Human immunodeficiency virus and oral microbiota: mutual influence on the establishment of a viral gingival reservoir in individuals under antiretroviral therapy.

The role of the oral microbiota in the overall health and in systemic diseases has gained more importance in the recent years, mainly due to the systemic effects that are mediated by the chronic inflammation caused by oral diseases, such as periodontitis, through the microbial communities of the mouth. The chronic infection by the human immunodeficiency virus (HIV) interacts at the tissue level (e.g. gut, genital tract, brain) to create reservoirs; the modulation of the gut microbiota by HIV infection is a good example of these interactions. The purpose of the present review is to assess the state of knowledge on the oral microbiota (microbiome, mycobiome and virome) of HIV-infected patients in comparison to that of HIV-negative individuals and to discuss the reciprocal influence of HIV infection and oral microbiota in patients with periodontitis on the potential establishment of a viral gingival reservoir. The influence of different clinical and biological parameters are reviewed including age, immune and viral status, potent antiretroviral therapies, smoking, infection of the airway and viral coinfections, all factors that can modulate the oral microbiota during HIV infection. The analysis of the literature proposed in this review indicates that the comparisons of the available studies are difficult due to their great heterogeneity. However, some important findings emerge: (i) the oral microbiota is less influenced than that of the gut during HIV infection, although some recurrent changes in the microbiome are identified in many studies; (ii) severe immunosuppression is correlated with altered microbiota and potent antiretroviral therapies correct partially these modifications; (iii) periodontitis constitutes a major factor of dysbiosis, which is exacerbated in HIV-infected patients; its pathogenesis can be described as a reciprocal reinforcement of the two conditions, where the local dysbiosis present in the periodontal pocket leads to inflammation, bacterial translocation and destruction of the supporting tissues, which in turn enhances an inflammatory environment that perpetuates the periodontitis cycle. With the objective of curing viral reservoirs of HIV-infected patients in the future years, it appears important to develop further researches aimed at defining whether the inflamed gingiva can serve of viral reservoir in HIV-infected patients with periodontitis.

Cytomegalovirus and Inflammatory Bowel Diseases (IBD) with a Special Focus on the Link with Ulcerative Colitis (UC).

Cytomegalovirus (CMV) infects approximately 40% of adults in France and persists lifelong as a latent agent in different organs, including gut. A close relationship is observed between inflammation that favors viral expression and viral replication that exacerbates inflammation. In this context, CMV colitis may impact the prognosis of patients suffering from inflammatory bowel diseases (IBDs), and notably those with ulcerative colitis (UC). In UC, the mucosal inflammation and T helper cell (TH) 2 cytokines, together with immunomodulatory drugs used for controlling flare-ups, favor viral reactivation within the gut, which, in turn, increases mucosal inflammation, impairs corticoid and immunosuppressor efficacy (the probability of steroid resistance is multiplied by more than 20 in the case of CMV colitis), and enhances the risk for colectomy. This review emphasizes the virological tools that are recommended for exploring CMV colitis during inflammatory bowel diseases (IBD) and underlines the interest of using ganciclovir for treating flare-ups associated to CMV colitis in UC patients.

Human herpesvirus 6 infection after autologous stem cell transplantation: A multicenter prospective study in adult patients.

OBJECTIVES: to prospectively evaluate the incidence and the clinical relevance on hematopoietic reconstitution of HHV-6 infection in autologous hematopoietic stem cell transplantation (ASCT) recipients. METHODS: HHV-6 DNA load was measured in whole blood specimens once during the 7 days before stem cell re-infusion and once a week after transplantation until hematopoietic recovery. Active HHV-6 infection was defined by 2 consecutive positive DNA loads. RESULTS: from July 2012 to February 2015, 196 adult patients undergoing ASCT were enrolled. Twenty-two (11.2%) patients developed active HHV-6 infection with a cumulative incidence of 19% at 40 days after transplantation. The onset of active HHV-6 infection occurred with a median of 13 days after stem cell re-infusion. HHV-6 infection was associated with an increased frequency of non-infectious complications (OR = 5.05; 95%CI 1.78-14.32; P < 0.001). Moreover, the severity of these non-infectious complications was higher in recipients exhibiting HHV-6 infection (OR = 4.62; 95%CI 1.32-16.2; p < 0.01). Delayed neutrophils 10 (IQR: 8-14) vs 8 (IQR: 6-11) days and platelets recoveries 15 (IQR: 11.8-18.5) vs 8 (IQR: 4-14) days were observed in patients with active HHV-6 infection compared to non-infected ones. CONCLUSIONS: in this study, 11.2% ASCT recipients presented active HHV-6 infection associated with significantly delayed hematologic reconstitution.

