Multilocus sequence type-dependent activity of human and animal cathelicidins against community-, hospital-, and livestock-associated methicillin-resistant Staphylococcus aureus isolates

• Published in: Journal of animal science and technology 2022, 64(3), , pp.515-530
• Main Authors: Kim, Sun Do, Kim, Geun-Bae, Lee, Gi Yong, Yang, Soo-Jin
• Format: Article
• Language: English
• Subjects: cathelicidin; community-associated methicillin-resistant staphylococcus aureus (ca-mrsa); healthcare-associated methicillin-resistant staphylococcus aureus (ha-mrsa); host adaptation; livestock-associated methicillin-resistant staphylococcus aureus (la-mrsa); methicillin-resistant staphylocuccus aureus; 축산학
• ISSN: 2055-0391; 2672-0191; 2055-0391; 2093-6281
• DOI: 10.5187/jast.2022.e32

Sequence type (ST) 5 methicillin-resistant (MRSA) with staphylococcal cassette chromosome (SCCmec) type II (ST5-MRSA-II) and ST72-MRSA-IV represent the most significant genotypes for healthcare- (HA) and community-associated (CA) MRSA in Korea, respectively. In addition to the human-type MRSA strains, the prevalence of livestock-associated (LA) MRSA clonal lineages, such as ST541 and ST398 LA-MRSA-V in pigs and ST692 LA-MRSA-V and ST188 LA-MRSA-IV in chickens, has recently been found. In this study, clonotype-specific resistance profiles to cathelicidins derived from humans (LL-37), pigs (PMAP-36), and chickens (CATH-2) were examined using six different ST groups of MRSA strains: ST5 HA-MRSA-II, ST72 CA-MRSA-IV, ST398 LA-MRSA-V, ST541 LA-MRSA-V, ST188 LA-MRSA-IV, and ST692 LA-MRSA-V. Phenotypic characteristics often involved in cathelicidin resistance, such as net surface positive charge, carotenoid production, and hydrogen peroxide susceptibility were also determined in the MRSA strains. Human- and animal-type MRSA strains exhibited clonotype-specific resistance profiles to LL-37, PMAP-36, or CATH-2, indicating the potential role of cathelicidin resistance in the adaptation and colonization of human and animal hosts. The ST5 HA-MRSA isolates showed enhanced resistance to all three cathelicidins and hydrogen peroxide than ST72 CA-MRSA isolates by implementing increased surface positive charge and carotenoid production. In contrast, LA-MRSA strains employed mechanisms independent of surface charge regulation and carotenoid production for cathelicidin resistance. These results suggest that human- and livestock-derived MRSA strains use different strategies to counteract the bactericidal action of cathelicidins during the colonization of their respective host species.