Evaluation of the effectiveness of the use of bacteriophages in the treatment of acute intestinal infections caused by opportunistic pathogens in infants

Acute intestinal infections caused by opportunistic microflora (OPM) are a pressing problem in infants. The purpose of this research was to investigate the treatment of enterocolitis caused by OPM in infants using antibacterial drugs and their detection by bacteriophages. Materials and methods used: a single-center retrospective cohort study of 106 pediatric patients aged 1 month to 1 year old with mild to moderate severity of acute intestinal infections caused by OPM and treated with an antibacterial drug (nifuroxazide), a bacteriophage (complex liquid pyophage) or a combination thereof, who were divided into the three groups as follows: G1 (“Nifuroxazide,” n=39), G2 (“Pyophage,” n=33) and G3 (“Combined drugs,” n=34), was conducted at the Scientific and Research Institute for Children’s Infections of the Russian Federal Biomedical Agency (Saint Petersburg, Russia) in 2018-2021. Data on pathogen elimination and duration of symptoms in patients were analyzed. The criteria for the effectiveness of therapy were the normalization of temperature, stool and coprograms and a decrease in the OPM titer in feces to a level of ≤104 CFU/g. Results: achievements of all applications of successful therapy occurred more often in G3 compared to G1 (0.007). An increased risk of treatment failure was evidenced by patients having OPM in a stool at the level of over 109 CFU/g (RR=14,09 [2,84; 69,96]) and the “visible entire” presence of erythrocytes (RR=6.26 [2.51; 15.62]) and leukocytes (RR=5,51 [2,22; 13,67]) in a coprogram. The probability of a response to therapy when using the active substances Nifuroxazide+Pyophage was lower (0.120 [0.037, 0.389]) than with monotherapy with Pyophage (0.227 [0.074, 0.692]) or Nifuroxazide (2.678 [1.14, 6.297]) alone. Conclusion: combined therapy of acute intestinal infections caused by OPM in infants using the antibacterial drugs coupled with Pyophage increases the effectiveness of OPM elimination and the disease’s clinical and laboratory symptoms’ relief.