Louis Pasteur Biography

Born: December 27, 1822 

Dôle, France 

Died: September 28, 1895 

Paris, France 

The French chemist and biologist Louis Pasteur is famous for his germ

theory and for the development of vaccines. He made major contributions to

chemistry, medicine, and industry. His discovery that diseases are spread

by microbes, which are living organisms—bacteria and viruses—that are

invisible to the eye, saved countless lives all over the world.

The tanner's son

Louis Pasteur was born on December 27, 1822, in the small town of Dôle,

France. His father was a tanner, a person who prepares animal skins to be

made into leather. The men in Pasteur's family had been tanners back to

1763, when his great-grandfather set up his own tanning business. Part of

the tanning process relies on microbes (tiny living organisms). In tanning,

microbes prepare the leather, allowing it to become soft and strong. Other

common products such as beer, wine, bread, and cheese depend on

microbes as well. Yet, at the time Pasteur was a child, few people knew that

microbes existed.

Pasteur's parents, Jean-Joseph Pasteur and Jeanne Roqui, taught their

children the values of family loyalty, respect for hard work, and financial

security. Jean-Joseph, who had received little education himself, wanted his

son to become a teacher at the local lycée (high school). Pasteur attended

the École Primaire (primary school), and in 1831 entered the Collège

d'Arboix. He was regarded as an average student, who showed some talent

as an artist. Nonetheless, the headmaster encouraged Pasteur to prepare

for the École Normale Supérieure, a very large training college for teachers

located in Paris. With this encouragement he applied himself to his studies.

He swept the school prizes during the 1837 and 1838 school year.

Pasteur went to Paris in 1838 at the age of sixteen. His goal was to study

and prepare for entering the École Normale. Yet, he returned to Arboix less

than a month later, overwhelmed with homesickness. In August of 1840 he

received his bachelor's degree in letters from the Collège Royal de

Besançon and was appointed to tutor at the Collège. In 1842, at age twenty,

he received his bachelor's degree in science. He then returned to Paris, and

was admitted to the École Normale in the autumn of 1843. His doctoral

thesis (a long essay resulting from original work in college) was on

crystallography, the study of forms and structures of crystals.

Investigations into crystals

In 1848, while professor of physics at the lycée of Tournon, the minister of

education granted Pasteur special permission for a leave of absence. During

this time, Pasteur studied how certain crystals affect light. He became

famous for this work. The French government made him a member of the

Legion of Honor and Britain's Royal Society presented him with the Copley

Medal.

Studies on fermentation

In 1852 Pasteur became chairman of the chemistry department at the

University of Strasbourg, in Strasbourg, France. Here he began studying

fermentation, a type of chemical process in which sugars are turned into

alcohol. His work resulted in tremendous improvements in the brewing of

beer and the making of wine. He also married at this time.

In 1854, at the age of thirty-one, Pasteur became professor of chemistry and

dean of sciences at the new University of Lille. Soon after his arrival at

Lille, a producer of vinegar from beet juice requested Pasteur's help. The

vinegar producer could not understand why his vinegar sometimes spoiled

and wanted to know how to prevent it.

Pasteur examined the beet juice under his microscope. He discovered it

contained alcohol and yeast. The yeast was causing the

Louis Pasteur. 

Reproduced by permission of the

Corbis Corporation

.

beet juice to ferment. Pasteur then demonstrated that controlled heating of the

beet juice destroyed the yeast, and prevented fermentation. This process, called

"pasteurization," was eventually applied to preserve a number of foods such as

cheese and milk. It also became the basis for dramatically reducing infection in the

operating room.

Studies on silkworms

In 1865 Pasteur was asked to help the ailing silk industry in France. An

epidemic among silkworms was ruining it. He took his microscope to the

south of France and set to work. Four months later he had isolated the

microorganism causing the disease. After three years of intensive work he

suggested methods for bringing it under control.

The theory of microbial disease

Pasteur's scientific triumphs coincided with personal and national tragedy.

In 1865 his father died. His two daughters were lost to typhoid fever in

1866. Overworked and grief-stricken, Pasteur suffered a cerebral

hemorrhage (a bleeding caused by a broken blood vessel in the brain) in

1868. Part of his left arm and leg were permanently paralyzed.

Nevertheless, he pressed on.

Pasteur saw the trains of wounded men coming home from the Franco-

German War (1870–71; war fought to prevent unification under German

rule). He urged the military medical corps to adopt his theory that disease

and infection were caused by microbes. The military medical corps

unwillingly agreed to sterilize their instruments and bandages, treating

them with heat to kill microbes. The results were spectacular, and in 1873

Pasteur was made a member of the French Academy of Medicine—a

remarkable accomplishment for a man without a formal medical degree.

Animal studies

A particularly devastating outbreak of anthrax, a killer plague that affected

cattle and sheep, broke out between 1876 and 1877. The anthrax bacillus (a

type of microbe shaped like a rod) had already been identified by Robert

Koch (1843–1910) in 1876. It had been argued that the bacillus did not

carry the disease, but that a toxic (poisonous) substance associated with it

did. Pasteur proved that the bacillus itself was the disease agent, or the

carrier of the disease.

In 1881 Pasteur had convincing evidence that gentle heating of anthrax

bacilli could so weaken its strength that it could be used to inoculate

animals. Inoculation is a process of introducing a weakened disease agent

into the body. The body gets a mild form of the disease, but becomes

immunized (strengthened against) the actual disease. Pasteur inoculated

one group of sheep with the vaccine and left another untreated. He then

injected both groups with the anthrax bacillus. The untreated sheep died

and the treated sheep lived.

