A study on macrolide and lincosamide resistance in pathogenic Gram positive cocci

Abstract

Erythromycin and clindamycin are clinically useful antibiotics. They are the major alternatives to β-lactam antibiotics in methicillin resistance infections and also for penicillin allergic patients. In the present study, two hundred clinical samples were collected from Microbiology lab at Cairo University Specialized Pediatric Hospital (CUSPH) in Cairo, Egypt, from September 2012 – February 2014. Samples were collected from different sources such as blood, sputum, wound, palate swabs and endotracheal aspirate. All the samples were collected from neonates, infants and children with age range from <1 – 13 years. Samples were cultured on blood agar and MacConkey agar media. Colonies were microbiologically investigated; those suspected of being staphylococci and streptococci were selected and screened for erythromycin resistance. Identification of staphylococci and streptococci was carried out by a variety of conventional phenotypic characters such as Gram stain, catalase test, coagulase test and optochin test. The antibiotics susceptibility test of erythromycin resistant isolates was detected by disk diffusion test. The prevalence of MLSB phenotypes was determined by double disk diffusion test (D- zone test). All erythromycin resistant staphylococcal isolates were tested by PCR for ermA, ermB, ermC, msrA and mef genes while Str. pneumoniae isolates were tested by m