Browsing by Author "Sousa, R."
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- Distribution, abundance and ecology of ticks in Portugal mainland: data from five years of a surveillance program REVIVEPublication . Santos-Silva, M.M.; Santos, A.; Lopes de Carvalho, I.; Sousa, R.; Luz, T.; Parreira, L.; Chainho, L.; Gomes, M.S.; Milhano, N.; Osório, H.; Alves, M.J.; Núncio, M.S.; REVIVE WorkgroupREVIVE (National Network for Vector Surveillance) aims to: i) Monitor the activity of hematophagous arthropods; ii) Characterize the species and its seasonal occurrence; iii) Identify important pathogens in Public Health, depending on the density of the vectors, the level of infection or the introduction of exotic species to alert for control measures.
- Diversity of microorganisms in Hyalomma aegyptium collected from spur-thighed tortoise (Testudo graeca) in North Africa and AnatoliaPublication . Norte, A.C.; Harris, D.J.; Silveira, D.; Nunes, C.S.; Núncio, M.S.; Martínez, E.G.; Giménez, A.; Sousa, R.; Lopes de Carvalho, I.; Perera, A.Ticks carry a diverse community of microorganisms including non-pathogenic symbionts, commensals, and pathogens, such as viruses, bacteria, protozoans, and fungi. The assessment of tick-borne microorganisms (TBM) in tortoises and their ticks is essential to understand their eco-epidemiology, and to map and monitor potential pathogens to humans and other animals. The aim of this study was to characterize the diversity of microorganisms found in ticks collected from the spur-thighed tortoise (Testudo graeca) in North Africa and Anatolia. Ticks feeding on wild T. graeca were collected, and pathogens were screened by polymerase chain reaction using group-specific primers. In total, 131 adult Hyalomma aegyptium ticks were collected from 92 T. graeca in Morocco (n = 48), Tunisia (n = 2), Algeria (n = 70), and Turkey (n = 11). Bacteria and protozoa detected included Hemolivia mauritanica (22.9%), Midichloria mitochondrii (11.4%), relapsing-fever borreliae (8.4%), Ehrlichia spp. (7.6%), Rickettsia spp. (3.4%), Borrelia burgdorferi s.l. (0.9%), Francisella spp. (0.9%), and Wolbachia spp. (0.8%). The characterization of Rickettsia included R. sibirica mongolitimonae (Algeria), R. aeschlimannii (Turkey), and R.africae (Morocco). Hemolivia mauritanica and Ehrlichia spp. prevalence varied significantly with the sampling region/country. We did not detect significant associations in microorganism presence within ticks, nor between microorganism presence and tick mitochondrial DNA haplogroups. This is the first report of Francisella persica-like, relapsing fever borreliae, M. mitochondrii, and Wolbachia spp. in H. aegyptium ticks collected from wild hosts from the South and Eastern Mediterranean region, and of R. sibirica mongolitimonae and R. africae in H. aegyptium from Algeria and Morocco, respectively. Given that T. graeca is a common species in commercial and non-commercial pet trade, the evaluation of the role of this species and its ticks as hosts for TBM is particularly relevant for public health.
- Diversity of microorganisms in Hyalomma aegyptium collected fromspur-thighedtortoise(Testudograeca)in North Africa and AnatoliaPublication . Norte, A.C.; Harris, D.J.; Silveira, D.; Nunes, C.S.; Núncio, M.S.; Martínez, E.G.; Giménez, A.; Sousa, R.; Lopes de Carvalho, I.; Perera, A.Ticks carry a diverse community of microorganisms including non-pathogenic symbionts, commensals, and pathogens, such as viruses, bacteria, protozoans, and fungi. The assessment of tick-borne microorganisms (TBM) in tortoises and their ticks is essential to understand their eco-epidemiology, and to map and monitor potential pathogenstohumansandotheranimals.Theaimofthisstudywastocharacterizethe diversity of microorganisms found in ticks collected from the spur-thighed tortoise (Testudo graeca) in North Africa and Anatolia. Ticks feeding on wild T. graeca were collected, and pathogens were screened by polymerase chain reaction using groupspecific primers. In total, 131 adult Hyalomma aegyptium ticks were collected from 92 T. graeca in Morocco (n = 48), Tunisia (n = 2), Algeria (n = 70), and Turkey (n = 11). Bacteria and protozoa detected included Hemolivia mauritanica (22.9%), Midichloria mitochondrii (11.4%), relapsing-fever borreliae (8.4%), Ehrlichia spp. (7.6%), Rickettsia spp. (3.4%), Borrelia burgdorferi s.l. (0.9%), Francisella spp. (0.9%), and Wolbachia spp. (0.8%). The characterization of Rickettsia included R. sibirica mongolitimonae (Algeria), R. aeschlimannii (Turkey), and R.africae (Morocco). Hemolivia mauritanica and Ehrlichia spp. prevalence varied significantly with the sampling region/country. We did not detect significant associations in microorganism presence within ticks, nor between microorganism presence and tick mitochondrial DNA haplogroups. This is the first report of Francisella persica-like, relapsing fever borreliae, M. mitochondrii, andWolbachia spp. in H.aegyptiumticks collected from wild hosts from the South and Eastern Mediterranean region, and of R. sibirica mongolitimonae and R. africae in H. aegyptium from Algeria and Morocco, respectively. Given that T. graeca is a common species in commercial and non-commercial pet trade, the evaluation of the role of this species anditsticksashostsforTBMisparticularlyrelevantforpublichealth
- Francisella-like endosymbiont and Rickettsia aeschlimannii co-infection in a Hyalomma marginatum tickPublication . Carvalho, C.L.; Sousa, R.; Santos-Silva, M.M.; Santos, A.S.; Núncio, M.S.; Lopes de Carvalho, I.
