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We report microbiologic analysis of 786 lymph node biopsy specimens from patients with suspected cat-scratch disease (CSD). The specimens were examined by standard, cell culture, and molecular methods. Infectious agents were found in samples from 391 (49.7%) of 786 patients. The most commonly identified infectious agent was Bartonella henselae (245 patients, 31.2%), the agent of CSD. Mycobacteriosis was diagnosed in 54 patients (6.9%) by culture and retrospectively confirmed by using a specific real-time PCR assay. Neoplasm was diagnosed in 181 specimens suitable for histologic analysis (26.0%) from 47 patients. Moreover, 13 patients with confirmed Bartonella infections had concurrent mycobacteriosis (10 cases) or neoplasm (3 cases). A diagnosis of CSD does not eliminate a diagnosis of mycobacteriosis or neoplasm. Histologic analysis of lymph node biopsy specimens should be routinely performed because some patients might have a concurrent malignant disease or mycobacteriosis.

Detection and treatment of pericarditis remains a challenging problem and the etiology is unknown in 40-85% of cases. As a result, a large proportion of cases are labeled idiopathic pericarditis. The advent of echocardiography, an accurate noninvasive method for the detection of effusion, has clarified the definition from pericarditis to pericardial effusion, which is a standardized and clear entity. A systematic approach to diagnostic testing based on standardized practice guidelines has been proposed. This strategy has led to a decrease in the number of cases classified as idiopathic and to the identification of treatable conditions. Percutaneous pericardiocentesis, guided by fluoroscopy or echocardiography, can now be carried out safely and rapidly and has also allowed the intrapericardial instillation of drugs, representing a new treatment strategy. The inclusion of flexible pericardioscopy, immunohistochemistry and contemporary molecular biology tools has improved the diagnostic value of the biopsy.

We developed an animal model reproducing several aspects of Whipple's disease. Immunocompetent mice were persistently infected with Tropheryma whipplei, its etiological agent, and developed liver granulomas. SCID mice were infected similarly but did not develop tissue lesions. The delayed clearance of T. whipplei suggests a protective role for innate immunity.

Background: Although the pathologic examination of cardiac valves remains the reference standard for the diagnosis of infective endocarditis, the detection of microorganisms often poses a challenge for pathologists. This can be done by use of nonspecific histochemical stains or by immunohistochemical analysis, but specific antibodies are often not available. We describe a novel method for the detection of microorganisms in valve specimens from patients with infective endocarditis., Methods: Detection of microorganisms was performed in valve specimens from patients with endocarditis caused by gram-positive cocci (25 specimens), blood culture-negative endocarditis (15 specimens: 6 cases caused by Coxiella burnetii, 5 caused by Tropheryma whipplei, and 4 caused by Bartonella species), or noninfective degenerative damage (30 specimens, used as negative controls), using the patients' own serum. This technique, called "autoimmunohistochemistry," is an immunohistochemical peroxidase-based method that we compared with results of culture and polymerase chain reaction (PCR) assay., Results: Bacteria were detected by autoimmunohistochemistry in 20 (80%) specimens from patients with endocarditis caused by gram-positive cocci and in 15 (100%) specimens from patients with blood culture-negative endocarditis but in no control specimens. The rate of detection of bacteria by autoimmunohistochemistry was significantly higher than that by culture but was similar to that by PCR., Conclusions: Autoimmunohistochemistry may be useful for the detection of microorganisms in samples of valves from patients with infective endocarditis. This new diagnostic tool may be particularly useful in cases of blood culture-negative endocarditis.

Background: As a greater number of HIV-infected patients survive despite profound immunodepression due to medical progress, we face complex infection with multiple agents in AIDS-patients., Case Presentation: We report the case of an AIDS patient with a primary clinical presentation suggestive of bacillary angiomatosis. We also found in cutaneous lesions Mycobacterium avium complex and cytomegalovirus., Conclusion: This clinical case illustrates the possibility of multiple coinfections in AIDS patients and the need to be exhaustive in evaluating infectious diseases in severely immunocompromised patients.

