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D Raoult

Publications and source records attributed to D Raoult.

At least 91 records · Page 5Linked to original sources
PubMed1995

MICs of 28 antibiotic compounds for 14 Bartonella (formerly Rochalimaea) isolates.

We assessed in vitro the antibiotic susceptibilities of 14 Bartonella isolates of the species B. quintana, B. vinsonii, B. henselae, and B. elizabethae. Columbia agar base supplemented with 5% horse blood was used as the antibiotic assay medium. Bacterial growth could be evaluated within 5 days after incubation of the plates at 37 degrees C in a 5% carbon dioxide atmosphere. The MICs at which 90% of isolates are inhibited (MIC90s) were 0.06 microgram/ml for penicillin G and amoxicillin and 0.25 microgram/ml for ticarcillin and cefotaxime. The MIC90s of oxacillin and cephalothin were 4 and 16 micrograms/ml, respectively. The MIC90s ranged from 1 to 4 micrograms/ml for aminoglycosides. Erythromycin, doxycycline, and rifampin displayed MIC90s of 0.12, 0.12, and 0.25 microgram/ml, respectively. MIC90s were 1 and 5 micrograms/ml for trimethoprim-and sulfamethoxazole, respectively, 64 micrograms/ml for fosfomycin, and 16 micrograms/ml for colistin and vancomycin. The study confirms the high levels of in vitro susceptibility of Bartonella agents to antibiotics.

Anti-Bacterial Agents↗
PubMed1995

Treatment of Pseudomonas aeruginosa-infected orthopedic prostheses with ceftazidime-ciprofloxacin antibiotic combination.

Indwelling device infections are associated with considerable morbidity and extremely high cost. Pseudomonas aeruginosa is the most frequent gram-negative etiologic agent associated with infections of indwelling catheters and foreign body implants. It is generally agreed that eradication of infection in the presence of a foreign body requires removal of the foreign body. Using a combination of ceftazidime and ciprofloxacin, we cured nine of nine patients with P. aeruginosa-infected osteosynthetic material and four of five patients with hip and knee prostheses without removing the foreign material. Follow-up was for a mean of 21 months (range, 6 to 60 months). Some patients experienced minor side effects (arthralgia in one patient and rash in another patient). We conclude that this combination is effective and safe and should be useful in the treatment of P. aeruginosa-infected orthopedic implants.

Adult↗
PubMed1995

Genotype characterization of the bacterium expressing the male-killing trait in the ladybird beetle Adalia bipunctata with specific rickettsial molecular tools.

The male-killing ladybird beetle (LB) bacterium (AB bacterium) was analyzed with specific rickettsial molecular biology tools in the LB Adalia bipunctata strains. Eight phenotype-positive LB strains showing mortality of male embryos were amplified with rickettsial genus-specific primers from the gene for citrate synthase (CS) and the gene for a 17-kDa protein and spotted fever group-specific primers from the gene for the 120-kDa outer membrane protein (ompB). The specificity of amplification was confirmed by Southern hybridization and the absence of the above-listed gene products in three phenotype-negative LB strains. Restriction polymorphism patterns of three examined amplicons from the CS gene, 17-kDa-protein gene, and ompB gene were identical among the eight phenotype-positive LB strains and were unique among all known rickettsiae of the spotted fever and typhus groups. Amplified fragments of the CS genes of the AB bacterium, Rickettsia prowazekii Breinl, Rickettsia typhi Wilmington, Rickettsia canada 2678, and Rickettsia conorii 7 (Malish) were sequenced. The greatest differences among the above-listed rickettsial and AB bacterium CS gene sequences were between bp 1078 and 1110. Numerical analysis based on CS gene fragment sequences shows the close relationships of the AB bacterium to the genus Rickettsia. Expanding of knowledge about rickettsial arthropod vectors and participation of rickettsiae in the cytoplasmic maternal inheritance of arthropods is discussed.

Amino Acid Sequence↗
PubMed1995

Rickettsia conorii entry into Vero cells.

