Occurrence of autogeny in a population of Ornithodoros fonsecai (Acari: Argasidae).

Ornithodoros fonsecai is an argasid tick that is endemic to Brazil and has been described in the municipality of Bonito, state of Mato Grosso do Sul. Some specimens of this species were found in a cave in the municipality of Nobres, state of Mato Grosso. The specific identification of this population was confirmed by means of morphology and molecular biology. The mitochondrial 16S rDNA partial sequence of this species from Nobres has been deposited in GenBank (MK158949). The objective of this study was to elucidate the biology of O. fonsecai from Nobres, and to report autogeny in this tick population. Along three laboratory generations was observed molting of first nymphal instar to the second instar without feeding, a typical behavior of species included in the subgenus Alectorobius. The first generation (F1) presented five nymphal instars (N1 to N5), and most of adults emerged through molting of N5. The last nymphal instar of second generation (F2) was N4, but most of adults emerged from N3. In the third generation (F3) the last nymphal instar was N5, with most of the adults emerging from N4. In F2, some females (n = 20) originated from N3 began laying eggs without a blood meal. It was observed that those N3 fed twice before they molted to autogenic females. However, autogenic behavior occurred in relation to third generation females (F3) with specimens originating from N4 (n = 12) that were fed only once as nymphs. This behavior has already been reported as obligatory for the genera Otobius and Antricola, while it is facultative for one species of genus Argas and for four species of genus Ornithodoros. However, the present report provides the first record of facultative autogeny for a species of Ornithodoros in Brazil.

Occurrence of autogeny in a population of Ornithodoros fonsecai (Acari: Argasidae)

Ornithodoros fonsecai is an argasid tick that is endemic to Brazil and has been described in the municipality of Bonito, state of Mato Grosso do Sul. Some specimens of this species were found in a cave in the municipality of Nobres, state of Mato Grosso. The specific identification of this population was confirmed by means of morphology and molecular biology. The mitochondrial 16S rDNA partial sequence of this species from Nobres has been deposited in GenBank (MK158949). The objective of this study was to elucidate the biology of O. fonsecai from Nobres, and to report autogeny in this tick population. Along three laboratory generations was observed molting of first nymphal instar to the second instar without feeding, a typical behavior of species included in the subgenus Alectorobius. The first generation (F1) presented five nymphal instars (N1 to N5), and most of adults emerged through molting of N5. The last nymphal instar of second generation (F2) was N4, but most of adults emerged from N3. In the third generation (F3) the last nymphal instar was N5, with most of the adults emerging from N4. In F2, some females (n?=?20) originated from N3 began laying eggs without a blood meal. It was observed that those N3 fed twice before they molted to autogenic females. However, autogenic behavior occurred in relation to third generation females (F3) with specimens originating from N4 (n?=?12) that were fed only once as nymphs. This behavior has already been reported as obligatory for the genera Otobius and Antricola, while it is facultative for one species of genus Argas and for four species of genus Ornithodoros. However, the present report provides the first record of facultative autogeny for a species of Ornithodoros in Brazil.

Occurrence of autogeny in a population of Ornithodoros fonsecai (Acari: Argasidae)

Ornithodoros fonsecai is an argasid tick that is endemic to Brazil and has been described in the municipality of Bonito, state of Mato Grosso do Sul. Some specimens of this species were found in a cave in the municipality of Nobres, state of Mato Grosso. The specific identification of this population was confirmed by means of morphology and molecular biology. The mitochondrial 16S rDNA partial sequence of this species from Nobres has been deposited in GenBank (MK158949). The objective of this study was to elucidate the biology of O. fonsecai from Nobres, and to report autogeny in this tick population. Along three laboratory generations was observed molting of first nymphal instar to the second instar without feeding, a typical behavior of species included in the subgenus Alectorobius. The first generation (F1) presented five nymphal instars (N1 to N5), and most of adults emerged through molting of N5. The last nymphal instar of second generation (F2) was N4, but most of adults emerged from N3. In the third generation (F3) the last nymphal instar was N5, with most of the adults emerging from N4. In F2, some females (n?=?20) originated from N3 began laying eggs without a blood meal. It was observed that those N3 fed twice before they molted to autogenic females. However, autogenic behavior occurred in relation to third generation females (F3) with specimens originating from N4 (n?=?12) that were fed only once as nymphs. This behavior has already been reported as obligatory for the genera Otobius and Antricola, while it is facultative for one species of genus Argas and for four species of genus Ornithodoros. However, the present report provides the first record of facultative autogeny for a species of Ornithodoros in Brazil.

Toxoplasma gondii antibodies in wild rodents and marsupials from the Atlantic Forest, state of São Paulo, Brazil.

