Week 14

This is the last week of my first semester. In this week, we learned about the other parts of microbial growth such as measurement of microbial growth, sterilization and disinfectants and antimicrobial chemotherapy. I've learned that there are different types of agents used to kill or inhibit the growth of microbes, and different agents have different usages and purposes. For example, sterilization kills all microbes in a very short period of time while antisepsis takes longer time to kill.
I've also learned the terms that I've came across before, which is antisepsis and sanitizer, of which I thought is the same before this. Overall, this topic is interesting in the sense that I can know how to kill microbes by using different methods, ranging from physical, chemical to biological method.


The activities for this week are :
1. Career Talk
2. Bacterial growth exercise
3. Quizz
4. Video assignment to summarize what we've learnt in this semester. Here's the link for my video: https://www.youtube.com/watch?v=HLk2SlYSnZw

Week 13

In this week, we had a visit to Yakult factory. This trip really widened my mind a lot. Before that, I just knew that Yakult is beneficial to us, but not really knowing the real benefits it brings. From the visit, especially from the explanation from the speaker and the booklet, I had gained a lot of information regarding the Lactobacillus casei shirota. For example, it can promote the growth of good bacteria and inhibit the growth of bad bacteria. Plus, it can ensure healthy skin growth too. Another thing that amazed me is the production process of Yakult. The whole production process is mainly conducted by machine, only the inspection and selection processes are done by manpower. 

We had lecture on microbial growth on Tuesday and Wednesday. It is interesting to know the factors that are required for microbes to grow. For example, even some microbes like fungus can grow at low temperature, that's the reason why mould can still grow in refrigerator. Same thing that some microbes can grow in acidic or alkaline condition, because in such condition, the microbes can consume the food from surrounding. Another thing that I learnt is water activity, fungus that have low water activity will only need low amount of water to grow.

One interesting fact that I learnt is the watermelon snow that Dr. Wan mentioned. It is also called as snow algae, pink snow, red snow,, or blood snow. The microbe that causes such phenomenon is Chlamydomonas nivalis, which is a species of green algae. Compressing the snow with these microbes will make the snows look red. This is normally found in California. Such fact is really mind-opening to me.

Lesson 19 (2/12/14)

Date : 2/12/14

Topic : Nomenclature and Classification of Microorganisms

Activities
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Notes

Taxonomy includes three parts: classification, identification and nomenclature.

Strain shows a small permanent genetic difference. Strain is a subgroup of species with one or more characteristics that distinguish it from other subgroups of the same species. It is identified by name, number or letter followed by specific epithet.

Rapid biochemical test must be standardized, rapid, reproducible, miniature, and mechanized.

Antiserum is a commercially available serum with specific antibody.

Serological techniques include ELISA and western blotting.

Phage typing is used to determine which phage a bacterium is susceptible to.

Techniques that apply the principle of nucleic acid hybridization includes Southern Blotting, DNA Chips, Ribotyping and Ribosomal RNA Sequencing, and FISH.

Methods used to classify and identify microorganisms after various analyses are Dichotomous Keys and Cladograms.

Name of microbes
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Random facts
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Muddiest point
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My own exploration
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Reflection on this topic

In order to name a microorganism, many steps are required. This is to ensure that the microorganisms named are specific and do not overlap. The system built is very complete and detailed, showing that a lot of researches and improvements have been done. It is really not an easy task to find a new microbe and name it accordingly.

Lesson 20 (5/12/14)

Date : 20/12/14

Topic : Microbial Metabolism and Nutritional Types of Microorganisms

Activities
1. Creating flashcards of definitions
2. Creating quizz

https://www.blendspace.com/lessons/be1rwq6O1lKasg/flashcards-on-microbial-metabolism

Notes


Microbial metabolism contributes to cycling of elements in ecosystems.

Enzymes are subjected to cellular controls.

Factors that influence enzymatic activity are temperature, pH, concentration of enzyme and substrate, and inhibitors.

Types of inhibition includes competitive inhibition, noncompetitive inhibition and feedback inhibition.

Energy can be produced from redox reaction or mechanisms of ATP generation.

Mechanisms of ATP generation can be done by substrate level phosphorylation, oxidative phosphorylation and photophosphorylation.

Aerobic respiration includes glycolysis, transition reactions, citric acid cycle, electron transport chain and chemiosmosis.

Lactic acid fermentation : Glucose > pyruvic acid > lactic acid
Homolactic fermenters : produce only lactic acid

Alcohol fermentation : Glucose > pyruvic acid > acetyldehyde + CO2
Heterolactic fementers : use pentose phosphate pathway to produce lactic acid and ethanol

Litho means reduced inorganic molecules

Cyanobacteria is oxygenic.

Green sulfur bacteria (Chlorobium) and purple sulfur bacteria (Chromatium) are anoxygenic. Both can be distinguished by the location of their bacteriochlrophyls, stored sulfur and ribosomal RNA.

Green nonsulfur bacteria (Rhodopseudomonas) is a photoheterotroph.


