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PubMed2004

Functional transfer of Salmonella pathogenicity island 2 to Salmonella bongori and Escherichia coli.

The type III secretion system (T3SS) encoded by the Salmonella pathogenicity island 2 (SPI2) has a central role in systemic infections by Salmonella enterica and for the intracellular phenotype. Intracellular S. enterica uses the SPI2-encoded T3SS to translocate a set of effector proteins into the host cell, which modify host cell functions, enabling intracellular survival and replication of the bacteria. We sought to determine whether specific functions of the SPI2-encoded T3SS can be transferred to heterologous hosts Salmonella bongori and Escherichia coli Mutaflor, species that lack the SPI2 locus and loci encoding effector proteins. The SPI2 virulence locus was cloned and functionally expressed in S. bongori and E. coli. Here, we demonstrate that S. bongori harboring the SPI2 locus is capable of secretion of SPI2 substrate proteins under culture conditions, as well as of translocation of effector proteins under intracellular conditions. An SPI2-mediated cellular phenotype was induced by S. bongori harboring the SPI2 if the sifA locus was cotransferred. An interference with the host cell microtubule cytoskeleton, a novel SPI2-dependent phenotype, was observed in epithelial cells infected with S. bongori harboring SPI2 without additional effector genes. S. bongori harboring SPI2 showed increased intracellular persistence in a cell culture model, but SPI2 transfer was not sufficient to confer to S. bongori systemic pathogenicity in a murine model. Transfer of SPI2 to heterologous hosts offers a new tool for the study of SPI2 functions and the phenotypes of individual effectors.

Animals↗
PubMed2005

H2-M3 major histocompatibility complex class Ib-restricted CD8 T cells induced by Salmonella enterica serovar Typhimurium infection recognize proteins released by Salmonella serovar Typhimurium.

Salmonella enterica serovar Typhimurium causes a typhoid-like disease in mice which has been studied extensively as a model for typhoid fever in humans. CD8 T cells contribute to protection against S. enterica serovar Typhimurium in mice, but little is known about the specificity and major histocompatibility complex (MHC) restriction of the response. We report here that CD8 T-cell lines derived from S. enterica serovar Typhimurium-infected BALB/c mice lysed bone marrow macrophages infected with S. enterica serovar Typhimurium or pulsed with proteins from S. enterica serovar Typhimurium culture supernatants. Cytoxicity was beta-2-microglobulin dependent and largely TAP dependent, although not MHC class Ia restricted, as target cells of several different MHC haplotypes were lysed. The data suggested the participation of class Ib MHC molecules although no evidence for the presence of Qa1-restricted T cells could be found, unlike in previous reports. Instead, the T-cell lines lysed H2-M3-transfected fibroblasts infected with S. enterica serovar Typhimurium SL3261 or treated with Salmonella culture supernatants. Thus, this report increases the number of MHC class Ib antigen-presenting molecules known for Salmonella antigens to three: Qa-1, HLA-E, and now H2-M3. It also expands the range of pathogens that induce H2-M3-restricted CD8 T cells to include an example of gram-negative bacteria.

Animals↗
PubMed2005

Selective capture of Salmonella enterica serovar typhi genes expressed in macrophages that are absent from the Salmonella enterica serovar Typhimurium genome.

Thirty-six Salmonella enterica serovar Typhi-specific genes, absent from the Salmonella enterica serovar Typhimurium genome, that were expressed in human macrophages were identified by selective capture of transcribed sequences. These genes are located on 15 unique loci of the serovar Typhi genome, including Salmonella pathogenicity islands (SPI-7, SPI-8, and SPI-10) and bacteriophages (ST15, ST18, and ST35).

Fimbriae Proteins↗
PubMed1986

Biosynthesis of enterobacterial common antigen requires dTDPglucose pyrophosphorylase determined by a Salmonella typhimurium rfb gene and a Salmonella montevideo rfe gene.

