الفهرس 
Arabic Summary
Incidence of Yersinia enterocoliticil in milk and some milk productsOnly 14 pages are availabe for public view
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Abstract
UMMARY
I - Incidence of 1’: enterocolitica in milk and some milk products:
Six hundred random samples of milk and milk products including raw milk (200), Kareish cheese (100), Damietta cheese, processed cheese, butter, yoghurt (50 samples each), and ice cream (100), were collected from different localities in Assiut city. The samples were examined for existance of Y. enterocolitica using two enrichment broths and two selective culture media.
The recorded data reveal that, when Trypticase soy broth was used as enrichment broth with eIN agar as a culture medium, Y. enterocolitica was detected in 2 (1 %) samples of raw milk and in 2
- ”
(2%) samples of ice cream. The organism failed to recover from the
other milk products examined, using Bismuth sulphate agar as a culture medium with Trypticase soy broth could detect Y. enterocolitica in 1.5% of raw milk (3 samples), in 2% of Kareish cheese (2 samples) and in 3% of ice cream (3 samples). On the other hand, the obtained results verify that Y. enterocolitica could be isolated from 7 samples of raw milk (3.5%), from one sample of Kareish cheese (1 0/0), from 2 samples of processed cheese (40/0) and from 2 samples of ice cream (2%), when Bismuth sulphate agar was used after enrichment of samples in phosphate buffer saline. While, using eIN agar with phosphate buffer saline failed to detect Y. enterocolitica in any of the examined samples. The gained results prove that there was fl good correlction between phosphate buffer
Summary 80
saline as an enrichment and Bismuth sulphate agar as a culture medium for recovery of Y. enterocolitica from milk and milk products.
11 - Virulence of ~ enterocolitica isolated from milk and milk products:
The virulence tests were• carried out on Y. enterocolitica (24 strains) recovered from milk and milk products using two different enrichment broths and two selective culture media. The obtained results prove that 22 (91.6%) out of 24 strains of Y. enterocolitica were virulent depending en Guinea pig conjur-ctivitis test, Mouse diarrhoea model and auto agglutination test. Only 2 strains (8.3%) of Y. enterocolitica recovered from processed cheese were non pathogenic.
111- Effect of pot. sorbate on growth and survival of ~ enterocolitica serotypes 0:8 and 0:9 during manufacture and storage of Damietta cheese:
Inoculated Damietta cheese blocks were prepared to contain different concentrations of pot. sorbate (0.2, 0.4 and 0.6%) and Y. enterocolitica serotypes, 0:8 and 0:9 with their control (pot. sorbate free cheese).
Damietta cheeses with their control were stored at room temp. for 8 weeks. The count of inoculated Y. enterocolitica was determined after inoculation, after curdling, from the finished cheese, and periodically every week thereafter.
Summary 81
The recorded results show that there was a substantial growth and multiplication of Y. enterocolitica serotype 0:8 during preparation of the 4 types of cheeses. The number of the organisms decreased gradually during weeks of storage to reach its minimum count (log 10 of 3.3/g) by the end of storage time of control cheese. A lower minimum counts were enumerated in cheeses containing the different concentrations of added pot. sorbate. The decreasing percentages, of Y. enterocolitica serotypes 0:8 in cheeses due to 0.2, 0.4 and 0.6% concentrations of added pot. sorbate were respectively, 95, 98 and 99.50/0.
Also, the recorded data show that Y. enterocolitica serotype 0:9 increased rapidly during preparation of cheese containing 0.2% added pot. sorbate and that free pot. sorbate (control). In cheese made from milk containing 0.4 and 0.6% added pot. sorbate, there was a slight increase in numbers of the organism during their preparation. Y. enterocolitica 0:9 decreased rapidly during the weeks of storage to reach a minimum population of log 10 of 3/9 in both types of cheese (control and cheese containing 0.2% added pot. sorbate). Lower numbers of Y. enterocolitica serotype 0:9 were counted in cheeses containing 0.4% and 0.6% added pot. sorbate by the end of storage time. The decreasing percentages of Y. enterocolitica serotype 0:9 in cheeses due to the effect of 0.4 and 0.6% concentrations of pot. sorbate were respectively, 90% and 99.
