ABSTRACT
Background: Methicillin resistant staphylococcus aureus [MRSA] has emerged as a serious and commonly occurring problem in diabetic patients with foot ulcers. Its ability to form biofilms helps the bacterium to survive hostile environment within the host, and is considered responsible for chronic or persistent infections
Objectives: To predict the prevalence of MRSA as well as its biofilm forming capacity among patients with infected diabetic foot ulcers and clarify potential risk factors related to this infection
Subjects and methods: Eighty two patients with infected diabetic foot ulcers was involved in this study. Samples obtained from ulcers were directly plated on MacConkey, blood and mannitol salt agar ,incubated aerobically, and anaerobic culture on GN and NS media was done, all colonies appeared were examined macroscopically and different pathogens identified by gram stain and the available biochemical reactions .Coagulase, catalase tests and APIStaph system for staphylococcus aureus [S.aureus]identification were done. All S.aureus isolates were examined by polymerase chain reaction [PCR] for MRSA mecA genedetection, then MRSA strains examined for biofilm formation via PCR detection of icaA and D gene and quantitative tissue culture plate method [TCP]
Results: A total of 103 isolates were detected from 82 infected diabetic ulcer specimens, averaging1.3 species per patient. The most frequent isolated organism was 43[41.7%] staphylococcus aureus .Among the 43 staphylococcus aureus, 21 [48.8%] were [MRSA] and among them 11 [52.4%] were biofilm producers .Screening of the extent of biofilm formation of the isolated MRSA by tissue culture assay [TCP] revealed that 7/11[63.6%] were strong adherent,2[18.2%] were moderate adherent and 2[18.2%] were non/weak adherent . Regarding the demographic and clinical characteristics of patients with MRSA and non MRSA infected diabetic foot ulcers, the risk for MRSA isolation was significantly increase with older age, longer duration of diabetes mellitus, larger size of the ulcer as well as presence of osteomyelitis [p?0.05]
Conclusion: MRSA and its biofilm were isolated frequently from infected foot ulcers of diabetic patients . Because of the different lines of treatment between MRSA and biofilm, rapid diagnosis and treatment of MRSA is important and screening for MRSA biofilm production in infected diabetic foot ulcers is mandatory