Pasteur also used inoculation to conquer rabies. Rabies is a fatal disease of

animals, particularly dogs, which is transmitted to humans through a bite. It

took five years to isolate and culture the rabies virus microbe. Finally, in

1884, in collaboration with other investigators, Pasteur perfected a method

of growing the virus in the tissues of rabbits. The virus could be weakened

by exposing it to sterile air. A vaccine, or weakened form of the microbe,

could then be prepared for injection. The success of this method was

greeted with excitement all over the world.

The question soon arose as to how the rabies vaccine would act on humans.

In 1885 a nine-year-old boy, Joseph Meister, was brought to Pasteur. He

was suffering from fourteen bites from a rabid dog. With the agreement of

the child's physician, Pasteur began his treatment with the vaccine. The

injections continued over a twelve-day period, and the child recovered.

Honors from the world

In 1888 a grateful France founded the Pasteur Institute. It was destined to

become one of the most productive centers of biological study in the world.

In 1892 Pasteur's seventieth birthday was the occasion of a national

holiday. A huge celebration was held at the Sorbonne. Unfortunately

Pasteur was too weak to speak to the delegates who had gathered from all

over the world. His son read his speech, which ended: "Gentlemen, you

bring me the greatest happiness that can be experienced by a man whose

invincible belief is that science and peace will triumph over ignorance and

war.… Have faith that in the long run … the future will belong not to the

conquerors but to the saviors of mankind."

On September 28, 1895, Pasteur died in Paris. His last words were: "One

must work; one must work. I have done what I could." He was buried in a

crypt in the Pasteur Institute. Years later Joseph Meister, the boy Pasteur

saved from rabies, worked as a guard at his tomb.

http://www.notablebiographies.com/Ni-Pe/Pasteur-Louis.html

Louis Pasteur Biography(born Dec. 27, 1822, Dole, France—died Sept. 28, 1895, Saint-Cloud) French chemist and microbiologist who was

one of the most important founders of medical microbiology. Pasteur's contributions to science, technology, and

medicine are nearly without precedent. He pioneered the study of molecular asymmetry; discovered that

microorganisms cause fermentation and disease; originated the process of pasteurization; saved the beer, wine, and

silk industries in France; and developed vaccines against anthrax and rabies.

Pasteur's academic positions were numerous, and his scientific accomplishments earned him France's highest

decoration, the Legion of Honour, as well as election to the Académie des Sciences and many other distinctions.

Today there are some 30 institutes and an impressive number of hospitals, schools, buildings, and streets that bear

his name—a set of honours bestowed on few scientists.

Early education

Pasteur's father, Jean-Joseph Pasteur, was a tanner and a sergeant major decorated with the Legion of Honour

during the Napoleonic Wars. This fact probably instilled in the younger Pasteur the strong patriotism that later was a

defining element of his character. Louis Pasteur was an average student in his early years, but he was gifted in

drawing and painting. His pastels and portraits of his parents and friends, made when he was 15, were later kept in

the museum of the Pasteur Institute in Paris. After attending primary school in Arbois, where his family had moved,

and secondary school in nearby Besançon, he earned his bachelor of arts degree (1840) and bachelor of science

degree (1842) at the Royal College of Besançon.

Research career

In 1843 Pasteur was admitted to the École Normale Supérieure (a teachers' college in Paris), where he attended

lectures by French chemist Jean-Baptiste-André Dumas and became Dumas's teaching assistant. Pasteur obtained

his master of science degree in 1845 and then acquired an advanced degree in physical sciences. He later earned

his doctorate in sciences in 1847. Pasteur was appointed professor of physics at the Dijon Lycée (secondary school)

in 1848 but shortly thereafter accepted a position as professor of chemistry at the University of Strasbourg. On May

29, 1849, he married Marie Laurent, the daughter of the rector of the university. The couple had five children;

however, only two survived childhood.

Molecular asymmetry

Soon after graduating from the École Normale Supérieure, Pasteur became puzzled by the discovery of the German

chemist Eilhardt Mitscherlich, who had shown that tartrates and paratartrates behaved differently toward polarized

light: tartrates rotated the plane of polarized light, whereas paratartrates did not. This was unusual because the

compounds displayed identical chemical properties. Pasteur noted that the tartrate crystals exhibited asymmetric

forms that corresponded to their optical asymmetry. He made the surprising observation that crystalline paratartrate

consisted of a mixture of crystals in a right-handed configuration. However, when these crystals were separated

manually, he found that they exhibited right and left asymmetry. In other words, a balanced mixture of both right and

left crystals was optically inactive. Thus, Pasteur discovered the existence of molecular asymmetry, the foundation of

stereochemistry, as it was revealed by optical activity. Over the course of the next 10 years, Pasteur further

investigated the ability of organic substances to rotate the plane of polarized light. He also studied the relationship

that existed between crystal structure and molecular configuration. His studies convinced him that asymmetry was

one of the fundamental characteristics of living matter.

Germ theory of fermentation

In 1854 Pasteur was appointed professor of chemistry and dean of the science faculty at the University of Lille. While

working at Lille, he was asked to help solve problems related to alcohol production at a local distillery, and thus he

began a series of studies on alcoholic fermentation. His work on these problems led to his involvement in tackling a

variety of other practical and economic problems involving fermentation. His efforts proved successful in unraveling

most of these problems, and new theoretical implications emerged from his work. Pasteur investigated a broad range

of aspects of fermentation, including the production of compounds such as lactic acid that are responsible for the

souring of milk. He also studied butyric acid fermentation.

In 1857 Pasteur left Lille and returned to Paris, having been appointed manager and director of scientific studies at

the École Normale Supérieure. That same year he presented experimental evidence for the participation of living

organisms in all fermentative processes and showed that a specific organism was associated with each particular

fermentation. This evidence gave rise to the germ theory of fermentation.

