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  1. 1. ‫الرحيم‬ ‫الرحمن‬ ‫ال‬ ‫بسم‬
  2. 2.  The study of living organisms which are very small and simple in structure (microorganisms)  There are 4 kinds of microorganisms of medical importance : Bacteria , Protozoa , Fungi, and viruses.
  3. 3.  Unicellular microorganism.  1/100 to 1/1000 mm in diameter ,  Has a very primitive cell with primitive nuclear material  Cytoplasm containing ribosomes and cell wall.
  4. 4.  Unicellular,  1/10 to 1/100 mm in diameter(larger than bacteria)  More complicated than bacteria , with well defined nucleus ,  Cytoplasm containing ribosomes and mitochondria.  Some protozoa can cause diseases such as toxoplasmosis , malaria, and amoebic dysentery.
  5. 5. Resemble primitive plants , They have a structure which is basically similar to protozoa Some fungi can cause diseases such as candidasis
  6. 6.  The smallest and simplest of all microorganisms 1/100,000 of mm in diameter only can be seen by electron microscopy.  Viruses are not proper cells ,they consists of strands of nucleic acid surrounded by a a protective protein coating.  Viruses cannot multiply by themselves , they reproduce by invading a living cell and facing it to manufacture new virus particles.  Some viruses can cause diseases such as influenza ,common cold , herps ,and poliomyelitis.
  7. 7. Bacteria Protozoa Fungi viruses Structure Unicellular Unicellular Resemble primitive plants are not proper cells Size 1/100to 1/1000 mm 1/10to 1/100 mm 1/100000 mm classificati on Primitive cell (prokaryotic( Eukarytic eukaryotik Nucleus Primitive nuclear material Well defined Well defined No cytoplasm Containing ribosomes and cell wall Containing ribosomes and mitochondria Ribosomes and mitochondria no
  8. 8. Bacterial cell
  9. 9. Structure of bacterial cell  Cell wall : It is the outermost layer of the bacterial cell. it is rigid to protect the bacterial cell from the environment , the rigidity is due to the presence of chemical substance called Peptidoglycan and this substance determine whether the bacteria will be stain or not by Gram stain  Cell membrane (cytoplasmic membrane ): It is located directly under the cell wall It is permeable to allow nutrients to enter and wastes to leave the bacterial cell , and to maintain water balance of the cell
  10. 10.  Cytoplasm : it is the soft gel that contain the different organs of the bacterial cell  Nuclear material : it is formed of DNA which is responsible for carrying the genetic information of the bacterial cell  Ribosome: They contain RNA They are responsible for manufacturing proteins and enzymes which are essential for cell growth and reproduction  Plasmid : They are formed of DNA and play an imporant role in transferring the resistance ability from one bacterium to another Structure of bacterial cell
  11. 11. Other structure  Pili: Delicate projection help the bacterial cell to attach to another living cell and transfer of genetic material from one cell to the other  Flagella long thread help the bacterial cell to propel with whipping movement  Fimbriae Shorter thinner and more numerous than flagella , they help the cell to attach to surface  Capsules : Protective coating around the cell wall  Spores : Version of cell which are highly resistant to atmospheric
  12. 12. Bacterial Reproduction:  There are 2 method of bacterial reproduction : 1- Asexual reproduction (simple binnary fission) more common 2- Seuxal reproduction (conjugation ) via plasmid transfer less common
  13. 13. Bacterial resistance:  There are 2 types of bacterial resistance to antibacterial agents : A-A- natural resistance :natural resistance : some bacteria are naturally resistant to particular antibiotics irrespective of previous contact with that antibiotic . This is a result of specific biochemistry or anatomy of the cell which renders it insensitive to that antibiotic (e.g most of gram –ve bacteria are resistant to penicillin –G)
  14. 14. Bacterial resistance:  Acquired resistance : This arises when bacteria were susceptible to an antibiotic and after exposure to that antibiotic become unsusceptible may develop by one of the following ways : 1- general mutation : Occasionally during bacterial reproduction ,DNA May by imperfectly replaced “mutation “ . Mutant daughter cell become more resistant to some types of antibiotics 2- Transfer of resistance by plasmid : plasmid is a fragment of DNA which float in the cytoplasm Plasmid can carry various kind of genetic information including information of antibiotic resistance (R-plasmid )
  15. 15.  R-plasmid can be transmitted from one cell to another by one of 2 methods: A- Conjugation: Transfer of R-plasmid During conjugation between cells B-Bacteriophage It is a virus which parasites on bacteria and during its reproduction it makes use of bacterial cell components including R-plasmid . When the offspring bacteriphages attack other bacterial cell , they transfer R-plasmid to their new host which they become resistance
  16. 16. Mechanism of resistant to Antibiotics: 1- production of inhibiting enzymes 2- changing metabolic pathways: Some bacteria develop resistance to sulphonamides by increasing their production of PABA so much that the antibiotic by fail to compete for the enzyme which utilize this substance 3- Altering cell membrane permeability : antibiotic will be unable to introduce into the cell to exert its function (e.g. pseudomonas )
  17. 17. Bacterial classificationBacterial classification I-According to habitat: 1- Saprophytes: they are harmless , they live in water 2-Parasites :they live only in living bodies (host), they may be harmless (commensals) or harmful (pathogens ) II-According to shape: 1- Cocci: rounded in shape , they are arranged in pairs (diplococci), chains (streptococci) or clusters (staphylococci) 2-Bacilli: Rod in shape , they are arranged in pairs or chain 3-spirochaetes : Spiral in shape 4- Vibrio: Comma- shaped .
