Seroprevalence of Neospora caninum in dairy and beef cattle with reproductive disorders in Japan

Serum samples from 145 dairy and 65 beef cattle with reproductive disorders and 54 normally calving dairy cattle (controls) in Japan were tested for presence of Neospora caninum antibodies by use of an indirect fluorescent antibody test (IFAT, titer 1:200). Overall, seroprevalence of N. caninum was significantly higher (P < 0.001) in dairy cattle (20.0%, 29/145) than in beef cattle (1.5%, 1/65). In cattle which aborted, seroprevalence of N. caninum was significantly higher (P = 0.041) in dairy cattle (26.1%, 23/88, compared with controls (3.7%, 2/54)) than in beef cattle (5.0%, 1/20), indicating that neosporosis might be a more common problem in dairy cattle than in beef cattle in Japan. Seropositive cattle were 9.2 times more likely to abort compared to seronegative cows. Abortions associated with N. caninum seropositivity in this study were most frequently observed in the second trimester, and the mean gestational age of the fetuses aborted from seropositive dams was 5.7 months. In conclusions, N. caninum seems to be causing serious economic losses in the dairy industry in Japan. This is the first report on an objective comparison of seroprevalence of dairy and beef cattle with reproductive disorders in Asia.     

Degenerative changes of the cranial cruciate ligament harvested from dogs with cranial cruciate ligament rupture

Degenerative cranial cruciate ligament (CCL) rupture is characterized histologically by degenerating extracellular matrix (ECM) and chondroid metaplasia. Here, we describe the progression of chondroid metaplasia and the changes in the expression of ECM components in canine CCL rupture (CCLR). CCLs from 26 stifle joints with CCLR (CCLR group) and normal CCLs from 12 young beagles (control group) were examined histologically and immunohistochemically for expression of type I (COLI), type II (COLII), type III collagen (COLIII) and Sry-type HMG box 9 (SOX9). Cell density and morphology of CCLs were quantified using hematoxylin–eosin staining. The percentage of round cells was higher in the CCLR group than in controls. COLI-positive areas were seen extensively in the connecting fibers, but weakly represented in the cytoplasm of normal CCLs. In the CCLR group, there were fewer COLI-positive areas, but many COLI-positive cells. The percentages of COLII-, COLIII- and SOX9-positive cells were higher in the CCLR group than in controls. The number of spindle cells with perinuclear halo was high in the CCLR group, and most of these cells were SOX9-positive. Deposition of COLI, the main ECM component of ligaments, decreased with increased COLIII expression in degenerated CCL tissue, which shows that the deposition of the ECM is changed in CCLR. On the contrary, expression of SOX9 increased, which may contribute to the synthesis of cartilage matrix. The expression of COLII and SOX9 in ligamentocytes showed that these cells tend to differentiate into chondrocytes.     

Selection for high and low oxygen consumption‐induced differences in maintenance energy requirements of mice

Maintenance energy requirements (MER) of mice selected for high (H) or low (L) oxygen consumption (OC) were compared. Forty‐four mice from H and L OC lines were weaned at 3 weeks and divided into four experimental groups: group A were sacrificed at 4 weeks; group B were fed ad libitum, and groups C and D were fed 2.8 and 2.4 g/day, respectively, from 4 to 8 weeks of age. Groups B–D were sacrificed at 8 weeks. Chemical components were estimated for all groups. MER was estimated using a model that partitioned metabolizable energy intake into that used for maintenance, and protein and fat deposition. The feed conversion ratio for the B group was significantly higher in the H than in the L line. Feed intake for metabolic energy content per metabolic body size was significantly also higher in the H line, whereas accumulated energy content per metabolic body size was significantly higher in the L line. MER of the H line was greater than that of the L line (P < 0.10). These results suggest that selection for H or L OC produced differences in chemical components, feed efficiency, and MER between the H and L lines.     

Correlations between mitochondrial respiration activity and residual feed intake after divergent genetic selection for high‐ and low‐ oxygen consumption in mice

The aims of the present study were to identify the differences between two mouse lines (high (H)‐ and low (L)‐oxygen consumption) in terms of mitochondrial respiratory activity when GMP (glutamate, malate, and pyruvate) and succinic acid are used as substrates and to examine the relationship between mitochondrial respiration activity and feed efficiency in both lines. The average daily feed intake, feed conversion ratio (FCR), and residual feed intake (RFI) were significantly higher in the H than the L line. The correlation between FCR and RFI was significant (r = 0.60, p < 0.05). RFI was effective as an indicator of feed efficiency. When succinic acid was used as a substrate, mitochondrial respiration states 2–4, ACR, and proton leak were significantly higher in the H than the L line. When GMP was used as a substrate, respiration states 3 and 4 in the H line were significantly higher than those in the L line, and there were significant positive correlations between FCR and RFI and mitochondrial respiration states 2–4. The results indicated that selection for high or low OC changed the basal metabolic rates estimated from liver mitochondrial respiration activity and feed efficiency.     

