Microbiology Lecture Notes PDF

Official (Open) HS1202 Anatomy and Physiology 1 Official (Open) Microbiology- lecture 1 Official (Open) Introduction to Microbiology- lecture 1  Once you get to the nursing attachment, you will come to understand how crucial hand hygie...

Official (Open) HS1202 Anatomy and Physiology 1 Official (Open) Microbiology- lecture 1 Official (Open) Introduction to Microbiology- lecture 1  Once you get to the nursing attachment, you will come to understand how crucial hand hygiene is.  As you may know, nosocomial infections continue to be a serious global health concern.  A nurse's understanding of microbiology is beneficial in all areas of healthcare.  Understanding the way that an infection spreads makes it easier to control its spread.  In this lesson, we'll study about bacteria, a significant class of microbes. Official (Open)  Lecture outline: o Introduction o Prokaryotes o Bacteria Good /bad Naming Classification Cell structure Growth requirement Endospores Pathogenesis - Chain of infection Medically Important Bacteria o Normal Flora o Carrier Official (Open) Introduction  Microorganisms o are seen with microscope o includes algae fungi protozoans bacteria Viruses Your body is made of 10 trillion cells Your gut has 100 trillion microbes Official (Open) Prokaryote  Karyo in Greek – nucleus  All living cells are divided into o Eukaryotes have nucleus e.g., plants, animals o Prokaryotes no nucleus e.g., bacteria Official (Open) Prokaryotes  Bacteria are Prokaryotic cells o They have no nucleus but has genetic material (DNA) scattered in the middle. o They also have no membranous organelles o Cell walls is are made of complex polysaccharide peptidoglycan o They divide by binary fission Binary fission Official (Open) Prokaryotes Official (Open) Bacteria - good / bad?  Majority are Beneficial o Helps in digestion & synthesis of vitamins e.g., Vit B, K o Food Products: bread, cheese, yogurt o Genetic engineering: e.g., insulin(see next slide), interferon  Some are harmful o produces disease Official (Open) Official (Open) Naming  Every living thing has a scientific name (in Latin)  This naming system was established by Carolus Linnaeus in 1735  Let's see an example - o E.g., Bacteria name: Staphylococcus aureus o Genus First name (capitalized) - Staphylococcus o species Second name (not capitalized) - aureus Specific for that organism aureus (means gold) grows in the medium as golden colonies Do you know ?? scientific name for human is Homo sapiens Official (Open) Bacteria - Classification  Based on Shape o Spherical-shaped - coccus o Rod-shaped - bacillus o Spiral-shaped – spirillum o Coccobacilli- looks like cocci and bacilli  Based on arrangement o Diplo – arranged in pairs- diplococci/ diplobacilli. E,g Neisseria o Strepto – arranged in chains – streptococci o Staphylo – arranged n clusters – staphylococci Official (Open) Official (Open) Bacteria – structure  Structures external to cell wall o Glycocalyx o Pili o Flagella  Cell wall  Structures internal to cell wall o Plasma Membrane o Cytoplasm o Ribosomes o Inclusions o Nucleoid and plasmids Official (Open) Bacteria – structure  Glycocalyx / capsule o Viscous, gelatinous polymer of protein and carbohydrate o Functions of Glycocalyx Protection from phagocytosis and dehydration Helps in attachment to host surface  Flagella o Long, filamentous appendages o Helps in movement of bacteria  Pili o Only found in Gram negative bacteria o Helps in attachment of bacteria to host. Official (Open) Bacteria – structure  Cell wall o Complex, rigid structure o Functions: Give shape to bacteria Anchor point for flagella Causes disease Official (Open) Bacteria – structure  Cell wall o Bacteria into 2 main groups based on cell wall o Gram positive bacteria Cell wall thick Many layers of peptidoglycan o Gram negative bacteria Cell wall thin Thin layer of peptidoglycan Outer to cell wall has outer membrane of lipopolysaccharides Lyses in the host releases as endotoxin  causes fever & shock in host. Official (Open) Gram-positive Gram-negative bacteria bacteria Official (Open) Gram Staining process- https://www.youtube.com/watch?v=OOFJyw0EYBU Official (Open) Bacteria – structure  Plasma Membrane -semi-permeable membrane  Cytoplasm o Internal matrix. o It has Ribosomes - synthesize proteins Inclusions - reserve deposits Nucleoid - cell’s genetic material Plasmids – has genes Official (Open) Plasmid and its uses Official (Open) Bacterial growth requirements  Physical o Preferred temperature – same as human o Preferred pH - 6.5 - 7.5 - human pH is 7.35 to 7.45 o Preferred solution - isotonic solutions All these shows why they prefer human blood. Official (Open) Bacterial growth requirements  Chemical o They need water, carbon and oxygen for their living. o Based on their oxygen requirements, they are of three types Obligate aerobes Obligate anaerobes Facultative anaerobes Need oxygen to live. No need oxygen to live. Can live with/ without oxygen e.g., Mycobacterium tuberculosis e.g., Clostridium tetani e.g., Escherichia. coli Official (Open) Endospores  When the growth environment becomes unfavorable, certain bacteria become endospores.  They become “resting” cells  These spores are highly durable, dehydrated cells with extra thick walls  Can remain dormant for thousands of years  Returns to vegetative state if conditions are favorable  They can be killed ONLY by autoclave  E.g., Clostridium tetani spores can be found in soil. o So, when a person gets an injury and comes in contact with soil, these spores can enter the body. o After entering they can become active bacteria and produce toxins. o These toxins can attack the nervous system resulting in severe spasms. Official (Open) Official (Open) Tetanus toxoid injection Neonatal tetanus Official (Open) Infection and pathogenesis  Infection: Lodgment and multiplication of microorganisms in the body.  Pathogenesis of infection (chain of infection) is the process of infection where the microorganism is spread from the reservoir to the host.  Chain of infection includes 1. Pathogen 2. Reservoir 3. Portal of exit 4. Methods of transmission 5. Portal of entry 6. Infection in the new host Official (Open) Official (Open) Chain of Infection  Pathogen - Infectious agent which causes disease o Can be a Bacteria Fungi Virus Parasite. Official (Open) Chain of Infection  Reservoirs - Source of pathogens o Human Mycobacterium tuberculosis Hepatitis (virus) o Animal Dog - Rabies (virus) Horseshoe bats – SARS (virus) o Non-living from soil, water – Tetanus Official (Open) Chain of Infection  Portal of exit - portals where the pathogen is released from the reservoir Skin – malaria Respiratory – viral influenzas Urogenital – gonorrhoea Gastrointestinal tracts – cholera Official (Open) Chain of Infection  Transmission of Infection - Refers to how a pathogen is moved from reservoir to host  3 ways o Contact – direct contact e.g., influenza, COVID o Vehicle – water, food, air e.g., typhoid o Vector – mosquitoes e.g., malaria o Some infections can be transmitted by more than one way. Official (Open) Official (Open) Chain of Infection  Portal of entry o Mucous membranes - nose, GIT o Skin - impenetrable when unbroken o Parenteral route -IV canula, injections etc. o Transplacental Official (Open) Chain of Infection  Infection in the new host depends on the microorganism’s o Virulence : ability to multiply and grow o Adherence : ability to get attached to host cell (using pili) o Pathogenicity : ability to produce a disease in the host by overcoming host defenses by Resisting phagocytosis Capsules and enzymes of pathogens avoids phagocytosis Damage host cells Direct damage - pathogens kill host cells by multiplying within them Indirect damage - Toxin release in blood toxemia  organ dysfunction shock Exotoxins - secretions produced by bacteria. E.g., Tetanus toxin Endotoxins - part of cell wall released when bacteria dies E.g., N. meningitidis Official (Open) Importance of breaking chain of infection  We health care workers play a very important role in breaking this chain of infection.  