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1.
Parasitology ; 151(4): 449-460, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38433581

RESUMO

We studied the relationships between functional alpha and beta diversities of fleas and their small mammalian hosts in 4 biogeographic realms (the Afrotropics, the Nearctic, the Neotropics and the Palearctic), considering 3 components of alpha diversity (functional richness, divergence and regularity). We asked whether (a) flea alpha and beta diversities are driven by host alpha and beta diversities; (b) the variation in the off-host environment affects variation in flea alpha and beta diversities; and (c) the pattern of the relationship between flea and host alpha or beta diversities differs between geographic realms. We analysed alpha diversity using modified phylogenetic generalized least squares and beta diversity using modified phylogenetic generalized dissimilarity modelling. In all realms, flea functional richness and regularity increased with an increase in host functional richness and regularity, respectively, whereas flea functional divergence correlated positively with host functional divergence in the Nearctic only. Environmental effects on the components of flea alpha diversity were found only in the Holarctic realms. Host functional beta diversity was invariantly the best predictor of flea functional beta diversity in all realms, whereas the effects of environmental variables on flea functional beta diversity were much weaker and differed between realms. We conclude that flea functional diversity is mostly driven by host functional diversity, whereas the environmental effects on flea functional diversity vary (a) geographically and (b) between components of functional alpha diversity.


Assuntos
Infestações por Pulgas , Interações Hospedeiro-Parasita , Sifonápteros , Animais , Sifonápteros/fisiologia , Sifonápteros/classificação , Infestações por Pulgas/parasitologia , Infestações por Pulgas/veterinária , Filogenia , Mamíferos/parasitologia , Biodiversidade
2.
Integr Zool ; 2024 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-38263720

RESUMO

We studied spatial variation in the effects of environment and network size on species positions and roles in multiple flea-mammal networks from four biogeographic realms. We asked whether species positions (measured as species strength [SS], the degree of interaction specialization [d'], and the eigenvector centrality [C]) or the roles of fleas and their hosts in the interaction networks: (a) are repeatable/conserved within a flea or a host species; (b) vary in dependence on environmental variables and/or network size; and (c) the effects of environment and network size on species positions or roles in the networks depend on species traits. The repeatability analysis of species position indices for 441 flea and 429 host species, occurring in at least two networks, demonstrated that the repeatability of SS, d', and C within a species was significant, although not especially high, suggesting that the indices' values were affected by local factors. The majority of flea and host species in the majority of networks demonstrated a peripheral role. A value of at least one index of species position was significantly affected by environmental variables or network size in 41 and 36, respectively, of the 52 flea and 52 host species that occurred in multiple networks. In both fleas and hosts, the occurrence of the significant effect of environment or network size on at least one index of species position, but not on a species' role in a network, was associated with some species traits.

3.
Med Vet Entomol ; 38(1): 112-117, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37850372

RESUMO

The parvorder Rhynchopthirina contains three currently recognised species of lice that parasitize elephants (both African savanna elephant Loxodonta africana and Asian elephant Elephas maximus), desert warthogs (Phacochoerus aethiopicus) and Red River hogs (Potamochoerus porcus), respectively. The Asian elephant lice and the African savanna elephant lice are currently treated as the same species, Haematomyzus elephantis (Piaget, 1869), based on morphology despite the fact that their hosts diverged 8.4 million years ago. In the current study, we sequenced 23 mitochondrial (mt) genes of African savanna elephant lice collected in South Africa and analysed the sequence divergence between African savanna elephant lice and previously sequenced Asian elephant lice. Sequence comparisons revealed >23% divergence for the 23 mt genes as a whole and ~17% divergence for cox1 gene between African savanna and Asian elephant lice, which were far higher than the divergence expected within a species. Furthermore, the mt gene sequence divergences between these lice are 3.76-4.6 times higher than that between their hosts, the African savanna and Asian elephants, which are expected for the co-divergence and co-evolution between lice and their elephant hosts. We conclude that (1) H. elephantis (Piaget, 1869) contains cryptic species and (2) African savanna and Asian elephant lice are different species genetically that may have co-diverged and co-evolved with their hosts.


