J Mol Evol, 1997 Mar, 44(3), 299 - 309 Relatedness and phylogeny within the family of periplasmic chaperones involved in the assembly of pili or capsule-like structures of gram-negative bacteria; Bonci A et al.; The structure of a Salmonella enterica serovar typhi gene located within the fim gene cluster and encoding a putative periplasmic chaperone-like protein involved in the assembly of type 1 pili was determined . This gene, named fimC, has the ability to encode a 26-kDa polypeptide which is similar, at the sequence level, to the PapD periplasmic chaperonin mediating the assembly of P pili of Escherichia coli, as well as to other periplasmic chaperone-like proteins involved in the biogenesis of pili or capsule-like structures of various Gram-negative bacteria . A comprehensive search through the literature and sequence databases identified 31 (putative) bacterial proteins that can be included in this protein family on the basis of sequence similarity . Results of a multiple sequence comparison analysis showed that several residues, including most of those known to be critical in maintaining the three-dimensional structure of PapD, are either conserved or conservatively substituted in all these proteins, suggesting an overall similar folding for all of them . It was also evident that members of this family are clustered into different subfamilies according to structural and phyletic data. Appl Environ Microbiol, 1997 Mar, 63(3), 1118 - 23 Identification of bacterial cells by chromosomal painting; Lanoil BD et al.; Chromosomal painting is a technique for the microscopic localization of genetic material . It has been applied at the subcellular level to identify regions of eukaryotic chromosomes . Here we describe the development of bacterial chromosomal painting (BCP), a related technology for the identification of bacterial cells . Purified genomic DNAs from six bacterial strains were labeled by nick translation with the fluorochrome Fluor-X, Cy3, or Cy5 . The average size of the labeled fragments was ca . 50 to 200 bp . The probes were hybridized to formaldehyde-fixed microbial cells attached to slides and visualized by fluorescence microscopy . In reciprocal comparisons, distantly related members of the class Proteobacteria (Escherichia coli and Oceanospirillum linum), different species of the genus Bacillus (B . subtilis and B . megaterium), and different serotypes of the subspecies Salmonella choleraesuis subsp . choleraesuis (serotype typhimurium LT2 and serotype typhi Ty2) could easily be distinguished . A combination of two probes, each labeled with a different fluorochrome, was used successfully to simultaneously identify two cell types in a mixture . Lysozyme treatment was required for the identification of Bacillus spp., and RNase digestion and pepsin digestion were found to enhance signal strength and specificity for all cell types tested . Chromosome in situ suppression, a technique that removes cross-hybridizing fragments from the probe, was necessary for the differentiation of the Salmonella serotypes but was not required to distinguish the more distantly related taxa . BCP may have applications in diverse branches of microbiology where the objective is the identification of bacterial cells. J Bacteriol, 1997 Mar, 179(5), 1622 - 7 Recent horizontal transmission of plasmids between natural populations of Escherichia coli and Salmonella enterica; Boyd EF et al.; Seventy-one natural isolates obtained from a Salmonella reference collection were examined for the presence of plasmids closely related to the Escherichia coli F plasmid . The collection consists of several serovars of the S . enterica Typhimurium complex, subspecies I, to which 99% of pathogenic salmonellae belong . Molecular genetic techniques of DNA hybridization, along with PCR and DNA sequencing, were used to examine the occurrence, distribution, and genetic diversity of F-like plasmids among Salmonella strains . The F plasmid genes examined were finO, traD, traY, and repA, which map at dispersed positions on the F plasmid of E . coli . Comparative sequence analysis of each of the four genes in Salmonella plasmids showed them to be homologous (in some cases, virtually identical) to those found in F plasmids of E . coli natural isolates . Furthermore, the frequency of F-like plasmids in Salmonella strains was approximately the same as that observed in the E . coli Reference Collection . However, in Salmonella, the distribution was confined predominately to the serovars Typhimurium and Muenchen . The unexpected finding of a shared pool of F-like plasmids between S . enterica and E . coli demonstrates the significant role of conjugation in the histories of these important bacterial species. J Bacteriol, 1997 Mar, 179(5), 1482 - 9 Pseudomonas aeruginosa B-band O-antigen chain length is modulated by Wzz (Ro1); Burrows LL et al.; The wbp gene cluster, encoding the B-band lipopolysaccharide O antigen of Pseudomonas aeruginosa serotype O5 strain PAO1, was previously shown to contain a wzy (rfc) gene encoding the O-antigen polymerase . This study describes the molecular characterization of the corresponding wzz (rol) gene, responsible for modulating O-antigen chain length . P . aeruginosa O5 Wzz has 19 to 20% amino acid identity with Wzz of Escherichia coli, Salmonella enterica, and Shigella flexneri . Knockout mutations of the wzz gene in serotypes O5 and O16 (which has an O antigen structurally related to that of O5) yielded mutants expressing O antigens with a distribution of chain lengths differing markedly from that of the parent strains . Unlike enteric wzz mutants, the P . aeruginosa wzz mutants continued to display some chain length modulation . The P . aeruginosa O5 wzz gene complemented both O5 and O16 wzz mutants as well as an E . coli wzz mutant . Coexpression of E . coli and P . aeruginosa wzz genes in a rough strain of E . coli carrying the P . aeruginosa wbp cluster resulted in the expression of two populations of O-antigen chain lengths . Sequence analysis of the region upstream of wzz led to identification of the genes rpsA and himD, encoding 30S ribosomal subunit protein S1 and integration host factor, respectively . This finding places rpsA and himD adjacent to wzz and the wbp cluster at 37 min on the PAO1 chromosomal map and completes the delineation of the O5 serogroup-specific region of the wbp cluster. J Clin Microbiol, 1997 Mar, 35(3), 714 - 8 An enzyme-linked immunosorbent assay to detect PCR products of the rfbS gene from serogroup D salmonellae: a rapid screening prototype; Luk JM et al.; We describe a digoxigenin-based enzyme-linked immunosorbent assay (DIG-ELISA) following a PCR to detect the amplified lipopolysaccharide rfbS gene as a means for rapid screening of serogroup D salmonellae in stool specimens . For pure bacterial cultures, the sensitivity of the PCR DIG-ELISA was approximately 10 bacteria . In the presence of stool materials, the salmonellae were first isolated by an immunomagnetic separation technique with an O9-specific monoclonal antibody . MATy-O9, followed by PCR and DIG-ELISA . The corresponding sensitivity was about 10 to 100 bacteria . To evaluate the assay performance clinically, 203 stool samples from patients with diarrhea were subjected to the routine culture techniques and the PCR ELISA method with overnight enrichment . The conventional culture method identified 145 salmonellae (31 serogroup B, 27 serogroup C, 83 serogroup D, and 5 serogroup E isolates) and 58 non-salmonella bacteria . The PCR ELISA method correctly identified all 82 serogroup D salmonellae (A405 by ELISA, 2.54 +/- 0.74) but was negative for the other Salmonella serogroups (A405, 0.26 +/- 0.08; n = 63) and non-Salmonella isolates (A405, 0.16 +/- 0.04; n = 58) . In order to obtain a visible result, the assay takes approximately 6 h (PCR, 4 h; ELISA, 2 h), along with brief enrichment cultivation of the samples (from 4 to 16 h) . Thus, the PCR DIG-ELISA offers a fast, accurate, semiquantitative means of detecting infectious agents such as salmonellae, and future robotic automation is possible. J Clin Microbiol, 1997 Mar, 35(3), 679 - 84 Production and characterization of monoclonal antibodies specific for the lipopolysaccharide of Escherichia coli O157; Westerman RB et al.; Identification of the O157 antigen is an essential part of the detection of Escherichia coli O157:H7, which is recognized as a major etiologic agent of hemorrhagic colitis . However, polyclonal antibodies produced against E . coli O157:H7 lipopolysaccharide (LPS) may react with several other bacteria including Brucella abortus, Brucella melitensis, Yersinia enterocolitica O9, Escherichia hermannii, and Stenotrophomonas maltophilia . We produced eight monoclonal antibodies (MAbs) specific for the LPS of E . coli O157 . Western blots (immunoblots) of both the phenol phase (smooth) and the aqueous phase (rough) of hot phenol-water-purified LPS indicated that three of the MAbs were specific for the O antigen and five were reactive with the LPS core . The eight MAbs could be further differentiated by their reactivities to Salmonella O30 LPS (group N), which is reported to be identical to the E . coli O157 antigen . All eight MAbs reacted strongly to all of the 64 strains of E . coli O157 tested, which included 47 isolates of O157:H7 and 17 other O157 strains . None of the eight MAbs cross-reacted with any of the 38 other E . coli serotypes tested, which consisted of 29 different O-antigen serotypes, or with 38 strains (22 genera) of non-E . coli gram-negative enteric bacteria. Pediatrics, 1997 Mar, 99(3), 399 - 402 Iguanas and Salmonella marina infection in children: a reflection of the increasing incidence of reptile-associated salmonellosis in the United States; Mermin J et al.; OBJECTIVE: To investigate clinical aspects and risk factors for Salmonella serotype Marina infection in the United States . METHODS: We identified all isolates of S Marina reported in 1994 to the National Salmonella Surveillance System . Patients were interviewed about demographic information, clinical course, diet, travel history, and contact with reptiles before illness . RESULTS: Twenty-six (81%) of 32 patients were infants (<1 year of age) and 24 (75%) were male . This differs from other Salmonella isolates reported to the Centers for Disease Control and Prevention in 1994, of which 14% were from infants and 49% from male patients . Eleven patients (34%) were hospitalized for a median of 3.5 days (range: 2 to 21 days), and 1 died . Of 28 patients (88%) with reported iguana exposure, only 4 (14%) touched the reptile, and only 12 respondents (43%) realized that it might have been the source of infection . Seven (32%) of 22 families who owned an iguana at the time of illness continued to own an iguana when contacted a median of 28 weeks later . Persons who thought that the iguana was the source of infection were more likely to have given away or sold the pet than those who did not . Four isolates (13%) were from blood . Bacteremia was associated with taking antibiotics during the 30 days before S Marina infection (odds ratio: 24; 95% confidence interval: 1.2-1309) . CONCLUSION: S Marina infection is a potentially serious illness associated with iguana exposure, and it reflects the larger problem of reptile-associated salmonellosis . Many parents do not know that owning an iguana puts their children at risk for Salmonella infection . Pediatricians, veterinarians, and pet store owners should inform their patients and customers of the potential risks of owning reptiles and provide appropriate preventive education. J Immunol, 1997 Mar 1, 158(5), 2334 - 9 Substance P-induced IL-12 production by murine macrophages; Kincy-Cain T et al.; Previous investigations in our laboratory have suggested that substance P (NK-1) receptor expression by macrophages contributes to the resistance against the intracellular bacterial pathogen, Salmonella . To investigate possible mechanisms for such resistance, macrophages were cultured with varying concentrations of a substance P agonist to investigate the ability of this neuropeptide to augment IL-12 expression . The substance P agonist was a potent inducer of both IL-12p35 and IL-12p40 mRNA expression in cultured macrophages . The kinetics of this response were maximal within 6 h and could be observed with concentrations of substance P agonist as low as 0.1 nM . The nonpeptide, substance P receptor antagonist, CP96-345, significantly blocked agonist-induced IL-12 mRNA expression, further demonstrating that this effect was mediated through an NK-1 receptor . Substance P agonist alone could stimulate substantial secretion of IL-12p40, but not IL-12p70, by cultured macrophages . Thus, the substance P agonist had the ability to augment IL-12p35 and IL-12p40 mRNA expression, but not to increase IL-12p70 secretion . Like IFN-gamma, we found that substance P could combine with LPS to significantly augment the secretion of bioactive IL-12p70 . The costimulatory effects of substance P agonist plus LPS on IL-12 mRNA expression were additive; however, this combination resulted in synergistic secretion of IL-12p70 by macrophages . Together, these results demonstrate the ability of NK-1 receptors to signal IL-12 production by macrophages and suggest mechanisms for substance P-induced modulation of cellular immunity. J Immunol, 1997 Mar 1, 158(5), 2268 - 77 Predominant appearance of NK1.1+ T cells producing IL-4 may be involved in the increased susceptibility of mice with the beige mutation during Salmonella infection; Enomoto A et al.; C57BL/6 mice with the beige mutation (beige mice) showed a high susceptibility to infection with Salmonella choleraesuis compared with