title: Antibacterial susceptibility patterns and cross-resistance of methicillin resistant and sensitive staphyloccus aureus isolated from the hospitalized patients in shiraz, iran.
abstract: Nosocomial infections caused by methicillin-resistant staphylococci (MRSA) pose a serious problem in many countries. This study aimed to determine the antibacterial susceptibility patterns of methicillin sensitive and resistant Staphylococcus aureus isolates from the hospitalized patients. Totally 356 isolates of Staphylococcus aureus (S. aureus) including 200, 137 and 19 corresponding to MSSA, MRSA, and intermediate MRSA strains, respectively were isolated. Antibacterial susceptibility patterns of the isolates to 14 antibiotics were examined using Kirby-Bauer method. MICs of 15 antibiotics to 156 MRSA isolates were determined by E test method. Cross-resistances of MRSA isolates (137+19) to the other tested antibiotics were also determined. S.aureus with high frequencies were isolated from the blood, sputum and deep wound samples. All of 200 MSSA isolates were sensitive to oxacillin, vancomycin, tecoplanin, rifampin, linezolid, quinupristin/dalfopristin, mupirocin and fusidic acid. A gradient of reduced susceptibility of MSSA to cephalexin, co-trimoxazole, ciprofloxacin, clindamycin, tetracycline, erythromycin and gentamicin were evident. MRSA isolates were sensitive to vancomycin, tecoplanin, linezolid, quinupristin/dalfopristin, mupirocin and fusidic acid, while reduced susceptibility of them to rifampin, co-trimoxazole, clindamycin, cephalexin, tetracycline, ciprofloxacin, erythromycin and gentamicin were observed. MRSA isolates exhibited a high range of cross-resistance to the eight tested antibiotics. Overall, co-trimoxazole, ciprofloxacin, clindamycin, tetracycline, erythromycin and gentamicin showed low activity against MSSA and MRSA isolates which may indicate they are not suitable to be used in clinical practices. To preserve the effectiveness of antibiotics, rational prescription and concomitant application of preventive measures against the spread of MRSA are recommended.
authors.affiliation: Professor Alborzi Clinical Microbiology Research Center , Shiraz University of Medical Sciences, Shiraz , Iran.
authors.forename: Aziz
authors.initials: A
authors.lastname: Japoni
authors.forename: Mazyar
authors.initials: M
authors.lastname: Ziyaeyan
authors.forename: Marzieh
authors.initials: M
authors.lastname: Jmalidoust
authors.forename: Shohreh
authors.initials: S
authors.lastname: Farshad
authors.forename: Abdolvahab
authors.initials: A
authors.lastname: Alborzi
authors.forename: Noraladdin
authors.initials: N
authors.lastname: Rafaatpour
authors.forename: Parisa
authors.initials: P
authors.lastname: Badiee
keywords: MRSA; empirical therapy; minimum inhibitory concentration
references.citation: Infect Dis Clin North Am. 2009 Mar;23(1):99-131
references.pmid: 19135918
references.citation: Proc Natl Acad Sci U S A. 2001 Sep 11;98(19):10886-91
references.pmid: 11517340
references.citation: Clin Microbiol Rev. 1992 Oct;5(4):387-99
references.pmid: 1423217
references.citation: Microbiology (Reading). 2008 Oct;154(Pt 10):3084-3094
references.pmid: 18832314
references.citation: Anim Health Res Rev. 2008 Dec;9(2):115-26
references.pmid: 19102787
references.citation: Emerg Infect Dis. 1999 Jan-Feb;5(1):9-17
references.pmid: 10081667
references.citation: Br J Clin Pract. 1989 Aug;43(8):284-8
references.pmid: 2516463
references.citation: J Hosp Infect. 2008 May;69(1):46-55
references.pmid: 18358563
references.citation: J Antimicrob Chemother. 2003 Feb;51(2):391-6
references.pmid: 12562708
references.citation: Emerg Infect Dis. 2005 Jun;11(6):808-13
references.pmid: 15963273
references.citation: Biochemistry. 2008 Apr 8;47(14):4228-36
references.pmid: 18335995
references.citation: J Antimicrob Chemother. 2005 Sep;56(3):455-62
references.pmid: 16046464
references.citation: Br Med J. 1963 Feb 2;1(5326):308-11
references.pmid: 13984091
references.citation: Rev Infect Dis. 1984 Jan-Feb;6(1):122-8
references.pmid: 6369479
references.citation: Jpn J Infect Dis. 2009 Jul;62(4):309-11
references.pmid: 19628913
references.citation: N Engl J Med. 2006 Aug 17;355(7):666-74
references.pmid: 16914702
references.citation: Expert Rev Anti Infect Ther. 2008 Jun;6(3):299-307
references.pmid: 18588495
references.citation: Br J Clin Pharmacol. 1999 Aug;48(2):109-24
references.pmid: 10417485
references.citation: J Clin Pathol. 1961 Jul;14:385-93
references.pmid: 13686776
references.citation: Clin Microbiol Infect. 2006 Apr;12(4):345-52
references.pmid: 16524411
references.citation: J Med Microbiol. 2009 Mar;58(Pt 3):331-336
references.pmid: 19208883
references.citation: BMJ. 2006 Aug 5;333(7562):281
references.pmid: 16798756
references.citation: Emerg Med Clin North Am. 2008 May;26(2):431-55, ix
references.pmid: 18406982
references.citation: Am J Clin Pathol. 1999 May;111(5):647-54
references.pmid: 10230355
references.citation: Antimicrob Agents Chemother. 2008 Nov;52(11):3955-66
references.pmid: 18725435
references.citation: J Hosp Infect. 2007 Feb;65(2):117-23
references.pmid: 17145105
references.citation: Intern Med J. 2001 Mar;31(2):97-103
references.pmid: 11480485