Pasteur effect

The realization that specific organisms were involved in fermentation was further supported by Pasteur's studies of

butyric acid fermentation. These studies led Pasteur to the unexpected discovery that the fermentation process could

be arrested by passing air (that is, oxygen) through the fermenting fluid, a process known today as the Pasteur effect.

He concluded that this was due to the presence of a life-form that could function only in the absence of oxygen. This

led to his introduction of the terms aerobic and anaerobic to designate organisms that live in the presence or absence

of oxygen, respectively. He further proposed that the phenomena occurring during putrefaction were due to specific

germs that function under anaerobic conditions.

Pasteurization

Pasteur readily applied his knowledge of microbes and fermentation to the wine and beer industries in France,

effectively saving the industries from collapse due to problems associated with production and with contamination

that occurred during export. In 1863, at the request of the emperor of France, Napoleon III, Pasteur studied wine

contamination and showed it to be caused by microbes. To prevent contamination, Pasteur used a simple procedure:

he heated the wine to 50–60 °C (120–140 °F), a process now known universally as pasteurization. Today

pasteurization is seldom used for wines that benefit from aging, since it kills the organisms that contribute to the aging

process, but it is applied to many foods and beverages, particularly milk.

Following Pasteur's success with wine, he focused his studies on beer. By developing practical techniques for the

control of beer fermentation, he was able to provide a rational methodology for the brewing industry. He also devised

a method for the manufacturing of beer that prevented deterioration of the product during long periods of transport on

ships.

Spontaneous generation

Fermentation and putrefaction were often perceived as being spontaneous phenomena, a perception stemming from

the ancient belief that life could generate spontaneously. During the 18th century the debate was pursued by the

English naturalist and Roman Catholic divine John Turberville Needham and the French naturalist Georges-Louis

Leclerc, count de Buffon. While both supported the idea of spontaneous generation, Italian abbot and physiologist

Lazzaro Spallanzani maintained that life could never spontaneously generate from dead matter. In 1859, the year

English naturalist Charles Darwin published his On the Origin of Species, Pasteur decided to settle this dispute. He

was convinced that his germ theory could not be firmly substantiated as long as belief in spontaneous generation

persisted. Pasteur attacked the problem by using a simple experimental procedure. He showed that beef broth could

be sterilized by boiling it in a “swan-neck” flask, which has a long bending neck that traps dust particles and other

contaminants before they reach the body of the flask. However, if the broth was boiled and the neck of the flask was

broken off following boiling, the broth, being reexposed to air, eventually became cloudy, indicating microbial

contamination. These experiments proved that there was no spontaneous generation, since the boiled broth, if never

reexposed to air, remained sterile. This not only settled the philosophical problem of the origin of life at the time but

also placed on solid ground the new science of bacteriology, which relied on proven techniques of sterilization and

aseptic manipulation.

Work with silkworms

In 1862 Pasteur was elected to the Académie des Sciences, and the following year he was appointed professor of

geology, physics, and chemistry at the École des Beaux-Arts (School of Fine Arts). Shortly after this, Pasteur turned

his attention to France's silkworm crisis. In the middle of the 19th century, a mysterious disease had attacked French

silkworm nurseries. Silkworm eggs could no longer be produced in France, and they could not be imported from other

countries, since the disease had spread all over Europe and had invaded the Caucasus region of Eurasia, as well as

China and Japan. By 1865 the silkworm industry was almost completely ruined in France and, to a lesser extent, in

the rest of western Europe. Pasteur knew virtually nothing about silkworms, but, upon the request of his former

mentor Dumas, Pasteur took charge of the problem, accepting the challenge and seizing the opportunity to learn

more about infectious diseases. He soon became an expert silkworm breeder and identified the organisms that

caused the silkworm disease. After five years of research, he succeeded in saving the silk industry through a method

that enabled the preservation of healthy silkworm eggs and prevented their contamination by the disease-causing

organisms. Within a couple of years, this method was recognized throughout Europe; it is still used today in silk-

producing countries.

In 1867 Pasteur resigned from his administrative duties at the École Normale Supérieure and was appointed

professor of chemistry at the Sorbonne, a university in Paris. Although he was partially paralyzed (left hemiplegia) in

1868, he continued his research. For Pasteur, the study of silkworms constituted an initiation into the problem of

infectious diseases, and it was then that he first became aware of the complexities of infectious processes.

Accustomed as he was to the constancy and accuracy of laboratory procedures, he was puzzled by the variability of

animal life, which he had come to recognize through his observation that individual silkworms differed in their

response to disease depending on physiological and environmental factors. By investigating these problems, Pasteur

developed certain practices of epidemiology that served him well a few years later when he dealt with animal and

human diseases.

Vaccine development

In the early 1870s Pasteur had already acquired considerable renown and respect in France, and in 1873 he was

elected as an associate member of the Académie de Médecine. Nonetheless, the medical establishment was

reluctant to accept his germ theory of disease, primarily because it originated from a chemist. However, during the

next decade, Pasteur developed the overall principle of vaccination and contributed to the foundation of immunology.

Pasteur's first important discovery in the study of vaccination came in 1879 and concerned a disease called chicken

cholera. (Today the bacteria that cause the disease are classified in the genus Pasteurella.) Pasteur said, “Chance

only favours the prepared mind,” and it was chance observation through which he discovered that cultures of chicken

cholera lost their pathogenicity and retained “attenuated” pathogenic characteristics over the course of many

generations. He inoculated chickens with the attenuated form and demonstrated that the chickens were resistant to

the fully virulent strain. From then on, Pasteur directed all his experimental work toward the problem of immunization

and applied this principle to many other diseases.

Pasteur began investigating anthrax in 1879. At that time an anthrax epidemic in France and in some other parts of

Europe had killed a large number of sheep, and the disease was attacking humans as well. German physicianRobert

Koch announced the isolation of the anthrax bacillus, which Pasteur confirmed. Koch and Pasteur independently

provided definitive experimental evidence that the anthrax bacillus was indeed responsible for the infection. This

firmly established the germ theory of disease, which then emerged as the fundamental concept underlying medical

microbiology.

