Sagar Aryal
Feb 8 th, 2015

Bacteriology-Top 1011 Comments

Top 10 Antibiotic Resistant Bacteria

Top 10 Dangerous Antibiotic Resistant Bacteria

Top 10 Antibiotic Resistant Bacteria

Antimicrobial resistance (AMR) is resistance of a microorganism to an antimicrobial drug that was originally effective for treatment of infections caused by it. Bacteria can become resistant to anti-bacterial agents, i.e. antibiotics, and in this setting the more specific term antibiotic resistance is used.

The bacteria listed below cover a range of diseases and levels of resistance. All of them present a threat to humans in some way or another. Some, like Tuberculosis for example, are already a huge challenge to overcome in their own right and will only become harder to control as their resistance to antibiotics grows.

Escherichia coli (E. coli)

First Documented: 1895

Illness Caused: Diarrhoea, Urinary Tract Infection, Meningitis

Antibiotic Resistance: High

Virulence: Worrying

Most E.coli is completely harmless and survives happily in the human digestive system. However, some strains of E.coli can cause serious illness and most commonly lead to severe food poisoning as well as meningitis and infections. A high level of resistance to antibiotics has been found across several strains of E.coli and while it is rare to find these strains causing illness, it is another concerning example of a bacteria that has the potential to cause problems if our use of antibiotics goes unchecked.

Acinetobacter baumannii

First Documented: 1911

Illness Caused: Pneumonia, Meningitis, Urinary Tract Infection

Antibiotic Resistance: High

Virulence: Worrying

Acinetobacter baumannii have become resistant to many antibiotics and like other bacteria are currently being countered most effectively through thorough hygiene in healthcare situations. The bacteria can survive in harsh conditions for long periods of time so are often difficult to deal with in weaker patients, and coupled with increasing resistance presents a tough challenge when encountered by doctors. Sometimes called Iraqibacter, Acinetobacter baumannii became very prevalent during the Iraq war amongst injured soldiers who passed through several different medical facilities.

Staphylococcus aureus (MRSA)

First Documented: 1884

Illness Caused: Pneumonia, Flesh Eating Disease

Antibiotic Resistance: Medium

Virulence: Dangerous

More commonly known as MRSA (which stands for Methicillin-resistant Staphylococcus aureus), this ‘superbug’ is very easily spread through human contact and can cause a range of illnesses from skin disorders to deadly diseases like meningitis and pneumonia. Most often treated with Penicillin type antibiotics, by 1960, 80 per cent of hospital samples were antibiotic resistant. A concerted effort in tracking the disease and improving hygiene measures in hospitals has seen cases of MRSA fall by 84.7 per cent in the UK between 2003 and 2011, proving that prevention is often the best form of defence against bacteria.

Mycobacterium tuberculosis

First Documented: 1882

Illness Caused: Tuberculosis

Antibiotic Resistance: Medium

Virulence: Deadly

Tuberculosis has been know by many names including scrofula and the White Plague and has been a huge cause of death and distraction throughout history, with evidence found in bodies estimated to be around 9,000 years old. It is believed that Nefertiti and her Pharaoh husband Akhenaten both died from tuberculosis in around 1330 BC, and documents remain from ancient Egypt that talk of the dangers of the disease. While instances of the disease reduced to only 5,000 a year in the UK in 1987, the increase in antibiotic resistance has seen a rise in cases in the early 90s.

Neisseria gonorrhoeae

First Documented: 1885

Illness Caused: Gonorrhoea

Antibiotic Resistance: Medium

Virulence: Worrying

Gonorrhoea is spread through sexual contact and causes various infections in both men and women. Certain strains of the bacteria have shown resistance to antibiotics and have mutated over the course of 50 years or so, slowly adapting different resistances as doctors change their approach by using different antibiotics to counter the disease. The small hairs or ‘pili’ on the bacteria act like hooks that are used to move the cell and attach it to other healthy cells. Using the pili the cell can exert a force 100,000 times its weight!

Klebsiella pneumoniae

First Documented: 1886

Illness Caused: Lung infections, Pneumonia

Antibiotic Resistance: Medium

Virulence: Worrying

Klebsiella pneumoniae can cause a range of infections and has proven to be very resistance to a range of antibiotics. Primarily affecting middle-aged and older men with weakened immune systems, this bacteria can be dangerous but is mostly ‘opportunistic’ and is far less likely to affect healthy adults. Due to its high levels of resistance, it is common in the US to perform tests to identify which strain is present in a patient to better inform doctors of how to treat them. This is slowing the rate at which resistance is built up but this bacteria is still of concern across the globe.

