In this video we'll talk about some basics in microbiology to get you introduced to this subject.

在這一集影片中，我們要談談一些微生物學的基礎，讓你認識一下這個主題。

So what is microbiology? Microbiology is the study of microscopic organisms such as: bacteria, viruses, fungi, and protozoa.

那麼什麼是微生物學？微生物學就是微觀的機體的研究，像是：細菌、病毒、真菌、和原蟲。

Most of these microorganisms are beneficial to us.

這些微生物大多數對我們是有益的。

In humans we have normal microbiota that helps in digestion.

在人類，我們有正常菌叢幫助消化。

In plants, the bacteria is responsible for nitrogen fixation and in animals it helps in cellulose digestion.

在植物，細菌負責固氮作用；而在動物，細菌協助纖維素的消化。

Also these microorganisms are used in industries.

這些微生物也可應用在工業。

Generally we divide the organisms these bacteria viruses and fungi according to their characteristics.

大致上我們依照特徵來給這些微生物分類，這些細菌、病毒、真菌。

So in bacteria we use Gram stain either: positive or negative to categorize them.

在細菌，我們使用革蘭氏染色：陽性或是陰性，加以分類。

In viruses we depend on their genome: DNA or RNA, whether it's single stranded or double stranded to categorize them.

對於病毒，我們依照基因體：DNA 或 RNA，單股或雙股來分類。

In fungi they're either divided into molds which is multicellular, or yeasts which are unicellular.

在真菌，他們被分為多細胞的黴菌或是單細胞的酵母菌。

We also have the hierarchy of classification we used to put each organism including us humans into its category "we took it in high school if you remember".

我們還有用來歸類各種生物體，包含我們人類，的分類階層，「高中學過，你還記得嗎？」

So from highest to lowest, it's domain > kingdom > phylum > class > order > family > genus > and species.

從最高到最低，依序是域、界、門、綱、目、科、屬、種。

You can use this mnemonic to help you remember.

你可以用這個口訣幫助記憶。

Dina's kids prefer candy over fried green spinach .

Dina 的孩子喜歡糖果勝過於炒綠菠菜。

Spinach is pretty underrated.

菠菜真是被低估了。

From the top we have three domains on this planet: bacteria, archaea and Eukarya.

從最頂端，地球上有三個域：細菌域、古菌域、真核域。

Both bacteria and archaea are considered as prokaryotes whereas Eukarya are considered as eukaryotes.

細菌與古菌都被認為是原核生物，而真核域則是真核生物。

The main differences between prokaryotes and eukaryotes are absence of cytoplasmic structures such as mitochondria, Golgi apparatus, and endoplasmic reticulum in prokaryotes.

原核生物和真核生物最大的不同在於原核生物沒有細胞質內結構如粒線體、高基氏體、以及內質網。

And then we have absence of cell wall in eukaryotes except for fungi and plants. Also they differ in the structure of the ribosomes.

而真核生物則是沒有細胞壁，除了真菌和植物。它們的核醣體結構也不同。

After that we go to the kingdom. Both bacteria and archaea have only one single kingdom which are bacteria and archaea, respectively.

之後來到界。細菌域與古菌域都只有一個界，分別是細菌界和古菌界。

And then we have the eukarya and it has four kingdoms: protists, fungi, plants, and animals.

而真菌域則有四個界：原生生物界、真菌界、植物界、以及動物界。

And then we continue the classification like this like we mentioned before: phylum, class, order, family, genus, and then species.

接著我們繼續剛剛提到的分類，門、綱、目、科、屬，然後種。

For now we will focus on bacteria. How do we name them? Basic structures in gram staining.

現在我們聚焦在細菌。怎麼命名它們呢？利用革蘭氏染色的基本結構。

Any bacteria's name is composed of two words: the first one refers to the name of the genus, and the second one refers to the species name.

任何細菌的命名都是由兩個字組成：第一個字是屬名，第二個字是種小名。

We'll take Staphylococcus aureus as an example.

我們以 Staphylococcus aureus 為例。

So Staphylococcus is the genus and aureus is species.

Staphylococcus 是屬，aureus 是種。

Also the name of the microorganism might refer to its shape.

微生物的名字也可能代表它的形狀。

Like in our example. Staphylo means a bunch of grapes or a cluster, and coccus means round cells.

如同我們的例子中，Staphylo 表示一串葡萄或一團，而 coccus 表示圓形的細胞。

Aureus means it looks like gold in color when we culture.

Aureus 表示培養時呈現金黃色。

Other than cocci the round cells, we have rods or bacilli, and then we have spirochete, which are curved.

除了 cocci 是圓形的細胞，還有桿狀的 rods 或 bacilli，以及彎曲的 spirochete。

And then we have diplococci which is basically two cocci or basically two round cells, and then we have cocco-bacilli which is a mixture of both a rod and a round cell.

還有 diplococci，基本上就是兩個球菌或兩顆圓形的細胞。還有 cocco-bacilli，是桿菌與球菌的混合。

And then we have vibrios which is a curved rod, then we have streptococci which are cocci in chains.