Effects of continuous low-dose infusion of lipopolysaccharide on expression of E-selectin and intercellular adhesion molecule-1 messenger RNA and neutrophil accumulation in specific organs in dogs

OBJECTIVE: To determine the effects of continuous low-dose infusion of lipopolysaccharide (LPS) on the expression of E-selectin and intercellular adhesion molecule-1 (ICAM-1) mRNA and neutrophil accumulation in the lungs, liver, spleen, small intestine, and pancreas in dogs. ANIMALS: 11 healthy adult Beagles. PROCEDURE: Dogs received a continuous infusion of a low dose (10 microg/kg/h, i.v.) of LPS (Escherichia coli 055:B5) or saline (0.9% NaCI) solution (20 mL/kg/h, i.v.) for 8 hours. Activity levels of tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), and interleukin-6 (1L-6) and the number of WBCs in circulation were examined before and 1, 2, 4, and 8 hours after the onset of LPS infusion. Expression of E-selectin and ICAM-1 mRNA and the number of neutrophils in each tissue were examined. RESULTS: After the onset of LPS infusion, serum TNF-alpha and IL-1beta activities transiently increased. Thereafter, IL-6 activity increased, and high IL-6 activity was maintained throughout the experiment. In dogs in the LPS group, expression of E-selectin mRNA increased only in the lungs, and expression of ICAM-1 mRNA increased in the lungs and liver; the number of neutrophils in the tissue increased in the lungs and liver. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that expression of E-selectin and ICAM-1 mRNA increased during sepsis, particularly in the lungs and liver, and that this increase was associated with neutrophil accumulation. Hence, inhibiting the activation of endothelial cells in the lung and liver may decrease organ damage caused by accumulated neutrophils and help regulate multiple-organ dysfunction.     

The repeatability,reproducibility, and influencing factors of intrarenal Doppler ultrasonography in dogs without heart disease

Renal impairment is concurrent with adverse outcomes such as heart disease in humans and dogs. Intrarenal Doppler ultrasonography (IRD) is used to assess intrarenal hemodynamics, and resistance index (RI) and venous impedance index (VII) are used to evaluate intrarenal hemodynamics in humans with heart failure. However, only a few studies have assessed the efficacy of IRD, especially VII, in dogs, and the methods differ between studies. Additionally, repeatability, reproducibility, and factors influencing IRD values have not been validated in dogs. This prospective, analytical study aimed to assess repeatability and reproducibility of IRD, and to clarify influencing factors of IRD in dogs without heart disease. We enrolled 78 dogs without heart disease. The RI and VII were highly reproducible, and the reference intervals for VII were 0.13–0.37. Differences in transducer (sector and convex) and posture (right lateral and supine decubitus position) had no effect on the IRD values. In contrast, RI and VII were higher in the renal vessels than in interlobar vessels. Age affected RI values (r = 0.39, P < 0.001), but there was no correlation between age, body weight, and VII. In conclusion, IRD is a repeatable and reproducible method to assess intrarenal hemodynamics in dogs. The findings also suggest that age should be considered while interpreting RI.     

Genetic association between GHSR1a 5′UTR‐microsatellite and nt‐7(C>A) loci and growth and carcass traits in Japanese Black cattle

We carried out a genetic association study between five nucleotide polymorphisms (5′UTR microsatellite ((TG)_n), nt‐7(C>A), L24V, DelR242 and Intron 1 microsatellite) of the GHSR1a gene and growth and carcass traits in 1285 steers sired by 117 Japanese Black bulls in a progeny testing program. We report herein, a significant association between the 5′UTR microsatellite and nt‐7(C>A) loci and growth and carcass traits. We also propose a translational hypothesis that the association is due to differences in the secondary structure of GHSR1b mRNA (the non‐spliced type with the 5′UTR microsatellite) among the GHSR1a gene haplotypes. Furthermore, we predicted the potential increase in profitability due to increased carcass weight in cow‐calf fattening enterprises through planned matings based on DNA testing of the 5′UTR microsatellite. Statistical analysis revealed that the 5′UTR microsatellite locus had a significant additive effect on carcass weight (CW) and average daily gain (ADG), but not on beef marbling score (BMS). One of the four major microsatellite alleles (19‐TG allele) with an allele frequency of 0.145, had a significantly (P < 0.0007) desirable effect on CW and ADG. We concluded that the 19‐TG allele could potentially be economically useful nucleotide markers for growth and carcass traits in Japanese Black cattle.     

A novel multiplex PCR assay to detect and distinguish between different types of Paenibacillus larvae and Melissococcus plutonius,and a survey of foulbrood pathogen contamination in Japanese honey

Paenibacillus larvae and Melissococcus plutonius are the causative agents of American and European foulbroods of honey bees, respectively. Since their virulence and resistance to disinfectants differ depending on the genotypes/phenotypes of the strains, the discrimination of strain types is important for the effective control of these diseases. Methods to detect and differentiate pathogens in honey are useful for surveying the contamination status of beehives/apiaries. In the present study, we selected a sequence (GenBank accession no. {"type":"entrez-nucleotide","attrs":{"text":"FI763267","term_id":"224923825"}}FI763267) as the specific target for enterobacterial repetitive intergenic consensus (ERIC) II-type P. larvae strains for the first time and developed a novel multiplex PCR assay that precisely distinguishes between the major types of foulbrood pathogens (ERIC I and II P. larvae and typical and atypical M. plutonius) in one reaction. In addition, we found that commercially available kits designed for DNA extraction from Mycobacterium in feces efficiently extracted DNA from foulbrood pathogens in honey. Using the multiplex PCR assay and DNA extraction kits, all the targeted types of P. larvae and M. plutonius were detected in honey spiked with the pathogens at a concentration of 100 bacterial cells/strain/ml. Moreover, 94% of the Japanese honey samples examined in the present study were contaminated with one or more types of the foulbrood pathogens. These results indicate that the newly developed methods are useful for detecting foulbrood pathogens in honey. The epidemiological information obtained by these methods will contribute to the effective control of foulbroods in apiaries.