality. Clin Transplant, 2001, 15 Suppl 4, 11 - 22 Gastrointestinal infectious disease complications following transplantation and their differentiation from immunosuppressant-induced gastrointestinal toxicities; Rubin RH; It is often very difficult to distinguish between infection-related and immunosuppression-related gastrointestinal (GI) complications after transplantation . The risk of infection itself is determined by the patient's net state of immunosuppression as well as the presence of anatomic or technical abnormalities and the patient's epidemiological exposures . Of the anatomic abnormalities, diverticulitis is a particular problem in transplant patients, with a high rate of perforation and abscess formation . The causes of infectious disease syndromes are very different immediately after, early after, and late after transplantation . Infection during the first month may result from a pre-existing infection in the donor or recipient, or from the surgical wound, endotracheal tube, vascular access or drainage . During 1-6 months after transplantation, viruses attack and, with sustained immunosuppression, make opportunistic infections possible . Beyond 6 months after transplantation, the 80% of patients with good result from the transplant are at risk primarily for community-acquired microbes, including such enteric pathogens as Salmonella . Of the remaining patients, 10% have chronic viral infections and the 10% who have poor allograft function are at greatest risk for opportunistic infection . This time line is helpful in determining whether a GI complication is likely to be related to infection rather than a specific effect of an immunosuppressant drug . Fever, inflammatory cells in the stool, abnormalities on endoscopy or computed tomography and leukocytosis can be useful in the diagnosis but are inconsistent markers for an infectious cause. Clin Diagn Lab Immunol, 2002 Jan, 9(1), 115 - 25 Effect of protein SV-IV on experimental Salmonella enterica serovar Typhimurium infection in mice; Romano-Carratelli C et al.; Seminal vesicle protein IV (SV-IV) is a secretory anti-inflammatory, procoagulant, and immunomodulatory protein produced in large amounts by the seminal vesicle epithelium of the rat under the strict transcriptional control of androgen . In particular, this protein was shown to possess the ability to markedly inhibit in vivo the humoral and cell-mediated immune responses of mice to nonbacterial cellular antigens (sheep erythrocytes and spermatozoa) . We report data that demonstrate that in mice treated with SV-IV and infected with Salmonella enterica serovar Typhimurium, SV-IV is able to downregulate some important immunological and biochemical parameters that serovar Typhimurium normally upregulates in these animals . This event did not correlate with a lower bacterial burden but was associated with a markedly increased one (300%) . Furthermore, the treatment of mice with SV-IV alone also produced a significant increase in the rate of mortality among serovar Typhimurium-infected animals . The mechanism underlying these phenomena was investigated, and the strong immunosuppression produced by SV-IV in serovar Typhimurium-infected mice was suggested to be the basis for the increased rate of mortality . The SV-IV-mediated immunosuppression was characterized by a decrease in the humoral and cell-mediated immune responses, altered lymphocyte-macrophage interaction, downregulation of cytokine and inducible nitric oxide synthase gene expression, inhibition of macrophage phagocytosis and intracellular killing activities, and absence of apoptosis in the splenocyte population of SV-IV- and serovar Typhimurium-treated mice . The immunosuppressive activity of SV-IV was specific and was not due to aspecific cytotoxic effects . SV-IV-specific receptors (K(d) = 10(-8) M) occurring on the macrophage and lymphocyte plasma membranes may be involved in the molecular mechanism underlying the SV-IV-mediated immunosuppression . Some results obtained by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay also revealed a functional impairment of mitochondria (a decrease in mitochondrial dehydrogenase activity), thus indicating the possible implication of these organelles in the immunosuppressive process. J Egypt Soc Parasitol, 2001 Dec, 31(3), 767 - 80 Effect of midgut bacteria of Culex pipiens L . on digestion and reproduction; Fouda MA et al.; An investigation was carried out to evaluate the influence of symbiotic bacteria associated with Culex pipiens L . on pre-oviposition and blood meal digestion periods, and reproductive potential (fecundity and fertility) . Aposymbiotic females were obtained by feeding the normal females on 10% sucrose solution mixed with antibiotic (Tarivid) for three days before feeding them on normal blood meals from a pigeon host . A total of 4 genera were previously isolated from the midgut of C . pipiens . These genera were: Bacillus, Streptococcus, Staphylococcus, and Salmonella and Shigella . It seems that the period of blood meal digestion preceded the pre-oviposition period of both bacterial free females and bacterial-free females treated with one of the aforementioned bacteria . In addition, it is obviously clear that, the presence of the two bacterial genera: Bacillus and Staphylococcus in the midgut of C . pipiens is essential for normal and high fecundity . Generally, it is evident that the symbionts (gut bacteria) are essential for the completion of embryonic development. J Clin Microbiol, 2002 Jan, 40(1), 52 - 60 Modeling of 5' nuclease real-time responses for optimization of a high-throughput enrichment PCR procedure for Salmonella enterica; Knutsson R et al.; The performance of a 5' nuclease real-time PCR assay was studied to optimize an automated method of detection of preenriched Salmonella enterica cells in buffered peptone water (BPW) . The concentrations and interactions of the PCR reagents were evaluated on the basis of two detection responses, the threshold cycle (C(T)) and the fluorescence intensity by a normalized reporter value (DeltaR(n)) . The C(T) response was identified as the most suitable for detection modeling to describe the PCR performances of different samples . DNA extracted from S . enterica serovar Enteritidis was studied in double-distilled H2O (ddH2O) and in two different enrichment media (brain heart infusion and BPW) with two PCR mixtures based on AmpliTaq Gold or rTTH: A descriptive model was proposed and fitted to the available experimental data . Equivalent PCR performances for the two PCR mixtures were obtained when DNA was diluted in ddH2O . However, the level of detection of DNA was