last lecture :(

19^th December 2014

Today we learnt about In -cidal Agents,-cideis suffix indicating that agent kills and - static Agents,- static is suffix indicating that agent inhibits growth.

Effectiveness of Antimicrobial Treatment is depends on:

·         number of microbes

·         duration of exposure

·         microbial characteristics

·         concentration or intensity of an antimicrobial agent

·         population composition

·         temperature

·         local environment

There are three type of Physical Control Method which are :

·         Heat

·         Filtration

·         Radiation

Moist Heat will destroy viruses, fungi, and bacteria. Steam Sterilization is carried out using an autoclave and effective against all types of microorganisms including spores. Dry heat sterilization kills by oxidation by Flaming, Incineration, Hot-air sterilization and less effective than moist heat sterilization. Low temperature inhibits microbial growth by Refrigeration, Deep freezing and Lyophilization. Filtration will reduce microbial population or sterilizes solutions of heat-sensitive materials by removing microorganisms. In radiation, we have UV radiation and gamma radiation.

There are three type of Chemical Control Agents which are:

·         Disinfection

·         Antisepsis

·         Sterilization

In Evaluating a disinfectant we Use-dilution test and Disk-diffusion method. 

Lastly, we can determine the types of Disinfectants is Halogens – Iodine, Halogens – Chlorine, alcohol, heavy metal, Surface-active agents or surfactants, Chemical food preservatives, Aldehydes and sterilizing gases.

Then, we continue our lecture on the next topic which is antimicrobial chemotheraphy. I know that chemotherapeutic agents is a chemical agents used to treat disease. Penicillin discovered by Alexander Fleming to observe penicillin activity on contaminated plate.

 The general characteristics of antimicrobial drug are:

·         selective toxicity,therapeutic dose

·         toxic dose

·         therapeutic index

Besides that, I can determine the level of antimicrobial activity which is dilution susceptibility test for MIC, disk diffusion tests, and the E-test MIC and diffusion. Antimicrobial drug is the inhibitor of cell wall synthesis, protein synthesis inhibitor, metabolic antagonists and nucleic acid synthesis inhibition. The in inhibitors of cell wall synthesis are penicillins, cephalosporins, vancomycin and teicoplanin.

 Aminoglycoside antibiotics are large family which all contains a cyclohexane ring and amino sugars. Tetracyclines is all have a four-ring structure to which a variety of side chains are attached. Macrolides is used for patients allergic to penicillin. Chloramphenicol now is chemically synthesized. I also know that metabolic antagonist acts as antimetabolites and structural analogs. Nucleic acid synthesis inhibition will block DNA replication. Antifungal drugs have fewer effective agents. Antiviral drug development has been slow because it is difficult to specifically target viral replication. Anti-HIV drugs have reverse transcriptase inhibitors, protease inhibitors, fusion inhibitors and most successful are drug cocktails to curtail resistance. The antiprotozoal drug is the mechanism of drug action for antiprotozoal drug is not known.

I also can identify factors influencing Antimicrobial Drugs which is:

·         ability of drug to reach site of infection

·         susceptibility of pathogen to drug

·         ability of drug to reach concentrations in body that exceed MIC of pathogen

Drug resistances will an increasing problem, microbes in abscesses or biofilms may be growing slowly and resistance mutants arise spontaneously.

Since today is our last lecture , I want to thank to Dr Wan for the lecture that she gives us, and I’ll miss you Dr. Wan! XOXO