Pseudomonas aeruginosa

First Documented: 1872

Illness Caused: Pneumonia, Various Infections

Antibiotic Resistance: Medium

Virulence: Worrying

Quick to mutate and adapt to counter different antibiotic treatments, Pseudomonas aeruginosa shows an innate ability to develop resistance to antibiotics. Described as ‘opportunistic’ because it primarily affects humans that are already critically ill, this bacteria can cause serious complications in the treatment of AIDS, cancer or cystic fibrosis patients. While it isn’t a massive threat to humanity currently, this bacteria will become an increasing threat over the next few years.

Clostridium difficile

First Documented: 1935

Illness Caused: Diarrhoea

Antibiotic Resistance: Low

Virulence: Dangerous

One of the better known ‘superbugs’ because of a consistent presence in hospitals around the world, C. difficile is, primarily, an easily spread type of diarrhoea that can lead to complications in the colon. Several significant outbreaks of C. difficile have made the news in the UK and despite a major effort in improving hygiene in hospitals, the bacteria is responsible for a significant number of deaths globally. The chance of catching C. Difficile is actually increased by exposure to antibiotics – you are more likely to get ill from C. difficile if your internal balance has been upset and the bacteria can exploit this.

Streptococcus pyogenes

First Documented: 1884

Illness Caused: Sore Throat, Skin disorders

Antibiotic Resistance: Low

Virulence: Deadly

Like other potentially dangerous bacteria such as E.coli, Streptococcus pyogenes can be found in 5 per cent – 15 per cent of all humans, residing in the lungs or throat without causing any harm. Streptococcus pyogenes causes over 700 million infections globally every year and has a high mortality rate of 25 per cent in serious cases – once you have an infection the bacteria can cause a range of diseases ranging from sore throat and impetigo up to scarlet fever. Luckily, the bacteria is affected by penicillin so is treated easily in most cases – however several strains are building resistance to various other antibiotics.

Burkholderia cepacia

First Documented: 1949

Illness Caused: Pneumonia

Antibiotic Resistance: Low

Virulence: Worrying

Discovered in 1949 as the bacterium that causes onions to rot, Burkholderia cepacia can be very dangerous to humans in the worst cases. While it mostly responds well to treatment with a combination of antibiotics, it has been shown to have high levels of resistance to several types of antibiotics and is able to survive in extreme conditions. Particularly dangerous to humans with preexisting lung conditions such as Cystic Fibrosis, scientists have been developing new ways to fight the bacteria as it evolves an increasing resistance to antibiotics.

Top 10 Dangerous Antibiotic Resistant Bacteria

11 Comments on this article

  • Ekeocha happines February 11, 2015

    Please i want to know why a microorganism can be resistant to drugs that it was initialy succeptible to

    • Mike Dawson March 2, 2015

      A lot of antimicrobial resistance is due to genetic mutation of key genes that affect pore formation, efflux mechanisms or enzyme production of the microbes.

      These mutations are caused by pressures that are applied to the organisms due to the presence of the antimicrobial.

      Simply, antimicrobial resistance is an example of Darwinian evolution at its best. If an antibiotic is introduced to an environment, a mutation occurs at the genetic level in the microbe that may or may not aid microbial survival against the antimicrobial. If the mutation produces resistance (even minor resistance) the organisms thrive and multiply, whilst those without the mutation die.

      Another method of developing resistance is the ability of microbes to exchange genetic material, in the form of plasmids, during times of stress. A simplified version of microbial sex.

      Hope this helps to start explain antimicrobial resistance.

