Mycobacterium tuberculosis Resides in Macrophages in Laryngeal Tuberculosis: A Case Report.

Laryngeal tuberculosis is a rare form of extrapulmonary tuberculosis that questions the natural history of this infection. We report one such case in which a pathological examination of a laryngeal biopsy revealed granulomatous inflammation with caseous necrosis. Further investigations combining immunofluorescence detection of macrophages and in situ hybridization of Mycobacterium tuberculosis indicated the presence of Mycobacterium tuberculosis (M. tuberculosis) in laryngeal granulomatous inflammatory lesions. This observation suggests that the natural history of laryngeal tuberculosis does not differ from that of other forms, guiding early diagnosis in patients with laryngeal lesions to ensure appropriate check-ups and treatment.

Infection and Persistence of Coxiella burnetii Clinical Isolate in the Placental Environment.

Infection by Coxiella burnetii, the etiological agent of Q fever, poses the risk of causing severe obstetrical complications in pregnant women. C. burnetii is known for its placental tropism based on animal models of infection. The Nine Mile strain has been mostly used to study C. burnetii pathogenicity but the contribution of human isolates to C. burnetii pathogenicity is poorly understood. In this study, we compared five C. burnetii isolates from human placentas with C. burnetii strains including Nine Mile (NM) as reference. Comparative genomic analysis revealed that the Cb122 isolate was distinct from other placental isolates and the C. burnetii NM strain with a set of unique genes involved in energy generation and a type 1 secretion system. The infection of Balb/C mice with the Cb122 isolate showed higher virulence than that of NM or other placental isolates. We evaluated the pathogenicity of the Cb122 isolate by in vitro and ex vivo experiments. As C. burnetii is known to infect and survive within macrophages, we isolated monocytes and placental macrophages from healthy donors and infected them with the Cb122 isolate and the reference strain. We showed that bacteria from the Cb122 isolate were less internalized by monocyte-derived macrophages (MDM) than NM bacteria but the reference strain and the Cb122 isolate were similarly internalized by placental macrophages. The Cb122 isolate and the reference strain survived similarly in the two macrophage types. While the Cb122 isolate and the NM strain stimulated a poorly inflammatory program in MDM, they elicited an inflammatory program in placenta macrophages. We also reported that the Cb122 isolate and NM strain were internalized by trophoblastic cell lines and primary trophoblasts without specific replicative profiles. Placental explants were then infected with the Cb122 isolate and the NM strain. The bacteria from the Cb122 isolate were enriched in the chorionic villous foetal side. It is likely that the Cb122 isolate exhibited increased virulence in the multicellular environment provided by explants. Taken together, these results showed that the placental isolate of C. burnetii exhibits a specific infectious profile but its pathogenic role is not as high as the host immune response in pregnant women.

A Massive Number of Extracellular Tropheryma whipplei in Infective Endocarditis: A Case Report and Literature Review.

Whipple's disease (WD) is a chronic multisystemic infection caused by Tropheryma whipplei. If this bacterium presents an intracellular localization, associated with rare diseases and without pathognomonic signs, it is often subject to a misunderstanding of its physiopathology, often a misdiagnosis or simply an oversight. Here, we report the case of a patient treated for presumed rheumatoid arthritis. Recently, this patient presented to the hospital with infectious endocarditis. After surgery and histological analysis, we discovered the presence of T. whipplei. Electron microscopy allowed us to discover an atypical bacterial organization with a very large number of bacteria present in the extracellular medium in vegetation and valvular tissue. This atypical presentation we report here might be explained by the anti-inflammatory treatment administrated for our patient's initial diagnosis of rheumatoid arthritis.

Influence of the healthcare pathway on the outcome of patients with infective endocarditis.

