Diphtheria (Corynebacterium diphtheriae)
Corynebacteria are Gram-positive, aerobic, nonmotile, rod-shaped bacteria related to the Actinomycetes. They do not form spores or branch as do the actinomycetes, but they have the characteristic of forming irregular shaped, club-shaped or V-shaped arrangements in normal growth. They undergo snapping movements just after cell division which brings them into characteristic arrangements resembling Chinese letters.
The genus Corynebacterium consists of a diverse group of bacteria including animal and plant pathogens, as well as saprophytes. Some corynebacteria are part of the normal flora of humans, finding a suitable niche in virtually every anatomic site. The best known and most widely studied species is Corynebacterium diphtheriae, the causal agent of the disease diphtheria.
History and Background
No bacterial disease of humans has been as successfully studied as diphtheria.
The etiology, mode of transmission, pathogenic mechanism and molecular basis of exotoxin structure, function, and action have been clearly established.
Consequently, highly effective methods of treatment and prevention of diphtheria have been developed.
The study of Corynebacterium diphtheriae traces closely the development of medical microbiology, immunology and molecular biology. Many contributions to these fields, as well as to our understanding of host-bacterial interactions, have been made studying diphtheria and the diphtheria toxin.
Hippocrates provided the first clinical description of diphtheria in the 4th century B.C. There are also references to the disease in ancient Syria and Egypt.
In the 17th century, murderous epidemics of diphtheria swept Europe; in Spain
"El garatillo" (the strangler"), in Italy and Sicily, "the gullet disease".
In the 18th century, the disease reached the American colonies and reached epidemic proportions in 1735. Often, whole families died of the disease in a few weeks. The bacterium that caused diphtheria was first described by Klebs in 1883, and was cultivated by Loeffler in 1884, who applied Koch's postulates and properly identified Corynebacterium diphtheriae as the agent of the disease.
In 1884, Loeffler concluded that C. diphtheriae produced a soluble toxin, and thereby provided the first description of a bacterial exotoxin.
In 1888, Roux and Yersin demonstrated the presence of the toxin in the cell-free culture fluid of C. diphtheriae which, when injected into suitable lab animals, caused the systemic manifestation of diphtheria.
Two years later, von Behring and Kitasato succeeded in immunizing guinea pigs with a heat-attenuated form of the toxin and demonstrated that the sera of immunized animals contained an antitoxin capable of protecting other susceptible animals against the disease. This modified toxin was suitable for immunizing animals to obtain antitoxin but was found to cause severe local reactions in humans and could not be used as a vaccine.
In 1909, Theobald Smith, in the U.S., demonstrated that diphtheria toxin
C. freundii is a non-spore forming, motile bacteria that are long rod-shaped with a typical length of 1-5 μm. The seven biochemical tests conducted to narrow down the gram-negative stain are Phe... ... middle of paper ... ... dentifying unknown bacteria are and its implications for humans and nature.
Whooping cough is a highly contagious and acute respiratory disease caused by an aerobic Gram negative encapsulated coco-bacillus bacterium, Bordetella pertussis. It is a strict human pathogen with no known animal or environmental reservoirs and an air-borne disease. On inhalation, Bordetella pertussis colonizes the ciliated cells of the bronchio-epithelium to cause disease characterised by; epithelial damage, hyper mucus secretion, pulmonary edema and paroxysmal coughing. It is often accompanied by pneumonia, otitis edema, seizures, post-tussive vomiting and encephalopathy (1).
After a series of biochemical tests and evaluation to determine several unknown bacteria, the bacterium Yersinia pestis was chosen to report. The discovery of Y. pestis dates back to 1894 by French/Swiss physician and bacteriologist named Alexandre Yersin. The name Yersinia pestis is synonymous with its more common name, the plague. Y. pestis is known to infect small rodents such as mice and rats, but is transmitted to humans through the bite of an infected animal or flea. Although this bacterium is known to still cause illness today, it is infamous for three pandemics that occurred in earlier centuries. According to the Centers for Disease Control and Prevention, the first recorded pandemic occurred in 541 A.D. and is known as the Justinian Plague. The second pandemic originated in China in 1334 and has received the egregious name the “Black Death.” Finally, the third outbreak took place in the 1860’s and is known as the Modern Plague. It wasn’t until the end of the Modern Plague that scientists discovered the causative agent and mode of transmission of the Yersinia pestis bacterium.
The first discovery was made in 1952, in the developing field of virology. Virology is the study of viruses and how they behave. To develop the vaccines for the viruses, researchers infected the HeLa cells with many types of infections, such as measles, mumps, and the infamous poliomyelitis virus, also known as Polio. According to the Centers for Disease Control and Prevention (CDC), whose mission is to save lives and protect people’s health security, Polio is a "crippling and potentially deadly infectious disease caused by a virus that spreads from person to person invading the brain and spinal cord and causing paralysis" (Freeman). Jonas Salk, who was a virologist at the National Foundation for Infantile Paralysis (NFIP), used inactivated viruses (virus particles grown in culture and then killed by a form of heat) to create a polio vaccine. Salk drew blood from about two million children, which the NFIP checked for immunization.Through the collection of many HeLa cells and trial and error, the polio vaccine wa...
