This study was designed to determine the prevalence of enterotoxigenic S. aureus in table eggs in El-Fayoum city, Egypt. A total of 250 table egg samples (75 Baladi hens’, 75 white farm hens’, 75 brown farm hens’ and 25 duck egg samples) were collected randomly from poultry farms, groceries, supermarkets, and street vendors in El-Fayoum city, Egypt. Each Baladi hen ҆s egg sample was represented by five eggs, while each farm hen ҆s and duck egg sample was represented by three eggs. The shells and contents of eggs were examined for the presence of Staphylococcus spp < /em>., coagulase (coa), and staphylococcal enterotoxins (Ses) genes. The obtained results revealed that the examined samples of shells and contents of Baladi hens ҆, poultry farms ҆ (white and brown), and ducks ҆ eggs were contaminated with Staphylococcus spp. with incidences of 24.0, 9.3, 5.3, 44.0, 8.0, 2.7, 1.3 and 12.0 %, respectively and coagulase-positive S. aureus with the incidences of 16.7, 14.3, 0.0, 18.2, 0.0, 0.0, 0.0 and 33.3 %, respectively. Enterotoxin profiling by PCR proved that two classical enterotoxin genes (Seb and Sed) were produced from three (42.86%) coagulase-positive S. aureus strains, as two Baladi hens’ ҆ eggshells produced Seb and one of the ducks ҆ egg contents produced Sed. The public health hazards of the isolated strains and enterotoxins had been discussed.

Infectious Coryza (IC) is an infectious upper respiratory disease of chickens and birds, caused by Avibacterium paragallinarum (Av. Paragallinarum). It is characterized by facial swelling and nasal discharge. Here, the study aimed to identify the causative agent of infectious coryza from diseased cases using conventional and molecular methods, forty-one different samples (swollen heads and nasal discharges) from layers and broiler chickens were examined bacteriologically for isolation of Av. Paragallinarum.  The total isolation percentage was 9.75%, and the percentage was 66.7% from total layer samples. The samples underwent examination by polymerase chain reaction (PCR) using HPG-2. Three samples were confirmed by PCR with a percentage of 7.3% (3/41). Multiplex PCR was used for typing the tested strains using HMTp210 gene thus, all strains were of type B. sequence analysis showed a maximum identity percentage (100%) between the tested strains of Av. paragallinarum. In conclusion, typical signs for IC diseases were appeared and identified bacteriologically as Av. paragallinarum also three strains were only confirmed by PCR and identified type B strains. PCR technique is a reliable and sensitive test for confirmation.

Pseudomonas species is one of the psychotropic bacteria that can survive in low-tempered milk and dairy products besides producing heat-resistant spoilage enzymes. In this study, one hundred and fifty samples of milk and some dairy products were analyzed. The overall prevalence of Pseudomonas spp. was 44.66% (0% pasteurized milk, 16% butter, 20% pasteurized cream, 48.5% Talaga cheese, 50% bulk milk tank, 66.6% raw market milk, and 70% in raw cream). From 67 positive samples, eighty-three isolates were confirmed biochemically as Pseudomonas spp. The most prominent species were P. aeruginosa, then P. fluorescence, P. Fragi, P. psychrophile, P. proteolytica, P. alcaligens, P. lundensis, and P. brenneri by a percent of 38.5%, 37.5%, 10.8%, 6%, 2.4%, 2.4%, 1.2%, and 1.2%, respectively. Fourteen antibiotic discs were selected to measure the antimicrobial susceptibility of 59 isolates of Pseudomonas spp. The higher antimicrobial resistance was against Ampicillin (100%) followed by Colistin (98%), while the antibiotic sensitivity was higher against Imipenem (96.6%) then Meropenem (91.5%). The average MAR index of isolated Pseudomonas spp. was 0.462. Ten isolates of antimicrobial resistance serotypes of P. aeruginosa were O11: E, O8: C, O5: B, O4: F, and O2: B. Molecular identification of P. aeruginosa, P. fluorescence, and P. fragi was carried out using polymerase chain reaction (PCR) to determine their virulence genes (LasB, ExoS, pilB for P. aeruginosa, aprX for P. fluorescence and carA gene for P. fragi). High levels of antimicrobial-resistant (AMR) Pseudomonas spp.  threaten public health and cause global concern. The economic and public health impacts were discussed.

This study targeted isolation and characterization of potential bacteriophages (phages) infecting MDR pathogenic bacteria recovered from chickens and analyzed their efficacy as bio-control agents. A total of 45 different bacterial isolates (18 E. coli, 16 Salmonellae spp., 5 Staphylococcus spp., 2 Pseudomonas spp., 1 Proteus mirbalis, 1 Citrobacter spp., 1 Enterobacter aerogenes and 1 Klebsiella pneumonia) were obtained from chickens in the current study and previous studies. The identified isolates were investigated for the presence of virulence genes and MDR using PCR and disc diffusion method, respectively. Nine purified phages classified morphologically into 3 families (Myoviridae, Siphoviridae and Podoviridae) using Transmission Electron Microscope were recovered from chicken intestinal contents and showed viability at wide pH range, resistance to organic solvents and thermostability at high temperatures (up to 80ºC). The potential phages exhibited various bacterial host ranges using the spot test and the efficiency of plating (EOP) assay. The results revealed the prevalent of pathogenic E. coli and salmonella serovars among the recovered isolates with different virulence and genotypic patterns. The lytic phages were highly stable and have the capacity to infect different pathogenic MDR bacterial strains. This study demonstrated that these promising phages of avian origin could be used to control the pathogenic MDR E. coli and Salmonella serovars which possess public concerns on human health and poultry industry.