1. Antibiotics and Antibiotic Resistance
Carl Heneghan
Professor of EBM
Nuffield Dept of Primary Care Health Sciences,
University of Oxford

2. Warm up quiz…..

3. Apple inc.

7. Antibiotics are powerful medicines that fight bacterial infection
Literal translation
anti – against
biotic – living things

8. How antibiotics work Antibiotics can be either
Broad Spectrum
Kill a wide range of bacteria e.g. Penicillin
Narrow Spectrum
Kill a specific type or group of bacteria e.g. Isoniazid
Antibiotics work in one of two ways
Bactericidal
Kills the bacteria
Bacteriostatic
Prevents the bacteria from dividing

9. The history of antibiotics
“When I woke up just after dawn on September 28, 1928, I certainly didn't plan to revolutionise all medicine by discovering the world's first antibiotic, or bacteria killer. But I suppose that was exactly what I did.”
1928, Sir Alexander Fleming

10. The history of antibiotics
Penicillin production in the beginning:
glass flasks and milk churns used for making early forms of penicillin
The US to produce 2.3 million doses in time for the invasion of Normandy in the spring of 1944.

13. Antibiotic prescribing across Europe
20.6 per 1000
10.8 per 1000

15. Antiobitic resistance
Selective toxicity - greater harm to microbes than host, done by interfering with essential biological processes common in bacteria but not human cells.
LD50 vs. MIC - Therapeutic index (the lowest dose toxic to the patient divided by the dose typically used for therapy). High TI are less toxic to the patient.
Bactericidal vs. bacteriostatic
Static rely on normal host defenses to kill or eliminate the pathogen after its growth has been inhibited. (UTIs) CIDAL given when host defenses cannot be relied on to remove or destroy pathogen.
Favorable pharmacokinetics - drug interxns, how drug is distributed, metabolized and excreted in body (unstable in acid, can it cross the Blood-brain barrier, etc)
Spectrum of activity
broad spectrum - wide
Narrow spectrum - narrow range (pathogen must be ID’d)
Lack of “side effects” allergic, toxic side effects, suppress normal flora
Little resistance development

16. Cuases of Antibiotic Resistance
Overuse
Antibiotics used to treat infections when they are not needed or not effective i.e. for viral infections e.g., influenza
Misuse
Not completing a prescribed course
Using antibiotics not prescribed for you

17. Causes of Antibiotic Resistance
Widespread antibiotic use has caused more bacteria to become resistant, a process called evolutionary pressure.
Increasing global availability since the 1950s
Uncontrolled sale resulting in antibiotics being used when not indicated. 
Use of broad-spectrum antibiotics when not indicated
Antibiotic use in livestock feed at low doses for growth promotion
Releasing large quantities into the environment during pharmaceutical manufacturing.

19. Clinical deployment of new antibiotics (blue bars) has quickly been followed by the evolution of bacteria able to resist their effects (red).

22. Discovery of teixobactin = a new class of antibiotics, first to be described in many years.
Teixobactin was able to kill bacteria that cause wound infections from cuts and scratches such as Staphylococcus aureus including MRSA, those that cause pneumonia (Streptococcus pneumoniae) and Mycobacterium tuberculosis (TB). .

23. Preventing Infections

25. Respiratory virus spread can be prevented by hygienic measures, such as handwashing, especially around young children.

27. Antimicrobial Stewardship
“…. the microbes are educated to resist penicillin and a host of penicillin-fast organisms is bred out… In such cases the thoughtless person playing with penicillin is morally responsible for the death of the man who finally succumbs to infection with the penicillin-resistant organism. I hope this evil can be averted.”
- Sir Alexander Fleming, June 1945
Lynfield, The Continued Assault of Antibiotic-Resistance; IDSA Congressional briefing. Accessed at

28. Thank You
@carlheneghan