RESUMO
Acute respiratory tract infections are one of the leading causes of morbidity and mortality worldwide. More data are needed on circulating respiratory microorganisms in different geographical areas and ecosystems. We analyzed nasopharyngeal swabs from 500 febrile patients living in the Niakhar area (Senegal), using FTDTM multiplex qPCR and simplex qPCR to target a panel of 25 microorganisms. We detected at least one microorganism for 366/500 patients (73.2%), at least one virus for 193/500 (38.6%), and at least one bacterium for 324/500 (64.8%). The most frequently detected microorganisms were Streptococcus pneumoniae (36.8%), Haemophilus influenzae (35.8%), adenovirus (11.8%), influenza viruses (6.4%), rhinovirus (5.0%), SARS-CoV-2 (4.0%), and RSV (4.0%). The main microorganisms significantly associated with respiratory symptoms, with a p-value ≤ 0.05, were influenza virus (11.9% in patients with respiratory symptoms versus 2.9% in patients without), RSV (6.5% versus 2.6%), metapneumovirus (5.4% versus 1.3%), HPIVs (7.6% versus 1.0%), S. pneumoniae (51.9% versus 28.0%), and H. influenzae (54.6% versus 24.5%). Co-infections were significantly associated with respiratory symptoms (65.4% versus 32.9%). All the epidemiological data show a high level of circulation of respiratory pathogens among febrile patients, including those preventable by vaccination such as S. pneumoniae, raising the question of the serotypes currently circulating. Furthermore, the availability of affordable real-time etiological diagnostic tools would enable management to be adapted as effectively as possible.
RESUMO
Bartonella species are involved in various human diseases, causing a range of clinical manifestations; animals are considered as the main reservoirs, transmitting diverse species of Bartonella through direct contact and haematophagous insects. Here, we characterize a new species, Bartonella raoultii sp. nov., within the genus Bartonella, using a taxonogenomic polyphasic approach. Strain 094T (= CSUR B1097T=DSM 28004T), isolated from the blood of an infected rodent (Mastomys erythroleucus) in Senegal, is an aerobic and rod-shaped bacterium. The annotated non-contiguous genome sequence is 1â952322 bp long and contains 37.2âmol% G+C content, 1686 protein-coding genes and 50 RNA genes, including seven rRNA genes.
Assuntos
Bartonella , Animais , Humanos , Senegal , Composição de Bases , RNA Ribossômico 16S/genética , DNA Bacteriano/genética , Filogenia , Análise de Sequência de DNA , Técnicas de Tipagem Bacteriana , Ácidos Graxos/química , Murinae/genéticaRESUMO
BACKGROUND: The human louse (Pediculus humanus) is a haematophagous ectoparasite that is intimately related to its host. It has been of great public health concern throughout human history. This louse has been classified into six divergent mitochondrial clades (A, D, B, F, C and E). As with all haematophagous lice, P. humanus directly depends on the presence of a bacterial symbiont, known as "Candidatus Riesia pediculicola", to complement their unbalanced diet. In this study, we evaluated the codivergence of human lice around the world and their endosymbiotic bacteria. Using molecular approaches, we targeted lice mitochondrial genes from the six diverged clades and Candidatus Riesia pediculicola housekeeping genes. METHODS: The mitochondrial cytochrome b gene (cytb) of lice was selected for molecular analysis, with the aim to identify louse clade. In parallel, we developed four PCR primer pairs targeting three housekeeping genes of Candidatus Riesia pediculicola: ftsZ, groEL and two regions of the rpoB gene (rpoB-1 and rpoB-2). RESULTS: The endosymbiont phylogeny perfectly mirrored the host insect phylogeny using the ftsZ and rpoB-2 genes, in addition to showing a significant co-phylogenetic congruence, suggesting a strict vertical transmission and a host-symbiont co-speciation following the evolutionary course of the human louse. CONCLUSION: Our results unequivocally indicate that louse endosymbionts have experienced a similar co-evolutionary history and that the human louse clade can be determined by their endosymbiotic bacteria.
