Ticks collected on birds in the state of São Paulo,Brazil

The present study reports a collection of Amblyomma spp. ticks in birds from several areas of the state of São Paulo, Brazil. A total of 568 tick specimens (404 larvae, 164 nymphs) were collected from 261 bird specimens. From these ticks, 204 (36%) specimens (94 larvae, 110 nymphs) were reared to the adult stage, being identified as Amblyomma longirostre (94 larvae, 90 nymphs), Amblyomma calcaratum (13 nymphs), Amblyomma nodosum (2 nymphs), and Amblyomma cajennense (5 nymphs). Additionally, 39 larvae reared to the nymphal stage and 8 nymphs that died before reaching the adult stage were identified as A. longirostre according to peculiar characters inherent to the nymphal stage of this species: scutum elongate, and hypostome pointed. The remaining 271 larvae and 46 nymphs were identified as Amblyomma sp. Ticks were collected from 51 species of birds distributed in 22 bird families and 6 orders. The order Passeriformes constituted the vast majority of the records, comprising 253 (97%) out of the 261 infested birds. Subadults of A. longirostre were identified from 35 species of Passeriformes, comprising 11 families (Cardinalidae, Dendrocolaptidae, Fringillidae, Furnariidae, Parulidae, Pipridae, Thamnophilidae, Thraupidae, Turdidae, Tyrannidae, and Vireonidae), and from 1 species of a non-passerine bird, a puffbird (Bucconidae). Subadults of A. calcaratum were identified from 5 species of Passeriformes, comprising 5 families (Cardinalinae, Conopophagidae, Pipridae, Thamnophilidae and Turdidae). Subadults of A. nodosum were identified from 2 species of Passeriformes, comprising two bird families (Thamnophilidae and Pipridae). Subadults of A. cajennense were identified from 2 species of non-passerine birds, belonging to 2 different orders (Ciconiiformes: Threskiornithidae, and Gruiformes: Cariamidae). Birds were usually infested by few ticks (mean infestation of 2.2 ticks per bird; range: 1–16). Currently, 82 bird species are known to be infested by immature stages of A. longirostre, with the vast majority [74 (90%)] being Passeriformes. Our results showed that Passeriformes seems to be primary hosts for subadult stages of A. longirostre, A. calcaratum, and A. nodosum. However, arboreal passerine birds seem to be the most important hosts for A. longirostre whereas ground-feeding passerine birds seem to be the most important for both A. calcaratum and A. nodosum. In contrast, the parasitism of birds by subadults of A. cajennense has been restricted to non-passerine birds.     

Comparative Metagenomic Profiling of Viromes Associated with Four Common Mosquito Species in China

Vast viruses are thought to be associated with mosquitoes. Anopheles sinensis, Armigeres subalbatus, Culex quinquefasciatus, and Culex tritaeniorhynchus are very common mosquito species in China, and whether the virome structure in each species is species-specific has not been evaluated. In this study, a total of 2222 mosquitoes were collected from the same geographic location, and RNAs were sequenced using the Illumina Miseq platform. After querying to the Refseq database, a total of 3,435,781, 2,223,509, 5,727,523, and 6,387,867 paired-end reads were classified under viral sequences from An. sinensis, Ar. subalbatus, Cx. quinquefasciatus, and Cx. tritaeniorhynchus, respectively, with the highest prevalence of virus-associated reads being observed in Cx. quinquefasciatus. The metagenomic comparison analysis showed that the virus-related reads were distributed across 26 virus families, together with an unclassified group of viruses. Anelloviridae, Circoviridae, Genomoviridae, Iridoviridae, Mesoniviridae, Microviridae, Myoviridae, Parvoviridae, Phenuiviridae, and Podoviridae were the top ten significantly different viral families among the four species. Further analysis reveals that the virome is species-specific in four mosquito samples, and several viral sequences which maybe belong to novel viruses are discovered for the first time in those mosquitoes. This investigation provides a basis for a comprehensive knowledge on the mosquito virome status in China.     