Staphylococcus aureus colonization and non-influenza respiratory viruses: Interactions and synergism mechanisms.

Viral infections of the respiratory tract can be complicated by bacterial superinfection, resulting in a significantly longer duration of illness and even a fatal outcome. In this review, we focused on interactions between S. aureus and non-influenza viruses. Clinical data evidenced that rhinovirus infection may increase the S. aureus carriage load in humans and its spread. In children, respiratory syncytial virus infection is associated with S. aureus carriage. The mechanisms by which some non-influenza respiratory viruses predispose host cells to S. aureus superinfection can be summarized in three categories: i) modifying expression levels of cellular patterns involved in S. aureus adhesion and/or internalization, ii) inducing S. aureus invasion of epithelial cells due to the disruption of tight junctions, and iii) decreasing S. aureus clearance by altering the immune response. The comprehension of pathways involved in S. aureus-respiratory virus interactions may help developing new strategies of preventive and curative therapy.

Anti-N-methyl-D-aspartate receptor encephalitis after Herpes simplex virus-associated encephalitis: an emerging disease with diagnosis and therapeutic challenges.

INTRODUCTION: Morbidity and mortality of Herpes simplex virus encephalitis (HSE) remain high. Relapses of neurological signs may occur after initial clinical improvement under acyclovir treatment. METHODS: We report here a case of post-HSE anti-N-methyl-d-aspartate receptor-mediated encephalitis in an adult and perform a systematic search on PubMed to identify other cases in adults. RESULTS: We identified 11 previously published cases, to discuss diagnostic and therapeutic management. Symptoms in adults are often inappropriate behaviors, confusion and agitation. Diagnosis of anti-NMDA-R encephalitis after HSE is often delayed. Treatment consists in steroids, plasma exchange, and rituximab. Prognosis is often favorable. CONCLUSION: Anti-NMDA-R antibodies should be searched in cerebrospinal fluid of patients with unexpected evolution of HSE. This emerging entity reopens the hot debate about steroids in HSE.

Cytomegalovirus and ulcerative colitis: Place of antiviral therapy.

The link between cytomegalovirus (CMV) infection and inflammatory bowel diseases remains an important subject of debate. CMV infection is frequent in ulcerative colitis (UC) and has been shown to be potentially harmful. CMV reactivation needs to be diagnosed using methods that include in situ detection of viral markers by immunohistochemistry or by nucleic acid amplification techniques. Determination of the density of infection using quantitative tools (numbers of infected cells or copies of the genome) is particularly important. Although CMV reactivation can be considered as an innocent bystander in active flare-ups of refractory UC, an increasing number of studies suggest a deleterious role of CMV in this situation. The presence of colonic CMV infection is possibly linked to a decreased response to steroids and other immunosuppressive agents. Some treatments, notably steroids and cyclosporine A, have been shown to favor CMV reactivation, which seems not to be the case for therapies using anti-tumor necrosis factor drugs. According to these findings, in flare-ups of refractory UC, it is now recommended to look for the presence of CMV reactivation by using quantitative tools in colonic biopsies and to treat them with ganciclovir in cases of high viral load or severe disease.

Oxygen and viruses: a breathing story.

The effect of oxygen on virus replication is complex, and the role of hypoxia-inducible factor 1α (HIF-1α) in the metabolism of virus-infected cells remains uncertain. Solid tumours are hypoxic, and some viruses use this low oxygen tension level to facilitate their replication in tumour cells, thereby causing cell lysis. In addition, the interactions between viruses and HIF-1α may stimulate a trained immunity. However, the evolutionary basis for the oxygen regulatory mechanism of virus replication is ill-defined and requires further investigation.

Infliximab Does Not Worsen Outcomes During Flare-ups Associated with Cytomegalovirus Infection in Patients with Ulcerative Colitis.

