Inhibition and Reduction of Biofilm Production along with Their Antibiogram Pattern among Gram-Negative Clinical Isolates

Ojaswee Shrestha; Nabina Shrestha; Sadhana Khanal; Sushant Pokhrel; Sujina Maharjan; Tika Bahadur Thapa; Puspa Raj Khanal; Govardhan Joshi

doi:10.1155/2023/6619268

Inhibition and Reduction of Biofilm Production along with Their Antibiogram Pattern among Gram-Negative Clinical Isolates

Int J Biomater. 2023 Nov 17:2023:6619268. doi: 10.1155/2023/6619268. eCollection 2023.

Authors

Ojaswee Shrestha^{1

2}, Nabina Shrestha¹, Sadhana Khanal¹, Sushant Pokhrel¹, Sujina Maharjan¹, Tika Bahadur Thapa^{1

2}, Puspa Raj Khanal², Govardhan Joshi¹

Affiliations

¹ Department of Laboratory Medicine, Manmohan Memorial Institute of Health Sciences, Kathmandu, Nepal.
² Department of Pathology, Sumeru Hospital Pvt Ltd, Lalitpur, Nepal.

Abstract

Background: Bacterial biofilm is a significant virulence factor threatening patients, leading to chronic infections and economic burdens. Therefore, it is crucial to identify biofilm production, its inhibition, and reduction. In this study, we investigated biofilm production among Gram-negative isolates and assessed the inhibitory and reduction potential of ethylene diamine tetra acetic acid (EDTA) and dimethyl sulfoxide (DMSO) towards them. In addition, we studied the antimicrobial resistance pattern of the Gram-negative isolates.

Methods: Bacterial isolation and identification was done using standard microbiological techniques, following the Clinical and Laboratory Standards Institute (CLSI) guideline, 28th edition. The Kirby-Bauer disk diffusion method was used to determine the antibiotic susceptibility pattern of the isolates, and β-lactamase production was tested via the combination disk method. Biofilm formation was detected through the tissue culture plate (TCP) method. Different concentrations of EDTA and DMSO were used to determine their inhibitory and reduction properties against the biofilm. Both inhibition and reduction by the various concentrations of EDTA and DMSO were analyzed using paired t-tests.

Results: Among the 110 clinical isolates, 61.8% (68) were found to be multidrug resistant (MDR). 30% (33/110) of the isolates were extended-spectrum β-lactamase (ESBL) producers, 14.5% (16/110) were metallo-β-lactamase (MBL), and 8% (9/110) were Klebsiella pneumoniae carbapenemase (KPC) producers. Biofilm formation was detected in 35.4% of the isolates. Biofilm-producing organisms showed the highest resistance to antibiotics such as cephalosporins, chloramphenicol, gentamicin, and carbapenem. The inhibition and reduction of biofilm were significantly lower (p < 0.05) for 1 mM of EDTA and 2% of DMSO.

Conclusion: Isolates forming biofilm had a higher resistance rate and β-lactamase production compared to biofilm nonproducers. EDTA and DMSO were found to be potential antibiofilm agents. Hence, EDTA and DMSO might be an effective antibiofilm agent to control biofilm-associated infections.