Search PubMed⌕ Search

Biomedical subjects

Pierre-Edouard Fournier

Publications and source records attributed to Pierre-Edouard Fournier.

At least 73 records · Page 4Linked to original sources
PubMed2003

Outcome and treatment of Bartonella endocarditis.

BACKGROUND: Endocarditis caused by Bartonella species is a potentially lethal infection characterized by a subacute evolution and severe valvular lesions. OBJECTIVES: To evaluate the outcome of patients with Bartonella endocarditis and to define the best antibiotic regimen using the following measures: recovery, relapse, or death. METHODS: We performed a retrospective study on 101 patients who were diagnosed in our laboratory as having Bartonella endocarditis between January 1, 1995, and April 30, 2001. Bartonella infection was diagnosed using immunofluorescence with a 1:800 cutoff, polymerase chain reaction amplification of DNA, and/or culture findings of Bartonella species from whole blood, serum, and/or valvular biopsy specimens. A standardized questionnaire was completed by investigators for each patient. RESULTS: Twelve of the 101 patients died and 2 relapsed. Patients receiving an aminoglycoside were more likely to fully recover (P =.02), and those treated with aminoglycosides for at least 14 days were more likely to survive than those with shorter therapy duration (P =.02). CONCLUSION: Effective antibiotic therapy for Bartonella endocarditis should include an aminoglycoside prescribed for a minimum of 2 weeks.

Adolescent↗
PubMed2003

African tick bite fever.

African tick bite fever is an acute febrile illness that is frequently accompanied by headache, prominent neck muscle myalgia, inoculation eschars, and regional lymphadenitis. The disease is caused by Rickettsia africae, a recently identified spotted fever group rickettsia, which is transmitted by ungulate ticks of the Amblyomma genus in rural sub-Saharan Africa and the French West Indies. Whereas reports on African tick bite fever in indigenous populations are scarce, the number of reported cases in travellers from Europe and elsewhere has recently increased significantly. Treatment with doxycycline is associated with rapid recovery in most patients. An immunofluorescence assay is recommended for the diagnosis but seroconversion is commonly delayed and this limits the usefulness of the test. Travellers to endemic areas should be informed of the risk of contracting African tick bite fever and be encouraged to take personal protective measures against tick bites.

Adult↗
PubMed2003

The geographical segregation of human lice preceded that of Pediculus humanus capitis and Pediculus humanus humanus.

In order to investigate human-louse phylogeny, we partially sequenced two nuclear (18S rRNA and EF-1 alpha) and one mitochondrial (COI) genes from 155 Pediculus from different geographical origins. The phylogenetic analysis of 18S rRNA and EF-1 alpha sequences showed that human lice were classified into lice from Sub-Saharan Africa and lice from other areas. In both clusters, head and body lice were clearly grouped into two separate clusters. Our results indicate that the earliest divergence within human pediculidae occurred between African lice and other lice, and the divergence between head and body lice was not the result from a single event.

Animals↗
PubMed2003

Bartonella and Coxiella antibodies in 334 prospectively studied episodes of infective endocarditis in Sweden.

Bartonella spp. have been identified as aetiological agents in culture-negative infective endocarditis (IE). Coxiella burnetii may cause chronic Q-fever with endocarditis, 334 blood samples collected from 329 patients (334 episodes) with IE diagnosed between 1984 and 1996 in Göteborg, Sweden, were investigated for antibodies to Bartonella spp. and C. burnetii. 71 of the episodes (21%) were blood culture negative. A microimmunofluorescence assay revealed immunoglobulin G (IgG) antibodies to Bartonella in 13 of the culture verified episodes and in 2 of the culture-negative episodes. Three of the patients had IgG antibodies to > or = 200 in the blood culture-verified group, but none had a titre > or = 800, the cut-off level for Bartonella endocarditis. One patient had elevated antibodies to C. burnetii, diagnosing chronic Q-fever endocarditis. In conclusion, serologically verified Bartonella endocarditis is not prevalent in western Sweden and Q-fever endocarditis is rare.