affected when BPW was present during amplification . Use of the rTth mixture generated a 1-log-unit wider linear range of amplification, and the DNA detection levels were 2 x 10(-13) g/microwell for the rTth mixture and 2 x 10(-12) g/microwell for the AmpliTaq Gold mixture . To verify the improved amplification capacity of the rTth mixture, BPW was inoculated with 1 CFU of S . enterica serovar Enteritidis per ml and the mixture was incubated at 30 degrees C . Samples for PCR were withdrawn every 4 h during a 36-h enrichment . Use of the rTth mixture resulted in an earlier PCR detection during enrichment than use of the AmpliTaq Gold mixture . For accurate detection (C(T) < or = 30) of S . enterica serovar Enteritidis inoculated in BPW, the rTth mixture required 8.4 h of enrichment, while the AmpliTaq Gold mixture needed 11.6 h . In conclusion, the principle applied can improve the methodology of 5' nuclease real-time PCR for numerical optimization of sample pretreatment strategies to provide automated diagnostic PCR procedures. Appl Environ Microbiol, 2002 Jan, 68(1), 181 - 6 Salmonella enterica serotype Bredeney: antimicrobial susceptibility and molecular diversity of isolates from Ireland and Northern Ireland; Cormican M et al.; Salmonella enterica serotype Bredeney has emerged as the third most commonly identified serotype among human clinical isolates referred to the Irish National Salmonella Reference Laboratory in the years 1998 to 2000 . A collection of 112 isolates of S . enterica serotype Bredeney collected during the period 1995 to 1999 from animal, food, and human sources from both Ireland and Northern Ireland were studied . Antimicrobial susceptibility testing, pulsed-field gel electrophoresis (PFGE), and DNA amplification fingerprinting (DAF) were performed on all isolates . Plasmid profiles were examined on a subset of 33 isolates . A high proportion (74%) of isolates were susceptible to all antimicrobial agents tested . Resistance to both sulfonamide and trimethoprim was observed in 21% of isolates, and resistance to multiple (five) antimicrobial agents was observed in a single isolate (0.9%) . Eight different PFGE patterns were obtained, with 87% of isolates grouping as PFGE type A . PFGE type A was predominant in animals, food, and humans . There was good overall concordance between the groups identified by PFGE and DAF . Overall results indicate that most S . enterica serotype Bredeney isolates in Ireland and Northern Ireland from animal and human sources are clonally related. Appl Environ Microbiol, 2002 Jan, 68(1), 86 - 92 Inoculation onto solid surfaces protects Salmonella spp . during acid challenge: a model study using polyethersulfone membranes; Gawande PV et al.; Salmonellae are the most frequently reported cause of outbreaks of food-borne gastroenteritis in the United States . In clinical trials, the oral infective dose (ID) for healthy volunteers was estimated to be approximately 1 million cells . However, in reports from various outbreaks, the ID of Salmonella species associated with solid foods was estimated to be as few as 100 cells . We found that fresh-cut produce surfaces not only provided suitable solid support for pathogen attachment but also played a critical role in increasing the acid tolerance of the pathogen . However the acidic nature of certain produce played no role in making salmonellae resistant to stomach acidity . Inoculation onto fresh-cut produce surfaces, as well as onto inert surfaces, such as polyethersulfone membranes and tissue paper, increased the survival of salmonellae during acid challenge (50 mM Na-citrate, pH 3.0; 37 degrees C; 2 h) by 4 to 5 log units . Acid challenge experiments using cells inoculated onto polyethersulfone membranes provided a model system suitable for studying the underlying fundamentals of the protection that occurs when Salmonella strains are associated with solid foods . The surface-associated acid protection, which was observed in several Salmonella strains, required de novo protein synthesis and was independent of stationary-phase sigma transcription factor. Exp Gerontol, 2002 Jan-Mar, 37(2-3), 235 - 47 Overproduction of monokines by leukocytes after stimulation with lipopolysaccharide in the elderly; Gabriel P et al.; The elderly suffer from an impaired immune function being obvious in a higher susceptibility to infections . Especially the rate of complications after infection with Salmonella, normally confined to the gastrointestinal tract, is raised . We compared in a whole blood assay and in vitro stimulation of peripheral blood mononuclear cell (PBMC) the secretion of interleukin (IL)-1-beta, IL-6, IL-8 and TNF-alpha, after stimulation with lipopolysaccharid (LPS) from Salmonella abortus equi and Escherichia coli, phytohaemagglutinin (PHA) and toxic shock syndrome toxin-1 (TSST-1) by leukocytes of healthy young donors, healthy elderly and healthy elderly fulfilling the SENIEUR protcol . Significantly higher secretion of IL-1-beta, IL-6 and IL-8 after stimulation with LPS were found in the SENIEUR elderly compared to young donors . IL-1-beta, IL-6 and IL-8 were elevated in the whole blood samples of the healthy elderly controls as well . After stimulation of whole blood samples from these healthy elderly with LPS, IL-1 and IL-6 secretion was significantly elevated, but stimulation of their PBMCs showed lower amounts of produced cytokines compared to the PBMCs of healthy young donors . The results suggest that the elvated cytokine releases are caused by an interaction of LPS with a serum factor in the blood of the elderly . Such an overproduction of these inflammatory cytokines by moncytes and neutrophils may be in part responsible for many symptoms elderly people suffer from during an infection with Salmonella. Biofizika, 2001 Nov-Dec, 46(6), 1081 - 5 {Effect of R plasmid on cell membrane structure in Salmonella derby}; Pepoian AZ et al.; The structure of membranes of Salmonella derby cells both containing R-plasmid and free of plasmid was studied by small- and large-angle X-ray diffraction . Reflections with interplane distances of 8 and 11 A were detected, which are typical of plasmid-carrying S . derby cells . These reflections are assumed to be due to equidistant well ordered positions of the polar groups of phosphatidylcholine and phosphatidylethanolamine molecules on membrane surface . It is also suggested that the formation of these structures is determined by peculiar hydrophilic-hydrophobic interactions of the phospholipid in membranes. J Food Prot, 2001 Dec, 64(12), 2083 - 7 Thermal lethality of Salmonella Senftenberg and Listeria innocua in fully cooked and