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ABSTRACTBiting midges of the genus Culicoidesare implicated as vectors for a wide variety of pathogens. The morphological identification of these arthropods may be difficult because of a lack of detailed investigation of taxonomy for this species in Africa. However, matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) profiling is efficient for arthropod identification at the species level. This study established a spectrum database of Culicoidesspp. from Senegal using MALDI-TOF. Identification of Culicoidesinsects to the species level before mass spectrometry was performed on the basis of morphological characters. MALDI-TOF MS reference spectra were determined for 437 field-caught Culicoidesof 10 species. The protein profiles of all tested Culicoidesrevealed several peaks with mass ranges of 2 to 20 kDa. In a validation study, 72 Culicoidesspecimens in the target species were correctly identified at the species level with a similarity of 95 to 99.9%. Four Culicoidesprotein profiles were misidentified. Nevertheless, six SuperSpectra (C. imicola, C. enderleini, C. oxystoma, C. kingi, C. magnus, and C. fulvithorax) were created. Abdomens of midges were used to amplify and sequence a portion of the mitochondrial cytochrome oxidase I gene (COI). The results obtained using the MALDI-TOF MS method were consistent with the morphological identification and similar to the genetic identification. Protein profiling using MALDI-TOF is an efficient approach for the identification of Culicoidesspp., and it is economically advantageous for approaches that require detailed and quantitative information of vector species that are collected in field. The database of African CulicoidesMS spectra created is the first database in Africa. The COI sequences of five Culicoidesspecies that were previously noncharacterized using molecular methods were deposited in GenBank.

ABSTRACT“Classical” Whipple's disease (cWD) is caused by Tropheryma whippleiand is characterized by arthropathy, weight loss, and diarrhea. T. whippleiinfectious endocarditis (TWIE) is rarely reported, either in the context of cWD or as isolated TWIE without signs of systemic infection. The frequency of TWIE is unknown, and systematic studies are lacking. Here, we performed an observational cohort study on the incidence of T. whippleiinfection in explanted heart valves in two German university centers. Cardiac valves from 1,135 patients were analyzed for bacterial infection using conventional culture techniques, PCR amplification of the bacterial 16S rRNA gene, and subsequent sequencing. T. whipplei-positive heart valves were confirmed by specific PCR, fluorescence in situhybridization, immunohistochemistry, histological examination, and culture for T. whipplei. Bacterial endocarditis was diagnosed in 255 patients, with streptococci, staphylococci, and enterococci being the main pathogens. T. whippleiwas the fourth most frequent pathogen, found in 16 (6.3%) cases, and clearly outnumbered Bartonella quintana, Coxiella burnetii, and members of the HACEK group (Haemophilusspecies, Actinobacillus actinomycetemcomitans, Cardiobacterium hominis, Eikenella corrodens, and Kingella kingae). In this cohort, T. whippleiwas the most commonly found pathogen associated with culture-negative infective endocarditis.

"Classical" Whipple's disease (cWD) is caused by Tropheryma whipplei and is characterized by arthropathy, weight loss, and diarrhea. T. whipplei infectious endocarditis (TWIE) is rarely reported, either in the context of cWD or as isolated TWIE without signs of systemic infection. The frequency of TWIE is unknown, and systematic studies are lacking. Here, we performed an observational cohort study on the incidence of T. whipplei infection in explanted heart valves in two German university centers. Cardiac valves from 1,135 patients were analyzed for bacterial infection using conventional culture techniques, PCR amplification of the bacterial 16S rRNA gene, and subsequent sequencing. T. whipplei-positive heart valves were confirmed by specific PCR, fluorescence in situ hybridization, immunohistochemistry, histological examination, and culture for T. whipplei. Bacterial endocarditis was diagnosed in 255 patients, with streptococci, staphylococci, and enterococci being the main pathogens. T. whipplei was the fourth most frequent pathogen, found in 16 (6.3%) cases, and clearly outnumbered Bartonella quintana, Coxiella burnetii, and members of the HACEK group (Haemophilus species, Actinobacillus actinomycetemcomitans, Cardiobacterium hominis, Eikenella corrodens, and Kingella kingae). In this cohort, T. whipplei was the most commonly found pathogen associated with culture-negative infective endocarditis.

ABSTRACTThe 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. whippleiin HEL cells detected by immunofluorescence staining. Over 3 years, we received 18 samples for T. whippleiculture 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.

ABSTRACTWe report the case of a patient hospitalized with endocarditis. The etiological diagnosis of Bartonellawas suggested by detection of high titers of antibodies by immunofluorescence and Western blotting. Two different nested PCRs performed on sera identified Bartonella vinsoniisubsp. arupensisby sequencing.