- Middle East respiratory syndrome coronavirus neutralising serum antibodies in dromedary camels: a comparative serological studyPublication . Reusken, C.; Haagmans, B.; Gutierrez, C.; Godeke, G.J.; Meyer, B.; Muth, D.; Raj, V.S.; Smits-De Vries, L.; Corman, V.M.; Drexler, J.F.; Smits, S.L.; Sousa, R.; van Beek, J.; Nowotny, N.; van Maanen, K.; Hidalgo-Hermoso, E.; Bosch, B.J.; Rottier, P.; Osterhaus, A.; Gortázar-Schmidt, C.; Drosten, C.; Koopmans, M.A new betacoronavirus-Middle East respiratory syndrome coronavirus (MERS-CoV)-has been identified in patients with severe acute respiratory infection. Although related viruses infect bats, molecular clock analyses have been unable to identify direct ancestors of MERS-CoV. Anecdotal exposure histories suggest that patients had been in contact with dromedary camels or goats. We investigated possible animal reservoirs of MERS-CoV by assessing specific serum antibodies in livestock. METHODS: We took sera from animals in the Middle East (Oman) and from elsewhere (Spain, Netherlands, Chile). Cattle (n=80), sheep (n=40), goats (n=40), dromedary camels (n=155), and various other camelid species (n=34) were tested for specific serum IgG by protein microarray using the receptor-binding S1 subunits of spike proteins of MERS-CoV, severe acute respiratory syndrome coronavirus, and human coronavirus OC43. Results were confirmed by virus neutralisation tests for MERS-CoV and bovine coronavirus. FINDINGS: 50 of 50 (100%) sera from Omani camels and 15 of 105 (14%) from Spanish camels had protein-specific antibodies against MERS-CoV spike. Sera from European sheep, goats, cattle, and other camelids had no such antibodies. MERS-CoV neutralising antibody titres varied between 1/320 and 1/2560 for the Omani camel sera and between 1/20 and 1/320 for the Spanish camel sera. There was no evidence for cross-neutralisation by bovine coronavirus antibodies. INTERPRETATION: MERS-CoV or a related virus has infected camel populations. Both titres and seroprevalences in sera from different locations in Oman suggest widespread infection. FUNDING: European Union, European Centre For Disease Prevention and Control, Deutsche Forschungsgemeinschaft.
- Molecular detection of Rickettsia spp. in ticks and feas collected from rescued hedgehogs (Erinaceus europaeus) in PortugalPublication . Barradas, P. F.; Mesquita, J. R.; Mateus, T. L.; Ferreira, P.; Amorim, I.; Gartner, F.; Sousa, R.Hedgehogs (e.g., Erinaceus europaeus, E. roumanicus) are wild mammals that frequently are observed near residential areas. The aim of this study was to investigate ticks and feas collected from European hedgehogs in Portugal and to evaluate the prevalence of Rickettsia in those ectoparasites. Ticks and feas were identifed by morphological and molecular methods, and molecular detection by PCR and genotypic characterization of Rickettsia spp. was performed targeting ompB, ompA and gltA gene fragments. In total, 1892 ticks and 213 feas were collected from 33 rescued European hedgehogs captured in seven districts of the north and centre of Portugal. Two tick species were identifed – Rhipicephalus sanguineus accounted for 91% (n=1719) of the total ticks collected and 9% (n=173) were Ixodes hexagonus. All feas were identifed as Archaeopsylla erinacei. Regarding pathogen detection, Rickettsia massiliae DNA was found in 22 of the 212 tested Rh. sanguineus. None of the 48 I. hexagonus tested showed to be positive for rickettsiae. Rickettsia asembonensis DNA was identifed in 55 A. erinacei feas tested (n=117). These results show that European hedgehogs are exposed to R. massiliae transmitted by ticks and to R. asembonensis via feas suggesting that these mammals might be involved in the natural transmission cycle of these Rickettsia species. This study is the frst report of R. asembonensis in feas in Portugal.