Certain times.. we can be affected as well.. So must use proper precautionary measures while handling such cases. o E.g., handwash, wearing gloves, PPE (personal protective equipment) Watch this story of EBOLA- how health care can break the chain of infection: https://www.youtube.com/watch?v=XCrOde-JYs0 Official (Open) Importance of breaking chain of infection  Control measures directed to break this chain of infection helps to stop further spread.  This varies from disease to disease  Interventions are directed at: o Controlling or eliminating pathogen at source of transmission E.g., Sick patient can be isolated and treated. o Protecting portals of exit from the reservoir E.g., airborne diseases wearing mask. o Protecting portals of entry to unaffected person E.g., condoms protect from sexually transmitted disease. Official (Open) Importance of breaking chain of infection o Controlling or eliminating transmission E.g., disinfection of surface. o Increasing host's defences E.g. Improve immunity of the individuals, taking antibiotics Official (Open) Medically important bacteria Cocci Bacilli Others  Gram positive cocci o Gram positive bacilli o Chlamydia trachomatis o Staphylococcus Clostridium tetani o Mycobacterium tuberculosis o Streptococcus Corynebacterium diphtheriae o Treponema pallidum  Gram negative cocci o Gram negative bacilli o Neisseria Escherichia coli Salmonella typhi Physiology Official (Open) 1B Gram positive Cocci Staphylococcus aureus:  It is most common grows in golden clusters (in growth medium) 30 - 40% adults are carriers nares most common site Diseases invasive diseases - abscess formation toxigenic diseases -food poisoning, toxic shock syndrome (from tampons) Aureus means gold – their growth colonies looks gold in color Official (Open) Gram positive Cocci  Staphylococcus aureus - Common cause of skin abscess Official (Open) Gram positive Cocci  Toxic shock syndrome: Usage of tampons for longer periods make these bacteria to grow in the tampons and release the toxins. The toxins entered can cause toxaemia and shock Physiology Official (Open) 1B Gram positive Cocci  Streptococcus o Form chains o important species S. pyogenes pyogenic diseases - e.g., pharyngitis immunologic diseases –e.g., rheumatic fever, glomerulonephritis S. pneumoniae Pneumonia Official (Open) Streptococcus. pneumoniae Physiology Official (Open) 1B Gram positive Cocci  Prevention o Basically, not many Gram-positive cocci has vaccines. o Best is to remove the source of infection e.g, Incision and drainage o Antibiotics can be given Inconsiderate use of antibiotics can sadly result in antibiotics resistance (where the bacteria will not respond to the antibiotics) Physiology Official (Open) 1B Recently another strain of carbapenem resistant Enterobacteriaceae is giving threat Physiology Official (Open) 1B Gram negative Cocci  Neisseria o Morphology gram negative cocci like paired kidney beans o Species Neisseria meningitidis causes meningitis spread by airborne droplets Neisseria gonorrhoeae causes gonorrhea spread by unprotected sexual contact Physiology Official (Open) 1B Gram negative Cocci  Neisseria gonorrhoeae- Gonorrhea o Infections of genital tract o In males, it causes urethritis, prostatitis, strictures of urethra, infertility o In females, it causes Cervicitis and pelvic infection Long term sequela – fallopian tube block –infertility and ectopic pregnancy Condom usage prevent pregnancy as well as sexually transmitted diseases.. Physiology Official (Open) 1B Gram negative Cocci Neisseria gonorrhoeae- Gonorrhea Under microscope Swab test Growth in chocolate agar 1B Official (Open) Gram positive bacilli  Clostridium tetani o Tetani spores are widespread in soil* o Any injury to skin and when the broken skin comes in contact with soil or rustic materials o Disease Causes Tetanus Exotoxin interferes with neurotransmitters Uncontrollable muscle spasms eg. lockjaw * some disease can never be eradicated- Tetanus is one among them. Official (Open) Physiology Official (Open) 1B Gram positive bacilli Clostridium tetani opisthotonos Risorius grin 1B Official (Open) Gram positive bacilli  Corynebacterium diphtheriae o Club shaped bacilli o Airborne droplet transmission Causes diphtheria exotoxin inhibits protein synthesis thick grey membrane in throat 1BOfficial (Open) Gram positive bacilli Corynebacterium diphtheriae 1B Official (Open) Gram negative bacilli  Escherichia Coli (E.coli) o Commonly found in lower intestine o Possess flagella o Normally commensal – usually doesn’t cause disease o Used now in genetic engineering for recombinant DNA 1B Official (Open) Gram negative bacilli  Escherichia Coli (E.coli) o Causes Intestinal tract infection Some virulent strains  exotoxins -> diarrhea Urinary tract infection More common in females due to short urethra close proximity to anal orifice most common cause of nosocomial UTI use of urinary catheters 1BOfficial (Open) Gram negative bacilli Escherichia Coli (E.coli) -Urinary Tract Infection 1BOfficial (Open) Catheter-associated urinary tract infection (CAUTI) one of the most common infections a person can contract in the hospital, Physiology Official (Open) 1B Gram negative bacilli  Salmonella typhi o Lives only in human o They are are common in developing countries where sewage, water treatment systems are poor. o Causes Enterocolitis- diarrhea Typhoid fever - Fever, bacteremia and diarrhea Septicemia – Fever, bacteremia and diarrhea and shock Official (Open) Intestinal perforation due to typhoid Physiology Official (Open) 1B Gram negative bacilli  Salmonella typhi  Read how typhoid made her famous  https://www.youtube.com/ watch?v=vG1lI1PxraI Official (Open) Other bacteria  Chlamydia trachomatis o Weak gram-negative bacilli o Most frequently reported sexually transmitted infections. Male – epididymitis and urethritis Female – cervicitis, urethritis, pelvic inflammatory disease. o It can lead to infertility in both men and women. Official (Open) Other bacteria  Mycobacteria tuberculosis o Aerobic acid-fast bacilli o Requires special stain (Ziehl-Neelsen stain) o humans are natural reservoir o Transmitted by droplet transmission, droplet nuclei o Causes Tuberculosis Official (Open) Official (Open) 1BOfficial (Open) Official (Open) Other bacteria  Mycobacteria tuberculosis o Bacilli enter lungs via airways Initially phagocytosed by macrophages Some bacilli multiply in macrophage and tubercle is formed Center of the tubercle undergoes necrosis forms caseous necrosis. Caseous tubercle ruptures, live bacilli spreads to via blood to other parts of the body. Outer surface of these tubercles gets calcified (seen on X-ray like eggshells) watch this https://youtu.be/UKV8Zn7x0wM Official (Open) Other bacteria  Mycobacteria tuberculosis o Prevention BCG (bacillus Calmette-Guerin)- Live attenuated M. bovis o Investigations Tuberculin skin test (Mantoux test) Injection of purified protein derivative in forearm Positive if 10 mm reaction occurs 48 - 72hrs after injection Staining of the sputum/ specimen Official (Open) Official (Open) Other bacteria  Spirochetes - Treponema Pallidum o Treponema Pallidum causes syphilis o Transmitted by Unprotected sexual contact congenital syphilis (mother to fetus via placenta) Physiology Official (Open) 1B Other bacteria Spirochetes - Treponema Pallidum Watch them moving https://www.youtube.com/watch?v=X9NQ8xJLy3E Official (Open) Other bacteria  Syphilis comes in three phases o Primary syphilis: (2-10 weeks) Characterised by chancre (painless ulcer) at site of infection - hallmark of syphilis o Secondary syphilis: (1-3 months) Characterised by rashes on skin, mucous membrane o Tertiary syphilis: (1- 10 years) If untreated, patients develops gummas (granuloma) palate, chest, organs – brain, heart Official (Open) Other bacteria Spirochetes - Treponema Pallidum Congenital syphilis is a chronic infectious disease caused by a spirochete (treponema pallidum) acquired by the fetus in the uterus before birth  Official (Open) Other bacteria  Spirochetes - Treponema Pallidum o Diagnosis Dark field microscopy – spiral shape Serological screening - VDRL o Treatment - penicillin Syphilis was called as great pox Official (Open) Normal Flora  Permanent population of organisms  ONLY bacteria & fungi (not viruses & parasites)  Found on linings of body surfaces, mucous membranes.  They are NEVER found in internal organs Official (Open) Normal Flora - Functions Protection Part of host defense mechanism Resident bacteria prevent pathogens from invading e.g. Lactobacillus Nutrition Intestinal bacteria produce several B vitamins and vitamin K Poorly nourished people on antibiotics can suffer these vitamin deficiencies Official (Open) Do you know…  When baby is born.. their intestines are completely sterile  Colon commensals appear after the newborns gets their feed by mother Official (Open) Normal Flora - dysfunction Opportunistic pathogen  Non-pathogenic microorganisms act as a pathogen in certain circumstances like o immunocompromised and debilitated patients. Opportunistic infection  An infection caused by opportunistic pathogen.  Candidiasis in AIDS patients Official (Open)  Oral candidiasis Official (Open) Carrier  Person who harbors a potential pathogen  Usually, asymptomatic  But becomes a potential source of infection o e.g., Streptococcus pneumoniae (nose, throat) o Salmonella typhi o Hepatis B virus Official (Open) Summary Bacteria -Prokaryotes – no nucleus Classification-shape, arrangement – cocci, bacilli, coccobacilli, spirochetes, diplo, strepto and staph Cell structure – structure outside (Glycocalyx, flagella, pili), inside cell wall (Ribosomes, inclusions, nucleoid, plasmids) Bacterial growth requirement- physical and chemical (oxygen (obligate aerobe, obligate anaerobes, facultative anaerobes) Endospores – resting cells, autoclave Pathogenesis- Chain of infection (Pathogen, reservoir, portal of exit, methods of transmission, portal of entry, Infection in the new host) Medically Important Bacteria Cocci – gram positive (staph and strepto), gram negative(neisseria) Bacilli – gram positive (clostridium), gram negative (E.coli, salmonella typhi) Others – Chlamydia trachomatis, Tuberculosis, syphilis Normal Flora- location, uses (protection, nutritional), opportunistic infection Carrier – definition Official (Open) Microbiology- lecture 2 Official (Open) Introduction to Microbiology- lecture 2  Microbiology is applied in clinical practice for the purpose of infection prevention and control.  Infections can impact nearly everybody system can be brought on by bacteria, fungi, viruses, or prions.  The number of viruses on Earth exceeds the number of stars in the cosmos by a factor of over 10 mill.  We now know that bacteria can spread infection when they have a distinct nucleus.  Please remember that even protein particles can spread infection.  Let's study about viruses and prion infections in this lecture. Official (Open)  Lecture outline: o Virus Introduction Characteristics Structure of Viruses Pathogenesis Acute infection chronic infection Latent infection Oncogenic infection o Prion disease Kuru Official (Open) Introduction  Virus are the smallest microorganisms in nature o 20-300 nm in diameter  Not visible by light microscope. Official (Open) Virus characteristics  Inert out of living host cells Become active only after entering host cell  Obligatory intracellular parasites Invade living cells to multiply-dependent on the resources of the infected cell  Do not have organelles no ribosomes, lysosomes, mitochondria  Have few or no enzymes must take over metabolic processes of cell  Shapes o Exists in different shapes Official (Open) Structure of an enveloped virus  Enveloped virus o Nucleic acids o Capsid o Envelope o Envelope proteins Official (Open) Structure of Viruses  Nucleic Acids o Located in core of virus o Genetic material of virus (genome) Consists of either DNA or RNA but not both Can be either single or double stranded  Capsid o Surrounds nucleic acid core o Identical units (capsomere) makes capsid layer. Official (Open) Official (Open) Structure of Viruses  Envelope and viral proteins: o Located outside capsid o Enveloped viruses are more sensitive to heat, detergents, lipid solvents, etc o Envelop has glycoprotein layer of proteins. Official (Open) Pathogenesis  Viruses can cause disease in several ways.  They are classified based on the onset of signs and symptoms o Acute infection o Chronic infection o Latent infection o Oncogenic infection Official (Open) 1. Acute Infection  Most common way in which viruses infect humans  Viruses enters the host cells at the site of infection, replicates and virions released into surrounding cells and spread to lymphatic vessels and blood stream ( systemic symptoms)  Can cause serious epidemics – Rabies, Zika, Dengue, COVID, influenzas  Some viral infections resolves quickly.  Many of the viral infections starts as acute infection. Official (Open) 1. Acute Infection Influenza  Enveloped RNA virus affects respiratory system mainly.  