Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 6/6/2008
Publication Date: 7/26/2008
Citation: Volozhantsev, N., Verevkin, V., Levchuk, V., Mitsevich, E., Mitsevich, I., Mvakinina, V., Krasilnikova, V., Bannov, V., Siragusa, G., Seal, B.S., Svetoch, E. 2008. Monitoring of anti-C. perfringens bacteriophage CpV1 persistence in gastrointestinal tracts of broilers. Edinburgh International Phage Conference. Interpretive Summary:
Technical Abstract: A factor limiting promotion of poultry products to the world market is any contamination of birds with pathogens, including Clostridium perfringens. The latter is often accountable for significant economical losses in production of commercial birds because of a possibility of the development of necrotic enteritidis (NE). For cure and prevention of NE antibiotic growth promoters (AGPs) are used. However, they may become a harmful source of human resistant pathogens. In spite of contradictory consequences of application of AGPs for animals and humans, they will probably stay in use unless new-generation efficient and cost-effective antibiotic alternative formulations are developed. Lytic bacteriophages and/or their lytic enzymes could become such formulations. In order to elaborate optimal schemes of application of bacteriophage formulations to cure and prevent C.perfringens infection in poultry, we have made a series of experiments to control persistence of C.perfringens lytic phage CpV1 in broiler gastrointestinal tracts (GIT). The phage suspension was once administered per os to 14-17 days old chicks (6×108 pfu/bird). To determine concentrations of the phage, materials from each compartment of the gastrointestinal tract (the crop, glandular stomach, the upper department of the small intestine, ileum, cecum, and the large intestine) were suspended with a phage buffer followed by agar layer titration on a lawn produced by CpV1 susceptible C. perfringens strain. Two independent experiments have shown that in one hour after the administration, the highest concentration of the phage in the crop is 6.9×107 pfu/g. In the glandular stomach its concentration varies between 2×103 and 3×105 pfu/g. The phage is not identified in the bottom department of the GIT. Within a period between 3 hours and 12 hours after the treatment, its concentration reaches 107 pfu/g in all cecal and ileum samples in all birds. Such high concentrations of the phage in these GIT departments are extremely important from the standpoint of further phage therapy of C.perfringens-associated infection. Ileum and cecae are known to be main sites for the agent to colonize and to proliferate. In ileum and cecum, as well as in the large intestine, the maximal phage concentration (more than 106pfu/g) is registered in 6 hours after the phage administration and remains at a rather high level (more than 105 pfu/g) at least for the next 6 hours. Next day after the administration its concentration in the GIT decreases significantly. But the phage is not fully eliminated even from the crop and is identified at the concentration of 500 pfu/g 48 hours later in one of the birds.