UNIT 1: INTRO TO MICROBIOLOGY

"Thou shalt not be afraid for the terror by night, nor for the arrow that flieth by day,

nor for the pestilence that walketh in darkness....psalm 91

Microbiology

• Microbiology: study of microscopic forms of life.

• Microorganism: minute living things that individually are toosmall to be seen with the naked eye.

BENIFICIAL ACTIVITIES OF MICROORGANISMS:

1. forms the basis of food chain in oceans, lakes and rivers.

2. Decomposition of sewage and solid and industrial waste.

3. Used in synthesis of certain chemical products such as alcohol,acetone and drugs.

4. Makes vitamins in digestive tract of humans.

microscope

5. Used in making foods such a pickles cheeses, yogurt, alcoholicbeverages, ect.

6. Produce theraputic substances such as growth hormone, insulin,ect..

7. Incorporate nitrogen gas from air into compounds in soil.

HARMUL EFFECTS:

1. Cause disease.

2. Food spoilage

HISTORY:

• 14th Century plague so severe Pope consecrated the river Rhone atAvignon so corpses flung in river might be considered to have hadChristian burial.

• 1590: Janseen invented microscope

• 1665: Robert Hooke published book called Micrographie which contained info on chemicals, a description of microscope, and microscopic illustrations. Showed that contained cork compartments called cells.

• Schleiden and Schwann: Cell Theory : all living things composed of cells. ( based on Hooke's observations)

• 1675: Van Leeuwenhook ( father microbiology) made microscopes ( magnification 270X) and proficient with them.

• Made detailed descriptions, of protozoa, bacteria, yeast and algae.

• Observed microorganisms in cloudy water and called them animalcules (1723 age 92) after his death microbiology had a period of dormancy for 150 yrs

SPONTANEOUS GENERATION:

• Belief that some forms of life could arise spontaneously from non-life.

• Example: .1. Flies from manure 2. maggots form rotting meat3. rats from dirty towels4. frogs and snakes from mud bottom of pond5. sperm injected into cucumber...people

BIOGENESIS: living cells arise only from preexisting living cells.

• 1668 Redi: Tried to disprove spontaneous generation through experimentation using Scientific method.

• 1748: Needham: reported that bacteria arose spontaneously where no living forms existed.

• 17th century bubonic plague caused collapse of eastern Roman Empire ( 24 million deaths in 6 yrs)

• 1760 Spallanzani: Questions Spontaneous generation

• 1774 Joseph Priestly discovered Oxygen and Lavoisier showed importance of oxygen to life.

• 1789 Edward Jenner: develops inoculation for small pox ( inoculation: variolation latin for small pox).

• Before Jenner, Doctors would "Sow pox" to help patients acquire immunity.

• llth century Chinese doctors would make a powder from dried scabs of victims with mild case of small pox and then have healthy patient inhale powder through straw... other would rub scab powder into would…

• Problem was a weak acting germ in one person might be virulent in another.

• 1831: 9 yr old boy sees a man mangled by rabid wolf, goes home and asks what makes wolf go mad...father answered the devil got into him....the boy was Louis Pastuer...the quest begin

• 1858 Virchow: challenged spontaneous generation , added to cell theory: all organisms made of cells, cell simplest unit of life.

• 1861: Pasteur : proved Biogenesis with swan neck flaskexperiment.

GOLDEN AGE OF MICROBIOLOGY 1857-1914:

• 1857 Pasteur: discovered yeast caused fermentation of wine.

• Pasteruization Pasteur found that bacteria could be destroyed by heating the juice to a temperature o f62.8 F for 30 min sets the foundation for the germ theory

• GERM THOER Y OF DISEASE: infectious diseases are caused by microorganisms.

• MI AM A: altered chemical quality of atmosphere. Most scientist thought miasma caused disease.

• Mid 1600 Kircher observed microscopic worms in plague victims.

• 1847 Semmelwies: performed autopsies on woman who died ofchildbed fever (1 in 4 giving birth in hospital died of this uterineinfection as opposed to less than 1 % of those who gave birth at home)... conclusion: doctors believed the bloodier, crustier the lab coat..the better the doctor...hence doctors performedautopsies on dead women the went to labor ward to deliver thebabies, transferring the infection.

• If wash hands in chlorine water it would cut down on infection in maternity patients ....

• sad note Semmelwies died of childbed fever 1865.

• 1860 Joseph Lister: Used carbolic acid treat surgical wounds(before this 8 out of 10 surgery patients died of infection termed surgical sepsis)( surgeon were used to the nauseating stench of putrefying flesh in the post surgical ward) ( body cavity surgeryimpossible except in direst circumstances such as burst appendix or ruptured spleen)

• 1876 Robert Koch: proved germ theory of diseases ( Koch's Postulates)

• Koch also developed the solid medium: agar ( with help from lab assistant Fanny Eishemius by using Japaneseseaweed (agar-agar) as solidifying agent....

• she used it in canning food. • He perfected dyes in staining

microorganisms on glass and id bacillus causing agent for tuberculosis

KOCH'S POSTULA TE:

1. microorganism must be identified in infected organism. Must befound in every case of disease that is checked.

2. Microorganisms must be isolated from infected organism and grown in pure culture (single organism, inject into animal must come down with disease and must be recovered)

3. Upon inoculation of microorganism into a healthy organism, the microorganism from the pure culture must cause the disease.

4. The same microorganism must be recovered from the experimentally in lab

• 1798 Edward Jenner: first vaccination. Used cowpox virus to infect a healthy individual against small pox.

• The cowpox virus was called vaccinia thus the name vaccination

1799 George Washington• suffering from sore throat and respiratory infection

received state of the art medical treatment:

• given poisonous compound of mercury by mouth and injections,

• forced to ingest poisonous white salt that made him perspire and vomit.