Assuntos
Anoplura , Pediculus , Animais , Anoplura/genética , Evolução Biológica , Genes Mitocondriais , Humanos , Pediculus/microbiologia , FilogeniaRESUMO
Background: Rodents are one of the most dangerous reservoirs and carriers of infectious diseases. Gradually, rats have become predominant in cities, sometimes staying in close vicinity to humans, pets, and other animals. Consequently, they tend to increase the transmission risk of pathogens. Case Description: Here, we report an original case of bacterial pneumonia in a street rat (Rattus norvegicus). The rat was found dead on a street in the chief town of Marseille (France) after being run over by a car. The necropsy of the corpse revealed generalized granulomatous pneumonia in almost all the pulmonary lobes. Lung lesions and predominantly multiple fibro-inflammatory areas are presumably the witness of an infectious etiology. Bacterial isolation was carried out from lung tissues. Colonies were identified by MALDI-TOF MS and confirmed by 16S rRNA sequencing. The following bacteria were identified: Staphylococcus cohnii, Bordetella bronchiseptica, Bordetella parapertussi, Corynebacterium glucuronolyticum, Pelistega suis and Rodentibacter rarus. Based on the histopathological diagnosis and the avoidance approach, the most likely etiological agent of pneumonia is therefore R. rarus, a little-known Pasteurellales bacterium that is closely related to Rodentibacter pneumotropicus. Conclusion: These data emphasize the severity of R. rarus infection in rodents. Thus, pointing out a potential risk for other animals (dogs, cats, and birds), as well as humans. The health monitoring program for rodents and rabbits pasteurellosis should now include R. rarus. Therefore, the pathological effect of the Rodentibacterspecies and/or strains needs to be better explored.
Assuntos
Infecções por Pasteurellaceae/veterinária , Pasteurellaceae/isolamento & purificação , Pneumonia Bacteriana/veterinária , Ratos , Doenças dos Roedores/diagnóstico , Animais , França , Masculino , Infecções por Pasteurellaceae/diagnóstico , Infecções por Pasteurellaceae/microbiologia , Pneumonia Bacteriana/diagnóstico , Pneumonia Bacteriana/microbiologia , Doenças dos Roedores/microbiologiaRESUMO
Non-human primate populations act as potential reservoirs for human pathogens, including viruses, bacteria and parasites, which can lead to zoonotic infections. Furthermore, intestinal microorganisms may be pathogenic organisms to both non-human primates and humans. It is, therefore, essential to study the prevalence of these infectious agents in captive and wild non-human primates. This study aimed at showing the prevalence of the most frequently encountered human enteric protozoa in non-human primate populations based on qPCR detection. The three populations studied were common chimpanzees (Pan troglodytes) in Senegal and gorillas (Gorilla gorilla) in the Republic of the Congo and in the Beauval Zoo (France). Blastocystis spp. were mainly found, with an occurrence close to 100%, followed by Balantidiumcoli (23.7%), Giardiaintestinalis (7.9%), Encephalitozoonintestinalis (1.3%) and Dientamoebafragilis (0.2%). None of the following protozoa were detected: Entamoebahistolytica, Enterocytozoonbieneusi, Cryptosporidiumparvum, C. hominis, Cyclosporacayetanensis or Cystoisosporabelli. As chimpanzees and gorillas are genetically close to humans, it is important to monitor them frequently against different pathogens to protect these endangered species and to assess potential zoonotic transmissions to humans.
