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Papers by Truls Nesbakken
Improving the Safety of Fresh Meat, 2005
This chapter focuses on the biological pathogens in animals. It discusses only a selection of the... more This chapter focuses on the biological pathogens in animals. It discusses only a selection of the zoonotic agents. The most important zoonotic pathogenic bacteria in food-producing animals are: Salmonella spp. ; Verotoxin (VT) producing Escherichia coli (EC) (VTEC), particularly in cattle and sheep; Campylobacter jejuni , often in poultry; Yersinia enterocolitica , usually in pigs; Listeria monocytogenes , mainly in cattle and sheep; and Staphylococcus aureus, on hide, skin, and in udder. Among the zoonotic parasites, listed in this chapter are: Cryptosporidium , a small intracellular protozoan in the intestinal tract of young cattle; Toxoplasma , a coccidian parasite with zoonotic significance as cysts in the muscles of sheep and pigs; the coccidian parasite, Sarcocystis , in the muscles of cattle and pigs; Trichinella , a historically important parasitic nematode that can occur as a reservoir of larvae in the muscles of pigs and horses; the infective intermediate stadiums of the tapeworms, Taenia saginata in the muscles of cattle ( Cysticercus bovis ) and cysts of Taenia solium in muscles of pigs.
Nordisk veterinaermedicin, 1976
Weekly milk samples were taken from mammary halves from 30 goats from 8 different herds each with... more Weekly milk samples were taken from mammary halves from 30 goats from 8 different herds each with from 2 to 5 experimental animals throughout their lactation periods. The physiological variations in the cell counts of goats milk during lactation were investigated by a projection microscope. Only small variations were found in the average cell counts in milk samples from goats in the same herd, but big variations from one herd to another (Table I and Fig. 3.). The curves of the average cell counts in milk samples of 5 herds showed a rise at the beginning of the season at pasture (Fig. 1 and Fig. 2). Also in the housed periods the cell count showed transitory rises. The herd with the lowest average cell count (220,000/ml) was milked by an ordinary bucket milking system, while the herd with the highest average cell count (1,490,000/ml) was milked by a pipeline milking system. Five herds milked by machine had an average cell count of 720,000/ml and three herds milked by hand 540,000/ml....
Nordisk veterinaermedicin, 1978
The cell counts in milk of goats seem to vary quite a lot. It is difficult to diagnose mastitis i... more The cell counts in milk of goats seem to vary quite a lot. It is difficult to diagnose mastitis in goats using only cell counts as a criterion. Clinical symptoms correlated with bacteriology and differences in the cell counts of milk samples from the two halves are probably the criteria of choice in the laboratory mastitis diagnosis in goats.
Nordisk veterinaermedicin, 1978
A case of mastitis in a goat caused by S. aureus is described. Cytological and bacteriological ex... more A case of mastitis in a goat caused by S. aureus is described. Cytological and bacteriological examinations of milk samples throughout the entire lactation period were made. The average cell counts/ml in millions in milk samples were 6,12 (right half with mastitis) and 0,51 (left half which was normal) throughout the entire lactation period.
Advances in Microbial Food Safety, 2015
Advances in Microbial Food Safety, 2015
Abstract: The evolution, pathogenicity, detection, epidemiology and control of Yersinia enterocol... more Abstract: The evolution, pathogenicity, detection, epidemiology and control of Yersinia enterocolitica and Yersinia pseudotuberculosis as foodborne pathogens are reviewed. A strong correlation between the pathogenic bio/serotypes of Y. enterocolitica isolated from humans and pigs in the same geographical region, and the ability of Y. enterocolitica to propagate at refrigeration temperatures, is noted and the implications for control of this pathogen in the whole food chain are discussed. The possibility for establishing health and breeding pyramids of pig herds free from Y. enterocolitica is explored. Abattoir procedures, including enclosure of the anus into a plastic bag after rectum-loosening and hygienic handling of the head are highlighted as important factors to avoid contamination of carcasses.
Emerging foodborne pathogens, 2006
Emerging Foodborne Pathogens, 2006
Nordisk veterinaermedicin
On the basis of two experiments on the storage of raw shrimps (Pandalus borealis) in ice and on s... more On the basis of two experiments on the storage of raw shrimps (Pandalus borealis) in ice and on samples taken out from different trawlers after different days at sea, we have attempted to find the criteria of choice for the lower limit of quality of raw shrimps which are meant for further processing for human consumption. A content of TVN of approximately 50 mg/100 g peeled shrimp and a content of TMA-N of approximately 10 mg/100 g peeled shrimp probably represent such an objective lower limit if a comparison with organoleptic assessment is made. Assuming suitable storage conditions, this corresponds to a maximum period of 7 days. In this paper we have also attempted to find the content of TMAO in fresh raw shrimps from different fishing grounds in the Barents sea and off the Eastern coast of Greenland. The content of TMA-N was found to vary from 166 to 211 mg/100 g peeled shrimp.