Q fever is an infectious disease caused by Coxiella burnetii, an obligate intracellular bacterium that replicates in macrophages. As cell-mediated immune response to microbial pathogens requires signals mediated by T-cell receptors and costimulatory molecules such as CD28, we wondered if CD28 is involved in protection against C. burnetii infection. CD28-deficient (CD28-/-) mice were inoculated with C. burnetii by intraperitoneal and intravenous routes. With both wild-type and CD28-/- mice, C. burnetii organisms were detected exclusively in spleen and liver. The antibody response against C. burnetii was impaired in CD28-/- animals, but, surprisingly, the lack of CD28 decreased C. burnetii burden in the infected tissues, whatever the manner of inoculation of bacteria. The CD28 deficiency had no effect on either granuloma formation, which reflects cell-mediated immunity against C. burnetii, or the production of gamma interferon and tumor necrosis factor, two cytokines known to be involved in granuloma formation. On the other hand, the production of interleukin-10 (IL-10) by peritoneal macrophages was highly impaired in CD28-/- mice. The results suggest that CD28 initiates a signal that favors C. burnetii replication through the modulation of the IL-10 pathway.

We report the first laboratory-confirmed human infection due to a new rickettsial genotype in India, "Candidatus Rickettsia kellyi," in a 1-year-old boy with fever and maculopapular rash. The diagnosis was made by serologic testing, polymerase chain reaction detection, and immunohistochemical testing of the organism from a skin biopsy specimen.

Lobular capillary hemangioma and bacillary angiomatosis due to Bartonella infection share several clinical and histopathologic characteristics. We sought to determine whether lobular capillary hemangioma is caused by the same agent as bacillary angiomatosis. Forty-five pathology specimens with a histologic diagnosis of lobular capillary hemangioma obtained from patients with the same clinical diagnosis were tested by immunohistochemistry and polymerase chain reaction for the presence of DNA elements of Bartonella spp. None of the 45 lobular capillary hemangioma specimens tested positive for Bartonella spp. We conclude that lobular capillary hemangioma is not associated with Bartonella spp infection. Further research is required to determine the etiologic agent.

The resolution of Q fever, a zoonosis caused by Coxiella burnetii, depends on efficient innate and adaptive immune responses. Such responses are influenced by Toll-like receptors (TLRs). TLR4 is involved only in part in immune responses against C. burnetii, suggesting a role for TLR2. We investigated C. burnetii infection in wild-type and TLR2(-/-) mice. C. burnetii organisms were similarly eliminated by wild-type and TLR2(-/-) mice. In contrast, the formation of granulomas, a marker for efficient cell-mediated immunity, was markedly impaired. These results show that TLR2 is required for inflammatory and immune response to C. burnetii, but is dispensable for bacterial clearance.

Whipple disease (WD) is a rare systemic disease caused by Tropheryma whipplei and is characterized by the presence of foamy macrophages with periodic acid-Schiff-positive inclusions in tissues such as lamina propria. For the first time, we report the gene-expression profile of macrophages in intestinal lesions from a patient with WD. Microarray and real-time polymerase chain reaction revealed that genes encoding CCL18, cathepsins, scavenger receptor, interleukin-10, and lipid metabolites were up-regulated in intestinal lesions. This transcriptional pattern corresponds to that of M2/alternatively activated macrophages. Our results suggest that the T helper 2 response in the intestinal environment may account for the pathophysiological properties of WD.

Background: The incidence of embolic events (EE) and death is still high in patients with infective endocarditis (IE), and data about predictors of these 2 major complications are conflicting. Moreover, the exact role of echocardiography in risk stratification is not well defined., Methods and Results: In a multicenter prospective European study, including 384 consecutive patients (aged 57+/-17 years) with definite IE according to Duke University criteria, we tested clinical, microbiological, and echocardiographic data as potential predictors of EE and 1-year mortality. Transesophageal echocardiography was performed in all patients. Embolism occurred before or after IE diagnosis (total-EE) in 131 patients (34.1%) and after initiation of antibiotic therapy (new-EE) in 28 patients (7.3%). Staphylococcus aureus and Streptococcus bovis were independently associated with total-EE, whereas vegetation length >10 mm and severe vegetation mobility were predictors of new-EE, even after adjustment for S aureus and S bovis. One-year mortality was 20.6%. In multivariable analysis, independently of the other predictors of death (age, female sex, creatinine serum >2 mg/L, moderate or severe congestive heart failure, and S aureus) and comorbidity, vegetation length >15 mm was a predictor of 1-year mortality (adjusted relative risk=1.8; 95% CI, 1.10 to 2.82; P=0.02)., Conclusions: In IE, vegetation length is a strong predictor of new-EE and mortality. In combination with clinical and microbiological findings, echocardiography may identify high-risk patients who will need a more aggressive therapeutic strategy.

