Metallo-Beta-Lactamase Producing Isolates of Escherichia coli and Klebsiella pneumoniae and their Resistance Profiles in Enugu, Nigeria: A Threat to Public Health

Uzoamaka Charity Maduakor *

Department of Medical Laboratory Sciences, Faculty of Health Sciences and Technology, College of Medicine, University of Nigeria, Nigeria.

Clara Idara Eleazar

Department of Microbiology, Faculty of Biological Sciences, University of Nigeria, Nsukka, Nigeria.

Chidi George Mba

College of Medicine, University of Nigeria, Enugu Campus, Nigeria.

Chiamaka Cynthia Obodochukwu

Department of Medical Laboratory Sciences, Faculty of Health Sciences and Technology, College of Medicine, University of Nigeria, Nigeria.

Chioma Lily Eberechukwu

Department of Medical Laboratory Sciences, Faculty of Health Sciences and Technology, College of Medicine, University of Nigeria, Nigeria.

Cornelius Osinachi Ogu

Department of Medical Laboratory Sciences, Faculty of Health Sciences and Technology, College of Medicine, University of Nigeria, Nigeria.

*Author to whom correspondence should be addressed.


Background: A potential threat to public health is the rapidly spreading enterobacteriaceae, especially Escherichia coli and Klebsiella pneumoniae which produce metallo-beta-lactamases (MBL). This study evaluated the prevalence of metallo-beta-lactamase (MBL) from clinical and non-clinical sources in Enugu Metropolis.

Methodology: The study was conducted in the Microbiology Laboratory of the University of Nigeria Teaching Hospital, Ituku-Ozalla between October 2020 and July 2021. A total of 150 isolates including 85 and 65 isolates of Escherichia coli and Klebsiella pneumoniae respectively was recovered. Standard microbiology procedures were used to identify and characterize the isolates. Antimicrobial susceptibility was done using the Kirby-Bauer disc diffusion technique. Phenotypic detection of Metallo-beta-lactamase production was determined using Combined Disk Tests.

Results: Imipenem resistance was detected in 22 (25.9%) isolates of E. coli and 18 (27.7%) isolates of K. pneumoniae. Of the 22 strains of E. coli that were imipenem resistant, 8 (9.4%) and 14 (16.5%) were found to be MBL producers and non-MBL respectively. Of the 18 strains of Klebsiella pneumoniae that were imipenem resistant, 10 (15.4%) were MBL producers and 8 (12.3%) were non-MBL producers. The highest prevalence of MBL was recovered from urine sources in both E. coli and K. pneumonieae. All MBL-producing isolates were multidrug resistant.

Conclusion: The overall prevalence of MBL in this study was 12.0%. Public health is at risk due to the occurrence of metallo-beta-lactamase. Antimicrobial stewardship and the implementation of infection control strategies are required to halt the spread of these resistant bacteria in the environment. The use of antibiotics should be with utmost prudence.

Keywords: Antibiotic resistance, carbapenemase, metallo-beta-lactamase, phenotypic detection, Escherichia coli, Klebsiella pneumoniae

How to Cite

Maduakor , Uzoamaka Charity, Clara Idara Eleazar, Chidi George Mba, Chiamaka Cynthia Obodochukwu, Chioma Lily Eberechukwu, and Cornelius Osinachi Ogu. 2024. “Metallo-Beta-Lactamase Producing Isolates of Escherichia Coli and Klebsiella Pneumoniae and Their Resistance Profiles in Enugu, Nigeria: A Threat to Public Health”. Journal of Advances in Microbiology 24 (2):11-19.


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Khalifa SM, Abd El-Aziz AM, Hassan R, Abdelmegeed ES. β–lactam resistance associated with β- lactamase production and porin alteration in clinical isolates of E.coli & K. pneumoniae. PLoS One. 2021;16(5):e0251594. Available:

Tamma PD, Simner PJ. Phenotypic detection of carbapenemase-producing organisms from clinical isolates. Journal of Clinical Microbiology. 2018;56:e01140.

