Proportion of abortions due to neosporosis among dairy cattle in Japan

A retrospective cohort study was conducted to clarify the association between seropositive reactions to Neospora caninum and subsequent reproductive disorders among dairy cattle in Japan. A statistically significant association between Neospora seropositive reactions and abortions was observed (P=0.016), and seropositive cattle were 6.1 times more likely to abort compared to seronegative cows. No significant differences were observed between seropositive reactions and other reproductive disorders such as conception failure, perinatal death and calf mortality. As indicated by estimation of the attributable fraction, 83.6% of abortions in Neospora seropositive animals may be attributed to N. caninum. Considering seroprevalence of N. caninum in the cattle which aborted in Japan, 21.8% of abortions were estimated to be caused by neosporosis in Japan.     

Development of a genetically modified nontoxigenic Pasteurella multocida toxin as a candidate for use in vaccines against progressive atrophic rhinitis in pigs

OBJECTIVE: To construct a genetically modified nontoxigenic Pasteurella multocida toxin (PMT) and examine its immunoprotective activity against challenge exposure with wild-type PMT in pigs. ANIMALS: 5 healthy pigs. PROCEDURE: A nontoxigenic PMT was created by replacing the serine at position 1164 with alanine (S1164A) and the cysteine at position 1165 with serine (C1165S). Toxic activity was determined by use of the guinea pig skin test and mouse lethality test. Three pigs were vaccinated twice with the modified PMT, and the remaining 2 pigs served as nonvaccinated control animals. Vaccinated and control pigs were challenge exposed with wild-type PMT. Pigs were euthanatized and necropsied on day 14 after challenge exposure. Turbinate atrophy was examined macroscopically and assigned a score. Serum anti-PMT antibodies were determined by use of an ELISA. RESULTS: The genetically modified PMT was characterized by a total lack of toxic activity. Pigs vaccinated with the modified PMT became seropositive; in contrast, control pigs remained seronegative. Necropsy revealed that the 2 control pigs had moderate and severe turbinate atrophy, respectively, whereas the 3 vaccinated pigs did not have any lesions in the turbinates or abnormalities in other organs. CONCLUSIONS AND CLINICAL RELEVANCE: Modification by use of S1164A and C1165S leads to a complete loss of toxic effects of PMT without impairment of the ability to induce protective immunity in pigs. Analysis of these results suggests that genetically modified PMT may represent a good candidate for use in developing a vaccine against progressive atrophic rhinitis in pigs.     

Molecular survey of Babesia infection in dogs in Okinawa, Japan

A total of 80 free-roaming dogs on Okinawa Island, Japan, were examined for Babesia infection using the polymerase chain reaction (PCR) and sequence analysis. Of 80 samples, 12 were positive in a Babesia genus-specific PCR. Consequent species-specific PCR for B. canis and B. gibsoni revealed that 5 (6.3%) and 7 (8.8%) dogs were infected with B. canis and B. gibsoni, respectively. Sequence analysis of the PCR products revealed that the 18S rRNA gene sequence of B. canis detected from dogs in Okinawa was very close to B. canis vogeli with sequence similarity of 99.94%.     

Comparative efficacy of two single-dose bacterins in the control of Mycoplasma hyopneumoniae in swine raised under commercial conditions in Brazil

A field study was conducted in Brazil to evaluate the efficacy of single vaccination of pigs with two bacterins to prevent Mycoplasma hyopneumoniae lung lesions. The first (T1) treatment group (174 pigs) was injected with 2 mL of saline solution; group T2 (177 pigs) with 2 mL of bacterin A, and group T3 (174 pigs) with 2 mL of bacterin B. On days-on-test (DOT) 0, 35, 66, 97 and 125, blood samples and tonsil swabs were collected from selected pigs for antibody determination (indirect ELISA) and PCR assay for the presence of M. hyopneumoniae. Pigs were slaughtered on DOT 126-129 and lung lesions were scored blindly. Bacterin A vaccinated pigs had significantly (P < or = 0.05) lower lung lesion scores (0.2%) than bacterin B (0.4%) or saline-treated pigs (1.2%); there was also a significantly lower (P < or = 0.05) number of pigs with lung lesions (27.1%), than bacterin B (38.2%) or saline-treated (55.4%) pigs. The two vaccines had similar (P>0.05) results in terms of mean weight gain, average daily weight gain, feed efficiency, frequency of PCR positives, and there was similar antibody conversion (ELISA). It was concluded that although the productivity parameters and antibody conversions were similar, bacterin A was more effective in preventing and reducing the severity of lung lesions than bacterin B.     

Innate lymphoid cells promote anatomical containment of lymphoid-resident commensal bacteria

The mammalian intestinal tract is colonized by trillions of beneficial commensal bacteria that are anatomically restricted to specific niches. However, the mechanisms that regulate anatomical containment remain unclear. Here, we show that interleukin-22 (IL-22)-producing innate lymphoid cells (ILCs) are present in intestinal tissues of healthy mammals. Depletion of ILCs resulted in peripheral dissemination of commensal bacteria and systemic inflammation, which was prevented by administration of IL-22. Disseminating bacteria were identified as Alcaligenes species originating from host lymphoid tissues. Alcaligenes was sufficient to promote systemic inflammation after ILC depletion in mice, and Alcaligenes-specific systemic immune responses were associated with Crohn's disease and progressive hepatitis C virus infection in patients. Collectively, these data indicate that ILCs regulate selective containment of lymphoid-resident bacteria to prevent systemic inflammation associated with chronic diseases.     

