Antibiotics: Cell Wall Synthesis Inhibitors: Part 1
Summary
TLDRこのビデオでは、抗生物質に関する基本的な知識と、主に細胞壁に作用する抗生物質について解説しています。ペニシリンやアモキシシリン、头孢菌素類をはじめとするβラクタム系抗生物質のメカニズムと抗性菌への対応方法を紹介。さらに、鎮痛剤ヴァンコマイシンの効能と、結核治療に用いるイソニアジドの働きについても触れています。
Takeaways
- 🔬 このビデオでは、抗生物質について説明され、特に細胞壁に作用する抗生物質に焦点が当てられています。
- 🌟 抗生物質のカテゴリーは多岐にわたりますが、全てを網羅することは困難であり、特にβラクタム系抗生物質に注目されています。
- 📚 グラム陽性菌とグラム陰性菌の細胞壁の違いについて説明され、それぞれ異なるペプチドグリカン層と細胞膜の構造に注意が喚起されています。
- 💊 ペニシリンは、主にグラム陽性菌と一部のグラム陰性菌に作用し、ペニシリン結合蛋白に結びつき、細胞壁の合成を妨害します。
- 🛡️ βラクタム系抗生物質は、ペニシリン結合蛋白を刺激して自壊酵素を活性化し、細胞壁の構造を崩壊させることで細菌を殺菌します。
- 💔 一部の細菌はβラクタムアゼを産生し、ペニシリンのβラクタム環を切断することで抗生物質の作用を無効にすることができます。
- 💊 アモキシシリンはペニシリンに似た作用機構を持ちますが、βラクタムアゼに対して非常に敏感であり、通常クロバニル酸と一緒に使用されます。
- 🌐 セファロスポリンは4つの世代に分類されており、第1世代と第2世代は主にグラム陽性菌に作用し、第3世代と第4世代はグラム陰性菌にも広範に作用します。
- 💪 バンコマイシンは、グラム陽性菌に特化しており、特にMRSA(メチシリン耐性金黄色葡萄球菌)やC.diff(クローストリジウム難病)に効果的です。
- 🛠️ バンコマイシンは、ペプチドグリカン層のカルボキシル末端に結びつき、ペプチド結合を妨害することで細胞壁の合成を中断し、細菌を殺菌します。
- 💊 イソニアジドは結核を治療するために使用され、マイコリック酸合成酵素を阻害して細胞壁の整合性を損なうことで細菌を殺菌します。
Q & A
βラクタム系抗生物質とはどのような構造を持つ物質ですか?
-βラクタム系抗生物質は、5つのリング構造と4つのリング構造を持ち、カーボンと窒素を含む特別な構造を持っています。これはβラクタムという名称の由来で、一般的に環状アミドという構造を持っています。
ペニシリンGやアモキシシリン、および頭孢菌素類はどのように細菌を殺菌するのですか?
-これらの抗生物質はペニシリン結合蛋白に結びつき、自己分解酵素を活性化させたり、トランスペプチダーゼの交差リンキングを阻害することで、細菌の細胞壁構造を破壊します。細胞壁が破壊されると、水分が細菌細胞内に漏れ出し、最終的には細胞が溶解して細菌を殺菌します。
ペニシリンの抗生物質作用はどのようにして細菌に抵抗性を持たせることができますか?
-βラクタムアーゼという酶を発現させることで、細菌はペニシリンのβラクタムリングを切断し、ペニシリン結合蛋白に結合できなくなります。これにより、ペニシリンの殺菌効果が失われるため、細菌は抗生物質に耐性が持ちます。
アモキシシリンはなぜクローワラン酸と一緒に使用されるのですか?
-アモキシシリンはβラクタムアーゼに対して非常に敏感で、この酶によってβラクタムリングが切断されます。クローワラン酸はβラクタムアーゼの抑制剤であり、共用することでアモキシシリンの効果を高めることができます。
頭孢菌素類にはいくつの世代がありますか?それぞれ何の特徴がありますか?
