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Clinical Microbiology Reviews Apr 2017Whipple's disease is a rare infectious disease that can be fatal if left untreated. The disease is caused by infection with , a bacterium that may be more common than... (Review)
Review
Whipple's disease is a rare infectious disease that can be fatal if left untreated. The disease is caused by infection with , a bacterium that may be more common than was initially assumed. Most patients present with nonspecific symptoms, and as routine cultivation of the bacterium is not feasible, it is difficult to diagnose this infection. On the other hand, due to the generic symptoms, infection with this bacterium is actually quite often in the differential diagnosis. The gold standard for diagnosis used to be periodic acid-Schiff (PAS) staining of duodenal biopsy specimens, but PAS staining has a poor specificity and sensitivity. The development of molecular techniques has resulted in more convenient methods for detecting infections, and this has greatly improved the diagnosis of this often missed infection. In addition, the molecular detection of has resulted in an increase in knowledge about its pathogenicity, and this review gives an overview of the new insights in epidemiology, pathogenesis, clinical manifestations, diagnosis, and treatment of infections.
Topics: Anti-Bacterial Agents; Humans; Tropheryma; Whipple Disease
PubMed: 28298472
DOI: 10.1128/CMR.00033-16 -
Microbiology and Molecular Biology... Mar 2016Actinobacteria are Gram-positive bacteria with high G+C DNA content that constitute one of the largest bacterial phyla, and they are ubiquitously distributed in both... (Review)
Review
Actinobacteria are Gram-positive bacteria with high G+C DNA content that constitute one of the largest bacterial phyla, and they are ubiquitously distributed in both aquatic and terrestrial ecosystems. Many Actinobacteria have a mycelial lifestyle and undergo complex morphological differentiation. They also have an extensive secondary metabolism and produce about two-thirds of all naturally derived antibiotics in current clinical use, as well as many anticancer, anthelmintic, and antifungal compounds. Consequently, these bacteria are of major importance for biotechnology, medicine, and agriculture. Actinobacteria play diverse roles in their associations with various higher organisms, since their members have adopted different lifestyles, and the phylum includes pathogens (notably, species of Corynebacterium, Mycobacterium, Nocardia, Propionibacterium, and Tropheryma), soil inhabitants (e.g., Micromonospora and Streptomyces species), plant commensals (e.g., Frankia spp.), and gastrointestinal commensals (Bifidobacterium spp.). Actinobacteria also play an important role as symbionts and as pathogens in plant-associated microbial communities. This review presents an update on the biology of this important bacterial phylum.
Topics: Actinobacteria; Anti-Bacterial Agents; Antifungal Agents; Biological Products; Herbicides; Insecticides; Microbial Interactions; Phylogeny; Pigments, Biological; Spores, Bacterial
PubMed: 26609051
DOI: 10.1128/MMBR.00019-15 -
Journal of Clinical Microbiology Jul 2022Next-generation sequencing (NGS) workflows applied to bronchoalveolar lavage (BAL) fluid specimens could enhance the detection of respiratory pathogens, although optimal...
Next-generation sequencing (NGS) workflows applied to bronchoalveolar lavage (BAL) fluid specimens could enhance the detection of respiratory pathogens, although optimal approaches are not defined. This study evaluated the performance of the Respiratory Pathogen ID/AMR (RPIP) kit (Illumina, Inc.) with automated Explify bioinformatic analysis (IDbyDNA, Inc.), a targeted NGS workflow enriching specific pathogen sequences and antimicrobial resistance (AMR) markers, and a complementary untargeted metagenomic workflow with in-house bioinformatic analysis. Compared to a composite clinical standard consisting of provider-ordered microbiology testing, chart review, and orthogonal testing, both workflows demonstrated similar performances. The overall agreement for the RPIP targeted workflow was 65.6% (95% confidence interval, 59.2 to 71.5%), with a positive percent agreement (PPA) of 45.9% (36.8 to 55.2%) and a negative percent agreement (NPA) of 85.7% (78.1 to 91.5%). The overall accuracy for the metagenomic workflow was 67.1% (60.9 to 72.9%), with a PPA of 56.6% (47.3 to 65.5%) and an NPA of 77.2% (68.9 to 84.1%). The approaches revealed pathogens undetected by provider-ordered testing (Ureaplasma parvum, Tropheryma whipplei, severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2], rhinovirus, and cytomegalovirus [CMV]), although not all pathogens detected by provider-ordered testing were identified by the NGS workflows. The RPIP targeted workflow required more time and reagents for library preparation but streamlined bioinformatic analysis, whereas the metagenomic assay was less demanding technically but required complex bioinformatic analysis. The results from both workflows were interpreted utilizing standardized criteria, which is necessary to avoid reporting nonpathogenic organisms. The RPIP targeted workflow identified AMR markers associated with phenotypic resistance in some bacteria but incorrectly identified genes in Pseudomonas aeruginosa as being associated with carbapenem resistance. These workflows could serve as adjunctive testing with, but not as a replacement for, standard microbiology techniques.
