title: Methicillin resistant coagulase negative staphylococcus: From colonizer to a pathogen.
abstract: The objective of our study was to determine the frequency of methicillin resistance in coagulase negative Staphylococcus (CoNS) and to determine its in-vitro antimicrobial susceptibility to various other routinely used antibiotics. It was a cross sectional study conducted at the department of Microbiology, Army Medical College, Rawalpindi, Pakistan from June 2011 to May 2012. The organisms were identified on the basis of colony morphology, Gram staining, catalase, DNAase and slide/tube coagulase tests. The organisms were considered to be methicillin resistant when the diameter of zone of inhibition was less than 25mm around 30μg cefoxitin disc. Antibiotic sensitivity was determined using the Modified Kirby-Bauer disc diffusion method. From a total of 337 CoNS, 201 were methicillin resistant and were included in the study. All were resistant to Penicillin, followed by Erythromycin (93•1%), Ciprofloxacin (77%), Co-trimoxazole (74•8%), Gentamicin (68•3%), Clindamycin (51•06%), Tetracycline (44•6%), Fusidic acid (40%), Rifampicin (39•5%), Chloramphenicol (19•3%), Linezolid (2%), Minocycline (1•1%), and Vancomycin (0%). More than half of CoNS were methicillin resistant. Vancomycin is the only drug to which all of the MRCoNS were sensitive, with more than 98% of the isolates being sensitive to Linezolid and Minocycline.
authors.affiliation: Department of Microbiology, Army Medical College Rawalpindi, National University of Sciences and Technology Islamabad, Pakistan.
authors.forename: Mehreen
authors.initials: M
authors.lastname: Gilani
authors.affiliation: Department of Microbiology, Army Medical College Rawalpindi, National University of Sciences and Technology Islamabad, Pakistan.
authors.forename: Javaid
authors.initials: J
authors.lastname: Usman
authors.affiliation: Department of Microbiology, Army Medical College Rawalpindi, National University of Sciences and Technology Islamabad, Pakistan.
authors.forename: Mahwish
authors.initials: M
authors.lastname: Latif
authors.affiliation: Department of Microbiology, Army Medical College Rawalpindi, National University of Sciences and Technology Islamabad, Pakistan.
authors.forename: Tehmina
authors.initials: T
authors.lastname: Munir
authors.affiliation: Department of Microbiology, Army Medical College Rawalpindi, National University of Sciences and Technology Islamabad, Pakistan.
authors.forename: Maria Mushtaq
authors.initials: MM
authors.lastname: Gill
authors.affiliation: Department of Microbiology, Army Medical College Rawalpindi, National University of Sciences and Technology Islamabad, Pakistan.
authors.forename: Rabia
authors.initials: R
authors.lastname: Anjum
authors.affiliation: Department of Microbiology, Army Medical College Rawalpindi, National University of Sciences and Technology Islamabad, Pakistan.
authors.forename: Nazish
authors.initials: N
authors.lastname: Babar
mesh_terms: D003030:Coagulase / Q000032:analysis; D016106:Methicillin Resistance; D008826:Microbial Sensitivity Tests; D013210:Staphylococcus / Q000187:drug effects* / Q000201:enzymology
chemical_list: D003030:Coagulase