Characteristics of body mass growth in semialtricial and altricial bird species during the nestling period

The dynamics of body mass growth were studied in nestlings of 22 semialtricial and altricial bird species based on materials collected in seven regions of Russia in the years 1976–2013. The bird species belong to four orders and 13 families. The results of the study indicate the nonuniform growth of nestlings in different bird species. Of the species investigated, only seven were found to reach or exceed the mass of adult birds. Over the nestling period, the nestlings of open-nesting species, such as the hooded crow (Corvus cornix), rook (Corvus frugilegus), magpie (Pica pica), fieldfare (Turdus pilaris), song thrush (Turdus philomelos), and goldfinch (Carduelis carduelis), do not reach the weight of adult birds and their growth continues after they leave the nest. In closed-nesting species, only the nestlings of the barn swallow (Hirundo rustica) reach or exceed the definitive mass, whereas the nestlings of the jackdaw (Corvus monedula), starling (Sturnus vulgaris), wryneck (Jynx torquilla), tree sparrow (Passer montanus), and great tit (Parus major) continue to grow after leaving the nest. The body mass of birds on the day of their hatching and before their departure from the nests and the mass of adult birds depend on the nesting type, duration of the nestling period, size groups of species, and their definitive size. The average specific growth rate of body mass and its maximum values for different species are also associated with these factors. The maximum specific growth rate in small-sized and medium-sized bird species was observed on the 0–1st days of life; in large bird species, on the 2nd–4th days. The specific growth rate did not depend on the type of nesting, but it was inversely related to the duration of the nestling period and the definitive sizes of birds.     

Mosquito-only flaviviruses,isolated from <Emphasis Type="Italic">Aedes albopictus</Emphasis> in Slovenia: results of a pilot mosquito monitoring program

Autochthonous transmissions of mosquito-borne diseases were described in close proximity to Slovenia where the knowledge of mosquito species and the viruses they transmit remains very scarce. Therefore we aimed to assess the burden mosquitoes bring to the local community and to test mosquitoes for the presence of the selected zoonotic arboviruses, i. e. Dengue (DENV), West Nile (WNV) and Chikungunya (CHIKV). A pilot mosquito monitoring was conducted in 2012 within two municipalities based on adult mosquito trapping. Altogether 2007 adult mosquitoes were caught. Females of Aedes albopictus and Culex pipiens represented the majority of the total mosquito catch. In sites with more households and nearby greenery, catches of Ae. albopictus were more abundant. Highest numbers of Cx. pipiens females were caught close to a nature reserve, where many bird species stop during their migrations. Trapping results are consistent with both species’ feeding behaviour. Female mosquitoes were grouped into 58 pools according to species, location and date of catch. Real time RT-PCRs for WNV, DENV and CHIKV were performed, but no arboviral genomes were detected in any of the tested mosquito pools. However, amplicons were obtained in three pools when using generic RT-PCR markers for flaviviruses. The viruses detected were propagated and isolated in mosquito cell line C3/36 and identified with sequencing as mosquito-only flaviviruses (MOFs). The important contributions of this study are a successful first isolation of MOFs and confirmation of the presence of the invasive mosquito Ae. albopictus in Slovenia.     

From species to individuals: combining barcoding and microsatellite analyses from non-invasive samples in plant ecology studies

By means of DNA barcoding and microsatellite analyses, we studied the species and individuals of legitimate seed dispersers of the Mediterranean shrub Pistacia lentiscus, a keystone species that represents the main source of food in winter for frugivorous birds. We collected dropping of birds containing seeds, and after DNA extraction we amplified and sequenced a fragment of the mitochondrial COI gene. Through BLASTN queries of the sequenced fragments against registered sequences in the GenBank database we identified the bird species that are currently dispersing P. lentiscus seeds. Further, through the amplification of specific nuclear microsatellite loci we calculated standard genetic diversity parameters of the population of birds from the genus Sylvia (the blackcap and Sardinian warbler), the most important dispersers of P. lentiscus. Five bird species were identified as seed dispersers through their barcode match. Further, we found that S. melanocephala displayed slightly lower levels of genetic diversity than S. atricapilla. In this study we show how the genetic analyses of environmental faecal samples can be a useful and convenient tool for the study of plant-frugivore interactions through the ascertainment of the identity of the species involved and through the analyses of genetic variability of their populations.     

