Vo Thi Hong Van, Department of Veterinary Medicine, National Chung Hsing University, Taichung 40249, Taiwan
Zhen-Shu Liu, Chronic Diseases and Health Promotion Research Center, Chang Gung University of Science and Technology, Chiayi 61363, Taiwan
Yueh Jen Hsieh, Department of Veterinary Medicine, National Chung Hsing University, Taichung 40249, Taiwan
Wei-Chen Shiu, Department of Veterinary Medicine, National Chung Hsing University, Taichung 40249, Taiwan
Bo-Yuan Chen, Department of Veterinary Medicine, National Chung Hsing University, Taichung 40249, Taiwan
Yu-We Ku, Animal and Plant Disease Control Center Yilan County, Wujie Township, Yilan County 268015, Taiwan
Po-Wen Chen, Department of Veterinary Medicine, National Chung Hsing University, Taichung 40249, TaiwanFollow

Urinary tract infections (UTIs) are highly prevalent bacterial infections that pose significant health risks. Specific probiotic strains have been recommended for UTI control and management of antibiotic resistance. Otherwise, paraprobiotics, defined as inactivated probiotic cells, offer potential advantages by minimizing risks associated with live microorganisms. However, the effectiveness of heat-killed probiotic strains against UTIs remains uncertain. Additionally, lactoferrin (LF), an iron-binding glycoprotein, exhibits immunomodulatory, antimicrobial, and anti-inflammatory properties. Recently, we had developed recombinant LF-expression probiotics, which can display considerate antibacterial activities against select food-borne pathogens in vitro. Thus, the present study aimed to evaluate the antibacterial activities of heat-killed natural and recombinant LF-expressing probiotics against UTIs in vitro and in vivo. Firstly, using in vitro assays, we assessed the antibacterial activity of heat-killed natural and recombinant LF-expressing probiotics against uropathogenic Escherichia coli and Klebsiella pneumoniae. Among the tested probiotics, 10 heat-killed LF-expressing strains displayed superior antibacterial efficacy compared to 12 natural probiotics. Based on their potent in vitro activity, selected probiotics were formulated into three probiotic mixtures: viable probiotic mixture (LAB), heat-killed probiotic mixture (HK-LAB), and heat-killed LF-expressing probiotic mixture (HK-LAB/LF). To further evaluate the therapeutic potential of these probiotic mixtures in vivo, we established a murine model of UTIs by intraurethral administration of E. coli to 40 female C57BL/6JNarl mice on day 0. Subsequently, mice received oral gavage of placebo, LAB, HK-LAB, or HK-LAB/LF for 21 consecutive days (n = 8 per group). An additional control group (n = 8) received ampicillin treatment for 7 days. To assess protective effects against re-infection or UTI relapse, all mice were challenged with E. coli on day 22 and E. coli plus K. pneumoniae on day 25. Results from the murine UTI model demonstrated that placebo administration did not reduce bacteriuria throughout the experiment. Conversely, supplementation with ampicillin, HK-LAB/LF, HK-LAB, or LAB significantly (p

Van, Vo Thi Hong; Liu, Zhen-Shu; Hsieh, Yueh Jen; Shiu, Wei-Chen; Chen, Bo-Yuan; Ku, Yu-We; and Chen, Po-Wen (2023) "Therapeutic effects of orally administration of viable and inactivated probiotic strains against murine urinary tract infection," Journal of Food and Drug Analysis: Vol. 31 : Iss. 4 , Article 2.
Available at: https://doi.org/10.38212/2224-6614.3474

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