ABSTRACT
El objetivo del presente trabajo es comunicar el hallazgo de Amblyomma triste por primera vez en la provincia de Santa Fe, Argentina, y sumar una nueva localidad para Amblyomma tigrinum en la misma provincia. Ambas especies de garrapatas son reconocidos vectores de Rickettsia parkeri, agente etiológico de la fiebre manchada. Los especímenes fueron colectados durante el mes de agosto de 2014 y diciembre de 2015 a partir de turistas en la Fundación Federico Wildermuth (31° 59'S, 61° 24'O), departamento de San Martín, provincia de Santa Fe. Se colectaron 5 garrapatas adultas que fueron identificadas morfológicamente como A. tigrinum (3 hembras y 1 macho) y A. triste (1 hembra). El presente hallazgo de A. triste y A. tigrinum representa el primero en incluir a ambas especies del complejo Amblyomma maculatum en una misma localidad y permite alertar sobre la presencia de vectores de R. parkeri en la zona. Nuevos estudios que incluyan el muestreo de un mayor número de garrapatas y la detección de R. parkeri permitirán dilucidar más aspectos sobre la situación de esta rickettsia en Santa Fe.
The aim of this communication is to report, for the first time, the occurrence of Amblyomma triste in Santa Fe province, Argentina, and to add a new isolation place for Amblyomma tigrinum. Both species of ticks are vectors of Rickettsia parkeri, a spotted fever group rickettsia. Ticks were recovered from tourists in August 2014 and December 2015 at the Federico Wildermuth Foundation (31° 59'S, 61° 24'O), San Martin Department, Santa Fe province. Five adult ticks were morphologically identified as A. tigrinum (3 females and 1 male) and A. triste (1 female). This is the first finding including both Amblyomma maculatum group species, A. triste and A. tigrinum, together in the same locality in Argentina. This finding suggests that this site might have favorable features for the development of both species of R. parkeri vector. Further studies including sampling of a larger number of ticks and detection of R. parkeri DNA are needed to better document the epidemiology of this rickettsia in Santa Fe.
Subject(s)
Humans , Animals , Male , Female , Arachnid Vectors/microbiology , Rickettsia Infections/transmission , Ixodidae/microbiology , Argentina , Rickettsia/isolation & purification , Ixodidae/classificationABSTRACT
Specimens of the hard tick Amblyomma triste were found infected with Rickettsia parkeri in an area of Argentina (General Lavalle, Buenos Aires Province) where cases of human illness attributed to this microorganism have been reported. Molecular detection of R. parkeri was based on polymerase chain reactions that amplify a ca. 400-bp fragment of the 23S-5S intergenic spacer and a ca. 500-bp fragment of the gene encoding a 190-kDa outer membrane protein. Three (6.97%) of 43 A. triste ticks were determined to be positive for R. parkeri. These results provide strong evidence that A. triste is the vector of R. parkeri in the study area. The findings of this work have epidemiological relevance because human parasitism by A. triste ticks has been frequently recorded in some riparian areas of Argentina and Uruguay and new cases of R. parkeri rickettsiosis might arise in the South American localities where humans are exposed to the bites of this tick species.
Subject(s)
Animals , Humans , Arthropod Vectors/microbiology , Rickettsia/isolation & purification , Ticks/microbiology , Argentina , Polymerase Chain Reaction , Rickettsia Infections/transmissionABSTRACT
At first Rickettsia conorii was implicated as the causative agent of spotted fever in Uruguay diagnosed by serological assays. Later Rickettsia parkeri was detected in human-biting Amblyomma triste ticks using molecular tests. The natural vector of R. conorii, Rhipicephalus sanguineus, has not been studied for the presence of rickettsial organisms in Uruguay. To address this question, 180 R. sanguineus from dogs and 245 A. triste from vegetation (flagging) collected in three endemic localities were screened for spotted fever group (SFG) rickettsiosis in southern Uruguay. Tick extracted DNA pools were subjected to PCR using primers which amplify a fragment of the rickettsial gltA gene. Positive tick DNA pools with these primers were subjected to a second PCR round with primers targeting a fragment of the ompA gene, which is only present in SFG rickettsiae. No rickettsial DNA was detected in R. sanguineus. However, DNA pools of A. triste were found to be positive for a rickettsial organism in two of the three localities, with prevalences of 11.8% to 37.5% positive pools. DNA sequences generated from these PCR-positive ticks corresponded to R. parkeri. These findings, joint with the aggressiveness shown by A. triste towards humans, support previous data on the involvement of A. triste as vector of human infections caused by R. parkeri in Uruguay.
Inicialmente, Rickettsia conorii fue señalada como el agente causal de la fiebre manchada en Uruguay, diagnosticada mediante pruebas serológicas. Posteriormente, Rickettsia parkeri fue detectada mediante técnicas moleculares en garrapatas Amblyomma triste colectadas sobre humanos. El vector natural de R. conorii, Rhipicephalus sanguineus, no ha sido estudiado en cuanto a rickettsias en Uruguay. Para abordar este tema, 180 R. sanguineus fueron colectados sobre perros y 245 A. triste sobre vegetación en tres localidades consideradas endémicas para fiebres manchadas en el sur de Uruguay. El ADN de las garrapatas fue extraído en pools y sometido a una primera PCR utilizando cebadores que amplifican un fragmento del gen gltA, presente en prácticamente todas las especies de Rickettsia. Las muestras positivas fueron sometidas a una segunda PCR con cebadores que amplifican un fragmento del gen ompA, presente sólo en rickettsias del grupo de las fiebres manchadas (GFM). No se detectó ADN rickettsial en R. sanguineus. Sin embargo, muestras de A. triste fueron positivas a rickettsiales en dos de las tres localidades estudiadas, con prevalencias de pools positivos del 11.8 y 37.5% respectivamente. La secuenciación del ADN evidenció la presencia de R. parkeri. Basados en estos resultados junto a los anteriores y la agresividad de A. triste hacia los humanos, se concluye que esta garrapata es vector de rickettsiosis humana por R. parkeri en Uruguay.