Vibrios 是彎曲的桿菌，streptococci 是成串的球菌。

And then we have the staphylococci like we mentioned in our example which are large cocci in irregular clusters.

我們舉例的 staphylococci 是不規則成團的大球菌。

And then we have tetrads which are cocci in a packet of four from the name tetrads.

Tetrads 是四顆球菌為一組。

Tetra which means four.

名字源於 tetra，也就是四。

Now we're going to discuss the bacterial architecture.

現在我們要來討論細菌的結構。

Since bacteria are considered as cells, that means they have genetic material, a cell membrane, and a cytoplasm.

既然細菌被歸類為細胞，那表示它們有遺傳物質、細胞膜、和細胞質。

In addition to that, they have a cell wall, a flagella which is used for locomotion.

此外，它們還有細胞壁、用以運動的鞭毛。

And then we have pili which is used for attachment, and then we have plasmid which is an extra chromosome of genetic material so it's not part of the DNA, and then we have a glycocalyx which is used for protection.

還有用來附著的菌毛、獨立於染色體以外的遺傳物質因而不屬於 DNA 一部分的質體、還有保護作用的醣外被。

The glycocalyx can be either capsule which is neatly organized and protects the bacterium from phagocytes.

醣外被可以是整齊排列、保護細菌免於被吞噬的莢膜。

Or biofilm which is an unorganized loose structure yet important for attachment.

或是沒有條理的疏鬆結構但對於附著有重要地位的生物膜。

But here also have porins these porins are transmembrane proteins that selectively allow some molecules to pass the cytosol of the bacteria.

另外還有孔道蛋白，是穿膜的蛋白質，選擇性地讓某些物質通過細菌的細胞質液。

Porins can mediate antibiotic resistance by inhibiting some antibiotics from entering the bacteria.

孔道蛋白可藉由抑制抗生素進入細菌體內而媒介了抗生素抗藥性。

They also have Mesosomes that are equivalent to mitochondria in eukaryotes.

還有間體，等同於真核生物的粒線體。

Remember bacteria doesn't have mitochondria, so they have Mesosomes instead. Bacteria depend on these Mesosomes for respiration.

記住，細菌並沒有粒線體，而有間體。細菌依賴這些間體來呼吸。

Mesosomes are formed by the invaginations of a plasma membrane into the cytosol.

間體是由細胞膜內翻入細胞質液形成。

Generally speaking this is how a bacterium looks like.

細菌大致上就長這樣。

However, each bacterium has its special characteristics that distinguish it from the rest.

然而，每個細菌之間有自己的特徵來區分。

Now move on to gram staining.

接著談談革蘭氏染色。

In gram staining we can classify bacteria into either gram positive or gram negative and that depends on the cell wall constituents and its ability to react with the Gram stain.

利用革蘭氏染色，我們可以把細菌分類為革蘭氏陽性或革蘭氏陰性，依據細胞壁的組成和對革蘭氏染劑的反應。

To classify them, gram positive react with the stain and give blue color, while gram negative react with the stain and give red or pink color.

分類方法是，革蘭氏陽性菌與染劑反應呈現藍色，而革蘭氏陰性菌與染劑反應呈現紅色或粉紅色。

If we look at the membranes of both gram-positive and gram-negative bacteria, from the inner layer, we see that both of them have plasma membrane.

看看革蘭氏陽性和陰性菌的膜，從內層，我們可以看到兩者皆有細胞膜。

However, on the outside the differences start appear.

然而，外層開始出現差異。

In gram positive, it has a thick peptidoglycan layer.

在革蘭氏陽性菌，有一層厚厚的肽聚醣。

This layer has techoic and lipotechoic acids.

這一層有磷壁酸和脂肪壁酸。

In gram negative bacteria and outer to the plasma membrane we have thin layer of peptidoglycan.

在革蘭氏陰性菌以及往外到細胞膜，有薄薄一層肽聚醣。

And then we have outer membrane composed of phospholipids that has trans-proteins and lipoproteins embedded into it and the last layer in gram-negative bacteria is a polysaccharide.

然後外層膜由磷脂組成，有穿膜蛋白和脂蛋白嵌入其中，而革蘭氏陰性菌的最後一層是多醣類。

The lipopolysaccharide layer is composed of three structures: o-antigen, core polysaccharide, lipid A, which is also known as endotoxin.

多醣層由三個結構組成：O 抗原、核心多醣、脂質 A，也稱為內毒素。

So we can conclude that the endotoxins are only present in gram-negative bacteria.

因此我們可以結論，內毒素只存在革蘭氏陰性菌。

These endotoxins are antigenic which means they can elicit an immune response causing some symptoms of: fever, weakness, aches, or shock to the patient.

這些內毒素具有抗原性，也就是它們可以引起免疫反應，造成發燒、虛弱、疼痛、休克等症狀。

So that's it for the intro hope you enjoyed!

今天的介紹就到這裡，希望你們喜歡！

Please give us your feedback so you can improve in the next videos.

請給我們你的回饋，以讓我們在下一部影片更進步。

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別忘了按讚和訂閱才能馬上看到我們最新的影片和解惑喔！