Evaluation of the effectiveness of colloidal silver for inhibiting biofilm formation in pathogens of bronchopneumonia in calves

Abstract

Microorganisms capable of forming biofilms are significantly resistant to antibiotics and bacteriophages. Cattle diseases caused by biofilm-forming pathogens are a serious problem for livestock production, since the presence of biofilm complicates the use of available therapeutic drugs. In addition, due to differences in antibiotic concentrations in biofilms, microbial cells are often exposed to concentrations below inhibitory concentrations and can develop resistance. The global increase in resistance to antimicrobial and chemotherapeutic drugs is a serious problem in livestock production. The matrix of extracellular polymeric substances within biofilms can physically impede the penetration of antibiotics and bacteriophages, which also contributes to the survival and spread of multidrug-resistant bacteria among farm animals. Therefore, it is necessary to find effective methods to combat biofilm-forming microorganisms. Silver nanoparticles (Ag) are well known for their bactericidal action and ability to reduce the synthesis of bacterial biofilms. Therefore, colloidal silver consisting of silver nanoparticles is an attractive addition to existing therapeutic and preventive measures in animal husbandry. In the course of the study, we assessed the intensity of biofilm formation of causative agents of calf bronchopneumonia (Escherichia coli (n = 30), Klebsiella pneumoniae (n = 10), Proteus mirabilis (n = 15), Proteus vulgaris (n = 10), Pseudomonas aeruginosa (n = 7), Moraxella bovoculi (n = 5), Mannheimia haemolytica (n = 6)) using the spectrophotometric method in the absence of inhibitors and with the introduction of colloidal silver. The obtained results demonstrate the potential possibility of including colloidal silver in a complex of therapeutic and preventive measures to combat pathogens of bronchopneumonia in young cattle that are capable of forming a biofilm.