  18. 18. III-According to Gram stain: Gram stain is to used stain bacteria and according to their ability to retain the stain , bacteria are classified into gram +ve and gram –ve . The thickness of the peptidoglycan layer is determining whether bacteria are gm +ve or gm –ve (gm +ve bacteria have a thicker layer than gm –ve ones ) IV- According to oxygen requirement: -Aerobic: survive only in presence of oxygen -Anaerobic: survive only in absence of oxygen -Facultative: can survive in presence or absence of oxygen Bacterial classificationBacterial classification
  19. 19. Some pathogenic 0rganisms which resemble bacteria  Chlamydia : organisms which have similarities to both bacteria and viruses. ► like bacteria : they contain both DNA and RNA and can be seen through an optical microscope . ► like viruses : They do not have well defined cell walls Chlamydia can only mulitiply inside living cells (obligatory intracellular parasites) Traditional methods for culturing bacteria are not successful with chlamydia but like viruses ,they can be cultured on special disk. Species : chlamydia ( trachomatis – genitalis – pneumonia ) Diseases : non specific urethritis – eye infections – pneumonia
  20. 20. Some pathogenic 0rganisms which resemble bacteria  Mycoplasmas : Very small microorganisms , smaller than bacteria , they don’t have a rigid cell wall and can therefore exhibit a variety of shapes and sizes .unlike chlamydia , mycoplasmas can be cultured on artificial media enriched with serum. Species : M.( pneumoniae – hominis ) Diseases : mycoplasmal pneumonia – UTI – peritonities – infections following abortion.
  21. 21. Some pathogenic 0rganisms which resemble bacteria  Acid fast bacilli : Mycobacteria Are slender rods which may be slightly curved . They have waxy capsule which makes them very resistant to physical and chemical attack and prevents them taking up the gram stain. Species : Mycobacterium tuberculosis Diseases : Tuberculosis
  22. 22. Some pathogens of medical importance  The classification of the following pathogens of medical importance is based on their morphology, staining characters, and oxygen tolerance 1-COCCi Gram +ve cocci Streptococcus spp(facultative) Staphylococcus spp (Aerobic) Gram –ve cocci Nesseria spp (Aerobic) Branhmella (Moraxella)spp (Aerobic)
  23. 23. Gram + ve CocciGram + ve Cocci SpeciesSpecies HabitatHabitat DiseasesDiseases Streptococcus pyogens )Beta –hemolytic streptococci( Mucous membrane of nose and throat of infected person •URT •Scarlet fever •Skin and wound infection Streptococcus pneumoniae )Pneumococci( Common in URT •Pneumonia-Otitis media •Meningitis -Endocarditis Streptococcus viridans )Alfa-hamaemolytic streptococci( Commensal in mouth •Dental abscess •Subacute bacterial endocarditis Streptococcus faecalis )Enterococci( Common in large intestine •Urinary tract infection •Cholecystitis –Peritioitis Staphococcous aureus Common skin and URT •Skin &wound infection •Pneumonia-otitia media •Osteomyelitis Staphococcous albus )S.epidermidis( Common in skin )grows in sweet gland( •Skin &wound infection •Catheter infection
  24. 24. Gram – ve cocci • •Neissria Gonorrhoea )Gonococci( Mucous membrane of genito –urinary tract •Gonorrhoea – PIDs •Eye infection •Neissria meningitides )meningococci( Common in nose & throatURTI & LRT Meningitis & septicemia Branhamella catarrhalis Upper respiratory tract URTI LRTI
  25. 25. Gram +veBacilli Gram -veBacilli Bacilli Aerobic and Facultative Anaerobic Aerobic and facultative Anaerobic -Bacillus spp Corynebacterium spp -Listeria spp clostridium spp -haemophillus spp -Bordtella spp -Brucella spp Enterobacteriacae -E coli -shigella spp -Proteus spp _Serratia spp -Klebsiella spp -Salmonella spp -Others: -Pseudomonas spp Pseudomonas spp -bacteroides spp
