J Bacteriol, 2004 Apr, 186(8), 2476 - 80 PhoP can activate its target genes in a PhoQ-independent manner; Lejona S et al.; The PhoP/PhoQ two-component system controls the extracellular magnesium depletion response in Salmonella enterica . Previous studies have shown that PhoP is unable to up-regulate its target genes in the absence of PhoQ function . In this work, we demonstrate that PhoP overexpression can substitute for PhoQ- and phosphorylation-dependent activation . Either a high concentration of PhoP or activation via phosphorylation stimulates PhoP self-association. J Bacteriol, 2004 Apr, 186(8), 2402 - 12 Genetic analysis of the Salmonella enterica type III secretion-associated ATPase InvC defines discrete functional domains; Akeda Y et al.; An essential component of all type III secretion systems is a highly conserved ATPase that shares significant amino acid sequence similarity to the beta subunit of the F(0)F(1) ATPases and is thought to provide the energy for the secretion process . We have performed a genetic and functional analysis of InvC, the ATPase associated with the Salmonella enterica type III secretion system encoded within its pathogenicity island 1 . Through a mutagenesis analysis, we have identified amino acid residues that are essential for specific activities of InvC, such as nucleotide hydrolysis and membrane binding . This has allowed us to define discrete domains of InvC that are specifically associated with different essential activities of this protein. Genes Genet Syst, 2004 Feb, 79(1), 1 - 8 Characterization of six flagellin genes in the H3, H53 and H54 standard strains of Escherichia coli; Tominaga A; Six flagellin genes in three H standard Escherichia coli strains for H3, H53 and H54 were characterized . Each strain has two flagellin genes, one of which is expressed as its standard H antigen . A pair of flagellin genes flkA3 (encoding for H3 antigen) and fliC16 (H16) was cloned from Bi7327-41, flkA53 (H53) and fliC-53 from E480-68, and flmA54 (H54) and fliC-54 from E223-69 . Two fliC genes, fliC-53 and fliC-54, are nonfunctional owing to the insertions of IS1 and IS1222, respectively . The flkA and flmA regions are located in the 3' end of the rnpB gene and near the nlpA gene, respectively . Each of them is followed by a gene homologous to fljA, which is known to repress the expression of fliC(i) in Salmonella enterica serovar Typhimurium . These results suggest that they are derived from the same origin of the fljBA operon . However, these regions contain neither the hin gene nor the invertible H segment . The four flagellin genes, fliC16, flkA3, flkA53 and flmA54, share high homology in nucleotide and amino-acid sequences with one another and with the S . enterica serovar Typhimurium flagellin genes . The promoter sequence of fliC16 is homologous to that of fliC(i), whereas the promoter sequences of flkA and flmA are homologous to that of fljB . The terminator sequences of the fliC16, fliC-53 and fliC-54 genes are conserved among themselves and identical with that of the E . coli fliC48 gene . Three FljA repressors, FljA3, FljA53 and FljA54, are homologous highly with one another and moderately with FljA of Salmonella . These results indicate that six flagellin genes analyzed are markedly similar to the Salmonella flagellin genes, suggesting their lateral transfer from Salmonella. Enferm Infecc Microbiol Clin, 2004 Apr, 22(4), 204 - 211 {Resistance to quinolones and beta-lactams in Salmonella enterica due to mutations in topoisomerase-encoding genes, altered cell permeability and expression of an active efflux system}; Miro E et al.; Background . The mechanisms of resistance to fluoroquinolones and beta-lactams were studied in isolates of Salmonella enterica resistant to both antimicrobial groups, isolated over time from two patients treated with fluoroquinolones . Methods . The clonal relationships among the various strains was established by serotyping and pulsed-field gel electrophoresis . MICs for beta-lactams, quinolones, chloramphenicol and tetracycline were determined . Presence of beta-lactamases was ruled out by a colorimetric assay . Quinolone resistance-determining regions of the gyrA, gyrB, parC, and parE genes were sequenced, and the relevance of the mutations in these regions was evaluated by complementation assays . Outer membrane protein profiles, the effect of phenyl-arginyl-naphtylamide (PAN, 20 mg/l) on the MICs of several quinolones, and norfloxacin accumulation in the absence and in the presence of a metabolic inhibitor were also determined . Results . The following mutations were found: gyrA (Asp87 → Gly; Ser83 → Phe; Asp87 → Lys), gyrB (Ser463 → Phe) and parC (Glu84 → Gly) . Altered outer membrane protein profiles, including decreased expression of a porin equivalent to OmpF from Escherichia coli was observed . Active efflux of norfloxacin was proved in both a clinical isolate and a mutant obtained in vitro . In the presence of PAN, nalidixic acid MICs decreased 4-32 times (except in one strain), pefloxacin MICs decreased 4-16 times for 5 out of 9 evaluated strains, and MICs of both norfloxacin and ciprofloxacin did not change or changed within a single dilution step . Conclusions . Quinolone-resistance is the consequence of a combination of mutations in topoisomerase-encoding genes, altered permeability and active efflux . Altered permeability and active efflux would also contribute to decreased susceptibility to beta-lactams. Cell Microbiol, 2004 May, 6(5), 459 - 71 Efficient Salmonella entry requires activity cycles of host ADF and cofilin; Dai S et al.; Entry of Salmonella into mammalian cells is strictly dependent on the reorganization of actin cytoskeleton induced by a panel of Salmonella type III secreted proteins . Although several factors have been identified to be responsible for inducing the actin polymerization and stability, little is known about how the actin depolymerization contributes to Salmonella-induced actin rearrangements . We report here that activity cycles of host actin depolymerizing factor (ADF and cofilin) are modulated by Salmonella during bacterial entry . Efficient Salmonella internalization involves an initial dephosphorylation of ADF and cofilin followed by phosphorylation, suggesting that ADF and cofilin activities are increased briefly . Expression of a kinase dead form of an ADF/cofilin kinase (LIM kinase 1) or a catalytically inactive ADF/cofilin phosphatase (Slingshot), but not constitutively active LIM kinase 1 or wild-type Slingshot, resulted in decreased invasion . These data suggest that ADF/cofilin activities play a key role in the actin polymerization/depolymerization process induced by Salmonella . The activation of ADF/cofilin is brief and has to be reversed to facilitate efficient bacterial entry . Surprisingly, co-expression of constitutive active ADF and cofilin prevented efficient Salmonella entry, whereas expression of either one alone had no effect . We propose that ADF and cofilin actin-dynamizing activities and their activity cycling via phosphorylation are required for efficient Salmonella internalization. Bratisl Lek Listy, 2003, 104(10), 323 - 8 Do dogs and cats present a risk of transmission of salmonellosis to humans? Kozak M, Horosova K, Lasanda V, Bilek J, Kyselova J. Examination of rectal swabs from 187 dogs and 13 cats showed that Salmonella spp . was present in only one dog, a 4-month old mongrel puppy, weighing 3.5 kg . It was identified as S . dublin, a species specific serovar of cattle . The animal exhibited no signs of disease during clinical examination . Of the total number of examined animals this positive dog represents only 0.5% . Within the group of patients included in our monitoring in none of those with gastrointestinal problems it was possible to isolate Salmonella spp . This indicates that the risk of transmission of salmonellosis from dogs and cats in the region of Kosice seems to be rather low . On the basis of literature and our own observations we identified the potential sources and the possible ways of the transfer of this disease . The most common appears to be the oral infection by infected feed of various types, particularly by direct contamination of feed with either animal or human contaminants . In dogs and cats salmonellosis occurs most frequently in a latent form . The clinical findings vary with regard to the number of pathogens, immune status of the host, occurrence of health complications and the form of associated disease units . There are suitable isolation and diagnostic methods for diagnostics of salmonellosis . Due to the need for continuous protection of health of humans and animals, screening of occurrence of zoonotic pathogens appears topical . (Tab . 3, Fig . 1, Ref . 35.). Can J Microbiol, 2004 Feb, 50(2), 107 - 12 Salmonella enterica subsp . enterica serovar Enteritidis harbours ColE1, ColE2, and rolling-circle-like replicating plasmids; Gregorova D et al.; Using DNA hybridization, at least three distinct groups of low molecular mass plasmids were identified in Salmonella enterica subsp . enterica serovar Enteritidis . After sequencing representative plasmids from each group, we concluded that they belonged to ColE1, ColE2, and rolling-circle-like replicating plasmids . Plasmid pK (4245 bp) is a representative of widely distributed ColE1 plasmids . Plasmid pP (4301 bp) is homologous to ColE2 plasmids and was present predominantly in single-stranded DNA form . The smallest plasmids pJ (2096 bp) and pB (1983 bp) were classified as rolling-circle-like replicating plasmids . Both encoded only a single protein essential for their own replication, and they must have existed in an unusual molecular structure, as (i) they were capable of hybridization without denaturation, (ii) their DNA could be linearized with S1 nuclease, and (iii) even after such treatment, the ability to hybridize without denaturation did not disappear. Poult Sci, 2004 Mar, 83(3), 352 - 8 Tubular glands of the isthmus are the predominant colonization site of Salmonella enteritidis in the upper oviduct of laying hens; De Buck J et al.; Salmonella enterica serovar Enteritidis is the serovar most frequently isolated from chicken eggs . Colonization of the upper oviduct of hens is believed to play an important role in egg contamination . The interaction of S . enteritidis with gland epithelial cells of the isthmus and the magnum was, therefore, studied in vitro and in vivo . In the first experiment, S . enteritidis bacteria were added to confluent monolayers of primary cultures of chicken tubular epithelial cells of the isthmus (ICTEC) or magnum (MCTEC) . Intracellular bacteria in ICTEC and MCTEC were confirmed by a gentamicin protection assay . Internalization in the glandular cells was corroborated by confocal scanning microscopy . Although S . enteritidis was able to invade and proliferate intracellularly during 24 h in the cell culture of both segments, this was significantly more so in the ICTEC . In a second experiment, an in vivo loop model was developed for investigation of the invasiveness of S . enteritidis in the oviduct of laying hens . Loops in the isthmus and magnum of laying hens were made under anaesthesia . S . enteritidis was inoculated into each loop . After 1 h, tubular gland cells were isolated from the infected tissue under gentamicin . S . enteritidis invasiveness was measured as the ratio of isolated bacteria per isolated tubular gland cell . This ratio was higher (P < 0.01) in the isthmus (1.3 x 10(-3)) than in the magnum (5.3 x 10(-5)) . In a third experiment, laying hens were intravenously infected with 5 x 10(7) cfu S . enteritidis bacteria . The number of intracellular bacteria was counted in the tubular gland cells of the isthmus and magnum after isolation under gentamicin . The ratio of isolated bacteria per isolated tubular gland cell was again significantly higher in the isthmus as compared with in the magnum . In all 3 assays, the tubular gland cells of the isthmus were more heavily invaded than those of the magnum. Can J Microbiol, 2001 Jan, 47(1), 25 - 32 Response to trisodium phosphate treatment of Salmonella Chester attached to fresh-cut green pepper slices; Liao CH et al.; A laboratory model using green pepper disks was developed to investigate the attachment of Salmonella Chester on plant tissue and to evaluate the effectiveness of sanitizer agents in inactivating attached bacteria on fruits . Pepper disks (14 mm in diam, and 3-4 mm in thickness) were immersed in a bacterial suspension containing 1.5 x 107 cfu x mL(-1) of S . Chester for 30 s and subsequently air-dried at room temperature for 10 min . Approximately 30% of the bacteria retained on the disk after immersion were firmly attached and could not be removed by two washes and agitation . A positive correlation was observed between the number of bacteria attached and the concentration of bacteria in the suspension . Population studies and scanning electron microscopic examinations revealed that attachment of S . Chester on pepper disks occurred mainly on the surfaces of injured (cut) tissue but rarely on the unbroken skin . When inoculated disks were treated with 3% to 12% (w/v) of trisodium phosphate (TSP) at pH 12.3 for 5 min, the population of bacteria on the disk was reduced by 10- to 100-fold . A small portion (0.7% to 7.1%) of bacteria attached to the disk were either resistant to or protected from the TSP treatment . When the pH of TSP solution was reduced from 12.3 to 4.5, the effectiveness of TSP in inactivating S . Chester on pepper disks was reduced by 26% . This study shows that surfaces of injured fruit tissue are the principal sites for bacterial attachment, and