We show two mechanisms of liver protection by the granulomatous reaction against Schistosoma mansoni eggs entrapped in the organ. First, eosinophil peroxidase and its substrate H(2)O(2) are released by inflammatory cells in the immediate vicinity of the parasite eggs. The efficiency of this process was demonstrated by administration of antioxidants to infected mice. The treatment, which reduces H(2)O(2) production, significantly improved the ability of parasite eggs to hatch after collection from the liver. Secondly, we labeled the released egg antigens in liver histological sections and we found that the lattice of collagen fibers which is built around eggs appears to create a barrier preventing released compounds from diffusing freely in surrounding tissues. Together, oxidative processes and antigen containment allow the parasitized liver to cope with the dual threat posed by parasite eggs, i.e. a highly resistant chitinous eggshell and the release of toxic substances.

Q fever is a worldwide zoonosis caused by Coxiella burnetii, a strictly intracellular bacterium that is a potential bioweapon. Humans usually acquires Q fever after inhalation of dust infected by subclinical animals. We used an aerosol exposure apparatus to challenge immunocompetent (BALB/c) and severe combined immunodeficient (SCID) mice with two different strains (strain Nine Mile and strain Q 212) of C. burnetii at two different inocula. Pathological lesions and dissemination of the bacteria were related to the size of the inoculum. SCID mice showed major pulmonary lesions, whereas similarly infected BALB/c mice were more able to eliminate the bacteria. Pathological differences were found between the strains, with Nine Mile showing more severe histological lesions and quantified spread of bacteria. Our animal model could provide a new tool for the study of acute Q fever pneumonia, the development of Q fever in immunodeficient hosts, and the differentiation of pathogenicity among C. burnetii isolates.

Purpose: Histologic examination of valve samples is considered as the gold standard for the diagnosis of infectious endocarditis. Molecular tools are also very promising for patients with negative-culture endocarditis. Thus, we studied the contribution of valvular histology, culture, and 16S rRNA PCR amplification plus sequencing to the diagnosis of infectious endocarditis in patients undergoing valve surgery., Subjects and Methods: We performed culture, histological examination, and broad-range PCR amplification plus sequencing on valve samples taken from 127 patients with infectious endocarditis and from 118 patients without endocarditis. The sensitivity and specificity of these tests for the diagnosis of endocarditis in patients undergoing valve surgery were studied., Results: The sensitivity of PCR was of 61% (64/105) whereas that of histological examination was of 63% (62/98) and that of valve culture was of only 13% (14/105). All 68 positive PCR results considered reliable according to an interpretation scheme were from patients with infectious endocarditis, resulting in a 100% (118/118) specificity of the interpreted molecular approach. The specificity of histology was also of 100% (118/118) when using stringent criteria (ie, presence of vegetation, microorganisms, and/or valvular inflammation with mainly polymorphonuclear cells). PCR identified an etiological agent in 38% (5/13) of definite blood culture-negative infectious endocarditis., Conclusion: We show that valvular histology with stringent criteria is the gold standard for the diagnosis of infectious endocarditis. Broad-range amplification of 16S rRNA gene is indicated for infectious endocarditis of unknown etiology, whereas valve culture is of limited sensitivity.

Background: Histological demonstration of microorganisms, vegetations, or active endocarditis in cardiac valve tissue is included in the Duke criteria and is considered to be a criterion of confirmed infective endocarditis. However, the histological features that characterize infective endocarditis are not accurately defined at the qualitative and quantitative levels., Methods: Pathologic analysis of tissue adjoining mechanical cardiac valves was undertaken retrospectively for 21 patients who underwent surgical removal of a mechanical valve because of suspected infective endocarditis and 69 patients who underwent surgical removal of a mechanical valve because of noninfectious dysfunction. To better define the histological criteria for infective endocarditis, we used quantitative image analysis to compare these 2 groups of patients with respect to valvular fibrosis, calcifications, vegetations, patterns of inflammation, and vascularization., Results: Histologically, infective endocarditis in patients with mechanical valves was characterized by the demonstration of microorganisms, vegetations, and significant neutrophil-rich inflammatory infiltrates with extensive neovascularization. In contrast, valve tissue specimens from patients with mechanical valves that were removed because of noninfectious complications showed significant rates of extensive fibrosis and, when present, inflammatory infiltrates that were mainly composed of macrophages and lymphocytes. A neutrophil surface area with a cutoff value of > or =2% of the total valve tissue surface is highly predictive of (90%) and specific for (98%) infective endocarditis., Conclusions: When no microorganisms are detected and vegetations are lacking in tissue adjacent to a mechanical valve, neutrophil-rich inflammation and extensive neovascularization might better histologically define the term "active endocarditis" in the Duke criteria. This definition would allow differentiation between infective endocarditis and inflammatory noninfectious valve processes in patients with mechanical cardiac valves.

