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Pierre-Edouard Fournier

Publications and source records attributed to Pierre-Edouard Fournier.

84 records · Page 5Linked to original sources
PubMed2002

Phylogenetic classification of Bartonella species by comparing groEL sequences.

Bartonella is a bacterial genus classified in the alpha-Proteobacteria on the basis of 165 rDNA sequence comparison. The highly conserved heat-shock chaperonin protein, GroEL, has proved to be a valuable resolving tool to classify ten Bartonella species. The groEL gene was amplified and sequenced from ten Bartonella isolates: Bartonella alsatica, Bartonella vinsonii subsp. arupensis, Bartonella taylorii, Bartonella tribocorum, Bartonella birtlesii, Bartonella henselae Marseille (URLLY8), B. henselae (90-615), B. henselae (Fizz), B. henselae (CAL-1) and B. henselae (SA-2). Then, phylogenetic relationships were inferred between our isolates and eight other species and subspecies from the comparison of both 16S rDNA and groEL sequences using parsimony, neighbour-joining and maximum-likelihood methods. By using groEL sequences, the first reliable classification of most known Bartonella species and subspecies was established. Four strongly supported subgroups were distinguished: firstly, the two human pathogens B. henselae and Bartonella quintana; secondly, a cluster including four rodent isolates, Bartonella elizabethae, B. tribocorum, Bartonella grahamii and B. taylorii; thirdly, a cluster including the B. vinsonii subspecies (B. vinsonii subsp. vinsonii, arupensis and berkhoffii); and lastly, B. birtlesii and 'Bartonella weissi'. 'Bartonella washoensis', B. alsatica, Bartonella doshiae, Bartonella bacilliformis and Bartonella clarridgeiae did not reliably cluster with any other Bartonella species. In addition, the groEL gene was shown to be useful in subtyping six B. henselae isolates into three variants: Houston, Marseille and Fizz.

Amino Acid Sequence↗
PubMed2002

Protein coding palindromes are a unique but recurrent feature in Rickettsia.

Rickettsia are unique in inserting in-frame a number of palindromic sequences within protein coding regions. In this study, we extensively analyzed repeated sequences in the genome of Rickettsia conorii and examined their locations in regard to coding versus noncoding regions. We identified 656 interspersed repeated sequences classified into 10 distinct families. Of the 10 families, three palindromic sequence families showed clear cases of insertions into open reading frames (ORFs). The location of those in-frame insertions appears to be always compatible with the encoded protein three-dimensional (3-D) fold and function. We provide evidence for a progressive loss of the palindromic property over time after the insertions. This comprehensive study of Rickettsia repeats confirms and extends our previous observations and further indicates a significant role of selfish DNAs in the creation and modification of proteins.

Amino Acid Sequence↗
PubMed2002

Kinetics of antibody responses in Rickettsia africae and Rickettsia conorii infections.

African tick-bite fever, caused by Rickettsia africae, is the most common tick-borne rickettsiosis in sub-Saharan Africa. Mediterranean spotted fever due to Rickettsia conorii also occurs in the region but is more prevalent in Mediterranean countries. Using microimmunofluorescence, we compared the development of immunoglobulin G (IgG) and IgM titers in 48 patients with African tick-bite fever and 48 patients with Mediterranean spotted fever. Doxycycline treatment within 7 days from the onset of disease significantly prevented the development of antibodies to R. africae. In patients with African tick-bite fever, the median times to seroconversion with IgG and IgM were 28 and 25 days, respectively, after the onset of symptoms. These were significantly longer by a median of 6 days for IgG and 9 days for IgM than the times for seroconversion in patients with Mediterranean spotted fever (P < 10(-2)). We recommend that sera collected 4 weeks after the onset of signs of patients with suspected African tick-bite fever should be used for the definitive serological diagnosis of R. africae infections.

Anti-Bacterial Agents↗
PubMed2002

Value of microimmunofluorescence for diagnosis and follow-up of Bartonella endocarditis.

