Rafael Antonio do Nascimento Ramos

Dr. Rafael Antonio do Nascimento Ramos

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Research Focus & Metrics

Academic Career Length

14Years (2013-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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23 August 2013 in Parasites & Vectors
Verified
Journal Article
Open access
FDFilipe Dantas-Torres
Filipe Dantas-Torres
GCGioia Capelli
Gioia Capelli
AGAlessio Giannelli
Alessio Giannelli
RRRafael Antonio do Nascimento Ramos
Rafael Antonio do Nascimento Ramos
RLRiccardo Paolo Lia
Riccardo Paolo Lia
Domenico OtrantoDomenico Otranto
Domenico Otranto
Background: Tick-borne diseases comprise a group of maladies that are of substantial medical and veterinary significance. A range of tick-borne pathogens, including diverse species of bacteria and protozoa, can infect both dogs and humans. Hence, the control of tick infestations is pivotal to decrease or prevent tick-borne pathogen transmission. Therefore, different commercial products with insecticidal, repellent or both properties have been developed for use on dogs. Recently, a collar containing a combination of imidacloprid 10% and flumethrin 4.5% has proven effective to prevent tick and flea infestations in dogs under field conditions and the infection by some vector-borne pathogens they transmit under laboratory-controlled conditions.Methods: From March 2011 to April 2012, a field study was conducted in a private shelter in southern Italy to assess the efficacy of the imidacloprid/flumethrin collar against tick and flea infestations and to determine if this strategy would decrease tick-borne pathogen transmission in young dogs. A total of 122 animals were enrolled in the study and randomly assigned to group A (n = 64; collared) or group B (n = 58; untreated controls). Dogs were examined monthly for ticks and fleas and systematically tested for selected tick-borne pathogens.Results: Compared to controls, the collar provided overall efficacies of 99.7% and 100% against tick and flea infestation, respectively. The overall efficacy for the prevention of tick-borne pathogens (i.e.,Anaplasma platysandBabesia vogeli) was 91.6%.Conclusions: This study demonstrates that the imidacloprid/flumethrin collar is efficacious against flea and tick infestation as well as tick-borne pathogen transmission to dogs under field conditions.

1 August 2016 in Veterinary Parasitology
Verified
Journal Article
Closed access
RRRafael Antonio do Nascimento Ramos
Rafael Antonio do Nascimento Ramos
ARAna Gabriela de Oliveira Do Rêgo
Ana Gabriela de Oliveira Do Rêgo
EFEverton Diogo de Farias Firmino
Everton Diogo de Farias Firmino
CRCarlos Alberto do Nascimento Ramos
Carlos Alberto do Nascimento Ramos
GCGílcia Aparecida de Carvalho
Gílcia Aparecida de Carvalho
LALeucio Câmara Alves
Leucio Câmara Alves

9 July 2018 in Parasites & Vectors
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Journal Article
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FDFilipe Dantas-Torres
Filipe Dantas-Torres
MLMaria Stefania Latrofa
Maria Stefania Latrofa
RRRafael Antonio do Nascimento Ramos
Rafael Antonio do Nascimento Ramos
RLRiccardo Paolo Lia
Riccardo Paolo Lia
GCGioia Capelli
Gioia Capelli
Domenico OtrantoDomenico Otranto
Domenico Otranto
The brown dog tick Rhipicephalus sanguineus (sensu stricto) is reputed to be the most widespread tick of domestic dogs worldwide and has also been implicated in the transmission of many pathogens to dogs and humans. For more than two centuries, Rh. sanguineus (s.s.) was regarded as a single taxon, even considering its poor original description and the inexistence of a type specimen. However, genetic and crossbreeding experiments have indicated the existence of at least two distinct taxa within this name: the so-called “temperate” and “tropical” lineages of Rh. sanguineus (sensu lato). Recent genetic studies have also demonstrated the existence of additional lineages of Rh. sanguineus (s.l.) in Europe and Asia. Herein, we assessed the biological compatibility between two lineages of Rh. sanguineus (s.l.) found in southern Europe, namely Rhipicephalus sp. I (from Italy) and Rhipicephalus sp. II (from Portugal). Ticks morphologically identified as Rh. sanguineus (s.l.) were collected in southern Portugal and southern Italy. Tick colonies were established and crossbreeding experiments conducted. Morphological, biological and genetic analyses were conducted. Crossbreeding experiments confirmed that ticks from the two studied lineages were able to mate and generate fertile hybrids. Hybrid adult ticks always presented the same genotype of the mother, confirming maternal inheritance of mtDNA. However, larvae and nymphs originated from Rhipicephalus sp. I females presented mtDNA genotype of either Rhipicephalus sp. I or Rhipicephalus sp. II, suggesting the occurrence of paternal inheritance or mitochondrial heteroplasmy. While biologically compatible, these lineages are distinct genetically and phenotypically. The temperate lineages of Rh. sanguineus (s.l.) studied herein are biologically compatible and genetic data obtained from both pure and hybrid lines indicate the occurrence of paternal inheritance or mitochondrial heteroplasmy. This study opens new research avenues and raises question regarding the usefulness of genetic data and crossbreeding experiments as criteria for the definition of cryptic species in ticks.

