Characterization of novel bacteriophage phiC119 capable of lysing multidrug-resistant Shiga toxin-producingEscherichia coliO157:H7

Abstract

BackgroundShiga toxin-producing Escherichia coli (STEC) is one of the most common and widely distributed foodborne pathogens that has been frequently implicated in gastrointestinal and urinary tract infections. Moreover, high rates of multiple antibiotic-resistant E. coli strains have been reported worldwide. Due to the emergence of antibiotic-resistant strains, bacteriophages are considered an attractive alternative to biocontrol pathogenic bacteria. Characterization is a preliminary step towards designing a phage for biocontrol.MethodsIn this study, we describe the characterization of a bacteriophage designated phiC119, which can infect and lyse several multidrug-resistant STEC strains and some Salmonella strains. The phage genome was screened to detect the stx-genes using PCR, morphological analysis, host range was determined, and genome sequencing were carried out, as well as an analysis of the cohesive ends and identification of the type of genetic material through enzymatic digestion of the genome.ResultsAnalysis of the bacteriophage particles by transmission electron microscopy showed that it had an icosahedral head and a long tail, characteristic of the family Siphoviridae. The phage exhibits broad host range against multidrug-resistant and highly virulent E. coli isolates. One-step growth experiments revealed that the phiC119 phage presented a large burst size (210 PFU/cell) and a latent period of 20 min. Based on genomic analysis, the phage contains a linear double-stranded DNA genome with a size of 47,319 bp. The phage encodes 75 putative proteins, but lysogeny and virulence genes were not found in the phiC119 genome.ConclusionThese results suggest that phage phiC119 may be a good biological control agent. However, further studies are required to ensure its control of STEC and to confirm the safety of phage use.

Bacteriophage cocktail for biocontrol of Escherichia coli O157:H7: Stability and potential allergenicity study

“…Analyses were performed based on the full-length FASTA criterion and the sliding 80mer FASTA-FAO/WHO criterion that defines a probable allergen as a protein that exhibits a local similarity match of 35% over 80 amino acids [ 35 ]. All proteins of the four phage did not show hits for the full-length FASTA criterion based on an identity greater than 50% and an E score less than 1e-7 ( Table 2 )[ 19 , 20 ].…”

“…Bacteriophages ΦJLA23, ΦKP26, ΦC119 and ΦE142 were provided by the National Laboratory for Research in Food Safety (LANIIA CIAD, Sinaloa, Mexico)[ 19 , 20 ]. E .…”

Antibiotic‐resistant Shiga toxin‐producing Escherichia coli: An overview of prevalence and intervention strategies

“…Since bacteriophages effectively reduce initial bacterial contamination (Carter et al, ), bacteriophage mixtures have been used to kill the pathogenic bacteria, including STEC at the pre‐harvest stage, on cattle hides (FSIS & USDA, ). A bacteriophage, phiC119, recently isolated from horse faeces was found to have bactericidal activity against MDR‐STEC and some Salmonella serotypes (Amarillas, Chaidez, Gonzalez‐Robles, Lugo‐Melchor, & Leon‐Felix, ). The phiC119 phage has good biocontrol potential as it lacks known virulence and lysogenic genes (Amarillas et al, ).…”

“…A bacteriophage, phiC119, recently isolated from horse faeces was found to have bactericidal activity against MDR‐STEC and some Salmonella serotypes (Amarillas, Chaidez, Gonzalez‐Robles, Lugo‐Melchor, & Leon‐Felix, ). The phiC119 phage has good biocontrol potential as it lacks known virulence and lysogenic genes (Amarillas et al, ). These studies suggest lytic bacteriophages can be used to target STEC without spreading antibiotic resistance.…”

“…Likewise, coliphages DT1 and DT6 that target E. coli have been shown to effectively reduce STEC counts when administered individually or together in a mix (Tomat et al, 2013). Since bacteriophages effectively reduce initial bacterial contamination (Carter et al, 2012) biocontrol potential as it lacks known virulence and lysogenic genes (Amarillas et al, 2016). These studies suggest lytic bacteriophages can be used to target STEC without spreading antibiotic resistance.…”