Susceptibilidad antimicrobiana en aislamientos cubanos de Vibrio cholerae O1 procedentes de muestras clínicas / Antimicrobial susceptibility in Cuban isolates of Vibrio cholerae O1 obtained from clinical samples

Introducción: la re-emergencia de cólera en Haití estableció un nuevo reservorio para el incremento de la séptima pandemia. Esto provocó su diseminación a República Dominicana y a otros países de la región del Caribe, como Cuba y México. Objetivo: estudiar la susceptibilidad antimicrobiana de aislamientos de Vibrio cholerae O1, serotipo Ogawa, biotipo El Tor aisladas de pacientes durante el evento epidemiológico de cólera ocurrido en Cuba entre junio de 2012 y agosto de 2013. Métodos: se realizó el estudio de la susceptibilidad antimicrobiana in vitro en 144 aislamientos de V. cholerae, mediante el método de Bauer-Kirby frente a nueve antimicrobianos: ampicilina, sulfonamida, trimetoprim/sulfametoxazol, cloranfenicol, tetraciclina, doxiciclina, azitromicina, ciprofloxacina y gentamicina, según las normas del Instituto de Estándares de Laboratorio Clínico de los Estados Unidos de América. Resultados: el total de los aislamientos resultaron resistentes al trimetoprim-sulfametoxazol; el 98,7 por ciento lo fue a la sulfonamida y el 90,3 por ciento a la ampicilina. Se obtuvieron valores de sensibilidad intermedia para ciprofloxacina (30,6 por ciento) y cloranfenicol (27,1 por ciento). Se apreciaron niveles de sensibilidad superior al 92 por ciento a los antimicrobianos de primera línea en el tratamiento de la enfermedad (doxiciclina, tetraciclina y azitromicina), así como también a la gentamicina. No se observaron cepas multirresistentes. Conclusiones: los datos aportados por este trabajo demuestran la efectividad in vitro de los antimicrobianos utilizados en el tratamiento la enfermedad diarreica aguda causada por V. cholerae en Cuba(AU)

Introduction: re-emergence of cholera in Haiti created a new reservoir for the increase of the seventh pandemic. This resulted in its spread to the Dominican Republic and other Caribbean countries, such as Cuba and Mexico. Objectives: study the antimicrobial susceptibility of isolates of Vibrio cholerae O1, Ogawa serotype, El Tor biotype, obtained from patients during the cholera epidemiological event occurring in Cuba from June 2012 to August 2013. Methods: a study was conducted of 144 V. cholerae isolates using the Bauer-Kirby method to determine in vitro susceptibility to nine antimicrobials: ampicillin, sulfonamide, trimethoprim/sulfamethoxazole, chloramphenicol, tetracycline, doxycycline, azithromycin, ciprofloxacin and gentamicin, in compliance with standards from the U.S. Clinical and Laboratory Standards Institute. Results: all isolates were resistant to trimethoprim/sulfamethoxazole; 98.7 percent to sulfonamide and 90.3 percent to ampicillin. Intermediate sensitivity values were obtained for ciprofloxacin (30.6 percent) and chloramphenicol (27.1 percent). Sensitivity levels above 92 percent were found for first-line antimicrobials (doxycycline, tetracycline and azithromycin), as well as gentamicin. Multi-drug resistant strains were not found. Conclusions: results reveal the effectiveness in vitro of the antimicrobials used in Cuba to treat acute diarrheal disease caused by V. cholerae(AU)

Hybrid & El Tor variant biotypes of Vibrio cholerae O1 in Thailand.

Background & objectives: El Tor Vibrio cholerae O1 carrying ctxBC trait, so-called El Tor variant that causes more severe symptoms than the prototype El Tor strain, first detected in Bangladesh was later shown to have emerged in India in 1992. Subsequently, similar V. cholerae strains were isolated in other countries in Asia and Africa. Thus, it was of interest to investigate the characteristics of V. cholerae O1 strains isolated chronologically (from 1986 to 2009) in Thailand. Methods: A total of 330 V. cholerae O1 Thailand strains from hospitalized patients with cholera isolated during 1986 to 2009 were subjected to conventional biotyping i.e., susceptibility to polymyxin B, chicken erythrocyte agglutination (CCA) and Voges-Proskauer (VP) test. The presence of ctxA, ctxB, zot, ace, toxR, tcpAC, tcpAE, hlyAC and hlyAE were examined by PCR. Mismatch amplification mutation assay (MAMA) - and conventional- PCRs were used for differentiating ctxB and rstR alleles. Results: All 330 strains carried the El Tor virulence gene signature. Among these, 266 strains were typical El Tor (resistant to 50 units of polymyxin B and positive for CCA and VP test) while 64 had mixed classical and El Tor phenotypes (hybrid biotype). Combined MAMA-PCR and the conventional biotyping methods revealed that 36 strains of 1986-1992 were either typical El Tor, hybrid, El Tor variant or unclassified biotype. The hybrid strains were present during 1986-2004. El Tor variant strains were found in 1992, the same year when the typical El Tor strains disappeared. All 294 strains of 1993-2009 carried ctxBC ; 237 were El Tor variant and 57 were hybrid. Interpretation & conclusions: In Thailand, hybrid V. cholerae O1 (mixed biotypes), was found since 1986. Circulating strains, however, are predominantly El Tor variant (El Tor biotype with ctxBC).

