Clinical characteristics, virulence factors and molecular typing of methicillin-resistant Staphylococcus aureus infections in Shenzhen City, China

• Published in: Epidemiology and infection 2016-10, Vol.144 (14), p.3037-3045
• Main Authors: HU, L., LI, Y., LU, Y., KLENA, J. D., QIU, Y., LIN, Y., JIANG, M., SHI, X., CHEN, L., LIU, X., MA, H., CHENG, J., WU, S., KAN, B., HU, Q.
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Agar; Aged; Aged, 80 and over; Amides; Amino acid sequence; Anti-Bacterial Agents; Antibiotic resistance; Antiinfectives and antibacterials; Antimicrobial agents; Antimicrobial resistance; Army; Assaying; Atopic dermatitis; Bacteria; Cards; Categories; Catheters; Chemotherapy; Child; Child, Preschool; China - epidemiology; Ciprofloxacin; Clindamycin; Clinical microbiology; Colonies; Colonization; Community-Acquired Infections - epidemiology; Community-Acquired Infections - microbiology; Computer programs; Cross Infection - epidemiology; Cross Infection - microbiology; Data processing; Deoxyribonucleic acid; Dermatitis; Dialysis; Disease control; DNA; Drug resistance; Epidemiology; Female; Genes; Genes, Bacterial - genetics; Geographical distribution; Health care; Hospitals; Humans; Infant; Infant, Newborn; Infections; Infectious diseases; Long-term care; Male; Medical equipment; Medicine; Methicillin - pharmacology; Methicillin Resistance; Methicillin-Resistant Staphylococcus aureus - genetics; Methicillin-Resistant Staphylococcus aureus - pathogenicity; Methicillin-Resistant Staphylococcus aureus - physiology; Microbiology; Middle Aged; Molecular Typing; Multiplexing; Occupational exposure; Original Papers; Outbreaks; Pathogens; Polymerase chain reaction; Prevention; Public health; Respiratory tract; Risk factors; Skin; Staphylococcal Infections - epidemiology; Staphylococcal Infections - microbiology; Staphylococci; Staphylococcus aureus; Staphylococcus infections; Statistical analysis; Surgery; Virulence Factors - genetics; Warning; Young Adult
• ISSN: 0950-2688; 1469-4409
• DOI: 10.1017/S0950268816001552

Methicillin-resistant Staphylococcus aureus (MRSA) has emerged as a serious hospital and community-acquired infection and some strains are associated with greater severity. We investigated the clinical variability and molecular characteristics of MRSA infections in Shenzhen, China through a study at nine sentinel hospitals from January to December 2014. MRSA infections were classified as community-associated (CA-MRSA), healthcare-associated (HA-MRSA), and healthcare-associated community-onset (HACO-MRSA). In total, 812 MRSA isolates were collected and 183 of these were selected for further study. Patients with HA-MRSA infections were generally of greater age compared to other groups. Distinct body site and clinical presentations were evident in infected patients, e.g. CA-MRSA (skin and soft tissue, 53%), HA-MRSA (respiratory tract, 22%; surgical site, 20%; trauma wounds, 20%) and HACO-MRSA (mastitis, 47%). In contrast to HA-MRSA, other categories of strains were significantly more susceptible to gentamicin, sulfamethoxazole/trimethoprim, and tetracycline. No resistance to vancomycin or linezolid was recorded. The predominant clonal lineage within each strain category was CC59-t437-SCCmec IV/V-agr I (CA, 51·4%; HA, 28·9%; HACO, 52·9%) which exhibited characteristics of a traditional CA clone together with agr I which is more often associated with HA clones. In conclusion, for the three categories of MRSA infections, there were significant differences in clinical characteristics of patients, but the predominant clone in each category shared a similar genetic background which suggests that transmission of MRSA strains has occurred between the community and hospitals in Shenzhen.