RESUMO
Leishmaniasis is among the world's most neglected diseases. Dogs are the main reservoirs/hosts of Leishmania infantum, causative agent of both canine and human visceral leishmaniosis. Canine leishmaniasis (CanL) represents a public health problem as one of the most prevalent zoonotic diseases worldwide. Current therapeutics present drawbacks; thus, there is a need for more effective, safer, and cheaper drugs. The aim of this study was to evaluate and to compare the efficacy of oral administration of artesunate or meglumine antimoniate/allopurinol in dogs with clinical leishmaniasis. Forty-two dogs with naturally occurring clinical leishmaniasis were included in this open-label, simple randomized positive-control clinical field trial with 6 months of follow-up. Dogs received meglumine antimoniate 100 mg/kg/day and allopurinol 30 mg/kg/day for 28 days (control group, n = 26) or artesunate 25 mg/kg/day for 6 days (test group, n = 16). The animals were evaluated for their clinical evolution, parasite load (by qPCR) and humoral response at different time points: 0, 30, 90, and 180 days after treatment. Data analyses showed a significant improvement in both groups in clinical scores, parasitemia and antibody titers after treatment. Compared to the control group, the artesunate group showed significantly lower clinical score (P = 0.0001), lower parasitemia (P = 0.0001) and antibody titers after 6 months of follow-up. Compared to baseline values, a rapid, significant reduction (P < 0.012) in antibody levels, 2.28- versus 3.04-fold for the control versus artesunate groups, respectively, was observed 30 days after treatment. Antibody levels continued to decrease further in the artesunate group, where 58% of cases became seronegative at the 6-month follow-up. All qPCR-positive dogs were negative after treatment with artesunate, while 14.3% remained positive with the appearance of two new cases in the control group. Artesunate was well tolerated, and no side effects were recorded. Treatment failures were similar in both groups with 27.27% (6/22), including 18.18% (4/22) mortality in the control group, versus 26.66% (4/15), including 13.33% (2/15) mortality in the artesunate group. This is the first report showing the potential of artesunate in the treatment of dogs with clinical leishmaniasis. Artesunate showed higher efficacy than the current first-line treatment for CanL without any adverse effects. It could be a good alternative chemotherapy for CanL, and may be considered for further studies in human leishmaniases. Further clinical trials are needed to confirm these findings, to determine if there are relapses after treatment and if dogs remain infective to sandflies, to define the ideal therapeutic dosage and duration of treatment with artesunate.
Assuntos
Alopurinol/uso terapêutico , Antiprotozoários/uso terapêutico , Artesunato/uso terapêutico , Doenças do Cão/tratamento farmacológico , Leishmania infantum/efeitos dos fármacos , Leishmaniose Visceral/veterinária , Antimoniato de Meglumina/uso terapêutico , Animais , Doenças do Cão/parasitologia , Cães , Feminino , Leishmaniose Visceral/tratamento farmacológico , Leishmaniose Visceral/parasitologia , Masculino , Carga Parasitária/veterinária , Parasitemia/tratamento farmacológico , ZoonosesRESUMO
Non-human primates (NHPs) are known hosts for adenoviruses (AdVs), so there is the possibility of the zoonotic or cross-species transmission of AdVs. As with humans, AdV infections in animals can cause diseases that range from asymptomatic to fatal. The aim of this study was to investigate the occurrence and diversity of AdVs in: (i) fecal samples of apes and monkeys from different African countries (Republic of Congo, Senegal, Djibouti and Algeria), (ii) stool of humans living near gorillas in the Republic of Congo, in order to explore the potential zoonotic risks. Samples were screened by real-time and standard PCRs, followed by the sequencing of the partial DNA polymerase gene in order to identify the AdV species. The prevalence was 3.3 folds higher in NHPs than in humans. More than 1/3 (35.8%) of the NHPs and 1/10 (10.5%) of the humans excreted AdVs in their feces. The positive rate was high in great apes (46%), with a maximum of 54.2% in chimpanzees (Pan troglodytes) and 35.9% in gorillas (Gorilla gorilla), followed by monkeys (25.6%), with 27.5% in Barbary macaques (Macaca sylvanus) and 23.1% in baboons (seven Papio papio and six Papio hamadryas). No green monkeys (Chlorocebus sabaeus) were found to be positive for AdVs. The AdVs detected in NHPs were members of Human mastadenovirus E (HAdV-E), HAdV-C or HAdV-B, and those in the humans belonged to HAdV-C or HAdV-D. HAdV-C members were detected in both gorillas and humans, with evidence of zoonotic transmission since phylogenetic analysis revealed that gorilla AdVs belonging to HAdV-C were genetically identical to strains detected in humans who had been living around gorillas, and, inversely, a HAdV-C member HAdV type was detected in gorillas. This confirms the gorilla-to-human transmission of adenovirus. which has been reported previously. In addition, HAdV-E members, the most often detected here, are widely distributed among NHP species regardless of their origin, i.e., HAdV-E members seem to lack host specificity. Virus isolation was successful from a human sample and the strain of the Mbo024 genome, of 35 kb, that was identified as belonging to HAdV-D, exhibited close identity to HAdV-D members for all genes. This study provides information on the AdVs that infect African NHPs and the human populations living nearby, with an evident zoonotic transmission. It is likely that AdVs crossed the species barrier between different NHP species (especially HAdV-E members), between NHPs and humans (especially HAdV-C), but also between humans, NHPs and other animal species.