Assuntos
Elefantes , Genoma Mitocondrial , Ftirápteros , Suínos , Animais , Elefantes/genética , Ftirápteros/genética , África do Sul
4.
Parasitology ; 150(11): 979-989, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37681253

RESUMO

The factors that influence parasite associated bacterial microbial diversity and the geographic distributions of bacteria are not fully understood. In an effort to gain a deeper understanding of the relationship between the bacterial diversity of Ctenocephalides fleas and host species and the external environment, we conducted a metagenetic analysis of 107 flea samples collected from 8 distinct sampling sites in South Africa. Pooled DNA samples mostly comprising of 2 or 3 individuals sampled from the same host, and belonging to the same genetic cluster, were sequenced using the Ion PGM™ Hi-Q™ Kit and the Ion 316™ Chip v2. Differences were detected in the microbiome compositions between Ctenocephalides felis, Ctenocephalides canis and Ctenocephalides connatus. Although based on a small sample, C. connatus occurring on wildlife harboured a higher bacterial richness when compared to C. felis on domestic animals. Intraspecific differences in the microbial OTU diversity were detected within C. f. felis that occurred on domestic cats and dogs. Different genetic lineages of C. f. felis were similar in microbial compositions but some differences exist in the presence or absence of rare bacteria. Rickettsia and Bartonella OTU's identified in South African cat fleas differ from those identified in the USA and Australia. Intraspecific microbial compositions also differ across geographic sampling sites. Generalized dissimilarity modelling showed that temperature and humidity are potentially important environmental factors explaining the pattern obtained.


Assuntos
Doenças do Gato , Ctenocephalides , Felis , Infestações por Pulgas , Sifonápteros , Animais , Gatos , Cães , África do Sul , Infestações por Pulgas/epidemiologia , Infestações por Pulgas/veterinária , Doenças do Gato/parasitologia
5.
Parasitology ; 150(9): 792-804, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37272490

RESUMO

Rodents are known hosts for various ectoparasite taxa such as fleas, lice, ticks and mites. South Africa is recognized for its animal diversity, yet little is published about the parasite diversity associated with wild rodent species. By focusing on a wildlife-human/domestic animal interface, the study aims to record ectoparasite diversity and levels of infestations of the Bushveld gerbil, Gerbilliscus leucogaster, and to establish the relationship between ectoparasite infestation parameters and host- and habitat factors. Rodents (n = 127) were trapped in 2 habitat types (natural and agricultural) during 2014­2020. More than 6500 individuals of 32 epifaunistic species represented by 21 genera and belonging to 5 taxonomic groups (fleas, sucking lice, ticks, mesostigmatan mites and trombiculid mites) were collected. Mesostigmatan mites and lice were the most abundant and fleas and mesostigmatan mites the most prevalent groups. Flea and mesostigmatan mite numbers and mesostigmatan mite species richness was significantly higher on reproductively active male than female rodents. Only ticks were significantly associated with habitat type, with significantly higher tick numbers and more tick species on rodents in the natural compared to the agricultural habitat. We conclude that the level of infestation by ectoparasites closely associated with the host (fleas and mites) was affected by host-associated factors, while infestation by ectoparasite that spend most of their life in the external environment (ticks) was affected by habitat type.


Assuntos
Ectoparasitoses , Infestações por Pulgas , Ácaros , Ftirápteros , Sifonápteros , Carrapatos , Trombiculidae , Animais , Masculino , Feminino , Humanos , Gerbillinae/parasitologia , Ectoparasitoses/epidemiologia , Ectoparasitoses/veterinária , Ectoparasitoses/parasitologia , Infestações por Pulgas/epidemiologia , Infestações por Pulgas/veterinária , Ecossistema
6.
Parasitology ; 149(1): 124-137, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-35184781

