Skip to main content

Multi-Drug Resistance


The proliferation of drug-resistant strains of many pathogenic organisms is an increasing public health problem. Many pathogenic organisms develop antibodies, enzymes, or other metabolic means of adaptation to drugs such as antibiotics that initially are efficacious. For example, staphylococci, gonococci, and pneumococci have all evolved an enzyme that denatures penicillin, rendering it useless. The bacillus of tuberculosis has evolved strains resistant to all the first-generation drugs developed to combat it. The malaria parasite has evolved strains that resist antimalarial drugs. Insecticides such as DDT that were initially 100 percent effective in destroying insect vectors such as the anopheline mosquito are similarly rendered inefficacious. This has happened because of widespread, often indiscriminate use of these drugs (and insecticides). Not all the exposed pathogens are killed, and those that survive selectively breed to produce resistant strains.

John M. Last

(see also: Antibiotics; Drug Resistance; Pathogenic Organisms )

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"Multi-Drug Resistance." Encyclopedia of Public Health. . 24 Mar. 2019 <>.

"Multi-Drug Resistance." Encyclopedia of Public Health. . (March 24, 2019).

"Multi-Drug Resistance." Encyclopedia of Public Health. . Retrieved March 24, 2019 from

Learn more about citation styles

Citation styles gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, cannot guarantee each citation it generates. Therefore, it’s best to use citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

The Chicago Manual of Style

American Psychological Association

  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.