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

Severe pneumonia in adults caused by Tropheryma whipplei and Candida sp. infection: a 2019 case series

Background

Whipple’s disease is a chronic infectious disease caused by the Gram-positive bacterium Tropheryma whipplei (TW), which not only affects the gastrointestinal tract and causes malabsorption of nutrients, but several other systems, such as the cardiovascular system, central nervous system, the joints, and the vascular system, can also be simultaneously involved. The aim of this report was to be able to alert the clinician to severe pneumonia caused by TW combined with Candida sp.

Case presentation

The case study was conducted on patients in September and November 2019. After routine examination and treatment, the results were not satisfactory. A bronchoalveolar lavage (BAL) using metagenomics next-generation sequencing was conducted on two adults who presented with fever, cough, and progressive dyspnea and who had no history of gastrointestinal symptoms, immunodeficiency diseases, or use of immunosuppressive agents. TW and Candida sp. were detected in in BAL.

Conclusions

This is a report of life-threatening pneumonia caused by TW combined with Candida sp. in a Chinese population.

Diagnostic Approach for Classic Compared With Localized Whipple Disease

Background

Whipple disease (WD), a rare systemic infection caused by Tropheryma whipplei, can be a diagnostic challenge due to its variable presentation. The role of T. whipplei polymerase chain reaction (PCR) is unclear as small bowel biopsy with Periodic acid-Schiff (PAS) staining remains the diagnostic gold standard. Individualized diagnostic approaches based on variable clinical manifestations are underutilized. We investigated the methodologies employed at our institution to diagnose WD.

Methods

We retrospectively collected all cases of WD diagnosed from 1994 to 2016. Microbiology laboratory and anatomic pathology databases were queried. Case characteristics and disease clinical phenotypes (classical, localized WD arthritis, and localized central nervous system [CNS] disease) were described. The diagnostic approach and testing yield were analyzed and reported.

Results

Thirty-three cases of WD were diagnosed (18 classic WD [CWD], 9 localized WD arthritis [LWD], 6 CNS WD). Misdiagnosis and delay in diagnosis were frequent. Diagnostic approach and test yield differed by classical vs localized WD involvement. Small bowel tissue biopsy PAS stain/PCR was overwhelmingly positive (86%/92%) in CWD, yet seldom positive (12%/42%) in LWD (P < .001). Affected joint synovial fluid PCR was frequently positive in both CWD (100%, 3/3) and LWD (85%, 6/7).

Conclusions

These results support the role of small bowel biopsy PAS stain/PCR in the diagnosis of CW, though this approach may be of limited utility in LWD or CNS WD without gastrointestinal symptoms. Affected joint synovial fluid or cerebrospinal fluid PCR was frequently positive in both CWD and LWD, supporting its diagnostic usefulness.

Clinical Manifestations, Treatment, and Diagnosis of Tropheryma whipplei Infections

Whipple's disease is a rare infectious disease that can be fatal if left untreated. The disease is caused by infection with Tropheryma whipplei, 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 T. whipplei infections, and this has greatly improved the diagnosis of this often missed infection. In addition, the molecular detection of T. whipplei 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 Tropheryma whipplei infections.

Current and past strategies for bacterial culture in clinical microbiology

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.

Molecular analysis of sarcoidosis lymph nodes for microorganisms: a case-control study with clinical correlates

INTRODUCTION

Sarcoidosis is an incurable, chronic granulomatous disease primarily involving the lungs and lymph nodes of unknown aetiology, treated with non-specific anti-inflammatory/immunosuppressive drugs. Persistently symptomatic patients worsen with a disabling, potentially fatal clinical course. To determine a possible infectious cause, we correlated in a case-control study the clinical information with the presence of bacterial DNA in sarcoidosis mediastinal lymph nodes compared with control lymph nodes resected during cancer surgery.

METHODS

We retrospectively studied formalin-fixed, paraffin-embedded, mediastinal lymph nodes from 30 patients with sarcoidosis and 30 control patients with lung cancer. Nucleic acids were extracted from nodes, evaluated by ribosomal RNA PCR for bacterial 16S ribosomal DNA and the results were sequenced and compared with a bacterial sequence library. Clinical information was correlated.

RESULTS

11/30 (36.7%) of lymph nodes from patients with sarcoidosis had detectable bacterial DNA, significantly more than control patient lymph nodes (2/30, 6.7%), p=0.00516. At presentation, 19/30 (63.3%) patients with sarcoidosis were symptomatic including all patients with detectable bacterial DNA. Radiographically, there were 18 stage I and 12 stage II patients. All stage II patients were symptomatic and 75% had PCR-detectable bacteria. After a mean follow-up of 52.8±32.8 months, all patients with PCR-detectable bacteria in this series were persistently symptomatic requiring treatment.