C57BL/6 (B6) control mice, as assessed by bacterial number in the peritoneal cavity and the liver . The appearance of NK1.1+ CD3- NK cells was significantly suppressed, while NK1.1+ T cells were increased in the peritoneal cavity of beige mice after Salmonella infection . The expression level of IL-4 mRNA was much higher in freshly isolated NK1.1+ T cells of the infected beige mice, but the expression level of IFN-gamma mRNA was lower than that in the infected control mice . The NK1.1+ T cells produced more IL-4 in response to TCR alphabeta cross-linking, whereas IFN-gamma production upon TCR triggering was significantly impaired in the beige mice compared to that in the control mice . Furthermore, the generation of Salmonella-specific Th1 cells producing IFN-gamma was significantly inhibited in the peritoneal cavity of beige mice after Salmonella infection . However, administration of anti-IL-4 neutralizing mAb to beige mice during salmonellosis restored the generation of Salmonella-specific Th1 cells and decreased the susceptibility to Salmonella . These results suggested that the predominant activation of NK1.1+ T cells producing IL-4 over those producing IFN-gamma may be at least partly involved in the poor generation of Salmonella-specific protective Th1 cells, resulting in the increased susceptibility of beige mice to Salmonella infection. J Exp Med, 1997 Feb 17, 185(4), 717 - 30 Natural resistance to infection with intracellular pathogens: the Nramp1 protein is recruited to the membrane of the phagosome; Gruenheid S et al.; The Nramp1 (natural-resistance-associated macrophage protein 1) locus (Bcg, Ity, Lsh) controls the innate resistance or susceptibility of mice to infection with a group of unrelated intracellular parasites which includes Salmonella, Leishmania, and Mycobacterium . Nramp1 is expressed exclusively in professional phagocytes and encodes an integral membrane protein that shares structural characteristics with ion channels and transporters . Its function and mechanism of action remain unknown . The intracellular localization of the Nramp1 protein was analyzed in control 129/sv and mutant Nramp1-/- macrophages by immunofluorescence and confocal microscopy and by biochemical fractionation . In colocalization studies with a specific anti-Nramp1 antiserum and a panel of control antibodies directed against known cellular structures, Nramp1 was found not to be expressed at the plasma membrane but rather localized to the late endocytic compartments (late endosome/lysosome) of resting macrophages in a Lamp1 (lysosomal-associated membrane protein 1)-positive compartment . Double immunofluorescence studies and direct purification of latex bead-containing phagosomes demonstrated that upon phagocytosis, Nramp1 is recruited to the membrane of the phagosome and remains associated with this structure during its maturation to phagolysosome . After phagocytosis, Nramp1 is acquired by the phagosomal membrane with time kinetics similar to Lamp1, but clearly distinct from those of the early endosomal marker Rab5 . The targeting of Nramp1 from endocytic vesicles to the phagosomal membrane supports the hypothesis that Nramp1 controls the replication of intracellular parasites by altering the intravacuolar environment of the microbe-containing phagosome. FEMS Microbiol Lett, 1997 Feb 15, 147(2), 259 - 65 Survival of Vi-capsulated and Vi-deleted Salmonella typhi strains in cultured macrophage expressing different levels of CD14 antigen; Hirose K et al.; We examined the intracellular survival of Vi-capsulated (lipopolysaccharide; (LPS)-masked) and Vi-deleted (LPS-exposed) Salmonella typhi strains inside macrophage cell lines . Growth of LPS-exposed S . typhi was inhibited in both mouse and human macrophage cell lines . However, the LPS-exposed strain survived in a CD14-deficient mouse macrophage cell lines . Wild-type S . typhi strain, which expressed the Vi antigen and masked LPS, survived in the resting human macrophage cell line . When the Vi-capsulated S . typhi entered the cells, the production of tumor necrosis factor-alpha (TNF-alpha) was suppressed . In contrast, S . typhimurium and LPS-exposed S . typhi stimulated the macrophages to produce a high level of TNF-alpha. Eur J Biochem, 1997 Feb 15, 244(1), 66 - 73 Molecular cloning, sequence analysis and functional characterization of the gene kdsA, encoding 3-deoxy-D-manno-2-octulosonate-8-phosphate synthase of Chlamydia psittaci 6BC; Brabetz W et al.; The kdsA gene encoding 3-deoxy-D-manno-2-octulosonate-8-phosphate (Kdo-8-P) synthase of Chlamydia psittaci 6BC was cloned by complementing the temperature-sensitive kdsA mutant Salmonella enterica serovar Typhimurium AG701i50 . The sequence analysis of a recombinant DNA fragment revealed an open reading frame of 807 nucleotides which codes for a polypeptide of 269 amino acids with a high degree of similarity to known KdsA proteins . In addition, alignments of Kdo-8-P synthases with bacterial and fungal 3-deoxy-D-arabino-2-heptulosonate-7-phosphate (Dha-7-P) synthases suggested that both classes of enzymes are structurally related and may belong to a family of 2-keto-3-deoxy-aldonic acid synthases . The chlamydial protein was overexpressed and functionally characterized in vitro to synthesize Kdo-8-P from D-arabinose 5-phosphate and phosphoenolpyruvate . A chlamydial DNA region upstream of the gene exhibiting similarities to the consensus sequence of sigma 70 promoters of Escherichia coli was responsible for the heterologous expression of kdsA. J Am Vet Med Assoc, 1997 Feb 15, 210(4), 528 - 30 Case-control study of an outbreak of clinical disease attributable to Salmonella menhaden infection in eight dairy herds; Anderson RJ et al.; OBJECTIVE: To identify risk factors associated with Salmonella menhaden associated disease in adult dairy cows during an outbreak in California . DESIGN: Case-control study . SAMPLE POPULATION: 8 case dairies that had > or = 1 adult animal that had clinical signs of salmonellosis and from which S menhaden was isolated and 22 control dairies, 16 of which were matched on the basis of herd size and county and 6 of which were matched on the basis of herd size, county, and breed (Jersey) . PROCEDURE: A questionnaire was developed and reviewed with the herdsman or owner of each dairy . Primary areas of concern were herd management, disease characteristics, and feed-related information . RESULTS: Use of 1 particular feed mill and feeding animal fat were significant risk factors for clinical disease attributable to S menhaden infection . CLINICAL IMPLICATIONS: Feed should not be overlooked as a potential source of Salmonella organisms in dairy herds. Prev Vet Med, 1997 Feb, 29(4), 247 - 61 Nation-wide Salmonella enterica surveillance and control in Danish slaughter swine herds; Mousing J et al.; A nation-wide Salmonella enterica surveillance and control programme was initiated in Danish finishing herds over the first quarter of 1995 . In Denmark, all swine for slaughter are identifiable by a unique herd code . For each herd code, and depending on the herd's annual kill, random samples ranging from four to more than 60 swine are obtained quarterly at the abattoir . A meat sample from each pig is frozen, and meat juice (harvested after thawing) is examined for specific antibodies against S . enterica using an indirect enzyme-linked immunosorbent assay (ELISA) . The ELISA combines several S . enterica O-antigens, and allows detection of antibody response after a variety of different S . enterica serovar infections . Results are transferred to a central database, which each month (based on meat-juice tests obtained in the previous 13 weeks) assigns all herds into three S . enterica infection levels: Level 1, in which the S . enterica prevalence is deemed low and acceptable; Level 2, where there is a moderate prevalence of S . enterica seroreactors (from > 50% in the smallest to > 10% in the largest herds); Level 3, in which S . enterica seroreactor prevalence is clearly unsatisfactory (> 50% for most herd sizes) . Irrespective of Salmonella level, all herds receive a monthly update on the current results of the S . enterica test results . If a herd is categorized in Level 2 or 3, it must receive an advisory visit by a practising veterinarian and a local swine extension specialist, and certain management hygiene precautions must be taken . If a herd is categorized in Level 3, the finishers from the herd must additionally be slaughtered under special hygiene precautions . This is supervised by the veterinary authorities . During 1995, 604000 samples were tested for S . enterica, corresponding to 3.0% of the total kill . In December 1995, 15522 herds (representing > 90% of the national production) were categorized into one of the three levels: 14551 herds (93.7%) in Level 1; 610 herds (3.9%) in Level 2; 361 herds (2.3%) in Level 3 . The proportion of serologically positive meat-juice samples collected during 1995 ranged from a mean of 2.9% in smaller herds (101-200 swine slaughtered per year) to 6.1% in relatively large herds (more than 5000 swine slaughtered per year). Arch Mal Coeur Vaiss, 1997 Feb, 90(2), 301 - 3 {Salmonella enteritidis pericarditis . Apropos of a case and review of the literature}; Victor F et al.; The authors report a case of Salmonella enteritidis pericarditis . The diagnosis was based on bacteriological analyses (blood and effusion cultures and pericardial biopsy) . The microbiology of bacterial pericarditis is reviewed underlying the exceptionally rare finding of a non typhi Salmonella in this condition. Inflammation, 1997 Feb, 21(1), 9 - 25 Neutralization of G-CSF inhibits ILK-induced heterophil influx: granulocyte-colony stimulating factor mediates the Salmonella enteritidis-immune lymphokine potentiation of the acute avian inflammatory response; Kogut MH et al.; Hematopoietic colony stimulating factors (CSF) regulate the growth and development of phagocytic cell progenitors and also augment functional activation of phagocytes . Granulocyte-CSF (G-CSF) is the CSF that acts specifically upon granulocyte progenitor cells and mature granulocytes . We have shown that lymphokines (ILK) from T cells of birds immunized against Salmonella enteritidis (SE) induce a granulocytic (PMN) inflammatory response in chicks challenged with SE . This inflammatory response was characterized by: (a) a dramatic emigration of granulocytic cells from the bone marrow into the peripheral blood, (b) an enhancement of the biological functions of the circulating PMNs, and (c) a directed influx of these activated PMNs to the site of bacterial invasion . In the current study, we determined the presence of G-CSF in ILK by Western blot analysis using a goat polyclonal antihuman G-CSF antibody (Ab) . Using this Ab, we then evaluated the role of G-CSF in the ILK-induced protective inflammatory response in chickens against SE . Pretreatment of ILK with the Ab totally abolished the colony-stimulating activity of the ILK . Furthermore, Ab treatment of ILK resulted in: (a) an elimination of the ILK-induced peripheral blood heterophilia with a dramatic inhibition of ILK-mediated protection against SE organ invasion and (b) an elimination of accumulation of inflammatory PMNs in the peritoneum with subsequent decrease in the survival rate of chicks challenged i.p . with SE . Taken together these studies demonstrate for the first time the contribution of G-CSF to avian PMN activation and the immunoprophylaxis of SE infection by ILK in neonatal chickens. An Esp Pediatr, 1997 Feb, 46(2), 151 - 5 {Bacteremia during the course of Salmonella gastroenteritis}; Prado Munoz S et al.; OBJECTIVE: Salmonella is the most frequent cause of bacterial acute gastroenteritis (AGE) in our setting . Usually its course is self-limited, but it sometimes can lead to bacteremia, principally in young infants and malnourished or immunosuppressed children . Bacteremia is less frequent in healthy people and in those over one year of age . This study was carried out to assess the incidence of bacteremia during Salmonella GE and to detect parameters that could lead to bacteremia . PATIENTS AND METHODS: A retrospective study of positive stool cultures in our hospital between 1991 and 1993 was performed . Data about the epidemiology, clinical features cultures and analytical procedures were drawn from clinical records . Data were analyzed using the Mann-Whitney test and Fisher's exact test . RESULTS: During this period of time, 860 cases of AGE were observed with 86 stool cultures positive for Salmonella (10%) . Six of them also had positive blood cultures (7%) . All 6 patients with bacteremia were healthy previously and five were over 12 months old . The outcome was good in all cases, without focalizations of the bacteremia . We could not detect any differences between patients with positive blood cultures and the patients without bacteremia . CONCLUSIONS: Bacteremia during Salmonella AGE is not infrequent and is not limited to young infants or patients with underlying diseases . None of the parameters analyzed were useful in predicting the possibility of bacteremia. Oral Microbiol Immunol, 1997 Feb, 12(1), 11 - 9 Recognition of antigenic epitopes in lipopolysaccharide and protein from Actinobacillus actinomycetemcomitans by serum antibodies in untreated rapidly progressive periodontitis patients; Ou JG et al.; Actinobacillus actinomycetemcomitans has been associated with early-onset periodontitis, including the localized juvenile and rapidly progressive forms . The immunodominant antigens of A . actinomycetemcomitans recognized by rapidly progressive periodontitis patients remain unidentified . Sera from 22 patients with rapidly progressive periodontitis