2 surface glycoproteins determines antigenic variation of the virus o Hemagglutinin (HA), Neuraminidase (NA) Different forms of Ag are given numbers - H1, H2, N1, N2  3 types o Influenza virus A o Influenza virus B o Influenza virus C o H1N1, caused Spanish flu in 1918. Official (Open) 1. Acute Infection  Zika o Caused by a virus transmitted primarily by Aedes mosquitoes. o Symptoms - fever, skin rash, conjunctivitis, muscle and joint pain, malaise or headache. o During pregnancy, virus affects foetus cause microcephaly and severe foetal brain defects. Official (Open) 1. Acute Infection  Rabies o Rabies is a zoonotic disease (a disease that is transmitted to humans from animals) that is caused by a virus. o After animal bite, virus reaches the nerve and reaches brain o Symptoms include headache, fever, confusion, pain or tingling at the site of the bite, hydrophobia (fear of water), paralysis and coma and death. Official (Open) Rabies Patient affected by rabies in his last few days - https://www.youtube.com/watch?v=- moG6JDmJdc Official (Open) 1. Acute Infection  Dengue o Is caused by flavivirus. o There are four serotypes. Immunity with one of these serotypes cannot provide to other types o Virus is transmitted by bite of female mosquito (Aedes) - usually breeds in stagnant fresh water. o Characterised by fever, chills, headache, eye pain and rashes. o In severe cases, it can end up bleeding all over the body (haemorrhagic fever). o Diagnosed by dengue serology tests Avoid stagnant water, use insect repellents Official (Open) Official (Open) 1. Acute Infection  SARS (Severe Acute Respiratory Syndrome) o Caused coronavirus (SARS-CoV) o Reported in 2003  caused global outbreak- pandemic o Originated from horseshoe bats- started as zoonotic disease o Transmission via respiratory droplet- direct / indirect o Causes respiratory symptoms deteriorates fast causes respiratory arrest Watch how all started - SARS Online Animation - YouTube Official (Open) 1. Acute Infection  COVID-19 -https://www.youtube.com/watch?v=5DGwOJXSxqg o Caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). o Declared as pandemic o Likely a zoonotic (from bats/ pangolins) o Transmitted from one person to another via respiratory droplets o Starts as common cold affects respiratory system pneumonia  respiratory failure. o Control measures were aimed at to prevent further transmission mainly by Isolating and the symptomatic treatment of affected, surface cleaning, using masks, social distancing. Watch the timeline of COVID - A timeline of COVID-19's discovery and global spread - YouTube Official (Open)  Role of vaccines in viral infections:  Each year, the World Health Organization predicts which strains of the virus are most likely to be circulating in the next year, allowing pharm companies to develop vaccines that will provide the best immunity against these strains. Official (Open) 2. Chronic Infection  Chronic infection is characterized by the continued presence of infectious virus following the primary infection.  Examples: o Human immunodeficiency virus o Hepatitis B virus o Hepatitis C virus Official (Open) 2. Chronic Infection Human Immunodeficiency Virus:  Initially came from chimpanzee (Simian Immunodeficiency Virus)  HIV spreads through four body fluids: semen, vaginal fluid, blood, breast milk.  HIV infection causes gradual deterioration of immune function.  Three stages: Acute infection – flu like symptoms Chronic infection- asymptomatic, virus slowly reproduces Acquired Immuno Deficiency syndrome (AIDS) Defined when CD4+ T cell count < 200 cells per µL. Prone for opportunistic infections Official (Open)  Red ribbon- AIDS awareness Official (Open) 2. Chronic Infection Hepatitis B and C Virus:  HBV and HCV can spread through four body fluids: semen, vaginal fluid, blood, breast milk.  It affects liver mainly.  Like HIV there is no definite cure.  Hepatitis C is more virulent than Hepatitis B. Official (Open) 3. Latent Infection  Virus after entering the host causes initial infection.  After the infection, virus remains in host  When the host’s immunity is good, virus stays in the system silent for a long period  When the host’s immune system is compromised, virus comes out and cause latent infection  E.g., herpes simplex virus and chicken pox Official (Open) 3. Latent Infection Herpes labialis (cold sores) o Caused by herpes simplex virus (HSV). o Initial infection usually acquired by direct contact causes blisters skin around lips o Virus enters the nerve and stay there. o Latent infections happens but when activated by stress  painful blisters Official (Open) 3. Latent Infection Chicken pox Herpes zoster or “shingles”  Caused by varicella zoster virus.  Initial infection (called as chicken pox) o Characterized by fever and generalized vesicular rash; recovery occurs within 2 weeks  Virus is remains in the roots/ ganglions of sensory nerves.  Latent infection: Stress/reduced immunity virus reactivated  virus travels along the sensory nerve causes painful vesicular rash along nerve distribution (called as shingles). Official (Open) Herpes zoster or “shingles” latent infection Initial infection Official (Open) Chicken pox and shingles Official (Open) 4. Oncogenic Infection  Causes malignant changes in host cells by activating oncogenes o They integrate their own genetic material into the host cell’s DNA o Human papilloma Virus (HPV) o Human Immunodeficiency Virus (HIV) o Hepatitis B Virus (HBV) Official (Open) 4. Oncogenic Infection Human papilloma virus  Diseases caused o Warts in both female and male o Cancer (ca cervix)  Mainly sexually transmitted  Vaccines available for strains causing cancer cervix and anal cancer o Gardasil and cervarix Official (Open) HPV-Typical skin wart Official (Open) 4. Oncogenic Infection Human Immunodeficiency Virus  Cause numerous cancer (commonest is Kaposi sarcoma) Official (Open) 4. Oncogenic Infection Hepatitis B and hepatitis C virus  Cause hepatocellular carcinoma Official (Open) Prion diseases  These are very rare diseases caused by prions.  Prions o are proteinaceous infectious particle. o they lacks nucleic acids o they has an altered shape, or conformation.  Mechanism of causing disease: wondering how a protein particle can infect o This distorted protein binds to normal protein of same type and generates new infectious material Official (Open) Prion diseases  Kuru o Affected only the primitive tribesmen in New Guinea who eat the brains of their dead relatives. o Mainly, women and children are affected as they have the propriety to eat brain. o Signs and symptoms occurs after a long incubation period due to slow disease process o Incubation period: 10 – 50yrs and above o Prions deposition in brain  damages the nervous system- irreversible damage. o The affected people gradually become insane and die. Official (Open) Kuru Watch this documentary to learn how this disease was diagnosed A Medical Detective Story on the Kuru Prion Disease from Paupa New Guinea - YouTube Official (Open) Summary  Virus - Introduction Characteristics- (Obligatory intracellular parasites, Inert out of host cells, Do not have organelles, have few or no enzymes) Structure of Viruses (Nucleic acids, capsid, envelope, viral proteins) Pathogenesis o Acute infection (influenza, zika, rabies, Dengue, SARS, COVID) o Chronic infection- HIV, HBV, HCV o Latent infection – herpes simplex and varicella zoster o Oncogenic infection – HPV, HIV, Hep B  Prion diseases - kuru Official (Open) Microbiology- lecture 3 Official (Open) Introduction to Microbiology- lecture 3  Fungal and parasitic infections were and are ubiquitous in human and animal populations.  