Assuntos
Infecções por Adenoviridae/epidemiologia , Infecções por Adenoviridae/veterinária , Mastadenovirus/classificação , Mastadenovirus/isolamento & purificação , Infecções por Adenoviridae/transmissão , Argélia/epidemiologia , Animais , Chlorocebus aethiops/virologia , Congo/epidemiologia , DNA Viral/genética , DNA Polimerase Dirigida por DNA/genética , Djibuti/epidemiologia , Fezes/virologia , Gorilla gorilla/virologia , Humanos , Macaca/virologia , Mastadenovirus/genética , Pan troglodytes/virologia , Papio hamadryas/virologia , Papio papio/virologia , Senegal/epidemiologia , Zoonoses Virais/epidemiologia , Zoonoses Virais/transmissãoRESUMO
We report 7 patients with interstitial lung disease seen at computed tomographic scan review. Coxiella burnetii infection was diagnosed in situ in 1 lung biopsy specimen. Q fever may be a cofactor of interstitial lung disease, especially in endemic areas.
Assuntos
Coxiella burnetii/isolamento & purificação , Doenças Pulmonares Intersticiais/microbiologia , Febre Q/diagnóstico , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de RiscoRESUMO
Strain FF7(T) was isolated from the peritoneal fluid of a 44-year-old woman who suffered from pelvic peritonitis. This strain exhibited a 16S rRNA sequence similarity of 94.8 % 16S rRNA sequence identity with Haemophilus parasuis, the phylogenetically closest species with a name with standing in nomenclature and a poor MALDI-TOF MS score (1.32 to 1.56) that does not allow any reliable identification. Using a polyphasic study made of phenotypic and genomic analyses, strain FF7(T) was a Gram-negative, facultatively anaerobic rod and member of the family Pasteurellaceae. It exhibited a genome of 2,442,548 bp long genome (one chromosome but no plasmid) contains 2,319 protein-coding and 67 RNA genes, including 6 rRNA operons. On the basis of these data, we propose the creation of Haemophilus massiliensis sp. nov. with strain FF7(T) (= CSUR P859 = DSM 28247) as the type strain.
RESUMO
Bacteria genetically related to Coxiella burnetii have been found in ticks. Using molecular techniques, we detected Coxiella-like bacteria, here named Candidatus Coxiella massiliensis, in skin biopsy samples and ticks removed from patients with an eschar. This organism may be a common agent of scalp eschar and neck lymphadenopathy after tick bite.
Assuntos
Coxiella/classificação , Coxiella/genética , Infecções por Bactérias Gram-Negativas/microbiologia , Infecções por Bactérias Gram-Negativas/transmissão , Carrapatos/microbiologia , Animais , Feminino , Genes Bacterianos , Humanos , Masculino , Filogenia , Doenças Transmitidas por Carrapatos/microbiologia , Doenças Transmitidas por Carrapatos/transmissãoRESUMO
Two tetrapeptides, HAEE and RADD, which are ionic-complementary to the primary zinc recognition site of amyloid-ß (Aß), have been reported to inhibit zinc-induced dimerization of the Aß metal-binding domain and slow Aß aggregation in vitro. In the present study, we investigate the impact of HAEE and RADD on the development of cerebral ß-amyloidosis in a mouse model of Alzheimer's disease. We have found chronic intravenous administration of each peptide results in significant decrease of amyloid plaque burden in the treated mice.
