Prevalence, Characterization, and Drug Resistance of Staphylococcus Aureus in Feces From Pediatric Patients in Guangzhou, China

Abstract

<b>Background:</b> <i>Staphylococcus aureus</i> (<i>S. aureus</i>) is a major pathogen of human infections. Its fecal carriage serves as a risk factor for nosocomial transmission and disease development. However, the rate of <i>S. aureus</i> fecal carriage among Chinese children has not yet been reported. Therefore, we sought to investigate the prevalence, characterization, and drug resistance of <i>S. aureus</i> isolated from pediatric patients' feces in Southern China. <b>Methods:</b> Fecal samples (2059) from pediatric patients in three centers in Guangzhou were cultured. From which, 412 <i>S. aureus</i> isolates were identified via selective mediums and automated VITEK Mass Spectrometer analysis. Antibiotic susceptibility was determined and DNA sequencing of seven housekeeping genes were used for multilocus sequence typing analysis. <b>Results:</b> The fecal carriage rates were 20.0% for <i>S. aureus</i> and 4.5% for methicillin-resistant <i>S. aureus</i> (MRSA). Moreover, <i>S. aureus</i> fecal carriage was positively correlated with outpatient status and gastroenteritis diagnosis. Moreover, age-related patterns were observed with respect to prevalence of <i>S. aureus</i>. Besides, a total of 76 sequence types (STs) were identified, including 25 newly assigned STs and 28 clonal complexes (CCs). ST188, ST6, and ST15 were the most prevalent methicillin-sensitive <i>S. aureus</i> (MSSA) clones, while ST59 and ST45 were the major MRSA clones. <i>S. aureus</i> isolates also exhibited high rates of penicillin (84.2%), erythromycin (38.8%), and clindamycin (35.9%) resistance. Specifically, all ST30 and ST338 isolates were resistant to erythromycin and clindamycin, 61% of ST7 were resistant to tetracycline, and 84% of ST45 exhibited resistance and intermediate resistance to rifampicin. Also, CC59 (ST338 and ST59) and CC45 exhibited different antibiotic resistance patterns. <b>Conclusion:</b> These results demonstrate the colonization dynamics and molecular epidemiology of <i>S. aureus</i> in child feces in Southern China. Further, they suggest an urgency for strengthening the surveillance programs in China and provide important information for the prevention and treatment of <i>S. aureus</i> infection.