Application of rrs gene sequencing to elucidate the clinical significance of Eggerthela lenta infection.
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Actinobacteria↗
Biomedical subjects
Florence Fenollar
Publications and source records attributed to Florence Fenollar.
A serum protein signature with high diagnostic value in bacterial endocarditis: results from a study based on surface-enhanced laser desorption/ionization time-of-flight mass spectrometry.
BACKGROUND: Bacterial endocarditis is a serious disease. Surface-enhanced laser desorption/ionization time-of-flight (SELDI-TOF) mass spectrometry (MS) based on serum protein profiling is a powerful approach that can generate biomarkers with diagnostic value. METHODS: To identify a protein signature associated with bacterial endocarditis, we retrospectively performed SELDI-TOF MS profiling of serum samples from 88 patients hospitalized because of clinical suspicion of endocarditis. The diagnosis was confirmed by conventional criteria for 34 patients (endocarditis positive) and was excluded for 54 patients (endocarditis negative). Serum samples were incubated with cation-exchange ProteinChip arrays. The protein profiles generated were subjected to biostatistical processing. RESULTS: Fifty-nine samples (23 endocarditis positive and 36 endocarditis negative) were randomly selected for a learning set, with the 29 remaining samples (11 endocarditis positive and 18 endocarditis negative) serving as an independent testing (validation) set. Sixty-six protein peaks were differentially expressed between the endocarditis-positive and the endocarditis-negative patients. By combining partial least squares and logistic regression methods, we built a serum protein model that perfectly discriminated between endocarditis-positive and endocarditis-negative patients. Importantly, when this model was tested on the independent testing set, a correct prediction rate of nearly 90% was demonstrated. Overall, sensitivity, specificity, positive predictive value, and negative predictive value were 94%, 98%, 96%, and 96%, respectively. CONCLUSIONS: SELDI-TOF MS profiling revealed a serum signature with high diagnostic potential for endocarditis.
Adolescent↗
Culture of T. whipplei from the stool of a patient with Whipple's disease.
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Actinomycetales↗
Endocarditis after acute Q fever in patients with previously undiagnosed valvulopathies.
We describe 3 cases of endocarditis after acute Q fever in 3 patients with clinically silent, undiagnosed valvulopathies, including mitral valve prolapse, minimal valvular leak, and biscuspid aortic valve. We conclude that, to prevent endocarditis, these minor valvulopathies must be actively searched for with echocardiography after diagnosis of acute Q fever.
Aortic Valve↗
Identification of candidate antigen in Whipple's disease using a serological proteomic approach.
Whipple's disease (WD) is a chronic multisystemic infection, caused by Tropheryma whipplei, a Gram-positive rod. Recently, a reliable method has been developed for cultivating T. whipplei in vitro. This together with the availability of complete genome sequence of T. whipplei prompted us to initiate proteome analysis of T. whipplei. The objective of the present study was to identify candidate proteins for serological diagnosis of WD. Immunoreactivities of sera collected from 18 patients with WD were compared with those of 24 control subjects who did not have WD. For this, we used 2-DE, immunoblotting, and MS. In total, we identified 23 candidate antigenic proteins. These included a subset of six proteins, each of which was found significantly more frequently in cases as compared to their controls. The remaining 17 proteins were found exclusively in cases. The methods we used in the current study enabled us to identify candidate antigens that, in our view, might be useful for serological diagnosis of WD.
Actinomycetales↗
18F-fluorodeoxyglucose positron emission tomography in Whipple's disease.
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Aged↗
Analysis of 525 samples to determine the usefulness of PCR amplification and sequencing of the 16S rRNA gene for diagnosis of bone and joint infections.
The 16S rRNA gene PCR in the diagnosis of bone and joint infections has not been systematically tested. Five hundred twenty-five bone and joint samples collected from 525 patients were cultured and submitted to 16S rRNA gene PCR detection of bacteria in parallel. The amplicons with mixed sequences were also cloned. When discordant results were observed, culture and PCR were performed once again. Bacteria were detected in 139 of 525 samples. Culture and 16S rRNA gene PCR yielded identical documentation in 475 samples. Discrepancies were linked to 13 false-positive culture results, 5 false-positive PCR results, 9 false-negative PCR results, 16 false-negative culture results, and 7 mixed infections. Cloning and sequencing of 16S rRNA gene amplicons in 6 of 8 patients with mixed infections identified 2 to 8 bacteria per sample. Rarely described human pathogens such as Alcaligenes faecalis, Comamonas terrigena, and 21 anaerobes were characterized. We also detected, by 16S rRNA gene PCR, four previously identified bacteria never reported in human infection, Alkanindiges illinoisensis, dehydroabietic acid-degrading bacterium DhA-73, unidentified Hailaer soda lake bacterium, and uncultured bacterium clone HuCa4. Seven organisms representing new potential species were also detected. PCR followed by cloning and sequencing may help to identify new pathogens involved in mixed bone infection.