Pasteur wanted to apply the principle of vaccination to anthrax. He prepared attenuated cultures of the bacillus after

determining the conditions that led to the organism's loss of virulence. In the spring of 1881 he obtained financial

support, mostly from farmers, to conduct a large-scale public experiment of anthrax immunization. The experiment

took place in Pouilly-le-Fort, located on the southern outskirts of Paris. Pasteur immunized 70 farm animals, and the

experiment was a complete success. The vaccination procedure involved two inoculations at intervals of 12 days with

vaccines of different potencies. One vaccine, from a low-virulence culture, was given to half the sheep and was

followed by a second vaccine from a more virulent culture than the first. Two weeks after these initial inoculations,

both the vaccinated and control sheep were inoculated with a virulent strain of anthrax. Within a few days all the

control sheep died, whereas all the vaccinated animals survived. This convinced many people that Pasteur's work

was indeed valid.

Following the success of the anthrax vaccination experiment, Pasteur focused on the microbial origins of disease. His

investigations of animals infected by pathogenic microbes and his studies of the microbial mechanisms that cause

harmful physiological effects in animals made him a pioneer in the field of infectious pathology. It is often said that

English surgeon Edward Jenner discovered vaccination and that Pasteur invented vaccines. Indeed, almost 90 years

after Jenner initiated immunization against smallpox, Pasteur developed another vaccine—the first vaccine against

rabies. He had decided to attack the problem of rabies in 1882, the year of his acceptance into the Académie

Française. Rabies was a dreaded and horrible disease that had fascinated popular imagination for centuries because

of its mysterious origin and the fear it generated. Conquering it would be Pasteur's final endeavour.

Because the microbe that caused rabies (now known to be a virus) was too small to be seen under Pasteur's

microscope, experimentation with the disease demanded the development of entirely new methodologies. Pasteur

chose to conduct his experiments using rabbits and transmitted the infectious agent from animal to animal by

intracerebral inoculations until he obtained a stable preparation. In order to attenuate the invisible microbe, he

desiccated the spinal cords of infected animals until the preparation became almost nonvirulent. He realized later

that, instead of creating an attenuated form of the microbe, his treatment had actually killed many of the infectious

organisms. Thus, rather unknowingly, instead of attenuated live microorganisms, he had produced dead organisms

and opened the way for the development of a second class of vaccines, known as inactivated vaccines.

On July 6, 1885, Pasteur vaccinated Joseph Meister, a nine-year-old boy who had been bitten by a rabid dog. The

vaccine was so successful that it brought immediate glory and fame to Pasteur. Hundreds of other bite victims

throughout the world were subsequently saved by Pasteur's vaccine, and the era of preventive medicine had begun.

An international fund-raising campaign was launched to build the Pasteur Institute in Paris, the inauguration of which

took place on Nov. 14, 1888.

Implications of Pasteur's work

The theoretical implications and practical importance of Pasteur's work were immense. Pasteur once said, “There are

no such things as pure and applied science; there are only science and the application of science.” Thus, once he

established the theoretical basis of a given process, he investigated ways to further develop industrial applications.

(As a result, he deposited a number of patents.)

However, Pasteur did not have enough time to explore all the practical aspects of his numerous theories. One of the

most important theoretical implications of his later research, which emerged from his attenuation procedure for

vaccines, is the concept that virulence is not a constant attribute but a variable property—a property that can be lost

and later recovered. Virulence could be decreased, but Pasteur suspected that it could be increased as well. He

believed that increased virulence was what gave rise to epidemics. In Louis Pasteur, Free Lance of Science (1950),

American microbiologist René Dubos quoted Pasteur:

Thus, virulence appears in a new light which may be disturbing for the future of humanity unless nature, in its long

evolution, has already had the occasions to produce all possible contagious diseases—a very unlikely assumption.

What is a microorganism that is innocuous to man or to a given animal species? It is a living being which does not

possess the capacity to multiply in our body or in the body of the animal. But nothing proves that if the same

microorganism should chance to come into contact with some other of the thousands of animal species in the

Creation, it might invade it and render it sick. Its virulence might increase by repeated passages through that species,

and might eventually affect man or domesticated animals. Thus might be brought about a new virulence and new

contagions. I am much inclined to believe that such mechanisms would explain how smallpox, syphilis, plague, yellow

fever, etc. have come about in the course of time, and how certain great epidemics appear once in a while.

Pasteur was the first to recognize variability in virulence. Today this concept remains relevant to the study of

infectious disease, especially with regard to understanding the emergence of diseases such as bovine spongiform

encephalopathy (BSE), severe acute respiratory syndrome (SARS), and acquired immunodeficiency syndrome

(AIDS).

After Pasteur's 70th birthday, which was acknowledged by a large but solemn celebration at the Sorbonne that was

attended by several prominent scientists, including British surgeon Joseph Lister, Pasteur's health continued to

deteriorate. His paralysis worsened, and he died on Sept. 28, 1895. He was buried in the cathedral of Notre-Dame de

Paris, but his remains were transferred to a Neo-Byzantine crypt at the Pasteur Institute in 1896.

During Pasteur's career, he touched on many problems, but a simple description of his achievements does not do

justice to the intensity and fullness of his life. He never accepted defeat, and he always tried to convince skeptics,

though his impatience and intolerance were notorious when he believed that truth was on his side. Throughout his life

he was an immensely effective observer and readily integrated relevant observations into conceptual schemes.