Antibodies, Bacterial↗
PubMed2003

Isolation of a rickettsia related to Astrakhan fever rickettsia from a patient in Chad.

We isolated a novel spotted fever group rickettsia from a patient coming back from Chad with fever and a maculopapulous rash. In Africa, only six pathogenic spotted fever group rickettsiae have been identified, R. conorii, R. africae, R. akari, R. aeschlimannii, "R. mongolotimonae," and R. felis. Our isolate was identified by PCR amplification and sequencing of the 16S rRNA (16S rDNA), citrate synthase (gltA), and rOmpA (ompA) encoding genes. The 16S rDNA, gltA, and ompA sequences of the isolate were found to be 99.7, 99.6, and 99.5% identical with that of Astrakhan fever rickettsia, respectively. This rickettsia is endemic in the Caspian sea area and has also recently been identified in Kosovo. Using mouse serotyping, the currently accepted method for the identification of spotted fever group rickettsiae, the Chad isolate exhibited a specificity difference of 2 when compared to Astrakhan fever rickettsia and at least 4 when compared with other members of the R. conorii complex. The Chad isolate should be considered a variant of Astrakhan fever rickettsia. This is the first description of Astrakhan fever rickettsia outside Europe and the bacterium may be responsible for cases of spotted fever in Chad. Although Astrakhan fever rickettsia is transmitted by Rhipicephalus ticks in Europe, further studies are indicated to identify its vector in Africa where these ticks are also prevalent.

Adult↗
PubMed2003

Detection of Astrakhan fever rickettsia from ticks in Kosovo.

Astrakhan fever is a summer spotted fever resembling Mediterranean spotted fever, endemic in Astrakhan, a region of Russia located by the Caspian sea. Its agent is a spotted fever group rickettsia, member of the Rickettsia conorii complex, transmitted to humans by Rhipicephalus sanguineus and Rhipicephalus pumilio ticks. In Summer 2001, French United Nations troops in Kosovo collected 2 ticks on asymptomatic soldiers (1 R. sanguineus and 1 Hyalomma marginatum) and 10 ticks on dogs (7 R. sanguineus, 2 Ixodes ricinus, and 1 H. marginatum) in the Morina region. By PCR amplification of both the gltA and ompA genes, we detected a rickettsia in 4 R. sanguineus, i.e., 3 of those collected on dogs and those taken from military personnel. As ticks were preserved in alcohol, culture was not possible. The sequences obtained from these PCR products identified, with a 100% homology, Astrakhan fever rickettsia. None of the other collected tick species was positive. The patient with the positive tick remained asymptomatic. Our study demonstrates, for the first time, the presence of Astrakhan fever rickettsia in ticks outside Russia. We suspect that the area of distribution of this rickettsia could be wider than initially suspected. Moreover, as R. sanguineus ticks bite humans, Astrakhan fever might be a cause of spotted fever in Kosovo.

Animals↗
PubMed2003

"Candidatus Rickettsia tarasevichiae" in Ixodes persulcatus ticks collected in Russia.

We collected 209 Ixodes persulcatus ticks in various regions of Russia, including the southern Urals and western and eastern Siberia. Using PCR amplification and sequencing of the citrate synthase-encoding gene (gltA), we detected a new rickettsial genotype, which we named "Candidatus Rickettsia tarasevichiae." This bacterium was found in 9.27%, 10.0%, and 20.5% of the ticks collected in western Siberia, eastern Siberia, and the southern Urals, respectively. "Candidatus Rickettsia tarasevichiae" exhibited a 98% and 96% nucleotide sequence homology, with the 16S rDNA and gltA sequence, respectively, of R. canadensis, a rickettsia previously only found in Haemaphysalis leporispalustris ticks in North America. The phylogenetic analysis of "Candidatus Rickettsia tarasevichiae" and other Rickettsia species allowed the creation of a new cluster with high bootstrap values within the Rickettsia genus involving this rickettsia, R. canadensis, and three uncultured rickettsiae from plant insects.

Animals↗
PubMed2003

An experimental model of human body louse infection with Rickettsia typhi.

