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A prevalent alpha-proteobacterium Paracoccus sp. in a population of the Cayenne ticks (Amblyomma cajennense) from Rio de Janeiro, Brazil.

Machado-Ferreira E, Piesman J, Zeidner NS, Soares CA - Genet. Mol. Biol. (2012)

Bottom Line: As Rocky Mountain Spotted Fever is the most common tick-borne disease in South America, the presence of Rickettsia sp. in Amblyomma ticks is a possible indication of its endemicity in certain geographic regions.In the present work, bacterial DNA sequences related to Rickettsia amblyommii genes in A. dubitatum ticks, collected in the Brazilian state of Mato Grosso, were discovered.Whether Paracoccus sp. represents another group of pathogenic Rhodobacteraceae or simply plays a role in A. cajennense physiology, is unknown.

View Article: PubMed Central - PubMed

Affiliation: Laboratório de Genética Molecular de Eucariontes e Simbiontes, Departamento de Genética, Instituto de Biologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil. ; Laboratório de Referência Nacional em Vetores das Riquetsioses, Instituto Oswaldo Cruz-FioCruz, Rio de Janeiro, RJ, Brazil.

ABSTRACT
As Rocky Mountain Spotted Fever is the most common tick-borne disease in South America, the presence of Rickettsia sp. in Amblyomma ticks is a possible indication of its endemicity in certain geographic regions. In the present work, bacterial DNA sequences related to Rickettsia amblyommii genes in A. dubitatum ticks, collected in the Brazilian state of Mato Grosso, were discovered. Simultaneously, Paracoccus sp. was detected in aproximately 77% of A. cajennense specimens collected in Rio de Janeiro, Brazil. This is the first report of Paracoccus sp. infection in a specific tick population, and raises the possibility of these bacteria being maintained and/or transmitted by ticks. Whether Paracoccus sp. represents another group of pathogenic Rhodobacteraceae or simply plays a role in A. cajennense physiology, is unknown. The data also demonstrate that the rickettsial 16S rRNA specific primers used forRickettsia spp. screening can also detect Paracoccus alpha-proteobacteria infection in biological samples. Hence, a PCR-RFLP strategy is presented to distinguish between these two groups of bacteria.

No MeSH data available.


Related in: MedlinePlus

Agarose gel of 16S rDNA PCR products digested with HinfI. PCR reactions were achieved using the Rickettsia spp. specific primer set, as described in the text. Lanes include amplicon digestions for Rickettsia sp. A45 (Lane 1) and Paracoccus sp-Cayenne (Lane 2), as well as the tick-total DNA samples Cav22F and Cav49F (Lanes 3–4). The non-digested PCR product for Cav49F was run in parallel (Lane 5). The molecular marker is presented in base pairs (bp). The expected bands for the Rickettsia sample include the 195 bp, 117 bp and 124 bp bands, the last two appearing as a single band in the gels. The Paracoccus sp-Cayenne expected profile includes the bands of 297 bp and 100 bp, as well as the faint band of 25 bp, not observed in the gels.
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f2-gmb-35-862: Agarose gel of 16S rDNA PCR products digested with HinfI. PCR reactions were achieved using the Rickettsia spp. specific primer set, as described in the text. Lanes include amplicon digestions for Rickettsia sp. A45 (Lane 1) and Paracoccus sp-Cayenne (Lane 2), as well as the tick-total DNA samples Cav22F and Cav49F (Lanes 3–4). The non-digested PCR product for Cav49F was run in parallel (Lane 5). The molecular marker is presented in base pairs (bp). The expected bands for the Rickettsia sample include the 195 bp, 117 bp and 124 bp bands, the last two appearing as a single band in the gels. The Paracoccus sp-Cayenne expected profile includes the bands of 297 bp and 100 bp, as well as the faint band of 25 bp, not observed in the gels.

