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In order to clarify the transmission process of human immunodeficiency virus type 1 (HIV-1) through the epithelial cell barrier, HeLa cells susceptible and non-susceptible to HIV-1 were cloned and designated as P6 HeLa and N7 HeLa cells, respectively. P6 HeLa cells could be infected with the LAI strain of HIV-1 and mediated HIV-1 transcytosis. In contrast, N7 HeLa cells exhibited neither HIV-1 infection nor transcytosis. CD4 and galactosylceramide as the receptors for HIV-1 were not detected on P6 HeLa cells, although an anti-CD4 monoclonal antibody (mAb) blocked HIV-1 infection. Since HIV-1-infected P6 HeLa cells exhibited no fusion and survived, we speculated that the P6 HeLa cells expressed molecules other than CD4 which facilitated HIV-1 infection. Two mAbs (A-14 ITK and C57 a9-9) which inhibited the HIV-1 infection of P6 HeLa cells were generated. Each mAb recognized distinct molecule(s) as shown by Western blotting. Transcytosis by the P6 HeLa cells was inhibited by C57 a9-9 but not by A-14 ITK or anti-CD4 mAb. Both infection and transcytosis may be responsible for HIV-1 transmission through epithelial cells in a complex manner. Although infection and transcytosis occurred via different mechanisms, the molecule(s) recognized by C57 a9-9 mAb may be associated with both processes. 相似文献
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Airi Palva Hannele Jousimies-Somer Pekka Saikku Pertti Väänänen Hans Söderlund Marjut Ranki 《FEMS microbiology letters》1984,23(1):83-89
Abstract Chromosomal DNA fragments from Chlamydia trachomatis serotype L2 were shotgun-cloned into pBR322. A C. trachomatis -specific clone was further subcloned to produce specific DNA reagents for the identification of C. trachomatis by nucleic acid sandwich hybridization. The chosen DNA reagents from serotype L2 also hybridized with all the other chlamydial serotypes tested, but not with the DNA from 41 unrelated organisms. The sensitivity of the sandwich hybridization test was 106 DNA molecules. The applicability of the test for routine diagnostic use was demonstrated by a pilot study in which C. trachomatis was directly detected from genital specimens. 相似文献
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基因芯片是近年发展起来的一种高通量的核酸分析技术,已成为“后基因组时代”的重要分析工具之一。本简述了基因芯片的概念、分类及特点,并对基因芯片技术在性传播疾病病原体淋球菌、沙眼衣原体、解脲脲原体和人乳头瘤病毒研究中的应用作了综述。 相似文献
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Several hypotheses have been proposed to explain why femalebirds eithercopulate repeatedly with a single mate or copulatewith multiple partners eventhough only a single copulationmay be sufficient to fertilize an entireclutch. We hypothesizethat females may directly benefit from high frequenciesof copulationand multiple copulation partners if they receive a cloacalinoculationof beneficial sexually transmitted microbes (STMs) that caneitherprotect them against future encounters with pathogensand/or serve as therapyagainst present infections. Experimentsin domestic animal production,wildlife rehabilitation, andclinical medicine indicate that inoculations ofbeneficial microbesderived from the indigenous microflora of hosts can leadtonutritional benefits, resistance to colonization by pathogens,theelimination of infection, and improved immune system functioninginrecipients. Our hypothesis predicts greater copulatory rateswhen theprobability of the transmission of beneficial microbesexceeds that ofpathogens and when the positive effects of beneficialmicrobes on host fitnessexceed the negative effects of pathogens.Patterns of copulatory behavior inbirds suggest the potentialutility of our hypothesis. We discuss ourhypothesis in thecontext of observed patterns of copulation in birds andproposesome ways to directly test our hypothesis. Information on theprobabilitiesof transmission during copulation of beneficial and pathogenicmicrobesand their relative potencies in birds are needed to directlytest thepredictions of our hypothesis. 相似文献
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Sterility virulence, or the reduction in host fecundity due to infection, occurs in many host–pathogen systems. Notably, sterility virulence is more common for sexually transmitted infections (STIs) than for directly transmitted pathogens, while other forms of virulence tend to be limited in STIs. This has led to the suggestion that sterility virulence may have an adaptive explanation. By focusing upon finite population models, we show that the observed patterns of sterility virulence can be explained by consideration of the epidemiological differences between STIs and directly transmitted pathogens. In particular, when pathogen transmission is predominantly density invariant (as for STIs), and mortality is density dependent, sterility virulence can be favored by demographic stochasticity, whereas if pathogen transmission is predominantly density dependent, as is common for most directly transmitted pathogens, sterility virulence is disfavored. We show these conclusions can hold even if there is a weak selective advantage to sterilizing. 相似文献
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Renu Singh Chetna Dhand Gajjala Sumana Rachna Verma Seema Sood Rajinder Kumar Gupta Bansi Dhar Malhotra 《Journal of molecular recognition : JMR》2010,23(5):472-479
Polyaniline/carbon nanotubes composite (PANI‐CNT) electrochemically deposited onto indium‐tin‐oxide (ITO) coated glass plate has been utilized for Neisseria gonorrhoeae detection by immobilizing 5′‐amino‐labeled Neisseria gonorrhoeae probe (aDNA) using glutaraldehyde as a cross‐linker. PANI‐CNT/ITO and aDNA‐Glu‐PANI‐CNT/ITO electrodes have been characterized using scanning electron microscopy (SEM), Fourier Transform Infrared (FT‐IR) spectroscopy, cyclic voltammetry (CV), and differential pulse voltammetry (DPV). This bioelectrode can be used to detect N. gonorrhoeae using methylene blue (MB) as redox indicator with response time of 60 s and stability of about 75 days when stored under refrigerated conditions. DPV studies reveal that this bioelectrode can detect complementary DNA concentration from 1 × 10?6 M to 1 × 10?17 M with detection limit of 1.2 × 10?17 M. Further, this bioelectrode (aDNA‐Glu‐PANI‐CNT/ITO) exhibits specificity toward N. gonorrhoeae species and shows negative response with non‐Neisseria gonorrhoeae Neisseria species (NgNS) and other gram negative bacteria (GNB). Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
