Phenotypic and molecular characterization of staphylococcus aureus isolated from hospitals and community in Bangalore

Abstract

The important observations in our study A total of 104 S. aureus from clinical samples, 23 S. aureus from hospital personnel and 50 S. aureus from healthy individuals were obtained.Among clinical isolates, most of the isolates were from pus, obtained from burns ward. Significant number of isolates were also obtained from sputum, urine and catheter tips.Among hospital personnel S. aureus isolation was highest in nursing assistants followed by nurses and doctors. S. aureus isolation among healthy individuals was maximum in school children followed by adults.In all 177 S. aureus isolates were obtained from hospitals and community.Among 177 S. aureus, 88 isolates were confirmed as MRSA by various phenotypic methods.We observed 100% concordance in the results obtained from various phenotypic methods. Remaining 89 S. aureus isolates were identified as MSSA. Overall S. aureus isolation rate was found to be 50.86% (177/348) and incidence of MRSA was 25.28% (88/348) incidence of MRSA carriage rate in healthy individuals of community was very low 6.3% (7/110) and was high (32.85%) (Table-9) in the clinical samples.The S. aureus isolates from clinical samples and hospital personnel showed higher MIC values ranging from 32-512 and#61549;g/ml, whereas S. aureus isolates from healthy individuals had lower oxacillin MIC ranging from 2 - 64 and#61549;g/ml.S. aureus isolates from clinical samples and hospital personnel showed high resistance to most of the antibiotics tested. S. aureus isolates from clinical specimens and hospital personnel (hospital acquired MRSA) were resistant to most of the antibiotics and were multi-drug resistant isolates.Whereas, MRSA isolates from healthy individuals were resistant to 7 to 8 antibiotics. Only 1 isolate was resistant to 10 antibiotics and all isolates were susceptible to vancomycin. newlineAmong the MRSA isolates (38) from all types of samples screened for the SCCmec typing, S. aureus isolates from clinical and hospital personnel possessed SCCmec type III or its variants and isolate community had type IV SCCmec.