-頭孢菌素類には4つの世代があります。第1世代と第2世代は主に革陽性菌に作用し、第3世代と第4世代は革陰性菌にも効果があります。各世代の頭孢菌素類は、細菌に対する広範な抗生物質効果を提供しています。
バンコマイシンはどのような細菌に対抗するために使用されますか?
-バンコマイシンは、メチシリン耐性黄色ブドウ球菌(MRSA)やクローストリジウムジフシレン感染症(C.diff)など、革陽性菌に対抗するために使用されます。
バンコマイシンはどのように細胞壁の合成を妨害するのですか?
-バンコマイシンはペプチドチェーンのカーボキシル末端に結合し、ペプチドボンド形成を阻害します。これにより、細胞壁の構造が破壊され、細菌細胞が溶解して死滅します。
イソニシアジドは結核を治療するためにどのように作用しますか?
-イソニシアジドは、結核菌のマイコリック酸合成酵素を阻害し、細胞壁のマイコリック酸の合成を妨害します。細胞壁の整合性が失われると、細菌細胞は死亡します。
ペニシリン結合蛋白とは何であり、抗生物質の作用にどのように関与しますか?
-ペニシリン結合蛋白は、細菌の細胞壁合成に関与する酵素であり、βラクタム系抗生物質が結合する標的です。これらの抗生物質がペニシリン結合蛋白に結合することで、細胞壁の合成が妨害され、細菌を殺菌する効果が得られます。
細菌が抗生物質に耐性を持つメカニズムにはどのようなものがありますか?
-細菌はβラクタムアーゼを産生することでβラクタム系抗生物質に耐性を持つことができます。また、他の抗生物質に対しても、抗生物質排出系、抗生物質分解酵素、または抗生物質標的の変異など、様々なメカニズムを通じて耐性を獲得する可能性があります。
Outlines
🔬 抗生物質の基礎知識とβラクタム系抗生物質
この段落では、抗生物質の基礎知識とβラクタム系抗生物質について説明しています。抗生物質は細菌の細胞壁に作用し、主にグラム陽性菌とグラム陰性菌の細胞壁の違いについて触れています。βラクタム系抗生物質は、ペニシリン、アモキシシリン、およびセフェム系を含み、細胞壁の合成を阻害することで細菌を殺菌します。ペニシリン結合蛋白に結びつき、オートリティック酵素を活性化し、細胞壁の構造を破壊します。
🛡️ 抗生物質による細胞壁構造の破壊メカニズム
この段落では、ペニシリンが細胞壁をどのように破壊するかについて詳しく説明しています。ペニシリンはペニシリン結合蛋白に結びつき、オートリティック酵素を刺激して細胞壁の構造を変化させ、細菌を殺菌するメカニズムを説明しています。また、抗生物質の耐性、特にβラクタム酶によるペニシリンの無効化についても触れられています。
💊 アモキシシリンとセフェム系抗生物質の治療範囲
アモキシシリンはβラクタム酶に対する敏感性があり、クローヴュラン酸と併用することで有効性を高めています。この段落では、アモキシシリンが治療できる疾患の範囲、例えば尿路感染や呼吸器感染、髄膜炎、サルモネラ感染、中耳炎などについて説明しています。セフェム系抗生物質も同様の作用機序を持っており、世代ごとに異なる細菌に対する治療効果があります。
🌟 セフェム系抗生物質の世代別特徴と治療対象
セフェム系抗生物質には4つの世代があり、それぞれ異なる細菌に対する治療効果を持っています。この段落では、第1世代と第2世代のセフェム系抗生物質が主にグラム陽性菌に作用し、第3世代と第4世代はグラム陰性菌にも効果があることを説明しています。具体的な抗生物質の名前と治療対象についても触れられています。
💥 ガンコマイシンの作用機序と抗生物質の他効果
ガンコマイシンは、グラム陽性菌に特に有効で、MRSAを含む耐性菌にも作用する抗生物質です。この段落では、ガンコマイシンが細胞壁の合成に必要なペプチドブオンド形成を阻害し、細菌を殺菌するメカニズムについて説明しています。さらに、他の抗生物質が細胞壁合成に作用する以外にも、フォリク酸経路を阻害する抗生物質も存在することを示唆しています。
🤒 抗結核薬イソニアジドの作用と抗生物質の応用
最後の段落では、結核を引き起こすマイコバクテリアに対する抗結核薬イソニアジドの作用機序について説明しています。マイコバクテリアの細胞壁はペプチドグリカンではなく、マイコリック酸から成り立っており、イソニアジドはこのマイコリック酸合成酵素を阻害して細胞壁の整合性を損なうことで細菌を殺菌します。
Mindmap
Keywords
💡抗生物質
💡β-ラクタン
💡ペニシリン結合蛋白
💡細菌の耐性
💡アモキシシリン
💡頭胞菌類
💡β-ラクタン酶
💡クローワラン酸
💡バニコマイシン
💡イソニアジド
Highlights
视频讨论了多种抗生素及其作用机制,但无法涵盖所有类型。
介绍了革兰氏阳性和阴性细菌的细胞壁结构差异。
β-内酰胺类抗生素,如青霉素和头孢类,通过影响细胞壁合成来杀菌。
青霉素通过结合青霉素结合蛋白,激活自溶酶,破坏细胞壁。
细菌对青霉素的抗药性主要是通过产生β-内酰胺酶实现。
阿莫西林与克拉维酸合用可抑制β-内酰胺酶,增强药效。
头孢类抗生素有四代,每代对革兰氏阳性和阴性细菌的覆盖范围不同。
第一代和第二代头孢类主要治疗革兰氏阳性细菌。
第三代和第四代头孢类增加了对革兰氏阴性细菌的治疗能力。
万古霉素作为糖肽类抗生素,用于治疗甲氧西林耐药金黄色葡萄球菌(MRSA)。
万古霉素通过结合肽链的羧基末端,阻止细胞壁合成,导致细菌死亡。
异烟肼是治疗结核病的主要药物,通过抑制结核分枝杆菌的细胞壁合成。
抗生素的作用机制包括激活自溶酶、抑制转肽酶,导致细胞壁破裂和细菌死亡。
抗生素的抗药性问题日益严重,需要合理使用以减缓抗药性发展。
视频将在未来讨论针对叶酸途径的抗生素。
抗生素的分类和使用需根据细菌类型和感染情况来决定。
视频提供了对抗生素作用机制的深入理解,有助于合理用药。
Transcripts
all right engineers in this video we're
going to talk about antibiotics all
right so the way we're going to do this
is we're going to go through at multiple
different types of antibiotics we're not
going to cover all of them it would just
be impossible to cover all of them and
all their different effects and
mechanisms of action we're going to
start off by looking at antibiotics that
are affecting the cell wall so it's
going to start there so if you look here
now bacterial if we're talking about
grandpa's anima gram-negative bacteria
we'll make a video on this but
gram-negative and gram-positive bacteria
really just differ and their overall
like if I were to have let's say I take
for example here I take two bacterial
cells just real quickly let's say here's
the bacteria and here's the bacteria
let's say this is gram-negative and
let's say this is gram positive the real
big difference between gram-negative and
gram-positive is that when you to look
at gram-negative bacteria they have a
very thin peptidoglycan layer so they're
peptidoglycan layer that we're going to
talk about that is very thin and another
thing is that they have a cell membrane
an outer cell membrane surrounding that
peptidoglycan layer and they have little
pores inside of it right so little
porins a gram positive bacteria is the
exact opposite it has a very very thick