Culture supernatants from V. cholerae O1 ElTor strains isolated from different geographic areas induce cell vacuolation and cytotoxicity / Cepas de V. cholerae O1 biotipo ElTor aisladas de diferente origen geográfico inducen vacuolización celular y citotoxicidad

OBJECTIVE: To investigate whether the HlyA-induced vacuolating effect is produced by V. cholerae O1 ElTor strains isolated from different geographic origins, including Mexico. MATERIAL AND METHODS: Supernatant-induced haemolysis, vacuolating activity and cytotoxicity in Vero cells were recorded. PCR, RFLP analysis and molecular cloning were performed. RESULTS: All ElTor strains analyzed induced cellular vacuolation. Ribotype 2 strains isolates from the U.S. gulf coast yielded the highest titer of vacuolating activity. Eight of nine strains were haemolytic, while all strains were PCR positive for the hlyA gene. We cloned the hlyA gene from two ElTor strains, a toxigenic (2514-88, ctxAB+) and a non-toxigenic Mexican strain (CM 91-3, ctxAB-). Supernatant from those recombinant E. coli strains induced haemolysis, cell vacuolation and cytotoxicity. RFLP-PCR analysis revealed similarities in the hlyA gene from all strains tested. CONCLUSION: The HlyA-induced vacuolating effect is a widespread phenotype of epidemic V. cholerae O1 ElTor strains.

OBJETIVO: Analizar el efecto vacuolizante de cepas de V. cholerae O1 ElTor aisladas de diferente origen geográfico, incluyendo México. MATERIAL Y MÉTODOS: Se realizaron pruebas de hemolisis, vacuolización y citotoxicidad en células Vero, así como PCR, análisis por RFLP y clonación molecular. RESULTADOS: Todas las cepas indujeron el efecto vacuolizante. Las cepas del ribotipo 2, aisladas de las costas del Golfo en Estados Unidos, presentaron títulos altos de vacuolización. El gen hlyA fue amplificado en las nueve cepas mediante PCR, aunque sólo ocho fueron hemolíticas. Se clonó el gen hlyA de una cepa toxigénica (2514-88, ctxAB+) y de una cepa no toxigénica aislada en México (CM 91-3, ctxAB-). El sobrenadante de las clonas recombinantes indujo hemólisis, efecto vacuolizante y citotoxicidad. El RFLP mostró alta similitud del gen hlyA de las cepas estudiadas. CONCLUSIÓN: El efecto vacuolizante es un fenotipo ampliamente distribuido en cepas epidémicas de V. cholerae O1 biotipo ElTor.

Detection of viable and viable nonculturable Vibrio cholerae O1 through cultures and immunofluorescence in the Tucumán rivers, Argentina

Vibrio cholerae has been sporadically isolated from rivers in Tucumán, Argentina, since the outbreak in 1991. The aim of this study was to determine the environmental reservoir of the bacterium in these rivers, assessing the presence of Vibrio cholerae non-O1 and O1 (the latter both in its viable culturable and non culturable state) and its relationship to environmental physicochemical variables. 18 water samplings were collected in the Salí River (in Canal Norte and Banda) and the Lules River between 2003 and 2005. Physical-chemical measurements (pH, water temperature, electrical conductivity and dissolved oxygen) were examined. Vibrio cholerae was investigated with conventional culture methods and with Direct Immunofluorescence (DFA-VNC) in order to detect viable non culturable organisms. All isolated microorganisms corresponded to Vibrio cholerae non-O1 and non-O139 (Lules 26 percent, Canal Norte 33 percent and Banda 41 percent). The majority was found during spring and summer and correlated with temperature and pH. Non culturable Vibrio cholerae O1 was detected year round in 38 of the 54 water samples analyzed. Application of the Pearson correlation coefficient revealed that there was no relationship between positive immunofluorescence results and environmental physicochemical parameters. Genes coding for somatic antigen O1 were confirmed in all DFA-VNC-positive samples, whereas the virulence-associated ctxA and tcpA genes were confirmed in 24 samples.

