Phenotypic Characterization of Multidrug-resistant Escherichia Coli with Special Reference to Extended-spectrum-beta-lactamases and Metallo-beta-lactamases in a Tertiary Care Center

  • Basudha Shrestha Department of Microbiology, Institute of Medicine, Maharajgunj, Kathmandu, Nepal.
  • Shovita Shrestha Department of Microbiology, Institute of Medicine, Maharajgunj, Kathmandu, Nepal.
  • Shyam Kumar Mishra Department of Microbiology, Institute of Medicine, Maharajgunj, Kathmandu, Nepal.
  • Hari Prasad Kattel Department of Microbiology, Institute of Medicine, Maharajgunj, Kathmandu, Nepal.
  • Tatsuya Tada Department of Infectious Diseases, Research Institute, Japan.
  • Hiroshi Ohara Department of International Medical Cooperation, National Center for Global Health and Medicine, Tokyo, Japan.
  • Teruo Kirikae Department of Infectious Diseases, Research Institute, Japan.
  • Basista Prasad Rijal Department of Microbiology, Institute of Medicine, Maharajgunj, Kathmandu, Nepal.
  • Jeevan Bahadur Sherchand Department of Microbiology, Institute of Medicine, Maharajgunj, Kathmandu, Nepal.
  • Bharat Mani Pokhrel Department of Microbiology, Institute of Medicine, Maharajgunj, Kathmandu, Nepal.
Keywords: e. coli; extended-spectrum-β-lactamase; metallo-β-lactamase; multidrug-resistance.


Introduction: The increasing reports on extended-spectrum-beta-lactamase and metallo-betalactamase producing Escherichia coli have addressed a potential threat to global health since it is found to be highly resistance to most of the currently available antibiotics including carbapenems. The present study was aimed to determine the antibiogram of extended-spectrum-beta-lactamase and metallo-beta-lactamase producing MDR E. coli isolates from various clinical samples.

Methods: This was a cross-sectional study conducted over a period of seven months (December 2013 to July 2014) at bacteriology laboratory of Tribhuvan University Teaching Hospital. A total of 250 clinical specimens (urine, pus, sputum, blood, body fluid, bile, tissue and central venous pressure line tip) were processed from inpatients, with multidrug-resistant Escherichia coli infections. Standard microbiological techniques were used for isolation and identification of the isolates. The presence of extended-spectrum-beta-lactamase was detected by phenotypic confirmatory test recommended by Clinical and Laboratory Standards Institute and imipenem (IMP) /EDTA combined disc method was performed to detect metallo-beta-lactamase mediated resistance mechanism.

Results: We found high level of beta lactamase mediated resistance mechanism as part of multidrug resistance. Among 250 MDR isolates, 60% isolates were extended-spectrum-beta-lactamase producers and 17.2% isolates were metallo-beta-lactamase producers. Co-existence of extended-spectrum-betalactamase and metallo-beta-lactamase identified in 6.8% isolates.

Conclusions: Beta-lactamase mediated resistance mechanisms are accounting very high in the multidrug resistant isolates of E. coli. Therefore, early detection of beta lactamase mediated resistant strains and their current antibiotic susceptibility pattern is necessary to avoid treatment failure and prevent the spread of MDR. 

Keywords: e. coli; extended-spectrum-β-lactamase; metallo-β-lactamase; multidrug-resistance.


