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PubMed2000

Methodology for sampling questing nymphs of Ixodes ricinus (Acari: Ixodidae), the principal vector of Lyme disease in Europe.

To assess the Lyme borreliosis vector population density we set up a methodology for sampling the Ixodes ricinus L. population host questing on the vegetation. We focused on the collection of the nymphal stage, which is the principal stage of disease transmission to humans. This study was carried out in Rambouillet forest (Yvelines, France) where seven study areas were demarcated. These areas are maximally homogeneous for plant species using a finer scale than the phytosociological classification as defined by the method of landscape diagnostics. Out of 23 collections performed from March 1997 to May 1998, 2,906 I. ricinus nymphs were collected. The sampling technique chosen was the cloth lure technique. The technical parameters were studied and fixed (cloth type, cloth size, sample size, researcher position). It appeared that toweling was the best cloth type to optimize the number of ticks collected; the position of the researcher had no effect on tick samples. To satisfy the criteria for correct sampling, we studied representativity, randomness, and nonselectivity of our methodology. The spatial distribution of nymphs in a homogeneous area was close to random and thus very few subsamples were needed to obtain a relative density which was representative. No significant differences were found between random samples and following transect samples; and nonselectivity was totally satisfied because we only worked on questing nymphs. We grouped the samples that presented no significant differences to attribute a density index, which varied from 0 to 5. This methodology, applied with the same parameters, offers potential for producing comparable results from studies in different geographical areas and at different times of the years.

Animals↗

PubMed2006

Pollen-mediated gene dispersal within continuous and fragmented populations of a forest understorey species, Trillium cuneatum.

Pollen movement plays a critical role in the distribution of genetic variation within and among plant populations. Direct measures of pollen movement in the large, continuous populations that characterize many herbaceous plant species are often technically difficult and biologically unreliable. Here, we studied contemporary pollen movement in four large populations of Trillium cuneatum. Three populations, located in the Georgia Piedmont, are exposed to strong anthropogenic disturbances, while the fourth population, located in the Southern Appalachian Mountains, is relatively undisturbed. Using the recently developed TwoGener analysis, we extracted estimates of the effective number of pollen donors (N(ep)), effective mating neighbourhood size (A(ep)) and the average distance of pollen movement (delta) for each population. We extended the TwoGener method by developing inference on the paternal gametic contribution to the embryo in situations where offspring genotypes are inferred from seeds and elaiosomes of species with bisporic megagametogenesis. Our estimates indicate that maternal plants do not sample pollen randomly from a global pool; rather, pollen movement in all four populations is highly restricted. Although the effective number of pollen donors per maternal plant is low (1.22-1.66) and pollen movement is highly localized in all populations, N(ep) in the disturbed Piedmont populations is higher and there is more pollen movement than in the mountains. The distance pollen moves is greater in disturbed sites and fragmented populations, possibly due to edge effects in Trillium habitats.

Gene Flow↗

PubMed2003

Effects of floral display and plant abundance on fruit production of Ryncholaelia glauca (Orchidaceae).

Flowering plant density can increase number of visits and fruit set in multi-flowering plants, however this aspect has not been studied on few flower species. We studied the effects of individual floral display and plant density on the fruit production of the epiphytic, moth-pollinated orchid, Ryncholaelia glauca, in an oak forest of Chavarrillo, Veracruz, Mexico. Species is non-autogamous, and produced one flower per flowering shoot each flowering season. We hypothesized that orchids with more flowering shoots and those on trees with clumps of conspecific should develop more fruits than isolated ones. R. glauca population flowers synchronouly, and individual flowers last up to 18 days, with flowers closing rapidly after pollination. Individuals produced few flowers per year, although some plants developed flowers in both seasons and fewer of them developed fruits both years. There was no relationship between flower number per orchid, or per host tree, with the number of fruits developed per plant. Host trees with flowering and fruiting orchids were randomly dispersed and the pattern of distribution of flowering and fruiting plants was not related. Apparently, pollinators visit the flowers randomly, with no evidence of density dependence. The fruit set of R. glauca was as low as fruit set of multi-flowered orchids moth pollinated, suggesting that fruit set on moth pollinated orchids could be independent of the number of flowers displayed.

Flowers↗

PubMed1990

Polymorphism of eimerian oocysts can be a problem in naturally infected hosts: an example from subterranean rodents in Bolivia.