a small portion of the bacteria attached to the tissue are resistant to the sanitizer treatment . Avoiding mechanical injuries to fresh fruits during and after harvest would reduce the chance of pathogen attachment and contamination on green pepper and fruits of similar nature. J Virol, 2004 Apr, 78(8), 4020 - 8 Protection from bacterial infection by a single vaccination with replication-deficient mutant herpes simplex virus type 1; Lauterbach H et al.; Adaptive immune responses in which CD8(+) T cells recognize pathogen-derived peptides in the context of major histocompatibility complex class I molecules play a major role in the host defense against infection with intracellular pathogens . Cells infected with intracellular bacteria such as Listeria monocytogenes, Salmonella enterica serovar Typhimurium, or Mycobacterium tuberculosis are directly lysed by cytotoxic CD8(+) T cells . For this reason, current vaccines for intracellular pathogens, such as subunit vaccines or viable bacterial vaccines, aim to generate robust cytotoxic T-cell responses . In order to investigate the capacity of a herpes simplex virus type 1 (HSV-1) vector to induce strong cytotoxic effector cell responses and protection from infection with intracellular pathogens, we developed a replication-deficient, recombinant HSV-1 (rHSV-1) vaccine . We demonstrate in side-by-side comparison with DNA vaccination that rHSV-1 vaccination induces very strong CD8(+) effector T-cell responses . While both vaccines provided protection from infection with L . monocytogenes at low, but lethal doses, only rHSV-1 vaccines could protect from higher infectious doses; HSV-1 induced potent memory cytotoxic T lymphocytes that, upon challenge by pathogens, efficiently protected the animals . Despite the stimulation of relatively low humoral and CD4-T-cell responses, rHSV-1 vectors are strong candidates for future vaccine strategies that confer efficient protection from subsequent infection with intracellular bacteria. Antimicrob Agents Chemother, 2004 Apr, 48(4), 1350 - 2 Evidence for a chromosomally located third integron in Salmonella enterica serovar Typhimurium DT104b; Daly M et al.; Salmonella enterica serovar Typhimurium isolates of phage types DT104 and DT104b are frequently associated with multiple antimicrobial resistance . We describe the characterization of a class 1 integron containing dfrA1 and aadA1, genes from two Salmonella serovar Typhimurium DT104b isolates . Genetic mapping located the integron to the bacterial chromosome in each case. Antimicrob Agents Chemother, 2004 Apr, 48(4), 1145 - 50 Expression of acrB, acrF, acrD, marA, and soxS in Salmonella enterica serovar Typhimurium: role in multiple antibiotic resistance; Eaves DJ et al.; Comparative reverse transcription-PCR in combination with denaturing high-pressure liquid chromatography analysis was used to determine the levels of expression of soxS, marA, acrF, acrB, and acrD in multiple-antibiotic-resistant (MAR) Salmonella enterica serovar Typhimurium isolates and mutants of S . enterica serovar Typhimurium SL1344 with defined deletions . Posttherapy MAR clinical isolates had increased levels of expression of all genes except soxS . S . enterica serovar Typhimurium SL1344 Delta acrB expressed 7.9-fold more acrF than the parent strain . A strain with an acrF deletion expressed 4.6-fold more acrB . Deletion of acrB and/or acrF resulted in 2.7- to 4.3-fold more marA mRNA and 3.6- to 4.9-fold increases in the levels of expression of acrD but had a variable effect on the expression of soxS . All mutants were hypersusceptible to antibiotics, dyes, and detergents; but the MIC changes were more noticeable for SL1344 with the acrB deletion than for the mutant with the acrF disruption . These mutants had different but overlapping phenotypes, and the concentrations of ciprofloxacin accumulated by the mutants were different . These data suggest that acrB, acrF, and acrD are coordinately regulated and that their expression influences the expression of the transcriptional activators marA and soxS. Res Vet Sci, 2004 Jun, 76(3), 243 - 7 Epithelial response to experimentally introduced intraluminal bacteria in the avian epididymal ducts; Aire TA et al.; The response of the epithelial cells of the various ducts of the avian epididymis, whose function is poorly understood, to intraluminal bacteria was evaluated by the injection of an avirulent strain of Salmonella gallinarium into the RT for 24 h . Ultrastructurally, bacteria and invading mononuclear cells were present in the lumina of the RT, proximal efferent ducts (PED) and distal efferent ducts . However, only the non-ciliated (Type I) cells of the PED epithelium ingested bacteria from the lumen . Fragments of bacteria also occurred in several intercellular spaces in the epithelium of the PED . Some mononuclear cells also contained fragments of bacteria . Neither cell death in the various epithelia nor mononuclear infiltration of the periductal tissue occurred . Therefore, in addition to the established function of absorbing most of the testicular fluid entering the epididymis, the Type I cells also appear capable of recognising and removing foreign particulate matter from the epididymal through-flow in the proximal part of the epididymis. Res Vet Sci, 2004 Jun, 76(3), 165 - 9 Genetic resistance to Salmonella infection in domestic animals; Wigley P; Genetic resistance to Salmonella infection in experimental animal models is well described . However, genetic resistance in domestic animals, which has potentially great value in terms of controlling Salmonella in the food chain, has been relatively poorly described . Recent advances in genetics and immunology have identified several factors that influence resistance in chickens and pigs in particular . Resistance to systemic salmonellosis in the chicken is encoded by a number of factors including Nramp1 (now termed Slc11a1) and a novel gene, SAL1 that leads to increased macrophage activity against Salmonella . Studies in outbred, and in particular, inbred chickens have revealed considerable differences in levels of colonization of the gastrointestinal tract and responses to vaccination . Factors influencing this appear to include innate immune function, MHC and Nramp . In pigs several immune factors, including polymorphonuclear cell activity, have been shown to influence resistance. Biol Neonate, 2004, 86(1), 39 - 47 Epub 2004 Mar 23. Endotoxin effects on markers of autonomic nervous system function in the piglet: implications for SIDS; Voss LJ et al.; The hypothesis was tested in 30 newborn piglets that the effects of a low dose of endotoxin (1 microg i.v . bolus; Salmonella abortus equi) would impair autonomic nervous system function . Two tests of autonomic function were performed following external warming (pre-endotoxin) and during endotoxin-generated thermogenesis: (1) analysis of heart rate variability in the time and frequency domains and (2) baroreflex sensitivity measured following intravenous injection of the vasoactive drugs nitroprusside and phenylephrine . Beat-to-beat heart rate variability (SDDeltaRR) fell by 2.2 ms from 7.0 ms before fever (p < 0.05) . Low-frequency spectral power fell by 2.4 ms(2) from 4.1 ms(2) before fever (p < 0.05) . The sensitivity of the baroreflex to changes in blood pressure induced by the vasoactive drugs decreased during fever by 0.72 ms/mm Hg for the nitroprusside test (p < 0.0005) and by 0.31 ms/mm Hg for the phenylephrine test (p < 0.005) . These results indicate that in the piglet the balance of autonomic tone is altered and autonomic responsiveness reduced during the thermogenic phase of a fever . These findings are consistent with known risk factors for sudden infant death syndrome . Infect Immun, 2004 Apr, 72(4), 2449 - 51 Salmonella flagellin is not a dominant protective antigen in oral immunization with attenuated live vaccine strains; Kodama C et al.; We found that oral immunization with flagellum-defective mutant strains of Salmonella enterica serovar Typhimurium with the ClpXP-deficient background protected mice against oral challenge with the virulent strain . These data indicate that Salmonella flagellin is not a dominant protective antigen in oral immunization with attenuated live vaccine strains. Infect Immun, 2004 Apr, 72(4), 2152 - 9 Rapid expression of chemokines and proinflammatory cytokines in newly hatched chickens infected with Salmonella enterica serovar typhimurium; Withanage GS et al.; Poultry meat and eggs contaminated with Salmonella enterica serovar Enteritidis or Salmonella enterica serovar Typhimurium are common sources of acute gastroenteritis in humans . However, the exact nature of the immune mechanisms protective against Salmonella infection in chickens has not been characterized at the molecular level . In the present study, bacterial colonization, development of pathological lesions, and proinflammatory cytokine and chemokine gene expression were investigated in the liver, spleen, jejunum, ileum, and cecal tonsils in newly hatched chickens 6, 12, 24, and 48 h after oral infection with Salmonella serovar Typhimurium . Very high bacterial counts were found in the ileum and cecal contents throughout the experiment, whereas Salmonella started to appear in the liver only from 24 h postinfection . Large numbers of heterophils, equivalent to neutrophils in mammals, and inflammatory edema could be seen in the lamina propria of the intestinal villi and in the liver . Interleukin 8 (IL-8), K60 (a CXC chemokine), macrophage inflammatory protein 1 beta, and IL-1 beta levels were significantly upregulated in the intestinal tissues and in the livers of the infected birds . However, the spleens of the infected birds show little or no change in the expression levels of these cytokines and chemokines . Increased expression of the proinflammatory cytokines and chemokines (up to several hundred-fold) correlated with the presence of inflammatory signs in those tissues . This is the first description of in vivo expression of chemokines and proinflammatory cytokines in response to oral infection with Salmonella in newly hatched chickens. Infect Immun, 2004 Apr, 72(4), 2002 - 13 Lon protease activity causes down-regulation of Salmonella pathogenicity island 1 invasion gene expression after infection of epithelial cells; Boddicker JD et al.; Salmonella enterica serovar Typhimurium causes self-limiting gastroenteritis in humans and a typhoid-like disease in mice that serves as a model for typhoid infections in humans . A critical step in Salmonella pathogenesis is the invasion of enterocytes and M cells of the small intestine via expression of a type III secretion system, encoded on Salmonella pathogenicity island 1 (SPI-1), that secretes effector proteins into host cells, leading to engulfment of the bacteria within large membrane ruffles . The in vitro regulation of invasion genes has been the subject of much scientific investigation . Transcription of the hilA gene, which encodes an OmpR/ToxR-type transcriptional activator of downstream invasion genes, is increased during growth under high-osmolarity and low-oxygen conditions, which presumably mimic the environment found within the small intestine . Several negative regulators of invasion gene expression have been identified, including HilE, Hha, and Lon protease . Mutations within the respective genes increase the expression of hilA when the bacteria are grown under environmental conditions that are not favorable for hilA expression and invasion . In this study, the intracellular expression of invasion genes was examined, after bacterial invasion of HEp-2 epithelial cells, using Salmonella strains containing plasmid-encoded short-half-life green fluorescent protein reporters of hilA, hilD, hilC, or sicA expression . Interestingly, the expression of SPI-1 genes was down-regulated after invasion, and this was important for the intracellular survival of the bacteria . In addition, the effects of mutations in genes encoding negative regulators of invasion on intracellular hilA expression were examined . Our results indicate that Lon protease is important for down-regulation of hilA expression and intracellular survival after the invasion of epithelial cells. Infect Immun, 2004 Apr, 72(4), 1964 - 73 Involvement of Salmonella pathogenicity island 2 in the up-regulation of interleukin-10 expression in macrophages: role of protein kinase A signal pathway; Uchiya K et al.; Salmonellae are facultative intracellular bacteria capable of surviving within macrophages . Salmonella pathogenicity island 2 (SPI-2) is required for growth within macrophages and for virulence in mice . In this study, we show the involvement of SPI-2 in a signal transduction pathway that induces cytokine expression in Salmonella-infected macrophages . High levels of interleukin-10 (IL-10) mRNA were induced in macrophages by infection with wild-type salmonellae compared to a strain carrying a mutation in the spiC gene, which is encoded within SPI-2 . The two strains had the same effect on the expression of proinflammatory cytokines such as IL-1 alpha, IL-6, and tumor necrosis factor alpha . IL-10 expression was dose dependently blocked by treatment of infected macrophages with the protein kinase A (PKA) inhibitor H-89, while IL-10 expression was increased by the PKA activator dibutyryl cyclic AMP . Cyclic AMP-dependent PKA activity was higher in macrophages infected with wild-type salmonellae compared to the spiC mutant, and Ser(132) phosphorylation of cyclic AMP response element-binding protein (CREB), which is an important mediator of PKA activation, correlated with the levels of PKA activity . Taken together, these