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.

We used broad-range PCR amplification and sequencing to detect and identify bacterial DNA in 156 valves of patients treated for infective endocarditis (IE). Bacterial DNA was found more frequently in patients who underwent valve replacement while on antibiotic treatment for IE (60%) than in patients who had completed antibiotic treatment for IE (37%; P = 0.02). We found specific bacterial DNA in valves removed from 11 of 30 patients who had completed antibiotic treatment for IE. Six had no histological evidence of IE. The presence of DNA was significantly correlated with the presence of histologic lesions (P = 0.001) and with the presence of bacteria detected by Gram staining (P < 0.001). Bartonella and streptococci were detected for much longer after antibiotic treatment by PCR than other species (P = 0.047 and 0.04, respectively), and coagulase-negative staphylococci were detected for much shorter periods (P = 0.02). The finding that bacterial DNA was more likely to be detected in valves of patients with active IE than in patients who had completed antibiotic treatment for IE shows that bacterial DNA is cleared slowly. There was no significant correlation between the duration of antibiotic therapy and the presence of bacterial DNA in valves. Since the persistence of bacterial DNA in valves does not necessarily indicate the persistence of viable bacteria, the detection of bacterial DNA in valves from IE patients should be interpreted with caution, in particular in those patients with a past history of treated IE.

In patients treated for breast carcinoma, unilateral lymphedema of the upper limb is usual. However, to the authors' knowledge, lower limb lymphedema has never been reported as a complication of breast carcinoma therapy. They report here the first case of a radiation-induced constrictive pericarditis revealed by severe lower limbs lymphedema. A 60-year-old woman was treated for left breast carcinoma with quadrantectomy, axillary lymphadenectomy, and combined radio chemotherapy (60 grays). Three and a half years later she suffered from a diffuse and increasing lower limbs lymphedema, which became huge and disabling. Radiation-induced constrictive pericarditis was evidenced by right cardiac cavities catheterization. A dramatic improvement was rapidly obtained after pericardectomy. Histopathologic analysis of the pericardium did not reveal neoplastic cells. Radiation-induced constrictive pericarditis is usually responsible for lower limbs edema, but lymphedema is exceptional. This case highlights the need to search for a constrictive pericarditis also in the case of lower limbs lymphedema, particularly in a patient treated with mediastinal radiotherapy or combined radio chemotherapy.

Coxiella burnetii, the causative agent of Q fever, is responsible for various clinical syndromes, but lymphadenitis has been described during Q fever in only three recent case reports. Four new cases of acute Q fever associated with lymphadenopathy are reported here, and these cases are discussed along with the three previously reported cases. Coxiella burnetii was isolated for the first time from a lymph node. Q fever should be considered an etiologic agent of lymphadenitis.

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.

Bartonella henselae uveitis was diagnosed in a 40-year-old woman with underlying HLA-B27 uveitis on the basis of immunodetection and molecular detection of the organism, a Marseilles genogroup and a CAL-1 genotype strain, in the vitreous fluid. This case illustrates that B. henselae should be included in the differential diagnosis of uveitis and the usefulness of immunodetection for rapid and specific diagnosis.

The role of Toll-like receptors (TLRs) in the recognition of extracellular and facultative intracellular bacteria by the innate immune system has been extensively studied, but their role in the recognition of obligate intracellular organisms remains unknown. Coxiella burnetii, the agent of Q fever, is an obligate intracellular bacterium that specifically inhabits monocytes/macrophages. We showed in this study that C. burnetii LPS is involved in the uptake of virulent organisms by macrophages but not in that of avirulent variants. The uptake of virulent organisms was dependent on TLR4 because it was reduced in macrophages from TLR4(-/-) mice. In addition, LPS was responsible for filamentous actin reorganization induced by virulent C. burnetii, which was prevented in TLR4(-/-) macrophages. In contrast, the intracellular fate of C. burnetii was not affected in TLR4(-/-) macrophages, suggesting that TLR4 does not control the maturation of C. burnetii phagosome and the microbicidal activity of macrophages. These results are consistent with in vivo experiments because the pattern of tissue infection and the clearance of C. burnetii were similar in wild-type and TLR4(-/-) mice. We also showed that the number of granulomas was decreased in the liver of infected TLR4(-/-) mice, and the formation of splenic granulomas was only transient. The impaired formation of granulomas was associated with decreased production of IFN-gamma and TNF. Taken together, these results demonstrate that TLR4 controls early events of C. burnetii infection such as macrophage phagocytosis, granuloma formation, and cytokine production.

