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Potential Reservoirs (potential + reservoir)
Selected AbstractsOral infectious diseases: a potential risk factor for HIV virus recrudescence?ORAL DISEASES, Issue 5 2009OA González As the highly active antiretroviral therapy (HAART) has transitioned human immunodeficiency virus (HIV) infection into a ,chronic disease' management strategy, there is growing evidence that infection with non-HIV pathogens in HIV+ patients may have important public health implications in undermining HAART success and acquired immunodeficiency syndrome progression. Several bacterial and host cell products during infections with non-HIV pathogens have shown the capacity to regulate HIV replication in latently infected cells. A high prevalence of oral infections caused by bacteria, viruses and fungi has been described in HIV+ patients, including periodontal disease. The oral cavity appears to be a site of HIV pathogenesis and potential reservoir for the disease as HIV RNA and DNA forms are present in saliva as well as in gingival crevicular fluid, and oral epithelial cells are susceptible to either cell free or cell-associated HIV infection. The clinical and biological bases of potential associations between chronic oral inflammatory disorders, such as periodontal disease, and exacerbation of HIV viraemia have received little attention. This review attempts to evaluate the current understanding of HIV reactivation as a result of co-infection and/or inflammation induced by non-HIV pathogens in HIV-infected patients, and presents a hypothetic model about the potential role of periodontitis as a global oral infection that potentially contributes to HIV recrudescence. [source] Role of mitogen-activated protein kinases, nuclear factor-,B, and interferon regulatory factor 3 in Toll-like receptor 4-mediated activation of HIV long terminal repeatAPMIS, Issue 2 2009RANDI S. BERG Monocytes/macrophages are known to represent a potential reservoir of human immunodeficiency virus type 1 (HIV-1), which ensures continuous replication of the virus in patients on highly active antiretroviral therapy (HAART). Infected macrophages are a highly productive source of HIV-1 during infections with common opportunistic pathogens. Previous studies report that toll like receptors (TLR)s play a role in HIV-1 replication in macrophages. Here, we investigate the three main pathways activated through TLR4 and the interactions with the HIV-1 long terminal repeat (LTR), using human embryonic kidney (HEK) 293 cells expressing TLR4 and transfected with a luciferase reporter under the control of the HIV-1 LTR. Here, we demonstrate, that TLR4-mediated activation of HIV-LTR is largely governed by the nuclear factor-,B pathway. Neither of the mitogen-activated protein kinases ERK1/2, JNK, or p38 nor the transcription factor interferon regulatory factor 3 were involved in the direct transactivation of HIV-LTR through stimulation of TLR4. [source] Native saltbush (Rhagodia spp.; Chenopodiaceae) as a potential reservoir for agromyzid leafminer parasitoids on horticultural farmsAUSTRALIAN JOURNAL OF ENTOMOLOGY, Issue 1 2010Glenys Wood Abstract Australia has to date been spared the introduction of highly polyphagous invasive pest agromyzid leafminers; however, their arrival and spread should be considered imminent. To develop a pre-emptive control strategy to deal with exotic leafminer outbreaks the first step is to identify Australian leafmining flies, their plant hosts and their parasitoids to gain an understanding of their population dynamics. Native vegetation may be providing resources for beneficial parasitic wasps plus access to alternative hosts and refuge from disturbance. Here, two Australian endemic saltbushes (Rhagodia candolleana and R. parabolica, Caryophyllales: Chenopodiaceae) have been investigated for their potential to act as reservoirs for endemic agromyzid hosts and their key parasitoids. Mined leaves of the two Rhagodia species were sampled on two commercial horticultural properties in the Virginia horticulture area on the Northern Adelaide Plains between September 2007 and April 2008. Leaf mines on both Rhagodia species were caused by an endemic leafminer species, putatively Phytoliriomyza praecellens Spencer (Diptera: Agromyzidae). Ten species of parasitoids (all Hymenoptera) emerged from R. candolleana mines and seven different species from R. parabolica mines, mainly from the family Eulophidae and with some Pteromalidae and Braconidae. Trigonogastrella