1.
Pathogenesis Of Salmonellosis With Respect To Carrier States In Poultry And Its Public Health Impact
by Younus, M | Prof. Dr. Zafar Iqbal Chaudhry | Prof.Dr.Abdul Rauf Shakoori | Prof.Dr.Muham | Faculty of Veterinary Sciences.
Material type: ; Format:
print
; Literary form:
not fiction
Publisher: 2006Dissertation note: The present research endevour was made to study and investigate the prevalence of Salmonella enteritidis and Salmonella typhimurium from poultry feed, poultry meat and poultry eggs and their role in the chain of transmission of salmonellae to human beings. The objective was to generate data to improve the quality of poultry products and human health awareness.
Salmonellosis is one of the most wide spread food borne zoonoses. The etiological agents Salmonella enteritidis and Salmonella typhimurium not only' produce the disease but during the convalescent phase (after the recovery of disease) remain carriers for indefinite period of time. In this study 400 samples were collected and were distributed and detailed as; poultry feed (n=100), poultry intestines (n100 Small and n=100 Large intestines) and eggs (n=100) were collected for the identification of the organism through polymerase chain reaction (PCR). The Positivity percentage as tested through PCR for Salmonella enteritidis in the poultry feed was 20,15,10,15 and 10 for layer starter, layer grower, layer finisher, broiler starter and broiler finisher respectively (P>0.05). The positivity percentage as tested through PCR for Salmonella typhimurium for layer starter, layer grower, layer finisher, broiler starter and broiler finisher feed was 15,10,10, 10, and 10 respectively (P>0.05). There was no significant difference between layers feed and broilers feed as far as identification of salmonella enteritidis and salmonella typhimurium was concerned (P>0.05) but the prevalence range of salmonella enteritidis and salmonella typhimuilum from poultry feed was 10-20% which was biologically significant. The positivity percentage rate of Salmonella enteritidis for small and large intestine in Desi birds (local breed) was 2 and 16 % respectively. Where as for broilers in small and large intestine it was 4 and 18% respectively. The positivity of Salmonella typhimurium in small and large intestine of Desi birds was 2 and 14% where as in broilers it was 4 and 16% in the small and large intestine respectively. There was a significant difference (P <0.05) between the positivity of percentage of salmonella enteritidis and salmonella typhimurium as far as identification of Salmonellae from Desi and broiler meat was concerned.
It was found that 16%, 8%, 16'Y0 and 16% egg albumin was found positive for Salmonella enteritidis in layer egg albumin, Desi (local breed) eggj albumin, double yolk albumin and broken egg albumin respectively. In each case 25 egg albumin were collected and tested for the detection of Salmonellae. Similarly the egg yolk from layers, Desi (local breed) double yolk and broken eggs was taken and positivity rate for Salmonella enteritidis was found 12%, 4%, 12% and 12% respectively. It was found that 12%, 4%, 12% and 12% egg albumin was found positive for Salmonella lyphimurium in layer egg albumin, Desi egg albumin, double yolk albumin and broken egg albumin respectively. In each case 25 egg albumin were collected and tested for the' detection of Salmonella. Similarly the egg yolk from layers, desi double yolk and broken eggs was taken and positivity rate for Salmonella enteritidis was found 8%, 4%, 8% and 4% respectively. The positively rate for Salmonella typhimurium in both albumin and yolk was relatively less in both albumin and yolk of layers, desi double yolk and broken eggs. Statistically there was no significant difference (P> 0.05) but the prevalence of Salmonella enteritidis and Salmonella typhimurium from different eggs ranged between 4-16% and 4-12% respectively which was biologically significant.