Mentions: In the Major-94 group, DNA samples from the 55 A. cajennense ticks collected in Sambaetiba (RJ) yielded numerous spurious PCR bands. According to initial-replicon analysis, re-amplification and sequencing, they were not identical to either Rickettsia sp., or to any other bacterial DNA. From these apparently positive samples, 17 tick-bulk DNA samples were also PCR analyzed, in an attempt to detect ompA, ompB, htrA and gltA genes. No amplification was obtained, confirming that they were in fact free of Rick-ettsia spp. (data not shown). Four randomly selected DNA samples of A. cajennense collected at Três Rios (RJ), and pertaining to the same group, were also sequenced and analyzed. Although these nucleotide sequences (GenBank EF531228) were all identical, there was no similarity to any Rickettsia spp. sequence. Even so, there was a close relationship to soil and invertebrate-associated alpha-proteobacteria Paracoccus spp., the latter mostly of the Paracoccus sp. SA5 strain (GenBank AY864654) and the soil P. alcaliphilus KTC002 (GenBank AJ294415), with 99% and 98% identity, respectively (Figure 1A). Thus, there is every indication that an A. cajennense population at Três Rios is infected with a specific Paracoccus sp. population, denoted here as “Paracoccus sp-Cayenne”. This bacterial population shows 96% 16S rRNA gene identity to the clinical P. yeeii strain G3060 (GenBank AY014179). PCR products from a total of 38 Três Rios tick samples, positive for the ∼430 bp 16S rDNA amplicon were subjected to additional endonuclease digestion. A RFLP strategy was designed to specifically assign these amplicons to either the Rickettsia or the Paracoccus 16S rDNA group. After analyzing the 16S rRNA gene sequences presented in Figure 1A, we observed that every Rickettsia 16S rRNA gene sequence included in the primer set fD1-Rc16S.452n amplicon generated the same HinfI digestion profile, with the presence of 117 bp, 124 bp and 195 bp bands, whereas all the Paracoccus sequences generated a profile with bands of 25 bp, 100 bp and 297 bp, this including P. sp-Cayenne. All 38 samples from Três Rios showed the typical restriction enzyme digestion profile expected for the Paracoccus group (Figure 2). The 14 Três Rios Cayenne-tick DNA samples were all negative for additional PCR reactions when using primer sets for ompA, ompB, gltA and htrA genes (data not shown), thereby confirming the absence of Rickettsia sp.


A prevalent alpha-proteobacterium Paracoccus sp. in a population of the Cayenne ticks (Amblyomma cajennense) from Rio de Janeiro, Brazil.

Machado-Ferreira E, Piesman J, Zeidner NS, Soares CA - Genet. Mol. Biol. (2012)

Agarose gel of 16S rDNA PCR products digested with HinfI. PCR reactions were achieved using the Rickettsia spp. specific primer set, as described in the text. Lanes include amplicon digestions for Rickettsia sp. A45 (Lane 1) and Paracoccus sp-Cayenne (Lane 2), as well as the tick-total DNA samples Cav22F and Cav49F (Lanes 3–4). The non-digested PCR product for Cav49F was run in parallel (Lane 5). The molecular marker is presented in base pairs (bp). The expected bands for the Rickettsia sample include the 195 bp, 117 bp and 124 bp bands, the last two appearing as a single band in the gels. The Paracoccus sp-Cayenne expected profile includes the bands of 297 bp and 100 bp, as well as the faint band of 25 bp, not observed in the gels.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3526095&req=5

