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. 2013;17(3):129-33.
doi: 10.6091/ibj.1107.2013.

Identification and characterization of metallo-β-lactamases producing Pseudomonas aeruginosa clinical isolates in University Hospital from Zanjan Province, Iran

Masoumeh Doosti  1 , Ali Ramazani  2 , Maryam Garshasbi  3
Affiliations

Identification and characterization of metallo-β-lactamases producing Pseudomonas aeruginosa clinical isolates in University Hospital from Zanjan Province, Iran

Masoumeh Doosti et al. Iran Biomed J. 2013.

Abstract

Background: Infectious by Pseudomonas aeruginosa has spread worldwide and metallo-beta-lactamases (MBL) are being reported with increasing frequency. The aim of this study was to investigate the antibiotic susceptibility and distribution of blaVIM and blaIMP genes in P. aeruginosa isolates from Zanjan Province of Iran.

Methods: A total of 70 P. aeruginosa isolates were identified from patients admitted at intensive care units. The antimicrobial susceptibility was tested by disk diffusion (Kirby-Bauer) method and for production of MBL using double-disk synergy test (DDST). After DNA extraction, the presence of blaVIM and blaIMP genes and class 1 integron were detected by PCR.

Results: Most of the isolates were resistant to meropenem, cefotaxime and imipenem (IPM). Also, 44/70 (62.85%) IPM resistant isolates were confirmed by DDST. Of the 44 clinical isolates, 41 (93%) isolates showed MIC≥4 µg/ml for IPM. Based on the DDST results, 36 (87.8%) were confirmed to be MBL producers. PCR amplification showed that 23/41 (56%) carried blaVIM and 10/41 (24.3%) possessed blaIMP gene. Also, 31/44 (70.5%) isolates contained class 1 integron gene.

Conclusion: Our results highlight that the genes for Verona integron-encoded metallo-β-lactamase, IPM β-lactamases and class 1 integrons were predominantly present among the IPM-resistant P. aeruginosa tested in our province and also the frequency of blaVIM type is higher than blaIMP. This is the first report of P. aeruginosa strains producing blaIMP with high frequency from Zanjan province of Iran.

Keywords: Pseudomonas aeruginosa; Beta-lactamases; PCR.

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Figures

Fig. 1
Fig. 1
Gel electrophoresis of PCR products following amplification with specific primers for blaIMP gene (587 bp). Lanes: 1, IMP-1 positive control; 2, 4, 5, 6 and 7, clinical isolates for blaIMP gene; 3, negative isolate; 8, negative control; 9, 1 kb DNA Ladder
Fig. 2
Fig. 2
Gel electrophoresis of PCR products following amplification with specific primers for blaVIM gene (391bp). Lanes: 1, 1 kb DNA ladder; 2, blaVIM gene positive control; 3-7, clinical isolates for blaVIM gene; 8, negative control
Fig. 3
Fig. 3
Gel electrophoresis of PCR products following amplification with specific primers for int1 gene (923 bp). Lanes: 1, negative control; 2-10, clinical isolates for int1 gene; 11, int1 positive control; 12, negative isolate; 13, 1 kb DNA Ladder.
See this image and copyright information in PMC

References

    1. Rodrigues AC, Chang MR, Nobrega GD, Rodrigues MS, Carvalho NC, Gomes BG, et al. Metallo-beta-lactamase and genetic diversity of Pseudomonas aeruginosa in intensive care units in Campo Grande, MS, Brazil. Braz J Infect Dis. 2011 May-Jun;15(3):195–9. - PubMed
    1. Behera B, Mathur P, Das A, Kapil A, Sharma V. An evaluation of four different phenotypic techniques for detection of metallo-beta-lactamase producing Pseudomonas aeruginosa. Indian J Med Microbiol. 2008 Jul-Sep;26(3):233–7. - PubMed
    1. Chin BS, Han SH, Choi SH, Lee HS, Jeong SJ, Choi HK, et al. The characteristics of metallo-beta-lactamase-producing gram-negative bacilli isolated from sputum and urine: a single center experience in Korea. Yonsei Med J. 2011 Mar;52(2):351–7. - PMC - PubMed
    1. Dong F, Xu XW, Song WQ, Lu P, Yu SJ, Yang YH, et al. Characterization of multidrug-resistant and metallo-beta-lactamase-producing Pseudomonas aeruginosa isolates from a paediatric clinic in China. Chin Med J (Engl) 2008 Sep;121(17):1611–6. - PubMed
    1. Juan C, Zamorano L, Mena A, Alberti S, Perez JL, Oliver A. Metallo-beta-lactamase-producing Pseudo-monas putida as a reservoir of multidrug resistance elements that can be transferred to successful Pseudomonas aeruginosa clones. J Antimicrob Chemother. 2010 Mar;65(3):474–8. - PubMed

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