Prevalence of Panton-Valentine leukocidin in methicillin-resistant Staphylococcus aureus clinical isolates at a university hospital in Northern Cyprus: a pilot study

Abstract

Objective: Panton-Valentine leukocidin (PVL)-positive methicillin-resistant Staphylococcus aureus (MRSA) is a healthcare problem worldwide. There are no reports on the virulence characteristics of MRSA in Northern Cyprus (NC). This study aimed to determine the presence of pvl among MRSA isolates from patients admitted to a university hospital in NC using molecular methods. Fifty S. aureus strains were included in this study. BD Phoenix automated identification system was used for bacterial identification and antibiotic susceptibility testing. Methicillin resistance was confirmed by disc diffusion assay. Presence of nuc and mecA genes was tested by multiplex PCR. Detection of pvl gene was performed by single-target PCR.

Results: Out of 50 S. aureus isolates identified as MRSA by BD Phoenix system, 3 were susceptible to cefoxitin with disc diffusion assay and were confirmed as methicillin-sensitive S. aureus (MSSA). All isolates (n = 50, 100%) tested positive for the presence nuc gene and 68% (n = 34/50) were mecA positive. pvl was detected in 27.7% (n = 13/47) of the MRSA isolates. Among PVL-positive MRSA isolates, 69.2% (9/13) were inpatients. PVL-MRSA was more common in isolates from deep tracheal aspirate (30.8%, 4/13) and abscess/wound (23.1%, 3/13). This represents the first study of PVL presence among MRSA in hospital setting in NC.

Keywords: Methicillin-resistant Staphylococcus aureus; Northern Cyprus; PCR; Panton-Valentine leukocidin; Prevalence; Virulence.

Fig. 1

Distribution of Staphylococcus aureus infections a according to hospital departments b according to body sites

Fig. 2

PCR detection of nuc, mecA and pvl genes a multiplex PCR for simultaneous detection of nuc and mecA in MRSA isolates. Lanes 1 and 3: nuc, mecA positive, Lane 2: nuc positive, PC: positive control, NC: negative control, M: 100 bp DNA ladder (Hibrigen); b detection of pvl in MRSA isolates by single target PCR. Lanes 1–4, 6–8, 10: pvl positive, Lanes 5, 9: pvl negative, PC: positive control, NC: negative control, M: 100 bp DNA ladder (Hibrigen)