Lytic Activity of Bacteriophages and Structure of Opportunistic Microbiota in Laboratory Primates

This paper summarizes five years of monitoring opportunistic bacteria in laboratory primates and assessing their phage sensitivity. The main representative of the microbiota in both healthy and sick animals was lactose-positive Escherichia coli (84.6% and 92.7%, respectively). Among other enterobacteria, Proteus spp., Enterobacter spp., and Klebsiella spp. were most frequently detected. Molecular genetic analysis revealed widespread circulation of pathogenic groups of E. coli, primarily enteroinvasive (92.9%) and enteropathogenic (63.4%) strains. Staphylococcus aureus carriage was noted in 41.6% of animals. Assessment of the lytic activity of bacteriophages showed limited effectiveness of phages targeting Gram-negative enterobacteria: Intesti bacteriophage lysed 25% of cultures, Klebsiella bacteriophage lysed 3.4%, and Proteus phages lysed 22.2-55.5%. In contrast, staphylococcal bacteriophage CH1 was active against all S. aureus cultures. No bacteriophages with broad activity against EIEC, EPEC, Klebsiella spp. or Proteus spp. were identified. The data highlight the similarity between primate and human microbiota and the need for individualized selection of bacteriophages to ensure microbiological safety and increase the effectiveness of phage prophylaxis in laboratory animal husbandry.