Multidrug-resistant Staphylococcus aureus nasal carriage among HIV-positive outpatients in Guangzhou, China: Prevalence, risk factors, phenotypic and molecular characteristics.

Introduction: Data on comprehensive characterization of multidrug-resistant (MDR) Staphylococcus aureus (S. aureus) carriage in human immunodeficiency virus (HIV)-positive patients are limited. The objective of the present study is to determine the prevalence, risk factors, phenotypic and molecular characterization of MDR S. aureus isolated from HIV-positive population.

Methods: A cross-sectional study was conducted to determine the characteristics of MDR S. aureus nasal carriage among HIV-positive outpatients in an HIV clinic from June to August 2017. Nasal swabs and risk factor data of the enrolled HIV-positive outpatients were collected. Phenotypic and molecular characteristics of MDR and non-MDR S. aureus isolates were analyzed. Risk factors for nasal carriage with MDR S. aureus were estimated by logistic regression. The relationship between phenotypic and molecular characteristics of S. aureus isolates was assessed by the correspondence analysis.

Results: Overall, 1001 HIV-positive outpatients were included. The prevalence of MDR S. aureus nasal carriage was 15.18% (152/1001), and the proportion of multidrug resistance among S. aureus isolates was 60.08% (152/253). Having a history of respiratory tract infection was the risk factor for MDR S. aureus nasal carriage (adjusted odds ratio = 1.90, 95% confidence interval: 1.25-2.89). Multidrug resistance of S. aureus isolates was in good corresponding relationships with clonal complex (CC)5, CC15, CC59 and CC398.

Conclusions: We found high burden of multidrug resistance among S. aureus isolated from HIV-positive outpatients, particularly in those who had upper respiratory tract infection. Moreover, CC59 and CC398 are highly related to multidrug resistance of S. aureus isolates.