3,004 research outputs found
Serodiversity and ecological distribution of Vibrio parahaemolyticus in the Venetian Lagoon, Northeast Italy
No full textVibrio parahaemolyticus is a natural inhabitant of estuarine and marine environments constituting part of the autochthonous microflora. This species is associated with human gastroenteritis caused by ingestion of contaminated water and undercooked seafood. During the past several years, the number of V. parahaemolyticus gastroenteritis cases have increased worldwide, causing over half of all food-poisoning outbreaks of bacterial origin. Vibrio populations in water are known to be influenced by environmental factors. Notably, it has been shown that in different parts of the world the distribution of V. parahaemolyticus in the marine environment is related to the water temperature. In this study, we identified environmental determinants affecting distribution of V. parahaemolyticus in the Venetian Lagoon, in the Italian North Adriatic Sea. Data obtained revealed that sea surface temperature constitutes the key factor influencing occurrence of V. parahaemolyticus, but salinity and chlorophyll concentration are also important. Serotyping of a collection of V. parahaemolyticus environmental isolates revealed high serodiversity, with serotypes O3:KUT and O1:KUT, belonging to the 'pandemic group', occurring with higher frequency. From our results, we conclude that there is no correlation between serotype and specific geographic site or season of the year. However, certain serotypes were isolated in the Lagoon during the entire 18 months of the study, strongly suggesting persistence in this environment
Effect on human cells of environmental Vibrio parahaemolyticus strains carrying type III secretion system 2
No full textV. parahaemolyticus is an inhabitant of estuarine and marine environments that causes seafood-borne gastroenteritis worldwide. Recently, a type 3 secretion system (T3SS2) able to secrete and translocate virulence factors into the eukaryotic cell has been identified in a pathogenicity island (VP-PAI) located on the smaller chromosome. These virulence-related genes have previously been detected only in clinical strains. Classical virulence genes for this species (tdh/trh) are rarely detected in environmental strains which are usually considered to lack virulence potential. However, during screening of a collection of environmental V. parahaemolyticus isolates obtained in the North Adriatic Sea in Italy, a number of marine strains carrying virulence-related genes, including genes involved in the T3SS2, were detected. In this study we investigated the pathogenic potential of these marine V. parahaemolyticus strains by studying their adherence ability, their cytotoxicity, their effect on zonula occludin protein1 (ZO-1) of the tight junctions and their effect on transepithelial resistance (TER) in infected Caco-2 cells. By performing a reverse transcription-PCR we also tested the expression of the T3SS2 genes vopT and vopB2 encoding an effector and a translocon protein, respectively. Our results indicate that, similarly to clinical strains, marine V. parahaemolyticus strains carrying vopT, vopB2 and other genes included in the VP-PAI are capable of adhering to human cells and of causing cytoskeletal disruption and loss of membrane integrity in infected cells. On the basis of data here presented, environmental V. parahaemolyticus strains should be included in coastal water surveillance plans as they may represent a risk for human health
Environmental Vibrio spp., isolated in Mozambique, contain a polymorphic group of integrative conjugative elements and class 1 integrons
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Persistence of adhesive properties of Vibrio cholerae after long term exposure to seawater.
No full textEmerging trends in the etiology of enteric pathogens as evidenced from an active surveillance of hospitalized diarrhoeal patients in Kolkata, India
No full textBackground: This study was conducted to determine the etiology of diarrhoea in a hospital setting in Kolkata. Active
surveillance was conducted for 2 years on two random days per week by enrolling every fifth diarrhoeal patient
admitted to the Infectious Diseases and Beliaghata General Hospital in Kolkata.
Results: Most of the patients (76.1%) had acute watery diarrhoea in association with vomiting (77.7%) and some
dehydration (92%). Vibrio cholerae O1, Rotavirus and Giardia lamblia were the important causes of diarrhoea. Among
Shigella spp, S. flexneri 2a and 3a serotypes were most predominantly isolated. Enteric viruses, EPEC and EAEC were
common in children <5 year age group. Atypical EPEC was comparatively higher than the typical EPEC. Multidrug
resistance was common among V. cholerae O1 and Shigella spp including tetracycline and ciprofloxacin. Polymicrobial
infections were common in all age groups and 27.9% of the diarrhoea patients had no potential pathogen.
