Bacteriophages as therapeutic & disinfectant agents to tackle multidrug-resistant Acinetobacter baumannii.

Background & objectives: Multidrug-resistant (MDR) Acinetobacter baumannii is a serious threat for human health worldwide. The studies on agents targeting A. baumannii are imperative due to identified A. baumannii co-infections in COVID-19. Bacteriophages are promising antibacterial agents against drug-resistant bacteria. This study intended to isolate bacteriophages against MDR A. baumannii from the water of river Ganga, to be used potentially as therapeutic and disinfectant particles. Methods: Acinetobacter phages were isolated from the Ganga water collected from Kanpur and further tested on 50 MDR A. baumannii isolates to determine host range. The phages were morphologically characterized by transmission electron microscopy. The disinfectant property of the isolated phages was tested by spraying of bacteriophage cocktail on MDR A. baumannii contaminated plastic surface, analyzed by colony-forming unit (CFU) and bioluminescence assay (adenosine triphosphate monitoring). Results: A total of seven bacteriophages were isolated against MDR A. baumannii. The bacteriophages lysed three MDR A. baumannii isolates out of 50 tested, showing narrow host range. Electron microscopy revealed hexagonal heads and long tails of bacteriophages, belonging to order Caudovirales. The bacteriophage cocktail reduced the MDR A. baumannii load efficiently on plastic surface, evidenced by reduction in CFUs and bioluminescence. Interpretation & conclusions: The findings of this study suggest that the isolated bacteriophages are potential lytic agents for MDR A. baumannii clinical isolates, and may be used as potential therapeutic agents as well as disinfectant to combat MDR A. baumannii with due consideration to phage host specificity, with further characterization.

Immunoglobulin Receptors Expression in Indian Colon Cancer Patients and Healthy Subjects Using a Noninvasive Approach and Flowcytometry.

BACKGROUND: Isolation of viable colonocytes from human stool is a noninvasive and convenient approach that can be used for diagnostic, screening, management, and research on various gastrointestinal (GI) diseases including colon cancer. Limited studies are available globally and for the first time in this article, we have reported the immunoglobulin (Ig) (IgA and IgG) receptors concentration on viable colonocytes for Indian colon cancer patients using this noninvasive approach. MATERIALS AND METHODS: Viable colonocytes from stool were isolated by the Somatic Cell Sampling and Recovery method (Noninvasive Technology, USA) and processed for the assessment of Igs (IgA and IgG) receptors expression using standard immunophenotyping and flow cytometry. RESULTS: IgA and IgG receptor expression was measured and reported on these viable colonocytes. There was a significant difference in the expression of IgA and IgG receptors on viable colonocytes between colon cancer patients and healthy individuals. CONCLUSION: This noninvasive technique is a promising approach for the detection of molecular and immunological markers that will help clinicians in the diagnosis, screening, monitoring, and management of different GI diseases including colon cancer.

Toll like receptors (TLRs) in response to human gut microbiota of Indian obese and lean individuals.

BACKGROUND: The rising incidence of obesity is one of the most serious public health issues in the developed as well as in developing countries like India. Obesity and overweight are most important risk factors for many chronic diseases, including cardiovascular diseases, diabetes and cancer. In this study the body mass index (BMI) cut off was taken as 18.5-22.9 kg/m2 for normal, 23.0-24.9 kg/m2 for Overweight and >25 kg/m2 for obese as per WHO recommendation for Asian Indians, which is different for developed and developing countries. Role of gut microbiota mediated immune response in the development of obesity has been studied but the literature on Indian population are lacking. Therefore, a study was conducted to determine Toll like receptors (TLRs) in response to human gut microbiota of Indian obese and lean individuals using viable colonocytes in a Non invasive technique and Flowcytometry. METHODS: A total of 20 healthy volunteer (10 obese and 10 lean) were enrolled in the study as per inclusion and exclusion criteria. Viable colonocytes were isolated from fecal samples using a Non invasive technique (SCSR Method). Toll like receptors (TLRs) and immunoglobulin (IgA &IgG) receptor concentration were measured by standard Flowcytometry methods using specific fluorochrome conjugated antibodies. RESULTS: Average TLR2 receptor concentration was significantly higher in obese (6.35 %) as compared to lean (2.9 %) (P = 0.01). TLR4 receptor concentration was 1.4 % in obese and 1.65 % in lean although the difference was not statistically significant (P = 0.59). IgA & IgG receptor concentration was 49.6 % & 11.2 % in the obese and 67.15 % & 8.05 % in the lean respectively but the differences among both the group were not statistically significant. CONCLUSION: The results of the present study will be helpful for physicians and researchers to find some biomarkers which can determine predisposition of the obesity in Indian population and helps to use alternative therapeutics such as probiotics to maintain gut homeostasis and immune modulation to prevent obesity.

Double-blinded randomized controlled trial for immunomodulatory effects of Tulsi (Ocimum sanctum Linn.) leaf extract on healthy volunteers.

ETHNOPHARMACOLOGICAL RELEVANCE: Tulsi (Ocimum sanctum Linn.) is considered as a sacred herb and traditionally it is believed that consumption of Tulsi leaf on empty stomach increases immunity. Experimental studies have shown that alcoholic extract of Tulsi modulates immunity. MATERIALS AND METHODS: The present study was designed to evaluate the immunomodulatory effects of ethanolic extract of Tulsi leaves through a double-blinded randomized controlled cross-over trial on healthy volunteers. Three hundred milligrams capsules of ethanolic extracts of leaves of Tulsi or placebo were administered to 24 healthy volunteers on empty stomach and the results of 22 subjects who completed the study were analyzed. The primary objective was to study the levels of Th1 and Th2 cytokines (interferon-γ and interleukin-4) during both pre and post intervention period in blood culture supernatants following stimulation with lipopolysaccharide and phytohaemagglutinin. Other immunological parameters such as T-helper and T-cytotoxic cells, B-cells and NK-cells also were analyzed using Flowcytometry. RESULTS: Statistically significant increase in the levels of IFN-γ (p=0.039), IL-4 (p=0.001) and percentages of T-helper cells (p=0.001) and NK-cells (p=0.017) were observed after 4 weeks in the Tulsi extract intervention group in contrast to the placebo group. CONCLUSIONS: These observations clearly ascertain the immunomodulatory role of Tulsi leaves extract on healthy volunteers.