DISCUSSION

36.6% of patients with sarcoidosis had detectable bacterial DNA on presentation, all of these patients were quite symptomatic and most were radiographically advanced stage II. These findings suggest that bacterial DNA-positive, symptomatic patients have more aggressive sarcoidosis that persists long term and might benefit from antimicrobial treatment directed against this presumed chronic granulomatous infection.

Tropheryma whipplei as a commensal bacterium

Tropheryma whipplei is the bacterial agent of the well-known and rare Whipple's disease, mainly observed among Caucasians. This bacterium has recently been involved in other chronic and acute infections. For a long time, the only known source of the bacterium was patients with Whipple's disease; however, thanks to the advent of molecular biology, T. whipplei has now been detected in specimens from healthy individuals, mainly in stool and saliva samples. The prevalence of carriage depends on several factors, such as age, exposure and geographical area, reaching 75% in stool specimens from children less than 4 years old in rural Africa. T. whipplei is a commensal bacterium that only causes Whipple's disease in a subset of individuals, probably those with a still-uncharacterized specific immunological defect.

Progressive dementia associated with ataxia or obesity in patients with Tropheryma whipplei encephalitis

Background

Tropheryma whipplei, the agent of Whipple's disease, causes localised infections in the absence of histological digestive involvement. Our objective is to describe T. whipplei encephalitis.

Methods

We first diagnosed a patient presenting dementia and obesity whose brain biopsy and cerebrospinal fluid specimens contained T. whipplei DNA and who responded dramatically to antibiotic treatment. We subsequently tested cerebrospinal fluid specimens and brain biopsies sent to our laboratory using T. whipplei PCR assays. PAS-staining and T. whipplei immunohistochemistry were also performed on brain biopsies. Analysis was conducted for 824 cerebrospinal fluid specimens and 16 brain biopsies.

Results

We diagnosed seven patients with T. whipplei encephalitis who demonstrated no digestive involvement. Detailed clinical histories were available for 5 of them. Regular PCR that targeted a monocopy sequence, PAS-staining and immunohistochemistry were negative; however, several highly sensitive and specific PCR assays targeting a repeated sequence were positive. Cognitive impairments and ataxia were the most common neurologic manifestations. Weight gain was paradoxically observed for 2 patients. The patients' responses to the antibiotic treatment were dramatic and included weight loss in the obese patients.

Conclusions

We describe a new clinical condition in patients with dementia and obesity or ataxia linked to T. whipplei that may be cured with antibiotics.

Systemic Tropheryma whipplei: clinical presentation of 142 patients with infections diagnosed or confirmed in a reference center

Culture of Tropheryma whipplei, the agent of Whipple disease (WD), was achieved in our laboratory in 2000, allowing new perspectives for the diagnosis of this disease and for the description of other potential clinical manifestations caused by this microorganism. Since 2000, we have developed new tools in our center in Marseille, France, to optimize the diagnosis of T whipplei infections. Classic WD was characterized by positive periodic acid-Schiff performed on duodenal biopsy. In the absence of duodenal histologic involvement, localized infections were defined by specific positive T whipplei polymerase chain reaction (PCR) results obtained using samples of other tissues and body fluids. The physicians in charge of patients were asked to complete a questionnaire. A total of 215 diagnoses were performed or confirmed and, among these, 142 patients with sufficient clinical data were included.Herein, we report epidemiologic data, clinical manifestations, and diagnostic tools of T whipplei infections. In the 113 patients with classic WD, the main symptom was arthralgia (88/113, 78%), which explains the many cases misdiagnosed as inflammatory rheumatoid disease (56/113, 50%). Frequently immunosuppressive treatments, more recently including tumor necrosis factor inhibitor, had been previously prescribed (50%) and were often responsible for more rapid clinical progression (43%). Sometimes a short course of antibiotics improved the clinical status.Endocarditis was the second most frequent manifestation of T whipplei, with 16 cases. The clinical picture of this entity corresponds to cardiovascular involvement with acute heart failure (50%) occurring without fever (75%) or previous valvular disease (69%). Neurologic symptoms were the third major manifestation. Other localized infections such as adenopathy, uveitis, pulmonary involvement, or joint involvement were sporadic. Infection with T whipplei resulted in multifaceted conditions. Some localized infections due to this agent have recently been reported and may correspond to emerging entities. Patients with inflammatory rheumatoid disease must be systematically interviewed to determine the efficacy of previous immunosuppressive and antibiotic therapies.

