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Florence Fenollar

Publications and source records attributed to Florence Fenollar.

28 records · Page 2Linked to original sources
PubMed2003

Whipple's disease: immunospecific and quantitative immunohistochemical study of intestinal biopsy specimens.

Whipple's disease may be diagnosed by periodic acid-Schiff (PAS) staining, electron microscopy, or polymerase chain reaction of intestinal biopsy specimens. The aim of this study was to evaluate the diagnostic value of immunohistochemistry and the quantification of infected cells in intestinal Whipple's disease. A total of 29 duodenal biopsy specimens from 15 patients with untreated and treated Whipple's disease were examined and compared with biopsy specimens from control patients with normal intestinal mucosa or various pathologic processes. Percentages of staining surfaces with PAS stain and antibodies directed against CD68, a macrophage marker, or the Whipple bacillus, Tropheryma whipplei, were studied quantitatively using a computerized system of image analysis. Positive detection of T. whipplei was obtained using immunohistochemistry in all 15 patients with Whipple's disease. No bacteria were detected in any of the negative controls. The use of quantitative image analysis showed a massive intestinal macrophagic infiltration before (20.3%) and after (13.4%) antibiotic therapy completion as compared with controls (2.1%). The 2 detection methods for T. whipplei, PAS stain and immunohistochemistry, were quantitatively similar before therapy (19.9% versus 17.5%), but the immunodetection-based surface area was significantly lower than the PAS staining surface area after therapy (2.8% versus 7.9%). Our findings indicate that immunohistochemistry is highly specific and sensitive and is applicable as a diagnostic method on intestinal tissue specimens to detect T. whipplei during active infection or in retrospective studies.

Actinobacteria↗
PubMed2003

Wolbachia pipientis growth kinetics and susceptibilities to 13 antibiotics determined by immunofluorescence staining and real-time PCR.

Wolbachia spp. are strict intracellular bacteria that infect a wide range of arthropods and filarial nematodes. Filarial nematodes are important causes of human diseases. There is increasing evidence that Wolbachia spp. influence important functions in the biology of the hosts, specifically, infertility. Preliminary experiments with humans and animals have suggested that antibiotics with activity against Wolbachia may help to treat filariasis. In this study, we determined using a real-time quantitative PCR assay the growth kinetics of a strain of Wolbachia pipientis from a mosquito grown in Aa23 cells. The doubling time was estimated to be 14 h. We then determined the susceptibilities of this strain to 13 antibiotics by two methods: an immunofluorescent-antibody test and a real-time quantitative PCR assay. Both techniques gave similar results. Doxycycline and rifampin were the most effective compounds, with MICs of 0.125 and 0.06 to 0.125 micro g/ml, respectively. Fluoroquinolones were less effective, with MICs of 2 to 4 micro g/ml for ciprofloxacin, 2 micro g/ml for ofloxacin, and 1 micro g/ml for levofloxacin. beta-Lactams (penicillin G, amoxicillin, ceftriaxone) were not effective at concentrations up to 128 micro g/ml. The MIC of erythromycin was >32 micro g/ml, whereas that of telithromycin was 8 micro g/ml. Other antibiotic compounds were bacteriostatic only at high concentrations, including gentamicin, co-trimoxazole, and thiamphenicol. The real-time PCR assay was a convenient and reliable technique for determination of the antibiotic susceptibilities of WOLBACHIA: It may help in the future to simplify antibiotic susceptibility testing of strict intracellular pathogens.

Animals↗
PubMed2003

Culture and phenotypic characterization of a Wolbachia pipientis isolate.

The recent isolation of Wolbachia pipientis in the continuous cell line Aa23, established from eggs of a strain of the Asian tiger mosquito Aedes albopictus, allowed us to perform extensive characterization of the isolate. Bacterial growth could be obtained in C6/36, another A. albopictus cell line, at 28 degrees C and in a human embryonic lung fibroblast monolayer at 28 and 37 degrees C, confirming that its host cell range is broader than was initially thought. The bacteria were best visualized by Diff-Quik and May-Grünwald-Giemsa staining. Proteins from 213 to 18 kDa with two major protein bands of 65 and 25 kDa were observed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. By Western blotting with specific polyclonal mouse and rabbit antisera, dominant immunoreactive antigens were found at approximately 100, 80, and 30 kDa. The genome size was calculated to be 1,790 +/- 17 kb by pulsed-field gel electrophoresis. The sequence of the citrate synthase gene (gltA) of W. pipientis was determined by gene walking. Its position in the phylogenetic tree constructed with gltA confirmed that found in a phylogenetic tree constructed with 16S rRNA genes and that it belongs in the alpha subgroup of the class Proteobacteria and that it is closely related to but independent from the genera Ehrlichia, Anaplasma, and Neorickettsia.

Animals↗
PubMed2003

Culture of Tropheryma whipplei from human samples: a 3-year experience (1999 to 2002).

