Prevention Of Intestinal Infections Research Articles

ANTAGONISTIC PROPERTIES OF LACTOBACILLUS STRAINS IN RELATION TO CONDITIONALLY PATHOGENIC BACTERIA, WHICH CAUSE INFLAMMATORY BOWEL DISEASES

The article presents the findings of the research on the antagonistic properties of lactobacillus strains against conditionally pathogenic clinical isolates that cause intestinal inflammation. Conditionally pathogenic clinical isolates of colon (large intestine) and rectum (straight intestine) were isolated and identified to the described species level. From a variety of dairy products, 28 milk-fermenting lactobacilli were isolated, screened, and their probiotic probiotic properties were studied. From 28 isolates of isolated milk-fermenting bacteria, 7 strains were selected. The selected strains showed high antimicrobial activity against clinical and typical conditional pathogenic isolates causing intestinal inflammatory diseases (ulcerative colitis). For this reason, these strains can be recommended as a means of treatment and prevention of intestinal infections.

135 YEARS OF HISTORY AND MODERNITY OF THE STATE INSTITUTION «I. I. MECHNIKOV INSTITUTE OF MICROBIOLOGY AND IMMUNOLOGY OF THE NATIONAL ACADEMY OF MEDICAL SCIENCES OF UKRAINE»

The article is devoted to the results of a retrospective study of the historical path of formation and development of scientific research in State Institution «I. I. Mechnikov Institute of Microbiology and Immunology of the NAMS of Ukraine». The Institute as a scientific institution of anti-epidemic profile was founded in May 1886. At the beginning of the last century, the Institute turned into a major scientific and practical center of pre-revolutionary Russia for the fight against infectious diseases. Already in 1913-1914 the Institute produced 6 types of sera and 7 vaccines. In 1920 the Institute was nationalized, became a state institution and received the name of the Bacteriological Institute, and in 1922 – the First Ukrainian Sanitary-Bacteriological Institute. The Institute was the first in the Soviet Union to begin the production of BCG and became one of the pioneers of the introduction of bacteriophage in the treatment and prevention of intestinal infections: dysentery, typhoid fever, cholera. From 1921 to 1940, the Institute produced more than 40 names of various drugs in an amount exceeding the previous 20 years by more than thirty times. In addition, the Institute currently produces the following serum: diphtheria, scarlet fever, dysentery, meningococcal, pneumococcal, streptococcal, staphylococcal, tetanus, botulinum and 4 gangrenous sera. Since the beginning of the war, the Institute has been evacuated first to Stalingrad and then to Chkalov. During the evacuation, the Institute continues to produce bacteriological preparations. From 1941 to 1945 the release of vaccines and serums amounted to 400% of the pre-war level, only in 1942 110 thousand wounded soldiers received serum against gas gangrene, more than 120 thousand soldiers received tetanus serum. After re-evacuation to Kharkiv, the Institute continued to work on the production of vaccines and serums and, starting in 1944, began the production of smallpox detritus, measles serum and typhus vaccine. At that time, in the laboratory of V. S. Derkach, the antibiotic pyocyanin (or sanazine) was studied and a method for its biosynthesis was developed, and together with the Academy of Sciences of the Ukrainian SSR, its new homologues were synthesized. Also in the laboratory after the war, neocide a drug against cancer was created. The problems of epidemiology at the Institute were developed by the outstanding microbiologist V. M. Zhdanov. From 1946 to 1950 V. M. Zhdanov headed the virological laboratory, and since 1948 – the Kharkov Institute of Microbiology and Epidemiology named I. I. Mechnikov. In 1950, a laboratory for the production of anti-influenza drugs was organized, and a year later, the study and improvement of dry polytype therapeutic and prophylactic anti-influenza serum began. The collection of mycobacterial phages, collected by Professor L. A. Kosobutsky, Doctor of Medical Sciences, was one of the three largest in the world. At the Institute, on the basis of fish oil, the drug «ektericide» was developed. V. L. Nadtoka became the founder of a new scientific direction for the development and use of antimicrobial preparations of plant origin. Under the leadership of V. L. Nadtoka developed dosage forms of the drug chlorophyllipt, which are introduced into production and clinical practice in Ukraine. Now the Institute is a methodological center for the development of theoretical provisions and practical use of laboratory diagnostic methods, anti-epidemic measures, treatment and prevention of infectious diseases, advanced training of bacteriologists, virologists, epidemiologists and other specialists. Currently, on the basis of the Institute, there are a number of divisions of industry-wide importance that coordinate scientific and methodological work in important areas of infection control: the Center for Specific Indication of Biological Pathogenic Agents, the Republican Reference Laboratory of Pathogens of Anaerobic Infections, the Laboratory of New and Little-Studied Infectious Diseases. In general, the staff of the Institute over the years of its existence has developed and introduced into production about 60 different vaccines, sera and other therapeutic and diagnostic immunobiological preparations. The Institute has developed drugs against 21 infections. In addition to immunobiological drugs, the Institute has developed and introduced a number of antimicrobial drugs, among which the most famous are chlorophyllipt, decamethoxin, ektericide, eucavan and others. Keywords: history of science, I.Mechnikov Institute of Microbiology and Immunology, bacteriological preparations, vaccines, serums, bacteriophages, antimicrobial agents, chlorophylipt

