Bacteriology_Antibiotics.pptxBacteriology_Antibiotics

Bacteriology_Antibiotics

1. Dr. Hafiz Muzzammel Rehman

2. A microbe is a microscopic small living creature and the science of microbes is called microbiology Microorganisms can be of various types such as bacteria, fungi, archaea, green algae, plankton, and planarian Th e fi e ld o f microbiology i n c lud e s par a sitolog y , b acteri o log y , virology, mycology, and other branches Most of the microorganisms are generally unicellular or single- cell organism Introdu c tion

3. Lee u w enh o e k microscope “ i s c al l ed "t h e i n v entor o f the Created a “simple” microscope that could magnify to about 275x, and published drawings of microorganisms in 1683 5 Microorganism: Historical perspective In the late sixteenth century, scientist Antonie van Leeuwenhoek had observed for the first time the structure of a microorganism using a microscope. There had been tremendous research on microbe’s anatomy, physiology, and its functionality. In 1876, scientist Robert Koch established that microbes can cause disease in animals and humans .

4. Shapes of Bacteria major groups Cocci – spherical/ oval shaped Bacilli – rod shaped Vibrios – comma shaped Spirilla – rigid spiral forms Spirochetes – flexible spiral forms Actinomycetes – branching filamentous bacteria Mycoplasmas – lack cell wall

5. Bacteria Have One of Three Cellular Shapes Rods (bacilli) Coc c oi d -Shap e d Spirilla

6. Arrangement of bacteria: Cocci Sarcina – groups of eight Cocci in chain - Streptococci Coccus Cocci in pair – Diplococcus Tetrad – groups of four Cocci in cluster - Staphylococci

7. Classification of Microorganisms

8. Organization of bacteria Bacteria are a large group of single-celled prokaryote microorganisms A-Structure of bacterium Bacterial cells are about one-tenth the size of eukaryotic cells and normally 0.5–5 mm in length The genus Mycoplasma is among the smallest bacteria, which measures only 0.3 µm Bacteria often attach to surfaces and form dense collections of cells called biofilms .

9. Anatomy of a Bacterial Cell

10. Intracellular structures Bacteria subsequently lack a nucleus, mitochondria, or chloroplasts that are present in eukaryotic cells, such as the endoplasmic reticulum and Golgi apparatus Microcompartments such as carbonxysome provide an additional level of organization, which are compartments within bacteria that are surrounded by polyhedral protein shells, rather than by lipid membranes. M o re int e re s tingl y , th e se polyhe d ral localize and bacterial organelles c o m p a rt m en t alize metabolism The genetic material of bacteria is typically a single circular chromosome positioned in the cytoplasm in the nucleoid

11. Carboxysomes are bacterial compartments consisting of polyhedral protein shells filled with the enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase ( RuBisCO ) -the predominant enzyme in carbon fixation and the rate limiting enzyme in the Calvin Cycle and a carbonic anhydrase bacterium Halothiobacillus neapolitanus :

12. Extracellular structures The b a ct e ri a l c e ll walls are n o r ma lly made of peptidogly c an, whi c h are polysaccharide chains cross linked by peptides enclosing d-amino acids G r a m -p o s i t i v e bac t e ria k e e p a th i ck c e ll wall c o n t aining many laye r s of peptidoglycan and teichoic acids, whereas in the case of Gram negative bacteria , the cell is thin and contains few layers of peptidoglycan enclosed by lipopolysaccharides and lipoproteins These differences in cell structure can produce differences in antibiotic vulnerability; for example, vancomycin can kill only Gram-positive bacteria and is found to be ineffective against Gram-negative pathogens, such as Haemophilus influenza. Cell wall provides chemical and physical protection

13. Differences Between Prokaryotic & Eukaryotic cells Character Prokaryotes Eukaryotes Nucleus Nuclear membr a ne Absent Present Nucleolus Absent Present Chromosome One circular One or more paired and linear Cell division Binary fission Mitosis Cytoplasmic membrane Structure and Composition fluid phospholipid bilayer, lacks sterols fluid phospholipid bilayer containing sterols Function Incapable of endocytosis (phagocytosis and pinocytosis) and exocytosis Capable of endocytosis and exocytosis

14. Character Prokaryotes Eukaryotes Cytoplasm Mitochondria Absent Present Lysosomes Absent Present Golgi apparatus Absent Present Endopla s mic reticulum Absent Present Vacuoles Absent Present Ribosomes 70 S 80 S Differences Between Prokaryotic & Eukaryotic cells

15. Character Prokaryotes Eukaryotes Cell Wall Present Animals & Protozoans – Absent Plants, Fungi & Algae - Present Composition Peptidoglycan – complex carbohydrate Cellulose or chitin Lo c omotor organelles Flagella Flagella/ Cilia Differences Between Prokaryotic & Eukaryotic cells

16. B-Bacterial genetics Have a single circular chromosome that can range in size from only 160,000 base pairs to 12,200,000 base pairs Bacterial genes usually contain a single unbroken DNA, plasmids, which are small extrachromosomal DNA that are accountable for the development of antibiotic resistant C-Nomenclature of bacteria Int e rn a tional Com m i ttee o n S y stemat i cs o f Pr o ka r y otes m a intains int e rna t ional rules for the description of bacteria Identification of bacteria is done using molecular tools such as PCR methods due to their specificity and speedy result

