What Are Antibiotics?Antibiotics, also known as antibacterials, are types ofmedications that destroy or slow down the growth of bacteriaThere r 2 types of antibacterials:
Spectrum of ActivityBroad spectrumantibacterialsNarrow spectrumantibacterials
Mode of Action
Mode of Action
Mode of ActionInhibitors of othermetabolic processes.Other antibiotics act on selected cellularprocesses essential for the survival of thebacterial pathogens.
How to useantibiotics?orallyinjectionapplied directly to the affected part of the body.or
Some antibiotics should not be consumed with certainfoods and drinks. Others should not be taken withfood in your stomach - these would normally be takenabout an hour before meals, or two hours after.Antibiotics are appropriate to use when :1.There is a known bacterial infection2.The cause of the infection is unknownand bacteria are suspected.
ANTIBIOTICS KILLBACTERIA, NOT VIRUSESIf a virus is making yousick, taking antibiotics may domore harm than good.most respiratory tractinfections are caused byviruses, so antibioticswon’t have any effect.
What kinds of infections arecaused by viruses and should notbe treated with antibiotics?• colds• Flu• Most coughs and bronchitis• Sore throats• Some ear infections
1.Diarrhea2.Feeling and being sick3.Fungal infections of themouth, digestive tract and vaginaWhat are the side-effects of antibiotics?
1. kidney stones 2.Abnormal blood clotting 3.Sensitivity to sun5.Deafness4.Blood disorders
It is a specific type of drug resistance.
Multi-drug resistant (superbug)• When bacteria resist to several types ofantibiotics• Due to plasmids• shigella (sul,chlo,str,tetra)• MRSA (hospital)• TB (tuberculosis)
DEVELOPMENT OF RESISTANCE• Bacterial cells that havedeveloped resistance arenot killed off.– They continue to divide– Resulting in a completelyresistant population.• Mutation and evolutionarypressure cause a rapidincrease in resistance toantibiotics.
There are two types of resistance;1-Natural Resistance: Bacteria may be inherently carryingresistant genes• Streptomyces• Penicillin2-Acquired Resistance:.Mutations. mobile genetic elements
•Examples of drug-resistant organisms include:•MRSA - methicillin/oxacillin-resistant Staphylococcus aureus•VRE - vanomycin-resistant enterococci•ESBLs -extended-spectrum beta lactamases (resistant to cephalosporins andmonobactams)•PRSP - penicillin-resistant Streptococcus pneumoniae•GISA - glycopeptide-intermediate Staphylococcus aureus•VISA - vancomycin-intermediate Staphylococcus aureus•VSRA - vancomycin-resistant Staphylococcus aureus (not yet found innature, but it is believed it will emerge or evolve from VISA),•MDR-TB- multidrug-resistant tuberculosis.LIST OF DRUG-RESISTANT BACTERIA
How bacteria become resistance?1. Inappropriate UseOne of the main causes ofantibiotics drug resistanceis antibioticoveruse, abuse, and insomecases, misuse, due to incorrectdiagnosis.2. Inadequate Diagnostics3. Hospital Use 4. Agricultural UseScientists also believe that thepractice of adding antibioticsto agricultural feed promotesdrug resistance.Critically ill patients are more susceptible toinfections and, thus, often require the aid ofantimicrobials. However, the heavier use ofantimicrobials in these patients can worsenthe problem by selecting for antimicrobial-resistant microorganisms
5. Mutation During replication, mutations arise andsome of these mutations may help an individualmicrobe survive exposure to an antimicrobial6. Gene Transfer Microbes also may get genes from eachother, including genes that make the microbe drugresistant.7. Selective PressureIn the presence of an antimicrobial, microbes are eitherkilled or, if they carry resistance genes, survive. Thesesurvivors will replicate, and their progeny will quicklybecome the dominant type throughout the microbialpopulation.
Mechanisms of being resistant• (A) Chromosomal mutations:• 1. Reduced permeability.• 2. Enhanced efflux• 3. Enzymatic inactivation (beta-lactamase)• 4. Alteration of drug target• 5. Loss of enzymes involved in drugactivation• (B) Plasmid or transposonmediated:
How does antibiotic resistancespread?Genetically, antibiotic resistance spreads through bacteriapopulations both "vertically," when new generations inheritantibiotic resistance genes, and "horizontally," when bacteriashare or exchange sections of genetic material with otherbacteria. Horizontal gene transfer can even occur betweendifferent bacterial species.Environmentally, antibiotic resistance spreads as bacteriathemselves move from place to place; bacteria can travel viaairplane, water and wind. People can pass the resistant bacteriato others; for example, by coughing or contact with unwashedhands.
Using antibiotics when you don’t need them may mean thatthey won’t work for you when you do need them in the future.If you have an antibiotic-resistant bacterial infection:•you will havethe infectionfor longer•you may be more likely tohave complications of theinfection•you could remaininfectious forlonger, and passyour infection toother people,which increases theproblem.
Can bacteria lose their antibiotic resistance?• Yes sure• but this reverse processoccurs more slowly• By selective pressure1- adequate diagnosis2-effective antibiotic3-apropriate doseMay take severalmonths or even years
preventionCan you imagine a day when antibiotics dontwork anymore?Its concerning to think that:could no longer workUnfortunately, the threat of untreatable infections isvery real.
So how can we prevent bacterial resistance againstantibiotics?Optimize UsePreventTransmissionPreventInfectionEffectiveDiagnosisand TreatmentPathogenAntimicrobial-ResistantPathogenAntimicrobialResistanceAntimicrobial UseInfection
Key Prevention StrategiesPrevent infection Diagnose and treatinfection effectivelyUse antimicrobialswiselyPrevent transmission
Prevent infection• Patients can do:Wash your hands frequently Dont share personal items Get vaccinated.
What else Patients can do:•Take antibiotics exactly as thedoctor prescribes.•Only take antibiotics prescribed for you•Do not save antibiotics for the next illness.•Do not ask for antibiotics when your doctor thinksyou do not need themPrevent antibiotic resistance
Healthcare providers can:•Prescribecorrectly:Bacteria and VirusesOn necessaryoverlaps in antibioticsCollaborate with each other and with patients"Are these really necessary?""antibiotic timeout"Stop and assess
What precautions might be inplace if I work in a hospital?Universal precautions:•Hand hygiene•Safe collection and disposal of sharps• Gloves for contact with body fluids, non-intact skin and mucous membranes•Wearing a mask, eye protectionand a gown if blood or other bodyfluids might splashAvoid Needle Stick Injuries
We need to preserve thisresource by workingtogetherBecauseNo action today,no cure tomorrowAntibiotics areinvaluable resources
• References:• 1.http://amrls.cvm.msu.edu/pharmacology/antimicrobials/effect-on-bacteria• 2.http://www.ccohs.ca/oshanswers/biol_hazards/drugresist.html• 3.http://www.nps.org.au/medicines/infections-and-infestations/antibiotic-4.medicines/antibiotics-for-respiratory-tract-infections/for-individuals/what-is-antibiotic-resistance• 5.http://www.medicinenet.com/antibiotic_resistance/page4.htm#causes_of_antimicrobial_drug_resistance• 6.http://www.cdc.gov/features/antibioticresistance/• 7.http://www.abc.net.au/science/slab/antibiotics/resistance.htm• 8.http://www.tufts.edu/med/apua/about_issue/about_antibioticres.shtml• 9.http://www.cdc.gov/getsmart/antibiotic-use/antibiotic-resistance-faqs.html• Book: Antibiotics the perfect storm by David M. shlaes