Paterson DL, Bonomo RA. Extended-Spectrum- β-Lactamases:
a clinical update. Clin Microbiol Rev. 2005;18(4):657-86.
2. Livermore DM. Beta-Lactamases in laboratory and clinical
resistance. Clin Microbiol Rev.1995;8(4):557-84.
3. Papp-Wallace KM, Endimiani A, Taracila MA, Bonomo RA.
Carbapenems: past, present and future. Antimicrob Agents
Chemother. 2011;55(11):4943-60.
4. Bush K, Fisher JF. Epidemiological expansion, structural
studies, and clinical challenges of new ß-lactamases from
gram-negative bacteria. Annu Rev Microbiol. 2011;65:455-78.
5. Diekema DJ, Pfaller MA, Jones RN, Doern GV, Winokur PL,
Gales AC, et al. Survey of bloodstream infections due to gramnegative
bacilli: frequency of occurrence and antimicrobial
susceptibility of isolates collected in the United States,
Canada, and Latin America for the SENTRY Antimicrobial
Surveillance Program,1997. Clin Infect Dis. 1999;29:595-607.
6. Yong D, Giske CG. Characterization of a new metallo-β-
lactamase gene, blaNDM-1 , and a novel erythromycin esterase
gene carried on a unique genetic structure in Klebsiella
pneumoniae sequence type 14 from India. Antimicrob Agents
Chemother. 2009;53:5046-54.
7. Tada T, Miyoshi-Akiyama T, Dahal RK, Sah MK, Ohara H,
Kirikae T, Pokhrel BM. NDM-8 metallo-β-Lactamase in a
multidrug-resistant Escherichia coli strain Isolated in Nepal.
Antimicrob Agents Chemother. 2013;57(5):2394-6.
8. Isenberg HD. Clinical Microbiology Procedures Handbook.
2nd ed. Washington, D.C: ASM Press 2004.
9. Clinical Laboratory Standard Institute (CLSI): Performance
standards for antimicrobial susceptibility testing; Twentysecond
informational supplement document. Wayne, PA:
CLSI: 2012;M100-S20.
10. Magiorakos AP, Srinivasan A, Carey RB, Carmeli Y, Falagas
ME, Giske CG, et al. Multidrug-resistant, extensively drugresistant
and pandrug-resistant bacteria: an international
expert proposal for interim standard definitions for acquired
resistance. Clin Microbiol Infect. 2012; 18: 268–81.
11. Franclin C, Liolios L, Peleg AY. Phenotypic detection of
carbapenem-susceptible metallo-beta-lactamase-producing
Gram-negative bacilli in clinical laboratory.J Clin Microbiol.
12. Chaudhary U, Aggrawal R. Extended- spectrum- β-lactamases
(ESBL)—an emerging threat to clinical therapeutics. Indian J
Med Microbiol. 2004;22(2):75-80
13. Mukherjee T, Pramod K, Gita S, Medha YR. Nosocomial
infections in geriatric patients admitted in ICU. J Ind Acad
Geriatrics. 2005;2:61-4.
14. Richards M, Edwards JR, Culver DH, Gaynes RP. Nosocomial
infections in combined medical-surgical intensive care
units in the United States. Infect Control Hosp Epidemiol.
15. Lee YL,Thrupp LD, Friis RH, Fine M, Maleki P, Cessario TC.
Nosocomial infection and antibiotic utilization in geriatric
patients- A pilot prospective surveillance program in nursing
facilities. Gerontology. 1992;38:223-32.
16. WHO. Prevention of hospital-acquired infection: a practical
guide. 2nd ed.Geneva: WHO;2002.
17. Sharma S, Bhat GK, Shenoy S. Virulence factors and drug
resistance in Escherichia coli isolated from extraintestinal
infection. Indian J Med Microbiol. 2007;25:369-73.
18. Goyal A, Prasad KN, Prasad A, Gupta S, Ghoshal U, Ayyagari
A. Extended spectrum β-lactamases in Escherichia coli &
Klebsiella pneumoniae& associated risk factors. Indian J Med
Res. 2009;129:695-700.
19. Owens RC Jr1, Rice L. Hospital-based strategies for combating
resistance. Clin Infect Dis. 2006;42 Suppl 4:S173-81.
20. Pandya NP, Prajapati SP, Mehta SJ, Kikani KM, Joshi PJ.
Evaluation of various methods for detection of metallobetalactamase(
MBL) production in Gram negative bacilli.Int
J Biol Med Res. 2011;2(3):775-7.
21. Tsakris A,Themeli-Digalaki K, Poulou A, Vrioni G, Voulgari
E, Koumaki V, et al. Comparative evaluation of combined
disk tests using different boronic acid compounds for
detection of Klebsiella pneumoniae carbapenemase – producing
Enterobacteriaceae clinical isolates. J Clin Microbiol.
22. Enwuru NV, Enwuru CA, Ogbonnia SO, Adepoju-Bello.
Metallo-beta-lactamase production by Escherichia coli and
Klebsiella species isolated from hospital and community
subjects in Lagos, Nigeria. Nature and Science. 2011;9(11):1-5.
23. Bora A, Sanjana R, Jha BK, Mahaseth SN, Pokharel K.
Incidence of metallo-beta-lactamase producing clinical
isolates of Escherichia coli and Klebsiella pneumoniae in central
Nepal. BMC Res Notes. 2014;7:557.
24. Bandekar N, Binodkumar CS, Basavarajappa KG, Prabhakar
PJ, Nagaraj P. Beta- lactamases mediated resistance amongst
the gram negative bacilli in burn infections. Int J Biol Res.
25. Iosifidis E, Antachopoulos C, Tsivitanidou M, Katraqkou A,
Farmaki E, Tsiakou M, et al. Differential correlation between
rates of antimicrobial drug consumption and prevalence of
antimicrobial resistance in a tertiary care hospital in Greece.
Infect Control Hosp Epidemiol. 2008;29(7):615-22.
26. Gupta V, Datta P, Chander J. Prevalence of metallo –
beta- lactamase (MBL) producing Pseudomonas spp. and
Acinetobacter spp. in a tertiary care hospital in India. J Infect.
27. Mishra SK, Acharya J, Kattel HP, Koirala J, Rijal BP, Pokhrel
BM. Metallo-beta-lactamase producing gram-negative
bacterial isolates. J Nepal Health Res Counc. 2012;10:208-13.
28. Khanal S, Bhatta DR, Devkota U, Pokhrel BM. Betalactamase-
producing multidrug-resistant bacterial
pathogens from tracheal aspirates of intensive care unit
patients at National Institute of Neurological and Allied
Sciences, Nepal. ISRN Microbiology. 2013:5.(http://dx.doi.
29. Kumar D, Singh AK, Ali MR, Chander Y. Antimicrobial
susceptibility profile of extended-spectrum-β-lactamase
(ESBL) producing Escherichia coli from various clinical
samples. Infect Dis. 2014;7:1-8.

