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At least 19 recordsLinked to original sources
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↗
PubMed1999

Genomic subtraction identifies Salmonella typhimurium prophages, F-related plasmid sequences, and a novel fimbrial operon, stf, which are absent in Salmonella typhi.

Salmonella typhimurium causes systemic and fatal infection in inbred mice, while the related serotype Salmonella typhi is avirulent for mammals other than humans. In order to identify genes from the virulent strain S. typhimurium ATCC 14028 that are absent in S. typhi Ty2, and therefore might be involved in S. typhimurium mouse virulence, a PCR-supported genomic subtractive hybridization procedure was employed. We have identified a novel putative fimbrial operon, stfACDEFG, located at centisome 5 of the S. typhimurium chromosome, which is absent in S. typhi, Salmonella arizonae, and Salmonella bongori but was detected in several other Salmonella serotypes. The fimbrial genes represent a genomic insertion in S. typhimurium compared to the respective region between fhuB and hemL in Escherichia coli K-12. In addition, the subtraction procedure yielded F plasmid-related sequences from the S. typhimurium virulence plasmid, a number of DNA fragments representing parts of lambdoid prophages and putative sugar transporters, and several fragments with unknown sequences. The majority of subtracted chromosomal sequences map to three distinct locations, around centisomes 5, 27, and 57.

Animals↗
PubMed2005

Effect of acid shock with hydrochloric, citric, and lactic acids on the survival and growth of Salmonella typhi and Salmonella typhimurium in acidified media.

The effect of acid shock with hydrochloric, citric, or lactic acid on the survival and growth of Salmonella Typhi and Salmonella Typhimurium in acidified broth was evaluated. Salmonella serovars were acid shocked (1 h at 35 degrees C) in Trypticase soy broth acidified with hydrochloric, citric, or lactic acid at pH 5.5. Unshocked cells were exposed to the same media that had been neutralized before use to pH 7.0. Shocked and unshocked cells were inoculated into broth acidified with hydrochloric acid (pH 3.0), citric acid (pH 3.0), or lactic acid (pH 3.8), and growth and survival ability were evaluated. The acid shock conferred protection to Salmonella against the lethal effects of low pH and organic acids. The adaptive response was not specific to the anion used for adaptation. The biggest difference in reduction of survival between shocked and unshocked strains (approximately 2 log CFU/ml) was observed when the microorganisms were shocked with lactic acid and then challenged with citric acid. Salmonella Typhi was more tolerant of citric acid than was Salmonella Typhimurium, but Salmonella Typhimurium had higher acid tolerance in response to acid shock than did Salmonella Typhi. The acid shock decreased the extension of the lag phase and enhanced the physiological state values of Salmonella Typhi and Salmonella Typhimurium when the pH of growth was 4.5. This increased ability to tolerate acidity may have an important impact on food safety, especially in the case of Salmonella Typhi, given the very low infectious dose of this pathogen.

Adaptation, Physiological↗
PubMed1993

Vi I typing phage for generalized transduction of Salmonella typhi.

Salmonella typhi Vi typing phages were used to transduce temperature-sensitive (Ts) mutants of Salmonella typhi. Antibiotic resistance and Ts+ markers were transduced at high frequency (> 10(-4) per virulent phage). Several markers were cotransduced by phage Vi I, suggesting that it may be useful for mapping studies of the S. typhi genome.

Bacteriophage Typing↗
PubMedDate not supplied

Unusual presentation of enteric fever: three cases of splenic and liver abscesses due to Salmonella typhi and Salmonella paratyphi A.

Enteric fever is a multisystem disorder caused mainly by Salmonella typhi and Salmonella paratyphi A. It continues to be a major public health problem, especially in developing countries. Unusual presentations of Salmonellosis are rare. We report 3 such cases of young adult males, one of splenic abscess due to Salmonella typhi and one each of liver abscess due to Salmonella typhi and Salmonella paratyphi A. A brief review of the literature pertaining to the cases is also given.

Abscess↗
PubMed1999

Role of genomic rearrangements in producing new ribotypes of Salmonella typhi.

Salmonella typhi is the only species of Salmonella which grows exclusively in humans, in whom it causes enteric typhoid fever. Strains of S. typhi show very little variation in electrophoretic types, restriction fragment length polymorphisms, cell envelope proteins, and intervening sequences, but the same strains are very heterogeneous for ribotypes which are detected with the restriction endonuclease PstI. In addition, the genome of S. typhi has been proven to undergo genomic rearrangement due to homologous recombination between the seven copies of rrn genes. The relationship between ribotype heterogeneity and genomic rearrangement was investigated. Strains of S. typhi which belong to 23 different genome types were analyzed by ribotyping. A limited number of ribotypes were found within the same genome type group; e. g., most strains of genome type 3 belonged to only two different ribotypes, which result from recombination between rrnH and rrnG operons. Different genome type groups normally have different ribotypes. The size and identity of the PstI fragment containing each of the seven different rrn operons from S. typhi Ty2 were determined, and from these data, one can infer how genomic rearrangement forms new ribotypes. It is postulated that genomic rearrangement, rather than mutation, is largely responsible for producing the ribotype heterogeneity in S. typhi.