RESUMO

We investigated the patterns of phylogenetic and functional (dis)similarity in the species composition of host spectra between co-habitating generalist flea species in regional assemblages from four continents (Europe, Asia, North America and Africa) using a recently developed ordination approach (Double Similarity Principal Component Analysis). From the functional perspective, we considered physiological [body mass and basal metabolic rate (BMR)] and ecological (shelter depth and complexity) host traits. We asked (a) whether host phylogeny, physiology or ecology is the main driver of (dis)similarities between flea host spectra and (b) whether the patterns of phylogenetic and functional (dis)similarity in host spectra vary between flea assemblages from different continents. Phylogenetic similarity between the host spectra was highest in Africa, lowest in North America and moderate in Europe and Asia. In each assemblage, phylogenetic clusters of hosts dominating in the host spectra could be distinguished. The functional similarity between the host spectra of co-occurring fleas was low for shelter structure in all assemblages and much higher for body mass and BMR in three of the four assemblages (except North America). We conclude that host phylogeny and shelter structure are the main drivers of (dis)similarity between the host spectra of co-habitating fleas. However, the effects of these factors on the patterns of (dis)similarity varied across continents.


Assuntos
Infestações por Pulgas , Sifonápteros , África , Animais , Ásia , Infestações por Pulgas/veterinária , Interações Hospedeiro-Parasita , Filogenia , Sifonápteros/fisiologia
7.
Parasitol Res ; 120(7): 2569-2584, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34137949

RESUMO

One of the challenges in studies of parasite community ecology is whether the input data for analyses should be parasite abundances/counts, i.e. count data (CD), or parasite incidences (presences/absences), i.e. incidence data (ID). We analysed species responses to environmental factors and species associations in the infracommunities of helminths and ectoparasites in four hosts from Europe (Sorex araneus and Myodes glareolus) and South Africa (Rhabdomys pumilio and Rhabdomys dilectus) and compared the results of four analyses [redundancy analysis (RD), RLQ analysis, joint species distribution modelling (JSDM) and Markov random fields (MRF)] that used either CD or ID as an input. In addition, we compared the differences between the CD and ID results of two analyses (JSDM and MRF) across parasite species between (a) host species within helminths and ectoparasites; (b) helminths and ectoparasites within a host species; and (c) parasite species with contrasting levels of intensity. The results of most analyses for the majority of parasite-host associations were qualitatively similar. However, models based on the ID input performed better than models based on the CD input in three out of four types of analyses (RDA, JSDM and MRF). The differences between the CD and ID models varied between host species (being the lowest in R. pumilio for JSDM and in S. araneus for MRF). However, they were not affected by the level of parasite intensity.


Assuntos
Interações Hospedeiro-Parasita , Parasitos/fisiologia , Doenças Parasitárias/epidemiologia , Animais , Biota , Europa (Continente)/epidemiologia , Feminino , Helmintos/crescimento & desenvolvimento , Helmintos/fisiologia , Especificidade de Hospedeiro , Incidência , Masculino , Cadeias de Markov , Modelos Biológicos , Murinae/parasitologia , Parasitos/crescimento & desenvolvimento , Doenças Parasitárias/parasitologia , África do Sul/epidemiologia
8.
Int J Parasitol ; 51(10): 865-876, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-33848500

RESUMO

The loss of a particular species from a community may have different effects on its functioning, depending on the presence or absence of functionally similar or phylogenetically close species in that community (redundancy). Redundancy is thus defined as the fraction of species diversity not expressed by functional or phylogenetic diversity. We assessed functional and phylogenetic alpha- and beta-redundancy in helminth and flea assemblages of two species of South African rodents, Rhabdomys dilectus and Rhabdomys pumilio, using community uniqueness as the inverse indicator of redundancy. We asked whether patterns of functional and phylogenetic alpha- and beta-uniqueness differed between (i) parasite groups (endo- versus ectoparasites), (ii) host species within parasite groups, and (iii) biomes within host species. We found differences between the two hosts in the functional and phylogenetic alpha-uniqueness (but not beta-uniqueness) of flea, but not helminth, assemblages. Significant correlations between the alpha-uniqueness of parasite assemblages and the total parasite prevalence were found only for phylogenetic uniqueness and only in helminths. Pairwise site-by-site dissimilarities in uniqueness (beta-uniqueness) and pairwise dissimilarity in prevalence were significantly associated (positively) in helminths but not in fleas. A between-biome difference in functional (but not phylogenetic) alpha-uniqueness was found in both helminth and flea assemblages harboured by R. pumilio. We conclude that the resilience of parasite assemblages in terms of the effect on hosts depends not only on their transmission strategy but also on traits of host species and environmental factors.