Determinants of avian malaria prevalence in mountainous Transcaucasia

Deforestation, urban development, and global climate change can lead to dramatic changes of ecological communities and increase prevalence of infectious diseases at higher latitudes and altitudes. Identification of factors responsible for the prevalence of parasites is of crucial importance to understand the dynamics of parasite distribution in a changing environment. Mountain areas are especially suitable for studies of factors governing parasite distribution and prevalence due to heterogeneity of landscapes, climatic regimes, and other biotic and abiotic conditions. We examined 903 avian blood smears collected in mountains of Transcaucasia for prevalence of Haemoproteus and Plasmodium. We found that the haemoparasites prevalence differed among bird species and localities, highlighting the environmental components affecting disease distribution. The prevalence of both Haemoproteus and Plasmodium was significantly higher in males, adults, and migratory species than in females, juveniles, and resident species. Geographic Information System (GIS) and linear regression analyses revealed that elevation and monthly average precipitation were strongly correlated with proportion of infected birds with Plasmodium, indicating that the prevalence increased with increase of monthly average temperature and elevation. Birds from forested and high grassed areas were also more infected with avian haemosporidia. Our study provides baseline data for modelling of parasites distribution under global climate change scenarios, which is of great importance for monitoring and management of communities and environment for conservation and human health.     

<Emphasis Type="Italic">Haematospirillum</Emphasis> and insect <Emphasis Type="Italic">Wolbachia</Emphasis> DNA in avian blood

In this study, blood samples of 259 Acrocephalus sp. warblers were molecularly analysed for Anaplasmataceae and Rhodospirillaceae based on PCR amplification of 16S rRNA gene fragments. One bird blood sample (from Reed Warbler, Acrocephalus scirpaceus) yielded a sequence with 99.8% identity to Haematospirillum jordaniae. This is the first molecular evidence for the occurrence of this species in the blood of any vertebrate other than human. Another bird blood sample (from Marsh Warbler: Acrocephalus palustris) yielded a Wolbachia sequence, closely related to a moth endosymbiont with 99.8% identity. A nematode origin of Wolbachia DNA detected here in avian blood can be excluded, because results of phylogenetic analysis showed its closest alignment with insect wolbachiae. This is the first finding of insect Wolbachia DNA in the circulatory system of birds, which can be explained either by the inoculation of wolbachiae by blood-sucking vectors, or passing of Wolbachia DNA from the gut into the blood of this insectivorous bird species.     

Synchronous fruiting and common seed dispersers of two endemic columnar cacti in the Caatinga,a dry forest in Brazil

This study evaluates the fruiting phenology, fruit traits, and seed dispersal in two Pilosocereus (Cactaceae) species that are widely distributed in Caatinga vegetation. We monitored the fruiting phenology of Pilosocereus gounellei and Pilosocereus chrysostele on a monthly basis for a period of 4 years (45 months from March 2009 to November 2012), including 30 individuals of each species. We also carried out focal observations, captured dispersers, and conducted germination tests, to identify the effective seed dispersers of these species. Both species exhibited sub-annual fruiting patterns and high fruiting synchrony index (O _jk 0.62), with peaks occurring from February to May for P. gounellei and February to April for P. chrysostele. In all, 248 visits by seven bird and two lizard species were recorded for P. gounellei, and 104 visits by five bird species were recorded for P. chrysostele. The two species shared five seed dispersers. The finch Lanio pileatus was the most frequently visiting bird species. The number of visits to the fruits of P. gounellei was higher than to the fruits of P. chrysostele. Passage of seeds through the digestive tracts of all bird species significantly increased the germination rate for P. chrysostele, whereas for P. gounellei, the birds Forpus xanthopterygius and L. pileatus decreased germination rates. Sub-annual fruiting patterns, similar fruit morphology, and high synchronous fruiting are factors that favor resource sharing among the dispersers of Pilosocereus in the Caatinga.     

