Prevalence, virulence attributes, and antibiogram of Bordetella avium isolated from turkeys in Egypt.

Turkey coryza is a major respiratory disease caused by Bordetella avium (B. avium). It occurs in all ages of turkeys and is characterized by high morbidity and low mortality rates. The present study aimed firstly at determination of the prevalence rates of B. avium in turkeys reared in Egypt at different ages using various diagnostic methods including clinical examination, histopathology, enzyme-linked immunosorbent assay (ELISA), bacterial culture, and polymerase chain reaction (PCR). Using PCR, virulence-associated genes were detected in the confirmed B. avium isolates. Furthermore, the antibiotic resistance profiles of the confirmed B. avium isolates were examined. The achieved results indicated isolation and identification of B. avium infection at different ages of turkeys reared in Egypt. The overall PCR-confirmed prevalence rate of B. avium was 22.95%. The identified B. avium strains harbored virulence-associated genes responsible for colonization in the respiratory tract of turkeys including Bordetella virulence gene (100%), fimbriae (71.14%), and filamentous hemagglutinin (85.68%). The isolated B. avium strains showed multidrug resistance profiles. B. avium isolates were resistant to penicillin (92.82%), ceftiofur (85.68%), nalidixic acid (78.54%), and lincomycin (71.40%). The identified B. avium strains showed clear sensitivities to both gentamicin and neomycin, suggesting these as possible antimicrobial candidates for the control of B. avium infection in turkeys.

Mutagenicity of modelled-heat-treated meat extracts: Mutagenicity assay, analysis and mechanism of mutagenesis.

Cooking of meat usually aims in producing microbiologically safe food suitable for human consumption. However, doing so at such high temperatures may produce some cooking toxicants or mutagens. The objectives of this study were to investigate the mutagenicity of modelled-heat-treated meat after different cooking methods (boiling, pan-frying and charcoal grilling) using Ames Salmonella typhimurium mutagenicity assay. In addition, the content of benzo[a]pyrene (B[a]P) in the meat extracts prepared under different cooking methods were measured using HPLC. In a trial to investigate the causes behind the mutagenicity of different meat extracts, HepG2 cell line was exposed to different modelled-heat-treated meat extracts. mRNA expression levels of various phase I and II xenobiotic metabolizing enzymes (XMEs) were examined using real time PCR. The results obtained declared that pan-fried and charcoal grilled-meat extracts significantly induced production of histidine+ revertants in the Ames mutagenicity assay. Grilled-meat extracts had the highest residual concentrations of B[a]P followed by pan-fried-meat, boiled meat and raw meat extracts, respectively. Induction of XMEs especially CYP1A1, CYP1A2 and NQO1 may contribute to the mutagenic ability of these extracts. It is highly advisable to control cooking temperature, time and method in order to reduce cooked-meat mutagens.

Prevalence and antibiogram of shigatoxinproducing E. coli in camel meat and offal.

Background: Camels are important animals in Egypt and other Arab countries on the basis of their economic value and ethnic culture. Escherichia coli is implicated in several gastrointestinal infections and outbreaks worldwide, especially in developing countries. It causes infections that might lead to death. Numerous biological activities, such as antioxidative, antibacterial, anti-diabetic, anti-mutagenic, anti-inflammatory, neuroprotective, and diuretic, are associated with coriander and coriander essential oils. Aim: This work targeted investigation of the prevalence, antibiogram, and occurrence of virulence genes of E. coli in camel meat liver and kidney. Besides, the anti-E. coli activity of coriander oil was further examined. Methods: Camel meat, liver, and kidneys were collected from local markets in Egypt. Isolation and identification of E. coli were performed. The antimicrobial susceptibility of the obtained E. coli isolates was screened using the disk diffusion assay. To detect the presence of virulence-associated genes (stx1, stx2, eaeA, and hylA gens), polymerase chain reaction was used. An experimental trial was done to investigate the anti-E. coli activity of coriander oil. Results: The obtained results revealed isolation of the following E. coli pathotypes: O17:H18, O128:H2, O119:H6, O103:H4, O145:H-, and O121:H7. The recovered E. coli isolates practiced multidrug resistance profiling with higher resistance toward Erythromycin, Nalidixic Acid, Clindamycin, and Ampicillin. However, the isolates were sensitive to Meropenem and cefoxitin. The recovered isolates had expressed different virulence attributes. Coriander oil of 2% could significantly reduce E. coli O128 count in camel meat by 65%. Conclusion: Therefore, strict hygienic measures are highly recommended during the processing of camel meat. The use of coriander oil during camel meat processing is highly recommended to reduce E. coli count.