Assuntos
Infestações por Pulgas , Helmintos , Sifonápteros , Animais , Infestações por Pulgas/epidemiologia , Infestações por Pulgas/veterinária , Interações Hospedeiro-Parasita , Murinae , Filogenia
9.
Mol Phylogenet Evol ; 155: 106990, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33096232

RESUMO

The cat flea, Ctenocephalides felis, is an obligate haematophagous ectoparasite of wildlife and domestic cats and dogs worldwide. Since cat fleas can affect the health of humans and their pets, an uncertain taxonomy of this taxon can greatly inhibit pest and disease management. To address the evolution and taxonomy of the cat flea, we set out to determine 1) how many genetically distinct taxa exist, 2) whether there is morphological support for the genetically distinct taxa, and 3) the role of host range and paleoclimatic events in speciation. We collected a total of 3352 fleas sampled from 576 domestic cats and dogs as well as 10 wildlife species across 30 localities in South Africa. A total of three flea genera, five species, and three of the currently recognized cat flea subspecies, C. f. damarensis, C. f. strongylus and C. f. felis were obtained. Geometric morphometric analyses on head shape were performed on 68 female and 107 male cat flea individuals. Principal component analysis demonstrated large overlap in head shape variation between C. f. strongylus and C. f. felis, rendering this character not useful for phylogenetic inferences. DNA was extracted from 188 Ctenocephalides spp. and mitochondrial COII and nuclear EF1-α sequences were generated. Bayesian and Maximum Likelihood analyses as well as a TCS parsimony haplotype network of the mitochondrial DNA confirmed the presence of three well supported monophyletic clades. These assemblages did not fully corroborate the existence of the three C. felis subspecies. A single well-supported molecular clade included only C. f. damarensis morphotypes that were mostly collected from wildlife. The recognition of this subspecies as a distinct taxon was further corroborated by sequence distances and also the number of plantar spiniform bristles on fore-tarsi V in males. Despite the overall lack of support for the recognition of C. f. damarensis and C. f. strongylus, a geographic trend was visible whereby one genetic lineage corresponded to the western dryer hot subregion, whereas the other was found throughout the region. Bayesian dating suggested that these two clades diverged during the early Pliocene (4.18 mya), a date that corresponds well with the establishment of a dry hot climate in the west of southern Africa. If so, the off-host environment, particularly temperature and humidity, are important factors to consider in the evolution of the cat flea. The present study rejects recent assertions that the three cat flea subspecies are valid entities and rather point to a situation where more sampling is required before the taxonomic status of C. f. damarensis can be resolved.


Assuntos
Evolução Biológica , Gatos/parasitologia , Ctenocephalides/classificação , Geografia , África Austral , Animais , Teorema de Bayes , Tamanho Corporal , Ctenocephalides/genética , Complexo IV da Cadeia de Transporte de Elétrons/genética , Feminino , Haplótipos/genética , Cabeça/anatomia & histologia , Masculino , Mitocôndrias/genética , Filogenia , Análise de Componente Principal , Especificidade da Espécie
10.
Parasitol Res ; 119(11): 3603-3616, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32996052

RESUMO

Nest design and characteristics can influence the microclimatic conditions in the nest. Nest-dwelling ectoparasites are sensitive to temperature and moisture and as such the conditions in the nest can influence parasite infestations. The endangered African penguin (Spheniscus demersus) breeds in different nest types and as yet little is known with regard to the microclimate and parasite infestation within these nests. This study characterized the microclimatic conditions in natural open, natural covered (with vegetation) and artificial nests, and assessed the relationship between nest characteristics (type, age, distance from the coast, orientation and entrance opening) and in-nest ectoparasite infestations and the health of African penguins in Stony Point, South Africa. Penguins (50 adults and 192 chicks) and their nests (n = 308) were sampled in 2016 and 2017. Soil temperature was higher in artificial than in natural nests, and soil and nest material moisture was lower in artificial and natural covered nests than natural open. Ectoparasite infestations were higher under warmer and drier conditions, in artificial nests and nests near the coastline. Penguin (adult and chick) body mass and chick body condition were lower in warmer nests and total plasma protein (in adults and checks) was lower in drier nests. Given the potential adverse effects of ectoparasites on host species, it is recommended that conservation agencies implement a monitoring programme to assess the ectoparasite infestation in artificial nests across multiple colonies. This information will facilitate a more holistic penguin conservation management plan that may prevent further detrimental effects on this endangered penguin species.