In group C1 salmonellae, rfe and rff genes linked to the ilv locus specify the synthesis of a glycolipid called the enterobacterial common antigen. In contrast, in group B salmonellae the synthesis requires in addition some of the genes in the rfb cluster, the main genetic determinant of the O side chains of lipopolysaccharide. In an effort to define the biochemical functions of these rfb genes, we looked in Salmonella typhimurium LT2 (group B) for rfb mutants in which the synthesis of both enterobacterial common antigen and the O side chains would be blocked in a manner suppressible by the wild-type rfe cluster of S. montevideo, of group C1. We found one mutant with these characteristics. This rfb mutation affected the activity of dTDPglucose pyrophosphorylase (glucose-1-phosphate thymidylyltransferase, EC 2.7.7.24). Whereas the rfe cluster of S. montevideo contained a gene producing this enzyme activity, there was no evidence for the presence of such a gene in the rfe cluster of group B strains. These results also showed that the synthesis of dTDP-glucose is necessary for the biosynthesis of enterobacterial common antigen; this conclusion fits with the recent demonstration of 4-acetamido-4,6-dideoxy-D-galactose as a component of enterobacterial common antigen (Lugowski et al., Carbohydr. Res. 118:173-181, 1983), because the biosynthesis of the donor of this sugar, dTDP-4-acetamido-4,6-dideoxy-D-galactose, requires dTDPglucose pyrophosphorylase.

Antigens, Bacterial↗
PubMed1983

Evaluation of sodium polyanethanol sulfonate as a blood culture additive for recovery of Salmonella typhi and Salmonella paratyphi A.

A total of 640 blood specimens from patients in an area endemic for enteric fever were cultured in parallel in tryptic soy broth with and without sodium polyanethanol sulfonate (SPS). A total of 95 specimens were positive for Salmonella spp., 54 for Salmonella typhi, and 41 for Salmonella paratyphi A in one or both bottles of a set. Significantly higher rates of recovery were obtained from the SPS-containing medium (P less than 0.01) upon subculturing blindly at 24 h and 3 days of incubation. Subcultures performed at 7, 14, and 21 days also yielded a greater number of positive cultures with SPS than without it, although the differences between the two media were not significant (P greater than 0.05). Neither of the media yielded 100% of the positive cultures. Moreover, even if the results of the two media were combined, 34 and 19% of the isolates would have been missed if the specimens had not been incubated to 14 and 21 days, respectively. The data indicate that SPS aids in early recovery of S. typhi and S. paratyphi A from blood cultures, and additionally, that under the conditions used in the study, incubation beyond a 1-week period is required for efficient isolation of these organisms from blood.

Benzenesulfonates↗
PubMed1986

Evaluation of blood clot cultures for isolation of Salmonella typhi, Salmonella paratyphi-A, and Brucella melitensis.

Two types of clot culture, one with taurocholate-streptokinase and the other with bile as a culture medium, and two conventional cultures of whole blood were evaluated in parallel in an area where typhoid fever and brucellosis are endemic. Each of the four systems contained 5 ml of blood or the clot derived from 5 ml of blood and sufficient broth to yield a 1:11 dilution of the specimen. Of 542 patients studied, Salmonella paratyphi-A was isolated from 61, S. typhi from 46, and Brucella melitensis from 30. The two clot cultures yielded the salmonellae equally well; both were superior to whole blood cultured in Trypticase soy broth (P less than 0.02) but not to whole blood cultured in bile (P greater than 0.05). Only two systems were successful for isolation of B. melitensis. Blood-Trypticase soy broth identified 28 (93%), and clot-streptokinase cultures identified 21 (70%) (P greater than 0.05). The data indicate that use of clots per se offers no advantage in sensitivity over procedures which use whole blood. Nonetheless, they are excellent for isolation of enteric fever salmonellae and can be performed with clots left over after serum is removed for serological, biochemical, or other tests.

Blood↗
PubMed1980

Absence of competition between salmonella phage P22 and coliphage P1 for adsorption sites on a Salmonella typhosa - Escherichia coli hybrid strain.