The Salmonella enteritidis and Salmonella typhimurium were isolated, identified and grown on the artificial and selective media. The virulence of the organisms of Salmonella enteritidis and Salmonella typhimurium were estimated through calculation of LD50. It was found as 10358/mI and 103/ml for Salmonella enteritidis and Salmonella typhimurium respectively, having significant difference (P< 0.05). In order to understand the pathogenesis and carrier states of salmonella organisms in poultry, a group of 300 broiler birds were procured and divided into three groups were studied upto the age of 3 months. The infection was orally given on the 7th day of their age. As an average 86.74% of the birds were maintaining the organism of the Salmonella enteritidis in the large intestine during the entire experimental period in contrast to the small intestine in which 0% were found positive (P< 0.05). Similarly an average 94.94% of the birds were maintaining the organism of the Salmonella typhimurium in the large intestine during the entire experimental period in contrast to the small intestine in which 0% were found positive (P< 0.05) but non of the samples of Small and Large intestine of control group (Group-C) were found positive for Salmonella enleritidis and Salmonella typhimurium. There was a significant difference between Salmonella enteritidis and Salmonella typhimurium in large intestine of poultry (P< 0.05). The histopathology of different organs of broiler chickens i.e liver, lung, spleen, kidney, small intestine, large intestine, bursa of fabracious and lean muscles at different phases of disease was also conducted for the better understanding of pathogenesis due to salmonellosis. The principal lesions in the liver at the age of 14 to 28 days in groups A and B were leukocytic infiltration, necrosis and haemmorrhage. No lesions were recorded in liver after 28 days of age in groups A and B. No lesions were recorded in group C. The principal lesions of the lungs at the age of 14 to 28 days in groups A and B were leukocytic infiltration,' mild necrosis, vascular congestion and haemrnorrhages. No lesions were recorded in lungs after 28 days of age in groups A and B. No lesions were recorded in group C. The principal lesions of the spleen were mild leukocytic infiltration, necrosis and congestion at the age of 14 to 28 days in groups A and B. No lesions were recorded in spleen after 28 days of age in groups A and B. No lesions were found in group C. The principal lesions of the kidneys were marked tubutar necrosis with glomerular degeneration and Ieukocytic infiltration and haemmorrhages at the age of 14 to 28 in groups A and B. No lesions were1 recorded in kidneys after 28 days of age in groups A and B. No lesions were found in group C. The principal lesions of the small intestine were degeneration of mucosa with inflammatory cells, necrosis, inflammation, superficial ulceration on mucosal lining of intestine at the age of 14 to 21 days. No lesions were recorded in small intestine after 21 days of age in group A and B. No lesions were recorded in control group C. The principal lesions of the large intestine were leukocytic infiltration with necrosis and inflammation at the age of 14 to 91 days. The lesions were recorded up to 91 days of age in group A and B. No lesions were recorded in control group C. The principal lesions of Bursa of1, fabricious were atrophy & necrosis of bursal follicles and leukocytic infiltration at the age of 14 to 21 in groups A and B. No lesions were recorded in Bursa of fabricious after 21 days of age in groups A and B. No lesions were found in group C. The principal lesions of lean muscle were muscular degeneration and necrotic areas at the age of 14 to 21 days in groups A and B. No lesions were recorded in lean muscles after 21 days of age in groups A and B. No lesions were found in group C.
The carrier state was not only the source of spread of disease with in the poultry but also caused typhoid fever and food poisoning in humans. The chain of transmission started fron poultry feed to poultry meat and ultimately to humans as dead end host. Finally, the 400 samples of stool and blood from 200 human patients (100 suspected of typhoid fever and 100 suspected of food poisoning) were also collected from four different hospitals from urban area of Lahore for the identification of Salmonella enteritidis and Salmonella typhimurium through PCR method in order to see the public health impact of Salmonellosis through consuming the meat and eggs of the carrier birds. A total of 14% and 10% stool samples were found positive for Salmonella enteritidis and Salmonella Typhimurium in case of suspected typhoid fever patients respectively. Similarly 6% and 2% blood samples were found positive for Salmonella enteritidis and Salmonella Typhimurium. There was a significant difference (P< 0.05) in the sero positivity of stool and blood samples of suspected typhoid fever patients and also as for as Salmonella enteritidis and Salmonella typhimurium was concerned. However there was no significant difference (P> 0.05) between the hospitals On the average 14 and 10 stool samples were found positive against Salmonella enteritidis and Salmonella typhimurium from each of the 25 patients of each hospital respectively in case of suspected food poisoning patients. Similarly on an average 5% and 6% blood samples were found positive from 25 patients of each hospital respectively. There was a significant difference (P< 0.05) in the sero positivity of stool and blood samples of suspected food poisoning patients as far as Salmonella enteritidis and Salmonella typhimurium was concerned. However there was no significant difference (P> 0.05) between the hospitals.