results indicate that salmonellae cause an SPI-2-dependent increase in PKA activity that leads to CREB phosphorylation, resulting in up-regulation of IL-10 expression in Salmonella-infected macrophages . Suppression of IL-10 expression by an antisense oligonucleotide did not affect the growth of wild-type salmonellae within macrophages, whereas growth was dose dependently inhibited by H-89, suggesting that the PKA signaling pathway plays a significant role in intramacrophage Salmonella survival. FEMS Immunol Med Microbiol, 2004 Apr 9, 40(3), 243 - 7 Injury recovery of foodborne pathogens in high hydrostatic pressure treated milk during storage; Bozoglu F et al.; Bacteria are expected to be injured or killed by high hydrostatic pressure (HHP) . This depends on pressure levels, species and strain of the microorganism and subsequent storage . Injured bacteria may be repaired which could affect the microbiological quality of foodstuffs with an important safety consideration especially in low acid food products . In this study two Gram-positive (Listeria monocytogenes CA and Staphylococcus aureus 485) and two Gram-negative (Escherichia coli O157:H7 933 and Salmonella enteritidis FDA) relatively pressure resistant strains of foodborne pathogens were pressurized at 350, 450 and 550 MPa in milk (pH 6.65) and stored at 4, 22 and 30 degrees C . The results of shelf life studies indicated two types of injury, I1 and I2, for all the pathogens studied . It is obvious that I2 type injury is a major injury and after its repair (I2 to I1), the cells can form colonies on non-selective but not on selective agar . The formation of colonies on both selective and non-selective agar occurs only after full recovery of injury (I1 to AC) . The results presented in this study show that even if injured cells are not detected immediately after HHP treatment, I2 type injury could be potentially present in the food system . Therefore, it is imperative that shelf life studies must be conducted over a period of time for potential repair of I2 type injury either to detectable injury (I1) or to active cells (AC) to ascertain microbiological safety of low acid food products. FEMS Immunol Med Microbiol, 2004 Apr 9, 40(3), 223 - 9 The probiotic Escherichia coli strain Nissle 1917 interferes with invasion of human intestinal epithelial cells by different enteroinvasive bacterial pathogens; Altenhoefer A et al.; The probiotic Escherichia coli strain Nissle 1917 (Mutaflor) of serotype O6:K5:H1 was reported to protect gnotobiotic piglets from infection with Salmonella enterica serovar Typhimurium . An important virulence property of Salmonella is invasion of host epithelial cells . Therefore, we tested for interference of E . coli strain Nissle 1917 with Salmonella invasion of INT407 cells . Simultaneous administration of E . coli strain Nissle 1917 and Salmonella resulted in up to 70% reduction of Salmonella invasion efficiency . Furthermore, invasion of Yersinia enterocolitica, Shigella flexneri, Legionella pneumophila and even of Listeria monocytogenes were inhibited by the probiotic E . coli strain Nissle 1917 without affecting the viability of the invasive bacteria . The observed inhibition of invasion was not due to the production of microcins by the Nissle 1917 strain because its isogenic microcin-negative mutant SK22D was as effective as the parent strain . Reduced invasion rates were also achieved if strain Nissle 1917 was separated from the invasive bacteria as well as from the INT407 monolayer by a membrane non-permeable for bacteria . We conclude E . coli Nissle 1917 to interfere with bacterial invasion of INT407 cells via a secreted component and not relying on direct physical contact with either the invasive bacteria or the epithelial cells. Nucleic Acids Res, 2004 Mar 22, 32(5), 1848 - 56 Print 2004. Quantitative oligonucleotide microarray fingerprinting of Salmonella enterica isolates; Willse A et al.; We report on a genome-independent microbial fingerprinting method using nucleic acid microarrays for microbial forensics and epidemiology applications and demonstrate that the microarray method provides high resolution differentiation between closely related microorganisms, using Salmonella enterica strains as the test case . In replicate trials we used a simple 192 probe nonamer array to construct a fingerprint library of 25 closely related Salmonella isolates . Controlling false discovery rate for multiple testing at alpha = 0.05, at least 295 of 300 pairs of S.enterica isolate fingerprints were found to be statistically distinct using a modified Hotelling T2 test . Although most pairs of Salmonella fingerprints are found to be distinct, forensic applications will also require a protocol for library construction and reliable microbial classification against a fingerprint library . We outline additional steps required to produce such a protocol. Mol Cell Probes, 2004 Feb, 18(1), 51 - 7 Twelve hour real-time PCR technique for the sensitive and specific detection of Salmonella in raw and ready-to-eat meat products; Ellingson JL et al.; Rapid pathogen testing is vital to the food industry . Enzyme immunoassays (EIA) provide reliable negative results in 48 h, but a presumptive positive (suspect) EIA result must be confirmed by traditional culture methods, requiring an additional 72 h . Polymerase chain reaction (PCR) testing technology is accepted as an accurate diagnostic tool . However, traditional PCR techniques can require several days . We sought to develop a rapid, real-time quantitative PCR technique for detecting Salmonella spp . in food products . Salmonella spp . was inoculated into raw and ready-to-eat beef products . Total DNA was extracted and used as template for PCR amplification in the LightCycler (Roche Diagnostics Corp., Idaho Technology Inc., Idaho Falls, ID) PCR instrument . Salmonella-specific PCR primers were designed to amplify a 251 base pair product from the junction of SipB and SipC . Fluorescently-labeled hybridization probes were designed to anneal to SipB and SipC . Salmonella was detected down to 1 colony forming unit/ml in food products . The results of real-time PCR correlated 100% to those of visual immunoprecipitate and culture . PCR methods using the LightCycler can detect and confirm the presence or absence of Salmonella spp . in raw and ready-to-eat beef products within 12 h with increased sensitivity compared to traditional culture and EIA methods. Curr Opin Microbiol, 2004 Feb, 7(1), 78 - 84 Salmonella redirects phagosomal maturation; Brumell JH et al.; Following invasion of host cells, Salmonella occupies an intracellular vacuole that superficially resembles a phagosome . However, unlike bona fide phagosomes that undergo a maturation process to become microbicidal phago-lysosomes, Salmonella avoid killing by arresting and diverting the maturation program of the invasion vacuole . As a result of this re-routing, the bacteria generate a protected niche where they survive and replicate. Mutat Res, 2004 Mar 14, 558(1-2), 145 - 54 Ex vivo modulation of chemical-induced mutagenesis by subcellular liver fractions of rats treated with rooibos (Aspalathus linearis) tea, honeybush (Cyclopia intermedia) tea, as well as green and black (Camellia sinensis) teas; Marnewick JL et al.; Male Fischer rats were given unprocessed (not oxidized) and processed (oxidized) rooibos and honeybush teas as well as green and black teas as a sole source of drinking fluid for 10 weeks, and sub cellular liver fractions were prepared . Cytosolic fractions of rats consuming the unprocessed herbal teas, green and black teas significantly (P < 0.05) protected against 2-acetylaminofluorene (2-AAF)-induced mutagenesis in the Salmonella mutagenicity test with strain TA 98, using Aroclor 1254-induced microsomes . A marginal or no protection was obtained with the processed herbal teas . The mutagenic response of aflatoxin B1 (AFB1) against Salmonella strain TA 100 was significantly (P < 0.05) inhibited by cytosolic fractions from rats treated with processed and unprocessed herbal teas, while no effect was obtained with the green and black teas . Microsomal fractions prepared from livers of rats treated with both the processed and unprocessed rooibos teas and the unprocessed honeybush tea, significantly (P < 0.05) reduced the activation of AFB1 while no protection was observed against 2-AAF-induced mutagenesis . In contrast, microsomal fractions from rats treated with the green, black and unprocessed honeybush teas significantly (P < 0.05) enhanced the mutagenic response of 2-AAF . None of the tea treatments significantly affected the concentration of the microsomal liver cytochrome P450. J Food Prot, 2004 Mar, 67(3), 616 - 23 Intensive investigation of bacterial foodborne disease outbreaks: proposed guidelines and tools for the collection of dose-response data by local health departments; Jones RC et al.; Local health departments that investigate foodborne disease outbreaks do not have adequate guidelines for collecting data that could be used to estimate dose-response relationships, a key component of hazard characterization in quantitative microbial risk assessment . To meet this need, criteria and a questionnaire template for the collection of appropriate dose-response data in the context of outbreaks were developed and applied in the investigation of a point-source outbreak linked to Salmonella serotype Enteritidis in a salmon entree in February 2000 . In this outbreak, the attack rate and risk of hospitalization increased with the amount of salmon entree consumed, and detailed data were obtained on illness severity measures and host susceptibility factors . Local health departments might consider broadening investigations to include the collection of additional data when investigating outbreaks that have met a specific set of conditions . These data could provide information needed by federal regulatory agencies and other organizations for quantitative microbial risk assessment . Intensive investigations of outbreaks could prevent future illnesses by providing information needed to develop approaches to minimizing risk. J Food Prot, 2004 Mar, 67(3), 493 - 8 Thermal lethality of salmonella in chicken leg quarters processed via an air/steam impingement oven; Murphy RY et al.; Chicken leg quarters were injected with 0.1 ml of the cocktail culture per cm2 of the product surface area to contain about 7 log(CFU/g) of Salmonella . The inoculated leg quarters were processed in an air/steam impingement oven at an air temperature of 232 degrees C, an air velocity of 1.4 m/s, and a relative humidity of 43% . The endpoint product temperatures were correlated with the cooking times . A model was developed for pathogen thermal lethality up to 7 log(CFU/g) reductions of Salmonella in correlation to the product mass (140 to 540 g) and cooking time (5 to 35 min) . The results from this study are useful for validating thermal lethality of pathogens in poultry products that are cooked via impingement ovens. J Food Prot, 2004 Mar, 67(3), 432 - 7 Effect of hot water and hydrogen peroxide treatments on survival of salmonella and microbial quality of whole and fresh-cut cantaloupe; Ukuku DO et al.; Cantaloupe melon has been associated with outbreaks of salmonellosis . Contamination might be introduced into the flesh from the rind by cutting or by contact of cut pieces with contaminated rinds . Our objectives were to investigate the efficacy of hot water or hot 5% hydrogen peroxide treatments in reducing the population of native microflora and inoculated Salmonella on cantaloupe rind and transfer to fresh-cut tissue during cutting . Whole cantaloupes, inoculated with a cocktail of Salmonella serovars to give 4.6 log CFU/cm2 and stored at 5 or 20 degrees C for up to 5 days, were treated with hot water (70 or 97 degrees C) or 5% hydrogen peroxide (70 degrees C) for 1 min at 0, 1, 3, or 5 days postinoculation . Aerobic mesophilic bacteria and yeast and mold on treated whole melon and fresh-cut pieces were significantly (P < 0.05) reduced by all three treatments . Treatments with hot water (70 and 97 degrees C) caused a 2.0- and 3.4-log CFU/cm2 reduction of Salmonella on whole cantaloupe surfaces irrespective of days of postinoculation storage prior to treatment up to 5 days at 5 or 20 degrees C, respectively . Treatment with 5% hydrogen peroxide (70 degrees C) caused a 3.8-log CFU/cm2 reduction of Salmonella . Fresh-cut pieces prepared from untreated inoculated melons and those treated with 70 degrees C hot water were positive for Salmonella . However, fresh-cut pieces prepared from inoculated whole melon dipped in water (97 degrees C) or hydrogen peroxide (70 degrees C) for 60 s were negative for Salmonella, as determined by dilution plating onto agar medium, but were positive after enrichment at days 3 and 5 of storage at 5 degrees C . The ability to detect Salmonella in fresh-cut pieces was dependent on the initial level of inoculation . The results of this study indicate that the use of hot water (97 degrees C) or heated hydrogen peroxide to reduce the population of Salmonella on contaminated whole cantaloupes will enhance the microbial safety of the fresh-cut product. Clin Infect Dis, 2004 Apr 1, 38(7), 951 - 7 Epub 2004 Mar 12. Short-course azithromycin for the treatment of uncomplicated typhoid fever in children and adolescents; Frenck RW Jr et al.; We studied 149 children and adolescents 3-17 years of age with clinical typhoid fever who were treated with either oral azithromycin (20 mg/kg per day; maximum dose, 1000 mg/day) or intravenous ceftriaxone (75 mg/day; maximum dose, 2.5 g/day) daily for 5 days . Blood and stool specimens