鱼类禽类哺乳类动物精子的冷冻保存和受精力（下）

公牛的精液稀释液和冷冻保护剂稀释液和冷冻保护液是冷冻保存技术的重要组成部分。Darii等(1979)进行了66种含单糖的稀释液与Laichiphos液(一种法国的商业稀释液)及乳糖-卵黄稀释液受胎率比较,在一次受胎率测定时,含有70％乳糖或蔗糖、20％果糖、10％蜜三糖、12mmMgSO_4加甘油和卵黄的冷冻稀释液受胎率达66.4％,而Lai-chiphos缓冲液的受胎率为(?)1.6％,Foulkes等(1980)给母鸡饲喂高浓度葵花油和牛、羊脂肪的仔鸡日粮,试图提高稀释液中卵黄的冷冻保护性能。虽然这样做卵黄的脂质成分发生     

Risk factors for Salmonella enterica subsp. enterica infection in senegalese broiler-chicken flocks

Our objective was to assess the association of managerial practices, general hygiene and Salmonella infection in Senegalese broiler flocks. Seventy broilers farms were studied from January 2000 to December 2001 around Dakar. A questionnaire was submitted to the farmers and samples of fresh broiler droppings were taken. A 28.6% of the flocks were infected by Salmonella (mainly Hadar and Brancaster serovars). Salmonella infection of the previous flock (OR=6.82) and of day-old chicks (OR=3.73), frequent poultry farmers’ visits (OR=5.38) and keeping sick birds inside the farm (OR=5.32) increased the risk of Salmonella infection. But, using antibiotics on day-old chicks (OR=0.17) and a detergent for cleaning (OR=0.16) decreased the risk.     

Disinfectant tests at 20 and 10 degrees C to determine the virucidal activity against circoviruses

To evaluate virucidal activity against porcine circovirus type 2 (PCV2), four disinfectants were tested under laboratory conditions. As basis to perform the testing the "Guidelines for testing chemical disinfectants" of the German Veterinary Association (DVG-guidelines) were applied. For simulation of field conditions, the tests were carried out in virus carrier tests, at 20 and 10 degrees C, and under protein load (40% foetal calf serum (FCS) in virus suspension). For disinfection of PCV2 at 20 degrees C an exposure time of 120 min in 2% Disinfectant 1 (20% glutaraldehyde, 12% 2-propenal, polymer with formaldehyde) or Disinfectant 2 (55% formic acid, 7% glyoxylic acid) was necessary. 1% of Disinfectant 3 (Component 1: Potassium peroxomonosulphate. Component 2: Active detergents) disinfected PCV2 on carriers within 180 min. After a reaction time of 120 min with 1% and 60 min with 2% Disinfectant 4 (21% glutaraldehyde, 17% formaldehyde) there could not be detected any virus. Reduction on effectivity through temperature reduction to 10 degrees C were more significant for aldehyde containing preparations Disinfectant 1 and Disinfectant 4 than for Disinfectant 2 and Disinfectant 3. These losses on effectivity could be corrected through extension of exposure time or increase of concentration.     

Genetic characterization of a herpesvirus isolate from a superb starling (Lamprotornis superbus) as a psittacid herpesvirus genotype 1

Four genotypes of the psittacid herpesvirus (PsHV) cause Pacheco disease in parrots. Viruses that are serologically cross-reactive to the PsHVs have also been isolated from passerine species. DNA was amplified from a herpesvirus isolated from a superb starling (Lamprotornis superbus) with PsHV-specific primers and polymerase chain reaction. A comparison of the partial sequence of the UL 16 gene from this herpesvirus with sequences from viruses of known PsHV genotypes showed that the herpesvirus from the superb starling was a PsHV genotype 1 virus. This finding expands the range of birds that are known to be susceptible to PsHV genotype 1 infections and suggests that PsHVs should be considered as a differential in passerines with herpesvirus infections.     

Pregnancy toxemia in a ferret

A late-gestation jill was presented for depression, anorexia, and weakness. The working diagnosis became pregnancy toxemia. Supportive care was initiated and an emergency cesarian section performed. Twelve live kits were delivered; however, all soon perished despite home care. Surgery and recovery are discussed, including information regarding pregnancy toxemia in general.     

In vitro susceptibility of field isolates of Francisella tularensis subsp. holarctica recovered in Spain to several antimicrobial agents

Forty-two recent (1997-1999) Spanish isolates of Francisella tularensis subsp.holarctica were tested in a broth microdilution method for their susceptibilities to 29 antimicrobial agents, including penicillins, cephalosporins, cephamicins, monobactams, penems, aminoglycosides, tetracyclines, macrolides, quinolones, chloramphenicol and fosfomycin. The isolates were resistant to beta-lactam antibiotics and susceptible to chloramphenicol, ciprofloxacin, levofloxacin and norfloxacin.     

