Chih-Jung Chen1,2, Tsai-Ling Yang Lauderdale3, Chin-Te Lu4, Yu-Yu Chuang5, Chien-Chang Yang2,6, Ting-Shu Wu2,6, Chun-Yi Lee7, Min-Chi Lu8,9, Wen-Chien Ko10, Yhu-Chering Huang1,2. 1. Division of Paediatric Infectious Diseases, Chang Gung Memorial Hospital, Taoyuan, Taiwan. 2. College of Medicine, Chang Gung University, Taoyuan, Taiwan. 3. National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Zhunan, Taiwan. 4. Department of Infectious Diseases, Lotung Poh-Ai Hospital, Yilan, Taiwan. 5. Department of Pediatrics, St Mary's Hospital, Yilan, Taiwan. 6. Division of Infectious Diseases, Department of Internal Medicine, Chang Gung Memorial Hospital, Taoyuan, Taiwan. 7. Department of Pediatrics, Chang Bing Show Chwan Memorial Hospital, Changhua, Taiwan. 8. Division of Infectious Diseases, Department of Internal Medicine, China Medical University Hospital, Taichung, Taiwan. 9. Department of Microbiology and Immunology, School of Medicine, China Medical University, Taichung, Taiwan. 10. Division of Infectious Diseases, Department of Internal Medicine, National Cheng Kung University Hospital, Tainan, Taiwan.
Abstract
OBJECTIVES: Clonal complex (CC) 9 is a prevalent livestock-associated (LA) MRSA clone in Asia whose pathogenicity in humans remains unknown. METHODS: In 2012, we identified a patient with CC9-MRSA infection linked to livestock. After screening 3328 clinical MRSA isolates from a national database, eight isolates (0.24%) collected between 1998 and 2012 were further confirmed to be of CC9. The detailed molecular features of the nine human CC9 strains and phylogenetic relatedness to animal CC9 strains were characterized with WGS. The antibiotic susceptibilities were determined and the clinical information was abstracted from medical records. RESULTS: WGS grouped the CC9 strains into two clades, which were respectively associated with distinct toxome profiles, resistance gene profiles and staphylococcal cassette chromosomes (SCCmecXII for 7 isolates and SCCmecVT for 2 isolates). The SCCmecXII strains were phylogenetically related to animal CC9-MRSA strains, negative for Panton-Valentine leucocidin and 100% resistant to ciprofloxacin, erythromycin, clindamycin, gentamicin and tigecycline. Four of the seven SCCmecXII isolates were associated with invasive diseases including bacteraemia leading to death (2) and osteomyelitis (2). Two SCCmecXII isolates were from patients with exposure to pigs before development of the MRSA diseases. CONCLUSIONS: The CC9-SCCmecXII MRSA prevailing in pigs in Asia is multidrug resistant and potentially pathogenic to humans. It is critical to continuously monitor the local epidemiology of MRSA and implement effective control measures to limit the spread of LA-MRSA between animals, to humans and in healthcare facilities.
OBJECTIVES: Clonal complex (CC) 9 is a prevalent livestock-associated (LA) MRSA clone in Asia whose pathogenicity in humans remains unknown. METHODS: In 2012, we identified a patient with CC9-MRSA infection linked to livestock. After screening 3328 clinical MRSA isolates from a national database, eight isolates (0.24%) collected between 1998 and 2012 were further confirmed to be of CC9. The detailed molecular features of the nine human CC9 strains and phylogenetic relatedness to animal CC9 strains were characterized with WGS. The antibiotic susceptibilities were determined and the clinical information was abstracted from medical records. RESULTS: WGS grouped the CC9 strains into two clades, which were respectively associated with distinct toxome profiles, resistance gene profiles and staphylococcal cassette chromosomes (SCCmecXII for 7 isolates and SCCmecVT for 2 isolates). The SCCmecXII strains were phylogenetically related to animal CC9-MRSA strains, negative for Panton-Valentine leucocidin and 100% resistant to ciprofloxacin, erythromycin, clindamycin, gentamicin and tigecycline. Four of the seven SCCmecXII isolates were associated with invasive diseases including bacteraemia leading to death (2) and osteomyelitis (2). Two SCCmecXII isolates were from patients with exposure to pigs before development of the MRSA diseases. CONCLUSIONS: The CC9-SCCmecXII MRSA prevailing in pigs in Asia is multidrug resistant and potentially pathogenic to humans. It is critical to continuously monitor the local epidemiology of MRSA and implement effective control measures to limit the spread of LA-MRSA between animals, to humans and in healthcare facilities.
Authors: Fangyou Yu; Astrid V Cienfuegos-Gallet; Marcus H Cunningham; Ye Jin; Bingjie Wang; Barry N Kreiswirth; Liang Chen Journal: mSystems Date: 2021-06-22 Impact factor: 6.496