Prevalence of plasmid-mediated quinolone-resistance determinants in Shigella flexneri isolates from Anhui Province, China

Abstract

Quinolones are used extensively to treat Shigella flexneri infection, and plasmid-mediated quinolone resistance (PMQR) determinants were recently reported. A total of 26 S. flexneri isolates collected from Anhui province, China, in 2005 were screened for PMQR determinants, bla gene, gyrA and parC genes, by PCR and sequencing. PMQR determinants were present in 53.8% (14 of 26) of isolates and qnrA 1 , qnrS 1 , qnrS 2 , aac(6¢)-Ib-cr and qepA were present in 30.8, 11.5, 3.8, 19.2 and 11.5% of those isolates, respectively. All PMQR determinants' positive isolates exhibiting 8 different genetic clones had mutations in gyrA and parC genes, and 11 carried bla genes, including 7 bla CTXÀM with resistance to cefotaxime. These isolates were resistant to nalidixic acid and 57.1% (8 of 14) of them were resistant to ciprofloxacin and levofloxacin. Our data show that there was a high prevalence of PMQR determinants in S. flexneri isolates from China.

Should School-Age Children Not Attending School and Adults Aged 20-44 Years Be Considered High-Risk Group for Bacillary Dysentery Infection in Guangzhou, China? A Review of 4775 Bacillary Dysentery Cases

“…This result is consistent with the study from some Chinese cities/provinces, such as Henan 5 , Anhui 13 , and Hangzhou 7 where IIDSPCP was also implemented by the government. However, our results implied that the same or even more attention should be given to school-age children not attending school, since they have become the noticeable infected occupational group in Guangzhou, a trend that appears to have increased over the years.…”

Prevalence of plasmid-mediated quinolone resistance determinants in association with β-lactamases, 16S rRNA methylase genes and integrons amongst clinical isolates of Shigella flexneri

“…qnrS was the most frequent allele (4/125, 3.2 %) of the qnr genes, followed by qnrB, which was identified in two (1.6 %) of the 125 S. flexneri isolates. However, qnrA, which was reported to be the most common qnr allele among the S. flexneri isolates in China (Xiong et al, 2010), was not found. In this study, all three qnrS2-positive isolates belonged to PFGE cluster B, indicating that clonal spread was responsible for the dissemination of the qnrS2 gene amongst the S. flexneri isolates.…”

“…Quinolones are among the most important antibacterial agents used extensively for the treatment of shigellosis. Recently, quinolone resistance has been rising among Shigella isolates (Xiong et al, 2010). Quinolone resistance mainly results from chromosomal mutations in the quinolone resistance-determining regions (QRDRs) of DNA gyrase and topoisomerase IV (Dutta et al, 2005).…”

“…The susceptibility of the 125 isolates to 16 antimicrobial agents was determined by the agar dilution method, according to the guidelines of the Clinical and Laboratory Standards Institute (CLSI, 2010). All clinical Shigella isolates were screened for the presence of qnr, aac(69)-Ib-cr and qepA genes using the methods described previously (Xiong et al, 2010;Yamane et al, 2007). Different blactamases genes, plasmid-borne bla AmpC , 16S rRNA methylase genes, integrons and mutations in the QRDRs were analysed by PCR for the PMQR-positive isolates (Dallenne et al, 2010;Doi & Arakawa, 2007;Hu et al, 2011;Dutta et al, 2005).…”

Prevalence and Characterization of Human Shigella Infections in Henan Province, China, in 2006

“…All of these belonged to the bla CTX-M-2 group (1). In 2004, a bla TEM-116 isolate from Zhengzhou, Henan Province, China, was obtained from a chicken (10), and human bla CTX strains were isolated in 2005 from Anhui Province, China (29). In 2006, four cases of shigellosis due to isolates harboring bla CTX-M-15 were described in New Zealand (25).…”