An Interview with Professor Manuel Varela: Who Named the Staphylococcus?

Nov 21, 2018 by

Michael F. Shaughnessy –

1) Professor Varela – two words that seem to permeate the microbiological literature are Staphylococcus aureus – the name of a bacterium. Who named it and when?  Who discovered it?

Indeed,in modern times certain strains of the bacterial species called Staphylococcu saureus are deemed serious infectious pathogens, causing a significant number of severe clinical ailments, some of which may be lethal. In fact, some strains are even considered to be super bugs, agents of infectious disease which are terribly difficult to treat medically. These Staphylococcus aureus super bugs contain an assortment of virulence factors, which can cause acute host cell and tissue damage. Moreover, many of these bacteria have multiple antimicrobial resistance mechanisms, which help the superbugs evade medical treatment. One notorious type in particular, called methicillin-resistant Staphylococcu saureus (MRSA), is at the forefront of the major bacterial pathogens, causing enormously frightening numbers of morbidity and mortality, on a yearly basis.

The first scientific investigator to name the microbe as Staphylococcus was Sir Dr. Alexander Ogston.  In 1881, he coined the term Staphylococcus from Greek to denote that the bacteria appeared like a cluster of grapes (staphyle) and had roundish cellular shapes that were reminiscent of berries (kokkos).  Indeed,when these bacteria are subjected to the Gram staining technique and then examined visually using light microscopy, the bacteria appear to look blueish-purple in color, clustered together exactly like a bunch of spherically shaped grapes. Sir Ogston had isolated his Staphylococcus bacteria in 1880 from the pus material of a clinical patient who had had a post-operative infection in his leg, an abscess of his knee. 

Inhis written description of these bacteria, Dr. Ogston had first called the pus-derived microbes as micrococcus.  He further recorded that he found two types of these micrococci.  The first micrococcus of which he called the Staphylococcus, and the second, which appeared like chains of the cocci, as if they were roundish pearls on a string. He conceded that these latter bacteria must the of the Streptococcus type, a name he had already known about, but admitted to having forgotten whohad named them as such. Apparently, Dr. Theodor Billroth had previously coined the Streptococcus terminology, in 1874.

Interestingly,the first investigator to record the results of a close laboratory examination of the Staphylococcus bacteria was Dr. Robert Koch himself.  In 1878, prior to the work of Dr. Ogston,without naming them, Dr. Koch had observed the bacteria from human-derived pus material, under the microscope. Dr. Koch had recorded that the bacteria seemed to cluster together as coccus shaped microbes. 

2) Is there a difference between Staphylococcus and Staphylococcus aureus?

The term Staphylococcus refers to the genus name of the bacterium, while the termaureus signifies the specific epithet, and together, the terms Staphylococcu saureus refer to the species name of the microbe.  In 1884, Dr. Friedrich Rosenbach had made the observation that colonies of Ogston’s bacteria were starkly golden in color when plated onto agar-based media in Petri dishes. Thus, Dr. Rosenbach added the specific epithet term aureus, which was derived the Latin term aurum, meaning gold, to complete the species name Staphylococcus aureus of Dr.Ogston’s pus-associated bacterial microbe.

Interestingly, Dr. Rosenbach noticed that an additional variant of the Staphylococcus genus appearedas colonies of white bacteria on agar media, and these variants he named Staphylococcus albus, derived from the Latin term denoting the white color.Because these Staphylococcus albus bacteria were later discovered to reside in healthy amounts on the skin of human beings, the species name was changed to Staphylococcus epidermidis. These latter bacteria are common members of the human skin microbiome.

3) Apparently, Ogston also introduced carbolic spray to Aberdeen. What exactly is carbolic spray and why is it important?

Carbolic acid is a phenol-containing chemical used early on in surgical medicine as anantiseptic. The phenols and their related phenolic compounds were first used by the great Prof. Joseph Lister, a surgeon who advocated its use as a surgical incision dressing and as a chemical spray to be applied in the surgical operating theatres, starting in 1867. Dr. Ogston adopted the new practice and introduced budding student surgeons to its use at the famous Aberdeen Royal Infirmary, where Dr. Ogston was housed.

These phenolic compounds, carbolic acid being an important member, will function to kill bacteria by two distinctive mechanisms. First, the carbolic acid degrades the membrane structures of both human and bacterial cells.  The important result is that microbes cannot maintain their cellular structures, losing valuable cytoplasmic contents to the outside world.  Microbes cannot live if their membranes are disrupted, and the phenols potently disrupt them. Second,carbolic acid unravels the polypeptide strings of proteins, thereby denaturing them and causing the unraveled proteins to lose their functions, thus,inhibiting the growth of bacteria or killing them outright.