P-selectin is a leukocyte adhesion receptor expressed on the surface of activated platelets and endothelial cells. Its role in the pathogenesis of cerebral malaria was explored in a murine model of cerebral malaria. Infection of mice with Plasmodium berghei ANKA led to P-selectin up-regulation in brain vessels of cerebral malaria-susceptible mice but not of cerebral malaria-resistant mice. Treatment of susceptible mice with anti-mouse P-selectin mAb failed to prevent the development of the neurological syndrome. However, P-selectin-deficient mice infected with Plasmodium berghei ANKA had a cumulative incidence of cerebral malaria which was significantly reduced compared to wild-type animals (4.5% versus 80%, respectively), despite identical levels of parasitemia, platelet and leukocyte accumulation. To determine whether P-selectin on platelets and/or endothelium was responsible for the microvascular pathology, cerebral malaria was assessed in chimeric mice deficient in platelet or endothelial P-selectin, which were generated by bone marrow transplantation. Mice deficient only in endothelial P-selectin did not show any sign of cerebral malaria (vascular plugging, hemorrhages, or edema), while mice lacking only platelet P-selectin showed signs of cerebral malaria similar to that seen in wild-type mice. These results indicate that endothelial P-selectin plays an important role in the pathogenesis of cerebral malaria.

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.

Vanin-1 is a membrane-anchored pantetheinase highly expressed in the gut and liver. It hydrolyzes pantetheine to pantothenic acid (vitamin B5) and the low-molecular-weight thiol cysteamine. The latter is believed to be a key regulating factor of several essential metabolic pathways, acting through sulfhydryl-disulfide exchange reactions between sulfhydryl groups of the enzymes and the oxidized form, cystamine. Its physiological importance remains to be elucidated, however. To explore this point, we developed Vanin-1-deficient mice that lack free cysteamine. We examined the susceptibility of deficient mice to intestinal inflammation, either acute (NSAID administration) or chronic (Schistosoma infection). We found that Vanin-1(-/-) mice better controlled inflammatory reaction and intestinal injury in both experiments. This protection was associated with increased gamma-glutamylcysteine synthetase activity and increased stores of reduced glutathione, as well as reduced inflammatory cell activation in inflamed tissues. Oral administration of cystamine reversed all aspects of the deficient phenotype. These findings suggest that one cysteamine function is to upregulate inflammation. Consequently, the pantetheinase activity of Vanin-1 molecule could be a target for a new anti-inflammatory strategy.

Q fever is a zoonosis caused by Coxiella burnetii and recently has been recognized as a potential agent of bioterrorism. In Q fever, men are symptomatic more often than women, despite equal seroprevalence. We hypothesized that sex hormones play a role in the pathogenesis of C. burnetii infection. When C57/BL6 mice were injected with C. burnetii, bacteria load and granuloma numbers were lower in females than in males. Ovarectomized mice showed increased bacteria load in the spleen and the liver, similar to that found in males. The granuloma number was also increased in ovarectomized mice and reached the levels found in males. Tissue infection and granulomatous response are largely under the control of estrogens: treatment of ovarectomized mice with 17beta-estradiol reduced both bacteria loads and granuloma numbers. These results show that sex hormones control host response to C. burnetii infection and may account for host-dependent clinical presentation of Q fever.

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.

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.

In this report we describe a 30-year old male patient with vertebral osteomyelitis and spleen abscesses with cat scratch disease. The diagnosis was made on the basis of molecular detection of Bartonella henselae either on lymph node biopsies or on bone biopsy, histology of the lymph node, serology using either our in-house microimmunofluorescence assay or a commercial kit (Focus Technologies). Immunofluorescent detection was also performed directly on slide appositions using a monoclonal antibody. Treatment consisted of administration of antibiotics with rapid clinical improvement and a stabilization of skeletal lesions on the magnetic resonance imaging performed three months later. Twenty two other cases of this unusual manifestation associated with cat scratch disease have been reported in the literature and are reviewed here. Our case represents the second case of osteomyelitis associated with cat scratch disease in which B. henselae has been specifically identified as the etiological agent using several direct and indirect methods.

