Isolation and therapeutic efficacy of enteropathogenic E. coli phage cocktail against colibacillosis in neonatal goats

Phage based therapeutics have shown promising results against the infections caused by the drug resistant bacteria. To combat the problem of antibiotic resistance posed by diarrhoeagenic E. coli, here, we identified and characterized 38 E. coli phages which were isolated from 70 solid sources (goat-faeces and soil). The in vitro lytic range of phage isolates (n=38) against 439 isolates of E. coli was found between 16 and 53%. Three phage isolates with highest host range showed lytic efficacy against 53, 48 and 46% of E. coli isolates, respectively. A preparation with above three phages was developed, and the phages of the preparation were found stable at wide range of temperature, pH and chloroform treatment. Endotoxin content of the preparation was found below the threshold level and it also passed safety and sterility tests. a total of 40 diarrheic goat kids were administered orally with the therapeutic phage preparation for two days twice daily. Total 21 diarrheic goat-kids were successfully treated using the therapeutic phage preparation, whereas 19 kids could not be treated (success rate: 52.5%; 21/40). The results of the current study provide insight for using lytic bacteriophages for therapeutic interventions against drug resistant E. coli responsible for colibacillosis in neonatal goat kids.