Assuntos
Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/química , Antipsicóticos/uso terapêutico , Oligopeptídeos/uso terapêutico , Precursor de Proteína beta-Amiloide/genética , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Encéfalo/patologia , Modelos Animais de Doenças , Humanos , Injeções Intravenosas , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Mutação/genética , Placa Amiloide/tratamento farmacológico , Placa Amiloide/genética , Presenilina-1/genéticaRESUMO
Strain FF4(T) was isolated from the skin flora of a 16-year-old healthy Senegalese female. This strain exhibited a 16S rRNA sequence similarity of 97.5 % with Bacillus fumarioli, the phylogenetically closest species with standing in nomenclature and a poor MALDI-TOF-MS score (1.1 to 1.3) that does not allow any identification. Using a polyphasic study consisting of phenotypic and genomic analyses, strain FF4(T) was Gram-positive, aerobic, rod-shaped, and exhibited a genome of 4,563,381 bp (1 chromosome but no plasmid) with a G + C content of 40.8 % that coded 4,308 protein-coding and 157 RNA genes (including 5 rRNA operons). On the basis of these data, we propose the creation of Bacillus dielmoensis sp. nov.
RESUMO
We report here the presence of Bartonella quintana in a demodex. Demodex are arthropods associated with acnea. Bartonella quintana was found by broad Spectrum 16rDNA PCR amplification and sequencing, and confirmed by specific PCR. Bartonella quintana may parasite several arthropods and not only lice.
Assuntos
Bartonella quintana/isolamento & purificação , Ácaros/microbiologia , Rosácea/microbiologia , Adulto , Animais , Bartonella quintana/genética , Feminino , Humanos , Pessoa de Meia-IdadeRESUMO
Here we report a case of co-infection with Orientia tsutsugamushi, the causative agent of scrub typhus, and Arsenophonus nasoniae in a woman with a rash and an eschar who returned from a trip to Southeast Asia. A. nasoniae was previously considered to be a secondary insect and tick endosymbiont of unknown pathogenicity in humans. We amplified both O. tsutsugamushi and A. nasoniae DNA from a skin eschar with qPCR, and a seroconversion for O. tsutsugamushi and A. nasoniae was observed with immunofluorescence assays and western blotting for this patient. And we used 2-D western blotting with an A. nasoniae antigen and polyclonal mouse anti-A. nasoniae antibodies produced in our laboratory to detect the specific antigenic A. nasoniae proteins.
Assuntos
Anticorpos Antibacterianos/sangue , Infecções por Enterobacteriaceae/complicações , Enterobacteriaceae/isolamento & purificação , Orientia tsutsugamushi/isolamento & purificação , Tifo por Ácaros/complicações , Pele/microbiologia , Adulto , Animais , Anticorpos Antibacterianos/imunologia , Antígenos de Bactérias/imunologia , Antígenos de Bactérias/isolamento & purificação , Sudeste Asiático , Proteínas de Bactérias/genética , Proteínas de Bactérias/isolamento & purificação , Proteínas de Bactérias/metabolismo , Biópsia , Coinfecção , Enterobacteriaceae/genética , Enterobacteriaceae/imunologia , Infecções por Enterobacteriaceae/diagnóstico , Infecções por Enterobacteriaceae/microbiologia , Feminino , França , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Orientia tsutsugamushi/genética , Orientia tsutsugamushi/imunologia , Reação em Cadeia da Polimerase , Tifo por Ácaros/diagnóstico , Tifo por Ácaros/microbiologia , Pele/patologia , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , ViagemRESUMO
Head and body lice are strict, obligate human ectoparasites with three mitochondrial clades (A, B, and C). Body lice have been implicated as vectors of human diseases, and as the principal vectors of epidemic typhus, relapsing fever, and Bartonella quintata-associated diseases (trench fever, bacillary angiomatosis, endocarditis, chronic bacteremia, and chronic lymphadenopathy). Using molecular methods (real-time and traditional PCR), we assessed the presence of Bartonella quintana DNA in black head lice collected from three locations in Sénégal. DNA from B. quintana was identified in 19 lice (6.93%) collected from 7 patients (7%) in Dakar. B. quintana-positive lice collected from three subjects were identified as clades C and A.