BACKGROUND: Immunosuppressive therapies used for treating ulcerative colitis are known to favor chronic and latent viral diseases. This study aimed at evaluating prospectively the association between colonic cytomegalovirus (CMV) reactivation and anti-tumor necrosis factor (TNF) monoclonal antibodies (mabs) by comparison to azathioprine (AZA) in a series of flare-ups occurring in consecutive ulcerative colitis patients. METHODS: A total of 109 flare-ups were recorded in 73 patients receiving a maintenance therapy by anti-TNF mabs (n = 69) or AZA (n = 40). The CMV DNA load in colonic tissue was determined by reverse transcription polymerase chain reaction on a pair of biopsies. RESULTS: The number of CMV reactivation was of 35% and 38% in patients receiving anti-TNF mabs and AZA, respectively. The median of CMV DNA load was 378 [10-29,800] and 8300 [10-3,25,000] copies/mg of tissue in patients treated by anti-TNF mabs and AZA, respectively (P = 0.11 by Mann-Whitney U test). In a subgroup of 45 patients under anti-TNF mabs requiring an optimized treatment by infliximab, clinical remission (partial Mayo score <3) was not significantly impacted by the presence of CMV reactivation at the time of flare-up (P = 0.52). Twenty of these patients underwent a second colonic biopsy 8 weeks after the initiation of flare-up therapy; except for 3 patients, the colonic CMV DNA load was stable or decreased. CONCLUSIONS: Patients under anti-TNF maintenance therapy are not at higher risk of CMV reactivation in case of flare-up. No reciprocal adverse influence was observed between anti-TNF mabs and CMV infection, suggesting that these drugs must be considered for treating flare-ups associated to CMV reactivation.

Acute acalculous cholecystitis, a rare complication of Epstein-Barr virus primary infection: report of two cases and review.

We described two cases of acalculous cholecystitis (AAC), due to EBV primary infection in two young Caucasian women and we reviewed other reported cases. In contrast with AAC of other etiologies, antibiotics and surgery are not useful in the management of AAC secondary to EBV.

Study of Coxsackie B viruses interactions with Coxsackie Adenovirus receptor and Decay-Accelerating Factor using Human CaCo-2 cell line.

BACKGROUND: Decay Accelerating Factor (DAF) and Coxsackievirus-Adenovirus Receptor (CAR) have been identified as cellular receptors for Coxsackie B viruses (CV-B). The aim of this study is to elucidate the different binding properties of CV-B serotypes and to find out if there are any amino acid changes that could be associated to the different phenotypes.Twenty clinical CV-B isolates were tested on CaCo-2 cell line using anti-DAF (BRIC216) and anti-CAR (RmcB) antibodies. CV-B3 Nancy prototype strain and a recombinant strain (Rec, CV-B3/B4) were tested in parallel. The P1 genomic region of 12 CV-B isolates from different serotypes was sequenced and the Trans-Epithelial Electrical Resistance (TEER) along with the virus growth cycle was measured. RESULTS: Infectivity assays revealed clear differences between CV-B isolates with regard to their interactions with DAF and CAR. All tested CV-B isolates showed an absolute requirement for CAR but varied in their binding to DAF. We also reported that for some isolates of CV-B, DAF attachment was not adapted. Genetic analysis of the P1 region detected multiple differences in the deduced amino acid sequences. CONCLUSION: Within a given serotype, variations exist in the capacity of virus isolates to bind to specific receptors, and variants with different additional ligands may arise during infection in humans as well as in tissue culture.

Epidemiology and microbiological investigations of community-acquired pneumonia in children admitted at the emergency department of a university hospital.

BACKGROUND: The management of children with community-acquired pneumonia (CAP) is largely influenced by the development of new molecular diagnostic tests that allow the simultaneous detection of a wide range of pathogens. OBJECTIVES: Evaluation of a diagnostic approach including multiplex PCR assays for revisiting the epidemiology and etiology of CAP in children at hospital. STUDY DESIGN: Children of all ages consulting at the Emergency Department of the University hospital of Saint-Etienne, France, during the 2012-2013 winter period were included. In addition to bacterial cultures, the following pathogens were detected using biplex commercially-available rt-PCR tests: adenovirus, respiratory syncytial virus, human metapneumovirus, bocavirus, rhinovirus/enterovirus, coronavirus, influenza viruses A and B, parainfluenza viruses, Mycoplasma pneumoniae and Chlamydophila pneumonia. RESULTS: From 85 patients with CAP, at least one pathogen was identified in 81 cases (95.3%), including 4 bacterial exclusive infections (4.7%), 53 viral exclusive infections (62.4%) and 24 mixed infections (28.2%). Coinfection by at least two viruses was observed in 37 cases (43.5%). Mean age was higher in the case of documented bacterial infection (P<0.05). In the subgroup of viral exclusive infection, the mean age of severe cases was 2.0 years vs 3.8 years in mild and moderate cases (P<0.05). CONCLUSIONS: These findings highlight the huge proportion of CAP of viral origin, the high number of co-infection by multiple viruses and the low number of bacterial CAP, notably in children under 5 years, and address the need to re-evaluate the indications of empiric antimicrobial treatment in this age group.