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Sara Bellinvia Paul R. Johnston Klaus Reinhardt Oliver Otti 《Ecological Entomology》2020,45(1):142-154
1. Microbes associated with reproductive organs of animals are either sexually transmitted or opportunistic. Both can affect host defence, immunity, and future colonisation with other microbes. There are only few studies on the microbiota of reproductive organs in insects and how they are affected by copulation. 2. This study examines the bacterial communities associated with reproductive organs in the common bedbug Cimex lectularius, a well-established insect model for the effects of microbes on male and female reproduction. Combining a metagenomic approach with a controlled mating scheme, we found 31 sequence variants (SVs) across 55 organ samples, with on average three SVs in each sample. Male and female reproductive organs harboured distinct bacterial communities in terms of present SVs. 3. Using a community ecology approach, we found three potential indications of sexual transmission of bacteria in the common bedbug: (i) copulation increased the similarity of the communities of male and female organs; (ii) mated individuals harboured bacteria that were found in non-mated individuals of the opposite sex but not in non-mated individuals of the same sex; and (iii) bacterial communities showed a high SV turnover between non-mated and mated individuals, suggesting a mating-induced replacement of bacteria. 4. Our findings show that the community ecology approach is useful to examine the bacterial dynamics on reproductive organs, especially when combined with studies that quantify the frequency of transmission and/or estimate the effect of the transmitted microbes on the host immune system and the host endosymbionts. 相似文献
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《Ethology, Ecology and Evolution》2012,24(4):327-340
In this work I introduce the Sexually Transmitted Disease (STD)-mediated Sperm Competition Model that establishes a link between sperm competition among males, sexually transmitted (ST) pathogens carried by the ejaculate and immune defences against ST-pathogens and spermatozoa in the female reproductive tract. Increased immune activity in the female reproductive system triggered by ST-pathogens may also result in increased immune attack against spermatozoa, thus setting the stage for competition amongst spermatozoa of different males to overcome the immune defences of females. Successful spermatozoa will have improved competitive abilities at fertilizing ova. 相似文献
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Jacqui A. Shykoff Erika Bucheli Oliver Kaltz 《Evolution; international journal of organic evolution》1997,51(2):383-392
Mating opportunities, pollination intensity, and pollen dispersal ability may vary with variation in floral traits such as color, size, and shape. Where these traits are selected by pollinators for enhanced elaboration, they should evolve toward the equilibrium between selection for further elaboration and selection against this through reduced fecundity or vitality. Here we show that pollinator-borne fungal diseases of plants may be a factor influencing the position of this equilibrium. Populations of the rock pink, Dianthus silvester often contain individuals infected with the anther smut fungus Microbotryum violaceum (= Ustilago violacea). In a naturally infected population in the Alps of eastern Switzerland we investigated how intrapopulation variation in flower size and nectar rewards influenced spore deposition and how floral traits varied with disease status. We found that spore deposition increased with increasing petal size, suggesting that large-flowered plants were at a greater risk of disease. Spore deposition was also higher for plants growing in patches with many or a high proportion of diseased neighbors. Multiple regression analyses showed that petal size or nectar reward influenced spore deposition when the effects of neighborhood disease abundance were controlled statistically. In sequential analyses, after removing the effects of disease density or frequency and plant gender, petal length explained significant variation in spore deposition. Diseased plants had reduced female reproductive organs, but calyx size was intermediate between that of healthy perfect and female flowers of this gynodioecious-gynomonoecious species, and diseased plants bore flowers with the largest petals. This may reflect a symptom of this disease or the cause, if larger-flowered plants are more likely to become infected. We conclude that investment to pollinator attraction may bring an enhanced risk of contracting this sterilizing pollinator-borne disease, so natural selection by the fungus M. violaceum acts to lower attractiveness to pollinators. 相似文献
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GREGORY D. D. HURST ROSIE G. SHARPE ANGELA H. BROOMFIELD LINDA E. WALKER TAMSIN M. O. MAJERUS ILIA A. ZAKHAROV MICHAEL E. N. MAJERUS 《Ecological Entomology》1995,20(3):230-236
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- 1 Sexually transmitted diseases (STDs) have rarely been reported in insects and other invertebrates. The majority of those reported involve organisms where sexual transmission is augmented by either vertical (i.e. inherited) transmission, or horizontal transmission, independent of host sexual activity.