Assuntos
Bartonella quintana/isolamento & purificação , Insetos Vetores/microbiologia , Infestações por Piolhos/epidemiologia , Pediculus/microbiologia , Febre das Trincheiras/microbiologia , Adolescente , Adulto , Animais , Bartonella quintana/genética , Sequência de Bases , Criança , Citocromos b/genética , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Mitocondrial/química , DNA Mitocondrial/genética , Feminino , Pessoas Mal Alojadas , Humanos , Infestações por Piolhos/parasitologia , Masculino , Dados de Sequência Molecular , Filogenia , Senegal/epidemiologia , Análise de Sequência de DNA , Febre das Trincheiras/epidemiologia , Febre das Trincheiras/transmissãoRESUMO
Tick-borne diseases comprise a complex epidemiological and ecological network that connects the vectors, pathogens, and a group of host species. The aim of this study was to identify bacteria from the genus Rickettsia associated with ixodid ticks infesting camels and cows in Egypt. Ticks were collected from 6 different localities: Qina, Giza, Qalet El Nakhl, New Valley, El Arish, and Minufia, from July to October 2008. Species were identified using PCR, followed by sequencing. The gltA and rOmpA genes were used for the initial detection of Rickettsia spp. Further characterization of positive samples utilized primers targeting rOmpB, sca4, and intergenic spacers (mppA-purC, dksA-xerC, and rpmE-tRNA(fMet)). Cows were infested with Hyalomma anatolicum excavatum and Boophilus annulatus. Camels were infested with Hyalomma dromedarii, H. impeltatum, and H. marginatum marginatum. Approximately 57.1% of H. dromedarii ticks collected from Qalet El Nakhl were infected with Rickettsia africae, exhibiting 99.1-100% identity to reference strains. Within H. impeltatum, 26.7% and 73.3% of ticks from El Arish were infected with R. africae and R. aeschlimannii, with 98.3-100% and 97.9-100% identity, respectively. Furthermore, 33.3% of H. marginatum marginatum ticks in Qalet El Nakhl were infected with the same two species as H. impeltatum, demonstrating 99.1-100% and 99.3-100% identity, respectively. By comparing percent identities and phylogenetic relationships, R. africae is identified for the first time in Egypt, in addition to R. aeschlimannii, which exhibits 100% identity with the Stavropol strain in GenBank. In conclusion, the obtained data underscore the medical and veterinary importance of tick-borne rickettsioses, which necessitate further investigation by authorities in Egypt. Moreover, additional characterization of these rickettsial isolates should be performed to designate their strains, using a polyphasic strategy combining genotypic and phenotypic tests, to facilitate their deposition in the rickettsial collection of the WHO and/or ATCC.