packaged chicken breast strips via steam pasteurization; Murphy RY et al.; Fully cooked chicken breast strips were surface inoculated to contain 9 log10 (CFU/g) Salmonella Senftenberg or Listeria innocua . The inoculated products were vacuum packaged in 0.2-mm-thick barrier bags (241 by 114 mm), then steam pasteurized at 88 degrees C in a continuous process for 26 to 40 min or in a batch process for 33 to 41 min . After the treatments, the products were analyzed for the survivors of Salmonella or Listeria . The models were developed to correlate the surviving rate of Salmonella and Listeria with cooking time for both continuous and batch processes . A cooking time of 34 min was needed to achieve 7 logs of the reduction in a batch process . To achieve the same log reduction, a longer (6 min) cooking time was needed in a batch process than in a continuous process . The results from this study will be useful for processors to evaluate postcooking treatment procedures for ready-to-eat meat products. J Food Prot, 2001 Dec, 64(12), 2067 - 70 Evaluation of subtherapeutic use of the antibiotics apramycin and carbadox on the prevalence of antimicrobial-resistant Salmonella infection in swine; Edrington TS et al.; The antibiotics apramycin and carbadox were fed to growing swine, and the prevalence of Salmonella isolates that are resistant to apramycin and related aminoglycoside antibiotics was examined . Three hundred twelve Salmonella-positive pigs raised on one of five farms in an integrated swine operation and slaughtered at a central plant were used . All farms fed carbadox during the grower phase, and two farms administered apramycin during the first 21 days of age . Ileocolic lymph nodes and cecal contents were sampled at slaughter . One hundred of the 312 pigs were randomly selected to examine apramycin- and carbadox-resistant Salmonella infection, while all 312 pigs were used to evaluate the association between apramycin exposure and infection with Salmonella organisms resistant to amikacin, gentamicin, kanamycin, and streptomycin . Antimicrobial resistance was determined using disk diffusion and breakpoint concentrations . Apramycin treatment appeared to have little effect on apramycin- (12.5 versus 20.9%) or streptomycin- (76.4 versus 73.5%) resistant Salmonella isolates when averaged across farms and compared to control animals . Feeding carbadox resulted in carbadox-resistant Salmonella infection in only 5.3% of the isolates on one farm . The prevalence of amikacin-, gentamicin-, and kanamycin-resistant Salmonella isolates on farms feeding apramycin and carbadox were 0, 0, and 1.8%, respectively . Serogroup B was the most prevalent serogroup isolated, followed by C1 and E1 . Apramycin and carbadox treatment did not appear to have any effect on the serogroup isolated . Subtherapeutic use of carbadox and apramycin did not appear to increase the prevalence of antimicrobial-resistant Salmonella in market-age swine. J Food Prot, 2001 Dec, 64(12), 2053 - 7 Fate of salmonellae in calcium-supplemented orange juice at refrigeration temperature; Sharma M et al.; Recent outbreaks of salmonellosis associated with orange juice have raised interest concerning the survival and growth of Salmonella in juice supplemented with calcium . A study was done to determine the influence of various calcium supplements on the survival of salmonellae in orange juice held at 4 degrees C for up to 32 days . Isolates of Salmonellal Muenchen (inoculum 1), Salmonella isolates from humans and animals (inoculum 2), and Salmonella isolates from produce outbreaks (inoculum 3) were inoculated into pasteurized orange juices with pH values ranging from 3.96 to 4.19 and containing 350 mg of calcium per 240-ml serving (1.46 mg of calcium/ml) . Populations of Salmonella declined rapidly in juice containing calcium lactate (CaL), with counts decreasing from 4.86 log10 CFU/ml to < 1 log10 CFU/ml within 16 days, regardless of the Salmonella serotypes present in inoculum . Counts decreased from 4.89 log10 CFU/ml to < 1 log10 CFU/ml in orange juice supplemented with CaL and tricalcium phosphate (TCP) within 30 days . These reductions were significantly (P < or = 0.05) higher than those of the control (no calcium added), in which Salmonella populations decreased 3.19 +/- 0.20 log10 CFU/ml over 32 days . Populations in orange juice containing TCP or calcium citrate (CC) declined 1.34 +/- 0.20 log10 CFU/ml and 1.96 +/- 0.20 log10 CFU/ml, respectively, over 32 days . These counts were significantly higher than respective control counts in juice stored for 32 days . Populations of Salmonella of inoculum 3 inoculated into juice containing calcium citrate malate (CCM) were significantly higher than in the control . Higher numbers of cells in inoculum 3 also survived compared to numbers of cells of inocula 1 or 2 in juice supplemented with CCM . This study reveals that the form of calcium used to supplement orange juice influences the ability of salmonellae to survive. J Food Prot, 2001 Dec, 64(12), 1917 - 21 Comparison of Salmonella Enteritidis infection in hens molted via long-term feed withdrawal versus full-fed wheat middling; Seo KH et al.; Molting is an important economic management tool for the layer industry as a means of maximizing the effective laying life of a flock . Previous work has shown that molting birds through feed removal (FM) increased the severity of a Salmonella Enteritidis (SE) infection . The current study was conducted to follow the progression of an SE infection in unmolted hens versus hens molted via 14-day FM or ad libitum feeding of wheat middlings (WM), in the presence or absence of 2.5% lactose administered in the drinking water . In two trials of the experiment, all hens were infected with approximately 1 x 10(7) SE at day 4 of molt and sampled for SE shedding on days 4, 10, 17, and 24 postinfection (PI) . Organ levels of SE were determined on day 7 PI . All molt procedures caused cessation of egg lay within 3 to 7 days . In trials 1 and 2, birds subjected to total FM shed 3 to 5 logs more SE than either the control birds (unmolted) or the birds fed WM on days 4 and 10 PI . Liver and spleen, ovary, and cecum counts were also significantly (P < 0.05) higher in the fasted birds in one trial and liver and spleen and cecum counts in the second . No differences in any of the SE counts were observed in unmolted versus WM-fed birds . Lactose supplementation in drinking water did not provide any advantage in reducing SE infection in either trial . These results indicate that there are alternative methods to long-term FM that can be used to molt birds and not increase the risk for SE problems . How these alternative methods compare with FM with regard to second-cycle egg production and the mechanisms involved in the reduced SE shedding remain to be investigated. J Food Prot, 2001 Dec, 64(12), 1912 - 6 Monitoring of chicken houses and an attached egg-processing facility in a laying farm for Salmonella contamination between 1994 and 1998; Murase T et al.; Two chicken houses and an attached egg-processing facility in a laying farm were sampled between 1994 and 1998 to investigate Salmonella contamination . Each of the houses was environmentally controlled and fitted with egg belts that transported eggs from the houses to the egg-processing facility . Four hundred twenty-eight Salmonella isolates were obtained from 904 environmental samples collected from the houses . Two hundred fifty-two of the 428 (58.9%) isolates yielded five serotypes as follows: Salmonella enterica subsp . enterica serovar Livingstone, Salmonella serovar Cerro, Salmonella serovar Montevideo, Salmonella serovar Mbandaka, and Salmonella serovar Corvallis . The remaining (41.1%, 176 of 428) isolates included four other serotypes and isolates that were untypeable . Salmonella isolates obtained from the drain water collected after the washing of the eggs in the egg-processing facility yielded the same serotypes as those found in the chicken houses . Strains having an identical pulsed-field gel electrophoresis (PFGE) pattern were continually recovered from a house for more than 1 year . Several strains of Salmonella Cerro, Salmonella Mbandaka, and Salmonella Montevideo obtained from both the houses and from the egg-processing facility were indistinguishable by PFGE, respectively . These results suggest that Salmonella organisms originating from a single clone colonized the chicken houses and that the egg belts are likely to be one of the means by which Salmonella organisms are spread from one house to the others. J Food Prot, 2001 Dec, 64(12), 1891 - 8 Use of green fluorescent protein expressing Salmonella Stanley to investigate survival, spatial location, and control on alfalfa sprouts; Gandhi M et al.; Laser scanning confocal microscopy (LSCM) was used to observe the interaction of Salmonella Stanley with alfalfa sprouts . The green fluorescent protein (gfp) gene was integrated into the chromosome of Salmonella Stanley for constitutive expression, thereby eliminating problems of plasmid stability and loss of signal . Alfalfa seeds were inoculated by immersion in a suspension of Salmonella Stanley (ca . 10(7) CFU/ml) for 5 min at 22 degrees C . Epifluorescence microscopy demonstrated the presence of target bacteria on the surface of sprouts . LSCM demonstrated bacteria present at a depth of 12 microm within intact sprout tissue . An initial population of ca . 10(4) CFU/g seed increased to 7.0 log CFU/g during a 24-h germination period and then decreased to 4.9 log CFU/g during a 144-h sprouting period . Populations of Salmonella Stanley on alfalfa seeds decreased from 5.2 to 4.1 log CFU/g and from 5.2 to 2.8 log CFU/g for seeds stored 60 days at 5 and 22 degrees C, respectively . The efficacy of 100, 200, 500, or 2,000 ppm chlorine in killing Salmonella Stanley associated with sprouts was determined . Treatment of sprouts in 2,000 ppm chlorine for 2 or 5 min caused a significant reduction in populations of Salmonella Stanley . Influence of storage on Salmonella Stanley populations was investigated by storing sprouts 4 days at 4 degrees C . The initial population (7.76 log CFU/g) of Salmonella Stanley on mature sprouts decreased (7.67 log CFU/g) only slightly . Cross-contamination during harvest was investigated by harvesting contaminated sprouts, then directly harvesting noncontaminated sprouts . This process resulted in the transfer of ca . 10(5) CFU/g Salmonella Stanley to the noncontaminated sprouts. Orv Hetil, 2001 Nov 18, 142(46), 2557 - 61 {Disorders of interferon-gamma activation pathways: new group of primary immune deficiency diseases}; Erdos M et al.; Protective immunity to intracellular bacteria such as mycobacteria and salmonella depends on intact cell-mediated immunity . Major effector mechanisms of cell-mediated immunity involve activation of macrophages by T helper-1 cytokines, particularly interferon-gamma . Patients with genetic deficiency of T helper-1 cytokines (IFN-gamma, IL-12) or T helper-1 cytokine receptors (IFN-gamma receptor, IL-12 receptor) are susceptible to infections with poorly pathogenic mycobacteria, and salmonella, suggesting that T helper-1 cytokines are essential in host defense against these pathogens . This review reports on the genetic and clinical characteristics of primary deficiencies of interferon-gamma activation pathways. J Vet Med Sci, 2001 Nov, 63(11), 1221 - 4 Effects of rearing conditions on the colonization of Salmonella enteritidis in the cecum of chicks; Asakura H et al.; Salmonella enteritidis is the cause of human salmonellosis associated with contaminated eggs . In this study, we artificially challenged S . enteritidis to chicks just after hatching, and the effects of breeding conditions on the intestinal carriage of S . enteritidis were examined . S . enteritidis was not directly detected from spleen, liver and blood, but were constantly isolated from the cecal contents throughout the experiment . When chicks were reared in the unsanitary conditions and in the high housing density, the numbers of S . enteritidis increased . The subsequent experiment was undertaken to examine whether the antibacterial additive in a feed would have any impact on S . enteritidis colonization in chicks . Some antibiotic effective on the growth promotion had an influence on S . enteritidis colonization. Res Microbiol, 2001 Dec, 152(10), 907 - 9 Supplement 2000 (no . 