Search results for "Rickettsiaceae"

Persistence of Antibodies to Rickettsia conorii After an Acute Attack of Boutonneuse Fever

1985

Circulating immune complexes in Fièvre boutonneuse.

1985

Circulating immune complexes (CIC) occurred in 36% of a group of 25 patients with Fièvre boutonneuse. CIC were present only in the first week of the disease and there was no evidence of other humoral immunological abnormalities or alterations of the coagulation factors studied. The presence of CIC was not associated with a more severe clinical manifestation or with symptoms or tissue injuries. It is considered that CIC do not play a major role in Fièvre boutonneuse.

Presence of Rickettsia conorii subsp. israelensis , the Causative Agent of Israeli Spotted Fever, in Sicily, Italy, Ascertained in a Retrospective St…

2005

ABSTRACT A retrospective analysis by molecular-sequence-based techniques was performed to correctly identify the etiological agent of 24 Mediterranean spotted fever cases occurring in Western Sicily, Italy, from 1987 to 2001. Restriction analysis of a 632-bp PCR-amplified portion of the ompA gene allowed presumptive identification of five clinical isolates as belonging to Rickettsia conorii subsp. israelensis , the etiological agent of Israeli spotted fever (ISF). The remaining 19 rickettsial isolates were Rickettsia conorii subsp. conorii , the only pathogenic rickettsia of the spotted fever group reported in Italy until the present. Sequence analysis of the ompA gene confirmed the identif…

Rickettsiae of the spotted fever group in dog fleas (Ctenocephalides spp.) in Western Sicily

1989

Subclinical Infections with Boutonneuse Fever in Western Sicily

1985

New Insight into Immunity and Immunopathology of Rickettsial Diseases

2011

Human rickettsial diseases comprise a variety of clinical entities caused by microorganisms belonging to the generaRickettsia,Orientia,Ehrlichia, andAnaplasma. These microorganisms are characterized by a strictly intracellular location which has, for long, impaired their detailed study. In this paper, the critical steps taken by these microorganisms to play their pathogenic roles are discussed in detail on the basis of recent advances in our understanding of molecularRickettsia-host interactions, preferential target cells, virulence mechanisms, three-dimensional structures of bacteria effector proteins, upstream signalling pathways and signal transduction systems, and modulation of gene exp…

Geographic distribution and inheritance of three cytoplasmic incompatibility types in Drosophila simulans.

1991

Abstract Wolbachia-like microorganisms have been implicated in unidirectional cytoplasmic incompatibility between strains of Drosophila simulans. Reduced egg eclosion occurs when females from uninfected strains (type W) are crossed with males from infected strains (type R). Here we characterize a third incompatibility type (type S) which is also correlated with the presence of Wolbachia-like microorganisms. Despite the fact that the symbionts cannot be morphologically distinguished, we observed complete bidirectional incompatibility between R and S strains. This indicates that the determinants of incompatibility are different in the two infected types. S/W incompatibility is unidirectional …

Multi-infections of feminizing Wolbachia strains in natural populations of the terrestrial isopod Armadillidium vulgare.

2013

7 pages; International audience; Maternally inherited Wolbachia (α-Proteobacteria) are widespread parasitic reproductive manipulators. A growing number of studies have described the presence of different Wolbachia strains within a same host. To date, no naturally occurring multiple infections have been recorded in terrestrial isopods. This is true for Armadillidium vulgare which is known to harbor non simultaneously three Wolbachia strains. Traditionally, such Wolbachia are detected by PCR amplification of the wsp gene and strains are characterized by sequencing. The presence of nucleotide deletions or insertions within the wsp gene, among these three different strains, provides the opportu…

Demonstration of spotted fever group rickettsiae in the tache noire of a healthy person in Sicily.

1984

A human case of rickettsial infection occurred in Sicily following tick bite. The patient did not have fever, the typical nodular rash, or other symptoms of illness other than development of a tache noire containing spotted fever group rickettsiae, which were demonstrated by immunofluorescence. A high titer of antibodies of the IgG class suggests that the patient may have had previous exposure to Rickettsia conorii or a related spotted fever group rickettsia. An anamnestic response may be hypothesized to have conferred partial immunity, with resulting containment of rickettsiae at the site of inoculation.