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P Brouqui

Publications and source records attributed to P Brouqui.

At least 109 records · Page 6Linked to original sources
PubMed1994

Serologic evidence for human ehrlichiosis in Africa.

Human ehrlichiosis is a recently recognized rickettsial disease. It is caused by Ehrlichia chaffeensis, an intraleucocytic Gram-negative, obligate intracellular bacterium, grouped within the genus Ehrlichiae. Most human cases of ehrlichiosis have been diagnosed in the USA. Two cases have been reported outside of the USA, one in Europe and one in Africa. From 1 January to 30 June 1992, 765 sera from blood donors or other asymptomatic subjects in 8 African countries, including Ivory Coast, Burkina Faso, Mali, Central African Republic, Angola, Zimbabwe, Mozambique and Commores Islands, were tested by indirect immunofluorescence for the presence of E. chaffeensis antibodies. Positive sera were confirmed by Western immunoblotting. Only two of 765 sera tested were positive. One serum obtained from Burkina Faso had an IgG titer of 1:200 and one from Mozambique had an IgG titer of 1:80. Human ehrlichiosis seems to occur infrequently in Africa, although many more sera from additional African countries need to be evaluated.

Africa↗
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

Serologic diagnosis of human monocytic ehrlichiosis by immunoblot analysis.

Human monocytic ehrlichiosis is caused by Ehrlichia chaffeensis, an intracellular bacterium probably transmitted by the tick Amblyomma americanum in the United States. Despite its lack of specificity in discriminating among infections by closely related Ehrlichia spp., immunofluorescence assay (IFA) is the most frequently used serological diagnostic method. To improve the specificity of the serological diagnosis, we compared antigenic profile of E. canis and E. chaffeensis antigen with homologous and heterologous sera, searching for the specificity of the presence of low-molecular-weight proteins. Western immunoblot analysis of IFA-positive human sera revealed 27- and 29-kDa proteins which are not found in E. canis IFA-positive sera from dogs. IFA-positive sera from dogs revealed a low-molecular-weight group of proteins (20 to 28 kDa) which were not found in human E. chaffeensis-positive sera except for a weak band at 22 kDa. The presence o antibodies directed against the 27- and 29-kDa proteins on Western blots is specific for E. chaffeensis infection, and we suggest that the Western blot might complete IFA in cases with low positive predictive value.

Animals↗
PubMed1994

Cytopathic effect, plaque formation, and lysis of Ehrlichia chaffeensis grown on continuous cell lines.

Ehrlichiae are strict intracellular bacterial pathogens that parasitize leukocytes or other blood cells. Only six agents of the tribe Ehrlichieae, namely, Cowdria ruminantium, Neorickettsia helminthoeca, Ehrlichia risticii, Ehrlichia sennetsu, Ehrlichia canis, and Ehrlichia chaffeensis, have been adapted to growth in continuous cell lines. E. chaffeensis, the agent of human ehrlichiosis, has been cultured only in a cell line of canine origin. We adapted purified cell-free E. chaffeensis for growth in human embryonic lung (HEL) fibroblasts (HEL 299), green monkey kidney cells (Vero), and a human cervical epithelioid carcinoma (HeLa) cell line. We observed a cytopathic effect with both Vero cells and HEL cells and plaque formation with cellular lysis when infected Vero cells were cultured in agar. Human fibroblasts are already commonly used for the isolation of viruses, coexiellae, and rickettsiae. Furthermore, the capability of these cells to support the growth of ehrlichiae suggests that they may be useful for primary isolation of ehrlichiae as well. The cytopathic effect produced in Vero or HEL cells offers a very helpful indicator of the infection. Plaque formation in Vero cells is a new phenomenon not yet reported for ehrlichiae and will allow the titration of inocula and clonal purification of this bacterium.

Adaptation, Physiological↗
PubMed1994

Further evidence for the efficacy of imidocarb dipropionate in the treatment of Ehrlichia canis infection.