44) to the Kauffmann-White scheme; Popoff MY et al.; This supplement reports the characterization of 12 new Salmonella serovars recognized in 2000 by the WHO Collaborating Centre for Reference and Research on Salmonella: nine were assigned to S . enterica subsp . enterica, two to subspecies salamae, and one to subspecies diarizonae. Water Res, 2002 Jan, 36(1), 25 - 32 Genotoxic response of Austrian groundwater samples treated under standardized UV (254 nm)--disinfection conditions in a combination of three different bioassays; Haider T et al.; Ground water samples from different geographic areas in Austria, with different amounts of natural and anthropogenic organic compounds were treated with a standardized low pressure UV (254 nm)-irradiation laboratory flow-through system (UV fluence: 800 J/m2) . The genotoxic activities of the water samples before and after the UV disinfection were investigated using a combination of three different bioassays which complement each other with regard to their sensitivity detecting different genotoxins . The test battery comprises the Salmonella/microsome assay (Ames test with TA98 . TA 100 and TA 102, with and without S9 mix) and two micronucleus tests with the plant Tradescantia (clone #4430) and with primary rat hepatocytes . Overall, the tested Austrian groundwater samples used for human consumption caused only weak genotoxic activities compared to drinking water samples reported from other countries under similar experimental conditions . With the exception of one weak positive result in the Ames test (only in strain TA98 without S9 mix) with an induction factor of 1.9) all samples after UV disinfection were devoid of additional mutagenic and clastogenic activities compared to the samples before UV disinfection. Water Environ Res, 2001 Sep-Oct, 73(5), 607 - 11 Persistency of bacterial indicators in biosolids stabilization with coal fly ash and lime; Wong JW et al.; Alkaline coal fly ash and lime were tested for their effectiveness in pathogen removal from biosolids at different time intervals and temperatures . Coal fly ash at 10 and 35% w/w was mixed with dewatered biosolids and then the ash-biosolids mixture was mixed separately with 0, 1.1, 2.2, 4.4, 8.5, 11, and 18% calcium oxide (w/w on a dry weight basis) with and without heating to 55 degrees C . Total bacteria, salmonella, and total coliforms were monitored at various time intervals . Both ash-biosolids mixtures with or without lime amendment had a significantly lower total bacterial population than the biosolids control, but the residual indigenous bacterial flora in the ash and lime stabilized biosolids still maintained a population of greater than 10(4) g(-1) dry biosolids . Alkaline-stabilized biosolids with a lime amendment rate greater than 8.5% could maintain pH greater than or equal to 12 for more than 2 hours, which effectively removed total coliforms and salmonella in the mixture . Heat treatment to 55 degrees C and a storage time of 14 days provided an added advantage resulting in a further reduction in pathogens for all treatments . It is recommended that 10% ash-biosolids mixture should be amended with a minimum of 8.5% lime on a dry weight basis for at least 2 hours to achieve acceptable levels of salmonella and total coliforms to ensure no pathogenic risk following land application. J Environ Health, 2001 Dec, 64(5), 9 - 12, 33; quiz 37-8 An outbreak of Norwalk-like viral gastroenteritis in a frequently penalized food service operation: a case for mandatory training of food handlers in safety and hygiene; Kassa H; In 1999, in Toledo, Ohio, an outbreak of gastroenteritis occurred among people who had attended a Christmas dinner banquet and had eaten food prepared by a local caterer . Overall, 93 of the 137 attendees (67.9 percent) reported illness . Eight sought medical care, and one was hospitalized . Case-control studies revealed that the illness was associated with eating tossed salad (odds ratio {OR} = 2.5, 95 percent confidence interval {CI} = 1.02-6.26) . Eleven of 12 stool specimens that were taken from ill people tested positive for a Norwalk-like virus (NLV) but were negative for E . coli O157:H7, Salmonella, and Shigella . The primary source of the outbreak was not determined, but an infected food handler may have played a role in the transmission of the virus . The catering facility had been cited frequently for food safety and hygiene violations . None of the personnel or food handlers at this facility had been appropriately trained in safe food-handling practices, nor had the personnel at another local caterer that had prepared food items suspected of causing a multistate outbreak of NLVs . In Toledo, food service operations with trained personnel/food handlers received better inspection reports than food service operations without trained personnel and were less likely to contribute to foodborne outbreaks . Training of personnel and food handlers may be important for preventing outbreaks. Int J Food Microbiol, 2001 Nov 8, 70(3), 231 - 42 Salmonella in slaughter pigs: the effect of logistic slaughter procedures of pigs on the prevalence of Salmonella in pork; Swanenburg M et al.; A substantial part of the finishing pigs in the Netherlands is infected with Salmonella . Infection of pigs with Salmonella can occur already on the farm . Pigs can also get infected or contaminated during transport, lairage or slaughter . The aim of this study was to evaluate the effect of separating pigs from Salmonella-infected farms from pigs from Salmonella-free farms during transport, lairage and slaughter on the prevalence of Salmonella on pork after slaughter . Two experiments were carried out . In the first experiment, farms were selected to participate, based on serology of the pigs (Dutch Salmonella ELISA) . The pigs were slaughtered at the beginning of the day: firstly, sero-negative herds, secondly, sero-positive herds and thirdly, again sero-negative herds . The latter were slaughtered to investigate the effect of a contaminated slaughterline due to a previously slaughtered positive herd . In the second experiment, farms were selected to participate, based on both serology and bacteriology of the pigs on the farm . Two hundred pigs from Salmonella-free farms were slaughtered after 200 pigs from Salmonella-infected farms . Results showed that the prevalence of Salmonella in pork samples of sero-negative herds was lower than in samples of sero-positive herds . Results also showed that Salmonella contamination of carcasses after slaughter was partially caused by Salmonella-infected herds that were slaughtered before, and partially by residential flora of the slaughterhouse . It is concluded that separate slaughter of sero-negative pig herds can be useful to decrease the prevalence of Salmonella-contaminated pork after slaughter . To avoid cross-contamination by residential flora from trucks, lairage and slaughterline, cleaning and disinfection have to be improved. Bratisl Lek Listy, 2001, 102(8), 374 - 6 Eradicative effect of cotrimoxazole and quinolones on non-typhoid salmonellae; Wawruch M et al.; Opinions on antibiotic treatment of salmonella gastroenteritis are still different . Many authors support an opinion that antimicrobial treatment has no effect on salmonella elimination . The authors of the study have tried to prove that fluoroquinolones shorten the elimination of salmonellae and therefore they are useful not only for the treatment of salmonella gastroenteritis in immunocompromised patients to prevent sepsis and extraintestinal manifestations of the infection, but also for eradication of salmonellae in food industry workers, whose carrier state might exclude them from their work . (Tab . 