Murine (endemic) typhus caused by Rickettsia typhi, one of the most widely distributed arthropod-borne diseases, is transmitted to humans mainly by the oriental rat flea. The human body louse, Pediculus humanus corporis, has been suspected to have a role in the transmission of R. typhi to humans. To evaluate the potential role of Pediculus humanus corporis as a vector of murine typhus, we used R. typhi in an experimental model of human body louse infection previously used with R. prowazekii. A rabbit was made bacteremic by inoculating it with 2 x 10(6) plaque-forming units of R. typhi; it remained bacteremic for at least 59 hours. Two hundred body lice infected by feeding on the bacteremic rabbit were compared to 200 uninfected control lice. Each louse population was fed once a day on the abdomen of a seronegative rabbit. On day 8 post-infection, as a result of disruption of the gut cells and leakage of the blood meal into the hemolymph, four infected lice became bright red and died within four hours. The life span of infected lice was 20 days less than that of the controls. Infected lice did not transmit R. typhi to their progeny (eggs and larvae) as demonstrated by PCR amplification and cell culture. With an immunofluorescence assay, R. typhi was detected in feces from day 7 post-infection, and the organism remained viable in feces for up to 80 days as demonstrated by cell culture. From the 21st day post-infection, the rabbit used to feed the R. typhi-infected lice developed an immunoglobulin response with a titer of 1:50 increasing to 1:200 at the 42nd day post-infection. It showed no clinical signs of infection. The rabbit that was used to feed uninfected lice remained seronegative. Although body lice are not clearly identified vectors of R. typhi, it seems that under certain circumstances they could transmit R. typhi.

Animals↗
PubMed2003

Comparison of PCR and serology assays for early diagnosis of acute Q fever.

Q fever is a potentially severe disease which can occur in large outbreaks of acute infections and is a possible bioterrorism agent. In order to lessen the delay in diagnosing acute Q fever, we compared LightCycler Nested PCR (LCN-PCR), a rapid nested PCR assay that uses serum sampled early during the disease as a specimen and the LightCycler as a thermal cycler, to serology by indirect immunofluorescence. We used the 20-copy htpAB-associated element as the DNA target. The detection sensitivity of this method was one Coxiella burnetii DNA copy. We applied this method to the first serum samples taken from 100 patients diagnosed in our laboratory as having acute Q fever on the basis of clinical manifestations and serology and to 80 controls. The LCN-PCR had a specificity of 100%. The sensitivity was 26% when no antibodies were detected but only 5% with seropositive patients (P < 10(-2)). The technique was most efficient in the first 2 weeks following the onset of symptoms (P = 0.02), when its sensitivity was 24% compared with 14% for serology. With combined use of LCN-PCR and serology within the first 2 weeks, the sensitivity was significantly increased over that with serology alone (P < 10(-2)). Thus, we propose a strategy for improving the early diagnosis of acute Q fever where LCN-PCR should be performed together with serology in the first 2 weeks of the disease but should be reserved for seronegative patients in the next 2 weeks and not used later than 4 weeks following onset, when serology is highly sensitive.

Adolescent↗
PubMed2003

Gene sequence-based criteria for identification of new rickettsia isolates and description of Rickettsia heilongjiangensis sp. nov.

We propose genetic guidelines for the classification of rickettsial isolates at the genus, group, and species levels by using sequences of the 16S rRNA (rrs) gene and four protein-coding genes, the gltA, ompA, and ompB genes and gene D. To be classified as a member of the genus Rickettsia, an isolate should exhibit degrees of rrs and gltA homology with any of the 20 Rickettsia species studied of >/=98.1 and >/=86.5%, respectively. A member of the typhus group should fulfill at least two of the following four criteria: pairwise nucleotide sequence homologies with rrs, gltA, ompB, and gene D of either Rickettsia typhi or Rickettsia prowazekii of >/=99.4, >/=96.6, >/=92.4, and >/=91.6%, respectively. A member of the spotted fever group should either possess the ompA gene or fulfill at least two of the following four criteria: pairwise nucleotide sequence homologies with rrs, gltA, ompB, and gene D of any member of this group of >/=98.8, >/=92.7, >/=85.8, and >/=82.2%, respectively. The existence of a distinct "ancestral" group should be questioned. To be classified as a new Rickettsia species, an isolate should not exhibit more than one of the following degrees of nucleotide similarity with the most homologous validated species: >/=99.8 and >/=99.9% for the rrs and gltA genes, respectively, and, when amplifiable, >/=98.8, >/=99.2, and >/=99.3% for the ompA and ompB genes and gene D, respectively. By use of our classification scheme, "Rickettsia heilongjiangii" belongs to a new species for which we officially propose the name Rickettsia heilongjiangensis sp. nov.

