Genome Sequences of Bacteriophages UPEC01, UPEC03, UPEC06, and UPEC07 Infecting Avian Pathogenic Escherichia coli

Abstract

Here, we present the genome sequences of four bacteriophages that infect avian pathogenic Escherichia coli. The phages were isolated from raw sewage in Kampala, Uganda. The genome sizes of the phages ranged between 143,140 bp and 178,307 bp, with an average G1C content of 41.25%. Phages infecting avian pathogenic Escherichia coli (APEC) have the potential to be applied as phage therapy in the management of avian colibacillosis, a devastating disease that is responsible for significant economic losses in the poultry industry (1). The emergence of multidrug-resistant pathogenic E. coli strains has sparked interest in the search for alternative control measures for bacterial pathogens, including, among others, the use of phages (2). In this study, whole-genome sequencing of bacteriophages was carried out to determine the genetic characteristics and the taxonomic identification or classification of these phages as part of a larger study aimed at identifying and establishing phage stocks that can be used to supplement the use of antibiotics in managing avian colibacillosis in Uganda. The bacteriophages in this study were isolated from sewage at the National Water and Sewerage Corporation treatment plant (Kampala, Uganda). Several E. coli field isolates (Table 1) obtained from chicken droppings were used as isolation hosts for the phages following previously described methods (3). Briefly, 10 mL of raw sewage was centrifuged (10,000 g for 10 min) to obtain a supernatant, which was added to 10 mL of 2 tryptic soy broth (TSB) containing 100 mL of overnight E. coli broth culture. The mixture was incubated (30°C for 48 h at 120 rpm) and centrifuged (7,000 rpm for 5 min at 4°C), and the supernatant was filtered (0.45mm). The phage lysate obtained was plaque purified three times to produce a uniform phage stock. The isolated phages that could infect the APEC isolates from chickens that had died from colibacillosis were selected (4). Genomic DNA was extracted from the phages using 2% SDS and purified using a Qiagen Genomic-tip 100/G kit according to the manufacturer’s instructions.