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1.
Viruses ; 16(5)2024 04 29.
Artículo en Inglés | MEDLINE | ID: mdl-38793583

RESUMEN

Papillomaviruses (PV) infect epithelial cells and can cause hyperplastic or neoplastic lesions. In felids, most described PVs are from domestic cats (Felis catus; n = 7 types), with one type identified in each of the five wild felid species studied to date (Panthera uncia, Puma concolor, Leopardus wiedii, Panthera leo persica and Lynx rufus). PVs from domestic cats are highly diverse and are currently classified into three genera (Lambdapapillomavirus, Dyothetapapillomavirus, and Taupapillomavirus), whereas those from wild felids, although diverse, are all classified into the Lambdapapillomavirus genus. In this study, we used a metagenomic approach to identify ten novel PV genomes from rectal swabs of five deceased caracals (Caracal caracal) living in the greater Cape Town area, South Africa. These are the first PVs to be described from caracals, and represent six new PV types, i.e., Caracal caracal papillomavirus (CcarPV) 1-6. These CcarPV fall into two phylogenetically distinct genera: Lambdapapillomavirus, and Treisetapapillomavirus. Two or more PV types were identified in a single individual for three of the five caracals, and four caracals shared at least one of the same PV types with another caracal. This study broadens our understanding of wild felid PVs and provides evidence that there may be several wild felid PV lineages.


Asunto(s)
Felidae , Genoma Viral , Papillomaviridae , Infecciones por Papillomavirus , Filogenia , Animales , Sudáfrica , Papillomaviridae/genética , Papillomaviridae/clasificación , Papillomaviridae/aislamiento & purificación , Infecciones por Papillomavirus/virología , Infecciones por Papillomavirus/veterinaria , Felidae/virología , Gatos , Metagenómica , Animales Salvajes/virología
2.
Mol Ecol ; 33(9): e17346, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38581173

RESUMEN

Wildlife populations are becoming increasingly fragmented by anthropogenic development. Small and isolated populations often face an elevated risk of extinction, in part due to inbreeding depression. Here, we examine the genomic consequences of urbanization in a caracal (Caracal caracal) population that has become isolated in the Cape Peninsula region of the City of Cape Town, South Africa, and is thought to number ~50 individuals. We document low levels of migration into the population over the past ~75 years, with an estimated rate of 1.3 effective migrants per generation. As a consequence of this isolation and small population size, levels of inbreeding are elevated in the contemporary Cape Peninsula population (mean FROH = 0.20). Inbreeding primarily manifests as long runs of homozygosity >10 Mb, consistent with the effects of isolation due to the rapid recent growth of Cape Town. To explore how reduced migration and elevated inbreeding may impact future population dynamics, we parameterized an eco-evolutionary simulation model. We find that if migration rates do not change in the future, the population is expected to decline, though with a low projected risk of extinction. However, if migration rates decline or anthropogenic mortality rates increase, the potential risk of extinction is greatly elevated. To avert a population decline, we suggest that translocating migrants into the Cape Peninsula to initiate a genetic rescue may be warranted in the near future. Our analysis highlights the utility of genomic datasets coupled with computational simulation models for investigating the influence of gene flow on population viability.


Asunto(s)
Flujo Génico , Genética de Población , Endogamia , Dinámica Poblacional , Animales , Sudáfrica , Densidad de Población , Urbanización , Migración Animal
3.
Surg Infect (Larchmt) ; 25(3): 192-198, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38407831

RESUMEN

Background: Appropriate antimicrobial therapy for the management of intra-abdominal infection (IAI) continues to evolve based on available literature. The Study to Optimize Peritoneal Infection Therapy (STOP-IT) trial provided evidence to support four days of antibiotic agents in IAI post-source control but excluded patients with a planned re-laparotomy. This study aimed to determine the short- and long-term recurrent infection risk in this population. Patients and Methods: This is a single-center, retrospective, observational study of adult patients admitted to a quaternary medical center between January 1, 2016, and August 1, 2022, with IAI requiring planned laparotomy. Patients were designated as receiving five or less days of antibiotic agents (short course) or more than five days (long course) after source control. The primary outcome was IAI recurrence within 30 days. Results: Of the 104 patients who met inclusion criteria, 78 were included in analysis. Average age was 57 ± 13.3 years, 56% were male, 94% Caucasian, with a mean Acute Physiology and Chronic Health Evaluation (APACHE) II score of 17 ± 7.09. All other baseline characteristics and clinical severity markers were similar between the two groups. Regarding the primary outcome of IAI recurrence, there was no difference when comparing those who received short course versus those who received long course therapy (41.2% vs. 44.4%; p = 0.781). No differences were found between groups with respect to secondary outcomes. Conclusions: In patients admitted with IAI managed with planned re-laparotomy those who received short course antimicrobial therapy were not found to have an increase in IAI recurrence compared to those with longer courses of therapy.