DNA, Ribosomal↗
PubMed2003

Diagnosis of Bartonella endocarditis by a real-time nested PCR assay using serum.

Bartonella endocarditis is a severe disease for which blood cultures frequently remain negative. We tested three PCR assays by using specimens of serum sampled early during the disease from 43 patients diagnosed in our laboratory as having Bartonella endocarditis on the basis of serological, culture, and/or valvular molecular detection. We tested a two-step nested PCR (TSN-PCR), a one-step nested PCR (OSN-PCR) with a regular thermal cycler, and a one-step nested PCR with the LightCycler (LCN-PCR). These assays were performed with primers derived from the riboflavin synthase-encoding gene ribC, never before amplified in our laboratory. Due to contamination of negative controls, the results of the TSN-PCR were not interpretable, and this technique was no longer considered. The LCN-PCR had a specificity of 100% and a sensitivity of 58.1%, higher than those of the OSN-PCR (18.6%; P < 0.01) and prolonged blood culturing (7.1%; P < 0.01). The LCN-PCR results correlated strictly with those of other direct diagnostic tests, when available, and identified the causative species for six patients previously diagnosed on the basis of serological analysis only. The efficacy of the LCN-PCR was not influenced by antibiotics (P = 0.96) but was altered by prolonged storage of serum specimens at -20 degrees C (P = 0.04). Overall, the LCN-PCR is specific and more sensitive than traditional methods (i.e., culturing and/or PCR with EDTA-treated blood). It can easily be applied to the diagnosis of patients with suspected Bartonella endocarditis, especially when only serum is available.

Bartonella↗
PubMed2003

A survey for spotted fever group rickettsiae and ehrlichiae in Amblyomma variegatum from St. Kitts and Nevis.

Eighty-nine Amblyomma variegatum ticks were collected from the islands of St. Kitts and Nevis in the Caribbean and preserved in 70% ethanol or local rum. After being washed in sterile water, their DNA was extracted and analyzed by a polymerase chain reaction (PCR) for DNA of spotted fever group rickettsiae and ehrlichiae. None of the tested ticks was positive in a PCR assay using the primers 16S EHRD and 16S EHRR for the 16S rRNA gene of Ehrlichia spp.. Forty-one percent of the A. variegatum (36 of 89 of which 34 [47%] of 72 were adult males, 2 (13%) of 16 were adult females, and 0 (0%) of 1 were nymphs) were positive in a PCR assay using the primer pair 190-70 and 190-701 for the outer membrane protein A (ompA) gene of spotted fever group rickettsiae. All PCR amplification products obtained had 100% sequence homology with Rickettsia africae, the agent of African tick-bite fever.

Animals↗
PubMed2003

First isolation of Rickettsia conorii from human blood in Croatia.