The entry of rickettsiae into eukaryotic cells is mediated by an induced phagocytosis, but rickettsiae have never been observed in a closed phagocytic vacuole. In this study, Rickettsia conorii entry into Vero cells was observed by transmission electron microscopy during a period of 3 to 20 min after bacterium-cell contact. The entry occurred within 3 min after bacterium-cell contact, and R. conorii was observed in the process of engulfment, within a phagocytic vacuole, or free in the cytosol. Escape from the phagosome is a very rapid step since phagosome lysis was only occasionally observed. By 12 min, 90% of bacteria were internalized and half were free in the cytosol. This report confirms that rickettsiae penetrate nonphagocytic cells by induced phagocytosis and is the first demonstration of rickettsiae within a complete phagocytic vacuole.

Animals↗
PubMed1995

Genomic and proteinic characterization of strain S, a rickettsia isolated from Rhipicephalus sanguineus ticks in Armenia.

Strain S, a spotted fever group (SFG) rickettsia isolated from Rhipicephalus sanguineus ticks collected in Armenia, was identified. Microimmunofluorescence, sodium dodecyl sulfate-polyacrylamide gel protein electrophoresis and Western immunoblotting, PCR and then restriction fragment length polymorphism analysis, pulsed-field gel electrophoresis, and 16S rRNA gene sequencing were used to compare strain S with reference isolates. Strain S was found to possess proteinic, antigenic, and genomic patterns which were unique among SFG rickettsiae. Strain S is characterized by its high degree of pathogenicity for experimental animals, but its role as a potential human pathogen should be determined. The role of R. sanguineus ticks in the epidemiology of SFG rickettsiae is discussed.

Animals↗
PubMed1995

Genomic study of Rickettsia akari by pulsed-field gel electrophoresis.

Pulsed-field gel electrophoresis of SmaI-, EagI-, and BssHII-digested DNA was used to perform restriction fragment length polymorphism analysis of Rickettsia akari strains isolated from humans, rodents, and mites in the United States and Ukraine. Although some differences in biological and serological characteristics were present between strains, the genomic studies demonstrated a high degree of intraspecies homogeneity of R. akari isolates. Our results confirm the value of pulsed-field gel electrophoresis-restriction fragment length polymorphism analysis for the identification of species of rickettsiae.

Animals↗
PubMed1995

Coxiella burnetii blood cultures from acute and chronic Q-fever patients.

Q fever, a worldwide zoonosis caused by Coxiella burnetii, may present as either an acute or a chronic disease. We correlated the results of 844 C. burnetii blood cultures with serological, clinical, and therapeutic data. C. burnetii was isolated from 17% of untreated patients with acute Q fever and from 53% of untreated patients with chronic Q fever. C. burnetii was not isolated from patients who were receiving antibiotics active against C. burnetii. For seven culture-positive patients with acute Q fever, serology was negative when C. burnetii was isolated. One patient with acute Q fever had a positive blood culture 25 days after the discontinuation of specific antibiotic therapy, and another had a positive blood culture after the resolution of symptoms. In one case of chronic Q fever, a positive blood culture resulted from noncompliance with treatment. The culture method described in this report is suitable for all laboratories with cell culture facilities. Our findings suggest that blood samples must be collected prior to the initiation of an antibiotic regimen if C. burnetii is to be successfully isolated.

Acute Disease↗
PubMed1995

Inter- and intraspecies identification of Bartonella (Rochalimaea) species.

Species of the genus Rochalimaea, recently renamed Bartonella, are of a growing medical interest. Bartonella quintana was reported as the cause of trench fever, endocarditis, and bacillary angiomatosis. B. henselae has been implicated in symptoms and infections of human immunodeficiency virus-infected patients, such as fever, endocarditis, and bacillary angiomatosis, and is involved in the etiology of cat scratch disease. Such a wide spectrum of infections makes it necessary to obtain an intraspecies identification tool in order to perform epidemiological studies. B. vinsonii, B. elizabethae, seven isolates of B. quintana, and four isolates of B. henselae were studied by pulsed-field gel electrophoresis (PFGE) after restriction with the infrequently cutting endonucleases NotI, EagI, and SmaI. Specific profiles were obtained for each of the four Bartonella species. Comparison of genomic fingerprints of isolates of the same species showed polymorphism in DNA restriction patterns, and a specific profile was obtained for each isolate. A phylogenetic analysis of the B. quintana isolates was obtained by using the Dice coefficient, UPGMA (unweighted pair-group method of arithmetic averages), and Package Philip programming. Amplification by PCR and subsequent sequencing using an automated laser fluorescent DNA sequencer (Pharmacia) was performed on the intergenic spacer region (ITS) between the 16 and 23S rRNA genes. It was found that each B. henselae isolate had a specific sequence, while the B. quintana isolates fell into only two groups. When endonuclease restriction analysis of the ITS PCR product was done, three enzymes, TaqI, HindIII, and HaeIII, allowed species identification of Bartonella spp. Restriction fragment length polymorphism after PCR amplification of the 16S-23S rRNA gene ITS may be useful for rapid species identification, and PFGE could be an efficient method for isolate identification.

