Detection of Rickettsia in Rhipicephalus sanguineus Ticks and Ctenocephalides felis Fleas from Southeastern Tunisia by Reverse Line Blot Assay

Khrouf, Fatma; M’ghirbi, Youmna; Znazen, Abir; Jemâa, Mounir Ben; Hammami, Adnène; Bouattour, Ali

doi:10.1128/jcm.01925-13

Cited by 28 publications

(17 citation statements)

References 36 publications

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“…In addition , Rickettsia spp. was identified, not only, in other several ixodid tick species as Amblyomma gemma (Koka et al, ), Dermacentor variabilis (3.6%) (Ammerman et al, ), Rhipicephalus sanguineus sensu lato (37.5%) (Khrouf et al, ) and Ixodes ricinus (38%) (Sfar et al, ), but also in the cat flea Ctenocephalides felis (0.3%) (Znazen et al, ), the Trombiculidae mites infesting rodents (32.46%) (Miťková et al, ) and the ovine blood‐sucking fly Melophagus ovinus (12.63%) (Liu et al, ). This may consolidate the major role of arthropod vectors, particularly ticks, in rickettsial spread (Parola et al, ).…”

Section: Discussionmentioning

confidence: 99%

“…Furthermore, potential zoonotic Rickettsia species were identified in ticks collected from Tunisia, namely R. monacensis and R. helvetica from Ixodes ricinus (Sfar et al, 2008), R. felis and R. conorii from the cat flea Ctenocephalides felis, R. conorii subsp. israelensis from Rhipicephalus sanguineus sensu lato (Khrouf et al, 2014;Znazen et al, 2013) and finally R. aeschlimannii from H. dromedarii (Demoncheaux et al, 2012).…”

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confidence: 99%

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Molecular epidemiology and phylogeny of spotted fever group Rickettsia in camels ( Camelus dromedarius ) and their infesting ticks from Tunisia

Selmi

Saïd

Yahia

et al. 2019

Transbound Emerg Dis

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Rickettsia species are adapted to a wide range of specific animal hosts. Camels (Camelus dromedarius) have been identified as a carrier of various zoonotic pathogens and became a focus of growing public health interest. This study reported the occurrence of rickettsial infection in camels and infesting ticks from five Tunisian governorates. Based on ompB PCR, eight out of 293 camels (2.7%) were found to be infected with Rickettsia spp. Furthermore, 13 tick specimens of Hyalomma impeltatum (10.4%) and 9 of H. dromedarii (8.0%) harboured DNA of Rickettsia bacteria with an overall prevalence rate of 9.2% (22/237). Molecular prevalence of Rickettsia infection varied significantly according to tick infestation for camels and among tick genders. Five rickettsial species, showing a potential public health interest, were revealed by sequencing. Based on ompB partial sequences, five species were identified corresponding to R. aeschlimannii, R. monacensis, R. helvetica and R. massiliae in camels and to R. africae, R. aeschlimannii, R. monacensis and R. helvetica in ticks. Based on ompA typing, three species were revealed corresponding to R. africae and R. monacensis in camels and to R. africae, R. aeschlimannii and R. monacensis in ticks. This is the first report consolidating the hypothesis that camels may serve as potential hosts for Rickettsia spp. and Hyalomma spp. ticks as possible vectors in arid and Saharan areas of Tunisia. The present data highlight the importance of preventive measures and survey that must be implemented in camel herds in order to limit the spread of these vector‐borne bacteria to animals and humans.

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Section: Discussionmentioning

confidence: 99%

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confidence: 99%

Molecular epidemiology and phylogeny of spotted fever group Rickettsia in camels ( Camelus dromedarius ) and their infesting ticks from Tunisia

Selmi

Saïd

Yahia

et al. 2019

Transbound Emerg Dis

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“…Thus, R. conorii , R. typhi, R. aeschlimannii and R. felis were characterized by serology [ 5 , 6 ]. Using molecular methods, R. conorii subsp conorii and R. conorii subsp israelensis were detected in humans [ 7 , 8 ], R. monacensis and R. helvetica in Ixodes ricinus [ 9 ] and recently R. massiliae in Rhipicephalus sanguineus [ 10 ].…”

