Antimicrobial resistance (amr)

Description about Antimicrobial resistance. what happens when antibiotics stop working accordingly.

1. ANTIMICROBIAL RESISTANCE (AMR) PRESENTED BY- SMRITI ACHARYA (38) SEJAL SHAHI(35) SANGITA SHRESTHA(34) 3 rd semester

2. CONTENT INTRODUCTION DEFINITION FACTORS MECHANISM TIMELINE CONTROL STRATEGY CONCLUSION

3. Introduction Microbial contamination- It is the multiplication of an infectious agents in the body. All infections do not invariably result in disease. Some infections may lead to development of signs & symptoms. There are two ways of contamination – Endogeneous and Exogeneous source Antibacterial Agents- Drugs have been used for the treatment of infectious disesases . Era of antimicrobial therapy began with the discovery of sulphonamides . Penicillin was the first antibiotic drug and is still the best. Those agents are the component that are natural, synthetic/semisynthetic that is active against microorganism.

4. Definition Antimicrobial resistance (AMR) is an ability of a microorganism (bacteria, viruses and some parasites) to stop an antimicrobials(antibiotics, antivirals, anti- malarials ) from working against it. Any antimicrobial treatment becomes ineffective as infections persist and may spread to others. This is responsible for millions of death worldwide and is concerned as major public health concern nowadays. The emergence of drug resistant bacteria is posing a major problem in antimicrobial therapy. At first there is an emergence of a small number of drug-resistant bacteria which sooner multiplies selectively in the presence of drug at the cost of sensitive bacteria.

5. AMR threatens the effective prevention and treatment of an ever increasing range of infections caused by microbes. Eg - Bacteria that are resistant to antibiotic include Methicillin-resistance Staphylococcus aureus (MRSA), Penicillin-resistance Enterococcus, multidrug –resistance Mycobacterium tuberculosis(MDR-TB), which is resistance to tuberculosis drugs, isoniazid and rifampicin. Bacteriostatic vs. Bacteriocidal - Static includes- Chloramphenicol, macrolides, clindamycin, trimethoprim, tetracyclines . Cidal includes- Aminoglycosides, beta-lactams, vancomycin , quinolones, rifampin and metronidazole.

6. Why resistance is a concern? Resistant organism leads to treatment failure. Increased mortality Resistance bacteria may spread in community Added burden of health care costs. Threatens to return pre-antibiotic era.

7. FACTORS AFFECTING ANTIMICOBIAL RISTANCE (AMR) Drug related factors Environmental factors Patient related factors Prescriber related factors

8. Drug related factors- Over the counter availability of antimicrobials Irrational fixed dose combination of antimicrobials . Increasing use of antibiotics . Environmental factors- Huge populations and overcrowding. Rapid spread due to better transport facilities. Poor sanitation. Increase in community acquired resistance.

9. Patient related factor- Lack of sanitation concept. Self medication Poverty Misconception Prescriber related factor- Inappropriate use of available drugs Inadequate dosing Lack of current knowledge and training Increased empiric poly-antimicrobial use. Also remember, there is natural resistance of bacteria against antibiotics, so it is not fault on these four factors.

10. Mechanism of amr How Antibiotic resistance happens? Intrinsic Or Natural Resistance- Intrinsic Resistance- Some microbes have always been resistant to certain Antimicrobials.

11. Contd … They lack the metabolic process or the target site which is affected by the particular drug. This type of resistance does not pose significant clinical problem. Eg - mycobacterium tuberculosis is resistant to tetracyclines . Aerobic organisms are not affected by metronidazole. G ram – ve bacilli are normally unaffected by penicillin G. Acquired Resistance- It is the development of resistance by an organism(which was earlier sensitive) due to the use of an AMAs over a period of time. This can happen with any microbes and is a major clinical problem.

12. Contd … This type of resistance develops either by gene transfer or by mutation or by modification in biochemical mechanism. GENETIC MECHAMISM- CHROMOSOMAL METHODS: MUTATION It refers to a stable and heritable change in the DNA structure of the bacterial gene. Spontaneous and random mutations occur in bacterial cells at a frequency of approximately one per million cells. I n any population of a microbe few mutant cells are present which require higher concentration of antibiotic for their elimination.

