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.
7
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.
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2.
Surveillance Of Tuberculosis In Buffaloes, Cattle And Derectton Of Mycobacterium Bovis And Mycobacterium Tuberculosis in Food of Animal Origin
by Muhammad Yasin Tipu | Prof. Dr. Zafar Iqbal Chaudhry | Dr. Muhammad Younus | Prof. Dr.
Material type: ; Format:
print
; Literary form:
not fiction
Publisher: 2010Dissertation note: The main objectives of this study were: to survey the prevalence of TB infection in livestock and their products in Pakistan; to standardize PCR based techniques for the detection of TB in buffaloes, cattle and animal products (milk and meat) as presently no such system has been developed for the detection of TB in animals and their products in Pakistan; to evaluate improved tests for the differentiation of Mycobacterium complex isolates in cattle, buffaloes and animal food products and to compare modern and conventional methods for rapid diagnosis of the Mycobacterial spp. The study was performed in different experiments to have surveillance of tuberculosis in Buffaloes and Cattle; and to detect the presence of different Mycobacteria in animal food products. One thousand animals from different areas of Lahore District were screened with the tuberculin test. The milk and blood of tuberculin tested animals were further studied for the presence of Mycobacterial spp. by conventional methods as well as Polymerase Chain Reaction (PCR). In other experiments one hundred market milk samples and ten thousand five hundred tissue samples from twenty-one hundred carcasses at Lahore slaughter house were screened with conventional microbiological tests and multiplex PCR for differentiation of Mycobacterium species. The results indicated that PCR had more sensitivity and required less time to detect and differentiate different Mycobacterial species as compared to conventional methods. It was also noted that M. bovis were found in milk and blood of milking animals as well as tissue sample collected from Lahore slaughter house. On the basis of findings, regular monitoring of the milking animals, animals to be slaughtered, and workers handling these animals is suggested. It is also recommended to review the current slaughter act to prevent the slaughtering of TB affected animals.
Availability: Items available for loan: UVAS Library [Call number: 1321,T] (1).
3.
Isolation, Characterization And Pathogenesis Of Capripox Virus
by Abdul Sajid | Prof. Dr. Zafar Iqbal Chaudhry | Dr. Aftab | Prof. Dr. Azhar Maqbool.
Material type: ; Format:
print
; Nature of contents: ; Literary form: Publisher: 2010Dissertation note: Goat pox is the most important pox diseases of livestock and it usually
causes huge economic losses. The economic losses occur in terms of mortality,
reduced productivity and lower quality of wool and leather. The clinical
manifestations of the disease include high temperature, lesions skin in the form of
macules, papules, vesicles, pustule and scabs on hairless areas of the body. The
disease is highly contagious having high morbidity and mortality in the infected
herds. The present study was conducted to document the prevalence of goat pox
disease in the different regions of Punjab. The study was based on clinical
manifestation of the disease in various collecting spots including slaughter houses,
cattle and hide markets and tanneries. The prevalence of goat pox at slaughter
houses in different regions was 9.93% in arid region followed by 8.69% and 7% in
southern and northern irrigated regions respectively. The prevalence of pox disease
in sheep was highest (8.54%) in the northern irrigated region, 7.69% and 6.62% in
arid and southern irrigated regions respectively.
The prevalence of pox recorded in the hide markets shows a trend of high
presence 7.29% in arid region followed by 6.22% and 3.84% in southern and
northern irrigated regions. Whereas in sheep the overall prevalence was 0.51 %,
4.44% and 1.66% in northern irrigated, arid and southern irrigated regions.
In tanneries the pox lesions were identified on the basis of method as
adopted in hide markets. The overall prevalence of pox in goat was 3.96%, 4.06%
and 4.09% while in sheep 9.58%, 2.41 % and 10% in northern irrigated, arid and
southern irrigated regions.
