High Prevalence of Panton-Valentine Leukocidin Among Staphylococcus aureus Causing Acute Hematogenous Bone and Joint Infections From a Tertiary Children's Hospital in Vietnam.

BACKGROUND: We aimed to investigate the clinical features, antimicrobial susceptibility and pvl gene expression in Staphylococcus aureus causing acute hematogenous bone and joint infections (BJIs) in children in Vietnam.

METHODS: In this prospective study, the demographics, microbiology and clinical outcomes of pediatric patients with acute hematogenous BJIs were collected from September 2022 to September 2023. Antimicrobial susceptibility profiles were determined using VITEK2 Compact system. The pvl gene encoding the Panton-Valentine leukocidin (PVL) toxin was detected by using polymerase chain reaction. Mann-Whitney, χ2 and Fisher test were used for statistical analysis.

RESULTS: In total, 78 patients (46 boys) with S. aureus acute hematogenous BJIs were recruited at the National Children's Hospital, Hanoi, Vietnam. Of all S. aureus isolates, 84.6% were methicillin-resistant S. aureus. All S. aureus isolates were susceptible to vancomycin, ciprofloxacin and levofloxacin; 97% of methicillin-resistant S. aureus isolates was resistant to clindamycin (minimum inhibitory concentration ≥8 μg/mL). The pvl gene was detected in 83.3% of isolates, including 57 methicillin-resistant S. aureus isolates. Patients in the pvl-positive group had significantly higher C-reactive protein levels than those in the pvl-negative group (P = 0.04). In addition, all 8 children with septic shock were infected with pvl-positive S. aureus.

CONCLUSIONS: PVL is a prevalent virulence factor of S. aureus in Vietnam. Furthermore, high inflammatory parameters (C-reactive protein) may be present at the time of diagnosis in PVL positivity-related acute hematogenous BJIs. Further research is necessary to enhance our understanding of the varying correlations between virulence factors and outcomes of S. aureus BJIs.