An in‐house 45‐plex array for the detection of antimicrobial resistance genes in Gram‐positive bacteria

Abstract

Identifying antimicrobial resistance (AMR) genes and determining their occurrence in Gram‐positive bacteria provide useful data to understand how resistance can be acquired and maintained in these bacteria. We describe an in‐house bead array targeting AMR genes of Gram‐positive bacteria and allowing their rapid detection all at once at a reduced cost. A total of 41 AMR probes were designed to target genes frequently associated with resistance to tetracycline, macrolides, lincosamides, streptogramins, pleuromutilins, phenicols, glycopeptides, aminoglycosides, diaminopyrimidines, oxazolidinones and particularly shared among Enterococcus and Staphylococcus spp. A collection of 124 enterococci and 62 staphylococci isolated from healthy livestock animals through the official Belgian AMR monitoring (2018–2020) was studied with this array from which a subsample was further investigated by whole‐genome sequencing. The array detected AMR genes associated with phenotypic resistance for 93.0% and 89.2% of the individual resistant phenotypes in enterococci and staphylococci, respectively. Although linezolid is not used in veterinary medicine, linezolid‐resistant isolates were detected. These were characterized by the presence of optrA and poxtA , providing cross‐resistance to other antibiotics. Rarer, vancomycin resistance was conferred by the vanA or by the vanL cluster. Numerous resistance genes circulating among Enterococcus and Staphylococcus spp. were detected by this array allowing rapid screening of a large strain collection at an affordable cost. Our data stress the importance of interpreting AMR with caution and the complementarity of both phenotyping and genotyping methods. This array is now available to assess other One‐Health AMR reservoirs.

Molecular epidemiology and characterization of antimicrobial-resistant Staphylococcus haemolyticus strains isolated from dairy cattle milk in Northwest, China

“…(2020) confirmed that flo R was found to be the predominant gene conferring resistance to florfenicol in different animal-derived bacteria. Among the aminoglycosides, both aad D and aac A- aph D genes were identified, which is in line with previously published studies ( Qu et al., 2019 ; Kowalewicz et al., 2023 ). The aac A- aph D gene code for a multifunctional enzyme confers resistance to multiple aminoglycosides such as amikacin, gentamicin, tobramycin, and kanamycin ( Schwarz et al., 2018 ), while aad D gene codes for adenyltransferase enzyme confer resistance to neomycin, kanamycin, tobramycin, and paromomycin ( Batool et al., 2021 ).…”

Multidrug-Resistant Commensal and Infection-Causing Staphylococcus spp. Isolated from Companion Animals in the Valencia Region

“…However, it is necessary to research the AMR problem from more perspectives. For this reason, Gram-positive bacteria belonging to the family Staphylococcaceae , which are considered part of the commensal microbiota of the skin and mucous membranes of animals and humans, are also used as an indicator of resistance [ 16 ]. Within this family, two groups are distinguished: coagulase-positive Staphylococcus (CoPS) [ 17 ] and coagulase-negative Staphylococcus (CoNS) [ 18 ].…”