scholarly journals Bacteriostatic and bactericidal activity of levofloxacin against Rickettsia rickettsii, Rickettsia conorii, 'Israeli spotted fever group rickettsia' and Coxiella burnetii

1997 ◽  
Vol 39 (6) ◽  
pp. 725-730 ◽  
Author(s):  
M. Maurin ◽  
D. Raoult
Keyword(s):  
Coxiella Burnetii ◽  
Bactericidal Activity ◽  
Spotted Fever ◽  
Rickettsia Conorii ◽  
Spotted Fever Group ◽  
Rickettsia Rickettsii ◽  
Spotted Fever Group Rickettsia

scholarly journals Isolation of an agent of the spotted fever group rickettsia from tick eggs in Madrid, Spain

1992 ◽  
Vol 108 (3) ◽  
pp. 555-557 ◽  
Author(s):  
C. Herrero ◽  
C. Pelaz ◽  
C. Martín-Bourgon
Keyword(s):  
Human Serum ◽  
Indirect Immunofluorescence ◽  
Spotted Fever ◽  
Vero Cells ◽  
Rickettsia Conorii ◽  
Spotted Fever Group ◽  
Suitable Material ◽  
Rural Villages ◽  
Spotted Fever Group Rickettsia

SUMMARYTicks recovered from dogs in rural villages around Madrid (Spain) were processed to isolate rickettsiae. One sample containing mixtures of ticks and four containing eggs, in which rickettsiae had been detected by indirect immunofluorescence with a human serum highly reactive toRickettsia conorii, were decontaminated, homogenized and inoculated onto Vero cells. Two egg samples yielded a cytopathic agent that reacted positively by immunofluorescence. One sample (14H) was successfully subcultured and identified as a member of the spotted fever group rickettsia. Tick eggs provide suitable material for isolation of rickettsia.

scholarly journals DETECTION OF A Rickettsia GENOTYPE RELATED TO THE OLD WORLD INFECTING Amblyomma sculptum TICK IN AN ENDEMIC AREA OF BRAZILIAN SPOTTED FEVER

2019 ◽  
Vol 48 (3) ◽  
pp. 161-169 ◽  
Author(s):  
Gilberto Gazêta ◽  
Tayra Sato ◽  
Nicole Moura-Martiniano ◽  
Vinícius Vizzoni ◽  
Arannadia Silva ◽  
...  
Keyword(s):  
Endemic Area ◽  
Spotted Fever ◽  
Epidemiological Surveillance ◽  
Southeastern Brazil ◽  
Spotted Fever Group ◽  
Rickettsia Rickettsii ◽  
Rickettsia Monacensis ◽  
Minas Gerais State ◽  
Brazilian Spotted Fever ◽  
Spotted Fever Group Rickettsia

Brazilian Spotted Fever is an important tick-borne disease caused by Rickettsia rickettsii and transmitted mainly by the human-biting tick Amblyomma sculptum. During an epidemiological surveillance in Pedro Leopoldo, an endemic area of Minas Gerais State, southeastern Brazil, ectoparasites were collected from vertebrate hosts and from the environment. Rickettsial genes were obtained from a male A. sculptum and the resulting phylogenetic tree grouped this bacterium with Rickettsia sp. isolate Pampulha, a strain closely related to the pathogenic species Rickettsia tamurae and Rickettsia monacensis. This is the first report of sequencesphylogenetically related to R. tamurae and R. monacensis infecting A. sculptum in Brazil. KEY WORDS: Spotted Fever Group Rickettsia; Amblyomma sculptum; Spotted Fever focus;Ixodidae; Brazil.

scholarly journals Seroprevalence of Rickettsia rickettsii and Rickettsia parkeri in dogs during a Brazilian Spotted Fever outbreak in the State of Rio de Janeiro

2018 ◽  
Vol 70 (3) ◽  
pp. 667-674 ◽  
Author(s):  
I.T. Poubel ◽  
N.C. Cunha ◽  
A.B.M. Fonseca ◽  
A. Pinter ◽  
A.H. Fonseca ◽  
...  
Keyword(s):  
Rio De Janeiro ◽  
Spotted Fever ◽  
Immunofluorescence Assay ◽  
Spotted Fever Group ◽  
Ambient Conditions ◽  
Rickettsia Parkeri ◽  
Rickettsia Rickettsii ◽  
Brazilian Spotted Fever ◽  
Spotted Fever Group Rickettsia ◽  
Janeiro State

