Microbiological quality of meat

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  • 1. Microbiological quality of meat and meat products marketed in Tripoli city, Libya: Review Dr. Yousef M. Elshrek

2. From safety perspective, refrigerated meat and meat products have been linked to outbreaks of pathogenic bacteria like E. coli O157:H7 and Salmonella, and many others, thus, consumers may be exposed to food borne illness through unsafe preparation of such products. Potential cross-contaminations were common, with an average events noted per household. Hands were the most commonly observed vehicle of potential cross- contamination. 3. The aim of this paper is to review some microbiological aspects of meat and meat products distributed in different local markets in Tripoli city, Libya. Studies were conducted separately and in different occasions, in the years 1986 and between 2005 2012. Samples were collected from different places mainly, restaurants, hotels, houses and other local markets in Tripoli area and its suburbs. 4. Minced meat: In a study by (Elshrek et. el. 1986), dealing with the microbiological quality of ground beef, fifty one samples were randomly collected from various butchers and markets in Tripoli and its suburbs. Results indicated that the total plate count (TPC) ranged between 5.2x103 to 5.1x 107cfu/g (Table 1). 5. Total plate count(TPC)Coliform bacteriaS. aureus No. of samples contamina- ted Range of Counts No. of samples contaminatedRange of Counts No. of samples contaminatedRange of Counts 045.2103-5.1104152.0102-2.0310222.0103-2.0104 025.2104-5.1105122.1104-2.0105162.1104-2.0105 105.2105-5.1106122.1105-2.0106102.1105-2.0106 355.2106-5.1107122.1106-2.0107032.1106-2.0107 Table (1): Total bacterial count, Coliform and S. aureus of ground meat sold in Tripoli Ref. (Elshrek et.al. 1986) 6. Beef Burger Results indicated that beef burger samples were highly contaminated with several pathogenic bacteria such as E. coli (74.5%), E. coli O157:H7 (27.1%), S. aureus (28.8%) and Aeromonas (18.6%), Table(2). Meat Status Pathogens and Contamination percentage (%) Aeromonase S. aureus E. coli E. coliO157:H7 Salmonella Uncooked 18.6 28.8 74.5 27.5 01.7 Cooked 09.6 03.2 05.4 11.9 01.0 Table (2) Percent of pathogenic bacteria Contamination of uncooked and cooked spiced beef burger sold in Tripoli Ref. Elshrek et.al. (2008) 7. Chicken burger: Ali ( 2007 ) investigated the microbiological quality of uncooked and cooked spiced chicken burger in some restaurants and fast food places in Tripoli city and surrounding areas, using 120 samples (64 cooked and 56 uncooked) . The results indicated that all the samples were heavily contaminated with pathogenic bacteria , Table (3). 8. Meat Status Pathogens and Contamination percentage (%) Aeromonase S. aureus E. coli E. coli O157:H7 Salmonella Uncooked 25.9 29.6 66.6 20.3 12.9 Cooked 03.12 01.65 10.9 04.68 01.56 Table (3) Percent of pathogenic bacteria Contamination Of uncooked / cooked chicken burger Ref. Ali (2007) 9. Kofta (Meat Balls): Alkhaldy(2007), investigated the microbiological quality of Libyan Kufta(meat balls), using 92 samples collected from 29 houses, 31 wedding places, 10 restaurants and 7 hotels in Tripoli city and its surrounding areas. As could be seen in Table 4 below 10. Types of pathogenic bacteria Contamination percentage (%) Houses Hotels Houses Hotels wedding places restaurants Uncooked Cooked S .aureus 40.0 42.0 07.0 43.0 23.0 20.0 E.coli 46.6 71.4 - - - - E.coli O157:H7 13.3 14.2 06.9 14.0 19.4 30.0 Salmonella ssp 20.0 14.2 03.0 0.0 23.0 03.0 Shigella ssp 0.0 0.0 0.0 0.0 0.0 0.0 Aeromonas ssp 13.3 42.0 06.9 14.0 16.0 10.0 Table (4) Percent of pathogenic bacteria Contamination of uncooked / cooked Kofta (Meat balls) prepared at different places in Tripoli Ref. (Alkhaldy 2007) 11. Camel Meat Abed Ala-el (2006) conducted a study dealing with the microbiological quality of camel meat, using fresh meat samples from 120 carcasses, their ages ranged between 1-3 years. The samples were collected from abattoirs in Tripoli area, belongs to the government and private sector. The study conducted over two season periods, the first (summer) period started on August first to the end of October 2004, and the second (winter) period was from December first to the end of February 2005 Results of this study showed in the folowing table(Table5). 12. Type of pathogen Contamination percentage (%) First Period Second period A. hydrophila 65.0 06.0 A. sobria 35.0 94.0 S. aureus 97.0 56.0 Salmonella anatum 04.0 0.0 E. coli 41.0 0.0 E. coli O157:H7 0.0 0.0 Campylobacter 0.0 0.0 Table (5) Percent of some pathogenic bacteria Contamination of camel meat Sold in Tripoli Ref. (Abed Ala- el (2006) 13. Fresh sausage (Mergaz) : A recent study was conducted by Abomengeal, ( 2010) aimed to evaluate the microbiological quality of sausages sold in some market places within Tripoli city using a total of 140 samples. Microbiological tests included: Total microbial count, psychrotrophic bacteria, coliforms and thermo-tolerant coliforms (fecal) counts (Table 6). In a recent study in the same area Ben-Hamza (2012) indicated that the percentage of contamination E. coli and E. coli0157:H7 was 81% and 49.95% respectively (Table 6). Using PCR technique aided by biochemical tests she confirmed the presence of E. coli 0157:H7 virulence genes Shiga toxin genes (stx1) and (stx 2) in 25% and 24.95% of the samples respectively (Table 6). 14. Type of pathogen Abomengeal study. 2010 Ben Hamza study 2012 E. coli --------- 81% E. coli O157:H7 39.3% 49.95% Salmonella 2.1% ------- Table (6) Percent of some pathogenic bacteria Contamination of Mergaz Sold in Tripoli Ref. (Abomengeal (2010) and Ben - Hamza (2012) 15. On the light of the above data, one could conclude that the microbiological quality of meat and meat products marketed in Tripoli during the period covered by the cited studies (2005-2012) were very low and could be considered unsafe from microbiological view point due to the high percentage of several pathogenic bacteria. This reflects the low measures of quality control and no concern regarding personal hygiene and sanitation and manufacturing practices.