Health Risk Assessment of Exposure to Heavy Metals from Sheep Meat and Offal in Kuwait.

ABSTRACT: A total of 600 sheep samples (200 each of muscle, liver, and kidney) collected from 200 sheep carcasses slaughtered at abattoirs in Kuwait were analyzed by atomic absorption spectrophotometry for concentrations of mercury (Hg), arsenic (As), lead (Pb), cadmium (Cd), and chromium (Cr). These metals were detected in all (100%) examined samples; higher concentrations occurred in kidney followed by liver and muscle. The mean (±standard error of the mean) values of the metals detected in sheep muscle, liver, and kidney samples were 0.320 ± 0.061, 0.488 ± 0.042, and 0.791 ± 0.152 µg/g, respectively for Hg; 349 ± 0.074, 0.504 ± 0.049, and 0.642 ± 0.113 µg/g, respectively, for As; 0.482 ± 0.098, 0.567 ± 0.042, and 0.706 ± 0.098 µg/g, respectively, for Pb; 0.301 ± 0.344, 0.433 ± 0.032, and 0.586 ± 0.064 µg/g, respectively, for Cd; and 0.362 ± 0.064, 0.585 ± 0.044, and 0.738 ± 0.111 µg/g, respectively, for Cr. The concentrations of all heavy metals except Cr exceeded the maximum permissible limits set by various international food agencies. The estimated daily intake of each metal was lower than its provisional tolerable daily intake. The target hazard quotient and hazard index values for Hg were >1.0 in all examined sheep samples, suggesting significant health risks to the public from the consumption of sheep meat and offal marketed in Kuwait.

Heavy Metal Residues in Some Fishes from Manzala Lake, Egypt, and Their Health-Risk Assessment.

A total of 600 freshly caught fish samples (200 each of Nile tilapia, flathead grey mullet, and African catfish) were collected from Manzala Lake, Egypt, and analyzed for determination of heavy metal residues using an atomic absorption spectrophotometer. Metal concentrations (µg/g wet weight) were detected in all examined samples in quantities of 0.045, 0.0145, and 0.017 µg/g for Hg; 0.511, 0.621, and 0.568 µg/g for As; 0.704, 0.635, and 0.64 µg/g for Pb; and 0.024, 0.006, and 0.020 µg/g for Cd in Nile tilapia, flathead grey mullet, and African catfish, respectively. The mean concentrations of Hg, Pb, and Cd among the three fish species tested followed the order Nile tilapia > African catfish > flathead grey mullet; meanwhile, As concentration followed the order flathead grey mullet > African catfish > Nile tilapia. The contamination levels of Hg and Cd showed significant differences between summer and winter in the three different fish species examined. Both the mullet and catfish tested revealed significant negative correlations between fish size and their residual levels of Hg, Pb, and Cd. Health-risk assessment indices suggesting that consuming such fishes from Manzala Lake could have a potential health hazard to consumers.

Prevalence, genetic characterization and virulence genes of sorbitol-fermenting Escherichia coli O157:H- and E. coli O157:H7 isolated from retail beef.

Sorbitol-fermenting (SF) Escherichia coli O157:H- strains have emerged as important pathogens and have been associated with a higher incidence of progression to hemolytic-uremic syndrome (HUS) than non-sorbitol fermenting (NSF) E. coli O157:H7. The present study was carried out to determine the prevalence of SF E. coli O157:H- and NSF E. coli O157:H7 strains in retail beef products in Mansoura, Egypt. The contamination rates with rfbEO157-positive E. coli O157 strains were 26.7% (8/30), 10% (3/30) and 3.7% (1/27) in ground beef, beef burger, and fresh beef samples, respectively with an overall mean of 13.8% (12/87) among all meat products tested. SF E. coli O157:H- were the most dominant among the isolated O157 strains. Of the fifteen O157 strains isolated, 11 (73.3%) were SF E. coli O157:H-, while the remaining 4 (26.7%) were NSF E. coli O157:H7. The 11 SF O157H- strains were genetically positive for sfpA gene. Restriction fragment length polymorphism (RFLP) analysis for fliC gene demonstrated a similar pattern for both SF and NSF O157 isolates. PCR assays verified the existence of stx1 gene in 7 (46.7%) and stx2 gene in 13 (86.7%) of the 15 O157 strains isolated. Unexpectedly, two of the 15 O157 strains isolated were negative for Shiga toxin genes. The eae gene was identified in all of the 15 O157 strains except in one NSF O157:H7 strain. EHEC-hlyA gene was detected in 14 (93.3%) of the 15 O157 isolates, nonetheless only 11 strains showed enterohemolytic phenotype on blood agar. A combination of the four virulence genes, stx1, stx2, eae and EHEC-hlyA were detected in 7 (46.7%) strains, while six (40%) strains were positive for stx2, eae and hlyA genes. This is the first record for isolation of E. coli O157: H- in Egypt as well as in the African continent.