Exemplar Abstract for Rickettsia africae Kelly et al. 1996.

ABSTRACTTicks are important disease vectors that can cause considerable economic losses by affecting animal health and productivity, especially in tropical and subtropical regions. In this study, we investigated the prevalence and diversity of bacterial and protozoan tick-borne pathogens in ticks collected from the vegetation and cattle in Nigeria by PCR. The infection rates of questing ticks were 3.1% forRickettsiaspecies, 0.1% forCoxiella burnetiiand 0.4% forBorreliaspecies. Other pathogens, such asBabesia,Theileria,Anaplasma, andEhrlichiaspecies, were not detected in ticks from the vegetation. Feeding ticks collected from cattle displayed infection rates of 12.5% forRickettsiaspecies, 14% forCoxiella burnetii, 5.9% forAnaplasmaspecies, 5.1% forEhrlichiaspecies, and 2.9% forTheileria mutans. BabesiaandBorreliaspecies were not detected in ticks collected from cattle. Mixed infections were found only in feeding ticks and mainlyRickettsiaspecies andCoxiella burnetiiwere involved. The diversity of tick-borne pathogens in Nigeria was higher in feeding than in questing ticks, suggesting that cattle serve as reservoirs for at least some of the pathogens studied, in particularC. burnetii. The total estimated herd infection rates of 20.6% for aRickettsia africae-like species, 27% forCoxiella burnetii, and 8.5% forAnaplasma marginale/centralesuggest that these pathogens may have considerable implications for human and animal health.

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Clinical, epidemiological, and laboratory features of Rickettsia africae infection, African tick-bite fever: A systematic review

Infezioni in Medicina ◽

10.53854/liim-2903-7 ◽

2021 ◽

Vol 29 (3) ◽

pp. 366-377

Keyword(s):

Systematic Review ◽

Tick Bite ◽

Rickettsia Africae ◽

African Tick Bite Fever ◽

Laboratory Features ◽

Tick Bite Fever

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Taxonomic Relationships among Spotted Fever Group Rickettsiae as Revealed by Antigenic Analysis with Monoclonal Antibodies

Journal of Clinical Microbiology ◽

10.1128/jcm.36.4.887-896.1998 ◽

1998 ◽

Vol 36 (4) ◽

pp. 887-896 ◽

Cited By ~ 18

Author(s):

Wenbin Xu ◽

Didier Raoult

Keyword(s):

Monoclonal Antibodies ◽

Phylogenetic Analyses ◽

Spotted Fever ◽

Rickettsia Conorii ◽

Spotted Fever Group ◽

Antigenic Analysis ◽

Taxonomic Relationships ◽

Rickettsia Africae ◽

Rickettsia Slovaca ◽

Rickettsia Sibirica

The spotted fever group (SFG) is made up of more than 20 different rickettsial species and strains. Study of the taxonomic relationships among the group has been attempted by phenotypic, genotypic, and phylogenetic analyses. In this study, we determined taxonomic relationships among the SFG rickettsiae by comparative analysis of immunogenic epitopes reactive against a panel of monoclonal antibodies. A total of 98 monoclonal antibodies, which were directed against epitopes on the major immunodominant proteins or on the lipopolysaccharide-like antigens of strains of Rickettsia africae, Rickettsia conorii, Rickettsia massiliae, Rickettsia akari, Rickettsia sibirica, and Rickettsia slovaca, were used in the study. The distribution and expression of the epitopes among 29 SFG rickettsiae and Rickettsia bellii were assessed by determination of reaction titers in a microimmunofluorescence assay. The results were scored as numerical taxonomic data, and cluster analysis was used to construct a dendrogram. The architecture of this dendrogram was consistent with previous taxonomic studies, and the implications of this and other findings are discussed.

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