Antibacterial activity of donkey’s milk against clinical isolate of Klebsiella pneumoniae
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Date
2022
Authors
Šarić, Ljubiša 
Pezo, Lato
Krulj, Jelena
Plavšić, Dragana
Jovanov, Pavle
Matić, Milana
Journal Title
Journal ISSN
Volume Title
Publisher
Croatian Dairy Union, Croatia
Abstract
The purpose of this study was to investigate the antibacterial activity of raw donkey milk toward the clinical isolate of Klebsiella pneumoniae at 9, 15 and 38 °C as well as to clarify the role of lysozyme, lactoferrin and calcium content in the antibacterial activity of donkey’s milk. The effects of contamination level and incubation period on this antibacterial activity were also examined. Antibacterial assays were performed by determing the bacterial count in intentionally contaminated (102, 103, 104 cfu/mL) donkey milk samples during 8 and 96 hours. Lab-on-a-chip electrophoresis and atomic absorption spectrometry were used for the determination of lysozyme, lactoferrin and calcium contents in donkey milk, respectively. The donkey milk samples showed varying degrees of antibacterial activity against the tested strain K. pneumoniae. The antibacterial synergism of lysozyme and lactoferrin was proven for this clinical strain as the samples with higher lactoferrin amount showed a stronger antibacterial activity. The correlation between calcium content and antibacterial activity of donkey milk samples was not established. Donkey milk showed stronger antibacterial potential at 15 °C compared to 9 °C, but this was limited by a higher growth rate of K. pneumoniae at 15 °C. The higher level of contamination resulted in a faster consumption of the antibacterial capacity of donkey milk. The artificial neural network model for prediction of K. pneumoniae count gave acurate fit to experimental data, showing a reasonably good (overall r2 for donkey milk was 0.986, with training error 4.67∙10-4, while r2 for nutrient broth was 0.982 and training error was 0.002).
Description
Keywords
Donkey milk, antibacterial activity, Klebsiella pneumonia
Citation
Šarić, Lj., Pezo, L., Krulj, J., Tomić, J., Plavšić, D., Jovanov, P., Matić, M. (2022). Antibacterial activity of donkey’s milk against clinical isolate of Klebsiella pneumoniae. Mljekarstvo, 72 (2), 63-76.