Definition for Antibiotic Resistant Bacteria:

Definition for antibiotic resistant bacteria:
WebMD definitions: Antibiotic resistance is a type of drug resistance where a microorganism is able to survive exposure to an antibiotic. Genes can be... en.wikipedia.org/wiki/Antibiotic-resistant_bacteria Antibiotics were designed to kill bacterium that infect us. Unfortunately, they are indiscriminate and also kill the good bacterium that are mostly found in the large intestinal tract. This leaves a person open to reinfection, or other more prevalent infections, during and after use.

he discovery of antibiotics has been one of the most important reasons of fall in mortality rates. It was the effect of antibiotics and vaccines that actually raised the life expectancy, allowed people to have smaller families and in more ways than one, changed the way we live. It is time we know some basics of antibiotics, so that we are aware of their potential as well as limitations, and avoid blind self medication

Antibiotics, along with vaccines, are the primary reason for the fall in death rate during the last century. Thanks to the efficacy of modern antibiotics, bacterial infections and epidemics, which had always been the greatest scourge of human civilization, have today been reduced to a far less common cause of human mortality and morbidity.
Antibiotics : an overviewAntibiotics are substances, which in very small quantities, can kill bacteria without damaging human cells. They do not affect virus or fungus and are usually not effective against other parasites like those causing Malaria and Amoebiosis. Thus their use is limited to bacterial infections.

Every antibiotic is not equally effective against every bacteria. A small group of antibiotics are effective against a large range of bacteria, and hence called 'broad spectrum antibiotics'. These broad spectrum antibiotics can be effective in multiple infections, but that does not necessarily make them the treatment of choice in every infection. For most bacteria, there is some particular antibiotic that is most effective, and hence used as treatment of choice.
History of antibioticsOne of the first antibiotics discovered by humanity was PENICILLIN. Discovered by Sir Alexander Fleming in 1928, it is a substance secreted by ‘Penicillium’ fungus, and has a capacity to destroy bacterial cells without adversely effecting human cells. However, the first group of antibiotics that caught our fancy and became very popular were the SULFONAMIDES. They were synthetically prepared and have been heavily used since 1930s.

These two groups of antibiotics changed the course of medical history by providing effective cure against a large number of infections, and it was their extraordinary efficacy in preventing infections that prompted further research and development of many more antibiotic substances.

Antibiotic resistance is a type of drug resistance where a microorganism is able to survive exposure to an antibiotic. While a spontaneous or induced genetic mutation in bacteria(Single-celled microorganisms, and most bacterial species are either spherical (called cocci) or rod-shaped (called bacilli) may confer resistance to antimicrobial drugs, genes that confer resistance can be transferred between bacteria in a horizontal fashion by conjugation, transduction, or transformation. Thus, a gene for antibiotic resistance that evolves via natural selection may be shared. Evolutionary stress such as exposure to antibiotics then selects for the antibiotic resistant trait. Many antibiotic resistance genes reside on plasmids, facilitating their transfer. If a bacterium carries several resistance genes, it is called multidrug resistant (MDR) or, informally, a superbug or super bacterium.
The extraordinary ability of certain bacteria to develop resistance to antibiotics—which are otherwise useful in speeding recovery from some illnesses—has been a hot topic on the minds of doctors, hospital staff, reporters, and the general public for several years. It is also heralded as a textbook example of evolution in action.
These bacteria are being studied by evolutionary scientists with the hope that they will reveal secrets as to how molecules-to-man evolution could have happened.
But are bacteria really evolving?

Genes for resistance to antibiotics, like the antibiotics themselves, are ancient.[1] However, the increasing prevalence of antibiotic-resistant bacterial infections seen in clinical practice stems from antibiotic use both within human medicine and veterinary medicine. Any use of antibiotics can increase selective pressure in a population of bacteria to allow the resistant bacteria to thrive and the susceptible bacteria to die off. As resistance towards antibiotics becomes more common, a greater need for alternative treatments arises. However, despite a push for new antibiotic therapies there has been a continued decline in the number of newly approved drugs.[2][clarification needed] Antibiotic resistance therefore poses a significant problem.
• Resistant pathogens o 3.1 Staphylococcus aureus o 3.2 Streptococcus and Enterococcus o 3.3 Pseudomonas aeruginosa o 3.4 Clostridium difficile o 3.5 Salmonella and E. coli o 3.6 Acinetobacter baumannii o 3.7 Mycobacterium tuberculosis
Prevention
Rational use of antibiotics may reduce the chances of development of opportunistic infection by antibiotic-resistant bacteria due to dysbacteriosis. In one study, the use of fluoroquinolones is clearly associated with Clostridium difficile infection, which is a leading cause of nosocomial diarrhea in the United States,[72] and a major cause of death, worldwide.[73]
Vaccines do not have the problem of resistance because a vaccine enhances the body's natural defenses, while an antibiotic operates separately from the body's normal defenses. Nevertheless, new strains may evolve that escape immunity induced by vaccines; for example an updated influenza vaccine is needed each year.
While theoretically promising, antistaphylococcal vaccines have shown limited efficacy, because of immunological variation between Staphylococcus species, and the limited duration of effectiveness of the antibodies produced. Development and testing of more effective vaccines is under way.[citation needed]
The Australian Commonwealth Scientific and Industrial Research Organization (CSIRO), realizing the need for the reduction of antibiotic use, has been working on two alternatives. One alternative is to prevent diseases by adding cytokines instead of antibiotics to animal feed.[citation needed] These proteins are made in the animal body "naturally" after a disease and are not antibiotics, so they do not contribute to the antibiotic resistance problem. Furthermore, studies on using cytokines have shown they also enhance the growth of animals like the antibiotics now used, but without the drawbacks of nontherapeutic antibiotic use. Cytokines have the potential to achieve the animal growth rates traditionally sought by the use of antibiotics without the contribution of antibiotic resistance associated with the widespread nontherapeutic uses of antibiotics currently used in the food animal production industries. Additionally, CSIRO is working on vaccines for diseases.[citation needed]