3, Ref . 10.) J Assoc Physicians India, 2001 Apr, 49, 477 - 8 An unusual paratyphoid fever; Biswas R et al.; Salmonella typhi is known to produce acalculous cholecystitis and related gall bladder perforation . Following is a documentation of a patient of sub-phrenic abscess and gall bladder perforation which was possibly a result of Salmonella paratyphi A. Ann Oncol, 2001, 12 Suppl 2, S19 - 25 Nerve-driven immunity: neuropeptides regulate cytokine secretion of T cells and intestinal epithelial cells in a direct, powerful and contextual manner; Levite M et al.; Throughout the body, immune cells of various types, both classical (such as T-cells) and less recognized (such as intestinal epithelial cells) are exposed to a variety of neurotransmitters secreted from local nerve fibers . Moreover, immune cells express specific neurotransmitter receptors . Based on the above we asked whether neurotransmitters . by direct interaction with their receptors, can either evoke or block immune functions in general, and cytokine secretion in particular . We found that several neuropeptides (SOM, Sub P, CGRP and NPY), in nM concentration and in the absence of any additional stimulatory molecules, induced a significant secretion of cytokines from Th0, Th1 and Th2 antigen specific T-cells . Moreover, some neuropeptides surprisingly drove committed Thl and Th2 populations to a 'forbidden' cytokine secretion: secretion of Th2 cytokines from Th1 cells, and vice versa . We further found that SOM by itself markedly affected the secretion of proinflammatory cytokines from intestinal epithelial cells, which play a major role in the gut immunity in the mucosal defense against invading microorganisms . Thus, somatostatin, through its specific receptor, inhibits (> 90%) of the spontaneous, TNF-alpha or bacteria (Salmonella)-induced secretion of IL-8 and IL-1beta from two intestinal epithelial cell lines . Taken together, these observations suggest that neuropeptides can by themselves induce both typical and atypical cytokine secretion from T-cells and intestinal epithelial cells . Since a myriad of immune reactivities are mediated by, and dependent on, specific cytokines secreted from immune cells, the neuropeptide-induced effects may have important implications for numerous physiological and pathological conditions, including autoimmune diseases, chronic inflammation and neoplasias. Przegl Epidemiol, 2001, 55(3), 261 - 73 {Collective outbreaks of foodborne infections and intoxications in Poland in 1985-1999.}; Przybylska A; In outbreaks of foodborne infections and intoxications in 1985-1999 in Poland among salmonellas S . Enteritidis amounted for 84.9% in 1986 and 97.8% in 1991-1992 . In 1985-1999, among the total number of diseases in outbreaks most of the cases occurred after eating of the dishes made from eggs (over 50%) . In 1987-1999, food prepared in private homes had the largest influence on the occurrence of the outbreaks (up to 65.4% of outbreaks) . The private homes were also the most frequent places of the consumption of that food . Contamination of the ready-made dishes was found to be due to the raw materials, mainly eggs coming from private farms . In Poland and in neighboring countries Salmonella of animal's source determines the epidemiological situation of foodborne infections and intoxications. J Med Microbiol, 2001 Dec, 50(12), 1049 - 54 Survival and distribution of cell-free SEF 21 of Salmonella enterica serovar Enteritidis in the stomach and various compartments of the rat gastrointestinal tract in vivo; Naughton PJ et al.; Rats were dosed for 6 days with purified SEF 21 fimbriae of Salmonella enterica serovar Enteritidis 10360 . The levels of fimbriae in gut contents associated with tissues and in the faeces were quantified by direct non-competitive ELISA . SEF 21 was distributed throughout the gut . The majority was found in the large intestine where it was primarily in the luminal contents . In contrast, a high proportion of SEF 21 detected in the ileum, the main site of salmonella colonisation and invasion, was tissue-bound . Thus, purified SEF 21 survived intestinal passage and associated with the stomach and gastrointestinal tract in a pattern similar to that found with whole Salmonella cells. Presse Med, 2001 Nov 17, 30(34), 1674 - 80 {Causes of fever in adults infected by HIV-1 . Ambulatory follow-up in the ANRS 059 trial in Abidjan, Ivory Coast}; Dakoury-Dogbo N et al.; OBJECTIVE: Describe the causes of fever in HIV-1 infected adults in Abidjan, Ivory Coast . METHODS: Exhaustive analysis of all the morbid episodes with raise in temperature to above 37.5 degrees C in patients followed-up prospectively, within the framework of the ANRS 059 study from April 1996 to March 1998 . RESULTS: One hundred and four patients presented 269 episodes of fever . At the start of these episodes, the mean CD4 count was of 311/mm3, fever had lasted a mean of 3.4 days and mean body temperature was 38.7 degrees C . The 269 episodes lead to 288 diagnoses: 152 specific etiologic diagnoses and 136 non-specific syndrome diagnoses . Community bacterial infections represented 55% of the specific diagnoses, followed by malaria (16%) and tuberculosis (12%) . The mean CD4 count during the bacterial episodes was 208/mm3, in malaria 384/mm3 and in tuberculosis 245/mm3 . Non-typhi salmonella, pneumococci and Escherischia coli represented 37%, 32%, and 15% respectively of the bacteria isolated . The mean duration between the first and last day of fever was 8.4 days . This time lapse was superior or equal to 30 days in 22 episodes (8%), 50% of which were mycobacterioses (36% tuberculosis and 14% atypic mycobacterioses) . Nineteen episodes (7%) lead to death within a mean delay of 58 days . The first cause of death was atypic mycobacteriosis (26%) . Death was significantly associated with a CD4 count < 200/mm3 and to prolongation of fever for more than 30 days . CONCLUSION: Other than the frequently described role of tuberculosis in HIV morbidity in sub-Saharian Africa, the role of bacterial diseases, responsible for early death, potentially severe, but curable should be underlined . The diffusion of antibiotic treatment algorithms adapted to the principle clinical syndromes encountered, might improve the treatment of adults infected by HIV consulting in sub-Saharian Africa. Scand J Infect Dis, 2001, 33(11), 862 - 5 Invasive Salmonella virchow infection in childhood; Bitsori M et al.; Salmonella virchow is generally