Pesquisa de Rickettsia spp em carrapatos Amblyomma cajennense e Amblyomma dubitatum no Estado de São Paulo

Pacheco, Richard C.; Horta, Maurício Cláudio; Pintér, Adriano; Moraes‐Filho, Jonas; Martins, Thiago Fernandes; Nardi, Marcello Schiavo; Souza, Savina Silvana Aparecida Lacerra de; Souza, Celso Eduardo de; Szabó, Matias Pablo Juán; Richtzenhain, Leonardo José; Labruna, Marcelo Bahia

doi:10.1590/s0037-86822009000300023

Cited by 52 publications

(45 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Although this result was in accordance with Guedes et al (2005), who also found no rickettsial infection in A. dubitatum from the same area of this study, it contrasts with other studies, especially in the state of São Paulo, where the majority of the A. dubitatum populations are infected with R. bellii (HORTA et al, 2007;PACHECO et al 2009). …”

Section: Discussionsupporting

confidence: 77%

“…Since we detected this rickettsial strain in nymphal pools, we suppose that the agent was infecting nymphs of one of the two Amblyomma species found at the study site, namely A. cajennense or A. dubitatum. Interestingly, this new rickettsial strain has never been reported before, even though hundreds of A. cajennense or A. dubitatum ticks have been tested for rickettsial infection in other areas (GUEDES et al 2005;SANGIONI et al, 2005;HORTA et al, 2007;PACHECO et al, 2009). Currently, R. tamurae is known to occur in Japan, where it infects the tick Amblyomma testudinarium (FOURNIER et al, 2006).…”

Section: Discussionmentioning

confidence: 99%

“…Regardless of being a common tick species in many BSF-endemic areas, A. dubitatum has never been found infected with R. rickettsii. Nevertheless, 6 to 45% of A. dubitatum ticks have been found to be infected by Rickettsia bellii (a rickettsia of unknown pathogenicity for humans) in many tick populations, including some from BSF-endemic areas (LABRUNA et al, 2004;HORTA et al, 2007;PACHECO et al, 2009). In addition, one study reported that 7.5% of the A. dubitatum ticks from a BSFendemic area of São Paulo were infected by the Rickettsia sp.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Rickettsia species infecting Amblyomma ticks from an area endemic for Brazilian spotted fever in Brazil

Guedes

Leite

Pacheco

et al. 2011

Rev. Bras. Parasitol. Vet.

Self Cite

View full text Add to dashboard Cite

This study reports rickettsial infection in Amblyomma cajennense and Amblyomma dubitatum ticks collected in an area of the state of Minas Gerais, Brazil, where Brazilian spotted fever is considered endemic. For this purpose, 400 adults of A. cajenennse and 200 adults of A. dubitatum, plus 2,000 larvae and 2,000 nymphs of Amblyomma spp. were collected from horses and from the vegetation. The ticks were tested for rickettsial infection through polymerase chain reaction (PCR) protocols targeting portions of three rickettsial genes (gltA, ompA, and ompB). Only two free-living A. cajennense adult ticks, and four pools of free-living Amblyomma spp. nymphs were shown to contain rickettsial DNA. PCR products from the two A. cajennense adult ticks were shown to be identical to corresponding sequences of the Rickettsia rickettsii strain Sheila Smith. DNA sequences of gltA-PCR products of the four nymph pools of Amblyomma spp. revealed a new genotype, which was shown to be closest (99.4%) to the corresponding sequence of Rickettsia tamurae. Our findings of two R. rickettsii-infected A. cajennense ticks corroborate the endemic status of the study area, where human cases of BSF were reported recently. In addition, we report for the first time a new Rickettsia genotype in Brazil.

show abstract

Section: Discussionsupporting

confidence: 77%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Rickettsia species infecting Amblyomma ticks from an area endemic for Brazilian spotted fever in Brazil

Guedes

Leite

Pacheco

et al. 2011

Rev. Bras. Parasitol. Vet.

Self Cite

View full text Add to dashboard Cite

show abstract

“…Therefore, it is possible that constant gene (and pathogen) exchange exists between ticks in the six sampled areas. Nonetheless, the present study corroborates a number of previous studies that have reported the presence of capybaras associated with the ticks A. cajennense and A. dubitatum in southeastern Brazil, in both BSF-endemic and non-endemic areas (GUEDES et al, 2005;PEREZ et al, 2008;TOLEDO et al, 2008;PACHECO et al, 2009;QUEIROGAS et al, 2012). The seasonal dynamics of A. cajennense has been well studied in southeastern Brazil, where this tick completes one generation per year, with larvae predominating in autumn, nymphs in winter and adults during spring and summer (OLIVEIRA et al, 2000(OLIVEIRA et al, , 2003LABRUNA et al, 2002).…”

Section: Discussionsupporting

confidence: 92%

Environmental infestation and rickettsial infection in ticks in an area endemic for Brazilian spotted fever

Brites-Neto¹,

Nieri-Bastos

Brasil³

et al. 2013

Rev. Bras. Parasitol. Vet.