Bartonella endocarditis is a disease of emerging importance that causes serious complications and high rates of mortality. Due to the fastidious nature of Bartonella species and their high degrees of antibiotic susceptibility, cultures of clinical samples most often remain sterile and valvular biopsy specimens, the best specimens for PCR amplification, are seldom available. Therefore, serology appears to be the easiest diagnostic tool. In order to determine the best cutoff value for serology and its predictive values for the detection of Bartonella endocarditis, we studied 48 patients with culture- and/or PCR-confirmed Bartonella endocarditis. We also applied these serological criteria to 156 patients with blood culture-negative endocarditis. Furthermore, we compared the kinetics of the antibody responses to Bartonella spp. in order to estimate the value of serology for prediction of the occurrence of relapses. A titer of > or = 1:800 for immunoglobulin G antibodies to either Bartonella henselae or B. quintana has a positive predictive value of 0.810 for the detection of chronic Bartonella infections in the general population and a value of 0.955 for the detection of Bartonella infections among patients with endocarditis. When this cutoff was applied to 156 patients with blood culture-negative endocarditis, we were able to diagnose Bartonella infections in an additional 45 patients with definite endocarditis for whom a positive Bartonella serology was the only evidence of infection. On follow-up, the kinetics of the decrease in antibody titers were significantly delayed in two patients with relapses. In conclusion, we recommend the determination of antibodies to both B. quintana and B. henselae and the use of a cutoff value of 1:800 for the diagnosis of Bartonella endocarditis. We propose that this criterion, which may also help with the detection of late relapses, be included as a major criterion in the Duke criteria for the diagnosis of infective endocarditis.

Antibodies, Bacterial↗
PubMed2002

Improved culture from lymph nodes of patients with cat scratch disease and genotypic characterization of Bartonella henselae isolates in Australia.

Over a 4-year period we detected Bartonella henselae isolates in 104 of 297 specimens (35.1%) from Australian patients clinically suspected of having cat scratch disease by amplification of a fragment of the htrA gene. We isolated 17 B. henselae strains (20.5%) from the 83 PCR-positive human specimens available for culture. Our culture method was based on prolonged incubation in a moist atmosphere of blood agar to which hemin was added. We obtained more B. henselae isolates than the number of all other isolates from lymph nodes reported in the literature. In order to identify and study the genetic variation of Australian B. henselae isolates, we determined the sequence of a fragment of the pap31 gene from our 17 human isolates and also from 8 Australian cat isolates. Thirteen of the human B. henselae isolates belonged to the Houston genotype, variant Houston-1 (76.5%), and four belonged to the Marseille genotype, variant CAL-1 (23.5%). In contrast, seven cat isolates were classified as B. henselae Marseille, variant CAL-1 (87.5%), and one was classified as B. henselae Houston, variant Houston-1 (12.5%). Our study describes an efficient culture method for the diagnosis of cat scratch disease and contributes to the description of the genotypic distribution of B. henselae in Australia.

Australia↗
PubMed2002

Genomic variation of Bartonella henselae strains detected in lymph nodes of patients with cat scratch disease.

Bartonella henselae is the primary agent of cat scratch disease (CSD). In order to study the genetic variation of B. henselae and the correlation of the various genotypes with epidemiological and clinical findings, two seminested, groEL- and pap31-based PCR assays were carried out with specimens from 273 patients. Amplicons were sequenced to determine the genotype of the causative Bartonella species. Compared to our reference intergenic spacer region-based PCR, the groEL- and pap31-based assays were 1.7 and 1.9 times more sensitive, respectively. All 107 positive patients were infected with B. henselae; neither Bartonella clarridgeiae nor other species were detected. Based on the groEL and pap31 sequences, B. henselae amplicons were classified into two genogroups, Marseille and Houston-1, and into four variants, Marseille, CAL-1, Houston-1, and a new variant, ZF-1. Patients infected with either one or the other genogroup did not exhibit different epidemiological or clinical characteristics. Our study highlights the genotypic heterogeneity of B. henselae in patients with CSD.

Adolescent↗
PubMed2002

Genetic identification of rickettsiae isolated from ticks in Japan.

Following the description in Japan of Japanese spotted fever, caused by Rickettsia japonica, a search for the vector of this disease led to the isolation of several rickettsiae from various tick species. Sixty-three rickettsial isolates were obtained from six different tick species, and six type strains were described by PCR and monoclonal antibody testing. We identified these six strains by amplification and sequencing of the genes encoding 16S rRNA and citrate synthase. We confirmed that the isolates from Dermacentor taiwanensis and Haemaphysalis flava ticks were R. japonica isolates. In Ixodes ovatus, Ixodes persulcatus, and Ixodes monospinosus, we identified a Rickettsia identical or closely related to Rickettsia helvetica, a species that is pathogenic for humans and that to date has only been found in Europe. Finally, we identified a new genotype of unknown pathogenicity, genotype AT, that was isolated from Amblyomma testudinarium ticks and that is closely related to a Slovakian genotype obtained from Ixodes ricinus ticks.

Animals↗
PubMed2002

Human pathogens in body and head lice.

Using polymerase chain reaction and sequencing, we investigated the prevalence of Rickettsia prowazekii, Bartonella quintana, and Borrelia recurrentis in 841 body lice collected from various countries. We detected R. prowazekii in body lice from Burundi in 1997 and in lice from Burundi and Rwanda in 2001; B. quintana infections of body lice were widespread. We did not detect B. recurrentis in any lice.

Animals↗