PENDAHULUAN MIKROBIOLOGI KESEHATAN : KLASIFIKASI DAN STRUKTUR SEL BAKTERI. Dr. Leonardus Widyatmoko

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1 PENDAHULUAN MIKROBIOLOGI KESEHATAN : KLASIFIKASI DAN STRUKTUR SEL BAKTERI Dr. Leonardus Widyatmoko

2 TUJUAN Setelah mempelajari materi pada hari ini diharapkan anda dapat : Memahami klasifikasi mikroba dan taksonomi bakteri Mampu membedakan antara sel prokariot (bakteri) dengan eukariot Mampu memahami struktur sel bakteri Mampu memahami perbedaan pada dinding sel bakteri

3 SUMBER PUSTAKA Mahon textbook of Diagnostic Microbiology 4th Ed. Jawetz et all Medical Microbiology 25th Ed.

4 Sebuah Ilustrasi

5 KLASIFIKASI BAKTERI

6 ISTILAH Taksonomi Pengelompokan suatu organisme dalam suatu hierarki yang menggambarkan kedekatan hubungan di alam Klasifikasi Proses pengelompokan ke dalam suatu grup taksonomi Nomenklatur Penamaan suatu organisme menurut suatu konsensus internasional berdasarkan karakteristiknya Identifikasi Praktik pengenalan suatu organisme dengan menggunakan algoritme/metode tertentu

7 Nomenklatur Klasifikasi Identifikasi Taksonomi Persamaan dan perbedaan dalam GENOTIPE (susunan genetik) dan FENOTIPE (Tampilan fisik dan fungsional)

8 CONTOH KLASIFI KASI Nomenklatur

9 Klasifikasi Phylogenetik :Pemahaman evolusi dan kedekatan hubungan pada bakteri

10 STRUKTUR SEL PROKARIOT DAN EUKARIOT

11 MICROBIAL WORLD The Microbial World

12 Eukaryotes

13 Prokaryotes (Bacteria)

14 Perbandingan Prokariot dan Eukariot

15 Perbandingan Prokariot dan Eukariot

16 STRUKTUR SEL BAKTERI

17 Unit for measurement : Micron or micrometer,μm: 1μm=10-3mm Size: SIZE OF BACTERIA Varies with kinds of bacteria, and also related to their age and external environment. Cocci: sphere, 1μm Bacilli: rods, μm in width -3 μm in length Spiral bacteria: 1~3 μm in length and μm in width

18 BACTERIAL STRUCTURE OVERVIEW Essential structures : cell wall cell membrane Cytoplasm nuclear material Particular structures : capsule flagella pili spore

19 1884: Christian Gram: First publication for the Gram stain method Cell membrane Nucleoid Flagellum Cell wall Gram + Pili Gram - Capsule Granule Cell (inner) membrane Outer membrane Ribosomes Cell wall Gram, C Ueber die isolirte Farbung der Schizomyceten in SchnittÄund Trockenpraparaten. Fortschritte der Medicin, Vol. 2, pages

20 Cell wall/dinding sel Merupakan bagian terluar, dengan ketebalan 15-30nm dan sekitar 10-25% dari berat

21 Cell wall :Lapisan Peptidoglycan Tersusun oleh N-acetyl glucosamine (NAG) dan N-acetylmuramic acid (NAM): ditemukan pada bakteri gram positif dan negatif Terdapat struktur tetrapeptide yang menempel pada NAM : menjadi tempat perlekatan AB pada bakteri Pada gram positif bakteri membentuk jalinan cross bridging : melindungi dari proses osmotik

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23 Special components of Gram positive cell wall Teichoic acid SPA / M POTEIN

