Concentration and prevalence of Escherichia coli O157 and Salmonella serotypes in sheep during slaughter at two Australian abattoirs     

LL Duffy  A Small  N Fegan 《Australian veterinary journal》2010,88(10):399-404

Objective This study aimed to determine the presence and concentration of Escherichia coli O157 and Salmonella spp. on fleece, faeces and carcases of sheep during slaughter. Procedure Faeces, fleece and pre-chill carcase samples were collected from 164 sheep slaughtered at two Australian abattoirs. The presence of E. coli O157 and Salmonella spp. were determined by use of automated immunomagnetic separation (AIMS) with enumeration by use of the ‘most probable number’ (MPN) method. Results Escherichia coli O157 was isolated from 5% of faeces, 3% of fleeces and 0.6% of pre-chill carcases. The mean log₁₀ count of E. coli O157 positive faecal samples was 2.32 MPN/g, but counts on fleeces and carcases were below the countable limit (−1 log₁₀ MPN/cm²). Salmonella spp. were isolated from 20% of faeces, 13% of fleeces and 1.3% of pre-chill carcases. The mean log₁₀ count of Salmonella spp. in faeces was 1.43 MPN/g and on fleece was −0.24 MPN/cm², but counts on carcases were below the countable limit (−1 log₁₀ MPN/cm²). Conclusion The prevalence and concentration of pathogens were low in the sheep tested in this study, indicating a low risk of human infection from products derived from these animals.  相似文献   

Effects of racing on lymphocyte proliferation in horses     

Nesse LL  Johansen GI  Blom AK 《American journal of veterinary research》2002,63(4):528-530

OBJECTIVE: To measure the lymphocyte proliferation response in horses 12 to 16 hours after completion of a race. ANIMALS: 8 Thoroughbreds that competed in 14 races and 3 control Thoroughbreds that did not race. PROCEDURE: Horses participated in races during the late afternoon or evening. Venous blood samples were collected on a morning before a race (1 or 2 days before the race or on the day of the race), on the afternoon of a race (40 to 60 minutes after the race), and on the morning of the day after a race (12 to 16 hours after the race). Lymphocyte proliferation responses and WBC count were measured in samples obtained in the mornings. Plasma cortisol was measured in all samples. RESULTS: Lymphocyte proliferation responses were significantly reduced and WBC counts significantly increased 12 to 16 hours after a race. Plasma cortisol concentrations were significantly increased 40 to 60 minutes after a race. In samples from the control horses, lymphocyte proliferation responses, WBC counts, or plasma cortisol concentrations did not differ significantly among time periods. CONCLUSIONS AND CLINICAL RELEVANCE: A decrease in proliferative responses of circulating lymphocytes can be found as late as 12 to 16 hours after a horse participates in a race. Although the clinical consequences of these exercise-related alterations of the immune response are not yet known, managers of horses should take into account that the immune system of a horse may be affected by racing.  相似文献   

No evidence of vertical transmission of naturally acquired feline immunodeficiency virus infection.     

K Ueland  L L Nesse 《Veterinary immunology and immunopathology》1992,33(4):301-308

A naturally occurring feline immunodeficiency virus (FIV) infection in a closed breeding colony of cats, was studied for a period of 9 months. The colony consisted of 25 adult cats, of which six proved to be infected with FIV as judged by serological examination and virus isolation. In all, 48 kittens were monitored for levels of antibodies against FIV during their first 6 months of life. All the kittens (n = 30) born of FIV-infected queens showed maternal antibodies against FIV, although these declined to undetectable levels by the age of 5 months. Antibodies against FIV were not shown in any of 18 kittens born of FIV-negative queens. An attempt to isolate the virus from 12 kittens between 2 and 6 weeks of age did not succeed. None of the cats in the colony seroconverted during the observation period. In conclusion, neither vertical nor horizontal transmission of FIV infection were demonstrated in the colony during the 9-month investigation period.  相似文献   

Technical note: use of laser diffraction for particle size distribution measurements in duodenal digesta     

Olaisen V  Nesse N  Volden H 《Journal of animal science》2001,79(3):761-765

Duodenal samples from three lactating cows were used to measure the particle size distribution by wet sieving and by laser diffraction (LD). The median particle size was calculated in the size range where the methods overlapped, and the median particle size was not different between the methods (P = 0.98). The particle size data were also fitted to a log normal distribution function. The logarithmic mean particle size (log10mean) tended to be larger for wet sieving (P = 0.06), and the logarithmic standard deviation (log10SD) was similar for the two methods (P = 0.32). In addition, duodenal samples from the same three animals were fractionated into five different size classes by wet sieving. Particle size distributions were measured by LD and by microscopic image analysis (MIA) for each of the size classes. The log10mean particle size calculated by LD was inside the sieve size range of the four smallest size classes. Log10mean particle size calculated by LD was smaller than log10mean calculated by MIA for two size classes (106 to 300 microm and 300 to 600 microm), and LD gave generally broader particle size distributions than MIA. This study showed that duodenal particle size distributions measured by LD and wet sieving were similar and LD is therefore an alternative method for particle size distribution measurements in postruminal digesta.  相似文献   

The influence of haemocyte number on the resistance of the freshwater crayfish, Pacifastacus leniusculus Dana, to the parasitic fungus Aphanomyces astaci     