  • Aurelian Udristioiu February 12, 2015

    Rapid diagnosis of acute respiratory infections by multiplex endpoint PCR technology

    Aurelian Udristioiu¹, Manole Cojocaru², Dana Alexandra Maria Panait³, Nica Badea Delia4
    ¹Clinical Laboratory, Department of Hematology, Emergency County Hospital Targu Jiu & UCB University, Romania,

    The multiplex endpoint PCR technology offers a number of potential advantages, results are available in a matter of hours rather than days, the extreme sensibility facilitates detection of even minutes the amounts of pathogen DNA in clinical samples and the test is not significantly affected by prior administration of antibiotics.
    The aim of this work was to rapidly identify the antibiotic resistance the monitoring of pathogen growth at the patients admitted in Hospitalization Intensive Care Unit of Emergency County Hospital Targu Jiu with the diagnosis of Community Acquired Pneumonia, (CAP), in months December/2013-March/2014.
    The Analyzer Unyvero™ Pneumonia Application was used in detection of pneumonia associated pathogens and their antibiotic resistance genes using the Pneumonia Unyvero™ System, following PCR pathogen species with sequencing of the amplified microbial DNA.
    The main pathogens of community acquired pneumonia from the cohort study, 36 cases, (20 males in mean age 35-66 years and 16 females in mean age 40-55 mean years) were Streptococcus pneumonia (16 cases), Staphilococcus aureus, (10 cases), Klebsiella pneumonia (5 cases), and other important agents were “atypical”, such as Haemophilus Influenzae, Chlamidophila pneumonie and Moraxela cataralis.
    A case with Acinetobacter baumani and Proteus Sp. was also widely resistance to mefA gene / ermB gene as all cases of analyzed. The more frequency of genes resistant (29 cases) are ermA gene / ermC / ermB for Staphilococcus aureus and the gene tem+shv / gene / ctx-M with the Chromosomal mutation (7 cases), as gyrA83_87 Ecoli / Pseu for Klebsiella pneumonia agents.
    Also most resistance antibiotics were Makrolides, (29 cases and Lincosamides (6 cases) and this cases have had the chromosomial integrates. The most resistance microbe, Pseudomonas aeruginosa(1 case), has been registered as multi drugs resistance [MDR]*.
    Conclusion The Unyvero™ results have been available 2 days before the primary microbiology report and 3 days before the final confirmation results, obtained by microbiology culture. The Unyvero Analyzer only provides rapid data to support the therapeutic decision of currant medic.

    Keyword: antibiotic resistance, PCR, gene, DNA, resistance markers, microbiology report

  • golnar February 12, 2015

    Mycobacterium tuberculosis complex is a worldwide problem and with the increasing of drug resistant cases and also role of a typical mycobacteria in causing diseases and importance of correct detection of species to prevent occurring drug resistant cases should be concidered

  • Md Jahangir Alam February 12, 2015

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    I want to have your blog adress, since i want to have all of your post.
    Lets be friend. My facebook id= “Homesick Jahangir Alam “.

  • Akshay Divase February 12, 2015
  • Ron February 28, 2015

    I would include Salmonella sp. in the top 10.

  • workneh October 24, 2015

    The basic mechanisms by which a microorganism can resist an antimicrobial agent are 1) to alter the receptor for the drug (the molecule on which it exerts its effect); (2) to decrease the amount of drug that reaches the receptor by altering entry or increasing removal of the drug; (3) to destroy or inactivate the drug; and (4) to develop resistant metabolic pathways. Bacteria can possess one or all of these mechanisms simultaneously. When we specifically MTB: It occurs mostly as a result of treatment non compliance i.e. lack of adherence to the therapy, poor medical or nursing practice in which incorrect treatment regimens are prescribed, or less commonly, because of physiological problems such as drug interaction or malabsorption.

  • Andrew Cross October 26, 2015

    Why do we not have an appropriate test standard that is suitable for measuring antimicrobial efficacy on touch surfaces?
    The standard protocols ISO 22196 and JIS Z 2801 measure microbial reduction at 24 hours exposure, under warm & wet conditions.

    Products that work under these test conditions do not all work under typical indoor conditions (20 deg C, 22% RH).. yet without an appropriate test standard, there is no easy way to specify an effective antimicrobial surface.

    Allowing this to continue sounds like the opposite of antimicrobial stewardship, and is likely to result in new forms of antimicrobial resistance. Should we campaign for an appropriate test standard that is relevant to indoor touch surfaces?

  • Anton Riemslag October 26, 2015

    Tests for Lyme borreliosis are, in my case, positive after 17 tests. How to make a list if the tests for Borrelia is 6% accurate?
    Is there a radiologist are are neurologist, who can determinate the white brain-spots. The treatment for MS ore Neuroborreliosis must be 100% accurate. Neuroborreliosis treating with Prednison,means death. Making the list is abstract. Free from political issues?

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