peptidoglycan layer a very thick
peptidoglycan layer okay and that is
going to be our grand positive so we're
looking at gram positive and gram
negative bacteria it really is important
to kind of have a basic idea of what
their overall cell wall looks like an
overall cell structure is consisting of
okay so again one more time
gram-negative has a very thin
peptidoglycan layer but as an outer cell
membrane it also has what's called
lipopolysaccharides with lipid a and let
me probably saccharides and stuff like
that that are the toxins and I'm here
grand positive bacteria just as a very
thick peptidoglycan layer but no outer
cell membrane okay so now that we know
that let's go ahead and dig into
antibiotics so the first antibiotics
that we're going to talk about here
we're going to talk about the beta
lactams okay so we're going to focus
here on our beta lactams
now what is a beta lactam now just
really really quickly it has a specific
structure so if you look at a beta
lactam usually you have a 5 ring
structure here and then you have a
little 4 ring structure right here and
then you have a little carbon eel and
then you have this little nitrogen group
here so it's kind of like a cyclic amide
this right here is the beta lactam this
component here this is the beta lactam
so these beta-lactam antibiotics you
usually have this beta-lactam ring which
is incorporated into it okay the beta
lactams we're going to focus on here
we're going to focus specifically on the
penicillins so we'll talk about
penicillin specifically like penicillin
G and then we're going to talk about
amoxicillin
okay so amoxicillin and then we're going
to talk about cephalosporins and we'll
talk about all the generations of
cephalosporins okay before I do that
let's take a look at the overall cell
wall structure again just a little bit
more in depth zooming in on that
peptidoglycan layer if we look in the
peptidoglycan layer what is the
peptidoglycan you see these blue
structures right here
those blue structures are specific
derivatives of carbohydrates like
glucose so what do I mean there are made
up of structures which is called NAMM
and nag so they're just derivatives of
glucose n am NAMM stands for in acetyl
uric acid in Ag stands for in acetyl
glucosamine all these are these blue
structures here they're just derivatives
of our carbohydrates like glucose okay
now coming up off of these carbohydrate
residues you see this like a violet
structure coming up out of this that
right there is like peptide bond is
actually a pentapeptide and then across
from that again you're going to have
another what would this be this would be
another an acetyl Meramec acid and this
could be another and acetyl glucosamine
these black proteins are coming
downwards from this part to this is
another pentapeptide and if you look
there this little orange structure
that's the cross link between them
that's the peptide bond between them
right
so this is the basic structure of our
peptidoglycan layer in a zoomed look you
see this little orange guy just kind of
sitting down
that's our penicillin binding protein so
that little red structure right there
which is actually going to be sitting
down there on the cell membrane is going
to be the penicillin binding protein so
what is this guy here called
he's called the penicillin binding
protein okay he's a pretty important
structure here because he's going to
what he's really what a lot of these
actual beta lactams are binding on to
alright next thing if you look here
these brown scissors those are little
auto lytic enzymes so we're going to
talk about them and then these little C
like orange enzymes there they're called
beta lactam ASIS ok so this little
orange structure up here this orange
structure here is called beta lactamase
and then these little brown structures
they are actually going to be called
