Publications (142) View all
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Article: Usefulness of rickettsial PCR assays for the molecular diagnosis of human rickettsioses.
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ABSTRACT: BACKGROUND: The effectiveness of PCR methods to amplify rickettsiae from clinical samples has still not been evaluated. Our aim was to determine the sensitivity and usefulness for Rickettsia species identification by PCR methods, targeting 16S rDNA, htrA, gltA, ompA, and ompB genes for molecular diagnosis of rickettsioses. METHODS: A total of 72 clinical samples (EDTA-blood, skin biopsies and ticks) taken from 52 patients in the early phase of the illness with PCR-confirmed rickettsioses were included. Single [16S rDNA, gltA (5' end), and htrA genes] and sequential (nested or semi-nested) PCR assays [ompB, gltA (central region) and ompA genes] were performed. RESULTS: For single-stage PCR assays, the greatest sensitivity (33.3%) was obtained using the gltA (5' end), while for sequential assays, the most sensitive results were obtained using the ompB assay (83.3%). The highest sensitivity (100%) was achieved using the three sequential PCRs. The ompA PCR method was the most reliable for identifying Rickettsia species, according to clinical features. CONCLUSIONS: PCR-based amplification methods are useful rickettsial diagnostic tools in the early phase of the illness. The three sequential PCR assays here investigated (ompB, gltA and ompA) appear to be useful tools for molecular diagnosis of rickettsioses. ompB PCR assay is effective for primary screening, since it detects a high percentage of positive samples. ompA assay is the most useful method to identify a Rickettsia species in human pathology. Nevertheless, epidemiology, clinical symptoms and the vector involved in the infection have to be taken into account for the diagnosis of rickettsioses.Enfermedades Infecciosas y Microbiología Clínica 09/2012; · 1.49 Impact Factor -
Article: Short-term and long-term clinical and immunological consequences of stopping antiretroviral therapy in HIV-infected patients with preserved immune function.
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ABSTRACT: OBJECTIVE: To assess the short-term and long-term consequences of stopping antiretroviral therapy (ART) in patients with preserved immune function. METHODS: Randomized, 144-week follow-up CD4+ count-guided treatment-interruption trial. HIV-1 infected adults with plasma HIV-1 RNA <50 copies/mL, CD4+ count >500/µL, and nadir CD4+ count >100/µL were randomized to continuous therapy (CT) or treatment interruption (TI) until CD4+ count decreased to <350/µL. The primary endpoints were AIDS-defining illnesses, death, CD4+ count <200/µL, or virologic failure after restarting ART. RESULTS: A total of 106 patients were included, 50 in the CT arm and 56 in the TI arm. A trend to a higher rate of primary endpoints was observed in the TI group (26.8% vs. 14%, difference: 12.8%, 95% CI -2.3% to 27.8%; p=0.105). In addition, 10 patients presented clinical events related with HIV rebound, including 8 cases of thrombocytopenia. The CD4+ count significantly decreased in the TI group (even in patients with persistently high CD4+ counts and no clinical events) versus the CT group (median change -408 cell/µL vs -21.5 cell/µL, p<0.001), whereas a significant increase in CD8+ count was observed (+256 cell/µL, vs -59 cell/µL, p<0.001). The time to ART re-initiation was significantly associated with nadir and baseline CD4+ counts. CONCLUSIONS: Discontinuation of ART in patients with preserved immune function is followed by significant immunological impairment even in those with no clinical events, and may be associated with an increased risk of HIV-related complications. Hence, patients who stop ART voluntarily should be closely monitored, regardless their CD4+ count. (www.controlled-trials.com, ISRCTN75856952).Antiviral therapy 07/2012; · 3.16 Impact Factor -
Article: Crimean-congo hemorrhagic Fever virus in ticks from migratory birds, morocco(1).
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ABSTRACT: Crimean-Congo hemorrhagic fever virus was detected in ticks removed from migratory birds in Morocco. This finding demonstrates the circulation of this virus in northwestern Africa and supports the hypothesis that the virus can be introduced into Europe by infected ticks transported from Africa by migratory birds.Emerging Infectious Diseases 02/2013; 19(2):260-3. · 6.79 Impact Factor -
Article: Rickettsia Species in Ticks Removed from Humans in Istanbul, Turkey.
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ABSTRACT: Abstract A total of 167 ticks collected from humans in Istanbul (Turkey) in 2006 were screened for Rickettsia species, and nested PCRs targeting gltA and ompA rickettsial fragment genes were carried out. Rickettsia monacensis (51), R. aeschlimannii (8), R. conorii subsp. conorii (3), R. helvetica (2), R. raoultii (1), R. africae (1), R. felis (1), and other Rickettsia spp. (2), were detected. To our knowledge, these Rickettsia species (except R. conorii) had never been reported in ticks removed from humans in Turkey. The presence of R. africae also had not been previously described, either in Hyalomma ticks or in any European tick species. In addition, R. aeschlimannii and R. felis had not been found associated with Rhipicephalus bursa specimens. The presence of human pathogenic Rickettsia in ticks removed from humans provides information about the risk of tick-borne rickettsioses in Turkey.Vector borne and zoonotic diseases (Larchmont, N.Y.) 08/2012; · 2.61 Impact Factor -
Article: Rickettsia sp. strain colombianensi (Rickettsiales: Rickettsiaceae): a new proposed Rickettsia detected in Amblyomma dissimile (Acari: Ixodidae) from iguanas and free-living larvae ticks from vegetation.
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ABSTRACT: From January to December 2009, 55 Amblyomma dissimile (Koch) ticks removed from iguanas in the municipality of Monteria and 3,114 ticks [458 Amblyomma sp. larvae, 2,636 Rhipicephalus microplus (Canestrini) larvae and 20 Amblyomma sp. nymphs] collected over vegetation in Los Cordobas were included in the study. The ticks were pooled into groups from which DNA was extracted. For initial screening of Rickettsia sp., each pool was analyzed by gltA real-time polymerase chain reaction (PCR). Positive pools were further studied using gltA, ompA, and ompB conventional PCR assays. Sequencing and phylogenetic analysis were also conducted. Rickettsial DNA was found in 28 pools of ticks (16 A. dissimile pools and 12 free-living larvae pools) out of 113 (24.7%) using real-time PCR. The same 28 pools were also positive using conventional PCR assays aimed to amplify gltA, ompA, and ompB. For each gene analyzed, PCR products obtained from 4/28 pools (two pools of A. dissimile, one pool of Amblyomma sp. larvae and one pool of Rh. microplus larvae) were randomly chosen and sequenced twice. Nucleotide sequences generated were identical to each other for each of the rickettsial genes gltA, ompA, and ompB, and showed 99.4, 95.6, and 96.4% identity with those of Rickettsia tamurae. They were deposited in the GenBank database under accession numbers JF905456, JF905458, and JF905457, respectively. In conclusion, we present the first molecular evidence of a novel Rickettsia (Rickettsia sp. strain Colombianensi) infecting A. dissimile ticks collected from iguanas, and also Rh. microplus and unspeciated Amblyomma larvae from vegetation in Colombia.Journal of Medical Entomology 07/2012; 49(4):960-5. · 1.76 Impact Factor
