Cloning, characterization and diagnostic performance of the salivary lipocalin protein TSGP1 from Ornithodoros moubata

The argasid tick Ornithodoros moubata is distributed throughout South and East Africa and Madagascar, where it colonizes wild and domestic habitats and feeds on warthogs, domestic swine, and humans. This argasid transmits the spirochete Borrelia duttonii, causing East African tick-borne relapsing fever in humans, and the African swine fever virus, which causes a highly lethal haemorrhagic disease in pigs. Tick surveillance and the elimination of O. moubata from synanthropic environments (human dwellings and pigsties) would facilitate the control and prevention of these two diseases. Since direct surveillance methods are impractical in this context, the development of an indirect method for the detection of specific antibodies against tick salivary proteins in samples taken from animal or human hosts living in the area under study would provide a more convenient surveillance and diagnostic tool. Previous work has indicated that the 20A1 salivary antigen of O. moubata could be an optimal candidate for the development of a specific serological test and identified it as an orthologue of the Ornithodoros savignyi TSGP1 lipocalin. The objectives of the present work were to clone, sequence, and molecularly characterize the O. moubata TSGP1, as well as its production as a recombinant protein in order to assess its usefulness as a diagnostic antigen in an ELISA test for tick surveillance. Our results show that O. moubata TSGP1 (OmTSGP1) conserves the tertiary structure of lipocalins and contains the biogenic amine-binding motif. We also show that OmTSGP1 shares 65% sequence identity with the O. savignyi TSGP1, demonstrating that they represent orthologous proteins and suggesting they share identical function as biogenic amine scavengers. A recombinant form of OmTSGP1 was produced, showing 100% sensitivity and 99.4% specificity in an ELISA test for the detection of anti-O. moubata antibodies in pig sera. This recombinant antigen represents a promising epidemiological tool for O. moubata surveillance that may help to implement control measures against O. moubata-borne diseases.     

实施产后健康监测 及时发现病牛

牛群健康的一个重要理念就是早发现早治疗,早发现甚至比治疗本身更重要。对于泌乳牛,更要强调这个观念,因为耽误治疗不仅会降低治愈率,而且会导致产奶量下降,影响繁殖性能,围产后期发生的疾病尤为如此。尽管实施产后健康监测使我们在产后牛管理上取得很大进步,但还是经常漏诊早期发病牛,导致延误治疗。     

Wild ostrich (<Emphasis Type="Italic">Struthio camelus</Emphasis>) ecology and physiology

This work discusses some of the important considerations of wild ostrich evolution, behaviour and ecology, as items included in ostrich production. In the process considerable research was conducted by collating information from peer-reviewed papers; textbooks; manuals; and PubMed and Agricola searches. Selected areas reviewed included activity of ostriches; feeding and water needs; sexual maturity; egg laying and natural incubation; selected physiological parameters; and predation. There is an immediate and urgent need to conserve and protect the rapidly declining populations of wild ostriches with the committed involvement of governments and funding bodies.     

Use of touch-down polymerase chain reaction to enhance the sensitivity of Mycobacterium bovis detection.

The confirmatory diagnosis of Mycobacterium bovis (M. bovis) in animal samples is carried out by culture in Stonebrink media. However, culture is very slow because of the extremely long duplication time of the bacillus and difficult because of the scarcity of bacilli in diagnostic samples. This study describes the development of a single-tube touch-down polymerase chain reaction (PCR) protocol for the detection of M. bovis using primers that target the IS6110 element. Spiked water and milk as well as routine diagnostic samples (milk and nasal swabs) from M. bovis-positive cattle were tested. This protocol allows the rapid and sensitive detection of M. bovis in bovine samples by enhancing the sensitivity of standard PCR amplification.     