5 February 2015 in Parasites & Vectors
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CCClaudia Cafarchia
Claudia Cafarchia
DIDavide Immediato
Davide Immediato
RIRoberta Iatta
Roberta Iatta
RRRafael Antonio do Nascimento Ramos
Rafael Antonio do Nascimento Ramos
RLRiccardo Paolo Lia
Riccardo Paolo Lia
Domenico OtrantoDomenico Otranto
Domenico Otranto
Rhipicephalus sanguineus sensu lato ticks are widespread worldwide due to their adaptability to survive under different environmental conditions. They may act as vectors of a wide range of pathogens to humans and animals and their control is based on the use of chemical products on dogs and in the environment. Alternative control strategies, such as the use of entomopathogenic fungi as bio-control agents have also been investigated. The ability of native strains of Beauveria bassiana sensu lato in causing mortality in different tick species (e.g., Amblyomma cajennense and Rhipicephalus microplus) has been demonstrated. However, limited studies have assessed the use of B. bassiana for the control of R. sanguineus s.l. and none of them have employed native strains of this fungus. Here we investigated the pathogenicity of a native strain of B. bassiana (CD1123) against all developmental stages of R. sanguineus s.l.. Batches of eggs, larvae, nymphs and adult ticks were immersed in a suspension of 107 conidia/ml of B. bassiana s.l., isolated from a R. sanguineus s.l. engorged female. All treatment and control groups were observed for 20 days, and the biological parameters (i.e., mortality, hatching, moulting percentage, pre-oviposition period, oviposition period and rate, eggs production efficiency, reproductive efficiency and fitness indexes) were assessed. The effect of the B. bassiana strain tested herein on eggs, larvae, nymphs and adults showed a significantly higher mortality than those of the control groups (p < 0.05) at 5 days post-infection. No infected eggs hatched and no infected larvae moulted. Only 15% of infected nymphs moulted into adults. All biological parameters of treated groups differed significantly (p < 0.001) from those of control groups. This study demonstrates that a suspension containing 107 conidia/ml of a native B. bassiana strain is highly virulent towards all life-cycle developmental stages of R. sanguineus s.l. and may be of potential interest as a biological control agent against these ticks.

12 April 2016 in Revista Brasileira de Parasitologia Veterinária
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MMMaria Fernanda Melo Monteiro
Maria Fernanda Melo Monteiro
RRRafael Antonio do Nascimento Ramos
Rafael Antonio do Nascimento Ramos
ACAndréa Maria Campos Calado
Andréa Maria Campos Calado
VLVictor Fernando Santana Lima
Victor Fernando Santana Lima
IRIngrid Carla Do Nascimento Ramos
Ingrid Carla Do Nascimento Ramos
LALeucio Câmara Alves
Leucio Câmara Alves
Gastrointestinal helminths are considered to be the most common parasites affecting cats worldwide. Correct diagnosis of these parasites in animals living in urban areas is pivotal, especially considering the zoonotic potential of some species (e.g. Ancylostoma sp. and Toxocarasp.). In this study, a copromicroscopic survey was conducted using fecal samples (n = 173) from domestic cats living in the northeastern region of Brazil. Samples were examined through the FLOTAC technique and the overall results showed positivity of 65.31% (113/173) among the samples analyzed. Coinfections were observed in 46.01% (52/113) of the positive samples. The most common parasites detected were Ancylostoma sp., Toxocara cati, Strongyloides stercoralis,Trichuris sp., Dipylidium caninum andCystoisospora sp. From an epidemiological point of view, these findings are important, especially considering that zoonotic parasites (e.g. Ancylostoma sp. and Toxocara sp.) were the nematodes most frequently diagnosed in this study. Therefore, the human population living in close contact with cats is at risk of infection caused by the zoonotic helminths of these animals. In addition, for the first time the FLOTAC has been used to diagnosing gastrointestinal parasites of cats in Brazil.

1 December 2015 in Revista da Sociedade Brasileira de Medicina Tropical
Verified
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ÉRÉlvio Machado da Rocha
Élvio Machado da Rocha
CLCarlos Wilson Gomes Lopes
Carlos Wilson Gomes Lopes
RRRafael Antonio do Nascimento Ramos
Rafael Antonio do Nascimento Ramos
LALeucio Câmara Alves
Leucio Câmara Alves
Key words: Toxoplasma gondii; Pregnant women; Risk factors