Background/Objective: Fish is one of the most valuable food for human consumption. However, fish may also act as a source of foodborne pathogens including Aeromonas species which caused a serious threat to a public health concern. This study aimed to investigate the prevalence and virulence characteristics of Aeromonas species isolated from fish farms in Egypt. Methods: A total of 100 random samples of freshwater fish represented by Nile tilapia and Mugil cephalus (50 of each) were collected from different fish farms in Kafr El-Sheikh governorate and examined bacteriologically and biochemically for the presence of Aeromonas species. Multiplex PCR was done to detect some virulence-associated genes in Aeromonas hydrophila isolates. Results: The obtained results revealed that the incidence of Aeromonas species in Nile tilapia and Mugil cephalus were 32 (64%) and 25 (50%), respectively. The most prevalent Aeromonas species isolated from Nile tilapia were Aeromonas caviae 13 (40.6%), Aeromonas hydrophila 8 (25%), Aeromonas sobria 7 (21.9%), Aeromonas veronii 3 (9.4%), and Aeromonas fluvialis 1 (3.1%), while from fresh Mugil cephalus were Aeromonas sobria 11 (44%), Aeromonas caviae 7 (28%), Aeromonas hydrophila 5 (20%), and Aeromonas veronii 2 (8%). The isolated Aeromonas hydrophila concealed some virulence genes responsible for their pathogenicities such as aerolysin gene (aerA) and cytotonic enterotoxin gene (altA). Conclusion: The hygienic measures should be applied to prevent fish contamination with Aeromonas species.

Background/aim: Fresh fish is highly susceptible to spoilage with shorter shelf life especially during refrigeration storage. This study aimed to evaluate the effect of essential oils (EOs) of Thyme (Thymus vulgaris), Cinnamon (Cinnamomic zeylanicum), and Garlic (Allium sativum) with concentrations of 0.5 and 1% of each on sensory acceptability of Nile tilapia (Oreochromis niloticus) fish fillet during refrigeration storage at 4 ±1˚C and their ability to increase shelf life. The impact of these EOs on Aeromonas hydrophila contamination was also investigated. Results:The results of the sensory evaluation showed that the overall acceptability of control samples significantly decreased as compared to EOs-treated samples. There was a higher significant (P< 0.05) difference in the overall acceptability among different EOs, with the lowest scores in garlic EOs and the highest in 1% thyme oil. There was a positive effect on the shelf-life extension of fish fillet samples which differed according to type and concentration of EOs. The shelf life of samples treated with thyme oil was 12 days in the refrigerator and still fit for human consumption. In addition to reduction percentage of Aeromonas hydrophila count with significance difference (P< 0.01) among different EOs showed better results for thyme oils compared to other EOs. Conclusion: Using EOs reduced Aeromonas hydrophila growth without any adverse effect on the sensory attributes of the treated Nile tilapia fillets samples.

A total of 150 samples of meat products (34 sausage, 35 beef burger, 39 minced meat and 42 luncheon samples) were collected randomly from different markets at Kafr-El-sheikh and El-Gharbiah governorates on Egypt .the samples were examined for isolation and identification of Salmonella Spp.. The PCR results showed that salmonella Spp were detected in 4 (11.8 %), 1(2.9%), 2 (5.1%) samples of examined sausage, beef burger and minced meat samples, respectively and not detected in luncheon samples. The isolated salmonellae were S. kentucky, S.saintpaul and S.tounouma in sausage samples, S.liverpool in beef burger samples and S. muenster and S. hadar in minced meat samples. These results showed that sausage, beef burger and minced meat might represent a source for salmonella as a food borne disease for human being.

A total of 100 samples of imported frozen liver were randomly collected from different markets at El-Gharbiah governorate, Egypt.The samples were examined for detection of molds and determination of aflatoxins produced by their aflatoxigenic strains. The results showed that 33 % of the samples were contaminated with different mold species and the average mold count (/g)was 3.8 × 10 4 ± 8.2× 10 3 /g. Genus Aspergilluswasthe predominant species detected in the positive samples (54.55 %) followed by Genus Penicillium(51.52%). The positive samples were examined for extraction and estimation of aflatoxins B1, B2, G1 and G2 using HPLC. The results indicated that aflatoxins B1, B2, G1 and G2 were detected in 24.2, 21.2, 18.2 and 15.1% of such liver samples, respectively. These results showed that imported frozen liver can represent a potential source of variousmold species and their toxinsconstituting, at times, a public health hazard.

A total of 200 meat product samples of beef burger, sausage, minced meat and luncheon were randomly collected from different shops and markets in El-Gharbia and Kafr-El-Sheikh governorates. The samples from 3 brands A, B and C were examined for the presence S. aureus using classical bacteriological and molecular methods. The obtained results revealed that the 2, 1 and 4 samples of beef burger, sausage and minced meat respectively, were positive for S. aureus by PCR. Additionally multiplex PCR was used for detection of five S. aureus virulence classic enterotoxin genes (sea, seb, sec, sed and see). The obtained results revealed that the beef burger samples harbored (1) seb gene; meanwhile sausage sample harbored (1) sea gene and minced meat samples harbored (2) sea, (1) sec and (1) sed genes. This study offers the basis for further phenotypic and molecular characterization S. aureus isolated from these products to guarantee safe consumption of meat products.