UMMARY
I - Incidence of 1’: enterocolitica in milk and some milk products:
Six hundred random samples of milk and milk products including raw milk (200), Kareish cheese (100), Damietta cheese, processed cheese, butter, yoghurt (50 samples each), and ice cream (100), were collected from different localities in Assiut city. The samples were examined for existance of Y. enterocolitica using two enrichment broths and two selective culture media.
The recorded data reveal that, when Trypticase soy broth was used as enrichment broth with eIN agar as a culture medium, Y. enterocolitica was detected in 2 (1 %) samples of raw milk and in 2
- ”
(2%) samples of ice cream. The organism failed to recover from the
other milk products examined, using Bismuth sulphate agar as a culture medium with Trypticase soy broth could detect Y. enterocolitica in 1.5% of raw milk (3 samples), in 2% of Kareish cheese (2 samples) and in 3% of ice cream (3 samples). On the other hand, the obtained results verify that Y. enterocolitica could be isolated from 7 samples of raw milk (3.5%), from one sample of Kareish cheese (1 0/0), from 2 samples of processed cheese (40/0) and from 2 samples of ice cream (2%), when Bismuth sulphate agar was used after enrichment of samples in phosphate buffer saline. While, using eIN agar with phosphate buffer saline failed to detect Y. enterocolitica in any of the examined samples. The gained results prove that there was fl good correlction between phosphate buffer
Summary 80
saline as an enrichment and Bismuth sulphate agar as a culture medium for recovery of Y. enterocolitica from milk and milk products.
11 - Virulence of ~ enterocolitica isolated from milk and milk products:
The virulence tests were• carried out on Y. enterocolitica (24 strains) recovered from milk and milk products using two different enrichment broths and two selective culture media. The obtained results prove that 22 (91.6%) out of 24 strains of Y. enterocolitica were virulent depending en Guinea pig conjur-ctivitis test, Mouse diarrhoea model and auto agglutination test. Only 2 strains (8.3%) of Y. enterocolitica recovered from processed cheese were non pathogenic.
111- Effect of pot. sorbate on growth and survival of ~ enterocolitica serotypes 0:8 and 0:9 during manufacture and storage of Damietta cheese:
Inoculated Damietta cheese blocks were prepared to contain different concentrations of pot. sorbate (0.2, 0.4 and 0.6%) and Y. enterocolitica serotypes, 0:8 and 0:9 with their control (pot. sorbate free cheese).
Damietta cheeses with their control were stored at room temp. for 8 weeks. The count of inoculated Y. enterocolitica was determined after inoculation, after curdling, from the finished cheese, and periodically every week thereafter.
Summary 81
The recorded results show that there was a substantial growth and multiplication of Y. enterocolitica serotype 0:8 during preparation of the 4 types of cheeses. The number of the organisms decreased gradually during weeks of storage to reach its minimum count (log 10 of 3.3/g) by the end of storage time of control cheese. A lower minimum counts were enumerated in cheeses containing the different concentrations of added pot. sorbate. The decreasing percentages, of Y. enterocolitica serotypes 0:8 in cheeses due to 0.2, 0.4 and 0.6% concentrations of added pot. sorbate were respectively, 95, 98 and 99.50/0.
Also, the recorded data show that Y. enterocolitica serotype 0:9 increased rapidly during preparation of cheese containing 0.2% added pot. sorbate and that free pot. sorbate (control). In cheese made from milk containing 0.4 and 0.6% added pot. sorbate, there was a slight increase in numbers of the organism during their preparation. Y. enterocolitica 0:9 decreased rapidly during the weeks of storage to reach a minimum population of log 10 of 3/9 in both types of cheese (control and cheese containing 0.2% added pot. sorbate). Lower numbers of Y. enterocolitica serotype 0:9 were counted in cheeses containing 0.4% and 0.6% added pot. sorbate by the end of storage time. The decreasing percentages of Y. enterocolitica serotype 0:9 in cheeses due to the effect of 0.4 and 0.6% concentrations of pot. sorbate were respectively, 90% and 99.