Q fever is a worldwide-occurring zoonosis caused by Coxiella burnetii. There are various clinical manifestations of acute Q fever, of which acute cholecystitis is a very rare clinical presentation. This study reports seven cases of acute cholecystitis associated with Coxiella burnetii and reviews two other cases from the literature. All patients were admitted to hospital for fever and abdominal pain in the right upper quadrant. Abdominal echography showed a distended gallbladder with biliary sludge without concrements in eight cases and with a single stone in one case. Diagnosis was made by specific serological investigation (microimmunofluorescence assay) for Coxiella burnetii. All nine patients were cured, six after laparoscopic cholecystectomy and three with antibiotics only. Histological examination of the gallbladders showed inflammation in five cases, although Coxiella burnetii was not detected by immunohistochemistry. The results show that laboratory investigations in patients admitted to hospital for symptoms consistent with acute acalculous cholecystitis should include a systematic search for Coxiella burnetii.

The pathologic features of Q fever endocarditis, which is caused by Coxiella burnetii, were histologically evaluated in cardiac valves from 28 patients. We used quantitative image analysis to compare valvular fibrosis, calcifications, vegetations, inflammation, and vascularization due to Q fever endocarditis with that due to non-Q fever endocarditis and valvular degeneration. We also studied the presence of C. burnetii in valves by immunohistochemical analysis, culture, and polymerase chain reaction (PCR). Histologically, Q fever endocarditis was characterized by significant fibrosis and calcifications, slight inflammation and vascularization, and small or absent vegetations. Despite antibiotic treatment, non-statistically significant variations at the histologic level were observed. These pathologic features could be confused with noninfectious valvular degenerative damage. We found that the detection of C. burnetii in cardiac valves by immunohistochemical analysis, culture, and PCR decreased significantly only after 1 year of antibiotic treatment, which emphasizes the long persistence of this organism in valve tissues. Pathologic and immunohistochemical analyses may contribute to the diagnosis of Q fever endocarditis.

We used broad-range eubacterial PCR amplification followed by direct sequencing to identify microbial pathogens in heart valve material from 29 patients with histologically confirmed infective endocarditis and 23 patients free of infective endocarditis. Microorganisms cultured by conventional techniques matched those identified by PCR in 21 cases. PCR alone identified the causative agent in three cases (Streptococcus bovis, Staphylococcus cohnii, and Coxiella burnetii), allowing better patient management. PCR corrected the initial bacteriological diagnosis in three cases (Streptococcus bovis, Streptococcus mutans, and Bartonella henselae). Among the 29 cases of histologically confirmed infective endocarditis, PCR findings were positive in 27 cases and were consistent with the bacterial morphology seen at Gram staining (26 cases) or with the results obtained by immunohistologic analysis with an anti-C. burnetii monoclonal antibody (one case). In two other cases of histologically confirmed infective endocarditis, PCR remained negative in a blood culture-negative case for which no bacteria were seen at histological analysis and in one case with visualization of cocci and blood cultures positive for Enterococcus faecalis. Ten clinical diagnoses of possible infective endocarditis were ruled out by histopathological analysis of the valves and subsequently by PCR. PCR was negative in 13 of the 14 patients in whom infective endocarditis was rejected on clinical grounds; the other patient was found to have Coxiella burnetii infective endocarditis on the basis of PCR and histopathological analysis and was subsequently included in the group of 29 definite cases. In total, PCR contributed to the diagnosis and management of infective endocarditis in 6 of 29 (20%) cases.

Rickettsia prowazekii is transmitted to humans by the body louse. A new experimental model of body louse infection with R. prowazekii is reported here. Eight hundred human lice were infected by feeding on a rabbit that was made bacteremic by injecting 2x106 plaque-forming units of R. prowazekii. The bacterium invaded the stomach cells and was released in feces, in which it was detected 5 days after infection. At day 6 after infection, as a result of the cell burst and the spread of erythrocytes in the hemolymph, the louse became bright red and died within 4 h. The life span of infected lice was shortened by 20-23 days, compared with that of uninfected control lice. Infected lice did not transmit R. prowazekii to their progeny. Through cell culture, rickettsiae were cultivated from fecal samples up to 10 days after their emission. The administration of doxycycline to the rabbit during louse feeding did not cure lice from R. prowazekii infection.