Salmonella typhimurium mutants sensitive to coliphage P1 are resistant to salmonella phage P22 and lose their P1-sensitivity upon reversion to P22-sensitivity. A tryptophan-requiring Salmonella typhosa - Escherichia coli hybrid, which has the unique ability to serve as recipient in transduction mediated by both P22 and P1, was sued to determine if P22 and P1 adsorb at the same or overlapping sites: (i) The adsorption of each of P1 and P22 is similar when added individually or together to the hybrid at a saturating multiplicity of infection (moi). (ii) P1 grown on trp+ E. coli yields the maximum frequency of Trp+ abortive transductions at an moi of 6 with the trp hybrid recipient; the presence of increasing numbers of P22 grown on trp S. typhimurium does not decrease the number of Trp+ transduction from P1. (iii) A mixture of P1 (grown on trp+ E. coli) and P22 (grown on trp+ S. typhimurium) yields more abortive transductions than does P1 alone. Thus phages P1 and P22 adsorb to the hybrid cells on different sites.

Adsorption↗
PubMed2003

Enrichment for isolating Salmonella Choleraesuis and other Salmonella spp. from pigs.

The growth of Salmonella Choleraesuis was examined in Rappaport Vassiliadis broth (RV) and Hajna-tetrathionate broth (HTT) at 37 and 42 degrees C. As the enrichment in RV at 37 degrees C was satisfactory for isolating S. Choleraesuis, we used this enrichment for isolation from the samples collected from 15 asymptomatic pigs reared on a S. Choleraesuis contaminated farm. S. Choleraesuis was frequently isolated from six pigs (40.0%) under field conditions. The isolation of other Salmonella serovars than S. Choleraesuis was attempted by using both RV enrichment at 37 degrees C and HTT enrichment at 42 degrees C. Salmonella organisms were isolated from 156 (44.8%) of 348 fecal samples and more frequently with HTT at 42 degrees C (43.4%) than with RV at 37 degrees C (20.9%). If other serovars in addition to S. Choleraesuis are to be surveyed, HTT enrichment should be used in combination with RV enrichment.

Animals↗
PubMed1991

Salmonella virchow: abscess former amongst the contemporary invasive Salmonellae?

Abscess formation associated with salmonella infections has long been recognized--but without implicating a particular serotype. The pathogenicity, invasiveness and increasingly frequent isolation of Salmonella virchow in the UK is well established. It's propensity to abscess formation is, however, less well recognised. We report 5 patients with abscesses due to S. virchow. This represents a disproportionate number of abscesses in relation to the salmonella isolations in North East Scotland during the 5-year period under scrutiny. We suggest that this organism should be considered as aetiologically relevant even where there is no history of preceding gastrointestinal infection.

Abscess↗
PubMedDate not supplied

Sequence polymorphism of the Salmonella plasmid virulence factor D (SpvD) in Salmonella enterica isolates of animal origin.

The nucleotide sequence encoding the Salmonella plasmid virulence factor D (SpvD) was determined in 17 Salmonella strains that were different in O and H antigen patterns, animal host and geographical origin, and year of isolation. Nucleotide sequence comparison revealed the existence of at least nine spvD alleles resulting in 8 SpvD protein variants although the nucleotide sequences were highly similar (identity 98.8-100%). The spvD gene products differed from each other in up to 4 amino acid residues only with the exception of the carboxy-terminally truncated SpvD variant of one S. Gallinarum field isolate. The highly conserved primary structure of SpvD in epidemiologically relevant salmonellae suggests that this virulence factor is a promising antigen candidate for diagnostic purposes (i.e. antibody detection in infected animals) but also for immunoprophylaxis in farm animal species.

ADP Ribose Transferases↗
PubMed1992

[Comparative plasmid profile analysis of Salmonella typhimurium var. Copenhagen strains from a Salmonella outbreak in hospitalized horses].