Asunto(s)
Antiinfecciosos , Infecciones Intraabdominales , Adulto , Humanos , Masculino , Persona de Mediana Edad , Anciano , Femenino , Antibacterianos/uso terapéutico , Laparotomía , Estudios Retrospectivos , Infecciones Intraabdominales/tratamiento farmacológico , Infecciones Intraabdominales/cirugía
4.
Sci Total Environ ; 914: 169912, 2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38184259

RESUMEN

The use of marine subsidies by terrestrial predators can facilitate substantial transfer of nutrients between marine and terrestrial ecosystems. Marine resource subsidies may have profound effects on predator ecology, influencing population and niche dynamics. Expanding niches of top consumers can impact ecosystem resilience and interspecific interactions, affecting predator-prey dynamics and competition. We investigate the occurrence, importance, and impact of marine resources on trophic ecology and niche dynamics in a highly generalist predator, the caracal (Caracal caracal), on the Cape Peninsula, South Africa. Caracals have flexible diets, feeding across a wide range of terrestrial and aquatic prey. We use carbon and nitrogen stable isotope analysis of fur samples (n = 75) to understand trophic position and niche shifts in coastal and inland foragers, as well as the implications of a diet rich in marine resources. We found significant differences in isotope signatures between these groups, with higher δ13C (P < 0.05) and δ15N values (P < 0.01) in coastal foragers. Isotope mixing models reveal that these elevated signatures were due to non-terrestrial food subsidies, where approximately a third of coastal foraging caracal diet comprised marine prey. The addition of marine prey species to diet increased both the trophic level and isotope niche size of coastal foraging caracals, with potential impacts on prey populations and competition. Our results suggest that marine prey are an important dietary resource for coastal foraging caracals, where seabirds, including two endangered species, are a major component of their diet. However, there are likely risks associated with these resource benefits, as routine consumption of seabirds is linked with higher pollutant burdens, particularly metals. Increased encounters between this terrestrial predator and seabirds may be a result of increased mainland colonies due to changes in habitat availability and the highly opportunistic and generalist foraging behaviour of a native predator.


Asunto(s)
Ecología , Ecosistema , Animales , Especies en Peligro de Extinción , Dieta , Isótopos de Nitrógeno/análisis , Cadena Alimentaria
5.
Sci Rep ; 13(1): 21582, 2023 12 07.
Artículo en Inglés | MEDLINE | ID: mdl-38062237

RESUMEN

Urbanisation critically alters wildlife habitat and resource distribution, leading to shifts in trophic dynamics. The loss of apex predators in human-transformed landscapes can result in changes in the ecological roles of the remaining mesocarnivores. Decreased top-down control together with increased bottom-up forcing through greater availability of anthropogenic foods can result in a predation paradox. Understanding these changes is important for conserving ecological function and biodiversity in rapidly urbanising systems. Here, we use stable isotope analysis to provide insight into longer term changes in trophic position, niche width and overlap of an elusive, medium-sized urban adapter, the caracal (Caracal caracal) in and around the city of Cape Town, South Africa. Using fur samples (n = 168) from individuals along a gradient of urbanisation we find that overall caracals have a broad isotopic dietary niche that reflects their large variation in resource use. When accounting for underlying environmental differences, the intensity of anthropogenic pressure, measured using the Human Footprint Index (HFI), explained variation in both food subsidy use (δ13C values) and trophic status (δ15N values). The significantly higher δ13C values (P < 0.01) and lower δ15N values (P < 0.001) of caracals in more urbanised areas suggest that predator subsidy consumption occurs via predictable, anthropogenic resource subsidies to synanthropic prey. These prey species are predominantly primary consumers, resulting in shifts in diet composition towards lower trophic levels. Further, caracals using areas with higher HFI had narrower isotope niches than those in less impacted areas, likely due to their hyperfocus on a few lower trophic level prey species. This pattern of niche contraction in urban areas is retained when accounting for caracal demographics, including sex and age. The removal of apex predators in human-transformed landscapes together with reliable resource availability, including abundant prey, may paradoxically limit the ecological influence of the remaining predators, and bring about a degree of predator trophic downgrading. The dampening of top-down control, and thus ecosystem regulation, likely points to widespread disruption of trophic dynamics in rapidly developing areas globally.