Most of us would have encountered ring worm and threadworm infection once in a lifetime.  In this lecture, lets learn about Fungal and parasitic infections. Official (Open)  Lecture outline: o Fungus Infections o Parasitic Infections Ringworm Protozoa Tinea versicolor Trichomonas Candidiasis Entamoeba Malaria Helminths Tapeworm Thread worm Round worm Hookworm Scabies Official (Open) Fungal Infections  Fungi are largely invisible to the naked eye  Eukaryotic organism and are free living; but different from plants.  Live for the most of their life in soil, dead matter or as a symbiotic relationship with plants, animals, or other fungi.  Most fungi are do not cause disease. E.g., yeasts, moulds, and mushrooms are examples  Some fungi remains as commensals in your skin. E.g., candida  Some fungi causes infections. Let's learn about a few fungus affecting humans. Official (Open) Fungal Infections  Common fungal infections o Ringworm o Tinea versicolor o Candidiasis “ of course, I ll need to run some tests; but offhand I ‘d say its some sort of fungus infection” Official (Open) Fungal Infections  Tinea (Ringworm) o Caused by dermatophytes o Infects superficial keratinized structures o Spread by direct contact o Cause chronic skin infection characterized by severe pruritus o Symptoms aggravated by heat, humidity Official (Open) Tinea corporis Tinea capitis Tinea pedis Official (Open) Fungal Infections  Tinea versicolor o Caused by Malassezia furfur (yeast) o Cause superficial skin infection -hypopigmented areas o Usually, asymptomatic o Occurs more frequently in hot, humid weather Official (Open) Fungal Infections  Candida albicans o Part of normal flora in skin, upper respiratory, gastrointestinal & female genital tract o Causes infection occurs ONLY when host defences are impaired (becomes opportunistic) a. White patches in mouth (oral thrush)* b. Vulvo-vaginitis with itching & vaginal (cottage cheese) discharge c. Chronic fingernail infections Albicans – white colonies in growing media Official (Open) Fungal infection of mouth & nail-candida albicans Official (Open) Candidia oesophagitis Official (Open) Parasitic infections  These organism are non-mutual symbiotic o the parasite, benefits at the expense of the host.  Only a few species causes disease in man  They may have life cycles that involve more than 1 host.  Parasitic infections are classified into 2 main groups: o single cell - protozoa o multicellular - helminths (worms) Official (Open) Protozoa o Only a few species cause disease in man o Organism in the body produce a cyst during adverse conditions. o Cyst formation enables the organism to survive outside a host without food, oxygen o This cyst when enters a new host gets is converted to adult. o Let's learn the following protozoa infections: 1. Trichomonas vaginalis 2. Entamoeba histolytica 3. Malaria Official (Open) Protozoa  Trichomonas vaginalis o Spindle shaped organism with 4 anterior flagella o Transmitted by sexual contact Causes vaginal and prostate infections o Symptoms watery foul-smelling greenish vaginal discharge itching, burning sensation around vagina asymptomatic in men Official (Open) Protozoa  Entamoeba histolytica o Is an anaerobic protozoa o Common in crowded living conditions & poor sanitation. o It spread through food or water contamination o Causes acute amoebic dysentery o invades the colon causing (loose stools mixed with blood and mucus) o Defecation is painful Official (Open) Protozoa  Plasmodium o Causes malaria o Obligate intracellular parasite. o There are five species o Transmitted by female Anopheles mosquito o Characterized by fever, chills, vomiting, headaches o Severe cases - death by renal failure, internal bleeding, respiratory failure Official (Open) Official (Open) Infects 515 million people and kills between one and three million people Official (Open) Helminths  Multicellular organisms with own digestive, circulatory, nervous, excretory, reproductive systems  Divided into  Cestodes - segmented worms o Tapeworms  Nematodes - Unsegmented worms o Pinworms o Roundworms (Ascaris) o Hookworms Official (Open) Helminths  Tapeworm (Taenia Solium) o Flattened segmented worms living in intestines o They obtain nutrients by direct absorption o Spread by faeco - oral route o Lifecycle Adult worm in human intestine releases eggs; eggs comes out via faeces Eggs in feces swallowed by intermediate host (cow / pig) In intermediate host, eggs hatches to larva. Larva reaches the muscle of the intermediate host (cysticercosis). When human consumes this infected uncooked muscle  eggs hatches  adult worm What is neurocysticercosis Official (Open) Official (Open) Helminths  Pinworm o Lives in intestines o They obtain nutrients by direct absorption o Spread by faeco-oral route o Lifecycle Adult worm lives in colon  Female pinworm leaves anus at night Female worm lays egg in anus (causes itching) - pruritis ani: most prominent feature Itching causes humans to scratch anus  eggs soiled hands  handles food  food with eggs enter another host  hatches to adult worm Official (Open) Official (Open) Pinworms in perianal region Official (Open) Helminths  Roundworm (Ascaris) o Adult worms live in the lumen and derive their nutrition from ingested food. o Spread by faecal - oral route o Lifecycle Adult worm lives in colon  adult worm release egg  comes out via faeces Eggs contaminated in food  hatches in human intestine to form larva Larvae penetrate intestine wall  migrate to lung  enter the alveoli  pass through the trachea In trachea, larva are swallowed  reaches intestine again Larva becomes adult worms  releases eggs. Official (Open) Official (Open) Eggs of Intestinal Helminths eg. Ascaris Official (Open) Official (Open) Helminths  Roundworm (Ascaris) o Damage occurs in intestine due to adult worms. o Damage occurs due to during larval migration (larva migrans). o Inflammation can occur in the lungs. o Children can be malnourished if they have a severe infection. Roundworm larva migrating in skin Roundworm bursting out of intestine Official (Open) Helminths  Hookworm o Adult worms live in the lumen and derive their nutrition from ingested food. o Spread by faeco - oral route o Lifecycle Worm lives in colon adult worm release egg in faeces Eggs in soil hatches in soil  to form larva Larvae penetrate intact skin  reaches lungs enter the alveoli pass up the trachea In trachea larva are swallowed  reaches intestine and become adult worms  releases eggs Official (Open) Official (Open) Hookworms are thought to infect 800 million people worldwide Hookworms Official (Open) Helminths  Hookworm o They feed on blood from the capillaries of the intestinal wall o Main damage is due to loss of blood in the small intestine resulting in iron deficiency anemia. Official (Open) Summary Fungus Infections Ringworm - dermatophytes tinea versicolor -Malassezia furfur Candidiasis – candida albicans Parasitic Infections Protozoa – single celled Trichomonas -Trichomonas vaginalis – genital infections Entamoeba histolytica – dysentery Malaria – plasmodium Helminths – multiple celled Tapeworm Thread worm Round worm Hookworm Official (Open) Microbiology- lecture 4 Official (Open) Introduction to Microbiology- lecture 4  The principles of asepsis are also based on microbiology.  