The significance of Aeromonas hydrophila in association with disease outbreaks in aquaculture production in the Zhejiang province of China was investigated. Bacteriological examination of moribund fish and crabs resulted in 95 bacterial isolates: 88 bacterial isolates from fish and 7 isolates from crabs. PCR and traditional biochemical methods were used for identification of A. hydrophila. Out of 69 motile aeromonads, 35 isolates were identified as A. hydrophila by biochemical tests. However, 6 of those were not identified as A. hydrophila by a species specific PCR method. Serotyping revealed 2 dominant serotypes (O9 and O97) among A. hydrophila isolates. The data presented show that approximately 42% of the motile aeromonads isolated from disease outbreaks among various fish species were A. hydrophila. It is noteworthy that A. hydrophila accounted for more than 50% of the isolated aeromonands isolated from crucian carp Carassius carassius and Wuchang bream Megalobrama amblycephala with haemorrhagic septicaemia. Although this species was the most frequently isolated organism from internal organs of diseased fish and crabs in the present study, other motile Aeromonas spp. were also found. The PCR assay was useful in preventing misidentification of A. hydrophila, which may occur when only phenotypic tests are employed. KEY WORDS: Aeromonas hydrophila · PCR · China · Haemorrhagic septicaemia · Fish diseases Resale or republication not permitted without written consent of the publisherDis Aquat Org 46: [23][24][25][26][27][28][29] 2001 primary pathogen of freshwater fish or a secondary opportunistic pathogen of compromised or stressed hosts (Jeney & Jeney 1995). A. hydrophila has been associated with tail and fin rot, haemorrhagic septicaemia and epizootic ulcerative syndrome (EUS) (Austin & Adams 1996, Roberts 1997. A. hydrophila has also been described as the dominant infectious agent of 'fish-bacterial-septicaemia' in freshwater cultured cyprinid fishes, mainly crucian carp Carassius carassius, Wuchang bream Megalobrama amblycephala and silver carp Hypophthalmichthys molitrix in the Zhejiang province and other provinces in the Southeast of China between 1989to 1993(Qian et al. 1997. 'Fish-bacterial-septicaemia' occurs each summer in the Zhejiang province and results in significant losses for the fish farmers of the region; from 1989 to 1991 the losses were estimated to have been approximately 2200 tons of fish per year (D. Qian pers. comm.).The taxonomy of the genus Aeromonas has been revised, and new motile, mesophilic species have been identified: A. allosaccharophila, A. veronii biogroups sobria and veronii and A. encheleia have been reported as fish pathogens (Toranzo et al. 1989, Paniagua et al. 1990, Joseph & Carnahan 1994, Esteve et al. 1995. Still, A. hydrophila is regarded as the predominant fish pathogen within the mesophilic aeromonads, although its importance may have been overestimated in the past.Thus, the purpose of the present study was to estimate the actual significance of Aeromonas...

The study investigated the symptoms of posttraumatic stress disorder (PTSD) and associated risk factors among adult survivors 3 months after the 2008 Sichuan earthquake in China. One thousand five hundred sixty-three earthquake survivors in two communities participated in the study. The prevalence of probable PTSD was 37.8% and 13.0%, respectively, in the two communities that were affected differently by the earthquake. The significant predictive factors for the severity of PTSD symptoms were female gender, subnationality, lower educational level, lower social support, and higher initial exposure level. The results indicate that PTSD is also a common mental health problem among earthquake survivors in China. Given inadequate knowledge and practices concerning the mental health of disaster victims in China, the information provided by this study is useful for directing, strengthening, and evaluating disaster-related mental health needs and interventions after the earthquake.

The ciliate Ichthyophthirius multifiliis is one of the most pathogenic parasites of fish maintained in captivity. In this study, effects of crude extracts, fractions, and compounds from the leaves of Macleaya cordata against I. multifiliis were investigated under in vitro conditions by bioactivity-guided isolation method. The dried ethanol extract of M. cordata was extracted successively in a separating funnel with petroleum ether, ethyl acetate, chloroform and n-butanol. Among them, only the chloroform extract showed promising activity and therefore, was subjected to further separation and purification using various chromatographic techniques. Four compounds were isolated from chloroform extract, but only one compound showed potent activity. The structure of the active compound was elucidated as sanguinarine by hydrogen, carbon-13 nuclear magnetic resonance spectrum and electron ionization mass spectrometry. In vitro antiparasitic efficacy tests exhibited that sanguinarine was 100% effective against I. multifiliis at a concentration of 0.7 mg l(-1), with LC(50) and LC(90) values of 0.437 and 0.853 mg l(-1) after 4 h of exposure. In vivo antiparasitic efficacy tests showed that the number of I. multifiliis on the gills in the treatment group (in 0.9 mg l(-1) sanguinarine) was reduced by 96.8%, in comparison to untreated group at 25°C for 48 h. Mortality of fish did not occur in the treatment group during the trail, although 40% of untreated fish died. Our results indicate that the studied plant extracts, as well as sanguinarine might be potential sources of new antiparasitic drug for the control of I. multifiliis.

No abstract

No abstract