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Seventy-six Taiwanese bacterial isolates including 74 from diseased, cultured, aquatic animals (54 grey mullet Mugil cephalus, 3 basket mullet Chelon alatus, 2 tilapia Oreochromis niloticus, 1 grouper Epinephelus coioides, 2 yellowfin seabream Acanthopagrus latus, 1 Borneo mullet Chelon macrolepis, 1 bullfrog Rana catesbeiana, 1 Japanese eel Anguilla japonica, and 9 giant freshwater prawns Macrobrachium rosenbergii), 1 wild-caught seafood species (squid muscle collected from a restaurant) and 1 human isolate (from a patient with a history of consuming raw squid in the previously mentioned restaurant), all collected between 1999 and 2006, were confirmed by PCR assay to be Lactococcus garvieae. The phenotypic characterization was determined by rabbit anti-KG+ and KG− serums, and 74 of the 76 Taiwanese strains displayed a KG− phenotype. The genetic characterization was investigated by pulsed-field gel electrophoresis (PFGE). Genomic DNA was digested with restriction endonucleases Apa I and Sma I and separated by PFGE. Ten different L. garvieae pulsotypes were identified. Predominant pulsotypes A1a/S1a were obtained from > 96% of strains (52 of 54) from grey mullet, demonstrating a clonal dissemination of L. garvieae in grey mullet in Taiwan. In experimental challenges with grey mullet and tilapia, L. garvieae pulsotypes A1/S1 and A11/S11 showed higher virulence compared with other pulsotypes.KEY WORDS: Lactococcosis · Pulsed-field gel electrophoresis · Pulsotype · Grey mullet · Tilapia · Giant freshwater prawn Resale or republication not permitted without written consent of the publisher

Largemouth bass (Micropterus salmoides) are common hosts of an epizootic bacterial infection by Nocardia seriolae. We conducted transcriptome profiling of M. salmoides to understand the host immune response to N. seriolae infection, using the Illumina sequencing platform. De novo assembly of paired-end reads yielded 47,881 unigenes, the total length, average length, N50, and GC content of which were 49,734,288, 1038, 1983 bp, and 45.94%, respectively. Annotation was performed by comparison against non-redundant protein sequence (NR), non-redundant nucleotide (NT), Swiss-Prot, Clusters of Orthologous Groups (COG), Kyoto Encyclopaedia of Genes and Genomes (KEGG), Gene Ontology (GO), and Interpro databases, yielding 28,964 (NR: 60.49%), 36,686 (NT: 76.62%), 24,830 (Swissprot: 51.86%), 8913 (COG: 18.61%), 20,329 (KEGG: 42.46%), 835 (GO: 1.74%), and 22,194 (Interpro: 46.35%) unigenes. Additionally, 8913 unigenes were classified into 25 Clusters of Orthologous Groups (KOGs) categories, and 20,329 unigenes were assigned to 244 specific signalling pathways. RNA-Seq by Expectation Maximization (RSEM) and PossionDis were used to determine significantly differentially expressed genes (False Discovery Rate (FDR) < 0.05) and we found that 1384 were upregulated genes and 1542 were downregulated genes, and further confirmed their regulations using reverse transcription quantitative PCR (RT-qPCR). Altogether, these results provide information on immune mechanisms induced during bacterial infection in largemouth bass, which may facilitate the prevention of nocardiosis.

16Grey mullet (Mugil cephalus) is an economically important fish species in Taiwan

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A new species of Kudoa lutjanus n. sp. (Myxosporea) is described from the brain and internal organs of cultured red snapper Lutjanus erythropterus from Taiwan. The fish, 260 to 390 g in weight, exhibited anorexia and poor appetite and swam in the surface water during outbreaks. Cumulative mortality was about 1% during a period of 3 wk. The red snapper exhibited numerous creamy-white pseudocysts, 0.003 to 0.65 cm (n = 100) in diameter, in the eye, swim bladder, muscle and other internal organs, but especially in the brain. The number of pseudocysts per infected fish was not correlated with fish size or condition. Mature spores were quadrate in apical view and suboval in side view, measuring 8.2 ± 0.59 µm in width and 7.3 ± 0.53 µm in length. The 4 valves were equal in size, each with 1 polar capsule. Polar capsules were pyriform in shape, measuring 3.62 ± 0.49 µm in length and 2.2 ± 0.49 µm in width. Mild inflammatory responses or liquefaction of host tissue were associated with K. lutjanus n. sp. infection. The junction of shell valves appeared as overlapping, straight lines. The polar filament formed 2 to 3 coils. A general PCR (polymerase chain reaction) primer for Kudoa amplified the small subunit (SSU) rDNA sequences, and the amplified gene was sequenced. It was evident from the phylogenetic tree that the 3 strains tested, AOD93020M, AOD93028M and AOD93028B, were identical and belonged to the Kudoa SS rRNA subgroup. The evolutionary tree showed that these strains form a unique clade, at a distance from other Kudoa species and myxosporeans. The spore's morphological and ultrastructural characteristics, as well as the SS rDNA properties of the isolates, were also essentially identical and served to distinguish them from representative Kudoa. It is, therefore, proposed that the strains isolated from the diseased red snapper be assigned to a new species. KEY WORDS: Myxosporea · Kudoa lutjanus n. sp. · Brain · Red snapper · Lutjanus erythropterus Resale or republication not permitted without written consent of the publisherDis Aquat Org 67: [115][116][117][118][119][120][121][122][123][124] 2005 a polar capsule (Hervio et al. 1997, Moran et al. 1999a, Pampoulie et al. 1999, Swearer & Robertson 1999, Whipps et al. 2004. Most Kudoa species appear in the skeletal musculature and have been connected with post mortem myoliquefaction in commercially valuable marine fishes (Moran et al. 1999a). Kudoa thyrsites Gilchrist, 1924 has been recorded from 27 fish species dispersed worldwide (Whitaker et al. 1994). For example, this parasite has both a worldwide distribution and a wide host range (Kabata & Whitaker 1989, Kent et al. 1994, Moran & Kent 1999, Moran et al. 1999b. K. thyrsites does not normally cause mortality, although 1 case of high mortality in farmed Atlantic salmon Salmon salar L. has been observed (Harrell & Scott 1985). The few remaining Kudoa species have been identified from tissues including the gills, brain, gallbladder, pericardial cavity and ovary (Lom & Dyková 1992, Swearer & Robertson 1...

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