Tuberculosis seroprevalence and comparison of hematology and biochemistry parameters between seropositive and seronegative captive Asian elephants of Nepal

We conducted a tuberculosis (TB) serosurveillance program of captive elephants in Nepal and compared hematology and biochemistry parameters between seropositive and seronegative elephants. A total of 153 elephants (male=20, female=133) from four national parks were tested for TB using the ElephantTB STAT-PAK^® Assay (ChemBio Diagnostic Systems, Inc., Medford, NY, USA). The mean reported age for 138 elephants was 38.5 years (range 2–71 years). Seroprevalence for TB was 21.56% (33/153). The majority of seropositive elephants were female (n=30) and from Chitwan National Park (n=29). The occurrence of TB seropositive cases in other more remote national parks suggests TB may be widespread among the captive elephant population of Nepal. Hematology and biochemistry analyses were performed on 13 and 22 seropositive elephants, respectively and, nine elephants from a seronegative TB herd for comparison. Hematology parameters (hemoglobin, packed cell volume, platelet, white blood cells, and erythrocyte sedimentation rate) were comparable between the two groups. Total protein, globulin, and lactate dehydrogenase were significantly higher in seronegative elephants, and bilirubin was significantly higher in seropositive elephants whereas blood urea nitrogen, creatinine, glutamic oxaloacetic transaminase/aspartate aminotransferase (GOT/AST), glutamic pyruvic transaminase/alanine aminotransferase (GPT/ALT), gamma glutamyl transferase (GT), and albumin were not significantly different. The range of biochemical parameters that were significantly different between seropositive and seronegative elephants had narrow ranges. Thus, the potential of these parameters as a direct biomarker for TB diagnosis is limited based on the findings in this study. We recommend including blood parameters in future TB surveillance studies.     

Radial movement of sapwood-injected rubidium into heartwood of Japanese cedar (<Emphasis Type="Italic">Cryptomeria</Emphasis><Emphasis Type="Italic">japonica</Emphasis>) in the growing period

Rubidium solution was injected in the sapwood of a Japanese cedar cultivar in the growing period, and its radial movement in stem was traced to investigate the accumulation of alkali metals in the heartwood. Sapwood-injected Rb was detected in outer heartwood at 10 days after the treatment, and continued increasing at 20 days after. Radial movement of Rb toward heartwood was considered to occur soon after the treatment, and to decline at a certain point of the time after Rb injection ceased. However, Rb continued moving in heartwood probably by diffusion even after the cease of Rb injection. In a series of injection experiment, radial movement of injected Rb is not corresponding to the seasonality of both cambial activity and cytological changes of ray parenchyma accompanied with heartwood formation. From the results on Rb’s behavior, we conclude that accumulation of K and other alkali metals in heartwood of Japanese cedar has two steps, active transport from sapwood to outer heartwood via ray, and diffusion in heartwood, and that these processes proceed independently from both cambial activity and cytological changes of ray parenchyma.     

Detection of hybrids between masu salmon <Emphasis Type="Italic">Oncorhynchus masou masou</Emphasis> and amago salmon <Emphasis Type="Italic">O. m. ishikawae</Emphasis> occurred in the Jinzu River using a random amplified polymorphic DNA technique

Identification of masu salmon Oncorhynchus masou masou and amago salmon O. m. ishikawae was accomplished using a random amplified polymorphic DNA (RAPD) technique. Of 80 primers screened, three primers amplified subspecies-specific fragments (OPA11-1095 ^*, OPB5-1618^* and OPD5-2038 ^*). Based on fragment patterns, 33 hybrids were detected among 150 upstream-migrating individuals in the Jinzu River, central Japan, a long-time habitat of masu salmon, to which amago salmon were recently introduced. All of the individuals examined in the 2000–2002 cohorts were identified as F ₁ and F _x as well as pure masu and amago forms. These results indicated continuing hybridization, the genetic pollution of the native masu salmon population by amago salmon possibly being a serious problem in the Jinzu River. Both standard length and body weight in F ₁ hybrids tended to be less than in pure masu salmon. However, F _x hybrids showed similar body sizes to masu salmon.     

Oxygen consumption and swim speed of the harbor porpoise Phocoena phocoena

ABSTRACT: The rate of oxygen consumption and energetic cost of locomotion of captive harbor porpoises Phocoena phocoena were studied in Hokkaido, Japan, using respirometry together with externally attached devices (a data logger) that recorded swim speed and dive depth. Harbor porpoises swam freely in a tank at a swim speed ranging 0.5–4.2 m/s. Swimming during most dives was relatively slow with mean swim speed being 0.76–0.91 m/s. Oxygen consumption rate of the swimming harbor porpoise increased with swim speed according to a cubed function. The minimum cost of transport during underwater swimming in the harbor porpoise was 2.39–2.43 J/kg per m at an average swim speed of 1.3–1.5 m/s. However, porpoises usually swam slower to conserve energy and dived aerobically. This explains why harbor porpoises can dive repeatedly and continuously without extended rest at the sea surface.     

