Evaluation of the Antimicrobial Activity of Four Plant Essential Oils against Some Food and Phytopathogens Isolated from Processed Meat Products in Egypt

Synthetic preservatives are widely utilized by the food industry to inhibit the microbial contamination and increase food safety and shelf life. The excessive utilization of synthetic preservatives can have a negative impact on human health and the environment. There is a great interest to find out natural substances as possible food-preservatives. The consumers' preference for food products with natural ingredients prompted food manufacturers to utilize natural-based preservatives in their production. It is worth noting that plant essential oils (EOs) among the natural-based substances have been efficiently used as antimicrobial agents against phyto- and food pathogens. The current study was conducted to evaluate the microbial contamination of three industrial meat products from five governorates in Egypt, identify the predominant bacterial and fungal isolates and determine the antimicrobial efficacy of some EOs (thyme, fennel, anise and marjoram) against the most predominant microbial isolates. A sensory test was also performed to estimate the customer preferences for specific organoleptic aspects of meat products after EOs treatment. Results showed that there is a promising antimicrobial activity of all studied EOs against some microbial isolates in a dose-dependent manner. In particular, thyme EO showed the highest significant antibacterial activity against P. fluorescence and E. coli. Whereas the marjoram EO showed the highest activity against P. aeruginosa. In addition, the sensory test revealed that the treatment with anise and marjoram EOs showed the highest acceptability by the testers and did not show significant differences on the organoleptic properties with respect to control. As overall, the obtained results of the current research are promising and proved feasibility of employing plant EOs as possible preservatives for processed meat products

Molecular Characterization of Escherichia coli O157:H7 and non-O157 Shiga Toxin Producing E. coli from Retail Meat and Humans

A total of 550 meat samples (300 minced beef and 250 chicken meat) marketed in Zagazig City, Sharkia Governorate, Egypt, as well as 150 human stool samples were examined for Shiga toxin producing E. coli. Results revealed that the isolation rates of E. coli O157:H7 versus non- O157 were 1.7% versus 2.3% in minced beef, 0.8% versus 2% in chicken meat and 0.7% versus 2.7% in human stools. Other identified serotypes were including O111:H8 (25%), O26:H11 (20.8%), O55:H7 (16.7%) and O113:H21 (4.2%). Virulence associated genes were identified in E. coli serotypes, stx1 and stx2 were characterized in 16.7% and 62.5% of the isolates, while, eaeA and hlyA genes were identified in 50% and 70.8% of the examined serotypes, respectively. Genotyping of E. coli O157:H7 serotype from different sources using Enterobacterial repetitive intergenic consensus polymerase chain reaction (ERIC-PCR) fingerprinting revealed heterogenicity of the isolates, however, human and minced beef isolates were grouped in the same cluster indicating potential transmission of infection from contaminated beef to human consumers. In conclusion, ERIC-PCR is a highly discriminatory, reliable and cost-effective tool for tracing sources of infection with bacteria. Public health education and application of strict hygienic measures during slaughtering, transportation and preparation of meat are essential to minimize the risk of contamination and transmission of infection to consumer

Mould contamination and aflatoxin residues in frozen chicken meat-cuts and giblets

Mould contamination of frozen chicken meat and giblets has a particular public health significance in the field of food safety due to its related food spoilage and production of mycotoxins. The objectives of this study were firstly, to investigate the incidence of mould contamination in frozenchicken meat-cuts and giblets. Secondly, to estimate aflatoxin residues in these products. The public health importance of the prevalent mould genera and aflatoxin residues was discussed. Frozen gizzards had the highest total mould count followed by frozen liver, breast and thigh respectively. The prevalent mould genera were Aspergillus, Penicillium, Cladosporium and alternaria. Aspergillus niger, flavus, parasiticus and versicolor were the identified Aspergilli. Examined frozen chicken samples had variable residual concentrations of total aflatoxins. Thus, strict hygienic precautions during processing of frozen chicken products should be adopted to reduce mould contamination and mycotoxin production

Prevalence, antibiogram, molecular characterization and reduction trial of Salmonella typhimurium isolated from different fish species

Salmonella is a major cause of food-borne outbreaks and infections in many countries worldwide. The present work aimed to investigate the prevalence, antibiotic sensitivity and detection of virulence-associated genes in Salmonella typhimurium isolated from fish samples (tilapia, mullet and catfish) collected from Zagazig city markets, Egypt. Salmonella typhimurium was isolated only from tilapia with a percentage of 13.3%. Antibiotic susceptibility testing of Salmonella typhimurium revealed marked susceptibility to ofloxacin. Two different virulence genes (ssaP and pipB) were expressed in the isolated Salmonella typhimurium. Dipping of tilapia in liquid smoke 5% for 30 min reduced Salmonella typhimurium count by 40%. In conclusion, our results confirm contamination of tilapia by Salmonella typhimurium. Dipping of fish in liquid smoke is an efficient strategy in reducing Salmonella typhimurium load in fish

