Bacteriological Examination of Cooked Meat and Chicken Meals

Cooked meat and chicken meals due to their high nutritive value and agreeable taste. Meat meals have an excellent source of high-quality protein, vitamin and mineral [1,2]. 

Raw materials of bad microbial quality, bad personal hygiene and consumption at room temperature lead to contamination of foods with pathogenic bacteria especially Salmonellae and coliforms, causing potential risk to human [3].

Incorrect habits responsible for microbial food borne illness reported [4] and typically involve cross contamination of raw and cooked foods, poor cooking and storage at unsuitable temperature. 

Staphylococcal food poisoning has rapid onset and its symptoms include nausea and strong vomiting with or without diarrhea [5].

Salmonella spp can persist on final raw products. Disease can result when these products are handled without good hygienic practices, not properly cooked and/or subjected to temperature abuse [6]. It is considered that the presence of Salmonella spp in products makes it unsafe for human consumption [7,8]. 

E.coli is an important organism involved in food – borne disease, it is considered as a good indicator of possible fecal contamination [9].

Therefore, the present study was planned out for determination of APC, Enterobacteriaceae & coliforms counts, isolation and identification of E. coli, Salmonella and Staph.aureus for ready to eat meat and chicken meals including meat, chicken, beef kofta and chicken kofta.

Collection of samples:

Sixty random samples of cooked chicken and meat meals including meat, chicken, beef kofta and chicken kofta (15 of each) were collected from different restaurants. Each sample was kept in a separate sterile plastic bag, put in an ice box then transferred to the laboratory under complete aseptic condition without any regard for the examination bacteriologically.

Preparation of samples [10]:

To 25 grams of the sample, 225 ml of sterile peptone water were added thoroughly mixed sterile blender for 2.5 minutes, from which tenth fold serial dilution was prepared. The prepared samples were subjected to the following bacteriological investigations: 

The results of bacteriological examination of cooked chicken and meat meals samples revealed that APC and coliform were highest in chicken kofta followed by beef kofta then chicken then meat. While, enterobacteriaceae was highest in chicken kofta followed by chicken then beef kofta then meat.

Isolation and identification of E.coli in the examined samples revealed that the incidence of E.coli was 26.67% in chicken , 20% in both of beef kofta and 13.33 in meat,12 isolates of E.coli represented as 13.33% from meat with serotypes O₂₆ : H₁₁ (6.67%) and O₁₁₁ : H₄ (6.67) 20% from beef kofta with serotypes O₂₆ : H₁₁ (13.33%) and O₁₂₄ (6.67%) 20% from chicken with serotypes O₇₈ (6.67%), O₁₂₇ : H₆ (6.67%) and O₁₄₆ : H₂₁ (6.67%) 26.67% from chicken kofta with serotypes O₂₆ : H₁₁ (13.33%), O₉₁ : H₂₁ (6.67%) and O₁₂₁ : H₇ (6.67%).

Isolation and identification of Salmonella in the examined samples revealed that the incidence of salmonella was equal in meat, beef kofta and chicken (6.67%) while in chicken kofta was the highest (20%).

6.67%from meat with serotype S. Heidelberg

6.67% from beef kofta with serotype S. Montevideo

6.67% from chicken with serotype S. Kentuckey

20%from chicken kofta with serotypes S. Anatum (6.67%), S. Infantis (6.67%) and S. Typhimurium (6.67%). 

Isolation and identification of Staphylococcus aureus revealed that there are 21 isolates of Staph.aureus were isolated from examined samples represented as 20% from meat, 40% from beef kofta, 33.33% from chicken and 46.67% from chicken kofta.

APC is very important for evaluation of sanitary condition of cooked meat meals. Limit is suggested for total aerobic bacterial count I in various foods range from10⁵ to 10⁷ microbes /g. [14].

It is evident from the results recorded in (Table 1) that the APC/g of the examined samples of cooked chicken and meat meals ranged from 2.1×10³ to 1.7×10⁴ with an average of 6.03×10³ ± 1.45×10³/(cfu/g) for meat, 4.6×10³ to 2.9×10⁴ with an average 9.91×10³ ± 2.18×10³/(cfu/g) for meat kofta, 3.5×10³ to 3.9×10⁴ with an average 8.58×10³ ± 1.65×10³/(cfu/g) for chicken and 6.0×10³ to 7.7×10⁴ with an average 2.03×10⁴ ± 0.43×10⁴ (cfu/g) for chicken kofta. The current results nearly similar to the results recorded by [15] found that the mean value of RTE kofta was 1.83×10⁴cfu/gm, while higher results was recorded by [16] who found that the mean value of APC of RTE kofta was 8.51×10⁵ cfu/g, also higher results was recorded by [17] found that the mean APC of RTE chicken meals was 1.9×10⁴ cfu/g and in RTE meat meals was 1.2×10⁴ cfu/g. High incidence of APC , may indicate that the cooking process was inadequate, or post cooking contamination had occurred, or the length of time and temperature control in storage or display facilities was inadequate to prevent bacterial contamination or that a combination of these factors was involved [18]. 

Table 1: Analytical results of Aerobic plate counts/g (APC) in the examined samples of cooked meat and chicken meals (n=15). 

