GENETIC CHANGES IN FOOD CONTAMINANTS BACTERIA ISOLATED FROM DIFFERENT ENVIRONMENTS
MOHAMED ABDEL-MAKSOUD ABDEL-WAHED;
Abstract
1. Isolation and Identification of Salmonella and Campylobacter from chicken meat and feces samples:
The present study has demonstrated that retail raw, poultry meat samples from markets in Cairo, Egypt were heavily contaminated with Salmonella. The average detection rates of Salmonella were 66.1%, 50%, 14.2%, 6.7% and 62% in chicken parts, chicken skin, minced meat, milk and chicken feces (environmental samples) respectively. Of note, egg yolks and eggshells were negative. This high level of contamination in poultry meat in Cairo Governorate suggests that all poultry meat should properly cooked before consumption to avoid any potential health risks.
Biochemical test results identified 141 of the isolates as Salmonella isolates with 89.4 – 99.9% probability. These isolates have shown differences in their biochemical pattern in arginine dihydrolysis, H2S production, and inositol-oxidation.
Isolation and identification of Campylobacter organisms reveled that 16% and 4.5% of chicken parts and chicken carcasses samples, were contaminated respectively. No Campylobacter was recovered from egg, milk, minced meat and feces samples. All Campylobacter isolates were biochemically identified as C. jejuni.
2. Serogrouping and serotyping of Salmonella isolates
When Salmonella spp. were classified into the various serogroups, it was found that those from poultry meat and feces belonged to groups C2, C1, B and D: 48.4%, 28.6%, 20.2% and 2.4% respectively. Whereas Salmonella human-derived isolates belonged to groups D, B, C2 and rough form: 41%, 34%, 20% group C2 and 4.5% respectively.
Salmonella serogroup C2 strains were predominant in poultry meat and feces samples, and the percentage of isolation were 46 and 61.5% respectively, suggesting that Salmonella spp. group C2 is wide-spread in chicken meat and feces.
Serological analysis revealed that the most prevalent serotype in the chicken meat samples analyzed were S. Kentucky 42.8%; S. Enteritidis 2.4% and other serotypes 55%. Interestingly, no S. Typhimurium was isolated from the various food sources in this study. This is contrary to findings in European countries and some Asian countries such as Thailand and Malaysia where S. Typhimurium and S. Enteritidis serotypes were found to be predominant in poultry products. This data also suggests that S. Enteritidis is not endemic in Egyptian poultry. Salmonella serotypes which frequently cause human salmonellosis worldwide, such as S. Typhimurium, S. Enteritidis have all been detected in this study in human stool isolates, again suggesting that Egypt is similar to other countries with regard to Salmonella food poisoning.
The serotype distribution for Salmonella human stool isolates were S. Enteritidis, S. Typhimurium, other serovars and roughform: 40.9%, 34%, 20.4% and 4.5% respectively with no S. Kentucky strains isolated from human stool specimens.
3. Antibiotic susceptibility of Salmonella and Cambylobacter isolates:
The antibiotic susceptibility study indicated alarming resistance frequencies in Salmonella isolates from food and feces sources in Egypt. Salmonella isolates showed resistance to 16 different antibiotics, with the percentage of resistance to sulfonamides, nalidixic acid and tetracycline being 96%, 95% and 95% to respectively. Salmonella isolates showed moderate resistance levels 56%-75% to ampicillin, streptomycin,
The present study has demonstrated that retail raw, poultry meat samples from markets in Cairo, Egypt were heavily contaminated with Salmonella. The average detection rates of Salmonella were 66.1%, 50%, 14.2%, 6.7% and 62% in chicken parts, chicken skin, minced meat, milk and chicken feces (environmental samples) respectively. Of note, egg yolks and eggshells were negative. This high level of contamination in poultry meat in Cairo Governorate suggests that all poultry meat should properly cooked before consumption to avoid any potential health risks.
Biochemical test results identified 141 of the isolates as Salmonella isolates with 89.4 – 99.9% probability. These isolates have shown differences in their biochemical pattern in arginine dihydrolysis, H2S production, and inositol-oxidation.
Isolation and identification of Campylobacter organisms reveled that 16% and 4.5% of chicken parts and chicken carcasses samples, were contaminated respectively. No Campylobacter was recovered from egg, milk, minced meat and feces samples. All Campylobacter isolates were biochemically identified as C. jejuni.
2. Serogrouping and serotyping of Salmonella isolates
When Salmonella spp. were classified into the various serogroups, it was found that those from poultry meat and feces belonged to groups C2, C1, B and D: 48.4%, 28.6%, 20.2% and 2.4% respectively. Whereas Salmonella human-derived isolates belonged to groups D, B, C2 and rough form: 41%, 34%, 20% group C2 and 4.5% respectively.
Salmonella serogroup C2 strains were predominant in poultry meat and feces samples, and the percentage of isolation were 46 and 61.5% respectively, suggesting that Salmonella spp. group C2 is wide-spread in chicken meat and feces.
Serological analysis revealed that the most prevalent serotype in the chicken meat samples analyzed were S. Kentucky 42.8%; S. Enteritidis 2.4% and other serotypes 55%. Interestingly, no S. Typhimurium was isolated from the various food sources in this study. This is contrary to findings in European countries and some Asian countries such as Thailand and Malaysia where S. Typhimurium and S. Enteritidis serotypes were found to be predominant in poultry products. This data also suggests that S. Enteritidis is not endemic in Egyptian poultry. Salmonella serotypes which frequently cause human salmonellosis worldwide, such as S. Typhimurium, S. Enteritidis have all been detected in this study in human stool isolates, again suggesting that Egypt is similar to other countries with regard to Salmonella food poisoning.
The serotype distribution for Salmonella human stool isolates were S. Enteritidis, S. Typhimurium, other serovars and roughform: 40.9%, 34%, 20.4% and 4.5% respectively with no S. Kentucky strains isolated from human stool specimens.
3. Antibiotic susceptibility of Salmonella and Cambylobacter isolates:
The antibiotic susceptibility study indicated alarming resistance frequencies in Salmonella isolates from food and feces sources in Egypt. Salmonella isolates showed resistance to 16 different antibiotics, with the percentage of resistance to sulfonamides, nalidixic acid and tetracycline being 96%, 95% and 95% to respectively. Salmonella isolates showed moderate resistance levels 56%-75% to ampicillin, streptomycin,
Other data
| Title | GENETIC CHANGES IN FOOD CONTAMINANTS BACTERIA ISOLATED FROM DIFFERENT ENVIRONMENTS | Other Titles | التغيرات الوراثية في البكتريا الملوثة للأغذيه المعزولة من أوساط بيئية مختلفة | Authors | MOHAMED ABDEL-MAKSOUD ABDEL-WAHED | Issue Date | 2014 |
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