North Africa has a great diversity of indigenous sheep breeds whose origin is linked to its environmental characteristics and to certain historical events that took place in the region. To date, few genome-wide studies have been conducted to investigate the population structure of North African indigenous sheep. The objective of the present study was to provide a detailed assessment of the genetic structure and admixture patterns of six Maghreb sheep populations using the Illumina 50K Ovine BeadChip and comparisons with 22 global populations of sheep and mouflon. Regardless of the method of analysis used, patterns of multiple hybridization events were observed within all North African populations, leading to a heterogeneous genetic architecture that varies according to the breed. The Barbarine population showed the lowest genetic heterogeneity and major southwest Asian ancestry, providing additional support to the Asian origin of the North African fat-tailed sheep. All other breeds presented substantial Merino introgression ranging from 15% for D'man to 31% for Black Thibar. We highlighted several signals of ancestral introgression between North African and southern European sheep. In addition, we identified two opposite gradients of ancestry, southwest Asian and central European, occurring between North Africa and central Europe. Our results provide further evidence of the weak global population structure of sheep resulting from high levels of gene flow among breeds occurring worldwide. At the regional level, signs of recent admixture among North African populations, resulting in a change of the original genomic architecture of minority breeds, were also detected.
Ibrahim Eldaghayes(8-2019)

Abstract: This study was carried out to detect different coliforms members with special reference to the occurrence of the pathogenic Escherichia coli existing in raw cow`s milk and some dairy products. 105 samples (35 raw milk, 35 fermented milk, and 35 ricotta cheeses) were randomly collected from different markets in Tripoli-city /Libya. In this study, two methods for coliform counting were used. The first one was the most probable number technique MPN using liquid Lauryl Sulphate Tryptone broth (LST) with a three-tube series and the second method was the plate count method using violet red bile lactose agar VRBA. Also different techniques were used to find comparative results by using the BD phoenix system, the VITEK® 2 Compact system and KB003Hi25™ Enterobacteriaceae Identification Kit methods for coliform counts in raw milk, fermented milk and ricotta chesses. The coliform bacteria were positive in all 35 (100%) samples of both raw milk and fermented milk, while 33 (94.3%) samples out of 35of ricotta cheese by using MPN-technique. Whereas, Coliform bacteria were positive in 25 (71.4%) samples of raw milk, 34 (97.1%) samples of fermented milk and in 22 (62.9%) samples of ricotta cheese by using VRBA-technique. However, the fecal Coliform bacteria were recorded in 30 (85.7%) samples of raw milk, 32 (91.4%) samples of fermented milk and in 24 (68.6%) samples of ricotta by the used MPN-technique. Whereas, fecal Coliform bacteria were detected in 11 (31.4%) samples of raw milk, 19 (54.3%) samples of fermented milk and in only 9 (25.7%) samples of ricotta cheese by the VRBA-technique. Moreover, the most commonly identified important pathogenic bacteria Gram-negative isolated the highest overall incidence rate was for Escherichia coli 117(58.5%) and Klebsiella pneumonia spp pneumonia 47(23.5%) out of 200 randomly selected from 900 isolates. These findings results revealed that a high number of bacteria, which provide an evidence for the lack of milk hygiene either during milking or transporting and storages Statistical analyses revealed significant T-test at level P
خديجة مختار التواتي (2015)

Background: This study was conducted to investigate the presence of Bacillus cereus in meat, meat products, and some seafood in Libya. Materials and Methods: One hundred and thirty-one samples were collected from different geographic localities in Libya. The samples were subjected to microbiological analysis for enumeration and isolation of B. cereus by conventional cultural, biochemical, and molecular identification using polymerase chain reaction (PCR) and partial sequencing of 16S rDNA techniques. Results: Of 131 samples, only 38 (29%) isolates were found to be B. cereus based on their cultural characteristics on Mannitol Egg-Yolk Polymyxin (MYP) medium that included 30% beef, 38.2% beef products (minced, burger, kabab, and sausage), 31.8% camel meat, and 48% chicken products (burger, sausage, kabab, and liver). However, B. cereus was not detected from mutton and seafood samples. Seventeen isolates were subjected to molecular identification using PCR and partial sequencing of 16S rDNA technique and confirmed to be B. cereus. The confirmed B. cereus strains were tested for their antibiotic sensitivity profiles and showed a high percentage of multiresistance phenotype. Conclusions: The results provide a better understanding of B. cereus isolated from food of animal origin in Libya and suggest that meat and meat products might play an important role in the spreading of B. cereus through the food chain with antimicrobial resistance characteristics.
Ibrahim Eldaghayes(6-2018)