Isolation and Molecular Characterization of Two Novel Lytic Bacteriophages for the Biocontrol of Escherichia coli in Uterine Infections: In Vitro and Ex Vivo Preliminary Studies in Veterinary Medicine

Abstract

E. coli is one of the etiological agents responsible for pyometra in female dogs, with conventional treatment involving ovariohysterectomy. Here, we report the isolation and full characterization of two novel lytic phages, viz. vB_EcoM_Uniso11 (ph0011) and vB_EcoM_Uniso21 (ph0021). Both phages belong to the order Caudovirales and present myovirus-like morphotypes, with phage ph0011 being classified as Myoviridae genus Asteriusvirus and phage ph0021 being classified as Myoviridae genus Tequatrovirus, based on their complete genome sequences. The 348,288 bp phage ph0011 and 165,222 bp phage ph0021 genomes do not encode toxins, integrases or antimicrobial resistance genes neither depolymerases related sequences. Both phages were shown to be effective against at least twelve E. coli clinical isolates in in vitro antibacterial activity assays. Based on their features, both phages have potential for controlling pyometra infections caused by E. coli. Phage ph0011 (reduction of 4.24 log CFU/mL) was more effective than phage ph0021 (reduction of 1.90 log CFU/mL) after 12 h of incubation at MOI 1000. As a cocktail, the two phages were highly effective in reducing the bacterial load (reduction of 5.57 log CFU/mL) at MOI 100, after 12 h of treatment. Both phages were structurally and functionally stabilized in vaginal egg formulations.

In Vitro Activity of Allium cepa Organosulfur Derivatives against Canine Multidrug-Resistant Strains of Staphylococcus spp. and Enterobacteriaceae

“…Several veterinary medicine studies have investigated the antimicrobial activities of natural products against canine Staphylococcus and Enterobacteriaceae spp. These studies explored a variety of natural sources, including herbal extracts, honey products and bacteriophages, among others [ 63 , 64 , 65 ]. These investigations provided valuable insights into the potential efficacy of natural compounds as alternative therapies, with botanical products being the most promising solutions, such as Garcinia mangostana or Harungana madagascariensis extracts [ 66 , 67 ].…”

An Edible Antibacterial Coating Integrating Lytic Bacteriophage Particles for the Potential Biocontrol of Salmonella enterica in Ripened Cheese

“…Evaluation of the Potential for Cytotoxicity of the Ediphage , Via Disc Diffusion Assay . The disc diffusion assay employing cell lines of immortalized human keratinocytes (HaCaT) and mouse fibroblasts (3T3) [ 26 , 27 , 28 ] was used for the evaluation of the cytotoxicity potential of the EdiPhage integrating the cocktail of lytic phages. A Petri plate containing the cells was filled with a small disc of sample (EdiPhage) and was incubated for 24 h at 37 °C in a 5% CO 2 atmosphere.…”

Characterization of Shiga toxin‐producing Escherichia coli bacteriophages isolated from agricultural environments and examination of their prevalence with bacterial hosts

“…The bacteriophage suspensions were also diluted in S.M. buffer (pH 7) and analyzed by Litesizer 500 (Anton Paar, Virginia, USA) with Dynamic Laser Light Scattering (DLS) system for the physical parameters such as zeta potential and electrophoretic mobility of the bacteriophage isolates as described elsewhere (Balcão et al, 2022).…”