title: Evaluation of an expanded microarray for detecting antibiotic resistance genes in a broad range of gram-negative bacterial pathogens.
abstract: A microarray capable of detecting genes for resistance to 75 clinically relevant antibiotics encompassing 19 different antimicrobial classes was tested on 132 Gram-negative bacteria. Microarray-positive results correlated >91% with antimicrobial resistance phenotypes, assessed using British Society for Antimicrobial Chemotherapy clinical breakpoints; the overall test specificity was >83%. Microarray-positive results without a corresponding resistance phenotype matched 94% with PCR results, indicating accurate detection of genes present in the respective bacteria by microarray when expression was low or absent and, hence, undetectable by susceptibility testing. The low sensitivity and negative predictive values of the microarray results for identifying resistance to some antimicrobial resistance classes are likely due to the limited number of resistance genes present on the current microarray for those antimicrobial agents or to mutation-based resistance mechanisms. With regular updates, this microarray can be used for clinical diagnostics to help accurate therapeutic options to be taken following infection with multiple-antibiotic-resistant Gram-negative bacteria and prevent treatment failure.
authors.affiliation: Animal Health and Veterinary Laboratories Agency, Weybridge, New Haw, Addlestone, Surrey, United Kingdom.
authors.forename: Roderick
authors.initials: R
authors.lastname: Card
authors.forename: Jiancheng
authors.initials: J
authors.lastname: Zhang
authors.forename: Priya
authors.initials: P
authors.lastname: Das
authors.forename: Charlotte
authors.initials: C
authors.lastname: Cook
authors.forename: Neil
authors.initials: N
authors.lastname: Woodford
authors.forename: Muna F
authors.initials: MF
authors.lastname: Anjum
mesh_terms: D000900:Anti-Bacterial Agents / Q000145:classification / Q000494:pharmacology*; D024881:Drug Resistance, Bacterial / Q000187:drug effects / Q000235:genetics*; D005798:Genes, Bacterial; D006090:Gram-Negative Bacteria / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D016905:Gram-Negative Bacterial Infections / Q000188:drug therapy / Q000382:microbiology; D006801:Humans; D008826:Microbial Sensitivity Tests; D020411:Oligonucleotide Array Sequence Analysis; D016133:Polymerase Chain Reaction; D012680:Sensitivity and Specificity
chemical_list: D000900:Anti-Bacterial Agents