Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2023 Nov 29;23(1):368.
doi: 10.1186/s12866-023-03126-y.

Molecular characterisation of Staphylococcus aureus in school-age children in Guangzhou: associations among agr types, virulence genes, sequence types, and antibiotic resistant phenotypes

Hao Cai  1 , Xueying Li  1 , Chao Zhang  1   2 , Huamin Zhong  1 , Yongqiang Xie  1 , Lianfen Huang  1 , Baidu Zhang  1 , Yan Long  1 , Zhenwen Zhou  3 , Bingshao Liang  4
Affiliations

Molecular characterisation of Staphylococcus aureus in school-age children in Guangzhou: associations among agr types, virulence genes, sequence types, and antibiotic resistant phenotypes

Hao Cai et al. BMC Microbiol. .

Abstract

Background: Staphylococcus aureus, one of the most prevalent opportunistic pathogens, mainly colonizes the nasal cavity and is a risk factor for severe infections. Virulence factors and accessory gene regulator (agr) are key to the severity and diversity of staphylococcal infection. In this study, we aimed to characterise S. aureus agr-types and virulence genes and correlated them with genetic background and antibiotic-resistant phenotypes.

Results: Agr types were identified in 704 isolates (98.5%), with only 11 isolates were negative for agr type. Most of our isolates were classified as agr type I, followed by types III, II and IV. The enterotoxin c gene (sec) was detected in 48.6% of isolates, showing the highest prevalence among the five enterotoxin genes detected. The positivity rates for the lukS/F-PV and tsst genes were 4% and 2.2%, respectively, while neither sed nor SasX were detected. ST45, ST59, ST338, ST188, ST6, ST7, ST22, ST25, ST398, and ST944 belonged to agr I group, while ST5 and ST15 belonged to agr II group. ST30 and ST1 were classified into agr III group, and ST121 was assigned into agr IV group. The tsst gene was found exclusively within agr I and III types belonging to ST7 and ST30 isolates, while the lukS/F-PV was predominantly carried by agr I type isolates primarily within CC59 and CC22 clones. Among the methicillin-resistant S. aureus (MRSA) isolates, 89.7% belonged to agr I group, and 97.8% of rifampicin-resistant or intermediate isolates were assigned to agr I group. MRSA isolates harboured more tested virulence genes compared to methicillin-susceptible S. aureus isolates.

Conclusions: We characterized the distributions of agr types and eight major virulence genes of 715 S. aureus isolates, and our findings revealed clear associations between agr types and STs, as well as virulence genes, and drug resistant phenotypes.

Keywords: Agr typing; Antibiotic resistance; Multi-locus sequence typing; Staphylococcus aureus; Virulence factors.

PubMed Disclaimer

Conflict of interest statement

The authors declare no competing interests.

Figures

Fig. 1
Fig. 1
Distribution between STs and different agr groups of 599 S. aureus strains. MLST multi-locus sequence typing, CC clonal complex, agr accessory gene regulator, ST sequence type. * indicates agr-negative.—indicates CCs are not specified
Fig. 2
Fig. 2
The tri-colour scale depicts the associations among S. aureus virulence genes, antigram, agr types, and STs. * indicates intermediate or rifampicin resistance. Antibiotics: PEN, penicillin; ERY, erythromycin; CLI, clindamycin; RIF, rifampicin; TCY, tetracycline; CIP, ciprofloxacin; SXT, sulfamethoxazole-trimethoprim; GEN, gentamicin; VAN, vancomycin
See this image and copyright information in PMC

References

    1. Rigaill J, Gavid M, Fayolle M, Morgene MF, Lelonge Y, Grattard F, Pozzetto B, Crepin A, Prades JM, Laurent F, et al. Staphylococcus aureus nasal colonization level and intracellular reservoir: a prospective cohort study. Eur J Clin Microbiol Infect Dis. 2023;42(5):621–9. - PubMed
    1. Liang B, Liang X, Gao F, Long Y, Mai J, Ai X, Wang J, Gao X, Xiong Z, Liang Z, et al. Active surveillance, drug resistance, and genotypic profiling of staphylococcus aureus among school-age children in China. Front Med Lausanne. 2021;8:701494. doi: 10.3389/fmed.2021.701494. - DOI - PMC - PubMed
    1. Krismer B, Weidenmaier C, Zipperer A, Peschel A. The commensal lifestyle of Staphylococcus aureus and its interactions with the nasal microbiota. Nat Rev Microbiol. 2017;15(11):675–687. doi: 10.1038/nrmicro.2017.104. - DOI - PubMed
    1. de Benedictis FM, Kerem E, Chang AB, Colin AA, Zar HJ, Bush A. Complicated pneumonia in children. Lancet. 2020;396(10253):786–798. doi: 10.1016/S0140-6736(20)31550-6. - DOI - PubMed
    1. Nurjadi D, Last K, Klein S, Boutin S, Schmack B, Mueller F, Heeg K, Ruhparwar A, Heininger A, Zanger P. Nasal colonization with Staphylococcus aureus is a risk factor for ventricular assist device infection in the first year after implantation: a prospective, single-centre, cohort study. J Infect. 2020;80(5):511–518. doi: 10.1016/j.jinf.2020.02.015. - DOI - PubMed

Publication types