Dienes phenomenon

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Dienes phenomenon, when two identical Proteus cultures are inoculated at different points on the same plate of non-inhibitory medium, the resulting swarming of growth coalesce without signs of demarcation. [1] [2] When, however, two different strains of Proteus are inoculated, the spreading films of growth fail to coalesce and remain separated by a narrow easily visible area. [2] The observation of this appearance, the Dienes phenomenon has been used to determine the identity or non-identity of strains in epidemiological studies. [2] [3]

<i>Proteus</i> (bacterium) genus of bacteria

Proteus is a genus of Gram-negative Proteobacteria. Proteus bacilli are widely distributed in nature as saprophytes, being found in decomposing animal matter, sewage, manure soil, the mammalian intestine, and human and animal feces. They are opportunistic pathogens, commonly responsible for urinary and septic infections, often nosocomial.

The terms inoculation, vaccination, and immunization are often used synonymously to refer to artificial induction of immunity against various infectious diseases. However, there are some important historical and current differences. In English medicine, inoculation referred only to the practice of variolation until the very early 1800s. When Edward Jenner introduced smallpox vaccine in 1798, this was initially called cowpox inoculation or vaccine inoculation. Soon, to avoid confusion, smallpox inoculation continued to be referred to as variolation and cowpox inoculation was referred to as vaccination. Then, in 1891, Louis Pasteur proposed that the terms vaccine and vaccination should be extended to include the new protective procedures being developed. Immunization refers to the use of all vaccines but also extends to the use of antitoxin, which contains preformed antibody such as to diphtheria or tetanus exotoxins. Inoculation is now more or less synonymous in nontechnical usage with injection and the like, and questions along the lines of "Have you had your flu injection/vaccination/inoculation/immunization?" should not cause confusion. The focus is on what is being given and why, not the literal meaning of the technique used.

Swarming motility rapid and coordinated translocation of a bacterial population across solid or semi-solid surfaces

Swarming motility is a rapid and coordinated translocation of a bacterial population across solid or semi-solid surfaces, and is an example of bacterial multicellularity and swarm behaviour. Swarming motility was first reported by Jorgen Henrichsen and has been mostly studied in genus Serratia, Salmonella, Aeromonas, Bacillus, Yersinia, Pseudomonas, Proteus, Vibrio and Escherichia.

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Agar plate

An agar plate is a Petri dish that contains agar as a solid growth medium plus nutrients, used to culture microorganisms. Sometimes selective compounds are added to influence growth, such as antibiotics.

<i>Proteus vulgaris</i> species of bacterium

Proteus vulgaris is a rod-shaped, nitrate-reducing, indole+ and catalase-positive, hydrogen sulfide-producing, Gram-negative bacterium that inhabits the intestinal tracts of humans and animals. It can be found in soil, water, and fecal matter. It is grouped with the Enterobacteriaceae and is an opportunistic pathogen of humans. It is known to cause wound infections and other species of its genera are known to cause urinary tract infections.

Malolactic fermentation The anaerobic enzymatic conversion of L-malate to L-lactate and carbon dioxide, yielding energy in the form of ATP.

Malolactic fermentation is a process in winemaking in which tart-tasting malic acid, naturally present in grape must, is converted to softer-tasting lactic acid. Malolactic fermentation is most often performed as a secondary fermentation shortly after the end of the primary fermentation, but can sometimes run concurrently with it. The process is standard for most red wine production and common for some white grape varieties such as Chardonnay, where it can impart a "buttery" flavor from diacetyl, a byproduct of the reaction.

<i>Proteus mirabilis</i> species of bacterium

Proteus mirabilis is a Gram-negative, facultatively anaerobic, rod-shaped bacterium. It shows swarming motility and urease activity. P. mirabilis causes 90% of all Proteus infections in humans. It is widely distributed in soil and water.

MacConkey agar culture medium used in microbiology

MacConkey agar is an indicator, a selective and differential culture medium for bacteria designed to selectively isolate Gram-negative and enteric bacilli and differentiate them based on lactose fermentation. The crystal violet and bile salts inhibit the growth of Gram-positive organisms which allows for the selection and isolation of gram-negative bacteria. Enteric bacteria that have the ability to ferment lactose can be detected using the carbohydrate lactose, and the pH indicator neutral red.

Crazing fine cracks on the surface of a material

Crazing is the phenomenon that produces a network of fine cracks on the surface of a material, for example in a glaze layer. Crazing frequently precedes fracture in some glassy thermoplastic polymers. As it only takes place under tensile stress, the plane of the crazing corresponds to the stress direction. The effect is visibly distinguishable from other types of fine cracking because the crazing region has different refractive indices from surrounding material. Crazing occurs in regions of high hydrostatic tension, or in regions of very localized yielding, which leads to the formation of interpenetrating microvoids and small fibrils. If an applied tensile load is sufficient, these bridges elongate and break, causing the microvoids to grow and coalesce; as microvoids coalesce, cracks begin to form.

The Weil–Felix test is an agglutination test for the diagnosis of rickettsial infections. It was first described in 1916. By virtue of its long history and of its simplicity, it has been one of the most widely employed tests for rickettsia on a global scale, despite being superseded in many settings by more sensitive and specific diagnostic tests.