Vibrio cholerae tem sido isolado esporadicamente nos rios da Província de Tucumán, Argentina, desde outubro de 1991. O objetivo deste estudo foi localizar os reservatórios nestes rios, identificar a presença de Vibrio cholerae O1 (em estado cultivável e não cultivável) e relacionar a presença desta bactéria com as variações físico-químicos da água. Foram coletadas dezoito amostras de água do rio Salí (nas localidades de Canal Norte e Banda) e do rio Lules, entre 2003 e 2005. Estas foram submetidas a análises físico-químicos como determinação de pH, temperatura, condutibilidade elétrica e oxigênio dissolvido. A presença de Vibrio cholerae foi verificada por métodos de cultivo convencional e por imunofluorescência direta (DFA-VNC). Todos os microrganismos isolados foram não O1 e não O139 (Lules 26 por cento, Canal Norte 33 por cento e Banda 41 por cento). A maioria foi encontrada na primavera e verão, indicando uma relação com a temperatura e pH. Das 54 amostras analisadas por DFA-VNC, 38 Vibrio cholerae não cultivável, foram detectadas em todas as épocas do ano. As amostras positivas foram confirmadas por PCR para o antígeno somático O1 e para os genes de virulência ctxA e tcpA. Coeficiente de correlação de Pearson revelou que não há relação entre os resultados obtidos por imunofluorescência e a variação dos parâmetros físico-químicos.

Changing profile of Vibrio cholerae O1, O139 in Delhi & its periphery (2003-2005).

BACKGROUND & OBJECTIVE: Cholera caused by either Vibrio cholerae O1 or O139 is endemic in Delhi and its peripheral areas. The present study was carried out to understand the changing epidemiology of V. cholerae in terms of prevalence of serotypes, antibiogram pattern and phage types. METHODS: A total of 9858 stool samples from the admitted diarrhoea patients were used for the isolation of V. cholerae O1 and O139. Subsets of isolates were tested against thirteen antimicrobials and phage typed. RESULTS: Among 4251 (43.1%) confirmed cases, 41.6 per cent were V. cholerae O1 and rest (1.5 %) V. cholerae O139. Detection of V. cholerae O1 serotype Inaba was 87.7 per cent during 2005 and rest were serotype Ogawa. Majority of cases (93.1%) were from Delhi. Male:Female ratio remained 1.5:1.0. Children below 5 yr age group constituted 32.7 per cent cases. Shift in the age groups and seasonal incidence were recorded. All 226 strains of V. cholerae O1 and O139 were resistant to nalidixic acid; 96 per cent V. cholerae O1 isolates were multidrug resistant (FX NA SXT). Phage type 27 (98.7%) was the most prevalent and the new phage types were 4, 16 and 25 in this area. INTERPRETATION & CONCLUSION: Enhanced surveillance helped in bringing down cases from 47.7 per cent in 2003 to 36.8 per cent in 2005. Additionally, the changing epidemiology of V. cholerae O1 and O139 infections and drug resistance need regular monitoring.

Septicemia caused by Vibrio cholerae O1 biotype El Tor, in São Paulo, Brazil

We reported a case of septicemia by Vibrio cholerae O1, in São Paulo, Brazil. A 70-year-old male patient, living in an urban area, entered the emergency service having sepsis, dying 12 hours later. Blood culture was positive for Vibrio cholerae O1. This is the first case of bacteremia by Vibrio cholerae O1 reported in South America.

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.

A recent outbreak of cholera due to Vibrio cholerae O1 Ogawa in & around Chandigarh, North India.

An outbreak of cholera caused by Vibrio cholerae O1 Ogawa occurred in and around Chandigarh during July 22-31, 2002. Of the 303 patients admitted to two hospitals, 82 were confirmed by culture. Two rehabilitation colonies located at the periphery of Chandigarh were mainly affected. The isolates were biotyped as Eltor and were susceptible to many antibiotics. Thirty one (35.2%) of 88 water samples showed evidence of faecal contamination. The survey of the area revealed sewage contamination of the drinking water supply. The outbreak was controlled by providing safe drinking water to the people and correcting the defects in the sewage and water pipelines.

Detección de Vibrio cholerae No 01 en algunos ambientes acuáticos de Colombia / Detection Vibrio cholerae No 01 in some aquatic environment of Colombia

Para detectar Vibrio cholerae spp. ambiental en algunos de las zonas de Colombia donde tuvo lughar la epidemia de 1991 a 1993, se tomaron muestras de agua y se procesaron de acuerdo con los métodos recomendados. A los aislados resultante se les practicaron pruebas bioquímicas, de crecimiento y de susceptibilidad a antibióticos. De las 11 muestras de agua, se seleccionaron de manera preliminar 690 calonias cuyas caracteríticas correspondían a Vibrio Cholerae. La selección definitiva se obtuvieron 4 aislamientos de Vibrio cholerae no 01, provenientes de Tumaco. Estos aislados resultaron resistentes a la mayoría de antbióticos utilizados, no productores de toxina ni con genes que codificaran tal función. La presencia de estos aislados no 01 puede indicar que se están constituyendo reservorios acúaticos, lo cual es un indicador de que el cólera en Colombia está pasando a una fase de endemia.