Tropheryma whipplei in children with gastroenteritis

This bacterium may be an etiologic agent of gastroenteritis.

Tropheryma whipplei, which causes Whipple disease, is found in human feces and may cause gastroenteritis. To show that T. whipplei causes gastroenteritis, PCRs for T. whipplei were conducted with feces from children 2–4 years of age. Western blotting was performed for samples from children with diarrhea who had positive or negative results for T. whipplei. T. whipplei was found in samples from 36 (15%) of 241 children with gastroenteritis and associated with other diarrheal pathogens in 13 (33%) of 36. No positive specimen was detected for controls of the same age (0/47; p = 0.008). Bacterial loads in case-patients were as high as those in patients with Whipple disease and significantly higher than those in adult asymptomatic carriers (p = 0.002). High incidence in patients and evidence of clonal circulation suggests that some cases of gastroenteritis are caused or exacerbated by T. whipplei, which may be co-transmitted with other intestinal pathogens.

Tropheryma whipplei in the skin of patients with classic Whipple's disease

Positive Tropheryma whipplei PCR results in skin biopsies were frequent in patients with classic Whipple's disease without skin manifestations. The bacterium was alive, as a strain was successfully cultured. The skin may be a reservoir for T. whipplei and may be helpful in the non-invasive diagnosis of the disease.

Whipple disease

Whipple disease (WD) is a rare disease caused by Tropheryma whipplei. The classic profile of the patient is that of a middle-aged man presenting with fever, chronic diarrhea, and arthralgias. Extragastrointestinal manifestations are not rare. A high degree of clinical suspicion for the disease is needed in atypical cases. Trimethoprim-sulfamethoxazole is the treatment of choice. We present two patients with WD. The first presented with melena and generalized hyperpigmentation. The second had depression for two years before the typical symptoms. Both hyperpigmentation and long-lasting depression without the typical manifestations of the disease are rare. Histologic examination of tissue biopsies was diagnostic for WD. Both patients were treated successfully with trimethoprim-sulfamethoxazole.

Prevalence of asymptomatic Tropheryma whipplei carriage among humans and nonhuman primates

BACKGROUND

The reservoir of the agent of Whipple disease is unknown. Asymptomatic carriage of Tropheryma whipplei in human stool and saliva is controversial.

METHODS

Stools and saliva specimens from 231 workers at a sewage treatment facility and from 10 patients with Whipple disease, stool specimens from 102 healthy people, and stool specimens from 127 monkeys or apes were tested for T. whipplei DNA by a quantitative real-time polymerase chain reaction with probe detection. Genotyping and culture of T. whipplei-positive samples were performed.

RESULTS

Asymptomatic carriage in stool was found in humans (ranging from a prevalence of 4% in the control group to 12% among a subgroup of sewer workers) but not in monkeys and apes. The T. whipplei load in stool was significantly lower in carriers than in patients with Whipple disease (P < .001). There was a significant prevalence gradient associated with employment responsibilities at the sewage treatment facility: workers who cleaned the underground portion of the sewers were more likely than other workers to carry T. whipplei in stool. Seven of 9 sewer workers tested positive 8 months later. Patients with Whipple disease were significantly more likely to have T. whipplei-positive saliva specimens (P = .005) and had a significantly greater T. whipplei load in saliva (P = .015), compared with asymptomatic stool carriers from the sewage facility. All non-stool carriers had T. whipplei-negative saliva specimens. T. whipplei strains were heterogeneic among sewer workers but identical within individual workers.

CONCLUSION

Chronic asymptomatic carriage of T. whipplei occurs in humans. Bacterial loads are lower in asymptomatic carriers, and the prevalence of carriage increases with exposure to sewage.

Prosthetic hip infection caused by Tropheryma whipplei

We report a case of prosthetic hip infection due to Tropheryma whipplei in a 74-year-old man not previously known to have Whipple's disease. Diagnosis was based on systematic 16S rRNA gene amplification and sequencing of samples obtained during revision hip arthroplasty.

