Microbiology: History and Key Figures

Introduction

• Anton van Leeuwenhook is the father of microbiology.

Timeline of Discoveries and Scientists

• 1665: Robert Hooke published the first description of microbes.
• 1667: Anton van Leeuwenhoek observed "Little Animals".
• 1796: Edward Jenner validated small pox vaccination.
• 1850: Ignaz Semmelweis advocated handwashing to prevent disease spread.
• 1861: Louis Pasteur disproved spontaneous generation.
• 1862: Louis Pasteur's paper supported germ theory of disease.
• 1867: Joseph Lister practiced antiseptic surgery.
• 1876: Robert Koch discovered Bacillus anthracis, proving germ theory.
• 1881: Robert Koch utilized solid culture media for bacterial growth and outlined Koch's postulates.
• 1882: Robert Koch discovered M. tuberculosis, and Paul Erlich developed the Acid-fast Stain.
• 1884: Hans Christian Gram developed the Gram stain.
• 1885: Louis Pasteur created the first rabies vaccination.
• 1887: Richard J. Petri invented the petri dish.
• 1892: Dmitri losifovich Ivanoski discovered viruses.
• 1893: T. Smith, F.I. Kilbourne first described Zoonosis.
• 1899: Martinus Beijerinck recognized viral dependence on living host cells for reproduction.
• 1900: Walter Reed proved mosquitoes carry the agent of yellow fever.
• 1910: Paul Erlich discovered a cure for syphilis.
• 1928: Alexander Flemming discovered penicillin.
• 1953: J. Watson and F. Crick proposed and built the DNA model.
• 1977: W. Gilbert and F. Sanger developed the DNA sequencing method.
• 1983: Kary Mullis invented the polymerase chain reaction (PCR).
• 1995: The Institute of Genomic Research published the first microbial genomic sequence.

Discovery of Specific Bacteria

• 1876: Robert Koch discovered Bacillus anthracis.
• 1879: Albert Neisser discovered Neisseria gonorroheae.
• 1880: Louis Pasteur discovered Staph, Strep, Pneomococcus.
• 1882: Robert Koch discovered Mycobacterium tuberculosis.
• 1883: Edward Klebs and Fredrick Loeffler discovered Corynebacterium diphtheriae.
• 1892: William Welch and George Nuttal discovered Clostridium perfringes.
• 1894: Emile John Yersin and S. Kitasato discovered Yersinia pestis.
• 1900: W. Ophuls and H.C. Moffett discovered Coccidiodes immitis (fungi).
• 1903: William Leishman discovered Leishmania donovani.
• 1905: Fritz R. Schandinn and Erich Hoffman discovered Treponema pallidum.
• 1918: Alice Evans discovered Brucella abortus.
• 1977: Joseph McDade and Charles Shepard discovered Legionella pneumophilla.
• 1982: Stanley Prusiner discovered Prions.

Microbiology Defined

• Microbiology studies microorganisms invisible to the naked eye.
• General microbiology deals with a wide spectrum of microorganisms.
• Medical microbiology studies pathogenic microorganisms.
• A pathogen is any microorganism causing harm/disease to humans.

Scope of Microbiology

• Pure microbiology includes bacteriology, parasitology, virology, mycology, and phycology.
• Integrative microbiology: medical, agricultural, industrial, environmental, immunology, biotechnology, food, and dairy.

Microbial Taxonomy

• Microbial taxonomy classifies microorganisms consistently.
• Classification: organizing microorganisms by physiology, morphology, and genetic makeup.
• Robert Whittaker used cellular classification and mode of nutrition for classification.
• Cellular classification distinguishes between unicellular and multicellular, prokaryotic and eukaryotic organisms.
• Nutritional modes include absorption (Monera, Protista, Fungi), ingestion (Animalia), and photosynthesis (Plantae, some Monera).

Five Kingdoms

• The five kingdoms are Animalia, Plantae, Monera, Fungi, and Protista.
• Monera includes true bacteria (Eubacteria) and ancient bacteria (Archeobacteria).

Carl Woese Domains

• Carl Woese used domains instead of kingdoms.
• The three domains are Bacteria/Prokaryoteya, Archea, and Eukaryoteya.

Levels of Classification

• Levels of classification include Kingdom, Phylum/Division, Class, Order, Family, Genus, Species, and Strain/Variant/Subspecies.
• Example: Monera/Eubacteria, Proteabacteria, Gamma-proteabacteria, Proteobacteriales, Enterobacteriaceae, Escherichia.