Nordisk veterinaermedicin, 1975
An acute case of bovine mastitis caused by clostridium perfringens type A is described. The condi... more An acute case of bovine mastitis caused by clostridium perfringens type A is described. The condition appeared before delivery and was characterised by gas formation in the udder and severe general signs. In spite of parenteral treatment with large doses of penicillin and streptomycin combined with frequent stripping of the udder the animal died two days after the onset of symptoms. The strain isolated proved sensitive to penicillin, chloramphenicol and tetracyclin, but resistant to streptomycin and sulphonamides.
Zoonoses and public health, 2015
As Specific Pathogen-Free (SPF) pig herds are designed and managed to prevent specific pig diseas... more As Specific Pathogen-Free (SPF) pig herds are designed and managed to prevent specific pig diseases, it might be feasible to expand the list of micro-organisms also including zoonotic pathogens such as Campylobacter coli as this agent has its origin in pigs. In a previous survey, 15 of 16 of SPF herds were found free from human pathogenic Yersinia enterocolitica. Accordingly, three nucleus and seven multiplying herds were surveyed for Campylobacter to investigate whether the Norwegian SPF pig pyramid also might be free from this agent. In conclusion, the intervention of Campylobacter at the herd level might be possible as four of 10 SPF herds tested negative in two sets of samples from both autumn 2008 and summer/early autumn 2010. The four negative herds were all located in remote areas several kilometres away from conventional pig farming while the positive SPF farms were all situated in neighbourhoods with conventional pig production. It seems more difficult to control Campylobac...
Contributions to microbiology and immunology, 1995
Contributions to microbiology and immunology, 1987
Contributions to microbiology and immunology, 1991
Zoonoses and Public Health, 2013
Impacts • Trichinella spp., Toxoplasma gondii, Salmonella and Leptospira spp. are the most import... more Impacts • Trichinella spp., Toxoplasma gondii, Salmonella and Leptospira spp. are the most important zoonotic agents in marine mammal meat. In addition, botulism remains a threat among native populations in the Arctic. • Mycoplasma spp., but also parapoxvirus and Mycobacterium spp., are important occupational risks for people handling marine mammals and marine mammal products. • Critical hygiene points in killing, dressing, and storage on board, as well as data gaps regarding hygiene control measures of marine mammal meat are identified.
Improving the Safety of Fresh Meat, 2005
This chapter focuses on the biological pathogens in animals. It discusses only a selection of the... more This chapter focuses on the biological pathogens in animals. It discusses only a selection of the zoonotic agents. The most important zoonotic pathogenic bacteria in food-producing animals are: Salmonella spp. ; Verotoxin (VT) producing Escherichia coli (EC) (VTEC), particularly in cattle and sheep; Campylobacter jejuni , often in poultry; Yersinia enterocolitica , usually in pigs; Listeria monocytogenes , mainly in cattle and sheep; and Staphylococcus aureus, on hide, skin, and in udder. Among the zoonotic parasites, listed in this chapter are: Cryptosporidium , a small intracellular protozoan in the intestinal tract of young cattle; Toxoplasma , a coccidian parasite with zoonotic significance as cysts in the muscles of sheep and pigs; the coccidian parasite, Sarcocystis , in the muscles of cattle and pigs; Trichinella , a historically important parasitic nematode that can occur as a reservoir of larvae in the muscles of pigs and horses; the infective intermediate stadiums of the tapeworms, Taenia saginata in the muscles of cattle ( Cysticercus bovis ) and cysts of Taenia solium in muscles of pigs.
Nordisk veterinaermedicin, 1976
Weekly milk samples were taken from mammary halves from 30 goats from 8 different herds each with... more Weekly milk samples were taken from mammary halves from 30 goats from 8 different herds each with from 2 to 5 experimental animals throughout their lactation periods. The physiological variations in the cell counts of goats milk during lactation were investigated by a projection microscope. Only small variations were found in the average cell counts in milk samples from goats in the same herd, but big variations from one herd to another (Table I and Fig. 3.). The curves of the average cell counts in milk samples of 5 herds showed a rise at the beginning of the season at pasture (Fig. 1 and Fig. 2). Also in the housed periods the cell count showed transitory rises. The herd with the lowest average cell count (220,000/ml) was milked by an ordinary bucket milking system, while the herd with the highest average cell count (1,490,000/ml) was milked by a pipeline milking system. Five herds milked by machine had an average cell count of 720,000/ml and three herds milked by hand 540,000/ml....