Assuntos
Ectoparasitoses/veterinária , Microclima , Spheniscidae/parasitologia , Animais , Ectoparasitoses/etiologia , Ectoparasitoses/parasitologia , Espécies em Perigo de Extinção , Comportamento de Nidação , África do Sul , Temperatura
11.
J Parasitol ; 106(4): 478-489, 2020 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-32679590

RESUMO

Two new species of sucking lice (Phthiraptera: Anoplura), Hoplopleura granti n. sp. (Hoplopleuridae) and Polyplax megacephalus n. sp. (Polyplacidae), are described from Grant's rock mouse, Micaelamys granti (Wroughton), from Northern Cape Province, South Africa. Adults of both sexes are illustrated via line drawings and differential interference contrast microscopy images, and are compared with previously described related species that parasitize related hosts: Hoplopleura patersoni Johnson from Aethomys chrysophilus (de Winton) (red veld rat), Aethomys kaiseri (Noack) (Kaiser's aethomys), and Micaelamys namaquensis (A. Smith) (Namaqua rock mouse); Hoplopleura aethomydis Kleynhans from M. namaquensis; Polyplax praomydis Bedford from A. chrysophilus and M. namaquensis; and Polyplax solivaga Johnson from A. chrysophilus. It is not known if these new species of lice are vectors of any pathogens.


Assuntos
Anoplura/classificação , Infestações por Piolhos/veterinária , Murinae/parasitologia , Doenças dos Roedores/parasitologia , Animais , Anoplura/anatomia & histologia , Anoplura/enzimologia , Anoplura/genética , Sequência de Bases , Feminino , Infestações por Piolhos/epidemiologia , Infestações por Piolhos/parasitologia , Masculino , Prevalência , Doenças dos Roedores/epidemiologia , África do Sul/epidemiologia
12.
Parasitology ; 147(9): 1038-1047, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32364099

RESUMO

Chigger mites (Trombiculidae) are temporary habitat-specific ectoparasites that often occur on rodents. Little ecological data are available on chiggers associated with rodents in South Africa. The study aims were to (1) record the chigger species associated with rodents in the savanna, (2) assess if chigger species display parasitope preference on the rodent body and (3) compare the distribution of chigger species in natural, agricultural and urban habitats. Rodents (n = 314) belonging to eight genera were trapped in the savanna biome during 2014 and 2015. Twelve chigger species, of which five are recently described species, were recorded from 161 rodent hosts. The data include three new country locality records. Microtrombicula mastomyia was the most prevalent species across sampling seasons and habitat types. Significant parasitope preference was recorded for two species, with the ear, face and tail base some of the preferred attachment sites. Sampling season and habitat type had a significant effect on chigger communities with summer and agricultural habitats recording the highest species richness, while the highest species diversity was recorded in natural habitats. The study contributes to our current knowledge regarding rodent-associated chigger diversity and distribution in South Africa and further highlights the importance of environmental characteristics in shaping chigger communities.


Assuntos
Distribuição Animal , Infestações por Ácaros/veterinária , Doenças dos Roedores/epidemiologia , Roedores , Trombiculidae/fisiologia , Animais , Pradaria , Incidência , Infestações por Ácaros/epidemiologia , Infestações por Ácaros/parasitologia , Prevalência , Doenças dos Roedores/parasitologia , Estações do Ano , África do Sul/epidemiologia , Trombiculidae/classificação
13.
Parasitol Res ; 118(10): 2863-2875, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31399870