Since 1986, 364 tuco-tucos (Ctenomys spp.) representing 7 species were collected from 16 major collecting areas representing at least 4 distinct ecological habitats in Bolivia, South America. All were examined for coccidia, and 125 (34%) had oocysts in their feces including 84 of 236 (36%) Ctenomys boliviensis from tropical palm/savanna habitats; 1 of 3 (33%) Ctenomys conoveri from a chaco thorn forest; 3 of 7 (33%) Ctenomys frater from medium altitude grass habitats; and 6 of 8 (75%) Ctenomys lewisi and 31 of 35 (88%) Ctenomys opimus from high altitude/puna habitats. None of 3 Ctenomys leucodon (high altitude/puna) or 72 Ctenomys steinbachi (tropical palm/savanna) were passing oocysts when examined. The 5 infected host species all had oocysts of Eimeria opimi Lambert, Gardner, and Duszynski, 1988, in their feces. These oocysts and their sporocysts varied greatly in size, both within and between host species, but qualitative characters (e.g., residua and wall texture) remained constant. Our conclusion, that all oocysts seen were E. opimi, was supported by multigroup discriminant analysis of 256 individual oocysts, 30-67 selected randomly from each Ctenomys sp. Minimum polygons enclosing the centroid (= multivariate mean) and the spread of individuals for each species group (OTU) showed significant overlap in discriminant space, and Geisser classification showed a 55% miss rate of individuals being classified into the wrong OTUs. Thus, oocyst and sporocyst lengths and widths cannot be used to separate morphotypes of E. opimi from different Ctenomys spp. from different geographic regions of Bolivia.

Animals↗

PubMed2003

[Systematics of the Lutzomyia species of the verrucarum Theodor group, 1965 (Diptera: Psychodiadae)].

The verrucarum group of phlebotomine sand flies includes vectors of Leishmania spp. and Bartonella bacilliformis, and from the perspective of public health is considered as one of the most important groups of neotropical phlebotomine sand flies. Due to marked morphological similarity among species constituting this group, the identification based on conventional taxonomic characters can be difficult. Consequently, the verrucarum group has been the focus of numerous taxonomic comparisons which have included the following methods: chaetotaxy, morphometry, larval spiracular system, chorionic structure, morphology of the genital atrium, cytogenetics, morphological phylogenetics, isoenzymes, random amplified polymorphic DNA, cuticular hydrocarbons, DNA probes, and nuclear and mitochondrial nucleotide sequences. Based on morphological characters of the male terminalia, the verrucarum group has been divided in four series, i.e., verrucarum, serrana, townsendi and pia. Since the revision of the group made by Young and Duncan in 1994, ten new species, principally of Andean origin, have been assigned to 3 of the series verrucarum (L. maranonensis, L. cajamarcensis, L. antioquiensis, L. falcaorum), serrana (L. robusta, L. guilvardae) and pia (L. suapiensis, L. tihuiliensis, L. tocaniensis, L. limafalcaoae). The total number of verrucarum group members is now 40. Explanations for this diversity of species include the isolation of ancestral populations in refugia of humid forest during the quaternary period, the Andean cordilleras as geographical barrier, and the appearance of the Isthmus of Panama. Biology systematics and evolution of the verrucarum group is reviewed with emphasis on the 19 species extant in Colombia.

Animals↗

PubMed2006

No evidence of population structure across three isolated subpopulations of Russula brevipes in an oak/pine woodland.

Russula brevipes is common ectomycorrhizal (EM) fungus that is associated with several hosts across temperate forest ecosystems. A previous study has demonstrated that substructuring across large geographic distances (1500 km) occurs in the western USA. To examine genetic structure over a more localized scale, basidiocarps of Russula brevipes from three subpopulations, separated by distances of 230-1090 m, were collected over two consecutive years in an oak/pine woodland. Microsatellite loci were used to test for population differentiation both among subpopulations and by year. No significant population differentiation was detected between subpopulations (theta(ST) = 0.01) or between years (theta(ST) = 0.01). Most loci were consistent with a Hardy-Weinburg equilibrium and 82% of the genets between seasons from similar sampling localities constituted new genotypes. These results indicate that R. brevipes constitutes a randomly mating population with no genetic differentiation between locations or across successive fruiting seasons.

Agaricales↗

PubMed2004

Genetic effects of chronic habitat fragmentation on tree species: the case of Sorbus aucuparia in a deforested Scottish landscape.

