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D Raoult

Publications and source records attributed to D Raoult.

At least 361 records · Page 20Linked to original sources
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↗
PubMed1994

Serotyping Coxiella burnetii isolates from acute and chronic Q fever patients by using monoclonal antibodies.

Four mouse monoclonal antibodies reacting with Coxiella burnetti lipopolysaccharide antigens were produced and used in serotyping 17 C. burnetii isolates from acute Q fever and Q fever endocarditis patients in France. Two monoclonal antibodies (1B2 and 3B6) were considered specific for the Priscilla strain, a representative of Q fever endocarditis isolates, and did not react with the Nine Mile strain, which is representative of acute Q fever isolates. Monoclonal antibodies Nos. 1B2 and 3B6 reacted with 75% (3/4) acute Q fever isolates and 85% (11/13) of endocarditis isolates from France. It is reasonable to conclude that Priscilla-like strains cause both acute Q fever and Q fever endocarditis. The hypothesis that Priscilla-like strains only are associated with Q fever endocarditis should be reconsidered.

Acute Disease↗
PubMed1994

Western blot as a seroepidemiologic tool for detecting foci of Mediterranean spotted fever (MSF).

We conducted a serosurvey on Mediterranean spotted fever (MSF), in a nonendemic area using western blot and microimmunofluorescence. Among 262 tested sera, 53 were positive by micro-immunofluorescence at a titer of 50. When 48 positive sera were western blot tested, 15 did not exhibited any reaction, 17 reacted against the non-specific lipopolysaccharide, and only 16 reacted against the specific protein antigens. Fourteen of the sera with a specific reaction were sampled in a village with a unique submediterranean climate. Western blot may be a more specific tool to determine the real seroprevalence of MSF.

Adult↗
PubMed1994

In vitro antistaphylococcal activity of collagen-sealed Dacron vascular prostheses bonded with rifampin, vancomycin, or amikacin.

The goals of this study were to evaluate the in vitro antistaphylococcal activity of vascular Dacron prostheses to which a type I collagen and an antibiotic had been bonded. Collagen was fixed to the prosthesis either by an original grafting procedure or by impregnation. The antibiotics used included rifampin, vancomycin, and amikacin. They were bonded to the prosthesis either at the same time as the collagen or by soaking the prosthesis in an antibiotic solution at the beginning of the experiment. Each prosthesis was sliced into 6 mm diameter circles and preserved in a solution of saline and albumin, which was changed every day. Three disks were retrieved from each prosthesis at the beginning of the experiment and then every 24 hours; these were placed in gelose smeared with Staphylococcus aureus. The diameter of the inhibition area of each disk was measured at 24 hours. The initial inhibition area (So), the time at which the inhibition area was equal to 50% of So, and the time at which the activity was nil were used to characterize the activity of the prostheses and to calculate a beta coefficient of decreasing activity. The prostheses bonded with vancomycin or amikacin did not show adequate activity. Those bonded with rifampin were effective for at least 4 days. When rifampin was grafted to the prosthesis, the So was 278.6 mm2, 50% of So was reached within 10.4 days, the duration of effective activity was 25.7 days, and the beta coefficient was 0.067. The two prostheses soaked in rifampin had a significantly more rapid decrease (beta = 0.19 and 0.56) and a shorter duration of effective activity (12.4 and 4.5 days). Both collagen-coated prostheses, whether impregnated or soaked with rifampin, have a sufficient duration of activity to be tested in an animal model.

Amikacin↗
PubMed1994

Immunohistologic demonstration of Coxiella burnetii in the valves of patients with Q fever endocarditis.

PURPOSE: Cardiac valves that were resected from patients with Q fever endocarditis were examined by immunohistologic methods to correlate the presence of Coxiella burnetii in the valves with the histopathologic, serologic, microbiologic, and clinical findings. PATIENTS: Seventeen patients with serologic and microbiologic or clinical evidence of Q fever endocarditis who presented with cardiac failure secondary to valvular dysfunction and required valve replacement surgery were selected from the clinical records of the Unité des Rickettsies, Marseille, France. METHODS: Clinical data were collected by questionnaire. Serologic characterization was performed by indirect immunofluorescent antibody testing; shell vial cultivation of C burnetii was performed from resected valves and blood when available; and pathologic and immunohistologic testing for localization of C burnetti in resected valves were performed by standard methods using both polyclonal and monoclonal C burnetti antibodies. RESULTS: Demographic and clinical findings were typical of patients with Q fever endocarditis. Pure chronic inflammation or mixtures of acute and chronic inflammation were the most frequent inflammatory patterns present and were associated with fibrin deposition, necrosis, and fibrosis. Well-formed granulomas were not present, but the granulomatous inflammation observed in 6 of these 17 patients was associated with foreign body reactions or with valvular calcifications secondary to preexisting valvular damage and could not be directly attributed to infection. C burnetii were present nearly exclusively in macrophages in sites of inflammation and valvular injury and only in the vegetations. Immunohistologic results confirmed the valve culture results in 10 of 14 cases. CONCLUSION: The pathologic findings in the valves of patients with Q fever endocarditis are nonspecific. The presence of empty or foamy macrophages is suggestive of infection by C burnetii; however, definitive identification rests upon the demonstration of the organism in the tissue by immunohistology. Q fever endocarditis probably results from infection of previously damaged heart valves. The finding of the absence of granulomas in these cases contrasts with the pathologic findings in patients with acute, self-limited Q fever and suggests an aberrant host immune response that permits persistence of the bacterium and chronic, prolonged valvular infection and injury. The pathologic findings and distribution of C burnetii in the damaged valve tissues explain the clinical findings of valve failure and occasional embolic episodes, as well as the frequent ability to isolate C burnetii from the peripheral blood of infected patients. Immunohistology may be a valuable diagnostic tool in places where serology and culture are not available.

Acute Disease↗
PubMed1994

Serological evidence for antigenic relationships between Ehrlichia canis and Cowdria ruminantium.

The sera from dogs experimentally infected with Ehrlichia canis reacted at very similar titres in indirect fluorescent antibody (IFA) tests with E canis and Cowdria ruminantium antigen. In Western blots these sera reacted strongly with the immunodominant antigens of E canis (27 kDa) and C ruminantium (25 and 32 kDa). The dogs experimentally infected with C ruminantium showed no clinical evidence of infection, though the presence of organisms in the blood was demonstrable, for up to two weeks after inoculation, by a polymerase chain reaction. The sera from these dogs were also reactive with both organisms in the IFA tests, but the antibody titres were four- to fivefold higher with C ruminantium than with E canis antigen. In Western blots, these sera reacted strongly with the 25 and 32 kDa antigens of C ruminantium but weakly with the 27 kDa antigen of E canis. These results provide strong evidence that the immunodominant antigens of E canis and C ruminantium contain cross-reacting epitopes.

Animals↗
PubMed1994

Coxiella burnetii infection of pseudoaneurysm of an aortic bypass graft with contiguous vertebral osteomyelitis.

We report the case of a 67-year-old man who had an infection of a pseudoaneurysm of an aortic graft with contiguous vertebral osteomyelitis. The infectious organism was identified as Coxiella burnetii, a strict intracellular pathogen causing Q fever infection in humans. The patient was treated successfully with removal of the infected material in conjunction with extraanatomic bypass and specific antibiotic therapy. He is doing well after more than 3 years, with no evidence of recurrent periaortic infection on successive computed tomographic scans. We suspect that C. burnetii vascular graft infections could be underdiagnosed, because this cause is not frequently evoked. We suggest that extending the etiologic search to C. burnetii could decrease the number of undocumented vascular graft infections.

Aged↗