[Bacteremia caused by Vibrio cholerae non-O1/non-O139 carrying a region homologous to pathogenicity island VpaI-7]. / Bacteriemia por Vibrio cholerae no-O1/no-O139 que porta una región homóloga a la isla de patogenicidad VpaI-7.

We report a case of V. cholerae non-O1 / non-O139 bacteremia in an 81-year-old woman with abdominal pain, fever, vomiting, liquid stools, choluria and jaundice, while visiting a rural area without access to potable water. The identification was made by the MALDI-TOF mass spectrometry technique and subsequently the non-toxigenic non-O1 / non-139 strain was confirmed in the national reference laboratory. The molecular characterization demonstrated the absence of the cholera toxin gene (CTX), and the TCP pilus, however, presented 5 of 6 virulence genes present in an island of homologous pathogenicity named VPaI-7 of V. parahaemolyticus (vcs N2 +, vcs C2 +, vcs V2 +, toxR-, vspD +, T vopF +) and in addition it was positive for hylAy rtxA virulence genes recognized outside the island. This is the first case reported in Chile of a clinical strain of V. cholerae non-O1, non-O139 isolated from blood culture that carries in its genome a homologous segment of the pathogenicity island named VPaI-7 of V. parahaemolyticus, which codifies for a type III secretion system (TTSS) that probably contributes to his virulence.

Bacteriemia por Vibrio cholerae no-O1/no-O139 que porta una región homóloga a la isla de patogenicidad VpaI-7 / Bacteremia caused by Vibrio cholerae non-O1/non-O139 carrying a region homologous to pathogenicity island VpaI-7

Resumen Presentamos un caso de bacteriemia por Vibrio cholerae no-O1/ no-O139 en una mujer de 81 años con un cuadro de dolor abdominal, fiebre, vómitos, diarrea, coluria e ictericia, mientras visitaba una zona rural sin acceso a agua potable. La identificación se realizó por la técnica de espectrometría de masa MALDI-TOF, confirmándose una cepa no toxigénica no-O1/no-139. La caracterización molecular del aislado demostró la ausencia del gen de la toxina del cólera (CTX), y pilus TCP; sin embargo, presentó cinco de los seis genes de virulencia presentes en la isla de patogenicidad homóloga denominada VPaI-7 del V. parahaemolyticus (vcs N2+, vcs C2+, vcs V2+,toxR-, vspD+, T vopF+). Además, el aislado presentó los genes de virulencia hylA y rtxA. Este es el primer caso reportado en Chile de una cepa clínica de V. cholerae no-O1, no-O139 aislada de hemocultivos portador de un segmento homólogo de la isla de patogenicidad denominada VPaI-7 de V. parahaemolyticus, el cual codifica para un sistema de secreción tipo III (TTSS), que probablemente contribuye a su virulencia.

We report a case of V. cholerae non-O1 / non-O139 bacteremia in an 81-year-old woman with abdominal pain, fever, vomiting, liquid stools, choluria and jaundice, while visiting a rural area without access to potable water. The identification was made by the MALDI-TOF mass spectrometry technique and subsequently the non-toxigenic non-O1 / non-139 strain was confirmed in the national reference laboratory. The molecular characterization demonstrated the absence of the cholera toxin gene (CTX), and the TCP pilus, however, presented 5 of 6 virulence genes present in an island of homologous pathogenicity named VPaI-7 of V. parahaemolyticus (vcs N2 +, vcs C2 +, vcs V2 +, toxR-, vspD +, T vopF +) and in addition it was positive for hylAy rtxA virulence genes recognized outside the island. This is the first case reported in Chile of a clinical strain of V. cholerae non-O1, non-O139 isolated from blood culture that carries in its genome a homologous segment of the pathogenicity island named VPaI-7 of V. parahaemolyticus, which codifies for a type III secretion system (TTSS) that probably contributes to his virulence.

[Evaluation of toxin producing abilities of non-O1/non-O139 serogroup Vibrio cholerae isolated from humans].

AIM: Determination of non-O1/non-O139 Vibrio cholerae toxin (CT) gene expression by using EIA, and biological effect of non-O1/non-O139 V. cholerae supernatant on cell cultures evaluation. MATERIALS AND METHODS: 39 V. cholerae strains from various serological groups were studied. Hemolytic activity of strains was determined by using Greig test, and cholera toxin production--in GM1-EIA and in continuous cell lines by registering cytotonic, cytotoxic and proteolitic effect. RESULTS: GM1-EIA method does not detect CT production in 29 museum strains of non-O1/non-O139 V. cholerae in vitro. CT was detected only in 1 non-O1/non-O139 V. cholerae strain supernatant with OD = 0.577 that is substantially lower than in O1 V. cholerae strains (OD = 2.176). In cell cultures non-O1/non-O139 V. cholerae supernatants diluted to 1:100 caused elongation only in single cells. CONCLUSION: Cytological model is a more sensitive technique to evaluate toxin producing abilities of non-O1/non-O139 V. cholerae strains and is appropriate for use.

Gene cloning and characterization of four MATE family multidrug efflux pumps from Vibrio cholerae non-O1.

There are six putative genes for multidrug and toxic compound extrusion (MATE) family multidrug efflux pumps in the chromosome of Vibrio cholerae. We have so far analyzed two MATE family pumps in V. cholerae non-O1 NCTC4716. Here we cloned four remaining genes for putative MATE family efflux pumps by the PCR method from this microorganism and designated them as vcmB, vcmD, vcmH and vcmN. Each one of the four genes was introduced and expressed in the drug hypersusceptible host Escherichia coli KAM32 cells. We observed elevated MICs of multiple antimicrobial agents, such as fluoroquinolones, aminoglycosides, ethidium bromide and Hoechst 33342 in the transformants. Energydependent efflux of substrate was observed with the transformed cells. We found that efflux activities of VcmB, VcmD and VcmH were Na+-dependent, but that of VcmN was Na+-independent. Thus, all six of the MATE family multidrug efflux pumps of V. cholerae non-O1 have been characterized. We also found that all six genes were expressed in cells of V. cholerae non-O1.