AIMS: To determine the prognosis of patients treated for infective endocarditis (IE) according to their healthcare pathway. To assess how the ESC guidelines are implemented concerning the performance of transoesophageal echocardiography, the use of antibiotic therapy, and the performance of valve surgery; and to compare the epidemiological profile of IE according to the type of centres in which the patients are hospitalized. METHODS AND RESULTS: In a prospective multicentric study including 22 hospitals in the South-East of France, 342 patients were classified into three groups according to their healthcare pathway: 119 patients diagnosed and taken care entirely in a reference centre or hospital with cardiac surgery [Referral Center (RC) group], 111 patients diagnosed and initially taken care in a non-RC (NRC), then referred in a centre including cardiac surgery [transferred to the Referral Center (TRC) group] and 112 patients totally taken care in the NRC (NRC group). One-year mortality was 26% (88 deaths) and was not significantly different between Groups 1 and 2 (20 vs. 21%, P = 0.83). Patients in the NRC group had a higher mortality (37%) compared with patients in the RC and TRC groups (P < 0.001). ESC guidelines were not implemented similarly depending on the healthcare pathway (P = 0.04). Patients in the NRC group were significantly older (P < 0.001) and had more comorbidities (P < 0.001) than patients treated in referral centres. CONCLUSION: Prognosis of patients with IE is influenced by their healthcare pathway. Patients treated exclusively in NRC have a worse prognosis than patients treated in referral or surgical centres.

Mitral valve repair is better than mitral valve replacement in native mitral valve endocarditis: Results from a prospective matched cohort.

BACKGROUND: In native mitral valve infective endocarditis (NMIE), the respective values of mitral valve repair (MVRep) and replacement (MVR) are still debated. AIM: To compare MVRep and MVR in a large prospective matched cohort. METHODS: Between 2010 and 2017, all consecutive patients operated on for NMIE in our centre were included prospectively. Clinical and outcome features were compared between the two groups. Primary endpoint was event-free survival, including death, reoperation and relapse. Univariate and multivariable survival analyses and a propensity score analysis were performed. RESULTS: Among 152 patients, 115 (75.7%) underwent MVRep, and 37 (24.3%) MVR. Median follow-up was 28±22months. Surgery was performed during the active phase in 75.0% of patients (25.7% on an urgent basis). Compared with the MVRep group, patients in the MVR group were more frequently intravenous drug abusers (10.8% vs. 0.9%; P=0.016), had a more frequent history of rheumatic fever (13.5% vs. 0%; P=0.001), more aortic abscesses (16.7% vs. 3.5%; P=0.018), larger vegetations (16.6±8.1mm vs. 12.6±9.9mm; P=0.042) and poorer New York Heart Association status (P=0.006). Overall mortality was lower in the MVRep group than in MVR group (11.3% vs. 29.3%; P=0.018). Event-free survival was better in the MVRep group than in the MVR group in univariate analysis (hazard ratio: 2.72, 95% confidence interval: 1.34-5.52; P=0.004). Survival analysis in the propensity-matched cohort showed that MVRep was safer than MVR (log rank test: P=0.018). Multivariable analysis using the Cox proportional hazard model confirmed this finding (hazard ratio: 3.48, 95% confidence interval: 1.15-10.61; P=0.03). CONCLUSIONS: MVRep is feasible in most cases of NMIE and, when technically possible, should be preferred, even in urgent surgery.

Infective endocarditis with neurological complications: Delaying cardiac surgery is associated with worse outcome.

BACKGROUND: Infective endocarditis (IE) is associated with a high mortality rate, related in part to neurological complications. Studies suggest that valvular surgery should be performed early when indicated, but is often delayed by the presence of neurological complications. AIM: To assess the effect of delaying surgery in patients with IE and neurological complications and to identify factors predictive of death. METHODS: In a prospective, single-centre study in a referral centre for IE, all patients with IE underwent systematic screening for neurological complications. The primary outcome was 6-month death. In patients presenting with neurological complications, the prognosis according to surgical status was analysed and a Cox regression model used to identify variables predictive of death. RESULTS: Between April 2014 and January 2018, 351 patients with a definite diagnosis of left-sided IE were included. Ninety-four patients (26.8%) presented with at least one neurological complication. Fifty-nine patients (17.7%) died during 6-month follow-up. Six-month mortality rates did not differ significantly between patients with and without neurological complications (P=0.60). Forty patients had a temporary surgical contraindication because of neurological complications. During the period of surgical contraindication, seven of these patients (17.5%) died, six (15.0%) presented a new embolic event, and 12 (30.0%) presented cardiac or septic deterioration. In multivariable analysis, predictive factors of death in patients presenting with neurological complications were temporary surgical contraindication (hazard ratio 7.36, 95% confidence interval 1.61-33.67; P=0.010) and presence of a mechanical prosthetic valve (hazard ratio 16.40, 95% confidence interval 2.22-121.17; P=0.006). CONCLUSIONS: Patients with a temporary surgical contraindication due to neurological complications had a higher risk of death and frequent major complications while waiting for surgery. When indicated, the decision to postpone surgery in the early phase should be weighed against the risk of infectious or cardiac deterioration.

