Microbial Biotechnology and Infectiology Course 5, Part 1 & 2 PDF

PEOPLE'S DEMOCRATIC REPUBLIC OF ALGERIA MINISTRY OF HIGHER EDUCATION AND SCIENTIFIC RESEARCH University of Science and Technology Houari Boumediene Faculty of Biological Sciences Module : INTRODUCTION TO BIOTECHNOLOGY Microbial biotechnology and infectiolog...

PEOPLE'S DEMOCRATIC REPUBLIC OF ALGERIA MINISTRY OF HIGHER EDUCATION AND SCIENTIFIC RESEARCH University of Science and Technology Houari Boumediene Faculty of Biological Sciences Module : INTRODUCTION TO BIOTECHNOLOGY Microbial biotechnology and infectiology Course No. 5 Part 1 (Natural and Life Sciences L2 Biotechnology) Directed by: -Dr BENCHIKH F. -Dr TILIOUA S. -Dr BENKHELIFA S. Academic Year 2024/2025  Plan 1. Interaction between microorganisms and humans 2. Definition of microbiota 3. Types of human microbiota 4. The beneficial actions of the microbiota for its host A. Role in digestion B. Role in the supply of molecules C. Role in the defense of our organism against pathogens D. Role of intestinal microbiota in health 5. Changing the intestinal microbiota: a therapeutic approach 6. The harmful actions of the microbiota on its host  1. Human-microorganism interaction  Favorable interaction= Harmful interaction = Pathogens Beneficial microorganisms which which causes diseases contribute to good health. Mutualism = Symbiosis Commensalism Parasitism Beneficial association for both Association one body benefits while the one body benefits at the expense partners second is not affected of the other  1. Human-microorganism interaction Terminology: Human Microbiome  Four basic categories of microorganisms live in and on the human body: bacteria, archaea, eukaryotes (which include fungi), and viruses. The words “microbes” and “microorganisms” are used interchangeably to refer to all four categories.  The term “microflora” is often used as if synonymous with “microbiota.” The original definition of microflora dates back to the early 1600s and originates from the Latin word “flor”, meaning flower. Although the definition has evolved, some dictionaries still refer to microflora as “microscopic plants or the plants or flora of a microhabitat.” These definitions and their origins make it obvious that microflora refers to plants and not microbes (Marchesi & Ravel, 2015); the assemblage of microbes living in a habitat is now referred to as microbiota (either singular or plural).  2. Microbiota Defenition: The word "microbiota" refers to all the microorganisms that live in close contact with us , on our skin , on our mucous membranes and in our intestines , which are mainly bacteria but also archaea , fungi and viruses.  3. Types of human microbiota Types of human microbiota depending on the environment concerned the gastrointestinal tract Cutaneous-mucosal (respiratory Skin Oral cavity (small intestine and large tract and urogenital tract) intestine). There are different microbiotas. The intestinal microbiota is the most important, with around 1013 microorganisms. There are almost as many intestinal microbiota bacteria as there are human cells per human!  4. The beneficial actions of the microbiota for its host 4.1. Role in digestion  Fermentation of substrates and non- digestible food residues  Facilitates the assimilation of nutrients  Regulates several metabolic pathways: absorption of fatty acids, calcium, magnesium, etc.  The fragmentation of large molecules (polysaccharides, etc.)  4. The beneficial actions of the microbiota for its host 2. Role in the supply of molecules  Role in providing essential molecules to the cells of our body.  It allows the synthesis of certain vitamins (vitamin K, B12, B8).  Emission of molecules important for maintaining the chemical balance of our cells.  4. The beneficial actions of the microbiota for its host 3. Role in the defense of our body against pathogens Acts again the colonization of the digestive tract by pathogenic germs (active fight) Allows the maturation of Maintains the function of the the immune system natural barrier (mucous membranes) Certain bacteria secrete anti- inflammatory molecules that help protect against IBD (chronic inflammatory bowel diseases)  4. The beneficial actions of the microbiota for its host 4. Role of intestinal microbiota in health  Some facts about gut: About 100 trillion bacteria reside in the gut and they produce metabolites that have health effects 70-80% of the body’s immune cells are concentrated in the gut There are 100 million neurons located along the gut which produce various neurotransmitters that regulate mood and satiety 95% of the body’s total serotonin is located in the gut  5. Changing the intestinal microbiota: A therapeutic approach Strategies to modify gut microbiota for disease treatment:  Consumption of prebiotics (e.g. polysaccharides exclusively fermented by certain intestinal bacteria)  or probiotics (e.g., a freeze-dried suspension of Lactobacillus spp. and Bifidobacterium spp.),  the use of antibiotics or bacteriophages (bacterial viruses),  Fecal microbiota transplantation.  