1. Topic: Antimicrobials
Presented by: Adeela Hussain
BIOT: 412

2. Antimicrobial Therapy
Antimicrobials???
Use of these Antimicrobials to treat diseases

3. Antimicrobial Therapy
Categorized as:
Empiric Definitive Prophylactic
Infecting organism not yet identified( i.e. specific organism)
Broad Spectrum
Infecting organism identified
Specific Therapy
Narrow Spectrum
Prevent previous infection or its recurrence after infection
Preventive

4. What do we need to know to treat with Antimicrobials???
Know the Drug
Know the Microbiology
Know the Patient

5. What do we need to know to treat with Antimicrobials???
Know the drug
Antimicrobials
Classification according to their mode of action
Know the microbiology
Culture results----Susceptible, Intermediate, or Resistant
Minimum inhibitory concentration
Specificity
Drug’s Activity
Know the patient
Dose and route of administration
Allergy
Age
Pregnancy
Genetic and metabolic abnormalities
Renal and hepatic function

7. Attributes of an Ideal Antimicrobial Agent
Solubility in body fluids
Selective toxicity
Toxicity not easily altered within the host (both so that toxicity to pathogen does not decrease and so that toxicity to host does not increase)
Non allergenic
Stability within body fluids (preferably over many hours such that dosing need not be repeated too often)
Resistance not easily acquired
Stability on shelf
Reasonable cost and availability

8. Antimicrobial Selection
The ability of an antimicrobial to harm a pathogen without harming the host is termed selective toxicity.
Higher selective toxicity-Higher Therapeutic index

9. Antimicrobial Resistance
Antimicrobial agents are considered "miracle drugs" that are our leading weapons in the treatment of infectious diseases. But……..
Antimicrobial resistance is the ability of certain microorganisms to withstand attack by antimicrobials, and the uncontrolled rise in resistant pathogens threatens lives and wastes limited healthcare resources.

10. Mechanism of Resistance
Some have innate resistance-----lack a target site
Some Acquire resistance by
Altered target site
Altered uptake
Antimicrobial inactivating enzymes

12. Mechanism of Resistance
Resistance spreads in bacteria in three ways:
Conjugation
Transformation
Transduction

14. Antifungals
An antifungal medication is a medication used to treat fungal infections such as
athlete's foot,
ringworm,
candidiasis (thrush),
serious systemic infections such as cryptococcal meningitis,
and others.

15. Some Common Examples Imidazoles Triazoles Thiazoles AllylAmines
Echinicandins
And many others

16. Mechanism of Action
Antifungals work by exploiting differences between mammalian and fungal cells to kill the fungal organism without dangerous effects on the host.
Unlike bacteria, both fungi and humans are eukaryotes. Thus fungal and human cells are similar at the molecular level. This makes it more difficult to find or design drugs that target fungi without affecting human cells.
As a consequence, many antifungal drugs cause side-effects. Some of these side-effects can be life-threatening if the drugs are not used properly

17. Antiparasites
Infections with parasitic helminthes and protozoa are important causes of morbidity and mortality worldwide.
No vaccines for antiparasitic infections
In contrast to viruses, bacteria, and protozoa, most helminthes do not directly replicate in the human body but reproduce sexually, giving rise to eggs or larvae that pass out of the body.
These drugs often affect some of the more complex systems of cellular physiology, such as microtubule formation or neuromuscular function.
The emergence of drug resistance in helminthes has been much more gradual and limited than in rapidly replicating protozoa, such as the malarial parasite Plasmodium falciparum.

18. Classification of Antiparasites
Antinematodes
Anticestodes
Antitrematodes
Antiamoebics
Antiprotozoals
Metradinazole

19. Natural Antimicrobials/Non Pharmaceutical Antimicrobials
Plants have been used as traditional healers to prevent or cure infectious diseases.
Study have been done on their antimicrobial activity and some inhibit the growth of pathogenic microorganisms.

20. Essential Oils
The antimicrobial properties of essential oils of 21 plant were investigated against five food-borne pathogens:
Campylobacter jejuni,Salmonella enteriditis,
Escherichia coli, Staphylococcus aureus and
Listeria monocytogenes.
The oils of bay, cinnamon, clove and thyme were the most inhibitory, each having a bacteriostatic concentration of 0.075% or less against all five pathogens.
Some Examples are: Eucalyptus oil, Garlic oil, Oregano oil, Lavender oil, Lemon oil, Mint oil etc.

21. Side Effects of Antimicrobials
Toxicities, the inability of a drug to completely distinguish host physiology from pathogen physiology
Allergies
Normal flora disruptions
Antimicrobial Resistance

23. Antimicrobial Nanotechnology
It is a recent addition to the fight against disease causing organisms, replacing heavy metals and toxins and may some day be a viable alternative.
Many heavy metal cations such as Hg2+, Cu2+, and Pb2+ have antimicrobial activities, but are also very toxic to other living organisms, thus making them unsuitable for treating infectious diseases.
Silver is commonly used as an antimicrobial in alternative medicine for its infection-fighting properties and it has a long and intriguing history as an antibiotic in human health care.

24. Questions