Whipple disease is a rare infection characterized clinically by diarrhea, fever, weight loss, arthralgia, malabsorption, and other systemic manifestations. The etiologic agent, Tropheryma whipplei, has been cultured only rarely. By using a polyclonal rabbit antibody produced against a cultured strain of T whipplei, tissue sections from 18 patients with Whipple disease were studied. Specimens from patients with histologic mimics and other infections served as control specimens. Immunostaining was identified in all 18 patients. Granular immunostaining was observed similar to that in periodic acid-Schiff (PAS) stains. In 2 patients, immunostaining was identified in specimens negative by H&E and PAS stains. In 4 patients studied before and after antibiotic therapy, immunostaining was retained but diminished in intensity and quantity. Immunostaining was not identified in any control specimen. Immunohistochemical analysis is a sensitive and specific method for the diagnosis of Whipple disease in paraffin-embedded tissue and may provide new opportunities to investigate the pathogenesis of the infection.

Infective endocarditis (IE) often presents diagnostic and therapeutic challenges and continues to cause high morbidity and mortality. Confirmation of the diagnosis of IE is important for the purposes of epidemiologic and clinical studies and is crucial for patient management. Despite recent advances in diagnostic techniques, about 10% of IE cases remain culture-negative. Because pathological examination of cardiac valves to demonstrate vegetations and valvular inflammation remains the gold standard for the diagnosis of IE, the role of the pathologist is often decisive, especially when bacteriologists fail to isolate a microorganism or when a microorganism that has been isolated may be a contaminant. Furthermore, the pathologist may play an important role in identification of previously unknown infectious agents.

A case of Q fever endocarditis was diagnosed in a patient with no sign of active endocarditis by performing PCR targeting eubacterial 16S rDNA on the resected mitral valve. The diagnosis was confirmed by detection of high levels of anti-Coxiella burnetti antibodies, positive immunohistologic analysis of the valve tissue with specific antibodies and culture of C. burnetti from the valve tissue. As this patient had an unexplained aggravation of valve dysfunction, we recommended routine serologic testing for C. burnetti to allow the diagnosis of Q fever endocarditis at a very early stage.

We report 2 patients who had sarcoidosis with skin involvement associated with bilateral anterior uveitis. During the follow-up, they developed chronic myelomonocytic leukemia. This association is of particular interest as sarcoidosis and chronic myelomonocytic leukemia may be considered as disorders of a common monocyte-macrophage cell lineage., (Copyright 2002 S. Karger AG, Basel)

Whipple's disease is a systemic infection sometimes associated with cardiac manifestations. Recently, there has been an increase in the number of reported cases of Whipple's endocarditis. The purpose of our study was to describe this entity. Data from 35 well-described cases of Whipple's endocarditis were collected and compared with those of blood culture-positive endocarditis, Q fever endocarditis, and Bartonella endocarditis. Some patients with generalized Whipple's disease presented with cardiac involvement, among other symptoms. Others presented with a nonspecific, blood culture-negative endocarditis with no associated symptoms. In comparison with cases of endocarditis due to other causes, congestive heart failure, fever, and previous valvular disease were less frequently observed in the cases of Whipple's endocarditis. Without examination of the excised valves, the diagnosis of infective endocarditis could not have been confirmed in most cases. Treatment is not well established. Whipple's endocarditis is a specific entity involving minor inflammatory reactions and negative blood cultures, and its incidence is probably underestimated.

Molecular hydrogen reacts with the hydroxyl radical, a highly cytotoxic species produced in inflamed tissues. It has been suggested therefore to use gaseous hydrogen in a new anti-inflammatory strategy. We tested this idea, with the aid of the equipment and skills of COMEX SA in Marseille, a group who experiments with oxygen-hydrogen breathing mixtures for professional deep-sea diving. The model used was schistosomiasis-associated chronic liver inflammation. Infected animals stayed 2 weeks in an hyperbaric chamber in a normal atmosphere supplemented with 0.7 MPa hydrogen. The treatment had significant protective effects towards liver injury, namely decreased fibrosis, improvement of hemodynamics, increased NOSII activity, increased antioxidant enzyme activity, decreased lipid peroxide levels and decreased circulating TNF-alpha levels. Under the same conditions, helium exerted also some protective effects, indicating that hydroxyl radical scavenging is not the only protective mechanism. These findings indicate that the proposed anti-inflammatory strategy deserves further attention.