Mite color alteration and acaricidal activity of 3,7-dimethyl-2,6-octadienal and its structural analogues against the stored food pest mite <Emphasis Type="Italic">Tyrophagus putrescentiae</Emphasis>

The study of cryptic species allows to describe and to understand biodiversity, and the evolutionary processes shaping it. Mites of the family Rhinonyssidae are permanent parasites of the nasal cavities of birds, currently including about 500 described species and 12 genera. Here, we tested the hypothesis that mites from five populations of the genus Tinaminyssus—three isolated from European turtle doves (Streptopelia turtur), and two from Eurasian collared doves (Streptopelia decaocto; Aves: Columbiformes)—are, in fact, two cryptic species inhabiting different hosts. First, we performed a morphometrical study on 16 traits. Then, we used the ITS1-5.8S rDNA-ITS2 nuclear region (ITS region), and a fragment of the mitochondrial cytochrome c-oxidase 1 (COI) to carry out phylogenetic and species delimitation analyses on Tinaminyssus species. Morphological analyses revealed a lack of biometric differentiation among Tinaminyssus populations from the two host species. However, molecular analyses indicated a high degree of genetic differentiation between populations of Tinaminyssus sp. from S. turtur and S. decaocto. Overall, results show that they can be considered as different cryptic species, suggesting a case of evolutionary stasis, likely because of the anatomical similarity between closely-related bird host species.     

The first Eocene tumbling beetle of the genus <Emphasis Type="Italic">Isotrilophus</Emphasis> (Insecta: Coleoptera: Mordellidae) from the Green River Formation (Colorado,United States)

The first fossil representative of the genus Isotrilophus Liljeblad (Mordellidae), I. rasnitsyni sp. nov., from the Lower Eocene of the Green River Formation (Colorado) is described. The new species differs from its only congener, I. erraticus (Smith, 1883), in the shape of eye, metepisternum, configuration of temporal angle, lateral edge of the prothorax, and in the length ratio of the prothorax and elytra. The first I. erraticus south of Nicaragua (e.g., in Costa Rica and Peru) are recorded.     

Nectar thieves or invited pollinators? A case study of tansy flowers and common house mosquitoes

Mosquitoes are generally considered nectar thieves that do not contribute to the pollination of the flowers they visit. Here we tested the hypothesis that the common house mosquito, Culex pipiens, contributes to the pollination of tansies, Tanacetum vulgare, and possibly the pollination of other members of the Asteraceae (Achillea millefolium, Leucanthemum vulgare, Solidago canadensis). To test this hypothesis, we (1) field-collected mosquitoes probing inflorescences of T. vulgare, A. millefolium, and L. vulgare, and recorded the number and distribution of pollen grains on their bodies, (2) exposed laboratory-reared Cx. pipiens to inflorescences of T. vulgare, A. millefolium, and S. canadensis, and (3) ran pollination experiments with Cx. pipiens and T. vulgare in a greenhouse. We found (1) that 41 of 164 field-collected Cx. pipiens carried pollen, (2) that 48, 34, and 34 % of Cx. pipiens accumulated pollen from T. vulgare, A. millefolium, and S. canadensis, respectively, during floral visits of greenhouse-grown specimens, and (3) that cross-pollination by Cx. pipiens resulted in significant seed set of T. vulgare in pollination experiments. Based on our observations that Cx. pipiens are frequent floral visitors and are able to carry pollen and to induce seed set in T. vulgare, it is clear that Cx. pipiens plays a role in the pollination of T. vulgare, and possibly other members of the Asteraceae.     

The first report of nine species of haemosporidian parasites (Haemosporida: <Emphasis Type="Italic">Haemoproteus,Plasmodium</Emphasis> and <Emphasis Type="Italic">Leucocytozoon</Emphasis>) in wild birds from Slovakia

During 2009 and 2010 samples from 251 wild birds (37 species) from nine sites of Slovakia were collected. Blood samples were tested for Plasmodium, Haemoproteus, and Leucocytozoon spp. parasites using both PCR-based and microscopy techniques. The overall prevalence of infection was 56.6%, while prevalence of Haemoproteus a Plasmodium spp. (were evaluated separately from Leucocytozoon) was 46.6% and the prevalence of Leucocytozoon spp. was 33.9%. After microscopic examination of stained blood smears the identification of haemoproteids was performed. There were 14 species of three genera identified, i.e., Haemoproteus parabelopolskyi, H. belopolskyi, H. magnus, H. fallisi, H. fringillae, H. balmorali, H. dolniki, H. tartakovskyi, H. lanii, Leucocytozoon majoris, L. dubreuili, Plasmodium vaughani, P. relictum, P. circumflexum. Except for H. fringillae, H. balmorali, H. belopolskyi, L. majoris and L. dubreuili, the mentioned species of parasites were recorded for the first time in Slovakia.     

