Phospholipase A of Yersinia enterocolitica Contributes to Pathogenesis in a Mouse Model

ABSTRACT Some isolates of Yersinia enterocolitica exhibit phospholipase activity, which has been linked to lecithin-dependent hemolysis (M. Tsubokura, K. Otsoki, I. Shimohira, and H. Yamamoto, Infect. Immun. 25:939–942, 1979). A gene encoding Y. enterocolitica phospholipase was identified, and analysis of the nucleotide sequence revealed two tandemly transcribed open reading frames. The first, yplA, has 74% identity and 85% similarity to the phospholipase A found in Serratia liquefaciens. Though the other, yplB, was less similar to the downstream accessory protein found in S. liquefaciens, the organization in both species is similar. Subsequently, a yplA-null Y. enterocoliticastrain, YEDS10, was constructed and demonstrated to be phospholipase negative by plate and spectrophotometric assays. To ascertain whether the phospholipase has a role in pathogenesis, YEDS10 was tested in the mouse model. In experiments with perorally infected BALB/c mice, fewer YEDS10 organisms were recovered from the mesenteric lymph nodes and Peyer’s patches (PP) than the parental strain at 3 or 5 days postinfection. Furthermore, bowel tissue and PP infected with YEDS10 appeared to be less inflamed than those infected with the parental strain. When extremely high doses of both the parental and YEDS10 strains were given, similar numbers of viable bacteria were recovered from the PP and mesenteric lymph nodes on day 3. However, the numbers of foci and the extent of inflammation and necrosis within them were noticeably less for YEDS10 compared to the parental strain. Together these findings suggest that Y. enterocolitica produces a phospholipase A which has a role in pathogenesis.

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Identification of Attenuated Yersinia pseudotuberculosis Strains and Characterization of an Orogastric Infection in BALB/c Mice on Day 5 Postinfection by Signature-Tagged Mutagenesis

Infection and Immunity ◽

10.1128/iai.67.5.2779-2787.2001 ◽

2001 ◽

Vol 69 (5) ◽

pp. 2779-2787 ◽

Cited By ~ 90

Author(s):

Joan Mecsas ◽

Inna Bilis ◽

Stanley Falkow

Keyword(s):

Gastrointestinal Tract ◽

Lymph Nodes ◽

Yersinia Pseudotuberculosis ◽

Proximal Colon ◽

Host Cells ◽

Wild Type ◽

Mesenteric Lymph Nodes ◽

Host Animal ◽

Gene Encoding ◽

Mesenteric Lymph

ABSTRACT Yersinia pseudotuberculosis localizes to the distal ileum, cecum, and proximal colon of the gastrointestinal tract after oral infection. Using signature-tagged mutagenesis, we isolated 13Y. pseudotuberculosis mutants that failed to survive in the cecum of mice after orogastric inoculation. Twelve of these mutants were also attenuated for replication in the spleen after intraperitoneal infection, whereas one strain, mutated the gene encoding invasin, replicated as well as wild-type bacteria in the spleen. Several mutations were in operons encoding components of the type III secretion system, including components involved in translocating Yop proteins into host cells. This indicates that one or more Yops may be necessary for survival in the gastrointestinal tract. Three mutants were defective in O-antigen biosynthesis; these mutants were also unable to invade epithelial cells as efficiently as wild-typeY. pseudotuberculosis. Several other mutations were in genes that had not previously been associated with growth in a host, including cls, ksgA, and sufl. In addition, using Y. pseudotuberculosis strains marked with signature tags, we counted the number of different bacterial clones that were present in the cecum, mesenteric lymph nodes, and spleen 5 days postinfection. We find barriers in the host animal that limit the number of bacteria that succeed in reaching and/or replicating in the mesenteric lymph nodes and spleen after breaching the gut mucosa.

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Molecular and Phenotypic Analysis of the CS54 Island of Salmonella enterica Serotype Typhimurium: Identification of Intestinal Colonization and Persistence Determinants

Infection and Immunity ◽

10.1128/iai.71.2.629-640.2003 ◽

2003 ◽

Vol 71 (2) ◽

pp. 629-640 ◽

Cited By ~ 105

Author(s):

Robert A. Kingsley ◽

Andrea D. Humphries ◽

Eric H. Weening ◽

Marcel R. de Zoete ◽

Sebastian Winter ◽

...

Keyword(s):

Lymph Nodes ◽

Terminal Ileum ◽

Salmonella Enterica ◽

Open Reading Frames ◽

Peyer's Patches ◽

Peyer’S Patches ◽

Mesenteric Lymph Nodes ◽

Phenotypic Analysis ◽

Mesenteric Lymph ◽

Insertional Inactivation

ABSTRACT The shdA gene is carried on a 25-kb genetic island at centisome 54 (CS54 island) of the Salmonella enterica serotype Typhimurium chromosome. In addition to shdA, the CS54 island of Salmonella serotype Typhimurium strain LT2 contains four open reading frames designated ratA, ratB, sivI, and sivH. DNA hybridization analysis revealed that the CS54 island is comprised of two regions with distinct phylogenetic distribution within the genus Salmonella. Homologues of shdA and ratB were detected only in serotypes of Salmonella enterica subsp. I. In contrast, sequences hybridizing with ratA, sivI, and sivH were present in S. enterica subsp. II and S. bongori in addition to S. enterica subsp. I. Deletion of the ratA and sivI genes did not alter the ability of Salmonella serotype Typhimurium to colonize the organs of mice. Insertional inactivation of the sivH gene resulted in defective colonization of the Peyer's patches of the terminal ileum but normal colonization of the cecum, mesenteric lymph nodes, and spleen. Deletion of the shdA gene resulted in decreased colonization of the cecum and Peyer's patches of the terminal ileum and colonization to a lesser degree in the mesenteric lymph nodes and spleen 5 days post-oral inoculation of mice. A strain containing a deletion in the ratB gene exhibited a defect for the colonization of the cecum but not of the Peyer's patches, mesenteric lymph nodes, and spleen. The shdA and ratB deletion strains exhibited a shedding defect in mice, whereas the sivH deletion strain was shed at numbers similar to the wild type. These data suggest that colonization of the murine cecum is required for efficient fecal shedding in mice.

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Yersinia enterocolitica Invasin-Dependent and Invasin-Independent Mechanisms of Systemic Dissemination

Infection and Immunity ◽

10.1128/iai.73.12.8453-8455.2005 ◽

2005 ◽

Vol 73 (12) ◽

pp. 8453-8455 ◽

Cited By ~ 22

Author(s):

Scott A. Handley ◽

Rodney D. Newberry ◽

Virginia L. Miller

Keyword(s):

Small Intestine ◽

Lymph Nodes ◽

Yersinia Enterocolitica ◽

Peyer's Patches ◽

Peyer’S Patches ◽

Mesenteric Lymph Nodes ◽

Mesenteric Lymph ◽

Systemic Dissemination

ABSTRACT We report here invasin-dependent and invasin-independent mechanisms in which the enteropathogen Yersinia enterocolitica is able to disseminate from the lumen of the small intestine to the spleen. The invasin-dependent route is clearly discernible in mice devoid of intestinal Peyer's patches and mesenteric lymph nodes.

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