Corrective Effect of Gentabiferon-S on Weaned Piglet Immune Status and Its Effectiveness in Prevention of Intestinal Infections

The objective of the survey was to study the corrective effect of the Gentabiferon-S preparation on the immune status of the weaned piglets and its effectiveness in prevention of intestinal infections. A positive effect of the preparation on the morphological and immunological variables expressing the increased levels was ascertained. The red blood cell count, the relative lymphocyte count, the relative and absolute T–lymphocyte counts, the relative and absolute B-cell counts, the complement system activity, the lysozyme level, the neutrophil phagocytic activity, the number of phagocytes, the phagocytic index, the spontaneous and stimulated NBT test, the neutrophil activation reserve and index, and the amount of total immunoglobulins increased by 10.8, 16.5, 16.8 and 14.0%, 21.0 and 20.0%, 23.5, 66.8, 15.9, 38.2, 16.2, 11.0 and 21.7%, 13.3 and 17.1%, and 9.7%, respectively. A high (100%) effectiveness of the preparation in prevention of the intestinal infections is ensured by the presence of the antibiotic with broad-spectrum antimicrobial activity and the porcine recombinant alpha and gamma interferon.

Сorrective influence of Нentabiferon-Сon the immune status of post-weaned piglets and its effectiveness in the prevention of intestinal infections

Сorrective influence of Нentabiferon-Сon the immune status of post-weaned piglets and its effectiveness in the prevention of intestinal infections

Antimicrobial Activity of Lactobacillus spp. Isolated From Fecal Flora of Healthy Breast-Fed Infants Against Diarrheagenic Escherichia coli.

Background:Among the enteric pathogens, diarrheagenic Escherichia coli are important causes of diarrhea in children in both developing and industrialized countries. Some Lactobacillus species are commonly used as probiotics, with effects especially against acute diarrhea in childhood.Objectives:The aim of this study was to explore antimicrobial activity of Lactobacillus strains isolated from fecal flora of healthy breast-fed infants against five diarrheagenic E. coli pathotypes such as enteroaggregative E. coli (EAEC), enterohaemorrhagic E. coli (EHEC) enteroinvasive E. coli (EIEC), enteropathogenic E. coli (EPEC) and enterotoxigenic E. coli (ETEC).Materials and Methods:Fecal samples were collected from seven healthy breast-fed infants between 1 to 18 months of age in Tehran city, Iran. Identification of Lactobacillus isolates was performed by biochemical and 16S rRNA gene sequencing methods. An agar well diffusion assay was used for detection of antimicrobial activity of Lactobacillus isolates against five diarrheagenic E. coli pathotypes.Results:A total of 20 Lactobacillus isolates were identified from stool samples. Lactobacillus fermentum was the most frequently isolated strain, followed by L. plantarum and L. rhamnosus. Seven Lactobacillus strains including L. fermentum (four isolates), L. paracasei (one isolate), L. plantarum (one isolate) and L. rhamnosus (one isolate) had a mild inhibitory activity against diarrheagenic E. coli. The mechanism of inhibitory activity of Lactobacillus strains appeared to be due to the production of organic acids or hydrogen peroxide.Conclusions:Our findings show that Lactobacillus strains with human origin had a mild inhibitory activity against the diarrheagenic E. coli, and these strains may be useful as probiotic candidates in prevention of intestinal infections caused by diarrheagenic E. coli.