Influences of the invasive tamarisk leaf beetle (<Emphasis Type="Italic">Diorhabda carinulata</Emphasis>) on avian diets along the Dolores River in Southwestern Colorado USA

The tamarisk leaf beetle (Diorhabda carinulata), introduced from Eurasia in 2001 as a biological control agent for the invasive plant Tamarix ramosissima, has spread widely throughout the western USA. With D. carinulata now very abundant, scientists and restoration managers have questioned what influence this introduced arthropod might have upon the avian component of riparian ecosystems. From 2009 through 2012 we studied the consequences of biological invasions of the introduced tamarisk shrub and tamarisk leaf beetles on the diets of native birds along the Dolores River in southwestern Colorado, USA. We examined avian foraging behavior, sampled the arthropod community, documented bird diets and the use of invasive tamarisk shrubs and tamarisk leaf beetles by birds. We documented D. carinulata abundance, on what plants the beetles occurred, and to what degree they were consumed by birds as compared to other arthropods. We hypothesized that if D. carinulata is an important new avian food source, birds should consume beetles at least in proportion to their abundance. We also hypothesized that birds should forage more in tamarisk in the late summer when tamarisk leaf beetle larvae are more abundant than in early summer, and that birds should select beetle-damaged tamarisk shrubs. We found that D. carinulata composed 24.0 percent (±?19.9–27.4%) and 35.4% biomass of all collected arthropods. From the gut contents of 188 birds (25 passerine species), only four species (n?=?11 birds) contained tamarisk leaf beetle parts. Although D. carinulata comprised one-quarter of total insect abundance, frequency of occurrence in bird gut contents was only 2.1% by abundance and 3.4% biomass. Birds used tamarisk shrubs for foraging in proportion to their availability, but foraging frequency did not increase during the late summer when more tamarisk leaf beetles were present and birds avoided beetle-damaged tamarisk shrubs. Despite D. carinulata being the most abundant arthropod in the environment, these invasive beetles were not frequently consumed by birds and seem not to provide a significant contribution to avian diets.     

Wild birds and urban pigeons as reservoirs for diarrheagenic <Emphasis Type="Italic">Escherichia coli</Emphasis> with zoonotic potential

In order to describe the role of wild birds and pigeons in the transmission of shiga toxigenic Escherichia coli (STEC) and enteropathogenic Escherichia coli (EPEC) to humans and other animals, samples were collected from cloacae and oropharynx of free-living wild birds and free-living pigeons. Two STEC (0.8%) and five EPEC strains (2.0%) were isolated from wild birds and four EPEC strains (2.0%) were recovered from pigeons. Serogroups, sequence types (STs) and virulence genes, such as saa, iha, lpfA _O113, ehxA, espA, nleB and nleE, detected in this study had already been implicated in human and animal diseases. Multidrug resistance (MDR) was found in 25.0% of the pigeon strains and in 57.0% of the wild bird strains; the wild birds also yielded one isolate carrying extended-spectrum β-lactamases (ESBLs) gene bla _CTX-M-8. The high variability shown by PFGE demonstrates that there are no prevalent E. coli clones from these avian hosts. Wild birds and pigeons could act as carriers of multidrug-resistant STEC and EPEC and therefore may constitute a considerable hazard to human and animal health by transmission of these strains to the environment.     