As stated in Chan-Tack and Bartlett’s article Botulism, “The incidence of foodborne botulism is approximately 24 cases per year. The incidence of wound botulism is 3 cases per year. The incidence of infant botulism is 71 cases per year, with a mean age of 3 months.” (2010). In addition, in merely fifteen percent of the Clostridium botulinium outbreaks are the toxin type undetermined. The first case descriptions of botulism were reported by Dr. Justinus Kerner, a German physician, in 1822. He had conducted experiments on himself and laboratory animals, which gave him this case findings (Taillac, & Kim, 2010).
Bacteria play a large role in our health, the environment, and most aspects of life. They can be used in beneficial ways, such as decomposing wastes, enhancing fertilizer for crops, and breaking down of substances that our bodies cannot. However, many bacteria can also be very harmful by causing disease. Understanding how to identify bacteria has numerous applications and is incredibly important for anyone planning to enter the medical field or begin a career in research. Having the background knowledge of identifying an unknown bacteria may one day aid healthcare professionals diagnose their patient with a particular bacterial infection or help researchers determine various clinical, agricultural, and numerous other uses for bacteria.
Most of these medical advances were a result and were an influence of World War I. Probably one of the most important medical advances was the discovery of penicillin in 1928 by a Scottish, microbiologist named Alexander Fleming, he had actually accidently discovered it, when he noticed that a bacteria culture he had been growing, had stopped, he realized that it had been contaminated by a rare form of mold called Penicillin and that it had killed the bacteria.
Rifkind, David, and Geraldine L. Freeman. The Nobel Prize Winning Discoveries in Infectious Diseases. London: Elsevier/Academic, 2005.
Diphtheria is caused by a pathogenic (disease causing) bacterium called Corynebacterium diphtheria also known as C. diphtheria (Nordqvist, 2004-2014). This bacterium usually effects the upper respiratory tract where inflammation is contracted. In a serious matter or event, this pathogen can be deadly once it enters the blood stream that leads to major parts of the body which includes the heart, brain and the nerves. This disease is also contagious and can be contracted by inhaling ultramicroscopic solid or liquid particles known as aerosolized secretions, direct contact with secretions or skin ulcer, and through contaminated items such as household or personal items.
Roos, Anna Marie E. "Plague, Early History." Infectious Diseases: In Context. Ed. Brenda Wilmoth Lerner and K. Lee Lerner. Vol. 2. Detroit: Gale, 2008. 627-634. In Context Series. Gale Virtual Reference Library. Web. 17 Mar. 2014.
Over a long period of time, scientists have wondered how the dosage of Tetrododoxin was perfected as the lethality of this toxin was
Edward Jenner invented a method to protect against smallpox in the late 1700s. The method involved taking substances from an open wound of someone with small-pox or cow-pox and injecting it into another person’s skin, also called “arm-to-arm inoculation”. The earliest actual documented examples of vaccination date all the way back to the tenth century in China (Lombard, “A brief history of vaccines and vaccinations”). The mention of early vaccination was taken note of by a French scholar, Henri Husson, written in one of his journals (Dictionaire des sciences médicale). The Ottoman Empire Turks also discovered a method of immunization a few centuries later. Lady Montagu of Great Britain, a famous writer and wife of the English ambassador of Istanbul, between 1716 -1718, came across the Turkish vaccine for small-pox. After surviving as a child with small-pox, she insisted her son be vaccinated (Henricy, “Letters of the Right Honourable Lady Wortley Montagu”). When she returned to England, she continued to publicize the Turkish tradition of immunization and spread their methods to the rest of her country. She also had all family members also vaccinated. Immunization was soon adopted in England, nearly 50 years before Jenner's smallpox vaccine in 1796 (Sharp, “Anti-vaccinationists past and present”). Edward Jenner’s target for smallpox was to eradicate it. And later by the 1940s, knowledge of the science behind vaccines had developed and soon reached the point where across-the-board vaccine production was a goal that was possible and where serious disease control efforts could start. Vaccines for many dangerous diseases, including ones protecting against pertussis, diphtheria, and tetanus were underway into production. ...
The domain for Klebsiella is Bacteria, it is in the Proteobacteria phylum, Gammaproteobacteria class, Enterobacteriales is the Order, the family is Enterobacteriacaea, the Genus is Klebsiella, and finally the species is Klebsiella pneumonia.
Arnold, P. (2009, September 27). History of Cholera - Who Discovered Cholera?.Bright Hub. Retrieved December 14, 2013, from http://www.brighthub.com/science/genetics/articles/50412.aspx
T. pallidum is highly sensitive to oxygen and has a decreased ability to survive when not in human body temperature environments 1. The mode of transmission is through sexual contact or vertical transmission from the mother to the fetus. T. pallidum lacks the lipopolysaccharide which is the endotoxin normally present in gram negative bacteria1. The bacterium does produce many lipoproteins which are thought to prompt the inflammatory mediators through the recognition of toll-like receptors1. T. pallidum has a virulence factor of being highly motile due to its ability to propel itself forward by rotating on a longitudinal axis1. The spirochetes easily penetrate the skin or mucosal membranes and spread throughout the lymph nodes and then the blood circulation, affecting many parts in the body1.