Occurrence of a canine distemper-like disease in aquarium seals

Outbreaks of a canine distemper-like acute disease brought high mortalities to seal populations in north-west Europe and Lake Baikal from late 1987 to 1988. During these outbreaks three seals which were introduced from Lake Baikal to an aquarium in Japan developed a distemper-like disease and other seals raised in the same room were similarly affected. Clinical signs of dead seals were anorexia, diphasic fever, dyspnea, and neuromuscular tics. Characteristic microscopic lesions of acute interstitial pneumonia seen in the lung were accompanied with hyperplasia and syncytial giant cell formation of type II pneumocytes. Eosinophilic intranuclear and cytoplasmic inclusion bodies were present in bronchial epithelial cells, type II pneumocytes, epithelial cells of bile ducts and interlobular ducts of pancreas, transitional epithelium of renal pelvis, and reticular cells of lymph nodes. Ultrastructure of inclusion bodies was similar to that seen in cells infected with morbilliviruses. Serum samples from recovered seals had virus-neutralization antibodies against canine distemper virus. The present cases were the first report of morbillivirus infection of aquarium seals in Japan.     

IDENTIFICATION OF ENDOPHYTIC BACTERIA ASSOCIATED WITH N2 FIXATION AND INDOLE ACETIC ACID SYNTHESIS AS GROWTH PROMOTERS IN CURCUMA ALISMATIFOLIA GAGNEP.

Endophytic bacteria carrying out dinitrogen (N₂) fixation and indole acetic acid (IAA) synthesis were firstly identified in C. alismatifolia, a globally important flower crop. Their potential as growth promoters to stimulate the rapid growth of host plant was also examined. It will be beneficial to reduce the propagation period of tissue culture plantlets, and also utilize as a biofertilizer for rhizome production in the field. Seven endophytic bacteria were isolated from the leaf, four isolates from the leaf base, and two from the rhizome. ECS203, a gram-negative bacterium with a round shape, showed the highest N₂ fixation at 4.2 nmol C₂H₄/10⁶ cells/hr, and ECS202 showed the highest IAA synthesis at 296 μL μg ^{? 1} protein. Three selected isolates of N₂-fixing and IAA synthesizing endophytic bacteria, i.e., ECS202, ECS203, and ECS204, isolated from the leaf base, were used to reinoculate Curcuma plantlets derived from tissue culture. Then, plants were grown in sterilized sand for 2 months and weekly supplied with N-free nutrient solution. Plant growth, colonization, nitrogen fixation, and IAA synthesis were measured at two months after planting. The inoculated plants clearly showed a better performance of plant growth and yield in terms of the plant height, plant weight, leaf area, and diameter of new rhizomes compared with uninoculated plants. The chlorophyll content and N concentration of leaves and roots also increased in inoculated plants. Endophytic bacteria from inoculated plants colonized the roots, rhizome, and leaf base. Partial sequence analysis using 16S rDNA indicated that the isolate ECS202 corresponded to Sphingomonas pseudosanguinis (99.2% similarity over 1,371 bp), ECS203 to Bacillus drentensis (99.4% similarity over 1,450 bp) and ECS204 to Bacillus methylotrophicus (99.9% similarity over 13,06 bp).     

Analyzing soil-available phosphorus by the Mehlich-3 extraction method to recommend a phosphorus fertilizer application rate for maize production in northern Mozambique

ABSTRACT

The available phosphorus (P) in soil is a major limiting factor for maize productivity in the Nacala corridor, Mozambique. In this study, soils were collected from three representative sites, Ribaue, Nampula, and Nacala, in the area, and each was used for maize pot experiment with five P fertilizer levels. The soil-available P content was determined by the Mehlich-3 method at 30 days after P fertilization. The shoot biomass and P concentration at the tasseling stage increased as the P fertilizer level increased and were significantly expressed as a function of soil-available P. Based on the function, the available P that attains 90% of the maximum shoot biomass was estimated as 79 mg P₂O₅ kg^?1. Consequently, the results in this study suggest a recommendation of 32–74 kg P₂O₅ ha^?1 fertilizer for maize production in the Nacala corridor although a field evaluation and economical evaluation are necessary.     

Root response to aerobic conditions in rice,estimated by Comair root length scanner and scanner-based image analysis

Precise evaluation of root system architecture is important for understanding how rice plants are adapted to non-puddled and non-flooded conditions in aerobic culture. The objective of this study was to compare estimates of root length by the Comair root length scanner and a flat bed scanner and image analysis software in rice grown in aerobic, near-saturated and flooded fields. Fine roots (diameter < 0.2 mm) accounted for >80% of root length in all hydrological conditions. The Comair root length scanner detected fewer fine roots than the software; root length estimated by the Comair scanner was between that of roots wider than 0.1 mm and roots wider than 0.2 mm estimated by image analysis software. Importantly, total root length under aerobic and near-saturated conditions was 10–30% of that under flooding by image analysis software, but not by the Comair scanner. Digital image analysis detected genotypic differences in fine root development in the subsurface layer in aerobic culture that the Comair root length scanner would have missed. Although root length measurement by image analysis software is still under development, this new tool will facilitate the phenotyping of root system architecture and shed light on the roles of fine roots in water-saving rice cultivation.     

Demonstration of the absence of intervening sequences (IVSs) within 16S rRNA genes of Taylorella equigenitalis and Taylorella asinigenitalis isolates

A total of 57 Taylorella equigenitalis (n=22) and Taylorella asinigenitalis (n=35) isolates was shown not to carry any intervening sequences (IVSs) within 16S rRNA gene sequences. By contrast, we have already shown the genus Taylorella group to carry several kinds of IVSs within the 23S rRNA gene sequences.     

Phagocytosis of bovine blood and milk polymorphonuclear leukocytes after ozone gas administration in vitro

To determine the effects of ozone on the phagocytosis of bovine polymorphonuclear leukocytes (PMNs), ozone gas was administered in vitro on the blood and milk of healthy lactating cows, cows with acute mastitis, and cows with milk fever. In the blood of healthy dairy cattle, although there was no significant effect of ozone gas on the viability of the leukocytes, phagocytosis of PMNs significantly decreased. In contrast, ozone gas administration in vitro significantly increased phagocytosis of PMNs from the blood of cows with acute mastitis and milk fever, and from mastitic milk. These findings showed that ozone administration in vitro has positive and negative effects on bovine PMN phagocytosis, depending on the health status of the animal.