M. PERSSON  L. CERENIUS  K. SÖDERHÄLL 《Journal of fish diseases》1987,10(6):471-477

Abstract. The number of circulating haemocytes in crayfish, Pacifastacus leniusculus Dana, was reduced after injection of yeast cell walls (Zymosan) into the animals. Crayfish harbouring the parasitic fungus A. astaci as a 'latent' infection in melanized areas in the cuticle died due to unrestricted growth of unmelanized hyphae when they were injected with Zymosan. The β–1,3–gIucan laminaran, introduced into the haemocoel of P. leniusculus harbouring A. astaci hyphae in the cuticle, also caused a decrease in the total haemocyte counts (THC), but these animals survived the treatment and no unmelanized hyphae of A, astaci were found. The recovery of THC was found to be more rapid after laminaran injection than after Zymosan injection, which could explain why laminaran treated crayfish retained their resistance and could combat the A. astaci hyphae in the cuticle. The importance of the number of haemocytes in defence and well-being of crayfish is discussed.  相似文献   

Intraguild interactions and behavior of Spodoptera frugiperda and Helicoverpa spp. on maize          下载免费PDF全文

José PF Bentivenha  Débora G Montezano  Thomas E Hunt  Edson LL Baldin  Julie A Peterson  Vinícius S Victor  Luiz ER Pannuti  Ana M Vélez  Silvana V Paula‐Moraes 《Pest management science》2017,73(11):2244-2251

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规模化猪场猪支原体肺炎控制及净化技术研究   总被引：10，自引：0，他引：10  

张道永  林毅  冯金传 《中国预防兽医学报》2000,22(1):71-72

在四川蒲江某规模化８养猪场 ,对该场的猪支原体肺炎采用以监测、免疫为主,隔离、治 疗、淘汰、消毒等综合防制技术进行控制与净化,对全场有猪支原体肺炎症状的猪及可疑病猪进行隔治疗,治愈后的猪经与易感猪同居感染不发病,分离猪肺炎支原体为阴性,试验表明治愈后的猪不带菌。对全场种猪和后备健康猪群进行猪支原体肺炎疫苗的免疫接种,经抗体监测和攻毒试验,免疫后２４０天猪支原体肺炎的ＩＨＡ抗体仍可达到１：１０,保护率  相似文献   

Characterisation of a novel Mannheimia sp from Australian feedlot cattle     

PJ BLACKALL  Ø ANGEN  N FEGAN  LL BLACKALL  R MUTTERS  M BISGAARD 《Australian veterinary journal》2001,79(9):634-639

OBJECTIVE: To characterise eight isolates of a Gram-negative organism obtained from the upper respiratory tract of cattle showing evidence of mild upper respiratory tract disease. DESIGN: The isolates were compared with the five recognised species within the genus Mannheimia - M haemolytica, M glucosida, M granulomatis, M ruminalis and M varigena--using a range of phenotypic and genotypic methods. RESULTS: Phenotypic characterisation indicated that the isolates belonged to the trehalose-negative [Pasteurella] haemolytica complex. This complex has recently been reorganised into five species within the new genus Mannheimia. Ribotyping performed using HindIII and a computerised analysis system indicated that the eight Australian isolates formed a distinct cluster that was related to, but different from, the five recognised species of Mannheimia. The 16S rRNA sequence of one isolate (BNO311) was determined and a phylogenetic analysis performed. Isolate BNO311 was distinct from the five named Mannheimia spp but did join a larger cluster consisting of rRNA cluster IV (M varigena) and the unnamed rRNA cluster V of Mannheimia. DNA:DNA hybridisation between isolate BNO311 and M haemolytica NCTC 9380T, M granulomatis P411 and Actinobacillus ligniersii NCTC 4189T all suggested similarities of approximately 30%. CONCLUSIONS: These phenotypic and genotypic characterisation studies suggest that the eight Australian isolates represent a new species of Mannheimia. Until further characterisation studies are performed, we are unwilling to propose a name for this taxon, preferring to refer to this possible new species as Bisgaard taxon 39 of cluster V of Mannheimia.  相似文献   

A human major histocompatibility complex (MHC) DNA probe recognizes goat genes     

L L Nesse  G Paulsen  M Syed  G Ruff 《Acta veterinaria Scandinavica》1988,29(2):193-198

A human major histocompatibility complex (MHC) class II (DR-β) probe was hybridized with restriction enzyme digest of genomic DNA from 14 goats. Nine of the animals belonged to one family. Digestion of the DNA with the restriction enzyme Eco RI gave 7 fragments in 13 animals and 6 fragments in the last animal. No other polymorphism could be detected. Bam HI digestion gave from 3 to 6 fragments which displayed a considerable polymorphism. In the family studied, polymorphic fragments were inherited together with serologically defined lymphocyte antigen specificities believed to be coded for by MHC class I genes.  相似文献   

GROWTH OF THE BOVINE PLEUROPNEUMONIA ORGANISM MYCOPLASMA MYCOIDES var. MYCOIDES, IN THE EMBRYONATED HEN EGG     

P. Elek  LL.D  B.V.Sc. G. S. Cottew  B.Sc. 《Australian veterinary journal》1961,37(5):163-168

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