Name of microbes
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Random facts
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Muddiest point
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My own exploration

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Reflection on this topic

I think the website to build flashcards is very convenient because it is very user friendly and can be used to recall easily with the games and quizzes it provided. The quizzes are very interesting, especially from kahoot because it makes the quizz more fun.

Lesson 18 (28/11/14)

Date : 28/11/14

Topic : Test 2 and NYAWA visit

Activities
1. Test 2
2. NYAWA visit


Reflection on this topic

The creativity of artists and lecturers made me feel amazing. I never thought that scientific stuffs can be so artistic and elegant. Not even have a thought that there will be an art exhibition on microbiology. This visit really opens up my mind a lot.

Lesson 17 (25/11/14)

Date : 25/11/14

Topic : The Epidemiology and Public Health Microbiology

Activities
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Notes

Sporadic : occasionally and at irregular intervals.
Endemic : relatively steady low-level frequency and at moderately regular interval
Hyperendemic : gradually increase above endemic but not to epidemic

Outbreak : sudden occurrence unexpectedly, small region (like cholera during feast)
Epidemic : sudden increase unexpectedly
Pandemic : worldwide

Incidence : new cases contracted within population
Prevalence : total number contracted within population

Disease spread can be due to common source outbreak or propagated epidemic

Study of epidemiology includes descriptive (physical aspect and spread)), analytical (cause-and-effect), experimental (experiment).

Infectious frequency can be measured from morbidity rate, mortality rate, prevalence rate (depend on duration and incidence rate).

Infectious reservoirs include human, animal (zoonosis), non-living things (soil, water).

Transmission can be due to contact (direct, indirect, droplets), vehicle (water, air, food), vector (mechanical, biological).

Herd immunity is resistance of population due to immunity of large percentage of the population.

Nosocomial infections are also known as hospital-acquired infections normally caused by normal microbiota. There are many antibiotic resistant hospital strains.

Sources of nosocomial can be endogenous pathogen, exogenous pathogen and autogenous pathogen.

Ways to control epidemics : reduce infection source, break connection from susceptible individual, reduce number of susceptible individuals

Adjuvants are mixed with antigens in vaccines to enhance the immunization.

Risk of vaccination includes attenuated microbes may revert to virulent.

DNA vaccines introduces DNA directly into host cell via air pressure or gene gun.

Name of microbes
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Random facts
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Muddiest point
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My own exploration

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Reflection on this topic

I thought epidemiology is a study that is very "far" and unrelated with us. However, infectious diseases actually exist around us, ranging from flu to nosocomial infections. I used to think that being particular at the cleanliness of door knob and other apparatus in hospital is too extreme. But now I know that there are lots of infections will be contracted and even the infection will become more resistant if no measures of cleaning and sterilization are taken.

Lesson 16 (21/11/14)

Date : 21/11/14

Topic : Virus and Acellular Infectious Agents + Genetic transfer and Recombination

Activities
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Notes

Genetic transfer in prokaryotes can be done by transformation, transduction and conjugation.

Recombinant is the resultant cell due to integration of some donor's DNA into the recipient's DNA.

Competence is the alterations in the cell wall that make it permeable to large DNA molecules.
Some bacteria are naturally competent but some need treatment to be competent.

Transduction can be carried out in two forms (generalized transduction and specialized transduction).

Types of plasmids include dissimilation plasmid, conjugative plasmid and R factors.

Conjugation of Gram-negative bacteria is done by using pili while for Gram-positive bacteria is sticky surface molecule.

Transporons are small segments of DNA that can move from one region of a chromosome to another region of same or different chromosome (jumping DNA).

Name of microbes
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Random facts

The hydrosphere (the sea) has the largest population of virus on Earth.

Poultry shouldn't be eaten before 21 days upon birth because they might have antibiotic residue that is harmful when eaten.

The culture in Papua New Guinea is eating the brain of dead family members, and this will cause Kuru disease due to virus infection.

Virus can be cultured using embryonic eggs. Accurate calculation has to be made in order to prevent the chicks from being born. Some mistakes previously caused deaths of chicks when being studied due to birth deformities.

Capsids are involved in the transfer of genetic materials.

Identification of virus can be done by identifying the envelope proteins (spikes or peplomers), while identification of Gram-positive bacteria can be done by identifying the teichoic acid.

Cytopathic effects are the changes done to the cells. Cytopathic effects can be tested using cell line or hepa cell cultured from the infected cells (taken from patient who has just passed away).

Satellites (one of the acellular infectious agent) is called so because its visibility required high beams of light produced from satellite-like structure.
 



Muddiest point
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My own exploration

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Reflection on this topic

Before the lecture, I felt that the topic of virus is quite boring because it looks very factual and do not have anything interesting to read. But after the explanation of Dr. Wan, then only I knew about the interesting facts of virus. Then only I found the topic very fun. For me, it becomes very fun and easy to learn with all these interesting facts because it makes the knowledge we learn more related to our lives. Thanks Dr. Wan.