Another reason that carbolic acid is important is that it has traditionally been the standard by which all subsequent antimicrobials are compared. The term phenol coefficient is used during these comparisons of antimicrobial activities between phenol and other compounds.

Since the carbolic acid agent and other phenolic compounds are disruptors of biological membranes, this group of chemicals can be toxic. Thus, these agents cannot be taken internally, and even if applied externally, say to surgical wounds, the external tissue can still be chemically burned, damaging the tissue. Another problem is that the phenolic compounds have a rather unpleasant pungent odor. This latter characteristic of the phenols often caused surgeons who were contemporaries of Drs. Lister and Ogston to be reluctant towards the medical application of carbolic acid post-operatively.

4) Many scientists have worked together- and Ogston reportedly collaborated with Joseph Lister- who inspired the name Listerine! What do we know about this collaboration?

In1869, it is reported that the two prominent surgeons met face-to-face. Dr.Ogston travelled to Edinburgh, where Dr. Lister was working, in order to pay him a visit. It is also recorded that Dr. Lister was unaware of who his new visitor was, as Dr. Ogston arrived  at his doorstep without a prior announcement or without a letter of introduction.Dr. Ogston wrote in his memoirs that Dr. Lister was both courteous and gracious to his visitor.

Carbolic acid is a chemical agent that was first championed by Dr. Lister, who used the agent to dress surgical wounds by soaking gauze-like material and using it to cover the wounds, making the chemical an effective surgical antiseptic. Dr.Ogston was one of the first physician-surgeons to invoke the carbolic acid technique during his surgical operations. He was noted to have sprayed a solution of the carbolic acid within the operating theatre prior to performing surgery. The carbolic acid is a member of the phenolic-based group of chemicals, which have potent antimicrobial action, especially with the bacteria. The result was that the technique helped to reduce the frequencies of post-operative infections in surgical patients. It is especially fortuitous,considering we now know that it is clinical personnel, such as the surgeons themselves, who may have transmitted many of these post-op infections. 

5) Apparently, Ogston was somewhat adamant that his medical students follow his procedures,and they apparently wrote a song, which appears below:

“The spray, the spray, the antiseptic spray
A.O. would shower it morning, night and day
For every sort of scratch
Where others would attach
A sticking plaster patch
He gave the spray.”

What exactly are his students talking about here- Obviously A.O, is Ogston….

Indeed,your insight about the identity of A.O. is spot on. After his visit with the famous Dr. Lister and learning about the technique of Listerism, Dr. Ogston had then travelled to Glasgow to observe the post-operative treatment of a surgical incision performed on a patient’s leg, using Lister antisepsis method, a classic example of applied Listerism. Dr. Ogston was reported to have been favorably impressed with the remarkably healed surgical incision on the patient’s knee joint. The work of Dr. Lister was an inspiration to Dr. Ogston.

Upon returning home to his infirmary, Dr. Ogston instructed the current medical students and surgeons-in-training on how to apply the Listerism approach,complete with the carbolic sprays and the antiseptic surgical dressings, with their periodic changings on a regular basis. As a tribute to Dr. Ogston, his grateful students wrote this musical tribute to him. The lyrics contrast the less-than-effective previous methods by others, amounting to a worthless“sticking plaster patch.” The previous methods of surgery without antisepsis was fraught with deadly post-operative infections. The antiseptic method of Lister, however, as effectively utilized by Dr. Ogston during surgery, vastly improved the outlook of surgical patients and of the overall practice of medicine. 

6) We have to mention that even at the age of 70 he was helping his fellowman on the battlefields of World War I ostensibly as a medic- in cases of trauma. What do we know about his time on the front?

Prior to his service during World War I, Dr. Ogston had served earlier in the Egyptian War, in 1884.  He also served military surgical duty during the Boer War, between 1899 and 1902. During both of these campaigns, Dr. Ogston was a military surgeon at the war front. His service was also associated with helping to establish, in 1898, the Royal Army Medical Corps.  Being younger than many of his colleagues, he unabashedly introduced the technique of Lister while surgically treating war wounds.