Auto lytic enzymes okay now that we've
done that let's go over these
antibiotics here alright penicillin
first so penicillin it's it is able to
treat in general gram-positive and
gram-negative bacteria however over the
past you know years certain bacteria
have become resistant to penicillin okay
how have they become resistant to
penicillin okay this beta lactamase
there's a specific part of it today beta
lactamase
so it's an enzyme right so look what it
can actually do I'm going to draw that
beta-lactam ring over here and it's got
that double bond right there with the NH
and then it's got the little five
membered ring there this is our
penicillin if we give someone penicillin
who already has bacteria that are very
resistant to the penicillin what do I
mean maybe they have plasmids that allow
for them to produce this enzyme called
beta lactamase what will the beta
lactamase do though it'll break the
beta-lactam ring if it cuts the
beta-lactam ring this penicillin is not
going to be able to bind to this
penicillin binding protein and mediate
its effects so because of that this will
be rendered ineffective
so that is the importance is that
certain bacteria become resistant by
developing beta-lactam Isis
so really it's more effective now just
being able to treat gram positive
bacteria with a little bit of
gram-negative coverage so what type of
bacteria is it a recover if you may it
can cover streptococcal okay that's the
main one it can cover streptococcal
bacteria so any type of streptococcal
bacteria okay it was able to develop you
know in the past treat you know
staphylococcal bacteria but again
they've developed resistance also so
streptococcal bacteria it's also able to
treat syphilis okay
so just a little bit on the penicillin
so what does penicillin actually do how
does it mediate these effects that it
can actually kill these bacteria because
it's bacteria SCYTL meaning you can kill
the bacteria so let's say here here's
the penicillin what the penicillin does
is it comes in and it binds on to this
penicillin binding protein so let's say
that we draw that here here's the
penicillin and he binds on to this
penicillin binding protein when he binds
to the penicillin binding protein he
stimulates the penicillin binding
protein and what this penicillin binding
protein does is it takes its hand and it
comes up there and it stimulates these
brown enzymes so then what does it do it
comes up here and stimulates these auto
lytic enzymes if these auto analytic
enzymes are activated what are they
going to do they're going to start
cutting up these bonds these peptide
bonds these glycosidic bonds and it's
going to start altering the overall
structure of the cell wall that's one
thing that happens second thing that
happens there's a lot of other enzymes
here there is other enzymes that
actually link these peptide bonds
together between these little
pentapeptides
so you get for having different types of
transpeptidase enzymes
whenever the penicillin binding protein
is stimulated he inhibits the
transpeptidase is from cross linking
these pentapeptides and if these are no
longer cross-linked the cell wall starts
becoming disrupted now when the cell
wall is disrupted it allows for water to
start leaking into the bacterial cells
and when water leaks into the
Piersol eventually can cause the cell to
lyse that is the way penicillin works so
again one more time because all the rest
of them are gonna do the same thing so
once we know penicillin we know what
these functions are - so one more time
what does penicillin do penicillin comes
in binds onto the penicillin binding
protein stimulates him when he becomes
stimulated he stimulates these Auto
lytic enzymes who start cleaving and
breaking up the cell wall then he also
inhibits let's say that I draw this