RESUMO

A fundamental aim of parasite ecology is to understand the mechanisms behind spatial variation in diversity and structure of parasite assemblages. To understand the contribution of individual parasite species and their assemblages to spatial variation in parasite communities, we examined species contributions to beta diversity (SCBD) and local contributions to beta diversity (LCBD) of parasitic gastrointestinal helminths (nematodes and cestodes) in two closely related rodents, Rhabdomys dilectus and Rhabdomys pumilio, from 20 localities across South Africa. Although the two Rhabdomys spp. are morphologically similar, they differ substantially in body size, habitat preference, and sociality. We asked whether the variation in life history traits and infection parameters are associated with SCBD of helminths and whether variation in environmental factors, host population density, and species richness of host communities are associated with LCBD of component assemblages of helminths. We also considered spatial factors to test whether LCBD of helminth assemblages demonstrate geographic structure. We found that the contribution of helminth species parasitic in both hosts to beta diversity significantly increased with characteristic prevalence of these species, whereas mean abundance, type of life cycle, and location in the host's gut had no effect on SCBD. The LCBD of helminth assemblages showed a significant positive correlation with environmental factors in both host species. Our results suggest that predictors of variation in SCBD and LCBD may substantially differ between parasites with different infection parameters and/or parasite communities at different hierarchical scales.


Assuntos
Cestoides/isolamento & purificação , Infecções por Cestoides/epidemiologia , Trato Gastrointestinal/parasitologia , Murinae/parasitologia , Nematoides/isolamento & purificação , Infecções por Nematoides/epidemiologia , Animais , Cestoides/classificação , Infecções por Cestoides/parasitologia , Infecções por Cestoides/veterinária , Ecologia , Ecossistema , Helmintíase Animal/epidemiologia , Helmintíase Animal/parasitologia , Especificidade de Hospedeiro , Estágios do Ciclo de Vida , Nematoides/classificação , Infecções por Nematoides/parasitologia , Infecções por Nematoides/veterinária , Densidade Demográfica , Prevalência , África do Sul/epidemiologia
14.
Syst Parasitol ; 96(8): 703-713, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31452131

RESUMO

A new chigger mite species, Schoutedenichia microcebi n. sp. is described from the grey mouse lemur Microcebus murinus (J.F. Miller) from Madagascar. The new species is closely related to S. dutoiti (Radford, 1948), a species described from a single specimen collected on a rodent in South Africa. Examination of the holotype and new material on S. dutoiti from South Africa enabled us to re-describe this species and provide new data on its hosts and geographical distribution.


Assuntos
Cheirogaleidae/parasitologia , Trombiculidae/classificação , Trombiculidae/fisiologia , Animais , Madagáscar , Camundongos , África do Sul , Especificidade da Espécie
15.
Parasitology ; 146(6): 791-804, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30724152

RESUMO

The African penguin (Spheniscus demersus) is a critically endangered species endemic to southern Africa. Limited information is available on the parasite diversity associated with the species in natural settings. This study explores the diversity and incidence of parasites associated with African penguins and their nests, and records the effect of host and environmental factors on parasite infestation. Ecto-, haemo- and helminth parasites were recorded from 210 adult birds, 583 chicks and 628 nests across five colonies (two mainland and three islands) along the south-western coast of South Africa, in 2016 and 2017. Mean nest density (total and active nests) and climate variables (temperature and precipitation) were obtained for each colony. Parapsyllus humboldti was the most abundant and prevalent ectoparasite on penguins and in nests (69.10 and 57.80%, respectively), while Piroplasmorida/Haemospororida (33.51%) and Cardiocephaloides spp. (56.17%) were the most prevalent haemo- and helminth parasites of penguins, respectively. In general parasite abundance and prevalence was significantly affected by penguin age (chicks vs adults), location (mainland vs islands), nest density (total and active nests) and season (spring vs autumn/winter). It is concluded that parasite infestations are structured and that penguin chicks at mainland colonies are more susceptible to parasite infestations during spring.