From April 1990 through June 1991 clinical salmonellosis and asymptomatic faecal excretion of Salmonella spp. were seen in hospitalized horses at two veterinary hospitals. 76 Salmonella strains from hospitalized horses and 18 strains from horses without any clinical contact were characterized by serotyping and plasmid profile analysis. From April 1990 through January 1991 97.8% of the hospitalized horses were infected with strains of S. typhimurium var. Copenhagen, which were closely related according to their similar plasmid patterns. Other strains of S. typhimurium var. Copenhagen and serotype S. enteritidis were isolated not before February 1991. In the same period various plasmid profile types of S. typhimurium var. Copenhagen and strains of S. typhimurium, S. enteritidis and S. lexington were isolated from horses of the control group. Our results suggest that the high incidence of salmonellosis and latent salmonella infection in hospitalized horses was mainly due to the spread of one particular strain of S. typhimurium var. Copenhagen and that this strain was obviously acquired during hospitalisation.

Animals↗
PubMed2005

[Influence of spv plasmid genes group in Salmonella Enteritidis virulence for chickens. I. Occurrence of spv plasmid genes group in Salmonella Enteritidis large virulence plasmid].

Many Salmonella Enteritidis virulence factors are encoded by genes localized on plasmids, especially large virulence plasmid, in highly conserved fragment, they create spv plasmid gene group. The aims of realized researches were spv genes occurrence evaluation and composition analysis among Salmonella Enteritidis strains caused infection in chickens. Researches were realized on 107 isolates, where in every cases large virulence plasmid 59 kbp size were detected. Specific nucleotides sequences of spv genes (spvRABCD) were detected in 47.7% of isolates. In the rest of examined bacteria spv genes occurred variably. Most often extreme genes of spv group, like spvR and spvD were absent, what could indicate that factors encoded by them are not most important for Salmonella Enteritidis live and their expressed virulence.

Animals↗
PubMed2006

Dissemination of Salmonella enterica serotype agona and multidrug-resistant Salmonella enterica serotype typhimurium in Cuba.

The molecular epidemiology, antimicrobial susceptibility, and mechanisms of resistance of 34 Salmonella spp. strains causing acute gastroenteritis, isolated from different provinces in Cuba, were determined. Sixty-four percent of the strains showed multiresistance. Salmonella typhimurium was the most frequent with 15 strains (44%), 13 of which belonged to phagotype 104 and presented similar genetic profiles of pulsed field gel electrophoresis. High levels of resistance to tetracycline (53%), spectinomycin (50%), ampicillin (44%), and chloramphenicol (41%) were found. Resistance to tetracycline was associated with the tet G and tet A genes. Resistance to ampicillin was caused by the presence of beta-lactamases, mainly the CARB type. The floR gene was the main mechanism of resistance to chloramphenicol. Our results showed an antimicrobial susceptible clone of Salmonella enterica serotype Agona in two separate regions. This is the first report of the widespread dissemination of a multiresistant clone of S. enterica serotype Typhimurium definitive phage type 104 in Cuba.

Anti-Bacterial Agents↗
PubMed1989

Comparative effects of cholera toxin, Salmonella typhimurium culture lysate, and viable Salmonella typhimurium in isolated colon segments in ponies.

Isolated segments of left dorsal colon and a side-to-side colocolostomy (between the left ventral colon and left dorsal colon) were surgically created in 6 adult ponies. Four segments, each separated by an empty segment, were inoculated (20 ml) with 1 of the following 4 solutions: phosphate buffered saline solution (PBSS)/1% polyethylene glycol (PEG); purified cholera toxin in PBSS/1% PEG (5 micrograms cholera toxin/ml of PBSS/1% PEG); lyophilized Salmonella typhimurium UCD 1755 culture lysate, reconstituted in PBSS/1% PEG; and viable S typhimurium UCD 1755 (10(8) organisms/ml of PBSS/1% PEG). Twenty hours following inoculation of the treatment solutions into the isolated colon segments, the ponies were reanesthetized. Fluid accumulation in the isolated segments was measured, and tissue samples from isolated segments were taken for examination by light microscopy and electron microscopy, and for measurement of mucosal cyclic adenosine monophosphate levels. There was fluid accumulation in segments inoculated with cholera toxin in 4 ponies (29.5 +/- 12.7 ml), and in segments inoculated with S typhimurium UCD 1755 culture lysate in 3 ponies (14.0 +/- 8.7 ml). There was no fluid accumulation in segments inoculated with either the control solution (PBSS/1% PEG) or viable S typhimurium UCD 1755. There was significantly (P less than 0.05) less cyclic adenosine monophosphate in segments inoculated with cholera toxin, Salmonella lysate, and viable Salmonella, compared with control segments. Histologically, there were minimal changes in control segments, consisting of mild to moderate submucosal edema and capillary congestion.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1977

