Project description:A fatal case of Mediterranean spotted fever associated with septic shock was reported in a 61-year-old man living in a village in southeastern Iran. The patient had a history of tick bite a few days before symptom onset. Phylogenetic analysis confirmed infection by Rickettsia conorii subspecies israelensis.
Project description:Rickettsia microorganisms are causative agents of several neglected emerging infectious diseases in humans transmitted by arthropods including ticks. In this study, ticks were collected from four geographical regions of Uganda and pooled in sizes of 1-179 ticks based on location, tick species, life stage, host, and time of collection. Then, they were tested by real-time PCR for Rickettsia species with primers targeting gltA, 17kDa and ompA genes, followed by Sanger sequencing of the 17kDa and ompA genes. Of the 471 tick pools tested, 116 (24.6%) were positive for Rickettsia spp. by the gltA primers. The prevalence of Rickettsia varied by district with Gulu recording the highest (30.1%) followed by Luwero (28.1%) and Kasese had the lowest (14%). Tick pools from livestock (cattle, goats, sheep, and pigs) had the highest positivity rate, 26.9%, followed by vegetation, 23.1%, and pets (dogs and cats), 19.7%. Of 116 gltA-positive tick pools, 86 pools were positive using 17kDa primers of which 48 purified PCR products were successfully sequenced. The predominant Rickettsia spp. identified was R. africae (n = 15) in four tick species, followed by R. conorii (n = 5) in three tick species (Haemaphysalis elliptica, Rhipicephalus appendiculatus, and Rh. decoloratus). Rickettsia conorii subsp. israelensis was detected in one tick pool. These findings indicate that multiple Rickettsia spp. capable of causing human illness are circulating in the four diverse geographical regions of Uganda including new strains previously known to occur in the Mediterranean region. Physicians should be informed about Rickettsia spp. as potential causes of acute febrile illnesses in these regions. Continued and expanded surveillance is essential to further identify and locate potential hotspots with Rickettsia spp. of concern.
Project description:The host response within the eschar of inoculation during Mediterranean spotted fever (MSF) has been poorly studied. Our objective was to evaluate the host response by comparing transcriptional profiles of eschars to controls using a whole-genome microarray. Hierarchical clustering revealed a signature of eschars consisting of 698 genes. The genes included in this signature were mainly up-regulated and were predominantly associated with immune response and signalling. New molecules involved notably in microbicidal and innate immunity response have also been found up-regulated in eschars such as MMP1, Defensin β4, the proinflammatory S100A9, and the T cell attracting CCL-18. Genes down-regulated were mainly associated with biological regulation. We also observed that eschars from severe cases of MSF displayed a specific signature with notably difference in degree of modulation compared to eschars from non severe MSF cases. Some parameters identified in this work should be tested as biomarkers for prognostic assessment in future studies.
Project description:The host response within the eschar of inoculation during Mediterranean spotted fever (MSF) has been poorly studied. Our objective was to evaluate the host response by comparing transcriptional profiles of eschars to controls using a whole-genome microarray. Hierarchical clustering revealed a signature of eschars consisting of 698 genes. The genes included in this signature were mainly up-regulated and were predominantly associated with immune response and signalling. New molecules involved notably in microbicidal and innate immunity response have also been found up-regulated in eschars such as MMP1, Defensin β4, the proinflammatory S100A9, and the T cell attracting CCL-18. Genes down-regulated were mainly associated with biological regulation. We also observed that eschars from severe cases of MSF displayed a specific signature with notably difference in degree of modulation compared to eschars from non severe MSF cases. Some parameters identified in this work should be tested as biomarkers for prognostic assessment in future studies. To evaluate the host response by comparing transcriptional profiles of eschars to controls
Project description:We sequenced DNA from spleens of rodents captured in rural areas of Qingdao, East China, during 2013-2015. We found 1 Apodemus agrarius mouse infected with Rickettsia conorii, indicating a natural Mediterranean spotted fever foci exists in East China and that the range of R. conorii could be expanding.
Project description:We report a series of 5 case-patients who had Israeli spotted fever, of whom 2 had purpura fulminans and died. Four case-patients were given a diagnosis on the basis of PCR of skin biopsy specimens 3-4 days after treatment with doxycycline; 1 case-patient was given a diagnosis on the basis of seroconversion. Rickettsia spp. from the 2 case-patients who died were sequenced and identified as Rickettsia conorii subsp. israelensis. Purpura fulminans has been described in association with R. rickettsii and R. indica, but rarely with R. conorii subsp. israelensis.