Inulin and oligofructose as prebiotics in the prevention of intestinal infections and diseases

Health and wellbeing are challenged constantly by pathogens. A number of defence mechanisms exist to protect the body from pathogen colonisation and invasion, with an important role to play for the natural intestinal bacterial flora (mainly by bifidobacteria and lactobacilli). The present paper reviews the evidence on the effects of inulin and oligofructose on colonisation and translocation of pathogens and the prevention of intestinal diseases. In vitro experiments have shown that lactic acid-producing bacteria have antagonistic (antibacterial) activity against pathogens partly because of the production of organic acids which are the endproducts of inulin and oligofructose fermentation. In addition, studies with epithelial layers have shown that inulin and oligofructose inhibit pathogen colonisation and that endproducts of their fermentation have the ability to support barrier function. Furthermore, studies in various animal models have shown that inulin and oligofructose accelerate the recovery of beneficial bacteria, slow down pathogen growth, decreasing pathogen colonisation and systemic translocation. Finally, data from human intervention trials either in patients with intestinal disorders or disease, or prone to critical illness, found that inulin and oligofructose restore the balance when the gut microbial community is altered, inhibit the progression of disease or prevent it from relapsing and/or developing. To conclude, the dietary use of inulin and oligofructose offers a promising approach to restore microbial communities and to support barrier function of the epithelia by their prebiotic action. This may offer the host protection against invasion and translocation of pathogens (endogenous and/or exogenous) and in the prevention of gastrointestinal diseases.

Prevention of Intestinal Infection by Glycomacropeptide

The preventive effects of glycomacropeptide (GMP) against intestinal infection were investigated, and conjugates of GMP with xylooligosaccharide (XOS) and carboxymethyldextran (CMD) were prepared by the Maillard reaction to enhance the effect of GMP. The binding ability of GMP to intestinal pathogenic bacteria was evaluated by a binding assay with biotinylated bacteria. GMP showed the ability to bind to Salmonella enteritidis and enterohemorrhagic Escherichia coli O157:H7 (EHEC O157). This binding ability was decreased by a sialidase treatment and completely eliminated by periodate oxidation. These results indicate that such carbohydrate moieties as sialic acid in GMP are involved in binding to S. enteritidis and EHEC O157. The preventive effect of GMP on the adhesion of pathogenic bacteria to Caco-2 cells was also investigated. GMP showed an inhibitory effect on the adhesion of EHEC O157 in a dose-dependent manner, although it was not a potent inhibitor of the adhesion of Salmonella infection. However, in the case of Salmonella infection, GMP-XOS and GMP-CMD significantly suppressed IL-8 production which was the index of infection. Our results indicate GMP to be a promising agent for preventing intestinal infection.

Prevention of intestinal amebiasis by vaccination with the Entamoeba histolytica Gal/GalNac lectin

Prevention of intestinal infection by Entamoeba histolytica would block both invasive disease and parasite transmission. The amebic Gal/GalNAc lectin mediates parasite adherence to the colonic surface and fecal anti-lectin IgA is associated with protection from intestinal reinfection in children. We tested if vaccination with the E. histolytica Gal/GalNAc lectin could prevent cecal infection in a C3H mouse model of amebic colitis. Two trials using native lectin purified from the parasite and two trials using a 64kDa recombinant fragment (“LecA”) were performed with a combined intranasal and intraperitoneal immunization regimen using cholera toxin and Freund’s adjuvants, respectively. Two weeks after immunization mice were challenged intracecally with trophozoites, and 4–12 weeks after challenge mice were sacrificed for histopathologic evaluation of infection. Vaccination prevented intestinal infection with efficacies of 84 and 100% in the two native lectin trials and 91 and 34% in the two LecA trials. Mice with detectable pre-challenge fecal anti-lectin IgA responses were significantly more resistant to infection than mice without fecal anti-lectin IgA responses. These results show for the first time that immunization with the Gal/GalNAc lectin can prevent intestinal amebiasis in mice and suggest a protective role for fecal anti-lectin IgA in vivo.

Interaction of bifidobacteria with the gut and their influence in the immune function

Bifidobacteria are predominant in the lumen of the large intestine and confer various health benefits on the host. They are also used in the preparation of new fermented milks (bioyogurts) or added to conventional yogurt to generate probiotic effects. The colonization of the gut by bacteria tends to be host specific due partly to the way in which bacteria adhere to the intestinal wall. Using a homologous strain of Bifidobacterium animalis in an experimental mouse model, we analyzed by immunofluorescence labelled-bacteria and transmission electronic microscopy the importance of the bacterial interaction with epithelial an immune cells associated to the gut, and the effect of feeding of B. animalis in the immune response. It was able to adhere and interact with both small and large intestine. In spite of this interaction with the gut, no modifications in the immune state (secretory or systemic response) were observed. A heterologous strain of Bifidobacterium adolescentis from human faeces, was neither incapable of binding to the intestine, nor influence the immune system activation, when it was administered during 2, 5 or 7 consecutive days; we believe that using a homologous strain, oral tolerance is developed even when the microorganism interacts with the immune cells associated with the intestine. However, we cannot ignore the beneficial effect of these microorganisms, especially in the prevention of intestinal infections. We think that this property exerted by bifidobacteria is more related to other mechanisms such as competitive inhibition, acid production or others, than enhancement of the immune state.