Several gut commensals have been shown to modulate host immune response. Recently, many food derived microbes have also been reported to affect the immune system. However, a mechanism to identify immunostimulatory and immunoregulatory microbes is needed. Here, we successfully established an in vitro screening system and identified an immunoregulatory bacterium, Lactobacillus pentosus KF340 (LP340), present in various fermented foods. LP340 induced a regulatory phenotype in mice Ag presenting cells which, in turn, induced IL-10 and IFN-γ producing Type 1 regulatory T cells (Tr1 cells) from naïve CD4⁺ T cells. Naïve CD4⁺ T cells co-cultured with LP340 treated dendritic cells highly expressed cytokine receptor IL-27R and were CD49b and lymphocyte-activation gene 3 double positive. Oral administration of LP340 in mice with atopic dermatitis reduced cellular infiltration in affected ear lobes and serum IgE levels, thus, ameliorating the disease symptoms. This suggests a systemic immunoregulatory effect of LP340. These findings demonstrate that LP340, a bacterium derived from food, prevents systemic inflammation through the induction of IL-10 producing Tr1 cells.
Administration, Oral ; Animals ; Dendritic Cells ; Dermatitis, Atopic ; Ear ; Immune System ; Immunoglobulin E ; In Vitro Techniques ; Inflammation ; Interleukin-10 ; Lactobacillus ; Mass Screening ; Mice ; Phenotype ; Receptors, Cytokine ; T-Lymphocytes ; T-Lymphocytes, Regulatory

OBJECTIVETo describe the epidemiology and severity of illness of children hospitalized with respiratory syncytial virus (RSV) infection, including those who received palivizumab prophylaxis, at Royal University Hospital (RUH), Saskatoon and Regina General Hospital (RGH) from July 2002 to June 2005.

METHODSChildren hospitalized for ≥ 24 hours with laboratory-confirmed RSV infection were enrolled, and their health records were retrospectively reviewed for patient demographics and referral patterns, use of palivizumab prophylaxis, severity of infection (length of hospitalization, need for and duration of pediatric intensive care and mechanical ventilation) and outcome of infection.

RESULTSA total of 590 children (324 males) were hospitalized over the three years. The median chronological age at admission was 5.3 months, and median hospital stay was 4.0 days. Gestational age at birth was ≥ 36 weeks in 82.4% of patients. RSV disease severity was mild to moderate in 478 patients (81.0%) and severe in 110 (18.6%). Thirty-nine patients (6.6%) required pediatric intensive care unit admission, for a median of 5.0 days. Twenty-two of these patients (56%) were mechanically ventilated for a median of 6.0 days. Two children died, not attributed to RSV infection. Twenty-two patients had received palivizumab prophylaxis before hospital admission, with 18 completing at least 2 of the monthly doses. Most of these children (17/22) had mild to moderate illness.

CONCLUSIONSRSV causes significant morbidity in Saskatchewan, affecting predominantly term infants. The majority of illness is mild to moderate. Some patients who have received palivizumab may still develop significant RSV disease.

Adolescent ; Antibodies, Monoclonal, Humanized ; therapeutic use ; Child ; Child, Preschool ; Female ; Hospitalization ; Humans ; Infant ; Infant, Newborn ; Male ; Palivizumab ; Respiratory Syncytial Virus Infections ; epidemiology ; prevention & control ; Saskatchewan ; epidemiology ; Tertiary Care Centers ; Time Factors

BACKGROUND/AIMS: The use of genetic probes for the diagnosis of pulmonary tuberculosis (TB) has been well described. However, the role of these assays in the diagnosis of intestinal tuberculosis is unclear. We therefore assessed the diagnostic utility of the Xpert Mycobacterium tuberculosis/rifampicin (MTB/RIF) assay, and estimated the prevalence of multidrug-resistant (MDR) TB in the Indian population. METHODS: Of 99 patients recruited, 37 had intestinal TB; two control groups comprised 43 with Crohn's disease (CD) and 19 with irritable bowel syndrome. Colonoscopy was performed before starting any therapy; mucosal biopsies were subjected to histopathology, acid-fast bacilli staining, Lowenstein-Jensen culture, and nucleic acid amplification testing using the Xpert MTB/RIF assay. Patients were followed up for 6 months to confirm the diagnosis and response to therapy. A composite reference standard was used for diagnosis of TB and assessment of the diagnostic utility of the Xpert MTB/RIF assay. RESULTS: Of 37 intestinal TB patients, the Xpert MTB/RIF assay was positive in three of 37 (8.1%), but none had MDR-TB. The sensitivity, specificity, positive predictive value, and negative predictive value of the Xpert MTB/RIF assay was 8.1%, 100%, 100%, and, 64.2%, respectively. CONCLUSIONS: The Xpert MTB/RIF assay has low sensitivity but high specificity for intestinal TB, and may be helpful in endemic tuberculosis areas, when clinicians are faced with difficulty differentiating TB and CD. Based on the Xpert MTB/RIF assay, the prevalence of intestinal MDR-TB is low in the Indian population.
Biopsy ; Colonoscopy ; Crohn Disease ; Diagnosis* ; Humans ; Irritable Bowel Syndrome ; Mycobacterium ; Nucleic Acid Amplification Techniques ; Prevalence ; Sensitivity and Specificity ; Tuberculosis* ; Tuberculosis, Multidrug-Resistant ; Tuberculosis, Pulmonary