Ejikeugwu C, Nworie O, Saki M. Metallo-β-lactamase & AmpC Genes in Escherichia coli, Klebsiella pneumoniae, and Psuedomonas aeruginosa isolates from abattoir and poultry origin in Nigeria. BMC Microbiology. 2021;21:124.

Durrmeyer X, Cohen R. Utilisation des carbapénèmesenpédiatrie. Archives de pédiatrie 2010; 17:S163-S170. Available:

Nordmann P, Carrer A. Les carbapénèmases des entérobactéries. Archives de Pédiatrie 2010; 17:S154-S162. Available:

Nordmann P, Dortet L,Poirel L. Carbapenem resistance in enterobacteriaceae: here is the storm! Trends in Molecular Medicine. 2012; 18:263-272. Available:

Halat DH, Moubareck CA. The current burden of carbapenemases: Review of significant properties and dissemination among gram-negative bacteria. Antibiotics 2020;9:186. DOI:10:3390/antibiotics904018

Bush K. Past and present perspectives on β-lactamases. Antimicrob. Agents Chemother. 2018; 62(10):e01076-18. DOI: 10.1128/AAC.01076-18

Ugwu MC, Shariff M, Nnajide, CM, Beri K, Okezie M, Iroha IR, Esimone CO. Phenotypic and molecular characterization of β-lactamases among enterobacterial uropathogens in Southeastern Nigeria. Canadian Journal of Infectious Diseases and Medical Microbiology. 2020;9(2):1-9.

Landelle C, Dautzenberg M, Wekesa A, Gniadkowski M, Antoniadou A, Giamarellou H. et al. The association between colonization with carbapenemase-producing enterobacteriaceae and overall ICU mortality. Critical Care Medicine. 2015; 43:1170-1177. Available:

Gupta V, Singh M, Datta P, Goel S, Singh S, Prasad K, Chander J. Detection of various beta-lactamases in Escherichia coli and Klebsiellasp: A study from tertiary care centre of North India. Indian J. Med Microbiol. 2020;38:390-396.

Javed H, Ejaz H, Zafar A, Rathore AW, Haq I. Metallo-beta-lactamase producing Escherichia coli and Klebsiella pneumoniae: A rising threat for hospitalized children. Journal of Pakistan Medical Association. 2016;66(9):1068-1071.

Sachdeva R, Sharma B, Sharma R. Evaluation of different phenotypic tests for detection of metallo-β-lactamases in imipenem-resistant Pseudomonas aeruginosa. Journal of Laboratory Physicians. 2017;9:249.

Fazlul MK, Nazmul MH, Najnin A, Munira B. Detection of metallo-β-lactamase encoding genes among clinical isolates of Escherichia coli in a tertiary care hospital, Malaysia. Journal of International Pharmaceutical Research. 2019;11(1):1-8. Available:

Baron EJ, Peterson LR, Finegold SM. Baily and Scott's Diagnostic Microbiology 9th Edition; Mosby Inc. St Louis Baltimore. 1994:362-385.

Clinical and laboratory standards institute. Performance standards for antimicrobial susceptibility testing: Twenty-fifth informational supplement M100-S21. Wayne, PA: Clinical and Laboratory Standards Institute; 2011.

Clinical and laboratory standards institute. Performance standards for antimicrobial susceptibility testing: Twenty-first informational supplement M100-S25. Wayne, PA: Clinical and Laboratory Standards Institute; 2015.

Franklin C, Liolios L, Peleg AY. Phenotypic detection of carbapenem-susceptible metallo-β-lactamase-producing gram-negative bacilli in the clinical laboratory. Journal of Clinical Microbiology. 2006;44(9):3139-3144.

Bora A, Sanjana R, Jha BK, Mahaseth SN, Pokharel K. Incidence of metallo-beta-lactamase producing clinical isolates of Escherichia coli and Klebsiella pneumonia in Central Nepal. BMC Research Notes. 2014;7:557.

