Pitout Johann D D, Wei Yi, Church Deirdre L, Gregson Daniel B
Division of Microbiology, Calgary Laboratory Services, University of Calgary, #9, 3535 Research Road NW, Calgary, Alberta, Canada T2L 2K8.
J Antimicrob Chemother. 2008 May;61(5):999-1002. doi: 10.1093/jac/dkn068. Epub 2008 Feb 21.
A study was designed to determine the prevalence of plasmid-mediated quinolone resistance (PMQR) determinants among clinical isolates of Enterobacteriaceae from the Calgary Health Region (CHR).
During January and February 2004 and January and February 2007, 564 non-repeat isolates of Escherichia coli, Klebsiella spp., Proteus mirabilis and Morganella morganii resistant to ciprofloxacin and/or tobramycin were screened for PMQR determinants using a multiplex PCR for qnrA, qnrS and qnrB and aac(6')-Ib genes; aac(6')-Ib-cr was further identified by digestion with BstF5I.
In 2004, 6/139 (4%) of the resistant E. coli were positive for aac(6')-Ib-cr. In 2007, 53/398 (13%) were positive for aac(6')-Ib-cr, 3/398 (0.8%) were positive for qnrS, and one isolate was positive for both. All the isolates were present in urines and the majority [40/63 (63%)] were submitted from community collection sites; 8 (13%) isolates co-produced AmpC beta-lactamases and 34 (54%) co-produced CTX-M-15. aac(6')-Ib-cr was present in one Klebsiella pneumoniae and one P. mirabilis, whereas one isolate of K. pneumoniae was positive for both aac(6')-Ib-cr and qnrB.
Our results showed that isolates with aac(6')-Ib-cr, often associated with CTX-M-15, are emerging among fluoroquinolone-resistant E. coli in the CHR. Our study suggests that surveillance for PMQR determinants should be undertaken on a regular basis.
开展一项研究以确定卡尔加里健康区域（CHR）肠杆菌科临床分离株中质粒介导喹诺酮耐药（PMQR）决定簇的流行情况。
在2004年1月和2月以及2007年1月和2月期间，对564株对环丙沙星和/或妥布霉素耐药的大肠埃希菌、克雷伯菌属、奇异变形杆菌和摩根摩根菌的非重复分离株，使用针对qnrA、qnrS和qnrB以及aac(6')-Ib基因的多重PCR筛选PMQR决定簇；通过用BstF5I酶切进一步鉴定aac(6')-Ib-cr。
2004年，6/139（4%）耐药大肠埃希菌的aac(6')-Ib-cr呈阳性。2007年，53/398（13%）的aac(6')-Ib-cr呈阳性，3/398（0.8%）的qnrS呈阳性，1株分离株两者均呈阳性。所有分离株均存在于尿液中，大多数[40/63（63%）]来自社区采集点；8株（13%）分离株共同产生AmpCβ-内酰胺酶，34株（54%）共同产生CTX-M-15。1株肺炎克雷伯菌和1株奇异变形杆菌存在aac(6')-Ib-cr，而1株肺炎克雷伯菌分离株的aac(6')-Ib-cr和qnrB均呈阳性。
我们的结果表明，携带aac(6')-Ib-cr且常与CTX-M-15相关的分离株正在CHR的耐氟喹诺酮大肠埃希菌中出现。我们的研究表明应定期对PMQR决定簇进行监测。
