Friday 13 October 2017

Microbiology Week 5

        Assalamualaikum and good morning everyone... How are you all ? πŸ˜ƒπŸ˜ƒπŸ˜ƒ This week is my fifth week of microbiology class huhu.... But actually I not yet adapt the environment in University Putra Malaysia as a degree student of microbiology. This week many things happened in my microbiology class. Firstly, For two days continuously Dr Wan gave some " tazkirah" which means advice to us because in class we are like not more curious to know about the microbes and all the things related to microbes. And also we even didn't look at what my friends posted in Open learning MOOC about the interesting things which are about Helicobacter pylori and Microbial interactions in termite guts. So, Dr Wan asked to make a group and each group have to choose one bacteria and we have to present it in three minutes. For my group, we were chose Magnetotatic bacteria. The Magnetotatic bacteria are quiet interesting because it is about magnetic. Others group also were chose about Mycobacterium tuberculosis, Serratia marcescens, Propiniobacterium acnes, Alcanivorax borkumensis and Pseudomonas aeruginosa. We were actually presented about our bacteria on friday. Each group must present 3 minutes, but some group presented more than 3 minutes because they want us to be more clear about what they are presented. Everyone were presented in our microbiology class for first time.   In my group , we were separated our work like one persons find about the history of that bacteria another about the characteristics of bacteria that my group chose. It is like team work and it make more closer to each other. So now I'm going to share about what I had studied for this week.

 Methods of classifying  and identifying microorganisms

        Morphological characteristics is easy to study and analaysed. Characteristics studied include cell type , shape and size, cellular grouping , external structures and internal structures. Differential staining which are Gram stain is classifies into gram positive or negative, Acid-fast stain is only stain bacteria with waxy material in their cell walls, Negative staining for capsule is use India ink to provide a contrasting background, then stain with simple stain and capsules to not accept simple stain, thus appear as halos surrounding bacterial cell, Endospore staining is appear green within pink cells and Flagella staining are too thin and use a mordant and stain carbolfuchsin to coat the flagella until they are thick enough to be seen. Biochemical test to verify its metabolic activity examples are Phenol Red broth, Gelatin test, Lipase test, Starch hydrolysis, Motility test and Catalase test. Serology is the science that studies serum and immune responses that are evident in serum and the background are Bacteria (antigen) enter a host, antibody will be produced by the host. The antibody will combine with the antigen ( bacteria) and this precipitates the antigen. Two types of serology which are Enzyme-linked immunosorbent assay (ELISA) is fast and utilised a computer scanner to read result and performed in microtiter plate and Western blotting is protein from an unknown bacterium or virus are separated by electrophoresis and transferred to a nitrocellulose filter by blotting.  Phage typing is to determine which phage a bacterium is susceptible to bacteriophage cause lysis of bacteria that they infect and infect only particular species or even strains. Fatty acid profiles is bacteria synthesise a wide variety of fatty acids these fatty acids are constant for a particular species. DNA Base Composition is the base composition of a single species is a fixed property that can be used to reveal the degree of species relatedness. DNA Fingerprinting is use of restriction enzyme to produce banding pattern. Nucleic Acid Hybridization can be used to determine extent of similarity based on degree of reunion. Techniques that apply the principle of nucleic acid hybridization are sounthern blotting, DNA chips, Ribotyping and Ribosomal RNA Sequencing and Fluorescent In Situ Hybridization. Methods use to classify and identify microorganisms after various analyses are Dichotomous Keys used for identification based on successive questions and Cladograms is show evolutionary relationships among organisms and constructed based on rRNA sequences with the aid of software.

Mycobacterium tuberculosis

Mycobacterium tuberculosis discovered by Robert Koch in 1882. Mycobacterium tuberculosis is a non motile, acid-fast, obligate aerobe. The bacilli are 2-4 micrometer in length and have a very slow generation of time between 15 to 20 hours. The cell wall of the Mycobaterium is unique in that it is composed mainly of acidic waxes, specifically mycolic acids. Mycobacterium tuberculosis is usually resistant to drying and chemicals, contributing to the ease with which it is transmitted. Mycobacterium tuberculosis is ropelike structure with peptidoglycan and found abundantly in soil. The tuberculin skin test currently used to diagnose infection with Mycobacterium tuberculosis has poor diagnostic value, especially in geographic areas where the prevalence of tuberculosis is low or where the environment burden of saprophytic, nontuberculous mycobacteria is high.




Alcanivorax borkumensis

Alcanivorax borkumensis is an alkane-degrading marine bacterium which naturally propagates and becomes predominant in crude-oil-containing seawater when nitrogen and phosphorus nutrients are supplemented. They are currently thought to be the world's most important oil-degrading organisms. This bacteria is useful in treating oil spillage because it is an oil-eating bacteria. A borkumensis is a rod-shaped bacterium without flagella that obtains its energy primarily from consuming alkanes. It is aerobic meaning it uses oxygen to gain energy and it is halophilic, meaning it tends to live in environments that contain salt, such as salty ocean water. It is also Gram-negative which essentially means it has a relatively thin cell wall. It is also non-motile, however other organisms that appear to be in the same genus are motile through flagella.





Propionibacterium acnes

 Propionibacterium acnes is the relatively slow-growing, typically aerotolerant anaerobic, Gram-positive bacterium (rod) linked to the skin condition of acne. P. acnes bacteria live deep within follicles and pores, away from the surface of the skin. In these follicles, P. acnes bacteria use sebum, cellular debris and metabolic byproducts from the surrounding skin tissue as their primary sources of energy and nutrients. Elevated production of sebum by hyperactive sebaceous glands (sebaceous hyperplasia) or blockage of the follicle can cause P. acnes bacteria to grow and multiply. P. acnes bacteria secrete many proteins, including several digestive enzymes. These enzymes are involved in the digestion of sebum and the acquisition of other nutrients. They can also destabilize the layers of cells that form the walls of the follicle. The cellular damage, metabolic byproducts and bacterial debris produced by the rapid growth of P. acnes in follicles can trigger inflammation. This inflammation can lead to the symptoms associated with some common skin disorders, such as folliculitis and acne vulgaris. P. acnes bacteria are susceptible to a wide range of antimicrobial molecules, from both pharmaceutical and natural sources. Antibiotics are commonly used to treat infections caused by P. acnes. Acne vulgaris is the disease most commonly associated with P. acnes infection. The antibiotics most frequently used to treat acne vulgaris are erythromycin, clindamycin, doxycycline, and minocycline. Several other families of antibiotics are also active against P. acnes bacteria, including quinolones, cephalosporins, pleuromutilins, penicillins, and sulfonamides.




     




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