Arthritis, Infectious↗
Use of shell-vial cell culture assay for isolation of bacteria from clinical specimens: 13 years of experience.
The shell-vial culture assay is performed routinely in our laboratory. Recently we revisited our experience of using the shell-vial culture assay for the isolation of microorganisms from various clinical samples. Over a 13-year period, we have isolated 580 bacterial strains (5%) from 11,083 clinical samples tested. Over the same period, 285 isolates of rickettsiae, bartonellae, or Coxiella burnetii were cultured from a total of 7,102 samples tested. These isolates include 55 Rickettsia sp. isolates, 95 Coxiella burnetii isolates, and 135 Bartonella sp. isolates. Based on our experience with the growth of fastidious microorganisms, we have used a centrifugation shell-vial technique called JNSP, for "je ne sais pas" ("I don't know [what I am growing]") for the isolation of other microorganisms. A total of 173 isolates were cultured from the 3,861 clinical samples tested using the JNSP method. Of these, 40 isolates had not been grown before on usual axenic medium. These include 2 Staphylococcus aureus isolates, 7 isolates of Streptococcus sp. and related genera, 6 Mycobacterium sp. isolates, 1 Nocardia asteroides isolate, 1 Actinomyces sp. isolate, 1 Brucella melitensis isolate, 2 Francisella tularensis isolates, 1 Mycoplasma pneumoniae isolate, and 1 Legionella pneumophila isolate. Using this protocol, we have also cultured intracellular bacteria such as Chlamydia trachomatis and we have performed the first culture and establishment of Trophyrema whipplei. Applied in our laboratory, the shell-vial culture generally exhibits a low rate of success. However, in some cases, this technique allowed microbial diagnosis when classical agar procedure and PCR were negative.
Animals↗
Bartonella vinsonii subsp. arupensis as an agent of blood culture-negative endocarditis in a human.
We report the case of a patient hospitalized with endocarditis. The etiological diagnosis of Bartonella was suggested by detection of high titers of antibodies by immunofluorescence and Western blotting. Two different nested PCRs performed on sera identified Bartonella vinsonii subsp. arupensis by sequencing.
Aged↗
Bacterial zoonoses and infective endocarditis, Algeria.
Blood culture-negative endocarditis is common in Algeria. We describe the etiology of infective endocarditis in this country. Samples from 110 cases in 108 patients were collected in Algiers. Blood cultures were performed in Algeria. Serologic and molecular analysis of valves was performed in France. Infective endocarditis was classified as definite in 77 cases and possible in 33. Causative agents were detected by blood cultures in 48 cases. All 62 blood culture-negative endocarditis cases were tested by serologic or molecular methods or both. Of these, 34 tested negative and 28 had an etiologic agent identified. A total of 18 infective endocarditis cases were caused by zoonotic and arthropodborne bacteria, including Bartonella quintana (14 cases), Brucella melitensis (2 cases), and Coxiella burnetii (2 cases). Our data underline the high prevalence of infective endocarditis caused by Bartonella quintana in northern Africa and the role of serologic and molecular tools for the diagnosis of blood culture-negative endocarditis.
Adolescent↗
Human Rickettsia felis infection, Canary Islands, Spain.
We report the first cases of human infection by Rickettsia felis in the Canary Islands. Antibodies against R. felis were found in 5 adsorbed serum samples from 44 patients with clinically suspected rickettsiosis by Western blot serology. Fleas from 1 patient's dog were positive for R. felis by polymerase chain reaction.
Adult↗
Cardiac valves in patients with Whipple endocarditis: microbiological, molecular, quantitative histologic, and immunohistochemical studies of 5 patients.
