Presentation on theme: "Introduction to Microbiology"— Presentation transcript:
1 Introduction to Microbiology Introduction to Clinical Laboratory SciencesIntroduction to MicrobiologyCLS 245
2 Introduction to Clinical Laboratory Sciences What is Microorganism?Microorganisms ( or Microbes) are vey small organism that can’t be seen by naked eyes.However, these Microbes can be seen with the aid of microscope.These microorganisms can be divided into 4 subgroups: Bacteria,, Fungi, Viruses and Parasites.Microbiology is a broad field that include the study of all types of microorganisms.https://www.le.ac.uk/se/centres/sci/selfstudy/eco7.htm
4 Cont.. Medical Microbiology is the study of microorganisms: Bacteria FungusParasitesVirusesMost can only be seen with the microscope!
5 Cont..Medical Microbiology studies are usually performed on human blood and body fluids.Microorganisms can cause disease in humans.Microbiologists determine the type of microorganism causing the disease and find a drug, usually an antibiotic, to inhibit the microorganism.Microbiologists continue to study the microorganisms through research to determine new antibiotics
6 Cont..Microorganisms are studied in clinical hospital laboratories, reference laboratories, and research facilities.
7 Prokaryotes vs Eukaryotes Introduction to Clinical Laboratory SciencesProkaryotes vs EukaryotesBefore getting into Microbiology, it is important tounderstand the differences between Prokaryotesand Eukaryotes.Adapted from:
8 Prokaryotes vs Eukaryotes Introduction to Clinical Laboratory SciencesProkaryotes vs Eukaryotes-ER , Golgi , Mitochondria and Lysosome are in Eukaryotes but not in pro-human are eukaryotesYeast also are eukaryotes, so when you get fungal infection it is hard to treat with antibiotics.
9 Introduction to Clinical Laboratory Sciences Viruses-Virology is study of viruses.-Viruses are very small microorganisms (smaller than bacteria) and they can’t grow or reproduce apart from living cells.-They are too small to be seen by microscope.-Viruses are not alive, why?Viruses are not a live, why?They can’t reproduce or grow apart from living cell, they also can’t produce energy.
10 Viruses Viruses have wide variety of structure but they all share 2 importantelement:Genetic material (DNA or RNA)Protein coat or capsid
11 Introduction to Clinical Laboratory Sciences FungiThe study of fungi is called Mycology.The fungi are a group of eukaryotic microorganisms, some of which are capable of causing superficial, cutaneous, subcutaneous, or systemic disease.However, some fungi are also directly important as a food for human (making a bread) or as a treatment ( producing penicillin).
12 Introduction to Clinical Laboratory Sciences Fungi contIntroduction to Clinical Laboratory SciencesMykes (Greek word) means Mushroom.Fungi are eukaryotes , differ from bacteria and otherprokaryotes.Fungi digest dead organic matter.Molds and mushroom are multicellular while Yeast areunicellularAdapted from DR T.V Rao MDYeast: unicellular fungiMolds: Multicellular fungi
14 Introduction to Clinical Laboratory Sciences ParasitesIntroduction to Clinical Laboratory SciencesMedical parasitology: “the study and medical implications of parasites that infect humans”A parasite: “a living organism that acquires some of its basic nutritional requirements through its intimate contact with another living organism”. Parasites may be simple unicellular protozoa or complex multicellular metazoaEukaryote: a cell with a well-defined chromosome in a membrane-bound nucleus. All parasitic organisms are eukaryotesProtozoa: unicellular organisms, e.g. Plasmodium (malaria)Metazoa: multicellular organisms, e.g. helminths (worms) and arthropods (ticks, lice)Adapted fromAngela Allen, Research Assistant, The School of Medicine, Swansea University, Swansea, UKDr. Stephen Allen, Senior Lecturer in Paediatrics and Honorary Consultant Paediatrician, The School of Medicine, Swansea University, Swansea, UK