Oxygen tension level and human viral infections.

The role of oxygen tension level is a well-known phenomenon that has been studied in oncology and radiotherapy since about 60 years. Oxygen tension may inhibit or stimulate propagation of viruses in vitro as well as in vivo. In turn modulating oxygen metabolism may constitute a novel approach to treat viral infections as an adjuvant therapy. The major transcription factor which regulates oxygen tension level is hypoxia-inducible factor-1 alpha (HIF-1α). Down-regulating the expression of HIF-1α is a possible method in the treatment of chronic viral infection such as human immunodeficiency virus infection, chronic hepatitis B and C viral infections and Kaposi sarcoma in addition to classic chemotherapy. The aim of this review is to supply an updating concerning the influence of oxygen tension level in human viral infections and to evoke possible new therapeutic strategies regarding this environmental condition.

Human papillomavirus and head and neck squamous cell carcinomas in the South-East of France: prevalence, viral expression, and prognostic implications.

CONCLUSION: Human papillomavirus (HPV) infection, especially by HPV 16, is frequently detected in oropharyngeal squamous cell carcinoma (OSCC). The expression of viral oncoproteins in tumoral tissues of OSCCs suggests the implication of HPV in tumorogenesis. It should now be systematically detected and considered in each patient's treatment and outcome. OBJECTIVES: To investigate the prevalence of HPV infection, the oncogenic role of HPV in patients from the South-East of France with head and neck squamous cell carcinoma (HNSCC), and the resulting clinical implications. METHODS: Biopsy samples from 200 patients with HNSCC were analyzed. For each patient, one or two biopsies of tumoral tissue were analyzed simultaneously with a biopsy of healthy tissue. Fresh frozen tissues were tested by molecular techniques for HPV DNA detection and genotyping as well as mRNA expression of oncoproteins E6 and E7. Expression of p16 was also analyzed by immunohistochemical staining. RESULTS: HPV DNA tested positive in 11.5% of biopsy samples. The HPV prevalence was higher in OSCCs (91.3 vs 27.3, p < 0.0001) and in patients not consuming tobacco (65.2% vs 95.4%, p < 0.0001). The estimated 3-year overall survival rates were 67.0% for HPV-infected patients versus 39.9% for non-infected patients. The high-risk HPV 16 was the most common type detected (65.2%). In 12 of 18 patients exhibiting DNA of high-risk HPV in their tumor tissue, the same viral genome was also present in normal tissue. E6 and E7 expression was found in 9 of 14 tumoral biopsies tested for these markers.

Management of cytomegalovirus infection in inflammatory bowel diseases.

Cytomegalovirus is a deoxyribonucleic acid virus that infects a large part of the human population; after primary infection, it develops a latent state and can be reactivated, notably after a decrease in host immune defences. In patients with inflammatory bowel diseases, cytomegalovirus is frequently involved, either as an agent of colitis or through local asymptomatic reactivation. Due to the immune context of inflammatory bowel diseases and to the immunosuppressive therapies that are used to treat them, cytomegalovirus entertains complex relationships with these diseases. Whereas Crohn's disease seems little impacted by cytomegalovirus, this agent interferes strongly with the natural progression of ulcerative colitis. While immune treatments have a clear influence on the occurrence of cytomegalovirus colitis in ulcerative colitis (favourable for steroids and cyclosporine and rather inhibitory for infliximab), the role of cytomegalovirus infection on ulcerative colitis is more debated with roles ranging from innocent bystander to key pathogen suggested. There is however growing evidence for a participation of intestinal cytomegalovirus infection in the resistance of ulcerative colitis to steroids and the investigation of cytomegalovirus infection in intestinal biopsies by immunohistochemistry or quantitative polymerase chain reaction assay is strongly recommended. In several studies, treatment of cytomegalovirus infection by ganciclovir was shown to restore the response to immunomodulatory therapies and even to prevent the need for colectomy. All of these recently acquired data need to be validated by randomised clinical trials conducted on a large panel of ulcerative colitis patients.