Self Cite

View full text Add to dashboard Cite

Brazilian spotted fever (BSF), caused by Rickettsia rickettsii, is endemic in the municipality of Americana, southeastern Brazil, where the disease is transmitted by the tick Amblyomma cajennense. This study evaluated the tick fauna and rickettsial infection in free-living ticks that were captured monthly using dry ice traps in areas endemic for BSF in Americana, from July 2009 to June 2010. Two tick species were captured: A. cajennense (6,122 larvae; 4,265 nymphs; 2,355 adults) and Amblyomma dubitatum (7,814 larvae; 3,364 nymphs; 1,193 adults). The immature stages of A. cajennense and A. dubitatum had similar distribution through the 12-month period, with larvae of both species collected in highest numbers between April and July, and nymphs between June and October. The highest numbers of A. cajennense adults were collected between October and December, whereas A. dubitatum adults were collected in relatively similar numbers throughout the 12-month period. Rickettsial infection was evaluated by means of PCR in 1,157 A. cajennense and 1,040 A. dubitatum ticks; only 41 (3.9%) A. dubitatum were found to be infected by Rickettsia bellii. The present study showed that the areas of Americana that are endemic for BSF are characterized by high environmental burdens of A. cajennense and A. dubitatum.

show abstract

“…Rickettsia bellii has been found in several tick species in the country, attaining high prevalence in both I. loricatus and A. dubitatum ticks, which may explain our serological results [6,10,27,32,37]. Reasons for the other probable homologous reactions, however, are less straightforward and deserve further investigation, particularly in the case of R. rickettsii.…”

Section: Discussionmentioning

confidence: 77%

Serologic evidence of the exposure of small mammals to spotted-fever Rickettsia and Rickettsia bellii in Minas Gerais, Brazil

Coelho

Limongi

Lemos

et al. 2016

J Infect Dev Ctries

Self Cite

View full text Add to dashboard Cite

Introduction: Sources of pathogenic Rickettsia in wildlife are largely unknown in Brazil. In this work, potential tick vectors and seroreactivity of small mammals against four spotted-fever group Rickettsia (R. rickettsii, R. parkeri, R. amblyommii and R. rhipicephali) and Rickettsia bellii from peri-urban areas of Uberlândia, a major town in Brazil, are described for the first time. Methodology: Small mammals were captured and blood samples collected. Ticks were collected from the surface of the host and the environment and posteriorly identified. Reactivity of small mammal sera to Rickettsia was tested by indirect immunofluorescence assay (IFA) using crude antigens from five Brazilian Rickettsia isolates. Results: Information was obtained from 416 small mammals (48 Marsupialia and 368 Rodentia). Forty-eight animals were parasitized and two tick species, Ixodes loricatus and Amblyomma dubitatum, were found on several host species, with a few tick-host relationships described for the first time. From the 416 tested sera, 70 reacted to at least one Rickettsia antigen (prevalence of 16.8%) and from these, 19 (27.1%) reacted to two or more antigens. Seroprevalence was higher for marsupials (39.6%) than for rodents (13.8%). Marsupial and Rhipidomys spp. sera reacted mainly (highest seroprevalence and titers) to R. bellii, and that of Necromys lasiurus mainly to R. rickettsii. Conclusions: Although the serologic assays poorly discriminate between closely related spotted-fever group Rickettsia, the observed small mammal seroreactivity suggests the circulation of Rickettsia in the peri-urban area of Uberlândia, albeit at low levels.

show abstract

Pesquisa de Rickettsia spp em carrapatos Amblyomma cajennense e Amblyomma dubitatum no Estado de São Paulo

Cited by 52 publications

References 16 publications

Rickettsia species infecting Amblyomma ticks from an area endemic for Brazilian spotted fever in Brazil

Rickettsia species infecting Amblyomma ticks from an area endemic for Brazilian spotted fever in Brazil

Environmental infestation and rickettsial infection in ticks in an area endemic for Brazilian spotted fever

Serologic evidence of the exposure of small mammals to spotted-fever Rickettsia and Rickettsia bellii in Minas Gerais, Brazil

Contact Info

Product

Resources

About