Proteus vulgaris

Proteus vulgaris is a species of bacterium. It is a bacillus, which means it has a rod-like shape. Vulgaris primarily grows in anaerobic environments, locations that lack free oxygen. Instead, it obtains oxygen from other compounds in its surroundings. It occurs naturally in the intestines of humans and other animals. It grows in fecal matter and contaminated water as well.

Bacteria species are characterized by the compounds they affect, contain, or lack. Vulgaris produces hydrogen sulfide, reduces nitrates in its environment, and contains indole and catalase. It is Gram negative, possessing a certain type of cell wall that is indicated based on the results of a Gram test.

Vulgaris is closely related to Proteus mirabilis, but the two species have some key differences. Mirabilis is indole-negative. Vulgaris resists some of the antibiotics that are most effective against mirabilis, such as ampicillin and cephalosporin. However, it is much less threatening to humans overall, typically only posing a serious danger to those who have weakened immune systems. Vulgaris-related infections are more common in other animals.

Background

Both the Proteus genus and vulgaris were first named by medical writer Gustav Hauser. While working at the University of Nuremberg at Bavaria in 1885, he wrote a monograph detailing his findings on three species of bacteria discovered in meat, which he called Proteus Vulgaris, P. mirabilis, and P. zenkeri. Proteus references a figure of Homer's epic The Odyssey, who was a herdsman in service of the god Poseidon.

Scientists' understanding of the Proteus genus and vulgaris in particular changed dramatically in the latter half of the twentieth century. In 1982, new discoveries led microbiologists to separate what they formerly considered vulgaris into three groups. Two of them were still considered the same species, and retained the name vulgaris. Microbiologists discovered that the third group, however, did not produce indole. This group was classified as a separate species, known as Proteus penneri.

When vulgaris is detected in humans, it is most commonly located in the intestines. To most humans, vulgaris generally poses very little threat. It is typically considered a normal flora species for the body—that is, a species expected to be present in a healthy human. In fact, its efforts to consume nutrition help with humans' digestive process. Its mere presence can help defend the body from more dangerous bacteria, since it consumes the nutrients that would draw other species to the area.

The entire Proteus genus is most commonly associated with urinary tract infections, or UTIs. Among the genus, mirabilis is by far the most dangerous to humans, accounting for 90 percent of human diseases caused by Protean bacteria. Mirabilis is the most common Protean cause of UTIs, but vulgaris can occasionally cause them as well. In most cases, UTI is not life threatening, but causes discomfort and pain, especially when urinating. Although Protean bacteria do not cause UTI as frequently as E. coli, they do infect kidneys more often than the latter bacteria. UTI can be much more serious if it reaches the kidneys, potentially leading to kidney stones or kidney failure. Vulgaris can also infect open wounds.

Impact

In 1915, a particular strain of vulgaris named OX19 was the subject of experiments by Arthur Felix and Edward Weil. They realized that OX19 created a similar reaction in the human immune system as certain other bacteria, and went on to develop the Weil-Felix test. This was designed to help detect infections by particular types of bacteria.

In World War II, Nazi Germany invaded Poland, occupying the entire country by 1941. The Nazis began rounding up Jews and other peoples that they considered undesirable, and confined them to isolated villages known as ghettos. They later began relocating these people to labor camps, and many were subjected to mass executions. It was during these roundups that a pair of Polish doctors, Eugene Lazowski and Stanislaw Matulewicz, learned about Proteus OX19. They learned that patients with healthy immune systems were generally not seriously endangered by the bacteria. However, the immune system's attack on vulgaris bore a strong resemblance to how it fought off the bacteria Ricksettia. Ricksettia is known for causing typhus.

Lazowski and Matulewicz began a secret campaign to introduce dead samples of vulgaris into the citizens of Rozavadow, Poland. While they did not exhibit symptoms of typhus, subjects' blood tests indicated them as carriers of the disease. Carriers are subjects that may not suffer the effects of an illness, but can transmit it to others. Germany had not experienced typhus in decades, so a hypothetical typhoid outbreak would have devastated the German population. Nazi officials deemed Rozavadow residents unusable for labor camps and left it and the surrounding area quarantined with minimal German interference. The secret infection campaign tricked the Germans and saved many lives.

