19 December 2014

Today 19 December 2014, we learn on control of microbial growth. This is important term that we should remember:

• Sterilization: Removal of all microbial life

• Commercial sterilization: Killing C. Botulinum endospores

• Disinfection: Destruction/removal of pathogens

• Antisepsis: Destruction/removal of pathogens from living .

Tissue

• Degerming: Removal of microbes from a limited area

• Sanitization: Lower microbial counts on eating utensils

• Biocide/Germicide: Kills microbes

• Bacteriostasis: Inhibiting, not killing, microbes

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 destroys 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 reduces 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 and 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 characteristic of antimicrobial drug are selective toxicity,therapeutic dose, toxic dose, therapeutic index, side effect, narrow-spectrum drugs, broad-spectrum drug,cidal agent and static agent,effect of an agent may very, and effectiveness expressed in two ways(MIC and MLC). Besides that, I can determine the level of antimicrobial activity which are 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 hibitors of cell wall synthesis are penicillins,cephalosporins, vancomycin and teicoplanin.

 Aminoglycoside antibiotics is large family which all contain 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 has fewer effective agent. 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 resistance will an increasing problem, microbes in abscesses or biofilms may be

growing slowly and resistance mutants arise spontaneously . since, today is our last class for this semester, I want to say thank you so much to dr.wan and pray us for success in exams later. I surely will remember all the sweet moment in this semester. thanks

Tuesday, 16 December

Tuesday, 16 December. We continue our lecture on isolation ,culturing , maintaining and preserving microbes. First, we need know the definition of aseptic technique. Aseptic technique refers to carrying out a procedure under controlled condition in a manner that will minimize the chance of contamination.

Culturing method have 2 basic technique which are liquid and qulture. Liquid can be reared in culture tubes in a liquid medium while qulture use plates where the liquid medium is solidified using agar and poured as a thin layer in the bottom of a culture dish.

Besides, we know how to get pure culture by using streak dilution plate methods.

this is how to obtain pure culture using pour plate method

there are 5 type of culture media which are chemically defined vs. complex media, liquid vs. semisolid media , selective media ,differential media and enrichment media.bacterial growth by budding, spores and fragmentation. Next, we learn on how to calculate number of generation and generation time .

This is the formula for the number of generation time and number of generation.

Generation time=60 min×hours)/ number of generation

Number of generation = Log number of cells (end) – log number of cells (beginning)

                                                                                   0.301

This is bacterial growth curve

Direct measurement of microbial growth , we use plate counts and filtration. Lastly, we can estimating the bacterial numbers by indirect methods using turbidity, periodic transfer of strains to fresh medium, incubate and store in the refrigerator,the short term storage and the long period storage.

11 December

Tuesday 11 December, we have a group quizzes on the microbial metabolism and nutritional. Then, we proceed to the microbial growth topic. There are two type of requirement for growth which is physical requirement and chemical requirement. The physical requirement is light, temperature, pH, water activity and osmotic pressure. The chemical requirement is water,  carbon, oxygen, nitrogen, phosphorus and sulfur, special growth factor and trace element . The bacteria cannot survive in the temperature that below than their optimum temperature or the bacteria will lower down their activity in this condition. For pH factor, we have acidophile at pH range 0-6, neutrophile pH at range 6-7.5, alkaliphiles pH at range 8-11. In chemical growth, water factor importance is for dissolve nutrient and cellular functions. In oxygen factor, there are 5 types which is obligate, facultative anaerobe, obligate anaerobe, aerotolerant anaerobes and microaerophiles. Trace element need in small amout but without them enzyme cannot function. In special growth factors we are introduce on the watermelon snow by the dr. I get exited to know about this. When we step on it, the white snow turn pinkish-red. Not only the colour, but it also smells like a watermelon. The reason why it turns res is because we actually step on algae.

8 December

Enjoyfull day in 8 December, we went to yakult factory in Seremban. 

