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

Infection and Drug Resistance 2020:13 2311–2321

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

Sushma Gurung¹ Sonali Kafle² Binod Dhungel¹ Nabaraj Adhikari¹ Upendra Thapa Shrestha¹

Bipin Adhikari³ Megha Raj Banjara¹ Komal Raj Rijal¹ 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, UK

 

ABSTRACT

Introduction: 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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Article on Infection and Drug Resistance

Plasmid Profiling and Occurrence of β-Lactamase Enzymes in Multidrug-Resistant Uropathogenic Escherichia coli in Kathmandu, Nepal

Upendra Thapa Shrestha ^# 1 2, Sabnum Shrestha ^# 1, Nabaraj Adhikari ^1 2, Komal Raj Rijal ², Basudha Shrestha ³, Bipin Adhikari ⁴, Megha Raj Banjara ², Prakash Ghimire ²

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·         PMID: 32606839

PMCID: PMC7320882

 

·         DOI: 10.2147/IDR.S250591

Free PMC article

Abstract

Introduction: Extended-spectrum β-lactamases (ESBL) among Gram-negative bacteria, predominantly Escherichia coli (E. coli), in Nepal, have been rising. The main objectives of this study were to determine the prevalence of uropathogenic E. coli, antibiotic resistance, ESBLs, ABLs (AmpC type β-lactamases), MBLs (metallo-β-lactamases) and KPCs (Klebsiella pneumoniae carbapenemases) and their correlation with plasmid profiling patterns among patients with urinary tract infections in a tertiary hospital in Kathmandu, Nepal.

Methods: The mid-stream urine samples collected from patients were inoculated in cystine-lactose-electrolyte-deficient (CLED) agar plates. E. coli producing ESBLs, ABLs, MBLs/KPC were identified phenotypically using standard microbiological methods. Plasmids were extracted by alkaline lysis method from E. coli isolates and profiled using agarose gel electrophoresis.

Results: Out of the total 2661 urine samples, E. coli were isolated in 64.34% (507/788), among which 170 (33.53%) were multidrug-resistant (MDR) isolates. All MDR isolates were resistant to amoxicillin and third-generation cephalosporins but were highly sensitive to imipenem (94.12%, 160/170), amikacin (92.94%, 158/170) and nitrofurantoin (86.47%, 147/170). Among 170 MDR isolates, 78.2% (133/170) were ESBLs, 46.3% (50/170) were AmpC, 11.2% (19/170) were MBL and 0.6% (1/170) were KPC producers. Coproduction of β-lactamases was detected in 24.12% (41/170) of isolates. E. coli isolates showed one plasmid (>33.5 kb), which was present in all the isolates. Overall, 44 different plasmid profile groups were identified based on molecular weight and number of plasmids. β-Lactamase producers were relatively resistant to the higher number of antibiotics tested (≤10) than non-producers (≤8), and the number of plasmids were higher in β-lactamase producers (≤7) than those in non-producers (≤5).

Conclusion: The higher prevalence of the ESBLs, AmpCs, KPCs and MBLs along with their coproduction in E. coli isolates highlights the importance of routine surveillance of ESBLs, AmpCs, KPCs and MBLs in microbiology laboratories using various phenotypic methods.

Keywords: AmpC type β-lactamases; ESBL; KPC; Klebsiella pneumoniae carbapenemases; MBL; antibiotic resistance; extended-spectrum β-lactamases; metallo-β-lactamases; uropathogenic Escherichia coli.

. 2020 Jun 23;13:1905-1917. 

doi: 10.2147/IDR.S250591. eCollection 2020.

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