Results given in (Table2) revealed that the Acceptability of the examined samples of cooked meat and chicken meals based on their APC was (86.67%) of meat samples were accepted samples but (13.33%) of meat samples were unaccepted, (73.33%) of beef kofta samples were accepted but (26.67%) of beef kofta samples were unaccepted, (80%) of chicken samples were accepted but (20%) of chicken samples were unaccepted and (60%) of chicken kofta were accepted but (40 %) of chicken kofta were unaccepted.

Table 2: Acceptability of the examined samples of cooked meat and chicken meals based on their APC (n=15).

*? Center for Food Safety (2014) for cooked meat meals

**?EOS (2005) for heat treated poultry meat. 

Results achieved in (Table 3) showed that the mean values of total enterobacteriaceae counts/g in the examined samples of cooked chicken and meat meals were 3.16×10³ ± 0.72×10³/(cfu/g) for meat, 5.25×10³ ± 0.86×10³/(cfu/g) for meat kofta, 6.53×10³ ± 1.24×10³/(cfu/g) for chicken and 9.14×10³ ± 2.06×10³/(cfu/g) for chicken kofta. the current results was nearly similar to recorded by [16] who found that the mean values of enterobacteriacea of RTE kofta was 7.15×10³/(cfu/g), while higher results recorded by [19] who found the mean value of enterobacteriacae of street vended kofta samples was 1.5×10⁷cfu/g.

Table 3: Analytical results of Enterobacteriaceae counts/g in the examined samples of cooked meat and chicken meals (n=15). 

From the results in (Table 4), it is obvious that the mean values of total coliform counts/(cfu/g) in the examined samples of cooked chicken and meat meals were 7.43×10² ± 1.05×10²/(cfu/g) for meat, 1.06×10³ ± 0.19×10²/(cfu/g) for meat kofta, 9.18×10² ± 2.07×10³/(cfu/g) for chicken and 3.32×10³ ± 0.45×10³/(cfu/g) for chicken kofta. the current results was nearly similar to the results recorded by [20] who found that the mean values of coliform was 5.17×10² ± 1.2×10²/cfu/g. while higher results was recorded by [21] who found the mean value of coliform count of kofta sandwiches was 1.8×10⁵/(cfu/g).

Table 4: Analytical results of coliform counts/g in the examined samples of cooed meat and chicken meals (n=15) 

From the results in (Tables 5 & 6) showed that there are 12 isolates of E.coli represented as 13.33% from meat with serotypes O₂₆ : H₁₁ (6.67%) and O₁₁₁ : H₄ (6.67) 20% from beef kofta with serotypes O₂₆ : H₁₁(13.33%) and O₁₂₄ (6.67%) 20% from chicken with serotypes O₇₈ (6.67%), O₁₂₇ : H₆ (6.67%) and O₁₄₆ : H₂₁ (6.67%) 26.67% from chicken kofta with serotypes O₂₆ : H₁₁ (13.33%), O₉₁ : H₂₁ (6.67%) and O₁₂₁ : H₇ (6.67%).

EIEC = Enteroinvasive E. coli EHEC= Enterohaemorrhagic E. coli 

Table 5: Incidence and serotyping of Enteropathogenic E. coli isolated from the examined samples of cooked meat meals (n=15).

EPEC = Enteropathogenic E. coli ETEC = Enterotoxigenic E. coli EHEC= Enterohaemorrhagic E. coli 

Table 6: Incidence and serotyping of Enteropathogenic E. coli isolated from the examined samples of cooked chicken meals (n=15).

From (Tables 7 & 8) showed the incidence and serotyping of Salmonella isolated from cooked meat and chicken meals is 6.67% from meat identified serologically as S. Heidelberg O_4,5,12 : H_r:1,2 6.67% from beef kofta identified serologically as S. Montevideo O_6,7,14 : H_g,m,s:1,7,2 6.67% from chicken identified serologically as S. Kentucky O_8,20 : H_i:Z6 20% from chicken kofta identified serologically as S. Anatum O_1,9,12 : H_g,m:1,7 (6.67%), S. Infant is O_6,7,14 : H_r:1,5 (6.67%) and S. Typhimurium O_1,4,5,12 : H_i:1,2 (6.67%). Salmonella microorganisms were previously isolated from cooked meat meals by [22,23] also salmonella failed to be isolated from cooked meat meals by [24] the symptoms the symptoms of salmonellosis include diarrhea, nausea, vomiting, fever and abdominal cramps [25].

Table 7: Incidence and serotyping of Salmonellae isolated from the examined samples of cooked meat meals (n=15).

Table 8: Incidence and serotyping of Salmonellae isolated from the examined samples of cooked chicken meals (n=15).

The results in (Tables 9 & 10) reported that Staph.aureus was isolated from 20% of meat, 40% of meat kofta, 33.33% of chicken and 46.67% of chicken kofta. Such organism was isolated previously from ready to eat meat meals by [22,24] who isolated Staph aureus from cooked samples. The presence of Staph.aureus in RTE meat meals may be due to their contamination from food handlers, bad cleaned equipment’s or post processing contamination [26].

The current results in this study allowing concluding that all examined samples were contaminated with different bacteria as E. coli, Salmonella and Staph.aureus and the highest APC was in chicken kofta followed with beef kofta, chicken and meat.

Table 9: Incidence of Staphylococcus aureus isolated from the examined samples of cooked meat meals (n=15).

Table 10: Incidence of Staphylococcus aureus isolated from the examined samples of cooked chicken meals (n=15).