AIM: To detect and isolate rickettsial strains from blood samples of patients with presumptive diagnosis of Mediterranean spotted fever (MSF) in the coastal region of south Croatia, and to compare the results with routine serology. METHODS: A "suicide" polymerase chain reaction (PCR), and a shell vial culture were done on samples of ethylenediamine tetra-acetic acid (EDTA) and citrate-anticoagulated blood samples. Indirect immunofluorescence was performed on sera collected from 17 patients clinically diagnosed with MSF during summer in three consecutive years, from 1998 to 2000. RESULTS: The primers used in PCR amplified the expected part of the rickettsia genomic DNA and Rickettsia conorii grew from the shell vial-cultured blood of a single patient. In 13 patients, the diagnosis was confirmed serologically by paired sera, whereas in 4 patients the diagnosis remained presumptive, since no paired sera were available. Analyzing sequences of the ompA and citrate synthase gene, respectively, derived from the shell vial isolate, a 100% similarity with Rickettsia conorii, strain Seven (Malish), was found. CONCLUSION: To the best of our knowledge, this is the first isolation of Rickettsia conorii from a human sample in Croatia, and the first proof of a causative agent of MSF in the country. Beside PCR-based methods and isolation, correct diagnosis of MSF could be still routinely reached by serology.

Base Sequence↗
PubMed2002

An experimental model of human body louse infection with Rickettsia prowazekii.

Rickettsia prowazekii is transmitted to humans by the body louse. A new experimental model of body louse infection with R. prowazekii is reported here. Eight hundred human lice were infected by feeding on a rabbit that was made bacteremic by injecting 2x106 plaque-forming units of R. prowazekii. The bacterium invaded the stomach cells and was released in feces, in which it was detected 5 days after infection. At day 6 after infection, as a result of the cell burst and the spread of erythrocytes in the hemolymph, the louse became bright red and died within 4 h. The life span of infected lice was shortened by 20-23 days, compared with that of uninfected control lice. Infected lice did not transmit R. prowazekii to their progeny. Through cell culture, rickettsiae were cultivated from fecal samples up to 10 days after their emission. The administration of doxycycline to the rabbit during louse feeding did not cure lice from R. prowazekii infection.

Animals↗
PubMed2002

Spotless rickettsiosis caused by Rickettsia slovaca and associated with Dermacentor ticks.

The pathogenic role of Rickettsia slovaca was first demonstrated in 1997 in a patient who presented with a single inoculation lesion of the scalp and enlarged cervical lymph nodes after receiving a bite from a Dermacentor tick. Subsequently, we evaluated the occurrence of R. slovaca infections among patients living in France and Hungary who presented with these symptoms. R. slovaca infections were confirmed by polymerase chain reaction (PCR) in 17 of 67 enrolled patients. Infections were most likely to occur in patients aged <10 years and in patients who were bitten during the colder months of the year. The median duration of incubation for the disease was 7 days. Fever was present in only 2 patients, and only 1 patient developed a rash. Sequelae included persistent asthenia (3 cases) and localized alopecia (4 cases). Immunofluorescence and/or Western blot analysis detected antibodies in 50% of tested patients. Three Dermacentor ticks obtained from patients revealed R. slovaca by PCR.

Animals↗
PubMed2002

Seroepidemiology of Rickettsia africae infection in Norwegian travellers to rural Africa.

Rickettsia africae is the causative agent of African tick bite fever (ATBF), an acute febrile illness frequently accompanied by inoculation eschars, regional lymphadenitis, myalgia and severe headache. Recently, ATBF has been recognized as an emerging health problem for international travellers to rural sub-Saharan Africa. To estimate the incidence, risk factors for and proportion of symptomatic cases of travel-associated R. africae infection, we performed a seroepidemiological study of 152 first-time Norwegian travellers to rural areas in sub-Equatorial Africa. Seropositivity was based on the detection of specific antibodies to R. africae in microimmunofluorescence and/or Western blotting assays. Thirteen (8.6%) travellers were seropositive to R. africae. Eight (62%) seropositive travellers reported symptoms consistent with ATBF; of these, 2 had received antirickettsial therapy. Using multiple logistic regression, the following factors were found to be significantly associated with seropositivity: hunting as the purpose of travel [odds ratio (OR) 10.1; 95% confidence interval (CI) 1.5-69; p=0.019] and stay in rural areas of > 7 d (OR 6.0; 95% CI 1.5-24; p=0.012). This first seroepidemiological study on travel-associated R. africae infection suggests that the infection may be common in international travellers to rural sub-Saharan Africa but that most cases are asymptomatic or clinically mild and self-limited.

Adolescent↗