Asunto(s)
Carnívoros , Ecosistema , Animales , Animales Salvajes , Cadena Alimentaria , Isótopos de Nitrógeno/análisis , Sudáfrica , Masculino , Femenino
6.
iScience ; 26(7): 107050, 2023 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-37534145

RESUMEN

Human activities increasingly challenge wild animal populations by disrupting ecological connectivity and population persistence. Yet, human-modified habitats can provide resources, resulting in selection of disturbed areas by generalist species. To investigate spatial and temporal responses of a generalist carnivore to human disturbance, we investigated habitat selection and diel activity patterns in caracals (Caracal caracal). We GPS-collared 25 adults and subadults in urban and wildland-dominated subregions in Cape Town, South Africa. Selection responses for landscape variables were dependent on subregion, animal age class, and diel period. Contrary to expectations, caracals did not become more nocturnal in urban areas. Caracals increased their selection for proximity to urban areas as the proportion of urban area increased. Differences in habitat selection between urban and wildland caracals suggest that individuals of this generalist species exhibit high behavioral flexibility in response to anthropogenic disturbances that emerge as a function of habitat context.

7.
Environ Pollut ; 327: 121585, 2023 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-37040831

RESUMEN

Urbanisation and associated anthropogenic activities release large quantities of toxic metals and metalloids into the environment, where they may bioaccumulate and threaten both wildlife and human health. In highly transformed landscapes, terrestrial carnivores may be at increased risk of exposure through biomagnification. We quantified metallic element and metalloid exposure in blood of caracals (Caracal caracal), an adaptable felid inhabiting the rapidly urbanising, coastal metropole of Cape Town, South Africa. Using redundancy analysis and mixed-effect models, we explored the influence of demography, landscape use, and diet on the concentration of 11 metals and metalloids. Although species-specific toxic thresholds are lacking, arsenic (As) and chromium (Cr) were present at potentially sublethal levels in several individuals. Increased use of human-transformed landscapes, particularly urban areas, roads, and vineyards, was significantly associated with increased exposure to aluminium (Al), cobalt (Co) and lead (Pb). Foraging closer to the coast and within aquatic food webs was associated with increased levels of mercury (Hg), selenium (Se) and arsenic, where regular predation on seabirds and waterbirds likely facilitates transfer of metals from aquatic to terrestrial food webs. Further, several elements were linked to lower haemoglobin levels (chromium, mercury, manganese, and zinc) and elevated levels of infection-fighting cells (mercury and selenium). Our results highlight the importance of anthropogenic activities as major environmental sources of metal contamination in terrestrial wildlife, including exposure across the land-ocean continuum. These findings contribute towards the growing evidence suggesting cities are particularly toxic areas for wildlife. Co-exposure to a suite of metal pollutants may threaten the long-term health and persistence of Cape Town's caracal population in unexpected ways, particularly when interacting with additional known pollutant and pathogen exposure. The caracal is a valuable sentinel for assessing metal exposure and can be used in pollution monitoring programmes to mitigate exposure and promote biodiversity conservation in human-dominated landscapes.


Asunto(s)
Arsénico , Contaminantes Ambientales , Mercurio , Metaloides , Metales Pesados , Selenio , Animales , Humanos , Arsénico/análisis , Selenio/análisis , Sudáfrica , Metales/análisis , Mercurio/análisis , Contaminantes Ambientales/análisis , Cromo/análisis , Metaloides/análisis , Animales Salvajes , Océanos y Mares , Metales Pesados/análisis , Monitoreo del Ambiente
8.
Sci Rep ; 12(1): 16768, 2022 10 06.
Artículo en Inglés | MEDLINE | ID: mdl-36202901

RESUMEN

Group-living animals that live in complex social systems require effective modes of communication to maintain social cohesion, and several acoustic, olfactory and visual signaling systems have been described. Individuals need to discriminate between in- and out-group odour to both avoid inbreeding and to identify recipients for reciprocal behaviour. The presence of a unique group odour, identified in several social mammals, is a proposed mechanism whereby conspecifics can distinguish group from non-group members. African elephants (Loxodonta africana) live in stable, socially complex, multi-female, fission-fusion groups, characterized by female philopatry, male dispersal and linear dominance hierarchies. Elephant social behaviour suggests that individuals use odour to monitor the sex, reproductive status, location, health, identity and social status of conspecifics. To date, it is not clear what fixed or variable information is contained in African elephant secretions, and whether odour encodes kinship or group membership information. Here we use SPME GC-MS generated semiochemical profiles for temporal, buccal and genital secretions for 113 wild African elephants and test their relationship with measures of genetic relatedness. Our results reveal the existence of individual identity odour profiles in African elephants as well as a signature for age encoded in temporal gland and buccal secretions. Olfactory signatures for genetic relatedness were found in labial secretions of adult sisters. While group odour was not correlated with group genetic relatedness, our analysis identified "group membership" as a significant factor explaining chemical differences between social groups. Saturated and short-chain fatty acids (SCFAs), derived from key volatile compounds from bacterial fermentation, were identified in temporal, buccal and genital secretions suggesting that group odour in African elephants may be the result of bacterial elements of the gut microbiome. The frequent affiliative behavior of African elephants is posited as a likely mechanism for bacterial transmission. Our findings favour flexible group-specific bacterial odours, which have already been proposed for other social mammals and present a useful form of olfactory communication that promotes bond group cohesion among non-relatives in fission-fusion mammals.


