The present study aimed to investigate the prevalence, antibiotic susceptibility profiles, and some toxin genes of Panton-Valentine leukocidin (PVL)-positive Staphylococcus aureus (S. aureus) in unpasteurized raw cow’s milk collected from retail outlets located at Mansoura, Dakahliya governorate, Egypt. In that context, a total of 700 raw cow’s milk samples were investigated for the presence of S. aureus, which was identified in 41.1% (288/700) of the samples. Among the S. aureus isolates, 113 PVL-positive S. aureus were identified and subjected for further analysis. The PVL-positive S. aureus were investigated for the existence of toxin-related genes, including hemolysin (hla), toxic shock syndrome toxin-1 (tst), and enterotoxins (sea, seb, sec, see, seg, sei, and selj). Genotypic resistance of PVL-positive strains was performed for the detection of blaZ and mecA genes. Among the PVL-positive S. aureus, sea, seb, and sec were detected in 44.2, 6.2%, and 0.9%, respectively, while the hla and tst genes were identified in 54.9% and 0.9%, respectively. The blaZ and mecA genes were successfully identified in 84.9 (96/113) and 32.7% (37/113) of the total evaluated S. aureus isolates, respectively. PVL-positive S. aureus displayed a high level of resistance to penicillin, ampicillin, and trimethoprim-sulfamethoxazole. Multidrug resistance (resistant to ≥3 antimicrobial classes) was displayed by all methicillin-resistant S. aureus (MRSA) and 38.2% of methicillin-sensitive S. aureus (MSSA) isolates. The obtained findings are raising the alarm of virulent PVL-positive MRSA clones in retail milk in Egypt, suggesting the requirement for limiting the use of β-lactam drugs in food-producing animals and the importance of implementing strong hygiene procedures in dairy farms and processing plants.

Aims Infection of seafood with pathogenic species of the genus Vibrio causes human food‐borne illnesses. This study was executed to examine the antimicrobial‐resistance phenotypes, biofilm‐forming capability, and virulence‐associated genes of Vibrio from fish and shellfishes. Methods and results Three hundred fresh water and marine fish and shellfish samples were collected from wet markets and supermarkets in Mansoura, Egypt. Bacteriological examination and PCR amplification identified 92 Vibrio spp., including 42 V. parahaemolyticus and 50 V. alginolyticus isolates from the examined fish and shellfish (infection rate: 30.67%). However, V. vulnificus was not found in this study. Vibrio spp. exhibited variable frequencies of antimicrobial resistance with higher percentages to ampicillin and penicillin. Multidrug resistance (MDR) was detected in 69.04% and 38% of V. parahaemolyticus and V. alginolyticus, respectively. PCR testing of virulence genes, tdh, trh and tlh revealed the presence of tlh and trh in 100% and 11.9% of V. parahaemolyticus isolates, respectively, and none of V. alginolyticus carried any of these genes. Biofilm‐forming capability was displayed by 76% of V. parahaemolyticus and 73.8% of V. alginolyticus isolates. Both V. parahaemolyticus and V. alginolyticus showed non‐significant weak positive correlations (r <0.4) between antimicrobial pairs belonging to different classes, however a significant positive correlation (P <0.05) between trh and resistance to erythromycin (r= 0.45) and imipenem (r= 0.38) was only identified in V. parahaemolyticus. Conclusions This study reports the existence of MDR strains of V. parahaemolyticus and V. alginolyticus from the common types of fishes and shellfishes in Egypt. Furthermore, the presence of virulence genes in these isolates and ability to produce a biofilm in vitro pose potential health hazards to consumers. Significance and impact Frequent monitoring of seafood for the presence of Vibrio spp. and their antimicrobial susceptibility, virulence determinants, and biofilm‐forming capability is important for assessing the risk posed by these organisms to the public and for improving food safety

Campylobacter species are one of the most common causative agents of gastroenteritis worldwide. Resistance against quinolone and macrolide antimicrobials, the most commonly used therapeutic options, poses a serious risk for campylobacteriosis treatment. Owing to whole genome sequencing advancements for rapid detection of antimicrobial resistance mechanisms, phenotypic and genotypic resistance trends along the “farm-to-fork” continuum can be determined. Here, we examined the resistance trends in 111 Campylobacter isolates (90 C. jejuni and 21 C. coli) recovered from clinical samples, commercial broiler carcasses and dairy products in Cairo, Egypt. Multidrug resistance (MDR) was observed in 10% of the isolates, mostly from C. coli. The prevalence of MDR was the highest in isolates collected from broiler carcasses (13.3%), followed by clinical isolates (10.5%), and finally isolates from dairy products (4%). The highest proportion of antimicrobial resistance in both species was against quinolones (ciprofloxacin and/or nalidixic acid) (68.4%), followed by tetracycline (51.3%), then erythromycin (12.6%) and aminoglycosides (streptomycin and/or gentamicin) (5.4%). Similar resistance rates were observed for quinolones, tetracycline, and erythromycin among isolates recovered from broiler carcasses and clinical samples highlighting the contribution of food of animal sources to human illness. Significant associations between phenotypic resistance and putative gene mutations was observed, with a high prevalence of the gyrA T86I substitution among quinolone resistant isolates, tet(O), tet(W), and tet(32) among tetracycline resistant isolates, and 23S rRNA A2075G and A2074T mutations among erythromycin resistant isolates. Emergence of resistance was attributed to the dissemination of resistance genes among various lineages, with the dominance of distinctive clones. For example, sub-lineages of CC828 in C. coli and CC21 in C. jejuni and the genetically related clonal complexes ‘CC206 and CC48’ and ‘CC464, CC353, CC354, CC574’, respectively, propagated across different niches sharing semi-homogenous resistance patterns.