We must know procedures for creating and maintaining a sterile field in the hospitals based on the knowledge of microbiology.  Know the importance of sterile equipment & atmosphere free of microorganisms in operation theatre.  In this lecture, lets learn about microbial sterilization & disinfection. Official (Open)  Lecture outline: o Nosocomial infections o Microbial Sterilization & Disinfection o Definitions o Mechanisms of Action o Chemical Agents o Physical Agents Official (Open) Nosocomial infections  Infections acquired as a result of stay in o hospital o nursing home o health-related facility  Risk factor due to presence of these 3 factors o microorganisms in health facility environment o compromised status of host o chain of transmission Official (Open) Nosocomial infections  Routes of Transmission o Direct contact staff to patient patient to patient o Indirect contact from fomites - iv equipment, urinary catheters, respiratory aids Official (Open) Nosocomial Infections  Common Nosocomial Infections o UTI (50%) - due to catheterization o Surgical wound infection (25%) - occur post-op especially in GI surgery o Lower resp tract infection - due to resp devices o Bacteremia - due to iv drips Official (Open) Nosocomial Infections Official (Open) Nosocomial Infection prevention Official (Open) Microbial Sterilization & Disinfection  The scientific concept of microbial growth began 100 years ago when Ignatz Semmelweis and Joseph Lister introduced methods such as: handwashing with disinfectants boiling instruments  This lowered the infection rate in hospitals Disinfection and Sterilization - YouTube 5 Official (Open) Definitions  Disinfection o killing of many but not all micro-organism o for adequate disinfection, pathogens must be killed o Disinfectant refers to chemical applied to an object.  Sterilization o Killing/removal of all microbes (including endospores) o Is absolute o Eg: Heat, radiation, chem agents 6 Official (Open) Action of Anti-Microbials Agent  Anti-microbial agents vary in their ability to kill microbes. Some have more than 1 mechanism of action, but few can achieve complete sterility.  Anti-microbial agents act by  Alteration of Membrane Permeability  Damage to Proteins, Nucleic Acids Cell Wall 9 9 Official (Open) Chemical agents Physical agents 1. Phenol 1. Heat 2. Chlorhexidine o Moist heat 3. Alcohol o Dry heat 4. Surface active agents o Pasteurization o Soaps 2. Filtration o Quaternary ammonium compounds 3. Radiation 5. Halogens – chlorine & iodine 6. Aldehydes o formaldehydes o glutaraldehyde Official (Open) Chemical Agents  Used to control the growth of microbes on living tissue and inanimate objects.  There is no one disinfectant that will be appropriate for all circumstances. 1.Phenol 2.Chlorhexidine 3.Alcohol 4.Surface active agents- Soaps and Quaternary ammonium compounds 5.Halogens - chlorine & iodine 6.Aldehydes - formaldehydes and glutaraldehyde Official (Open) Phenol  Originally used by Joseph Lister in the operating theatre  Its acts by damaging the microbe's cell membrane as well as denaturing proteins 12 Official (Open) A surgical operation showing carbolic spray in use Official (Open) Phenolic Derivatives 1. Cresol Good surface disinfectant Used in Lysol 2. Hexachlorophene Soaps, lotions (pHisohex) Effective against Staph, Strep Excessive use can cause neurological damage 13 Official (Open) Chlorhexidine  Combined with a detergent or alcohol for surgical scrubs and preoperative skin preparations  More rapid onset of action compared to hexachlorophene  Killing effect is related to its damage to the plasma membrane  Not sporicidal 14 Official (Open) Alcohol  Widely used to clean skin  Acts and evaporates rapidly; leaves no residue  Kills bacteria, fungi but not naked viruses  Disrupts cell membrane by dissolving lipid component, denatures proteins  Unsatisfactory when applied to wounds as they cause coagulation of a layer of protein under which bacteria continue to grow  Examples: ethanol, isopropanol 15 Official (Open) Surface-Active Agents  Divided into o Soaps o Quaternary ammonium compounds Bactericidal against Gram positive bacteria Do not kill endospores Certain bacteria, eg Pseudomonas, can survive and grow in them Examples: Cepacol 16 Official (Open) Halogens Are effective against microbes Chlorine o used to purify water, treat swimming pools o strong oxidising agent that inactivates enzymes o Example:Hypochlorite in Chlorox Iodine o one of the oldest and most effective antiseptic o inactivates enzymes, proteins Official (Open) Compounds of Iodine  Tincture o Solution of iodine with alcohol o Used to prepare skin before bld culture o Disadvantage is that it stains, irritates the skin  Iodophor o complex of iodine with detergents o less irritating and do not stain o used to cleanse skin before surgery o Pseudomonas can survive in it o Eg: Betadine, Isodine Official (Open) Aldehydes Among the most effective anti-microbials 1. Formaldehyde Available as formalin Carcinogenic Used to preserve tissue specimens 2. Glutaraldehyde 10 times more effective less toxic Example: Cidex (used to sterilize respiratory therapy equipment) 22 Official (Open) Physical Agents I. Heat o Most common method by which microbes are killed. o Economical and easy to control o Kills microbes by denaturing their enzymes o Three types Moist heat Dry heat Pasteurization Official (Open) Physical Agents 1. Moist Heat A. Boiling  1000 C kills most pathogens in 10 mins  steam also effective  some viruses, endospores not destroyed B. Autoclaving  Most frequently used method in clinics  Steam under pressure (1210 C for 15 mins)  Most effective when microbes in direct contact with steam  Kills all organism and endospores Official (Open) Physical Agents 2. Dry Heat A. Direct flaming o Simplest method B. Hot Air Sterilization o Requires temperature of 1800 C for 2 hr o Used to sterilize glassware Official (Open) Physical Agents 3. Pasteurization o Used mainly for milk o Heating milk to 620 C for 30 mins, followed by rapid cooling o Kills most milk-borne pathogens o Keeps refrigerated for several days Official (Open) Official (Open) Physical Agents II. Filtration o The passage of a liquid through porous material to trap particles larger than the pore size o Used to sterilize heat-sensitive materials E.g. culture media, enzymes, vaccines o Latest filters can retain viruses (0.01 μm pore) Official (Open) Physical Agents III. Radiation o E.g. X-rays, Gamma rays, UV rays o Used to sterilize heat-sensitive materials Official (Open) Summary Nosocomial infections – definition, risk factor, routes of transmission, common nosocomial infections Microbial Sterilization & Disinfection Definitions Mechanisms of Action (membrane permeability and damage to proteins) Chemical Agents –Phenol, chlorhexidine, alcohol, surface active agents, halogens and aldehydes) Physical Agents - Heat (Moist heat (boiling autoclave), Dry heat, Pasteurization, Filtration , Radiation Official (Open) Microbiology - lecture 5, 6 SELF DIRECTED LEARNING  By now you will be familiar with…. Official (Open) Microbiology 1  Bacteria is a prokaryote… what karyo means? What is a prokaryotic like cell found in human?  