Asunto(s)
Elefantes , Perfumes , Animales , Elefantes/genética , Femenino , Masculino , Odorantes , Feromonas , Conducta Social
9.
Sci Total Environ ; 822: 153581, 2022 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-35104517

RESUMEN

Wildlife around cities bioaccumulate multiple harmful environmental pollutants associated with human activities. Exposure severity can vary based on foraging behaviour and habitat use, which can be examined to elucidate exposure pathways. Carnivores can play vital roles in ecosystem stability but are particularly vulnerable to bioaccumulation of pollutants. Understanding the spatial and dietary predictors of these contaminants can inform pollutant control, and carnivores, at the top of food webs, can act as useful indicator species. We test for exposure to toxic organochlorines (OCs), including dichloro-diphenyl-trichloroethane (DDT) and polychlorinated biphenyls (PCBs), in a medium-sized felid, the caracal (Caracal caracal), across the peri-urban and agricultural landscapes of the city of Cape Town, South Africa. Concentrations in both blood (n = 69) and adipose tissue (n = 25) were analysed along with detailed spatial, dietary, demographic, and physiological data to assess OC sources and exposure risk. The analysis revealed widespread exposure of Cape Town's caracals to organochlorines: detection rate was 100% for PCBs and 83% for DDTs in blood, and 100% for both compounds in adipose. Caracals using human-transformed areas, such as vineyards and areas with higher human population and electrical transformer density, as well as wetland areas, had higher organochlorine burdens. These landscapes were also highly selected foraging areas, suggesting caracals are drawn into areas that co-incidentally increase their risk of exposure to these pollutants. Further, biomagnification potential was higher in individuals feeding on higher trophic level prey and on exotic prey. These findings point to bioaccumulation of OC toxicants and widespread exposure across local food webs. Additionally, we report possible physiological effects of exposure, including elevated white blood cell and platelet count, suggesting a degree of immunological response that may increase disease susceptibility. Cape Town's urban fringes likely represent a source of toxic chemicals for wildlife and require focused attention and action to ensure persistence of this adaptable mesocarnivore.


Asunto(s)
Hidrocarburos Clorados , Venenos , Bifenilos Policlorados , Animales , Ecosistema , Monitoreo del Ambiente , Humanos , Hidrocarburos Clorados/análisis , Contaminantes Orgánicos Persistentes , Venenos/análisis , Bifenilos Policlorados/análisis , Sudáfrica
10.
Virology ; 562: 176-189, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34364185

RESUMEN

Anellovirus infections are highly prevalent in mammals, however, prior to this study only a handful of anellovirus genomes had been identified in members of the Felidae family. Here we characterise anelloviruses in pumas (Puma concolor), bobcats (Lynx rufus), Canada lynx (Lynx canadensis), caracals (Caracal caracal) and domestic cats (Felis catus). The complete anellovirus genomes (n = 220) recovered from 149 individuals were diverse. ORF1 protein sequence similarity network analysis coupled with phylogenetic analysis, revealed two distinct clusters that are populated by felid-derived anellovirus sequences, a pattern mirroring that observed for the porcine anelloviruses. Of the two-felid dominant anellovirus groups, one includes sequences from bobcats, pumas, domestic cats and an ocelot, and the other includes sequences from caracals, Canada lynx, domestic cats and pumas. Coinfections of diverse anelloviruses appear to be common among the felids. Evidence of recombination, both within and between felid-specific anellovirus groups, supports a long coevolution history between host and virus.