- Agnes Ullmann

http://www.biography.com/articles/Louis-Pasteur-9434402?part=1

Louis Pasteur

Louis Pasteur (  / ̍ l uː i  p æ s ̍ t ɜ r / , French pronunciation [lwi pastœʁ]; December 27, 1822 – September 28, 1895) was a French chemist and microbiologist born in Dole. He is remembered for his remarkable breakthroughs in the causes and preventions of diseases. His discoveries reduced mortality from puerperal fever, and he created the firstvaccine for rabies and anthrax. His experiments supported the germ theory of disease. He was best known to the general public for inventing a method to stop milk and wine from causing sickness, a process that came to be called pasteurization. He is regarded as one of the three main founders of microbiology, together with Ferdinand Cohn andRobert Koch. Pasteur also made many discoveries in the field of chemistry, most notably the molecular basis for the asymmetry of certain crystals.[2] His body lies beneath the Institute Pasteur in Paris in a spectacular vault covered in depictions of his accomplishments in Byzantine mosaics.[3]

Early life and biography

The house in which Pasteur was born, Dole

Louis Pasteur was born on December 27, 1822, inDole in the Jura region of France, into the family of a poor

tanner. Louis grew up in the town of Arbois.[2] He gained degrees in Letters and in Mathematical Sciences

before entering the École Normale Supérieure, an elite college. After serving briefly asprofessor of physics at

Dijon Lycée in 1848, he became professor of chemistry at the University of Strasbourg,[2] where he met and

courted Marie Laurent, daughter of the university's rector, in 1849. They were married on May 29, 1849, and

together had five children, only two of whom survived to adulthood; the other three died of typhoid. These

personal tragedies inspired Pasteur to try to find cures for diseases such as typhoid.

Work on chirality and the polarization of light

Pasteur separated the left and rightcrystal shapes from each other to form two piles of crystals: in solution one form rotated light to

the left, the other to the right, while an equal mixture of the two forms canceled each other's effect and, does not rotate

thepolarization of light.

In Pasteur's early work as a chemist, he resolved a problem concerning the nature of tartaric acid(1848).[4][5][6]

[7] A solution of this compound derived from living things (specifically, wine lees) rotated the plane of

polarization of light passing through it. The mystery was that tartaric acid derived by chemical synthesis had no

such effect, even though its chemical reactions were identical and its elemental composition was the same.

[8] This was the first time anyone had demonstrated chiral molecules.

Pasteur's doctoral thesis on crystallography attracted the attention of W. T. Fuillet and he helped Pasteur

garner a position of professor of chemistry at the Faculté (College) of Strasbourg.[2]

In the year of 1854, Louis was named Dean of the new Faculty of Sciences in Lille. (It was on this occasion that

Pasteur uttered his oft-quoted remark: "...dans les champs de l'observation, le hasard ne favorise que les

esprits préparés" (In the field of observation, chance favors only the prepared mind.)[9]) In 1856, he was made

administrator and director of scientific studies of theÉcole Normale Supérieure.[2]

Germ theory of disease

Pasteur demonstrated that fermentation is caused by the growth of micro-organisms, and that the emergent

growth of bacteria in nutrient broths is not due to spontaneous generation[2] but rather to biogenesis (Omne

vivum ex ovo).

Bottle en col de cygne (Swan neck duct) used by Pasteur

Institut Pasteur de Lille

He exposed boiled broths to air in vessels that contained a filter to prevent all particles from passing through to

the growth medium, and even in vessels with no filter at all, with air being admitted via a long tortuous tube that

would not allow dust particles to pass. Nothing grew in the broths unless the flasks were broken open;

therefore, the living organisms that grew in such broths came from outside, as spores on dust, rather than

spontaneously generated within the broth. This was one of the last and most important experiments disproving

the theory of spontaneous generation. The experiment also supported germ theory.[2]

While Pasteur was not the first to propose germ theory (Girolamo Fracastoro, Agostino Bassi,Friedrich

Henle and others had suggested it earlier), he developed it and conducted experiments that clearly indicated its

correctness and managed to convince most of Europe it was true. Today he is often regarded as the father of

germ theory and bacteriology, together with Robert Koch.[10]

Pasteur's research also showed that the growth of micro-organisms was responsible for spoiling beverages,

such as beer, wine and milk. With this established, he invented a process in which liquids such as milk were

heated to kill most bacteria and moulds already present within them. He and Claude Bernard completed the

first test on April 20, 1862. This process was soon afterwards known as pasteurization.[10]

Beverage contamination led Pasteur to the idea that micro-organisms infecting animals and humans cause

disease. He proposed preventing the entry of micro-organisms into the human body, leading Joseph Lister to

develop antiseptic methods in surgery.

In 1865, two parasitic diseases called pébrine and flacherie were killing great numbers ofsilkworms at Alais

(now Alès). Pasteur worked several years proving it was a microbe attacking silkworm eggs which caused the

disease, and that eliminating this microbe within silkworm nurseries would eradicate the disease.[2][10]

Pasteur also discovered anaerobiosis, whereby some micro organisms can develop and live without air

or oxygen, called the Pasteur effect.

Immunology and vaccination

Pasteur's later work on diseases included work on chicken cholera. During this work, a culture of the

responsible bacteria had spoiled and failed to induce the disease in some chickens he was infecting with the

disease. Upon reusing these healthy chickens, Pasteur discovered that he could not infect them, even with

fresh bacteria; the weakened bacteria had caused the chickens to become immune to the disease, even

though they had caused only mild symptoms.[2][10]

His assistant Charles Chamberland (of French origin) had been instructed to inoculate the chickens after

Pasteur went on holiday. Chamberland failed to do this, but instead went on holiday himself. On his return, the

month-old cultures made the chickens unwell, but instead of the infection's being fatal, as it usually was, the

chickens recovered completely. Chamberland assumed an error had been made, and wanted to discard the

apparently faulty culture when Pasteur stopped him. Pasteur guessed the recovered animals now might be

immune to the disease, as were the animals at Eure-et-Loir that had recovered from anthrax.[11]

In the 1870s, he applied this immunization method to anthrax, which affected cattle, and aroused interest in

combating other diseases.