Section: Introductionmentioning

confidence: 99%

Multispacer typing of Rickettsia isolates from humans and ticks in Tunisia revealing new genotypes

et al. 2013

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BackgroundRickettsioses are important remerging vector born infections. In Tunisia, many species have been described in humans and vectors. Genotyping is important for tracking pathogen movement between hosts and vectors. In this study, we characterized Rickettsia species detected in patients and vectors using multispacer typing (MST), proposed by Founier et al. and based on three intergenic spacers (dksA-xerC, rmpE- tRNAfMet, mppA-pruC) sequencing.MethodsOur study included 25 patients hospitalized during 2009. Ticks and fleas were collected in the vicinity of confirmed cases. Serology was performed on serum samples by microimmunofluorescence using Rickettsia conorii and Rickettsia typhi antigens. To detect and identify Rickettsia species, PCR targeting ompA, ompB and gltA genes followed by sequencing was performed on 18 obtained skin biopsies and on all collected vectors. Rickettsia positive samples were further characterized using primers targeting three intergenic spacers (dksA-xerC, rmpE- tRNAfMet and mppA-purC).ResultsA rickettsial infection was confirmed in 15 cases (60%). Serology was positive in 13 cases (52%). PCR detected Rickettsia DNA in four biopsies (16%) allowing the identification of R. conorii subsp israelensis in three cases and R. conorii subsp conorii in one case. Among 380 collected ticks, nine presented positive PCR (2.4%) allowing the identification of six R. conorii subsp israelensis, two R. massiliae and one R. conorii subsp conorii. Among 322 collected fleas, only one was positive for R. felis. R. conorii subsp israelensis strains detected in humans and vectors clustered together and showed a new MST genotype. Similarly, R. conorii subsp conorii strains detected in a skin biopsy and a tick were genetically related and presented a new MST genotype.ConclusionsNew Rickettsia spotted fever strain genotypes were found in Tunisia. Isolates detected in humans and vectors were genetically homogenous despite location differences in their original isolation suggesting epidemiologic circulation of these strains.

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“…The PCR-RLB assay has been shown to be a sensitive and specific assay for detection and identification of pathogenic and nonpathogenic Rickettsia spp. ( 22 , 23 , 46 , 47 ). Notably, adding a nested step in the PCR amplification of the 23S-5S IGS fragments substantially improved the sensitivity of the assay for detection of rickettsiae at low abundance.…”

Section: Discussionmentioning

confidence: 99%

Development and Validation of an Improved PCR Method Using the 23S-5S Intergenic Spacer for Detection of Rickettsiae in Dermacentor variabilis Ticks and Tissue Samples from Humans and Laboratory Animals

et al. 2016

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A novel nested PCR assay was developed to detect Rickettsia spp. in ticks and tissue samples from humans and laboratory animals. Primers were designed for the nested run to amplify a variable region of the 23S-5S intergenic spacer (IGS) of Rickettsia spp. The newly designed primers were evaluated using genomic DNA from 11 Rickettsia species belonging to the spotted fever, typhus, and ancestral groups and, in parallel, compared to other Rickettsia-specific PCR targets (ompA, gltA, and the 17-kDa protein gene). The new 23S-5S IGS nested PCR assay amplified all 11 Rickettsia spp., but the assays employing other PCR targets did not. The novel nested assay was sensitive enough to detect one copy of a cloned 23S-5S IGS fragment from “Candidatus Rickettsia amblyommii.” Subsequently, the detection efficiency of the 23S-5S IGS nested assay was compared to those of the other three assays using genomic DNA extracted from 40 adult Dermacentor variabilis ticks. The nested 23S-5S IGS assay detected Rickettsia DNA in 45% of the ticks, while the amplification rates of the other three assays ranged between 5 and 20%. The novel PCR assay was validated using clinical samples from humans and laboratory animals that were known to be infected with pathogenic species of Rickettsia. The nested 23S-5S IGS PCR assay was coupled with reverse line blot hybridization with species-specific probes for high-throughput detection and simultaneous identification of the species of Rickettsia in the ticks. “Candidatus Rickettsia amblyommii,” R. montanensis, R. felis, and R. bellii were frequently identified species, along with some potentially novel Rickettsia strains that were closely related to R. bellii and R. conorii.

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Detection of Rickettsia in Rhipicephalus sanguineus Ticks and Ctenocephalides felis Fleas from Southeastern Tunisia by Reverse Line Blot Assay

Cited by 28 publications

References 36 publications

Molecular epidemiology and phylogeny of spotted fever group Rickettsia in camels ( Camelus dromedarius ) and their infesting ticks from Tunisia

Molecular epidemiology and phylogeny of spotted fever group Rickettsia in camels ( Camelus dromedarius ) and their infesting ticks from Tunisia

Multispacer typing of Rickettsia isolates from humans and ticks in Tunisia revealing new genotypes

Development and Validation of an Improved PCR Method Using the 23S-5S Intergenic Spacer for Detection of Rickettsiae in Dermacentor variabilis Ticks and Tissue Samples from Humans and Laboratory Animals

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