Asunto(s)
Anelloviridae/genética , Felidae/virología , Anelloviridae/clasificación , Animales , Coevolución Biológica , Coinfección/veterinaria , Coinfección/virología , ADN Viral/genética , Felidae/clasificación , Variación Genética , Genoma Viral/genética , Sistemas de Lectura Abierta , Filogenia , Recombinación Genética , Análisis de Secuencia de ADN
11.
J Hered ; 112(4): 385-390, 2021 07 15.
Artículo en Inglés | MEDLINE | ID: mdl-33950221

RESUMEN

Current management models for many endangered species focus primarily on demographic recovery, often ignoring their intrinsic ecological requirements. Across the protected area network of southern Africa, most southern white rhinoceros are managed in populations of less than 50 individuals, experiencing restricted dispersal opportunities, and limited breeding male numbers due to their exclusive home range requirements. In the absence of information on the breeding structure of these populations, poor management decisions may require females to either forego a breeding opportunity or select to inbreed with close relatives. Here, we use a combination of social pedigree data together with genetic analyses to reconstruct the parentage of all 28 offspring produced in a 5-year period in a managed free-ranging southern white rhinoceros population. During this period, all breeding females (founders and first-generation daughters) had access to both a founder male (father to most of the daughters) and two recently introduced inexperienced males. We report that while founder females were more likely to breed with the founder male, their daughters, in contrast, were more likely to breed with the introduced males, thus avoiding inbreeding. However, we also found evidence of father-daughter inbreeding in this population, and contend that in the absence of choice, rather than forego a breeding opportunity, female white rhinoceros will inbreed with their fathers. We argue that to effectively conserve the southern white rhinoceros, managers need to understand the breeding structure of these small populations, particularly in terms of parentage and kinship.


Asunto(s)
Endogamia , Perisodáctilos , Animales , Especies en Peligro de Extinción , Femenino , Masculino , Perisodáctilos/genética
12.
Parasit Vectors ; 13(1): 220, 2020 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-32354342

RESUMEN

BACKGROUND: Wild carnivores living alongside humans and domestic animals are vulnerable to changes in the infectious disease dynamics in their populations. The aims of this study were to determine the prevalence and diversity of selected tick-borne pathogens (TBPs) of veterinary and/or zoonotic concern in wild populations of caracals (Caracal caracal) occurring in human-modified landscapes in South Africa. Using molecular techniques, we screened 57 caracal blood samples for infection by rickettsial bacteria and piroplasms in three regions of South Africa: rangeland in the Central Karoo (n = 27) and Namaqualand (n = 14) as well as the urban edge of the Cape Peninsula (n = 16) of South Africa. To characterise pathogen identity, we sequenced the 18S rRNA and 16S rRNA genes from positive samples and analysed sequences within a phylogenetic framework. We also examine the diversity of potential tick vectors. RESULTS: All individuals tested were infected with at least one tick-borne pathogen. Pathogens included Hepatozoon felis, Babesia felis, Babesia leo and a potentially novel Babesia species. An Anaplasma species previously described in South African domestic dogs was also found in 88% of urban edge caracals. Higher rates of co-infection characterised urban edge caracals (81% vs 15% and 0% in the two rangeland populations), as well as a greater incidence of mixed infections. Host attached tick species include Haemaphysalis elliptica, an important pathogen vector among carnivore hosts. CONCLUSIONS: This study confirms the occurrence of previously undocumented tick-borne pathogens infecting free-ranging caracals in human-modified landscapes. We identify clear differences in the pathogen profiles among our study populations and discuss the likely health costs to caracals living adjacent to urban areas.


Asunto(s)
Felidae/microbiología , Insectos Vectores/microbiología , Insectos Vectores/parasitología , Enfermedades por Picaduras de Garrapatas/epidemiología , Enfermedades por Picaduras de Garrapatas/microbiología , Enfermedades por Picaduras de Garrapatas/parasitología , Garrapatas/microbiología , Garrapatas/parasitología , Anaplasma/clasificación , Anaplasma/genética , Anaplasma/aislamiento & purificación , Animales , Animales Domésticos , Animales Salvajes/microbiología , Babesia/clasificación , Babesia/genética , Babesia/aislamiento & purificación , Gatos , Coccidios/clasificación , Coccidios/genética , Coccidios/aislamiento & purificación , Coinfección/microbiología , Coinfección/parasitología , Perros , Humanos , Filogenia , ARN Ribosómico 16S/genética , ARN Ribosómico 18S/genética , Rickettsia/clasificación , Rickettsia/genética , Rickettsia/aislamiento & purificación , Sudáfrica/epidemiología , Enfermedades por Picaduras de Garrapatas/diagnóstico
13.
Ecol Evol ; 10(8): 3605-3619, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32313621