UMMARY
I - Incidence of 1’: enterocolitica in milk and some milk products:
Six hundred random samples of milk and milk products including raw milk (200), Kareish cheese (100), Damietta cheese, processed cheese, butter, yoghurt (50 samples each), and ice cream (100), were collected from different localities in Assiut city. The samples were examined for existance of Y. enterocolitica using two enrichment broths and two selective culture media.
The recorded data reveal that, when Trypticase soy broth was used as enrichment broth with eIN agar as a culture medium, Y. enterocolitica was detected in 2 (1 %) samples of raw milk and in 2
- ”
(2%) samples of ice cream. The organism failed to recover from the
other milk products examined, using Bismuth sulphate agar as a culture medium with Trypticase soy broth could detect Y. enterocolitica in 1.5% of raw milk (3 samples), in 2% of Kareish cheese (2 samples) and in 3% of ice cream (3 samples). On the other hand, the obtained results verify that Y. enterocolitica could be isolated from 7 samples of raw milk (3.5%), from one sample of Kareish cheese (1 0/0), from 2 samples of processed cheese (40/0) and from 2 samples of ice cream (2%), when Bismuth sulphate agar was used after enrichment of samples in phosphate buffer saline. While, using eIN agar with phosphate buffer saline failed to detect Y. enterocolitica in any of the examined samples. The gained results prove that there was fl good correlction between phosphate buffer
Summary 80
saline as an enrichment and Bismuth sulphate agar as a culture medium for recovery of Y. enterocolitica from milk and milk products.
11 - Virulence of ~ enterocolitica isolated from milk and milk products:
The virulence tests were• carried out on Y. enterocolitica (24 strains) recovered from milk and milk products using two different enrichment broths and two selective culture media. The obtained results prove that 22 (91.6%) out of 24 strains of Y. enterocolitica were virulent depending en Guinea pig conjur-ctivitis test, Mouse diarrhoea model and auto agglutination test. Only 2 strains (8.3%) of Y. enterocolitica recovered from processed cheese were non pathogenic.
111- Effect of pot. sorbate on growth and survival of ~ enterocolitica serotypes 0:8 and 0:9 during manufacture and storage of Damietta cheese:
Inoculated Damietta cheese blocks were prepared to contain different concentrations of pot. sorbate (0.2, 0.4 and 0.6%) and Y. enterocolitica serotypes, 0:8 and 0:9 with their control (pot. sorbate free cheese).
Damietta cheeses with their control were stored at room temp. for 8 weeks. The count of inoculated Y. enterocolitica was determined after inoculation, after curdling, from the finished cheese, and periodically every week thereafter.
Summary 81
The recorded results show that there was a substantial growth and multiplication of Y. enterocolitica serotype 0:8 during preparation of the 4 types of cheeses. The number of the organisms decreased gradually during weeks of storage to reach its minimum count (log 10 of 3.3/g) by the end of storage time of control cheese. A lower minimum counts were enumerated in cheeses containing the different concentrations of added pot. sorbate. The decreasing percentages, of Y. enterocolitica serotypes 0:8 in cheeses due to 0.2, 0.4 and 0.6% concentrations of added pot. sorbate were respectively, 95, 98 and 99.50/0.
Also, the recorded data show that Y. enterocolitica serotype 0:9 increased rapidly during preparation of cheese containing 0.2% added pot. sorbate and that free pot. sorbate (control). In cheese made from milk containing 0.4 and 0.6% added pot. sorbate, there was a slight increase in numbers of the organism during their preparation. Y. enterocolitica 0:9 decreased rapidly during the weeks of storage to reach a minimum population of log 10 of 3/9 in both types of cheese (control and cheese containing 0.2% added pot. sorbate). Lower numbers of Y. enterocolitica serotype 0:9 were counted in cheeses containing 0.4% and 0.6% added pot. sorbate by the end of storage time. The decreasing percentages of Y. enterocolitica serotype 0:9 in cheeses due to the effect of 0.4 and 0.6% concentrations of pot. sorbate were respectively, 90% and 99.