13. Contd … During a course of antibiotic therapy, the resistant bacteria continue to grow and multiply resulting in ‘selection of mutants’ which confer resistance to the antibiotic. Mutants resulting from chromosomal mutation have reduced pathogenecity , except in cases of Mycobacteria (both tuberculosis and leprosy) and Methicillin Resistant Staphylococcus aureus . EXTRA-CHROMOSOMAL METHOD :PLASMID Plasmids are extra-chromosomal genetic materials serving as vectors for carrying DNA molecule. Plasmids can replicate independently in cytoplasm.

14. Contd … Plasmids which carry genes resistant to antibiotics are called R-plasmids. These r-genes can get readily transferred from one R-plasmid to another plasmid . Most of the drug resistance encountered in clinical practice is plasmid mediated. Transfer of resistant genes can occur between bacteria of same species or of different species. BIOCHEMICAL MECHANISM By producing Antibiotic inactivating enzymes Gram – ve rods produce Beta-lactamase enzyme which cleaves the beta-lactam ring inactivating beta lactam antibiotics.

15. Contd … Some Gram – ve and Gram + ve bacteria inactivates chloramphenicol by the enzyme chloramphenicol acetyltranferase . Inactivation of Aminoglycosides by some Gram - ve and Gram + ve bacteria are mediated by the enzymes acetyltransferase , phospotransferases and adenyltranferases (plasmid and transposon mediated). By preventing drug accumulation within bacterium It is mediated either by promoting efflux or by preventing the influx of the drug. Efflux pumps are cytoplasmic membrane transport proteins which commonly operates in E.coli , S. typhi , Staph. aureus , mycobacteria and enterococci .

16. Contd … These efflux pumps are the major mechanism of resistance for tetracyclines , fluroquinolones and erythromycin. Some Gram – ve bacteria inhibit plasmid mediated synthesis of porin channels, which obstructs the influx of antibiotic agents (ampicillin). By modifying or protecting the target site Ribosomal point mutations for tetracyclines , macrolides and clindamycin. Altered DNA gyrase and topoisomerase for fluoroquinolones . Modified penicillin binding protein(PBPs) in Strepto . pneumoniae leading to penicillin resistance.

17. Contd … By use of alternative pathways for Metabolism Resistance to antibiotics can be conferred by developing an alternative pathway that bypasses the reaction inhibited by the antibiotic Eg - sulphonamide resistance occurs from overproduction of PABA(Para- Aminobenzoic Acid). SHORTLY, the mechanism are- A) Permeability B) Altered structural target C) Product of enzymes D) Altered metabolic pathway

18. What is difference between antibiotic and antimicrobial resistance? Antibiotics are medicines used to prevent and treat bacterial infections. Bacteria, not human becomes antibiotic resistant. These bacteria may then infect humans and are harder to treat than non-resistance bacteria. Antimicrobial resistance is a broader term, encompassing resistance to drugs to treat infections caused by other microbes as well, such as parasites ( eg - malaria), viruses( eg - HIV) and fungi ( eg - candida).

19. Strategy to control amr Judicious use of existing Anti-microbial Agents. Development of new Anti-microbial Agents. WHO recommended that farmers and food industry stop using antibiotics. Preserve the effectiveness of antibiotics by reducing their unnecessary use in animals Strong sustained action across all sectors is vital if we are to turn back the tide of antimicrobial resistance. Consumers and suppliers drive the major food chains adopting antibiotic- free policies.

20. Alternative options to using antibiotics for disease prevention in animals. Preserve the effectiveness of the most critical antibiotics for medicine. Use of antibiotics only when prescribed by a doctors. No sharing of antibiotic with others or using leftover prescriptions. Nepal has made important advances in reducing mortality and increases health coverage, but has not yet taken steps to address antibiotic resistance.

21. conclusion Anti microbial resistance is an emerging global threat. Strategies to prevent development of antimicrobial resistance should be devised. Judicious use of antimicrobial agents by health care professionals & general population. Preventing un-judicious use of antibiotics in animal husbandry and farming practices. Avoiding incorporation of antibiotics in commercial cleansing products. Proper pharmaceutical waste management. Discovery of antimicrobials created a new era in pharmaceutical science.

22. reference Chakraborty microbiology book. www.medicalnewstoday.com World Health Organization:Antimicrobial Resistance. Shrestha k. Potential Antimicrobial Resistance Threat-Nepal.

23. Choose the appropriate antimicrobials Think before prescribing and consuming. Are we using Right drug for Right bug??? THANK YOU