Epidermal mucus, a major determinant in fish health: a review.

Fish epidermal mucus contains innate immune components, secreted by globlet cells that provide the primary defence against different pathogenic microbes and act as a barrier between fish and its immediate niche. The major function of mucus includes entrapment and sloughing of microbes. The mucus also contains many factors such as antimicrobial peptides (AMPs), lysozymes, lectins, proteases, etc that provide innate immunity. The AMPs secreted by epidermal mucus cells displayed antimicrobial activity against a variety of pathogens. Besides, mucosal lysozyme was found to produce significant bacteriolytic action whereas different proteases found in skin mucus of fish can kill the pathogens by cleaving its protein or by activating immunological mechanisms. Lectins are also mucosal agglutinins that play a diverse role in innate immunity like opsonization, activation of complement, etc. Epidermal mucus in fish thus provides an innate and fast acting protection which is non-specific and is found to be relatively temperature independent. The aim of the present review is to provide a broad overview of the different components of epidermal mucus including AMPs, proteases, lysozymes as well as their mode of action on pathogens.

A simple and rapid method for the quantitation of secreted hepatitis B virions in cell culture models.

Cell culture models for hepatitis B virus (HBV) remain the mainstay for screening and testing the efficacy of anti-hepatitis B virus agents. Gradient-based ultracentrifugation followed by Southern Blotting is used for hepatitis B virion estimation in cell culture; this method has several limitations. We report the development of an assay using a commercially available HBsAg-ELISA plate for immunocapture followed by real-time PCR for quantification of hepatitis B virions in cell cultures. This assay is rapid, highly sensitive (50 copies/reaction) and highly specific for virion-associated DNA. In addition, the assay requires only 20 µL of supernatant, allowing scaling down of transfections.

[Parvovirus B19 in the Czech Republic. Seroepidemiologic study]. / Parvovirus B 19 v Ceské republice. Séroepidemiologická studie.

Erythema infectiosum which is caused by parvovirus B 19 is notified in the Czech Republic similarly as some other viral exanthemas under the diagnosis "Other viral infections affecting the skin and mucosae, not listed elsewhere" (B08). Analysis of the epidemiological position in the Czech Republic in 1993-1995 was based on EPIDAT data, documentation of epidemic of 1993 in the Liberec district and serologically confirmed minor epidemics (1994, 1995). An increased number of cases (in particular in late winter and early spring) is observed in several years' (cca four-year) cycles and only in some districts. Children aged 3-10 years (88.2%) are affected predominantly. All the year round however sporadic cases affecting people of all age groups are notified. Concurrent illness of several family members (usually two) was confirmed by laboratory tests only in 9 of cca 200 investigated cases. The source of infection is usually not identified. The increase in the number of cases in a given locality rose rapidly after brief time intervals. The longest interval between two cases was 24 days. In families all affected members contracted the disease with 24 hours. According to the seroprevalence of the IgG parvovirus B 19 in different age groups the majority of cases in subadult and adult subjects is not diagnosed and notified. Seroprevalence of IgG antibodies of the parvovirus B 19 in subjects with arthropathies was 72.4%, in subjects with suspect borreliosis 69.9% an in the normal population cca 50%.

[Seroprevalence of IgG antibodies against parvovirus B19 in the population of the Czech Republic]. / Séroprevalence protilátek trídy IgG proti parvoviru B 19 v populaci Ceské republiky.

The human parvovirus B 19 was discovered in 1975 by Cossart in England. Later (1984) evidence was provided that this virus is the etiological agent of erythema infectiosum and hydrops foetalis, and in 1985 it was provided that it is also the etiological agent of some types of arthritis or arthropaties and vasculitis. The diagnosis of the disease caused by this agent is most frequently based on evidence of specific immunoglobulins. The epidemiological and clinical impact of parvoviral infections in the Czech Republic was not known so far. Examination of sera from 562 subjects aged 0-60 years assembled in 1992 in three Czech regions revealed in children, age 0 - 4 years 9.8%, during preschool and school age 27 - 35.7% and in age groups above 15 years a 53.3 - 57.7% seroprevalence of IgG parvovirus B 19, roughly equally distributed among both sexes. The more frequent prevalence of specific immunoglobulins was proved in small groups of female workers in nurseries (66.7%), nursery schools (91.7%) and in blood transfusion stations (77.8%). The seropositivity of the general female population of matched age groups, with the exception of women aged 20 - 24 years, was 53.86%.