and 20 periodontally normal subjects were tested by enzyme-linked immunosorbent assay (ELISA) for immunoglobulin G antibodies to whole-cell sonicate, protein, purified lipopolysaccharide and lipopolysaccharide fractions of A . actinomycetemcomitans . The median titers of rapidly progressive periodontitis patients and control subjects to whole-cell sonicate were 25.0 and 14.5 ELISA units, respectively (not significantly different) . Binding of antibody from patient sera occurred to both the lipopolysaccharide and the protein fractions, with greater binding to lipopolysaccharide than to protein . We show for the first time that patient sera contain antibodies that bind specifically to antigenic epitopes in lipid A and in the core carbohydrate of lipopolysaccharide that were previously considered to be inaccessible and unavailable, as well as to epitopes in the O side chains . Sera manifesting antibody titers 2-fold or greater than the median titer for control sera were judged to be seropositive . More patients were seropositive for lipid A than for any of the other antigen preparations studied, and the median titer for patient sera to lipid A but to none of the other purified lipopolysaccharide fractions was significantly elevated relative to control values . Of 22 patients, 10 were seropositive to whole-cell sonicate, 7 to protein, 8 to lipopolysaccharide, 7 to the high-molecular-weight lipopolysaccharide-polysaccharide fraction rich in O side chains, and 16 to lipid A . The core carbohydrate did not adhere to the test plate surface, and this precluded ELISA measurements . However, when the core carbohydrate was used in the ELISA inhibition assay, it reduced antibody binding to lipopolysaccharide-coated plates by up to 45%, thereby demonstrating antibody binding to core carbohydrate . The core carbohydrate fraction from the Re mutant of Salmonella minnesota known to contain no O-side chains also inhibited binding of specific antibody to plates coated with A actinomycetemcomitans lipopolysaccharide . Overall, there was extreme variation in responses among patients to the various antigen preparations, with no single pattern dominating . Lipopolysaccharide and its components appear to be the immunodominant epitopes, since most rapidly progressive periodontitis patients are seropositive for lipopolysaccharide and/or its components and they have titers relative to those for proteins. Food Chem Toxicol, 1997 Feb, 35(2), 199 - 206 Heterocyclic aromatic amine content in pre-processed meat cuts produced in Canada; Stavric B et al.; In an ongoing survey, the presence of heterocyclic aromatic amines (HAAs) was determined in processed, ready-to-eat meat products sold as 'meat cuts' . HAAs are a group of recently recognized mutagenic/carcinogenic contaminants in foods that are produced during the heat processing of meat . 16 samples of meat cuts (e.g . turkey breast, salami, chicken loaf, cooked ham, all beef meat, pepperoni, etc.), randomly purchased from supermarkets and specialty food stores in the Ottawa area, were analysed for the presence of eight HAAs . The isolation of HAAs was based on sequential liquid-liquid extraction procedures of the samples at both acidic and basic pH values . The mutagenic activity of these samples was determined using the Ames/Salmonella microsome assay with the strain TA98 plus rat liver S-9 metabolic activation . The mutagenicity of these samples ranged from undetectable to slightly active . The highest mutagenic activity, 141 induced revertants/g, was found in a smoked turkey breast sample . 11 samples were not mutagenic, including two that indicated a tendency for inhibition of the spontaneous revertants . The remaining four samples exhibited very low mutagenic activity . For chemical analysis, the extracts were purified with two solid phase extraction cartridges . Quantitative analysis was performed by using liquid chromatography for separation and mass spectrometry for detection . With the exception of trace amounts (0.4 ng/g) of 2-amino-3,8-dimethylimidazo{4,5-f}quinoxaline (MeIQx) in the sample with highest mutagenic activity, the chemical analysis did not detect the presence of any of the eight most frequently found HAAs in fried or broiled meat products . These data suggest that consumption of meat cuts does not present a serious health risk from HAA-type contaminants. Food Chem Toxicol, 1997 Feb, 35(2), 185 - 97 Mutagenic heterocyclic aromatic amines (HAAs) in 'processed food flavour' samples; Stavric B et al.; Eight samples of 'processed food flavours' (PFFs), chosen from five different categories, were analysed for their mutagenic activity using the Ames Salmonella assay, and also for the presence of eight heterocyclic aromatic amines (HAAs), namely 2-amino-3-(trideuteromethyl)imidazo{4,5-f}quinoline (IQ), 2-amino-3,8-dimethyl-imidazo{4,5-f}quinoline (MeIQ), 2-amino-3,8-dimethylimidazo{4,5-f}quinoxaline (MeIQx), 2-amino-3,7,8-trimethylimidazo{4,5-f}quinoxaline (7,8-DiMeIQx), 2-amino-3,7,8-trimethylimidazo{4,5-f}quinoxaline (4,7,8-TriMeIQx), 2-amino-I-methyl-6-phenylimidazo{4,5-b}pyridine (PhIP), 3-amino-1,4-dimethyl-5H-pyrido{4,3-b}indole (Trp-P-1) and 3-amino-1-methyl-5H-pyrido{4,3-b}indole (Trp-P-2) using liquid chromatography and mass spectrometry (LC/MS) . The isolation of HAAs was based on sequential liquid-liquid extraction procedures of samples at both acidic and basic pH values . The recoveries and the clean-up were monitored by introduction of quality control samples and by spiking with three tri-deuterated standards of HAAs . Although the results for the mutagenicity assay were comparable by testing less-purified and highly-purified extracts, the analysis for identification and quantification of HAAs by LC/MS required highly purified concentrates . Four samples had little or no mutagenic activity and these results were in agreement with their LC/MS results: they had no detectable levels (detection limits 1-3 ppb) of any of the HAAs monitored . The mutagenic activity of one sample was in complete agreement with the quantification of HAAs by LC/MS . Two samples produced strong mutagenic responses (3115 and 2664 revertants/g) . In one sample, LC/MS analysis revealed the presence of 9.6 ppb IQ, whereas LC/MS of the other could not confirm the presence of any of the eight HAAs monitored . Two samples produced mild mutagenic activity (204 and 160 revertants/g), but relatively elevated concentrations of IQ (6.7 and 6.8 ng/g) by LC/MS . The extracts from all samples were tested for their modifying effects on mutagenicity of four HAAs . The discrepancy between the Ames test and the LC/MS analysis of some samples indicates several possibilities, such as the presence of some other HAAs, of their isomers or of other mutagens . In addition, the presence of mutagen modifiers (inhibitors or synergists) was observed in most samples . The results indicate that although chemical tests (e.g . LC/MS) can provide quantitative data for the HAAs monitored, the Ames mutagenicity test should also be conducted to determine the mutagenic activities of PFFs, in order to assess their health risk potential. Immunol Lett, 1997 Feb, 55(2), 105 - 8 Expression of NRAMP1 molecule in human peripheral blood leukocytes; Yoshida T et al.; Natural resistance or susceptibility of host to infection with several intracellular pathogens, such as Mycobacterium, Salmonella and Leishmania, is controlled in mice by the expression of a single dominant gene locus designated Lsh/Ity/Bcg . Natural resistance-associated macrophage protein gene 1 (Nramp1) was isolated as a candidate gene . Nramp1 gene encodes a 60 kDa polypeptide with 10-12 potential transmembrane domains and an evolutionary conserved consensus transport motif . The present study shows that the human NRAMP1 gene is expressed in all established hematopoietic cell lines examined, including monocytes/macrophages and B- and T-lymphocytes . In contrast, cell type-specific expressions are observed in human peripheral blood leukocytes . NRAMP1 expression is very low level in granulocytes . B- and T-lymphocytes are equivalent in the level of NRAMP1 expression . Notable expression of NRAMP1 gene can be detected in the monocyte population . These results have important implications for the host defence mechanisms and the pathogenesis of intracellular pathogens which are recognized and ingested by the mononuclear phagocyte system including monocytes/macrophages. Vaccine, 1997 Feb, 15(3), 321 - 4 In a vaccine model, selected substitution of a highly stimulatory T cell epitope of hen's egg lysozyme into a Salmonella flagellin does not result in a homologous, specific, cellular immune response and may alter the way in which the total antigen is processed; Vanegas RA et al.; A 13 amino acid peptide corresponding to a potent BALB/c mouse T cell epitope of hen's egg lysozyme (HEL) was substituted singly at five sites in the d flagellin of Salmonella muenchen . The resulting chimeric proteins were unable to expand T cells capable of being stimulated by the HEL epitope and induced T cell populations which either failed to respond or responded at a low level to a normally highly stimulatory flagellin T cell epitope that was present in all chimeras . The results suggested that substitution of a T cell epitope in flagellin may alter the processing of the resulting immunogen. Ann Cardiol Angeiol (Paris), 1997 Feb, 46(2), 81 - 7 {The effect of HIV infection on high incidence of heart diseases in Kinshasa (Zaire) . Echocardiographic study}; Longo-Mbenza B et al.; Invasion of the heart by HIV has become a clinical problem over the last decade . The objective of the present study was to systematically detect the excess HIV-related cardiac lesions in Kinshasa by performing echocardiography . The study population consisted of 166 HIV-infected patients and 166 HIV-seronegative patients with heart disease (control group) . 69% of patients were at stage A of HIV infection and 31% were at stage AIDS C3 according to CDC 1993 criteria . A higher incidence of echocardiographic abnormalities was observed in HIV-seropositive subjects (28.3%) than in control subjects (13%) (p = 0.035) . Systolic function was very severely impaired at the stage of AIDS (%R = 21,6 +/- 8.7) showing a highly significant difference (p < 0.01) compared to HIV-seropositive patients at stage A (% R = 29.2 +/- 11.9) and control subjects (%R = 28.9 +/- 5) . One patient (0.6%) developed Salmonella enteritidis infectious endocarditis . Echocardiography, a noninvasive technique, contributes to the diagnosis of cardiac lesions associated with HIV infection . HIV has a predominant role in the severity of dilatation and alteration of the left ventricular systolic function in black Africans compared to Caucasian populations. Am J Physiol, 1997 Feb, 272(2 Pt 2), H843 - 50 Effects of inhibition of nitric oxide synthase by aminoguanidine in acute endotoxemia; Hock CE et al.; Nitric oxide (NO) has been implicated in the pathogenesis of the circulatory dysfunction of endotoxin shock . We investigated the effect of aminoguanidine (AG), an inhibitor of nitric oxide synthase (NOS) that is more selective for the inducible NOS, on the circulatory and inflammatory sequelae after administration of a bolus (10 mg/kg iv) of lipopolysaccharide (LPS) (Salmonella enteritidis) . Rats receiving LPS + vehicle (LPS + Veh) exhibited a 73% decrease in mean arterial blood pressure (MABP) and a 50% decrease in cardiac index (CI) and SV index (SVI) within 10 min after LPS administration . MABP recovered to 64 +/- 3, 81 +/- 6, and 79 +/- 8 mmHg, at 60, 120, and 180 min post-LPS, respectively . However, CI and SVI remained depressed by 40-50% for the entire experimental period . Systemic vascular resistance (SVRI), heart rate (HR), and hematocrit were significantly elevated at 180 min after LPS administration . There was a 15-fold increase in plasma nitrite/nitrate and significantly elevated tissue nitrite/nitrate in the lung, heart, liver, and intestine after 3 h of acute endotoxemia . Treatment with AG markedly decreased plasma nitrite/nitrate but did not alter the initial hypotension or cardiac depression . However, at 60 min after LPS administration the HR, MABP, and SVRI were higher in the AG-treated rats compared with vehicle, whereas CI and SVI remained depressed . Myeloperoxidase activity was significantly increased in the lung but not in the other tissues after LPS . The AG infusion significantly reduced tissue nitrite/nitrate in the lung and heart compared with LPS + Veh . The data suggest that neither NO nor acute inflammatory cell accumulation is solely responsible for the depressed cardiovascular function after intravenous administration of LPS. Eur J Epidemiol, 1997 Feb, 13(2), 243 - 5 Occurrence of Salmonella enterica serotype Enteritidis phage types in the Slovak Republic; Majtanova L; Phage typing of 741 isolates of Salmonella enterica serotype Enteritidis from the Slovak Republic in 1995 has been carried out using the scheme of Ward and colleagues (1987) . 202 strains (51 isolated from food) were from 9 outbreaks, 536 isolates were from sporadic cases and 3 isolates were from nosocomial infections of new-born babies . 704 isolates (95%) from all sources were typeable and belonged to 7 different phage types (PTs) . PT8 was the phage type most frequently identified (72.6%) . Other epidemiologically relevant phage types were PT2 (8.5%), 4 (7.9%) and 1 (4.2%) . With an incidence of 1.3-0.1% isolates of PTs 21, 6, 9 were found . 