RESUMEN

Anthropogenic mortality of wildlife is typically inferred from measures of the absolute decline in population numbers. However, increasing evidence suggests that indirect demographic effects including changes to the age, sex, and social structure of populations, as well as the behavior of survivors, can profoundly impact population health and viability. Specifically, anthropogenic mortality of wildlife (especially when unsustainable) and fragmentation of the spatial distribution of individuals (home-ranges) could disrupt natal dispersal mechanisms, with long-term consequences to genetic structure, by compromising outbreeding behavior and gene flow. We investigate this threat in African leopards (Panthera pardus pardus), a polygynous felid with male-biased natal dispersal. Using a combination of spatial (home-range) and genetic (21 polymorphic microsatellites) data from 142 adult leopards, we contrast the structure of two South African populations with markedly different histories of anthropogenically linked mortality. Home-range overlap, parentage assignment, and spatio-genetic autocorrelation together show that historical exploitation of leopards in a recovering protected area has disrupted and reduced subadult male dispersal, thereby facilitating opportunistic male natal philopatry, with sons establishing territories closer to their mothers and sisters. The resultant kin-clustering in males of this historically exploited population is comparable to that of females in a well-protected reserve and has ultimately led to localized inbreeding. Our findings demonstrate novel evidence directly linking unsustainable anthropogenic mortality to inbreeding through disrupted dispersal in a large, solitary felid and expose the genetic consequences underlying this behavioral change. We therefore emphasize the importance of managing and mitigating the effects of unsustainable exploitation on local populations and increasing habitat fragmentation between contiguous protected areas by promoting in situ recovery and providing corridors of suitable habitat that maintain genetic connectivity.

14.
J Wildl Dis ; 55(4): 951-953, 2019 10.
Artículo en Inglés | MEDLINE | ID: mdl-30920906

RESUMEN

We investigated Toxoplasmosis gondii antibody seroprevalence in free-ranging caracals (Caracal caracal) in Cape Town, South Africa, from 2014 to 2017. Seropositivity was 83% (24/29), which is substantially higher than that detected in sympatric feral domestic cat (Felis catus) populations. The impact of this pathogen on local human and wildlife communities may be of concern.


Asunto(s)
Felidae/sangre , Toxoplasmosis Animal/sangre , Animales , Animales Salvajes , Anticuerpos Antiprotozoarios/sangre , Ciudades , Femenino , Masculino , Estudios Seroepidemiológicos , Sudáfrica/epidemiología , Toxoplasma , Toxoplasmosis Animal/epidemiología , Zoonosis
15.
Sci Total Environ ; 666: 581-590, 2019 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-30807948

RESUMEN

Anticoagulant rodenticides (ARs) are used worldwide to control rodent populations. ARs bioaccumulate across trophic levels and threaten non-target wildlife. We investigated the prevalence of AR exposure in seven predator species in the rapidly developing Greater Cape Town region of South Africa - a mosaic of natural, urban, and agricultural areas within a global biodiversity hotspot. We focused sampling on caracals (Caracal caracal, n = 28) as part of a larger caracal ecology study, but also opportunistically sampled Cape Clawless otters (Aonyx capensis, n = 9), large-spotted genets (Genetta tigrina, n = 4), honey badger (Mellivora capensis, n = 1), water mongoose (Atilax paludinosus, n = 1), small gray mongoose (Galerella pulverulenta, n = 1), and Cape Eagle owl (Bubo capensis, n = 1). We tested livers from all species, and blood from ten caracals, for eight AR compounds to assess prevalence and amount of exposure for each compound. We used generalized linear models to test spatial, demographic, and seasonal risk factors for ten measures of AR exposure in caracals. We detected at least one of the four most toxic AR compounds in six species. Exposure was high for caracals (92%) and all species combined (81%). For caracals, proximity to vineyards was the most important AR exposure risk factor. Vineyards in Cape Town do not use ARs to protect their vines but do host commercial hospitality structures where ARs are used. Vineyards may thus link caracals that forage within vineyards to the rat poisons used in and around their commercial structures. Residue levels were unexpected in large-spotted genets and Cape Clawless otters, suggesting invertebrate vectors. ARs may present a cryptic threat to populations already vulnerable to increasing habitat loss, vehicle collisions, poachers and fire. Targeted mitigation should include a mix of environmentally responsible policies that reduce AR use, particularly in areas near wildlife habitat.