Sustainable forest restoration and management practices require a thorough understanding of the influence that habitat fragmentation has on the processes shaping genetic variation and its distribution in tree populations. We quantified genetic variation at isozyme markers and chloroplast DNA (cpDNA), analysed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in severely fragmented populations of Sorbus aucuparia (Rosaceae) in a single catchment (Moffat) in southern Scotland. Remnants maintain surprisingly high levels of gene diversity (HE) for isozymes (HE = 0.195) and cpDNA markers (HE = 0.490). Estimates are very similar to those from non-fragmented populations in continental Europe, even though the latter were sampled over a much larger spatial scale. Overall, no genetic bottleneck or departures from random mating were detected in the Moffat fragments. However, genetic differentiation among remnants was detected for both types of marker (isozymes Theta n = 0.043, cpDNA Theta c = 0.131; G-test, P-value < 0.001). In this self-incompatible, insect-pollinated, bird-dispersed tree species, the estimated ratio of pollen flow to seed flow between fragments is close to 1 (r = 1.36). Reduced pollen-mediated gene flow is a likely consequence of habitat fragmentation, but effective seed dispersal by birds is probably helping to maintain high levels of genetic diversity within remnants and reduce genetic differentiation between them.

DNA, Chloroplast↗

PubMed2003

Fine-scale genetic structure and gene flow within Costa Rican populations of mahogany (Swietenia macrophylla).

Fine-scale structure of genetic diversity and gene flow were analysed in three Costa Rican populations of mahogany, Swietenia macrophylla. Population differentiation estimated using AFLPs and SSRs was low (38.3 and 24%) and only slightly higher than previous estimates for Central American populations based on RAPD variation (20%). Significant fine-scale spatial structure was found in all of the surveyed mahogany populations and is probably strongly influenced by the limited seed dispersal range of the species. Furthermore, a survey of progeny arrays from selected mother trees in two of the plots indicated that most pollinations involved proximate trees. These data indicate that very little gene flow, via either pollen or seed, is occurring between blocks of mahogany within a continuous or disturbed forest landscape. Thus, once diversity is removed from a forest population of mahogany, these data suggest that recovery would be difficult via seed or pollen dispersal, and provides an explanation for mahogany's apparent susceptibility to the pressures of logging. Evidence is reviewed from other studies of gene flow and seedling regeneration to discuss alternative extraction strategies that may maintain diversity or allow recovery of genetic resources.

Biological Evolution↗

PubMed2006

A common mode of attraction of larvae and adults of insect predators to the sex pheromone of their prey (Hemiptera: Matsucoccidae).

The attraction of several adult predators, genera Elatophilus, Hemerobius and Sympherobius, to the sex pheromones of pine bast scales, Matsucoccus Cockerell, has already been demonstrated. Here, the hypothesis that the larvae of these predators are similarly attracted to the host prey sex pheromone is tested. The response of predators was tested in field trials using pine tree arenas baited with the sex pheromones of M. josephi Bodenheimer & Harpaz, M. feytaudi Ducasse and M. matsumurae Kuwana. Experiments were conducted in Israel in stands of Pinus halepensis infested by M. josephi and in Portugal in stands of P. pinaster infested by M. feytaudi, respectively. The selectivity of larvae for the three sex pheromones was tested in Petri dish arenas in the laboratory. In the field, the larval stages exhibited similar modes of attraction to those of the conspecific adults: Elatophilus hebraicus Pericart in Aleppo pine forest, E. crassicornis Reuter and Hemerobius stigma Stephens in the maritime pine forests. Laboratory choice tests confirmed the kairomonal selectivity of larvae. Both forest and laboratory tests demonstrated the response of a coccinellid of the genus Rhyzobius to the sex pheromones of M. feytaudi and M. matsumurae. A unique chemical communication system among several taxa of predators of Matsucoccus spp. was highlighted that may be attributed to their coevolution on a geological time scale.

Animal Communication↗

PubMed2002

Regeneration status of mangrove forests in Mida Creek, Kenya: a compromised or secured future?