Subject(s)
Animals , Dogs , Female , Humans , Male , Arthropod Vectors/microbiology , Ixodidae/microbiology , Rickettsia/genetics , DNA Primers/analysis , DNA, Bacterial/analysis , Polymerase Chain Reaction , Rhipicephalus sanguineus/microbiology , Rickettsia Infections/transmission , Rickettsia/isolation & purification , UruguayABSTRACT
Un total de 50 caninos de áreas rurales de los estados Lara, Yaracuy, Carabobo y Falcón, Venezuela, fueron examinados visualmente y mediante palpación cutánea con el fin de detectar la presencia de garrapatas. Ninguno de los animales se encontró parasitado por Rhipicephalus sanguineus, la garrapata común del perro. Se colectaron 139 especimenes adultos del género Amblyomma Koch, 1844: 72 hembras y 65 machos de la especie Amblyomma ovale Koch, 1844, y dos hembras de la especie Amblyomma triste Koch, 1844. La identificación de los especimenes se realizó mediante observación en lupa estereoscópica y con la ayuda de claves taxonómicas. Los Estados donde se colectó el mayor número de ixódidos fueron Falcón con 52 especimenes y Lara con 49, representando 38 y 36%, respectivamente. A. ovale ha sido reportada como vector natural de Hepatozoon canis en áreas rurales. La especie A. triste fue colectada sólo en un canino del estado Yaracuy. Esta especie ha sido incriminada como el vector biológico de varios agentes rickettsiales patógenos, tanto para humanos como para animales domésticos y salvajes, por lo que se resalta la importancia del género Amblyomma en la transmisión de enfermedades zoonóticas.
Fifty dogs from the rural areas of Lara, Yaracuy, Carabobo and Falcón States of Venezuela were sampled through the visual and touch techniques in search of the presence of ticks. All the dogs were free of the brown dog tick Rhipicephalus sanguineus. A total of 139 adult ticks of the genus Amblyomma Koch, 1844 were collected: of them, 65 males and 72 females were identified as Amblyomma ovale Koch, 1844, whereas two females belonged to the species Amblyomma triste Koch, 1844. The observation through stereomicroscope, as well as the use of taxonomic keys, were employed in the identification of the collected specimens. Most of the ticks were collected in Falcón and Lara States, totalling 52 (38%) and 49 (36%), respectively. The species A. ovale has been reported as a natural vector of the protozoan Hepatozoon canis in rural areas. A. triste was collected only in one dog in Yaracuy State. This species has been incriminated as a biological vector of several rickettsial agents to the men and animals. The actual role of the genus Amblyomma as vector of zoonotic disease agents is highlighted.
Subject(s)
Animals , Dogs , Ticks/pathogenicity , Dogs/parasitology , Rural Areas , Parasitology/trends , Veterinary MedicineABSTRACT
O objetivo deste trabalho foi identificar as espécies de carrapatos observadas sobre capivaras na Estação Ecológica do Taim, Rio Grande- RS, Brasil. Foram examinadas 27 capivaras encontradas mortas por atropelamento na BR 471, em seu trecho que corta a Estação, sendo cole lados 497 carrapatos das espécies Amblyomma cooperi (=A. lutzi; = A. ypisilophorum), Amblyomma triste, Amblyomma tigrinum e ninfas do gênero Amblyomma. A. cooperi representou 68,41 por cento dos carrapatos identificados, com uma freqüência de parasitismo de 92,60 por cento dos hospedeiros, enquanto A. triste representou 24,75 por cento dos carrapatos em 44,43 por cento dos hospedeiros e A. tigrinum foi coletado em 14,81 por cento dos hospedeiros, totalizando 1,21 por cento dos carrapatos. As ninfas de Amblyomma sp. foram cotetadas em 18,51 por cento dos hospedeiros apresentando um percentual de 5,63 por cento do total de carrapatos. A relação macho : fêmea apresentou valores de 2,3 : 1 e 2 : l para o A. cooperi e A. triste, respectivamente. Todos hospedeiros apresentavam-se parasitados, com uma média de 18,4 carrapatos, variando de 1 a 64 carrapatos coletados por hospedeiro.
The aim of this article was the identification ofthe tick species observed on capybara in wildlife in the Ecologic Area of Taim, Rio Grande - RS; Brazil. Twenly seven capybaras found dead by trample in the road BR 471 in the Ecologic Area, wereexamined ticks coilected of the species Amblyomma cooperi (= A. lutzi and = A. ypisilophorum), Amblyomma triste, Amblyomma tigrinum and ninphs of the Genus Amblyomma. Amblyomma cooperi represented 68.41 percent of the ticks with a frequency of parasitism of 92.60 percent of the hosts; Amblyomma triste species represented 24.75 percent of the collected ticks m 44.43 percent of the hosts; Amblyomma tigrinum species were coilected m 14.81 percent of the hosts from a total of 1.21 percent of the found ticks and, the nimphs of Amblyomma were coilected in 18.51 percent of the hosts per forming 5.63 percent of the ali ticks coilected. The relation mate .female showed values of 2.3:1 and 2:1 to A. cooperiand and A. triste, respectivety. All examined hosts were found wiih ticks, with a mean of 18.4 ticks per host.