MEDISCOPE | ISSUE 2 | 02 DECEMBER 2020

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ANTIBIOTIC RESISTANCETHE RISE OF RESISTANCEThe war between bacteria and humans has beengoing on for millennia. Bacteria being the cause ofmany medical catastrophes such as cholera,plague, and tuberculosis. But the discovery ofantibiotics ended this brutal conflict. Or so wethought.The Plague1The Black Death was the worst pandemic of alltime. It was caused by a species of bacteria calledYersinia Pestis carried by infected fleas on blackrats. It caused three diseases: bubonic plague,septicaemic plague (reproduction in blood), andpneumonic plague (reproduction in lungs).Approximately 75 to 200 million people diedacross Eurasia and North Africa. Public healthservices and sanitation were incredibly poor inthe 14th century. However, the black death didintroduce the “quarantine”: a forty-day period ofisolation, which became a quintessential methodin controlling outbreaks.Cholera2Cholera is a bacterial disease caused by thebacterium vibrio cholerae. There were four majorcholera outbreaks in London during the 19thcentury. London was a cramped, dirty city withouta good sewage system. The 1854 Broad Street3outbreak occurred in Soho and killed 616 people.The Board of Health attributed choleratransmission to “bad air” a theory called miasma.But physician John Snow had a different idea:germ theory. He believed an unknown germ wastransmitted by people ingesting infected water.He researched the water companies providingwater to London and found that theneighbourhoods dying from cholera receivedwater from companies that used thecontaminated Thames water. He mappedcontaminated water sources and the areas thathad outbreaks. He also researched the pump onBroad Street and found that it was contaminatedand was the cause of deaths in the area.John Snow laid the foundation for germ theoryand is known as the first epidemiologist and aspearhead of the improvement of public healthand sanitation in London. The change in healthBy Myah Darkwah 12Nand sanitation caused a great decrease ininfectious diseases.AntibioticsThe biggest breakthrough in the fight againstbacteria has been antibiotics. Sir AlexanderFleming discovered penicillin in September 1928.He observed that a petri dish containingstaphylococcus culture had been contaminatedby a mould and the staphylococci in closeproximity to the mould had died (inhibition zone).He extracted a sample of the mould and found itto be from the penicillium genus and the mould“juice” that was secreted, he called penicillin.But how do antibiotics work?Antibiotics kill bacteria or slow their growth byattacking the cell wall or covering; interferingwith reproduction; or blocking protein production.There are two types of bacteria: gram-positive4and gram-negative. Gram-positive bacteria canbe destroyed by penicillin because they have alarge amount of peptidoglycan (glycoprotein) intheir cell walls. Penicillin interferes with thesynthesis of peptidoglycan. However gramnegativebacteria have a slime covering orcapsule that is hard for antibiotics like penicillinto penetrate. There are five main groups of5antibiotics. Carbapenems, such as penicillin andmeropenem, are commonly used for severe orhigh-risk infections such as meningitis. Thenthere are fluoroquinolones, such as Ciprofloxin,which are used to treat common infectionsincluding respiratory and urinary tract infections.Polymyxins are antibiotics that are effectiveagainst Gram-negative bacteria like E. coli. Thereare also aminoglycosides for very seriousillnesses, so they are only used in hospitals. Theyhave drastic side effects such as hearing loss andkidney damage. The last group is tetracyclines;these are used against sexually transmittedinfections and Lyme’s disease which is actually anon-bacterial infection.ResistanceAntibiotic resistance is a type of antimicrobialresistance (when microbes become resistant toantimicrobials) and it means that bacteria evolve7
