Because milk is rich in nutrients, it creates an environment conducive to the growth of bacteria that could be harmful to consumers. Therefore, assessing of its bacteriological quality and the resistance of these pathogens to several antibiotic groups is very important. VITEK 2 compact detected E. coli, Salmonellae spp., S. aureus and B. cereus in the examined samples while it failed to detect Listeria spp. The serological identification of E. coli showed the presence of O44: H18, O127: H6, O159, O15: H2, and O91: H21. Also, Salmonella serotypes as           S. enteritidis (25%), S. infantis (12.5%), S. kentucky (12.5%), S. montevideo (6.25%), S. shangani (12.5%), S. tsevie (12.5%). S. typhimurium (18.75%).  Furthermore, the entero-toxigenic strains of S. aureus were 31.25% of the identified strains; the percentage of entero-toxigenic strains that secrete A, A&C and D enterotoxin were 60%, 20% and (20%); respectively. Ampicillin, amoxicillin / clavulanic acid, cefpodoxime, cefovecin, ceftiofur, and trimethoprim / sulfamethoxazole were all ineffective against the isolated E. coli strains. Intermediate sensitive to cefalothin while they were sensitive to cefalexin, imipenem, amikacin, gentamicin, neomycin, enrofloxacin, marbofloxacin, pradofloxacin, doxycycycline, tetracycline, nitrofurantoin and chloramphenicol. Additionally, the isolated S. aureus exhibited resistance to tetracycline, benzylpenicillin, oxacillin, gentamycin, ciprofloxacin, levofloxacin, and moxifloxacin also; it showed intermediate resistance to rifampicin. The identified S. aureus strains were also susceptible to linezolid, nitrofurantoin, vancomycin, tigecycline, and trimethoprim / sulfamethoxazole.

Staphylococci are the most typical bacteria found in cattle with mastitis, either Staphylococcus aureus or coagulase-negative Staphylococci (CNS). The study’s goal was to determine the prevalence of Staphylococci in bovine mastitis, the antimicrobial profile, and evaluate the concentration of pro-inflammatory interleukins (IL-4, IL-6, IL-10) related to the inflammatory response in clinical mastitis by ELISA. S. aureus (54%) and CNS (19%) were detected in 400 samples of milk from both clinical and subclinical bovine mastitis. The S. aureus isolates revealed higher resistance to ampicillin (100%), followed by amoxicillin-clavulanic acid (98.1%), cefotaxime (88.9%), erythromycin (63.2%), cefuroxime (63%), and tetracycline (61.1%). Furthermore, the CNS isolates showed high resistance against amoxicillin-clavulanic acid (100%), followed by ampicillin (94.7%), cefotaxime (89.5%), erythromycin (79.6%), cefuroxime (89.5%), and tetracycline (73.7%). However, the high susceptibility of S. aureus and CNS was observed to imipenem and ciprofloxacin. Furthermore, Cows with clinical mastitis reported high levels of IL-6 in both their serum and their milk. While they have much lower levels of IL-4 and IL-10 than normal ones (P < 0.001). In conclusion, it is recommended that laboratory results be carefully interpreted to avoid antimicrobial therapy for Staphylococci that is not clinically relevant and to ensure the advisable use of antimicrobials. Also, further study on the application of interleukins as therapeutic agents against bovine mastitis should be considered.

