Molecular cloning and sequence analysis of feline interferon-stimulated gene 15

The interferon-stimulated gene 15 (ISG15) is induced by type I interferon (IFN). Recent studies have revealed that like ubiquitin, ISG15 is conjugated with target proteins. In this study, the feline ISG15 (FeISG15) gene was cloned from feline IFNomega (FeIFNomega)-stimulated feline kidney epithelial (CRFK) cells. According to gene sequence results, cDNA was 474bp long and encoded a protein of 157 amino acids. The putative amino acid sequences showed 62.5-72.1% identity with those of other mammalian ISG15s. Similar to human and mouse ISG15, FeISG15 included tandem ubiquitin-like domains; its homology with feline ubiquitin was 36.3-39.5%. The LRLRGG conjugating motif was located only in the carboxyl terminal ubiquitin-like domain. FeISG15 also lacked the carboxyl terminal extension after the LRLRGG motif, which is present in mouse and human ISG15. Recombinant FeISG15 protein was expressed as a His-tagged fusion protein in Escherichia coli and purified by ion-exchange chromatography followed by affinity chromatography. Monoclonal anti-FeISG15 antibodies revealed free FeISG15 and FeISG15 conjugated with target proteins in cells after IFNomega stimulation by Western blotting analysis. Furthermore, mRNA of IFNgamma was detected from peripheral blood mononuclear cells (PBMCs) after stimulation with rFeISG15 extracellularly by RT-PCR. Taken together, these results suggested that FeISG15 had ubiquitin- and cytokine-like activity, as in other species.     

Effects of 3-methyl-4-nitrophenol in diesel exhaust particles on the regulation of reproductive function in immature female Japanese quail (Coturnix japonica)

In a previous study, we found that 3-methyl-4-nitrophenol (PNMC), a component of diesel exhaust particles and also a degradation product of the insecticide fenitrothion, exhibits reproductive toxicity in the adult male Japanese quail. The present study investigated the toxicity of PNMC in the female Japanese quail and its ability to influence reproduction in immature females. The quail (21-day-old) were injected intramuscularly (im) with PNMC at doses 0.1, 1 or 10 mg/kg body weight daily for 3 days. There was no significant difference in body growth between the PNMC-administered and control birds. However, the weights of the oviducts were significantly lower in the PNMC-treated birds at all doses. Furthermore, the plasma concentrations of luteinizing hormone (LH) and estradiol-17 beta were significantly decreased with 1 and 10 mg/kg of PNMC. These findings suggest that PNMC might influence the hypothalamo-pituitary-gonadal axis with decreasing in secretion of GnRH, LH and ovarian steroid hormones and subsequently disturb growth of the reproductive organs of immature female quail. This study indicates that PNMC induces reproductive toxicity at the central level and disrupts reproductive function in the immature female quail.     

Recovery of the everted cystacanth of seven acanthocephalan species of birds from feral raccoons (Procyon lotor) in Japan

Acanthocephalan everted cystacanths were detected in the intestines of 61 out of 555 feral raccoons (Procyon lotor) trapped between May 2003 and April 2005 in the western region of mainland Japan (Honshu). All collected specimens were identified as the species of birds including 3 Centrorhynchus species (C. bazaleticus, C. elongatus, and C. teres), Sphaerirostris lanceoides, Plagiorhynchus ogatai, Porrorchis oti, and Southwelina hispida. Three species, C. bazaleticus, C. teres, and S. lanceoides, were new to distribution records in Japan and the Far East. Recovery rates of these acanthocephalans were higher from the raccoons trapped in spring and early summer (range 8.3-36.8%, average 21.5%) than during the remainder of the year (range 0-20.0%, average 6.3%). The reason for this seasonal change is unknown. There is little information on the acanthocephalan fauna of wild birds in Japan, however, recovery of the cystacanths from the feral raccoons captured through the year might provide useful information on the fauna and geographical distribution of avian acanthocephalans.     