Conclusions: Increase in V. cholerae O1 infection among <2 years age group, resistance of V. cholerae O1 to tetracycline,
rise of untypable S. flexnerii, higher proportion of atypical EPEC and G. lamblia and polymicrobial etiology are some of
the emerging trends observed in this diarrhoeal disease surveillance
Author Co-Citation Analysis (ACA): a powerful tool for representing implicit knowledge of scholar knowledge workers
No full textIn the last decade, knowledge has emerged as one of the most important and valuable organizational assets. Gradually this importance caused to emergence of new discipline entitled ―knowledge management‖. However one of the major challenges of knowledge management is conversion implicit or tacit knowledge to explicit knowledge. Thus Making knowledge visible so that it can be better accessed, discussed, valued or generally managed is a long-standing objective in knowledge management. Accordingly in this paper author co- citation analysis (ACA) will be proposed as an efficient technique of knowledge visualization in academia (Scholar knowledge workers)
Analysis of MicroRNA Expression in Embryonic Developmental Toxicity Induced by MC-RR
No full textAs cynobacterial blooms frequently occur in fresh waters throughout the world, microcystins (MCs) have caused serious damage to both wildlife and human health. MCs are known to have developmental toxicity, however, the possible molecular mechanism is largely unknown. This is the first toxicological study to integrate post-transcriptomic, proteomic and bioinformatics analysis to explore molecular mechanisms for developmental toxicity of MCs in zebrafish. After being microinjected directly into embryos, MC-RR dose-dependently decreased survival rates and increased malformation rates of embryos, causing various embryo abnormalities including loss of vascular integrity and hemorrhage. Expressions of 31 microRNAs (miRNAs) and 78 proteins were significantly affected at 72 hours post-fertilisation (hpf). Expressions of miR-430 and miR-125 families were also significantly changed. The altered expressions of miR-31 and miR-126 were likely responsible for the loss of vascular integrity. MC-RR significantly reduced the expressions of a number of proteins involved in energy metabolism, cell division, protein synthesis, cytoskeleton maintenance, response to stress and DNA replication. Bioinformatics analysis shows that several aberrantly expressed miRNAs and proteins (involved in various molecular pathways) were predicted to be potential MC-responsive miRNA-target pairs, and that their aberrant expressions should be the possible molecular mechanisms for the various developmental defects caused by MC-RR
Oral cholera vaccine use in Zanzibar: socioeconomic and behavioural features affecting demand and acceptance
No full textBACKGROUND: Cholera remains a serious public health problem in low-income countries despite efforts in the past to promote oral rehydration therapy as major treatment. In 2007, the majority of worldwide cases (94%) and deaths (99%) were reported from Africa. To improve cholera control efforts in addition to maintaining and improving existing water supply, sanitation and hygiene behaviour measures, the World Health Organization has recently started to consider the use of vaccines as an additional public health tool. To assess this new approach in endemic settings, a project was launched in Zanzibar to vaccinate 50,000 individuals living in communities at high risk of cholera with an oral two-dose vaccine (Dukoral). Immunisation programmes in low-income countries have suffered a reduced coverage or were even brought to a halt because of an ignorance of local realities. To ensure the success of vaccination campaigns, implementers have to consider community-held perceptions and behaviours regarding the infectious disease and the vaccine of interest. The main aim of this study is to provide advice to the Ministry of Health and Social Welfare of Zanzibar regarding routine introduction of an oral cholera vaccine from a socioeconomic and behavioural perspective as part of a long-term development for a sustained cholera prevention strategy. METHODS AND DESIGN: Qualitative and quantitative methods of health social science research will be applied on four stakeholder levels before and after the mass vaccination campaign. Rapid assessment individual interviews and focus groups will be used to describe cholera- and vaccine-related views of policy makers, health care professionals and community representatives. The cultural epidemiological approach will be employed on the individual household resident level in a repeated cross-sectional design to estimate determinants of anticipated and actual oral cholera vaccine acceptance. DISCUSSION: The study presented here is designed to inform about people's perceptions regarding cholera and about socioeconomic and behavioural factors determining anticipated and actual oral cholera vaccine acceptance in Zanzibar. Its pre- and post-intervention design using a mixed-methods approach on different stakeholder levels in communities at high risk of cholera outbreaks will ensure the collection of locally valid data relevant for public health action and plannin
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