Animals↗
PubMed1995

Identification of Bartonella (Rochalimaea) species among fastidious gram-negative bacteria on the basis of the partial sequence of the citrate-synthase gene.

The bacterial genus Bartonella (Rochalimaea) includes emerging human pathogens with five recognized species. These are fastidious gram-negative bacteria, exhibiting few phenotypic characteristics and whose identification relies upon serotyping, cellular fatty acid analysis, and molecular typing. Most of the isolates have been recovered from the blood of patients, and three of the four pathogenic Bartonella species are associated with infectious endocarditis. We performed PCR-restriction fragment length polymorphism (RFLP) analysis of the blood culture bottle supernatant for the routine identification of Bartonella species among fastidious gram-negative bacteria. The amplification of the citrate-synthase gene with primers previously reported (R. L. Regnery, C. L. Spruill, and B. D. Plikaytis, J. Bacteriol. 173:1576-1589, 1991) yielded a 379-bp product from Bartonella species and a 382-bp product for Capnocytophaga ochracea but no product from any of the other 15 genotypically or phenotypically related species tested. We determined the sequences of the citrate-synthase gene-amplified products for Bartonella species and C. ochracea in order to predict the optimal restriction enzyme to be used in RFLP analysis. TaqI and AciI allowed identification of Bartonella species and C. ochracea. We propose that acridine orange and Gram staining, followed by PCR-RFLP analysis of the blood bottle supernatant, be included in the examination of blood samples from patients with suspected infectious endocarditis.

Bartonella↗
PubMed1995

[Acute pericarditis in Coxiella burnetti infection. Apropos of a case].

The authors report a case of pleuro-pericarditis during an acute Coxiella burnetii infection. They point out the rarity of this mode of presentation of acute Q fever and the diagnostic difficulties in the absence of focal pulmonary or hepatic signs. The diagnosis was confirmed by serological changes, essentially indirect immunofluorescence. They underline the importance of early diagnosis before the disease become chronic, exposing the patient to more serious cardiac disease which may be difficult to treat.

Acute Disease↗
PubMed1994

[Infections of cutaneous wounds].

Infection of cutaneous wounds can be defined as proliferation of microorganisms at an interruption in the mucocutaneous covering. The phenomenon depends on an association of local and general factors which disturb the balance in host-pathogen interactions, in favor of the latter. In addition to infections by nonspecific pyogenic germs, whether posttraumatic or postsurgical, there are specific infections where the wound is the departure point for a systemic infection. Even today, tetanus and gaseous gangrene should be apprehended and systematically prevented. Similarly, the high incidence of infection of bite or scratch wounds (animal or human) should suggest prophylactic antibiotic treatment as well as evaluation of the risk of rabies in the case of animal bites or scratches. In any case, even if antibiotic treatment must be undertaken as an emergency measure, previous bacteriological investigation should be carried out if possible since it permits subsequent adaptation in case of failure of the initial antibiotic treatment.

Animals↗
PubMed1994

Species-specific BALB/c mouse antibodies to rickettsiae studied by western blotting.