UMMARY
I - Incidence of 1’: enterocolitica in milk and some milk products:
Six hundred random samples of milk and milk products including raw milk (200), Kareish cheese (100), Damietta cheese, processed cheese, butter, yoghurt (50 samples each), and ice cream (100), were collected from different localities in Assiut city. The samples were examined for existance of Y. enterocolitica using two enrichment broths and two selective culture media.
The recorded data reveal that, when Trypticase soy broth was used as enrichment broth with eIN agar as a culture medium, Y. enterocolitica was detected in 2 (1 %) samples of raw milk and in 2
- ”
(2%) samples of ice cream. The organism failed to recover from the
other milk products examined, using Bismuth sulphate agar as a culture medium with Trypticase soy broth could detect Y. enterocolitica in 1.5% of raw milk (3 samples), in 2% of Kareish cheese (2 samples) and in 3% of ice cream (3 samples). On the other hand, the obtained results verify that Y. enterocolitica could be isolated from 7 samples of raw milk (3.5%), from one sample of Kareish cheese (1 0/0), from 2 samples of processed cheese (40/0) and from 2 samples of ice cream (2%), when Bismuth sulphate agar was used after enrichment of samples in phosphate buffer saline. While, using eIN agar with phosphate buffer saline failed to detect Y. enterocolitica in any of the examined samples. The gained results prove that there was fl good correlction between phosphate buffer
Summary 80
saline as an enrichment and Bismuth sulphate agar as a culture medium for recovery of Y. enterocolitica from milk and milk products.
11 - Virulence of ~ enterocolitica isolated from milk and milk products:
The virulence tests were• carried out on Y. enterocolitica (24 strains) recovered from milk and milk products using two different enrichment broths and two selective culture media. The obtained results prove that 22 (91.6%) out of 24 strains of Y. enterocolitica were virulent depending en Guinea pig conjur-ctivitis test, Mouse diarrhoea model and auto agglutination test. Only 2 strains (8.3%) of Y. enterocolitica recovered from processed cheese were non pathogenic.
111- Effect of pot. sorbate on growth and survival of ~ enterocolitica serotypes 0:8 and 0:9 during manufacture and storage of Damietta cheese:
Inoculated Damietta cheese blocks were prepared to contain different concentrations of pot. sorbate (0.2, 0.4 and 0.6%) and Y. enterocolitica serotypes, 0:8 and 0:9 with their control (pot. sorbate free cheese).
Damietta cheeses with their control were stored at room temp. for 8 weeks. The count of inoculated Y. enterocolitica was determined after inoculation, after curdling, from the finished cheese, and periodically every week thereafter.
Summary 81
The recorded results show that there was a substantial growth and multiplication of Y. enterocolitica serotype 0:8 during preparation of the 4 types of cheeses. The number of the organisms decreased gradually during weeks of storage to reach its minimum count (log 10 of 3.3/g) by the end of storage time of control cheese. A lower minimum counts were enumerated in cheeses containing the different concentrations of added pot. sorbate. The decreasing percentages, of Y. enterocolitica serotypes 0:8 in cheeses due to 0.2, 0.4 and 0.6% concentrations of added pot. sorbate were respectively, 95, 98 and 99.50/0.
Also, the recorded data show that Y. enterocolitica serotype 0:9 increased rapidly during preparation of cheese containing 0.2% added pot. sorbate and that free pot. sorbate (control). In cheese made from milk containing 0.4 and 0.6% added pot. sorbate, there was a slight increase in numbers of the organism during their preparation. Y. enterocolitica 0:9 decreased rapidly during the weeks of storage to reach a minimum population of log 10 of 3/9 in both types of cheese (control and cheese containing 0.2% added pot. sorbate). Lower numbers of Y. enterocolitica serotype 0:9 were counted in cheeses containing 0.4% and 0.6% added pot. sorbate by the end of storage time. The decreasing percentages of Y. enterocolitica serotype 0:9 in cheeses due to the effect of 0.4 and 0.6% concentrations of pot. sorbate were respectively, 90% and 99.