Browsing by Author "Santos, A.S."
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- An insight into the transcriptome of Rhipicephalus bursa: differential gene expression upon feeding and in response to salivary glands infection with Babesia ovisPublication . Couto, J.; Antunes, S.; Ferrolho, J.; Santos, A.S.; Santos-Silva, M.M.; de la Fuente, J.; Domingos, A.Understanding the paradigm of the pathogen-tick-host triad remains an intricate issue. Basic research focusing on each one of these interplays is necessary to better comprehend this dynamic system. One of such complex association is the Babesia ovis, transmitted by the Rhipicephalus bursa ticks. B. ovis is an intra-erythrocytic protozoan parasite highly pathogenic parasite, causing severe infection in sheep. Pathogen and vector co-evolved and during infection a substantial molecular dialogue/interchanges takes place. The pathogen is adapted to both its hosts, and remarkably transovarial and transstadial transmissions are present in the vector. In ticks, the salivary glands (SG) play important role in both, feeding and pathogen interaction, being a vehicle for pathogen transmission and a barrier that they need to surpass.
- Anaplasma marginale and Theileria annulata in questing ticks from PortugalPublication . Antunes, S.; Ferrolho, J.; Domingues, N.; Santos, A.S.; Santos-Silva, M.M.; Domingos, A.Ticks are ubiquitous arthropods and vectors of several pathogenic agents in animals and humans. Monitoring questing ticks is of great importance to ascertain the occurrence of pathogens and the potential vector species, offering an insight into the risk of disease transmission in a given area. In this study 428 host-seeking ticks, belonging to nine species of Ixodidae and collected from 17 of the 23 Portuguese mainland subregions, were screened for several tick-borne agents with veterinary relevance: Anaplasma marginale, Anaplasma ovis, Anaplasma centrale, Babesia spp., Coxiella burnetii and Theileria spp. Prevalence was assessed by PCR and amplified amplicons sequenced for validation of results. Twenty ticks, in a total of 428, were found positive: one Ixodes ventalloi for Theileria annulata and four Dermacentor marginatus, one Haemaphysalis punctata, five Ixodes ricinus, five I. ventalloi, and four Rhipicephalus sanguineus sensu lato for A. marginale. According to the reviewed literature, this is the first report of A. marginale and T. annulata detection in I. ventalloi. Furthermore, the amplification of A. marginale DNA in several tick species suggests a broad range for this agent in Portugal that might include other uncommon species as R. sanguineus s.l. This work provides new data towards a better understanding of tick-pathogen associations and also contributes to the surveillance of tick-borne agents in geographic areas with limited information.
- Chronic Q fever with no elevation of inflammatory markers: a case reportPublication . Boattini, M.; Almeida, A.; Barata Moura, R.; Abreu, J.; Santos, A.S.; Rico, M.T.Chronic q Fever with no elevation of inflammatory markers: a case report. Boattini M, Almeida A, Moura RB, Abreu J, Santos AS, Toscano Rico M. SourceDepartment of Internal Medicine, St. Marta's Hospital, 1169-024 Lisbon, Portugal. Abstract We describe the case of a 55-year-old man with a biological prosthetic aortic valve who suffered from epigastrium and right hypochondrium pain associated with intermittent night sweats. Liver biopsy showed infectious hepatitis pattern without pathognomonic features. Coxiella burnetii serology was suggestive of chronic Q fever, and modified Duke's criteria for endocarditis were also fulfilled. The authors present a brief literature review concerning chronic Q fever, emphasizing absent previous reports of chronic Q fever with hepatitis and endocarditis and no increase in inflammatory markers.
- Coxiella burnetii DNA detected in domestic ruminants and wildlife from PortugalPublication . Cumbassá, A.; Barahona, M.J.; Cunha, M.V.; Azorín, B.; Fonseca, C.; Rosalino, L.M.; Tilburg, J.; Hagen, F.; Santos, A.S.; Botelho, A.Coxiella burnetii is the etiological agent of Q fever or Coxiellosis, a zoonosis mainly affecting domestic ruminants. Information on the population structure and epidemiology of C. burnetii in animals is scarce in Portugal. Evidence of C. burnetti infection was sought in domestic, wild and captive animals based on the detection of bacterial DNA. Tissue samples from 152 domestic animals (cattle = 24, goats = 51, sheep = 76 and swine = 1), 55 wild carnivores (Egyptian mongoose = 45, red fox = 4, common genet = 3, weasel = 2 and European badger = 1) and 22 zoo animals (antelopes = 15, impala = 1; rhinoceros = 1, deer = 2, zebras = 2 and giraffe = 1) were screened by nested-touchdown PCR. Cloacae swabs from 19 griffon vultures were also analysed. Among the domestic ruminants, goats presented the highest prevalence of infection (23.53%), followed by cattle, (20.83%) and sheep (10.53%). C. burnetii DNA was also detected in five Egyptian mongooses and two antelopes and one giraffe. Using a 6-locus multiple-locus variable-number tandem repeat analysis (MLVA-6) six complete genotypes, T, I and CM and the first reported CN, CO and CP, were identified, respectively, in small ruminants and Egyptian mongooses. Clustering analysis of genotypes exposed four distinct groups, according to detection source, enlightening an apparent association between C. burnetii genotype and host.
