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Rickettsia spp. in rodent-attached ticks in Estonia and first evidence of spotted fever group Rickettsia species Candidatus Rickettsia uralica in Europe.

BACKGROUND: Rickettsia spp. are human pathogens that cause a number of diseases and are transmitted by arthropods, such as ixodid ticks. Estonia is one of few regions where the distribution area of two medically important tick species, Ixodes persulcatus and I. ricinus, overlaps. The nidicolous rodent-associated Ixodes trianguliceps has also recently been shown to be present in Estonia. Although no data are available on human disease(s) caused by tick-borne Rickettsia spp. in Estonia, the presence of three Rickettsia species in non-nidicolous ticks has been previously reported. The aim of this…

[Rickettsia infections in Portugal].

After a brief introduction about rickettsioses, we analyse Mediterranean Spotted Fever (MSF) in Portugal, and review Portuguese medical literature. We focussed on the seasonal summer pattern of the disease. MSF is very frequent in Portugal, nearly 1,000 cases are reported every year and young age groups are the most afflicted. Although usually regarded as a benign condition, MSF has emerged as a potentially lethal disease in recent years. The clinical presentation is protean, but usually suggestive enough to allow a clinical diagnosis. The complications are well documented, elderly and people

Rickettsiae and rickettsioses in Portugal.

The only rickettsiae recorded in Portugal till now were Rickettsia conorii and Coxiella burnetii. Boutonneuse fever is one of the most important transmissible diseases in Portugal. Though the annual number of cases is not exactly known, it is estimated to be not far from 20,000 in some years. Q fever is the other rickettsiosis widely disseminated throughout the country. The serological prevalence and the incidence of those rickettsioses in Portugal are presented in this communication. In recent research in southern Portugal, about 4,000 adult ticks of nine species were screened by the haemocyt…

Rickettsiae and rickettsial diseases.

This paper summarizes present knowledge on rickettsiae and rickettsial diseases, and on their epidemiological characteristics, control, and public health significance. There are many natural foci of rickettsial diseases, from where the disease may spread to other areas in the world under changing socioeconomic conditions. Because of rapid long-distance travel, sporadic cases of serious rickettsial diseases may today appear far from endemic areas where the infection occurred. Even in endemic areas the disease may be misdiagnosed and deaths may occur as a result of inadequate treatment. Rapid tr…

Seroprevalence of Rickettsia typhi and Rickettsia conorii infection among rodents and dogs in Egypt.

A serological survey of 1813 rodent and 549 dog sera, collected from 1979 to 1986 from animals in 16 Egyptian Governorates were tested for antibody to Rickettsia typhi and Rickettsia conorii by the indirect fluorescent antibody test. Only three of 82 (4%) sera from Rattus rattus collected near Aswan had antibody to R. conorii. The prevalence of R. typhi antibody in dog sera was only 0.4% (n = 549) while 25% (n = 547) of Rattus norvegicus and 11% (n = 1138) of R. rattus had measurable antibodies. Among the other rodents, antibody was demonstrated in only 2% (n = 45) of Arvicanthis spp., and 1% …

Rickettsia massiliae and Rickettsia conorii Israeli Spotted Fever Strain Differentially Regulate Endothelial Cell Responses.

Rickettsiae primarily target microvascular endothelial cells. However, it remains elusive how endothelial cell responses to rickettsiae play a role in the pathogenesis of rickettsial diseases. In the present study, we employed two rickettsial species with high sequence homology but differing virulence to investigate the pathological endothelial cell responses. Rickettsia massiliae is a newly documented human pathogen that causes a mild spotted fever rickettsiosis. The "Israeli spotted fever" strain of R. conorii (ISF) causes severe disease with a mortality rate up to 30% in hospitalized patien…

Rickettsia infection in dogs and Rickettsia parkeri in Amblyomma tigrinum ticks, Cochabamba Department, Bolivia.