[Epidemiological studies on salmonella in a particular area ("Walcheren Project"). III. The incidence of salmonella in man, insects, gulls as well as foods scrapings from butcher's blocks, effluents of sewage treatment plants and drains from butcher's shops (author's transl)].

In continuation of previous studies, various materials (meat and meat products, insects, gull droppings, scrapings from butcher's blocks, effluents of sewage treatment plants, drains from butcher's shops and faeces of patients) were examined again at the same time for the presence of Salmonella in a relatively small are (Walcheren) over a period of three months. As was also the case in previous studies, S. typhi murium (27.5 per cent), S. panama (22.2 per cent) and S. brandenburg (9.2 per cent) were the three serotypes most frequently isolated. The three most frequently isolated phage types of S. typhi murium were II 505 (62.1 per cent), II 502 (5.3 per cent) and I 650 (4.2 per cent). The serotypes and phage types were present in nearly all the materials studied which again emphasizes the fact that there are contamination cycles of Salmonella. These studies showed that the route of contamination divides in the butcher's shop. Salmonella ogranisms carried with the meat frome the slaughter-house find their way into the drains on the one hand, and, by meat and meat products, to consumers on the other. Moreover, the high degree of contamination of effluents is not in accordance with the small number of cases of salmonellosis.

Animal Feed↗
PubMed1978

[Effect of protein in the feed on the resistance of poultry artificially infected with Salmonella galinarum pullorum and Salmonella typhimurium].

Studied is the effect of the low protein level in rations of birds, experimentally infected with Salmonella gallinarum-pullorum and Salmonella typhimurium. Birds of different ages of the Leghorn and Cornish breeds are included in the experiments. Results obtained from the experiments indicate that the lowered level of protein in rations to young birds at the age of five months makes them more resistant to salmonella infection. This dependence is markedly demonstrated in particular in the case of the Leghorn breed.

Animal Feed↗
PubMedDate not supplied

Oral salmonella antigens for the control of salmonella in chickens.

Multivalent antigen preparations of sonicated lyophilized cells derived from up to 6 different salmonella serotypes were added in decreasing levels to broiler feed throughout the broiler's life. Several preliminary experiments challenging chicks via contaminated feed with some of the homologous serotypes showed that salmonellae were cleared more rapidly from treated chicks than from untreated controls and that fewer isolations of salmonellae were made from their ceca.

Administration, Oral↗
PubMed1997

[A Salmonella epidemic by Salmonella subspecies II 4,12,12,27:b:- at the University Hospital of Tübingen in April 1996].

In April 1996 four patients at the University Hospital of Tübingen became ill with diarrhoea at short intervals; one of the patients also suffered from fever. From stool samples of all four patients Salmonella subspecies II 4,12,27:b:- was isolated; from the patient who had fever the pathogen was also isolated from one blood culture. The patients were treated at different wards of the hospital. All four patients suffered from underlying diseases. In the course of a microbiological examination of the central kitchen staff of the hospital Salmonella subspecies II 4,12,27:b:- was isolated from a stool sample of one of the employees. No contact to cold blooded animals, no travel abroad and no symptoms of gastroenteritis were reported by the employee. When the employee had been temporarily suspended no further Salmonella infections occurred.

Adult↗