Assuntos
Biodiversidade , Parasitos/classificação , Parasitos/isolamento & purificação , Doenças Parasitárias em Animais/epidemiologia , Doenças Parasitárias em Animais/parasitologia , Spheniscidae/parasitologia , Animais , Incidência , Prevalência , África do Sul/epidemiologia
16.
Vector Borne Zoonotic Dis ; 19(4): 242-248, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30571537

RESUMO

Bartonella is a species-rich bacterial genus that infects a wide variety of wild and domestic animals, including rodents. Despite high levels of murid rodent diversity in Africa, associated Bartonella prevalence and diversity remains understudied, particularly within the southern African subregion. To address this, we sampled endemic four-striped mice, Rhabdomys pumilio, from three rural and two urban localities in the Western Cape Province, South Africa. PCR screening and multilocus sequence analysis inclusive of five genome regions (gltA, nuoG, ribC, rpoB, and ITS), were respectively used to evaluate Bartonella status and diversity in these synanthropic rodent populations. An overall infection rate of 15% was recovered, ranging from 0% for an urban locality to 36.4% for a rural locality, consistent with the higher flea abundance recorded at the latter sites. Nucleotide sequencing and phylogenetic analyses confirmed the presence of three distinct Bartonella lineages (I-III), with lineages II and III grouping with bartonellae previously detected in R. pumilio from nature reserves in the Free State Province of South Africa, and lineage I being novel and sister to Bartonella strains identified previously in Micaelamys namaquensis. Our results indicate significant landscape effects on infection rates, highlight differential PCR assay performance, and identify three host-associated Bartonella lineages in Rhabdomys from South Africa.


Assuntos
Infecções por Bartonella/veterinária , Bartonella/isolamento & purificação , Murinae/microbiologia , Doenças dos Roedores/microbiologia , Animais , Bartonella/classificação , Bartonella/genética , Infecções por Bartonella/microbiologia , Filogenia , África do Sul
17.
BMC Evol Biol ; 18(1): 131, 2018 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-30176805

RESUMO

BACKGROUND: The specialist-generalist variation hypothesis (SGVH) in parasites suggests that, due to patchiness in habitat (host availability), specialist species will show more subdivided population structure when compared to generalist species. In addition, since specialist species are more prone to local stochastic extinction events with their hosts, they will show lower levels of intraspecific genetic diversity when compared to more generalist. RESULTS: To test the wider applicability of the SGVH we compared 337 cytochrome oxidase I mitochondrial DNA and 268 nuclear tropomyosin DNA sequenced fragments derived from two co-distributed Laelaps mite species and compared the data to 294 COI mtDNA sequences derived from the respective hosts Rhabdomys dilectus, R. bechuanae, Mastomys coucha and M. natalensis. In support of the SGVH, the generalist L. muricola was characterized by a high mtDNA haplotypic diversity of 0.97 (±0.00) and a low level of population differentiation (mtDNA Fst = 0.56, p < 0.05; nuDNA Fst = 0.33, P < 0.05) while the specialist L. giganteus was overall characterized by a lower haplotypic diversity of 0.77 (±0.03) and comparatively higher levels of population differentiation (mtDNA Fst = 0.87, P < 0.05; nuDNA Fst = 0.48, P < 0.05). When the two specialist L. giganteus lineages, which occur on two different Rhabdomys species, are respectively compared to the generalist parasite, L. muricola, the SGVH is not fully supported. One of the specialist L. giganteus species occurring on R. dilectus shows similar low levels of population differentiation (mtDNA Fst = 0.53, P < 0.05; nuDNA Fst = 0.12, P < 0.05) than that found for the generalist L. muricola. This finding can be correlated to differences in host dispersal: R. bechuanae populations are characterized by a differentiated mtDNA Fst of 0.79 (P < 0.05) while R. dilectus populations are less structured with a mtDNA Fst = 0.18 (P < 0.05). CONCLUSIONS: These findings suggest that in ectoparasites, host specificity and the vagility of the host are both important drivers for parasite dispersal. It is proposed that the SGHV hypothesis should also incorporate reference to host dispersal since in our case only the specialist species who occur on less mobile hosts showed more subdivided population structure when compared to generalist species.


