We determined partial cDNA sequences of four immunoglobulin (Ig) classes-IgM, IgG1, IgE, and IgA-of Mongolian gerbil (Meriones unguiculatus). Each deduced Ig heavy-chain constant (IGHC) region-Cµ, Cγ1, Cε, and Cα-is structurally similar to its counterparts in the mouse and rat, and phylogenetic analysis suggests that the gerbil Igs are evolutionarily close to their counterparts. In spite of the high sequence homology to the other rodent Cγ sequences, the gerbil Cγ1 sequence differs from our previously reported Cγ2. This result indicates that the gerbil has at least two IgG subclasses. These four gerbil IGHC cDNA sequences will be useful for determining gerbil Ig isotypes and examining the expression of gerbil Ig mRNAs in response to parasitic and bacterial infections.
We applied previously published PCR primer pairs to amplify alleles at three polymorphic microsatellite loci to determine the genetic relationship of 6 bottlenose dolphins (Tursiops truncatus) that were living together in a Japanese aquarium. The three microsatellite loci were sufficient to determine the haplotype relationships of the six dolphins, which represented three different generations. It was confirmed that this genotyping method is simple and economical for assessing, establishing and maintaining genetic diversity in captive populations and will become a very effective technique for ex situ conservation in aquariums and zoos.
Abstract Antimicrobial resistance (AMR) is an important issue for public, animal and environmental health. It has been suggested that livestock farms could be a source origin of AMR, and some wild animals that inhabit this area may play an important role in the spread of AMR in the natural environment. The prevalence of AMR in Escherichia coli was examined from Okinawa rails ( Gallirallus okinawae ), an endemic bird in Okinawa Main Island, Japan. Forty‐eight faecal samples of wild Okinawa rails were collected from around a livestock farm area (LA), near human settlements, in which a population of the Okinawa rail had newly inhabited for feeding, and a forest area (FA), their natural habitat. Among 16 E. coli ‐positive faecal samples collected around LA, 11/16 (69%) showed antimicrobial resistance and five multiple drug resistance patterns were identified. However, among 15 E. coli ‐positive faecal samples from FA, 3/15 (20%) showed antimicrobial resistance, and three multiple drug resistance patterns were identified. These results indicate that the endangered Okinawa rail may also play an important role as a potential vector for the spread of AMR in the natural environment. To maintain ecological health, it is imperative that in situ/ex situ conservation projects that include translocation plans for endangered species are aware of these data.
Antimicrobial resistance (AMR) in pathogens has become a social problem across humans and wild animals. In particular, the environmental contamination caused by AMR should be monitored. In this study, we analyzed the prevalence of Escherichia coli and its AMR, as well as the distribution and genotype of E. coli in environmental soil and water samples from the habitat of the Hypotaenidia okinawae (Okinawa rail), to elucidate the potential of AMR pollution between the bird and its habitat. The habitat of Okinawa rail was divided into a livestock farm area (LA) near human settlements and a forest area (FA) as a non-human living environment. We found that the prevalence of E. coli in environmental samples collected from the LA was 38.2% (13/34), of which 84.6% (11/13) were antimicrobial resistant. In contrast, the prevalence of E. coli in environmental samples collected from the FA was 25.5% (12/47), of which 16.7% (2/12) were antimicrobial resistant. These results indicate that antimicrobial resistant E. coli was more prevalent in the LA than FA. Furthermore, pulsed-field gel electrophoresis analysis revealed a similar pattern of E. coli prevalence. This suggests that the occurrence of environmental pollution of AMR from livestock farms and that the Okinawa rail may become a carrier of antimicrobial-resistant E. coli in the Yambaru region of Okinawa.
In comparison with terrestrial mammals, dolphins require a large amount of haemoglobin in blood and myoglobin in muscle to prolong their diving time underwater and increase the depth they can dive. The genus Cetobacterium is a common gastrointestinal bacterium in dolphins and includes two species: C. somerae and C. ceti . Whilst the former produces vitamin B 12 , which is essential for the biosynthesis of haem, a component of haemoglobin and myoglobin, but not produced by mammals, the production ability of the latter remains unknown. The present study aimed to isolate C. ceti from dolphins and reveal its ability to biosynthesize vitamin B 12 . Three strains of C. ceti , identified by phylogenetic analyses with 16S rRNA gene and genome-based taxonomy assignment and biochemical features, were isolated from faecal samples collected from two captive common bottlenose dolphins ( Tursiops truncatus ). A microbioassay using Lactobacillus leichmannii ATCC 7830 showed that the average concentration of vitamin B 12 produced by the three strains was 11 (standard deviation: 2) pg ml −1 . The biosynthesis pathway of vitamin B 12 , in particular, adenosylcobalamin, was detected in the draft genome of the three strains using blastKOALA. This is the first study to isolate C. ceti from common bottlenose dolphins and reveal its ability of vitamin B 12 biosynthesis, and our findings emphasize the importance of C. ceti in supplying haemoglobin and myoglobin to dolphins.
Several species of birds in Minami Daito Island, an oceanic island located in the far south from the main islands of Japan, were found to be infected with avian Plasmodium. However, no vector species of the avian malaria in this island have been revealed yet. To speculate potential vectors, we collected mosquitoes there and investigated using a PCR procedure whether the mosquitoes harbor avian malaria or not. Totally 1,264 mosquitoes including 9 species were collected during March 2006 to February 2007. The mosquitoes collected were stored every species, sampled date and location for DNA extraction. Fifteen out of 399 DNA samples showed positive for the partial mtDNA cytb gene of avian Plasmodium. Estimated minimum infection rate among collected mosquitoes was 1.2% in this study. Four species of mosquitoes; Aedes albopictus, Culex quinquefasciatus, Lutzia fuscanus and Mansonia sp. had avian Plasmodium gene sequences. Detected DNA sequences from A. albopictus and L. fuscanus were identical to an avian Plasmodium lineage detected in bull-headed shrike (Lanius bucephalus) captured in the island. Different sequences were detected from C. quinquefasciatus, which were corresponding to an avian Plasmodium from a sparrow (Passer montanus) and Plasmodium gallinaceum. Our results suggest that A. albopictus, Lutzia fuscanus, C. quinquefasciatus, and Mansonia sp. could be potential vectors of avian malaria in Minami Daito Island. This study was the first report of molecular detection of avian Plasmodium from mosquitoes in Japan.
We investigated the prevalence of Salmonellaenterica and its antimicrobial resistance from 79 green anoles, the invasive alien species inhabits Haha-jima of the Ogasawara archipelago. Samples were collected during the period between 2009 and 2010. The resistance of S. enterica of these samples against 12 common antimicrobial agents was also determined. Salmonella strains, including serovar Oranienburg and Aberdeen, were detected from the large intestines of 30.4% of 79 green anole samples. And 37.5% of which were resistant to Oxytetracycline. This study suggests that green anoles may play an important role of the infection of S. enterica on this island. Attention is needed from the aspect of public and ecological health.
