Characterization of staphylococci sampled from diabetic foot ulcer of Jordanian patients.

AIMS: The aim of this study was to isolate and characterize staphylococcal isolates from diabetic foot ulcers (DFU) in Jordanian patients. METHODS AND RESULTS: Selected aerobic pathogens recovered from DFU specimens and patients' nares with a focus on staphylococci were investigated. Antimicrobial susceptibilities and the prevalence of methicillin-resistant staphylococci (MRS) were determined. SCCmec types and toxigenic characteristics were analysed and spa typing was performed for methicillin-resistant Staphylococcus aureus (MRSA) isolates. The relationship between toxigenic characteristics of MRSA and the Wagner ulcer grading system was statistically analysed. A total number of 87 DFU patients were recruited for the study. The DFU cultures were polymicrobial. Members of the genus Staphylococcus were the most common among DFU-associated isolates found in 48·3% (n = 42) of all patients enrolled. Coagulase-negative staphylococci (CoNS) comprised 63·3% of staphylococci isolated from DFUs predominated by Staphylococcus epidermidis in both DFU (7·6%) and nares (39·2%). Staphylococcus aureus was isolated from DFUs and nares in 14·2 and 9·8%, respectively, while 93 and 70% of these isolates were MRSA. Most of MRSA carried SCCmec type IV (76·2%) while SCCmec elements were non-typeable in most methicillin resistant coagulase negative staphylococci (MR-CoNS) (61·9%). The most frequent MRSA spa type was t386 (23·8%). Most MRSA and MR-CoNS exhibited resistance towards aminoglycosides, fluoroquinolones and macrolides and susceptibility towards vancomycin, mupirocin and linezolid. No association was found between the possession of pvl, tst, sea and hlg toxins and Wagner ulcer grading system (P value >0·05). CONCLUSIONS: This analysis of Jordanian DFU culture demonstrated its polymicrobial nature with predominance of Staphylococcus sp. SIGNIFICANCE AND IMPACT OF THE STUDY: This study is the first of its type to assess the microbiology of DFU among Jordanian patients. The results will help in the appropriate application of antimicrobial chemotherapy in the management of DFU.

[Persistent and recurrent skin and soft tissue infections by Staphylococcus aureus. Impact of the small colony-variant (SCV) phenotype and of Panton-Valentine leukocidin (PVL)-positive S. aureus isolates]. / Chronisch rezidivierende Infektionen der Haut und Weichgewebe durch Staphylococcus aureus. Klinische Bedeutung des Small-colony-variant (SCV)-Phänotyps und von Panton-Valentine-Leukozidin (PVL)-positiven S.-aureus-Isolaten.

Staphylococcus aureus is one of the major pathogens causing chronic skin and soft tissue infections. Particularly isolates producing Panton-Valentine leukocidin (PVL) comprising methicillin-susceptible and community-associated methicillin-resistant S. aureus (CA-MRSA) have been associated with more aggressive and persistent or relapsing courses. Beyond classical resistance mechanisms, functional resistance as shown by the small colony-variant (SCV) phenotype could be also responsible for treatment failures, despite the administration of antibiotics tested in vitro as susceptible. Also this phenotype has been associated with chronic courses of infections often with multiple exacerbations. Due to their ability to persist intracellularly, SCVs are protected from host defense and antibiotic treatment if only extracellularly active agents are administered. Reduced growth, abnormal colony morphology and changes in the metabolism of the SCVs aggravate drastically their identification, differentiation and susceptibility testing. The diagnostic and therapeutic challenges of PVL-positive and SCV isolates necessitate close collaboration with microbiological and infectious disease specialists.

The epidemiology and molecular characterization of methicillin-resistant staphylococci sampled from a healthy Jordanian population.

The prevalence of natural carriage and molecular epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant coagulase-negative staphylococci (MR-CoNS) isolates in a Jordanian community were investigated. The MRSA nasal carriage rate in 227 healthy volunteers was 7·5% and the majority (81%) of MRSA harboured the resistance element SCCmec type IVe and were of a novel spa type t9519 (76%); other significant spa gene types were t223 (14·7%) and t044 (5·9%). All MRSA isolates were susceptible to other classes of antibiotics, and tested positive for at least three virulence factor encoding genes, but only two harboured the pvl gene. MR-CoNS carriage was 54·2% and these isolates were characterized by single, double and untypable SCCmec elements, with Staphylococcus epidermidis SCCmec type IVa predominating. Of eight subjects with nasal co-colonization of MR-CoNS + MRSA, three shared SCCmec type IV in both groups of organisms. This is the first report of methicillin-resistant staphylococci carriage in a Jordanian community and its findings are important for epidemiological study and infection control measures of these organisms.