  26. 26. Gram –ve bacilliGram –ve bacilli Species Habitat Diseases Hemophilus influenza Common in respiratory tract URT & LRT Conjunctivitis meningitis Haemophilus ducreyi Genitalia Chancroid Haemophilus aegypticus URT of infected person Muco-purulent conjunctivitis Brodetella pertussis URT of infected person Pertussis )whooping cough( Echerichia coli Commensal in large intestine Urinary tract infection Gastro-enteritis Peritonitis &Septicemia Kbsiella pneumonia )friedlander,s bacillus( Respiratory tract friedlander,s pneumonia )hospital acquired pneumonia( Proteus mirabilis Commensal in large intestine Urinary tract infection Serratia marcescens GIT of man and animals UTI & RTI Spticaemia & Osteomylitis Shigella dysenteriae Faceas of infected person Bacillary dysentery Pseudomonas aeruginosa Commensal in large bowel Wound &burn infect Urinary tract infection Spticaemia diabetic foot ca[pylobacter jejuni Helicobacter jejuni Campylobacter pyloridis Small intestine of infected person Gastric mucosa Gastro-enteritis Gastritis & peptic ulcer Salmonella Thypi Pratypri  Small bowel of infected person Small bowel o infected person Typhoid fever Paratyphoid fever
  27. 27. Legionella pneumophila Stagnant water&AC Legionnaire,s diseases Bacteroides fragilis Commensal in large intestine , mouth, vagina Wound infection Peritonitis Septicaemia M coacterium tuberculosis Human lungs T.B Vibrio cholerae Faeces of infected person Cholera Spirochaetes)treponema pallidum( Gential tract of infected person syphilis Toxiplasma gondii Cats toxolasmosis Rickettsia prowazekii Blood ofinfected person Thypus fever Clamydia Trachomatis Pneumonia vaginalis Gential tract ofinfected person Resp.tratct of infected person Eye infection -- urethritis Pneumonia )LRTI(- URTI Mucoplasm Pneumonia Hominis Commensal in resp. tract Commensal in G.U tract Pneumonial )LRTI(-URTI Gentio-urinary tract infection
  28. 28. Gram +ve BacilliGram +ve Bacilli  Bacillus spp )bacillus antracis anthrax(:gram +ve spore forming bacilli  Corynebacterium spp )corynebacterium diphtheriae;Diptheria(: gram +ve non spore forming bacilli  Listeria spp )listeria monocytogenes ;menio- encephalitis  Clostriduim spp :anaerobic spore forming bacteria produce fetal toxins  Clostridium tetani :tetanus  Clostridium welchii :gas gangrene
  29. 29. Common pathogens responsible for urinaryCommon pathogens responsible for urinary tract infectiontract infection  Cocci  Gram +ve cocci : Strept.faecalis: commensal in large intestine Staph Epidermidis: commensal in skin –)catheter infection (  Gram –ve cocci Nesseria gonorrhoea )gonorhroea & PID(  Bacilli Gram –ve bacilli Escherichia coli : commensal in large intestine Proteus mirabilis : commensal in large intestine Psedomonas aeruginosa : commensal in large bowel Serratia marcescenc: GIT of man & animals  Atypical pathogens : Clamydia Mycoplasm hominis: gento urinary tract infection Ureaplasm urealyticum: pelvic inflammatory diseases
  30. 30. Common pathogens responsible for respiratoryCommon pathogens responsible for respiratory tract infectiontract infection  Cocci  Gram +ve cocci *streptococcus pyogenes *streptococcus pneumoniae )pneumococci( *streptococcus aureus *streptococcus Viridans  Gram –ve cocci *Branhamella catarhalis )moraxella catarrhalis (  Atypical pathogens : *Mycoplasm pneumoniae
  31. 31. Some pathogenic organisms which resemble bacteriaSome pathogenic organisms which resemble bacteria::  Chlamydia: They are organisms which have similarities to both bacteria &viruses Like bacteria they contain both DNA &RNA However, like viruses they don’t have well –defined cell wall . Chlamydia can only multiply inside living cell and therfore sometimes described as obligatory intracellular parasites Chlamydia , like viruses can be cultured on special disk SpeciesSpecies NotableNotable featuresfeatures HabitatHabitat DiseasesDiseases Caused in manCaused in man Chlamydia )Trachomatis( Genitalis( Pneumonia( Can only Multiply Inside living cells Gential tract of infected person Non-specific urethritis Lymphogranuloma venereum , eye infections, pneumonia especially in neonates