Mapping of B-cell epitopes in the N-terminal repeated peptides of Anaplasma marginale major surface protein 1a and characterization of the humoral immune response of cattle immunized with recombinant and whole organism antigens

Major surface protein (MSP) 1a of the genus type species Anaplasma marginale (Rickettsiales: Anaplasmataceae) together with MSP1b forms the MSP1 complex. MSP1a has been shown to be involved in adhesion, infection and tick transmission of A. marginale, as well as to contribute to protective immunity in cattle. A differential antibody response to MSP1a and MSP1b was observed in cattle immunized with A. marginale derived from bovine erythrocytes (anti-MSP1a response) or cultured tick cells (anti-MSP1b response). In this study, we further characterized the MSP1a antibody response of cattle using several immunogens, including recombinant MSP1a (rMSP1a) protein, erythrocyte- or tick cell culture-derived A. marginale, or a combination of tick cell culture-derived A. marginale and rMSP1a. The MSP1a antibody response to all these immunogens was directed primarily against the N-terminal region of MSP1a that contains tandemly repeated peptides, whereas low antibody levels were detected against the C-terminal portion. Linear B-cell epitopes of MSP1a were mapped using synthetic peptides representing the entire sequence of the protein that were prepared by SPOT synthesis technology. Only two peptides in the N-terminal repeats were recognized by sera from immunized cattle. These peptides shared the sequence SSAGGQQQESS, which is likely to contain the linear B-cell epitope that was recognized by the pools of bovine sera. The average differential of antibody titers against MSP1a minus those against MSP1b correlated with lower percent reductions in PCV. A preferential antibody response to MSP1a was observed in cattle immunized with erythrocyte-derived, cell culture-derived plus rMSP1a or rMSP1a alone, and the percent reduction PCV was significantly lower in these cattle as compared with the other immunization groups. These results provide insight into the bovine antibody response against A. marginale and the role of MSP1a in protection of cattle against A. marginale infection.     

Changes in antimicrobial susceptibility of Actinobacillus pleuropneumoniae isolated from pigs in Spain during the last decade

A total of 229 Spanish Actinobacillus pleuropneumoniae isolates recovered from diseased pigs with pleuropneumonia from 1997 to 2004 was tested for their susceptibility to 11 antimicrobials in a broth microdilution method. All the isolates were susceptible to florfenicol and most of them to cephalothin; however, a high rate of resistance was observed to tetracycline. A bimodal or multimodal distribution of isolates over the MIC range were observed for penicillins, tetracycline, trimethoprim, sulfisoxazole and nalidixic acid, suggesting the development of acquired resistance. Eight resistance patterns were established, and 21.1% of the isolates were resistant to at least two antimicrobials. In addition, a considerable increase in the resistance to tetracyclines was observed during the last decade in Spain, when compared with other A. pleuropneumoniae strains isolated during 1987-1988 (Gutiérrez, C.B., Píriz, S., Vadillo, S., Rodríguez Ferri, E.F., 1993. In vitro susceptibility of Actinobacillus pleuropneumoniae strains to 42 antimicrobial agents. Am. J. Vet. Res. 54, 546-550); this finding was also observed for gentamicin in minor percentage.     

Molecular characterization of Haemophilus parasuis ferric hydroxamate uptake (fhu) genes and constitutive expression of the FhuA receptor

Bacteria have evolved a set of highly specialized proteins to capture iron in iron-depleted environments. The acquisition and uptake of iron present in the extracellular milieu of eukaryotic organisms is indispensable for the growth and survival of microbial pathogens in the course of infection. Haemophilus parasuis is the causative agent of Gl?sser disease, which is responsible for considerable financial losses in pig-rearing worldwide. To gain insight into the mechanisms involved in siderophore-mediated iron uptake in H. parasuis, genes in the H. parasuis ferric hydroxamate uptake (Fhu) region were amplified in the work being reported here. As has been described in A. pleuropneumoniae, an Fhu genomic region was also present in H. parasuis, being composed of four potential consecutive open reading frames (ORF) designated as fhuC, fhuD, fhuB, and fhuA, respectively. By immunoblotting, using a cross-reactive polyclonal antibody raised against Actinobacillus pleuropneumoniae FhuA protein, it was demonstrated that this protein was constitutively expressed in H. parasuis and its level of expression was not modified under conditions of restricted iron availability. This is the first report describing the presence of the fhu genes in H. parasuis. Our results indicate that FhuA protein expression is not affected under iron-restricted conditions, however, it is one of the targets of the humoral immune response.