Another classification system is based on biological activity ; in this classification, antibacterials are divided into two broad groups according to their biological effect on microorganisms: bactericidal agents kill bacteria, and bacteriostatic agents slow down or stall bacterial growth.

A bactericidal activity of antibacterials may depend on the bacterial growth phase, and it often requires ongoing metabolic activity and division of bacterial cells.

Drying is one of the most ancient food preservation techniques, which reduces water activity sufficiently to prevent bacterial growth.

These were significant for their activity against β-lactamase-producing bacterial species, but were ineffective against the methicillin-resistant Staphylococcus aureus ( MRSA ) strains that subsequently emerged.

Each substitution is associated with a number of specific adverse reactions, as well as increased activity against bacterial infections, whereas the quinoline ring, in and of itself, has been associated with severe and even fatal adverse reactions.

Inside a bacterial host, the restriction enzymes selectively cut up foreign DNA in a process called restriction ; host DNA is methylated by a modification enzyme ( a methylase ) to protect it from the restriction enzyme ’ s activity.

This is important to know because most bacterial growth ceases at low levels of water activity.

Normally, such material eventually decays by oxidation or bacterial activity.

The chance of fossilisation is higher when the sedimentation rate is high ( so that a carcass is quickly buried ), in anoxic environments ( where little bacterial activity occurs ) or when the organism had a particularly hard skeleton.

Originally, it was believed that, in the bacterial RNase P complex, the protein subunit was responsible for the catalytic activity of the complex, which is involved in the maturation of tRNAs.

Although the RNase P complex also exists in eukaryotic organisms, his later work revealed that in those organisms, the protein subunits of the complex are essential to the catalytic activity, in contrast to the bacterial RNase P.

The specific activity of these sewage bacteria is typically three to four times greater than that of the autochthonous ( background ) bacterial population.

# an increase in bacterial enzyme activity

# A further factor is an increase in the bacterial mass and activity of the ileum as some fibers e. g., pectin are digested by bacteria.

The bacterial mass increases and cecal bacterial activity increases.

Trimethoprim has shown to have activity against a variety of Gram-positive bacterial pathogens.

Chopra states topical silver is regaining popularity in the management of open wounds, “ due largely to the spread of methicillin-resistant Staphylococcus aureus and the resultant reduction in first-line antibiotic prescribing ”, and “ ome silver-based dressings appear to provide an effective alternative to antibiotics in the management of wound infection .” Silver has proven broad-spectrum antimicrobial activity that includes antibiotic-resistant bacteria, with minimal toxicity toward mammalian cells at low concentrations, and has a less likely tendency than antibiotics to induce resistance due to its activity at multiple bacterial target sites.

New functions for chaperones continue to be discovered, such as assistance in protein degradation, bacterial adhesin activity, and in responding to diseases linked to protein aggregation ( e. g. see prion ).

A dryer and cooler starter has less bacterial activity and more yeast growth, which results in the production of more acetic acid relative to lactic acid.

Pyrogenicity can vary: In extreme examples, some bacterial pyrogens known as superantigens can cause rapid and dangerous fevers.

* Numerous antibody-mediated tests for CSF are available in some countries: these include rapid tests for antigens of common bacterial pathogens, treponemal titers for the diagnosis of neurosyphilis and Lyme disease, Coccidioides antibody, and others.

After rapid and destructive local spread ( which can take hours ), systemic spread of bacteria and bacterial toxins may result in death.

In bacteria, however, the analogous process ( defined as " the origin of new bacterial species that occupy definable ecological niches ") might be more common because bacteria are less constrained by the homogenizing effects of sexual reproduction and prone to comparatively dramatic and rapid genetic change through horizontal gene transfer.

2006 was also important to BD growth as the company acquired GeneOhm Sciences — a leader in the development of molecular diagnostic testing for the rapid detection of bacterial organisms and TriPath Imaging — a cancer diagnostics company.

The cellular damage, metabolic byproducts and bacterial debris produced by the rapid growth of P. acnes in follicles can trigger inflammation.

