Antimicrobial resistance genotypes and phenotypes from multidrug-resistant bacterial wound infection isolates in Cambodia

This study aimed to identify the molecular determinants responsible for antibiotic resistance among human wound isolates in Cambodia. Staphylococcus spp. (n = 10) and a variety of Gram-negative isolates (n = 21) were taken from a larger collection of wound isolates collected during 2011-2013 and were analysed for the presence of >230 resistance determinants using a broad-spectrum DNA microarray. These isolates were chosen to represent the species most commonly found in wound isolates referred during this time and to include some of the most resistant strains. Resistance determinants detected among the staphylococci included blaZ (90%), mecA (100%), erm(B) (70%), erm(C) (20%), tet(38) (90%), tet(K) (40%), tet(L-p) (10%), tet(M) (20%), Inu(A)/lin(A) and Inu(B)/lin(B) (10% each), msr(A)/msr(B)/msr(SA) (10%), norA (80%) and dfrA (10%). Eleven different beta-lactamase genes were detected among the Gram-negative bacteria, including genes encoding the TEM (48%), CTX-M-1 (48%), CTX-M-9 (5%), SHV (5%) and VEB (10%) families of broad-spectrum and extended-spectrum beta-lactamase enzymes, as well as the carbapenemase gene bla(OXA-23). Forty additional genes were also detected in the Gram-negative isolates conferring resistance to aminoglycosides (11 genes), phenicols (5 genes), macrolides [4 genes, including mph(A)/mph(K) (10%)], lincosamides [Inu(F)Ilin(F), Inu(G)Ilin(G)1, tetracycline (4 genes), rifampicin [arr (29%)], quaternary amines [qacE Delta 1 (43%)], quinolones [qnrS (14%) and qnrB (5%)], sulfonamides [sul1 (29%), sul2 (38%) and sul3 (10%)], streptothricin (sat2) and trimethoprim (6 genes). The results obtained here provide a snapshot of the broad variety of resistance determinants currently circulating within Cambodia. Published by Elsevier Ltd on behalf of International Society for Chemotherapy of Infection and Cancer.