Louis Pasteur in his laboratory, painting by A. Edelfeldt in 1885

Pasteur publicly claimed he had made the anthrax vaccine by exposing the bacillus to oxygen. His laboratory

notebooks, now in the Bibliothèque Nationale in Paris, in fact show Pasteur used the method of rival Jean-

Joseph-Henri Toussaint, a Toulouse veterinary surgeon, to create the anthrax vaccine.[8][12] This method used

the oxidizing agent potassium dichromate. Pasteur's oxygen method did eventually produce a vaccine but only

after he had been awarded a patent on the production of an anthrax vaccine.

The notion of a weak form of a disease causing immunity to the virulent version was not new; this had been

known for a long time for smallpox. Inoculation with smallpox was known to result in far less scarring, and

greatly reduced mortality, in comparison with the naturally acquired disease.Edward Jenner had also

discovered vaccination, using cowpox to give cross-immunity to smallpox (in 1796), and by Pasteur's time this

had generally replaced the use of actual smallpox material in inoculation. The difference between smallpox

vaccination and anthrax or chicken choleravaccination was that the weakened form of the latter two disease

organisms had been generated artificially, and so a naturally weak form of the disease organism did not need

to be found.

This discovery revolutionized work in infectious diseases, and Pasteur gave these artificially weakened

diseases the generic name of vaccines, in honour of Jenner's discovery. Pasteur produced the first vaccine

for rabies by growing the virus in rabbits, and then weakening it by drying the affected nerve tissue.

The rabies vaccine was initially created by Emile Roux, a French doctor and a colleague of Pasteur who had

been working with a killed vaccine produced by desiccating the spinal cords of infected rabbits. The vaccine

had been tested only on eleven dogs before its first human trial.[2][8]

This vaccine was first used on 9-year old Joseph Meister, on July 6, 1885, after the boy was badly mauled by a

rabid dog.[8] This was done at some personal risk for Pasteur, since he was not a licensed physician and could

have faced prosecution for treating the boy. After consulting with colleagues, Pasteur decided to go ahead with

the treatment. Meister did not contract the disease. It is sometimes said that Pasteur saved the boy's life; but

this cannot be maintained with certainty, since the risk of contracting rabies after such an exposure is estimated

at around 15%.[13] Nonetheless, Pasteur was hailed as a hero and the legal matter was not pursued. The

treatment's success laid the foundations for the manufacture of many other vaccines. The first of the Pasteur

Institutes was also built on the basis of this achievement.[8]

Legal risk was not the only kind Pasteur undertook. In The Story of San Michele, Axel Munthe writes of the

rabies vaccine research:

“ Pasteur himself was absolutely fearless. Anxious to secure a sample of saliva straight from the jaws of a rabid dog, I once saw him with the glass tube held between his lips draw a few drops of the deadly saliva from the mouth of a rabid bull-dog, held on the table by two assistants, their hands protected by leather gloves. ”

Louis Pasteur portrait in his later years.

Because of his study in germs, Pasteur encouraged doctors to sanitize their hands and equipment before

surgery. Prior to this, few doctors or their assistants practiced the procedure of washing their hands and

equipment.

Allegations of deception

In 1995, the centennial of the death of Louis Pasteur, the New York Times ran an article titled "Pasteur's

Deception". After having thoroughly read Pasteur's lab notes, the science historianGerald L. Geison declared

that Pasteur had given a misleading account of the preparation of the anthrax vaccine used in the experiment

at Pouilly-le-Fort.[14] Max Perutz published a vigorous defense of Pasteur in the New York Review of Books.[15]

Faith and spirituality

Although his grandson, Louis Pasteur Vallery-Radot, wrote that Pasteur had only kept from his Catholic

background a spiritualism without religious practice,[16] Catholic observers often said that Louis Pasteur

remained throughout his whole life an ardent Christian, and his son-in-law, in perhaps the most complete

biography of Louis Pasteur, writes:

“ Absolute faith in God and in Eternity, and a conviction that the power for good given to us in this world will be continued beyond it, were feelings which pervaded his whole life; the virtues of the gospel had ever been present to him. Full of respect for the form of religion which had been that of his forefathers, he came simply to it and naturally for spiritual help in these last weeks of his life.[17] ”

Maurice Vallery-Radot, grandson of the brother of the son-in-law of Pasteur and outspoken Catholic, also holds

that Pasteur fundamentally remained Catholic.[18] According to both Pasteur Vallery-Radot and Maurice Vallery-

Radot, the well-known quotation attributed to Pasteur: "The more I know, the more nearly is my faith that of the

Breton peasant. Could I but know all I would have the faith of a Breton peasant's wife."[2] is apocryphal.[19]

Principal works

Pasteur's principal works are: "Etudes sur le Vin", (1866); "Etudes sur le Vinaigre" (1868); "Etudes sur la

Maladie des Vers à Soie" (2 vols., 1870); "Quelques Réflexions sur la Science en France" (1871); "Etudes sur

la Bière" (1876); "Les Microbes organisés, leur rôle dans la Fermentation, la Putréfaction et la Contagion"

(1878); "Discours de Réception de M.L. Pasteur à l'Académie Française" (1882); "Traitement de la Rage"

(1886).[2]

Honors and final days

Vulitsya Pastera or Pasteur Street inOdessa, Ukraine.

His death occurred in 1895, near Paris, from complications of a series of strokes that had started in 1868.[8] He

died while listening to the story of St Vincent de Paul, whom he admired and sought to emulate.[2] He was

buried in the Cathedral of Notre Dame, but his remains were reinterred in a crypt in the Institut Pasteur, Paris,

where he is remembered for his life-saving work.

