An enzyme-linked immunosorbent assay (ELISA) for detection of antibodies against Toxocara vitulorum in water buffaloes

Toxocara vitulorum, a parasite of the small intestine of cattle and water buffaloes, is mainly acquired by calves via the colostrum/milk from infected cows. To understand the development of immune responses in calves, antibody levels to a soluble extract antigen (Ex) from T. vitulorum infective larvae were measured by an indirect ELISA with sera of 15 buffalo calves, which were sampled every 15 days for the first 180 days after birth and 9 buffalo cows during the perinatal period. From all serum samples examined during the first 180 days, antibody level was lowest and highest in calves at 1 day of age before and after suckling colostrum, respectively, suggesting that the origin of antibodies was the colostrum. Immediately after birth, antibody levels in suckled calves remained at high levels until day 15, began to decrease to lower levels between 15 and 30 days and remained relatively stable until 120 days. By comparing the immune responses of these animals with their parasitological status it was considered possible to determine if passively acquired or actively produced antibodies provided protection against the infection. High numbers of T. vitulorum eggs in the feces between 30 and 60 days indicated that passively acquired antibodies did not provide protection against the infection, at least during these first days, and the maximum fecal egg counts during 30-45 days were coincident with decreased antibody levels. Between 60 and 120 days, when serum antibodies were detected at reduced, but stable levels, adult nematodes were expelled from the intestines and no more T. vitulorum eggs were found, suggesting development of acquired resistance. However, the potential and functional protective role of the antibodies against T. vitulorum infection and the process of self-cure requires further investigation.     

Osteological Development of the Garfish (Belone belone) Larvae

Garfish, Belone belone (Linnaeus, 1761) is an elongate, slander fish inhabiting the Eastern Atlantic and Mediterranean Sea. These fish from the Belonidae (Actinopterygii) family have important commercial value for Croatian fisheries. Samples for research were collected from experimental hatching in the Novigrad Sea. Preparation techniques included fixation in buffered formalin, trypsin clearing and staining with alcian blue and alizarin red. As little is known of garfish osteology and bone morphology, the main goal of this study was to describe ossification process in garfish fry. At hatching, no skeletal structure is present. Newly-hatched larvae also had no osteological elements. Ossification started at 7 day post-hatching (DPH) [total length (TL) 18 mm] with head bones and vertebral neural arch. Head skeleton continued to develop mostly over the period from 7 to 10 DPH. At 21 DPH (TL 49 mm), ossification process seemed to be finished, but it was not possible to distinguish borders of all bones. The primary interest of our research was to understand the growth dynamics as well as transformation of supporting body elements from cartilage to bone. At the end, developmental characteristics and functional aspects of this formation in different fish species are discussed.     

A physiologically based pharmacokinetics model for florfenicol in crucian carp and oral‐to‐intramuscular extrapolation

Yang, F., Sun, N., Sun, Y. X., Shan, Q., Zhao, H. Y., Zeng, D. P., Zeng, Z. L. A physiologically based pharmacokinetics model for florfenicol in crucian carp and oral‐to‐intramuscular extrapolation. J. vet. Pharmacol. Therap.  36 , 192–200. In this study, an oral physiologically based pharmacokinetics (PBPK) model was developed for florfenicol in crucian carp (Carassius auratus). Subsequently, oral‐to‐intramuscular extrapolation was performed and the two models were used to predict florfenicol concentrations in the edible tissues of crucian carp. The oral model gave good predictions in most tissues, except for kidney and liver in which the florfenicol concentrations were underestimated at the later time points. In contrast, using the intramuscular model, the concentrations in the kidney were overestimated at the later time points. Both models had the best predictive ability in the main edible tissue, the muscle. The oral model also accurately predicted the florfenicol concentrations in the muscle after multiple doses. The present study demonstrated the feasibility of predicting florfenicol concentrations in the edible tissues of crucian carp using a route‐to‐route extrapolation method.     

Development and characterization of monoclonal antibodies to subgroup A avian leukosis virus

Avian leukosis virus subgroup A (ALV‐A) is a retrovirus which infects egg‐type chickens and is the main pathogen of lymphoid leukosis (LL) and myeloid leukosis (ML). In order to greatly enhance the diagnosis and treatment of clinical avian leukemia, two monoclonal antibodies (MAbs) to ALV‐A were developed by fusion between SP2/0 and spleen cells from mice immunized with expressed ALV‐A env‐gp85 protein. Using immunofluorescence assay (IFA), two MAbs reacted with ALV‐A, but not with subgroups B and J of ALV. Western blot tests showed that molecular weight of ALV‐A envelope glycoprotein recognized by MAbs was about 53 kD. Isotyping test revealed that two MAbs (A5C1 and A4C8) were IgG1 isotypes. These MAbs can be used for diagnosis and epidemiology of ALV‐A.     