Biological responses of xenobiotic metabolizing enzymes to lead exposure in cultured H4IIE rat cells.

This study was undertaken to investigate the constitutive response of xenobiotic metabolizing enzymes (XMEs) to lead (Pb2+) exposure in cultured rat liver (H4IIE) cell lines. Phase I enzymes such as CYP1A1 and CYP1A2 had mRNA expressions that were slightly induced after exposure to low concentrations of Pb2+; however, under higher concentrations of Pb2+, the mRNA expressions of CYP1A1 and CYP1A2 were significantly down-regulated. These effects were in correspondence with AhR mRNA expression. Phase II enzymes had mRNA expressions that were reduced upon exposure to Pb2+. Metallothionein mRNA expression was induced after treatment with Pb2+ in a dose-dependent trend. In conclusion, Phase I and II enzymes were significantly modulated upon lead exposure indicating some toxicological implications for lead exposure in cultured H4IIE cells.

Antibiotic residues in food: the African scenario.

Antibiotics are substances either produced naturally by living organisms or synthetically in the laboratory, and they are able to kill or inhibit the growth of microorganisms. Antibiotics are also used as feed additives for the purpose of livestock health maintenance. Antibiotic residues in feedstuffs are currently a problem of some magnitude in different parts of the world, particularly due to associated public health concerns that include hypersensitivity reactions, antibiotic resistance, toxicity, teratogenicity, and carcinogenicity. In Africa, as in other parts of the world, antibiotic residues in animal-derived foods have been extensively recorded in many African countries; these residues have exceeded the WHO maximum residue levels in many cases. It has been reported that tetracyclines are the most predominantly prescribed antibiotics in Africa, and of all antibiotic-associated residues they represent 41% of cases, followed by beta-lactams at 18%. Great care should be taken to monitor antibiotic cessation periods before the release of animal-derived foods for human consumption. In addition, strict legislation should be implemented in order to minimize the abuse of antibiotics.

Oxytetracycline residues in bovine carcasses slaughtered at Mansoura Abattoir, Egypt.

Oxytetracycline residues were examined in 600 samples (200 each of muscles, livers and kidneys) collected randomly from bovine carcasses slaughtered at Mansoura abattoir in Dakahlia Province, Egypt. A microbial inhibition test using Bacillus subtilis ATCC- 6633 was employed to screen the obtained samples for antibiotic residues in meat. The results showed that 2% of samples were positive. Oxytetracycline residues exceeded the maximum residue limits (MRLs) in 1.33% of the examined samples. Thus, regulatory authorities should insure proper withdrawal period before slaughtering of the animals (28 days for oxytetracycline). Public health importance was discussed.

In vitro diazepam metabolism in horses.

There is little information about drug metabolism and pharmacokinetics in horses. Therefore, it is necessary to characterize the profiles of drug metabolites for the safe use of drugs. In this study, we focused on cytochrome P450 enzymes (CYPs), which represent an important enzyme group to determine pharmacological effects of drugs. We chose diazepam as the drug of choice for this study. The aim of this study was to elucidate the metabolic pathway of diazepam in horses in comparison with rats, and to clarify CYP subfamilies responsible for diazepam metabolism in horses. Our results showed temazepam was the major diazepam metabolite produced from microsomal reactions in horse liver, but horses produced drastically less p-hydroxydiazepam as compared with rats. Furthermore, CYP3A was a major contributor from the CYP subfamily of temazepam production.

Heavy metal residues in canned fishes in Egypt.

A total of 75 random canned fish samples, 25 each of canned (canned tuna, sardine and mackerel) during 2009, were collected from Zagazig Markets for determination of lead, cadmium, zinc, copper and tin residues using atomic absorption spectrophotometer. The obtained results revealed that the mean values of the lead residues in the examined canned tuna, sardine and mackerel were 0.127 +/- 0.02, 0.013 +/- 0.004 and 0.023 +/- 0.01 (ppm) respectively. The mean concentrations of cadmium residues were 0.022 +/- 0.001, 0.048 +/- 0.003 and 0.027 +/- 0.003 ppm, respectively. While in case of zinc, the residual levels were 1.97 +/- 0.12, 2.369 +/- 0.32 and 1.126 +/- 0.24 ppm, respectively. Copper residual levels in the examined samples were 0.293 +/- 0.08, 0.221 +/- 0.03 and 0.08 +/- 0.02 ppm, respectively. In case of tin, the residual levels were 1.496 +/- 0.30, 1.209 +/- 0.26 and 0.379 +/- 0.11 ppm respectively.

