Seroprevalence of Ehrlichia canis, Ehrlichia equi, and Ehrlichia risticii in sick dogs from North Carolina and Virginia

Ehrlichia canis, E. equi, and E. risticii seroprevalence was determined by microimmunofluorescent antibody testing (IFA) in a sequential population of 1,845 sick dogs admitted during a 1-year period to the North Carolina State University Veterinary Teaching Hospital. A seroreactor was defined by a reciprocal IFA titer of > or =80 to E. canis, E. equi, or E. risticii antigens. Of the 48 IFA seroreactors, 44 dogs were seroreactive to E. canis, 21 to E. equi, and 0 to E. risticii. Seventeen dogs reacted to both E. canis and E. equi antigens. There was concordance of E. canis IFA and western immunoblot (WI) test results for 36/44 dogs. Because of cross-reactivity of E. canis sera with E. equi antigens, WI was of less utility to confirm E. equi exposure. After elimination of E. canis seroreactors, there was concordance of 2/4 E. equi IFA and WI test results. Based upon a retrospective review of medical records, ehrlichiosis was diagnosed in 10/48 (21%) IFA seroreactive dogs, 9 of which were confirmed positive by WI. Of the remaining 38 IFA seroreactors, 29 also were confirmed by E. canis or E. equi WI. These results indicate that (1) ehrlichiosis was not diagnosed in the majority of serologically confirmed cases, (2) based upon E. canis and E. equi WI analysis, IFA testing was not specific (21% false positive), (3) E. canis sera cross-react with E. equi antigens, and (4) serologic evidence of E. risticii infection was lacking in the dog population studied.     

Sacha inchi meal as a fish-meal replacer in red hybrid tilapia (Oreochromis niloticus × O. mossambicus) feeds: effects on dietary digestibility,growth metrics,hematology, and liver and intestinal histology

Aquaculture International - The utilization of sustainable and innovative raw materials to substitute for traditional fishmeal (FM) ingredients is required for the aquaculture sector. Sacha inchi...     

Serologic and molecular evidence of coinfection with multiple vector-borne pathogens in dogs from Thailand

Forty-nine dogs from Thailand were evaluated for serologic evidence of exposure or polymerase chain reaction (PCR) evidence of infection with vectorborne pathogens, including Ehrlichia sp. (Ehrlichia canis, Ehrlichia chaffeensis, Ehrlichia equi, and Ehrlichia risticii), Bartonella vinsonii subsp. berkhoffi (Bvb), spotted fever group (SFG) rickettsiae (Rickettsia rickettsii), Typhus group (TG) rickettsiae (Rickettsia canada, Rickettsia prowazekii, and Rickettsia typhi), and Babesia sp. (Babesia canis and Babesia gibsonii). All study dogs had at least 1 of 3 entry criteria: fever, anemia, or thrombocytopenia. By immunofluorescence antibody (IFA) testing, seroreactivity was most prevalent to E chaffeensis (74%) and E canis (71%) antigens, followed by E equi (58%), Bvb (38%), E risticii (38%), R prowazekii (24%), B canis (20%), R rickettsii (12%), R canada (4%), and B gibsonii (4%) antigens. There was 100% concordance between E canis IFA and Western blot immunoassay (WI) for 35 of 35 samples; 2 samples were IFA and WI reactive only to E equi antigens. By PCR amplification, 10 dogs were found to be infected with E canis, 5 with Ehrlichia platys, and 3 with B canis. Sequencing of PCR products was undertaken to compare Ehrlichia strains from Thailand to strains originating from the United States. Partial DNA sequence analysis confirmed infection with E canis and E platys, with identical 16S rRNA sequence alignment to E canis (U26740) and to E platys (M83801), as reported in GenBank. Partial E canis P28.1 and P28.2 amino acid sequences from Thai dogs were divergent from analogous sequences derived from North American E canis (AF082744) strains, suggesting that the Thai dogs were infected with a geographically distinct strain of E canis compared to North American strains. The results of this study indicate that dogs in Thailand have substantial exposure to vectorborne diseases and that coinfection with these pathogens may be common.     

Potential Bacillus probiotics enhance bacterial numbers, water quality and growth during early development of white shrimp (Litopenaeus vannamei)

Epidemics of epizootics and occurrence of multiresistant antibiotics of pathogenic bacteria in aquaculture have put forward a development of effective probiotics for the sustainable culture. This study examined the effectiveness of forms of mixed Bacillus probiotics (probiotic A and probiotic B) and mode of probiotic administration on growth, bacterial numbers and water quality during rearing of white shrimp (Litopenaeus vannamei) in two separated experiments: (1) larval stages and (2) postlarval (PL) stages. Forms of Bacillus probiotics and modes of probiotic administration did not affect growth and survival of larval to PL shrimp. The compositions of Bacillus species in probiotic A and probiotic B did not affect growth and survival of larvae. However, postlarvae treated with probiotic B exhibited higher (P<0.05) growth than probiotic A and controls, indicating Bacillus probiotic composition affects the growth of PL shrimp. Total heterotrophic bacteria and Bacillus numbers in larval and PL shrimp or culture water of the treated groups were higher (P<0.05) than in controls. Levels of pH, ammonia and nitrite of the treated shrimp were significantly decreased, compared to the controls. Microencapsulated Bacillus probiotic was effective for rearing of PL L. vannamei. This investigation showed that administration of mixed Bacillus probiotics significantly improved growth and survival of PL shrimp, increased beneficial bacteria in shrimp and culture water and enhanced water quality for the levels of pH, ammonia and nitrite of culture water.     