水貂毛皮成熟期皮肤中EGF、IGF-Ⅰ及IGF-ⅠR基因的表达

为探讨水貂皮肤和毛囊发育机理,试验运用组织学和免疫组化方法对水貂毛皮成熟期皮肤及毛囊中表皮生长因子（epidermal growth factor, EGF）和胰岛素样生长因子-Ⅰ（insulin-like growth factor-Ⅰ,IGF-Ⅰ）及其受体（insulin-like growth factor-Ⅰreceptor,IGF-ⅠR）进行了研究。结果表明,水貂皮肤表皮细胞和毛囊外根鞘细胞中都有IGF-Ⅰ、IGF-ⅠR和EGF基因的强阳性表达,3种基因主要分布于细胞质中,细胞核呈空泡状未见到阳性染色,呈苏木精复染的蓝色,皱褶区域和表皮下胶原结缔组织出现了阳性染色为非特异性阳性结果。IGF-Ⅰ、IGF-ⅠR和EGF基因在水貂皮肤表皮和毛囊外根鞘细胞中广泛表达,直接参与调控皮肤和毛囊的发育。表明EGF、IGF-Ⅰ和IGF-ⅠR基因在水貂皮肤及其衍生结构的发育中发挥着重要作用。     

Clinical Leptospira interrogans serogroup Australis serovar lora infection in a stud farm in the Netherlands

Summary

A Leptospira interrogans serogroup australis serovar lora infection in a stud farm is reported. During three successive years (1984–1986) clinical leptospirosis with a severe often rapid, fatal course was seen in 12 foals.

Clinical examination revealed severe respiratory distress, depression and pyrexia. Other symptoms were diarrhea (2), jaundice (1), and an unsteady gait (1). Morphological characteristics of the disease were massive pulmonary haemorrhage and haemorrhagicthrombotic or extracapillary glomerulonephritis with tubulonephrosis and interstitial oedema. In most foals high or increasing MAT titres to serovar bratislava were found; from one foal Leptospira interrogans serovar lora was isolated.

Serological examination of all 56 mares at the farm (August 1986) revealed antibodies to serovar bratislava in 64 per cent of the animals. These findings support the idea that Leptospira interrogans serovar bratislava and closely related strains (in this study serovar lora) may be adapted to and maintained by the horse population.     

Distribution,quantitative load and characterization of Salmonella associated with swine farms in upper-northern Thailand

This study was conducted to analyze the prevalence and quantitative loads of Salmonella spp. on pig farms in Chiang Mai, Lamphun, Thailand to assess loading levels before slaughtering. The serotype diversity, antimicrobial-resistance pattern and pulse-field type of Salmonella spp. were also characterized to assess the dynamic propagation of the pathogen. The Salmonella-positive prevalence was 246/805 (30.56%), and the quantitative loads varied from 1.48~4.04 Log₁₀MPN/g, with a mean ± standard deviation of 2.11 ± 0.57. AMP/S/TE (ampicillin/streptomycin/tetracycline) was the highest frequency antimicrobial resistance pattern found in this study. In addition, Salmonella Rissen was the primary serotype in this region. PFGE results indicated the occurrence of infection by cross contamination among pig farms. Our study showed that pork is easily contaminated with this pathogen. Farm control programs must be based on strict biosecurity and hygienic measures, which could further reduce the contamination pressure at slaughterhouses or retail shops.     

Influence of varying dietary electrolyte balance on broiler performance under tropical summer conditions

A 6‐week feeding trial was conducted to determine the effects of varying dietary electrolyte balance (DEB) on growth performance and physiological responses in broiler chicks reared during hot summer months (26.1–37.5 °C). The average minimum and maximum room temperatures recorded from 14 to 42 days of age were 26.1 and 37.5 °C, respectively, with relative humidity ranging from 51% to 55%. Five DEB treatments supplying 0, 50, 150, 250 and 350 (Na⁺+K⁺–Cl^?) mEq/kg of diet were prepared by adding NaHCO₃ and/or NH₄Cl to basal diet that contained 185 mEq/kg from 1 to 28 days and 172 mEq/kg from 29 to 42 days. These DEB diets were randomly offered to six experimental units of 20 chicks each. Improved 42‐day body weight gain (BWG), feed:gain (F:G) and reduced mortality was noted with DEB 50, 150 and 250 mEq/kg compared to DEB 0 and 350 mEq/kg. A quadratic effect of increasing DEB level was observed on BWG and F:G, whereas the effect was linear for feed intake, water intake and litter moisture. The DEB 50, 150 and 250 maintained better blood pH, pCO₂ and HCO₃ concentrations during acute heat stress periods than that of 0 and 350. The blood heterophil and lymphocyte percent as well as heterophil:lymphocyte were remained unaffected. The lowest DEB (0 mEq/kg) diet reduced the feed intake and promoted metabolic acidosis. At 350 mEq/kg DEB, water intake and metabolic alkalosis were promoted probably due to high levels of dietary NaHCO₃. The study concluded that overall better performance was recorded with DEB 50, 150 and 250 mEq/kg. These results indicated that single optimal DEB value could not be recommended to combat heat stress in broilers.     

Macroscopic Anatomy of the Lower Respiratory System in Mole rats (Spalax leucodon)

The morphologic and morphometric features of the lower respiratory system in mole rats were examined. It was seen that the low respiratory system of this species leading a special life under highly hypoxic/hypercapnic conditions underground is structurally similar to other mammals living on land in terms of the parts examined; trachea was formed by 29.5 ± 4 oval‐formed cartilaginous tracheals arranged backwards and became gradually more stenotic diameter from cranial to the caudal of the neck. The trachea was separated in two principal bronchus at the fourth thoracal intercostal spatium level. The angle between the two main principal bronchi was 60.5 ± 2.35°. The lung constituted 1.29 ± 0.03% of the body weight and the right lung was heavier than the left lung. Fissura inter‐lobaris was deep and separated the lung lobes wholly, and the right lung was separated in four lobes, whereas the left lung was not separated into the lobes. Also, the medial lobe of the left lung was the lightest lobe.