Three dogs experimentally infected with Ehrlichia canis developed thrombocytopaenia and high antibody titres to E. canis in indirect fluorescent antibody tests. One dog also became leukopaenic. At Weeks 6 and 8 post-infection, the dogs were treated with imidocarb dipropionate (5 mg kg-1 subcutaneously) and a further dose was administered at Week 12 (5 mg kg-1 intramuscularly). Twelve weeks after the last treatment (post-treatment), all dogs had normal platelet counts which persisted for a further 10 weeks until the end of the experiment. The leukopaenia resolved 20 weeks post-treatment. Although antibody titres (< 1/5) to E. canis could not be detected prior to infection, titres of 1/2 560 to 1/5 120 developed by Week 6. By Week 8 post-treatment titres began to decline and by the end of the experiment were 5- to 6-fold serum dilutions lower (1/80 to 1/320). Sub-inoculation experiments 18 weeks post-treatment, failed to cause disease or stimulate antibody responses in susceptible dogs. Serology and sub-inoculation studies on 2 dogs experimentally infected with E. canis but not treated with imidocarb dipropionate, showed that these animals remained infected for the duration of the experiment. The results of these experiments confirm that imidocarb dipropionate is effective in the treatment of canine ehrlichiosis.

Animals↗
PubMed1993

Infections with Babesia canis and Ehrlichia canis in dogs in Zimbabwe.

Of 105 dogs examined at a veterinary hospital in Harare, Zimbabwe, 52 per cent had antibodies reactive with Ehrlichia canis in indirect fluorescent antibody tests, 26 per cent had Babesia canis parasites in peripheral blood smears and 17 per cent had both infections. None of the dogs with serological evidence of ehrlichiosis had typical E canis morulae detectable in blood smears. The infections were regarded as incidental findings not readily related to the reasons for examination in 46 per cent of the dogs with antibodies to E canis and 17 per cent of the dogs with both infections. The most common laboratory abnormalities were anaemia and thrombocytopenia and the prevalence and severity of these in concurrent infections were intermediate to those found in individual infections. There were no pathognomonic clinical signs or laboratory abnormalities which could be used to distinguish between individual and concurrent infections. However, there was a significantly higher prevalence of non-regenerative anaemia in dogs with antibodies to E canis than in dogs with both infections. The prevalence of thrombocytopenia was significantly higher in dogs with babesiosis than in dogs with antibodies to E canis and the prevalence of hyperglobulinaemia was significantly higher in dogs with both infections than in dogs with antibodies to E canis.

Anemia↗
PubMed1993

Demonstration of Rickettsia conorii-induced endothelial injury in vivo by measuring circulating endothelial cells, thrombomodulin, and von Willebrand factor in patients with Mediterranean spotted fever.

The endothelial cell (EC) is the primary target for Rickettsia conorii (RC) in Mediterranean spotted fever (MSF). Clinical manifestations such as thrombosis and vasculitis are mediated by pathologic changes localized in blood vessels. To study the in vivo endothelial injury induced by RC, markers of endothelial damage, including circulating EC (CEC), plasmatic thrombomodulin (TM), and von Willebrand factor (vWF), were investigated in 12 patients with MSF. CEC were counted in whole blood by a new immunomagnetic separation assay using a specific anti-EC antibody, S-Endo 1. Plasmatic TM and vWF antigens were measured by enzyme-linked immunosorbent assay. High levels of CEC and cell fragments were found in patients with a severe or malignant form of MSF. Sequential studies of CEC showed a decrease from 162 +/- 454 cells/mL before treatment to 6 +/- 7 cells/mL during treatment and recovery. Mean plasma TM and vWF levels that were also elevated before therapy (TM, 106 +/- 27 ng/mL; vWF, 420% +/- 164%) decreased progressively (TM, 55 +/- 43 ng/mL; vWF, 148% +/- 26%) during treatment. The measurement of cellular and molecular markers of vascular damage such as CEC, plasmatic TM, and vWF contributes to the definition of the Rickettsia-induced endothelial injury in vivo.

Antibodies, Monoclonal↗
PubMed1993

Chronic Q fever. Ninety-two cases from France, including 27 cases without endocarditis.