Nomenclature

• Nomenclature names microorganisms by established rules and guidelines.
• Binomial nomenclature includes genus and species (e.g., Escherichia coli).

Identification

• Identification describes key features of microorganisms.
• Phenotypic traits: size, shape, arrangement, biochemical characteristics, serological identification, environmental requirements, staining property, and nutritional requirements.
• Genotypic traits relate to an organism's genetic makeup.
• IJSB (International Journal for Systematic Bacteriology) is now IJSEM (International Journal for Systematic & Evolutionary Microbiology).

Prokaryotic vs. Eukaryotic Cells

• Prokaryotes lack a nucleus; eukaryotes have a nucleus.
• Prokaryotes have peptidoglycan cell walls (murein); eukaryotes lack peptidoglycan.
• Prokaryotes have cytoplasmic membranes made of phospholipids; eukaryotes have membranes with sterols.
• Prokaryotes lack organelles like mitochondria and lysosomes; eukaryotes possess them.
• Prokaryotes have 70S ribosomes; eukaryotes have 80S ribosomes.
• Protein synthesis occurs in the cytoplasm of prokaryotes and the endoplasmic reticulum of eukaryotes.
• Energy production occurs on the cytoplasmic membrane of prokaryotes and in the mitochondria of eukaryotes.
• Prokaryotes reproduce asexually via binary fission (mitosis); eukaryotes reproduce sexually (meiosis) and asexually (mitosis).
• Pili and flagella may be present in prokaryotes; microtubules may be present in eukaryotes.

Bacterial Cell Wall

• The bacterial cell wall provides shape and rigidity.
• It's responsible for antigenic and pathogenic properties.
• • Example, S. pyogenes - M protein and Gram (-) - endotoxin
• The Gram (+) cell wall has surface proteins and a thick peptidoglycan layer (murein).
• The peptidoglycan layer is made of N-acetyl-D-muramic acid and N-acetyl-D-glucosamine subunits.
• Teichoic acid is not anchored in the cell membrane in Gram(+), and act as passageways
• Types of teichoic acid are Ribitol Teichoic Acid = S. aureus and Glycerol Teichoic Acid = S. epidermydis
• Lipoteichoic acid - anchors cell membrane and is alcohol insoluble
• Mycobacterium & Nocardia cells contain Hydroxymetoxy Acid/Mycolic Acid - To differentiate them, Mycobacterium is Acid fast.
• The Gram (-) cell wall has surface proteins, an outer membrane with LPS, porins, endotoxins (Lipid A), and phospholipids.
• The Gram (-) cell wall has a thin peptidoglycan layer and a periplasmic space/periplasm.

Staining Types

• Staining uses dyes/reagents to artificially color cells.
• Simple staining uses one dye.
• Differential staining uses two or more dyes.

Gram Staining

• Crystal violet stains all cells purple.
• Gram's iodine acts as a mordant, intensifying the purple stain.
• Acetone alcohol decolorizes Gram-negative cells.
• Safranin counterstains Gram-negative cells red, while Gram-positive cells remain purple.

Acid-Fast (AFB) Staining

• Ziehl-Neelsen stains with steam, hot method.
• Carbol fuchsin is used, along with acid alcohol and methylene blue.
• AFB stains red, and Non-AFB blue
• Mordant: Tergitol #7 and method Kinyoun Cold
• Pappenheim's method uses uses Rosalic acid for Acid Alcohol, M. tuberculosis is read and M. smegmatis is blue.
• Baumgarten's method uses Alcoholic fuchsin instaead of Carbol fuchsin, M. tuberculosis = blue and M. leprae = red
• Special stains identify specific structures such as Hiss/Tyler/Muir (capsule stain), Albert/Neisser/LAMB (metachromatic granules), and flagella stain.

Special Stains

• Capsule Stain uses Welch & Novelli and Hiss, Tyler, and Muir.
• Metachromatic granules uses Albert, Neisser, and Lindergren & Ljubinsky.

Other Stains

• Leiffson
• Gray method & Silver technique = flagella
• Endospore uses Fulton & Schaeffer & Dorner
• Negative - India ink Stain && Nigrossin Stain = Direct/Relief

Rules For Gram Staining - Cocci

• All Cocci stain Gram+ except Neisseria Moraxella Veilonella.