Classify bacteria based on shape and arrangement…  Draw a bacterial cell and label the parts below: o Cell wall, structures inside and outside cell wall  What are bacterial resting cells called as? Which type of sterilization kills them?  List out the growth requirements of bacteria  Classify the bacteria based on oxygen requirement? Cite with examples  Normal Flora- location, uses (protection, nutritional), opportunistic infection  Carrier – definition, example  List out the components of chain of infection o Pathogen o Reservoir o portal of exit o methods of transmission o portal of entry o Infection in the new host o construct chain of infection for common cold – remember this will be the base for written assignment  spell a bacterium and say which is genus and species name  By now you will be familiar with…. Official (Open)  Outline the chain of infection for the following medically Important Bacteria: o Cocci – gram positive (Staph and Strepto), gram negative (Neisseria) o Bacilli – gram positive (Clostridium), gram negative (E. coli, Salmonella) o Others – Chlamydia, Tuberculosis, Syphilis Virus  How is a virus different from Bacteria in structure?  Outline the chain of infection for the following viruses: o Acute infection (influenzas, zika, rabies, SARS, COIVID) o Slow infection- HIV o Latent infection – herpes and chicken pox o Oncogenic infection – HPV, Hep B, HIV  Outline the chain of infection for kuru infection  Outline the chain of infection for following fungal infection: o Ringworm - dermatophytes o tinea versicolor -Malassezia furfur o Candidiasis – candida albicans  By now you will be familiar with…. Official (Open) Parasitic Infections  Outline the chain of infection for following parasites.  Protozoa – single celled o Trichomonas -Trichomonas vaginalis – genital infections o Entamoeba histolytica – dysentery o Plasmodium -Malaria o Helminths – multiple celled o Tapeworm o Thread worm o Round worm o Hookworm Nosocomial infections Define the risk factor, routes of transmission of common nosocomial infections Microbial Sterilization & Disinfection  Definitions  Mechanisms by which the microorganism is killed.  Chemical Agents  Physical Agents Official (Open) Think and answer..  Why is it difficult when it comes in manufacturing medications / vaccines for viral infections??  Triple swabs is commonly done for vaginal infections. Why is this called as triple swabs? What infections are screened?  Elevator buttons or public toilet – which has more microorganism??? Official (Open) Hand washing steps Follow strict hand hygiene 1. Before /after touching patient 2. Before / after any procedure 3. After touching patient surrounding Official (Open) Patient A Patient B  You are a wound nurse working in a outpatient clinic.  Using your microbiology knowledge, padlet me how will you handle this patient A with clean wound and patient B with wound infection. Official (Open) Heard about zombie ants Official (Open) Official (Open) Microbiology Fu n Fa c t s a b o u t Mic r o b io lo g y Te s t y o u r s e lf Dr Vasundra Official (Open) As a nurse… You play a key role in controlling infections in medical facility. Microbiology is a subject dealing with microbes… Official (Open) Bits of history ANTONY VON LEEUWENHOEK I worked in a linen shop I used magnifying glass to count threads I started grinding glasses to make microscope to visualise cloth fibres One fine day– I saw this fine moving objects – I named it as little animalcules That’s how I discovered microbes Official (Open) Bits of history Louis Pasteur Hey… I am the father of microbiology - I proved the theory of biogenesis – microbes can come only from microbes. My 3 kids died due to typhoid which made me to discover vaccines for anthrax and rabies I suggested my fellow surgeons to boil the surgical instruments before surgery... I found the pasteurisation procedure. Official (Open) Bits of history Robert Koch Hi all... I am the father of modern microbiology I was a military surgeon, I felt my interest in infectious disease especially anthrax. I discovered TB bacilli in my lab, for which I was given Nobel prize Official (Open) Bits of history Joseph Lister I am the father of antiseptic surgery. My fellow surgeons thought it was the bad air which caused post op infections. I started using carbolic spray and saw the reduction in mortality. I even treated queen Victoria – I always joke to my medical students, "Gentlemen, I am the only man who has ever stuck a knife into the queen!" I have a mouth wash and a mountain named after me Official (Open) Bits of history Alexander Flemming I won Nobel prize in physiology of medicine.. Funny way I invented penicillin: I smeared some Staphylococcus bacteria on a culture plate before going on holiday. While I wasn’t there, a mold spore had flown into the laboratory from another nearby laboratory where molds were being studied. When I returned, I noted Staphylococcus bacteria had grown and covered the entire plate except for one area, which was covered in mold. I found a substance in that mold that prevented the bacteria from growing, even if it was diluted 800 times. Hurray that’s penicillin. So go for a holiday to get a break in your life… Official (Open) Intro.. Normal flora –good guys Opportunistic pathogens – part time bad guys Pathogens – full time bad guys Virus Bacteria Fungi Parasites Official (Open) Bacteria Here… there ….. I am everywhere – even in bottom of ocean trenches I have so much relatives all around you, as well as inside you I don have nucleus… I am a prokaryotes guys.. Sometimes – not feeling good – I become dormant – spores Virus I am smaller than bacteria I can infect a bacterium too Official (Open) infections - Who am I??? Answers last page Official (Open) 1. Who am I??? Gram-positive Gold colonies Common cause of skin abscesses MRSA – the scariest one Official (Open) 2. Who am I??? I am the primary cause of bacterial pneumonia. I appear in chains. Gram-positive. Official (Open) 3. Who am I??? I am Gram-negative. I resemble kidney beans. I cause genital infections in both males and females. During pregnancy, I can also affect the fetus. Official (Open) 4. Who am I??? I am a Gram-positive rod. I reside as spores in soil and rusted items. If I manage to enter the skin, I produce a toxin that attacks nerves. I am anaerobic. I am not contagious from person to person. I can affect neonates through ingestion of contaminated soil or spores during childbirth." Official (Open) 5. Who am I??? I am a Gram-positive rod. I spread through the air to enter vulnerable hosts. I produce a pseudomembrane over the pharynx. I cannot infect those vaccinated with the DPT vaccine because the vaccine provides immunity against me. Official (Open) 6. Who am I??? I reside in the intestine and am usually harmless. My