The structure and regeneration patterns of Mida Creek mangrove vegetation were studied along belt transects at 2 forest sites of Mida Creek (3 degrees 20'S, 40 degrees 00'E): Uyombo and Kirepwe. Based on the species importance values, the dominant mangrove tree species in Mida were Ceriops tagal (Perr.) C. B. Robinson and Rhizophora mucronata Lamk. Tree density varied from 1197 trees ha(-1) at Kirepwe to 1585 trees ha(-1) at Uyombo and mean tree height was higher at the former site compared to the latter. The size-class structure at both localities of Mida showed the presence of more small trees than large ones. Spatial distribution pattern of adults and juveniles varied greatly between sites and they showed a close to uniform pattern (Morisita's Index I0 << 1) for trees, but a tendency to random distribution (I0 = 1) for juveniles. The present paper shows that unmanaged but exploited mangroves do not necessarily disappear, but change qualitatively from locally preferred R. mucronata to the less preferred C. tagal. Whereas the effects of this change on the ecological function of the mangrove cannot be estimated yet, the economical function of the mangrove has evidently weakened.

Animals↗

PubMed2004

Azithromycin for acute lower respiratory tract infections.

BACKGROUND: The spectrum of acute lower respiratory tract infection ranges from acute bronchitis and acute exacerbations of chronic bronchitis to pneumonia. Annually approximately five million people die of acute respiratory tract infections. Among these, pneumonia represents the most frequent cause of mortality, hospitalization and medical consultation. Azithromycin is a new macrolide antibiotic, structurally modified from erythromycin and is noted for its activity against some gram-negative organisms associated with respiratory tract infections, particularly Haemophilus influenzae (H. influenzae). OBJECTIVES: To compare the effectiveness of azithromycin to amoxycillin or amoxycillin/clavulanic acid (amoxyclav) in the treatment of LRTI, in terms of clinical failure, incidence of adverse events and microbial eradication. SEARCH STRATEGY: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 4, 2003), MEDLINE (January 1966 to January Week 3, 2004), and EMBASE (January 1988 to 2003). SELECTION CRITERIA: Randomised and quasi-randomised controlled trials, which compared azithromycin to amoxycillin or amoxycillin/clavulanic acid in patients with clinical evidence of acute LRTI: acute bronchitis, pneumonia, and acute exacerbation of chronic bronchitis were studied. DATA COLLECTION AND ANALYSIS: The criteria for assessing study quality were generation of allocation sequence, concealment of treatment allocation, blinding, and completeness of the trial. All types of acute lower respiratory tract infections were initially pooled in the meta-analyses. Funnel plot was used to examine publication bias. The heterogeneity of results was investigated by the forest plot and Chi-square test. Index of I(2) was also used to measure inconsistency results among trials. Subgroup analysis was conducted for age, types of respiratory tract infection and types of antibiotic in control groups. Sensitivity analysis was conducted under the condition of trial size and concealment of treatment allocation. MAIN RESULTS: Fourteen trials with 2,521 enrolled patients used 2,416 patients in the analysis. A total of 1,350 patients received azithromycin and 1,066 received amoxicillin or amoxicillin-clavulanic acid. The pooled analysis of all trials showed that there was no significant difference in the incidence of clinical failure on about day 10 to 14 after therapy started between the two groups (relative risk (RR) (random effects) 0.96; 95% CI 0.58 to 1.57). Sensitivity analysis showed that a reduction of clinical failure in azithromycin-treated patients (RR 0.52; 95% CI 0.24 to 1.12) in three adequately concealed studies, compared to RR 1.14 (95% CI 0.62 to 2.08) in eleven studies with inadequate concealment. Eleven trials reported the incidence of microbial eradication and there was no significant difference between the two groups (RR 0.98; 95% CI 0.91 to 1.07). The reduction of adverse events in azithromycin group was RR 0.75 (95% CI 0.56 to 1.00). REVIEWERS' CONCLUSIONS: There is unclear evidence that azithromycin is superior to amoxicillin or amoxicillin-clavulanic acid in treating acute LRTI. Future trials with high methodological quality are needed.

Acute Disease↗

PubMed2005

Sampling the soil in long-term forest plots: the implications of spatial variation.

Long-term monitoring of forest soils as part of a pan-European network to detect environmental change depends on an accurate determination of the mean of the soil properties at each monitoring event. Forest soil is known to be very variable spatially, however. A study was undertaken to explore and quantify this variability at three forest monitoring plots in Britain. Detailed soil sampling was carried out, and the data from the chemical analyses were analysed by classical statistics and geostatistics. An analysis of variance showed that there were no consistent effects from the sample sites in relation to the position of the trees. The variogram analysis showed that there was spatial dependence at each site for several variables and some varied in an apparently periodic way. An optimal sampling analysis based on the multivariate variogram for each site suggested that a bulked sample from 36 cores would reduce error to an acceptable level. Future sampling should be designed so that it neither targets nor avoids trees and disturbed ground. This can be achieved best by using a stratified random sampling design.

