Abstract
Staphylococcus aureus is highly pathogenic and can cause diseases in both humans and domestic animals. In animal species, including ruminants, S. aureus may cause severe or sub-clinical mastitis. This study aimed to investigate the molecular profile, antimicrobial resistance, and genotype/phenotype correlation of 212 S. aureus isolates recovered from cases of bovine mastitis from 2014 to 2015 in the Shanghai and Zhejiang areas of China. Nineteen sequence types (STs) were determined by multi-locus sequence typing, while the dominant ST was ST97, followed by ST520, ST188, ST398, ST7, and ST9. Within 14 methicillin-resistant S. aureus (MRSA) isolates and 198 methicillin-susceptible S. aureus (MSSA) isolates, ST97 was the predominant MSSA clone and ST9-MRSA-SCCmecXII-spa t899 was the most common MRSA clone. The MRSA strains showed much higher rates of resistance to multiple antibiotics than did MSSA strains. Compared with other MSSA strains, MSSA ST398 was more resistant to clindamycin, erythromycin, and ciprofloxacin. No isolates were resistant to vancomycin, teicoplanin, or linezolid. The molecular profiles of the virulence genes varied in different strains. ST520 strains carried seg-sei-sem-sen-seo genes, and ST9 and ST97 harbored sdrD-sdrE genes. Virulence phenotype analysis showed diversity in different clones. Biofilm formation ability was significantly enhanced in ST188 and ST7, and red blood cell lysis capacity was relatively strong in all S. aureus strains of animal origin except ST7. Our results indicate that MSSA was the predominant S. aureus strain causing bovine mastitis in eastern regions of China. However, the presence of multidrug resistant and toxigenic MRSA clone ST9 suggests that comprehensive surveillance of S. aureus infection should be implemented in the management of animal husbandry products.
Highlights
Staphylococcus aureus is a common facultative pathogenic bacterium that has long been recognized as a challenge in both human and veterinary medicine (Nemeghaire et al, 2014)
212 S. aureus isolates from bovine mastitis were collected in this study, including 198 (93.4%) methicillin-susceptible S. aureus (MSSA) and 14 (6.6%) methicillin-resistant S. aureus (MRSA) isolates
Nineteen distinct sequence types (STs) were identified within the 212 isolates, with ST97 as the most frequently represented isolate (39.2%, 83/212), accounting for more than one third of all S. aureus isolates, followed by ST520 (16%, 34/212), ST188 (10%, 21/212), ST398 (7.1%, 15/212), ST7 (5.2%, 11/212), and ST9 (4.7%, 10/212)
Summary
Staphylococcus aureus is a common facultative pathogenic bacterium that has long been recognized as a challenge in both human and veterinary medicine (Nemeghaire et al, 2014) In cattle, it is responsible for approximately one-third of cases of clinical and subclinical mastitis (Bradley et al, 2007; Botrel et al, 2010), a disease that causes major economic loss in the dairy industry worldwide. LA-SA ST398 was originally reported to have emerged in the Netherlands among pigs and pig farmers in 2003 (Voss et al, 2005), and was later found in Austria, Germany, and Denmark (Van Cleef et al, 2011; Bal et al, 2016) It developed into an overwhelmingly dominant lineage in Europe and North America (Vanderhaeghen et al, 2010; Cuny et al, 2013). The present study was designed to analyze the molecular characteristics of S. aureus strains in bovine mastitis isolated from 2014 to 2015 in the Shanghai and Zhejiang areas
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