Prevalence of Antibiotic-Resistant Vibrio Isolated from Some Marketed Fish in Egypt with a Decontamination Trial by Lemon juice

      Vibrio species are major sea foodborne pathogens that cause gastroenteritis as a serious disease of human public health due to the consumption of undercooked or raw fish. In the current study, a total of 100 fish samples (Nile tilapia, Nile perch, Meagre, and Sea bass) were collected randomly from retail markets in Egypt to investigate the prevalence of Vibrio species. The results revealed that Vibrio species isolated with an overall percentage of 52% of all examined fish. Bacteriological and chemical examinations revealed 42.3% V. parahaemolyticus, 26.92% V. mimicus, 19.23% V. alginolyticus, 9.62% V. vulnificus and 1.92%V. cholera. Antibiotic sensitivity declared high resistance of the isolates to different antimicrobial agents used in Egypt including Ampicillin (100%), Nalidixic acid (88.3%), Streptomycin (84.2%), Sulphamethoxazol (70.7%) and Oxytetracycline (64.8%) and it had sensitivity to Amikacin (94%), Ciprofloxacin (70.5%), Gentamicin (58.9%) with an average MAR index of 0.576. By polymerase chain reaction, all examined Vibrio isolates were positive for 16SrRNA specific for Vibrio spp. and harbored toxR gene virulence gene.  Finally, dipping of tilapia in lemon juice 5% for 2 h reduced V. parahaemolyticus count by 0.42log cfu/g (62.08%). Consequently, hygienic measures should be approved to control the contamination of fish in the markets and the aquatic environment. Regular monitoring of fish for antibiotic resistance by Vibrio species, and their molecular characterization is necessary to improve the safety of seafood. Dipping fish in lemon juice is an efficient strategy for reducing V. parahaemolyticus load in fish

Health Risk Assessment of Some Heavy Metal Residues in Some Fish Retailed in Sharkia Governorate, Egypt

The aim of this study was to explore the residual concentrations of four heavy metals; mercury (Hg), arsenic (As), lead (Pb), and cadmium (Cd) in Mullet, Brush tooth lizard, and Coral fish collected from fish markets in Zagazig city, Sharkia Governorate, Egypt. Besides, metal’s dietary intake and public health risk were calculated. Atomic absorption spectrometry (AAS) was used to analyze  these toxic heavy metals in 60 fish samples of Mullet, Brush tooth lizard, and Coral ( 20 of each). The concentration (mg/ kg) of Hg were the same value (0.02 ± 0.01) in Mullet, Brush tooth lizard, and Coral fish. However, for As were 0.35 ± 0.10, 0.32 ± 0.10, and 0.30 ± 0.08, respectively; meanwhile, Pb concentration was 0.09 ± 0.04 for both Mullet and Brush tooth lizard and it was 0.10 ± 0.04 for Coral fish Cd concentrations were 0.02 ± 0.01 in all examined fish. The estimated daily intake (EDI) of Hg, As, Pb, and Cd were 0.011, 0.191, , 0.049  and 0.011µg/ kg BW/ day , respectively in Mullet; 0.011, 0.174, 0.049, and 0.011 µg/ kg BW/ day in, respectively Brush tooth lizard; 0.011, 0.163, 0.054, and 0.011 µg/ kg BW/ day , respectively in Coral fish, that was below the tolerable daily intake (TDI) recommended by Joint Expert Committee on Food Additives (JECFA). The Target hazard quotient (THQ) of Hg, As, Pb, and Cd from consumption of examined fish was less than one which means that there was no hazard from consumption of these fish.&nbsp

A Review: Accumulation of Toxic Metals among Meat from Different Species

Meat contamination is a problem that must be addressed since it can affect consumers' health. Standard acceptable limits for heavy metals in meat and organs have been established by many international organizations. Livestock including sheep, cattle, camels, and goats side by side with other poultry species are the most significant sources of meat for protein. Heavy metal contamination in animal products may be harmful to people's health. The earth's crust naturally contains heavy metals, but uncontrolled human activity has significantly changed their geochemical cycles and biological equilibrium. This causes a buildup of metals in animal tissue that contain secondary metabolites, which gives rise to a specific pharmacological action. Humans can have negative health effects from prolonged exposure to heavy metals as lead, cadmium, arsenic, and mercury. This review showed that most of the studies conducted in different countries on heavy metals were mostly in red meat, and the research was few in the cases of domesticated birds and very rare in game birds, although it is considered a good example for investigating heavy metals in the environmen

