Determining the Patterns of Antimicrobial Susceptibility and the Distribution of blaCTX-M Genes in Strains of Acinetobacter Baumannii Isolated from Clinical Samples

Document Type : Original Article (s)

Authors

1 Department of Biology, Islamic Azad University, Science and Research Branch, Tehran, Iran

2 Assistant Professor, Molecular Biology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran

3 Associate Professor, Department of Microbiology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran

Abstract

Background: Nowadays, multidrug resistant (MDR) Acinetobacter baumannii (A. baumannii) strains are as one of the problematic opportunistic pathogens, especially in intensive care units in the world. The purpose of current study was to define the antibiotic susceptibility patterns and detect the prevalence of producing strains of extended-spectrum β-lactamase (ESBL) and the appearance of betalactamase CTX-M-II enzymes in A. baumannii strains.Methods: This study was conducted in 3 major hospitals in Tehran, Iran, on 500 clinical samples during one year. After the identification of isolates in species, test sensitivity was carried out to 4 antibiotics by using the disk diffusion method according to Clinical and Laboratory Standards Institute (CLSI) guidelines; also minimum inhibitory concentrations (MIC) was determined for cefepime, cefotaxime and ceftazidime; and finally, to identify the producing strains of ESBL, phenotypic method of combined-disk was used and then, isolates were considered for presence of blaCTX-M-II gene by polymerase chain reaction (PCR) assay.Findings: 130 Acinetobacter species were isolated from the patients. The majority of isolates was from blood specimens and revealed the highest resistance to cefepime and ceftriaxone. The MIC of cefepime in 91%, for ceftazidime in 84%, and for cefotaxime in 80% of the studied isolates was more than 128 μg/ml. The results of the combined-disk test demonstrated that 20% of samples were ESBL positive. The PCR results showed that 19% of our isolates had bla CTX-M-II gene.Conclusion: Multidrug resistant (MDR) A. baumannii is widespread in Iran and is considered as hazard risk for hospitalized patients; also by virtue of the results of this survey, there are more significant mechanisms than ESBL bacteria such as secretory pumps and changes in purine resistance which causes more resistance, too, and should be consider.