- 2 We here demonstrate the existence of an STD in the coccinellid beetle Adalia bipunctata. This species bears a parasitic mite of the genus Coccipolipus. We show that, like many other podapolipid mites, this mite is transmitted between host individuals at a high rate during copulation. It also appears to be transmitted at a low rate between non-copulating individuals.
- 3 We show that infected female A.bipunctata produced eggs at a reduced rate, and that the eggs produced by infected females have highly decreased viability. However, no effect of infection upon host longevity was observed.
- 4 The results are discussed in relation to the incidences of sexually transmitted disease in invertebrates in general, the causes of disease symptoms, and the importance of this disease in the evolution of A.bipunctata.
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The parasite pressure exerted by the slavemaker ant Protomognathus americanus on its host species Leptothorax longispinosus was analyzed demographically and genetically. The origin of slaves found in colonies of the obligate slavemaker was examined with nuclear and mitochondrial DNA markers to make inferences about the frequency and severity of slave raids. Relatedness of enslaved L. longispinosus workers in the same nest was very low, and our data suggest that, on average, each slavemaker nest raids six host colonies per season. Therefore, the influence of slavemaker species on their hosts is much stronger than simple numerical ratios suggest. We also found that slave relatedness was higher in small than in large slavemaker nests; thus, larger nests wield a much stronger influence on the host. We estimated that in the study population, on average, a host nest has a 50% chance of being attacked by a slavemaker colony per year. Free-living Leptothorax colonies in the vicinity of slavemaker nests did not represent the source of slaves working in P. americanus colonies, which suggests that raided nests either do not survive or migrate after being raided. Colony composition and intranest relatedness of free-living L. longispinosus colonies differed markedly between areas with slavemakers and those that are parasite-free. In the presence of slavemakers, host colonies were less likely to be polygynous and had fewer workers and a higher relatedness among worker brood. Host nests with slavemaker neighbors allocated more resources into sexuals, possibly caused by these shifts in nest demography. Finally, enslaved Leptothorax workers in P. americanus nests appeared to be less efficient than their counterparts in free-living colonies. Thus, slavemakers exert a much stronger impact on their hosts than had previously been suspected and represent an unique system to study parasite-host coevolution. 相似文献
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Robert J. Knell 《Evolution; international journal of organic evolution》1999,53(3):957-961
Few studies have investigated the consequences of parasite-mediated sexual selection on the parasites involved. In some cases parasite-mediated sexual selection could lead to increased virulence, but I develop a simple model that shows that, if a parasite is sexually transmitted (i.e., is a sexually transmitted disease, or STD) and if mating success of the host is adversely affected by the parasite, then less virulent STDs will be selected for because transmission of the STD depends on the mating success of the host. This selection for reduced virulence could have important consequences for the role of STDs in sexual selection. 相似文献
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《Ethology, Ecology and Evolution》2012,24(3):251-258
Cloacal microparasites such as viruses, bacteria and fungi are expected to condition choice of sexual partner, as they can not only affect the expression of secondary sexual traits used in courtship, but they could be also directly transmitted to partners through copulation. We investigated the distribution of three cloacal microparasites (the bacterium Chlamydia psittaci and the yeasts Candida albicans and Kloeckeria sp.) among males and females of the sexually plumage dichromatic Malurus cyaneus and Sericornis frontalis, and the plumage monochromatic Manorina melanophrys. Males tended to be more parasitized than females within species, but the effect was stronger for the sexually dichromatic S. frontalis than for the sexually monochromatic M. melanophrys. In addition, parasitized males of the sexually dichromatic M. cyaneus had more conspicuous ear tufts (a secondary sexual trait used in courtship) than unparasitized males. The above evidence suggest that mate choice may involve a cost in terms of transmission of cloacal microparasites. 相似文献
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ALAN D. CHRISTIAN EMY M. MONROE ALLISON M. ASHER JEANNETTE M. LOUTSCH DAVID J. BERG 《Molecular ecology resources》2007,7(4):570-573
Freshwater mussels (Unionidae) are among North America's most imperilled organisms. Mussels produce small larvae (glochidia) that parasitize aquatic vertebrates. We modified the Epicentre QuickExtract protocol to extract DNA from a single glochidium, collected directly from the marsupium of a female mussel, to use as template in polymerase chain reactions (PCRs). Yield per glochidium in a 40 µL extraction volume provided enough DNA for ≥ 15 PCRs per individual. We were successful in using this DNA for microsatellite analysis of up to three loci per individual. Offspring from one female showed evidence for multiple paternity within her brood. Our results are the first documentation of this phenomenon in freshwater mussels. 相似文献