This is made possible by the rapid reduction of nitrofurantoin inside the bacterial cell by flavoproteins ( nitrofuran reductase ) to multiple reactive intermediates that attack ribosomal proteins, DNA, respiration, pyruvate metabolism and other macromolecules within the cell.

The physiological consequences of fructose malabsorption include increased osmotic load, rapid bacterial fermentation, altered gastrointestinal motility, the formation of mucosal biofilm and altered profile of bacteria.

It appears to bind to the membrane and cause rapid depolarization, resulting in a loss of membrane potential leading to inhibition of protein, DNA and RNA synthesis, which results in bacterial cell death.

Today's commercial buttermaking is a product of the knowledge and experience gained over the years in such matters as hygiene, bacterial acidifying and heat treatment, as well as the rapid technical development that has led to the advanced machinery now used.

The predomination of free swimming ciliated protozoa is indicative of a high bacterial population.

The antibacterial treatment may select for bacterial strains with physiologically or genetically enhanced capacity to survive high doses of antibacterials.

Antibacterials such as penicillin and erythromycin, which used to have high efficacy against many bacterial species and strains, have become less effective, because of increased resistance of many bacterial strains.

They have many properties that make them useful for treating high blood sugar, migraine headaches, bacterial and fungal infections, and gastric ulcers.

Using a high speed blender they were able to force the bacteriophages from the bacterial cells after adsorption.

When they encounter an infection site the particles gain a positive charge provoked by the slightly acidic environment at the infection sites, allowing them to bind to the negatively charged bacterial cell walls and release antibiotics at locally high concentration.

This accumulation of microorganisms subject the teeth and gingival tissues to high concentrations of bacterial metabolites which results in dental disease.

The frequency of certain specific bacterial infections ( Pseudomonas, H. flu, Staph ) has prompted two other popular categories of hypotheses: that the high salt content may interfere with defensins and lysosome, and / or may encourage the growth of the several bacterial species typically infecting the ordinarily-sterile lower lungs of CF patients.

It can also contaminate water courses unless collected and treated – the high nutrient content can lead to eutrophication ( growth of bacterial or algal blooms ).

Different nitrogen-fixing bacterial strains have been isolated from the caper bush rhizosphere, playing a role in maintaining high reserves of that growth-limiting element.

* The enzyme lactate dehydrogenase can be measured to help distinguish meningitides of bacterial origin, which are often associated with high levels of the enzyme, from those of viral origin in which the enzyme is low or absent.

High-level disinfection kills all organisms, except high levels of bacterial spores, and is effected with a chemical germicide cleared for marketing as a sterilant by the U. S. Food and Drug Administration ( FDA ).

A 2007 study on Australian nuggets ruled out speculative theories of supergene formation via in-situ precipitation, cold welding of smaller particles, or bacterial concentration, since crystal structures of all of the nuggets examined proved they were originally formed at high temperature deep underground ( i. e., they were of hypogene origin ).

When a vessel ( typically a tube or bottle ) containing a mixture of proteins or other particulate matter, such as bacterial cells, is rotated at high speeds, the angular momentum yields an outward force to each particle that is proportional to its mass.

Because of its extremely small grain size, oolitic sand has a lot of surface area, which promotes high bacterial growth.

Robert Guthrie developed a simple method using a bacterial inhibition assay that could detect high levels of phenylalanine in blood shortly after a baby was born.

* an acute illness resembling bacterial pneumonia, with symptoms of high fever, chills, a productive cough, and pleuritic chest pain.

Heavy rain can result in high sediment levels in rivers and land runoff, and can contain bacterial contamination from livestock.

The high mycolic acid content of certain bacterial cell walls, like those of Mycobacteria, is responsible for the staining pattern of poor absorption followed by high retention.

Materials research into superior anti fouling surfaces for fluidized bed reactors suggest that low wettability plastics such as Polyvinyl chloride (" PVC "), high-density polyethylene and polymethylmethacrylate (" plexiglas ") demonstrate a high correlation between their resistance to bacterial adhesion and their hydrophobicity.