To analyze the antimicrobial resistance profiles(ARPs) of Staphylococcus aureus (SAU) isolated from primary medical institutions in Guangdong region from 2017 to 2021, to provide a basis for the use of antibiotics in the treatment of SAU infections.

The SAU strains were collected from Guangdong region from 2017 to 2021 and inspected by Guangzhou Kingmed Center for Clinical Laboratory. Identification and antibiotic susceptibility tests were carried out by BioMérieux VITEK^® MS microbial mass spectrometry system and Vitek-2 compact antibiotic susceptibility analysis system. Statistical analysis of the distribution and drug resistance of pathogenic bacteria were carried out using WHONET 5.6 software.

A total of 9713 non-replicating SAU were collected from 2017 to 2021, in which 4959 strains (51.06%)were identified as methicillin-resistant Staphylococcus aureus (MRSA). The main specimen sources of SAU were sputum 41.50%, wound secretions 31.87%, pus 8.87%, pharyngeal swabs 5.34%, and blood 4.74%. Sputum, urine, alveolar lavage fluid, blood, puncture fluid and pharyngeal swab MRSA isolation rate exceeded 50.00%. For SAU, the resistance to penicillin, oxacillin, erythromycin and clindamycin were all up to 50.00%. The isolation rate of multidrug-resistant methicillin-susceptible Staphylococcus aureus (MSSA) was 20.09%, and showed a decreasing trend yearly. The isolation rate of penicillin-sensitive MSSA (MSSA-PEN^S) showed an increasing trend. Among the MRSA strains, 41.51% were resistance to ten antibiotics, 12.54% were resistant to four antibiotics and 11.57% were resistant to five antibiotics. There were 105 ARPs of MRSA, 59 of which had more than two isolates, and 10 ARPs with more than 100 isolates. The dominant ARPs were ARPs Ⅶ: PEN/OXA/ERY/CLI/CIP; ARPs Ⅷ: PEN/OXA; ARPs Ⅸ: PEN/OXA/ERY/CLI; ARPs Ⅹ: PEN/OXA/TET/CIP/LEV/MXF/ERY/CLI/GEN. The isolation rate of MRSA on ARPs Ⅶ and Ⅸ were decreasing, while the isolation rate of MRSA strains on ARPs Ⅷ and Ⅹ were increasing.

The rate of MRSA isolation in primary care institutions in Guangdong Province is high, the susceptibility of MSSA bacteria to antibiotics such as penicillin is increasing, and the APRs of MRSA are changing. The primary medical institutions need to strengthen nosocomial infection surveillance and drug resistance tests, as well as raise awareness of medical workers about prevention. Clinical departments should further make reasonable use of antibiotics to prevent the prevalence and outbreaks of SAU and MRSA.