ANTIMICROBIAL SUSCEPTIBILITY PATTERN OF STAPHYLOCOCCUS AUREUS ON CLINICAL ISOLATES AND EFFICACY OF LABORATORY TESTS TO DIAGNOSE MRSA: A MULTI-CENTRE STUDY
Abstract
Background: The global problem of increasing trend in antimicrobial resistance is particularly pressingin the developing countries, where the Methicillin-Resistant Staphylococcus aureus (MRSA) is often thesevere casual agent in hospital-acquired infections. Methods: This multi-centre surveillance prospectivestudy was planned to define the magnitude of problem of MRSA among clinical isolates from fourteaching hospitals of Lahore Pakistan; Mayo, Services, Jinnah and Shaikh Zayed Hospitals during April2006–March 2008. Identification of organisms was done by the standard Microbiology methods. MRSAisolates identified on Kirby-Bauer disc diffusion were further evaluated by minimum inhibitoryconcentration on BD PhoenixTM system and detection of mecA gene by pulsed-field gel electrophoresis(PFGE) PCR. Results: Of the total 1,102 S. aureus isolates, oxacillin resistance was found in 462 on discdiffusion and 420 on MIC while mecA gene was detected from 307 strains. The prevalence of MRSAamong S. aureus isolates was 41.9%, 38.1% and 27.9% on disc diffusion, MIC, and mecA genedetection respectively. Hospital acquired-MRSA strains were multi drug resistant while communityacquired-MRSA showed susceptibility to clindamycin (63%), ciprofloxacin (24.2%) and SMZ/TMP(3.9%). In diagnosing MRSA, the sensitivity and specificity rates of disc diffusion test were 100% and83.7% while MIC 96.2% and 93.3% respectively. Conclusion: There is an increasing trend inemergence MRSA and the conventional method of antimicrobial susceptibility testing showed falsepositive tests. This is the reason of misuse of vancomycin by physicians which may further increaseMRSA in Pakistan. Therefore, molecular diagnostic facilities are recommended to avoid falsesusceptibleresults.Keywords: S. aureus, MRSA, mecA gene, MICReferences
Oliveira CD, Tomaz A, Lencastre H. Secrets of success of a human
pathogen: molecular evolution of pandemic clones of methicillinresistant Staphylococus aureus. Lancet 2002;2:180–89.
Hsu LY, Wijaya L, Tan BH. Management of healthcare-associated
methicillin-resistant Staphylococcus aureus. Expert Rev Anti Infect
Ther 2005;3:893–905.
Zafar A, Stone M, Ibrahim S, Parveen Z, Hasan Z, Khan E, et al.
Prevalent genotypes of meticillin-resistant Staphylococcus aureus:
report from Pakistan. J Med Microbiol 2011;60:56–62.
Francois P, Pittet D, Bento M. Rapid detection of Methicillinresistant Staphylococcus aureus directly from sterile or nonsterile
clinical samples by a new molecular assay. J Clin Microbiol
;41:254–60.
CLSI. Performance standards for antimicrobial susceptibility
testing. CLSI approved standard M100-S15. Wayen USA: Clinical
and Laboratory Standards Institute; 2007.
Safdar N, Narans L, Gordon B, Maki DG. Comparison of culture
screening methods for detection of nasal carriage of methicillinresistant Staphylococcus aureus: a prospective study comparing
methods. J Clin Microbiol 2003;41:3163–6.
Ashiq B, Tareen AK. Methicillin resistant Staphylococcus aureus
in a teaching hospital of Karachi-a laboratory study. J Pak Med
Assoc 1989;39:6–9.
Qureshi AH, Hannan A. The prevalence and susceptibility pattern
of Methicillin resistant Staphylococcus aureus. Pak J Pathol
;2:41–4.
Siddique M, Karamat KA, Hannan A. Prevalence of Resistance to
methicillin resistant Staphylococcal aureus (MRSA) A study at
PAF Hospital Sargodha. Pak J Pathol 1999;10:26–9.
Latif S, Anwar MS, Chaudhry NA. The susceptibility pattern of
nosocomial Methicillin resistant Staphylococcus aureus (MRSA)
isolates to vancomycin and other anti-staphylococcal antibiotics.
Biomedical 2000;16:32–5.
Hafiz S, Hafiz AN, Ali L, Chughtai AS. Methicillin resistant
Staphylococcus aureus: A multicentre study. J Pak Med Assoc
;52:312–515.
Anwar MS, Jaffery G, Bhatti KU, Tayyab M, Bokhari SR.
Staphylococcus aureus and MRSA nasal carriage in general
population. J Coll Physicians Surg Pak 2004;14:661–4.
Bukhari MH, Iqbal A, Khatoon NA. Laboratory study of
susceptibility of methicillin-resistant Staphylococcus aureus
(MRSA). Pak J Med Sci 2004;20:229–33.
Perwaiz S, Barakzi Q, Farooqi BJ, Khursheed N, Sabir N.
Antimicrobial susceptibility pattern of clinical isolates of methicillin
resistant Staphylococcus aureus. J Pak Med Assoc 2007;57:2–4.
Chen Z, Fan X, Lu X. Combination PCR of mecA, femA genes for
detection of MRSA. Sichuan Da Xue Xuc Bao Yi Xue Ban
;34:663–6.
