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Teresa Merino-Ramos Miguel A. Martín-Acebes Jordi Casal Juan-Carlos Saiz Elizabeth Loza-Rubio 《Food and environmental virology》2016,8(2):156-159
The hepatitis E virus (HEV) is the causative agent of Hepatitis E, an enterically transmitted disease. HEV infections in pigs and humans have been reported worldwide, but data from Mexico are scarce. In the present study, the prevalence of anti-HEV IgG antibodies was investigated in a quite large number of swine from Mexico by means of an ELISA based on a recombinant open reading frame 2 protein of HEV genotype 3. Serum samples from 683 healthy pigs (1–48 months old), collected during 2010–2013 in 109 herds from 48 municipalities located in 9 states in the centre of the country were assayed. A 30.75 % (210/683) of the sera tested were positive, and they were distributed along all the states included in the study. The prevalence of anti-HEV antibodies varied widely between municipalities and herds, and it was higher in pigs 4–6 months of age. No relationships were detected between seroprevalences and farm characteristics. Forty individual faecal samples were analysed by RT-PCR and all resulted negative. These data indicate that HEV infection is widespread in Mexican pigs; thus, representing a potential zoonotic risk for humans. 相似文献
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Larval settlement in the marine polychaete Hydroides elegans (Haswell) is induced by certain bacteria in marine biofilms. The exact nature of the settlement cue that larvae of H. elegans receive from these bacteria remains unknown. In this study, we revealed some properties of the bacterially derived larval
settlement cue by investigating the larval settlement inductive activity of two bacterial strains after various treatments.
These two bacterial strains, Roseobacter sp. and an α-subclass Proteobacteria, are highly inductive to larval settlement of H. elegans. The larvae responded similarly to Roseobacter and Proteobacteria in all the larval settlement bioassays, suggesting that the larval settlement-inducing substances produced by these bacteria
may share common characteristics. First of all, the larvae did not settle in the seawater conditioned by the bacteria attached
as a film or by the bacteria that were freely suspended in seawater. The results suggest that the putative larval settlement
cue is not released into seawater and, therefore, should be associated with the surface of the bacteria. Secondly, formaldehyde
treatment entirely eliminated the larval settlement induction activity of the bacterial films, and streptomycin treatment
reduced the percentage of larval settlement on the bacterial films in a concentration-dependent manner. Since both treatments
can kill bacteria with little damage to the surface chemistry of bacterial cells, the decline in larval settlement is suggested
be due to a reduction of the viable bacterial population in the bacterial films. In fact, the reduction of larval settlement
in the streptomycin treatments coincided with the decrease in viable bacterial populations in broth cultures containing respective
concentrations of streptomycin. These results suggest that the viability of Roseobacter and Proteobacteria is important to their settlement induction effect. Since the larval settlement induction activity of the bacterial strains
appears to correlate with their viability, we suggest that the putative larval settlement cue is derived from a metabolic
pathway in the bacteria and that the cue is exported to and concentrated at the extracellular polymer matrix of the bacterial
cell, at which the larvae establish contact with the bacteria. The larval settlement cue may be highly susceptible to degradation
so that a metabolically active bacterial film is needed to maintain the putative cue at a concentration that surpasses the
threshold for induction of larval settlement.
Received: 14 October 1998 / Accepted: 5 September 2000 相似文献
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Rachael M. Tomb Michelle Maclean John E. Coia Elizabeth Graham Michael McDonald Chintamani D. Atreya Scott J. MacGregor John G. Anderson 《Food and environmental virology》2017,9(2):159-167
The requirement for novel decontamination technologies for use in hospitals is ever present. One such system uses 405 nm visible light to inactivate microorganisms via ROS-generated oxidative damage. Although effective for bacterial and fungal inactivation, little is known about the virucidal effects of 405 nm light. Norovirus (NoV) gastroenteritis outbreaks often occur in the clinical setting, and this study was designed to investigate potential inactivation effects of 405 nm light on the NoV surrogate, feline calicivirus (FCV). FCV was exposed to 405 nm light whilst suspended in minimal and organically-rich media to establish the virucidal efficacy and the effect biologically-relevant material may play in viral susceptibility. Antiviral activity was successfully demonstrated with a 4 Log10 (99.99%) reduction in infectivity when suspended in minimal media evident after a dose of 2.8 kJ cm?2. FCV exposed in artificial faeces, artificial saliva, blood plasma and other organically rich media exhibited an equivalent level of inactivation using between 50–85% less dose of the light, indicating enhanced inactivation when the virus is present in organically-rich biologically-relevant media. Further research in this area could aid in the development of 405 nm light technology for effective NoV decontamination within the hospital environment. 相似文献
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