Purification and characterization of a 45-kDa concealed antigen from the midgut membranes of Ornithodoros erraticus that induces lethal anti-tick immune responses in pigs

Ornithodoros erraticus is an argasid tick that can transmit severe diseases such as human relapsing fever and African swine fever. In the search for a vaccine against this parasite, a crude extract of tick midgut membranes (GME) was obtained that in pigs and mice induced a protective response able to kill up to 80% of the nymphs in the first 72 h post-feeding and to reduce the fecundity of females by more than 50%. To identify the protective antigens, the GME was subjected to successive biochemical fractionations and the resulting simpler protein fractions were inoculated in pigs. A 45-kDa antigen, the so-called Oe45, was detected, purified and demonstrated to be responsible for the protection induced by the GME. Oe45 seems to be a membrane protein that is presumably expressed on the luminal membrane of midgut epithelial cells. Oe45 consists of at least two differently charged bands (cationic and neutral), which show antigenic cross-reactivity. The possibility that these bands might be different isoforms of the same protein is discussed. Although Oe45 is constitutively expressed at low levels throughout the trophogonic cycle, its expression is up-regulated by the ingestion of blood, as suggested by the higher levels observed between 6 and 72 h post-feeding.     

Feed enzyme supplementation does not ameliorate foot pad dermatitis in broiler chickens fed on a corn-soyabean diet

1.?Foot Pad Dermatitis (FPD) can be a serious health, quality and welfare problem in poultry production, with a significant affect on the economics of production. The physico-chemical properties of (NSP) have been correlated with increases in excreta viscosity and adherence, and hence FPD in broiler chickens.

2.?Two broiler experiments were conducted to evaluate the effects of different dietary non-starch polisaccharide (NSP) applications to corn-soyabean based diets in replicated floor pens. In addition to live performance, the incidence and severity of FPD was scored and, in experiment 2, intestinal viscosity and ammonia volatilization were measured.

3.?Live performance did not vary with the different treatments in either experiment and the incidence and severity of FPD, and ammionia volatisation in experiment 2, were unaffected. However, birds reared on enzyme supplemented diets had lower (P? 4.?In this study with corn-soyabean meal based diets, dietary enzyme supplementation had no affect on the incidence and severity of FPD. The lack of an association between the excreta viscosity and FPD is attributed to the multifactorial etiology of this condition.     

Analysis of growth curves of fowl. I. Chickens.

1. The Richards function was used to describe the growth curves (n = 989) of 9 broiler lines. Chickens were fed ad libitum and body weight was recorded every second week from hatching to 26 weeks of age. 2. The accuracy of curve fit measured by the coefficient of determination (R2) was better for males than for females (0.9986-0.9995 vs 0.9972-0.9988, respectively). 3. The estimation of the asymptotic final weight (A) for different lines enabled the degree of maturity (ut = yt/A) to be determined at any fixed point of the curve. At the age of 7 weeks this had a value of 0.318-0.369 for cockerels and 0.325-0.377 for pullets and represented the slaughter maturity of individual lines. The ratio of inflection/asymptotic weight (y+/A = 0.370-0.388) indicated that in some cases chicken growth can be described approximately by the Gompertz function (y+/A = 0.368). 4. It was found that the age at the inflection point of curves (t+ 48.2-55.7 d for cockerels and t+ = 47.8-52.8 d for pullets) roughly corresponds to the slaughter age of the chickens. 5. The interline differences in the parameters of maturation rate for weight (y+/A, k, t+, u7) are low in comparison with the differences in body weight (A, y+, y7) and absolute growth rate (v, v+). 6. The intragroup phenotypic correlation among growth parameters and the importance of the mathematical models are discussed.     

Correct equations for comparing models in diallel analysis

SUMMARY: Correct equations are given to express the parameter estimates of four models for complete diallels as a function of the parameter estimates in the model of Eisen et al. (1983). In recent literature these equations have been partly incorrect. ZUSAMMENFASSUNG: Korrekte Gleichungen für den Vergleich von Modellen in der Diallelanalyse Für die Darstellung der Parametersch?tzwerte von vier Modellen für vollst?ndige Diallele als Funktion der Parametersch?tzwerte des Modells von Eisen et al. (1983), die in der Literatur teilweise fehlerhaft erfolgte, werden korrekte Formeln angegeben.