- Multiple genotoxic activities of ptaquiloside in human lymphocytes: aneugenesis, clastogenesis and induction of sister chromatid exchangePublication . Gil da Costa, R.M.; Coelho, P.; Sousa, R.; Bastos, M.M.S.M.; Porto, B.; Teixeira, João Paulo; Malheiro, I; Lopes, C.Ptaquiloside, a norsesquiterpene glycoside from bracken (Pteridium aquilinum), is a known carcinogen towards animals. Its genotoxicity is mainly attributed to its DNA-alkylating and clastogenic properties. This study analyses various modes of genotoxic action of ptaquiloside in human mononuclear blood cells. The alkaline comet assay was performed on cells exposed to 5μg/ml ptaquiloside for 5, 10, 20, 30, 40 or 50min. Tail length was used as a DNA-damage parameter. Assays to determine structural and numerical chromosomal aberrations and sister-chromatid exchange were conducted on cells exposed to 5, 10 or 20μg/ml ptaquiloside for 48h. The tail length showed maximum DNA damage at 20-30min, diminishing onwards. Highly significant (p<0.001) dose-dependent increases in structural and numerical chromosomal aberrations and SCE were observed in response to ptaquiloside. These results indicate that ptaquiloside is not only a DNA-alkylating agent, but expresses its genotoxicity through multiple mechanisms including clastogenesis, aneugenesis and the mechanism underlying SCE induction, which is not entirely understood. Recent studies support the role played by aneuploidy in oncogenesis, highlighting the importance of this endpoint for mutagenicity screening. SCE are thought to represent the long-term effects of mutagens and are an important genotoxicity biomarker. The present results also agree with data from epidemiological studies and from animal in vivo studies, further supporting the hypothesis that ptaquiloside may represent a significant threat to human health.
- Rickettsia lusitaniae sp. nov. isolated from the soft tick Ornithodoros erraticus (Acarina: Argasidae)Publication . Milhano, N.; Palma, M.; Marcili, A.; Núncio, M.S.; Lopes de Carvalho, I.; Sousa, R.In this study a novel Rickettsia from the spotted fever group, isolated from Ornithodoros erraticus soft ticks collected from pigpens in the south of Portugal, is described. After initial screening revealed Rickettsia-positive ticks, isolation attempts were then performed. Successful isolates were achieved by shell-vial technique using Vero E6 cells at 28°C. Molecular characterization of the isolate was performed based on analysis of five rickettsial genes gltA, ompA, ompB, sca1 and htr with their subsequent concatenation along with other rickettsial species resulting in a clustering of the new isolate with Rickettsia felis and Rickettsia hoogstraalii. The degree of nucleotide sequence similarity with other rickettsiae fulfills the criteria for classification of our isolate as a novel species. The name Rickettsia lusitaniae sp. nov. (=CEVDI PoTiRo) is proposed for this new species found in O. erraticus.
- Rickettsia slovaca infection in humans, PortugalPublication . Sousa, R.; Pereira, B. I.; Nazareth, C.; Cabral, S.; Ventura, C.; Crespo, P.; Marques, N.; Cunha, S.Fifteen years after the initial detection of Rickettsia slovaca in ticks in Portugal, 3 autochthonous cases of R. slovaca infection were diagnosed in humans. All patients had an eschar on the scalp and lymphadenopathy; 2 patients had facial edema. R. slovaca infection was confirmed by serologic testing, culture, and PCR.
- Serological and molecular survey of Anaplasma species infection in dogs with suspected tickborne disease in PortugalPublication . Santos, A.S.; Alexandre, N.; Sousa, R.; Núncio, M.S.; Bacellar, F.; Dumler, J.S.Fifty-five dogs with suspected tickborne disease were tested by immunofluorescence assay and PCR for Anaplasma phagocytophilum infection. Thirty (54·5 per cent) of the dogs were seropositive and five of them fulfilled the serological criteria for an active infection, with either seroconversion or a fourfold increase in antibody titres. Fragments of DNA of the expected size were detected by PCR in two seropositive and three seronegative dogs. However, direct amplicon sequencing failed to identify active A phagocytophilum infections, but revealed the presence of Anaplasma platys DNA in the PCR-positive animals.