Original Articles

Investigation of Class I, II and III Integrons among Acinetobacter Strains Isolated from Ventilator-Associated Pneumonia Patients in Intensive Care Unit of Rasoul Akram Hospital in Tehran, Iran


Background: Multi-drug resistant strains of Acinetobacter spp. have created therapeutic problems worldwide. The objective of this study was to detect integrons  in Acinetobacter  spp. isolates  from Ventilator-Associated  Pneu- monia patients using PCR method.Methods: A total 51 Bronchoalveolar lavage samples were obtained from patients in ICU and examined for Acinetobacter spp. infection by biochemical and PCR methods using blaOXA51-like primers. Antimicrobial susceptibility testing was performed using disk diffusion and MIC methods.Results: Among 51 patients with VAP (62.7% males, 35.2% females, mean age 53 year), 50 (98%) were positive, with a high prevalence of gram-nega- tive bacteria, mainly Acinetobacter spp. (70%), from which A. baumani was detected in 34 (68%) and A. lwoffii in 1 (2%) of isolates. More than 90% of isolates were resistant to imipenem,  piperacillin+tazobactam,  third genera- tion cephalosporins and gentamicin, while the most effective antibiotic was colistin (100%). The correlation coefficient between disk diffusion and MIC was 0.808 (p = 0.001). Three Acinetobacter isolates (8%) harbored integrase I gene but none of isolates contained Class II or III integrons.Conclusion: The results showed that colistin was an effective antibiotic and can be used for treatment  of patients in ICU. Due to the high number of MDR isolates lacking Integrons it can be concluded that although class I in- tegrons are important among clinical isolates of A. baumannii, they have no significant  role  in  dissemination  of  antibiotic  resistance  genes  in  Rasoul Akram  Hospital in Tehran, Iran. The presence of IntI in A. lwoffii may be related to transfer of integron to A. baumannii which can be considered as an important threat for hospitalized patients.

Bergogne-Berezin E, Towner KJ. Aci- netobacter spp. as nosocomial pathogen s: microbiologfical, clinical and epide - mi ological Features. Clin Microbiol Rev 1996; 9: 148-65.

Bergogne-Berezin E., 1996. Resistance of Acinetobacter spp. to antimicrobials overview of clinical resistance patterns and therapeutic problems. In: Bergogne- Berezin E. Jully-guilon ML, Towner KJ. Acinetobacter Microbiology, epidemic ology, infections, management. CRC press, Boca raton, pp. 225-36.

Koeleman JG, Stoof MJ, Van der Bijl MW, et al. Identification of epidemic strains of Acinetobacter baumannii by integrase gene PCR. J Clin Microbiol 2001; 39 (1): 8-13.

Ruiz J, Navia MM, Casals J, et al. Inte- gron-mediated antibiotic resistance in Acinetobacter baumannii clinical iso- lates from Spain. Clin Microbiol Infect 2003; 9 (9): 907-11.

Rådström, Sköld PO, Swedberg G, et al.Transposon Tn5090 of plasmid R751, which carries an integron, is related to Tn7, Mu, and the retroelements. J Bacteriol 1994; 176 (11): 3257-68.

Stokes HW, Hall RM. A novel family of potentially mobile DNA elements encoding specific gene-integration fun- ctions: integrons. Mol Microbiol 1989;3 (12): 1669-83.

Fournier PE, Vallenet D, Barbe V, et al. Comparative genomics of multidrug resistance in Acinetobacter baumannii. PLoS Genet 2006; 2 (1): e7.

Kazama H, Kizu K, Iwasaki M, et al.Isolation and structure of new inregron that includes a streptomysin resistance gene from the R plasmid of Pseudomo- nas aeruginosa. FEMS Microbiol Lett 1995; 134 (2-3): 137-41.

Turton JF, Woodford N, Glover J, et al.Identification of Acinetobacter bauma- nnii by detection of the blaOXA-51- like carbapenemase gene intrinsic to this species. J Clin Microbiol 2006; 44 (8): 2974-6.

Husni RN, Goldstein LS, Arroliga AC, et al. Risk factors for an outbreak of multi-drug-resistant Acinetobacter no- socomial pneumonia among intubated patients. Chest 1999; 115 (5): 1378-82.

CLSI. Method for antimicrobial disk diffusion susceptibility testing of gram negative bacteria. Approved guideline 2010.

