Antibiotic resistance develops through natural and acquired means. Naturally, bacteria can destroy drugs, change permeability or targets to become tolerant. Acquired resistance occurs through genetic changes like mutation, conjugation, transduction or transformation that allow resistance traits to spread. Rational antibiotic use and preventing misuse and overuse can slow resistance development. Individuals should only take antibiotics as prescribed, while policymakers regulate use and improve infection control, and health professionals prescribe appropriately and prevent infections.

1. Review About:
Development and Prevention of Antibiotic-resistance
Reviewed by:
Zubayar Rahman
Department of Pharmacy
University of Asia Pacific

2. Antibiotic Resistance
If the concentration of drug requires to inhibits or Kills the microorganism is
greater than he concentration that can safely be achieved, then the microorganism
is considered to be resistant to the drug.
Resistance to bacteria develops by two ways
• Natural way (non-genetic origin).
• Acquired way (genetic origin)
Natural way (non-genetic origin)
A) Destroying the drug:
Microorganisms produce enzymes that destroy the active drug, e.g. Staphylococci
resistant to Penicillin-G. Staphylo-Cocci produce penicillinase which destroy the
Penicillin-G.
B) By developing drug tolerance:
1. Microorganisms change their cell permeability drug, e.g. tetracycline
resistant bacteria.
2. Microorganisms develop an altered structural target for the drug, e.g.
erythromycin resistant organisms.
3. Microorganisms develop an altered metabolic pathway which bypasses the
reaction inhibited by the drug, e.g. sulfonamide resistant bacteria.
4. Microorganisms develop an altered enzyme can still perform its metabolic
function, e.g. some sulphonamide susceptible bacteria.
5. Microorganisms increase production of metabolite with which the drug
competes, e.g. increase production of PABA, to oppose the action of
Sulphonamide.
6. Bacteria utilise the drug for its own metabolic activity. This phenomenon
is called drug dependence.

3. Acquired way (genetic origin)
This mainly involves the genetic change, heritable to generation to generation.
Genetically originated resistance may develop in following ways:
1. Mutation: Any large population of antibiotic susceptible bacteria is likely
to contain some mutants that are relatively resistant to drugs.
Resistance may occur in a single step mutation (e.g. Streptomycin) or it
may develop gradually in a series of small steps over a period of days (e.g.
Erythromycin) even more slowly.
2. Conjugation: The passage of resistant gene from cell to cell by direct
contact through a sex pilus or bridge is termed conjugation.
3. Transduction: Passage of resistant gene from an insensitive organism to a
sensitive organism by bacteriophage (virus which infects bacteria).
4. Transformation: DNA released on cell lysis is incorporated directly into
bacteria that is contained in its environment. This is essentially confined to
Gram (-ve) bacteria
5. Transposition: An exchange of short DNA sequences (transposons), which
carry only a few genes occurs between one plasmin and another or between
a plasmid and a portion of bacterial chromosome within a bacterial cell.
Rational use of antibiotics
1. Use appropriate antibiotics with adequate bacteriological information.
2. Antibiotics should be used in proper dose and for appropriate duration.
3. Combination of antibiotic should be used where single drug is ineffective
or to overcome the chance of microbial resistance to antibiotics.
4. A bactericidal antibiotic should not be used with a bacteriostatic antibiotic
at the same time (antibiotic antagonism)
5. Broad spectrum antibiotics should not use indiscriminately.

4. 6. Therapy for undiagnosed microorganisms should be started with broad
spectrum antibiotics and with combination of antibiotic (against gram +ve
and gram -ve microbes).
7. Consider the patient’s condition during selection antibiotics (e.g. in renal
failure ciprofloxacin is contra-indicated).
8. Should not use the newer member of group of antibiotics so long as the
currently used drugs are effective.
Prevention and control
Antibiotic resistance is accelerated by the misuse and overuse of antibiotic, as
well as poor infection prevention and control. Steps can be taken at all levels of
society to reduce the impact and limit the spread of resistance.
Individuals
To prevent and control the spread of antibiotic resistance, individuals can:
• Only use antibiotics when prescribed by a certified health professional.
• Never demand antibiotics if your health worker says you don’t need them.
• Always follow your health worker’s advice when using antibiotics.
• Never share or use leftover antibiotics.
• Prevent infections by regularly washing hands, preparing food
hygienically, avoiding close contact with sick people, practising safer sex,
and keeping vaccinations up to date.
• Prepare food hygienically, following the WHO Five Keys to Safer Food
(keep clean, separate raw and cooked, cook thoroughly, keep food at safe
temperatures, use safe water and raw materials) and choose foods that have
been produced without the use of antibiotics for growth promotion or
disease prevention in healthy animals.

5. Policy makers
To prevent and control the spread of antibiotic resistance, policy makers can:
• Ensure a robust national action plan to tackle antibiotic resistance is in
place.
• Improve surveillance of antibiotic -resistant infections.
• Strengthen policies, programmes, and implementation of infection
prevention and control measures.
• Regulate and promote the appropriate use and disposal of quality
medicines.
• Make information available on the impact of antibiotic resistance.
Health professionals
To prevent and control the spread of antibiotic resistance, health professionals
can:
• Prevent infections by ensuring your hands, instruments, and environment
are clean.
• Only prescribe and dispense antibiotic when they are needed, according to
current guidelines.
• Report antibiotic -resistant infections to surveillance teams.
• Talk to your patients about how to take antibiotics correctly, antibiotic
resistance and the dangers of misuse.
• Talk to your patients about preventing infections (for example,
vaccination, hand washing, safer sex, and covering nose and mouth when
sneezing).