What is cross-resistance in microbiology?
Definition of cross-resistance : tolerance (as of a bacterium) to a usually toxic substance (such as an antibiotic) that is acquired not as a result of direct exposure but by exposure to a related substance.
What is an example of cross-resistance?
A real example of cross-resistance occurred for nalidixic acid and ciprofloxacin, which are both quinolone antibiotics. When bacteria developed resistance to ciprofloxacin, they also developed resistance to nalidixic acid because both drugs work by inhibiting topoisomerase, a key enzyme in DNA replication.
What is cross-resistance in insects?
Cross-resistance occurs when resistance to one insecticide confers resistance to another insecticide, even where the insect has not been exposed to the latter product.
How does an organism become resistant?
Bacteria develop resistance mechanisms by using instructions provided by their DNA. Often, resistance genes are found within plasmids, small pieces of DNA that carry genetic instructions from one germ to another. This means that some bacteria can share their DNA and make other germs become resistant.
What is positive cross resistance?
Cross-resistance can be positive, when a resistance mechanism against one natural enemy also offers resistance to another; or negative, in the form of a trade-off, when an increase in resistance against one natural enemy results in a decrease in resistance against another.
What is the difference between multidrug resistance and cross resistance?
Multidrug-Resistant Microbes and Cross Resistance MDRs are colloquially known as “superbugs” and carry one or more resistance mechanism(s), making them resistant to multiple antimicrobials. In cross-resistance, a single resistance mechanism confers resistance to multiple antimicrobial drugs.
What is positive cross-resistance?
What is an example of pesticide resistance?
A classic example is the house fly. Populations of this insect that became resistant to DDT in the 1950s, also exhibited resistance, with no previous exposure, to pyrethroid insecticides used decades later. DDT and pyrethroids have the same MOA. This phenomenon is known as cross-resistance.
What is negative cross-resistance?
Negative cross-resistance refers to a situation in which an insect population that is tolerant (resistant, virulent) to one insecticide is hyper-sensitive (avirulent) to a second insecticide and insects hyper-sensitive to the first compound are tolerant to the second.
resistance to a particular antibiotic that often results in resistance to other antibiotics, usually from a similar chemical class, to which the bacteria may not have been exposed. Cross-resistance can occur, for example, to both colistin and polymyxin B or to both clindamycin and lincomycin.
What happens when pesticides are used in sequence or cross-resistance?
This can happen when pesticides are used in sequence, with a new class replacing one to which pests display resistance with another. Cross-resistance, a related phenomenon, occurs when the genetic mutation that made the pest resistant to one pesticide also makes it resistant to others, often those with a similar mechanism of action.
What does multidrug resistance mean?
multidrug resistance ( multiple drug resistance) a phenomenon seen in some malignant cell lines: cells that have developed natural resistance to a single cytotoxic compound are also resistant to structurally unrelated chemotherapy agents. Called also cross-resistance.
What is antibiotic resistance and how does it spread?
Antibiotics also kill good bacteria that protect the body from infection. Antibiotic-resistant germs can multiply. Some resistant germs can also give their resistance directly to other germs. Once antibiotic resistance emerges, it can spread into new settings and between countries. Antibiotics fight germs (bacteria and fungi).