Cytomegalovirus load in inflamed intestinal tissue is predictive of resistance to immunosuppressive therapy in ulcerative colitis.

OBJECTIVES: Previous studies have suggested an association between cytomegalovirus (CMV) infection and steroid-refractory inflammatory bowel disease. In this study, the use of CMV DNA load during acute flare-ups of ulcerative colitis (UC) to predict resistance to immunosuppressive therapy was evaluated in intestinal tissue. METHODS: Forty-two consecutive patients (sex ratio M/F: 0.9, mean age: 43.6 years) hospitalized for moderate to severe UC and treated with IV steroids were included prospectively. A colonoscopy was performed for each patient at inclusion; colonic biopsy samples of the pathological tissue, and if possible, of the healthy mucosa, were tested for histological analysis and determination of CMV DNA load by real-time polymerase chain reaction assay. Patients were treated as recommended by the current guidelines. RESULTS: Sixteen patients were found positive for CMV DNA in inflamed intestinal tissue but negative in endoscopically healthy tissue; all of these patients were positive for anti-CMV IgG, three exhibited CMV DNA in blood, and none was positive for intestinal CMV antigen by immunohistochemistry detection. In the 26 remaining patients, no stigmata of recent CMV infection were recorded by any technique. By multivariate analysis, the only factor associated with CMV DNA in inflammatory tissue was the resistance to steroids or to three lines of treatment (risk ratio: 4.7; 95% confidence interval: 1.2-22.5). A CMV DNA load above 250 copies/mg in tissue was predictive of resistance to three successive regimens (likelihood ratio+=4.33; area under the receiver-operating characteristic curve=0.85). Eight UC patients with CMV DNA in inflamed tissue and therapeutic failure received ganciclovir; a clinical remission was observed in seven cases, with a sustained response in five of them. CONCLUSIONS: The CMV DNA load determined in inflamed intestinal tissue predicts resistance to steroid treatment and to three drug regimens in UC. Initiation of an early antiviral treatment in these patients might delay the occurrence of resistance to current treatments.

Drug-resistant cytomegalovirus in transplant recipients: a French cohort study.

OBJECTIVES: Cytomegalovirus (CMV) drug resistance is a therapeutic challenge in the transplant setting. No longitudinal cohort studies of CMV resistance in a real-life setting have been published in the valganciclovir era. We report findings for a French multicentre prospective cohort of 346 patients enrolled at initial diagnosis of CMV infection (clinical trial registered at clinicaltrials.gov: NCT01008540). PATIENTS AND METHODS: Patients were monitored for detection of CMV infection for ≥2 years. Real-time detection of resistance by UL97 and UL54 gene sequencing and antiviral phenotyping was performed if viral replication persisted for >21 days of appropriate antiviral treatment. Plasma ganciclovir assays were performed when resistance was suspected. RESULTS: Resistance was suspected in 37 (10.7%) patients; 18/37 (5.2% of the cohort) had virological resistance, associated with poorer outcome. Most cases involved single UL97 mutations, but four cases of multidrug resistance were due to UL54 mutations. In solid organ transplant recipients, resistance occurred mainly during primary CMV infection (odds ratio 8.78), but also in two CMV-seropositive kidney recipients. Neither CMV prophylaxis nor antilymphocyte antibody administration was associated with virological resistance. CONCLUSIONS: These data show the feasibility of surveying resistance. Virological resistance was frequent in patients failing antiviral therapy. More than 1/5 resistant isolates harboured UL54 mutations alone or combined with UL97 mutations, which conferred a high level of resistance and sometimes were responsible for cross-resistance, leading to therapeutic failure.

Comparative evaluation of a commercially available automated system for extraction of viral DNA from whole blood: application to monitoring of epstein-barr virus and cytomegalovirus load.

The NucliSENS easyMAG automated system was compared to the column-based Qiagen method for Epstein-Barr virus (EBV) or cytomegalovirus (CMV) DNA extraction from whole blood before viral load determination using the corresponding R-gene amplification kits. Both extraction techniques exhibited a total agreement of 81.3% for EBV and 87.2% for CMV.