26 (3.5%) isolates were designated RDNC and 11 (1.5%) were untypeable. Eur J Epidemiol, 1997 Feb, 13(2), 239 - 41 Evolution of susceptibility of non-typhi Salmonella in a Spanish hospital (1992-1994) and report of a Salmonella ser . Typhimurium isolate resistant to quinolones; Campo P et al.; We report the evolution of the antimicrobial resistance of non-typhi Salmonella (1992-1994) in a Spanish hospital in relation with a case of infection due to a fluoroquinolone-resistant strain of Salmonella ser . Typhimurium . None of the isolates were resistant to ciprofloxacin . The resistance to ampicillin has increased from 20.6% (1992) to 29.5% (1994) whereas no significative differences in chloramphenicol and cotrimoxazole susceptibility were noted. Zentralbl Bakteriol, 1997 Feb, 285(3), 379 - 88 Genomic analyses of Salmonella enteritidis phage type 4 strains from Austria and phage type 8 strains from the United States; Buchrieser C et al.; Forty illness associated phage-type (PT) 4 and PT 8 strains of Salmonella enteritidis were analyzed by the pulsed-field technique of clamped homogeneous electric fields (CHEF) electrophoresis . Using NotI and XbaI, the 40 strains were subdivided by each enzyme into seven restriction endonuclease digestion profiles (REDP) . The 35 PT 4 isolates from Austria were subdivided into six NotI and five XbaI REDP, while the five PT 8 isolates from the United States displayed a single NotI and two XbaI REDP . When highly-concentrated, uncleaved genomic DNA was subjected to CHEF electrophoresis, plasmid DNA in the size range of 350 kb relative to a linear DNA standard was discernible in 38 of the 40 strains . Subsequent isolation and restriction analyses of plasmid DNA from one strain (E40) revealed a single plasmid (pE40; ca . 54 kb) with one XbaI and two NotI cleavage sites that was similar in size to the S . enteritidis virulence plasmid pRQ29 . Hybridization of the PE40 probe with S . enteritidis genomic DNAs identified a 54 kb fragment within the XbaI REDP and two fragments, 20 and 34 kb, in NotI REDP of plasmid-positive strains . It was not possible to identify plasmid-specific bands in NotI REDP without hybridization due to comigrating chromosomal and plasmid DNA fragments . Regardless of PT, all 40 S . enteritidis strains showed highly related REDP . The similarity between PT 4 and PT 8 strains as further revealed by Dice similarity coefficients was 90% to 95% for NotI REDP and 79% to 93% for XbaI REDP . These results support the hypothesis that the pandemic observed today is the result of the efficient spread of a single clone, or clusters of closely related clones, of S . enteritidis. Lett Appl Microbiol, 1997 Feb, 24(2), 113 - 6 Detection of Salmonella spp . in food products by polymerase chain reaction and hybridization assay in microplate format; Soumet C et al.; Here, hybridization assay of amplified products is described which detect Salmonella spp . from chicken fillets and other food homogenates within 24 h . This technique is composed of four steps: (1) sample is pre-enriched overnight in phosphate buffered peptone water; (2) total DNA is extracted; (3) a Salmonella spp . specific DNA target sequence is amplified by polymerase chain reaction; (4) amplified products are captured by a probe covalently bound onto NH-Covalink (Nunc, Danemark) microwells and detected by a chemiluminescent enzymatic reaction . This hybridization of amplified products was demonstrated as sensitive as their analysis on agarose gel . Compared to a bacteriological method for Salmonella spp . detection, its specificity was estimated at 100% and its sensitivity was 93.2% from analysis of 207 naturally contaminated chicken fillets samples. Am J Trop Med Hyg, 1997 Feb, 56(2), 192 - 9 Evaluation of immunogenicity of an oral Salmonella vaccine expressing recombinant Plasmodium berghei merozoite surface protein-1; Toebe CS et al.; A repetitive region of Plasmodium berghei merozoite surface protein-1 (PbMSP-1) was expressed as a fusion protein with either maltose binding protein or the B subunit of heat-labile enterotoxin from Escherichia coli . Vaccination of mice with the fusion proteins indicates that this region of PbMSP-1 is antigenic as evidenced by an antibody response . The fusion proteins were also expressed in Salmonella and mice were orally immunized with the recombinant Salmonella . Some of the vaccinated mice survived a challenge with P . berghei blood-stage parasites without developing parasitemia . All control mice became patent and succumbed to the challenge infection . This partial protection was also observed with purified recombinant protein and was independent of the adjuvant used . Mice immunized with recombinant Salmonella showed either extremely low or no antibody response to PbMSP-1, suggesting that cell-mediated immunity is important for the observed protection . These studies show that it is feasible to develop a cost effective oral vaccine against the blood stage of the malarial parasite. Vaccine, 1997 Feb, 15(2), 155 - 62 Oral delivery of foreign antigens by attenuated Salmonella: consequences of prior exposure to the vector strain; Attridge SR et al.; Several strains of Salmonella have been used as vectors for the delivery of Escherichia coli fimbrial proteins to the gut-associated lymphoid tissue (GALT) of the mouse . Plasmids carrying a complementing thyA+ gene, together with genes specifying synthesis of K88 or K99, were introduced into non-reverting thyA Salmonella mutants . The resulting constructs expressed the foreign pilin protein on their surfaces and, provided the vector was able to colonize the GALT, elicited strong serum responses to K88 or K99 . These responses were dramatically impaired however, in recipients with pre-existing immunity to the vector strain . Mice initially infected with Salmonella stanley ca 4, 10 or 20 weeks prior to oral administration of S . stanley-K88 showed greatly reduced serum responses to K88 as determined by ELISA . The hypo-responsiveness seen in vector-primed mice could be largely overcome by changing the serotype of the strain subsequently used to deliver the foreign protein. J Med Microbiol, 1997 Feb, 46(2), 129 - 38 Immune response to a Murray Valley encephalitis virus epitope expressed in the flagellin of an attenuated strain of Salmonella; Whittle BL et al.; Recent developments in vaccine construction include the use of attenuated, avirulent strains of Salmonella as carriers of foreign antigens . These recombinant strains can elicit a heterologous immune response when injected into animals, demonstrating potential for their use in the construction of many vaccines . In the present study, a B-cell epitope of Murray Valley encephalitis virus (MVE) was identified and expressed in a Salmonella strain to evaluate its potential to induce a specific immune response to MVE . A synthetic oligonucleotide encoding the B-cell epitope (residues E201-224) of the envelope protein of MVE was inserted into the cloned flagellin gene of the Salmonella strain . The construct was sequenced to ensure correct orientation of the epitope . Expression of the epitope was demonstrated by Western blot analysis and immunogold electron microscopy with monoclonal antibody specific to the epitope . Electron microscopy analysis revealed multiple copies of the epitope along the flagella . The recombinant Salmonella carrying the hybrid flagellin gene elicited an immune response to the MVE epitope in a mouse model . The MVE-specific antibodies partially neutralised the virus in vitro . The significance of this system for engineering vaccines for other medically important flaviviruses is discussed. Biol Pharm Bull, 1997 Feb, 20(2), 201 - 3 StyD4I restriction-modification system of Salmonella typhi D4: cloning and sequence analysis; Miyahara M et al.; A plasmid (5.4 kbp) from Salmonella Typhi D4 has been identified as encoding a restriction and modification (R-M) system . DNA fragments (2537 bp) that carried the genes for restriction endonuclease and methyltransferase encoded on the plasmid were sequenced . Two divergently arranged open reading frames of 957 bp for the restriction endonuclease consisting of 318 aa (amino acids) and 1140 bp for the DNA methyltransferase consisting of 379 aa were identified . These sequences were similar to the sequences of the SsoII R-M system, including the interspace between the two genes. J Am Vet Med Assoc, 1997 Feb 1, 210(3), 382 - 5 Prevalence of Salmonella organisms in swine feed; Harris IT et al.; OBJECTIVE: To test feed and feed ingredients on swine farms for Salmonella organisms and to analyze data from these farms to determine risk factors associated with Salmonella organisms in the feed and feed ingredients . DESIGN: Epidemiologic survey and retrospective case-control study . SAMPLE POPULATION: 30 swine farms . PROCEDURE: Samples of feed and feed ingredients and information regarding herd characteristics were collected from 30 swine farms . Samples were tested for Salmonella organisms, and data compiled from herd information forms were examined for associated risk factors between herd characteristics and isolation of Salmonella organisms . RESULTS: Salmonella organisms were isolated from 36 of 1,264 (2.8%) feed and feed ingredient samples and from 14 of 30 (46.7%) farms . Thirteen Salmonella sp serotypes and 2 untypeable isolates were cultured . Recovery of Salmonella organisms from at least 1 feed or feed ingredient on a farm was significantly associated with 6 herd characteristics (lack of bird-proofing, using farm-prepared feed for finishing-age pigs rather than purchased feed, and housing pigs in facilities other than total confinement in the growing, finishing, gestating, and breeding stages of production, respectively) . Isolation of Salmonella sp was not associated with a history of salmonellosis on a farm . CLINICAL IMPLICATIONS: Salmonella organisms were readily isolated from samples of feed and feed ingredients, illustrating that salmonellae are ubiquitous in a farm environment . Implementing sanitary and pest-control measures continues to be a prudent recommendation . Salmonella serotypes found in feed and feed ingredients have the potential to cause disease in pigs that consume the feed or, ultimately, in people that consume pork. Poult Sci, 1997 Feb, 76(2), 280 - 8 Immune and physiological responses of turkeys with green-liver osteomyelitis complex; Bayyari GR et al.; A study of field turkeys was undertaken in order to determine the involvement of relative immunological differences in the etiology of turkey osteomyelitis complex (TOC) . Lame and normal turkeys were sampled from commercial flocks just prior to processing in two separate trials . After testing for functions of both humoral and cellular immunity, the turkeys were necropsied and examined for lesions of TOC . There were significantly higher relative spleen and over weights and significantly lower body weights and relative bursal weights in birds with TOC . The birds with TOC had lower response to phytohemagglutinin-P in both in vivo and in vitro tests as well as lower circulating lymphocyte counts and higher monocyte, heterophil, and total white blood cell counts . There was a significantly higher antibody response to sheep red blood cells in turkeys with TOC, whereas antibody response to Salmonella pullorum antigen was not different . There were no significant differences in the percentages of mononuclear cells or heterophils able to phagocytize bacteria or latex particles, or kill bacteria; however, the heterophils from turkeys with TOC lesions did phagocytize significantly fewer latex particles per cell than did those of the healthy turkeys . Total serum protein, uric acid, and blood urea nitrogen levels were higher in birds with TOC, whereas hemoglobin, iron, alkaline phosphatase, and gamma-glutamyl-transferase levels were lower . Although many of the differences in birds with TOC could be caused by the normal host reaction to infection, further study may reveal innate differences that contribute to susceptibility to TOC. Indian J Med Res, 1997 Feb, 105, 53 - 7 100 years of Widal test & its reappraisal in an endemic area; Shukla S et al.; A reappraisal of the Widal test was made for its diagnostic utility in typhoid fever in an endemic area of Central India . The significant basal antibody level in the normal population based on 1200 voluntary/relative blood donors at the cut-off titre of 80 or above was observed in 13.83 and 8.0 per cent for 'O' and 'H' antigens of Salmonella typhi respectively . A retrospective study (1991-1995) over 138 bacteriologically proven cases of typhoid showed a positivity of 64.49 and 78.26 per cent respectively for 'O' and 'H' antibodies at the titre of 80 or above and 44.2 and 63.04 per cent at the titre of 160 and above . The retrospective data also showed a greater positivity (46.41%) in 1991 which decreased to 25 per cent in 1995 and appeared to follow the incidence of multi drug resistant S . typhi over the period . The detection of 'H' antibodies is no less important than the 'O' antibodies in the present study . Our data bring out the diagnostic limitations of Widal test done on single samples collected in the early phase of illness (4-10 days) from patients suspected to have typhoid in an endemic area of Central India. Microbiology, 1997 Feb, 143 ( Pt 2), 653 - 62 O-antigenic determinants in Salmonella species of serogroup C1 are expressed in distinct immunochemical populations of chains; Nnalue NA et al.; The O-antigenic specificities found among Salmonellae of serogroup C1 are O:6(1),7, O:6(2),7, O:6(1),6(2),7 and O:6,7,14, as defined by classical serology . Factor O:7 is the group-wide determinant while factors O:6(1), O:6(2) and O:14 are found in some strains but not others . Strains of the O:6(2),7 specificity are subject to lysogenic conversion by phages 6(1) and 14 to the O:6(1),7 and O:6,7,14 specificities, respectively . To further delineate antigenic complexity and serological relationships among strains of this serogroup monoclonal antibodies (mAbs) were generated against the O:6(1),6(2),7 polysaccharide of Salmonella thompson . Five mAbs of either the O:6(1) or O:6(2) specificities did not bind O:6,7,14 strains or LPS, showing that the O:6 determinant in these strains is neither O:6(1) nor O:6(2) . Thus antigenic conversion of O:6(2),7 strains by phage 14 is accompanied by addition of O:14 as well as loss of O:6(2) . Three mAbs which demonstrated group-wide reactivity, and were thus specific for O:7, recognized clearly by separable epitopes hereby defined as sub-specificities, O:7(1), O:7(2) and O:7(3) . Immunoblotting of mAbs against electrophoretically resolved LPS showed that factors O:6(1) and O:6(2) are expressed only in LPS molecules of high molecular mass whereas O:7(2) and O:7(3) are expressed only in relatively low-molecular-mass chains . These results are consistent with the expression of different antigenic determinants in structurally distinct subpopulations of O chains . The implications of the existence of distinct subpopulation of chains is that the published structure of the O:6,7 repeat unit is not fully representative of the O-antigenic structure of this group. Am J Gastroenterol, 1997 Feb, 92(2), 349 - 51 Transient radiological and colonoscopic features of inflammatory bowel disease in a patient with severe Salmonella gastroenteritis; Dagash M et al.; Salmonella is the most commonly reported cause of food-borne outbreaks of gastroenteritis . We report a case of a severe and toxic form of enteritis caused by Salmonella enteritidis . Findings of colonoscopy, an upper G1 tract series, and small bowel follow-through were consistent with those of inflammatory bowel disease, but the enteritis was self-limited, and the patient recovered after supportive treatment only and has remained well. Can J Surg, 1997 Feb, 40(1), 48 - 50 Osteomyelitis of the spine due to Salmonella infection--conservative treatment with quinolone: a case report; Tsui HF et al.; Although osteomyelitis due to Salmonella infection is known to be associated with sickle cell anemia, various hemoglobinopathies and immune suppressive states, it may also occur in normal hosts . A 16-year-old Chinese boy without sickle cell disease or any other condition that would compromise the immune system had osteomyelitis of the lumbar spine caused by Salmonella enteritidis . The condition was treated conservatively with ciprofloxacin (quinolone group) . This may be the first reported case in which a patient with spinal osteomyelitis due to Salmonella infection, who was otherwise healthy, was successfully treated nonoperatively with quinolone. Appl Environ Microbiol, 1997 Feb, 63(2), 775 - 8 Comparison of commercially available kits with standard methods for detection of Salmonella strains in foods; Hanai K et al.; Six commercial kits were compared with the U.S . Food and Drug Administration (USFDA) method and the Japanese standard method for Salmonella isolation in foods . When only Salmonella serovars were tested, many of the methods performed well; however, when foods were artificially inoculated, only the USFDA method and immunomagnetic separation coupled with the xylose-lysine-brilliant green agar method (MS-XLBG) could positively detect Salmonella serovars . All seven wild-type Salmonella serovars were detected by the USFDA method, and the MS-XLBG method detected salmonellae from six samples. Appl Environ Microbiol, 1997 Feb, 63(2), 757 - 60 Analysis of whole-cell fatty acid profiles of verotoxigenic Escherichia coli and Salmonella enteritidis with the microbial identification system; Steele M et al.; Differentiation of strains within bacterial species, based on gas chromatographic analysis of whole-cell fatty acid profiles, was assessed with 115 strains of verotoxigenic Escherichia coli and 315 strains of Salmonella enteritidis . Fatty acid-based subgroups within each of the two species were generated . Variability of fatty acid profiles observed in repeat preparations from the same strain approached that observed between subgroups, limiting the usefulness of using fatty acid profiles to subgroup verotoxigenic E . coli and S . enteritidis strains. J Bacteriol, 1997 Feb, 179(4), 1409 - 12 Plasmid virulence gene expression induced by short-chain fatty acids in Salmonella dublin: identification of rpoS-dependent and rpo-S-independent mechanisms; El-Gedaily A et al.; The Salmonella plasmid virulence spvABCD genes are growth phase regulated and require RpoS for maximal expression in stationary phase . We identified a growth phase-independent expression of spv which is mediated by short-chain fatty acids . During this fatty acid-mediated expression of spv, RpoS is required for induction only during exponential phase . In stationary phase, an rpoS-independent mechanism is responsible for expression of spv. J Bacteriol, 1997 Feb, 179(4), 1262 - 7 Identification and characterization of the dTDP-rhamnose biosynthesis and transfer genes of the lipopolysaccharide-related rfb locus in Leptospira interrogans serovar Copenhageni; Mitchison M et al.; Immunity to leptospirosis is principally humorally mediated and involves opsonization of leptospires for phagocytosis by macrophages and neutrophils . The only protective antigen identified to date is the leptospiral lipopolysaccharide (LPS), which biochemically resembles typical gram-negative LPS but has greatly reduced endotoxic activity . Little is known about the structure of leptospiral LPS . A 2.1-kb EcoRI fragment from the chromosome of serovar Copenhageni was cloned in pUC18 in Escherichia coli, after which flanking regions were cloned from a genomic library constructed in bacteriophage lambda GEM12 . Sequence analysis identified four open reading frames which showed similarity to the rfbC, rfbD, rfbB, and rfbA genes, transcribed in that order, which encode the four enzymes involved in the biosynthesis of dTDP-rhamnose for the assembly of LPS in Salmonella enterica, E . coli, and Shigella flexneri . An additional open reading frame downstream of the rfbCDBA locus showed similarity with the rhamnosyltransferase genes of Shigella and Yersinia enterocolitica but not Salmonella . Comparison of deduced amino acid sequences showed up to 85% similarity of the leptospiral proteins with those of other gram-negative bacteria . Polyacrylamide gel electrophoresis of recombinant clones identified the putative RfbCDBA proteins, while reverse transcriptase-mediated PCR analysis indicated that the rfbCDBA gene cluster was expressed in Leptospira . Moreover, it could restore normal LPS phenotype to a defined rfbB::Tn5 mutant of S . flexneri which was deficient in all four genes, thereby confirming the functional identification of a part of the leptospiral rfb locus. Infect Immun, 1997 Feb, 65(2), 708 - 17 Role of SefA subunit protein of SEF14 fimbriae in the pathogenesis of Salmonella enterica serovar Enteritidis; Ogunniyi AD et al.; In this study, the role of the SefA subunit protein of SEF14 fimbriae in the pathogenesis of Salmonella enterica serovar Enteritidis was investigated . This was accomplished by mutating the sefA gene in the chromosome of two strains of S . enterica serovar Enteritidis by allelic exchange with a copy that has been inactivated by interruption with a nonpolar kanamycin resistance (aphA-3) cassette . The effect of this mutation on the ability of the S . enterica serovar Enteritidis strains to colonize the intestinal epithelium and to invade other tissues was assessed in BALB/c mice and in vitro by adherence and invasion of HeLa cells . Our results show that an avirulent S . enterica serovar Enteritidis vaccine strain, 11RX (no somatic antigen; flagellum antigen phase 1, g,m; flagellum antigen phase 2, -), colonized better and persisted longer in the Peyer's patches of these mice than did its SefA-deficient counterpart . However, no such difference was observed between a highly virulent S . enterica serovar Enteritidis strain, 7314 (somatic antigen, O1, O9, O12; flagellum antigen phase 1, g,m; flagellum antigen phase 2 {1,7}), and its SefA-deficient isogenic mutant . These findings were correlated with in vitro adherence and invasion of HeLa cells . Furthermore, we could not demonstrate a role for SefA in the virulence of S . enterica serovar Enteritidis as assessed by 50% lethal dose determinations . The implications of these findings are discussed. Infect Immun, 1997 Feb, 65(2), 452 - 6 Safety of live oral Salmonella typhi vaccine strains with deletions in htrA and aroC aroD and immune response in humans; Tacket CO et al.; A single-dose, oral Salmonella typhi vaccine strain has been sought as a carrier or vector of cloned genes encoding protective antigens of other pathogens . Such a hybrid vaccine, administered orally, would stimulate immune responses both at the mucosal surface and in the systemic compartment and would potentially provide protection against multiple pathogens . S . typhi CVD 908 and CVD 906, which harbor deletions in aroC and aroD, were further engineered by deletion in htrA to produce strains CVD 908-htrA and CVD 906-htrA, which are unable to sustain growth and are severely impaired in their ability to survive in host tissues . These strains were fed to humans at doses of 5 x 10(7) to 5 x 10(9) CFU with buffer, and safety and immune responses were assessed . CVD 908-htrA and CVD 906-htrA were well tolerated in volunteers; mild diarrhea in 3 of 36 volunteers and mild fever in 1 volunteer were the only notable adverse responses . The vaccine strains were not detected in blood cultures and only transiently detected in stool . Serum immune responses to S . typhi lipopolysaccharide and H antigens were observed in 75 to 100% of volunteers who received 5 x 10(8) to 5 x 10(9) CFU, and cells secreting S . typhi-specific antibodies were found in all volunteers after ingestion of either strain . Sixty-three percent to 83% of volunteers developed lymphoproliferative responses to S . typhi flagellar and particulate antigens after the higher doses . These studies demonstrate the potential of CVD 908-htrA as a live vector for the delivery of heterologous genes, and a clinical trial of such a construct is planned. Infect Immun, 1997 Feb, 65(2), 395 - 404 Salmonella typhi stimulation of human intestinal epithelial cells induces secretion of epithelial cell-derived interleukin-6; Weinstein DL et al.; Interleukin 6 (IL-6) is a multifunctional cytokine that has been shown to be associated with both systemic and tissue-specific responses within the host . Moreover, IL-6 is produced by both lymphoid and nonlymphoid cells and has been identified as a growth-inducing, growth-inhibiting, and differentiation-inducing factor for these cells . Recent studies of uropathogenic and upper respiratory pathogens have suggested that epithelial cell-derived IL-6 plays a role in mucosal host-parasite interactions . Since many mucosal enteric pathogens enter the host through the epithelial cells of the distal small intestine, a role for intestinal epithelial cell-derived IL-6 in the initial interaction between bacteria and host might also be predicted . However, no studies to date have determined whether the interaction of any bacteria with the epithelial cells that line the small intestine of the host can induce IL-6 . To address this issue, we have established an in vitro model to evaluate the capacity of the gram-negative bacterium Salmonella typhi to induce IL-6 in the small intestine epithelial cell line Int407 and in other intestinal epithelial cell lines . The results demonstrate that both wild-type and live, attenuated S . typhi vaccine strains induce small and large intestine epithelial cells to secrete IL-6, and kinetic analysis suggests that IL-6 may be one of the earliest responses following adherence and invasion of enteric organisms . Thus, these studies suggest a physiologic role for epithelial cell-derived IL-6 in the initial interactions between host and bacterium in the small intestine. Infect Immun, 1997 Feb, 65(2), 380 - 6 Nramp1 transfection transfers Ity/Lsh/Bcg-related pleiotropic effects on macrophage activation: influence on antigen processing and presentation; Lang T et al.; The natural resistance-associated macrophage protein (Nramp1) regulates macrophage activation . One of its pleiotropic effects on macrophage function is to regulate expression of major histocompatibility class II molecules . In this study macrophages stably transfected with the wild-type (infection-resistant) or the natural mutant (infection-susceptible) allele of the Nramp1 gene were used to study class II expression and processing and presentation of recombinant protein antigens to CD4+ T-cell hybridomas . As demonstrated previously for macrophages from Nramp1-resistant and -susceptible congenic mouse strains, transfected macrophage clones carrying the wild-type allele showed enhanced upregulation of class II molecules in response to gamma interferon compared to that shown by macrophage clones carrying an endogenous mutant allele or transfected with the mutant allele expressed under a viral long terminal repeat promoter . The wild-type allele-transfected macrophage clones also demonstrated an enhanced, lipopolysaccharide-dependent ability to process the recombinant leishmanial antigen LACK-delta 1 (the Leishmania homolog of receptors for activated C kinase) for presentation to LACK-specific CD4+ T cells . An influence on antigen processing must therefore be added to the growing list of pleiotropic effects of the Nramp1 gene potentially contributing to its role in infectious and autoimmune disease susceptibility . These results