The overall prevalence of pox disease in goat was 5%, 5.79% and 5.34% in
Northern irrigated, arid and southern irrigated regions respectively. Where as in
sheep, pox was 3.133%, 4.11 % and 2.67% in Northern irrigated, arid and southern
irrigated regions respectively. The highest trend of incidence of disease was present
in the arid regions followed by southern and northern regions. The slaughter houses
shows high incidence of disease as compared to cattle and hide market and
tanneries. The result was significant (P<0.05) among the regions and samples
collecting spots.
A total of 100 samples consisting of 55 scabs and 45 skin tissues were
randomly selected from the different collecting spots of the three regions. The scabs
and skin tissue samples were processed on dehydrated minimum essential media
tor virus isolation. The virus was isolated on Vero cell line culture and its
characteristics were observed on the basis of specific cytopathic effects. All 55 scab
samples consisting 20 from cattle markets, 20 from slaughter house and 15 from
hide market and tannery were tested through cell culture. The cell culture positive
result for scabs was 60% cattle markets, 20% hide market and tannery and 40%
slaughter house.
All 45 skin tissue samples including 5 from cattle markets and tannery, 20
from hide market and 20 from slaughter house were subjected to virus isolation on
Vero cell line. The cell culture positive result for skin tissue samples was 100% cattle
markets, 30% hide market and tannery and 60% slaughter house. In this way the
total cell culture result for scabs and skin tissue samples from all areas become
41.82% and 51.11 % respectively.
The isolated virus was confirmed through peR. All the collected samples
were also analyzed through peR in order to compare the two techniques for disease
diagnosis. Out of 40 samples from slaughter houses 18 scabs and 15 tissues
sample were positive through peR with 82.5%. Out of 25 samples collected from
cattle markets consisting of 20 scabs and 5 skin tissues, 17 of scabs and 5 skin
tissues were positive with 92%.
Similarly a total of 35 samples out of which 15 were scabs and 20 were skin
tissues collected from hide markets and tanneries. The peR of 7 scabs and 14 skin
tissues was positive with 60%. In this way the total peR result for scabs and skin
tissue from all areas was 42% and 34% respectively.
In the 3rd study of the present project the isolated virus was inoculated in to
experimental animal to study the detail pathogenesis. The disease followed the
same pattern as in the natural outbreak. But however the routes of inoculation affect
the severity of the disease. During the study the diseased animals were periodically
slaughter at weekly interval after the appearance of 1 st clinical signs. The detailed
lesions were observed in different visceral organs and the tissues were collected
and preserved in 10% formalin. The tissues were processed for histopathology and
immunohistochemical examination. The IHC was successfully optimized for the
detection of viral antigen in the tissues of skin, lung and lymph nodes.
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4.
Toxicity Problems Associated With Declofenac In Avaian Species And Its Substitute
by Muhammad Ramzan | Dr. Haji Ahmad Hashmi | Dr. Zafar Iqbal Chaudhry | Prof. Dr. Talat.
Material type: ; Format:
print
; Literary form:
drama
Publisher: 2010Dissertation note: A catastrophic decline in vulture populations was first observed in 1996-97 in Keoladeo National Park, Bharatpur, Rajasthan, India. Later, similar situations were reported in many south Asian countries including Pakistan, Nepal and Bangladesh. Now, the International Union for the Conservation of Nature (IUCN) has listed three vulture species i.e. Gyps bengalensis, Gyps indicus and Gyps tenuirostris as 'critically endangered'.
Vultures are natural scavengers and play a key role in keeping the environment clean by consuming carcasses of dead livestock and wildlife. The unconsumed animal carcasses pose a serious threat to both human and animal health because decaying animal carcasses may contaminate groundwater and become a potential source of diseases such as tuberculosis and anthrax for humans and other animals. Also, due to the declines in vulture populations, a rise in the numbers of other scavengers like dogs has been observed. Therefore, the risk of dog bite and transmission of dangerous diseases, including rabies, has also increased. Furthermore, vultures play a vital role in the disposal of human corpses of the followers of the Parsi religion because they place their dead bodies before vultures for disposal rather burial beneath the earth.
In the South Asian region, different communities have different attitudes toward the use of meat and its products. For example, Muslims do not use meat of dead animals, whereas Hindus abstain from cow's meat altogether because of religious bindings. For many centuries, the disposal of such meat has been done by vultures.