Girault sp. (Pteromalidae), Zagrammosoma latilineatum Ubaidillah and Hemiptarsenus varicornis Girault (both Eulophidae) were the most abundant species on R. candolleana, whereas two Opius Wesmael spp. (Braconidae) were the most abundant species on R. parabolica. Findings from this survey suggest an opportunity to plant purpose-designed refuges that could play a role in conservation biological control as part of an Integrated Pest Management strategy developed prior to incursion of pest leafminers such as Liriomyza species. [source] Cot mattresses as reservoirs of potentially harmful bacteria and the sudden infant death syndromeFEMS IMMUNOLOGY & MEDICAL MICROBIOLOGY, Issue 1 2004Richard E. Sherburn Abstract Cot mattress materials were investigated as potential reservoirs of bacteria in relation to the sudden infant death syndrome (SIDS). The sleeping position of the infant significantly influenced bacterial population density of cot mattress polyurethane foams (p<0.0000001) and their covers (p<0.004). Staphylococcus aureus was isolated at significantly higher frequency (p<0.03) from the infant's head region of cot mattress materials. Significantly higher bacterial population densities (p<0.001) were associated with polyurethane foams from non-integral mattresses (exposed polyurethane foam), when compared to those from mattresses completely covered by polyvinyl chloride (integral type mattress). The frequency of isolation of S. aureus from polyurethane foams from non-integral mattresses was also significantly higher (p=0.03) than from foams from the integral type. The following factors were significantly associated with increased frequency of isolation of S. aureus: from the polyurethane foam, previous use of non-integral mattresses by another child (p=0.03 for all sample sites, p=0.01 for torso region); from the covers, sleeping in the prone position (p=0.003 head region, p=0.001 torso region). Prone sleeping was also significantly associated with increased bacterial population levels (p=0.01) and increased frequency of isolation of Escherichia coli (p=0.02) from the torso region of cot mattress covers. These findings could explain some recently identified risk factors for SIDS associated with type and previous use of cot mattresses. Clostridium perfringens was isolated at very low frequency and Streptococcus pyogenes was not isolated from any cot mattress materials tested. [source] Cloning and comparison of phylogenetically related chitinases from Listeria monocytogenes EGD and Enterococcus faecalis V583JOURNAL OF APPLIED MICROBIOLOGY, Issue 6 2009J.J. Leisner Abstract Aims:, To compare enzymatic activities of two related chitinases, ChiA and EF0361, encoded by Listeria monocytogenes and Enterococcus faecalis, respectively. Methods and Results:, The chiA and EF0361 genes were amplified by PCR, cloned and expressed with histidine tags, allowing easy purification of the gene products. ChiA had a molecular weight as predicted from the amino acid sequence, whereas EF0361 was 1840 Da lower than expected because of C-terminal truncation. The ChiA and EF0361 enzymes showed activity towards 4-nitrophenyl N,N,-diacetyl-,- d -chitobioside with Km values of 1ˇ6 and 2ˇ1 mmol l,1, respectively, and kcat values of 21ˇ6 and 6ˇ5 s,1. The enzymes also showed activity towards 4-nitrophenyl ,- d - N, N,, N,-triacetylchitotriose and carboxy-methyl-chitin-Remazol Brilliant Violet but not towards 4-nitrophenyl N- acetyl-,- d -glucosaminide. Chitinolytic specificities of the enzymes were supported by their inactivity towards the substrates 4-nitrophenyl ,- d -cellobioside and peptidoglycan. The pH and temperature profiles for catalytic activities were relatively similar for both the enzymes. Conclusion:, The ChiA and EF0361 enzymes show a high degree of similarity in their catalytic activities although their hosts share environmental preferences only to some extent. Significance and Impact of the Study:, This study contributes to an understanding of the chitinolytic activities by L. monocytogenes and Ent. faecalis. Detailed information on their chitinolytic systems will help define potential reservoirs in the natural environment and possible transmission routes into food-manufacturing plants. [source] Real-time PCR for the detection and quantitative analysis of IHNV in salmonidsJOURNAL OF FISH DISEASES, Issue 6 2001K Overturf The rapid identification and quantification of virus in diseased fish is a goal both conservationists and commercial aquaculturists have struggled