Inside our jurisdiction the Aptima Combo 2 assay (Gen-Probe Inc. using

Inside our jurisdiction the Aptima Combo 2 assay (Gen-Probe Inc. using nucleic acid extracts of specimens sent for Aptima testing. Thirty-four samples submitted for both Aptima testing and culture from the same anatomic location (within 24 h) were included in the study. Sequence type was determined based on the sequence of the and genes and amino acid changes in the PBP 2 protein encoded by the RS-127445 gene were considered representative for the assessment of antimicrobial susceptibility. Sequence identity of 100% was observed between the sequences obtained from Aptima-analyzed samples and culture samples. Sequencing results showed an association between decreased susceptibility to extended-spectrum cephalosporins (ESCds) allele 110 ST 1407 and amino acid changes (G545S I312M and V316T) in the PBP 2 protein. Our data generated based on a few representative genes suggest that gonococcal samples positive by Aptima testing can be used to determine single nucleotide polymorphisms associated with ESCds and the sequence type based on molecular strain typing. Confirmation of these findings may obviate the need for gonorrhea culture in the future. INTRODUCTION is a common Rabbit polyclonal to ANAPC10. sexually transmitted infection that affects mucosal surfaces and causes a spectrum of conditions including urethritis endocervicitis pelvic inflammatory disease and infertility (1). Over the years gonococci have developed resistance to multiple classes of antibiotics including penicillins tetracyclines macrolides and quinolones (2). Of recent concern is a RS-127445 steady increase in the MICs to extended-spectrum cephalosporins including cefixime and ceftriaxone in several countries including Canada with reported levels at 0.12 μg/ml one doubling dilution away from the Clinical and Laboratory Standards Institute (CLSI) limit of 0.25 μg/ml for susceptibility (3-7; CLSI standard M100-S23 January 2013). According to a recent U.S. Centers for Disease Control and Prevention (CDC) update untreatable gonorrhea could soon be a reality in the United States ( The agency noted that seems RS-127445 to be developing resistance to the oral antibiotic cefixime and it no longer recommends cefixime at any dose as a first-line regimen for treatment of RS-127445 gonococcal infections. The recent isolation of two extensively ceftriaxone-resistant strains in Japan and France (4 8 intensified these concerns. A comprehensive understanding of the prevalence of decreased susceptibility to extended-spectrum cephalosporins (ESCds) and the sequence types (ST) of circulating strains within patient populations may help to guide key decisions in planning for the management of testing is routinely done by molecular methods alone and the lack of culture has made routine susceptibility testing and strain analysis impossible. In our laboratory molecular testing for is performed using the FDA-approved Aptima Combo 2 assay (Gen-Probe Inc. San Diego CA) (9). Our laboratory also receives specimens from the sentinel surveillance clinics in the province (two sexually transmitted infections [STI] clinics) where additional swabs are collected for culture and the isolates are used for susceptibility testing and strain analysis. One key concern is that the shift to molecular testing for diagnosis and the availability of limited numbers of specimens for culture may lead to biases in our understanding of antimicrobial susceptibility patterns and circulating strains in the populations not attending sentinel surveillance sites or not having cultures prepared from clinical specimens. One approach is to utilize specimens that test positive by a molecular method for further analysis of antimicrobial resistance and strain typing. Several RS-127445 studies have shown that accumulation of mutations in chromosomal genes can lead to the phenotype of ESCds. The genes studied include allele have been significantly associated with ESCds in (4 12 13 PBP 2 is a membrane-bound enzyme involved in cell wall synthesis and mutations in different positions may result in various extents of increased MICs. Several reports have suggested that the resistant strains are largely clonal and contain specific PBP 2 mosaic patterns such as type XXXIV RS-127445 (3). Sequence type 1407 based on the and genes has also been associated with ESCds (14 15 In this study we evaluated samples submitted for.