Salmonella enterica serovar typhi: molecular analysis of strains with decreased susceptibility and resistant to ciprofloxacin in india from 2001-2003

• Autor(a) principal: Capoor,Malini R.
• Data de Publicação: 2007
• Outros Autores: Nair,Deepthi, Aggarwal,Pushpa, Mathys,Vanessa, Dehem,Marie, Bifani,Pablo Juan
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Brazilian Journal of Infectious Diseases
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1413-86702007000400011
• topic: Salmonella enterica; S.Typhi; ciprofloxacin; resistance

Chromosomally-mediated reduced susceptibility to ciprofloxacin narrows the therapeutic options in enteric fever. We made a molecular comparison of clinical isolates of fluoroquinolone-resistant strains of Salmonella enterica serotype Typhi from January 2001 to May 2003; 178 isolates were subjected to antimicrobial susceptibility testing by the Kirby-Bauer method of disk diffusion, and agar dilution was used to determine the minimum inhibitory concentration (MIC) to ciprofloxacin. Nalidixic-acid resistant strains (NARST) were observed in 51% of the isolates, of which 98.9% had decreased susceptibility (MIC>0.125-1µg/mL) to ciprofloxacin. A single strain (4 µg/mL) was resistant to ciprofloxacin and double mutations were found in the gyrA gene (76 Asp->Asn, 44 leu->Ileu). Among seven NARST strains with reduced susceptibility, a single mutation was found in five strains, one of which had 76 Asp->Asn and two each had mutations at 87 Asp->Asn and 72 Phe->Tyr, respectively); no mutations could be detected in two isolates. Routine antimicrobial surveillance, coupled with molecular analysis of fluoroquinolone resistance, is crucial for revision of enteric fever therapeutics.