This Week in Science History: 13-9-10

By Peter Dearden 13/09/2010 1


This week in Science History

Megan Leask, PhD student, Laboratory for Evolution and Development

This week in science history we celebrate the ’little things’ in life.

Hans Christian Joachim Gram Born 13th September 1853

A Gram stain of mixed Staphylococcus aureus (Gram positive cocci, purple) and Escherichia coli (Gram negative bacilli, pink). (Image: Y Tambe, Wikimedia Commons)
A Gram stain of mixed Staphylococcus aureus (Gram positive cocci, purple) and Escherichia coli (Gram negative bacilli, pink). (Image: Y Tambe, Wikimedia Commons)

Danish pharmacologist and pathologist Hans Christian Joachim Graminvented the Gram stain, the best known and most widely used bacteriological staining method that is almost always the first test performed for the identification of bacteria. Gram staining differentiates bacterial species into two large groups (Gram-positive and Gram-negative) based on the chemical and physical properties of their cell walls.

The term ’bacteriophage’ is coined in a note from Dr. Félix d’Hérelle to the French Academy of Sciences dated the 15th September 1917

An electron micrograph of bacteriophages attached to a bacterial cell. (Image: Graham Colm, Wikimedia Commons)
An electron micrograph of bacteriophages attached to a bacterial cell. (Image: Graham Colm, Wikimedia Commons)

French-canadian microbiologist Félix d’Hérelle, working at the Pasteur Institute in Paris discovered “an invisible, antagonistic microbe of the dysentery bacillus”. For d’Hérelle, there was no question as to the nature of his discovery: “In a flash I had understood: what caused my clear spots was in fact an invisible microbe … a virus parasitic on bacteria.’ Bacteriophage cause spots of lysis on agar plates that have a layer of bacteria on them. Basically bacteriophage infect bacteria and can either lay dormant in the bacteria’s genome or lyse the cell after making copies of itself. D’Hérelle called the virus a bacteriophage or bacteria-eater (from the Greek phagein meaning to eat). Bacteriophages have been used for over 60 years as an alternative to antibiotics in the former Soviet Union and Eastern Europe and are seen as a possible therapy against multi drug resistant strains of many bacteria.

Sir Ronald Ross died 16th September 1932 (born 13 May 1857)

Plasmodium falciparum ring-forms and gametocytes in human blood. (Image: Wikimedia Commons)
Plasmodium falciparum ring-forms and gametocytes in human blood. (Image: Wikimedia Commons)

Sir Ronald Ross was a British bacteriologist who received the Nobel Prize for Physiology or Medicine in 1902 for his work on malaria. His discovery of the malarial parasite (a unicellular organism from the genus Plasmodium) in the gastrointestinal tract and saliva of the Anopheles mosquito led to the realization that malaria was transmitted from person to person through the bite of the mosquito. Malaria is widespread in tropical regions and each year kills between one and three million people. When a mosquito bites an infected person, a small amount of blood is taken, which contains malaria parasites. These develop within the mosquito, and about one week later, when the mosquito takes its next blood meal, the parasites are injected with the mosquito’s saliva into the person being bitten. In the liver of the infected person, the malaria parasites start to multiply within red blood cells, causing symptoms that include fever, and headache. In severe cases the disease worsens leading to hallucinations, coma, and death. Malaria transmission can be reduced by preventing mosquito bites by distribution of inexpensive mosquito nets and insect repellents, or by mosquito-control measures such as spraying insecticides inside houses and draining standing water where mosquitoes lay their eggs.

Antonie van Leeuwenhoek discovers unicellular organisms, 17th September, 1683

In 1683, the Dutch scientist commonly known as “the Father of Microbiology“, and considered to be the first microbiologist wrote to the Royal Society reporting his discovery of microscopic living ’animalcules’ (unicellular organisms). Using his handcrafted microscopes he made observations from the plaque between his own teeth “in the said matter there were many very little living animalcules.” He was also the first to record microscopic observations of muscle fibers, bacteria, spermatozoa and blood flow in capillaries.


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