Sequence analysis of gyrA and parC homologues of vibrio parahaemolyticus ciprofloxacin resistant mutants from patients and enviroment

Abstract

Vibrio parahaemolyticus is a marine bacteria which can cause gastroenteritis through seafood consumption with antimicrobial therapy is needed in some cases. Seventy isolates of Vibrio parahaemolyticus from several aquatic sources were obtained from Chonburi and Suratthani province in March 2000. Antimicrobial susceptibility test tot ciprofloxacin has revealed 21 environmental Vibrio parahaemolyticus isolates, which have MIC≥ 1µg/ml, consisting of 15 sediment isolates and 6 shrimp isolates with the highest MIC values 8 µg/ml of shrimp isolate from Chonburi province. Nucleotide sequence analysis in gyrA and parC QRDR have showed the mutations in gyrA of 19 isolates at codon 83 resulting in amino acid substitution from Ser to Leu. The mutations in parC were found in 20 isolates at codon 85 resulting in amino acid substitution from Ser to Phe. However, the MIC range which have caused the mutations in parC found in Vibrio parahaemolyticus from natural sources were not corresponded to previous study by Okuda et al. which have done in laboratory-induced ciprofloxacin resistant Vibrio parahaemolyticus.