Streptococcus agalactiae is a zoonotic human and animal pathogen that causes global economic losses in aquaculture and fatal outcomes in Tilapia. This study aimed to identify S. agalactiae isolated from different fish sources intended for human consumption phenotypically and genotypically and to characterize the virulence-associated genes fbsA (fibrinogen-binding protein FbsA), cfb (CAMP factor), and pbp1A/ponA (penicillin-binding protein 1A). Three hundred Nile Tilapia fish (Oreochromis niloticus) were collected from different farms and retail shops in Dakahlia and Damietta, Egypt, during the summer of 2020. The samples were examined using routine phenotypic methods, then characterized using polymerase chain reaction (PCR) targeting S. agalactiae-specific dltS gene. All S. agalactiae isolates were examined for the susceptibility to ten antimicrobial agents by the disc diffusion method. The virulence-associated genes (fbsA, cfb, and pbp1A/ponA) were characterized using multiplex-PCR. Streptococcus agalactiae was detected in 7% (n = 21/300) samples. The isolates showed high resistance against ampicillin and erythromycin (20/21; 95%) for each. The most predominant antibiotypes through isolates were P, CN, SXT, CRO, TE, CTX, E, AMP, at 10.5% for each antibiotype. A total of 19 (90.5%) of S. agalactiae isolates showed multi-drug resistance (MDR), and those were recovered from market Tilapia fish. The virulence-associated genes (fbsA, cfb, and pbp1A/ponA) were identified in the S. agalactiae as 100%, 76%, and 52%, respectively. The MDR S. agalactiae detected in raw Tilapia fish pose a significant health hazard to consumers due to their zoonotic characteristics.

The study aimed to investigate the mastitis’ emerging causative agents and their antimicrobial sensitivity, in addition to the hematological, biochemical indicators, oxidative biomarkers, acute phase protein (APP), and inflammatory cytokine changes in dairy farms in Gamasa, Dakahlia Governorate, Egypt. One hundred Holstein Friesian dairy cattle with clinical and subclinical mastitis were investigated and were allocated into three groups based on a thorough clinical examination. Escherichia coli and Staphylococcus aureus were found responsible for the clinical and subclinical mastitis in dairy farms, respectively. Multiple drug resistance (MDR) was detected in 100%, and 94.74% of E. coli and S. aureus isolates, respectively. Significantly low RBCs count, Hb, and PCV values were detected in mastitic cows compared with both subclinical mastitic and control groups; moreover, WBCs, lymphocytes, and neutrophil counts were significantly diminished in mastitic cows compared to the controls. Significantly higher levels of AST, LDH, total protein, and globulin were noticed in both mastitic and subclinical mastitic cows. The haptoglobin, fibrinogen, amyloid A, ceruloplasmin, TNF-α, IL-1β, and IL-6 levels were statistically increased in mastitic cows compared to the controls. Higher MDA levels and reduction of TAC and catalase were identified in all the mastitic cases compared to the controls. Overall, the findings suggested potential public health hazards due to antimicrobial resistance emergence. Meanwhile, the APP and cytokines, along with antioxidant markers can be used as early indicators of mastitis.

Aim: The present study was designed to investigate the occurrence and distribution of Salmonella serotypes in chicken meat samples, and to explore the susceptibility of the strains to antimicrobials, as well as their virulence-associated genes. Materials and Methods: Two-hundred retail chicken meat samples from different shops, as well as 25 stool specimens from retail shop workers, were included in the study. The collected samples were examined bacteriologically for the presence of salmonellae. Salmonella isolates were serotyped using a slide agglutination test for O and H antigens and were screened for the presence of five virulence genes (stn, pef, invA, sopB, and avrA) using a uniplex polymerase chain reaction assay and for their susceptibility to 18 antimicrobial agents using the disk diffusion method. Results: Thirty-one Salmonella isolates belonging to 12 different serovars were identified. Salmonella Enteritidis and Salmonella Kentucky were the dominant serovars (22.6% each). Salmonella isolates displayed a high antibiotic resistance against erythromycin, sulfamethoxazole/trimethoprim, doxycycline, cephalexin, cefaclor, tetracycline, polymyxin B, cefuroxime, vancomycin, and streptomycin. All Salmonella isolates exhibited multidrug resistance (MDR) and demonstrated different virulence genes. The majority of Salmonella serovars (87.1%) harbored sopB gene, 54.8% carried avrA and pef genes, while all isolates carried invA and stn genes. Conclusion: The presence of virulent MDR Salmonellae in raw chicken meat could allow the possibility of transmission of these resistant serovars to humans. Therefore, strict hygienic measures should be followed on the whole poultry production chain to decrease the potential transmission of Salmonella infection from poultry meat to humans.