ST7 Becomes One of the Most Common Staphylococcus aureus Clones After the COVID-19 Epidemic in the City of Wuhan, China

Jihong Gu; Shucheng Shen; Mengyuan Xiong; Jin Zhao; Hongpan Tian; Xiao Xiao; Yirong Li

doi:10.2147/IDR.S401069

ST7 Becomes One of the Most Common Staphylococcus aureus Clones After the COVID-19 Epidemic in the City of Wuhan, China

Infect Drug Resist. 2023 Feb 13:16:843-852. doi: 10.2147/IDR.S401069. eCollection 2023.

Authors

Jihong Gu^#¹, Shucheng Shen^#¹, Mengyuan Xiong^{1

2}, Jin Zhao^{1

2}, Hongpan Tian¹, Xiao Xiao^{1

3}, Yirong Li^{1

2

3}

Affiliations

¹ Department of Laboratory Medicine, Zhongnan Hospital of Wuhan University, Wuhan, People's Republic of China.
² Wuhan Research Center for Infectious Diseases and Tumors of the Chinese Academy of Medical Sciences, Wuhan, People's Republic of China.
³ Hubei Engineering Center for Infectious Disease Prevention, Control and Treatment, Wuhan, People's Republic of China.

^# Contributed equally.

Abstract

Background: Staphylococcus aureus (S. aureus) was able to rapidly evolve and adapt under the pressure of antibiotics, host immune and environmental change. After Corona Virus Disease 2019 (COVID-19) epidemic in Wuhan, China, a large number of disinfectants were used, which might result in rapid evolution of S. aureus.

Methods: A total of 619 S. aureus isolates were collected from Zhongnan Hospital, Wuhan University from 2018 to 2021, including group BEFORE (309 strains collected before COVID-19 pandemic) and group AFTER (310 strains collected after COVID-19 pandemic), for comparing the changes of molecular epidemiology. The molecular characteristics of isolates were analyzed by Multi-locus sequence typing (MLST), spa, chromosomal cassette mec (SCCmec) typing, virulence genes were screened by the PCR, antibiotic susceptibility test was carried out by the VITEK system.

Results: Thirty-six sequence types (STs) belonging to 14 clone complexes (CCs) were identified. ST5 was the most prevalent clone in both groups, and ST7, ranking the sixth in group BEFORE, became the second dominant clone in group AFTER (6.5% vs 10.0%), whereas ST239 decreased from the seventh to the fourteenth (5.8% vs 1.9%). ST7 in group AFTER had a higher positive rate of virulence genes, including hlb, fnbB, seb, lukDE, sdrE and the proportion of ST7-t091 MRSA strains increased from 19.1% to 50% compared with group BEFORE. Though no significant difference of MRSA proportion was found between two groups, SCCmec type-III in group AFTER decreased (p<0.01). Though the rate of multidrug-resistance (MDR) decreased, the virulence genes hlb, hlg, fnbB, seb and pvl carrying rates were significantly elevated in MRSA strains of group AFTER.

Conclusion: After COVID-19 pandemic, ST7 becomes one of the predominant S. aureus clones in Wuhan and the carrying rate of SCCmec and virulence genes is on the rise. Therefore, it is essential to strengthen the surveillance of ST7 S. aureus clone.

Keywords: Staphylococcus aureus; antimicrobial resistance; disinfectant; molecular characterization; virulence gene.

Grants and funding

This study was supported by the National Natural Science Foundation of China (NO. 82172333); Key Research and Development Program of Hubei Province (2022BCA019); 2021 Hubei Provincial Leading Public Health Talents Project (WSJKRC2022012); Establishment of accurate etiological diagnosis strategy for severely infected children (2021YFC2701803).