were obtained for culture before the initiation of therapy and were repeated on days 4 and 8 of treatment . Isolation of Salmonella enterica serovar Typhi or S . enterica serovar Paratyphi from the initial culture was required for inclusion in the final analysis . S . Typhi was isolated from 68 patients, 32 of whom were receiving azithromycin . Cure was achieved in 30 (94%) of 32 patients in the azithromycin group and in 35 (97%) of 36 patients in the ceftriaxone group (P=NS) . Mean time to clearance of bacteremia was longer in the azithromycin group than in the ceftriaxone group . No patient who received azithromycin had a relapse, compared with 6 patients who received ceftriaxone . A 5-day course of azithromycin was found to be an effective treatment for uncomplicated typhoid fever in children and adolescents. J Immunol, 2004 Apr 1, 172(7), 4463 - 9 Toll-like receptors are temporally involved in host defense; Weiss DS et al.; Toll-like receptors (TLRs) are evolutionarily conserved proteins that recognize microbial molecules and initiate host defense . To investigate how TLRs work together to fight infections, we tested the role of TLRs in host defense against the Gram-negative bacterial pathogen, Salmonella . We show that TLR4 is critical for early cytokine production and killing of bacteria by murine macrophages . Interestingly, later on, TLR2, but not TLR4, is required for macrophage responses . Myeloid differentiation factor 88, an adaptor protein directly downstream of TLRs, is required for both early and late responses . TLR4, TLR2, and myeloid differentiation factor 88 are involved in murine host defense against Salmonella in vivo, which correlates with the defects in host defense observed in vitro . We propose a model where the sequential activation of TLRs tailors the immune response to different microbes. J Chem Inf Comput Sci, 2004 Mar-Apr, 44(2), 352 - 8 Structure-mutagenicity study of 12 trimethylimidazopyridine isomers using orbital energies and "spectrum-like representation" as descriptors; Vracko M et al.; The set of 12 trimethylimidazopyridine isomers with mutagenic potency toward two strains of Salmonella was treated in this study . Ten isomers with known mutagenic properties were taken to build the models . Fifteen molecular orbital energies, or a "spectrum-like" representation of 3D structures, were taken as descriptors . As modeling techniques the multiple linear regression and the counter propagation neural network were applied . Models were tested with the recall ability test and the leave-one-out cross-validation tests . For two isomers, which have not been synthesized yet, we report predicted values for both mutagenic potencies obtained with different models . The best models were found when unoccupied molecular orbital energies are among the descriptors. Dev Cell, 2004 Mar, 6(3), 314 - 5 Bacterial invasion: a new strategy to dominate cytoskeleton plasticity; Cossart P; Some bacterial pathogens enter mammalian cells by injecting, directly into the host cytosol, proteins that trigger cytoskeletal rearrangements necessary for internalization . In the February 27 issue of Molecular Cell, McGhie et al . identify mechanisms by which the Salmonella protein SipA interferes with ADF/cofilin and gelsolin function . Thus Salmonella not only triggers actin polymerization but also counteracts the major F-actin destabilizing proteins. Afr J Med Med Sci, 2003 Sep, 32(3), 307 - 10 Determination of baseline antibody titre to S . typhi/paratyphi in Ile-Ife, Nigeria; Zailani SB et al.; The aim of the study is to determine the baseline antibody titres to Salmonella typhi/paratyphi in healthy individuals with a view to establishing the significant titre for Widal agglutination test in Ile-Ife, Western Nigeria . Three hundred and ten healthy volunteers were admitted into the study and forty-eight clinically diagnosed and culture positive cases of Enteric fever were used as purposeful controls . Widal test was performed on each serum . Slide agglutination test was first done, then positive samples were further subjected to tube agglutination for quantitative titration . Of the 310 healthy volunteers, 274 (97.2%) had reciprocal antibody titre of < or = 80 to O antigen and 265 (95.0%) had reciprocal antibody titre of < or = 80 to H . antigen of S . typhi . On the other hand, in 48 control cases, 43 (89.6%) had reciprocal antibody titre of > or = 160 to O antigen and 38 (78.2%) had reciprocal titre of > or = 160 to H . antigen . The sensitivity and specificity of the test were 89.9% and 94.2% for O antibody, and 79.2% and 92.3% for H . antibody respectively . The baseline titre to S . typhi/paratyphi for both O & H antibody is 1:80 whilst the significant titre for O & H antibodies is 1:160 and above in Ile-Ife, Nigeria. Medicine (Baltimore), 2004 Mar, 83(2), 123 - 38 The spectrum of cardiovascular infections due to Salmonella enterica: a review of clinical features and factors determining outcome; Fernandez Guerrero ML et al.; Cardiovascular infections due to Salmonella enterica are infrequently reported, so their clinical features, prognosis, and optimal treatment are not completely known . Mortality associated with aortitis and endocarditis caused by nontyphoidal Salmonella remains exceedingly high.In this review of cases of cardiovascular infections due to Salmonella enterica studied in 2 hospitals in Madrid, we tried to assess the clinical manifestations and the procedures leading to diagnosis in addition to treatment and outcome . To complete the spectrum of infections related to cardiovascular surgery, cases of postoperative mediastinitis, pericarditis, and infections associated with cardiac devices were also included.Twenty-three patients were reviewed: 11 had mycotic aneurysms; 7 had endocarditis; 2 had device-related infections; and 3 had pericarditis, mediastinitis, and infection of an arteriovenous fistula, respectively . The risk of endovascular infection in patients older than 60 years with bacteremia due to nontyphoidal Salmonella was 23% . Most patients with aortitis had risk factors for atherosclerosis, and 6 had preexisting atherosclerotic aortic aneurysms . All except 1 patient with endocarditis had underlying cardiac disorders . Acquired immunodeficiency disease (AIDS) was a major risk factor for salmonella bacteremia in 1 patient with aortitis and 1 with endocarditis . Fever, unremitting sepsis, "breakthrough" and relapsing bacteremia were the most common clinical findings . In addition, abdominal or thoracic pain and cardiac failure and pericarditis were common features in patients with aortitis and endocarditis respectively . Computed tomography (CT) scan, arteriography, and echocardiography were the main diagnostic tools.Mortality associated with mycotic aneurysms and endocarditis due to S . enterica was 45% and 28%, respectively . Thoracic aneurysms, rupture, and shock at the time of diagnosis were associated with increased mortality in patients with aortitis . In situ bypass grafting was successfully performed in most cases . After surgery, antimicrobial therapy was continued for 4-9 weeks . No relapses were observed after a mean follow-up of 64 months . Antimicrobial therapy alone or combined with valve replacement or excision of a ventricular aneurysm was successful treatment for most patients with salmonella endocarditis . Combined medical and surgical treatment was required for patients with mediastinitis and pericarditis, and patients with device-related infections needed removal of the complete device.Diagnosis of aortitis due to nontyphoidal Salmonella should be established as early as possible to reduce mortality . Patients older than 60 years who have positive blood cultures for Salmonella along with fever and back, abdominal, or chest pain should have an extensive workup for infective aortitis . Immediate bactericidal antimicrobial therapy should be started and a CT scan should be performed on an emergency basis . If a mycotic aneurysm is found, surgical resection should follow as soon as possible . Resection of the aneurysm with in situ bypass grafting is the procedure of choice . Postoperative antimicrobial therapy for 6-8 weeks seems enough to avoid relapses . Optimal treatment of patients with endocarditis occurring on ventricular aneurysms must include resection of the aneurysmal sac . Salmonella endocarditis can be successfully treated with antimicrobials alone . Valve replacement should be reserved for patients with cardiac failure or persisting sepsis, and for those who relapse after discontinuation of antimicrobial therapy. Risk Anal, 2004 Feb, 24(1), 289 - 99 Differences in perception of risk between people who have and have not experienced Salmonella food poisoning; Parry SM et al.; It is believed that food hygiene precautions in domestic kitchens are an important strategy in efforts to reduce the incidence of sporadic food poisoning, but recent research has shown that people who have suffered food poisoning handle the same types of foods and adopt similar food hygiene precautions in their kitchens to the rest of the population . This suggests the need to examine other factors . A case-control study of sporadic Salmonella food poisoning was conducted to investigate several domestic kitchen risk factors . Measures of perception of risk, knowledge, and control associated with food poisoning in case and control respondents are reported here . It was found that perceived personal risk from food poisoning in the home was less than perceived risk to other people . In contrast, ratings of personal knowledge about food poisoning and personal control over food poisoning in the home were seen to be greater than other people's knowledge and control . There were no differences between the cases and the controls in their ratings of knowledge about food poisoning or their control over food poisoning . However, cases perceived their personal risk from food poisoning to be higher than controls . Both case and control samples exhibited optimistic bias but this was reduced in the case sample, suggesting that experience with food poisoning may reduce optimistic bias. Risk Anal, 2004 Feb, 24(1), 255 - 69 A Bayesian approach to quantify the contribution of animal-food sources to human salmonellosis; Hald T et al.; Based on the data from the integrated Danish Salmonella surveillance in 1999, we developed a mathematical model for quantifying the contribution of each of the major animal-food sources to human salmonellosis . The model was set up to calculate the number of domestic and sporadic cases caused by different Salmonella sero and phage types as a function of the prevalence of these Salmonella types in the animal-food sources and the amount of food source consumed . A multiparameter prior accounting for the presumed but unknown differences between serotypes and food sources with respect to causing human salmonellosis was also included . The joint posterior distribution was estimated by fitting the model to the reported number of domestic and sporadic cases per Salmonella type in a Bayesian framework using Markov Chain Monte Carlo simulation . The number of domestic and sporadic cases was obtained by subtracting the estimated number of travel- and outbreak-associated cases from the total number of reported cases, i.e., the observed data . The most important food sources were found to be table eggs and domestically produced pork comprising 47.1% (95% credibility interval, CI: 43.3-50.8%) and 9% (95% CI: 7.8-10.4%) of the cases, respectively . Taken together, imported foods were estimated to account for 11.8% (95% CI: 5.0-19.0%) of the cases . Other food sources considered had only a minor impact, whereas 25% of the cases could not be associated with any source . This approach of quantifying the contribution of the various sources to human salmonellosis has proved to be a valuable tool in risk management in Denmark and provides an example of how to integrate quantitative risk assessment and zoonotic disease surveillance. Risk Anal, 2004 Feb, 24(1), 41 - 9 Dose-response model for 13 strains of salmonella; Oscar T; Data from a human feeding trial with healthy men were used to develop a dose-response model for 13 strains of Salmonella and to determine the effects of strain variation on the shape of the dose-response curve . Dose-response data for individual strains were fit to a three-phase linear model to determine minimum, median, and maximum illness doses, which were used to define Pert distributions in a computer simulation model . Pert distributions for illness dose of individual strains were combined in an Excel spreadsheet using a discrete distribution to model strain prevalence . In addition, a discrete distribution was used to model dose groups and thus create a model that simulated human feeding trials . During simulation of the model with @Risk, an illness dose and a dose consumed were randomly assigned to each consumption event in the simulated feeding trial and if the illness dose was greater than the dose consumed then the model predicted no illness, otherwise the model predicted that an illness would occur . To verify the dose-response model predictions, the original feeding trial was simulated . The dose-response model predicted a median of 69 (range of 43-101) illnesses compared to 74 in the original trial . Thus, its predictions were in agreement with the data used to develop it . However, predictions of the model are only valid for eggnog, healthy men, and the strains and doses of Salmonella used to develop it . When multiple strains of Salmonella were simulated together, the predicted dose-response curves were irregular in shape . Thus, the