It is recorded that during his duty in the Boer War, Dr. Ogston endured the typhoid fever, nearly dying from the illness after being admitted to the hospital at Bloemfontein.  In a memoir of the experience, titled “Reminiscence of Three Campaigns,” Dr .Ogston relayed the story that during his feverish delirium that had been brought about by the typhoid fever, he had an out-of-body experience, and he claimed to have been able to clearly see through the walls of the hospital from his room without physically leaving his hospital bed! In fact, during his Typhoid fever stupor,he claimed to have witnessed several specific incidents through the wall of his room, such as the death of another patient in an adjacent room—he described how the hospital personnel covered the corpse and removed the shoeless body from the room. In his memoir, Dr. Ogston claimed that the next morning when he relayed these incidents to the sisters attending to him, they had confirmed his observations.

Apparently,Dr. Ogston’s service in the First World War, known also as the Great War, was as a 70-year old civilian, rather than as a military field surgeon.  During the Great War, in 1915, he directed the British Belgrade Auxiliary Hospital, and in 1916, he served in the 1stBritish Ambulance Unit after moving to Italy. His involvement during the Great War also involved membership to several medically based committees, such as in a regional Red Cross branch committee.His bacteriological work also helped to identify infectious microbes in war wounds.

7) Staphylococcus seems to be linked to inflammation- what do we know about this link?

Indeed,species of the Staphylococcus bacteria are serious causative agents of inflammation in a variety of host tissues. The Staphylococcus aureus are particularly worrisome. As long as these pathogens can gain access to the host tissue,the list of inflammatory-based illnesses is seemingly endless. Virtually all types of host tissue can be susceptible, as long as transmission to the tissue of an individual is possible.

Oneof the most common tissues that can suffer from the pathogenic Staphylococcu Saureus is the skin. One notorious inflammatory skin disease caused by Staphylococcus aureus is called impetigo, producing skin lesions characterized by flat and red patches of vesicles, filled with pus. 

Another inflammatory illness of the skin and produced by the Staphylococcus aureus is the condition called folliculitis, involving infection of hair follicles. The lesion produced by the pathogen is known as a furuncle. If more than one furuncular lesions are involved, the condition is referred to as a carbuncle.If the eyelashes are affected the condition is called a sty.

If the Staphylococcus aureus bacteria manage to gain access to the membranous lining called the endocardium that surrounds the heart, then the patient will suffer from the inflammatory process called endocarditis. With approximately half of the patients who experience this condition being killed, it can be a particularly precarious aliment for patients of the endocarditis.

Another type of inflammation occurs if the Staphylococcus aureus pathogens invade bones as a result of a physical trauma or transmission through the patient’s blood circulation.  This ailment caused is called osteomyelitis.  This condition encompasses an inflammation of the internal bone marrow of the patient.

More recently, it was discovered that inflammation caused by Staphylococcus Aureus may be involved somehow with diabetes. A connection in some way exists between obesity, diabetes, and Staphylococcus aureus infections. This bacterial pathogen produces a so-called super antigen, which in turn stimulates a variety of physiological factors, leading to elevated insulin resistance and an impairment of glucose tolerance.

8) Like many other great scientists, his initial work was met with skepticism. What happened and what eventually happened?

Dr. Ogston’s early work had to do with his observations that the micrococci were found in two types, the rather pathogenic Staphylococcus Aureus and the more benign Staphylococcus type, later known as the Staphylococcus epidermid is bacteria.  His work showed that these bacteria could be readily killed with heat and,importantly, with Lister’s phenolic compound carbolic acid. He had observed that the Staphylococcus epidermidis bacteria were pathogenic when introduced internally, but relatively non-pathogenic when present on external wounds.  He speculated that this type was probablypart of a resident microbial flora that lived freely on an individual’s skin.

As you alluded to above in your inquiry, he had difficulty convincing his medical colleagues of the validity of his work. Apparently,  his devoted students who had no trouble accepting the basic tenets of his theories had spoiled him. He received immediate pushback from members of the British Medical Association, as well as from the editor of the prestigious British Medical Journal. The editor had apparently been rather harsh in his rebuff of Dr. Ogston, inquiring in writing whether anything good could possibly come out of Aberdeen.

Because of the widespread incredulity he faced regarding his ideas, Dr. Ogston took his findings, in 1880, to Germany and presented them there, receiving immediate general acceptance of his work. He did manage to publish his some of his work in the British Medical Journal in a backdoor sort of fashion, as a grant report, rather than as a bona fide full-length scientific paper.  Subsequent manuscripts that he submitted to the same journal as proper papers were summarily rejected.

Therefore, Dr. Ogston sent his manuscripts to another journal, this one called Journal of Anatomy and Physiology, where the editors were more receptive and published his work. Thanks to this reception, the rest of the world has benefited from Dr. Ogston’s infectious disease work.

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