ABSTRACT The present paper is the first to perform this evaluation in dogs from the cities of Natividade, Porciuncula and Varre-Sai. The aim of this study is to search for Spotted Fever Group Rickettsia in canine sera using indirect immunofluorescence assay and to identify the probable causative agent of sera reactions in animals. Of the 253 sampled canines, 67.59% (171/253) were seroreactive for Rickettsia rickettsii and 11.07% (28/253) for Rickettsia parkeri, both in dilution 1:64. Titration of tested sera against R. rickettsii antigens reached 1:131.072 and, for R. parkeri, 1:4.096. We conclude that dogs are important sentinels for R. rickettsii infection, and can be infected regardless of sex, age, the habit of visiting woodlands or being in direct contact with equines and capybaras. Serological diagnosis has highlighted many dogs infected by R. rickettsii, and ambient conditions, such as the presence of flowing water bodies, was important for the occurrence of Brazilian Spotted Fever in the northwestern of Rio de Janeiro State.

scholarly journals Serosurvey of antibodies against spotted fever group Rickettsia spp. in horse farms in Northern Paraná, Brazil

2010 ◽  
Vol 19 (4) ◽  
pp. 259-261 ◽  
Author(s):  
Katia Tamekuni ◽  
Roberta dos Santos Toledo ◽  
Mauro de Freitas Silva Filho ◽  
Valeska Bender Haydu ◽  
Richard Campos Pacheco ◽  
...  
Keyword(s):  
Spotted Fever ◽  
Immunofluorescence Assay ◽  
Spotted Fever Group ◽  
Santa Fe ◽  
Southern Brazil ◽  
Seropositivity Rate ◽  
Rickettsia Rickettsii ◽  
Horse Farms ◽  
Brazilian Spotted Fever ◽  
Spotted Fever Group Rickettsia

Brazilian spotted fever (BSF) is an emerging disease most likely caused by Rickettsia rickettsii. The objective of the present study was to estimate the seroprevalence of BSF rickettsia infections in equines from six horse farms located in Londrina County, Paraná, Southern Brazil. Six owners of horse farms situated in Cambé, Santa Fé, Guaraci and Londrina municipalities participated in the study. All farms were located in areas where BSF has not been reported. A total of 273 horses were sampled and their sera were tested by indirect Immunofluorescence assay (IFA) using R. rickettsii and R. parkeri antigens. Titers equal to and greater than 64 were considered positive. Of 273 sera tested, 15 (5.5%) reacted to R. rickettsii and 5 (1.8%) to R. parkeri. Five out of the six farms studied revealed seropositive animals and seropositivity rate ranged from 0 to 13%. The titers ranged from 64 to 512, and four samples had a titer of 512. Nine animals reacted to R. rickettsii with titers four-fold higher than those for R. parkeri. These results suggest that horses in Northern Paraná may have been exposed to rickettsiae identical or closely related to R. rickettsii.

Mitbringsel aus den Ferien

Praxis ◽  
2005 ◽  
Vol 94 (47) ◽  
pp. 1869-1870
Author(s):  
Balestra ◽  
Nüesch
Keyword(s):  
Rocky Mountains ◽  
Spotted Fever ◽  
Rocky Mountain ◽  
Rickettsia Conorii ◽  
Rocky Mountain Spotted Fever ◽  
Klinische Diagnose ◽  
Rickettsia Rickettsii

Eine 37-jährige Patientin stellt sich nach der Rückkehr von einer Rundreise durch Nordamerika mit einem Status febrilis seit zehn Tagen und einem makulösem extremitätenbetontem Exanthem seit einem Tag vor. Bei suggestiver Klinik und Besuch der Rocky Mountains wird ein Rocky Mountain spotted fever diagnostiziert. Die Serologie für Rickettsia conorii, die mit Rickettsia rickettsii kreuzreagiert, war positiv und bestätigte die klinische Diagnose. Allerdings konnte der beweisende vierfache Titeranstieg, möglicherweise wegen spät abgenommener ersten Serologie, nicht nachgewiesen werden. Nach zweiwöchiger antibiotischer Therapie mit Doxycycline waren Status febrilis und Exanthem regredient.

scholarly journals Quantitative Analyses of Variations in the Injury of Endothelial Cells Elicited by 11 Isolates of Rickettsia rickettsii