also have important implications for analysis of T-cell responses to vaccination, especially where antigens are presented to the immune system using live Salmonella species or Mycobacterium bovis BCG as a vaccine vehicle. FEMS Microbiol Lett, 1997 Jan 15, 146(2), 175 - 9 Detection of the induction of Salmonella enterotoxin gene expression by contact with epithelial cells with RT-PCR; Dinjus U et al.; All strains of Salmonella enterica investigated were found to carry the Salmonella enterotoxin gene (stn) as determined by PCR and hybridization studies . However, when using CHO-K1 cells for testing the toxicity of the strains, not all strains showed a toxic effect (cell elongation) on the cells or did so only at a low level . The cultivation of Salmonella in contact with epithelial cells (IEC-6) led to an increase in the production of toxin . The stn gene expression was detectable with the help of the RT-PCR after 3 h of incubation . The RNA of the strains was isolated, transcribed into cDNA (with MMLV-reverse transcriptase) and amplified using PCR . The PCR products were separated electrophoretically using a polyacrylamide gel and detected by silver staining. J Immunol, 1997 Jan 15, 158(2), 574 - 9 Homing potentials of circulating lymphocytes in humans depend on the site of activation: oral, but not parenteral, typhoid vaccination induces circulating antibody-secreting cells that all bear homing receptors directing them to the gut; Kantele A et al.; Specific Ab-secreting cells (ASC) appear in the human blood as a response to oral and parenteral vaccination . The actual contribution of these cells to the defense of the body depends on their final effector site . The homing potentials of mucosally and parenterally induced ASC were compared by examining the homing receptor (HR) expression of circulating specific ASC in the blood of volunteers vaccinated orally or parenterally with the same Ag, Salmonella typhi Ty21a . Circulating lymphocytes were separated into receptor-positive and -negative populations, and the numbers of specific ASC were assayed . The alpha4 beta7 integrin, which acts as a gut HR, was expressed on all (99%) of the mucosally activated ASC, but on only 58% of the parenterally induced ASC or 58% of all Ig-secreting cells of the unvaccinated controls . L-selectin, the peripheral lymph node HR, showed an inverse distribution; it was found on 42% of mucosally activated ASC and on 86% of parenterally induced ASC . These results reveal that all of the circulating ASC after oral vaccination are committed to migrate to the mucosal compartment of the immune system, strongly arguing for a recirculation of activated mucosal cells in humans . By contrast, ASC induced by parenteral vaccination with the same Ag are mostly directed to the systemic compartment, yet a part of them has mucosal homing attitudes as well . These differences indicate that the site of Ag encounter determines the homing potential of the cell. Vestn Ross Akad Med Nauk, 1997, (6), 48 - 52 {Stable expression of heterologous proteins in salmonella: problems and approaches to their designing}; Abaev IV et al.; Live attenuated Salmonella vaccines may be used as carriers of heterologous antigens . The optimum expression system for each heterologous antigen requires to be established on an individual basis . This will ensure that the antigen in question is produced at appropriate levels and in the correctly folded conformation . Different techniques for producing stable recombinant Salmonella strains suitable for their use as bivalent vaccines. World Health Stat Q, 1997, 50(1-2), 81 - 9 Foodborne salmonellosis; Gomez TM et al.; Foodborne diseases caused by non-typhoid Salmonella are a very important public health problem and an economic burden in many parts of the world . Salmonellosis data from the WHO Global Databank on Foodborne Disease, from the literature and from the WHO Surveillance Programme in Europe were reviewed for the years 1985-1995, showing an apparent increase in the incidence of salmonellosis in many parts of the world . In industrialized countries, this increase may be due to the emergence and increase of S . enteritidis and S . typhimurium DT104 . In order to reduce the incidence of human foodborne salmonellosis, measures should be taken simultaneously during the production, processing, distribution, retail marketing and handling/preparation of food to prevent the introduction of Salmonella and its multiplication . These control measures need to be supported by effective foodborne disease surveillance programmes which make it possible to recognize and investigate outbreaks and emerging pathogens, and to assess the need for and evaluate interventions by monitoring longer term trends. J Environ Pathol Toxicol Oncol, 1997, 16(2-3), 101 - 9 Biological activity of particle exhaust emissions from light-duty diesel engines; Carraro E et al.; Whole diesel exhaust has been classified recently as a probable carcinogen, and several genotoxicity studies have found particulate exhaust to be clearly mutagenic . Moreover, genotoxicity of diesel particulate is greatly influenced by fuel nature and type of combustion . In order to obtain an effective environmental pollution control, combustion processes using alternative fuels are being analyzed presently . The goal of this study is to determine whether the installation of exhaust after treatment-devices on two light-duty, exhaust gas recirculation (EGR) valve-equipped diesel engines (1930 cc and 2500 cc) can reduce the mutagenicity associated with particles collected during U.S.A . and European driving cycles . Another interesting object was to compare the ability of alternative biodiesel and conventional diesel fuels to reduce the mutagenic activity associated with collected particles from two light duty diesel engines (both 1930 cc) during the European driving cycle . SOF mutagenicity was assayed using the Salmonella/microsome test (TA 98 and TA 100 strains, +/- S9 fraction) . In the first part of our study, the highest mutagenicity was revealed by TA98 strain without enzymatic activation, suggesting a direct-acting mutagenicity prevalence in diesel particulate . The 2500 cc engine revealed twofold mutagenic activity compared with the 1930 cc engine (both EGR valve equipped), whereas an opposite result was found in particulate matter amount . The use of a noncatalytic ceramic trap produced a decrease of particle mutagenic activity in the 2500 cc car, whereas an enhancement in the 1930 cc engine was found . The catalytic converter and the electrostatic filter installed on the 2500 cc engine yielded a light particle amount and an SOF mutagenicity decrease . A greater engine stress was obtained using European driving cycles, which caused the strongest mutagenicity/km compared with the U.S.A . cycles . In the second part of the investigation, even though a small number of assays were available, exhaust emission generation by biodiesel fuel seemed to yield a smaller environmental impact than that of the referenced diesel fuel . The results point out the usefulness of mutagenicity testing in the research of both newer, more efficient automotive aftertreatment devices and less polluting fuels. Bull Soc Pathol Exot, 1997, 90(1), 27 - 9 {Visceral leishmaniasis in Niger: six new parasitologically confirmed cases}; Djidingar D et al.; From January 1992 to January 1995, six cases of Kala-azar have been observed in young soldiers at Niamey, Niger . All the patients had spent some time at Tin-Galene, in Air mountains, Northern Niger where they had been apparently contaminated . One patient was also infected with Salmonella and an other with Mycobacterium, but none of the six was positive for HIV . The 6 cases have been confirmed by the presence of Leishmania in the sternum bone-marrow . Four patients recovered after a treatment with Glucantime; two died because the treatment was too late . In Niger, Kala-azar prevalence is probably much higher than estimated previously . So far all the cases described or suspected were in the Saharan mountains of Air . The strains have not been typed and it is not possible to state if it is L . infantum or L . donovani . The vector of the two species Ph . orientalis and Ph . alexandri are known to occur in the area. Scand J Infect Dis, 1997, 29(3), 265 - 9 Antimicrobial resistance pattern and plasmid profile of Salmonella typhi isolated from an outbreak in Tehran province; Bahrmand AR et al.; The antimicrobial resistance patterns and plasmid profiles of Salmonella typhi isolates from sporadic cases (n = 33) and an outbreak (n = 48) were compared . Of 28 sporadic drug-resistant isolates, 24 (85.7%) were multiply resistant . The predominant antibiotic resistance pattern was TeCmSmSxTAp, which was also the most common pattern of the outbreak isolates . 13 drug-resistant strains isolated before the outbreak (46.4%) were able to transfer the whole resistance pattern or part of it to Escherichia coli K 12 by conjugation . Although 20 of the sporadic strains contained plasmid DNA, transferable R plasmids were only detected in 13 (65%) of them . Among the outbreak strains, the rate of R plasmid transfer was 92.3%, with only the TeCmSmSxTAp pattern transferred . Plasmid profiling and Hind III endonuclease digestion of plasmid DNA identified a 91.2 megadaltons (Mda) plasmid that was recovered from most of the outbreak isolates and from 4 strains collected before the outbreak . This plasmid coded for TeCmSmSxtAp and transferred the pattern of resistance in toto . The results indicate multidrug-resistant S . typhi as a potential cause of infection in the region. Zh Mikrobiol Epidemiol Immunobiol, 1997 Jan-Feb, (1), 63 - 6 {The identification of salmonellae by means of a rapid polymerase chain reaction}; Satorov S et al.; The results of the rapid method for the detection and identification of epidemically related and unrelated causative agents of Salmonella infections . To analyze the chromosomal DNA of these strains, rapid polymerase chain reaction (PCR) was used . The analysis of the electrophoregrams of products obtained in rapid PCR revealed that the number of DNA fragments is constant for the cultures of the concrete serovar or phagovar . Using rapid PCR, the detection of S . typhi atypical strains was succeeded. Adv Exp Med Biol, 1997, 412, 413 - 20 Immunoprophylaxis of Salmonella gallinarum infection by Salmonella enteritidis-immune lymphokines in broiler chicks; Kogut M et al.; Research on the control of intestinal and tissue colonization of breeder and table-egg producing flocks by invasive Salmonella enteritidis (SE) has focused on the advancement of anti-salmonella feed additives, microbiological strategies, and the development of vaccines . Recent investigations in our laboratories have concentrated on the development of immunoprophylactic measures to control Salmonella infections . We have found an increased resistance to Salmonella enteritidis (SE) organ infectivity in chickens conferred by the prophylactic administration of SE-immune lymphokines (SE-ILK) . Fowl typhoid, caused by Salmonella gallinarum (SG), is a septicemic disease of domestic birds resulting in morbidity with moderate to very high mortality within the first 2 weeks of age . The objective of the present studies was to evaluate the effect of a prophylactic treatment of neonatal broiler chicks with lymphokines derived from S . enteritidis (SE)-immunized chickens (SE-ILK) on the birds' resistance to an experimental infection with S . gallinarum (SG) . On the day-of- hatch, chicks were intraperitoneally administered either SE-ILK, control nonimmune lymphokines (NILK), or nothing . Thirty min later, all chicks were gavaged with either 10(4) cfu or 10(6) cfu SG . For 10 days after challenge, the chicks were observed twice daily for morbidity and mortality . Chicks that died during the experiment had their livers cultured for SG . Chicks that survived throughout the 10 day experimental period were killed and their livers, spleens, and cecal tonsils cultured for SG . The prophylactic treatment of chickens with SE-ILK induced significant protection against an extraintestinal SG infections when compared to NILK as evidenced by: 1) a significant reduction (P < 0.005) in the mortality of chicks challenged with either 10(4) and 10(6) cfu sg; 2) increased average weight gains of chicks challenged with either 10(4) and 10(6) efu SG; and 3) a significant (P < 0.001) reduction in the total number of SG-organ-culture positive chicks . The results suggest that the prophylactic administration of SE-ILK can non-specifically confer protection to chicks against a pathogenic salmonellae as seen by reduced morbidity, mortality, and organ infectivity of SG in broiler chicks while enhancing weight gain during the first ten days of life. Adv Exp Med Biol, 1997, 412, 341 - 8 Unique Salmonella choleraesuis surface protein affecting invasiveness . Possible inv related sequence; Maddox CW et al.; TnphoA mutagenesis of a Salmonella choleraesuis isolate recovered from septicemic infection of feeder pigs resulted in 56 PhoA+ KnR StrR mutants . Thirty-five mutants exhibited reduced levels of invasion in the Hep-2 cell model and were examined by SDS-PAGE Western Blot analysis using an anti-alkaline phosphatase antibody to visualize the insertion gene products . A mutant which produced a gene fusion product of 95 kDa and exhibited > 90% reduction in invasion was subcloned . A 10 Kb BamHI fragment of the chromosome containing the phoA insert was detected by hybridization and cloned into a pGEM vector . The resulting 1657 base sequence contained a 1104 bp ORF with two short regions of homology with S . typhimurium invF and invG . one region of