• Caustic poltice were applied to body that made skin blister,

• was forced to inhale vinegar vapor that burned lungs and raised blisters inthroat.

• More that 5 pints of blood drained from his body....All to no avail...he died shortly.

• "There are some remedies worse than the disease" Publilis Syrus

Pasteur

• 1880 Pasteur; found principle behind how vaccinationswork.

• Found that bacteria causing cholera lost the abilityto cause disease.

• This was 1st vaccine made form germ thatcaused disease rather than from a different but closely related germ.

• 1881 Pasteur's Farm experiment with Anthrax ( 24 sheep, 1 goat, 6 cows vaccinated) equal number Not vaccinated both groups exposed to Anthrax, vaccinated animals survive, unvacinated all died)

• 1884 Pasteur develops rabies vaccine. • Before this vaccination 100% mortality. • Symptoms included fever, depression,

restlessness, uncontrollable excitement, throat muscle convulsions, salivation, great thirst, but smallest amount of water caused more convulsions

• hence name hydrophobia.• The virus cells were cultivated in the brains

ofhealthy dogs by drilling hole into dog brain and injecting with rabies virus.

• Diptheria (developed by Pasteur assistant) and tetanus vaccines soon followed using modifiedforms of their toxins.

• 1885 Joseph Meister (boy) bitten by rabid dog and gets vaccine (60 hr after bite) 14 doses in 10 days and survives.Later in life Meister was gate keeper of Pasteur Institute in Paris which houses crypt of Pasteur.

• 1940 ,55 yrs after Pasteur saved his life Nazi invaders demand Pasteur's crypt be opened rather than doing so he commits suicide.

SYNTHEITIC DRUGS

• : Chemotherapeutic agents prepared from chemicals in lab.

ANTIBIOTICS : chemicals produced naturally from bacteria or fungi.

• 1910 Erhlich: Develops first chemotherapeutic substancediscovered and evaluated and went on the market.

• Was an arsenic compound called Salvarsan which was used to treatsyphilis.

• 1928 Fleming: Agar plates inoculated with Staplococcus aureuswere contaminated with Penicillium notataum

• Named antibiotic penicillin.

• It was not isolated and put on the market until the1940s

• 1st tested in 1941 on a 43 yr old police constable who had been scratched near mouth by rose thorn resulting in staphylococcus and Streptococcus infections: multiple abscess of head and face, lungs infected 1 eye removed, great pain, only hope was a quick merciful death.

• Within one day of penicillin injection fever gone, however penicillin lasted only a few days thus doctors began filtering urine and collecting the penicillin, the man continued to improve until penicillin ran out, he then relapsed and died.

• 1929 Rene Dubos (father of antibiotics) develops first antibiotic to treat cranberry bog bacillus (CBB) but soon replaced by Johannes Domask's Prontosil due to less side effects.

• 1944 Albert Schatz: working for Selman Waksman develops first successful antibiotic to work against Tuberculosis...

• Waksman received Nobel prize for work not Schatz.... THE DRUG WAS STREPTOMYCIN.

THE 3 BIG WONDER DRUGS:

• 1. STREPTOMYCIN,

• 2. PRONTOSIL

• 3. PENICILLIN

• 1954 Jonas Salks' Polio vaccine .

Back to the Future

• The war on disease was over! • Antimicrobial drugs had won. • Prontosil, penicillin, and streptomycin were

followed by more powerful drugs with greater ability to wipe out pathogens.

• Laurie Garrett, in her encyclopedic work The Coming Plague, says: "By 1965 more than 25,000 different antibiotic products had been developed; physicians and scientists felt that bacterial diseases, and the microbes responsible, were no longer of great concern or of .research interest."

• Twenty-nine years later Rachel Novak, in an article in Science, would write, "Childbirth is a gamble with death. Dental surgery potentially disabling.

• Even a facial boil can end in a trip to the morgue.• " Alexander Tomasz, microbiologist at Rockefeller

University, recently confessed that we are on the verge of a medical nightmare that would turn back the clock to the days before antibiotics, when a paper cut or a skinned knee could lead to fatal infection.

• In U.S. hospitals, deaths from sepsis have increased sevenfold in the last fifteen years.

• Deaths from infectious disease are up 58 percent since 1980. Yet there are more antibiotics on the market today than there ever have been.

• Why have infections, once again, become untreatable?

Resistance

The answer in a word is resistance. Microbes are finding ways to counteract or

neutralize the effects of antibiotics, rendering them useless.

Despite the more-than-160 dif ferent antibiotics, they are variations of only fifteen major compounds and five modes of action.

The germs have found ways to foil these modes of action. They are the ultimate survivors.

.

Take penicillin for example It works by inactivating an enzyme that bacteria

need to make their cell wall. Without cell walls, bacteria cannot multiply and

cause infection. They have developed resistance to penicillin by

breaking it down before it can inactivate the cell-wall-making enzyme or by making a new enzyme that the penicillin cannot recognize. It took bacteria two years to develop penicillin resistance.

The miracle drug came into wide use in 1944, and the first resistant pathogens were reported in 1946.

By the late 1950s penicillin resistance was widespread.

• Microbes have found ways of besting the other antibiotics as well.

• Every germ has drug-resistant versions. • The terrifying part is that some of them have

developed resistance to every known antibiotic. They are untreatable!

• Presently these untreatables are restricted to a group of bacteria called enterococcus.

• It is not a very common group and does its infecting opportunistically, primarily in hospitals among the sick and elderly—people with compro mised immune systems.

• It causes urinary tract and wound infections and occasionally blood poisoning and menin gitis, where it is quickly fatal.