Rules for Gram staining - Bacilli

• All Bacilli stain Gram- except Bacillus Clostridium Mycobacterium Corynebacterium Nocardia Erysipelothrix Actinomyces Listeria.

Rules for Gram staining - Spirals

• All Spirals stain Gram- but are hard to stain, Borrelia Treponema & Spirochetes are the examples.

Rules for AFB Staining

• All Stain Non-Acid Fast BUT for Bacteria exception when it’s Mycobacteria and Nocardia

Internal Parts of the Cell

• Responsible for the viability of the cell, for the permeability of the cell, Site of energy production is the function.
• The internal parts of a cell are the plasma membrane/cell membrane/cytoplasmic membrane, free ribosomes, and metachromatic granules.
• Plasma membrane: has the layer after the cell wall and made up of lipoprotein and functions with Site of septum formation during cell division & Site of attachment of naked chromosome and with Site of enzymatic activity of the cell.
• Free Ribosomes has the Site of protein synthesis.
• Metachromatic granules Used as food reserve with example such as Corynebacterium diptheriae, or Mycobacterium tuberculosis, and Yersinia pestis

Endospore/Spore

• A spore is used to resist extreme conditions (high temp, dryness) in G+ bacilli = Clostridium & Bacillus and are based on location by using location.
• Central/Equatorial spore B. subtilis, B. anthracis & B. subtilis, B. anthracis also has the Terminal, Terminal and Sub.
• A Nucleiod is where: the genetic makeup is found
• A Plasmid Is made: of Extra chromosomal circular pieces of DNA often carrying antibiotic resistant genes and virulent genes

External Parts of the Cell

• The capsule surrounds the cell wall and is a thick, slimy layer for mucoid colonies made of virulence factors + antigenic property.
• Virulence Factor the capsule makes bacteria antiphagocytic and Antigenic property is for antigen property.
• N. meningitidis & K. pneumoniae are example for capsule.
• Flagellum is composed of flagellin, with Functions for locomotion/movement & Provide antigenic property and it’s Types is also is Monotrichous & Amphitrichous & Lophotrichoues and Peritrichous w/Atrichous

Pili/fimbriae

• Pili/fimbriae are tiny and hairlike.
• Fimb. serve for Attachment while Sex pili for genetic transfer for bacterial .
• Axial are made of protein responsible for like movement with Treponema and Leptospira.

Bacterial Growth

• Bacterial growth reproduces by binary fission.

Bacterial Growth Requirements

• Macronutrients are needed in large amounts and such Macronutrients consist of Carbon from CO2 + Organic + Heterotroph/Organotroph and Nitrogen for free , and Culture media for Nitrogen and Sulfates+Nutrients source
• Micronutrients (trace elements, Zn/Mn) are needed in small amounts for biological metabolic activity.
• Example - X Factor-Hemophilus & V Factor -Nicotinamide Adenine

Environmental Requirements

• Gas: Obligate such requires oxygen or its toxic Singlet oxygen
• Temperature Requirements, Psychrophiles ,Mesophiles, Thermophiles, Hyperthermophiles, Sternothermophilic

Temperature requirements range

• Optimum-like 42 -60 degrees optimums for Hyperther. and also 42 -40, 30 -40 and 25 degrees

pH requirement

• Acidophile, Needs acidic and is º 3 while Neutrophile pH 7 & º 10 for Alkaliphile/Basophile

Osmotic Pressure

• Pressures - 0.55 with Osmophilic = requires high somotic /high/ requires
• Phases is, the Phases are: Log; Stationary, and Death phase.

Bacterial Growth Curve Phases

• Lag phase: preparing for new environment but with no multiplication for and will happen from Susceptible-like state till 4 or 12 Hr by which is: • Physiologic or with Microorganisms-like setup.

• Log phase because constant/ multiplication/ binary

• Stationary a level phase where death levels =the -living from H 19 or with 60-80 hr: • Number=the- same with 10th hr till 19 hrs later till decline that’s for:

• Death like at 1 hour stage

• Microbls that will die than = live by -24 Hours!