17. D- Bacteria: Friends or foes

18. E-Pathogenic bacteria Tuberculosis is the disease caused by the bacterium Mycobacterium tuberculosis; Pneumonia is caused by bacteria such as Streptococcus and Pseudomonas, and food-borne illnesses are caused by bacteria such as Shigella, Campylobacter, and Salmonella. Pathogenic bacteria are also known to cause infections such as typhoid fever, diphtheria, syphilis, tetanus, and leprosy. Staphylococcus or Streptococcus are also part of the normal human flora and usually occur on the skin and they do not cause any diseases

19. What is the Microbiome? The human microbiome is the population of more than 100 trillion microorganisms that colonize our gut, mouth, skin and elsewhere in our body. Thousands of different microbial species colonize our bodies, together contain over one hundred times more genes than in our genome. This group of microorganisms is called the microbiome and helps keep us alive. Human body mainly made up of the microbiome, then there’s the human part of us that provides the environment for all of those microbes to live in.

20. Where does our microbiome come from? Breast milk: baby’s first microbes. The microbial world largely invisible to the human eye, but it is almost beyond imagination. There are hundreds, thousands of different kinds of bacteria (leaving aside other kinds of microbes: archaea, viruses, fungi, and protists), living in every possible environment including deep seabed, high in the clouds, in the boiling hot springs. Multicellular organisms created an entirely new set of habitats, in and on all those animals and plants.

21. Where is the microbiome located, and what is it doing? The human body is exposed to the outside world, there is a microbial community. That means the entire surface of the skin, and the linings of the nasal passages, lungs, digestive and urogenital tracts are all home to microbial communities. Some of these communities are extremely dense and others more sparse What the microbiome is doing also varies from place to place and many of its functions have not yet been worked out.

22. Synthesize and excrete vitamins Vitamin K and Vitamin B12 Prevent colonization by pathogens competing for attachment sites or for essential nutrients May antagonize other bacteria the production of substances which inhibit or kill non-indigenous species(nonspecific fatty acids, peroxides, bacteriocins). Stimulate the development of certain tissues i.e., intestines, certain lymphatic tissues, capillary density Stimulate the production of cross-reactive antibodies. Low levels of antibodies produced against components of the normal flora are known to cross react with certain related pathogens, and thereby prevent infection or invasion. Benefits of the Normal Flora

23. SKIN: Microbes live on all skin surfaces as well as within Pores and sweat glands, and along hair shafts. The composition of the skin microbiome varies from place to place, with dry areas. Skin microbes can help keep away pathogens MOUTH: About 1000 microbial species have been found in the human mouth, the mouth contains many different microhabitats including tooth surfaces, tongue, cheeks, and gums.

24. GUT: The gut contains the largest, densest, and most diverse microbial community in the human body. The human large intestine, is among the densest microbial ecosystems ever observed. The gut microbiome acts as a highly efficient bioreactor, helping to extract energy and nutrients from the food we eat Compounds that humans cannot digest on their own can be broken down by microbes , these microbial capabilities allowed humans to benefit from a wider variety of foodstuffs The gut microbiome has complex effects on human metabolism and changes in its composition have been linked to a number of diseases including inflammatory bowel disease, autoimmune disorders, and even diabetes and obesity

25. What is the relationship between the microbiome, health, and disease? There have been many studies that show a correlation between certain mixtures of microbes and certain disease states, but evidence that any particular microbial community actually causes a particular disease is still limited. The early history of microbiology was dominated by the quest to identify the microbes responsible for disease, and find ways to stop them. Identification and study of causative agents was the first step in developing ways to prevent and cure infectious diseases.

26. Mic r ob e s ca n com m u n ic a te each other b y chemical language They interact each other by signals and respond to the signals by using chemical language This Phenomenon is called “ Quorum Sensing” Quorum Sensing signals are called auto inducers All auto inducers are chemical language signals to one another. Quorum Sensing is a system of stimulus and response correlated to population density. Many species of bacteria use quorum sensing to coordinate gene expression according to the density of their local population

27. Does the microbiome change over time? The microbiome definitely changes dramatically between birth and the age of about two years, when it begins to look like a typical adult microbiome After the adult-like microbiome is established, does it change over time, or can it be intentionally changed? On the simplest level, the answer to both questions is yes. The microbiome can change as a result of changing diet, treatment with antibiotics, or a move to a new environment. The microbiome can change in different ways some species will be found at all times while others will come and go.

28. Is everyone’s microbiome the same? Yes! and No! Each individual’s microbiome carries out many similar functions, but the jobs are not necessarily done by the same microbial species in each person. Also, the species carrying out the various functions in any given individual may change over time. The situation is analogous to any other kind of ecosystem, for example analogy is that of a city: every city has fire-fighters, police officers, bus drivers, and garbage collectors, but different people fill those roles in each city.

29. Does everyone have a microbial “fingerprint”? W e d o no t y e t know enough about how mu c h v ari a tion the r e individuals’ microbiomes, d o we kn o w ho w m u c h or i s b e t w een nor how quickly microbiomes change over time, to use such data in a forensic setting. Valid use of microbiome information for forensic wi l l r equi r e a m u c h la r g er d a t ab a s e than i s c u r r e n t ly purposes r e f e r ence available.