Kumarasamy KK, Toleman MA, Walsh TR, Bagaria J, Butt F, Balakrishnan R, et al . Emergence of a new antibiotic resistance mechanism in India, Pakistan, and the UK: A molecular, biological, and epidemiological study. Lancet Infect Dis. 2010;10(9):597-602. DOI: 10.1016/S1473-3099(10)70143-2

Panchal CA, Oza SS, Mehta SJ. Comparison of four phenotypic methods for detection of metallo- β-lactamase-producing gram-negative bacteria in rural teaching hospital. J. Lab Physicians. 2017;9:81-3.

Kulkarni SS, Mulay MV. Phenotypic detection of metallo-beta-lactamase production in clinical isolates of Escherichia coli and Klebsiella pneumoniae in a tertiary care hospital. MGM J. Med Sci. 2022;9:149-153.

Agarwal N, Chauhan S, Sing P, Sharma VK. Pheontypic detection of carbapenem resistance and metallo-beta-lactamase among Enterobacteriaceae from clinical samples in tertiary care hospital. Int. J. Res Med Sci. 2019;7:2373-6.

Kanj SS, Kanafani ZA. Current concepts in antimicrobial therapy against resistant gram-negative organisms: Extended-spectrum beta-lactamase-producing, Enterobacteriaceae, carbapenem-resistant Enterobacteriaceae, and multidrug-resistant Pseudomonas aeruginosa. Mayo Clin. Troc. 2011;86:250-25.

Mittal S, Mamoria VP , Singla A, Bacchani D, Chaudhary P. Phenotypic detection of metallo-β-lactamase in carbapenem resistant clinical isolates of Klebsiella pneumoniae ssp. pneumoniaeat a tertiary care hospital in Jaipur. Journal of Medical Science and Clinical Research. 2020;8(3):703-708.

Oberoi L, Singh N, Sharma P, Agarwal A. ESBL, MBL and Ampc β lactamases producing superbugs – havoc in the intensive care units of Punjab India. Journal of Clinical and Diagnostic Research. 2013 Jan;7(1):70-73.

Shahandeh Z, Sadighian F, Rekabpou KB. Phenotypic study of extended-spectrum beta-lactamase, AmpC and carbapenemase among E.coli clinical isolates in affiliated hospitals of babol university of medical sciences. Int J Health Syst Disaster Manage. 2015;3:74-78.

Nepal K, Pant ND, Neupane B, Belbase A, Baidhya R, Shrestha RK, Lekhak B, Bhatta DR, Jha B. Extended spectrum beta‑lactamase and metallo beta‑lactamase production among Escherichia coli and Klebsiella pneumoniae isolated from different clinical samples in a tertiary care hospital in Kathmandu, Nepal. Ann Clin Microbiol Antimicrob. 2017;16:62. DOI:10:1186/s12941-017-0236-7

Adhikary M, Chakrabarty PS. Evaluation of metallo-beta-lactamase enzyme among gram-negative isolates from patients admitted in a tertiary care hospital, India. J Dental Med Sci. 2017;16: 95-100.

Andrade LN, Vitali L, Gaspar GG, Bellissimo-Rodrigues F, Martinez R, Darini AL. Expansion and evolution of a virulent, extensively drug-resistant (polymixin B-resistant), QnrSI-, CTX-M-2-, and KPC-2-producing Klebsiella pneumoniae ST11 international high-risk clone. J. Clin Microbiol. 2014;52:2530-2535.

Singh M, Kakati B, Agarwal RK, Kotwal A. Detection of Klebsiella pneumonia carbapenemases (KPCs) among ESBL / MBL producing clinical isolates of Klebsiella pneumoniae. International Journal of current Microbiology and Applied Sciences. 2015; 4(4):726-731. ISSN: 2319-7706

Kamble D. Phenotypic detection of ESBL and MBL in gram negative bacilli isolated from clinical specimens. Int J Med Res Rev. 2015;3(8):866-870.

Shrestha A, Acharya J, Amatya J, Paudyal R, Rijal N. Detection of beta-lactamases (ESBL and MBL) Producing gram-negative pathogens in national public health laboratory of Nepal. International Journal of Microbiology; 2022.