ORIGINAL PAPER Prevalence of multidrug-resistant Staphylococcus aureus in diabetics clinical samples S. Raju Æ Ajay Kumar Oli Æ S. A. Patil Æ R. Kelmani Chandrakanth Received: 19 May 2009 / Accepted: 8 August 2009 / Published online: 25 August 2009 Ó Springer Science+Business Media B.V. 2009 Abstract Antibiotic resistance in 40 Staphylococcus aureus clinical isolates from 110 diabetic patients (36%) was evaluated. Of these, 32 (80%) of the isolates showed multidrug-resistance to more than eight antibiotics and 35% isolates were found to be methicillin resistant S. aureus (MRSA). All 40 S. aureus strains (100%) screened from diabetic clinical specimens were resistant to penicillin, 63% to ampicillin, 55% to streptomycin, 50% to tetracycline and 50% to gentamicin. Where as low resis- tance rate was observed to ciprofloxacin (20%) and rif- ampicin (8%). In contrast, all (100%) S. aureus strains recorded susceptibility to teicoplanin, which was followed by vancomycin (95%). Genotypical examination revealed that 80% of the aminoglycoside resistant S. aureus (ARSA) have aminoglycoside modifying enzyme (AME) coding genes; however, 20% of ARSA which showed non-AME mediated (adaptive) aminoglycoside resistance lacked these genes in their genome. In contrast all MRSA isolates possessed mecA, femA genetic determinants in their genome. Keywords Methicillin resistant Staphylococcus aureus Á Aminoglycoside modifying enzymes Á mecA and femA Introduction Diabetic patients are vulnerable to various infections due to impaired leukocyte function associated vascular diseases, poor glucose control and altered host responses (McMahon and Bistrian 1995). Though limb-threatening infections in the diabetic individual are frequently polymicrobial, Staphylococcus aureus is a major pathogen in these infections (Gresham et al. 2000). Type 1 diabetic patient show more frequent colonization of the nose and skin by S. aureus than non-diabetic and non–insulin dependent dia- betic individuals (Dang et al. 2002). Once infected, it is difficult to treat since the clinical course of the infection is more fulminant and severe, and poses a greater threat to the glycemic status of the patient. As a result, diabetic patients may require weeks or months of broad-spectrum antibiotic treatment. Staphylococcus aureus is the predominant pathogen causing bloodstream infections, skin and soft tissue infec- tions, and pneumonia (Lowy 1998). Although limb- threatening infections are usually polymicrobial, S. aureus is a major determinant of these infections particularly in diabetic patients (Karchmer 2002). Unfortunately this pathogen has been developing increased resistance to antimicrobial agents. Since the first isolation of MRSA in the UK in 1961, increasing rates of methicillin resistance among S. aureus strains have been a cause for concern. In addition, MRSA has become resistant to multiples of other antimicrobial agents. MRSA strains have become increas- ingly prevalent among both nosocomial and community- acquired infections (Nadig et al. 2006). Vancomycin had S. Raju Á A. K. Oli Á R. Kelmani Chandrakanth Department of Biotechnology, Gulbarga University, Gulbarga, Karnataka 585 106, India S. A. Patil Department of Neuromicrobiology, National Institute of Mental Health and Neuro Sciences, Bangalore, Karnataka 560 029, India S. Raju (&) Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, Karnataka 560 012, India e-mail: rajusungar@gmail.com 123 World J Microbiol Biotechnol (2010) 26:171–176 DOI 10.1007/s11274-009-0157-5