Determination of organochlorine pesticides (OCPs) in the edible offal of Egyptian buffalo.

Environmental contamination by OCPs has a great concern, since most of these pesticide compounds are very toxic and harmful to human and ecosystems. This study was conducted to determine the concentrations of OCPs residues in the edible offal (livers, kidneys and tongues) of Egyptian buffalo collected from three locations (Zagazig, Ismailia and Mansoura) in Egypt. Examined samples from Mansura city had the highest OCPs contamination load. Tongues had the highest concentration of these toxic residues in a comparison to livers and kidneys in the examined samples. The overall results showed that OCPs residues did not exceed the Egyptian maximum permissible limits in all of the samples analyzed from the three different locations.

Effects of aflatoxin B1 on human breast cancer (MCF-7) cells: cytotoxicity, oxidative damage, metabolic, and immune-modulatory transcriptomic changes.

Aflatoxin B1 (AFB1) is a potent mycotoxin that is commonly produced by molds such as Aspergillus (A.) flavus and A. parasiticus. AFB1 is associated with several health adverse effects in humans including mutagenesis and carcinogenesis. Aflatoxin is commonly secreted in the milk leading to deleterious effects on breast tissue and potential nursing infants. However, the effects of aflatoxins, particularly AFB1, on the breast cells are less investigated. In this study, AFB1-associated effects on human breast cancer cell lines (MCF-7) were investigated. AFB1 caused significant cytotoxicity on MCF-7 cells. Such cytotoxicity had a positive correlation with the induction of oxidative stress. In addition, AFB1 caused significant transcriptomic alterations in xenobiotics and drug-metabolizing enzymes, transporters, and antioxidant enzymes. Besides, AFB1 upregulated pro-inflammatory markers such as tumor necrosis factor-α and cyclooxygenase-2 with a significant reduction of mRNA expressions of the immunity-related genes including interleukins 8 and 10.

Cytochrome P450 3A mRNA expression along goat and rat gastrointestinal tracts.

The cytochrome P450 (CYP) 3A family is involved in the elimination processes of almost 50% of commonly used drugs. CYP3A mRNA expressions in goat and rat gastrointestinal tracts in comparison to the liver were investigated using real-time PCR. In goats, the expression of CYP3A-like mRNAs was comparatively higher in the liver than in the gastrointestinal tract. The intestinal expression of CYP3A-like mRNA showed a gradual decrease from the duodenum to the ileum. In rats, the highest CYP3A62 mRNA expression was found in the duodenum followed by the liver. This study provides insights into the contribution of CYP3A enzymes to xenobiotic metabolism, especially in small ruminants such as goats.

Prevalence of multidrug resistant Salmonella spp. in dairy products with the evaluation of the inhibitory effects of ascorbic acid, pomegranate peel extract, and D-tryptophan against Salmonella growth in cheese.

The present study aimed at investigation of the prevalence and antimicrobial susceptibility of Salmonella spp. in the retailed dairies in Egypt. Besides, the inhibitory effects of some natural additives, including, ascorbic acid, pomegranate peel extract, and D-tryptophan against the isolated Salmonella were evaluated using soft cheese as a food matrix. To reach to this end, different Egyptian retail dairy products were investigated; 30 samples of each product were analyzed. Kariesh cheese samples had the highest Salmonella prevalence rate at 16.67%, followed by market raw milk, and bulk tank milk at 6.66% each, and white soft cheese at 3.33%. Serological examination exhibited 5 different Salmonella serotypes, namely S. Enteritidis, S. Typhimurium, S. Virchow, S. Larochelle, and S. Apeyeme. Antimicrobial susceptibility testing indicated that 100% of the isolates possessed resistance to erythromycin, oxacillin, and nalidixic acid. Some isolates of S. Typhimurium and S. Enteritidis were resistant to all 14 examined antibiotics. Isolates of S. Enteritidis obtained in this study were used to contaminate the freshly prepared soft cheese. Treatment of the artificially Salmonella-contaminated soft cheese with pomegranate peel extract, ascorbic acid, and D-tryptophan revealed a significant (P < 0.05) reduction in Salmonella growth in a dose-dependent manner. Therefore, the examined natural additives can be viewed as a promising new line of preservatives for dairy industry.

Antimicrobial-resistant foodborne pathogens in the Middle East: a systematic review.