Carbon↗

PubMed2000

Rainbow trout sleeping disease virus is an atypical alphavirus.

Sleeping disease (SD) is currently a matter of concern for salmonid fish farmers in most parts of the world. A viral etiology of SD has recently been suspected, since virus-like particles have been observed in infected rainbow trout cells. In salmonid-derived cell lines, the maximal rate of virus production was observed at 10 degrees C, while little virus was produced at 14 degrees C. Through biochemical, physicochemical, and morphological studies, SD virus (SDV) was shown to be an enveloped virus of roughly 60 nm in diameter. The genome consists of 12 kb of RNA, with the appearance of a 26S subgenomic RNA during the time course of SDV replication. The screening of a random-primed cDNA library constructed from the genomic RNA of semipurified virions facilitated the identification of a specific SDV cDNA clone having an open reading frame related to the alphavirus E2 glycoproteins. To extend the comparison between SDV structural proteins and the alphavirus protein counterparts, the nucleotide sequence of the total 4.1-kb subgenomic RNA has been determined. The 26S RNA encodes a 1,324-amino-acid polyprotein exhibiting typical alphavirus structural protein organization. SDV structural proteins showed several remarkable features compared to other alphaviruses: (i) unusually large individual proteins, (ii) very low homology (ranging from 30 to 34%) (iii) an unglycosylated E3 protein, and (iv) and E1 fusion domain sharing mutations implicated in the pH threshold. Although phylogenetically related to the Semliki Forest virus group of alphaviruses, SDV should be considered an atypical member, able to naturally replicate in lower vertebrates.

Alphavirus↗

PubMed2006

A roadmap of tandemly arrayed genes in the genomes of human, mouse, and rat.

Tandemly arrayed genes (TAGs) play an important functional and physiological role in the genome. Most previous studies have focused on individual TAG families in a few species, yet a broad characterization of TAGs is not available. Here we identified all TAGs in the genomes of humans, mouse, and rat and performed a comprehensive analysis of TAG distribution, TAG sizes, TAG orientations and intergenic distances, and TAG functions. TAGs account for about 14-17% of all genes in the genome and nearly one-third of all duplicated genes, highlighting the predominant role that tandem duplication plays in gene duplication. For all species, TAG distribution is highly heterogeneous along chromosomes and some chromosomes are enriched with TAG forests, whereas others are enriched with TAG deserts. The majority of TAGs are of size 2 for all genomes, similar to the previous findings in Caenorhabditis elegans, Arabidopsis thaliana, and Oryza sativa, suggesting that it is a rather general phenomenon in eukaryotes. The comparison with the genome patterns shows that TAG members have a significantly higher proportion of parallel gene orientation in all species, corroborating Graham's claim that parallel orientation is the preferred form of orientation in TAGs. Moreover, TAG members with parallel orientation tend to be closer to each other than all neighboring genes in the genome with parallel orientation. The analyses of Gene Ontology function indicate that genes with receptor or binding activities are significantly overrepresented by TAGs. Computer simulation reveals that random gene rearrangements have little effect on the statistics of TAGs for all genomes. Finally, the average proportion of TAGs shows a trend of increase with the increase of family sizes, although the correlation between TAG proportions in individual families and family sizes is not significant.

Animals↗

PubMed1976

Influences of soil acidity on Streptomyces populations inhabiting forest soils.

The Streptomyces populations inhabiting five acidic forest soils were examined. It was found that lowering the pH of a medium selective for streptomycetes (starch-casein agar) to the pH of the particular soil horizon being plated influenced both the total numbers and types of streptomycetes that were isolated from the soils examined in this study. On the acidified medium both the numbers of streptomycetes and the percentage of total bacteria on the plates represented by streptomycetes increased (as compared with the same medium with a pH of 7.2). These differences were greatest on the isolations from the most acid soils. The largest concentrations of streptomycetes were found in the surface horizon (0 to 15 cm) and the litter layer immediately over the surface mineral horizon. Acidity tolerance tests demonstrated that random samplings of isolates contained acidophilic, neutrophilic, and acidoduric strains, with the largest numbers of acidophiles being found on the acidified media from the most acid soils. There were no differences between overall utilization of selected carbohydrates among the isolates taken from either the neutral or acidic media, although a larger proportion of the acid media isolates produced acid from the carbohydrates. Evidence is presented which indicates that different types of streptomycetes were isolated on the acid media, and possible reasons for the presence of these acid-tolerant populations are discussed.