sigmoid shape of dose-response curves in feeding trials with one strain of Salmonella may not accurately reflect dose response in naturally contaminated food where multiple strains may be present. Anat Histol Embryol, 2004 Feb, 33(1), 5 - 10 Dynamics of mast cells in lymph node following antigenic stimulation; Dabak DO et al.; Dynamics of mast cells in rat cervical lymph nodes were examined using conventional histological techniques after injection of Salmonella paratyphi B-H antigen . There was no significant change in the number of mast cells at sixth hour and on the first day of stimulation compared with the controls . The number of mast cells was increased in all lymph node compartments on the second day of stimulation, which continued in the following 3 days . On the eighth day of stimulation, although the mast cell number decreased in the subcapsular area, it was still high in the paracortical area and medullary sinuses of the lymph nodes . On the second day of stimulation, the mast cell number was apparently increased in the subcapsular area than those of the other compartments . In the following days of stimulation, the highest number of mast cells was seen in the medullary sinuses . The highest paracortical mast cell number was determined on the third day of stimulation and some mast cells were observed near the high endothelial venules (HEVs) . The changes of mast cell number among the lymph node compartments after antigenic stimulation support the hypothesis that the migration of mast cells occurred . This migration pattern indicates that mast cells enter the lymph node via afferent lymphatics and migrate to the lymph node compartments following antigenic stimulation. Biologicals, 2004 Mar, 32(1), 11 - 6 Detection of O-acetylated Vi polysaccharide of Salmonella enterica subspecies typhi by enzyme immunoassay; Rijpkema S et al.; Immunisation with capsular Vi polysaccharide (Vi PS) of Salmonella enterica serovar Typhi (S . typhi) protects against typhoid . This protection depends on the presence of O-acetyl groups on the Vi PS, which form an immunodominant epitope . An antiserum raised against conjugated Vi PS was used as the basis for an indirect Enzyme Immunoassay (EIA) . The antiserum did not react with lipopolysaccharide of five gram negative bacteria including S . typhi . Vi PS from three different sources was tested, and all but one of 18 native Vi PS preparations had EIA values comparable to a standard Vi PS preparation . The sensitivity of the EIA for the detection of O-acetyl groups on Vi PS was compared to an NMR spectroscopy assay (Biologicals 28 (2000) 17-24) . The EIA distinguished between O-acetylated and de-O-acetylated Vi PS preparations . However, significantly lower EIA reactivity was observed only for samples which had O-acetylation levels of 25% or less . This assay should facilitate batch control of Vi vaccines. Indian J Pathol Microbiol, 2003 Jul, 46(3), 498 - 500 A steady decrease in occurrence of Salmonella typhi infection in Rourkela, Orissa; Bhattacharya SS et al.; Between January 1999 and December 2001, the isolation rate of Salmonella typhi in Rourkela was found to be under steady fall as compared to the isolation rate encountered between 1996 and 1998 . Of 4378 blood samples tested, 254 were found positive for S . typhi giving an over all per cent positivity of 5.8 . Enteric fever was found to occur almost through out the year . An over all 30.7 per cent of multi drug resistant (MDR) strains of S . typhi have appeared during this period . Proper and timely health education besides undertaking corrective measures in sanitary system and water supply management, appeared to have a cumulative effect in the steady reduction of enteric fever morbidity in this region. Indian J Pathol Microbiol, 2003 Apr, 46(2), 268 - 70 Outbreak of neonatal meningitis caused by Salmonella enterica serotype Worthington; Ghadage D et al.; We report an outbreak of Salmonella meningitis in a nursery unit due to serotype Worthington . The organism was isolated from blood and CSF samples of five babies . The isolates were found to be resistant to commonly used antibiotics such as ampicillin, cefotaxime, cefiriaxone and amikacin but were sensitive to ciprofloxacin . Serotype Worthington appears to be an emerging pathogen in neonatal units. Vet Microbiol, 2004 Apr 5, 99(2), 139 - 43 Pulsed-field gel electrophoresis-based subtyping of DNA degradation-sensitive Salmonella enterica subsp . enterica serovar Livingstone and serovar Cerro isolates obtained from a chicken layer farm; Murase T et al.; Salmonella enterica serovar subsp . enterica Livingstone and serovar Cerro isolates from a commercial egg-producing farm, which had previously been untypeable by pulsed-field gel electrophoresis (PFGE) because of DNA degradation during the PFGE process, successfully gave banding patterns using electrophoresis buffer supplemented with 50 microM thiourea . By PFGE in the presence of thiourea, DNA degradation-sensitive S . enterica serovar Cerro isolates from the commercial egg-producing farm were found to be genetically unrelated to S . enterica serovar Cerro isolates that gave the patterns in the absence of thiourea . Forty-five of 50 (90%) S . enterica serovar Livingstone isolates from the farm showed arbitrarily designated XbaI-digested patterns X1 and X2 that were distinguished by one-band difference and had an identical BlnI-digested pattern . In one of the two layer houses in the farm, the numbers of isolates having the pattern X2 increased from 57% in 1997 to 89% in 1998, whereas virtually all the isolates obtained from the other house in the same period showed the profile X1 . This suggests that strains having the pattern X2 might have an advantage to preferentially colonize in the former house. Vet Microbiol, 2004 Apr 5, 99(2), 113 - 20 Detection of specific antibodies against deflagellated Salmonella Enteritidis and S . Enteritidis FliC-specific 9kDa polypeptide; Mizumoto N et al.; Specific antibody levels of laying hens and young chickens experimentally infected with Salmonella Enteritidis and vaccinated farm flocks were evaluated by enzyme-linked immunosorbent assays (ELISAs) with two different antigens, deflagellated S . Enteritidis whole cell (DEWC) and S . Enteritidis FliC-specific 9kDa polypeptide (SEP9) . Infected laying hens excreted S . Enteritidis throughout the experimental period, and the specific antibody titers in DEWC-ELISA, were significantly higher than the uninfected group . It suggests that this DEWC-specific antibody will serve as an effective indicator of S . Enteritidis infection, especially for non-vaccinated laying flocks . SEP9-specific antibodies were detected in spray-inoculated young chickens but not in oral-inoculated young chickens . Compared with greatly high SEP9-specific antibody levels of vaccinated farm flocks, no response was observed in orally infected hens . These results indicate that S . Enteritidis discontinues expressing SEP9 once it has crossed the intestinal barrier, and that SEP9-ELISA will serve as a valuable monitoring tool for the status of S . Enteritidis vaccination on a flockwide basis, independent of stable S . Enteritidis infections. Pediatr Infect Dis J, 2004 Mar, 23(3), 226 - 30 Double blind comparison of ibuprofen and paracetamol for adjunctive treatment of uncomplicated typhoid fever; Vinh H et al.; BACKGROUND: Antipyretics reduce the prolonged, high fever characteristic of typhoid fever . The benefits of nonsteroidal drugs in this role have not been quantified . There have been concerns about the safety of antipyretics in typhoid . METHODS: In a double blind randomized study, 80 Vietnamese children with uncomplicated typhoid fever were randomized to receive identical syrup preparations of ibuprofen (10 mg/kg) or paracetamol (12 mg/kg) every 6 h until 36 h after defervescence . Children with a nalidixic acid-susceptible (Na) isolate of Salmonella typhi were treated with ofloxacin (15 mg/kg/day) for 3 days and those with a nalidixic acid-resistant (Na) isolate were treated for 7 days . RESULTS: S . typhi was isolated from 36 of 40 children randomized to ibuprofen (11 isolates Na) and 37 of 40 randomized to paracetamol (13 isolates Na) . The median (range) fever clearance time (hours) was shorter in the ibuprofen group than the paracetamol group (68, 4 to 260 vs . 104, 12 to 404; P = 0.055) as was the area under the temperature time curve above 37 degree C (74, 0 to 237 vs . 127, 0 to 573; P = 0.013) . The differences occurred predominantly in the children infected with a NaS . typhi whose infections responded more slowly to antibiotic treatment . There were no major side effects associated with the use of either drug . There were no differences between the two treatment arms in the concentrations of circulating interleukin-6 and tumor necrosis factor alpha during the course of treatment . CONCLUSION: The antipyretic effect of ibuprofen is superior to that of paracetamol in children with typhoid fever, particularly those with prolonged fever . Both antipyretics appeared to be safe. Mol Biol Evol, 2004 Jun, 21(6), 1110 - 22 Epub 2004 Mar 10. A phylogenomic study of endosymbiotic bacteria; Canback B et al.; Endosymbiotic bacteria of aphids, Buchnera aphidicola, and tsetse flies, Wigglesworthia glossinidia, are descendents of free-living gamma-Proteobacteria . The acceleration of sequence evolution in the endosymbiont genomes is here estimated from a phylogenomic analysis of the gamma-Proteobacteria . The tree topologies associated with the most highly conserved genes suggest that the endosymbionts form a sister group with Escherichia coli, Salmonella sp., and Yersinia pestis . Our results indicate that deviant tree topologies result from high substitution rates and biased nucleotide patterns, rather than from lateral gene transfer, as previously suggested . A reinvestigation of the relative rate increase in the endosymbiont genomes reveals variability among genes that correlate with host-associated metabolic dependencies . The conclusion is that host-level selection has retarded both the loss of genes and the acceleration of sequence evolution in endocellular symbionts. Carbohydr Res, 2004 Feb 25, 339(3), 613 - 21 Blocking nonspecific adsorption of native food-borne microorganisms by immunomagnetic beads with iota-carrageenan; Irwin P et al.; We present herein the partitioning characteristics of anti-Salmonella and anti-Escherichia coli O157 immunomagnetic beads (IMB) with respect to the nonspecific adsorption of several nontarget food-borne organisms with and without an assortment of well-known blocking agents, such as casein, which have been shown to be useful in other immunochemical applications . We found several common food-borne organisms that strongly interacted with both types of IMB, especially with anti-Salmonella form (av DeltaG0=-20 +/- 4 kJ mol(-1)) even in the presence of casein {1% (w/v): DeltaG0=-18 +/- 3 kJ mol(-1); DeltaDeltaG0 approximately -2 kJ mol(-1)} . However, when one of the most problematic organisms (a native K12-like E . coli isolate; DeltaG0=-19 +/- 2 kJ mol(-1)) was tested for nonspecific binding in the presence of iota-carrageenan (0.03-0.05%), there was an average decline of ca . 90% in the equilibrium capture efficiency xi (DeltaG0=-11 +/- 4 kJ mol(-1); DeltaDeltaG0 approximately -8 kJ mol(-1)) . Other anionic polysaccharides (0.1% kappa-carrageenan and polygalacturonic acid) had no significant effect (av DeltaG0=-19 +/- 1 kJ mol(-1); DeltaDeltaG0 approximately 0 kJ mol(-1)) . Varying iota-carrageenan from 0% to 0.02% resulted in xi significantly diminishing from 0.69 (e.g., 69% of the cells captured; DeltaG0=-19 +/- 3 kJ mol(-1)) to 0.05 (DeltaG0=-11 +/- 2 kJ mol(-1); DeltaDeltaG0 approximately -9 kJ mol(-1)) at about 0.03% iota-carrageenan where xi leveled off . An optimum blocking ability was achieved with 0.04% iota-carrageenan suspended in 100 mM phosphate buffer . We also demonstrated that the utilization of iota-carrageenan as a blocking agent causes no great loss in the IMBs capture efficiency with respect to the capture of its target organisms, various salmonellae. J Ethnopharmacol, 2004 Feb, 90(2-3), 273 - 7 Modulation of rat and human cytochromes P450 involved in PhIP and 4-ABP activation by an aqueous extract of Phyllanthus orbicularis; Ferrer M et al.; Phyllanthus orbicularis HBK (Euphorbiaceae) is a medicinal plant, endemic to Cuba, whose aqueous extract has proven antimutagenic effects against hydrogen peroxide and some promutagenic aromatic amines (AAs), in addition to its antiviral properties . In this paper, antimutagenesis of this extract against two carcinogenic AAs, 2-amino-1-methyl-6-phenylimidazo{4,5-b}pyridine (PhIP) and 4-aminobiphenyl (4-ABP) has been studied . Liver microsomal fractions from both induced rats and humans were used to metabolise both procarcinogenic compounds in the Salmonella assay . The plant extract was effective in reducing the mutagenesis of these AAs, activated by both kinds of fractions . The optimal antimutagenic effect was obtained when both AAs were metabolised by human enzymes, with an almost total reduction of 4-ABP mutagenesis and a decrease of about 75% of PhIP mutagenicity . Mutagenicity of both AAs, activated by induced rat fraction, was only decreased by about 50% . Inhibition by plant extract of alkoxyresorufin O-dealkylation activities, dependent on CYP1A, of both fractions was determined . In accordance with the results obtained, the inhibition or modulation of CYP1A subfamily activities, and possibly of CYP1A2, is thought to be the main mechanism of antimutagenesis of the aqueous extract of Phyllanthus orbicularis against 4-ABP and PhIP. Med