homology with lcrD of Yersinia pseudotuberculosis but contained largely unique sequences not contained in Gene Bank . The full length sequence was not obtained as there was no stop codon detected . The % G+C was 44%, considerably lower than that of the Salmonella chromosome, but compatible with the proposed Yersinia origin of the inv genes . The NH2 387 a.a . sequence includes 5 transmembrane regions, resembling the model derived from the hydrophobicity plot of S . typhimurium InvA. Adv Exp Med Biol, 1997, 412, 289 - 93 Interactions of enteric pathogens with human epithelial cells . Bacterial exploitation of host processes; Finlay BB; Many bacterial pathogens interact with surfaces on the body resulting in disease . These interactions are usually tightly regulated . Several of these pathogens also exploit host processed which contribute to their pathogenesis . Enteropathogenic existing epithelial cells using sophisticated mechanisms that exploit existing epithelial signal transduction pathways and host cytoskeleton components . Unlike EPEC, Salmonella species actually enter into epithelial cells (invade) and function as intracellular parasites . During invasion Salmonella exploit various host signal transduction pathways and cause cytoskeletal rearrangements . Salmonella enter an intracellular vacuole which remains separated from the main epithelial cell, Salmonella species trigger the formation of a novel intracellular organelle which is associated with intracellular growth . Comparison of the virulence mechanisms used by these two pathogens and their exploitation of epithelial cells illustrates several principles used by bacterial pathogens to cause disease. Adv Exp Med Biol, 1997, 412, 279 - 87 Genetics of virulence of enteropathogenic E . coli; Kaper JB et al.; Enteropathogenic E . coli (EPEC) are a major cause of diarrhea in infants throughout the world . Although this pathogen was described 50 years ago, it is only recently that the pathogenic mechanisms employed by this organism have been elucidated . The characteristic histopathology induced by this organism, called "attaching and effacing", consists of intimate adherence of the bacterium to the epithelial cell with marked cytoskeletal changes including effacement of microvilli . A 35 kb region of chromosomal DNA, called the LEE for locus of enterocyte effacement has recently been described which contains all known genes necessary for production of this characteristic histopathology . Within this region is the eae gene encoding intimin, a 94 kDa OMP involved in intimate adherence . Also within this region are genes encoding proteins secreted extracellularly by EPEC (esp) and a type III secretion apparatus (sep) which shares homology with similar systems in Yersinia, Shigella, and Salmonella . Additional genes on a 60 MDa plasmid encode a type IV pilus (BFP) and a positive transcriptional activator (per) of multiple chromosomal and plasmid virulence genes. Adv Exp Med Biol, 1997, 412, 185 - 92 Plasminogen receptors . Turning Salmonella and Escherichia coli into proteolytic organisms; Korhonen TK et al.; We evaluated in vitro the hypothesis that bacterial adhesiveness to the mammalian extracellular matrix and the activation of plasminogen on bacterial plasminogen receptors promote bacterial penetration through basement membranes . We used the strain SH401 of Salmonella enterica serovar Typhimurium, which adheres to the high-mannose chains of laminin, a major glycoprotein of basement membranes, and expresses plasminogen receptors . Bacterium-bound plasmin was able to degrade laminin and extracellular matrix preparations as well as to potentiate the penetration of bacteria through a reconstituted basement membrane . The results suggest that metastatic tumour cells and bacterial pathogens use similar mechanisms to penetrate through tissue barriers. Lupus, 1997, 6(4), 404 - 7 Mycotic aneurysm of a coronary artery in SLE--a rare complication of salmonella infection; Howe HS et al.; We describe a 27y old female systemic lupus erythematosus (SLE) patient with salmonella bacteraemia who presented with fever, back pain and an enlarging heart size . A two dimensional echocardiogram (2D Echo) showed a mass in the right atrium . Subsequent computer tomographic (CT) and magnetic resonance imaging (MRI) studies showed that this had become a ring shaped lesion at the posterior end of the interventricular septum with an area communicating with the right atrial cavity . At operation a ruptured mycotic aneurysm of the right coronary artery was found . This is the first report of an SLE patient with a coronary artery mycotic aneurysm due to salmonella and the first reported case of survival following rupture of such aneurysm. Br J Clin Pract, 1997 Jan-Feb, 51(1), 8 - 10 A clinical comparison of typhoid fever caused by susceptible and multidrug-resistant strains of Salmonella typhi; Alsoub H et al.; The clinical features and response to therapy with ciprofloxacin were studied in two groups of patients: those infected by susceptible strains of Salmonella typhi and others infected by multidrug-resistant strains . There was no significant difference in the clinical presentation, laboratory findings and outcome between the two groups . Patients infected with multidrug-resistant strains, however, defervesced in significantly longer time (5.5 days) than those infected by susceptible strains (4.35 days) (p = 0.031) . In areas with high prevalence of multidrug-resistant Salmonella infection, empiric treatment with quinolones or third-generation cephalosporins of all patients with suspected typhoid fever until the results of culture sensitivity tests are available may lead to better outcome. Scand J Gastroenterol Suppl, 1997, 222, 88 - 92 A clinical hepatologist's predictions about non-absorbed carbohydrates for the early twenty-first century; Conn HO; To put these predictions into perspective, the primary indication for lactulose therapy in the treatment of HE and SHE is presented and discussed . Six secondary indications for lactulose therapy are also listed and briefly commented upon . A dozen predictions about the status of lactulose are presented and briefly discussed . A . Lactulose will be the treatment of choice for HE.B . TIPS will be the most common cause of HE.C . Lactulose will not be approved in Mexico . D . Lactulose plus anti-diarrheal drugs will be agents for treatment of HE . E . Lactulose will not be the treatment of choice for constipation . F . Lactulose will not be used for Salmonella or Shigella carrier states . G . Lactulose will be routinely administered prophylactically after TIPS . H . Lactulose will be administered prophylactically to cirrhotic patients with portal hypertension . I . Lactulose plus anti-diarrheal drugs will be used for a variety of diverse purposes: (i) Suppression of bacterial growth; (ii) prevention of bacteriuria; (iii) diminution of cholesterol saturation of bile; (iv) adjunct treatment of gallstones with ursodeoxycholic acid; (v) Prevention of colon carcinoma. Environ Mol Mutagen, 1997, 29(3), 312 - 22 Predicting rodent carcinogenicity from mutagenic potency measured in the Ames Salmonella assay; Fetterman BA et al.; Many in vitro tests have been developed to identify chemicals that can damage cellular DNA or cause mutations, and secondarily to identify potential carcinogens . The test receiving by far the most use and attention has been the Salmonella (SAL) mutagenesis test developed by Ames and colleagues {(1973): Proc Natl Acad Sci USA 70:2281-2285; (1975): Mutat Res 31:347-364}, because of its initial promise of high qualitative (YES/NO) predictivity for cancer in rodents and, by extension, in humans . In addition to the initial reports of high qualitative predictivity, there was also an early report by Meselson and Russell {in Hiatt HH et al (1977): "Origins of Human Cancer, Book C: Human Risk Assessment," pp 1473-1481} of a quantitative relationship between mutagenic potency measured in SAL and carcinogenic potency measured in rodents, for a small number of chemicals . However, other reports using larger numbers of chemicals have found only very weak correlations . The primary purpose of this study was to determine whether mutagenic potency, as measured in a number of different ways, could be used to improve predictivity of carcinogenicity, either qualitatively or quantitatively . To this end, eight measures of SAL mutagenic potency were used . This study firmly establishes that the predictive relationship between mutagenic potency in SAL and rodent carcinogenicity is, at best, weak . When predicting qualitative carcinogenicity, only qualitative mutagenicity is useful; none of the quantitative measures of potency considered improves the carcinogenicity prediction . In fact, when qualitative mutagenicity is forced out of the model, the quantitative measures are still not predictive of carcinogenicity . When predicting quantitative carcinogenicity, several possible methods were considered for summarizing potency over all experiments; however, in all cases, the relationship between mutagenic potency predictors and quantitative carcinogenicity is very weak. Arch Toxicol, 1997, 71(5), 314 - 9 Mutagenicity testing of organic extracts of diesel exhaust particles after fractionation and recombination; Ostby L et al.; A new strategy for the evaluation of mixtures is presented . The mixture used was the organic extract of diesel exhaust particles (DEP) . After extraction with dichloromethane (DCM), the crude extract was fractionated according to polarity into five fractions: aliphatic hydrocarbons, polycyclic aromatic hydrocarbons (PAHs), nitro-PAHs, dinitro-PAHs, and polar compounds . After dissolving in dimethylsulphoxide (DMSO), the three fractions containing the primary mutagens (fractions 3-5) were recombined in different combinations to create new extracts . The blend matrix was obtained using a mixture design at three dose levels to support an empirical model with linear, interaction, and quadratic terms (Taylor polynome) . The recombined extracts were tested in the Ames Salmonella assay using strain TA100 . Multivariate data analysis was performed with projections to latent structures (PLS) . The best model describing the relation between the mutagenicity (response) and the three fractions (variables) contained two interaction terms . The model showed high correlation (r2) and prediction properties (Q2), the latter obtained after cross validation . Interaction terms are only indications of possible synergism or antagonism and have to be evaluated with respect to dose-additivity and response-additivity . The incorporation of dose in the design reduced the number of samples (recombined extracts) significantly, compared to determining dose-response curves on each sample (i.e . the recombined extracts in different dilutions) . Furthermore, instead of running two independent experiments as required in the standard procedure for the Ames test, predictions and verifications of a few new samples were used . The principle of fractionation and recombination, and the use of mixture design may in principle be extended to an unlimited number of variables . An adaptation of mixture design to the isobole method is discussed. Microbiol Immunol, 1997, 41(3), 265 - 9 Supernatant from cultured intestinal cells inhibits the growth of gram-negative bacteria; Kops SK et al.; Bacterial growth chambers of Transwell units bearing intestinal epithelial monolayers (C2BBe) was consistently observed to be stagnant during the course of transmigration studies with Salmonella typhi . This limitation could not be explained by varying the bacterial load in the inoculum . Conditioned media produced by cultured C2BBe cells would not support bacterial growth . Growth support of the media was restored by heating to 95 C for 10 min . C2BBe conditioned media had bacteriostatic activity for a large variety of gram-negative, enteropathogenic bacteria but had no effect on gram-positive bacteria. J Appl Microbiol, 1997 Jan, 82(1), 19 - 31 Enterotoxin and cytotoxin production by Salmonella enteritidis strains isolated from gastroenteritis outbreaks; Rumeu MT et al.; Seventy-six Salmonella enteritidis, three Salmonella virchow and one Salmonella bradenrup strains were screened for enterotoxigenicity by using the Chinese hamster ovary (CHO), Y1 adrenal, Vero and HeLa cell tests . All the strains gave positive reactions for enterotoxin production, except one, and the relative sensitivity to the toxin exhibited by the different cell lines was evaluated . An enterotoxic activity has been identified in sonicated extracts of Salm . enteritidis . This enterotoxin was purified on Agarose A-5m (Bio-Rad) and Superose 12 HR 10/30 column . The enterotoxic activity was eluted from the Superose column in the first peak . Like Vibrio cholerae toxin CT and Escherichia coli enterotoxin LT, it was blocked by GM1 ganglioside, but at a higher concentration . In addition, a cytotoxic factor has been partially identified . The procedure for isolating the cytotoxin included ammonium sulphate precipitation, size-exclusion chromatography and anion exchange chromatography . This cytotoxin factor caused inhibition of protein synthesis in cultured cells, as determined by flow cytometry and {3H}-leucine incorporation . Flow cytometry analysis also showed an activation of CHO cells when exposed to this cytotoxic factor resulting in a state of active growth . Cytotoxic activity was not blocked by gangliosides. Vet Res, 1997, 28(2), 165 - 78 In vitro cellular responses from sheep draining lymph node cells after subcutaneous inoculation with Salmonella abortusovis; Doucet F et al.; Salmonella abortusovis infection