Carbohydrate Metabolism↗

PubMed1995

Equine parafilariosis in Iran.

From March to September 1991, horses (n = 1567), donkeys (n = 112) and mules (n = 96) were examined for equine parafilariosis by random sampling from different areas of Iran. The clinical signs of equine parafilariosis were observed in 136 cases of two northern areas (1.4% and 41.3% infection rate) and one northeastern area (6.3% infection rate). Most of the infected cases were confirmed by laboratory findings. All infected cases were followed up to establish the epidemiological features. The results suggest that there is one enzootic area in Iran, the Caspian coast and Persian Turkman steppes. An annual period of appearance of clinical signs coinciding with warm months was observed in all infected areas. No clinical sign was observed in cases less than 2 or more than 15 years of age. The highest infection rates (41.1-73.3%) were observed in equidae 4-9 years of age. The enzootic area encompasses the Caspian littoral, steppes and forest steppes and has an altitude of up to 1500 m. It has a temperature-wet climate. The treatment of 15 infected cases with ivermectin subcutaneously at 0.2 mg kg-1, was 100% effective with only one injection.

Aging↗

PubMed2003

Adoption of biomass improved cookstoves in a patriarchal society: an example from Sudan.

The economic, social, ecological and environmental roles and benefits of forests are obvious and need no emphasis. Inefficient use of fuel wood is considered one of the important causes of deforestation. Use of more efficient improved cookstoves is proposed as one of the measures that can reduce demand for fuel wood and charcoal and help in lowering the annoying deforestation rate in many developing countries. During the 1980s and 1990s several programs aiming at testing and disseminating energy saving technologies were implemented in Sudan. One of these technologies was improved cookstoves, which was intended to increase the efficiency of using energy from biomass sources. This study is carried out to examine the adoption rate and the factors affecting adoption of improved cookstoves in Khartoum State. The study is based on primary data collected through personal interviews with husbands and wives in 300 randomly selected households. Regression analysis was used to analyze the data. The results showed that the device's adoption rate was very low. The improved cookstove's relative advantage, housewife's exposure to messages about improved cookstoves, educational level of the housewife and the average educational level of the female household's members had significant positive effect on the household's innovativeness regarding adoption of improved cookstove. Wife's age and the educational level of the husband had negative significant effects. In the Sudanese patriarchal society all the household domestic tasks, particularly food preparation and related activities, are considered women's responsibilities and all the decisions related to them are taken by women. Therefore, these results could be understood as a reflection of the division of labor, gender relations and decision-making process in the Sudanese household.

Adult↗

PubMedDate not supplied

Molecular epidemiology of human polyomavirus JC in the Biaka Pygmies and Bantu of Central Africa.

Polyomavirus JC (JCV) is ubiquitous in humans and causes a chronic demyelinating disease of the central nervous system, progressive multifocal leukoencephalopathy which is common in AIDS. JCV is excreted in urine of 30-70% of adults worldwide. Based on sequence analysis of JCV complete genomes or fragments thereof, JCV can be classified into geographically derived genotypes. Types 1 and 2 are of European and Asian origin respectively while Types 3 and 6 are African in origin. Type 4, a possible recombinant of European and African genotypes (1 and 3) is common in the USA. To delineate the JCV genotypes in an aboriginal African population, random urine samples were collected from the Biaka Pygmies and Bantu from the Central African Republic. There were 43 males and 25 females aged 4-55 years, with an average age of 26 years. After PCR amplification of JCV in urine, products were directly cycle sequenced. Five of 23 Pygmy adults (22%) and four of 20 Bantu adults (20%) were positive for JC viruria. DNA sequence analysis revealed JCV Type 3 (two), Type 6 (two) and one Type 1 variant in Biaka Pygmies. All the Bantu strains were Type 6. Type 3 and 6 strains of JCV are the predominant strains in central Africa. The presence of multiple subtypes of JCV in Biaka Pygmies may be a result of extensive interactions of Pygmies with their African tribal neighbors during their itinerant movements in the equatorial forest.

Adolescent↗