considered to be one of the less invasive non-typhoidal Salmonellae species; however, several invasive cases have previously been reported . We report 3 cases of otherwise healthy children with S . virchow bacteraemia, monoarthritis and prevertebral abscess, only 1 of whom had previously had gastroenteritis . All 3 children responded to antibiotic regimens consisting of cefotaxime for 10 d, ceftriaxone for 3 weeks and ceftriaxone plus clindamycin for 4 weeks, respectively . In conclusion, S . virchow may be a more invasive serotype in immunocompetent children and present with a wider spectrum of manifestations than considered previously. Int J Food Microbiol, 2001 Oct 22, 70(1-2), 37 - 51 Modeling non-linear survival curves to calculate thermal inactivation of salmonella in poultry of different fat levels; Juneja VK et al.; Survival curves of a cocktail of eight serotypes of Salmonella in ground poultry of different fat levels (1-12%), when heated rapidly to specified temperatures (58-65 degrees C), were examined . Because many of the survival curves were concave, values for two parameters: the asymptotic D-value and the "lag" times were estimated and used to develop secondary models for estimating the time needed to obtain a 7 log10 relative reduction as a function of fat level and temperature . To compute the necessary time, at a given temperature and fat level, the estimated lag time should be added to the product of 7 and the estimated asymptotic D-value . A model was also developed for estimating the standard error of the estimated times, so that upper confidence bounds for the necessary times can be computed . It was found that lag times increase with higher fat levels . The effect of fat on D-values depended on the species; it is estimated that, for a given increase of fat level, the increase of the D-value would be greater for ground chicken than that for ground turkey . In addition, there was a statistically significant species effect on D-values, with higher D-values for ground turkey than for ground chicken at the higher temperatures studied . The thermal death curves displayed a non-linear tendency, however, for estimation purposes, a linear curve was assumed . There was not a statistically significant interaction effect of fat levels and temperatures on D-values, thus, for modeling, it was assumed that z-values were not dependent on the fat levels . The z-values for ground chicken and turkey were estimated to be 5.5 degrees C and 6.1 degrees C, respectively, and are statistically significantly different . These findings should have substantial practical importance to food processors of cooked poultry, allowing them to vary their thermal treatment of ready-to-eat poultry products in a safe manner. Int J Food Microbiol, 2001 Oct 22, 70(1-2), 29 - 35 Antimicrobial susceptibilities of isolates of Staphylococcus aureus, Listeria species and Salmonella serotypes associated with poultry processing; Geornaras I et al.; The broth microdilution method was used to determine the activities of selected antimicrobial agents used in the South African poultry industry (danofloxacin, neomycin, chlortetracycline, oxytetracycline, tylosin and colistin) and vancomycin against bacterial isolates previously obtained from carcasses and selected equipment surfaces and environmental sources associated with poultry processing . The antimicrobial susceptibilities of 38 isolates of Staphylococcus (S.) aureus, 25 Listeria (L.) innocua, 18 L . monocytogenes, and 62 isolates belonging to six Salmonella (Salm.) serotypes (Salm . agona, Salm . blockley, Salm . enteritidis, Salm . isangi, Salm . reading and Salm . typhimurium) were determined . The most active antimicrobial agent against all the isolates tested was danofloxacin with minimum inhibitory concentrations (MICs) for 90% of the isolates (MIC90) not exceeding 0.25 and 2 microg/ml for gram-negative and gram-positive isolates, respectively . Conversely, high MICs were recorded for all the isolates tested against chlortetracycline and oxytetracycline (MIC90 range of 32 to > 512 microg/ml), except for the L . monocytogenes and Salm . enteritidis isolates (MIC range of < or = 0.5-4 microg/ml) . Neomycin was found to be active against S . aureus, L . innocua, L . monocytogenes, Salm . enteritidis and Salm . isangi isolates, with MICs not exceeding 8 microg/ml . MIC ranges for tylosin and vancomycin, which were only tested against the gram-positive isolates, were from 1 to > 512 microg/ml and from 1 to 4 microg/ml, respectively . The MIC range for the remaining antimicrobial agent, colistin, which was only tested against the Salmonella isolates, was 0.5-16 microg/ml . The lack of MIC breakpoints for the antimicrobial agents used in the poultry industry did not allow for definite conclusions as to the level of resistant bacteria associated with poultry carcasses and the processing environment in this study. Int J Food Microbiol, 2001 Oct 22, 70(1-2), 131 - 41 Growth of Salmonella enteritidis in artificially contaminated eggs: the effects of inoculum size and suspending media; Cogan TA et al.; Growth profiles of two isolates of Salmonella enteritidis phage type (PT) 4 inoculated into either the albumen of whole shell eggs or into separated albumen were found to be markedly affected by the size of the inoculum and the composition of the medium used to suspend the cells prior to inoculation . Using our model with an inoculum of two cells, multiplication of the Salmonella was not seen in 93% of eggs held at 20 degrees C for 8 days . In approximately 7% of eggs, however, growth occurred during the 8 days of storage . If the inoculum equaled or exceeded 25 cells per egg when eggs were subsequently stored at 20 degrees C, or 250 cells per egg when eggs were stored at 30 degrees C, high levels of growth of Salmonella in the egg occurred significantly more frequently than when the inoculum was two cells . High levels of growth were also seen more frequently if the inoculum was suspended in buffered peptone water or maximal recovery diluent rather than in phosphate buffered saline . Growth of Salmonella in separated albumen occurred very infrequently (1.1% of samples) at low inoculum levels and did not become significant until the inoculum was 250 cells or greater . Growth in the albumen was unaffected by the composition of the suspending medium . Provided that the inoculum was approximately 2 cells per egg and the bacteria were suspended in PBS, observed growth profiles of S . enteritidis inoculated into the albumen of whole eggs resembled those in naturally contaminated eggs. Med Dosw Mikrobiol, 2001, 53(2), 185 - 96 {Phage types, plasmid