TY - JOUR
T1 - Fluoroquinolone resistance mechanisms of Shigella flexneri isolated in Bangladesh
AU - Azmi, Ishrat J.
AU - Khajanchi, Bijay K.
AU - Akter, Fatema
AU - Hasan, Trisheeta N.
AU - Shahnaij, Mohammad
AU - Akter, Mahmuda
AU - Banik, Atanu
AU - Sultana, Halima
AU - Hossain, Mohammad A.
AU - Ahmed, Mohammad K.
AU - Faruque, Shah M.
AU - Talukder, Kaisar A.
N1 - Copyright:
Copyright 2014 Elsevier B.V., All rights reserved.
PY - 2014/7/16
Y1 - 2014/7/16
N2 - Objective: To investigate the prevalence and mechanisms of fluoroquinolone resistance in Shigella species isolated in Bangladesh and to compare with similar strains isolated in China. Methods: A total of 3789 Shigella isolates collected from Clinical Microbiology Laboratory of icddr,b, during 2004-2010 were analyzed for antibiotic susceptibility. Analysis of plasmids, plasmid-mediated quinolone-resistance genes, PFGE, and sequencing of genes of the quinolone-resistance-determining regions (QRDR) were conducted in representative strains isolated in Bangladesh and compared with strains isolated in Zhengding, China. In addition, the role of efflux-pump was studied by using the efflux-pump inhibitor carbonyl cyanide-m-chlorophenylhydrazone (CCCP). Results: Resistance to ciprofloxacin in Shigella species increased from 0% in 2004 to 44% in 2010 and S. flexneri was the predominant species. Of Shigella spp, ciprofloxacin resistant (CipR) strains were mostly found among S. flexneri (8.3%), followed by S. sonnei (1.5%). Within S. flexneri (n = 2181), 14.5% were resistance to ciprofloxacin of which serotype 2a was predominant (96%). MIC of ciprofloxacin, norfloxacin, and ofloxacin were 6-32 mg/L, 8-32 mg/L, and 8-24 mg/L, respectively in S. flexneri 2a isolates. Sequencing of QRDR genes of resistant isolates showed double mutations in gyrA gene (Ser 83Leu, Asp87Asn/Gly) and single mutation in parC gene (Ser80Ile). A difference in amino acid substitution at position 87 was found between strains isolated in Bangladesh (Asp87Asn) and China (Asp87Gly) except for one. A novel mutation at position 211 (His→Tyr) in gyrA gene was detected only in the Bangladeshi strains. Susceptibility to ciprofloxacin was increased by the presence of CCCP indicating the involvement of energy dependent active efflux pumps. A single PFGE type was found in isolates from Bangladesh and China suggesting their genetic relatedness. Conclusions: Emergence of fluoroquinolone resistance in Shigella undermines a major challenge in current treatment strategies which needs to be followed up by using empirical therapeutic strategies.
AB - Objective: To investigate the prevalence and mechanisms of fluoroquinolone resistance in Shigella species isolated in Bangladesh and to compare with similar strains isolated in China. Methods: A total of 3789 Shigella isolates collected from Clinical Microbiology Laboratory of icddr,b, during 2004-2010 were analyzed for antibiotic susceptibility. Analysis of plasmids, plasmid-mediated quinolone-resistance genes, PFGE, and sequencing of genes of the quinolone-resistance-determining regions (QRDR) were conducted in representative strains isolated in Bangladesh and compared with strains isolated in Zhengding, China. In addition, the role of efflux-pump was studied by using the efflux-pump inhibitor carbonyl cyanide-m-chlorophenylhydrazone (CCCP). Results: Resistance to ciprofloxacin in Shigella species increased from 0% in 2004 to 44% in 2010 and S. flexneri was the predominant species. Of Shigella spp, ciprofloxacin resistant (CipR) strains were mostly found among S. flexneri (8.3%), followed by S. sonnei (1.5%). Within S. flexneri (n = 2181), 14.5% were resistance to ciprofloxacin of which serotype 2a was predominant (96%). MIC of ciprofloxacin, norfloxacin, and ofloxacin were 6-32 mg/L, 8-32 mg/L, and 8-24 mg/L, respectively in S. flexneri 2a isolates. Sequencing of QRDR genes of resistant isolates showed double mutations in gyrA gene (Ser 83Leu, Asp87Asn/Gly) and single mutation in parC gene (Ser80Ile). A difference in amino acid substitution at position 87 was found between strains isolated in Bangladesh (Asp87Asn) and China (Asp87Gly) except for one. A novel mutation at position 211 (His→Tyr) in gyrA gene was detected only in the Bangladeshi strains. Susceptibility to ciprofloxacin was increased by the presence of CCCP indicating the involvement of energy dependent active efflux pumps. A single PFGE type was found in isolates from Bangladesh and China suggesting their genetic relatedness. Conclusions: Emergence of fluoroquinolone resistance in Shigella undermines a major challenge in current treatment strategies which needs to be followed up by using empirical therapeutic strategies.
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U2 - 10.1371/journal.pone.0102533
DO - 10.1371/journal.pone.0102533
M3 - Article
C2 - 25028972
AN - SCOPUS:84904364913
VL - 9
JO - PLoS One
JF - PLoS One
SN - 1932-6203
IS - 7
M1 - e102533
ER -