Amino acid substitution in Ace paralogous acetylcholinesterase accompanied by organophosphate resistance in the spider mite Tetranychus kanzawai

Insecticide resistant strains of the kanzawa spider mite, Tetranychus kanzawai, with insensitive AChE have spread widely throughout Japan. To clarify the molecular mechanism of this insensitivity, acetylcholinesterase (AChE) cDNA of the resistant strains of T. kanzawai was determined based on the AChE cDNA sequence of Tetranychus urticae and the sequences compared between the two spider mite species. The cDNA encoded 687 amino acids of AChE primary structure showing high homology to T. urticae. Amino acid homology indicated that the AChE is an Ace paralogous type of insect AChE. There were only three substitutions of amino acid residues between the AChEs of the two species. In the AChE of the resistant strain of T. kanzawai, one of the three amino acid substitutions was Phe439Trp, which lines the acyl pocket of the enzyme active site. Considering that the same substitution was found at the equivalent position of Ace paralogous AChE in the resistant strain of Culex tritaeniorhynchus, Phe439Trp substitution likely plays an important role in the insecticide insensitivity of the mite AChE.     

Identification of the Cryptosporidium isolate from chickens in Japan by sequence analyses

The Cryptsosporidium isolate from chickens in Japan by Itakura et al. is not yet accurately identified because of several discrepancies in phenotypic features. We attempted to identify this isolate by analyzing the partial sequences of the 18S rRNA, COWP and HSP70 genes. The chicken isolate showed nearly 100% homology in each gene with C. baileyi, but less than 91% homology with C. meleagridis. In addition, these genes were classified into the same cluster with C. baileyi other than C. meleagridis by phylogenetic analysis. From these results, the Cryptosporidium isolate from chickens in Japan is considered to be one of the strains of C. baileyi.     

Mutual antagonism between sterol demethylation inhibitors and phosphorothiolate fungicides on Pyricularia oryzae and the implications for their mode of action

Joint action between a phosphorothiolate (PTL) fungicide, iprobenfos, and a sterol demethylation inhibitor (DMI), pefurazoate, was tested by crossed paper technique on three types of field isolates of Pyricularia oryzae Cavara that differed in PTL sensitivity and metabolism. Mutual antagonism in anti-fungal action between iprobenfos and pefurazoate was observed in a wild-type field isolate of the fungus sensitive to PTL and in an isolate moderately resistant to PTL, but not in a PTL-resistant isolate lacking the ability to metabolize PTL. Antagonism of the antifungal action of iprobenfos by pefurazoate seemed to be a result of inhibition of activation by cleavage of the P-S bond of iprobenfos mediated by mixed-function oxygenase (mfo) activity, while antagonism of the anti-fungal action of pefurazoate by iprobenfos may be caused by the binding of pefurazoate by large amounts of an iprobenfos-induced mfo which results in reduced inhibition of ergosterol biosynthesis. In the PTL-resistant isolate, the mutually antagonistic action was not observed, presumably because the induction of the mfo-metabolizing iprobenfos was lacking. Similar antagonism was also observed when another PTL, edifenphos, was used instead of iprobenfos, and when other DMIs, propiconazole, prochloraz and hexaconazole were used instead of pefurazoate. The results of the present experiment indicate that DMIs may also bind to and inhibit an inducible type of fungal mfo which metabolizes xenobiotics, and that PTLs may be activated by an mfo prior to their anti-fungal action.     

The enhancement of Th1 immune response by anti-PD-L1 antibody in cattle infected with Mycobacterium avium subsp. paratuberculosis

Johne’s disease, caused by Mycobacterium avium subsp. paratuberculosis (MAP), is a chronic enteritis of ruminants. Previous studies have shown that programmed death-ligand 1 (PD-L1) is associated with the disease progression, and PD-L1 blockade activates MAP-specific Th1 responses in vitro. Here, we performed anti-PD-L1 antibody administration using 2 MAP-infected cattle at the late subclinical stage of infection. After administration, bacterial shedding was reduced or maintained at a low level. Additionally, MAP-specific Th1 cytokine production was upregulated, and CD69 expression was increased in T cells. Collectively, the treatment has a potential as a novel control method against Johne’s disease.