Comparison of the prevalence of Salmonella infection in layer hens from commercial layer farms with high and low rodent densities

A comparison on the prevalence of Salmonella infection in layer hens from commercial layer farms with high and low rodent densities was investigated. Out of 280 laying hens sampled from three commercial layer farms with high rodent densities, Salmonella enterica subsp. enterica serovar Enteritidis (Salmonella Enteritidis) was isolated from 20 (7.14%) hens and Salmonella enterica subsp. enterica serovar Infantis (Salmonella Infantis) from three (1.07%) hens. In contrast, layer hens sampled from four commercial layer farms with low rodent densities were negative for any salmonellae. Significant differences (P < 0.05) in the isolation rates of Salmonella from various organs of infected layer hens were also noted. For Salmonella Enteritidis, liver (55.0%) and the oviduct (55.0%) had the highest isolation rates while all Salmonella Infantis isolates were from the oviduct. Pulsed field gel electrophoresis (PFGE) analysis of BlnI-digested chromosomal DNA of Salmonella Enteritidis isolated from layer hens and rodents showed similar patterns. PFGE analysis of Salmonella Infantis isolated from layer hens, rodents, eggs, and the environment yielded identical patterns. In this study, the significantly higher prevalence rate (P < 0.05) of Salmonella Enteritidis and Salmonella Infantis in layer hens from high rodent density farms could be attributed to the high rodent population density. The persistent Salmonella Enteritidis and Salmonella Infantis infection inside layer houses may have been amplified by the increasing numbers in the rodent population over the years, which increased the opportunity for environment-rodent-chicken interaction and the transmission of salmonellae to chickens. Monitoring of salmonellae from rodents inside poultry premises is recommended to be an effective additional tool in the assessment of the Salmonella status of layer flocks.     

Effect of trehalose supplementation in milk replacer on the incidence of diarrhea and fecal microbiota in preweaned calves

Trehalose, a nonreducing disaccharide consisting of d-glucose with α,α-1,1 linkage, was evaluated as a functional material to improve the gut environment in preweaned calves. In experiment 1, 173 calves were divided into two groups; the trehalose group was fed trehalose at 30 g/animal/d with milk replacer during the suckling period, and the control group was fed nonsupplemented milk replacer. Medication frequency was lower in the trehalose group (P < 0.05). In experiment 2, calves (n = 20) were divided into two groups (control group [n = 10] and trehalose group [n = 10]) based on their body weight and reared under the same feeding regimens as in experiment 1. Fresh feces were collected from individual animals at the beginning of the trial (average age 11 d), 3 wk after trehalose feeding (experimental day 22), and 1 d before weaning, and the fecal score was recorded daily. Fecal samples were analyzed for fermentation parameters and microbiota. The fecal score was significantly lower in the trehalose group than in the control group in the early stage (at an age of 14 to 18 d; P < 0.05) of the suckling period. Calves fed trehalose tended to have a higher proportion of fecal butyrate on day 22 than calves in the control group (P = 0.08). Population sizes of Clostridium spp. were significantly lower (P = 0.036), whereas those of Dialister spp. and Eubacterium spp. tended to be higher in the feces of calves in the trehalose group on day 22 (P = 0.060 and P = 0.083). These observations indicate that trehalose feeding modulated the gut environment and partially contributed to the reduction in medication frequency observed in experiment 1.     

Effects of whey protein hydrolysate on growth promotion and immunomodulation in mouse pups in artificial rearing system

This study aimed to investigate the effects of whey protein hydrolysate (WPH) on the growth and immunity of mouse pups in artificial rearing (AR) system. Mouse pups were reared in the AR system with artificial milk including 5% WPH (AR with WPH) or not (AR without WPH), and the remaining pups were reared by their mother (dam) for 14 days after birth. The body weight change and body weight gain rates in the AR with WPH group were significantly higher than those observed in the AR without WPH group and similar to those in the dam group. Moreover the feed and protein efficiencies in the AR with WPH group were significantly higher than those of the AR without WPH group. In addition, the supplement of WPH in the AR system was shown to significantly elevate the number of CD3⁺CD8⁺, B220⁺CD19⁺, IA/IE⁺CD11c⁺, and CD11b⁺ in the thymocyte and/or splenocyte, and the thymus weight. Furthermore, MALDI‐TOF/MS analysis identified the amino acid sequences corresponding to some peptides, and indicated that VRTPEVDDE had the highest relative intensity among the peptides from tested WPH. Therefore, WPH would be required to not only promote growth, but also exert immunomodulatory activities in mouse pups in AR system.