enzyme out here I'm just going to draw
some little dude out here here's this
little dude and he's got his hand in
this bond right there okay these are
transpeptidase enzyme what are these
transpeptidase enzymes doing they're
helping to link these actual
pentapeptides
he will inhibit these transpeptidase
enzymes so now they can no longer cross
link these little peptide chains and
because that the cell wall will be
disrupted
once it's disrupted water can leak in
when water leaks in to cell lysis okay
so we're set there amoxicillin same
mechanism of action cephalosporins same
mechanism of action but now amoxicillin
he is very very susceptible to these
beta lactamase is very very susceptible
so when you give someone a moxa stealing
you usually want to give it to them with
clavulanic acid
clavo lonex acid why do you want to give
that because clavulanic acid is a
beta-lactamase inhibitor so if you give
them clavulanic acid what is it going to
do it's going to inhibit the beta
lactamase enzyme if the beta lactamase
is inhibited now this amoxicillin is
going to have more available to start
exhibiting this effect okay so that's
the job of clavulanic acid
what can a moxa sill entreat it can
treat a lot of different things so
amoxicillin is good at being able to
treat urinary tract infections he's
going to being able to treat respiratory
tract infections he's also good at being
able to treat meningitis and he can also
treat infections that are caused by
salmonella - so we can also treat
infections caused by salmonella and you
know he's also really good at being able
to treat
middle ear infections on Titus media too
so Titus media middle ear infections
right okay so that is going to be the
amok Ahsan so he's going to be able to
treat urinary tract infections
respiratory tract infections meningitis
salmonella otitis media okay
cephalosporins mechanism of action same
thing activates the penicillin binding
proteins and inserts all those effects
cephalosporins though are very
interesting okay so there's four
generations of cephalus horns right so
let's go ahead and go over those real
quickly so their first generation
so we could say first generation so
first generation is actually going to be
we could take for example
cephalexin so cephalexin is one example
here of a first generation cephalosporin
then we could take for example a second
generation now a second generation will
be like Seth a rock scene set for rock
scene okay and then we could take for
example a third-generation cephalosporin
so a third-generation cephalosporin
could be like ceftriaxone and then
there's even fourth generation so fourth
generation would be like cefepime so
fourth generation would be like cefepime
now why am i mentioning this well the
reason why is cephalosporins the first
and second generation are really only
good at being able to treat mainly gram
positive bacteria so these are really
only good at being able to treat gram
positive bacteria okay whereas what's
happened over the years is that the
ceftriaxone and the SEPA pean have
actually had a little bit more ability
to treat more of the gram-negative
bacteria okay so again first generation
could be like cephalexin and second
generation could be like cefuroxime but
the big takeaway is these aren't really
used anymore but they're good to treat
gram positive third generation fourth
generation have a little bit more gram
negative coverage so except try Oksana
cefepime
okay so what would be the coverage so
for example let's say that I used
cephalexin and cefuroxime they really
only have grand positive coverage so
what I really use these guys for I would
probably use these guys for more of your
Staphylococcus aureus and streptococcus
pyogenes so even streptococcus pyogenes
okay now if we use ceftriaxone and
cefepime they can treat gram-negative so
what can I use that for I could use that