Advances in Tropheryma whipplei research: the rush to find biomarkers for Whipple's disease

Whipple's disease (WD) is a systemic chronic infection, caused by the Gram-positive bacterium Tropheryma whipplei. There are several clinical traits linked to WD: histological lesions in the GI tract in association with diverse clinical manifestations (classic WD), endocarditis with negative blood cultures, and isolated neurological infection. WD is rare, predominantly affects middle-aged men and is fatal without treatment. The most recent strategy for diagnosing WD uses the results of diastase-resistant periodic acid Schiff staining and PCR in parallel, both performed on involved organ/tissue biopsy (small intestine, cardiac valve and cerebrospinal fluid). The generation of rabbit polyclonal antibodies has enabled the detection of the bacterium in tissues by immunohistochemical staining. However, the diagnosis of WD remains an invasive procedure. The recent achievement of stable bacterial culture and sequencing of the T. whipplei genome has opened a framework for the development of a biomarker platform. Several studies in different fields have been performed, for example, transcriptomics, immunoproteomics and comparative proteomics. Biomarker candidates have been proposed for the development of less invasive procedures for diagnosing WD.

Whipple disease revealed by musculocutaneous symptoms, with muscle biopsy cultures positive for Tropheryma whipplei

A patient experienced sudden onset of musculocutaneous symptoms 3 years after being diagnosed with polyarthritis. Biopsies from the duodenum, skin, and muscle established the diagnosis of Whipple disease. Cultures of muscle biopsy specimens grew Tropheryma whipplei. Adequate antibiotic therapy ensured a favorable outcome. To our knowledge, this is the first case in which T. whipplei was recovered from muscle biopsy specimens, confirming the infectious nature of muscle involvement in Whipple disease.

Molecular basis of Tropheryma whipplei doxycycline susceptibility examined by transcriptional profiling

OBJECTIVES AND METHODS

Tropheryma whipplei is a poorly studied bacterium responsible for Whipple's disease. In this study, its susceptibility to doxycycline was investigated at a transcriptional level using a whole-genome DNA microarray.

RESULTS

Exposure of T. whipplei to the MIC of doxycycline (0.5 mg/L) induced antibiotic-specific primary expression profiles, while indirect effects were detected at 10 x MIC. In contrast to what was observed for several microorganisms exposed to antibiotics, the heat-shock proteins were not affected. Consistent with the mode of action of this translation inhibitor, genes encoding for ribosomal proteins and translation factors were differentially transcribed. This analysis also evidenced the regulation of genes that should account for cell growth arrest. Long-term survival of non-replicating bacteria is likely to be ensured by an increased level of ppGpp, the nucleotide effector of the stringent response. The gene expression profile observed with 10 x MIC was mainly characterized by the up-regulation of ABC transporters that possibly form efflux and detoxification systems, through which T. whipplei may limit the effects of this bacteriostatic compound. Obtained microarray data showed good agreement with real-time quantitative PCR (R2 = 0.969).

CONCLUSIONS

This work represents the first comprehensive genomic approach providing insights into the expression signature triggered by the exposure of T. whipplei to antibiotics.

Cultivation ofTropheryma whipplei from the synovial fluid in Whipple's arthritis

This report describes a patient who presented with fever, weight loss, diarrhea, and adenopathy. At the time of presentation he had a 28-year history of unusually severe destructive polyarthritis. Duodenal biopsy revealed periodic acid-Schiff-positive macrophages. Polymerase chain reaction studies showed positivity for Tropheryma whipplei in synovial fluid, synovial tissue, and lymph node specimens, and Whipple's disease was diagnosed. T whipplei was successfully cultivated from the synovial fluid by both cell culture and axenic culture. This strain (named ART1) was subcultured and subsequently established and genotyped. Antibiotic treatment was instituted in the patient, after which his symptoms remitted. These findings show for the first time that Whipple's arthritis may be, at least in some cases, a septic arthritis.

Intervening sequence acquired by lateral gene transfer in Tropheryma whipplei results in 23S rRNA fragmentation

Completion of Tropheryma whipplei genome sequencing may provide insights into the evolution of the molecular mechanisms underlying the pathogenicity of this microorganism. The first postgenomic application was the successful design of a comprehensive culture medium that allows axenic growth of this bacterium, which is particularly recalcitrant to cultivation. This achievement in turn permitted analysis of T. whipplei RNA without contaminating eukaryotic nucleic acids. To obtain high-quality RNA, several extraction methods were compared, but under all conditions tested an atypical profile was observed. By using a Northern blot assay we demonstrated that an insertion sequence previously described in T. whipplei 23S rRNA is in fact an intervening sequence excised during maturation. This cleavage could involve an RNase III identified in the genome of this microorganism. Among the bacteria with a 23S rRNA insertion sequence, T. whipplei is the only gram-positive microorganism. We present phylogenetic evidence that this mobile genetic element was acquired by lateral gene transfer from another enteric bacterium.

