Genomic basis of antimicrobial resistance in non-toxigenic Clostridium difficile in Southeast Asia. (December 2020)

• Record Type: Journal Article
• Authors: Imwattana, Korakrit; Kiratisin, Pattarachai; Riley, Thomas V.; Knight, Daniel R.
• Is Part Of: Anaerobe. Volume 66(2020)
• Publication Date: 2020-12
• Subjects: Non-toxigenic Clostridium difficile -- Southeast Asia -- Antimicrobial resistance -- Genotype; Anaerobic infections -- Periodicals; Anaerobic bacteria -- Periodicals; Bacterial diseases -- Periodicals; Computer network resources; Anaerobic protozoa -- Periodicals; 579.3
• DOI: 10.1016/j.anaerobe.2020.102290
• Languages: English
• ISSNs: 1075-9964

Abstract

Abstract: Despite being incapable of causing Clostridium difficile infection, non-toxigenic C. difficile (NTCD) may still be relevant. This study explored the role of NTCD as a reservoir of accessory antimicrobial resistance (AMR) genes in NTCD from Southeast Asia. This region has high rates of antimicrobial use, a high prevalence of NTCD and phenotypic AMR in such strains. More than half of the 28 NTCD strains investigated had at least one accessory AMR gene on mobile genetic elements (MGEs) which were similar to the elements found in other bacteria, including Erysipelothrix rhusiopathiae and Streptococcus suis, both of which are found in the pig gut. Thus, C. difficile may facilitate the movement of AMR genes between different hosts within a wide range of pathogenic bacteria. C. difficile β-lactamases were not located on MGEs and were unlikely to be transferred. Concordance between the MLSB resistance genotype and phenotype was low, suggesting multiple resistance mechanisms, many of which remain unknown. On the contrary, there was a high concordance between resistance genotype and phenotype for both fluoroquinolones and rifaximin. From an epidemiological perspective, NTCD populations in Southeast Asia comprised members of evolutionary clades 1 and 4, which are thought to have originated from Europe and Asia, respectively. This population structure reflects the close relationship between the people of the two regions. Highlights: Non-toxigenic C. difficile can carry multiple antimicrobial resistance (AMR) genes. Known gyrA, gyrB and rpoB alleles can be used to screen for resistance genotypes. Accessory AMR genes may be exchanged in vivo between various pathogenic bacteria.