Nordisk veterinaermedicin, 1978
The cell counts in milk of goats seem to vary quite a lot. It is difficult to diagnose mastitis i... more The cell counts in milk of goats seem to vary quite a lot. It is difficult to diagnose mastitis in goats using only cell counts as a criterion. Clinical symptoms correlated with bacteriology and differences in the cell counts of milk samples from the two halves are probably the criteria of choice in the laboratory mastitis diagnosis in goats.
Nordisk veterinaermedicin, 1978
A case of mastitis in a goat caused by S. aureus is described. Cytological and bacteriological ex... more A case of mastitis in a goat caused by S. aureus is described. Cytological and bacteriological examinations of milk samples throughout the entire lactation period were made. The average cell counts/ml in millions in milk samples were 6,12 (right half with mastitis) and 0,51 (left half which was normal) throughout the entire lactation period.
Advances in Microbial Food Safety, 2015
Advances in Microbial Food Safety, 2015
Abstract: The evolution, pathogenicity, detection, epidemiology and control of Yersinia enterocol... more Abstract: The evolution, pathogenicity, detection, epidemiology and control of Yersinia enterocolitica and Yersinia pseudotuberculosis as foodborne pathogens are reviewed. A strong correlation between the pathogenic bio/serotypes of Y. enterocolitica isolated from humans and pigs in the same geographical region, and the ability of Y. enterocolitica to propagate at refrigeration temperatures, is noted and the implications for control of this pathogen in the whole food chain are discussed. The possibility for establishing health and breeding pyramids of pig herds free from Y. enterocolitica is explored. Abattoir procedures, including enclosure of the anus into a plastic bag after rectum-loosening and hygienic handling of the head are highlighted as important factors to avoid contamination of carcasses.
Emerging foodborne pathogens, 2006
Emerging Foodborne Pathogens, 2006
Nordisk veterinaermedicin
On the basis of two experiments on the storage of raw shrimps (Pandalus borealis) in ice and on s... more On the basis of two experiments on the storage of raw shrimps (Pandalus borealis) in ice and on samples taken out from different trawlers after different days at sea, we have attempted to find the criteria of choice for the lower limit of quality of raw shrimps which are meant for further processing for human consumption. A content of TVN of approximately 50 mg/100 g peeled shrimp and a content of TMA-N of approximately 10 mg/100 g peeled shrimp probably represent such an objective lower limit if a comparison with organoleptic assessment is made. Assuming suitable storage conditions, this corresponds to a maximum period of 7 days. In this paper we have also attempted to find the content of TMAO in fresh raw shrimps from different fishing grounds in the Barents sea and off the Eastern coast of Greenland. The content of TMA-N was found to vary from 166 to 211 mg/100 g peeled shrimp.
Nordisk veterinaermedicin, 1975
An acute case of bovine mastitis caused by clostridium perfringens type A is described. The condi... more An acute case of bovine mastitis caused by clostridium perfringens type A is described. The condition appeared before delivery and was characterised by gas formation in the udder and severe general signs. In spite of parenteral treatment with large doses of penicillin and streptomycin combined with frequent stripping of the udder the animal died two days after the onset of symptoms. The strain isolated proved sensitive to penicillin, chloramphenicol and tetracyclin, but resistant to streptomycin and sulphonamides.
Zoonoses and public health, 2015
As Specific Pathogen-Free (SPF) pig herds are designed and managed to prevent specific pig diseas... more As Specific Pathogen-Free (SPF) pig herds are designed and managed to prevent specific pig diseases, it might be feasible to expand the list of micro-organisms also including zoonotic pathogens such as Campylobacter coli as this agent has its origin in pigs. In a previous survey, 15 of 16 of SPF herds were found free from human pathogenic Yersinia enterocolitica. Accordingly, three nucleus and seven multiplying herds were surveyed for Campylobacter to investigate whether the Norwegian SPF pig pyramid also might be free from this agent. In conclusion, the intervention of Campylobacter at the herd level might be possible as four of 10 SPF herds tested negative in two sets of samples from both autumn 2008 and summer/early autumn 2010. The four negative herds were all located in remote areas several kilometres away from conventional pig farming while the positive SPF farms were all situated in neighbourhoods with conventional pig production. It seems more difficult to control Campylobac...
Contributions to microbiology and immunology, 1995
Contributions to microbiology and immunology, 1987
Contributions to microbiology and immunology, 1991
Zoonoses and Public Health, 2013
Impacts • Trichinella spp., Toxoplasma gondii, Salmonella and Leptospira spp. are the most import... more Impacts • Trichinella spp., Toxoplasma gondii, Salmonella and Leptospira spp. are the most important zoonotic agents in marine mammal meat. In addition, botulism remains a threat among native populations in the Arctic. • Mycoplasma spp., but also parapoxvirus and Mycobacterium spp., are important occupational risks for people handling marine mammals and marine mammal products. • Critical hygiene points in killing, dressing, and storage on board, as well as data gaps regarding hygiene control measures of marine mammal meat are identified.