30 research outputs found
VITAL, Monitoring and Control for Virus Safe Pork
VITAL is an ongoing (2008-2011) EU funded project on monitoring and control of food-borne viruses. The concept of VITAL is the integrated risk assessment and management of contamination of the European farm to market food chain by pathogenic viruses, such as norovirus and hepatitis E virus. The project’s focus is on the production and processing phase, moving away from the concept of endpoint monitoring towards input monitoring
Comparative study of enteric viruses, coliphages and indicator bacteria for evaluating water quality in a tropical high-altitude system
<p>Abstract</p> <p>Background</p> <p>Bacteria used as indicators for pathogenic microorganisms in water are not considered adequate as enteric virus indicators. Surface water from a tropical high-altitude system located in Mexico City that receives rainwater, treated and non-treated wastewater used for irrigation, and groundwater used for drinking, was studied.</p> <p>Methods</p> <p>The presence of enterovirus, rotavirus, astrovirus, coliphage, coliform bacteria, and enterococci was determined during annual cycles in 2001 and 2002. Enteric viruses in concentrated water samples were detected by reverse transcriptase-polymerase chain reaction (RT-PCR). Coliphages were detected using the double agar layer method. Bacteria analyses of the water samples were carried out by membrane filtration.</p> <p>Results</p> <p>The presence of viruses and bacteria in the water used for irrigation showed no relationship between current bacterial indicator detection and viral presence. Coliphages showed strong association with indicator bacteria and enterovirus, but weak association with other enteric viruses. Enterovirus and rotavirus showed significant seasonal differences in water used for irrigation, although this was not clear for astrovirus.</p> <p>Conclusion</p> <p>Coliphages proved to be adequate faecal pollution indicators for the irrigation water studied. Viral presence in this tropical high-altitude system showed a similar trend to data previously reported for temperate zones.</p
How long do nosocomial pathogens persist on inanimate surfaces? A systematic review
BACKGROUND: Inanimate surfaces have often been described as the source for outbreaks of nosocomial infections. The aim of this review is to summarize data on the persistence of different nosocomial pathogens on inanimate surfaces. METHODS: The literature was systematically reviewed in MedLine without language restrictions. In addition, cited articles in a report were assessed and standard textbooks on the topic were reviewed. All reports with experimental evidence on the duration of persistence of a nosocomial pathogen on any type of surface were included. RESULTS: Most gram-positive bacteria, such as Enterococcus spp. (including VRE), Staphylococcus aureus (including MRSA), or Streptococcus pyogenes, survive for months on dry surfaces. Many gram-negative species, such as Acinetobacter spp., Escherichia coli, Klebsiella spp., Pseudomonas aeruginosa, Serratia marcescens, or Shigella spp., can also survive for months. A few others, such as Bordetella pertussis, Haemophilus influenzae, Proteus vulgaris, or Vibrio cholerae, however, persist only for days. Mycobacteria, including Mycobacterium tuberculosis, and spore-forming bacteria, including Clostridium difficile, can also survive for months on surfaces. Candida albicans as the most important nosocomial fungal pathogen can survive up to 4 months on surfaces. Persistence of other yeasts, such as Torulopsis glabrata, was described to be similar (5 months) or shorter (Candida parapsilosis, 14 days). Most viruses from the respiratory tract, such as corona, coxsackie, influenza, SARS or rhino virus, can persist on surfaces for a few days. Viruses from the gastrointestinal tract, such as astrovirus, HAV, polio- or rota virus, persist for approximately 2 months. Blood-borne viruses, such as HBV or HIV, can persist for more than one week. Herpes viruses, such as CMV or HSV type 1 and 2, have been shown to persist from only a few hours up to 7 days. CONCLUSION: The most common nosocomial pathogens may well survive or persist on surfaces for months and can thereby be a continuous source of transmission if no regular preventive surface disinfection is performed
Quantitative PCR Detection and Characterisation of Human Adenovirus, Rotavirus and Hepatitis A Virus in Discharged Effluents of Two Wastewater Treatment Facilities in the Eastern Cape, South Africa
Review of currently applied methodologies used for detection and typing of foodborne viruses
Molecular studies on pig cryptosporidiosis in Poland
Cryptosporidium intestinal parasites have been detected in farmed pigs worldwide. Infections are usually asymptomatic with a low number of oocysts shed in pig feces. This makes the recognition of infection difficult or unsuccessful when microscopic methods are used. The aim of this study was molecular identification of Cryptosporidium species in pig herds raised in Poland with regard to the occurrence of zoonotic species. In total, 166 pig fecal samples were tested. The examined pigs were aged 1 to 20 weeks. Overall, 39 pig farms were monitored for parasite presence. The detection and identification of Cryptosporidium DNA was performed on the basis of PCR-RFLP and nucleotide sequence analysis of the amplified 18 SSU rRNA and COWP gene fragments. Infected animals were housed in 21 (53.8%) of the pig farms monitored. The presence of Cryptosporidum was confirmed in 46 (27.7%) samples of pig feces. Among positive fecal samples, 34 (29.3%) were collected from healthy animals, and 12 (24%) from diarrheic pigs. Most infected animals (42.1%) were 2 to 3 months old. The following parasite species were detected: C. scrofarum, C. suis and C. parvum. Indeed, asymptomatic infections caused by C. scrofarum were observed in the majority of the herds. Mixed infections caused by C. suis and C. scrofarum were not common; however, they were observed in 8.6% of the positive animals. C. parvum DNA was found only in one sample collected from a diarrheic pig. The application of molecular diagnostic tools allowed for detection and identification of Cryptosporidium species in pigs. The sporadic findings of C. parvum are subsequent evidence for the contribution of pigs in the transmission of cryptosporidiosis from animals to humans
VITAL, Monitoring and Control for Virus Safe Pork
VITAL is an ongoing (2008-2011) EU funded project on monitoring and control of food-borne viruses. The concept of VITAL is the integrated risk assessment and management of contamination of the European farm to market food chain by pathogenic viruses, such as norovirus and hepatitis E virus. The project’s focus is on the production and processing phase, moving away from the concept of endpoint monitoring towards input monitoring.</p
Pulsed UV-light in activation of poliovirus and adenovirus
To study the pulsed ultraviolet (UV) inactivation of poliovirus and adenovirus. Viral suspensions of 2 ml volume were exposed to varying numbers of polychromatic light pulses emitted from a xenon flashlamp. Ten pulses produced an approximately 4 log10 reduction in poliovirus titre, and no infectious poliovirus remained after 25 pulses. With adenovirus, 10 pulses resulted in an approximately 1 log10 reduction in infectivity. Adenovirus required 100 pulses to produce an approximately 3 log10 reduction in infectivity, and 200 pulses to produce a greater than 4 log10 reduction. Adenovirus was more resistant to pulsed UV treatment than poliovirus although both viruses showed susceptibility to the treatment. Pulsed UV-light treatment proved successful in the inactivation of poliovirus and adenovirus, and represents an alternative to continuous-wave UV treatment