Assuntos
Ácaros/classificação , Modelos Biológicos , Parasitos/classificação , Filogeografia , Animais , Sequência de Bases , Núcleo Celular/genética , DNA Mitocondrial/genética , Variação Genética , Geografia , Haplótipos/genética , Especificidade de Hospedeiro , Ácaros/genética , Mitocôndrias/genética , Murinae/genética , Murinae/parasitologia , Parasitos/genética
18.
J Morphol ; 279(9): 1282-1289, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30187940

RESUMO

Several muroid rodent species are distributed throughout southern Africa. Some species are reportedly classified as opportunistic omnivorous rodents consuming plant, seed, and insect material. This study aims to provide a detailed morphometric analysis of the gastrointestinal tract (GIT) of four such omnivorous species, including stomach content analysis. Fixed GIT specimens (n = 5 of each) of Rhabdomys dilectus (Mesic four-striped grass mouse), Rhabdomys pumilio (Xeric four-striped grass mouse), Aethomys chrysophilus (Red rock rat), and Lemniscomys rosalia (Single-striped grass mouse) were weighed. Length and circumference measurements of each anatomically distinct GIT region were determined to calculate the basal surface area (BSA). Histological sections from each GIT region were used to calculate a surface enlargement factor (SEF). The BSA and SEF were multiplied to calculate the luminal surface area (LSA) of each GIT region. Stomach content was analyzed both macroscopically and histologically. All species had a similar GIT morphology, namely a unilocular, hemiglandular stomach with a clear limiting ridge, which indicated the transition from stratified squamous epithelium to glandular epithelium. A large loosely spiralled cecum was present in all species. A narrowing of the cecal apex accompanied by lymph aggregates, confirmed histologically in both Rhabdomys species, indicated a cecal appendix. A single short colonic loop with a unique folding pattern for each species was present in the proximal colon. The colonic mucosal surface presented with proximal V-shaped, and distal longitudinal folds. Intermediate transitional S-shaped folds were present in three species (R. dilectus, R. pumilio, and L. rosalia). Colonic mucosal folds indicated hindgut specialization similar to other muroid rodents. The hindgut specialization was further supported by morphometric analysis, which indicated large BSA and LSA measurements in the cecum and colon. These adaptations are consistent with herbivory, despite stomach content analysis revealing omnivorous tendencies.


Assuntos
Trato Gastrointestinal/anatomia & histologia , Roedores/anatomia & histologia , Animais , Ceco/anatomia & histologia , Colo/anatomia & histologia , Conteúdo Gastrointestinal/química , Estômago/anatomia & histologia
19.
J Evol Biol ; 31(10): 1529-1543, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29964350

RESUMO

Measuring contemporary dispersal in highly mobile terrestrial species is challenging, especially when species are characterized by low levels of population differentiation. Directly transmitted viruses can be used as a surrogate for traditional methods of tracking host movement. Feline immunodeficiency virus (FIV) is a species-specific lentivirus, which has an exceptionally high mutation rate and circulates naturally in wild felids. Using samples derived from 35 lion (Panthera leo) prides, we tested the prediction that FIV in lions (FIVPle ) can be used to track the dispersal of individuals between prides. As FIVPle subtypes are geographically structured throughout Africa, we predicted that this marker could be used to detect phylogeographic structure of lions at smaller spatial scales. Phylogenetic analyses of FIVPle pol-RT sequences showed that core pride members (females and subadults) shared evolutionary close viral lineages which differed from neighbouring core prides, whereas sequences from sexually mature males associated with the same pride were always the most divergent. In six instances, natal pride associations of divergent male lions could be inferred, on the assumption that FIVPle infections are acquired during early life stages. Congruence between the genetic pattern of FIV and pride structure suggests that vertical transmission plays an important role in lion FIV dynamics. At a fine spatial scale, significant viral geographic structuring was also detected between lions occurring north of the Olifants River within the Kruger National Park (KNP) and those occupying the southern and central regions. This pattern was further supported by phylogenetic analyses and the confinement of FIVPle subtype E to the northern region of KNP. The study provides new insights into the use of retroviral sequences to predict host dispersal and fine-scale contemporary geographic structure in a social felid species.


Assuntos
Síndrome de Imunodeficiência Adquirida Felina/epidemiologia , Vírus da Imunodeficiência Felina/genética , Vírus da Imunodeficiência Felina/patogenicidade , Leões/virologia , Animais , Gatos , Síndrome de Imunodeficiência Adquirida Felina/transmissão , Feminino , Variação Genética , Haplótipos , Interações Hospedeiro-Patógeno , Transmissão Vertical de Doenças Infecciosas , Masculino , Filogenia , Filogeografia , Prevalência , África do Sul
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