Topics: Bronchoalveolar Lavage Fluid; COVID-19; Communicable Diseases; High-Throughput Nucleotide Sequencing; Humans; Metagenomics; SARS-CoV-2; Workflow
PubMed: 35695488
DOI: 10.1128/jcm.00526-22 -
Clinical Microbiology Reviews Jan 2015A pure bacterial culture remains essential for the study of its virulence, its antibiotic susceptibility, and its genome sequence in order to facilitate the... (Review)
Review
A pure bacterial culture remains essential for the study of its virulence, its antibiotic susceptibility, and its genome sequence in order to facilitate the understanding and treatment of caused diseases. The first culture conditions empirically varied incubation time, nutrients, atmosphere, and temperature; culture was then gradually abandoned in favor of molecular methods. The rebirth of culture in clinical microbiology was prompted by microbiologists specializing in intracellular bacteria. The shell vial procedure allowed the culture of new species of Rickettsia. The design of axenic media for growing fastidious bacteria such as Tropheryma whipplei and Coxiella burnetii and the ability of amoebal coculture to discover new bacteria constituted major advances. Strong efforts associating optimized culture media, detection methods, and a microaerophilic atmosphere allowed a dramatic decrease of the time of Mycobacterium tuberculosis culture. The use of a new versatile medium allowed an extension of the repertoire of archaea. Finally, to optimize the culture of anaerobes in routine bacteriology laboratories, the addition of antioxidants in culture media under an aerobic atmosphere allowed the growth of strictly anaerobic species. Nevertheless, among usual bacterial pathogens, the development of axenic media for the culture of Treponema pallidum or Mycobacterium leprae remains an important challenge that the patience and innovations of cultivators will enable them to overcome.
Topics: Bacteria; Bacterial Infections; Bacteriological Techniques; Culture Media; History, 20th Century; History, 21st Century; Microbiology
PubMed: 25567228
DOI: 10.1128/CMR.00110-14 -
Viszeralmedizin Jun 2014Whipple's disease (WD) is rarely the cause of a malabsorption syndrome. The disease is a chronic infection of the intestinal mucosa with the bacterium Tropheryma... (Review)
Review
BACKGROUND
Whipple's disease (WD) is rarely the cause of a malabsorption syndrome. The disease is a chronic infection of the intestinal mucosa with the bacterium Tropheryma whipplei, which leads to a lymphostasis with an impaired absorption of the nutrition. Due to its low incidence (1:1,000,000) and the non-specific early symptoms, the disease is often diagnosed only after many years.
METHODS
Based on a selective literature review and the clinical experience of the authors, the current knowledge of WD regarding pathogenesis, clinical presentation, diagnosis, and therapy are presented in this paper.
RESULTS
Recent studies suggest that a host-specific dysfunction of the intestinal macrophages is responsible for the chronic infection with T. whipplei. Prior to patients reporting symptoms of a malabsorption syndrome (chronic diarrhea/steatorhea, weight loss), they often suffer from non-specific symptoms (polyarthralgia, fever, fatigue) for many years. Misdiagnoses such as seronegative polyarthritis are frequent. Furthermore, neurological, cardiac, ocular, or dermatological symptoms may occur. The standard method concerning diagnosis is the detection of PAS(periodic acid-Schiff)-positive macrophages in the affected tissues. Immunohistochemical staining and PCR(polymerase chain reaction)-based genetic analysis increase the sensitivity and specificity of conventional detection methods. Endoscopically, the intestinal mucosa appears edematous with lymphangiectasias, enlarged villi, and white-yellowish ring-like structures. The German treatment recommendations include a two-week intravenous induction therapy with ceftriaxone, which is followed by a three-month oral maintenance therapy with trimethoprim/sulfamethoxazole.
CONCLUSION
WD is rarely responsible for a malabsorption syndrome. However, if WD is not recognized, the disease can be lethal. New diagnostic methods and prospectively approved therapeutic concepts allow an adequate treatment of the patient. Due to the host-specific susceptibility to T. whipplei, a lifelong follow-up is necessary.
PubMed: 26288590
DOI: 10.1159/000363781 -
Emerging Infectious Diseases May 2010
Topics: Actinomycetales Infections; Humans; Terminology as Topic; Tropheryma
PubMed: 20409378
DOI: 10.3201/eid1605.e1605 -
Gut Microbes 2021, is an actinobacterium that causes different infections in humans, including Whipple's disease. The bacterium infects and replicates in macrophages, leading to a...