Calreticulin expression in neoplastic versus normal dog mammary glands: a cDNA subtraction-based study

This is the first report describing the expression of canine calreticulin (cCRT) in canine mammary gland tumour (MGT). Using cDNA subtraction method, it is found that mRNAs of CRT, cathepsin A, ovostatin, and lactotransferrin were differentially expressed in mammary adenocarcinoma as compared to hyperplasia, both of which were obtained from the dog. Furthermore, the mRNA expression levels of CRT and cathepsin A were significantly higher in canine MGT samples than in nontumour samples. In contrast, immunohistochemical studies have indicated that the expression of cCRT protein found to be detected in most of mammary gland tissues and was not correlated to the types of canine MGTs. Furthermore, cCRT was molecularly cloned, and the amino acid sequence of cCRT was found to be very similar to those of other species. Further studies are required to elucidate additional roles of cCRT in canine MGT.     

Anaplastic atypical myeloma with extensive cutaneous involvement in a dog

A 7-year-old, male, mixed breed dog was referred to the Veterinary Teaching Hospital at Kitasato University because of anorexia, lameness and multiple cutaneous lesions. Observation of bone marrow plasmacytosis, osteolytic bone lesions, serum myeloma protein and cutaneous infiltration of myeloma cells led us to a diagnosis of multiple myeloma (MM) with cutaneous involvement. Polymerase chain reaction and sequence analysis for the rearranged genes of immunoglobulin and T-cell receptor demonstrated that the neoplastic cells found in skin lesions or bone marrow are of B-lymphocyte lineage and share a common original precursor cell. The dog was treated with UW-Madison protocol or melphalan/prednisone protocol and survived 175 days. This is rare case of anaplastic MM with cutaneous involvement in dog.     

Identification and characterization of lactic acid bacteria isolated from mixed pasture of timothy and orchardgrass,and its badly preserved silage

In order to understand the relationship between lactic acid bacteria (LAB) species and silage fermentation, a total of 65 LAB strains isolated from mixed pasture of timothy (Phleum pratense L.) and orchardgrass (Dactylis glomerata L.), and its badly preserved silages were subjected to phenotypic and genetic analysis. According to these analyses, the isolates were divided into 13 groups, including Enterococcus gallinarum, Lactobacillus acidipiscis, L. coryniformis subsp. coryniformis, L. coryniformis subsp. torquens, L. curvatus, L. paraplantarum, L. plantarum subsp. argentoratensis, L. plantarum subsp. plantarum, L. sakei subsp. carnosus, Lactococcus garvieae, Lactococcus lactis subsp. cremoris, Leuconostoc pseudomesenteroides, Pediococcus acidilactici, Pediococcus pentosaceus, Weissella hellenica, Weissella paramesenteroides and Carnobacterium divergens. This is the first report to document that C. divergens, L. acidipiscis, L. sakei subsp. carnosus, L. garvieae, phenotypically novel L. lactis subsp. cremoris, E. gallinarum and W. hellenica are present in vegetative forage crops. L. plantarum group strains were most frequently isolated from the badly preserved silages. Some isolates showed a wide range of growth preferences for carbohydrate utilization, optimal growth pH and temperature in vitro, indicating that they have a high growth potential. These results are useful in understanding the diversity of LAB associated with decayed silage of timothy and orchardgrass.     

Remote sensing analysis of forest damage by selection logging in the Kabaung Reserved Forest, Bago Mountains, Myanmar

Selection logging is a principal management scheme in natural teak-bearing forests in Myanmar. Monitoring the spatial extent and intensity of selection logging is important for sustainable forest management. This study applied the normalized difference vegetation index (NDVI) image differencing method using two SPOT-5 pan-sharpened images (2.5 m spatial resolution) taken in October 2007 and January 2009 to analyze canopy changes associated with damage from forest harvesting. According to the pixel-based analysis, NDVI changes were larger in most logging road/log landing points whereas smaller NDVI changes were seen in most unlogged points. NDVI changes in teak stump areas were related to distance from a logging road and the number of stumps within the estimated crown area (a circular area with a 10 m radius from the center of each stump). A Fisher’s exact test showed that one of the main factors causing the high NDVI change in teak stump areas was the effect of road construction. The distribution pattern of teak stumps indicated that teak stumps with estimated crown areas that contained more than one stump had high mean change in NDVI. The spectral difference between before and after logging revealed that logging roads had a greater effect on canopy changes than teak stumps.     

Measurement of suspended sediment for model experiments using general-purpose optical sensors

A specialized measurement system for measuring suspended sediment concentration in model experiments was developed; it utilizes general-purpose optical sensors to perform measurements. A photoelectric sensor was used for measuring the transmitted light, and a fiber optic sensor was used for measuring the backscattered light. The values of the light absorbance and intensity of backscattered light for turbid standard solutions measured with these sensors show a linear relationship with the turbidity. The calibration lines for sand particles with a large settling velocity were established by using a calibration tank containing upwelling water. The vertical profiles of the sediment concentration measured with the photoelectric sensor corresponded well to those of the sediment concentration measured with a water sampler in an artificial channel. This result suggests that the measurement system using a photoelectric sensor functions satisfactorily. The sediment concentrations measured using the fiber optic sensor correlate well with the concentrations measured through siphon sampling; however, the values measured with the fiber optic sensor are approximately 25% larger than those measured with the siphon. This disagreement may result from the differences in the optical conditions between the calibration tank and the actual channel. Thus, it may be possible to utilize fiber optic sensors calibrated on the basis of siphon sampling for the measurement of sediment concentration.