Foodborne pathogens are known as significant public health hazards worldwide, particularly in the Middle East region. Antimicrobial resistance (AMR) among foodborne pathogens becomes one of the top challenges for the environment, public health, and food safety sectors. However, less is known about antimicrobial-resistant foodborne pathogens in the Middle East region. Possibly because of the lack of surveillance, documentation, and reporting. This review focuses on the current status of antimicrobial resistance profiling among foodborne pathogens in the Middle East. Therefore, PubMed and other relevant databases were searched following PRISMA guidelines. Subject heading and texts were searched for "antimicrobial resistances," "foodborne," and "Middle East" to identify observational studies on AMR foodborne pathogens published during the last 10 years (2011 to 2020). Article retrieval and screening were done using a structured search string and strict inclusion/exclusion criteria. Median and interquartile ranges of percent resistance were calculated for each antibiotic-bacterium combination. A total of 249 articles were included in the final analysis from ten countries, where only five countries had more than 85% of the included articles. The most commonly reported pathogens were Escherichia coli, Salmonella spp. Staphylococcus aureus, and Listeria spp. An apparent rise in drug resistance among foodborne pathogens was recorded particularly against amoxicillin-clavulanic acid, ampicillin, nalidixic acid, streptomycin, and tetracycline that are commonly prescribed in most countries in the Middle East. Besides, there is a lack of standardization and quality control for microbiological identification and susceptibility testing methods in many of the Middle East countries.

Content of total aflatoxin, lead, and cadmium in the bovine meat and edible offal: study of their human dietary intake, health risk assessment, and molecular biomarkers.

The objectives of the present study were first to determine the residual contents of total aflatoxins (AFTs), lead (Pb), and cadmium (Cd) in the edible tissues of the cattle reared in Al-Ahsa, Saudi Arabia. Al-Ahsa is the largest governorate in the Eastern Province of Saudi Arabia. The two main economic activities of Al-Ahsa are oil production (industrial) and agriculture. Besides, dietary intake and possible health risks for Saudi population were further calculated. In order to establish potential molecular biomarkers for xenobiotic exposure in cattle, the mRNA expression of xenobiotic-metabolizing enzymes (XMEs) including cytochrome P450 (CYP) 1A1, NAD(P)H dehydrogenase [quinone] 1 (NQO1), metallothionein (MT) 1A, and heat shock protein (HSP) 70 was investigated in the different tissues of the cattle. The tested XMEs were selected because of their specific roles in the metabolism and detoxification of AFTs, Pb, and Cd. The obtained results revealed that the liver had significantly the highest AFT content, while all examined muscle samples had no AFT residues. Consumption of the bovine liver and kidneys represents the highest source for the dietary exposure to total AFTs (0.05-0.98 µg/kg/day), Pb (0.06-0.19 mg/kg/day), and Cd (0.08-0.19 mg/kg/day) among the examined tissues. Therefore, excessive intake of such organs might pose a public health concern, particularly among children. Significant upregulation of mRNA expressions of CYP1A1, NQO1, MT1A, and HSP70 was observed in the different tissues of the cattle in comparison with the muscle. This upregulation had significant positive correlation with the accumulated AFTs, Pb, and Cd. This indicates the possible use of CYP1A1, NQO1, MT1A, and HSP70 as potential biomarkers for the exposure of the cattle to AFTs, Pb, and Cd.

Formation of biogenic amines in fish: Dietary intakes and health risk assessment.

Biogenic amines (BAs) are toxicants that are produced during the proteolytic activities of some microorganisms, or naturally during the metabolism of their precursor amino acids. The objective of this study was to estimate the formed BAs in six types of fish retailed in Egypt including tilapia, mullet, mackerel, sardine, herring, and tuna. In addition, total mesophilic (TMC) and total psychrophilic (TPsC) bacterial counts were investigated. Furthermore, the estimated daily intakes (EDI) of BAs via the ingestion of various types of fish in Egypt were calculated, and their potential health risks were discussed. The achieved results indicated the formation of histamine (HIS), tyramine (TYR), cadaverine (CAD), putrescine, spermine, and spermidine at different concentrations. Tilapia had the lowest concentration levels for the different BAs. In contrast, mackerel and tuna had the highest concentrations of BAs. Total biogenic amines (TBAs) showed significant positive correlations with TMC in the examined fish species. The recorded EDI values of the different BAs in the current study would not have adverse effects, except for mackerel and tuna. Excessive consumption of fish contaminated with BA might have serious health hazards such as symptoms of histamine poisoning, including rashes, flushing, palpitations, and asthma. Therefore, the adoption of strict hygienic measures during the processing, storage, and distribution of fish is highly recommended to reduce the formation of BAs in fish.

Identification and phylogenetic analysis of novel cytochrome P450 1A genes from ungulate species.