Effect of Cryoprotectants on Suppression of Protein Structure Deterioration Induced by Freeze-thaw Cycle in Pacific White Shrimp

This study aimed to elucidate the changes in Pacific white shrimp (Litopenaeus vannamei) myofibrillar protein as influenced by multiple freeze-thaw cycles as well as the stabilization effects of sucrose and trisodium citrate on shrimp myofibrils. Shrimp myofibrils in 0.1 M NaCl, 20 mM Tris-HCl (pH 7.5) were mixed individually with sucrose and citrate at concentrations of 0.05 M and were evaluated for Ca²⁺-ATPase activity, salt solubility, total and reactive sulfhydryl, and surface hydrophobicity during three freeze-thaw cycles. Sucrose and citrate had strong cryoprotective effects against freeze denaturation by retaining higher Ca²⁺-ATPase activity and salt-soluble myosin and actin, by slowing the reduction of reactive sulfhydryl (SH) and by exposing less hydrophobic groups at the surface of the protein compared with the no-additive sample. Results indicated that both cryoprotectants had suppressive effect against protein denaturation and helped stabilize white shrimp myofibrillar protein during the freeze-thaw process. This study suggests that sucrose and citrate stabilized the protein structure by retarding the unfolding of protein; thus, the native protein could be protected during frozen storage.     

Alaska pink salmon (Oncorhynchus gorbuscha) spoilage and ethanol incidence in the canned product

Ethanol was quantified in canned salmon produced from whole fish showing different stages of decomposition due to storage at 1 and 14 degrees C for up to 3 and 16 days, respectively. Ethanol incidence in the canned salmon was correlated to results from skin aerobic plate counts and sensory evaluations of the whole fish and with sensory evaluations of the canned product. Panelists rejected whole salmon after 3 and 12 days of storage at 14 and 1 degrees C, respectively. Skin aerobic plate counts reached 4.8 log CFU/cm2 when fish were rejected, regardless of storage temperature. Panelists rejected canned salmon produced with fish stored for a maximum of 2 and 16 days at 14 and 1 degrees C, respectively. Ethanol concentrations in the cans produced with fish stored at 14 degrees C correlated well with sensory evaluation results; however, ethanol concentrations in the cans produced with salmon stored at 1 degrees C did not agree with sensory results. A correlation could not be established between ethanol concentration in the canned product and microbial content of whole salmon.     

大蒜播种机排种器及开沟器设计与控制（摘选）

目前的大蒜播种机为8行式,本研究侧重于通过减少播种机的设计方案以增加播种能力,通过增加最佳行数和种子均匀度来增加田间作业效率。对于新设计的10行式大蒜播种机,来自农场的测试结果以下列标准为基础:工作速度1.68kmh,输种管高于地面30cm,且为最低变量。田间工作效率0.13hm2h,株距11.73cm,打滑率10.36%。开沟器为靴式,2行,行间距为250mm,拉力为10.3N行,且保持不变。大蒜平均发芽率为74.57%,平均单产26919kghm2,而农户的平均种植产量为30419kghm2。人力种植的精度值为20.93%,而10行大蒜播种机的精度值平均为21.0%。      

The immunologic response of dogs to Bartonella vinsonii subspecies berkhoffii antigens: as assessed by Western immunoblot analysis.

Bartonella vinsonii subspecies berkhoffii is a recently recognized zoonotic pathogen that causes endocarditis, granulomatous rhinitis, and granulomatous lymphadenitis in dogs. Isolation of B. vinsonii (berkhoffii) from blood or tissue samples is frequently unsuccessful; therefore, diagnosis is primarily dependent on serologic or molecular testing modalities. Because previous canine serologic studies have used an indirect immunofluorescence assay (IFA), without Western immunoblot (WI) confirmation, the overall objective of this study was to examine the diagnostic use of WI for confirmation of B. vinsonii (berkhoffii) infection in dogs. To confirm that agar-grown and cell culture-grown organisms yielded similar patterns of WI antigenic protein recognition, the 2 preparations were compared using IFA-reactive sera obtained from dogs experimentally infected with B. vinsonii (berkhoffii). Temporal changes in the pattern of antigenic protein recognition were characterized using sera obtained from dogs at various time points after experimental B. vinsonii (berkhoffii) infection. The specificity of B. vinsonii (berkhoffii) WI was examined by testing canine sera that were reactive to B. henselae, B. clarridgeiae, Ehrlichia canis, Rickettsia rickettsii, Babesia canis, Anaplasma phagocytophilum (previously E. equi), or Brucella canis antigens. Clinical accessions including serum samples obtained from B. vinsonii (berkhoffii) culture-positive dogs and B. vinsonii (berkhoffii) culture-negative dogs that were IFA seroreactive to B. vinsonii (berkhoffii) antigens were examined by WI. The results of this study indicate that WI using agar-grown or cell culture-grown B. vinsonii (berkhoffii) antigens produce identical patterns of antigenic protein recognition. After experimental infection, there is a progressive increase in the number of antigenic proteins that are recognized by WI, with the 33-kD antigen representing the first and the most persistent antigen recognized by B. vinsonii (berkhoffii)-infected dogs. Regarding specificity, sera from dogs that were reactive to various heterologous antigens did not recognize B. vinsonii (berkhoffii) antigens by IFA or WI, and sera from dogs experimentally infected with B. henselae did not recognize B. vinsonii (berkhoffii) antigens by WI. Regarding clinical accessions, there was good agreement between B. vinsonii (berkhoffii) IFA test results and WI analysis. Western immunoblot analysis can be used to detect or confirm exposure to B. vinsonii (berkhoffii) in dogs.