The culture of Tropheryma whipplei, the bacterium responsible for Whipple's disease, has been established only recently. Our objective is to describe, based on our experience, the culture of T. whipplei in HEL cells detected by immunofluorescence staining. Over 3 years, we received 18 samples for T. whipplei culture from 15 patients with Whipple's disease. Ten duodenal biopsy specimens from 10 patients with digestive symptoms were available. Five cardiac valves and three blood samples from five patients with endocarditis were also available. We correlated the results of culture with the type of sample and the culture procedure. Seven isolates were obtained, and three were subsequently established for more than 4 passages. The mean delay for the primary detection was 30 days. The bacterium was isolated more frequently from sterile specimens (5 of 8) than from duodenal biopsy specimens (2 of 10), but the difference (P = 0.14) was not significant. Decontamination of digestive samples containing colistin, amphotericin B, and cephalotin or ciprofloxacin did not impair the isolation of T. whipplei. The use of vancomycin precludes the primary isolation (7 of 12 versus 0 of 6; P = 0.08) and the establishment of T. whipplei (3 of 12 versus 0 of 6; P = 0.5). Omitting samples cultured with vancomycin, the establishment of the strain was significantly higher when antibiotics were prescribed for no more than 7 days (3 of 4 versus 0 of 8; P = 0.03). Our results demonstrate that samples must be collected within 1 week of an antibiotic regimen's initiation for the successful establishment of the bacterium.

Actinomycetales↗
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

Q fever during pregnancy: diagnosis, treatment, and follow-up.

BACKGROUND: Q fever, caused by Coxiella burnetii, may result in abortions, premature deliveries, and stillbirths in infected pregnant women. OBJECTIVE: To evaluate the best treatment strategy for Q fever during pregnancy. METHODS: We evaluated the prognosis of 17 pregnant women who developed Q fever with and without co-trimoxazole (trimethoprim-sulfamethoxazole) treatment. RESULTS: The outcome of the pregnancy was found to depend on the trimester. Abortions occurred in 7 of 7 insufficiently treated patients infected during the first trimester vs 1 of 5 patients infected later. Co-trimoxazole given until delivery protected against abortion (0/4) but not against the development of chronic infections, and it did not significantly reduce the colonization of the placenta (2/4 vs 4/4). CONCLUSIONS: Our results show that C burnetii infections cause abortion and that women who develop Q fever while pregnant should be treated with co-trimoxazole for the duration of pregnancy, specifically when infected during the first trimester.

Acute Disease↗
PubMed2002

Emended description of Rickettsia felis (Bouyer et al. 2001), a temperature-dependent cultured bacterium.

On the basis of phenotypic data obtained on the strain Marseille-URRWFXCal2(T), isolated from the cat flea Ctenocephalides felis, the description of Rickettsia felis (Bouyer et al., 2001) is emended and Marseille-URRWFXCal2(T) is proposed as the type strain of the species. On the basis of polyphasic characterization, especially the inability to grow at temperatures higher than 32 degrees C on Vero cells that allow growth of other Rickettsia to at least 35 degrees C, it is confirmed that this agent, although different from other recognized rickettsial species, is genotypically indistinguishable from bacteria previously detected within cat fleas and provisionally named ELB. Comparison of the phenotypic characteristics previously described for R. felis and those observed for the isolate in this study indicated some differences, although concurrent analysis of the two was not possible as no extant isolates of the first isolate of R. felis exist.

Animals↗
PubMedDate not supplied

Molecular genetic methods for the diagnosis of fastidious microorganisms.

Technological innovations in the detection and identification of microorganisms using molecular techniques such as polymerase chain reaction (PCR) have ushered in a new era with respect to diagnostic microbiology. PCR using universal or specific primers followed by identification of amplified product, mainly by sequencing, has enabled the rapid identification of cultured or uncultured bacteria. Thus, PCR may allow quick diagnosis of infections caused by fastidious pathogens for which culture could be extremely difficult. However, several pitfalls, such as false positives, have been observed with PCR, underlining the necessity to interpret the results obtained with caution. At present, certain improvements in the molecular genetic methods may be helpful for the diagnosis of infectious diseases. Indeed, the recent development of bacterial genome sequencing has provided an important source of potential targets for PCR, allowing rational choice of primers for diagnosis and genotyping. In addition, the development of new techniques such as real-time PCR offers several advantages in comparison to conventional PCR, including speed, simplicity, reproducibility, quantitative capability and low risk of contamination. Herein, we review the general principles of PCR-based diagnosis and molecular genetic methods for the diagnosis of several hard-to-culture bacteria, such as Rickettsia spp., Ehrlichia spp., Coxiella burnetii, Bartonella spp., Tropheryma whipplei and Yersinia pestis.

Actinomycetales↗
PubMedDate not supplied

Tropical sprue in two foreign residents, with evidence of Tropheryma whippelii in one case.

Tropical sprue is a rare disease in travelers. Its etiology remains unclear. We report two cases of tropical sprue occurring in long-term residents in Nepal and Cameroon. In one case, Tropheryma whippelii, the agent of Whipple's disease, was identified. Many infectious agents have been suggested to be the etiological agent of tropical sprue, but no association with Whipple's disease has yet been reported.

Actinobacteria↗