As part of an ongoing effort to understand the biological response of wild and domestic ungulates to different environmental pollutants such as dioxin-like compounds, cDNAs encoding for CYP1A1 and CYP1A2 were cloned and characterized. Four novel CYP1A cDNA fragments from the livers of four wild ungulates (elephant, hippopotamus, tapir and deer) were identified. Three fragments from hippopotamus, tapir and deer were classified as CYP1A2, and the other fragment from elephant was designated as CYP1A1/2. The deduced amino acid sequences of these fragment CYP1As showed identities ranging from 76 to 97% with other animal CYP1As. The phylogenetic analysis of these fragments showed that both elephant and hippopotamus CYP1As made separate branches, while tapir and deer CYP1As were located beside that of horse and cattle respectively in the phylogenetic tree. Analysis of dN/dS ratio among the identified CYP1As indicated that odd toed ungulate CYP1A2s were exposed to different selection pressure.

Expression and sequence of CYP1A1 in the camel.

In this study, we determined a partial sequence of CYP1A1 in the camel and its phylogenetic position. The deduced amino acid sequence of camel CYP1A1 showed the highest identity 94% with those of sheep and cattle CYP1A1. In a phylogenetic analysis, the camel CYP1A1 isoform was located beside sheep and cattle CYP1A1. When we studied the distribution of camel CYP1A1 mRNA in different tissues, we found that this isoform was expressed in all tissues except the hump. Interestingly, the lungs of all the camels and tongues of two of the three animals showed high expressions of CYP1A1 mRNA, and this may indicate exposure to ligands of aryl hydrocarbon receptor such as environmental pollutants or flavonoids.

Cytochrome P450 1A-dependent activities in deer, cattle and horses.

The objective of this study was to investigate and characterize the metabolic activities of CYP1A in deer, cattle and horses in comparison to those of rats using ethoxyresorufin O-deethylation (EROD) and methoxyresorufin O-demethylation (MROD) assays. We performed an inhibition study for these activities using anti-rat CYP1A1 antibody and identified that these activities were due to the CYP1A subfamily. Interspecies differences in the CYP1A-dependent activities were highly observed in this study. In particular, we found that the horse had the highest EROD and MROD activities among the examined animal species. In the kinetic analysis, the horses showed the highest Vmax and catalytic efficiency (Vmax/Km), followed by the cattle, deer and rats.

Correction to: Deoxynivalenol-induced alterations in the redox status of HepG2 cells: identification of lipid hydroperoxides, the role of Nrf2-Keap1 signaling, and protective effects of zinc.

The original version of this paper was published with error. The presentation of author name "Tan Hui" should be "Hui Tan".

Deoxynivalenol-induced alterations in the redox status of HepG2 cells: identification of lipid hydroperoxides, the role of Nrf2-Keap1 signaling, and protective effects of zinc.

Deoxynivalenol (DON) is a type B trichothecenes that is widely contaminating human and animal foods, leading to several toxicological implications if ingested. Induction of oxidative stress and production of lipid peroxides were suggested to be the reasons for DON-induced cytotoxicity. However, detailed and comprehensive profiling of DON-related lipid hydroperoxides was not identified. Furthermore, the mechanisms behind DON-induced cytotoxicity and oxidative stress have received less attention. Zinc (Zn) is an essential element that has antioxidant activities; however, the protective effects of Zn against DON-induced adverse effects were not examined. Therefore, this study was undertaken to investigate DON-induced cytotoxicity and oxidative damage to human HepG2 cell lines. Furthermore, a quantitative estimation for the formed lipid hydroperoxides was conducted using LC-MS/MS. In addition, DON-induced transcriptomic changes on the inflammatory markers and antioxidant enzymes were quantitatively examined using qPCR. The protective effects of Zn against DON-induced cytotoxicity and oxidative stress, the formation of lipid hydroperoxides (LPOOH), and antioxidant status in HepG2 cells were investigated. Finally, the effects of DON and Zn on the Nrf2-Keap1 pathway were further explored. The achieved results indicated that DON caused significant cytotoxicity in HepG2 cells accompanied by significant oxidative damage and induction of the inflammatory markers. Identification of DON-related LPOOH revealed the formation of 22 LPOOH species including 14 phosphatidylcholine hydroperoxides, 5 triacylglycerol hydroperoxides, and 3 cholesteryl ester hydroperoxides. DON caused significant downregulation of Nrf2-regulated antioxidant enzymes. Zn administration led to significant protection of HepG2 cells against DON-induced adverse effects, probably via activation of the Nrf2-Keap1 pathway.