Ayan M, Durmaz R, Aktas E, et al.Bacteriological, clinical and epidemiological characteristics of hospital-ac- quired Acinetobacter baumannii infec- tion in a teaching hospital. J Hosp In- fec 2003; 54 (1): 39-45.

Asadollahi KH, Taherikalani M, Ma- leki A, et al. Diversity of aminoglyco- side modifying enzyme genes among multidrug resistant Acinetobacter baumannii genotypes isolated from noso- comial infections in Tehran hospitals and their association with class 1 integrons. Acta Microbiol Immunol Hung2011; 58 (4): 359-70.

Falagas ME, Koletsi PK, Bliziotis IA.The diversity of definitions of multi- drug-resistant (MDR) and pandrugresistant (PDR) Acinetobacter baum-an- nii and Pseudomonas aeruginosa. J Med Microbiol 2006; 55 (pt 12): 1619-29.

Garnacho-Montero J, Ortiz-Leyba C, Jiménez-Jiménez FJ, et al. Treatment of multidrug-resistant Acinetobacter ba umannii Ventilatorassociat-ed Pneumo nia (VAP) with Intravenous Colistin: AComparison with imipenem-susceptibl VAP. Clin Infect Dis 2003; 36 (9):1111-8.

Baraibar J, Correa H, Mariscal D, et al.Risk factors for infection by Acineto- bacter baumannii in intubated patients with nosocomial pneumonia. Chest 1997; 112 (4): 1050-4.

Trouillet JL, Chastre J, Vuagnat A, et al. Ventilator-associated pneumonia caused by potentially drug-resistant bacteria. Am J Respir Crit Care Med 1998; 157(2): 531-9.

Garnacho-Montero J, Ortiz-Leyba C,Fernandez-Hinojosa E, et al. Acinetobacter baumannii ventilator-associated pneumonia: Epidemiological and clini- cal findings. Intensive Care Med 2005;31 (5): 649-55.

Taherikalani M, Maleki A, Sadegifard N, et al. Dissemination of class 1, 2 and 3 Integrons among different multidrug resistant isolates of Acinetobacter baumannii in Tehran hospitals, Iran. Pol J Microbiol 2011; 60 (2): 169.

Basustaoglu AC, Kisa O, Sacilik SC, et al. Epidemiological characterization of hospital-acquired Acinetobacter bauma nnii isolates from a 1500-bed teachinghospital by phenotypic and genotypic methods. J Hosp Infec 2001; 47 (3): 246-7.

Lewis JR, Lewis SA. Colistin interactions with mammalian urothelium. Am J physiol Cell Physiol 2004; 286 (4): 913-22.

Levin AS, Barone AA, Penco J, et al. Intravenous colistin as therapy for no- socomial infections caused by multi- drug-resistant pseudomonas aeruginosa and Acinetobacter baumannii. Clin In- fect Dis 1999; 28 (5): 1008-11.

Japoni S, Japoni A, Farshad SH, et al.Association between Existence of Integrons and Multi-Drug Resistance in Acinetobacter Isolated from Patients in Southern Iran. Pol J Microbiol 2011;60 (2): 163-8.

Bratu S, Landman D, Martin DA, et al. Correlation of antimicrobial resistance with beta-lactamases, the OmpA-like porin, and efflux pumps in clinical isolates of Acinetobacter baumannii en- demic to New York City. Antimicrob Agents Chemother 2008; 52 (9): 2999-3005.

Yan ZQ, Shen DX, Cao JR, et al. Sus- ceptibility patterns and molecular epidemiology of multidrug-resistant Aci- netobacter baumannii strains from thr- ee military hospitals. Int J Antimicrob Agents 2010; 35 (3): 269-73.

IssueVol 1 No 3-4 (2012) QRcode
SectionOriginal Articles
Pneumonia Ventilator-Associated Bronchoalveolar lavage Acinetobacter Integrons

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How to Cite
Mohammadi-Barzelighi H, Talebi-Taher M, Adabi M, Javad-Moosavai SA, Jabbari M, Rastegar-Lari A. Investigation of Class I, II and III Integrons among Acinetobacter Strains Isolated from Ventilator-Associated Pneumonia Patients in Intensive Care Unit of Rasoul Akram Hospital in Tehran, Iran. J Med Bacteriol. 2015;1(3-4):1-9.