Pasteur won the Leeuwenhoek medal, microbiology's highest Dutch honor in Arts and Sciences, in 1895. He

was a Grand Croix of the Legion of Honor–one of only 75 in all of France. Both Institute Pasteur and Université

Louis Pasteur were named after him.

In many localities worldwide, there are streets named in his honor. For example, in the USA: the Medical

school at Stanford University, Palo Alto and Irvine, California, Boston, Massachusetts and Polk, Florida,

adjacent to the University of Texas Health Science Center at San Antonio; Jonquière, Québec; San Salvador

de Jujuy and Buenos Aires (Argentina), Great Yarmouth in Norfolk, in the United Kingdom, Jericho and

Wulguru in Queensland, (Australia); Phnom Penh inCambodia; Ho Chi Minh City in Vietnam; Batna

in Algeria; Bandung in Indonesia, Tehran in Iran, adjacent to the Odessa State Medical University

in Odessa, Ukraine; Milan in Italy and Bucharest,Cluj-Napoca and Timişoara in Romania. A large university

hospital is named after him inKošice,Slovakia.

In his honor, there is a statue for him located on the campus of San Rafael High School in San Rafael,

California. Also there is a Pasteur institute in Ootakamund, a hill station in south India, which is involved in

vaccine trials and also rabies diagnosis.

Statements

In his triumphal lecture at the Sorbonne in 1864, Pasteur said "Never will the doctrine of spontaneous

generation recover from the mortal blow struck by this simple experiment" (referring to his swan-neck flask

experiment wherein he proved that fermenting micro-organisms would not form in a flask containing

fermentable juice until an entry path was created for them).

http://en.wikipedia.org/wiki/Louis_Pasteur

Louis Pasteur (1822 - 1895)Pasteur was a French chemist and biologist who proved the germ theory of disease and invented

the process of pasteurisation.

Louis Pasteur was born on 27 December 1822 in Dole in the Jura region of France. His father was

a tanner. In 1847, he earned a doctorate from the École Normale in Paris. After several years

research and teaching in Dijon and Strasbourg, in 1854, Pasteur was appointed professor of

chemistry at the University of Lille. Part of the remit of the faculty of sciences was to find

solutions to the practical problems of local industries, particularly the manufacture of alcoholic

drinks. He was able to demonstrate that organisms such as bacteria were responsible for souring

wine and beer (he later extended his studies to prove that milk was the same), and that the

bacteria could be removed by boiling and then cooling the liquid. This process is now called

pasteurisation.

Pasteur then undertook experiments to find where these bacteria came from, and was able to

prove that they were introduced from the environment. This was disputed by scientists who

believed they could spontaneously generate. In 1864, the French Academy of Sciences accepted

Pasteur's results. By 1865, Pasteur was director of scientific studies at the École Normale, where

he had studied. He was asked to help the silk industry in southern France, where there was an

epidemic amongst the silkworms. With no experience of the subject, Pasteur identified parasitic

infections as the cause and advocated that only disease-free eggs should be selected. The

industry was saved.

Pasteur's various investigations convinced him of the rightness of the germ theory of disease,

which holds that germs attack the body from outside. Many felt that such tiny organisms as

germs could not possibly kill larger ones such as humans. Pasteur now extended this theory to

explain the causes of many diseases - including anthrax, cholera, TB and smallpox - and their

prevention by vaccination. He is best known for his work on the development of vaccines for

rabies. In 1888, a special institute was founded in Paris for the treatment of diseases. It became

known as the Institut Pasteur. Pasteur was its director until his death on 28 September 1895. He

was a national hero and was given a state funeral.

http://www.bbc.co.uk/history/historic_figures/pasteur_louis.shtml

LOUIS PASTEUR (1822-95)

 

 

 

 

 

 

Louis Pasteur with tribute paid to him as a benefactor of humanity.

  The Welcome Institute, London.

 

WHO WAS LOUIS PASTEUR?

Louis Pasteur was a world renowned French chemist and biologist. He was born on December 27 1822 in the town of Dole in Eastern France. Pasteur's parents were peasants, his father was a tanner by trade. He spent the early days of his life in the small town of Arbois where he attended school and where it seems that Pasteur did not do very well, preferring instead to go fishing. His headmaster, however, spotted potential in Pasteur and encouraged him to go to Paris to study. So, aged fifteen Pasteur set off for Paris hoping to study for his entrance exams. Unfortunately, the young Pasteur was so homesick that his father had to travel to Paris to bring him home. He then continued to study locally at Besancon, until he decided to try again in Paris. This time he succeeded and went on to study at the Ecole Normale Superieure. Curiously, although the young Pasteur worked hard during his student days he was not considered to be exceptional in any way at chemistry.

In 1847 Pasteur was awarded his doctorate and then took up a post as assistant to one of his teachers. He spent several years teaching and carrying out research at Dijon and Strasbourg and in 1854 moved to the University of Lille where he became professor of

chemistry. Here he continued the work on fermentation he had already started at Strasbourg. By 1857 Pasteur had become world famous and took up a post at the Ecole Normale Superieure in Paris. In 1863 he became dean of the new science faculty at Lille University. While there, he started evening classes for workers. In 1867 a laboratory was established for his discovery of the rabies vaccine, using public funds. It became known as the Pasteur Institute and was headed by Pasteur until his death in 1895.

SO WHAT DID PASTEUR ACTUALLY DO?

 

Pasteur founded the science of microbiology and proved that most infectious diseases are caused by micro-organisms. This became known as the "germ theory" of disease. He was the inventor of the process of pasteurisation and also developed vaccines for several diseases including rabies. The discovery of the vaccine for rabies led to the founding of the Pasteur Institute in Paris in 1888.