The pathological features of Whipple endocarditis, which is caused by Tropheryma whipplei, were histologically evaluated in cardiac valves from 5 patients. We used quantitative image analysis to compare the valvular fibrosis, calcifications, vegetations, inflammation, and vascularization due to Whipple endocarditis with those due to non-Whipple endocarditis and degenerative valves. We also studied the presence of T. whipplei in valves by immunohistochemical analysis, culture, and polymerase chain reaction (PCR). In histologic analysis, Whipple endocarditis was characterized by significant fibrosis, a lack of calcifications, slight inflammation and vascularization, and vegetations of intermediate size. Inflammatory infiltrates consisted mainly of foamy macrophages and lymphocytes. We found that the detection of T. whipplei in cardiac valves, by immunohistochemical analysis, was correlated with the detection of the bacterium by culture and PCR. We report, for the first time, the immunodetection of T. whipplei in a surgically removed arterial embolus. Pathological and immunohistologic analyses may contribute to the diagnosis of Whipple endocarditis.
Adult↗
Multifocal discitis caused by Staphylococcus warneri.
Staphylococcus warneri is a coagulase-negative staphylococcus that is a normal inhabitant of the skin but occasionally causes septicemia and endocarditis. We report a case of multifocal discitis caused by S. warneri in an immunocompetent patient. Only three cases of spinal S. warneri infections have been reported in the literature. They illustrate the atypical clinical presentation, with chronic pain of increasing severity in the thoracic or lumbar spine instead of the abrupt onset that characterizes S. aureus discitis. In our patient, despite the multifocal distribution of the lesions, heretofore unreported, clinical presentation suggested common low back pain. This presentation may be ascribable to the unique bacteriological characteristics of S. warneri. The case reported here illustrates the diagnostic challenges sometime raised by discitis due to coagulase-negative staphylococci.
Aged↗
Use of genome selected repeated sequences increases the sensitivity of PCR detection of Tropheryma whipplei.
The availability of the Tropheryma whipplei genome offers the putative possibility of choosing logical DNA targets. We applied a PCR assay (targeting repeated sequences of T. whipplei) to samples from patients with Whipple's disease and to those from members of a control group. When compared to the results seen with regular PCR, the sensitivity of repeat PCR was significantly enhanced (P = 0.02) without alteration of its specificity.
Actinomycetales↗
Mycoplasma endocarditis: two case reports and a review.
We describe 2 patients with endocarditis for whom blood cultures and cardiac valve cultures were repeatedly sterile. Broad-range eubacterial polymerase chain reaction (PCR) amplification performed on cardiac valve specimens from these 2 patients detected DNA of Mycoplasma hominis, for one patient, and of Ureaplasma parvum, for the other patient. Three other cases of infective endocarditis caused by mycoplasmas were identified in the literature. It is important to rule out a diagnosis of mycoplasma endocarditis because the evolution of the disease may be fatal and it requires an adequate and specific antibiotic therapy.
Adult↗
Whipple disease associated with giardiasis.
We tested 53 fixed duodenal biopsy samples from 25 patients with Whipple disease for the presence Giardia and 6 fresh duodenal biopsy samples for Giardia duodenalis DNA by polymerase chain reaction (PCR). We also used histological examination and PCR assay to determine the prevalence of G. duodenalis in duodenal biopsy samples from 150 control patients without Whipple disease. Three of 25 patients with Whipple disease had histological evidence of giardiasis, whereas only 1 of 150 control patients was affected (P<.001). By PCR, we found Giardia in 2 of 6 patients with Whipple disease whom we tested, but in only 2 of 150 control patients (P<.001). In a literature review, we identified 15 other cases of coinfection. The occurrence of these diseases may be promoted by a common immune defect or a common source of infection, or infection with one may predispose to infection with the other.
Actinomycetales↗
Whipple's disease.
Whipple's disease is an infectious disease caused by a gram-positive bacterium, Tropheryma whipplei. The first case was reported in 1907 by GH Whipple. Its classic symptoms are diarrhea and arthralgias, but symptoms can be various. Cardiac or central nervous system involvement, not always associated with digestive symptoms, may also be observed. For a long time, diagnosis has been based on duodenal biopsy, which is positive using periodic acid-Schiff staining. However, for patients without digestive symptoms, results can be negative, leading to a delay in diagnosis. For 10 years, a tool based on polymerase chain reaction targeting the 16S rDNA sequence has been used. In vitro culture of the bacterium, achieved 3 years ago, has allowed new perspectives for diagnosis and treatment. The natural evolution of the disease without treatment is always fatal. Current treatment is based on administration of trimethoprim-sulfamethoxazole for at least 1 year.
Diagnosis, Differential↗