Project description:Santa Catarina State in southern Brazil is the state with the second highest number of laboratory-confirmed cases of spotted fever illness in Brazil. However, all these cases were confirmed solely by serological analysis (seroconversion to spotted fever group rickettsiae), which has not allowed identification of the rickettsial agent. Here, a clinical case of spotted fever illness from Santa Catarina is shown by seroconversion and molecular analysis to be caused by Rickettsia sp. strain Atlantic rainforest. This is the third confirmed clinical case due to this emerging rickettsial agent in Brazil. Like the previous two cases, the patient presented an inoculation eschar at the tick bite site. Our molecular diagnosis was performed on DNA extracted from the crust removed from the eschar. These results are supported by previous epidemiological studies in Santa Catarina, which showed that nearly 10% of the most common human-biting ticks were infected by Rickettsia sp. strain Atlantic rainforest.

| S-EPMC5014257 | biostudies-literature

Genetic diversity of bats coronaviruses in the Atlantic Forest hotspot biome, Brazil.

Project description:Bats are notorious reservoirs of genetically-diverse and high-profile pathogens, and are playing crucial roles in the emergence and re-emergence of viruses, both in human and in animals. In this report, we identified and characterized previously unknown and diverse genetic clusters of bat coronaviruses in the Atlantic Forest Biome, Brazil. These results highlight the virus richness of bats and their possible roles in the public health.

| S-EPMC7106056 | biostudies-literature

Spotted fever group Rickettsia sp. closely related to Rickettsia japonica, Thailand.

Project description: Not available

| S-EPMC2671449 | biostudies-literature

Successional, spatial, and seasonal changes in seed rain in the Atlantic forest of southern Bahia, Brazil.

Project description:Seed arrival is a limiting factor for the regeneration of diverse tropical forests and may be an important mechanism that drives patterns of tree species' distribution. Here we quantify spatial and seasonal variation in seed rain of secondary forests in southern Bahia, Brazil. We also examine whether secondary forest age enhances seed dispersal and whether seed rain density and diversity in secondary forests decay with distance from mature forest. Across a chronosequence of 15 pairs of mature and secondary forests, 105 seed traps were installed and monitored for one year. We tested the effects of secondary forest age, distance from mature forest, and seasonality on monthly seed rain density, diversity, seed dispersal mode, and diaspore size. We found that secondary forest age had strong, positive effects on the diversity of seed rain, which was generally higher during the wet season. Moreover, contrasting patterns among diversity indices revealed that seeds of rare species occurred more often in 40 yr old secondary forests and mature forests. While the proportion of biotically and abiotically dispersed seeds did not change significantly with distance from mature forest across all forest age classes, we found that biotically dispersed seeds contributed disproportionately more to seed rain diversity. Our results emphasize the importance of biotic dispersal to enhance diversity during secondary succession and suggest that changes in secondary forest structure have the potential to enhance the diversity of tropical secondary forests, principally by increasing dispersal of rare species.

| S-EPMC6913908 | biostudies-literature

Circulation of canine parvovirus among dogs living in human-wildlife interface in the Atlantic forest biome, Brazil.

Project description:Despite of the role of domestic dogs as reservoirs for threatening viral diseases for wild carnivores, few studies have focused to identify circulation of viruses among dogs living in human/wildlife interfaces. To identify canine parvovirus (CPV) types circulating in dogs living in an Atlantic forest biome, faecal samples (n = 100) were collected at the same period (one week) corresponding to each of four areas, during 2014 to 2016 and corresponded to 100 different individuals. CPV was isolated in cell culture from 67 out 100 (67%) samples from healthy dogs. Cytopathic effects were characterized by total or partial cell culture lysis. Genome sequences of CPV-2a (10%), CPV-2b (7%) and CPV-2c (50%) were concomitantly detected by PCR and nucleotide sequencing. The current study addresses the importance of monitoring CPV circulation among dogs presenting potential contact with wildlife species.

| S-EPMC5772843 | biostudies-literature

Spotted-fever group Rickettsia in Dermacentor variabilis, Maryland.

Project description:Three-hundred ninety-two adult Dermacentor variabilis were collected from six Maryland counties during the spring, summer, and fall of 2002. Infection prevalence for spotted fever group Rickettsia was 3.8%, as determined by polymerase chain reaction. Single strand conformational polymorphism (SSCP) analysis followed by sequencing indicated that all infections represented a single rickettsial taxon, Rickettsia montanensis.

| S-EPMC3320417 | biostudies-literature

Novel spotted fever group rickettsiosis, Brazil.

Project description:We report a clinical case of spotted fever group rickettsiosis acquired in Sao Paulo, Brazil. Definitive diagnosis was supported by seroconversion between acute-phase and convalescent-phase serum samples. Molecular analysis of skin samples indicated the agent was a novel spotted fever group strain closely related to Rickettsia africae, R. parkeri, and R. sibirica.

| S-EPMC3322033 | biostudies-literature

Cutaneous Immunoprofiles of Three Spotted Fever Group Rickettsia Cases.

Project description:Spotted fever group rickettsia (SFGR) can cause mild to fatal illness. The early interaction between the host and rickettsia in skin is largely unknown, and the pathogenesis of severe rickettsiosis remains an important topic. A surveillance of SFGR infection by PCR of blood and skin biopsy specimens followed by sequencing and immunohistochemical (IHC) detection was performed on patients with a recent tick bite between 2013 and 2016. Humoral and cutaneous immunoprofiles were evaluated in different SFGR cases by serum cytokine and chemokine detection, skin IHC staining, and transcriptome sequencing (RNA-seq). A total of 111 SFGR cases were identified, including 79 "Candidatus Rickettsia tarasevichiae," 22 Rickettsia raoultii, 8 Rickettsia sibirica, and 2 Rickettsia heilongjiangensis cases. The sensitivity to detect SFGR in skin biopsy specimens (9/24, 37.5%) was significantly higher than that in blood samples (105/2,671, 3.9%) (P < 0.05). As early as 1 day after the tick bite, rickettsiae could be detected in the skin. R. sibirica infection was more severe than "Ca Rickettsia" and R. raoultii infections. Increased levels of serum interleukin-18 (IL-18), IP10, and monokine induced by gamma interferon (MIG) and decreased levels of IL-2 were observed in febrile patients infected with R. sibirica compared to those infected with "Ca Rickettsia." RNA-seq and IHC staining could not discriminate between SFGR-infected and uninfected tick bite skin lesions. However, the type I interferon (IFN) response was differently expressed between R. sibirica and R. raoultii infections at the cutaneous interface. It is concluded that skin biopsy specimens were more reliable for the detection of SFGR infection in human patients although the immunoprofile may be complicated by immunomodulators induced by the tick bite.

| S-EPMC7093127 | biostudies-literature

Israeli spotted fever Rickettsia in Sicilian Rhipicephalus sanguineus ticks.

Project description: Not available

| S-EPMC3023446 | biostudies-literature