The high prevalence of pathogenic Vibrio harveyi with multiple antibiotic resistance in scale drop and muscle necrosis disease of the hybrid grouper, Epinephelus fuscoguttatus (♀) × E. lanceolatus (♂), in China.

Scale drop and muscle necrosis disease with high mortality widely occurred recently in the hybrid grouper (Epinephelus fuscoguttatus ♀ × E. lanceolatus ♂), a crucial cultured marine fish species in China. In this study, 30 Harveyi clade isolates of 27 Vibrio harveyi strains were isolated from diseased hybrid groupers in the south-east and north-east coastal areas of China. A total of 22 V. harveyi strains were determined to be pathogenic, and most challenged fish died within 2 days of infection; surviving individuals exhibited scale drop and deep dermal lesions as naturally diseased fish. Although five typical virulence genes, including luxR, toxRVh , chiA, serine protease and vhh widely existed in V. harveyi, no obvious correlation was established between virulent strains and virulence genes harboured in them. Furthermore, multiple antibiotic resistance was widely exhibited in Harveyi clade strains, particularly for penicillins, polypeptides, lincomycins, acetylspiramycin, streptomycin, metronidazole and bacitracin. And the multiple antibiotic resistance indices were gradually decreased from southern to northern areas of China. This study demonstrated that the pathogenic V. harveyi with multiple antibiotic resistance is highly prevalent in hybrid grouper in China, which requires particular attention.

Infections of nervous necrosis virus in wild and cage-reared marine fish from South China Sea with unexpected wide host ranges.

The concerns about the impact of the nervous necrosis virus (NNV) infections in wild fish have been raised. This paper presents the results of quarterly surveys of NNV in wild and cage-reared marine fish from South China Sea. Samples of 892 wild fish belonging to 69 species and 381 cage-reared fish belonging to 11 species were collected and were detected by seminested PCR and nested PCR. In the case of seminested PCR, the positive signal was detected in 3.0% and 3.1% samples of wild and cage-reared fish, respectively. However, by nested RT-PCR, the positive signal was observed in 42.3% and 63.0% samples of wild and cage-reared fish, respectively. If the fish species were considered, the positive signal was detected in 21.7% and 72.7% species of wild and cage-reared fish by seminested PCR assay, respectively. However, by nested RT-PCR, the positive signal was observed in 65.2% and 100% species of wild and cage-reared fish, respectively. The nucleotide sequences of the nested PCR products were determined. Phylogenetic tree showed that all the obtained viral isolates belonged to the red-spotted grouper nervous necrosis virus (RGNNV) genotype. Thirty-five species of the marine fish were the new hosts of NNV.

Shortened menstrual cycles in LCD manufacturing workers.

BACKGROUND: Many chemical agents used in liquid crystal display (LCD) manufacturing have been evaluated in animal studies of female reproductive toxicity. Knowledge of their reproductive toxicity in humans is scant. AIMS: To determine the effect of organic solvents on menstrual cycle characteristics of workers in LCD manufacturing. METHODS: Cross-sectional study of female premenopausal workers in an LCD plant in Taiwan. Menstrual cycle characteristics were assessed from self-administered questionnaires, and chemical exposure was assessed using hand-held volatile organic compound (VOC) monitors with 24h canister sampling. RESULTS: There was a response rate of 94%, and the final study population after exclusions was 288. Canister sampling found many chemical compounds with potential reproductive effects in the fabrication areas of the plant. Concentrations of total VOC were higher in the panel and module fabrication areas than in other areas of the plant. The prevalence of short menstrual cycles (>24 days) was higher in panel workers (adjusted odds ratio [OR]: 7.68; 95% confidence interval [CI]: 1.51-39.15) and module workers (adjusted OR: 8.38; 95% CI: 1.72-40.95) than in array fabrication workers and office workers. CONCLUSIONS: We found evidence for a possible link between repeated exposure to multiple organic solvents such as ethanol and acetone and increased prevalence of short menstrual cycles in premenopausal women.

Filariasis and its control in Fujian, China.

