1.SYSTEMIC BACTERIOLOGY

2. CLASSIFICATION OF BACTERIA 3.

TAXONOMY

Includes

Classification

Identification

Nomenclature

4.

CLASSIFICATION

Is the arrangement of organisms into taxonomic groups on the basis of similarities or relationships (i.e. common properties).

IDENTIFICATION:

Is the practical use of a classification scheme to : Isolate & identify the causative agent of a disease.

NOMENCLATURE

Is naming of an organism by international rules according to its characteristics. Genera Species Sub species .

5. CLASSIFICATION OF MEDICALLY IMPORTANTBACTERIA BACTERIA RIGID THICK-WALLEDCELLS FLEXIBLE, THIN-WALLED CELLS WALL-LESS CELLS 6. CLASSIFICATION OF MEDICALLY IMPORTANT BACTERIA RIGID THICK-WALLEDCELLS FREE LIVING(EXTRACELLULAR ) NON FREE LIVING (OBLIGATE INTRACELLULARPARASITES) 7. FREE LIVING BACTERIA GRAM POSITIVE BACTERIA GRAM NEGATIVEBACTERIA ACID-FAST BACTERIA COCCI

• RODS

SPOREFORMING NONSPOREFORMING COCCI RODS 8. TETANUS CLOSTRIDIA (b)ANAEROBIC ANTHRAX BACILLUS (a) AEROBIC SPORE FORMING RODS (AEROBIC/ ANAEROBIC) RODS(SPORE FORMING RODS/ NON SPORE FORMING RODS) PNEUMONIA, PHARYNGITIS CELLULITIS STREPTOCOCCI ABSCESS SKIN & OTHER ORGANS STAPHYLOCOCCI COCCI DISEASE GENUS CHARACTERISTICS GRAM POSITIVE BACTERIA (COCCI/ RODS) CLASSIFICATION OF MEDICALLY IMPORTANT BACTERIA 9. GONORRHEA MENINGITIS NEISSERIA COCCI GRAM NEGATIVE BACTERIA (COCCI/RODS) NOCARDIOSIS NOCARDIA ACTINOMYCOSIS ACTINOMYCES FILAMENTOUS MENINGITIS LISTERIA DIPHTHERIA CORYNEBACTERIUM NON FILAMENTOUS NON-SPORE FORMING RODS CLASSIFICATION OF MEDICALLY IMPORTANT BACTERIA 10. BRUCELLOSIS BRUCELLA

ZOONOTIC

ORGANISMS

LEGIONELLAPNEUMONIA WHOOPING COUGH BORDETELLA MENINGITIS HAEMOPHILUS

RESPIRATORY

ORGANISMS

STRAIGHT RODS( RESPIRATORY/ZOONOTIC/ENTERIC) DISEASE GENUS CHARACTERISTICS ANAEROBICRODS AEROBIC RODS FACULTATIVE RODS (STRAIGHT/ CURVED) GRAM NEGATIVE RODS 11. PNEUMONIA KLEBSIELLA ENTEROCOLITIS TYPHOID SALMONELLA UTI ENTEROBACTER UTI, DIARRHEA ESCHERICHIA

ENTERIC & RELATED ORG.

PLAGUE YERSINIA CELLULITIS PASTEURELLA TULAREMIA FRANCISELLA ZOONOTIC DISEASE GENUS CHARACTERISTIC 12. TB, LEPROSY MYCOBACTERIUM ACID FAST BACTERIA PERITONITIS BACTEROIDES ANAEROBIC RODS UTI, PNEUMONIA PSEUDOMONAS AEROBIC RODS CHOLERA VIBRIO GASTRITIS, PEPTIC ULC HELICOBACTER ENTROCOLITIS CAMPYLOBACTER CURVED F. RODS DISEASE GENUS CHARACTERISTC 13. CLASSIFICATION OF MEDICALLY IMPORTANT BACTERIA RIGID THICK-WALLEDCELLS FREE LIVING(EXTRACELLULAR ) NON FREE LIVING (OBLIGATE INTRACELLULARPARASITES) 14. URETHRITIS, TRACHOMA, PSITTACOSIS CHLAMYDIA ROCKY MOUNTAIN SPOTTED FEVER RICKETSSIA DISEASE GENUS CHARACTERISTIC NON FREE LIVING (OBLIGATE INTRACELLULARPARASITES) 15. CLASSIFICATION OF MEDICALLY IMPORTANTBACTERIA BACTERIA RIGID THICK-WALLEDCELLS FLEXIBLE, THIN-WALLED CELLS WALL-LESS CELLS 16. LYME DISEASE BORRELIA LEPTOSPIROSIS LEPTOSPIRA SYPHILIS TREPONEMA DISEASE GENUS FLEXIBLE, THIN WALLED CELLS (SPIROCHETES ) 17. PNEUMONIA MYCOPLASMA DISEASE GENUS WALL-LESS BACTERIA 18. Definitions

Epidemiology

• The study of the transmission of disease

Communicable Disease

• A disease that can be transmitted from one individual to another

Contagious Disease

• A communicable disease that is easily spread from one individual to another

Noncommunicable Disease

• A disease that is not transmitted from one individual to another

19. III. A. Definitions

Epidemic Disease

• A disease condition present in a greater than usual percentage of a specific population

Pandemic Disease

Endemic Disease

• A disease condition that is normally found in a certain percentage of a population

• An epidemic affecting a large geographical area; often on a global scale

20. III. A. Definitions

Reservoir of Infection

• The source of an infectious agent

Carrier

• An individual who carries an infectious agent without manifesting symptoms, yet who can transmit the agent to another individual