Asunto(s)
Anticoagulantes/metabolismo , Exposición a Riesgos Ambientales/análisis , Felidae/metabolismo , Rodenticidas/metabolismo , Animales , Anticoagulantes/sangre , Ciudades , Monitoreo del Ambiente , Feliformes/metabolismo , Rodenticidas/sangre , Sudáfrica , Estrigiformes/metabolismo
16.
Zootaxa ; 4483(3): 428-454, 2018 Sep 24.
Artículo en Inglés | MEDLINE | ID: mdl-30313776

RESUMEN

The low vagility of the southern African Notonemouridae (stoneflies, Plecoptera), and their restriction to temperate montane refugia, make them a useful model for examining the evolution and biogeography of the rich palaeogenic fauna of the region. Here we use maximum parsimony tree reconstruction based on morphological characters and a partial COI mtDNA sequence to explore the evolutionary history and biogeography of the family in southern Africa. Morphological and molecular parsimony cladograms were largely in agreement, and supported monophyly of all six genera in the region. Previously undocumented morphological features in Plecoptera are identified: the first record of paraproct glands, and the presence of paired spermathecae in Aphanicercopsis Barnard females (all other Plecoptera have a single or a divided spermatheca). Some phylogenetically useful characters were the degree of fusion of the ventral abdominal nerve cord ganglia, male paraproct glands (presence and shape), and accessory glands of the male seminal vesicle. Two main biogeographic zones were defined: Eastern Highlands and the Cape Fold Mountains, with an additional outlying zone, the Namaqualand Highlands. Almost 41% of species were endemic to a single mountain range group. The most species-rich region was the intersection of the Southern and Western Cape Fold Mountains. It is hypothesized that, after the separation of Gondwanaland, the common ancestor of the region's six genera dispersed from a Cape Fold Mountain origin to the Amatola and Drakensberg montane areas of the southern tip of the African continent. The high number of species within the Cape Fold Mountains compared to other mountain ranges in the region is likely a reflection of the topographic complexity of this mountain system and its influence on vicariant events.


Asunto(s)
Insectos , Filogenia , África Austral , Animales , ADN Mitocondrial , Femenino , Lepidópteros , Masculino
17.
Plant J ; 95(6): 1023-1038, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-29952120

RESUMEN

Most metal hyperaccumulating plants accumulate nickel, yet the molecular basis of Ni hyperaccumulation is not well understood. We chose Senecio coronatus to investigate this phenomenon as this species displays marked variation in shoot Ni content across ultramafic outcrops in the Barberton Greenstone Belt (South Africa), thus allowing an intraspecific comparative approach to be employed. No correlation between soil and shoot Ni contents was observed, suggesting that this variation has a genetic rather than environmental basis. This was confirmed by our observation that the accumulation phenotype of plants from two hyperaccumulator and two non-accumulator populations was maintained when the plants were grown on a soil mix from these four sites for 12 months. We analysed the genetic variation among 12 serpentine populations of S. coronatus, and used RNA-seq for de novo transcriptome assembly and analysis of gene expression in hyperaccumulator versus non-accumulator populations. Genetic analysis revealed the presence of hyperaccumulators in two well supported evolutionary lineages, indicating that Ni hyperaccumulation may have evolved more than once in this species. RNA-Seq analysis indicated that putative homologues of transporters associated with root iron uptake in plants are expressed at elevated levels in roots and shoots of hyperaccumulating populations of S. coronatus from both evolutionary lineages. We hypothesise that Ni hyperaccumulation in S. coronatus may have evolved through recruitment of these transporters, which play a role in the iron-deficiency response in other plant species.


Asunto(s)
Níquel/metabolismo , ARN de Planta/genética , Senecio/metabolismo , Perfilación de la Expresión Génica , Variación Genética/genética , Genómica , Níquel/análisis , Brotes de la Planta/química , Brotes de la Planta/metabolismo , Senecio/genética , Suelo/química , Transcriptoma/genética
18.
Eur J Nutr ; 57(6): 2217-2225, 2018 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28687934