• All will-be spore forming instead = or that 24hr stage

Measurement of Microblal Growth

• Refers to the Colonies number to = Grow on loop area AND will use loop in samples: • AND=Urine or which samples at 0.01 ml; • Infectd. @ > 100,000 or @ (U/s (col)
• B/ By- Direct: Plate or = Counts
• And w serial-Like for count/broth or with Use Mcf-with (sal soln)
• Or Memb. filt AND @ Chamber
• By - Indirect: - for Tur-bid -o/ by - Spect-r, (L.)-ike

Cultivation of bacteria

• Culture - to: Grow micro with: to grow, plant and isolate

B. Culture Media in (La/):

• Nutrition/Organisms for- soil-& (Foods). C-I: The/s of Specs & (s/ : Med)

Requirements for cultivating bacteria

• 1- For Culture Mediums-with medium needs • TRUE in source as or Pure AND • Specs that = ( = ase-like for).

Types of Streaking

• Overlap & 1 Culture by Edge OR @ 0 ,
• Or multiple ,Ino., and, ( 0 isolated 0 like

Types+Cul

To - Pure: Or Mix =2, = - grow Contaminated: Accidental AND from Inoculating loops.

Classification of Culture media

State: Broth & No & Hard W/T , or Tsb+Bhib+N With. Agar+ Med. For 1-3 or can be .S/ & With Sim AND For: • Solid = - Agar

And /With- Med Agar - / - * Solid, like and Medium that - ,Bact And 2 and: • For= with: Sem- • Bi - phase, or medium, With Like:

• Basic, ,Basal,:Only, Basic & +Media. • Synth: C- ly is • Non.: N/Chemicals To Disp+Like : Tube + Test "Solid ++ Slant, and 3/ -Weigh4/: / = 1.

Med +Dish - To with Plate With, "Weigh & "Dissolve With

", Sterilize: Autoclav- with.

• 50 to "Disp or:
• 150- 15 ml for Big.P 60--1- for Small.

(D) -Func: "L U":Simple+ ,For Non Fast E - is: ++for + Organ- - Med for ++++ Organ.

• Is:++ Of Organ +P+B,
• Sterile+ Flora+

To Enrlc Med and Bact that+

• Sele + with or for . ""ForInhi - Subst that for Un: Gro and . Inhib. Org L Sw- Phenom -"" for-On in Plate in Pr+++, C Inhibited/s Like -

:Med and Antibiotics that

• T+agar(antibs)-& M+++, that.

Page - Used & Chemical.

• B-St: M + and to 0, 00. 0+and ( Steriles). +Septis +P micro/l/ and Abs+ -

Collection & preservation

• S+ (To iso + ID for S- if clinical - to test micro/D/antibs).

• Meds/s - For /C/ Specimens if to - .

• Specimen : (Meds Chemical/ ) - Acid And + for that B+Sal To - Stools.

• Stor + "P"/4 C 0 and to and 30 /L

Media to: And 1- 2 And s. L+ B/ For/s and B/ C Used 2 AND "

1- (3) and 10 AND and 6" 3 AND 9". To Microbe Co + ++( and To 2" .

Sputum (For):

(I - Res - Low Tract +D/P and +A ++ MAC . Ind Sp For test that is: * For and stain .

: By M/O

• To ++ To org ( and, To kill/to 0).

Specimens parts for test if:

For: for and test. ,+

Blood collection steps (I) for & -

1- F: Ori and B* With for > to =Seps ,+""T 1 And 0 = that's Ant, +To & (and), - ,and

Types of micro-test and results for blood-culture in and 2" *

: Bact For/Sp /For 3+ L - Test In / Test + / Test to ++ Test, and the++ for the/ is and The .

• And + / - on Culture/test 1 and to.++ + - and . .++
• And 1 2 3 . . =BA"D =4+1 ++"A++ / And++

Urine and its test (16" + C - To Test)C

From "" ""and is "C." for - From Test -15" .

From And can - To 2++ Bacs . .L++++, (From . and And+++ and for to * 3* (C + 13+

• ( .""0+++++, . C and / . From
• ( ."( . . .3

Urine test methods

From: B And *+ from the Test : In( - and "to "00 and L( From And /L (1".

• ( )/ - to =To to and Like . L/Like ++ And +++, = A.++B.C Like+++13."* .

Test & "0" +C ++ and+ .+++.. + + L

""To =*To 0 Test From + ++ "" and +++ = Test " and =

• :From + To++ - From Tests+ from And * the Test

Other specimens and test

• Sputum++ Lw- Like+++- For and *Like +A++- *1 /L * (A +and++And And , ++++",to /+++

• To = 0 /From A+to+++++ &++++ TEST*"TO AND FROM * "