The vulture population decline issue was investigated by researchers with the support of various international organizations dedicated to bird conservation in collaboration with regional ornithological societies. Scientists looked into the problem from different angles and considered a variety of reasons of this decline. These included food shortages, losses of habitat, persecution, human disturbances, infectious agents, environmental contaminants, intentional poisoning, and accidental poisoning through food or water. Initially, the outbreak of some infectious disease and/or poisoning appeared to be the most plausible basis of this crisis. Recent studies have ruled out presence of a widespread infection and have focused on some form of poisoning. Now, it is believed that diclofenac, a veterinary drug, was responsible for the huge fatalities in vultures, in part because the onset of the crisis was coincident with the introduction of this drug in veterinary practice.
Diclofenac belongs to a class of drugs called, non-steroidal anti-inflammatory drugs (NSAIDs). Diclofenac served as an effective analgesic (pain killer), antipyretic (reduces fever), and anti-inflammatory (reduces swelling) drug. Initially, this drug was used in human beings for various indications such as arthritis. The use of diclofenac was started in domestic animals in the region a decade ago. It was reported that the presence of diclofenac in the bodies of dead animals that had been treated with this drug shortly before death was harming the vultures feeding on contaminated carcasses (Oaks et al., 2004; Shultz et al., 2004; Swan et al., 2005).
The Department of Pharmacology and Toxicology, at the University of Veterinary and Animal Sciences, Lahore, has been given the task to investigate this problem. A series of experiments was conducted to study the likely causes of this problem and, if possible, find its solution by developing safer and efficacious alternatives to diclofenac for the treatment of animals. For this purpose, a chicken experimental model was developed to study the toxicity of diclofenac and other NSAIDs. These studies have shown that diclofenac produced similar toxic effects and mortalities in broiler chickens as had been reported from studies of diclofenac-poisoned vultures. Later on, therapeutic efficacy studies of safer alternative NSAIDs of diclofenac were conducted in horses, buffaloes.
On the basis of these current studies, it was concluded that diclofenac was toxic to chickens and no significant difference was present in the death rates in bird groups treated with toxic doses of diclofenac via oral and intramuscular routes. Sodium and potassium salts of diclofenac caused comparable casualties in broiler chickens (unpublished study). A number of other NSAIDs were screened for their toxicity profile using the chicken model. This study showed that phenylbutazone, dipyrone, meloxicam, piroxicam and ketoprofen were comparatively safer than diclofenac. However, phenylbutazone and dipyrone may not be appropriate alternatives for diclofenac in food-producing animals because they are known to cause a condition called agranulocytosis in human and animals. Agranulocytosis involves marked reductions in numbers of white blood cells that are responsible for maintaining the body's immunity against various diseases.
To evaluate the efficacy of safer drugs, fever was induced in buffalo calves with Escherichia coli endotoxin (lipopolysaccharide), and the animals were then treated them with ketoprofen, meloxicam orpiroxicam. Although, all three drugs were effective in lowering body temperature, ketoprofen was the most efficient. In another experiment, these drugs were used in the treatment of lameness in horses, and it was concluded that meloxicam was more effective followed by piroxicam and ketoprofen for the treatment of this particular problem.
Based on these observations, it is concluded that ketoprofen, meloxicam and piroxicam may prove quite safe drugs for the scavenging birds and may be used as safe alternatives to diclofenac in veterinary practice. It has been observed during this study that ketoprofen, piroxicam, and meloxicam are less toxic for broiler chickens and may prove better alternates to be used in place of diclofenac in animals. The use of these NSAIDs may be less toxic for scavenger birds. The commercial preparations of ketoprofen and meloxicam for veterinary use are available at least in two south-east Asian countries i.e. Pakistan and India. The prices of these NSAIDs are comparable with those of the veterinary preparations of diclofenac which were previously available in the region. On the basis of results of this study it is concluded that ketoprofen, piroxicam, and meloxicam are effective NSAIDs in domestic animals, hence may replace diclofenac in veterinary practice.
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