Infection and Drug Resistance (Jul 2020)

Detection of OXA-48 Gene in Carbapenem-Resistant Escherichia coli and Klebsiella pneumoniae from Urine Samples

  • Gurung S,
  • Kafle S,
  • Dhungel B,
  • Adhikari N,
  • Thapa Shrestha U,
  • Adhikari B,
  • Banjara MR,
  • Rijal KR,
  • Ghimire P

Journal volume & issue
Vol. Volume 13
pp. 2311 – 2321

Abstract

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Sushma Gurung,1 Sonali Kafle,2 Binod Dhungel,1 Nabaraj Adhikari,1 Upendra Thapa Shrestha,1 Bipin Adhikari,3 Megha Raj Banjara,1 Komal Raj Rijal,1 Prakash Ghimire1 1Central Department of Microbiology, Tribhuvan University, Kirtipur, Kathmandu, Nepal; 2Alka Hospital, Lalitpur, Nepal; 3Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UKCorrespondence: Komal Raj RijalCentral Department of Microbiology, Tribhuvan University, Kirtipur, Kathmandu, NepalEmail [email protected]: Resistance to carbapenem in Gram-negative bacteria is attributable to their ability to produce carbapenemase enzymes. The main objective of this study was to detect the presence of blaOXA-48 genes in carbapenem-resistant uropathogenic Escherichia coli and Klebsiella pneumoniae isolated from urine samples from patients attending Alka Hospital, Jawalakhel, Lalitpur, Nepal.Methods: A total of 1013 mid-stream urine samples were collected from patients with suspected urinary tract infection (UTI) between April and September 2018. The identified isolates underwent antibiotic susceptibility testing using the modified Kirby–Bauer disc-diffusion method. Phenotypic carbapenemase production was confirmed by the modified Hodge test, and the blaOXA-48 gene was detected using conventional polymerase chain reaction.Results: Out of 1013 urine samples, 15.2% (154/1013) had bacterial growth. Among the isolates, 91.5% (141/154) were Gram-negative bacteria, and E. coli was the most common bacterial isolate (62.9%; 97/154), followed by K. pneumoniae 15.6% (24/154). Among 121 bacterial isolates (97 E. coli isolates and 24 K. pneumoniae isolates), 70.3% (52/121) were multidrug-resistant E. coli and 29.7% (22/121) were multidrug-resistant K. pneumoniae. In addition, 9.1% (11/121) were carbapenem resistant (both imipenem and meropenem resistant). Development of multidrug resistance and development of carbapenem resistance were significantly associated (p< 0.05). Of the 11 carbapenem-resistant isolates, only seven were carbapenemase producers; of these, 28.6% (2/7) were E. coli, 72.4% (5/7) were K. pneumoniae and 42.8% (3/7) had the blaOXA-48 gene. Of the three bacterial isolates with the blaOXA-48 gene, 33.3% (1/3) were E. coli and 66.7% (2/3) were K. pneumoniae.Conclusion: One in ten isolates of E. coli and K. pneumoniae were carbapenem resistant. Among carbapenem-resistant isolates, one-third of E. coli and two-thirds of K. pneumoniae had the blaOXA-48 gene. OXA-48 serves as a potential agent to map the distribution of resistance among clinical isolates.Keywords: antimicrobial resistance, AMR, carbapenem, carbapenemase, modified Hodge test, MHT, blaOXA-48 gene

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