BALB/c mice were inoculated intraperitoneally either once only, or up to four times at weekly intervals, with viable Rickettsia rickettsii, Rickettsia conorii or the Israeli spotted fever group rickettsia. Sera collected one week after the last inoculation were tested for the presence of antibodies reactive with the above organisms by indirect fluorescent antibody testing and Western blot. With repeated inoculations there was a general progressive rise in homologous and heterologous immunofluorescence titers although the increase after the first inoculation was always the greatest. For each rickettsia, the homologous titers were higher than the heterologous titers. Western blots showed that the reactive antibodies were against rickettsial high molecular mass species specific protein antigens and homologous species-specific antibody reactions were detectable earlier than heterologous cross-reacting antibody reactions. Antibodies in mice sera did not react with the group specific lipopolysaccharide-like antigens of the rickettsiae although such reactivity was strong in Western blots with sera from patients suffering from acute Rickettsia conorii infections. Our findings suggest that the intraperitoneal route of inoculation of BALB/c mice can be used for the differentiation of spotted fever group rickettsiae.

Animals↗
PubMed1994

[New bacterial infections in the course of AIDS].

The authors reviewed the recent data on unusual or newly described bacterial infection in AIDS. Mycoplasma species are frequently associated with AIDS and hypothesized to play as a cofactor in AIDS evolution (Mycoplasma fermentans and Mycoplasma penetrans). Rochalimea henselea and Rochalimea quintana are the agents of peliosis and bacillary angiomatosis. Some Mycobacterium and Campylobacter species, not previously considered as human pathogens, have been recently involved in severe infection in patients with AIDS.

AIDS-Related Opportunistic Infections↗
PubMed1994

Reactivity of sera collected from dogs in Mutare, Zimbabwe, to antigens of Ehrlichia canis and Cowdria ruminantium.

Six of 20 sera from apparently healthy dogs in Mutare, Zimbabwe, contained antibodies which were reactive with Cowdria ruminantium and Ehrlichia canis in indirect fluorescent antibody tests at similar titres. In Western blots these sera recognised the immunodominant antigen bands of the two organisms. Sera with high titres (> 1/80) recognised additional antigen bands of each organism. It was not possible to determine whether these dogs had been exposed to C ruminantium, E canis or other Ehrlichia species. In areas where these organisms coexist serological tests for canine ehrlichiosis should be interpreted with caution.

Animals↗
PubMed1994

[Research of Lyme's disease in facial paralysis. A French multicenter study].

OBJECTIVES: Apparent a frigore facial palsy could possibly mask manifestations of unrecognized Lyme's disease. Since commonly used corticosteroid treatment could be deleterious if Borrelia burgdorferi infection was indeed the cause, we conducted a prospective study to search for possible infections in cases of recently diagnosed a frigore facial palsy. METHODS: For 3 years, 1990-1992, 49 French centres diagnosed a facial palsy in 346 patients (310 adults, 36 children under 15 years of age; mean age 38; range 16 months to 83 years). The patients were divided into three groups: a) facial palsy alone, b) zoster origin recognized due to outer ear eruption and c) cases with meningoradiculitis or joint signs or cases with facial diplegia. A questionnaire was used to evaluate exposure to risk of tick bits. A control group was established with 246 serum samples from subjects matched with the patients for age, geographical origin and exposure to risk of tick bits. Laboratory tests (indirect immunofluorescence and Western blot) were performed to search for anti-Borrelia burgdorferi antibodies in serum samples, and cerebral spinal fluid when possible, collected at presentation, on day 30 and on day 90. RESULTS: Sixty percent of the patients were urban dwellers, 15% lived in rural and 25% in semi-rural areas. There were 294 patients with facial palsy alone and their serum results were compared with those of the matched controls. There was no significant difference in the positivity for Borrelia burgdorferi antibodies between these two groups. CONCLUSION: These findings indicate that, unless there are clinical signs suggestive of borreliosis, it would not be necessary to test for Lyme's disease in patients with apparent a frigore facial palsy.

Adolescent↗
PubMed1994

[A new bacterium: Rochalimaea].

Originally limited to trench fever, infections due to Rochalimaea now comprise manifestations particular to patients with human immunodeficiency virus (bacillary angiomatosis and hepatic peliosis), but also manifestations as diverse as isolated fever, septicaemia, endocarditis, lymphocytic meningitis, or central neurological disorders, in immunodepressed or immunocompetent subjects. The involvement of Rochalimaea in cat-scratch fever remains debated. Microbiological analysis used for diagnosis has been modified to allow isolation of these new bacteria, whose culture is slow and difficult, in the course of the above-cited clinical manifestations, which should further extend the range of Rochalimaea infections.

Alphaproteobacteria↗