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.

[Whipple's disease endocarditis: report of 5 cases and review of the literature]

PURPOSE

Endocarditic lesions (infectious endocarditis) associated with Whipple's disease are exceptional. We report five cases from the cardiovascular and pneumologic hospital Louis Pradel in Lyon.

METHOD

We have collected all cases of Tropheryma whipplei endocarditis diagnosed between 1995 and 2004.

RESULTS

Five men with a mean age of 53 years at time of diagnosis. The symptoms were essentially cardiovascular: murmur, embolism in 3 cases, and heart failure secondary to valvular insufficiency in 2 cases. The valvular involvement, double in 3 cases, was more often aortic. Vegetations were present in all patients and valvular destruction sometimes very important. A low grade fever was present in 4 cases, associated with weight loss in 2 cases. The only extra-cardiac symptoms were arthralgias or arthritis in all cases, considered in 3 patients as seronegative rheumatoid arthritis, B27+ spondylarthritis, and psoriasic arthritis. Their was no other clinical manifestations of Whipple's disease, particularly digestive, ocular, neurologic or adenopathy, and duodenal biopsies secondarily performed in 4 cases were non contributive. This differs from literature as an extra-cardiac location was identified in 11 out of 17 cases. The diagnosis was obtained by histology and PCR on the cardiac valves, as all the patients underwent surgery. The evolution was favourable with a prolonged antibiotic therapy.

CONCLUSIONS

These report confirms the existence of endocarditic forms of the Whipple's disease, in which the single extra-cardiac manifestation is rheumatologic, and reminds us the usefulness of histology and PCR on the cardiac valves at the time of valvular surgery.

Molecular evaluation of antibiotic susceptibility of Tropheryma whipplei in axenic medium

OBJECTIVES AND METHODS

Whipple's disease is a rare multisystem chronic infection, involving the intestinal tract as well as various other organs. Tropheryma whipplei is a slow-growing facultative intracellular bacterium that remains poorly understood. In vitro antibiotic susceptibility testing has previously been assessed in cells using a real-time quantitative PCR assay. In this study, we have evaluated the antibiotic susceptibility of three strains of T. whipplei grown in axenic medium using the same assay.

RESULTS

The active compounds in axenic medium were doxycycline, macrolide compounds, penicillin G, streptomycin, rifampicin, chloramphenicol, thiamphenicol, teicoplanin, vancomycin, amoxicillin, gentamicin, aztreonam, levofloxacin and ceftriaxone, with MICs in the range 0.06-1 mg/L. Cefalothin was less active, with MICs in the range 2-4 mg/L. We found that co-trimoxazole was active with MICs in the range 0.5-1 mg/L, and sulfamethoxazole alone was active with MICs in the range 0.5-1 mg/L. MICs of trimethoprim varied from 64-128 mg/L.

CONCLUSIONS

Co-trimoxazole was effective in vitro, but this activity was due to sulfamethoxazole alone. These results were in accordance with the fact that T. whipplei does not contain the encoding gene for dihydrofolate reductase, the target for trimethoprim.

Antibiotic susceptibility of Tropheryma whipplei in MRC5 cells

Whipple's disease is considered a rare chronic disease with a broad spectrum of clinical manifestations. Several antibiotics have been used for the treatment of this disease, and the current reference treatment was determined empirically on the basis of only a few clinical observations. Patients should be treated for months, and many relapse after antibiotic withdrawal. We report here the first extensive study on the susceptibilities of three reference strains of Tropheryma whipplei to antibiotic in cell culture by using a real-time PCR assay as previously described. We found that doxycycline, macrolides, ketolides, aminoglygosides, penicillin, rifampin, teicoplanin, chloramphenicol, and trimethoprim-sulfamethoxazole were active, with MICs ranging from 0.25 to 2 microg/ml. Vancomycin was somewhat active at an MIC of 10 microg/ml. We found heterogeneity in the susceptibility to imipenem, with one strain being susceptible and the two other strains being resistant. Cephalosporins, colimycine, aztreonam, and fluoroquinolones were not active. We also demonstrated that a combination of doxycycline and hydroxychloroquine was bactericidal. This combination has been shown to be active in the treatment of patients suffering from chronic infections with Coxiella burnetii, a bacterium that is also found intracellularly in acidic vacuoles. We believe, then, that this combination therapy should be further evaluated in clinical trials for the treatment of Whipple's disease.

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.