Mosquitoes (Diptera,Culicidae) of the Morava River floodplain,Slovakia

Research on the Morava River floodplain mosquito fauna was carried out from April to October in 2009 and 2010. Altogether, 5864 adults were collected and identified from 12 selected sites. The presence of 28 mosquito species belonging to 6 genera were confirmed in the study area. The floodplain of the Morava River is known for its frequent inundation every year. The floods are quite irregular and often followed by the mass production of mosquitoes. The most abundant species were Aedes vexans (41.4%), Ae. cinereus (7.5%), Ae. rossicus (16.7%), Ochlerotatus sticticus (20.5%), and Culex pipiens (3.1%). Ae. vexans and Oc. sticticus are typical outbreak species for the Morava River floodplain. The years 2009 and 2010 differed in the number of floods, which influenced the mosquito faunal composition and abundance during the year.     

Dispersal of remnant endangered trees in a fragmented and disturbed forest by frugivorous birds

Most endangered plant species in a fragmented forest behave as a unique source population, with a high dependence on frugivorous birds for recruitment and persistence. In this study, we combined field data of dispersal behavior of birds and GIS information of patch attributes to estimate how frugivorous birds could affect the effective dispersal pattern of Chinese yew (Taxus chinensis) in a fragmented and disturbed forest. Nine bird species were observed to visit T. chinensis trees, with Urocissa erythrorhyncha, Zoothera dauma and Picus canus being the most common dispersers. After foraging, six disperser species exhibited different perching patterns. Three specialist species, P. canus, Turdus hortulorum, and Z. dauma stayed in the source patch, while three generalist species, U. erythrorhyncha, Hypsipetes mcclellandii, and H. castanonotus, could perch in bamboo patches and varied in movement ability due to body size. As a consequence of perching, dispersers significantly contributed to the seed bank, but indirectly affected seedling recruitment. Moreover, the recruitment of T. chinensis was also affected by patch attributes in a fragmented forest (distances to source patch, patch type, size). Our results highlighted the ability of unique source population regeneration of T. chinensis in a fragmented forest, with high dependence on both frugivorous birds and patch attributes, which should be considered in future planning for forest management and conservation.     

Prevalence of blood parasites in seabirds - a review

Introduction

While blood parasites are common in many birds in the wild, some groups seem to be much less affected. Seabirds, in particular, have often been reported free from blood parasites, even in the presence of potential vectors.

Results

From a literature review of hemosporidian prevalence in seabirds, we collated a dataset of 60 species, in which at least 15 individuals had been examined. These data were included in phylogenetically controlled statistical analyses of hemosporidian prevalence in relation to ecological and life-history parameters. Haemoproteus parasites were common in frigatebirds and gulls, while Hepatozoon occurred in albatrosses and storm petrels, and Plasmodium mainly in penguins. The prevalence of Haemoproteus showed a geographical signal, being lower in species with distribution towards polar environments. Interspecific differences in Plasmodium prevalence were explained by variables that relate to the exposure to parasites, suggesting that prevalence is higher in burrow nesters with long fledgling periods. Measures of Plasmodium, but not Haemoproteus prevalences were influenced by the method, with PCR-based data resulting in higher prevalence estimates.

Conclusions

Our analyses suggest that, as in other avian taxa, phylogenetic, ecological and life-history parameters determine the prevalence of hemosporidian parasites in seabirds. We discuss how these relationships should be further explored in future studies.

     

Phylogenetic evidence for an ancestral coevolution between a major clade of coccidian parasites and elasmobranch hosts

Cartilaginous fishes are the oldest jawed vertebrates and are also reported to be the hosts of some of the most basal lineages of Cestoda and Aporocotylidae (Digenea) parasites. Recently a phylogenetic analysis of the coccidia (Apicomplexa) infecting marine vertebrates revealed that the lesser spotted dogfish harbours parasite lineages basal to Eimeria Schneider, 1875 and the group formed by Schellackia Reichenow, 1919, Lankesterella Ames, 1923, Caryospora Leger, 1904 and Isospora Schneider, 1881. In the present study we have found additional lineages of coccidian parasites infecting the cownose ray Rhinoptera bonasus Mitchill and the blue shark Prionace glauca Linnaeus. These lineages were also found as basal to species from the genera Lankesterella, Schellackia, Caryospora and Isospora infecting higher vertebrates. These results confirm previous phylogenetic assessments and suggest that these parasitic lineages first evolved in basal vertebrate hosts (i.e. Chondrichthyes), and that the more derived lineages infect higher vertebrates (e.g. birds and mammals) conforming to the evolution of their hosts. We hypothesise that elasmobranchs might host further ancestral parasite lineages harbouring unknown links of parasite evolution.     

