Caracterización de aislamientos de Vibrio cholerae no-O1, no-O139 asociados a cuadros de diarrea / Characterization of Vibrio cholerae non-O1 and non-O139 isolates associated with diarrhea

La infección por Vibrio cholerae, el agente causal del cólera, se trasmite al hombre por ingestión de agua y alimentos contaminados. Aunque son los serogrupos O1 y O139 los que habitualmente se asocian al cólera epidémico, los aislamientos de otros serogrupos también son causales de gastroenteritis e infecciones extra-intestinales. Durante el período 2003-2005, se investigó la presencia de V. cholerae en la materia fecal de niños con diarrea atendidos en el Hospital del Niño Jesús, Tucumán. Se recuperaron 34 aislamientos de V. cholerae no-O1, no-O139. Se determinaron sus perfiles de virulencia por PCR, la sensibilidad a los antimicrobianos y la diversidad genética por electroforesis en campo pulsado. Se obtuvieron ocho perfiles de virulencia, aunque ningún aislamiento fue positivo para la toxina colérica ni para la toxina termoestable. Cuatro aislamientos fueron positivos para el sistema de secreción de tipo tres. El 17,6% de los aislamientos fueron resistentes o de sensibilidad intermedia a ampicilina y el 5,9% fueron resistentes a trimetoprima-sulfametoxazol. Los aislamientos resultaron muy diversos: se hallaron 27 patrones distintos en 29 aislamientos tipificables por electroforesis en campo pulsado. A pesar de su baja incidencia, V. cholerae continúa siendo un agente causal de diarrea en niños, los que se ven afectados por una amplia variedad de cepas circulantes.

Vibrio cholerae, etiologic agent of cholera, is transmitted to humans by ingestion of contaminated food or water. Even though serogroups O1 and O139 are the ones usually associated to epidemic cholera, isolates from other serogroups also cause gastroenteritis and extraintestinal infections. During the period 2003-2005, presence of V. cholerae in stools was investigated in children with diarrhea that seaked assistance at the Niño Jesús Hospital in Tucumán. Thirty four isolates of V. cholerae non-O1, non-O139 were recovered. We characterized the isolates studying its virulence factors by PCR, antimicrobial susceptibility patterns and genetic diversity by pulsed-field gel electrophoresis. Eight virulence patterns were obtained although no isolate was positive for the cholera toxin or the thermostable toxin. Four isolates were positive for the type three secretion system. The 17.6% of the isolates were resistant or intermediate to ampicillin and 5.9% were resistant to trimethoprim-sulfamethoxazole. By SfiI-PFGE, all isolates were genetically very diverse, as 27 different patterns were identified in 29 typeable isolates by pulsed-field gel electrophoresis. Although it has a low incidence, V. cholerae continues to be a causative agent of diarrhea in children, who are affected by a variety of circulating strains of V. cholerae non-O1, non-O139.

Non-O1/non-O139 Vibrio cholerae septicemia with peritonitis.

A 67-year-old Thai female with alcoholic cirrhosis presented with fever and abdominal pain for 5 days. On examination, there was marked ascites with generalized abdominal tenderness. The result of ascitic fluid analysis showed yellow turbid fluid, a WBC count of 6,100 cells/mm3 with polymorphonucleocytes predominant. Blood cultures yielded non-O1/ non-O139 Vibrio cholerae. The patient improved gradually and recovered fully after 1 week of parenteral antibiotic.

A cólera no Estado do Rio Grande do Norte--Brasil--perfil sorológico e de sensibilidade do Vibrio cholerae a diferentes antimicrobianos / Cholera in Rio Grande do Norte State--Brazil: sorology and sensitivity of Vibrio cholerae to different antimicrobials

PURPOSE: The emergence of multiple resistance to antimicrobials in Vibrio cholerae isolated in the state of Ceará, Brazil, alerted researchers in this area to the sensitivity to antimicrobials of strains isolated in Rio Grande do Norte (RN), Brazil. METHODS: One hundred and four strains of V. cholerae of human origin, isolated by Laboratório Central de Saúde Pública Dr. Almino Fernandes, were serologically typified and evaluated for in vitro sensitivity to eight antibiotics belonging to different groups (polymyxine, tetracycline, chloramphenicol, nitrofurantoin, sulphazotrin, pefloxacine, erythromycine, ampicillin). The strains were collected from patients suspected of contracting choleric diarrhea in the year 1999, in Natal/RN/Brazil. RESULTS: From the sample total, 100 were identified as V. cholerae, serogroup O:1, biotype El Tor, with 99 (95.3%) belonging to serovar Ogawa and only 1 (0.9%) to serovar Inaba. The 4 remaining were characterized as non O:1 V. cholerae, with 3 (2.9%) biochemically identified as Heiberg type I and 1 (0.9%) as type II. All the V. cholerae serogroup O:1 strains were sensitive to tetracycline, chloramphenicol, sulphazotrin, pefloxacine, erythromycine and resistant to polymyxine. In relation to nitrofurantoin, only 1 was sensitive. Only 1 was resistant to ampicillin. The non O:1 V. cholerae strains were resistant to polymyxine. CONCLUSIONS: The results showed sensitivity in 100% of the V. cholerae serogroup O:1 strains to tetracycline, an elective drug in the treatment of cholera, and an absence of multiple resistant strains in our environment. An interesting finding was the frequency of serovar Ogawa in 1999, considering the greater incidence of serovar Inaba in other years of cholera outbreaks in RN.