The role of European starlings in the spread of coccidia within concentrated animal feeding operations

To investigate the relationship between European starlings and bovine coccidiosis we collected samples from European starlings, cattle feed bunks, cattle water troughs, and cattle feces within concentrated animal feeding operations (CAFOs). These samples were screened for coccidia spp. to investigate (i) the prevalence of coccidia in starlings using CAFOs; (ii) if there is a relationship between bovine coccidiosis and starling numbers; (iii) if coccidia contamination of cattle feed and water is related to the number of starlings observed on CAFOs. Coccidia belonging to the genus Eimeria were detected in cattle feces and one water sample but no Eimeria spp. were detected in European starlings or cattle feed. However, many European starling samples were positive for Isospora. Starling use of CAFOs did not appear to be associated with coccidia spp. shedding by cattle and there was no correlation between starling numbers and contamination of cattle feed and water, suggesting that starling do not contribute to the amplification and spread of Eimeria in CAFOs.     

Effects of diet restriction on life span and age-related changes in dogs

OBJECTIVE: To evaluate the effects of 25% diet restriction on life span of dogs and on markers of aging. DESIGN: Paired feeding study. ANIMALS: 48 Labrador Retrievers. PROCEDURES: Dogs were paired, and 1 dog in each pair was fed 25% less food than its pair-mate from 8 weeks of age until death. Serum biochemical analyses were performed, body condition was scored, and body composition was measured annually until 12 years of age. Age at onset of chronic disease and median (age when 50% of the dogs were deceased) and maximum (age when 90% of the dogs were deceased) life spans were evaluated. RESULTS: Compared with control dogs, food-restricted dogs weighed less and had lower body fat content and lower serum triglycerides, triiodothyronine, insulin, and glucose concentrations. Median life span was significantly longer for dogs in which food was restricted. The onset of clinical signs of chronic disease generally was delayed for food-restricted dogs. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that 25% restriction in food intake increased median life span and delayed the onset of signs of chronic disease in these dogs.     

Quantitative analysis of pro-inflammatory cytokine mRNA expression in Theileria annulata-infected cell lines derived from resistant and susceptible cattle

The pathogenic mechanisms involved in tropical theileriosis, caused by the tick-borne protozoan parasite Theileria annulata, are unclear. Pathology is associated with the schizont stage of the parasite, which resides within bovine macrophages. Breed-specific differences in pathology have been observed in cattle, several Bos indicus breeds are relatively resistant to tropical theileriosis whilst Bos taurus cattle are highly susceptible. Infected cells express pro-inflammatory cytokines and it has been hypothesized that these cytokines play a major role in the pathology of the disease. Therefore, using quantitative RT-PCR we investigated the expression of the key candidates, interleukin 1 beta (IL-1beta), IL-6 and tumour necrosis factor alpha (TNF-alpha), in T. annulata low passage infected cell lines derived ex vivo from experimental infection of resistant and susceptible cattle. mRNA for each cytokine was detected in all cell lines investigated at levels higher than those observed in resting monocytes. However, the analyses did not identify any breed-specific differences. Therefore, these results are not consistent with the hypothesis that differential regulation of infected cell derived pro-inflammatory cytokines (IL-1beta, IL-6 and TNF-alpha) accounts for the breed-related differences in resistance and susceptibility to T. annulata infection. Other, currently unknown mechanisms may be of greater importance.     

First feeding of diploid and triploid yellowtail tetra Astyanax altiparanae: An initial stage for application in laboratory studies

In this study, the aim was to establish a protocol for first feeding of diploid and triploid yellowtail tetra Astyanax altiparanae in laboratory conditions. The fry were fed with five different diets: (i) Artemia franciscana nauplii, (ii) plankton, (iii) dry food, (iv) Artemia franciscana nauplii + plankton, and (v) Artemia nauplii + plankton + dry food. Additionally, the growth and survival rates of diploid and triploid individuals were also evaluated. On day 10, the length of the fish between the treatments differed significantly (p = .0001) and ranged from 4.07 ± 0.06 mm (dry food) to 8.50 ± 0.64 mm (plankton + Artemia). The sizes of the fish increased with time, except for the fish fed with dry food. The survival rates were similar for the fish fed with the four diets and ranged from 80.7 ± 5.4% (dry food + plankton + Artemia to 92.0 ± 1.6% (plankton + Artemia), but differed from the fish fed with dry food (17.7 ± 5.8%, p = .0017). Diploids and triploids did not present differences on day 0 (p = .2252) and on day 10 (p = .4844) when the fish presented 6.77 ± 0.25 mm and 6.54 ± 0.15 mm respectively. Survival of diploids (87.3 ± 5.13%) and triploids (74.67 ± 2.30%) were also similar (p = .0285). These data are innovative and useful for establishing protocols for this species in both academic and applied sciences.     

A Burkholderia pseudomallei toxin inhibits helicase activity of translation factor eIF4A

The structure of BPSL1549, a protein of unknown function from Burkholderia pseudomallei, reveals a similarity to Escherichia coli cytotoxic necrotizing factor 1. We found that BPSL1549 acted as a potent cytotoxin against eukaryotic cells and was lethal when administered to mice. Expression levels of bpsl1549 correlate with conditions expected to promote or suppress pathogenicity. BPSL1549 promotes deamidation of glutamine-339 of the translation initiation factor eIF4A, abolishing its helicase activity and inhibiting translation. We propose to name BPSL1549 Burkholderia lethal factor 1.     

Genotyping Common Bean for the Potyvirus Resistance Alleles I and bc-1(2) with a Multiplex Real-Time Polymerase Chain Reaction Assay

ABSTRACT A multiplex real-time polymerase chain reaction (PCR) assay was developed to simultaneously genotype plants for the I and bc-1(2) alleles, which condition resistance in beans to Bean common mosaic virus and Bean common mosaic necrosis virus. A segregating F(2) population was derived from the cross between pinto bean breeding line P94207-189A (bc-1 bc-1 I I) and Olathe (bc-12 bc-1(2) i i). Real-time PCR assays were developed that were specific for each allele, and a multiplex PCR reaction could unambiguously assign F(2) plants to one of nine genotypes. Remnant F(1) plants were used as a comparative reference sample. PCR results among this sample fit a normal distribution for both real-time PCR assays, and 99% probability distributions were determined for heterozygotes. F(2) plants were genotyped based on results relative to the probability distributions for heterozygotes. F(2) plants also were genotyped for the I and bc-1(2) alleles by performing F(3) family progeny tests for virus resistance. Agreement between the two methods was 100% (198/198) for the bc-1(2) allele, and 92.4% (183/198) for the I allele. Erroneous genotyping was due to recombination between the amplicon and the I allele. Realtime PCR assays provide a robust method for genotyping seedlings and, in some cases, may eliminate the need for progeny testing.     

Bacterial diseases of potatoes: from classical phytobacteriology to molecular pathogenicity

Various bacterial pathogens attack potato plants and tubers. These pathogens includeErwinia, Corynebacterium (Clavibacter), Psuedomonas andStreptomyces. Over the past few years there have been significant advances in the molecular biological analysis of several of these pathogens and this is now helping us to understand the major aspects of virulence mechanisms. However, to date, such information is not sufficiently useful to allow us to intervene rationally in these potato diseases, except by the standard practises of good husbandry.