OBJECTIVE: Chronic Q fever is seldom recognized; before 1989, only 234 cases had been reported in the literature. The 92 cases of chronic Q fever collected at the French National Reference Center for Rickettsioses from 1982 through 1990 represent the largest series ever reported. PATIENTS: The patients included in the study were diagnosed between July 31, 1982, and August 1, 1990, at the French National Reference Center for Rickettsioses as having chronic Q fever by the following criteria: presence of antibody against Coxiella burnetii phase I antigen at a titer greater than or equal to 800 for IgG and 50 for IgA by the indirect immunofluorescence test. Epidemiologic, clinical, laboratory, and treatment data were collected from 39 different collaborative hospitals throughout France. MAIN OUTCOME MEASURE: For each serologically selected patient, a computerized questionnaire was utilized to record 188 different items of demographic, epidemiologic, clinical, laboratory, and therapeutic data, which were analyzed. RESULTS: Chronic Q fever occurs more frequently in city dwellers than in rural inhabitants, and exposure to domestic ruminants and raw milk is an important feature. Immunocompromising conditions (20.2%) and underlying heart disease (88.4%) or vascular disease are the most important risk factors to consider in potential cases of chronic Q fever. The mortality in these patients with endocarditis was high (23.5%). The clinical spectrum of 84 patients included 57 cases of endocarditis, three cases of vascular prosthesis infection, three cases of aneurysmal infection, three cases of osteoarthritis, four cases with lung localizations, nine asymptomatic cases, three cases of hepatitis, and two cases with cutaneous forms of the disease. CONCLUSIONS: In patients with unexplained fever, negative blood cultures, and a history of underlying vascular or cardiac disease, Q fever should be considered.

Adult↗
PubMed1993

Proteinase K-sensitive and filterable phagosome-lysosome fusion inhibiting factor in Afipia felis.

Afipia felis is one of the putative agents of cat scratch disease (CSD). Its intracellular location was previously demonstrated in tissue sections. It has been recently grown in human monocytes and in HeLa cells. We report that A. felis may infect human macrophages and the P 388 D1 murine macrophage cell line, yet is unable to grow in the cell-free culture medium. In both human macrophages and P 388 D1, the organisms multiply in a vacuole after active inhibition of phagosome-lysosome fusion (P-L) as demonstrated with cationized ferritin-labeled lysosomes. This P-L fusion inhibition is diffusable and is due to a filterable factor which is inactivated by protease digestion. The pathogenic role of A. felis in CSD may result from its ability to invade and multiply in macrophages.

Animals↗
PubMed1993

Detection of Ehrlichia chaffeensis in human tissue by using a species-specific monoclonal antibody.

A mouse monoclonal antibody (MAb 1A9) was produced and used in detection of Ehrlichia chaffeensis in human tissues including kidney, liver, and lung by using an indirect immunohistologic stain. MAb 1A9 was specific to E. chaffeensis and did not react with other bacteria, including Ehrlichia canis, which is the organism most closely related to E. chaffeensis. It reacted with an epitope present in two surface proteins of E. chaffeensis with molecular masses of 29 and 27 kDa. E. chaffeensis was easily detected in human tissue by immunohistology with MAb 1A9. This study demonstrates that our MAb can provide a specific and simple method for detection of E. chaffeensis in clinical specimens for establishing an etiologic diagnosis of human ehrlichiosis; it may also provide a tool for the investigation of immunopathologic characteristics in infected patients.

Animals↗
PubMed1993

[Treatment of eruptive rickettsioses. Review of the literature from the microbiology to the clinic].

The authors review the literature concerning the treatment of rickettsiosis including Rocky Mountain spotted fever, Mediterranean spotted fever, murine typhus, and Scrub typhus. They report in vitro antibiotic susceptibilities of the causing organisms and in vivo activity on animal models. They also report their clinical experience and these of the literature in the treatment of rickettsiosis.

Animals↗
PubMed1993

Western blot and indirect fluorescent antibody testing for antibodies reactive with Ehrlichia canis in sera from apparently healthy dogs in Zimbabwe.

Sera were collected from apparently healthy dogs in 3 major centres in Zimbabwe to establish the prevalence of antibodies reactive with Ehrlichia canis by indirect fluorescent antibody (IFA) testing at titres of 1/20 or greater. The overall seroprevalence was 42% (39/93) with dogs from Mutare (40%) and Harare (33%) having similar rates which were lower than those for Bulawayo (68%). The majority of the IFA positive dogs from Harare (67%) had no haematological or biochemical evidence of canine ehrlichiosis. Total protein, albumin and globulin values were determined in sera from blood collected from Bulawayo and Mutare and all values were within normal reference ranges. Western blot profiles of sera from dogs with IFA titres of greater than 1/160 were similar to those using sera from dogs experimentally infected with E. canis Oklahoma strain. Our results indicate that an organism which is antigenically very similar or identical to E. canis is present in Zimbabwe and that dogs are commonly exposed to this organism.

Animals↗