Pseudomonas aeruginosa is a bacteria responsible for many hospital-acquired infections. Phages are promising alternatives for treating P. aeruginosa infections, which are often intrinsically resistant. The combination of phage and antibiotics in clearing bacterial infection holds promise due to increasing reports of enhanced effectiveness when both are used together. The aim of the study is to isolate and characterize a novel P. aeruginosa phage and determine its effectiveness in in vitro combination with antibiotics in controlling P. aeruginosa. In this study, a novel jumbo myophage HPP-Temi infecting P. aeruginosa Pa9 (PP334386) was isolated from household sewage. Electron micrographs of the phage were obtained to determine the morphological features of HPP-Temi virions. Complete genome analysis and a combination of Pseudomonas phage HPP-Temi with antibiotics were examined. The phage HPP-Temi was able to productively infect P. aeruginosa ATCC 9027 but was unable to infect a closely related genus. The phage was stable at 4–37 °C, 0.5% NaCl, and pH 8 for at least one hour. The HPP-Temi genome is a 302,719-bp-long dsDNA molecule with a GC content of 46.46%. The genome was predicted to have 436 ORFs and 7 tRNA genes. No virulence factor-related genes, antimicrobial resistance, or temperate lifestyle-associated genes were found in the phage HPP-Temi genome. Phage HPP-Temi is most closely related to the known or tentative representatives of the Pawinskivirus genus and can be proposed as a representative for the creation of a novel phage species in that genus. The phage and antibiotics (Ciprofloxacin) combination at varying phage titers (10³, 10⁶, 10⁹) were used against P. aeruginosa Pa9 (PP334386) at 3.0 × 10⁸ CFU/mL, which was carried out in triplicate. The result showed that combining antibiotics with phage significantly reduced the bacteria count at 10³ and 10⁶ titers, while no growth was observed at 10⁹ PFU/mL. This suggests that the effect of phage HPP-Temi in combination with antibiotics is a potential and promising agent for the control of P. aeruginosa infections.

Farm animals harbour bacterial pathogens, which are often viewed as important indicators of animal health and determinants of food safety. To better understand the prevalence and inform treatment, we audited laboratory data at the Bacteriology Laboratory of the NVRI from 2018–2021. Antibiotics were classified into seven basic classes: quinolones, tetracyclines, beta-lactams, aminoglycosides, macrolides, nitrofuran, and cephalosporins. Trends were analysed using a generalised linear model with a log link function for the Poisson distribution, comparing proportions between years with an offset to account for the variability in the total number of organisms per year. Avian (73.18%) samples were higher than any other sample. The major isolates identified were Escherichia. coli, Salmonella spp., Klebsiella spp., Staphylococcus spp., Proteus spp., and Pseudomonas spp. We found that antimicrobial resistance to baseline antibiotics increased over the years. Of particular concern was the increasing resistance of Klebsiella spp. to cephalosporins, an important second-generation antibiotic. This finding underscores the importance of farm animals as reservoirs of pathogens harbouring antimicrobial resistance. Effective biosecurity, surveillance, and frugal use of antibiotics in farms are needed because the health of humans and animals is intricately connected.

Salmonella is a zoonotic pathogen whose virulence factors play important roles in pathogenesis. Antimicrobial resistance poses a threat to the effective prevention and treatment of bacterial infections. The aim of this study was to determine the prevalence of virulence and antimicrobial resistance genes in Salmonella isolated from humans and poultry-associated sources. Of the 1,239 samples tested, 242 (19.5%) were positive for Salmonella using Microbact 24E and VITEK 2 COMPACT systems. Antimicrobial susceptibility testing was performed on 200 Salmonella isolates purposively selected from the 242 confirmed isolates to ensure representation of isolates from the different sample types and study locations. All isolates (100%) were resistant to erythromycin, nalidixic acid and oxacillin. Additionally, high resistance was observed to ciprofloxacin (96%), cefotaxime (86%), ceftazidime (52%), and streptomycin (68%). However, the isolates showed high susceptibility to gentamicin (74%), meropenem (72%), ampicillin (51%), and amoxicillin-clavulanic acid (70%). Fourteen selected Salmonella isolates were subjected to PCR for three virulence genes (invA, spiC and pipD) and five antimicrobial resistance genes (aadA2, blaCTX-M, gyrA, tetA and mphA). The aadA2, blaCTX-M, and invA genes were detected in all the isolates (100%), while gyrA, mphA, pipD, spiC and tetA were detected in 71.4%, 7.1%, 85.7%, 14.3% and 92.8% of isolates, respectively. The study revealed that Salmonella enterica carrying antimicrobial resistance and virulence genes was recovered from humans and poultry-associated sources. Prudent antimicrobial use is therefore essential to limit the emergence and spread of multidrug-resistant Salmonella in poultry production systems.