Pseudomonas aeruginosa is an opportunistic pathogen of public health concern. This study aimed to investigate the prevalence of P. aeruginosa, some virulence factors, and antimicrobial resistance patterns and highlight the potential pathways of horizontal bla_SHV-resistant gene transfer from diverse sources. A total of 220 samples were collected from fish (n = 90), water (n = 30), poultry (n = 50), and humans (n = 50). All samples were isolated, confirmed by the Vitek 2 system, and tested against antimicrobial agents. Some virulence and resistance genes were examined by PCR and sequenced for the bla_SHV-resistant gene from four selected isolates from each source. SPSS v26, with chi-squared tests and Pearson correlations (p < 0.05), was implemented for statistical investigation. P. aeruginosa was isolated at 33.3%, 20%, 14%, and 24% from fish, water, poultry, and humans, respectively. Using the diffusion disk method, extensively drug-resistant (XDR) and multidrug-resistant (MDR) strains were detected. All strains harbored the oprL and toxA genes, while the lasB gene was present in 40% of fish samples but not present in human samples. All strains lacked the exoS gene. The tetA, sul1, bla_SHV, and bla_TEM resistance genes were detected at different percentages. The bla_SHV genes from fish and water isolates were closely related to each other and showed similarity to those of the human isolates. The poultry isolates formed a separate phylogenetic lineage. The emergence of XDR and MDR P. aeruginosa highlights a possible public health threat. Based on the gene similarity between fish and water isolates, our results suggest that these isolates have a common origin. The similarity between the human isolates and environmental isolates (fish and water) raises concerns about possible transmission to humans.

The present study was conducted to investigate the effects of colloidal nanoparticles of silver (Nano-Ag) on the expression of myogenesis-related genes in chicken embryos. The investigated genes included the members of the myogenic regulatory factors family (MRFs) and myocyte enhancer factor 2A (MEF2A) genes. A total of 200 fertilized broiler eggs (Indian River) were randomly distributed into four groups; non-injected control, injected control with placebo, treatment I in ovo injected with 20 ppm Nano-Ag, and treatment II in ovo injected with 40 ppm Nano-Ag. The eggs were then incubated for 21 days at the optimum temperature and humidity conditions. Breast muscle tissues were collected at the 5th, 8th, and 18th days of the incubation period. The mRNA expression of myogenic determination factor 1 (MYOD1), myogenic factor 5 (MYF5), myogenic factor 6 (MYF6), myogenin (MYOG), and MEF2A was measured at the three sampling points using real-time quantitative PCR, while MYOD1 protein expression was evaluated on day 18 using western blot. Breast muscle tissues were histologically examined on day 18 to detect the changes at the cellular level. Our results indicate that myogenesis was enhanced with the low concentration (20 ppm) of Nano-Ag due to the higher expression of MYOD1, MYF5, and MYF6 at the transcriptional level and MYOD1 at the translational level. Moreover, histological analysis revealed the presence of hyperplasia (31.4% more muscle fibers) in treatment I (injected with 20 ppm). Our findings indicate that in ovo injection of 20 ppm Nano-Ag enhances the development of muscles in chicken embryos compared with the 40-ppm dosage and provide crucial information for the use of silver nanoparticles in poultry production.

This notice provides additional clarification to the original publication