Title:Virulence Potential of Staphylococcus aureus Strains Isolated from Diabetic Foot Ulcers Among Patients from Southern Poland
Volume: 14
Issue: 6
Author(s): Monika Pobiega, Iwona Myjak, Monika Pomorska-Wesolowska, Dorota Romaniszyn, Grzegorz Ziólkowski, Agnieszka Chmielarczyk, Joanna Maciag, Anna Szczypta and Jadwiga Wojkowska-Mach
Affiliation:
Keywords:
Diabetic foot ulcers, methicillin-resistant Staphylococcus aureus, antimicrobial resistance, virulence, mupirocin,
Poland.
Abstract: The prevalence of methicillin-resistant Staphylococcus aureus (MRSA)
was investigated among infected diabetic foot ulcers in hospitalized and nonhospitalized
patients in southern Poland to assess the virulence patterns and antimicrobial
resistance among these strains. MRSA was detected in 10.3% of all studied
isolates, from the hospitalized patients only. The rest of the isolates was methicillin
susceptible. The minimal inhibitory concentration that inhibits 50% of bacterial isolates
(MIC50) for vancomycin was 1.0 mg/mL. The mupA gene was detected in six
(8.8%) isolates, in one MRSA strain and five methicillin-sensitive S. aureus (MSSA)
strains. Among the mupA-positive strains, two were resistant to mupirocin (1 MRSA
and 1 MSSA). Such results raise serious concern about the usage of mupirocin in
MRSA decolonization. The pvl gene was not detected among the study isolates. The majority of isolates
(70.6%) possessed the lukE gene, with no significant difference in prevalence between MRSA and MSSA
isolates. An interesting finding was the presence of enterotoxin genes among the study isolates. Diabetic
foot may therefore be a reservoir of bacteria, containing genes localized on mobile genetic elements that
could be easily transferred to other non-pathogenic strains. The prevalence of MRSA was alarmingly high
(as also suggested by others), as evaluated by the presence of the mup gene among strains, highlighting
the importance of appropriate clinical management of MRSA infections in patients with diabetic foot
ulcers. In this group of patients, screening of ulcer samples before antimicrobial therapy would enable
informed choices regarding the selection of antimicrobial agents (e.g. octenidine, authorized for the
treatment of chronic wounds) maximizing the chances of positive therapy.