Pseudomonas aeruginosa in Fish and Fish Products: A review on the Incidence, Public Health Significance, Virulence Factors, Antimicrobial Resistance, and Biofilm Formation

Pseudomonas aeruginosa (P. aeruginosa) is a psychotropic pathogenic bacterium that is considered one of the most common spoilage microorganisms related to seafood’s consumption. P. aeruginosa is widely distributed in nature and isolated from soil, plants, animals, and water. Because of its high resistance to a wide range of antibiotics, P. aeruginosa is more dangerous than other spoilage bacteria. It possesses a diverse set of virulence factors capable of causing severe and aggressive infections in humans and animals. Antibiotic resistance genes are easily transmitted to humans via contaminated seafood, resulting in a serious antibiotic resistance.  The ability of P. aeruginosa to form a biofilm maintains its environmental survival and allows its quick adaptation to harsh environments. Therefore, for the benefit of customers and public health globally, the safety and bacteriological quality of commercially processed fish and its products are crucial

Prevalence of Antibiotic Resistant Aeromonas and Molecular Identification of Aeromonas hydrophila Isolated from Some Marketed Fish in Egypt

      Aeromonas hydrophila, is an important foodborne bacterial disease in the aquaculture. The present study aimed to investigate the prevalence of Aeromonas species, virulence genes associated in A. hydrophila and to determine the antimicrobial susceptibility of Aeromonas spp. isolated from fish samples (tilapia, mugil, tuna, saurus, pagrus and shrimp) collected from Zagazig city markets, Sharkia Governorate, Egypt. Aeromonas spp. was isolated with a percentage of 39.3% of all examined fish samples. Four Aeromonas species (A. hydrophila, A. caviae, A. fluvials and A. sobria) were isolated from the tested fish samples (12%, 15.3%, 2.7% and 9.3%, respectively). A. hydrophila was only isolated from Tilapia, Saurus and Shrimp samples (16%, 28% and 28%, respectively). Aerolysin (aerA) and haemolysin (ahh1) were expressed in 100% and 75% of the A. hydrophila isolates. Antibiotic susceptibility testing of Aeromonas spp. revealed marked resistant for testing antibiotics; Ampicillin (100 %), Erythromycin (100 %), Tetracycline (83.3 %), Sulphamethoxazol (75 %), Cefotaxime (50 %) and Cephalothin (50 %). Dipping of Nile tilapia in lemon juice 5% for 2 h reduced A. hydrophila counts by 0.45 log cfu/g (64.44%). In conclusion, the present study confirms contamination of fish by Aeromonas spp. Immersion of fish in in lemon juice 5% is an efficient policy for reducing A. hydrophila in fish

Antibiotic Resistance Profile and Molecular Characterization of Vibrio parahaemolyticus and Vibrio cholerae Isolated From Fish

The current study was planned for the isolation and identification of Vibrio spp. from fish samples (tilapia, mugil, tuna, saurus, pagrus, and shrimp) retailed in Zagazig city, Sharkia Governorate, Egypt. In addition to determine the antimicrobial susceptibility of the isolates. The PCR screening for virulence genes of V. parahaemolyticus and V. cholerae was also determined. The results in the present study revealed that the most contaminated samples with Vibrio spp. were pagrus (56%), followed by tilapia (52 %), then mugil (44 %), saurus (40 %), tuna (36 %), and shrimp (36 %). The most prevalent Vibrio spp. were V. para­haemolyticus (18.6%) followed by V. mimicus (11.3%), and V. alginolyticus (10%). V. cholerae was isolated in a percentage of 0.7%. Vibrio species in the current study were highly resistant to erythromycin (100%), ampicillin (75%), cephalothin (66.7%), sulphamethoxazole (66.7%), and amikacin (50%). PCR screening of virulence genes among various Vibrio spp. revealed that V. parahaemolyticus harbored tlh (100 %), tdh (80 %), and trh (80 %). While, V. cholerae was positive for rtxC, hylA, and ompU genes. As a result, the current data proves Vibrio spp. contamination of fish, which displayed various degrees of antibiotic resistance. In addition, the isolated Vibrio spp. had virulent genes that could be dangerous to the consumer's health.