Severe pneumonia in a street rat (Rattus norvegicus) caused by Rodentibacter rarus strain RMC2.

Background: Rodents are one of the most dangerous reservoirs and carriers of infectious diseases. Gradually, rats have become predominant in cities, sometimes staying in close vicinity to humans, pets, and other animals. Consequently, they tend to increase the transmission risk of pathogens. Case Description: Here, we report an original case of bacterial pneumonia in a street rat (Rattus norvegicus). The rat was found dead on a street in the chief town of Marseille (France) after being run over by a car. The necropsy of the corpse revealed generalized granulomatous pneumonia in almost all the pulmonary lobes. Lung lesions and predominantly multiple fibro-inflammatory areas are presumably the witness of an infectious etiology. Bacterial isolation was carried out from lung tissues. Colonies were identified by MALDI-TOF MS and confirmed by 16S rRNA sequencing. The following bacteria were identified: Staphylococcus cohnii, Bordetella bronchiseptica, Bordetella parapertussi, Corynebacterium glucuronolyticum, Pelistega suis and Rodentibacter rarus. Based on the histopathological diagnosis and the avoidance approach, the most likely etiological agent of pneumonia is therefore R. rarus, a little-known Pasteurellales bacterium that is closely related to Rodentibacter pneumotropicus. Conclusion: These data emphasize the severity of R. rarus infection in rodents. Thus, pointing out a potential risk for other animals (dogs, cats, and birds), as well as humans. The health monitoring program for rodents and rabbits pasteurellosis should now include R. rarus. Therefore, the pathological effect of the Rodentibacterspecies and/or strains needs to be better explored.

Ultrastructure of a late-stage bacterial endocarditis valve vegetation.

Infective endocarditis (IE) remains a severe illness with high mortality rate, despite advances in antibiotic therapy and cardiac surgery. If infectious bacteria and platelets are two key players of human IE vegetation developmental process, their interactions and respective roles in fully developed late-stage IE vegetations remain obscure. The objective of this study was to better understand the organization of the different components of the IE vegetation and to provide a detailed description of this vegetation ultrastructure. A late stage Staphylococcal endocarditic vegetation was provided from a 13 years teenager patient. After reception of the surgical piece, we carried out a histological study using routine methods, notably the hematoxylin-eosin-saffron staining. Labeling with the anti-CD 61 antibody was also carried out. In a second step, we used transmission electron microscopy to describe the different regions making up the vegetation. Our ultrastructural study revealed vegetation was clearly composed by three different regions and identified the specific location of the bacteria and platelets in the vegetation tissues. Histological analysis showed that platelets and Staphylococcus aureus were not co-localized. Electron microscopy study confirmed that S. aureus were found at distance from platelets, as well from immune cells, embedded in a biofilm and/or a necrotic area. These results reveal a development of a deep bacteria-only niche in vegetation, raising questions about medication access to these microorganisms. Vegetation composed of three regions: a region rich in bacteria incorporated into the necrotic tissue, the second region composed of fibrin filaments and the third region rich in platelets and free of bacteria.

FDG-PET/CT Incidental Detection of Cancer in Patients Investigated for Infective Endocarditis.

Background: Fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) is an imaging technique largely used in the management of infective endocarditis and in the detection and staging of cancer. We evaluate our experience of incidental cancer detection by PET/CT during IE investigations and follow-up. Methods and Findings: Between 2009 and 2018, our center, which includes an "endocarditis team," managed 750 patients with IE in a prospective cohort. PET/CT became available in 2011 and was performed in 451 patients. Incidental diagnosis of cancer by PET/CT was observed in 36 patients and confirmed in 34 of them (7.5%) (colorectal n = 17; lung n = 7; lymphoma n = 2; melanoma n = 2; ovarian n = 2; prostate n = 1; bladder n = 1; ear, nose, and throat n = 1; brain n = 1). A significant association has been found between colorectal cancer and Streptococcus gallolyticus and/or Enterococcus faecalis [12/26 vs. 6/33 for other cancers, p = 0.025, odds ratio = 3.86 (1.19-12.47)]. Two patients had a negative PET/CT (a colon cancer and a bladder cancer), and two patients, with positive PET/CT, had a benign colorectal tumor. PET/CT had a sensitivity of 94-100% for the diagnosis of cancer in this patient. Conclusions: Whole-body PET/CT confirmed the high incidence of cancer in patients with IE and could now be proposed in these cases.