Babypadmini S, Appalaraju B. Extended-spectrum-β-
lactamases in urinary isolates of E. coli and K. pneumoniae—
prevalence and susceptibility pattern in a tertiary care
hospital. Indian J Med Microbiol. 2004;22(3):172-4.
31. Queenan AM, Bush K. Carbapenemases: the versatile
β-lactamases. Clin Microbiol Rev. 2007;20(3):440-58.
32. Oberoi L, Singh N, Sharma P, Aggarwal A. ESBL, MBL, AmpC
β-Lactamases Producing Superbugs – Havoc in the intensive
care units of Punjab, India. J Clin Diag Res. 2013;7(1):70-3.
33. Urban C, Bradford PA, Tuckman M, Segal-Maurer S, Wegbeh
W, Grenner L, et al. Carbapenem-resistant Escherichia
coli harboring Klebsiella pneumoniae carbapenemase-beta-
Lactamases associated with long-term care facilities. Clin
Infect Dis. 2008;46(1):127-30.
How to Cite
Shrestha, B., Shrestha, S., Mishra, S. K., Kattel, H. P., Tada, T., Ohara, H., Kirikae, T., Rijal, B. P., Sherchand, J. B., & Pokhrel, B. M. (2015). Phenotypic Characterization of Multidrug-resistant Escherichia Coli with Special Reference to Extended-spectrum-beta-lactamases and Metallo-beta-lactamases in a Tertiary Care Center. Journal of Nepal Medical Association, 53(198), 83-88.
Original Article