Clin (Barc), 2004 Feb 21, 122(6), 223 - 6 {Miller-Fisher syndrome: clinical features, associated infections and clinical course in 8 cases}; Rodriguez Uranga JJ et al.; BACKGROUND AND OBJECTIVE: Miller-Fisher syndrome (MFS) is considered the most common variant of Guillain-Barre syndrome (GBS) and is characterized by the clinical triad of ophthalmoplegia, ataxia and areflexia . Respiratory involvement and relapses are unusual . Patients with MFS usually have a good recovery and no residual deficits . We describe the clinical features, associated infections and evolution in eight patients with MFS . PATIENTS AND METHOD: Eight cases of MFS and sixty-one of GBS were studied between 1994 and 2003 . All cases showed the clinical triad of MFS without major limb weakness or other signs suggestive of CNS involvement . RESULTS: The proportion of MFS with respect to GBS during the same period was 13.1% . Four had a positive serology for Epstein-Barr virus, Salmonella enteritidis, Chlamydia pneumoniae and Mycoplasma pneumoniae . Our cases showed facial palsy (75%), dysphagia (75%), pupillary abnormalities (37.5%) and ventilation support (37.5%) . Antiganglioside antibodies, determined in three cases (4 episodes), were positive {GQ1b (50%) and GD1b (50%)} . In all cases, there was a markedly reduced amplitude of the distal sensory as well as frequent axonal degeneration signs . The oldest three patients relapsed and required ventilation support . CONCLUSIONS: We report for the first time an association between S . enteritidis and C . pneumoniae and MFS . Older patients in our series suffered a faster disease progression with need of ventilation support . We conclude that an older age correlates with poor prognosis and relapses. J Appl Microbiol, 2004, 96(4), 887 - 93 Comparison of 40 Salmonella enterica serovars injured by thermal, high-pressure and irradiation stress; Sherry AE et al.; AIM: To investigate and compare the inherent resistance of 40 Salmonella serovars to heat, irradiation and high-pressure stress . METHODS AND RESULTS: D10 values for each of the three stresses were calculated for four serovars, chosen as representatives from a catalogue of 40 . Based on these results, conditions for each stress were defined, which produced, on average, a three-log reduction in viability . Heat stress (57 degrees C for 13 min), high-pressure stress (350 MPa for 10 min at 20 degrees C) and irradiation stress (1.5 kGy at 20 degrees C) were applied to all 40 serovars in the collection . Injury and loss of viability for all serovars were determined . CONCLUSIONS: Cluster analysis identified five groupings of isolates in terms of resistance to the applied stresses . The independent response of each isolate to all three stresses suggests that there is no relationship between resistances . SIGNIFICANCE AND IMPACT OF THE STUDY: Each serovar is inherently different . For modelling of real-life food preservation processing the most resistant isolates for that process should be chosen . The results also emphasize the importance of including multiple stress resistant strains when food preservation systems apply multiple stresses. J Appl Microbiol, 2004, 96(4), 787 - 94 Influence of bovine manure as fertilizer on the bacteriological quality of organic Iceberg lettuce; Johannessen GS et al.; AIM: To investigate the bacteriological quality, and the occurrence of selected pathogenic bacteria from organically grown Iceberg lettuce fertilized with bovine manure in the form of compost, firm manure and slurry in a 2-year field trial . METHODS AND RESULTS: Samples of soil, fertilizer, fertilized soil, seedlings and lettuce were analysed for aerobic plate counts (APC), thermotolerant coliform bacteria (TCB), Escherichia coli, E . coli O157:H7, Salmonella spp . and Listeria monocytogenes . No difference in bacteriological quality could be shown in lettuce at harvest, however, APC varied significantly from year to year in the study . The various treatments gave significantly different APC and numbers of TCB isolated from fertilized soil . Escherichia coli O157:H7 was isolated from firm manure and slurry, and soils fertilized with the respective fertilizers the second year, but were not recovered from the lettuce . CONCLUSIONS: No difference in bacteriological quality could be detected in lettuce at harvest after application of various types of manure-based fertilizers grown under Norwegian conditions . SIGNIFICANCE AND IMPACT OF THE STUDY: The results may indicate that the use of manure does not have considerable influence on the bacteriological quality of organic lettuce . However, others have suggested that there is a risk by using manure . There is a need for more research in the field. J Appl Microbiol, 2004, 96(4), 709 - 15 Isolation of Salmonella strains from reptile faeces and comparison of different culture media; Corrente M et al.; AIMS: To provide information on epidemiology and isolation of Salmonella strains from reptiles . METHODS AND RESULTS: Ninety-one samples collected from reptiles of the zoo of Rome or belonging to private owners were analysed using a standard protocol for isolation of Salmonella from food . Salmonella strains were tested for susceptibility to 15 antimicrobics by a disc-agar diffusion method . Forty-six samples (50.5%) were positive for Salmonella . Of the 22 strains serotyped, 17 belonged to Salmonella enterica subsp . I, four to the subsp . IIIa and one strain resulted untypeable . Rappaport-Vassiliadis broth (RVB) allowed to recover more Salmonella strains when bacterial growth in buffered peptone water (BPW) was scarce, while selenite cystine broth (SCB) was more efficient, whereas growth in BPW was abundant . The maximum isolation score was obtained by plating onto xylose lysine desoxycholate agar (XLD) . The strains exhibited resistance at high percentages to colistin sulphate (58.7%), sulphamethoxazole (55.5%), streptomycin (32.6%), tetracycline (19.6%), ampicillin (17.4%) and nalidixic acid (13.1%) . CONCLUSIONS: A high prevalence of Salmonella in reptiles was observed . For isolation, the choice of the enrichment broth depending on the degree of growth in BPW followed by plating onto XLD may be suggested . SIGNIFICANCE AND IMPACT OF THE STUDY: This paper provides epidemiological data on the prevalence of Salmonella and laboratory protocols useful for isolation of Salmonella from faeces of reptiles. J Appl Microbiol, 2004, 96(4), 693 - 9 Anti-Salmonella activity of (2E)-alkenals; Kubo I et al.; AIMS: This study investigated the effect of a series of naturally occurring aliphatic (2E)-alkenals against Salmonella choleraesuis subsp . choleraesuis ATCC 35640 and evaluated their antibacterial action . METHOD AND RESULTS: A homologous series of aliphatic (2E)-alkenals from C5-C13 were tested for their antibacterial activity against Salm . Choleraesuis . The antibacterial action of (2E)-alkenals against Salm . choleraesuis increases with increasing carbon chain length . (2E)-Dodecenal (C12) was the most effective against this food-borne bacterium with minimum bactericidal concentration (MBC) of 6.25 microg ml-1 (34 micromol l-1), followed by (2E)-undecenal (C11) with an MBC of 12.5 microg ml-1 (77 micromol l-1) . The activity was found to correlate with the hydrophobic alkyl chain length from the hydrophilic aldehyde group . The time-kill curve study showed that (2E)-dodecenal was bactericidal against Salm . choleraesuis at any growth stage . CONCLUSIONS: The antibacterial activity of (2E)-alkenals against Salm . choleraesuis was found to correlate with the hydrophobic alkyl chain length . The conjugated double bond is not essential in eliciting the activity but is associated with increasing it . SIGNIFICANCE AND IMPACT OF THE STUDY: Because of their easy availability and wide distribution in many edible plants, (2E)-alkenals can be used as anti-Salmonella agents. Curr Mol Med, 2004 Feb, 4(1), 41 - 9 Non-antigen presenting effects of HLA-B27; Penttinen MA et al.; Spondyloarthropathies (SpA) are a group of chronic rheumatic diseases, which show a strong asoociation with human leukocyte antigen (HLA)-B27 . Although the association between HLA-B27 and the susceptibility to SpA was discovered thirty years ago, the exact mechanism by which HLA-B27 predisposes to disease development remains unclear . The classical role of MHC class I molecules is to present peptides for CD8+ T cells . Therefore, it has been proposed that the antigen presenting function of HLA-B27 is somehow altered in the patients developing SpA . However, despite extensive research, the attempts to create a comprehensive theory that would explain the role of HLA-B27 as an antigen presenting molecule in the development of SpA have been unsuccessful . Reactive arthritis (ReA) belongs to the group of SpA . It is a joint inflammation developing after certain bacterial infections e.g . Salmonella, Yersinia, and Chlamydia . Several unrelated observations indicate that HLA-B27 modulates the interaction between ReA-triggering bacteria and host cell . These findings suggest that HLA-B27 may possess functions, which are unrelated to antigen presentation . In this paper, we summarize these findings and discuss their potential impact in the development of SpA. Am J Physiol Gastrointest Liver Physiol, 2004 Apr, 286(4), G613 - 26 Functional modulation of enterocytes by gram-positive and gram-negative microorganisms; Otte JM et al.; Clinical studies have suggested that so-called probiotic bacteria may be effective as therapy in inflammatory bowel disease . However, the molecular mechanisms of their interaction with the intestinal surface remain undefined . The influence of whole probiotic bacteria {Escherichia coli Nissle 1917 (EcN); probiotic mixture VSL#3 (PM)}, bacterial cell lysates, and conditioned media on transepithelial resistance (TER), IL-8 secretion, mucin gene expression, and tight junction proteins were determined in T84 and HT-29 intestinal epithelial cells (IEC) . In addition, effects on pathogen (Salmonella dublin)-induced alterations were analyzed . EcN as well as debris and cell extracts induced IL-8 secretion from IEC, whereas no such effect was observed following incubation with the PM . The PM and soluble protein(s) released from the PM increased TER, prevented pathogen-induced decrease in TER, and were shown to stabilize tight junctions . The PM induced expression of mucins in IEC, and these organisms as well as EcN diminished S . dublin-induced cell death . Inhibition of MAPKs with PD-98059 or SB-203580 significantly decreased alterations in IL-8 synthesis and mucin expression and affected the regulation of TER . Probiotics and protein(s) released by these organisms may functionally modulate the intestinal epithelium of the host by different mechanisms, including the competition of whole organisms for contact with the epithelial surface as well as stabilization of the cytoskeleton and barrier function and the induction of mucin expression . Gram-negative and gram-positive organisms differ in the mechanisms activated, and a combination of organisms might be more effective than the application of a single strain. Vet Immunol Immunopathol, 2004 Apr, 98(3-4), 193 - 201 Live Salmonella enterica serovar Typhimurium (S . Typhimurium) elicit dendritic cell responses that differ from those induced by killed S . Typhimurium; Norimatsu M et al.; The immune response of bovine monocytes-derived dendritic cells (DC) exposed to either live or killed Salmonella enterica serovar Typhimurium was compared . Both live and killed bacteria induced changes in morphology with distinctive formation of processes and up-regulation of the ability of DC to stimulate allogeneic T-cell proliferation . Also, both live and killed bacteria up-regulated the expression of MHC-I, MHC-II and CD80 . However, live bacteria induced greater up-regulation of the expression of CD40 and CD86 than killed bacteria . Live bacteria also induced greater up-regulation of transcription for IL-6, IL-12 and GM-CSF than killed bacteria as measured by quantitative RT-PCR . These data suggest that blood-monocyte-derived DC may follow distinct maturation pathways following exposure to live or killed bacteria . These differences are likely to have consequences for the priming of the adaptive immune responses. Mol Microbiol, 2004 Mar, 51(6), 1817 - 26 Post-transcriptional regulation of bacterial motility by aconitase proteins; Tang Y et al.; Escherichia coli and Bacillus subtilis aconitases can act as iron and oxidative stress-responsive post-transcriptional regulators . Here, it is shown that a Salmonella enterica serovar Typhimurium LT2 acnB mutant exhibits impaired binding to the surface of J774 macrophage-like cells . Proteomic analyses were used to investigate further the binding defect of the acnB mutant . These revealed that the levels of the flagellum protein FliC were much lower for the acnB mutant . This strain was correspondingly less motile and possessed fewer flagella than either the parental strain or the acnA and acnAB mutants . The acnB lesion did not alter fliC transcription, nor did apo-AcnB select the fliC transcript from a library of S . enterica transcripts; thus, the effect of AcnB on FliC is indirect . Evidence is presented to show that apo-AcnB regulates FliC synthesis via interaction with the ftsH transcript to decrease the intracellular levels of FtsH . The lower levels of FtsH protease activity then influence sigma32, DnaK and, ultimately, FliC production. Mol Microbiol, 2004 Mar, 51(6), 1729 - 44 Large-scale identification of essential Salmonella genes by trapping lethal insertions; Knuth K et al.; A novel screening approach based on insertion-duplication