<Emphasis Type="Italic">Salmonella</Emphasis> in Wild Birds Utilizing Protected and Human Impacted Habitats,Uganda

As human populations in Africa expand, humans encroach and modify wildlife habitats for farming, fishing, tourism, or settlement. Anthropogenic activities in shared environments may promote transmission of zoonotic pathogens between humans, domestic animals, and wildlife. Between July 2012 and February 2014, we evaluated Salmonella prevalence, serovars, genotypes, and antibiotic resistant phenotypes in resident and migratory birds utilizing human-impacted habitats in northwestern Lake Victoria and protected habitats in Queen Elisabeth National Park. Salmonella occurrence in the urban environment was assessed by sampling storm-water and wastewater from a channel that drains Kampala City into Lake Victoria. Salmonella was detected in 4.3% pooled bird fecal samples, and 57.1% of environmental samples. While birds in impacted and protected areas shared serovars, the genotypes were distinct. We found distinct strains in birds and the environment suggesting some strains in birds are host adapted, and strains circulating in the environment may not necessarily disseminate to birds. Conversely, birds in both impacted and protected areas shared strains with the urban environment, suggesting Salmonella disseminates between impacted environments and birds across sites. Overall, more strains were observed in the urban environment compared to birds, and poses risk of Salmonella reemergence in birds and transmission across species and space.     

Genetic characterization of Hawaiian isolates of <Emphasis Type="Italic">Plasmodium relictum</Emphasis>reveals mixed-genotype infections

Background

The relatively recent introduction of a highly efficient mosquito vector and an avian pathogen (Plasmodium relictum) to an isolated island ecosystem with naïve, highly susceptible avian hosts provides a unique opportunity to investigate evolution of virulence in a natural system. Mixed infections can significantly contribute to the uncertainty in host-pathogen dynamics with direct impacts on virulence. Toward further understanding of how host-parasite and parasite-parasite relationships may impact virulence, this study characterizes within-host diversity of malaria parasite populations based on genetic analysis of the trap (thrombospondin-related anonymous protein) gene in isolates originating from Hawaii, Maui and Kauai Islands.

Methods

A total of 397 clones were produced by nested PCR amplification and cloning of a 1664 bp fragment of the trap gene from two malarial isolates, K1 (Kauai) and KV115 (Hawaii) that have been used for experimental studies, and from additional isolates from wild birds on Kauai, Maui and Hawaii Islands. Diversity of clones was evaluated initially by RFLP-based screening, followed by complete sequencing of 33 selected clones.

Results

RFLP analysis of trap revealed a minimum of 28 distinct RFLP haplotypes among the 397 clones from 18 birds. Multiple trap haplotypes were detected in every bird evaluated, with an average of 5.9 haplotypes per bird. Overall diversity did not differ between the experimental isolates, however, a greater number of unique haplotypes were detected in K1 than in KV115. We detected high levels of clonal diversity with clear delineation between isolates K1 and KV115 in a haplotype network. The patterns of within-host haplotype clustering are consistent with the possibility of a clonal genetic structure and rapid within-host mutation after infection.

Conclusion

Avian malaria (P. relictum) and Avipoxvirus are the significant infectious diseases currently affecting the native Hawaiian avifauna. This study shows that clonal diversity of Hawaiian isolates of P. relictum is much higher than previously recognized. Mixed infections can significantly contribute to the uncertainty in host-pathogen dynamics with direct implications for host demographics, disease management strategies, and evolution of virulence. The results of this study indicate a widespread presence of multiple-genotype malaria infections with high clonal diversity in native birds of Hawaii, which when coupled with concurrent infection with Avipoxvirus, may significantly influence evolution of virulence.

Reviewers

This article was reviewed by Joseph Schall (nominated by Laura Landweber), Daniel Jeffares (nominated by Anthony Poole) and Susan Perkins (nominated by Eugene Koonin).