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A superbug is a microorganism that has developed the ability to withstand the effects of an antibiotic.Antibiotic resistance develops through mutation or plasmid exchange between bacteria of the same species. If a bacterium carries several resistance genes, it is called multiresistant or, informally, a superbug.
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Bacteria are living organisms. They are microscopic and mostly unicellular, with a relatively simple cell structure lacking a cell nucleus, cytoskeleton, and organelles such as mitochondria and chloroplasts.
Bacteria are the most abundant of all organisms. They are ubiquitous in soil, water, and as symbionts of other organisms. Many pathogens are bacteria. Most are minute. They generally have cell walls, like plant and fungal cells, but with a very different composition (peptidoglycans). Many move around using flagella, which are different in structure from the flagella of other groups.
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Bacteria reproduce and multiply asexually. They reproduce by binary fission, or simple cell division. During this process, one cell divides into two daughter cells with the development of a transverse cell wall.
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An antibiotic is a drug that kills or slows the growth of bacteria. Antibiotics are one class of 'antimicrobials', a larger group which also includes anti-viral, anti-fungal, and anti-parasitic drugs. They are relatively harmless to the host, and therefore can be used to treat infections. The term originally described only those formulations derived from living organisms, but is now applied also to synthetic antimicrobials, such as the sulfonamides.
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Staphylococcus aureus ('Staph aureus') is one of the major resistant pathogens. It is often found in the nose or on the skin of a healthy person, it is extremely adaptable to antibiotic pressure. It was the first bacterium in which penicillin resistance was found - in 1947, just four years after the drug started being mass-produced. Methicillin was then the antibiotic of choice. MRSA (methicillin-resistant Staphylococcus aureus) was first detected in Britain in 1961 and is now 'quite common' in hospitals. MRSA was responsible for 37 percent of fatal cases of blood poisoning in the UK in 1999, up from 4 percent in 1991. Half of all S. aureus infections in the US are resistant to penicillin, methicillin, tetracycline and erythromycin.
This left vancomycin as the only effective agent available at the time. However, VRSA (Vancomycin-resistant Staphylococcus aureus) was first identified in Japan in 1997 and has since been found in hospitals in England , France and the US . VRSA is also termed GISA (glycopeptide intermediate Staphylococcus aureus) or VISA (vancomycin intermediate Staphylococcus aureus), indicating resistance to all glycopeptide antibiotics.
A new class of antibiotics, oxazolidinones, became available in the 1990s, and the first commercially available oxazolidinone, linezolid, is comparable to vancomycin in effectiveness against MRSA. Linezolid-resistance in Staphylococcus aureus was reported in 2003.
Enterococcus faecium is another superbug found in hospitals: penicillin resistance was seen in 1983, vancomycin resistance (VRE) in 1987 and linezolid resistance (LRE) in the late 1990s.
Penicillin-resistant pneumonia (or pneumococcus, caused by Streptococcus pneumoniae) was first detected in 1967, as was penicillin-resistant gonorrhea. Resistance to penicillin substitutes is also known beyond S. aureus. By 1993 Escherichia coli was resistant to five fluoroquinolone variants. Mycobacterium tuberculosis is commonly resistant to isoniazid and rifampin and sometimes universally resistant to the common treatments. Other pathogens showing some resistance include Salmonella, Campylobacter, and Streptococci.
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Antibiotic resistance is a consequence of evolution via natural selection. The antibiotic action is an environmental pressure; those bacteria which have a mutation allowing them to survive will live on to reproduce. They will then pass this trait to their offspring, which will be a fully resistant generation.
Several studies have demonstrated that patterns of antibiotic usage greatly affect the number of resistant organisms which develop. Overuse of broad-spectrum antibiotics, such as second- and third-generation cephalosporins, greatly hastens the development of methicillin resistance, even in organisms that have never been exposed to the selective pressure of methicillin per se. Other factors contributing towards resistance include incorrect diagnosis, unnecessary prescriptions, improper use of antibiotics by patients, and the use of antibiotics as livestock food additives for growth promotion.
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- Prevention
Wash hands properly to reduce the chance of getting sick and spreading infection. Wash fruits and vegetables thoroughly. Avoid raw eggs and undercooked meat, especially in ground form. Do not demand antibiotics from your physician. When given antibiotics, take them exactly as prescribed and complete the full course of treatment; do not hoard pills for later use or share leftover antibiotics.
- Vaccines
Vaccines do not suffer the problem of resistance. This is because a vaccine enhances the body's natural defences, while an antibiotic operates separately from the body's normal defences. Nevertheless, new strains may evolve that escape immunity induced by vaccines.
While theoretically promising, anti-staphylococcal 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.
Source: Wikipedia
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Five primary activities are associated with the majority of needlestick injuries. They are:
- Disposing of needles, including collection and disposal of materials used
duringpatient care procedures
- Administering injections
- Drawing blood
Recapping needles (not allowed under the Bloodborne Pathogens Standard)
Handling trash and dirty linens (termed "downstream injuries", these usually affect the by the housekeeping department (Chiarello, 1992).
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For more than 50 years, HBV infection, a well-documented and recognized occupational hazard, has been and continues to be one of the most common bloodborne pathogens among healthcare workers. Studies conducted prior to implementation of recommendations to prevent bloodborne pathogen transmission (1976-1985) show that healthcare workers had a prevalence of HBV infection three to five times higher than the general U.S. population.
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All needlestick injuries are not preventable, but research has shown that almost 83% of injuries from hollowbore needles can be prevented . Many of these needlesticks can be prevented by using devices that have needles with safety features or eliminate the use of needles altogether (e.g., needleless IV connectors, self re-sheathing needles, and blunted surgical needles).
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