Medical Microbiology: An IntroductionMahesh ChaudharyAsst.ProfessorDept. of MicrobiologyKIST Medical College,Imadol

ObjectivesAn overview of Medical MicrobiologyBrief historyChallenges we meet nowBooks

What is Microbiology?Micro - too small to be seen with the naked eyeBio - lifelogy - study of

Medical microbiology is the study of microbes that infect humans, the diseases they cause, and their diagnosis, prevention and treatment. It also deals with the response of the human host to microbial antigens.

Size of bacteria1micron()- one thousand of mm1 millimicron (m) or nanometer (nm)- one thousand of a micron or one millionth of mm1 Angstrom (A)- one tenth of nanometerResolution of Eye- 200 (m)Bacteria size- 0.2-1.5 x 3-5 m in length

Branches of MicrobiologyBacteriology : study of bacteria Virology : study of virusesParasitology : study of parasitesMycology : study of fungus

*Immunology : study of immunity and immune response of the human host to microorganisms.

Organisms Related To Medical MicrobiologyAcellular microbesVirusesProkaryotic microbesBacteriaEubacteria ChlamydiaSpirochetesRickettsiaeMycoplasmaActinomycetesEukaryotic microbesFungi

Microbes are capable of causing many diseasesPneumoniaWhooping Cough Botulism Typhoid Fever MeaslesCholeraLeprosy MumpsSyphilisGonorrhea Herpes 1Chlamydial inf.Tuberculosis Herpes 2Meningitis Tetanus RabiesStrep ThroatLyme Disease AIDSDiarrhea Gangrene

NowadaysNew pathogens emerged continuouslyHepatitis virusesHIVInfluenza virus

The mutations of traditional pathogens Drug resistance became more severeMycobacterium tuberculosis

Brief History of Microbiology

Antony van Leeuwenhoek 1674 - 1st person to actually see living microorganisms wee animalcules

Louis Pasteur1822- 1895French ChemistFermentationSterilizationGrowth needs of bacteria

Louis Pasteur- contd.Coined vaccineStudies on pebrine, anthrax, chicken cholera, and hydrophobiaDevelopments of methods and techniques for cultivation of microbesConclusive evidence of microorganism in disease production

Joseph Lister(1867)Father of antiseptic surgeryAntiseptic technique in surgeryCarbolic acid used in hand washing

Robert KochFather of medical microbiologyGerman- 1843-1910Staining techniquesSolid media (agar)Discovered MTB, CholeraAnthrax

Robert Koch- PostulatesBacterium should constantly associated with the lesions of the disease

It should be able to isolate the bacterium in pure culture from the lesions

Contd..Inoculation of such pure culture into suitable animals should reproduce the lesion

It should be possible to re-isolate the bacterium in pure culture from the lesions produced in the experimental animal

Specific antibodies to the bacterium should be demonstrable in the serum of the patients suffering from the disease

Exceptions to Kochs Postulates1. Some organisms have never been grown in pure culture on artificial mediaTreponema pallidum - Syphilis

Mycobacterium leprae LeprosyNever been grown in pure culture on artificial mediaAbdominal cavity of the Seven Banded ArmadilloExceptions to Kochs Postulates

Koch established the Microbial Etiology of 3 important diseases of his day1. Cholera (fecal-oral disease)Vibrio cholerae2. Tuberculosis (pulmonary infection)Mycobacterium tuberculosis3. Anthrax (sheep and cattle)Bacillus anthracis

Other ScientistsHansen(1874)-Lepra bacilliNeisser(1881)-GonococcusKlebs Loefflers- DiphtheriaFrankel (1886)-Pneumococcus

Weichselbum- meningococcusRoux and Yersin - Diphtheria toxinYersin Plague bacillus

Discovery of VirusIwanovskia Russian chemist, 1892Tobacco Mosaic Disease

Walter Reed, USAYellow fever virusIst human virusTobacco mosaic disease, caused by the tobacco mosaic virus

BooksText Book of Microbiology Microbiology- R. Ananthanarayan and CK Jayaram Paniker A Text Book of Microbiology Microbiology P ChakraborthyText Book of Parasitology- Chatterjee, Panikar, Icchpujani