6. The harmful actions of the microbiota on its host Infectiology Definition Infectiology is the study of infectious diseases. It is a branch of medicine that deals with the diagnosis, treatment, and prevention of infectious diseases.  6. The harmful actions of the microbiota on its host Infections An infection refers to the invasion and A. Defenition multiplication of microorganisms within a living organ of the body. A contamination is transmitted to a living being (human or animal), from an animal or a non-living medium (water, food, object, etc.) and persists there. We will speak about infection when this contamination leads to a disease.  6. The harmful actions of the microbiota on its host Infections B. Phases Takes place in 4 phases:  Adhesion  Invasion  Colonization: symptoms at their peak  Termination: healing or death  6. The harmful actions of the microbiota on its host Infections C. Types of infections Acute Chronic Chronic infections are Acute infections are of caused by pathogens with relatively short duration slow growth rates with rapid recovery promoting an infection that is persistent for long-term periods.  6. The harmful actions of the microbiota on its host Infections D. Infection agents Infections are mainly caused by  Bacteria are responsible for  Virus  Fungi or mycoses e.g. various forms of infections such as:  The flu, Candida albicans infection.  tuberculosis  measles, candidiasis, aspergillosis  cystitis,  rubella,  meningitis,  Parasites malaria,  mumps, amoebiasis, toxoplasmosis....  some pneumonias,  AIDS, etc. are well-known Management of a fever,  abscesses, examples. Most colds and many Vaccinations, Advice to  diarrhea, ear infections, etc. forms of sore throats and diarrhea travelers, before and after the are also caused by viruses. trip  Toxiinfection such as botulism  6. The harmful actions of the microbiota on its host Infections The pathogenicity of microorganisms is linked to physiological and genetic mechanisms allowing them to colonize hosts and cause infection. 2 major processes involved in pathogen virulence:  Attachment and colonization of specific tissues  Production of substances (toxins, enzymes and others)  6. The harmful actions of the microbiota on its host Infections Examples: Enteropathogenic strains of E. coli (small intestine): - Colonization factor: ability to attach to epithelial cells The pathogenic effect: production of at least 2 toxins: - Hemolysin (lyses red blood cells) - Enterotoxin (diarrhea = excretion of water + salts )  6. The harmful actions of the microbiota on its host Infections E. Transmission routes  Airborne: Respiratory infection  Saliva droplets  Hand-carried : enteric infection  Sexual STI: syphilis, HIV  Blood: transfusion deep wounds  6. The harmful actions of the microbiota on its host Infections F. Transmission by Organic products  Blood  Stools, urine, sweat and milk  Semen and vaginal secretions  Biological samples, surgical specimen  Puncture fluid  6. The harmful actions of the microbiota on its host Human microbiota dysbiosis contributes to various diseases  PEOPLE'S DEMOCRATIC REPUBLIC OF ALGERIA MINISTRY OF HIGHER EDUCATION AND SCIENTIFIC RESEARCH University of Science and Technology Houari Boumediene Faculty of Biological Sciences Module : INTRODUCTION TO BIOTECHNOLOGY Microbial biotechnology and infectiology Course No. 5 Part 2 (Natural and Life Sciences L2 Biotechnology) Directed by: -Dr BENCHIKH F. -Dr TILIOUA S. -Dr BENKHELIFA S. Academic Year 2024/2025 6. The harmful actions of the microbiota on its host Example 1  6. The harmful actions of the microbiota on its hosts Nosocomial infections Definition Nosocomial infections, also called health- care-associated or hospital-acquired infections, are a subset of infectious diseases acquired in a health-care facility. To be considered nosocomial, the infection cannot be present at admission; rather, it must develop at least 48 hours after