Bacterial Typing Techniques↗
PubMed2003

Cutaneous infection caused by Salmonella typhi.

Salmonella typhi is a flagellated, gram-negative bacillus belonging to the family Enterobacteriaceae responsible for typhoid fever, which is a prolonged bacteraemic, systemic illness with minimal, at least initially, diarrhoea. Localized infection is a not uncommon complication of salmonella septicaemia, particularly occurring in immunocompromised patients. However, salmonella localization to the skin presenting as cutaneous ulceration is regarded as a rare event. We report a unique case of such a presentation as the sole clinical manifestation of infection with S. typhi and highlight the possible salmonella aetiology for unusual cutaneous lesions in individuals coming from endemic areas.

Adult↗
PubMed1997

[Gluteal hematoma infected with multiresistant Salmonella typhi].

Salmonella infections usually presents with diarrhea and fever. Localized salmonella infection with abscess formation is an uncommon but significant manifestation of salmonellosis. An infected gluteal haematoma caused by multi resistant Salmonella typhi is described. Etiologic diagnosis, appropriate chemotherapy, surgical intervention and isolation is important. There was no nosocomial infections related to this case and treatment was effective. It is important to be aware of unusual manifestations of salmonella infections, which may occur without any previous history of exposure.

Adult↗
PubMed1989

Intragenic recombination in a flagellin gene: characterization of the H1-j gene of Salmonella typhi.

Salmonella typhi, the etiologic agent of typhoid fever, typically has only a phase-1 flagellar antigen, d, but some isolates, found only in Indonesia, have antigen j instead, and may have a second flagellar antigen, z66. It appears that intragenic recombination involving a directly repeated 11 bp sequence in the H1-d flagellin gene changed the flagellar antigen to j, by deleting 261 bp in its central, antigenically determinant, part. Sequencing of the hypervariable regions of genes H1-d and H1-j, and hybridization of such genes, after amplification by the polymerase chain reaction, with oligonucleotide probes specific for the deleted segment or for the sequence produced by the recombination confirmed that all the j alleles have the postulated deletion. By applying the polymerase chain reaction to study S. typhi isolates from Jakarta, not previously tested in respect to flagellar antigen, we showed that gene H1-j was nearly as common as H1-d in these isolates.

Antigens, Bacterial↗
PubMed1988

Construction of delta aroA his delta pur strains of Salmonella typhi.

Salmonella typhi strains with two deletion mutations, each causing an attenuating auxotrophy, have been constructed from strains Ty2 and CDC 10-80 for possible use as oral-route live vaccines. An aroA(serC)::Tn10 transposon insertion was first transduced from a Salmonella typhimurium donor into each wild-type S. typhi strain. Transductants of the Aro- SerC- phenotype were treated with transducing phage grown on an S. typhimurium strain with an extensive deletion at aroA; selection for SerC+ yielded transductants, some of which were delta aroA. A his mutation was next inserted into a delta aroA strain in each line by two steps of transduction. Two deletions affecting de novo purine biosynthesis were used as second attenuating mutations: delta purHD343, causing a requirement for hypoxanthine (or any other purine) and thiamine, and delta purA155, causing an adenine requirement. The purHD343 deletion was introduced into the delta aroA his derivatives of each strain by cotransduction with purH::Tn10, and the purA155 deletion was introduced into the CDC 10-80 delta aroA his derivative by cotransduction with an adjacent silent Tn10 insertion by selection for tetracycline resistance. Tetracycline-sensitive mutants of each of the three delta aroA his delta pur strains were isolated by selection for resistance to fusaric acid. The tetracycline-sensitive derivative of the CDC 10-80 delta aroA his delta purA155 strain, designated 541Ty, and its Vi-negative mutant, 543Ty, constitute the candidate oral-route live-vaccine strains used in a recent volunteer trail (M. M. Levine, D. Herrington, J. R. Murphy, J. G. Morris, G. Losonsky, B. Tall, A. A. Lindberg, S. Stevenson, S. Baqar, M. F. Edwards, and B. A. D. Stocker, J. Clin. Invest. 79:885-902, 1987). Tetracycline-sensitive mutants of the delta aroA his delta purHD derivative of strains Ty2 and CDC 10-80 may also be appropriate as live vaccines but have not been tested as such.

Animals↗
PubMed1988

Distribution of Salmonella typhi and Salmonella paratyphi B phage types in Italy from 1974 through 1985.

