title: Epidemiology and antimicrobial resistance of staphylococci isolated from different infectious diseases.
abstract: A total of 187 isolates from 470 clinical specimens were collected from three hospitals in El-Minia governorate and identified as 132 Staphylococcus aureus strains and 55 coagulase-negative staphylococci (CoNS) strains. Susceptibility of isolates to antimicrobial agents was tested by the agar dilution method. The isolated S. aureus strains showed low resistance to vancomycin (1.5%), amikacin (2.3%) and gatifloxacin (3.8%). Vancomycin was the most effective antibiotic against CoNS. The ampicillin-resistant isolates were tested for β-lactamase production where, 61.7% of S. aureus and 42.9% of CoNS were positive for β-lactamase enzyme. Beta-lactamase producing strains were screened for their plasmid profile using alkaline lysis method. Some of these strains carried at least one plasmid suggesting plasmid-mediated antibiotic resistance. When cells of these strains were exposed to curing agent ethidium bromide, the production of the β-lactamase was lost. Resistance by efflux was studied by a modified fluorometric assay. Addition of uncoupler carbonyl cyanide m-chlorophenylhydrazone (CCCP) increased norfloxacin accumulation in quinolone resistant S. aureus strains, suggesting endogenous energy-dependent efflux. Combinations of ciprofloxacin with four antimicrobial agents against methicillin resistant S.aureus (MRSA) strains were investigated using decimal assay for additivity (DAA) technique. Synergistic interaction was observed between ciprofloxacin and oxacillin. ciprofloxacin plus cefepime and gentamicin appeared to be additive, while ciprofloxacin plus erythromycin was antagonistic.
authors.affiliation: Microbiology Department, Faculty of Pharmacy , El-Minia University , Egypt.
authors.forename: Gamal Fadl M
authors.initials: GF
authors.lastname: Gad
authors.forename: Abd
authors.initials: A
authors.lastname: El-Ghafar
authors.forename: Ramadan A A
authors.initials: RA
authors.lastname: El-Domany
authors.forename: Zeinab Shawky
authors.initials: ZS
authors.lastname: Hashem
keywords: CCCP; DAA technique; efflux; fluorometric assay; β-lactamase
references.citation: Eur J Clin Microbiol Infect Dis. 1997 Jul;16(7):535-7
references.pmid: 9272391
references.citation: Genet Mol Res. 2003 Mar 31;2(1):63-76
references.pmid: 12917803
references.citation: Pak J Pharm Sci. 2007 Oct;20(4):299-304
references.pmid: 17604253
references.citation: Med Mal Infect. 2008 Jan;38(1):18-24
references.pmid: 18065180
references.citation: Int J Antimicrob Agents. 2007 May;29 Suppl 3:S23-32
references.pmid: 17659209
references.citation: Antimicrob Agents Chemother. 1993 Feb;37(2):260-4
references.pmid: 8452356
references.citation: Clin Infect Dis. 1998 May;26(5):1179-81
references.pmid: 9597249
references.citation: Expert Opin Ther Targets. 2003 Jun;7(3):311-28
references.pmid: 12783569
references.citation: Intern Med J. 2005 Dec;35 Suppl 2:S3-16
references.pmid: 16271060
references.citation: Indian J Ophthalmol. 2007 Jan-Feb;55(1):9-13
references.pmid: 17189880
references.citation: J Med Microbiol. 2004 Sep;53(Pt 9):941-944
references.pmid: 15314204
references.citation: Ann Intern Med. 1982 Sep;97(3):339-44
references.pmid: 6981367
references.citation: Antimicrob Agents Chemother. 2002 Jul;46(7):2276-8
references.pmid: 12069989
references.citation: Mem Inst Oswaldo Cruz. 2007 Feb;102(1):29-33
references.pmid: 17293995
references.citation: J Antimicrob Chemother. 2001 Mar;47(3):261-70
references.pmid: 11222558
references.citation: Int J Antimicrob Agents. 2003 Nov;22(5):502-7
references.pmid: 14602369
references.citation: Antimicrob Agents Chemother. 1989 Jan;33(1):27-9
references.pmid: 2540707
references.citation: Biochem Pharmacol. 2006 Mar 30;71(7):949-56
references.pmid: 16290174
references.citation: J Bacteriol. 2000 Apr;182(8):2170-8
references.pmid: 10735859
references.citation: J Clin Microbiol. 2005 Jan;43(1):179-85
references.pmid: 15634969
references.citation: J Antimicrob Chemother. 1994 Mar;33(3):465-81
references.pmid: 8040112
references.citation: Infection. 1995 May-Jun;23(3):154-61
references.pmid: 7499004
references.citation: Biochimie. 2005 Dec;87(12):1137-47
references.pmid: 15951096
references.citation: Antimicrob Agents Chemother. 1996 Aug;40(8):1835-42
references.pmid: 8843290
references.citation: J Antimicrob Chemother. 1999 Sep;44(3):343-9
references.pmid: 10511401
references.citation: Wien Klin Wochenschr. 2004 Jul 31;116(14):489-94
references.pmid: 15379145
references.citation: J Infect Dis. 1991 May;163(5):1080-6
references.pmid: 1850442
references.citation: Singapore Med J. 2007 Aug;48(8):741-3
references.pmid: 17657382