title: Molecular investigation of carbapenem resistance among multidrug-resistant Pseudomonas aeruginosa isolated clinically in Thailand.
abstract: Carbapenem resistant Pseudomonas aeruginosa were isolated among multidrug-resistant (CR-MDR) organisms from tertiary hospitals in Thailand. Decreased expression of oprD mRNA (93.65%) was predominant followed by increased expression of mexAB-oprM mRNA (92.06%) and mexXY mRNA (63.49%). Interestingly, 23 of 126 (18.25%) isolates were susceptible to imipenem with down-regulated oprD expression and non-up-regulated mexCD-oprJ mRNA expression. Metallo-β-lactamases production was clearly positive in 24 isolates (18.46%) and weakly positive in 12 isolates (9.23%). Among both of these sets of isolates, imp-1, imp-14 and vim-2 were identified. Hyperproduction of AmpC β-lactamase had the lowest prevalence rate (3.97%). It was concluded that CR-MDR P. aeruginosa clinical isolates in Thailand possess multifactorial resistance mechanisms.
authors.affiliation: Department of Microbiology, Mahidol University, 447 Sri Ayudthaya Road, Rachathevi, Bangkok, 10400, Thailand.
authors.forename: Piyatip
authors.initials: P
authors.lastname: Khuntayaporn
authors.forename: Preecha
authors.initials: P
authors.lastname: Montakantikul
authors.forename: Pitak
authors.initials: P
authors.lastname: Santanirand
authors.forename: Pattarachai
authors.initials: P
authors.lastname: Kiratisin
authors.forename: Mullika Traidej
authors.initials: MT
authors.lastname: Chomnawang
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D015780:Carbapenems / Q000494:pharmacology*; D024901:Drug Resistance, Multiple, Bacterial; D020869:Gene Expression Profiling; D006801:Humans; D008826:Microbial Sensitivity Tests; D011552:Pseudomonas Infections / Q000382:microbiology*; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000302:isolation & purification; D062606:Tertiary Care Centers; D013785:Thailand; D001618:beta-Lactamases / Q000096:biosynthesis
chemical_list: D000900:Anti-Bacterial Agents; D015780:Carbapenems; D001618:beta-Lactamases