CONCLUSION
A series of five experiments were conducted and carried out to study and explore the project Pathogenesis of Salmonellosis with respect to carrier states in poultry and its public health impact."
For this purpose, in the 1st phase, identification, isolation and characterization of Salmonella enteritidis and Salmonella typhimurium was attempted. It was followed by the estimation of LD 50 and carrier states and histopathological study at different phases of disease in broiler chickens experimentally infected with Salmonella enteritidis and Salmonella typhimurium to ascertain the nature of carrier states in terms of maintenance of the Salmonellae by different organs leading to histopathological changes and finally to the stage of shedding of the organism through the feces in the environment. Dissemination to human beings and the Public health impact of Salmonellosis was studied in the human subjects who consumed the meat and eggs of the carrier birds which were followed by testing their stool and blood samples through polymerase chain reaction (PCR). In this way the pathogenesis and chain of Salmonellas enteritidis and Salmonella typhimurium infection through poultry feed, meat, eggs and humans beings was transmissible. However, the humans were considered as dead end host. It was concluded that Salmonella enteritidis and Salmonella typhimurium was maintained in the large intestine of the poultry and has transmitted from poultry feed, poultry meat and poultry eggs to human beings and thus, causing typhoid fever and food poisoning.
RECOMMENDATIONS /SUGGESTIONS
Major aim of this research endeavour was to help in understanding the basic principles involved in the chain of infectious cycle of SalmoneUosis. In addition to that the application of the quality control of poultry products with respect to Salmonella infection to broiler chicks and broiler meat available in the market for human consumption is the ultimate goal of this project. The objective was to reduce the risk of Salmonellosis in poultry and humans. The following measures are suggested.
1. PREVENTION AND CONTROL OF SALMONELLOSIS IN POULTRY! ANIMALS
A. Monitoring
o The poultry and their environment should be monitored by frequente testing of Salmonellae.
o Bacteriological profile of poultry house environment.
o Serological testing of flock and removal of infected birds.
o Culturing of tissues from selected birds.
o Egg sheils, egg albumin & egg yolk culturing.
B. Hygiene and Sanitation
o Eggs from infected layer flocks should be pasteurized before consumption.
o Salmonella positive breeder flocks should be given pellet feed.
o Hatching sanitation
o Proper disinfection of hatching eggs.
o Proper sanitation and disinfection of farm premises.
o The provision of salmonella-free feed i.e pellet feed is of prime importance for the prevention of salmonella infections of poultry flocks and parent flocks.
o Control of rodent, insects and wild birds
C. Managemental
o For routine treatment of eggs and progeny, only those antibiotics should be used that do not cause microbial resistance against drugs widely used in humans
o Resistance of Campylobacter spp, and Salmonella spp. to fluoroquinolones has become a public health risk. This does not exclude well targeted and transient use of antibiotics as essential measures in salmonellosis control programmes.
o Vaccination of breeder flock is recommended for decrease of the salmonella infection pressure.
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1. MEASURES FOR THE PREVENTION AND CONTROL OF SALMONELLOSIS IN HUMANS
A. Meat and Eggs
o Wrap fresh meat in plastic bags at the market to prevent blood from1 dripping on other foods.
o Cook poultry products at temperature of 170°F for breast meat and at 180°F for thigh meat.
o Avoid eating raw or under cooked meat and egg.
o Cook poultry meat and egg thoroughly.
o Purchase only inspected grade AA eggs and animal food products.
o Handle raw eggs carefully:
o Keep eggs refrigerated
o Throw away cracked or dirty eggs.
o Do not eat half fried and half boiled eggs.
o Wash hands immediately after handling raw poultry or raw eggs.
o Full fried and full boiled eggs should be used for eating to prevent food borne Salmonellosis problem.
b. PERSONNEL HYGIENE MEASURES
o Washing of hands with soap and warm water before and after handling foods, after using the bath rooms.
o Refrigerate foods properly.
- Use bleach to wash cutting boards and counters used for preparation immediately after use to avoid cross contamination of other foods.
o People who have Salmonellosis should not prepare food for others.
o Educate the food handlers and persons who prepare food. Educational programmes covering pre- and post harvest food safety procedures, especially salmonella control, should be initiated in the animal and food production sectors for the public awareness.