Toxoplasma gondii is a protozoan parasite that infects a large spectrum of warm-blooded animals, including humans. Small rodents and marsupials play an important role in the epidemiology of T. gondii because they are sources of infection for domestic and feral cats. Serum samples from 151 rodents and 48 marsupials, captured in the Atlantic Forest, São Paulo State, southeastern Brazil, were analyzed for the presence of T. gondii antibodies. Antibodies detected by the modified agglutination test (MAT ≥ 25) were found in 8.6% (13/151) of the rodents and 10.4% (5/48) of the marsupials, with titers ranging from 25 to 6400 and from 25 to 3200, respectively for the rodents and marsupials. Three of the eight species of rodents (Akodon spp., Oligoryzomys nigripesand Rattus norvegicus), and one from the four marsupial species (Didelphis aurita) presented positive animals. T. gondii was described for the first time in the rodent Oligoryzomys nigripes.

Candidatus Rickettsia andeanae, a spotted fever group agent infecting Amblyomma parvum ticks in two Brazilian biomes.

Adult ticks of the species Amblyomma parvum were collected from the vegetation in the Pantanal biome (state of Mato Grosso do Sul) and from horses in the Cerrado biome (state of Piauí) in Brazil. The ticks were individually tested for rickettsial infection via polymerase chain reaction (PCR) targeting three rickettsial genes, gltA, ompA and ompB. Overall, 63.5% (40/63) and 66.7% (2/3) of A. parvum ticks from Pantanal and Cerrado, respectively, contained rickettsial DNA, which were all confirmed by DNA sequencing to be 100% identical to the corresponding fragments of the gltA, ompA and ompB genes of Candidatus Rickettsia andeanae. This report is the first to describe Ca. R. andeanae in Brazil.

Noteworthy records of Ixodes schulzei (Acari: Ixodidae) on rodents from the State of Parana, southern Brazil.

Ixodes schulzei Aragão & Fonseca is an endemic tick to Brazil and has already been reported in the northern (State of Rondonia), southeastern (States of Minas Gerais, Rio de Janeiro and Sao Paulo) and southern (State of Santa Catarina) regions, always found in association with the water rat Nectomys squamipes (Brandt). This communication records the first occurrence of this tick species in the State of Parana, southern region of Brazil, and it constitutes its first report on Akodon montensis (Thomas) and Oryzomys russatus (Wagner) hosts.

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

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.

Environmental infestation and rickettsial infection in ticks in an area endemic for brazilian spotted fever / Infestação ambiental e infecção por rickéttsias em carrapatos de área endêmica para Febre Maculosa Brasileira

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.

A Febre Maculosa Brasileira (FMB) é uma antropozoonose endêmica no município de Americana/SP, causada pela bactéria Rickettsia rickettsii e transmitida pelo carrapato Amblyomma cajennense. Este estudo avaliou a fauna de carrapatos e a infecção por riquétsias em carrapatos de vida livre capturados mensalmente com armadilhas de CO2, em áreas de risco para FMB de Americana, de julho de 2009 a junho de 2010. Duas espécies foram capturadas, A. cajennense (6.122 larvas; 4.265 ninfas; 2.355 adultos) e Amblyomma dubitatum (7.814 larvas; 3.364 ninfas; 1.193 adultos). Os estágios imaturos de A. cajennense e A. dubitatum apresentaram uma distribuição anual semelhante, com larvas de ambas as espécies sendo coletadas em maior número no período de abril a julho e ninfas de junho a outubro. Maior número de adultos de A. cajennense foi coletado de outubro a dezembro, enquanto que os adultos de A. dubitatum foram coletados em número relativamente semelhante durante todo o ano. A infecção por Rickettsia foi avaliada pela PCR em 1157 carrapatos A. cajennense e 1040 A. dubitatum, com apenas 41 (3,9%) A. dubitatum infectados com Rickettsia bellii. Este estudo demonstrou que as áreas de risco para FMB de Americana são caracterizadas por elevadas infestações ambientais de A. cajennense e A. dubitatum.

Noteworthy records of Ixodes schulzei (Acari: Ixodidae) on rodents from the State of Parana, southern Brazil / Relatos de Ixodes schulzei (Acari: Ixodidae) em roedores do estado do Paraná, sul do Brasil

Ixodes schulzei Aragão & Fonseca is an endemic tick to Brazil and has already been reported in the northern (State of Rondonia), southeastern (States of Minas Gerais, Rio de Janeiro and São Paulo) and southern (State of Santa Catarina) regions, always found in association with the water rat Nectomys squamipes (Brandt). This communication records the first occurrence of this tick species in the State of Parana, southern region of Brazil, and it constitutes its first report on Akodon montensis (Thomas) and Oryzomys russatus (Wagner) hosts.

Ixodes schulzei Aragão & Fonseca é um carrapato endêmico do Brasil e já foi relatado nas regiões Norte (estado de Rondônia), Sudeste (estados de Minas Gerais, Rio de Janeiro e São Paulo) e Sul (estado de Santa Catarina), tendo sido encontrado sempre em associação com o rato d'água Nectomys squamipes (Brandt). Esta comunicação registra a primeira ocorrência dessa espécie de carrapato no estado do Paraná, região Sul do Brasil e constitui o primeiro relato de Akodon montensis (Thomas) e Oryzomys russatus (Wagner) como hospedeiros.

