Isolation and identification of Salmonella pullorum bacteriophage YSP2 and its use as a therapy for chicken diarrhea

Abstract

Salmonella pullorum is the major pathogen that is harmful to the poultry industry in developing countries, and the treatment of chicken diarrhea caused by S. pullorum has become increasingly difficult. In this study, a virulent bacteriophage YSP2, which was able to specifically infect Salmonella, was isolated and characterized. Phage YSP2 was classified in the Siphoviridae family and had a short latent period of 10 min. No bacterial virulence- or lysogenesis-related ORF is present in the YSP2 genome, making it eligible for use in phage therapy. Experiments in vivo investigated the potential use of phages as a therapy against diarrhea in chickens caused by S. pullorum in a chicken diarrhea model, demonstrating that a single oral administration of YSP2 (1 × 10 PFU/mL, 80 μL/chicken) 2 h after S. pullorum oral administration at a double median lethal dose was sufficient to protect chickens against diarrhea. Gross inspection showed that YSP2 can effectively reduce organ damage and significantly relieve hemorrhage in the intestine and liver tissue. Moreover, YSP2 can maintain a high curative effect when diluted to 10 PFU/mL. In light of its therapeutic effect on chicken diarrhea, YSP2 may serve as an alternative treatment strategy for infections caused by S. pullorum.

Comprehensive Evaluation of the Safety and Efficacy of BAFASAL® Bacteriophage Preparation for the Reduction of Salmonella in the Food Chain

“…Based on the results, we have concluded that the administration of phages was well tolerated at all examined doses, without any adverse effects that could be correlated with the bacteriophages' treatment. These findings are aligned with other scientific reports determining the safety of bacteriophage application in chicken broilers [25,[68][69][70][71]. For the final safety assessment of BAFASAL ® , we conducted two genotoxicity studies, i.e., the micronucleus test (MNA), and the Mouse Lymphoma Assay (MLA).…”

Characteristics of a Series of Three Bacteriophages Infecting Salmonella enterica Strains

“…In fact, many papers have been published recently which described bacteriophages that might be used in phage therapy against Salmonella . They include reports on characterization of previously unknown bacteriophages having the potential for use in phage therapy [ 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 ], experimental studies with bacteriophages applied to poultry [ 21 , 22 , 23 , 24 , 25 , 26 ], and the use of bacteriophages in experimental phage therapy in mouse [ 27 , 28 , 29 , 30 ] or pig [ 31 ] models. Although promising results were obtained in these studies, and economic analyses have been performed to assess costs and benefits of the use of phage therapy for the control of Salmonella in poultry [ 9 , 32 ], it is evident that the host range of the vast majority of Salmonella phages is restricted to specific strains or serovars.…”

Bacteriophage Growth Promoters in Poultry

“…Según los trabajos realizados, el pH = 7 es el óptimo para estos virus, observándose reducción de títulos de fagos a medida que disminuye el pH y no resisten a medios muy ácidos con pH < 3. Teniendo en cuenta que el pH gástrico de los pollos es aproximadamente 2,8 [25], es natural que muchos se pierdan en ese tramo del tracto digestivo y es necesario protegerlos [22,23,25]. Además, se observó disminución de títulos de fagos a temperatura de 70°C durante 40 min o más y que no resisten temperaturas mayores o iguales a 80°C [23], por lo que el proceso de peletizado o extrusión puede disminuir los títulos de fagos y es necesario protegerlos [23,25].…”