The Yakult factory in Malaysia is located in Seremban, Negeri Sembilan and it produces Yakult for the whole of Malaysia, as well as for export to neighbouring countries.. Firstly, we are have been introduced on the yakult production in a room. Yakult is a probiotic dairy product made by fermenting a mixture of skimmed milk with a special strain of the bacterium Lactobacillus casei Shirota. It was created by Japanese scientist Minoru Shirota, who graduated from the Medical School of Kyoto University in 1930. I knew the different between the beneficial bacteria and harmful bacteria . The beneficial bacteria will suppress growth of harmful bacteria, in contrast, harmful bacteria will cause intestinal putrefaction. By consuming 3 bottle of yakult per day it will increase good bacteria and reduce harmful bacteria and boosts on immune system. Yakult has high calcium with 58.8mg and fortified with vitamin B6, vitamin B12, vitamin D, Calcium and Niacin.

The variety of yakult bottle shape and size  from many country.

Yakult in medicine

Yakult in cosmetic

This is map of yakult factory  

We followed  the whole production process from a lobby on the first floor. The walls are made of glass, which makes every step of the production process clearly visible.

Friday 11 December

Friday 11 December, we have game class first before we go to lecture. Everyone need to make flashcards on the topics microbial nutritional and microbial metabolism and share it on blenspace. And we make a group crossword quizzes on website proprofs and we enjoy play the quizzes game together in the class. I learn the definition of term like Metabolism, Catabolic reactions, Anabolic reactions  , Catabolism, Anabolism and Enzymes. The mechanism of enzyme action is Active site, Enzyme-substrate complex,transformation,release the products of the reaction,the unchanged enzyme is now free to react with other substrate molecules. Factors influencing enzymatic activity is temperature, pH and concentration and inhibitors. 2 aspects of energy production which is concept of oxidation-reduction and mechanisms of ATP generation. Oxidative phosphorylation is energy released as electrons are passed to a series of electron acceptors/carriers and finally to O2 or other inorganic or organic molecules. Photophosphorylation is energy from light is trapped by chlorophyll, and electrons are passed through a series of electron acceptors. I also know Cellular respiration of Aerobic respiration,Anaerobic respiration and Fermentation . lastly on this topic I can identify the alcohol fermentation and lactic acid fermentation.

There are 2 major nutritional concern which is Source of energy and Source of carbon. In Energy sources we have phototrophs which is light as primary energy source and chemotrophs is inorganic and organic compunds as primary energy source . in Combine the energy and carbon sources, there is Photoautotrophs,  Photoheterotrophs, Chemoautotrophs and Chemoheterotrophs. 

2 December

2 December, we learnt on classification of organism. I knew how create official names for new microorganisms and identify how to plan strategy and select methods for classification and identification of microorganisms. taxonomy can be divide into 3 part which is classification , identification and nomenclature.

1)nomenclature-assignment of names to taxonomic groups in agreement with published rules

2)classification- arrangement of organisms into groups or taxon based on mutual similarity relatedness

3)identification- process of discovering and recording the traits of organisms.

Nomenclature- genus name+ specific epithet  eg. Homo sapiens or Homo sapiens

                          -general rules in nomenclature

                         1) genus name always capitalized

                         2) species name is never capitalized

                         3) species name is never use without the genus name

                        4) genus name may be used without species name

                        5) genus and species are always italicized

                        6) first timeà spell out, thereafter àabbreviated

                        7)species name never abbreviated

                       8)less simple genus abbreviation if different genus start with same alphabet

Stain can be identify by a name or number or letter follows by species epithet.the inspiration of name is based on shape, where it found,nutrition it uses, who discovered it and what disease it causes

There are two ways of classification which is phonetic classification and phylogenetic classification. Differential staining is gram staining, acid-fast stain, negative staining for capsule, endospore staining and flagella staining. Serology is the science studies serum and immune responses that are evident in serum. The serological technique is enzyme linked immunosorbent assay and webstern blotting. Phage typing is to determine which phage a bacterium is susceptible to bacteriophages cause lysis of bacteria that they infect. DNA based composition is expressed as % of guanine plus cytosine. DNA fingerprinting is use of restriction enzyme to produce banding pattern. Nucleic acid hybridization is when dsDNA is heated , complementary strands will separate as the H bonds between bases break and if ssDNA  are cooled, complementary strands will reunite. The southern blotting is when DNA probes are used in the hydridization process. Lastly, I knew the methods use to classify and identify microorganism after various analyses which are dichoto,ous keys and cladograms.