Availability: Items available for loan: UVAS Library [Call number: 0938,T] (1).
2.
Pathobiological Investigations Of Peste Des Petits Ruminants (Ppr) Virus With Reference To Antiviral Activity Of Nigella Sativa (Black Seed)
by Kiran Aqil (2008-VA-456) | Dr. Muti Ur Rehman Khan | Prof. Dr. Asim Aslam | Dr. Aqeel Javeed.
Material type: ; Literary form:
not fiction
Publisher: 2017Dissertation note: Peste des Petits Ruminants (PPR) is a highly contagious, infectious, acute or sub-acute transboundary viral disease of domestic and wild small ruminants. It is an economically important viral disease of sheep and goats causing varying degree of morbidity and mortality in susceptible animals which may be as high as 100 and 90 per cent, respectively. PPR is responsible for serious socioeconomic problems. There is no data available regarding pathogenesis and field virus characterization to compare it with vaccinal strain for any difference. Nigella sativa(Black Seed) has antiviral activity against many viruses. Therefore present studywas undertaken to investigate the antiviral effect of Black Seed in vivo and in vitro against PPR virus. Further more time course detection of virus is still needed to be studied.
Nigella sativa (Black seed) has antiviral activity against PPR virus.
Pathogenesis can better be studied through histopathology, necropcy findings and morphometric changes.
A total of 250 clinically positive samples suspected for PPR virus were included in the study. Samples were consisted of nasal, ocular and anal swabs; whole blood in EDTA were collected from suspected animals. In case of mortality morbid material included lungs, liver, spleen and mysenteric lymph nodes were included in the study. Samples were subjected to immune capture Elisa for detection of viral antigen in suspected samples. Samples which found positive foe IC – Elisa were then subjected to RT-PCR for confirmation of virus. After confirmation of virus through IC – Elisa and RT-PCR the positive samples were subjected to virus isolation on vero cell. After isolation of virus, the TCID 50 of the virus was calculated for preparation of inoculum for further use. In this experiment mesenteric lymph nodes and spleen found to be major organ for isolation of PPRV.RT-PCR found to be most reliable and confirmatory diagnostic test for PPRV. Field Virus adaptation on vero cells found to be difficult to optimize.
In this experiment antiviral activity of black seed was checked on vero cells infected with PPRV. Three extracts of N. Sativa were prepared to check the in vitro antiviral activity of black seed. In this study poly saccharides extracted from black seed found to be more effective against PPRV. Adaptation of field virus was done on Vero cell line. Antiviral activity of Black Seed extract was determined in vitro on Vero cell on bases of CPE (Cytopathic effect). The ethanolic and aqueous extract were found to be more toxic to consistency of monolayer of vero cells. The TCID50 of virus was calculated after treating cells with different extracts. In this study poly saccharides extract exhibit lower TCID50‘s as compared to ethanolic and aqueous extract which showed higher TCID50’s.So less cytopethic effect was observed in vero cells treated with black seed extracts. Antiviral activity was determined on base of CPE.
Pathogenesis of virus in natural host was studied through time course detection of virus in body secretions, blood, organs. Histopathological changes were studied.20 goats were procured from market divided into four groups (n=5) A,B,C and D. In animals of group A prophylactic effect of N.Sativa was studied. In group B complete pathogenesis of PPR virus was studied without any prophylactic or therapeutic measure. In group C therapeutic effect of N. Sativa was studied after onset of clinical picture of disease. At the end of this experiment, clinical picture, gross pathology, histopathology, and morphometric changes revealed that N. Sativa has noticeable prophylactic effect on PPR infected goats. It can be used as a therapeutic agent in PPR infected goats but it can’t control pathological effect of virus after onset of infection.
SUMMARY
130
Data collected were statistically analyzed by using Microsoft Excel (Microsoft Excel, 2007) and SPSS (for Windows, Version 16.0). The data were put the descriptive analysis and Chi square test was employed to test the significance and test of hypotheses
It was concluded that Black Seed therapy possessed marvelous prophylective effect against PPR virus and RT-PCR was the most efficient methodology to confirm the virus. Availability: Items available for loan: UVAS Library [Call number: 2890-T] (1).