profiles and chromosomal restriction profiles of Salmonella enterica subsp . enterica ser . enteritidis (S . enteritidis) isolated in Poland in 1999-2000}; Cieslik A et al.; Salmonella Enteritidis strains are the most often isolated Salmonella serovars in Poland . In the present study, phage typing, plasmid profile analysis, and PFGE have been applied to characterize 140 Polish S . Enteritidis isolates originated from human cases of salmonellosis and from other sources . The typing phages of Ward and colleagues scheme were used to type a total of 140 S . Enteritidis strains coming from Poland . All 140 strains were typable and six different phage types were observed . A total of 125 (89%) of 140 isolates examined belonged to PT 4 . The others PTs were represented by small amount of strains (PT1-2, PT6-6, PT7-1, PT8-4 and PT21-2 strains) . Among all tested isolates six different plasmid profiles were observed . Of the 140 examined strains, 128 (91.4%) contained the 57 kb plasmid alone . After XbaI digestion four distinct pulse field chromosomal restriction profiles among studied S . Enteritidis were observed . XbaI and SpeI chromosomal restriction profiles of S . Enteritidis PT4 were identical with reference strain profiles . Our findings confirmed earlier suggestions that the increase of human salmonellosis cases in Poland was caused by S . Enteritidis PT4 and was due to consumption of contaminated food . This study confirmed the importance of using PFGE in combination with phage typing, plasmid typing and antibiotic resistance testing for studying the epidemiology of S . Enteritidis. Med Dosw Mikrobiol, 2001, 53(1), 17 - 29 {Multidrug resistance to antibacterial drugs of Salmonella enterica subsp . enterica strains isolated in Poland in the 1998-1999 period}; Szych J et al.; A total of 510 Salmonella enterica subsp . enterica strains representing 56 serotypes, isolated from human stool specimens during 1998-2000 in sanitary-epidemiological units in Poland were tested for their susceptibility by a standard disk diffusion method for: ampicillin, cefotaxime, chloramphenicol, tetracycline, streptomycin, gentamicin, kanamycin, nalidixic acid, ciprofloxacin, furazolidone, cotrimoxazole, sulfonamides and trimethoprim . For 201 of the investigated strains, belonging to 5 most common isolated serotypes (S . Enteritidis, S . Typhimurium, S . Hadar, S . Infantis and S . Virchow) the minimal inhibitory concentrations (MICs) for the aforementioned antibiotics, as well as for amoxicillin with clavulanian were determined . Selected strains were screened for production extended spectrum b-lactamases (ESBLs) . It was observed that 42.9% of Salmonella enterica subsp . enterica strains were resistant to 2 or more antibiotics, with the highest prevalence of MDR strains among serotypes Typhimurium, Hadar and Virchow . Resistance to ampicillin, streptomycin, tetracycline, nalidixic acid, furazolidone and sulphonamides was observed most frequently . Over 93% of S . Virchow strains were resistant to furazolidone . No strains resistant to ciprofloxacin were detected according to the NCCLS guidelines, but 31.3% of isolates exhibiting reduced ciprofloxacin susceptibility (MICs ranging between 0.125 and 0.5 mg/l) . Two strains S . Mbandaka and Salmonella group D (variant motility--) were resistant to cefotaxime and probably produced ESBL. Dev Comp Immunol, 2002 Apr, 26(3), 295 - 304 Interactions of Salmonella enterica serovar Muenchen with macrophages of the turtle Trachemys scripta scripta; Pasmans F et al.; Interactions of Salmonella with macrophages have been studied in birds and, most extensively, in mammals . In these homeothermic animals, interactions between Salmonella and macrophages are characterized by the following processes . After macropinocytosis, spacious phagosomes are formed within the macrophage . Partial inhibition of phagosome-lysosome fusion and resistance to the formation of reactive oxygen species and reactive nitrogen intermediates enable the bacterium to survive and even multiply within the host macrophage . Eventually, Salmonella will induce apoptosis of the macrophage . In this study, interactions of peritoneal macrophages of the turtle Trachemys scripta scripta with Salmonella enterica serovar Muenchen were examined in vitro . Turtle macrophages were able to phagocytise Salmonella efficiently at both 30 and 37 degrees C . Exposure of macrophages to Salmonella induced the production of reactive oxygen species, which could be partially suppressed by adding the NADPH oxidase inhibitor diphenylene iodonium . Initially, most of the intracellular bacteria were killed . However, Salmonella proved to be able to persist and multiply inside turtle macrophages at both 30 and 37 degrees C for at least 48 h, despite the production of reactive nitrogen intermediates by inducible NO synthase . Salmonella infection of turtle macrophages killed the phagocytes at both 30 and 37 degrees C . These findings demonstrate that no obvious qualitative differences exist between macrophage-Salmonella interactions from homeothermic animals and from turtles . This indicates that other factors are responsible for the different course of Salmonella infections in homeothermic and poikilothermic hosts. Microbes Infect, 2001 Nov-Dec, 3(14-15), 1353 - 60 Gene array technology to determine host responses to Salmonella; Rosenberger CM et al.; Gene expression array technology is a powerful new tool that has already been used to expand our understanding of host-pathogen interactions . There has been a rapid increase in published reports describing use of this approach to profile host responses to pathogenic bacteria and viruses . The large number of array studies currently in progress coupled with increasing accessibility of this new technology promises a plethora of gene expression data on host response to infection in the near future . Recent insights into macrophage and epithelial cell responses to Salmonella infection garnered from array studies are outlined and used as a basis to discuss various future research directions using gene arrays that will advance the field of cellular microbiology . There is an exciting potential for the gene expression data generated in such studies to provide insights into host physiology, the pathophysiology of disease and novel therapeutics. Microbes Infect, 2001 Nov-Dec, 3(14-15), 1345 - 52 Use of mixed infections with Salmonella strains to study virulence genes and their interactions in vivo; Beuzon CR et al.; In the Salmonella-mouse model of systemic infection, high dose inoculation results in the multiplication of many of the cells present in the inoculum