# The Influence of L-Lysine-Alpha-Oxidase on the Biofilm Formation of Opportunistic Microorganisms Associated with Inflammatory Diseases of the Urinary Tract

## TL;DR

This study explores how the enzyme L-lysine-alpha-oxidase (LO) inhibits biofilm formation in bacteria and fungi linked to urinary tract infections.

## Contribution

The study demonstrates LO's strong inhibitory effect on biofilm formation, particularly when added early in incubation.

## Key findings

- LO inhibited biofilm formation more effectively than culture liquid concentrate in several bacterial strains.
- Scanning electron microscopy revealed morphological changes in bacteria exposed to LO.
- LO shows promise as a treatment for biofilm-related infections.

## Abstract

Urinary tract infections occupy a special niche among diseases of infectious etiology. Many microorganisms associated with urinary tract infections, such as Klebsiella oxytoca, Enterococcus spp., Morganella morganii, Moraxella catarrhalis, Pseudomonas aeruginosa, Proteus mirabilis, Staphylococcus aureus, Staphylococcus spp., and Candida spp., can form biofilms. The aim of this research was to study the effect of the enzyme L-lysine-Alpha-oxidase (LO) produced by the fungus Trichoderma harzianum Rifai on the biofilm formation process of microorganisms associated with urinary tract infections. Homogeneous LO showed a more pronounced effect than the culture liquid concentrate (cCL). When adding samples at the beginning of incubation, the maximum inhibition was observed in relation to Enterococcus faecalis 5960—cCL 86%, LO 95%; Enterococcus avium 1669—cCL 85%, LO 94%; Enterococcus cloacae 6392—cCL 83%, LO—98%; and Pseudomonas aeruginosa 3057—cCL 70%, LO—82%. The minimum inhibition was found in Candida spp. Scanning electron microscopy was carried out, and numerous morphological and structural changes were observed in the cells after culturing the bacterial cultures in a medium supplemented with homogeneous LO. For example, abnormal division was detected, manifesting as the appearance of joints in places where the bacteria diverge. Based on the results of this work, we can draw conclusions about the possibility of inhibiting microbial biofilm formation with the use of LO; especially significant inhibition was achieved when the enzyme was added at the beginning of incubation. Thus, LO can be a promising drug candidate for the treatment or prevention of infections associated with biofilm formation.