Anaerobes


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Related to Anaerobes: Facultative anaerobes

Anaerobes

 

(also known as anaerobic organisms, an-aerobionts, and anoxybionts), organisms capable of living and developing in the absence of free oxygen and obtaining energy for vital activities by the breakdown of organic and inorganic substances. The term “anaerobes” was introduced by L. Pasteur, who in 1861 discovered the microbes of butyric acid fermentation.

Anaerobes are classified as obligate or facultative. The obligate anaerobes develop well in the complete absence of oxygen. The vegetative forms of these anaerobes die quickly upon coming into contact with the air, while the spores are resistant to oxygen. They are devoid of enzyme systems which are capable of transferring hydrogen to free oxygen. The obligate anaerobes include the vectors of tetanus, gas gangrene, certain streptococci, and other pathogenic microbes. There are also the bifid bacteria, which live in human and animal intestines and play an antagonistic role in relation to harmful microbe flora, and bacteria (including butyric acid bacteria), which develop in media devoid of oxygen (deep portions of a wound, maturing cheese, the mud of benthic deposits, and so forth). Obligate anaerobes are not encountered among multicelled organisms.

Facultative anaerobes are capable of developing both with and without oxygen. Among the facultative anaerobes are microorganisms (yeasts, pyogenic cocci, typhoid bacillus, anthrax bacteria, and others), certain protozoans and multicelled organisms which dwell in rotting mud (ciliata, oligochaeta, mollusks, and others), and parasites in the intestines of large animals (infusoria, nematodes, and platyhelminths). In the facultative anaerobes, the relationship to oxygen varies: in some, development is better in its absence, and in others, development is better in its presence. This is because in many facultative anaerobes, in addition to the enzymes which are capable of transferring hydrogen to various easily reducible compounds (as occurs in the obligate anaerobes), there are also enzymes which transfer the hydrogen to the free oxygen. For this reason, the difference between the anaerobes and the aerobes is to a large extent hypothetical. Anaerobes are found widely in nature (in the soil, in sea water at great depths, in benthic deposits, and so forth), and they play an important role in the conversion of organic and inorganic matter.

REFERENCES

Brand, T. Anaerobioz u bespozvonochnykh. Moscow, 1951. (Translated from English.)
Ierusalimskii, N. D. Osnovy fiziologii mikrobov. Moscow, 1963.
Metabolizm bakterii. Moscow, 1963. (Translated from English.)
References in periodicals archive ?
The anaerobes should not only be cultured in the appropriate conditions but transported to the laboratory in an environment that preserves the sample at zero percent oxygen within minutes.
aeruginosa, pyrosequencing identified other microorganisms including the strict anaerobes, Peptostreptococcus, and Fusobacterium.
Sachdeva et al (45) also observed that "vaginal discharge of patients with BV is notable for its lack of (Polymorphs) PMNs' typically 1 or less than 1 PMN per vaginal epithelial cell." Distribution of anaerobes was as follows: curved gram-negative rods suggestive of Mobiluncus spp.
Because a general count was desired, a selective media was chosen for fastidious anaerobes. Media were checked for quality control with the designated microorganisms.
The average reduction of the anaerobes (51.7%) in the subjects treated with ozonated water was greater than the reduction of the total bacterial load (45.3%).
Anaerobes were identified using the Finegold system, which included selective growth media, biochemical profiles and susceptibility to antimicrobial agents, and by the use of rapid ID 32A API panels.
Lab M, producers of microbiological culture media, have added Differential Reinforced Clostridial Medium ISO (DRCM) to their highly respected anaerobe range.
Before going into the incubator, anaerobic plates were placed in either an anaerobic pouch or jar in order to maintain the appropriate environment for the growth of anaerobes (12).
A comparison of the findings from the two swabs led to two important observations: (1) the pretherapy culture-positive rate increased from 74% (recovered bacteria) to 80% (recovered and detected bacteria) and (2) numerous anaerobes were present in the otorrhea specimen that were not being recovered (unpublished data).
It exerts strong antibacterial effects against gram-positive and gram-negative bacteria, aerobes, anaerobes as well as Pseudomonas aeruginosa.
Conversely, water with a negative ORP (-300 to -400mV) has been hypothesized to facilitate optimum growth of strict anaerobes in the gut (3).
Hydrogen peroxide-producing lactobacilli were associated with a significant decrease in cervicovaginal lavage HIV RNA concentrations, and Trichomonas vaginalis, Prevotella bivia, Mycoplasma hominis, and other anaerobes were associated with increases in cervicovaginal lavage HIV RNA concentrations.