Monoclonal antibodies (MAbs) which react with heat-resistant proteins with molecular masses of 32 to 33 kDa of 14 different Bartonella species were produced. These antibodies did not react with antigens of 26 diverse bacterial strains by microimmunofluorescence assay except MAb B3D4, which reacted with Chlamydia psittaci and Chlamydia trachomatis at low titers. The identification of a common Bartonella antigenic protein will make it possible to later produce a diagnostic antigen by cloning and expressing it in Escherichia coli. Moreover, these MAbs allow all Bartonella species to be identified to the genus level.

Background: Sicca syndrome after Stevens-Johnson syndrome is classically described. However, to our knowledge, authentic Sjögren's syndrome following epidermal necrolysis has not been described previously., Case Report: A 36-year-old woman with Steven-Johnson syndrome developed transient hepatitis and a persistent sicca syndrome. Fourteen years later an authentic Sjögren's syndrome was identified with presence of antinuclear and anti-SSA antibodies and lymphocytes infiltration of the accessory salivary glands, i.e. grade IV disease in the Chisholm classification., Discussion: The initial mucosal destruction observed in our patients may have laid the ground for Sjögren's syndrome via abnormal antigen presentation in a predisposed dysimmune context.

A laboratory colony of human body lice was experimentally infected by feeding on rabbits made artificially bacteremic with a green fluorescent protein-expressing Bartonella quintana. B. quintana was detected in the gut and feces until death but not in the eggs. The life span of the lice was not modified. The rabbit model should provide valuable clues to the role of lice in the transmission of B. quintana.

Before the first 12 hours, diagnosis of early myocardial infarctions is always difficult for forensic pathologists. We tested complement C9 expression in 121 formalin-fixed and paraffin-embedded heart samples by an immunohistochemical procedure. The heart specimens were separated into four groups: 33 cases in group 1 with typical ischemic damages histologically located, 20 cases in group 2 with death related to myocardial infarction on the basis of ischemic presentation on electrocardiogram but no obvious histological ischemic damage, 35 cases in group 3 with severe coronary disease without cause of death found at the autopsy, and 33 cases in group 4 without sign of myocardial infarction and without coronary disease. In the first group, all 33 heart samples showed a well-defined C9 expression in the necrotic areas. The second group in 17 of 20 cases showed positive areas for C9 expression. In the other three heart specimens, only few stained cells were observed whereas the painful symptoms had begun less than 1 h before death. The third group showed C9 immunopositive areas in six of 35 cases, few stained cells in 8 cases, and no C9 deposition in the 21 other cases. The last group showed no staining area. To avoid nonspecific C9 staining due to tissue autolysis, we studied C9 expression during a controlled putrefactive process in four cases included in group 1; staining was found only in infarcted myocardial areas, and was observed up to ten days. Specificity of C9 expression was evaluated to be 100% [89.4 to 100%] and sensitivity to be 85% [62.11 to 96.79%]. In conclusion, evaluation of immunohistochemical expression of C9 appears to be a highly sensitive and specific marker of early myocardial infarction, useful in forensic medicine if survival is more than 1 h after the beginning of myocyte damage.

Context: Culture of Tropheryma whippelii has been established only once, in human fibroblast cell lines from a heart valve inoculum. Molecular-based diagnostic techniques, although highly sensitive, may be less specific. New diagnostic tools involving isolation of bacteria from contaminated intestinal biopsies and immunohistological detection need to be developed., Objective: To describe a novel method for detection and culture of T whippelii strains., Design, Setting, and Subjects: Laboratory analysis of duodenal biopsy specimens from a patient with typical relapsing Whipple disease with intestinal involvement, performed Marseille, France, in March 2000. Biopsy specimens were decontaminated with antimicrobial agents and inoculated onto cell cultures. Mouse anti-T whippelii polyclonal antibodies were used to detect T whippelii in fixed specimens taken from the patient before and after relapse, compared with specimens from 10 controls. The genotype of the isolate was determined by amplification and sequencing of 2 DNA fragments (ITS and 23S rRNA)., Main Outcome Measure: Isolation and genotyping of a new strain(s) of T whippelii from the case patient's biopsy specimens., Results: A strain was grown from the case patient's intestinal specimen that has a genotype different from the first strain isolated. During 2 episodes of Whipple disease, T whippelii bacteria were detected by immunochemistry in the patient's duodenal biopsy specimens, but not in controls., Conclusions: A second strain of T whippelii has been isolated and a protocol for isolation from the intestine has been proven to be efficient. Immunodetection of T whippelii in intestinal biopsy specimens may provide a useful tool for the diagnosis and follow-up of patients with Whipple disease. Both techniques need further evaluation and confirmation.