leads to ovine abortion . The basis for immunity against this infection is unknown . Immune responses were studied from prescapular lymph node (PSLN) cells of sheep infected with either a subcutaneous inoculation of virulent (15/5) or a vaccine (Rv6) strain and compared with those of uninfected sheep . PSLN cell phenotypes were characterized by immunofluorescence staining associated with flow cytometry . The in vitro responses were analysed using the PSLN cell proliferative response to several antigens, their secreted IL-2-like activities and their level of nitric oxide (NO) release . The phenotype analyses showed that the CD4(+)-T cell percentages decreased whereas B and MHC-II+ cell percentages increased in the infected sheep . This phenomenon occurred earlier for the virulent strain . The PSLN enlargement was greater and in vitro proliferation more frequent for the sheep infected with the virulent strain compared with the vaccine-infected ones . Proliferation occurred as a result of cell exposure to whole killed bacteria or to the cell wall fraction from S abortusovis but not to the homologous lipopolysaccharide . The secreted IL-2-like activities increased in parallel . The mitogenic response to concanavalin A decreased for infected sheep . For infected sheep, the level of NO release was maximal at the beginning of the infection . It was downregulated by in vitro exposure to S abortusovis antigens but remained unchanged for concanavalin A . NO release was not detected in uninfected sheep . This preliminary investigation provided some keys to the understanding of ovine response to S abortusovis infection and suggested that it shared common features with the mouse immune response. Scand J Infect Dis, 1997, 29(1), 37 - 40 Impact of infecting dose on severity of disease in an outbreak of food-borne Salmonella enteritidis; Rejnmark L et al.; We conducted a cross-sectional study 72 h after a private dinner party, at which 33/59 participants (attack rate 56%) became infected with Salmonella enteritidis, phage type 6 . All were interviewed and stool samples were obtained from 55 persons (93%) . Only 2/33 cases were asymptomatic (6%) . The median incubation period was 21 h . 14 of the cases (42%) were admitted to hospital . A significant association was found between infection and 1 of the egg-containing dishes (kabab) . Cross-contamination to other dishes was likely . As an indirect measure of infecting dose, all persons were divided into exposure groups according to self-reported amount of consumed kabab, which was associated with risk of becoming ill (p = 0.00002) and the risk of hospitalization (p = 0.0005) . Among the symptoms experienced by the patients, only fever was significantly associated with the amount of consumed kabab (p = 0.008) . The present data suggest an existence of a dose-effect relationship in infections with S . enteritidis, phage type 6. Berl Munch Tierarztl Wochenschr, 1997 Jan, 110(1), 5 - 11 {Significance of causes of infectious abortion in sheep flocks in northern Baden-Württemberg with special reference to Chlamydia psittaci}; Sting R et al.; Investigations on the reasons of infectious abortion cases in sheep flocks in northern parts of Baden-Wuerttemberg eludicate the wide-spreading of Chlamydia psittaci (C . psittaci) and its significance as the most frequent cause of abortions in sheep . Another important pathogen agent causing abortions is Salmonella abortus ovis (S . abortus ovis) which could be demonstrated by using a serological ELISA test . A less important role than C . psittaci and S . abortus ovis plays Coxiella burnetii in abortion of sheep . A high prevalence of Toxoplasma gondii and border disease infections in sheep flocks could be revealed by serological studies, too . Statistical evaluations of the obtained results demonstrate a significantly increased number of positively reacting female sheep in flocks suffering from abortions in comparison to those deriving from flocks devoid of abortion cases . Serological studies on leptospirosis and brucellosis exclude a participation of these pathogen agents in abortion cases in the investigated flocks at present . The significance of zoonosis originated from sheep is emphasized. Dtsch Tierarztl Wochenschr, 1997 Jan, 104(1), 33 - 5 Surveillance on Salmonella in turkey flocks and processing plants; Hafez HM et al.; The present investigation was carried out to investigate the occurrence and distribution of Salmonella infection on all stages of turkey production . Therefore, samples from turkey parent flocks, hatchery, meat turkey flocks, turkey feed and finally from the surveillanced flocks at different steps in processing plant were examined . Salmonella was isolated from 4 out of 6 turkey parent flocks (66.7%), but none of the examined 485 samples from the hatchery revealed positive Salmonella results . Eight out of 24 monitored meat turkey flocks were free from Salmonella during the entire rearing period (33.3%); seven flocks (29.2%) appeared to be infected with only one serovar and in another 9 flocks (37.5%) two or more different serovars were isolated during the rearing period, in some cases at the same time . In 20 out of 506 examined feed samples Salmonella was isolated (3.95%) . During processing, bacteriological investigations on the presence of Salmonella were carried out on the monitored flocks at different processing steps . Cross contamination seems to be very common during processing and even in several flocks contamination appeared to have started already during transport. Avian Dis, 1997 Jan-Mar, 41(1), 117 - 24 The effects of induced molting on the severity of acute intestinal inflammation caused by Salmonella enteritidis; Macri NP et al.; This study describes and compares early inflammation caused by Salmonella enteritidis in molted and nonmolted hens . Adult white leghorn chickens were orally infected with Salmonella enteritidis 4 days after feed removal . At 2, 4, 8, 10, 24, 48, 72, and 96 hr after infection, the hens were euthanatized, and the duodenum, jejunum, ileum, cecum, and colon were evaluated by light microscopy . Two trials were conducted, and in both trials inflammation occurred more frequently and was significantly greater in the cecum and colon of molted-infected hens compared with nonmolted-infected hens beginning at 8 hr after infection . In one trial, inflammation was more severe in the ileum of molted-infected hens compared with nonmolted-infected hens . Results indicated that molting by feed deprivation shortened the time of onset and increased the severity of acute intestinal inflammation caused by Salmonella enteritidis. Avian Dis, 1997 Jan-Mar, 41(1), 58 - 61 Destruction of Salmonella enteritidis in poultry feed by combination of heat and propionic acid; Matlho G et al.; A factorial laboratory experiment was conducted to assess the effects of heating times of 0, 20, 40, and 80 sec at 160 F and propionic acid concentrations of 0, 0.1%, and 0.2% on reduction of Salmonella enteritidis in poultry feed with approximately 15% moisture . The results showed that after 80 sec heating time an approximately 10,000-fold reduction in living salmonella was obtained in the samples with 0.2% propionic acid . Survival in the 0.2% acid group was 2 log10 lower than in the 0.1% and control groups . This difference was statistically significant . Multivariate analysis with repeated measures showed there was no interaction between heating time and propionic acid concentration (P = 0.4113) . There were overall significant effects for both acid concentration (P < 0.00001) and heating time (P < 0.0001). J Pathol, 1997 Jan, 181(1), 25 - 30 Correlation of granuloma structure with clinical outcome defines two types of idiopathic disseminated BCG infection; Emile JF et al.; Bacillus Calmette Guerin (BCG) is an attenuated strain of Mycobacterium bovis that is currently used as a live vaccine for human tuberculosis . Disseminated BCG infection may rarely occur following vaccination of children . In half of the cases, regarded as idiopathic, no well-defined immunodeficiency condition can account for the infection . However, the high rates of parental consanguinity and familial forms and the associated opportunistic infections with Salmonella suggest that these idiopathic BCG infections result from one or several new type(s) of inherited immune disorder(s) . As an approach to the description and understanding of this newly described condition, the associated lesions were examined . Samples from 14 patients collected from a French national retrospective study were analysed . Pathological data from 22 cases reported in the world literature were also reviewed . Two types of granuloma were found . The first type (type I, tuberculoid) consisted of well-circumscribed and well-differentiated granulomas, with epithelioid and multinucleated giant cells containing very few acid-fast rods, surrounded by lymphocytes and fibrosis and occasionally with central caseous necrosis . The second type (type II, lepromatous-like) consisted of ill-defined and poorly differentiated granulomas, with few if any giant cells and lymphocytes but widespread macrophages loaded with acid-fast bacilli . Most children displayed a single type of granuloma . One half displayed type 1 lesions and the other half displayed type II lesions . There was a strong correlation between the type of granuloma and the clinical outcome . Tuberculoid lesions were associated with survival, whilst lepromatous-like lesions correlated with death . Correlation of granuloma structure with clinical outcome defines two types of idiopathic disseminated BCG infection . The phenotypic heterogeneity of the course of BCG infection reflects distinct pathogenic mechanisms and probably results from a genotypic heterogeneity of the underlying inherited immune disorder. Carcinogenesis, 1997 Jan, 18(1), 193 - 9 Genotoxic effects of cyclopenta-fused polycyclic aromatic hydrocarbons in different types of isolated rat lung cells; Johnsen NM et al.; The genotoxic effects of the environmental contaminants benz{j}aceanthrylene (B{j}A), benz{l}aceanthrylene (B{l}A) and benzo{a}pyrene (B{a}P), and the metabolism of radiolabelled B{j}A, were studied using rat lung microsomes and various types of isolated rat lung cells from control and Aroclor 1254 (PCB) treated animals . All three compounds (10 or 20 microg/plate) resulted in low, but detectable, levels of His+ revertants in the Salmonella assay when plated with control lung microsomes . The two cyclopenta polycyclic aromatic hydrocarbons (CP-PAH) B{j}A and B{l}A, gave increased levels of revertants when plated with microsomes from PCB-treated animals . Clara cells, type 2 cells and alveolar macrophages isolated from control rats were exposed to B{j}A, B{l}A or B{a}P (30 microg/ml, 1 h), but neither of the cell types showed any DNA damage when measured by alkaline filter elution . However, both B{j}A and B{l}A (30 microg/ml, 2 h) caused DNA adducts in all three cell types, measured by the 32P-post-labelling technique, whereas no B{a}P adducts were detected (30 microg/ml, 2 h) . The total DNA adduct levels in Clara cells, type 2 cells and macrophages exposed to B{j}A were 0.085 +/- 0.033, 0.053 +/- 0.001 and 0.170 +/- 0.030 fmol/microg DNA, respectively, whereas the total levels in cells exposed to B{l}A were 0.140 +/- 0.070, 0.140 +/- 0.030 and 0.220 +/- 0.080 fmol/microg DNA, respectively . Cells exposed to B{j}A revealed only one adduct which corresponds with the B{j}A-1,2-oxide DNA adduct . Judged from high performance liquid chromatography (HPLC) analysis using radiolabelled B{j}A (30 microg/ml, 30 min), the major metabolite formed in control microsomes was B{j}A-1,2-diol . Thus, oxidation at the cyclopenta ring appears to be the most important activation pathway for B{j}A with control rat lung cells . Exposure of lung cells to CP-PAH (30 microg/ml, 2 h) isolated from PCB pretreated rats resulted in slightly increased DNA adduct levels in Clara cells and macrophages when compared to cells isolated from control rats . Furthermore, the adduct pattern had shifted, and no apparent B{j}A-1,2-oxide adduct could be detected on the thin layer chromatography (TLC) plate . In contrast, the major metabolite formed with microsomes from PCB-treated animals was still the B{j}A-1,2-diol. J Antimicrob Chemother, 1997 Jan, 39(1), 85 - 7 Novel transferable beta-lactam resistance with cephalosporinase characteristics in Salmonella enteritidis; Gaillot O et al.; An isolate of Salmonella enteritidis was found to produce a plasmid-encoded beta-lactamase (DHA-1) that conferred resistance to extended-spectrum cephalosporins and cephamycins . The substrate and inhibition profiles of this enzyme resemble a class C beta-lactamase . This is the first report of a plasmid-mediated cephalosporinase of this class in the Salmonella genus. Life Sci, 1997, 60(8), 519 - 28 Increased microbicidal activity of human monoblastoid cells upon long-term exposure to dideoxycytidine; Brandi G et al.; 2',3'-Dideoxycytidine (ddC) is a nucleoside analogue currently used in AIDS therapy . We had previously found that long term exposure of U937 human monoblastoid cells to ddC induces the selection of drug-resistant cells (U937-R) . In the present work we investigated some important biochemical properties and functional activities of these resistant cells . The results obtained show that U937-R maintained the properties of cell aggregation, adhesion and differentiation . Basal respiration, protein kinase C activity, superoxide anion release and intracellular free calcium were all increased in the drug-resistant line . Phagocytosis of fungi (Candida albicans) and bacteria (Staphylococcus aureus and <