Epidemiological survey of filariasis in Fujian Province, China showed that malayan filariasis, transmitted by Anopheles lesteri anthropophagus was mainly distributed in the northwest part and bancroftian filariasis with Culex quinquefasciatus as vector, in middle and south coastal regions. Both species of filariae showed typical nocturnal periodicity. Involvement of the extremities was not uncommon in malayan filariasis. In contrast, hydrocele was often present in bancroftian filariasis, in which limb impairment did not appear so frequently as in the former. Hetrazan treatment was administered to the microfilaremia cases identified during blood examination surveys, which were integrated with indoor residual spraying of insecticides in endemic areas of malayan filariasis when the vector mosquito was discovered and with mass treatment with hetrazan medicated salt in endemic areas of bancroftian filariasis. At the same time the habitation condition was improved. These factors facilitated the decrease in incidence. As a result malayan and bancroftian filariasis were proclaimed to have reached the criterion of basic elimination in 1985 and 1987 respectively. Surveillance was pursued thereafter and no signs of resurgence appeared.

Molecular epidemiology and phylogenetic analysis of a marine fish infectious spleen and kidney necrosis virus-like (ISKNV-like) virus.

Infectious spleen and kidney necrosis virus-like (ISKNV-like) virus causes a serious systemic disease with high morbidity and mortality of freshwater and marine fishes. Based on the ISKNV putative major capsid protein (MCP), the vascular endothelial growth factor (VEGF), the mRNA capping enzyme (Capping), and the tumor necrosis factor receptor-associated protein (TNFR) genes, primers were designed and used in PCR to determine the host range of ISKNV-like viruses. From the sampling of >1600 marine fishes representing 6 orders, 25 families, and 86 species collected in the South China Sea, 13 cultured fish species (141 fish) and 39 wild fish species (102 fish) were confirmed hosts of ISKNV-like viruses. The average percentage of infection of ISKNV-like viruses was 14.6%. The results from phylogenetic analysis of these genes revealed that ISKNV-like viruses could be placed into two clusters: cluster I was more related to ISKNV; cluster II included OSGIV (orange-spotted grouper iridovirus) and RBIV (rock bream iridovirus), and was quite different from ISKNV. The results of this study can contribute to the prediction and prevention of ISKNV disease outbreaks.

A reovirus disease in cultured mud crab, Scylla serrata, in southern China.

A reovirus, designated mud crab reovirus (MCRV), associated with large economic losses was recently isolated from marine cultured mud crab, Scylla serrata, in southern China. The complete viral particle is 70 nm in diameter, icosahedral and non-enveloped. The virus infects connective tissue cells of the hepatopancreas, gills and intestine in mud crab and develops in the cytoplasm. Hundred per cent mortality was observed in mud crab experimentally infected by intramuscular injection, bath inoculation and oral inoculation, while cohabitation infection caused 80% mortality. The viral genome consists of 13 linear dsRNA segments, with an electrophoretic pattern 1/5/7. The results of this study suggest that the virus is highly pathogenic and can be transmitted enterically as well as via the body surface of mud crab. Although the genomic organization of this virus is different from that of the other crab reoviruses, CcRV-W2 and DpPV, all three of these reoviruses have similar electrophoresis patterns. Therefore, MCRV may be a new member of the DpPV and CcRV-W2 group.

Complete genome analysis of the mandarin fish infectious spleen and kidney necrosis iridovirus.

The nucleotide sequence of the infectious spleen and kidney necrosis virus (ISKNV) genome was determined and found to comprise 111,362 bp with a G+C content of 54.78%. It contained 124 potential open reading frames (ORFs) with coding capacities ranging from 40 to 1208 amino acids. The analysis of the amino acid sequences deduced from the individual ORFs revealed that 35 of the 124 potential gene products of ISKNV show significant homology to functionally characterized proteins of other species. Some of the putative gene products of ISKNV showed significant homologies to proteins in the GenBank/EMBL/DDBJ databases including enzymes and structural proteins involved in virus replication, transcription, protein modification, and virus-host interaction. In addition, one major repeated sequence showing significant homology to the Red Sea bream iridovirus (RSIV) genome was identified. Based on the information obtained from biological properties (including histopathology, tissue tropisms, natural host range, and geographic distribution), physiochemical and physical properties, and genome analysis, we suggest that ISKNV, RSIV, sea bass iridovirus, grouper iridovirus, and African lampeye iridovirus may belong to a new genus of the Iridoviridae family and are tentatively referred to as cell hypertrophy iridoviruses.