f2-gmb-35-862: Agarose gel of 16S rDNA PCR products digested with HinfI. PCR reactions were achieved using the Rickettsia spp. specific primer set, as described in the text. Lanes include amplicon digestions for Rickettsia sp. A45 (Lane 1) and Paracoccus sp-Cayenne (Lane 2), as well as the tick-total DNA samples Cav22F and Cav49F (Lanes 3–4). The non-digested PCR product for Cav49F was run in parallel (Lane 5). The molecular marker is presented in base pairs (bp). The expected bands for the Rickettsia sample include the 195 bp, 117 bp and 124 bp bands, the last two appearing as a single band in the gels. The Paracoccus sp-Cayenne expected profile includes the bands of 297 bp and 100 bp, as well as the faint band of 25 bp, not observed in the gels.
Mentions: In the Major-94 group, DNA samples from the 55 A. cajennense ticks collected in Sambaetiba (RJ) yielded numerous spurious PCR bands. According to initial-replicon analysis, re-amplification and sequencing, they were not identical to either Rickettsia sp., or to any other bacterial DNA. From these apparently positive samples, 17 tick-bulk DNA samples were also PCR analyzed, in an attempt to detect ompA, ompB, htrA and gltA genes. No amplification was obtained, confirming that they were in fact free of Rick-ettsia spp. (data not shown). Four randomly selected DNA samples of A. cajennense collected at Três Rios (RJ), and pertaining to the same group, were also sequenced and analyzed. Although these nucleotide sequences (GenBank EF531228) were all identical, there was no similarity to any Rickettsia spp. sequence. Even so, there was a close relationship to soil and invertebrate-associated alpha-proteobacteria Paracoccus spp., the latter mostly of the Paracoccus sp. SA5 strain (GenBank AY864654) and the soil P. alcaliphilus KTC002 (GenBank AJ294415), with 99% and 98% identity, respectively (Figure 1A). Thus, there is every indication that an A. cajennense population at Três Rios is infected with a specific Paracoccus sp. population, denoted here as “Paracoccus sp-Cayenne”. This bacterial population shows 96% 16S rRNA gene identity to the clinical P. yeeii strain G3060 (GenBank AY014179). PCR products from a total of 38 Três Rios tick samples, positive for the ∼430 bp 16S rDNA amplicon were subjected to additional endonuclease digestion. A RFLP strategy was designed to specifically assign these amplicons to either the Rickettsia or the Paracoccus 16S rDNA group. After analyzing the 16S rRNA gene sequences presented in Figure 1A, we observed that every Rickettsia 16S rRNA gene sequence included in the primer set fD1-Rc16S.452n amplicon generated the same HinfI digestion profile, with the presence of 117 bp, 124 bp and 195 bp bands, whereas all the Paracoccus sequences generated a profile with bands of 25 bp, 100 bp and 297 bp, this including P. sp-Cayenne. All 38 samples from Três Rios showed the typical restriction enzyme digestion profile expected for the Paracoccus group (Figure 2). The 14 Três Rios Cayenne-tick DNA samples were all negative for additional PCR reactions when using primer sets for ompA, ompB, gltA and htrA genes (data not shown), thereby confirming the absence of Rickettsia sp.

Bottom Line: As Rocky Mountain Spotted Fever is the most common tick-borne disease in South America, the presence of Rickettsia sp. in Amblyomma ticks is a possible indication of its endemicity in certain geographic regions.In the present work, bacterial DNA sequences related to Rickettsia amblyommii genes in A. dubitatum ticks, collected in the Brazilian state of Mato Grosso, were discovered.Whether Paracoccus sp. represents another group of pathogenic Rhodobacteraceae or simply plays a role in A. cajennense physiology, is unknown.

View Article: PubMed Central - PubMed

Affiliation: Laboratório de Genética Molecular de Eucariontes e Simbiontes, Departamento de Genética, Instituto de Biologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil. ; Laboratório de Referência Nacional em Vetores das Riquetsioses, Instituto Oswaldo Cruz-FioCruz, Rio de Janeiro, RJ, Brazil.

ABSTRACT
As Rocky Mountain Spotted Fever is the most common tick-borne disease in South America, the presence of Rickettsia sp. in Amblyomma ticks is a possible indication of its endemicity in certain geographic regions. In the present work, bacterial DNA sequences related to Rickettsia amblyommii genes in A. dubitatum ticks, collected in the Brazilian state of Mato Grosso, were discovered. Simultaneously, Paracoccus sp. was detected in aproximately 77% of A. cajennense specimens collected in Rio de Janeiro, Brazil. This is the first report of Paracoccus sp. infection in a specific tick population, and raises the possibility of these bacteria being maintained and/or transmitted by ticks. Whether Paracoccus sp. represents another group of pathogenic Rhodobacteraceae or simply plays a role in A. cajennense physiology, is unknown. The data also demonstrate that the rickettsial 16S rRNA specific primers used forRickettsia spp. screening can also detect Paracoccus alpha-proteobacteria infection in biological samples. Hence, a PCR-RFLP strategy is presented to distinguish between these two groups of bacteria.

No MeSH data available.


Related in: MedlinePlus