to survive exposure to the antibiotics that killthem. Mutations in the genome of bacteria maycause resistance and are passed on to offspring.Resistant genes may be in plasmids which can betransferred to offspring, or they may be directlyinserted into the circular DNA as pathogenicityislands.What does antibiotic resistance mean for publichealth services?Antibiotic resistance has become an increasinglyprevalent problem, and by 2050 superbugs couldkill more people than cancer. In the United Statesmore than 23 000 people die from resistantbacteria each year.MRSA is now commonly associated with hospitals.The over sterile conditions provide the perfectplace for staphylococcus aureus to be exposed toantibiotics and become resistant to them.According to the annual epidemiological report byPublic Health England, the all-case rate of MRSAdropped from 2007/08 to 2018/19 by 7.2 per100,000 however recently this decline hasstopped: the average rate of MRSA cases has6remained stable from 2015 to 2019. The sameobservation can be made in the United States. TheCDC saw the rate of MRSA cases decrease by 17.1%each year from 2005 to 2012. However from 20137to 2016 no significant change was detected.For public health services antibiotic resistance is avery significant threat. Many treatments requirethe use of antibiotics so that the patient does notsuffer from bacterial infections that could worsentheir condition. For example, those undergoingchemotherapy are more vulnerable to infectionand require antibiotics. Additionally, the secondmajor cause of death of those on dialysistreatment is infection, which makes antibioticsvital for the patient’s survival. Furthermore thosereceiving organ transplants have to take immunosuppressantdrugs which also increase the risk ofinfection.How do we tackle resistant bacteria?Microbiologists have been using genomesequencing technology to map the genome ofspecies of bacteria. This means a mutant resistantstrain can be compared with the existing sequenceof the normal bacteria genome to see exactlywhich genes are causing the resistance.There are also ways of slowing the spread ofantibiotic resistance. The overuse of antibiotics isone of the major causes of antibiotic resistance.Therefore healthcare professionals should onlyprescribe antibiotics in cases of severe bacterialinfection. Patients should be cautious and finishthe antibiotic course exactly as specified so thatthe stronger bacteria do not remain and duplicate.Viral infections such as influenza do not requireantibiotics.However there are some causes of antibioticresistance that individuals cannot directly control.For example, in some countries, antibiotics used inlivestock are not regulated and many animalsinvolved in meat production are overfedantibiotics. This overuse provides the opportunityfor bacteria to become resistant. However the EUdid introduce regulations in 2006 to stop thismisuse in Europe but there are still many countriesthat do not impose laws on this issue.BacteriophagesThere are one group of non-living organisms thatcan destroy bacteria: bacteriophages. They areviruses that specialise to kill specific types ofbacteria. Up to 40% of bacteria in the ocean arekilled by bacteriophages. They work by insertingtheir genetic material into them and releasing anenzyme called endolysin that punctures a hole inthe bacterium. The pressure builds and thebacterium bursts releasing many morebacteriophages.Bacteriophages are not harmful to humans and asbacteria evolve, bacteriophages do also. The goodnews for humanity is that in order for bacteria tobecome resistant to bacteriophages they wouldhave to give up their resistance to antibiotics.The FutureUnfortunately, bacteriophage treatment is stillexperimental and pharmaceutical companies arereluctant to invest in a treatment withoutapproval. A worldwide pioneer clinical trial ofphage therapy was conducted between 2013 and82017 and produced informative results. Hopefullymore research will be conducted intobacteriophages because we do need a solution toantibiotic resistance. We need one quickly.A Bacterium8ANTIBIOTIC RESISTANCE
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Page 3 and 4: CONTENTSNutrition and Obesity:- Nut
Page 5 and 6: MYOCARDITISMyocarditis is the name
Page 7: elective procedures and clinics wer
Page 11 and 12: THE ANGEL OF DEATHBy Phoebe Yan Chu
Page 13 and 14: NARCISSISTS AND SOCIOPATHSBy Rania
Page 15 and 16: Utilitarianism is a consequentialis
Page 17 and 18: was claimed to be ‘more accurate
Page 19 and 20: 15passengers they will not . Having
Page 21 and 22: happens when your body temperature
Page 23 and 24: MEDICAL DATES IN DECEMBERDecember i
Page 25 and 26: THE CASE OF MR REID - PBL CASEBy Se
Page 27 and 28: CROSSWORDPUZZLESAcross3. Antibiotic
Page 29 and 30: ISSUE 1 QUIZ + PUZZLE ANSWERSQuiz1)
Page 31 and 32: Categorised below are some example

MEDISCOPE | ISSUE 2 | 02 DECEMBER 2020

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