Cystine–lactose–electrolyte-deficient agar culture medium used in microbiology

CLED agar is a valuable non-inhibitory growth medium used in the isolation and differentiation of urinary microbes. It contains cystine and lactose and is electrolyte-deficient; the latter trait prevents the swarming of Proteus species. Cystine promotes the formation of cystine-dependent dwarf colonies. Bromothymol blue is the indicator used in the agar, it changes to yellow in case of acid production during fermentation of lactose or changes to deep blue in case of alkalinization. Lactose-positive bacteria build yellow colonies. Bacteria which decarboxylate L-Cystine cause an alkaline reaction and build deep blue colonies

Lumpy skin disease (LSD) is an infectious disease in cattle caused by a virus of the family Poxviridae, also known as Neethling virus. The disease is characterized by fever, enlarged superficial lymph nodes and multiple nodules on the skin and mucous membranes. Infected cattle also may develop edematous swelling in their limbs and exhibit lameness. The virus has important economic implications since affected animals tend to have permanent damage to their skin, lowering the commercial value of their hide. Additionally, the disease often results in chronic debility, reduced milk production, poor growth, infertility, abortion, and sometimes death.

Proteus OX19 is a strain of the Proteus vulgaris bacterium.

Streaking (microbiology) microbiological method for isolation

In microbiology, streaking is a technique used to isolate a pure strain from a single species of microorganism, often bacteria. Samples can then be taken from the resulting colonies and a microbiological culture can be grown on a new plate so that the organism can be identified, studied, or tested.

Microbial inoculants also known as soil inoculants or bioinoculants are agricultural amendments that use beneficial rhizospheric or endophytic microbes to promote plant health. Many of the microbes involved form symbiotic relationships with the target crops where both parties benefit (mutualism). While microbial inoculants are applied to improve plant nutrition, they can also be used to promote plant growth by stimulating plant hormone production.

Funk Brothers Seed Co. v. Kalo Inoculant Co., 333 U.S. 127 (1948), is a United States Supreme Court decision in which the Court held that a facially trivial implementation of a natural principle or phenomenon of nature is not eligible for a patent.

L-form bacteria

L-form bacteria, also known as Sam Cannon, L-phase variants, and cell wall-deficient (CWD) bacteria, are strains of bacteria that lack cell walls. They were first isolated in 1935 by Emmy Klieneberger-Nobel, who named them "L-forms" after the Lister Institute in London where she was working.

Swarm (spacecraft) ESAs space program to study Earths magnetic field

Swarm is a European Space Agency (ESA) mission to study the Earth's magnetic field. High-precision and high-resolution measurements of the strength, direction and variations of the Earth's magnetic field, complemented by precise navigation, accelerometer and electric field measurements, will provide data for modelling the geomagnetic field and its interaction with other physical aspects of the Earth system. The results offer a view of the inside of the Earth from space, enabling the composition and processes of the interior to be studied in detail and increase our knowledge of atmospheric processes and ocean circulation patterns that affect climate and weather.

<i>Proteus penneri</i> species of bacterium

Proteus penneri is a Gram-negative, facultatively anaerobic, rod-shaped bacterium. It is an invasive pathogen and a cause of nosocomial infections of the urinary tract or open wounds. Pathogens have been isolated mainly from the urine of patients with abnormalities in the urinary tract, and from stool. P. penneri strains are naturally resistant to numerous antibiotics, including penicillin G, amoxicillin, cephalosporins, oxacillin, and most macrolides, but are naturally sensitive to aminoglycosides, carbapenems, aztreonam, quinolones, sulphamethoxazole, and co-trimoxazole. Isolates of P. penneri have been found to be multiple drug-resistant (MDR) with resistance to six to eight drugs. β-lactamase production has also been identified in some isolates.

Yeast in winemaking

The role of yeast in winemaking is the most important element that distinguishes wine from grape juice. In the absence of oxygen, yeast converts the sugars of wine grapes into alcohol and carbon dioxide through the process of fermentation. The more sugars in the grapes, the higher the potential alcohol level of the wine if the yeast are allowed to carry out fermentation to dryness. Sometimes winemakers will stop fermentation early in order to leave some residual sugars and sweetness in the wine such as with dessert wines. This can be achieved by dropping fermentation temperatures to the point where the yeast are inactive, sterile filtering the wine to remove the yeast or fortification with brandy or neutral spirits to kill off the yeast cells. If fermentation is unintentionally stopped, such as when the yeasts become exhausted of available nutrients and the wine has not yet reached dryness, this is considered a stuck fermentation.

Lactococcus garvieae is a known fish pathogen affecting saltwater fish in the Far East, specifically in rainbow trout, Japanese yellowtail, and grey mullet. This bacteria causes lesions in the vascular endothelium, leading to hemorrhages and petechias at the surface of internal organs. As few as 10 bacterial cells per fish can cause an infection. L. garvieae is isolated in saltwater fish in the Far East and specifically in European Rainbow Trout.

References

  1. "Essentials of Microbiology" . Retrieved 28 December 2016.
  2. 1 2 3 Budding, AE; Ingham, CJ; Bitter, W; Vandenbroucke-Grauls, CM; Schneeberger, PM. "The Dienes phenomenon: competition and territoriality in Swarming Proteus mirabilis" (PDF). J Bacteriol. 191: 3892–900. doi:10.1128/JB.00975-08. PMC   2698385 . PMID   19251852.
  3. "dienes phenomenon – microregistrar" . Retrieved 28 December 2016.