15 Introduction to Clinical Laboratory Sciences Cont. ParasiteHost: “the organism in, or on, which the parasite lives and causes harm”Intermediate host: “the organism in which the parasite lives during a period of its development only”Vector: “a living carrier (e.g.an arthropod) that transports a pathogenic organism from an infected to a non-infected host”. A typical example is the female Anopheles mosquito that transmits malariaAdapted fromAngela Allen, Research Assistant, The School of Medicine, Swansea University, Swansea, UKDr. Stephen Allen, Senior Lecturer in Paediatrics and Honorary Consultant Paediatrician, The School of Medicine, Swansea University, Swansea, UK
17 Introduction to Clinical Laboratory Sciences What do they look like?Three basic shapesRod shaped called bacilli (buh-sill-eye)Round shaped called cocci (cox-eye)Spiral shapedSome exist as single cells, otherscluster togetherBacilliCocciSpiralCluster of cocci
18 Introduction to Clinical Laboratory Sciences Bacteria are ALIVE!What does it mean to be alive?They reproduce (make more of themselves)They need to eat
19 Introduction to Clinical Laboratory Sciences How do bacteria eat?Photosynthetic bacteriaSome make their own food from sunlight—like plantsSome are scavengersShare the environment around themExample: The bacteria in your stomach are now eating what you ate for breakfastSome are warriors (pathogens)They attack other living thingsExample: The bacteria on your face can attack skin causing infection and acneHarmless bacteria on the stomach liningE. Coli O157:H7is a pathogen
20 Introduction to Clinical Laboratory Sciences What is a pathogen?Bacteria that make you sickWhy do they make you sick?To get food they need to survive and reproduceHow do they make you sick?They produce poisons (toxins) that result in fever, headache, vomiting, and diarrhea and destroy body tissue
21 Where do you get a pathogen? Introduction to Clinical Laboratory SciencesWhere do you get a pathogen?Indirect contactContact with people who are sickDirect or indirectFood, Water, or other Surfaces that are contaminatedFoods that could be contaminatedDirect contact
23 Tools and instruments in Microbiology lab Safety hoods are used to avoid splashing andinhaling possible pathogens.Agar plate for bacterial growthSlide used to make Bacterial smear And stain themMicroscope to visualize the bacteria
24 Introduction to Clinical Laboratory Sciences Types of staining techniquesSimple staining(use of a single stain)Differential staining(use of two contrasting stainsseparated by a decolorizing agent)For visualization of morphologicalshape & arrangement.IdentificationVisualizationof structureGramstainAcid faststainSporestainCapsulestain
25 Introduction to Clinical Laboratory Sciences Gram Stain:It is the most important differential stain used in bacteriology becauseit classified bacteria into two major groups:b) Gram negative:Appears red after Gram’s stainGram positive:Appears violet after Gram’s stain
26 Introduction to Clinical Laboratory Sciences Crystal violet↓IodineAlcoholSafranin
27 Introduction to Clinical Laboratory Sciences Gram –veE.coliGram +veS.aureusStep 1: Crystal VioletStep 2: Gram’s IodineStep 3: Decolorization(Aceton-Alcohol)Step 4: Safranin Red
29 Introduction to Clinical Laboratory Sciences Gram-positive bacteriaHave a thick peptidoglycan layer surrounds the cell.The stain gets trapped into this layer and the bacteria turned purple.Retain the color of the primary stain (crystal violet) after decolorization with alcoholGram-negative bacteriahave a thin peptidoglycan layer that does not retain crystal violet stain.Instead, it has a thick lipid layer which dissolved easily upon decoulorization with Aceton-Alcohol.Therefore, cells will be counterstained with safranin and turned red.
30 Types of culture media Based on their consistency a) solid medium b) liquid medium (ex: Blood culture)c) semi solid medium (for motility)-Some media are used for bacterial growth, some for Bacterial differentiation and others for bacterial selection.Macconkey agar which is selective for gram negative bacteria and differential them for lactoseFermentation.
31 Introduction to Clinical Laboratory Sciences Blood CultureBlood is sterile in normal conditionBlood cultures are incubated and monitored electronically for bacterial and fungus growth.