2001 ◽  
Vol 8 (4) ◽  
pp. 788-796 ◽  
Author(s):  
Marina E. Eremeeva ◽  
Gregory A. Dasch ◽  
David J. Silverman
Keyword(s):  
North Carolina ◽  
Endothelial Cells ◽  
Reduced Glutathione ◽  
Spotted Fever ◽  
Ixodid Ticks ◽  
Spotted Fever Group ◽  
Cellular Injury ◽  
Rickettsia Rickettsii ◽  
Cytopathic Effects ◽  
Group I

ABSTRACT Eleven isolates of spotted fever group rickettsiae from the blood of patients or ixodid ticks from North and South America were characterized. All isolates were identified as Rickettsia rickettsii using restriction fragment length polymorphism analysis of a 532-bp rOmpA gene fragment obtained by PCR. The ability of the R. rickettsii isolates to elicit cytopathic effects and parameters of oxidative injury were examined in cultured human EA.hy 926 endothelial cells. Cytopathic effects were determined by direct observation of infected cultures, by measuring the release of cytoplasmic lactate dehydrogenase (LDH), and by determination of intracellular pools of peroxide and reduced glutathione. Four biotypes of R. rickettsii were defined. Group I included two highly cytopathic isolates from Montana, Bitterroot and Sheila Smith, and three isolates from Maryland, North Carolina, and Brazil. These isolates rapidly damaged cells, released large amounts of cytoplasmic LDH, caused accumulation of intracellular peroxide, and depleted intracellular pools of reduced glutathione. Group II contained three isolates, two from Montana, Hlp#2 and Lost Horse Canyon, and an isolate from Colombia, which were similar to group I but caused either lower responses in LDH release or smaller changes in intracellular peroxide levels. The group III isolates, Sawtooth from Montana and 84JG from North Carolina, caused lower cellular injury by all measures. Group IV isolate Price T from Montana was the least cytopathic and caused minimal alterations of all parameters measured. Understanding the molecular basis for the varied cellular injury caused by different isolates of R. rickettsii may contribute to improved treatment of Rocky Mountain spotted fever and to the rapid identification of those isolates which are more likely to cause fulminant disease.

scholarly journals Significant Growth by Rickettsia Species within Human Macrophage-Like Cells Is a Phenotype Correlated with the Ability to Cause Disease in Mammals

Pathogens ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 228
Author(s):  
M. Nathan Kristof ◽  
Paige E. Allen ◽  
Lane D. Yutzy ◽  
Brandon Thibodaux ◽  
Christopher D. Paddock ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Spotted Fever ◽  
Growth Characteristic ◽  
Human Macrophage ◽  
Rickettsia Conorii ◽  
Spotted Fever Group ◽  
Rocky Mountain Spotted Fever ◽  
Phagocytic Cells ◽  
Pathogenic Potential ◽  
Rickettsia Species

Rickettsia are significant sources of tick-borne diseases in humans worldwide. In North America, two species in the spotted fever group of Rickettsia have been conclusively associated with disease of humans: Rickettsia rickettsii, the causative agent of Rocky Mountain spotted fever, and Rickettsia parkeri, the cause of R. parkeri rickettsiosis. Previous work in our lab demonstrated non-endothelial parasitism by another pathogenic SFG Rickettsia species, Rickettsia conorii, within THP-1-derived macrophages, and we have hypothesized that this growth characteristic may be an underappreciated aspect of rickettsial pathogenesis in mammalian hosts. In this work, we demonstrated that multiple other recognized human pathogenic species of Rickettsia, including R. rickettsii, R. parkeri, Rickettsia africae, and Rickettsiaakari can grow within target endothelial cells as well as within PMA-differentiated THP-1 cells. In contrast, Rickettsia bellii, a Rickettsia species not associated with disease of humans, and R. rickettsii strain Iowa, an avirulent derivative of pathogenic R. rickettsii, could invade both cell types but proliferate only within endothelial cells. Further analysis revealed that similar to previous studies on R. conorii, other recognized pathogenic Rickettsia species could grow within the cytosol of THP-1-derived macrophages and avoided localization with two different markers of lysosomal compartments; LAMP-2 and cathepsin D. R. bellii, on the other hand, demonstrated significant co-localization with lysosomal compartments. Collectively, these findings suggest that the ability of pathogenic rickettsial species to establish a niche within macrophage-like cells could be an important factor in their ability to cause disease in mammals. These findings also suggest that analysis of growth within mammalian phagocytic cells may be useful to predict the pathogenic potential of newly isolated and identified Rickettsia species.

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