Study The Gene Expression Of blaoxa23 And blaoxa24 Genes In Imipenem Resistant Acinetobacter baumannii Isolated From Burn Wounds

Year 2018, Volume: 12 Issue: 2, 8 - 11, 25.09.2018

Kais Kassim Ghaima , Shurook M.k. Saadedin

Abstract

The aim of this study was to identify changes in the gene expression of blaOXA genes in Acinetobacter baumannii, isolated from burn wounds, in response to subinhibitory concentrations of Imipenem. The gene expression of blaOXA genes was conducted by using real-time quantitative PCR assay. Ten isolates were chosen which had high resistance to Imipenem with minimum inhibitory concentrations (MICs) from 16 to >256 μg/ml and also contained the two blaOXA genes 23 and 24. It was found that the highest value of gene expression fold was recorded for the gene blaOXA23 (6.96) in the local isolate K5 in contrast with the Imipenem untreated samples, while the highest value of fold for blaOXA24 gene was 3.68. It was obvious there was a direct proportion between MICs values and folds of gene expression, therefore the increase of antibiotic concentration in the growth medium led to increasing of gene expression. The results of 16S rRNA gene expression, which was used as a reference gene, demonstrated that this gene was well suited as housekeeping gene because of the minimal variations of expression of this gene whether in Imipenem treated and untreated samples. It was concluded that the resistance of A. baumannii to Imipenem was related to the genes blaOXA23 and blaOXA24 but the main role may be due to blaOXA23. The presence of both genes increases the resistance of this species to Imipenem.

Keywords

Acinetobacter baumannii, gene expression, blaOXA

References

• Kempf M, Rolain JM. 2012. Emergence of resistance to carbapenems in Acinetobacter baumannii in Europe: clinical impact and therapeutic options. Int. J. Antimicrob. Agents. 39: 105–114.
• Keen EF, Robinson BJ, Hospenthal DR, Aldous WK, Wolf SE, Chung KK, Murray CK. 2010. Prevalence of multidrug resistant organisms recovered at a military burn center. Burns. 36: 819–825.
• Urban C, Segal-Maurer S, Rahal JJ. 2003. Considerations in control and treatment of nosocomial infections due to multidrug resistant Acinetobacter baumannii. Clin. Infect. Dis. 36:1268-1274.
• Rossolini GM, Mantengoli E, Docquier JD, Musmanur A, Cortaza G. 2007. Epidemiology of infections caused by multiresistant gram-negatives: ESBLs, MBLs, panresistant strains. New Microbiol. 30: 332-339.
• Woodford N, Ellington MJ, Coelho JM, Turton JF, Ward ME, Brown S, Amyes SG, Livermore DM. 2006. Multiplex PCR for genes encoding prevalent OXA carbapenemases in Acinetobacter spp. Int. J. Antimicrob. Agents. 27: 351-353.
• Ghaima KK, Saadedin SMK, Jassim KA. 2016. Prevalence of blaOXA Like Carbapenemase Genes in Multidrug Resistant Acinetobacter baumannii Isolated From Burns and Wounds in Baghdad Hospitals. Res. J. Pharmaceut. Biologic. Chem. Sci. 7(3): 1247.
• Higgins PG, Wisplinghoff H, Stefanik D, Seifert H. 2004. Selection of topisomerase mutations and overexpresson of adeB mRNA transcripts during an outbreak of Acinetobacter baumannii. J. Antimicrob. Chemother. 54: 821-823.
• Schmittgen TD, Livak KJ. 2008. Analyzing real-time PCR data by the comparative (CT) method. Nat. Protoc. 3: 1101–1108.
• Rebouças EDL, Costa JJDN, Passos MJ, Passos JRDS, Hurk RVD, Silva JRV. 2013. Real time PCR and importance of housekeeping genes for normalization and quantification of mRNA expression in different tissues. Brazilian Archives of Biology and Technology. 56(1): 143-154.
• Rawat D, Nair D. 2010. Extended-spectrum β-lactamases in Gram Negative Bacteria. J. Glob. Infect. Dis. 2(3): 263–274.
• Higgins PG, Dammhayn C, Hackel M, Seifert H. 2010. Global spread of carbapenem-resistant Acinetobacter baumannii. J. Antimicrob. Chemother. 65:233–238.
• Corvec S, Poirel L, Naas T, Drugeon H, Nordmann P. 2007. Genetics and expression of the carbapenem-hydrolyzing oxacillinase gene blaOXA-23 in Acinetobacter baumannii. Antimicrob. Agents Chemother. 51: 1530-1533.
• Kuo HY, Yang SP, Lee YT. 2013. Dissemination of imipenem-resistant Acinetobacter baumannii with new plasmidborne blaOXA-72 in Taiwan. BMC Infectious Diseases.13: 319.
• Dheda K, Huggett J, Chang J, Kim L, Bustin S. 2005. The implications of using an inappropriate reference gene for real-time reverse transcription PCR data normalization. Anal. Biochem. 344: 141–143.
• Huggett J, Dheda K, Bustin S, Zumla A. 2005. Real-time RT-PCR normalisation; strategies and considerations. Genes Immun. 6: 279–284.
• Vandecasteele S, Peetermans W, Merckx R, Van Eldere J. 2001. Quantification of expression of Staphylococcus epidermidis housekeeping genes with Taqman quantitative PCR during in vitro growth and under different conditions. Journal of Bacteriology. 183: 7094-7101.
• Hansen M, Nielsen A, Molin S, Hammer K, Kilstrup M. 2001. Changes in rRNA levels during stress invalidates results from mRNA blotting: Flourescence in situ rRNA hybridization permits renormalization for estimation of cellular mRNA levels. J. Bacteriol. 183(16): 47-51.