RESUMEN

PURPOSE: Use of polypharmacy in the treatment of diabetes is the norm; nonetheless, optimal control is often not achieved. Konjac-glucomannan-based fibre blend (KGB) and American ginseng (AG) have individually been shown to improve glycaemia and CVD risk factors in type 2 diabetes. The aim of this study was to determine whether co-administration of KGB and AG could improve diabetes control beyond conventional treatment. METHOD: Thirty-nine participants with type 2 diabetes (6.5 > A1c < 8.4%) were enrolled between January 2002 and May 2003 at the Risk Factor Modification Centre at St Michaels Hospital in a randomized, placebo-controlled, crossover trial with each intervention lasting 12-weeks. Medications, diet and lifestyle were kept constant. Interventions consisted of 6 g of fibre from KGB together with 3 g of AG (KGB and AG) or wheat bran-based, fibre-matched control. Primary endpoint was the difference in HbA1c levels at week 12. RESULTS: Thirty participants (18M:12F; age: 64 ± 7 years; BMI: 28 ± 5 kg/m2; HbA1c: 7.0 ± 1.0%) completed the study, and consumed 5.5 and 4.9 g/day of fibre from KGB and wheat bran control, respectively, and 2.7 g/day of AG. At week 12, HbA1c levels were 0.31% lower on the KGB and AG compared to control (p = 0.011). Mean (±SEM) plasma lipids decreased on the KGB and AG vs control by 8.3 ± 3.1% in LDL-C (p = 0.002), 7.5 ± 2.4% in non-HDL-C (p = 0.013), 5.7 ± 1.9% in total-C (p = 0.012), 4.1 ± 2.1% in total-C:HDL-C ratio (p = 0.042), 9.0 ± 2.3% in ApoB (p = 0.0005) and 14.6 ± 4.2% in ApoB:ApoA1 ratio (p = 0.049). CONCLUSIONS: Co-administration of KGB and AG increases the effectiveness of conventional therapy through a moderate but clinically meaningful reduction in HbA1c and lipid concentrations over 12 weeks in patients with type 2 diabetes. CLINICAL TRIALS REGISTRATION: NCT02806349 ( https://clinicaltrials.gov/ ).


Asunto(s)
Amorphophallus , Diabetes Mellitus Tipo 2/metabolismo , Índice Glucémico/efectos de los fármacos , Metabolismo de los Lípidos/efectos de los fármacos , Panax , Extractos Vegetales/farmacología , Adulto , Anciano , Amorphophallus/química , Glucemia , Canadá , Estudios Cruzados , Femenino , Humanos , Lípidos , Masculino , Persona de Mediana Edad , Panax/química
19.
Ecol Lett ; 19(6): 679-86, 2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-27132885

RESUMEN

Detectability of different colour morphs under varying light conditions has been proposed as an important driver in the maintenance of colour polymorphism via disruptive selection. To date, no studies have tested whether different morphs have selective advantages under differing light conditions. We tested this hypothesis in the black sparrowhawk, a polymorphic raptor exhibiting a discrete white and dark morph, and found that prey provisioning rates differ between the morphs depending on light condition. Dark morphs delivered more prey in lower light conditions, while white morphs provided more prey in brighter conditions. We found support for the role of breeding season light level in explaining the clinal pattern of variation in morph ratio across the species range throughout South Africa. Our results provide the first empirical evidence supporting the hypothesis that polymorphism in a species, and the spatial structuring of morphs across its distribution, may be driven by differential selective advantage via improved crypsis, under varying light conditions.


Asunto(s)
Conducta Apetitiva/fisiología , Luz , Pigmentación , Rapaces/fisiología , Animales , Masculino , Fenotipo , Polimorfismo Genético , Sudáfrica , Análisis Espacial
20.
BMC Res Notes ; 8: 477, 2015 Sep 26.
Artículo en Inglés | MEDLINE | ID: mdl-26409884

RESUMEN

BACKGROUND: The Cape horseshoe bat, Rhinolophus capensis, is endemic to the Cape region of South Africa. Coalescent analysis of mitochondrial DNA sequence data suggests extensive historical gene flow between populations despite strong geographic variation of their echolocation call phenotype. Nevertheless the fine-scale genetic structure and evolutionary ecology of R. capensis remains poorly understood. Here we describe the development of 10 novel polymorphic microsatellite loci to investigate of the dispersal ecology of R. capensis and to facilitate taxonomic studies of Rhinolophus species in southern Africa. FINDINGS: We report 10 microsatellite primer pairs that consistently amplify scorable and polymorphic loci across 12 African rhinolophid species. Initial analysis of two populations of R. capensis from South Africa revealed moderate to high levels of allelic variation with 4-14 alleles per locus and observed heterozygosities of 0.450-0.900. No evidence of linkage disequilibrium was observed and eight of the loci showed no departure from Hardy-Weinberg equilibrium. Cross-species utility of these markers revealed consistently amplifiable polymorphic loci in eleven additional rhinolophid species. CONCLUSIONS: The cross-amplification success of the microsatellites developed here provides a cost-effective set of population genetic marker for the study of rhinolophid evolutionary ecology and conservation in southern Africa.


Asunto(s)
Quirópteros/genética , Repeticiones de Microsatélite/genética , Reacción en Cadena de la Polimerasa/métodos , Animales , Sitios Genéticos , Datos de Secuencia Molecular , Especificidad de la Especie
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