- Coxiella burnetii screening in petsPublication . Raposo Duarte, L.; Almeida, B.; Ramos, J.; Henriques, J.; Alves, M.; Santos, A.S.
- Critical Aspects for Detection of Coxiella burnetiiPublication . Mori, M.; Mertens, K.; Cutler, S.J.; Santos, A.S.Coxiella burnetii is a globally distributed zoonotic γ-proteobacterium with an obligatory intracellular lifestyle. It is the causative agent of Q fever in humans and of coxiellosis among ruminants, although the agent is also detected in ticks, birds, and various other mammalian species. Requirements for intracellular multiplication together with the necessity for biosafety level 3 facilities restrict the cultivation of C. burnetii to specialized laboratories. Development of a novel medium formulation enabling axenic growth of C. burnetii has facilitated fundamental genetic studies. This review provides critical insights into direct diagnostic methods currently available for C. burnetii. It encompasses molecular detection methods, isolation, and propagation of the bacteria and its genetic characterization. Differentiation of C. burnetii from Coxiella-like organisms is an essential diagnostic prerequisite, particularly when handling and analyzing ticks.
- Detection and phylogenetic characterization of Theileria spp. and Anaplasma marginale in Rhipicephalus bursa in PortugalPublication . Ferrolho, A.; Antunes, S.; Santos, A.S.; Velez, R.; Padre, L.; Cabezas-Cruz, A.; Santos-Silva, M.M.; Domingos, A.Ticks are obligatory blood-sucking arthropod (Acari:Ixodida) ectoparasites of domestic and wild animals as well as humans. The incidence of tick-borne diseases is rising worldwide, challenging our approach toward diagnosis, treatment and control options. Rhipicephalus bursa Canestrini and Fanzago, 1877, a two-host tick widely distributed in the Palearctic Mediterranean region, is considered a multi-host tick that can be commonly found on sheep, goats and cattle, and occasionally on horses, dogs, deer and humans. R. bursa is a species involved in the transmission of several tick-borne pathogens with a known impact on animal health and production. The aim of this study was to estimate R. bursa prevalence in Portugal Mainland and circulating pathogens in order to contribute to a better knowledge of the impact of this tick species. Anaplasma marginale and Theileria spp. were detected and classified using phylogenetic analysis. This is the first report of Theileria annulata and Theileria equi detection in R. bursa ticks feeding on cattle and horses, respectively, in Portugal. This study contributes toward the identification of currently circulating pathogens in this tick species as a prerequisite for developing future effective anti-tick control measures.
- Detection of Anaplasma phagocytophilum, Candidatus Neoehrlichia sp., Coxiella burnetii and Rickettsia spp. in questing ticks from a recreational park, PortugalPublication . Santos, A.S.; de Bruin, A.; Veloso, A.R.; Marques, C.; Pereira da Fonseca, I.; De Sousa, R.; Sprong, H.; Santos-Silva, M.M.Tick-borne agents with medical relevance have been recorded in Portugal but little is known about their oc-currence in urban outdoor leisure areas. This study aimed to investigate ticks and tick-borne agents in threepublic parks of Lisbon’s metropolitan area. A total of 234 questing ticks belonging to eight species were found inParque Florestal de Monsanto (PFM). Ixodes ventalloi represented 40% of collections. Mitochondrial genesconfirmed Ixodes morphological identification, evidencing the intraspecific variability of I. ricinus and particu-larly I. frontalis populations. Regarding tick-borne agents, Rickettsia massiliae DNA were found in 21 (9.0%) ticks,Coxiella burnetii in 15 (6.4%), Anaplasma phagocytophilum in five (2.1%), an agent closely related to CandidatusNeoehrlichia mikurensis in two (0.9%), Rickettsia sibirica mongolitimonae and Rickettsia monacensis each in one(0.4%). Active enzootic cycles were suggested for these agents by the detection of positives in different timeperiods. Five tick species were founded with C. burnetii, including I. ventalloi which seems to be a new associationrecord. This tick was also the only species found positive for A. phagocytophilum and the Candidatus Neoehrlichiamikurensis-like agent. Two A. phagocytophilum variants were detected in PFM, one of them representing a po-tentially new ecotype already found in I. ventalloi from another Portuguese area. To the authors´ knowledge, thisis also the first report of such a Candidatus Neoehrlichia mikurensis-like microorganism. These data show aninteresting diversity of ticks and tick-borne agents with potential public health relevance in PFM, an urbanrecreational area commonly frequented by humans and their pets.
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