24 Special components of Gram negative cell wall

25 COMPARISON

26 Hasil Pengecatan Gram Streptococcus Gram + Neisseria Gram -

27 Hasil Pengecatan ZN: Mycobacterium tuberculosis Acid-fast stain. 1000X magnification.

28 Functions of Cell Wall Maintaining the cell's characteristic shape- the rigid wall compensates for the flexibility of the phospholipid membrane and keeps the cell from assuming a spherical shape Countering the effects of osmotic pressure Providing attachment sites for bacteriophages Providing a rigid platform for surface appendagesflagella, fimbriae, and pili all emanate from the wall and extend beyond it Play an essential role in cell division Be the sites of major antigenic determinants of the cell surface Resistance of Antibiotics

29 Wall-less forms of Bacteria. When bacteria are treated with 1) enzymes that are lytic for the cell wall e.g. lysozyme or 2) antibiotics that interfere with biosynthesis of peptidoglycan, wall-less bacteria are often produced. Usually these treatments generate non-viable organisms. Wall-less bacteria that can not replicate are referred to as spheroplasts (when an outer membrane is present) or protoplasts (if an outer membrane is not present).

30 Cell membrane Berperan dalam proses biosintesis DNA, polimerisasi dinding sel dan membran lipid melalui proses selective permeability untuk transpor ke dalam sel Terjadi proses transpor elektron dan fosforilasi oksidatif Mengekskresi exoenzim hidrolitik

31 Cytoplasm Composed largely of water, together with proteins, nucleic acid, lipids and small amount of sugars and salts Ribosomes: numerous, 15-20nm in diameter with 70S; distributed throughout the cytoplasm; sensitive to streptomycin and erythromycin site of protein synthesis Plasmids: extrachromosomal genetic elements Inclusions: sources of stored energy, e,g volutin

32 Plasmid Plasmids are small,circular/line, extrachromosomal,double-stranded DNA molecules They are capable of self-replication and contain genes that confer some properties,such as antibiotic resistance,virulence factors Plasmids are not essential for cellular survival. granulose Inclusions are aggregates of various compounds that are normally involved in storing energy reserves or building blocks for the cell. Inclusions accumilate when a cell is grown in the presence of excess nutrients and they are often observed under laboratory conditions. Inclusions of Bacteria Corynebacterium

33 Nucleus Lacking nuclear membrane, absence of nucleoli, hence known as nucleic material or nucleoid, one to several per bacterium.

34 Capsules and slime layers Attachment Protection from phagocytic engulfment. Resistance to drying. Depot for waste products. Reservoir for certain nutrients. Mucoid colony These are structures surrounding the outside of the cell envelope. They usually consist of polysaccharide; however, in certain bacilli they are composed of a polypeptide (polyglutamic acid). They are not essential to cell viability and some strains within a species will produce a capsule, whilst others do not. Capsules are often lost during in vitro culture.

35 Some bacterial species are mobile and possess locomotory organelles - flagella. Flagella consist of a number of proteins including flagellin The diameter of a flagellum is thin, 20 nm, and long with some having a length 10 times the diameter of cell. Due to their small diameter, flagella cannot be seen in the light microscope unless a special stain is applied. Bacteria can have one or more flagella arranged in clumps or spread all over the cell. Identification of Bacteria Pathogenesis Motility of bacteria Flagella Monotrichate/Amphitrichate/Lophotrichate/Peritrichate

36 Pili Pili are hair-like projections of the cell, They are known to be receptors for certain bacterial viruses. Chemical nature is pilin Classification and Function a. Common pili or fimbriae: fine, rigid numerous, related to bacterial adhesion b. Sex pili: longer and coarser, only 1-4, related to bacterial conjugation

37 Pilli vs Flagel Shigella: common pili Salmonella: common pili & peritrichious flagella

38 Pilli sex & konjugasi

39 Endospores (spores) Identification of Bacteria Pathogenesis Resistance Dormant cell Resistant to adverse conditions - high temperatures - organic solvents Produced when starved Contain calcium dipicolinate DPA, Dipicolinic acid Bacillus and Clostridium

40 Proses sporulasi

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