Prevalence and Molecular Characterization of Metallo β-Lactamase Producing Gram-Negative Pathogens Causing Eye Infections

Gunasekaran Rameshkumar; Ranjithkumar Dhandapani; Prajna Lalitha; Siva Ganesa Karthikeyan Rajapandian; Velmurugan Palanivel; Sathiamoorthi Thangavelu; Abdullah A Alyousef; Thamer Albalawi; Pravej Alam; Mohammad Zubair; Fayez M Saleh; Fuad Abdullah Alatawi; Fohad M Husain

doi:10.3389/fpubh.2022.870354

Prevalence and Molecular Characterization of Metallo β-Lactamase Producing Gram-Negative Pathogens Causing Eye Infections

Front Public Health. 2022 Jun 14:10:870354. doi: 10.3389/fpubh.2022.870354. eCollection 2022.

Authors

Affiliations

¹ Medical Microbiology Laboratory, Department of Microbiology, Alagappa University, Karaikudi, India.
² Department of Ocular Microbiology, Aravind Eye Hospital, Madurai, India.
³ Centre for Material Engineering and Regenerative Medicine Bharath Institute of Higher Education, Chennai, India.
⁴ Clinical Laboratory Sciences Department, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia.
⁵ Department of Biology, College of Sciences and Humanities, Prince Sattam Bin Andulaziz University, Alkharj, Saudi Arabia.
⁶ Department of Medical Microbiology, Faculty of Medicine, University of Tabuk, Tabuk, Saudi Arabia.
⁷ Department of Biology, Faculty of Science, University of Tabuk, Tabuk, Saudi Arabia.
⁸ Department of Food Science and Nutrition, King Saud University, Riyadh, Saudi Arabia.

Abstract

Purpose: Metallo β-lactamases (MβL) production is a worldwide problem, particularly in gram-negative bacteria. As scanty data is available on the prevalence of MBL, the present study is being undertaken to determine the prevalence, antibacterial sensitivity patterns, and molecular characterization of MβL associated resistant genes in gram-negative bacteria isolated from ocular infections.

Material and methods: At a tertiary eye care center in south India, 359 gram-negative pathogens, 200 isolates from eye infections, and 159 isolates from normal flora of the eye were studied. A gold standard microbiology method was used to identify the isolates. An antibiotic double disc synergy test and a combination disc test were used to detect MβL production. Multiplex PCR was used to investigate the molecular characteristics of the MβL encoding genes bla_VIM, bla_IMP, and bla_NDM.

Results: Of the 359 gram-negative bacterial pathogens, Pseudomonas aeruginosa 108 (30.1%) and Enterobacter agglomerans 46 (12.8%) were commonly isolated. High prevalence of P. aeruginosa 81% (17 strains) was detected as an MβL producer and it shows 100% resistance to 2nd and 3rd generation cephalosporins and meropenem. Multiplex PCR detected only the bla_VIM gene in 56 (28%) of various eye infections and 27 (17%) of normal flora of the gram-negative bacteria (GNB). The bla_VIM gene is detected predominantly in 51.8% of keratitis and 21.4% of postoperative endophthalmitis. High prevalence of the gene was detected in P. aeruginosa 42.9% (24 of 56) and Alcaligens denitrificans 10.7% (6 of 56) from eye infections. Whereas, in the control group, P. aeruginosa and E. coli each had 14.8% (4 of 27) that were shown positive.

Conclusion: The emerging MβLs mediated resistance among P. aeruginosa is a challenging task for ophthalmologists, especially in patients with endophthalmitis and bacterial keratitis. This local knowledge will aid in advising appropriate antibiotic use and avoiding unnecessary antibiotic prescriptions, which are highly warranted.

Keywords: Enterobacteriaceae; Metallo β-lactamases; gram-negative bacilli; non-Enterobacteriaceae; normal flora.

MeSH terms

Anti-Bacterial Agents / pharmacology
Anti-Bacterial Agents / therapeutic use
Endophthalmitis* / drug therapy
Endophthalmitis* / epidemiology
Escherichia coli
Eye Infections* / drug therapy
Gram-Negative Bacteria / genetics
Humans
Microbial Sensitivity Tests
Prevalence
Pseudomonas aeruginosa / genetics
beta-Lactamases / genetics

Substances

Anti-Bacterial Agents
beta-Lactamases