The temporal changes in occurrence and distribution in Salmonella typhi and paratyphi B phage types in Italy during a twelve year period are considered. From 1974 to 1985, 2.075 isolates of Salmonella typhi and 830 isolates of Salmonella paratyphi B were phage typed at the National Centre for Enterobacteria in Rome and the three Regional Centres for Enterobacteria in Milan, Palermo and Pisa. The most prevalent types of Salmonella typhi were A, C1, D1, Vi degraded strains E1, I+IV and C4. Types A, C1 and D1 accounted for 59.1% of the total. The distribution of the phage types as A, B2, C1, D1, D4, D9, E1, F1, N, 28 and I+IV, Vi degraded and Vi negative strains in the three time periods (1974-77; 1978-81 and 1982-85) was quite similar; some types such as D8, E2, 0 and 43 were found sporadically and others like C9, D6, F4, H and 45 which were present in the first period, disappeared in the last. The most prevalent types of Salmonella paratyphi B were Tauton, Dundee, 1, and 3a. Type 2, frequently found in the 1974-77 period was however not seen during 1981-85.

Bacteriophage Typing↗
PubMed1994

Comparison of Salmonella typhi and Salmonella typhimurium invasion, intracellular growth and localization in cultured human epithelial cells.

Invasion of the cultured epithelial cell lines HeLa, Henle-407, and Caco-2 (polarized and nonpolarized) by Salmonella typhi and Salmonella typhimurium were compared using conventional gentamicin invasion assays. Additionally, the mechanisms of invasion and intracellular trafficking by S. typhi and S. typhimurium were compared in HeLa cells using indirect immunofluorescence microscopy. S. typhi strain Ty2 was invasive in all human cell lines tested, including apical uptake into polarized Caco-2 cell monolayers. This strain also replicated at levels similar to S. typhimurium strain SL1344 inside HeLa and Henle-407 cells. Indirect immunofluorescence microscopy confirmed that S. typhi, like S. typhimurium, induced membrane ruffles and cytoskeletal rearrangements upon contact with HeLa cell surfaces. Ruffling induced by S. typhi and S. typhimurium was accompanied by macropinocytosis of the fluid phase endocytic marker fluorescein-dextran-sulphate and by aggregation of cell surface class I MHC heavy chain. Intracellular lysosomal trafficking of S. typhi and S. typhimurium in HeLa cells was also studied. The lysosomal membrane glycoprotein marker h-lamp-2 colocalized with S. typhi-containing vacuoles, as previously shown for S. typhimurium. The soluble lysosomal enzyme marker cathepsin D also was found within S. typhi-containing vacuoles to the same extent as previously published for S. typhimurium. The results from this study suggest that S. typhi and S. typhimurium use similar mechanisms for invasion and intracellular trafficking in cultured human epithelial cells.

Bacterial Adhesion↗
PubMed1990

Expression of host resistance to Salmonella typhi and Salmonella typhimurium: bacterial survival within macrophages of murine and human origin.

Cell-association of various strains of Salmonella typhi and Salmonella typhimurium with different populations of macrophages was studied. Macrophages were infected, exposed to gentamicin, washed, and counts of viable bacteria protected from gentamicin killing were made. J774A.1 cells, a continuous macrophage-like cell line, were the most permissive, all strains tested achieving similar high recoveries. Virulent S. typhimurium 779C-Sms, but not avirulent S. typhimurium 779C-SmD, survived well in mouse peritoneal macrophages and human monocyte-derived macrophages. Virulent S. typhi Ty2 were killed by mouse peritoneal macrophages, but were able to survive within human monocyte-derived macrophages. Viable counts of clinical isolates of S. typhi within the human monocyte-derived phagocytes were lower as compared with those of S. typhi Ty2. Phagocytosis of opsonized and non-opsonized virulent S. typhi Ty2 and S. typhimurium 779C-SmS by mouse peritoneal macrophages failed to trigger their respiratory burst as assessed by the intracellular reduction of nitroblue tetrazolium dye (NBT). These experiments support the view that the intracellular survival of Salmonella is in part host dependent and specific in nature. They also suggest that virulence influences the survival and intracellular multiplication of Salmonella within macrophages, and that their ultimate fate within macrophages may not be related to oxygen-dependent mechanisms.

Animals↗
PubMed1991

Study on the pH of ogi, Nigerian fermented weaning food, and its effect on enteropathogenic Escherichia coli, Salmonella typhi and Salmonella paratyphi.

The pH values of both cooked and uncooked ogi samples were determined and the survival of nalidixic acid-resistant enteropathogenic Escherichia coli OB 26 34/20, Salmonella typhi and Salmonella paratyphi A when seeded into cooked ogi were studied. The pH values of ogi ranged from pH 3.0 to 3.9. Cooked ogi had a slightly lower pH value than uncooked ogi. Our survival experiments showed that the inoculated enteric pathogens were considerably inhibited in cooked ogi during storage for 24 h. The antibacterial effect of cooked ogi was more pronounced on enteropathogenic E. coli with a log10 5 decline in bacterial count within 6 h.

Diarrhea, Infantile↗