Keywords

References

  1. Peleg AY, Seifert H, Paterson DL. Acinetobacter baumannii: emergence of a successful pathogen. Clin Microbiol Rev 2008; 21(3): 538-82.
  2. Gaynes R, Edwards JR. Overview of nosocomial infections caused by gram-negative bacilli. Clin Infect Dis 2005; 41(6): 848-54.
  3. Fournier PE, Richet H. The epidemiology and control of Acinetobacter baumannii in health care facilities. Clin Infect Dis 2006; 42(5): 692-9.
  4. Diomedi A. Acinetobacter baumannii pandrug-resistant: update in epidemiological and antimicrobial managing issues. Rev Chilena Infectol 2005; 22(4): 298-320. [In Spanish].
  5. Livermore DM, Woodford N. The beta-lactamase threat in Enterobacteriaceae, Pseudomonas and Acinetobacter. Trends Microbiol 2006; 14(9): 413-20.
  6. El SA, Walsh TR, Chouchani C. Extended spectrum beta-lactamases, carbapenemases and mobile genetic elements responsible for antibiotics resistance in Gram-negative bacteria. Crit Rev Microbiol 2013; 39(2): 113-22.
  7. Bonnet R. Growing group of extended-spectrum beta-lactamases: the CTX-M enzymes. Antimicrob Agents Chemother 2004; 48(1): 1-14.
  8. Bush K, Jacoby GA. Updated functional classification of beta-lactamases. Antimicrob Agents Chemother 2010; 54(3): 969-76.
  9. Ambler RP. The structure of beta-lactamases. Philos Trans R Soc Lond B Biol Sci 1980; 289(1036): 321-31.
  10. Clinical and Laboratory Standards Institute. Performance standards for antimicrobial susceptibility testing; twenty-second informational supplement. CLSI document M100-S22. Wayne, PA: Clinical and Laboratory Standards Institute; 2012.
  11. Kim J, Jeon S, Rhie H, Lee B, Park M, Lee H, et al. Rapid detection of extended spectrum β-Lactamase (ESBL) for Enterobacteriaceae by use of a Multiplex PCR-based Method. Infection and Chemotherapy 2009; 41(3): 181-4.
  12. Constantiniu S, Romaniuc A, Iancu SL, Filimon R, Tarasi I. Cultural and biochemical characteristics of Acinetobacter spp. Strains isolated from hospital units. The Journal of preventive Medicine 2004; 12(3-4): 35-42.
  13. Rit K, Saha R. Multidrug-resistant acinetobacter infection and their susceptibility patterns in a tertiary care hospital. Niger Med J 2012; 53(3): 126-8.
  14. Bassetti M, Righi E, Esposito S, Petrosillo N, Nicolini L. Drug treatment for multidrug-resistant Acinetobacter baumannii infections. Future Microbiol 2008; 3(6): 649-60.
  15. Leung WS, Chu CM, Tsang KY, Lo FH, Lo KF, Ho PL. Fulminant community-acquired Acinetobacter baumannii pneumonia as a distinct clinical syndrome. Chest 2006; 129(1): 102-9.
  16. Michalopoulos A, Falagas ME. Treatment of Acinetobacter infections. Expert Opin Pharmacother 2010; 11(5): 779-88.
  17. Wang SH, Sheng WH, Chang YY, Wang LH, Lin HC, Chen ML, et al. Healthcare-associated outbreak due to pan-drug resistant Acinetobacter baumannii in a surgical intensive care unit. J Hosp Infect 2003; 53(2): 97-102.
  18. Smolyakov R, Borer A, Riesenberg K, Schlaeffer F, Alkan M, Porath A, et al. Nosocomial multi-drug resistant Acinetobacter baumannii bloodstream infection: risk factors and outcome with ampicillin-sulbactam treatment. J Hosp Infect 2003; 54(1): 32-8.
  19. Shahcheraghi F, Akbari Shahmirzadi N, Abbas Alipour Bashash M, Jabari H, Amir Mozafari N. Detection of blaCTX ,blaTEM Beta-Lactamases gene in clinical isolates of Acinetobacter spp from selected Tehran hospitals. Iran J Med Microbiol 2009; 3(1): 1-9. [In Persian].
  20. Huang LY, Chen TL, Lu PL, Tsai CA, Cho WL, Chang FY, et al. Dissemination of multidrug-resistant, class 1 integron-carrying Acinetobacter baumannii isolates in Taiwan. Clin Microbiol Infect 2008; 14(11): 1010-9.
  21. Yong D, Shin JH, Kim S, Lim Y, Yum JH, Lee K, et al. High prevalence of PER-1 extended-spectrum beta-lactamase-producing Acinetobacter spp. in Korea. Antimicrob Agents Chemother 2003; 47(5): 1749-51.
  22. Deiham B, Halvaee. The pattern of drug resistance Acinetobacter baumannii isolated from clinical specimens and phenotypic identified extended –spectrum beta-lactamases producing. Iran J Med Sci 2012 ; 37(3) : 267.
  23. Sinha M, Srinivasa H, Macaden R. Antibiotic resistance profile & extended spectrum beta-lactamase (ESBL) production in Acinetobacter species. Indian J Med Res 2007; 126(1): 63-7.
  24. Celenza G, Pellegrini C, Caccamo M, Segatore B, Amicosante G, Perilli M. Spread of bla(CTX-M-type) and bla(PER-2) beta-lactamase genes in clinical isolates from Bolivian hospitals. J Antimicrob Chemother 2006; 57(5): 975-8.
  25. Hashemizadeh Z, Zargani AB, Emami A, Rahimi MJ. Acinetobacter antibiotic resistance and frequency of ESBL-producing strains in ICU patients of Namazi Hospital (2008-2009). J Qazvin Univ Med Sci 2010; 14(2): 47-53. [In Persian].
Journal of Isfahan Medical School
Volume 31, Issue 252 - Serial Number 252
July and August 2013
Pages 1443-1451

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History

  • Receive Date: 24 April 2013
  • Revise Date:
  • Accept Date: 06 April 2022

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