Asunto(s)
Proteínas Fimbrias/genética , Vibrio cholerae O1/genética , Vibrio cholerae O1/aislamiento & purificación , Técnicas Bacteriológicas/métodos , ADN Bacteriano/química , ADN Bacteriano/genética , Genotipo , Humanos , India , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa/métodos , Análisis de Secuencia de ADNRESUMEN
A PCR-based assay was developed to discriminate the classical, El Tor, and Haitian types of ctxB alleles. Our retrospective study using this newly developed PCR showed that Haitian ctxB first appeared in Kolkata during April 2006, and 93.3% of strains isolated during 2011 carried the new allele. Dendrogram analysis showed a pulsed-field gel electrophoresis (PFGE) pattern of the new variant strains isolated recently that was distinct from the PFGE pattern of the strains carrying classical ctxB that closely matched the 2006 to 2007 variant strains.
Asunto(s)
Toxina del Cólera/genética , Cólera/microbiología , Reacción en Cadena de la Polimerasa/métodos , Vibrio cholerae O1/clasificación , Vibrio cholerae O1/genética , Análisis por Conglomerados , ADN Bacteriano/química , ADN Bacteriano/genética , Electroforesis en Gel de Campo Pulsado , Humanos , India , Datos de Secuencia Molecular , Tipificación Molecular , Estudios Retrospectivos , Análisis de Secuencia de ADN , Vibrio cholerae O1/aislamiento & purificaciónRESUMEN
The incidence rates of travelers' diarrhea (TD) have remained high for the last 50 years. More recently, there have been increasing recommendations for self-initiated therapy and use of prophylactic drugs for TD. We last examined the in vitro susceptibilities of commonly used antibiotics against TD pathogens in 1997. We now examine 456 enteropathogens isolated from adult travelers to Mexico, India, and Guatemala with diarrhea acquired between 2006 and 2008 to determine changes in susceptibility against 10 different antimicrobials by the agar dilution method. Traditional antibiotics, such as ampicillin, trimethoprim-sulfamethoxazole, and doxycycline, continue to show high levels of resistance. Current first-line antibiotic agents, including fluoroquinolones and azithromycin, showed significantly higher MICs than in our earlier study, and MIC(90) levels were above the Clinical and Laboratory Standards Institute cutoffs for resistance. There were significant geographical differences in resistance patterns when Central America was compared with India. Entertoxigenic Escherichia coli (ETEC) isolates showed increased resistance to ciprofloxacin (P = 0.023) and levofloxacin (P = 0.0078) in India compared with Central America. Enteroaggregative E. coli (EAEC) isolates from Central America showed increased resistance to nearly all of the antibiotics tested. Compared to MICs of isolates 10 years prior, there were 4- to 10-fold increases in MIC(90) values for ceftriaxone, ciprofloxacin, levofloxacin, and azithromycin for both ETEC and EAEC. There were no significant changes in rifaximin MICs. Rising MICs over time imply the need for continuous surveillance of susceptibility patterns worldwide and geographically specific recommendations in TD therapy.
Asunto(s)
Antibacterianos/farmacología , Diarrea/microbiología , Bacterias Gramnegativas/efectos de los fármacos , Viaje , Adolescente , Adulto , Azitromicina/farmacología , Ciprofloxacina/farmacología , Farmacorresistencia Bacteriana , Escherichia coli Enterotoxigénica/efectos de los fármacos , Escherichia coli Enterotoxigénica/aislamiento & purificación , Escherichia coli/efectos de los fármacos , Escherichia coli/aislamiento & purificación , Bacterias Gramnegativas/aislamiento & purificación , Infecciones por Bacterias Gramnegativas/microbiología , Guatemala , Humanos , India , México , Pruebas de Sensibilidad Microbiana , Rifamicinas/farmacología , RifaximinaRESUMEN
This study examined established enteric pathogens, Arcobacter species and enterotoxigenic Bacteroides fragilis (ETBF), in 201 U.S. and European travelers with acute diarrhea acquired in Mexico, Guatemala, and India. Arcobacter butzleri and ETBF were detected in 8% and 7% of diarrhea cases, respectively.