mutagenesis (IDM) was established to efficiently screen for essential genes of Salmonella enterica serovar Typhimurium under laboratory conditions . Small, randomly generated genomic fragments were cloned into a conditionally replicating vector, and the resulting library of single Salmonella clones was grown under permissive conditions . Upon switching to non-permissive temperature, discrimination between lethal and non-lethal insertions following homologous recombination allowed the trapping of genes with essential functions . Further characterization of a total of 498 fragments resulting in such lethal knockout revealed 145 known essential genes and 112 functionally characterized or hypothetical genes not yet shown to encode essential genes, among them three Salmonella-specific genes . The essentiality was demonstrated for a prioritised set of 15 putative indispensable genes by creating conditional lethal phenotypes . The results of this large-scale screening indicate that in rich media, the class of Salmonella genes indispensable for growth is composed of approximately 490 genes. Appl Environ Microbiol, 2004 Mar, 70(3), 1393 - 6 Comparison of PCR, electrochemical enzyme-linked immunosorbent assays, and the standard culture method for detecting salmonella in meat products; Croci L et al.; An electrochemical enzyme-linked immunosorbent assay (ELISA) coupled with flow injection analysis (ELISA-FIA) and a PCR-based method using ST11 and ST15 primers for detecting salmonellae in meat were evaluated in comparison with the International Organization for Standardization (ISO) culture method . The methods were applied to experimentally contaminated and naturally contaminated meat samples . The results showed that both ELISA-FIA and PCR allowed detection of salmonella in a product contaminated with a low number of the microorganisms (1 to 10 salmonellae/25 g) after only 5 h of incubation of preenrichment broth, and they were just as effective as the ISO method. Ann Trop Paediatr, 2004 Mar, 24(1), 45 - 51 Aeromonas spp associated with children's diarrhoea in Tehran: a case-control study; Soltan Dallal MM et al.; The study sought a possible pathogenic role for Aeromonas spp in Tehranian children presenting with diarrhoea . During a 10-month period (February to October 2001), 310 children <10 years of age with diarrhoea and a group of 310 age- and sex-matched controls were selected . Both groups were investigated for diarrhoeal pathogens . Of 310 children who presented with acute diarrhoea, Aeromonas spp was isolated from 14 (4.5%) (A . veronii biovar sobria 8, A . caviae 5 and A . hydrophila 1) . The isolation rate was significantly higher than in the controls (p<0.001) . Other enteropathogens were also more commonly isolated in children with diarrhoea: 57 (18.4%) Shigella spp (p<0.0001), 8 (2.6%) Salmonella spp (p<0.01), 7 (2.3%) enteropathogenic E . coli (p<0.05) and 8 (2.6%) Giardia lamblia (p<0.01) . No enteropathogens were isolated in the control group . Dysentery was the dominant clinical feature in children positive for Aeromonas spp. Yonsei Med J, 2004 Feb 29, 45(1), 43 - 8 Salmonella enterica serovar London infections associated with consumption of infant formula; Park JK et al.; Epidemiologic studies were conducted on 31 cases of Salmonella group E infection detected in 2000 through a laboratory-based pathogen surveillance in Gangwon Province, Korea . Data were collected on the environmental exposures and the patients' foods, including the brand(s) of milk consumed before the onset of diarrhea . The patients' medical records were also reviewed . All of the patients were infants under 10 months of age except one 7-year old child . Surprisingly, all of the infants were fed with infant formulas from Company A, although two infants were fed with infant formulas from both Company A and Company B . Antimicrobial susceptibility test and pulsed-field gel electrophoresis (PFGE) were performed in 25 out of 31 isolates from the patients and in 1 isolate from an opened packet of infant formula collected from the home of an infected infant . All of the 26 isolates were Salmonella enterica serovar London . They showed a single PFGE pattern, and all of the isolates were susceptible to the 18 antibiotics tested . The causative agent of the salmonella outbreaks in the Gangwon Province and its surrounding areas was Salmonella London, and the highly likely source of the infection was infant formula from Company A. J Clin Microbiol, 2004 Mar, 42(3), 1155 - 62 Random amplified polymorphic DNA and phenotyping analysis of Salmonella enterica serovar enteritidis isolates collected from humans and poultry in Uruguay from 1995 to 2002; Betancor L et al.; Molecular and phenotyping techniques were applied to study Salmonella enterica serovar Enteritidis strains both from human cases of infection and of avian origin isolated in Uruguay from 1995 to 2002 . A group of 62 isolates was subjected to random amplified polymorphic DNA (RAPD) assay and analysis of antibiotic resistance patterns . Twenty-one of these strains were further characterized by phage typing and analysis of their protein expression profiles . RAPD fingerprinting with five different primers discriminated 10 different genetic profiles . Of the 62 strains tested, 48 had a single major genetic profile, whereas the other nine profiles were evenly distributed among the other strains . The genetic diversity was greater among strains of animal origin than among isolates of human origin . Comparative examination of the results obtained by RAPD analysis and phenotypic analysis and by strain source provided evidence of the reliable discriminatory power of RAPD analysis in our study . Six avian isolates with antibiotic resistance were detected: two were nalidixic acid resistant and four had a particular beta-lactam resistance pattern . The last four isolates all had the same unusual phage type (phage type 4b); however, RAPD analysis differentiated them into two groups . Two isolates with unique RAPD profiles were recovered from distinct human cases, suggesting that the technique differentiates unrelated strains . Overall, the results show the existence of a predominant genetic type that is present in poultry and that is transmitted to humans . There are also several other genotypes, but only a few of them could be recovered from human sources, suggesting the existence of different pathogenic traits among strains circulating in the country. J Microbiol Methods, 2004 Apr, 57(1), 23 - 31 Rapid screening method for the detection of antimicrobial substances; Vesterlund S et al.; Bioluminescence is phenomenon where living organisms produce light and this production is directly dependent on metabolic activity of the organism . Genes encoding enzymes, luciferases, responsible for light production can be cloned into indicator strains, thus allowing sensitive detection of antimicrobial activity . This study utilized bacterial luciferase genes cloned into Staphylococcus aureus, Escherichia coli and Salmonella enterica serovar Typhimurium indicator strains and showed that the detection of antimicrobial activity can be obtained already in 2 h without laborious plate counting and overnight incubation . Indicator strains used in the study harboured luxAB genes responsible of producing light as well as luxCDE genes for synthesis of long-chain fatty aldehyde as substrate for light production . As a consequence, no exogenous aldehyde addition was needed allowing stable light production . Furthermore, the method was used for the detection of antimicrobial activity from lactic acid bacteria after the effect of organic acids was eliminated. Dig Liver Dis, 2004 Feb, 36(2), 141 - 6 Colonoscopic manifestations of typhoid fever with lower gastrointestinal bleeding; Lee JH et al.; BACKGROUND: Intestinal bleeding in patients with typhoid fever usually occurs in the ileum . However, endoscopic findings in such patients are not well established . We examined the colonoscopic manifestations of intestinal lesions with bleeding in patients with typhoid fever . PATIENTS AND METHODS: The colonoscopic findings of seven patients who presented with haematochezia due to typhoid fever were reviewed retrospectively . Typhoid fever was diagnosed when the Salmonella typhi was isolated or when the Widal test showed strongly positive reactions . RESULTS: Clinical data and colonoscopic findings were reviewed in seven patients (four men and three women with an average age of 42 years) . The most commonly involved area was the terminal ileum (100%), followed by the ileocecal valve (57%), the ascending colon (43%), and the transverse colon (29%) . Left colon was intact in all cases . The most common colonoscopic finding was multiple variable-sized punched-out ulcers with slightly elevated margin, as found in five patients . In two patients, only several oedematous hyperaemic mucosal patches with haemorrhagic spots or shallow erosions were seen . Active bleeding was noticed only in one patient, who received endoscopic haemostasis twice . The remaining six patients were treated by conservative treatment including antibiotic therapy . There was no complication during or after the colonoscopic examination . CONCLUSIONS: Intestinal bleeding in typhoid fever usually occurs from the ulcers in the ileum or proximal colon, and the most common colonoscopic manifestations are multiple variable-sized punched-out ulcerations. Scand J Infect Dis, 2004, 36(1), 72 - 5 Prosthetic valve endocarditis caused by Salmonella enteritidis; Gonen C et al.; Until now, only 12 cases of prosthetic valve endocarditis caused by Salmonella spp . have been reported in the English literature . High complication and mortality rates, a fulminant course and the requirement for early surgical intervention deserve special attention in this kind of infective endocarditis . A new case of Salmonella prosthetic valve endocarditis complicated by sepsis-induced cholestasis and a literature review are presented in this report. Clin Infect Dis, 2004 Mar 15, 38(6), 857 - 63 Epub 2004 Feb 27. Efficacy and tolerability of ClO2-generating gloves; Barza M; The transmission of pathogenic microorganisms by the hands of workers continues to be a problem in the medical field and the food industry . Compliance with hand hygiene is often poor, and gloves may be contaminated after being donned and may transmit microorganisms . A novel, patented technology allows materials to be impregnated with microspheres that, when activated by light or moisture, generate ClO2 at sustained rates to produce a disinfecting microatmosphere . Gloves that were seeded with bacteria and then exposed to light were able to reduce the numbers of Staphylococcus aureus, Escherichia coli, Salmonella serotype Typhimurium, and Listeria monocytogenes by 1-3 logs within 20 min, both on the gloves and on the hands of wearers . The gloves look and feel like their standard counterparts and were well tolerated in the Draize test . This technology holds promise for reducing cross-contamination and the transmission of pathogens in the medical and food handling environments. Clin Infect Dis, 2004 Mar 15, 38(6), 771 - 9 Epub 2004 Feb 26. Postmarketing safety surveillance for typhoid fever vaccines from the Vaccine Adverse Event Reporting System, July 1990 through June 2002; Begier EM et al.; Vaccines against Salmonella enterica serotype Typhi are used for prophylaxis of international travelers and have potential use as counterbioterrorism agents . The Vaccine Adverse Event Reporting System (VAERS) cannot usually establish causal relationships between vaccines and reported adverse events without further research but has successfully detected unrecognized side effects of vaccine . We reviewed reports to VAERS for US-licensed typhoid fever vaccines for the period of July 1990 through June 2002 . We received 321 reports for parenteral Vi capsular polysaccharide vaccine and 345 reports for live, oral, attenuated Ty21a vaccine, with 7.5% and 5.5%, respectively, describing death, hospitalization, permanent disability, or life-threatening illness . Unexpected frequently reported symptoms included dizziness and pruritus for Vi vaccine and fatigue and myalgia for Ty21a vaccine . Gastroenteritis-like illness after receipt of Ty21a vaccine and abdominal pain after receipt of Vi vaccine, which are previously recognized events, occasionally required hospitalization . Nonfatal anaphylaxis was reported after both vaccines . VAERS reports do not indicate any unexpected serious side effects that compromise these vaccines' use for travelers' prophylaxis. J Bone Miner Metab, 2004, 22(2), 94 - 103 Periodontal ligament cells under intermittent tensile stress regulate mRNA expression of osteoprotegerin and tissue inhibitor of matrix metalloprotease-1 and -2; Tsuji K et al.; We studied the mRNA expression of osteoprotegerin (OPG), receptor activator of NF-kappa B ligand (RANKL), tissue inhibitor of matrix metalloprotease (TIMP)-1 and -2, and matrix metalloprotease (MMP)-1 and -2 by human periodontal ligament (PDL) cells under intermittent tensile stress using a Flexercell Strain Unit . Analysis by reverse transcriptase-polymerase chain reaction showed that mechanical force upregulated OPG mRNA . We also demonstrated that the protein concentration of OPG in conditioned medium increased upon loading with tensile stress, as determined by enzyme-linked immunosorbent assay . TIMP-1 and -2 mRNA levels also increased, whereas levels of RANKL, MMP-1, and MMP-2 mRNA were barely affected . We further examined the effect of loading with tensile stress and addition of Salmonella abortus equi lipopolysaccharide (LPS) on the mRNA expression