admission. These infections can lead to serious problems like sepsis and even death. Schematic illustration of transmission routes of hospital acquired infections (HAI) or nosocomial infection  6. The harmful actions of the microbiota on its host Nosocomial infections  6. The harmful actions of the microbiota on its host Nosocomial infections 6. The harmful actions of the microbiota on its host Example 2 Botulism  6. The harmful actions of the microbiota on its host Botulism Botulism is a rare but serious illness. It is caused by a toxin that attacks the body’s nerves and causes difficulty breathing, muscle paralysis, and even death. The toxin is made by Clostridium botulinum and sometimes Clostridium butyricum and Clostridium baratii bacteria (germs). These bacteria can produce the toxin in food, wounds, and the intestines of infants.  1. Method of transmission 2. How to prevent Botulism of botulism There are 2 main modes of transmission: Exogenous Ingestion of toxin = food botulism or direct exogenous transmission. Inoculation of the bacillus = inoculation botulism or indirect exogenous transmission.  Endogenous when the toxin is produced inside the body. This latter mode is specific to the infant's intestine Botulism 3. Symptoms  5. Physiopathology of botulism :  Bacterial multiplication is accompanied by the release of a neurotropic toxin, initially in the form of a protoxin, not very virulent.  Once in the human body and under the action of certain enzymes, the protoxin is transformed into a very virulent and very dangerous toxin responsible for the disease.  At present, this toxin constitutes the most dangerous poison on earth.  The toxin has as its site of action the synapses of the ANS (Autonomic Nervous System) and the neuromuscular junctions.  5. Physiopathology of botulism : Botulinum neurotoxins E (BoNT/E) and A (BoNT/A) act by cleaving Synaptosome- Associated Protein 25 (SNAP25) at two different C-terminal sites.  4. Diagnosis of Botulism  Toxinotype using the contaminated food by serum neutralization in mice.  SERS (Surface Enhaced Raman Scarttering) Immunoassay  Electromyogram  4. Diagnosis of Botulism ELISA (which stands for enzyme-linked immunosorbent assay) is a technique to detect the presence of antigens in biological samples. An ELISA, like other types of immunoassays, relies on antibodies to detect a target antigen using highly specific antibody-antigen interactions.  4. Diagnosis of Botulism Detection of Botulism by ELISA: Schematic of cell-based assay for botulinum neurotoxin 6. Clinical Features of Botulism 6. Clinical Features of Botulism Infantile Botulism  Botulism 7. Serotherapy Knowledge of the serotypes allows us to know the degree of serotherapy. It is an excellent prognostic indicator. For the reservoir, Clostridium botulinum is telluric, Anaerobic canning represents a very great danger.  Botulism 7. Serotherapy Definition  Serotypes are groups within a single species of microorganisms, such as bacteria or viruses, which share distinctive surface structures.  Serotherapy, also called passive artificial immunization , is the treatment of disease by the injection of serum containing antibodies to the disease. Botulism 7. Serotherapy Serotherapy helps to neutralize:  A microbial antigen.  A bacteria.  A toxin.  A virus.  A venom.  Botulism 7. Serotherapy Mechanisms used by immunoglobulins to destroy infectious agents and toxins. (1) Complement-associated immunolysis, (2) opsonization (immunophagocytosis), (3) toxin/virus neutralization, and (4) antibody-dependent cell-mediated cytotoxicity (ADCC). (5) The unmentioned fifth mechanism, which involves the blockade of toxin secretion by immunoglobulins.  8. Prognosis of Botulism The severity of botulism depends on: The toxin and its virulence. Type of toxin. The amount of toxin ingested. The incubation time. The area of occurrence (affects more men than women.) Age of onset (around 40 years old.) The conditions for treating the disease.  9. Treatments of Botulism Antitoxin Botulism is treated with antitoxin, which prevents the toxin treatment from causing any more harm. Antitoxin does not heal the damage the toxin has already done. If disease is severe, patient may have respiratory (breathing) Ventilation problems. Patient may even have respiratory failure if the toxin paralyzes the muscles involved in breathing. In the case of wound botulism, patient might need surgery to Surgery remove the source of the bacteria. Patient also might need to take antibiotics. FIN