SO HOW DID PASTEUR MAKE HIS DISCOVERIES?

When he was only twenty-six years old Pasteur solved a problem that had been puzzling the great chemists of the day. He found that when light was passed through tartaric acid - this was found in wine dregs, it produced a strange effect. Pasteur proved that this was because the acid is actually not one acid but a mixture of different acids. This find impressed the scientists of influence and established Pasteur's reputation.

While at the University of Strasbourg he became interested in fermentation and this interest continued when he moved to the University of Lille. The faculty had been established partly to serve as a means of applying science to the problems of the industries of the region, especially the production of alcoholic drinks. This work in fermentation enabled Pasteur to identify that the changes brought about when beer or wine ferments, milk turns sour or meat decays, occur when special micro-organisms are present.

As a result of these findings Pasteur was asked to help the local breweries where the beer had turned bad. The souring of wine and beer was a major economic problem in France. Pasteur looked at some droplets of bad beer through a microscope and observed that the beer contained small rod shaped bacteria, instead of round yeast cells. Although micro-organisms are essential in fermentation they must be the right ones. This was a major discovery. Pasteur made brewing a more scientific procedure and showed brewers how to culture the right organisms for good beer. He also demonstrated to the wine industry that if wine is gently heated to sixty degrees celsius for a short time, the growth of harmful bacteria is prevented and the wine does not go sour in bottles or barrels.

Pasteur then extended this to other problems such as the souring of milk. He proposed heating the milk to a high temperature and pressure before bottling. The process is now in widespread use and is called pasteurisation.

WHAT OTHER DISCOVERIES DID PASTEUR MAKE?

By 1857 Pasteur had become world famous and took up an appointment as director of scientific studies at the Ecole Normale in Paris. He was asked to help to investigate a serious disease that was ruining the silk industry in southern France. The disease known as pebrine attacked the silk worms. The signs of the disease were that the eggs did not hatch or the worms would die before making their silk cocoons. It had now reached epidemic proportions and even disease free worms brought in from Spain and Italy had been contaminated. By 1864 there were no uncontaminated eggs left, except for those brought in from Japan.

Pasteur observed through his microscope that the diseased caterpillars and eggs all contained tiny organisms. He identified these as disease producing organisms. He managed to obtain some healthy worms and he divided them into two lots. He fed one lot with mulberry leaves smeared with the remains of diseased worms and fed the others with mulberry leaves smeared with the remains of healthy worms. Pasteur was able to show that the worms fed on diseased smeared leaves got the disease, whereas those fed on

uncontaminated leaves remained disease free. He then worked with the silk industry to devise a simple way of keeping silk worms under healthy conditions and therefore disease free.

Not only had Pasteur rescued the French silk industry but he had established the connection between bacteria and disease. The connection had not been fully understood before.

This was a major discovery.

Pasteur's work on the link between bacteria and disease came to the attention of the famous Edinburgh surgeon Lord Lister. Lord Lister was concerned with the number of people who died after having operations in hospital. To combat infection, Lister introduced disinfectant sprays during operations, these prevented bacteria from entering a wound. He also introduced the use of dressings soaked in carbolic acid and strict hygiene rules to combat sepsis. The sterile methods introduced by Lister, drastically reduced the number of hospital deaths.

In France at that time many cattle suffered from anthrax, a serious disease from which many of them died. Pasteur made a careful study of anthrax and noticed that some cows developed the disease more severely than others. So he decided to inject two cows with a strong dose of the anthrax bacteria, fully expecting them to die. To Pasteur's amazement neither of them developed the disease. Later, he found that both animals had already suffered from anthrax. Could they be immune to it? Could they be protected in some other way? Pasteur believed that if it were possible to give an animal a mild attack, this might be sufficient to prevent it from getting the disease later on.

Eventually, after many experiments Pasteur succeeded in producing a weakened and harmless culture of anthrax bacteria. He inoculated cattle and sheep with this giving them a mild form from which they recovered. When these animals were put with others who had a severe form they remained unaffected. They were immune.

Pasteur worked throughout the rest of his life on the various causes of diseases and how these could be prevented by vaccination.

PASTEUR AND RABIES

Pasteur is particularly renowned for his work on the vaccine for rabies, a highly contagious infection which attacks the central nervous system. It enters the body through the bite of an infected animal or through infected saliva entering an existing wound. After experimenting with the saliva of animals suffering from the disease, Pasteur concluded that the disease rests in the central nervous system of the body. When an extract from the spinal column of an rabid dog was injected into healthy animals symptoms of rabies were produced. By studying the tissues of infected animals- rabbits, Pasteur was able to produce an attenuated form of the virus. This could be used for inoculation.

On July 6 1885, Pasteur tested his pioneering rabies vaccine on man for the first time. He saved the life of a young man called Joseph Meister who had been bitten by a rabid dog. Pasteur was urged to treat him with his new method. The treatment lasted 10 days and at the end he recovered and remained healthy. Since then thousands have been saved by this treatment.

On March 1886, Pasteur was invited to present his results to the Academy of Sciences and in 1888 went on to found the Pasteur Institute in Paris. This was a pioneering clinic for the study of infectious diseases, the treatment of rabies and a centre for teaching. Pasteur directed the Institute personally until he died. The Pasteur Institute is still one of the most important centres in the world.

Pasteur became a national hero and was honoured in many ways. He died at Saint-Cloud on 28 September 1895 and was given a state funeral at the Cathedral of Notre Dame and his body placed in a permanent crypt at the Pasteur Institute.

Modifications of the Pasteur method are still used in rabies therapy today. The traditional vaccine contains inactivated rabies virus grown in duck eggs. A newer vaccine which contains virus prepared from human cells grown in the laboratory is safer and requires a shorter course of injections.

 http://www.zephyrus.co.uk/louispasteur.html