to treat them they have a lot of good
things that they could treat
now Pseudomonas is a really big one they
can treat Pseudomonas so like
Pseudomonas aeruginosa they can treat
certain types of bacteria that cause
meningitis um they're also pretty good
at being able to treat infections caused
by Klebsiella so Klebsiella which is
very common a bacteria that can cause
pneumonia so pneumonia so this is
actually a bacteria that cause pneumonia
more commonly it can cause other
infections but more commonly pneumonia
and even other different types of entero
bacteria so even different types of
inteiro bacteria all right so that's our
cephalosporins there is other beta
lactams and different types of
penicillin derivatives that I could have
mentioned like pip Tazo I could have
been to mention carbapenems you know a
pip Tazo can treat Pseudomonas
carbapenems are actually going to be
able to treat very very problematic
abdominal infections so they can treat
that too all right but that's pretty
much going to cover our beta lactam so a
quick review and we're going to move on
to the next ones really here we go
penicillins what do they actually do
they're going to come down here by onto
the penicillin binding proteins then
what activate the auto lytic enzymes
which we're going to cut up some of the
cell wall structures disrupting cell
wall also penicillin binding proteins
are going to inhibit these enzymes that
are called trans peptidases so if you
inhibit them they can't cross link these
actual peptide chains cell walls
disrupted what happens as a result water
leaks in and then eventually cause the
cell
to lice and kills itself so these are
bacteria sidle you need to kill the
bacteria what could be certain types of
beta lactams penicillin amoxicillin
cephalosporins right and I can even
included carbapenems or pepper selling
with hazel back in like pip Tazo but
again what is penicillin treating grand
positive and gram-negative mainly
streptococcal because there's a
staphylococcal bacteria become resistant
he can also treat syphilis
what about amoxicillin he's very very
sensitive to the beta lactamase is who
cleaved the beta lactam rings so in
order to make them effective what are
you give them with clavulanic acid what
can they treat UTIs respiratory tract
infections bacteria that cause
meningitis salmonella otitis media okay
and then cephalus points you said there
are four main generations there is five
fifth I said can you eat Marissa first
generation second generation are mainly
for gram positive first generation could
be like cefalexin second generation
could be like cefuroxime so they can
treat Staphylococcus aureus and
streptococcus pyogenes okay and then
third and fourth generation are more for
the gram-negative coverage and so those
third generations to be like ceftriaxone
and cefepime right what can they treat
like Pseudomonas aeruginosa meningitis
Klebsiella which can cause pneumonia as
well as entero bacteria okay what other
kind of drugs affect the cell wall
because there is other drugs besides
these ones very very powerful one we
have to mention this one this very very
powerful one is actually called it's
like glycol peptide
so let's actually put that down so let's
actually this is actually a group under
the glycol peptides
so what glycol peptide is this this
glycol peptide is very very strong this
is called Vanko Mison and vancomycin is
actually really good at being able to
treat mersa what is what is Marissa
Marissa stands for methicillin-resistant
Staphylococcus aureus now methicillin is
an antibiotic but they don't really use
that anymore okay but certain bacteria
have become resistant right to
penicillin or methicillin so you have to
give Vanko because that can kill the
Marissa
okay now venko is actually really good
mainly at being able to treat gram
