TY - JOUR
T1 - Characterization of staphylococcal cassette chromosome mec in Staphylococcus haemolyticus ST3 and ST42 isolates from bovine mastitis milk
T2 - identification of novel variant in class C1 mec complex
AU - Thanasak, Jitkamol
AU - Wongsurawat, Thidathip
AU - Jenjaroenpun, Piroon
AU - Phumthanakorn, Nathita
N1 - Publisher Copyright:
© The Author(s) 2024. Published by Oxford University Press on behalf of British Society for Antimicrobial Chemotherapy. All rights reserved.
PY - 2024/10/1
Y1 - 2024/10/1
N2 - Background: Methicillin-resistant Staphylococcus haemolyticus (MRSH) is an important pathogenic agent of bovine mastitis. Among the prominent clone lineages in dairy cows are MRSH sequence types ST3 and ST42. Little information is available on the complete characterization of SCCmec elements in MRSH. Objective: In this study, two clinical isolates of MRSH ST3 and ST42 from bovine mastitis milk were selected, and their nontypable SCCmec structures were compared. Methods: Two MRSH strains, MRSH-ST3 strain M62.3 and MRSH-ST42 strain M81.1, were identified from bovine mastitis milk in Thailand in 2022. Minimum inhibitory concentration was used to screen for antimicrobial resistance susceptibility. Oxford Nanopore Technologies and Illumina sequencing were performed in combination to complete the genome. Their gene organization and structure of SCCmec types were analysed and compared with the whole sequences of other strains in the same sequence types. Results: Both MRSH-ST3 strain M62.3 and MRSH-ST42 strain M81.1 possessed the class C1 mec complex but lacked the ccr gene complex. Notably, MRSH-ST42 strain M81.1 contained a novel variant of C1 mec complex, which consisted of IS431-mecA-ISSha1-paaZ-upgQ-IS431, with IS431 organized in the same orientation. Apart from class C1 mec and the heavy metal-resistant cluster, the gene composition and order of the SCCmec element varied. In ST3, variations in the SCCmec type, gene content and organization were observed. Conclusions: The distinct evolution of the MRSH lineage was indicated by the various SCCmec elements. The insertion of ISSha1 resulted in a unique variant of class C1 mec complex that demonstrated the important role of the insertion sequence in SCCmec diversification.
AB - Background: Methicillin-resistant Staphylococcus haemolyticus (MRSH) is an important pathogenic agent of bovine mastitis. Among the prominent clone lineages in dairy cows are MRSH sequence types ST3 and ST42. Little information is available on the complete characterization of SCCmec elements in MRSH. Objective: In this study, two clinical isolates of MRSH ST3 and ST42 from bovine mastitis milk were selected, and their nontypable SCCmec structures were compared. Methods: Two MRSH strains, MRSH-ST3 strain M62.3 and MRSH-ST42 strain M81.1, were identified from bovine mastitis milk in Thailand in 2022. Minimum inhibitory concentration was used to screen for antimicrobial resistance susceptibility. Oxford Nanopore Technologies and Illumina sequencing were performed in combination to complete the genome. Their gene organization and structure of SCCmec types were analysed and compared with the whole sequences of other strains in the same sequence types. Results: Both MRSH-ST3 strain M62.3 and MRSH-ST42 strain M81.1 possessed the class C1 mec complex but lacked the ccr gene complex. Notably, MRSH-ST42 strain M81.1 contained a novel variant of C1 mec complex, which consisted of IS431-mecA-ISSha1-paaZ-upgQ-IS431, with IS431 organized in the same orientation. Apart from class C1 mec and the heavy metal-resistant cluster, the gene composition and order of the SCCmec element varied. In ST3, variations in the SCCmec type, gene content and organization were observed. Conclusions: The distinct evolution of the MRSH lineage was indicated by the various SCCmec elements. The insertion of ISSha1 resulted in a unique variant of class C1 mec complex that demonstrated the important role of the insertion sequence in SCCmec diversification.
UR - http://www.scopus.com/inward/record.url?scp=85205524846&partnerID=8YFLogxK
U2 - 10.1093/jac/dkae242
DO - 10.1093/jac/dkae242
M3 - Article
C2 - 39082161
AN - SCOPUS:85205524846
SN - 0305-7453
VL - 79
SP - 2479
EP - 2483
JO - Journal of Antimicrobial Chemotherapy
JF - Journal of Antimicrobial Chemotherapy
IS - 10
ER -