Assuntos
Ixodidae/microbiologia , Filogenia , Reação em Cadeia da Polimerase/métodos , Rickettsia/classificação , Rickettsia/isolamento & purificação , Animais , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , DNA Bacteriano/genética , DNA Intergênico/genética , Egito , Regulação Bacteriana da Expressão Gênica/fisiologia , Rickettsia/genéticaRESUMO
BACKGROUND: Obligate intracellular bacteria of arthropods often exhibit a significant role in either human health or arthropod ecology. METHODOLOGY/PRINCIPAL FINDINGS: An obligate intracellular gamma-proteobacterium was isolated from the actively questing hard tick Ixodes ricinus using mammalian and amphibian cell lines. Transmission electron microscopy revealed a unique morphology of the bacterium, including intravacuolar localization of bacteria grouped predominantly in pairs and internal structures composed of electron-dense crystal-like structures and regular multilayer sheath-like structures. The isolate 20B was characterized to determine its taxonomic position using a polyphasic approach. Comparative 16S rRNA gene sequence analysis showed that this strain belongs to the family Coxiellaceae, order Legionellales of Gamma-proteobacteria, and the closest relatives are different Rickettsiella spp. The level of 16S rRNA gene sequence similarity between strain 20B and other recognized species of the family was below 94.5%. Partial sequences of the rpoB, parC and ftsY genes confirmed the phylogenetic position of the new isolate. The G+C content estimated on the basis of whole genome analysis of strain 20B was 37.88%. On the basis of its phenotypic and genotypic properties, together with phylogenetic distinctiveness, we propose that strain 20B to be classified in the new genus Diplorickettsia as the type strain of a novel species named Diplorickettsia massiliensis sp. nov. CONCLUSIONS/SIGNIFICANCE: Considering the source of its isolation (hard tick, often biting humans) the role of this bacterium in the pathology of humans, animals and ticks should be further investigated.
Assuntos
Gammaproteobacteria/genética , Ixodidae/microbiologia , Animais , Composição de Bases/genética , Gammaproteobacteria/classificação , Gammaproteobacteria/isolamento & purificação , Gammaproteobacteria/ultraestrutura , Microscopia Eletrônica de Transmissão , Dados de Sequência Molecular , Filogenia , Reação em Cadeia da Polimerase , RNA Ribossômico 16S/genéticaRESUMO
We recently reported the first documented cases of a new rickettsial disease caused by Rickettsia heilongjiangensis in the Russian Far East (Far Eastern tick-borne rickettsiosis). Here we report the amplification of DNA of R. heilongjiangensis from both the skin biopsy of an acutely ill patient and the tick removed from him prior to the disease development. The tick has been identified as Haemaphysalis spp. The clinical picture was that of a spotted fever group rickettsiosis and a seroconversion was noted with R. heilongjiangensis antigen. Screening testing of both species of Haemaphysalis ticks inhabiting Russian Far Eastern regions showed that up to 28.13% of H. concinnae and 4.48% of H. japonica douglasii ticks harbor R. heilongjiangensis. It has been concluded that H. concinnae may serve as the main vector for the transmission of R. heilongjiangensis. H. japonica douglasii ticks harbor several varieties of rickettsiae. DNA of "Candidatus Rickettsia tarasevichiae," previously found in Ixodes persulcatus ticks, was amplified from one male tick. Two sequenced complete gltA genes belong to the novel spotted fever group rickettsial species provisionally called here "Candidatus Rickettsia principis" variants Hjd54 and Hjd61. The rate of infection has been found to be not higher than 1.5%.
Assuntos
Infecções por Rickettsia/diagnóstico , Doenças Transmitidas por Carrapatos/diagnóstico , Adulto , Idoso , Animais , DNA Bacteriano/isolamento & purificação , Ásia Oriental , Humanos , Insetos Vetores , Federação Russa , Testes Sorológicos , CarrapatosRESUMO
An acute tick-borne rickettsiosis caused by Rickettsia heilongjiangensis was diagnosed in 13 patients from the Russian Far East in 2002. We amplified and sequenced four portions of three rickettsial genes from the patients' skin biopsy results and blood samples and showed that the amplified rickettsial genes belong to R. heilongjiangensis, which was recently isolated from Dermacentor sylvarum ticks in nearby regions of China. This rickettsia, belonging to subgroup of R. japonica, was previously suggested to be pathogenic for humans on the basis of serologic findings. We tested serum samples with different rickettsial antigens from 11 patients and confirmed increasing titers of immunoglobulin (Ig) G and IgM to spotted fever group rickettsiae, including R. heilongjiangensis. Clinical and epidemiologic data on these patients show that this disease is similar to other tick-borne rickettsioses.