of PDL cells . The amount of OPG mRNA induced by mechanical strain was found to decrease with the addition of LPS to cultures . The induction of OPG mRNA expression by stretching was inhibited in the presence of indomethacin or genistein, whereas TIMP-1 mRNA expression induced by stretching was inhibited by the addition of cycloheximide, suggesting that tensile stress regulates cyclooxygenase activities, tyrosine phosphorylation, and de novo protein synthesis in PDL cells through the induction of OPG and TIMP-1 mRNA expression . These results provide evidence that the mechanical stimulus of stretching is responsible for the observed regulation of bone resorption and tissue degradation in PDL tissue. Expert Opin Biol Ther, 2004 Feb, 4(2), 157 - 68 Bacteria-mediated DNA transfer in gene therapy and vaccination; Loessner H et al.; The use of live attenuated bacterial vaccine strains allows the targeted delivery of macromolecules to mammalian cells and tissues via the mucosal route . Depending on their specific virulence mechanisms and inherent metabolic preferences, bacteria invade certain cell types and body niches where they consequently deliver their cargo . Recently, the ability of attenuated strains of Salmonella, Shigella and Yersinia spp., as well as Listeria monocytogenes and invasive Escherichia coli, to deliver eukaryotic expression plasmids into mammalian cells in vitro and in vivo has been discovered . The great potential of bacteria-mediated transfer of plasmid DNA encoding vaccine antigens and/or therapeutic molecules was demonstrated in experimental animal models of infectious diseases, tumours and gene deficiencies . The exact mechanism of DNA transfer from the bacterial vector into the mammalian host is not yet completely known . The understanding of molecular events during bacterial DNA transfer, however, will further the development of bacterial vector systems with great promise for various clinical applications. J Clin Immunol, 2004 Jan, 24(1), 42 - 52 Lipopolysaccharide induces CD25-positive, IL-10-producing lymphocytes without secretion of proinflammatory cytokines in the human colon: low MD-2 mRNA expression in colonic macrophages; Shirai Y et al.; Despite the huge number of colonized Gram-negative bacteria in the colon, the normal colon maintains its homeostasis without any excessive immune response . To investigate the potential mechanisms involved, human colonic lamina propria mononuclear cells (LPMCs) obtained from uninflamed mucosa were cultured with lipopolysaccharide (LPS) prepared from Bacteroides vulgatus (BV-LPS) or Bacteroides fragilis (BF-LPS), as representatives of indigenous flora, or pathogenic Salmonella minnesota (SM-LPS) . Colonic LPMCs failed to produce inflammatory cytokines in response to any type of LPS . Colonic macrophages barely expressed mRNA for MD-2, an essential association molecule for LPS signaling via Toll-like receptor 4 . Further, BV-LPS induced CD25 and Foxp3 expression in lymphocytes and CD4(+)CD25(+) cells expressed IL-10 mRNA . Thus, the low expression of functioning LPS receptor molecules and induction of IL-10-producing CD4(+)CD25(+) lymphocytes by indigenous LPS may play a central role in the maintenance of colonic immunological homeostasis. J Bacteriol, 2004 Mar, 186(6), 1890 - 2 The eutD gene of Salmonella enterica encodes a protein with phosphotransacetylase enzyme activity; Brinsmade SR et al.; The EutD protein of Salmonella enterica is homologous to the catalytic domain of the phosphotransacetylase (Pta) enzyme . The Pta-like activity level of the EutD enzyme compared favorably to that of other Pta enzymes . High-pressure liquid chromatography and mass spectrometry verified that acetyl-coenzyme A was the product of the reaction . The EutD protein restored growth of an S . enterica pta strain on acetate as the source of carbon and energy. J Bacteriol, 2004 Mar, 186(6), 1869 - 78 Isolation and characterization of beta-ketoacyl-acyl carrier protein reductase (fabG) mutants of Escherichia coli and Salmonella enterica serovar Typhimurium; Lai CY et al.; FabG, beta-ketoacyl-acyl carrier protein (ACP) reductase, performs the NADPH-dependent reduction of beta-ketoacyl-ACP substrates to beta-hydroxyacyl-ACP products, the first reductive step in the elongation cycle of fatty acid biosynthesis . We report the first documented fabG mutants and their characterization . By chemical mutagenesis followed by a tritium suicide procedure, we obtained three conditionally lethal temperature-sensitive fabG mutants . The Escherichia coli {fabG (Ts)} mutant contains two point mutations: A154T and E233K . The beta-ketoacyl-ACP reductase activity of this mutant was extremely thermolabile, and the rate of fatty acid synthesis measured in vivo was inhibited upon shift to the nonpermissive temperature . Moreover, synthesis of the acyl-ACP intermediates of the pathway was inhibited upon shift of mutant cultures to the nonpermissive temperature, indicating blockage of the synthetic cycle . Similar results were observed for in vitro fatty acid synthesis . Complementation analysis revealed that only the E233K mutation was required to give the temperature-sensitive growth phenotype . In the two Salmonella enterica serovar Typhimurium fabG(Ts) mutants one strain had a single point mutation, S224F, whereas the second strain contained two mutations (M125I and A223T) . All of the altered residues of the FabG mutant proteins are located on or near the twofold axes of symmetry at the dimer interfaces in this homotetrameric protein, suggesting that the quaternary structures of the mutant FabG proteins may be disrupted at the nonpermissive temperature. J Bacteriol, 2004 Mar, 186(6), 1678 - 82 DNA amplification and rearrangements in archival Salmonella enterica serovar Typhimurium LT2 cultures; Porwollik S et al.; Variations in genome size and gene order were observed in archival Salmonella enterica serovar Typhimurium cultures stored for over 40 years . In one strain, microarray analysis revealed a large, stable amplification . PCR analysis of the same strain revealed a genomic duplication that underwent a translocation . Other strains had smaller duplications and deletions . These results demonstrate that storage in stabs over time at room temperature not only allows for further bacterial growth but also may produce an environment that selects for a variety of mutations, including genomic rearrangements. J Bacteriol, 2004 Mar, 186(6), 1629 - 37 The Tricarballylate utilization (tcuRABC) genes of Salmonella enterica serovar Typhimurium LT2; Lewis JA et al.; The genes of Salmonella enterica serovar Typhimurium LT2 encoding functions needed for the utilization of tricarballylate as a carbon and energy source were identified and their locations in the chromosome were established . Three of the tricarballylate utilization (tcu) genes, tcuABC, are organized as an operon; a fourth gene, tcuR, is located immediately 5' to the tcuABC operon . The tcuABC operon and tcuR gene share the same direction of transcription but are independently transcribed . The tcuRABC genes are missing in the Escherichia coli K-12 chromosome . The tcuR gene is proposed to encode a regulatory protein needed for the expression of tcuABC . The tcuC gene is proposed to encode an integral membrane protein whose role is to transport tricarballylate across the cell membrane . tcuC function was sufficient to allow E . coli K-12 to grow on citrate (a tricarballylate analog) but not to allow growth of this bacterium on tricarballylate . E . coli K-12 carrying a plasmid with wild-type alleles of tcuABC grew on tricarballylate, suggesting that the functions of the TcuABC proteins were the only ones unique to S . enterica needed to catabolize tricarballylate . Analyses of the predicted amino acid sequences of the TcuAB proteins suggest that TcuA is a flavoprotein, and TcuB is likely anchored to the cell membrane and probably contains one or more Fe-S centers . The TcuB protein is proposed to work in concert with TcuA to oxidize tricarballylate to cis-aconitate, which is further catabolized via the Krebs cycle . The glyoxylate shunt is not required for growth of S . enterica on tricarballylate . A model for tricarballylate catabolism in S . enterica is proposed. J Bacteriol, 2004 Mar, 186(6), 1620 - 8 Regulation of Escherichia coli hemolysin E expression by H-NS and Salmonella SlyA; Wyborn NR et al.; The Escherichia coli hlyE gene (also known as clyA or sheA) codes for a novel pore-forming toxin . Previous work has shown that the global transcription factors FNR and CRP positively regulate hlyE expression by binding at the same site . Here in vivo transcription studies reveal that FNR occupies the hlyE promoter more frequently than CRP, providing a mechanism for the moderate upregulation of hlyE expression in response to two distinct environmental signals (oxygen and glucose starvation) . It has been reported that H-NS interacts with two large regions of the hlyE promoter (PhlyE), one upstream of the -35 element and one downstream of the -10 element . Here we identify two high-affinity H-NS sites, H-NS I, located at the 3' end of the extended upstream footprint, and H-NS II, located at the 5' end of the extended downstream footprint . It is suggested that these high-affinity sites initiate the progressive formation of higher order complexes, allowing a range of H-NS-mediated regulatory effects at PhlyE . Finally, the identification of a SlyA binding site that overlaps the H-NS I site in PhlyE suggests a mechanism to explain how SlyA overproduction enhances hlyE expression by antagonizing the negative effects of H-NS. Int J Food Microbiol, 2004 Mar 1, 91(2), 175 - 83 Occurrence of inhibitory compounds in spent growth media that interfere with acid-tolerance mechanisms of enteric pathogens; Chen Y et al.; Understanding the acid-tolerance ability of enteric human pathogens is critical in determining microbial food safety and the associated risk . We have discovered naturally occurring compounds in the spent growth media, which inhibit the acid-tolerance ability of several enteric human pathogens when challenged at pH 3.0 for 2 h at 37 degrees C . The compounds were detected in the spent growth media obtained from Escherichia coli O157:H7, Salmonella spp., and Vibrio cholera, but not from Shigella flexneri . The compounds were effective in reducing pathogen survival by 5-logs during acid-challenge assay . The low molecular weight (<300 Da) and heat resistant nature (121 degrees C, 15 min, at 15 psi) of the compounds make them excellent candidates to explore their suitability as food additives that would increase microbial food safety. Mol Cell, 2004 Feb 27, 13(4), 497 - 510 Control of actin turnover by a salmonella invasion protein; McGhie EJ et al.; Salmonella force their way into nonphagocytic host intestinal cells to initiate infection . Uptake is triggered by delivery into the target cell of bacterial effector proteins that stimulate cytoskeletal rearrangements and membrane ruffling . The Salmonella invasion protein A (SipA) effector is an actin binding protein that enhances uptake efficiency by promoting actin polymerization . SipA-bound actin filaments (F-actin) are also resistant to artificial disassembly in vitro . Using biochemical assays of actin dynamics and actin-based motility models, we demonstrate that SipA directly arrests cellular mechanisms of actin turnover . SipA inhibits ADF/cofilin-directed depolymerization both by preventing binding of ADF and cofilin and by displacing them from F-actin . SipA also protects F-actin from gelsolin-directed severing and reanneals gelsolin-severed F-actin fragments . These data suggest that SipA focuses host cytoskeletal reorganization by locally inhibiting both ADF/cofilin- and gelsolin-directed actin disassembly, while simultaneously stimulating pathogen-induced actin polymerization. Drugs Today (Barc), 1998 Sep, 34(9), 739 - 45 Community-acquired pneumonia in patients with HIV; Cunha BA; Patients with HIV frequently present at some time in their illness with community-acquired pneumonia (CAP) . Early in the prognosis of HIV when CD4 counts are somewhat decreased, HIV patients with CAP are infected with the same pulmonary pathogen as normal hosts plus Legionella, Salmonella or Chlamydia pneumoniae . Later in HIV, when the CD4 counts are markedly reduced, Pneumocystis carinii (PCP), CMV and acid-fast organisms (TB or MAI) are important pulmonary pathogens . This article presents a clinical approach to empiric antibiotics based on chest x-ray appearance and CD4 count . This permits a rational therapeutic approach to avoid excessive coverage commonly employed by clinicians because of the multiplicity of potential pulmonary pathogens in HIV patients with CAP. J Antimicrob Chemother, 2004 Apr, 53(4), 657 - 9 Epub 2004 Feb 25. Role of TolC and parC mutation in high-level fluoroquinolone resistance in Salmonella enterica serotype Typhimurium DT204; Baucheron S et al.; OBJECTIVES: To study the role of TolC and of parC mutation in high-level fluoroquinolone resistance in clonal clinical strains of Salmonella enterica serotype Typhimurium phage type DT204 (S . Typhimurium DT204) . METHODS: Deletion of the tolC gene (DeltatolC) was first performed in a susceptible S . Typhimurium DT104 strain lacking target gene mutations involved in fluoroquinolone resistance . P22 transduction was further used to transduce DeltatolC from this strain to a high-level fluoroquinolone-resistant S . Typhimurium DT204 strain carrying several target gene mutations, including one in parC (ciprofloxacin MIC of 32 mg/L) . RESULTS: Deletion of tolC in the high-level fluoroquinolone-resistant S . Ty