Staphylococcus aureus is a major pathogen that affects both people and animals. Staphylococcus aureus causes food poisoning in addition to invasive diseases as arthritis and septicemia. This study was done on 70 chicken samples obtained from 7 different farms of chickens with symptoms of arthritis in Kafr El-sheikh government, Egypt. In this study out of 70 samples of chickens from different farms, 37 (52.8%) samples were recognized as coagulase-positive staphylococci (CoPS) and 33 (47.1%) were recognized as coagulase-negative staphylococci (CoNS). By using the microtitre plate method, seven out of 37 (18.9%) CoPS were positive for biofilm production with variable degrees. The pattern of antibacterial sensitivity of 7 Staphylococcus aureus isolates against 12 commercially available antibiotic discs showed 100 % resistance to oxytetracycline then Amoxicillin (71.43%), Erythromycin (57.14%), Norfloxacin (14.29%), Tetracycline (42.86), Sulphamethoxazole (42.86%), Gentamicin (42.86%), Ampicillin (42.86%), kanamycin (28.57), cephatotin (28.57), doxycycline (0%) and the least was observed with chloramphenicol (0%). seven of positive S. aureus isolates were introduced in order to identify the staphylococcal enterotoxin genes, SEA, SEB, SEC, SED, and SEE and integron by PCR test Which 4 out of 7 isolates (57.1 %) were positive for SEB and SED only while were other isolate were negative for all SE gene. Class 1 integron cassettes were detected in 6 isolates from 7 (85.7%) of tested isolates. In conclusion, this is the first study to report the detection and identification of enterotoxin and class 1 integron in S. aureus isolated from poultry meat of chicken that suffered from arthritis.

This study was conducted to determine the antimicrobial activity of starch-based biodegradable antimicrobial films incorporated with biosynthesized silver nanoparticles (Ag-NPs) against multiple drug-resistant Staphylococcus aureus food isolates. Herein, the in-vitro antimicrobial activities of Origanum marjorana (OM) leaf extract, OM essential oil, OM nano-emulsion, chemically synthesized Ag-NPs (chem-Ag-NPs), and OM-based biosynthesized Ag-NPs (bio-Ag-NPs) using OM extracts were determined against a cocktail of three pathogenic Staphylococcus (S.) aureus strains isolated from meat products, using the agar well diffusion assay (AWDA). Afterward, homemade starch-based biodegradable antimicrobial films (SBAF) were incorporated with the suitable antimicrobials, based on AWDA and preliminary experiments, and investigated for their antimicrobial properties against S. aureus cocktail through the disc diffusion assay (DDA). The obtained results showed that in WDA, bio-Ag-NPs (1mM) had a significantly higher antimicrobial activity than chem-Ag-NPs (1mM), with inhibition zones accounting for 23 and 19mm, respectively. Whereas both types of nanoparticles were significantly more potent in their antimicrobial properties than different concentrations of OM extract, essential oil, and nano-emulsion (p<0.05). In concern to SBAF incorporated with antimicrobials, SBAF incorporated with chem-Ag-NPs (SBAF/chem-Ag-NPs) showed a significantly stronger antimicrobial effect than SBAF incorporated with bio-Ag-NPs (SBAF/bio-Ag-NPs) in the DDA, while both types of films produced significantly larger zones of inhibition than other antimicrobials (p<0.05). These homemade biodegradable films incorporated with bio-Ag-NPs could be a good alternative to petroleum-based packaging (plastic) in food packaging applications and meanwhile improve food safety and quality. Further studies investigating the effectiveness of these films on bacterial isolates inoculated in real food samples are suggested.

Drug interaction is the effect produced by combination of various drugs administered in a biological system which may produce beneficial or adverse effects.Due to continuous usage of antibiotics to bacterial infections, pathogenic bacteria developed resistance mechanisms which leads to reduced antibacterial activity of different antibiotics. Combination of antibiotics with phytochemicals became an alternative to enhance the efficacy of antibiotics. In this connection,in the present study, the effect of certain phytochemicals namely Quercitin, Morin, Ellagic acid,  Chloragenic acid Rutin and Naringenin in combination with antibiotics Amoxycillin and Ciprofloxacin were evaluated. Staphylococcus aures and Escherichia coli were used as test organisms. They were isolated from the mastitis milk samples and their presence was confirmed using Polymerse Chain Reaction .The antibacterial activity of the antibiotics and antibiotics in combination with phytochemicals were determined using broth dilution method and agar well diffusion assay. The MIC and zones of inhibition were used as indicators for drug interaction.