A Novel Approach for Detecting Unique Variations among Infectious Bacterial Species in Endocarditic Cardiac Valve Vegetation.

Infectious endocarditis (IE) remains one of the deadliest heart diseases with a high death rate, generally following thrombo-embolic events. Today, therapy is based on surgery and antibiotic therapy. When thromboembolic complications in IE patients persist, this is often due to our lack of knowledge regarding the pathophysiological development and organization of cells in the vegetation, most notably the primordial role of platelets and further triggered hemostasis, which is related to the diversity of infectious microorganisms involved. Our objective was to study the organization of IE vegetations due to different bacteria species in order to understand the related pathophysiological mechanism of vegetation development. We present an approach for ultrastructural analysis of whole-infected heart valve tissue based on scanning electron microscopy and energy-dispersive X-ray spectroscopy. Our approach allowed us to detect differences in cell organization between the analyzed vegetations and revealed a distinct chemical feature in viridans Streptococci ones. Our results illustrate the benefits that such an approach may bring for guiding therapy, considering the germ involved for each IE patient.

T-Bet Controls Susceptibility of Mice to Coxiella burnetii Infection.

T-bet is a transcription factor known to initiate and coordinate the gene expression program during Th1 differentiation, which is crucial for clearance of intracellular pathogens. Q fever is a worldwide zoonosis caused by Coxiella burnetii. This bacterium is transmitted to humans by aerosol. Indeed, the inhibition of the Coxiella-specific adaptive Th1 immune response leads to persistent infection and organ injury. How deficiency of T-bet affects host infection by C. burnetii has not been investigated. Here, using mice with a deletion of the T-bet gene and an airborne mode of infection to reproduce the natural conditions of C. burnetii infection, we show that infected T-bet-/- mice were more affected than wild-type mice. The lack of T-bet leads to defective bacterial control, intense replication, persistent infection, and organ injury manifesting as an increased number of granulomas. The absence of T-bet was also associated with an impaired immune response. Indeed, the production of the immunomodulatory cytokines interleukin (IL)-6 and IL-10 was increased, whereas the expression of microbicidal genes by splenocytes was impaired. Moreover, the absence of T-bet exhibited impaired production of interferon-γ, the principal cytokine released by Th1 effector cells. Thus, our study highlights the key role of T-bet in the control of C. burnetii infection in mice and leads to a reappraisal of granulomas in the pathogenesis of Q fever disease.

Blood Culture-Negative Cardiovascular Infection in a Patient With Multiple Sclerosis.

A patient with multiple sclerosis presented with seronegative C. burnetii endocarditis diagnosed using C. burnetii-specific polymerase chain reaction and fluorescence in situ hybridization on cardiovascular biopsy. This case supports the necessity of a systematic polymerase chain reaction testing of removed cardiac valves because blood culture-negative endocarditis can be pauci-symptomatic, and serological tests can be negative in cases of immunosuppression.

Fluorescent in situ hybridization can be used as a complementary assay for the diagnosis of Tropheryma whipplei infection.

BACKGROUND: Immunohistochemistry and Periodic acid-Schiff (PAS) staining have been routinely used for the diagnosis of Whipple's disease (WD). However, these methods present limitations. As a result, the last years, Fluorescence in situ hybridization (FISH) has been increasingly used as a complementary tool for the diagnosis of WD from various tissue samples. CASE REPORT: In this study, we visualized, by FISH, Tropheryma whipplei within macrophages of a lymph node from a patient with WD. Moreover, we report in this study a patient with a pulmonary biopsy compatible with WD by PAS, immunostaining and FISH, although the specific molecular assays for T. whipplei were negative. Sequencing analysis of the 16S rDNA revealed a T. whipplei-related species with unknown classification. CONCLUSION: FISH can be a valuable method for the detection of Tropheryma species in formalin-fixed paraffin-embedded tissues. FISH cannot replace the other already approved diagnostic techniques for WD, it can be used as a complementary tool and can provide supplementary information in a relatively short time.

Limbic encephalitis as a relapse of Whipple's disease with digestive involvement and spondylodiscitis.