to attain. Recently a technique for the detection of viral mRNA particles that uses fluorescent tagging and amplification has been developed. Utilizing primers and fluorescent labelled probes generated for the specific identification of the nucleocapsid (N) and glycoprotein (G) genes of infectious haematopoietic necrosis virus (IHNV), and an instrument that measures cyclic emittance of fluorescence, the presence or absence of virus can be easily and rapidly confirmed. This method is not only useful in confirming viral presence but is effective in measuring the relative or absolute quantity of virus present within the sample. This allows for the determination of the health status of a carrier fish by measuring the quantity of viral genomes or transcribed viral genes present. Because this method is based on sequence detection, instead of virus isolation in cell culture, it is also effective in determining the presence of pathogenic organisms from water, fish feeds, or other potential reservoirs of infection. [source] TURBIDITE, SLUMP AND DEBRIS FLOW DEPOSITS AT THE KALCHINSKOE AND ZIMNEE OILFIELDS, WEST SIBERIAN BASINJOURNAL OF PETROLEUM GEOLOGY, Issue 1 2005S. F. Khafizov This paper discusses specific facies associated with Cretaceous deep-water slumps and sandstone intrusions in the West Siberian Basin. The slumps were formed during sea-level falls when storms caused sediment masses to be discharged into deep-water areas where they imposed a significant load on the underlying semi-consolidated black shales, deforming and partially destroying them. Multiple slump / avalanche events are observed at the boundary between the Lower Cretaceous (Neocomian) and Upper Jurassic (Tithonian) sequences and form potential targets for oil exploration. High-resolution sequence stratigraphic analyses show that both slump and distal fans are genetically related to lower slope/basin floor sediments and were deposited during regressions and subsequent lowstands. Two key depositional environments are recognized: the proximal parts of fans, where the most prospective potential reservoirs are found; and the more distal parts of slumps, which are principally composed of deformed shale clasts in a silt-mudstone matrix. A third facies ("slump head") is only observed on seismic profiles and is probably related to horizontally displaced "shingled" semi-consolidated black shales. [source] Assessment of the potential of dogs and cats as urban reservoirs of Ross River and Barmah Forest virusesAUSTRALIAN VETERINARY JOURNAL, Issue 1-2 2002AM BOYD Objective To determine whether dogs and cats are potential reservoirs of Ross River (RR) and Barmah Forest (BF) viruses Method Young seronegative female dogs and cats were experimentally exposed to the viruses using Ochlerotatus vigilax(Skuse) mosquitoes. Results Only one of the 10 dogs and one of the 10 cats exposed to RR developed neutralising antibody. None of the animals developed detectable viraemia or clinical signs. One dog and three cats exposed to BF developed neutralising antibody. In addition, a serological survey of sera obtained from domestic dogs and cats residing in the Brisbane region indicated that 23.7% and 1.3% of dogs, and 14% and 2% of cats, had neutralising antibodies to RR and BF respectively. Conclusions Although dogs and cats are exposed naturally to these viruses, and can become infected, they are unlikely to be important urban reservoirs of either virus. [source] Assessment of the potential of dogs and cats as urban reservoirs of Ross River and Barmah Forest virusesAUSTRALIAN VETERINARY JOURNAL, Issue 1 2002AM BOYD Objective To determine whether dogs and cats are potential reservoirs of Ross River (RR) and Barmah Forest (BF) viruses Method Young seronegative female dogs and cats were experimentally exposed to the viruses using Ochlerotatus vigilax(Skuse) mosquitoes. Results Only one of the 10 dogs and one of the 10 cats exposed to RR developed neutralising antibody. None of the animals developed detectable viraemia or clinical signs. One dog and three cats exposed to BF developed neutralising antibody. In addition, a serological survey of sera obtained from domestic dogs and cats residing in the Brisbane region indicated that 23.7% and 1.3% of dogs, and 14% and 2% of cats, had neutralising antibodies to RR and BF respectively. Conclusions Although dogs and cats are exposed naturally to these viruses, and can become infected, they are unlikely to be important urban reservoirs of either virus. [source] | ||||||||||||||||