, is an actinobacterium that causes different infections in humans, including Whipple's disease. The bacterium infects and replicates in macrophages, leading to a Th2-biased immune response. Previous studies have shown that harbors complex surface glycoproteins with evidence of sialylation. However, the exact contribution of these glycoproteins for infection and survival remains obscure. To address this, we characterized the bacterial glycoprofile and evaluated the involvement of human β-galactoside-binding lectins, Galectin-1 (Gal-1) and Galectin-3 (Gal-3) which are highly expressed by macrophages as receptors for bacterial glycans. glycoproteins harbor different sugars including glucose, mannose, fucose, β-galactose and sialic acid. Mass spectrometry identification revealed that these glycoproteins were membrane- and virulence-associated glycoproteins. Most of these glycoproteins are highly sialylated and N-glycosylated while some of them are rich in poly-N-acetyllactosamine (Poly-LAcNAc) and bind Gal-1 and Gal-3. modulates the expression and cellular distribution of Gal-1 and Gal-3. Although both galectins promote infection by enhancing bacterial cell entry, only Gal-3 is required for optimal bacterial uptake. Finally, we found that serum levels of Gal-1 and Gal-3 were altered in patients with infections as compared to healthy individuals, suggesting that galectins are also involved . Among membrane-associated proteins, poly-LacNAc rich-glycoproteins promote infection through interaction with galectins. modulates the expression of Gal-1 and Gal-3 both and . Drugs interfering with galectin-glycan interactions may provide new avenues for the treatment and diagnosis of infections.
Topics: Bacterial Proteins; Blood Proteins; Galactose; Galectin 1; Galectins; Glycoproteins; Glycosylation; Humans; Macrophages; Polysaccharides, Bacterial; Tropheryma; Virulence; Whipple Disease
PubMed: 33573443
DOI: 10.1080/19490976.2021.1884515 -
Annals of Clinical Microbiology and... Dec 2022The prevalence of Tropheryma whipplei varies depending on age, region, and underlying disease. We estimated the prevalence of T. whipplei in the stools of Korean...
BACKGROUND
The prevalence of Tropheryma whipplei varies depending on age, region, and underlying disease. We estimated the prevalence of T. whipplei in the stools of Korean patients with diarrhea using real-time PCR (RT-PCR) and compared three RT-PCR targets, rpoB, hsp65, and Dig15.
METHODS
A total of 1404 nucleic acid samples extracted from the stools of Korean patients with diarrhea were tested using an initial RT-PCR targeting T. whipplei-specific regions of 16S-23S rRNA intergenic spacer. Subsequently, the samples positive for the initial RT-PCR were tested using the follow-up RT-PCRs targeting rpoB, hsp65, and Dig15 and analyzed by sequencing to confirm the presence of T. whipplei. We estimated the prevalence of T. whipplei and compared them according to gender and age. We also compared the performance of three targets in the follow-up RT-PCRs.
RESULTS
T. whipplei was detected in 1.4% of all samples (20 of 1404), and there were no differences according to gender and age. In pediatric samples (≤ 19 years), T. whipplei was detected higher in children aged 6-19 than in those aged 1-5 (2.7% vs. 0.7%, P = 0.01). Sensitivities of the rpoB, hsp65, and Dig15 RT-PCR were 50.0%, 85.0%, and 95.0%, respectively; specificities were 100.0%, 100.0%, and 84.6%, respectively.
CONCLUSIONS
This is the first study that estimated the prevalence of T. whipplei in the stools of Korean patients with diarrhea. This study demonstrated the presence of T. whipplei in stools of Koreans, even though the bacterium was detected low. The RT-PCRs targeting hsp65 and Dig15 showed reliable performance, and a multiplex PCR including these targets is expected to be useful for T. whipplei detection.
Topics: Humans; Child; Tropheryma; Real-Time Polymerase Chain Reaction
PubMed: 36474214
DOI: 10.1186/s12941-022-00543-1 -
Emerging Infectious Diseases Nov 2013Tropheryma whipplei endocarditis differs from classic Whipple disease, which primarily affects the gastrointestinal system. We diagnosed 28 cases of T. whipplei... (Review)
Review
Tropheryma whipplei endocarditis differs from classic Whipple disease, which primarily affects the gastrointestinal system. We diagnosed 28 cases of T. whipplei endocarditis in Marseille, France, and compared them with cases reported in the literature. Specimens were analyzed mostly by molecular and histologic techniques. Duke criteria were ineffective for diagnosis before heart valve analysis. The disease occurred in men 40-80 years of age, of whom 21 (75%) had arthralgia (75%); 9 (32%) had valvular disease and 11 (39%) had fever. Clinical manifestations were predominantly cardiologic. Treatment with doxycycline and hydroxychloroquine for at least 12 months was successful. The cases we diagnosed differed from those reported from Germany, in which arthralgias were less common and previous valve lesions more common. A strong geographic specificity for this disease is found mainly in eastern-central France, Switzerland, and Germany. T. whipplei endocarditis is an emerging clinical entity observed in middle-aged and older men with arthralgia.
Topics: Adult; Aged; Aged, 80 and over; Endocarditis, Bacterial; Europe; Heart Valves; Humans; Immunosuppressive Agents; Male; Middle Aged; Treatment Outcome; Tropheryma; Whipple Disease
PubMed: 24207100
DOI: 10.3201/eid1911.121356