  32. 32. MycoplasmasMycoplasmas  Are very small Microorganism than bacteria ,they pass through filters which retain bacteria they do not have a rigid cell wall and can therefore , exhibit a variety of shapes and sizes  Mycoplasm can be cultured on artificial media enriched with serum speciesspecies Notable featuresNotable features habitathabitat Disease caused inDisease caused in manman Mycoplasm pneumoniae Able to survive and multiply inside human cell Commensal in the genitourinary tract Mycoplasmal pneumonia tonsllitis Ureaplasm urealyticum Able to survive and multiply inside human cell COMMENSAL IN THE GENITOURINARY tract Pelvic inflammatory diseases MYCOPLASMA HOMINIS Able to survive and multiply inside human cell GENITOURINARY tract Urinary tract infection,bartholinitis, salpingitis , peritonitis< infection
  33. 33. Acid fast bacilliAcid fast bacilli:: Mycobacterium are slender rods which may be slightly curved , they have waxy capsule which makes them very resistant to physical and chemical attack and prevent them taking up gram stain SpeciesSpecies Notable featuresNotable features HabitatHabitat Diseases caused inDiseases caused in manman Mycobacteriu m tubercluosis Also know as the tubercle bacillus Human lungs tuberculosis Mycobacteriu m avium Mycobacteriu m Intracellulare These two species are so similar that they are often referred to as the mycobacterium avium –intracelluare complex Widely distributed in soil water , dust, etc Produce diseases in birds and animals Infection of the lung, lymph nodes , skin, bones , soft tissue and geiti-urinary tract Seer and widespread infection may occur in immunocompromised patient as AIDS
  34. 34.  Upper respiratory tract infections (URTI) : Pharyngitis Tonsillitis Sinusitis Otitis media Diphtheria Infectious diseases
  35. 35. Infectious diseases  Lower respiratory tract infection (LRTI) :  Acute bronchitis  Pneumonia ( a typical)  Pneumonia ( typical)  Pertussis ( Whooping cough)
  36. 36. Summary of URTI & LRTI Disease Causative organism Clinical features Treatment Pharingitis /tonsilitis Strep.pyrogens Chlamydia trachomatis Mycoplasma pneumoniae Inflamed throat, swollen tonsils, fever Macrolids , penicillins , cephalosporins sinusitis Streptococcus pneumoniae, Haemophilus influenzae anaerobes Facial pain Nasal discharge Penicillins , tetracyclines , macrolides Otitis media Diphtheria Acute bronchitis Pnumonia pertussis
  37. 37. Urinary tract infectionsUrinary tract infections  Definitions  Bacteruria : bacteria in voided urine  Dysuria : discomfort / pain during urination  Pyuria : pus in urine  Hematuria : blood in urine  Urithritis : infection of the urethra  Cystitis : infection of the bladder  Pyelonephritis : infection of the kidney.
  38. 38. Urinary system
  39. 39. Urinary tract infectionsUrinary tract infections  Definition : It’s a common infection that usually occures when bacteria enter the opening of the urethra and multiply in the urinary tract.  Classification of UTI anatomical : Lower Upper Cystitis acute or chronic pyelonephritis Urithritis renal or perirenal abscess prostatitis
  40. 40. Etiologic agents of UTIsEtiologic agents of UTIs  Uncomplicated : usually gm -ve bacteria that are part of the intestinal flora . 80 – 90 % due to E.coli 10 – 20 % due to Proteus , Klebsiella , Enterococcus , staph.saprophyticus.  Complicated :mostly gm –ve but gm +ve and fungi also. 10 – 20 % Due to E.coli 80 – 90 % due to Proteus , Klebsiella , Enterococcus , Serratia , Pseudomonas , enterobacter , Staph.aureeus , and candidia
  41. 41. Signs and symptoms of UTIsSigns and symptoms of UTIs  Dysuria ( burning pain upon urination)  Frequency  Urgency  Voiding in small amounts  Inability to void  Incomplete emptying of bladder  Low back suprapubic pain
  42. 42. Treatment of UTIs  Antibiotics  Analgesics  Increase fluids  Repeat urine culture and sensitivity after antibiotics are finished.
  43. 43. Chemotherapy of UT infections  Sulfonamides : In combinations with trimethoprim often used in UTIs , Otitis , Bronchitis , Sinusitis Several drug resistance cases have restricted their use  The Quinolone antibiotics : Wide spectrum antimicrobial agents Successfully used in the treatment of UTI , prostatitis , STDs , bacterial diarrhea . Not recommended in children or pregnancy.
  44. 44. Thank you and good luckThank you and good luck