Krishnan PU, Miles K, Shetty N. Detection of methicillin and
mupirocin resistance in Staphylococcus aureus isolates using
conventional and molecular methods: a descriptive study from a
burns unit with high prevalence of MRSA. J Clin Pathol
;55:745–48.
Zeeshan M, Jabeen K, Khan E, Irfan S, Ibrahim S, Parween Z,
Zafar A. Comparison of different methods of detection of
methicillin resistance in Staphylococcus aureus with molecular
detection of mecA gene. J Coll Physicians Surg Pak
;17:666–70.
Geha DJ, Uhl JR, Gustaferrro CA, Persing DH. Multiplex PCR for
identification of methicillin-resistant Staphylococci in the clinical
laboratory. J Clin Microbiol 1994;32:1768–72.
Robert LS, Lars V, Pallesen RL, Poulsen, Espersen F. Evaluation
of a new 3-h hybridization method for detecting the mecA gene in
Staphylococcus ureus and comparison with existing genotypic and
phenotypic susceptibility testing methods. J Antimicrob Chemo
;43:467–75.
Ojulong J, Mwambu TP, Joloba M, Bwanga F, Kaddu-Mulindwa
DH. Relative prevalence of methicilline resistant Staphylococcus
aureus and its susceptibility pattern in Mulago Hospital, Kampala,
Uganda. Tanzan J Health Res 2009;11(3):149–53.
Nevet A, Ashkenazi S, Samra Z, Livni G. Community-associated
methicillin-resistant Staphylococcus aureus infections in Israel. Isr
Med Assoc J 2010;12:428–30.
Majumder D, Bordoloi JS, Phukan AC, Mahanta J. Antimicrobial
susceptibility pattern among methicillin resistant staphylococcus
isolates in Assam. Indian J Med Microbiol 2001;19:138–40.
Araj GF, Talhoulk RS, Simaan CJ, Maasad MJ. Discrepancies
between mecA PCR and conventional tests used for detection of
methicillin-resistant Staphylococcus aureus. APMIS
;102:241–5.
Cekovska Z, Panovski N, Petrovska M, Kristof K, Rozgonyi F.
Incidence of Staphylococcus aureus isolated from patients treated
at the Clinical Center of Skopje, Macedonia, with special attention
to MRSA. Acta Microbiol Immunnol Hung 2005;52:373–84.
Sisirak M, Zvizdic A, Hukic M. Methicillin-resistant
Staphylococcus aureus (MRSA) as a cause of nosocomial wound
infections. Bosn J Basic Med Sci 2010;10(1):32–7.
Malik N, Butt T, Arfan-ul-Bari. Frequency and antimicrobial
susceptibility pattern of methicillin resistant Staphylococcus aureus.
J Coll Physicians Surg Pak 2009;19:287–90.
Shrestha B, Pokhrel BM, Mohapatra TM. Antibiotic susceptibility
pattern of nosocomial isolates of Staphylococcus aureus in a tertiary
care hospital, Nepal. J Nepal Med Assoc 2009;48:234–8.
Bukharie HA. Increasing threat of community-acquired methicillinresistant Staphylococcus aureus. Am J Med Sci 2010;340:378–81.
Cataldo MA, Taglietti F, Petrosillo N. Methicillin-resistant
Staphylococcus aureus: a community health threat. Postgrad Med
;122(6):16–23.
Marchese A, Gualco L, Maioli E, Debbia E. Molecular analysis and
susceptibility patterns of meticillin-resistant Staphylococcus aureus
(MRSA) strains circulating in the community in the Ligurian area, a
northern region of Italy: emergence of USA300 and EMRSA-15
clones. Int J Antimicrob Agents 2009;34(5):424–8.
Downloads
Published
Issue
Section
License
Journal of Ayub Medical College, Abbottabad is an OPEN ACCESS JOURNAL which means that all content is FREELY available without charge to all users whether registered with the journal or not. The work published by J Ayub Med Coll Abbottabad is licensed and distributed under the creative commons License CC BY ND Attribution-NoDerivs. Material printed in this journal is OPEN to access, and are FREE for use in academic and research work with proper citation. J Ayub Med Coll Abbottabad accepts only original material for publication with the understanding that except for abstracts, no part of the data has been published or will be submitted for publication elsewhere before appearing in J Ayub Med Coll Abbottabad. The Editorial Board of J Ayub Med Coll Abbottabad makes every effort to ensure the accuracy and authenticity of material printed in J Ayub Med Coll Abbottabad. However, conclusions and statements expressed are views of the authors and do not reflect the opinion/policy of J Ayub Med Coll Abbottabad or the Editorial Board.
USERS are allowed to read, download, copy, distribute, print, search, or link to the full texts of the articles, or use them for any other lawful purpose, without asking prior permission from the publisher or the author. This is in accordance with the BOAI definition of open access.
AUTHORS retain the rights of free downloading/unlimited e-print of full text and sharing/disseminating the article without any restriction, by any means including twitter, scholarly collaboration networks such as ResearchGate, Academia.eu, and social media sites such as Twitter, LinkedIn, Google Scholar and any other professional or academic networking site.