INTRODUCTION: Many clinical manifestations can be related to Tropheryma whipplei infection. CASE REPORT: We report a Tropheryma whipplei limbic encephalitis developed as a relapse of classical Whipple's disease. DISCUSSION: This case is to the best of our knowledge the first proof of the effective brain-blood barrier crossing of both doxycycline and hydroxychloroquine as demonstrated by direct concentration monitoring on brain biopsy.

Intracranial haemorrhage in infective endocarditis.

BACKGROUND: Although intracranial cerebral haemorrhage (ICH) complicating infective endocarditis (IE) is a critical clinical issue, its characteristics, impact, and prognosis remain poorly known. AIMS: To assess the incidence, mechanisms, risk factors and prognosis of ICH complicating left-sided IE. METHODS: In this single-centre study, 963 patients with possible or definite left-sided IE were included from January 2000 to December 2015. RESULTS: Sixty-eight (7%) patients had an ICH (mean age 57±13 years; 75% male). ICH was classified into three groups according to mechanism: ruptured mycotic aneurysm (n=22; 32%); haemorrhage after ischaemic stroke (n=27; 40%); and undetermined aetiology (n=19; 28%). Five variables were independently associated with ICH: platelet count<150×109/L (odds ratio [OR] 2.3, 95% confidence interval [CI] 1.01-5.4; P=0.049); severe valve regurgitation (OR 3.2, 95% CI 1.3-7.6; P=0.008); ischaemic stroke (OR 4.2, 95% CI 1.9-9.4; P<0.001); other symptomatic systemic embolism (OR 14.1, 95% CI 5.1-38.9; P<0.001); and presence of mycotic aneurysm (OR 100.2, 95% CI 29.2-343.7; P<0.001). Overall, 237 (24.6%) patients died within 2.3 (0.7-10.4) months of follow-up. ICH was not associated with increased mortality (P not significant). However, the 1-year mortality rate differed according to ICH mechanism: 14%, 15% and 45% in patients with ruptured mycotic aneurysm, haemorrhage after ischaemic stroke and undetermined aetiology, respectively (P=0.03). In patients with an ICH, mortality was higher in non-operated versus operated patients when cardiac surgery was indicated (P=0.005). No operated patient had neurological deterioration. CONCLUSIONS: ICH is a common complication of left-sided IE. The impact on prognosis is dependent on mechanism (haemorrhage of undetermined aetiology). We observed a higher mortality rate in patients who had conservative treatment when cardiac surgery was indicated compared with in those who underwent cardiac surgery.

Experimental Inoculation in Rats and Mice by the Giant Marseillevirus Leads to Long-Term Detection of Virus.

The presence of the giant virus of amoeba Marseillevirus has been identified at many different sites on the human body, including in the bloodstream of asymptomatic subjects, in the lymph nodes of a child with adenitis, in one adult with Hodgkin's disease, and in the pharynx of an adult. A high seroprevalence of the Marseillevirus has been recorded in the general population. Whether Marseillevirus can disseminate and persist within a mammal after entry remains unproven. We aimed to assess the ability of the virus to disseminate and persist into healthy organisms, especially in the lymphoid organs. Parenteral inoculations were performed by intraperitoneal injection (in rats and mice) or intravenous injection (in rats). Airway inoculation was performed by aerosolization (in mice). Dissemination and persistence were assessed by using PCR and amebal co-culture. Serologies were performed by immunofluorescent assay. Pathological examination was conducted after standard and immunohistochemistry staining. After intraperitoneal inoculation in mice and rats, Marseillevirus was detected in the bloodstream during the first 24 h. Persistence was noted until the end of the experiment, i.e., at 14 days in rats. After intravenous inoculation in rats, the virus was first detected in the blood until 48 h and then in deep organs with infectious virus detected until 14 and 21 days in the liver and the spleen, respectively. Its DNA was detected for up to 30 days in the liver and the spleen. After aerosolization in mice, infectious Marseillevirus was present in the lungs and nasal associated lymphoid tissue until 30 days post inoculation but less frequently and at a lower viral load in the lung than in the nasal associated lymphoid tissue. No other site of dissemination was found after aerosol exposure. Despite no evidence of disease being observed, the 30-day long persistence of Marseillevirus in rats and mice, regardless of the route of inoculation, supports the hypothesis of an infective potential of the virus in certain conditions. Its constant and long-term detection in nasal associated lymphoid tissue in mice after an aerosol exposure suggests the involvement of naso-pharyngeal associated lymphoid tissues in protecting the host against environmental Marseillevirus.