positive bacteria okay so like MRSA and
c-diff so Clostridium difficile colitis
so it's good at being able to treat c
diff so c diff is the one that makes you
pee out your butthole all right so it's
really nasty one really really
infectious diarrhea and it also can
retreat certain types of bacteria which
are like resistant resistant coagulase
so coagulase negative now remember i'm
saying negative resistant coagulates
negative bacteria okay and this is Vanko
so vanko's are pretty powerful
antibiotic now what does vancomycin do
he does something different he has the
overall same effect of these beta
lactams but different mechanism of
action what exactly is he doing thank ou
is very very interesting so you know
that every protein usually has what's
called a carboxy terminus and then as an
amino terminus right and then really if
I were to show the peptide bond
correctly it's really what's linking in
this part together right here's what's
interesting let's say I take Vanko if I
give someone Vanko look what it's doing
it's binding onto this carboxyl end when
it binds onto the carboxyl end this
can't form a peptide bond so now what
happens is vancomycin binds onto the
carboxyl end of these actual peptide
chains and if it blocks onto it Xterra
Clee hinders that peptide bond formation
so now if you can't form a peptide bond
this cell wall is disrupted if this cell
wall is disrupted what happens water
flows in as water flows in what happens
the cell lysis so this is a bacterial
cell antibiotic okay so one more time
what does Vanko doing it's binding onto
the carboxyl end of these peptide chains
as it binds on to the carboxyl end it's
sterically hindered this amine group
from being able to form a peptide bond
and as a result of cell wall is
disrupted water enters in and the cell
lysis so it's a bacterial Seidel
antibiotic okay so we've covered our
glycol peptides now let's go over here
let's cover a very
weird type of bacteria that's not for
grandpas and for gram negative bacteria
okay so this one that I'm going to talk
about is mainly important for being able
to treat tuberculosis okay so it's
mainly used to treat tuberculosis so
caused by the Mycobacterium now
Mycobacterium don't have a cell wall
that's made up of peptidoglycan they are
made up of these little orange
structures you know what these orange
structures are called they're called
mycolic acid so can you see this enzyme
right here this blue enzyme this blue
enzyme is called a mycolic acid synthase
source in space it's called I so nyeh
SID and again what is this antibiotic do
this antibiotic is mainly treating
tuberculosis caused by the Michel
bacterium so what it does is it has a
specific point word actually here let's
say here's the isoniazid it's actually
going to come in and inhibit this
mycolic acid synthase our synthetase
enzyme if this enzyme is inhibited can
it synthesize the mycolic acids to make
up the cell walls no and if it can't
synthesize this mycolic acid the cell
wall integrity is altered if the cell
walls integrity is altered can that cell
survive no water might flush into it and
cause the bacteria to die so again
isoniazid is used to treat tuberculosis
caused by the micro bacterium it's cell
walls consisting of these mycolic acid
residues what happens is if you give
ionize it and hits the mycolic acid
synthesis or synthase enzyme which then
can no longer synthesize mycolic acid if
it can't synthesize mycolic acid the
cell walls integrity is altered and then
what happens the bacterial cell dies
okay alright guys so that pretty much
covers on this part the antibiotics that
are treating for specifically the cell
wall synthesis and structure in the next
video we're going to talk about the
antibiotics that are mainly used to
target the folic acid pathway
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