In the early twenty-first century, studies conducted in India found strains of vulgaris and other bacteria that were becoming increasingly resistant to some antibiotics and other medications. The study hypothesized that this was due to numerous citizens taking either inappropriate types or the incorrect amounts of medication. This allowed vulgaris to gain exposure to different antibiotics; exposure to non-lethal doses allowed it to build up resistance.

Vulgaris exhibits what is known as swarming motility. This is a means of movement that allows bacteria to advance along a solid surface. Vulgaris use their many flagella—narrow, whip-like appendages—to move.

Like many swarming bacteria, the flagella of vulgaris grow in a peritrichous arrangement. This means groups of flagella grow randomly across a bacterium, rather than in an even distribution. This allows multiple flagella to move as one, and push with more force. The different Proteus species also release a liquid substance that reduces the surface tension of the object that they're navigating.

Vulgaris also display what is called multicellular behavior. Several Protean bacteria come together and use their combined secretions to move and spread, demonstrating a level of cooperation among single-celled organisms that most scientists believed impossible as recently as the late twentieth century. There are many aspects of swarming motility and multicellular behavior that remain unknown to scientists. Since it seems to require communication between individual bacteria, scientists have been trying to discover the methods they use.

Bibliography

Armbruster, Chelsie, Harry Mobley, Dora Szabo, & David Paterson. "Proteus Species." Antimicrobe, 2002, www.antimicrobe.org/b226.asp. Accessed 28 Mar. 2017.

Benedek, Thomas & Alicia Zhu. "The Origin of the Name Proteus." Antimicrobe, www.antimicrobe.org/h04c.files/history/proteus-history.asp. Accessed 30 Mar. 2017.

"Bladder Infection (Urinary Tract Infection—UTI) in Adults." National Institute of Diabetes and Digestive and Kidney Diseases, www.niddk.nih.gov/health-information/urologic-diseases/bladder-infection-uti-in-adults. Accessed 29 Mar. 2017.

Kearns, Daniel. "A Field Guide to Bacterial Swarming Motility." Nature Reviews Microbiology, vol. 8, no. 9, Sep. 2010, pp. 634-644.

Kreston, Rebecca. "Sheep in Wolf's Clothing: The 'Epidemic' That Duped the Nazis." Discover Magazine, 31 May 2016, blogs.discovermagazine.com/bodyhorrors/2016/05/31/2157/#.WOO0qqIpCUk. Accessed 2 Apr. 2017.

Mazumder, Shirin Al. "Proteus Infections." Medscape, 21 Feb. 2023, emedicine.medscape.com/article/226434-overview?form=fpf. Accessed 19 Nov. 2024.

"Medical Conditions That We Treat." Phage Therapy Center, www.phagetherapycenter.com/pii/PatientServlet?command=static‗proteus. Accessed 28 Mar. 2017.

O'Hara, Caroline, Frances Brenner, & J. Michael Miller. "Classification, Identification, and Clinical Significance of Proteus, Providencia, and Morganella." Clinical Microbiology Reviews, vol. 13, no.4, Oct. 2000, pp. 534-546.

"S. Aureus and P. Vulgaris: Microbiology Unknown Lab Report." CPR Memphis, 14 Aug. 2013, acls-bls-memphis.com/674/s-aureus-and-p-vulgaris-microbiology-unknown-lab-report/. Accessed 1 Apr. 2016.

"Strain: BacDive ID: 5069." BacDive, bacdive.dsmz.de/index.php?search=5069&submit=Search. Accessed 3 Apr. 2017.

Sudhakar, P. "Superbug Is a Reality, Say Tirunelveli Researchers." The Hindu, 28 Aug. 2016, www.thehindu.com/todays-paper/Superbug-is-a-reality-say-Tirunelveli-researchers/article14594222.ece. Accessed 30 Mar. 2017.