Spotted fever group Rickettsia infecting ticks (Acari: Ixodidae) in the state of Santa Catarina, Brazil

During 2006-2008, a total of 260 adult ticks were collected from domestic and wild animals in different regions of the state of Santa Catarina (SC), Brazil, including areas where human cases of Brazilian spotted fever have been reported. Collected ticks belonging to nine species (Amblyomma aureolatum, Amblyomma cajennense, Amblyomma dubitatum, Amblyomma longirostre, Amblyomma ovale, Amblyomma tigrinum, Dermacentor nitens, Rhipicephalus microplus and Rhipicephalus sanguineus) were tested by polymerase chain reaction (PCR) for rickettsial infection. Overall, eight (3.1 percent) ticks were found to be infected with Rickettsia species. After sequencing the PCR products, we determined that the sequences generated from three A. aureolatum, one A. ovale and one R. sanguineus from the municipality of Blumenau, one A. ovale from the municipality of Águas Mornas and one A. ovale from the municipality of Urussanga were identical to the corresponding partial rickettsial ompA gene sequence of Rickettsia parkeri strain Atlantic rainforest. The sequence generated from one A. longirostre from Blumenau was 100 percent identical to the corresponding partial rickettsial ompA gene sequence of Rickettsia amblyommii strain AL. Because R. parkeri strain Atlantic rainforest was recently shown to have caused two cases of human spotted fever in other states of Brazil, the role of this rickettsial agent as a possible etiological agent of spotted fever in SC is discussed.

Carios mimon (Acari: Argasidae): description of adults and redescription of larva.

Carios mimon is an argasid tick common on Chiroptera, originally described from larvae collected on bats Mimon crenulatum from Bolivia and Eptesicus brasiliensis from Uruguay. Later it was also registered from Argentina and recently included among the Brazilian tick fauna. In Brazil, this species is very aggressive to man, resulting in intense inflammatory response and pain. It is known only by the larval description and its morphology resembles that from other species currently included into the genus Carios, formerly classified into the subgenus Alectorobius, genus Ornithodoros. Here we describe adults and redescribe the larva of C. mimon, based on light and scanning electron microscopy. Remarks about its morphological similarity with other species of this genus are also discussed. Molecular analysis inferred from a portion of the 16S rRNA mitochondrial gene placed C. mimon in a cluster supported by maximal bootstrap value (100%) with other argasid species (mostly bat parasites in the New World), which have been classified into either the genus Ornithodoros or Carios, depending on the Argasidae classification adopted by different authors.

Spotted fever group Rickettsia infecting ticks (Acari: Ixodidae) in the state of Santa Catarina, Brazil.

During 2006-2008, a total of 260 adult ticks were collected from domestic and wild animals in different regions of the state of Santa Catarina (SC), Brazil, including areas where human cases of Brazilian spotted fever have been reported. Collected ticks belonging to nine species (Amblyomma aureolatum, Amblyomma cajennense, Amblyomma dubitatum, Amblyomma longirostre, Amblyomma ovale, Amblyomma tigrinum, Dermacentor nitens, Rhipicephalus microplus and Rhipicephalus sanguineus) were tested by polymerase chain reaction (PCR) for rickettsial infection. Overall, eight (3.1%) ticks were found to be infected with Rickettsia species. After sequencing the PCR products, we determined that the sequences generated from three A. aureolatum, one A. ovale and one R. sanguineus from the municipality of Blumenau, one A. ovale from the municipality of Águas Mornas and one A. ovale from the municipality of Urussanga were identical to the corresponding partial rickettsial ompA gene sequence of Rickettsia parkeri strain Atlantic rainforest. The sequence generated from one A. longirostre from Blumenau was 100% identical to the corresponding partial rickettsial ompA gene sequence of Rickettsia amblyommii strain AL. Because R. parkeri strain Atlantic rainforest was recently shown to have caused two cases of human spotted fever in other states of Brazil, the role of this rickettsial agent as a possible etiological agent of spotted fever in SC is discussed.

Carios mimon (Acari: Argasidae) description of adults and redescription of larva

Carios mimon is an argasid tick common on Chiroptera, originally described from larvae collected on bats Mimon crenulatum from Bolivia and Eptesicus brasiliensis from Uruguay. Later it was also registered from Argentina and recently included among the Brazilian tick fauna. In Brazil, this species is very aggressive to man, resulting in intense inflammatory response and pain. It is known only by the larval description and its morphology resembles that from other species currently included into the genus Carios, formerly classified into the subgenus Alectorobius, genus Ornithodoros. Here we describe adults and redescribe the larva of C. mimon, based on light and scanning electron microscopy. Remarks about its morphological similarity with other species of this genus are also discussed. Molecular analysis inferred from a portion of the 16S rRNA mitochondrial gene placed C. mimon in a cluster supported by maximal bootstrap value (100%) with other argasid species (mostly bat parasites in the New World), which have been classified into either the genus Ornithodoros or Carios, depending on the Argasidae classification adopted by different authors.