flagella aid in my movement. I can cause urinary tract infections in females. Official (Open) 7. Who am I??? I made Ms. Mary famous (referring to Salmonella being the cause of typhoid fever, which affected Mary Mallon). I prefer the intestine, but I can enter the blood in cases of sepsis. I like to travel through food or water." Official (Open) 8. Who am I??? I thrive in lungs, especially at the apex, and also affect other organs. I resemble fungus when grown in liquid media. I was responsible for the death of Akhenaten and his wife Nefertiti. I require a special stain for identification. I cause gradual weight loss in humans. I am also known as white plaque. Official (Open) 9. Who am I??? I am commonly spread by unprotected intercourse. I cause Gummas (soft, tumor-like growths). Penicillin is effective against me. I am also known as great pox. Dark field microscopy and VDRL tests can identify me. Official (Open) 10. Who am I??? I cause the common flu. I can lead to pneumonia in vulnerable individuals. My H1N1 strain once caused a pandemic. Due to my high mutation rate, a specific vaccine typically provides protection for only a few months. Official (Open) 11. Who am I??? Mosquitoes are my friends. During pregnancy, I can affect the fetus, leading to microcephaly. Official (Open) 12. Who am I??? I target the brain, reaching it via nerves. Even a bite or lick on a cut surface can allow me to enter the skin. I cause the affected person to fear water and light. Once signs and symptoms appear, fatality is almost certain. Official (Open) 13. Who am I??? I originated from horseshoe bats. I can cause acute respiratory arrest and death. The Metropole Hotel in Hong Kong is infamous as ground zero for a SARS 'super spreader' in the 2003 outbreak. Official (Open) 14. Who am I??? I originated from horseshoe bats. I can cause acute respiratory arrest and death. I am now a pandemic. Symptomatically, I resemble the SARS virus. Hand hygiene, wearing masks, isolation, and safe distancing are essential measures to control my spread. Official (Open) 15. Who am I??? I am Kuru. I am reluctant to show symptoms quickly. I affected only the Fore tribe in New Guinea, specifically those who practiced cannibalism. I weaken the nervous system, causing insanity and death." Official (Open) 16. Who am I??? I affect those who had chickenpox before. I reside in ganglia and travel via nerves. I cause a painful warning before I appear. Official (Open) 17. Who am I??? I prefer the liver – I am named after this organ. I am more infectious than HIV. There is a vaccine that can prevent my infection in humans. Chronic inflammation of the liver can lead to cancer. Official (Open) 18. Who am I??? I favor the cervix. I can cause warts. Certain serotypes can lead to cervical cancer. I am susceptible to vaccines like Gardasil and Cervarix. Official (Open) 19. Who am I??? I am named after my appearance on the skin. I make humans itch and scratch incessantly Official (Open) 20. Who am I??? I appear white when I grow in colonies. I typically remain dormant but can cause infection if the individual's immunity decreases. Official (Open) 21. Who am I??? I have four flagella. I cause greenish discharge. I can make the cervix appear 'strawberry-like'. Official (Open) 22. Who am I??? I am a parasite. I replicate in mosquitoes and humans. In humans, I destroy their blood cells and liver. I am active at night (nocturnal). If you find rings inside the red blood cells, then it's me causing malaria. Official (Open) 23. Who am I??? I am like a ribbon I have multiple packs. I can grow upto 6 metres I need a cow or pig to complete my cycle I spread by feco- oral route Official (Open) 24. Who am I??? I look like a small coiled threads My mother lays eggs in perianal region. I can cause Itchy itchy bottoms I spread by feco- oral route Official (Open) 25. Who am I??? I am like a thick noodle I spread by feco- oral route I hatch first in intestine, then migrate to reach lungs. I reach trachea and make a sharp U turn into the GI tract where I become a adult worm. Official (Open) 26. Who am I??? I have a sucker to suck blood I can cause anaemia I enter via intact skin of your feet I hatch first in intestine, then migrate inside the human to reach lungs. I reach trachea and make a sharp U turn into the GI tract where I form adult worm. Official (Open) 1. ______ is the ability of the bacteria to get attached to the bacteria. 2. ______ is the degree of pathogenicity. 3. Human acts as a ______ in spreading tuberculosis. 27. Fill 4. Normal flora has function of ________ and ________. in the 5. E.coli is a ___________ based on its oxygen requirement. blanks 6. ________ is a separate double-stranded DNA molecule. 7. Gram negative bacteria uses ______ for attachment. 8. _________Cocci that form grape-like clusters. Official (Open) 28. Three people in a medical ward were diagnosed with MRSA infection. It was noted that Mr. G in the same ward was harboring MRSA, but he was asymptomatic. Official (Open) 29. A 55-year-old chronic smoker was admitted for chronic cough. He underwent a chest X-ray which showed opacities in the right upper lung. He also experienced coughing up blood. He had a history of weight loss and loss of appetite for the past 5 months. It was noted that his coworker also had similar symptoms.Impression? Official (Open) 30. Mrs. V, a 76-year-old woman, fell down in the toilet and was taken to A&E where she was diagnosed with a hip fracture. She underwent surgery and was admitted to the general ward. Three weeks later, she developed a cough and was noted to have lung consolidation (which was clear during admission). Official (Open) 31.. 1. Next time when you go for a clinical attachment or visit a hospital, observe the disinfectants they use in different places (e.g., in reception, near the lift, in the operation theatre). Name them. 2. What is the most common method used for sterilization in hospitals? Name it. 3. What is the most effective antiseptic used in homes up till now? Name it. 4. Which chemical agent is used to purify water? 5. Which chemical agent is used on the skin before injection? 6. What method is used for sterilizing glassware? 7. What method is used for sterilizing vaccines? 8. What method is used for sterilizing heat-sensitive materials? Official (Open) 27. 1. Staphylococcus aureus 13.SARS virus 1. Adherence 2. Virulence 2. Streptococcus pneumonia 14. COVID – 19 3. Reservoir 3. Neisseria gonorrhoea 15. Kuru 4. Protection, nutrition 4. Clostridium tetani 16. Shingles 5. Facultative anaerobe 6. Plasmid 5. Corynebacterium diphtheria 17. Hepatitis B virus 7. Pili 6. E. coli 18. Human papilloma virus 8. Staphylococcus 7. Salmonella typhi 19. Ringworm 28. Carrier 8. Mycobacterium tuberculosis 20. Candida albicans 29. Tuberculosis 9. Treponema pallidum 21. Trichomonas vaginalis 30. Nosocomial infection 10. Influenza virus 22. Malaria 31. 11. Zika virus 23. Tapeworm 1. Chlorhexidine, betadine 12. Rabies virus 24. Threadworm 2. Autoclave 3. Tincture iodine/ betadine 25. Ascaris 4. Chlorine 26. Hookworm 5. Alcohol Answers 6. Hot air sterilisation 7. Filtration 8. Radiation Official (Open)