Only few published data are available on ticks and tick-borne zoonotic pathogens in Bolivia. To evaluate rickettsial seroprevalence and infection in dogs and ticks, during February-April 2007, we collected whole blood, sera, and ticks from dogs living in the rural, peri-urban, and urban areas of Cochabamba, Bolivia. Dog sera were subjected to enzyme-linked immunosorbent assay test to detect IgG antibodies against Rickettsia rickettsii and 68.2% of samples were found to be positive (n = 30; 95% confidence interval [CI]: 52.4-81.4). Blood samples and ticks were tested using polymerase chain reac…

Специфические моноколональные антитела для Рикиттсиа джапоники, недавно обнаруженной группы рикеттсии.

В общей сложности 192 гибридомы были разработаны из мышей, иммунизированных Рикитсией джапоники, недавно выявленной группой рикеттсии патогенной для людей. Из этих гибридом, 101 вид был специфичным, 37 были замечены в группе респираторной лихорадки, а остальные 54 также реагировали с одним или несколькими другими патогенными видами пятнистой группы лихорадки рикетсиа, Рикитциа акари, Рикиттсиа аустралис, Рикитсия conorii, Рикитсия рикеттсии и Рикиетсия сибрица. Были описаны семь моноклонных антител, характерных для конкретных видов. Эти моноклонные антитела принадлежат к классу иммуноглобулина

Совпадение в аннотации оригинала
A total of 192 hybridomas were developed from mice immunized with Rickettsia japonica, a newly identified spotted fever group rickettsia pathogenic for humans. Of these hybridomas, 101 were species specific, 37 were spotted fever group reactive, and the other 54 were also reactive with one or more of the other pathogenic species of spotted fever group ricket…

Seroepidemiological survey to investigate Rickettsia rickettsii and Rickettsia parkeri in municipalities of the southeast Brazil.

Spotted fever is a tick-borne rickettsiosis caused by several Rickettsia species-including R. rickettsii, R. parkeri, and others-with varying degrees of pathogenicity. Its nonspecific symptoms often lead to misdiagnosis such as dengue. This study investigated anti-R. rickettsii and R. parkeri antibodies in 152 patients with acute febrile illness who tested negative for dengue. Serological analysis using immunofluorescence assay found 29 reactive samples (19%) at a 1:64 dilution. Among them, 20.6% were male and 58.6% female, with an average age of 42.6 years. The average sample collection time …

Effects of exposure to Rickettsia bellii on reservoir competence of guinea pigs for Rickettsia rickettsii.

BACKGROUND: Amblyomma sculptum is the main vector implicated in the transmission of Rickettsia rickettsii in southeastern Brazil, where capybaras are known to be the main amplifying hosts of this pathogen. Interestingly, many areas inhabited by large populations of capybaras and A. sculptum remain free of R. rickettsii, suggesting that other drivers may be involved in the pathogen perpetuation. A. sculptum frequently occurs in sympatry with Amblyomma dubitatum ticks, sharing the same hosts with them. Considering that A. dubitatum ticks are frequently infected with Rickettsia bellii, a possible…

Evidence of infection in humans with Rickettsia typhi and Rickettsia felis in Catalonia in the Northeast of Spain.

Murine typhus is a cause of fever of intermediate duration in the south of Spain, where antibodies against Rickettsia typhi and Rickettsia felis were observed in humans. This study presents the first report from the northeast of Spain. Human serum samples were tested by serological test. R. typhi and R. felis seroprevalences were 8.8% and 3.2%, respectively.

Genotypic characterization of rickettsiae by DNA probes generated from Rickettsia prowazekii DNA.

Southern blot analysis of HindIII-cleaved rickettsial DNA was used for genotypic characterization of the typhus group (TG) species (R. prowazekii, R. typhi, R. canada) and a few species of the spotted fever group (SFG) rickettsiae (R. sibirica, R. conorii, R. akari). Four different DNA probes were employed. PBH11 and PBH13 probes were morphospecific HindIII fragments of R. prowazekii DNA. MW218 probe contained the gene for 51 K antigen and MW264 probe contained the citrate synthase gene of R. prowazekii. All the probes hybridized with the tested TG and SFG rickettsial DNAs, forming from 1 to 5…