Fomites

• Any inanimate object capable of being an intermediate in the indirect transmission of an infectious agent

21. III. A. Definitions

Animal Vectors

• An animal (nonhuman) that can transmit an infectious agent to humans

• Two types: mechanical and biological

• • Biological animal vectors: The infectious agent must incubate in the animal host as part of the agents developmental cycle; eg, the transmission of malaria by infected mosquitoes

• • Mechanical animal vectors: The infectious agent is physically transmitted by the animal vector, but the agent does not incubate or grow in the animal; eg, the transmission of bacteria sticking to the feet of flies

22. GRAM POSITIVE COCCI

GENUS

STAPHYLOCOCCI

STREPTOCOCCI

GENERAL PROPERTIES

NON MOTILE, NON SPORE-FORMING

STAPHYLOCOCCI:CATALASE POSITIVE

IN CLUSTER

STREPTOCOCCI :CATALASE NEGATIVE

IN CHAINS

23. STAPHYLOCOCCI 24. INTRODUCTION

Staphyloccocci - derived from Greek stapyle (bunch of grapes)

Gram positive cocci arranged in clusters

Hardy organisms surviving many non physiologic conditions

Include a majorhuman pathogen and skin commensals

25. 26. Groupingfor Clinical Purposes

1. Coagulase positive Staphylococci

• Staphylococcus aureus

2. Coagulase negative Staphylococci

• Staphylococcus epidermidis

• Staphylococcus saprophyticus

27. A. Staphylococcus aureus

Major human pathogen

Habitat - part of normal flora insome humans (nose , sometimes skin esp hospital staff and patients, vagina of 5% females) and animals

Source of organism - can be infected human host, carrier, fomite or environment

28. DISEASES

Due to direct effect of organism

• Local lesions of skin

• Deep abscesses

• Systemic infections

Toxin mediated

• Food poisoning

• toxic shock syndrome

• Scalded skin syndrome

29. IMPORTANT PROPERTIES

Gram positive cocci, arranged in clusters

Non spore forming, non motile

Catalase positive (breaks H2O2 into O2 & H2O)

S. aureus: Coagulase positive, Hemolytic, Ferments Mannitol.

Plasmid mediated Antibiotic resistance in S. aureus

Cell wall components of S. aureus

30. Cell wall components & antigens of S.aureus

Protein A (binds to Fc portion of Ig G at complement binding site)

Teichoic acid (adherence, antibody formation)

Microcapsule (11 serotypes)

Peptidoglycan has endotoxin-like properties.

31. Factors predisposing to S. aureus infections

Host factors

• Breach in skin

• Chemotaxis defects

• Opsonisation defects

• Neutrophil functional defects

• Diabetes mellitus

• Presence of foreign bodies

Pathogen Factors

• Catalase (counteracts host defences)

• Coagulase

• Hyaluronidase

• Lipases (Imp. in disseminating infection)

• B lactasamase(ass. With antibiotic resistance)

32. Factors predisposing to S. aureus infections

Toxins produced by S. aureus

Enterotoxin

Toxic shock syndrome toxin (TSST is a super antigen)

Exfoliatin (epidermolytic)

Leucocidins

Alpha toxin (tissue necrosis)

Staphylokinase

33. SKIN LESIONS (Pyogenic)

Styes

Furuncles(infection of hair follicle)

Carbuncles (infection of several hair follicles)

Wound infections(progressive appearance of swelling and pain in a surgical wound after about 2 days from the surgery)

Impetigo(skin lesion with blisters that break and become covered with crusting exudate)

Cellulitis

34. IMPETIGO 35. SYMPTOMS OF STAPH INFECTIONS

The symptoms of a staph infection depends on where the infection is.The staph bacteria can cause:

Boils an abscess, bump, or swelling within the skin.Also called a furuncle.

36.

Cellulitis a flat skin infection which can make the skin red, painful and warm but does not have pustules.

37.

Folliculitis an infection of the hair follicles

38.

Impetigo pustules (bulbous impetigo) or honey colored crusted lesions on the skin

39. 40. 41. Staphylococcol Infection 42. DEEP ABSCESSSES

Can be single or multiple

Breast abscess can occur in 1-3% of nursing mothers in puerperium

Can produce mild to severe disease

Other sites - kidney, brain from septic foci in blood

43. Systemic Infections

1.With obvious focus

• Osteomyelitis, septic arthritis

2. No obvious focus

• • heart (infective endocarditis)

• • Brain(brain abscesses)

3. Ass. With predisposing factors

• multiple abscesses, septicaemia (IV drug users)

• Staphylococcal pneumonia (Post viral)

44. B. TOXIN MEDIATED DISEASES

1. Staphylococcal food poisoning

• Due to production of entero toxins

• Superantigen IL-1 & 2

• heat stable entero toxin acts on gut

• produces severe vomiting, non bloody diarrhea following a very short incubation period

• Resolves on its own within about 24 hours

45. 2. Toxic shock syndrome

High fever, diarrhoea, shock and erythematous skin rash which desquamate

Mediated via toxic shock syndrome toxin super antigen

10% mortality rate

ass. With young women using tampones during menstruation & wound infection

46. 47. 3. Scalded skin syndrome

Disease of young children

Mediated through minor Staphylococcal infection by epidermolytic toxin producing strains

Mild erythema and blistering of skin followed by shedding of sheets of epidermis

Children are otherwise healthy and most eventually recover

48. S. aureus-- Kawasaki syndrome

Unknown etiology

Vasculitis of medium & small sized arteries.

Strawberry tongue

49. DIAGNOSIS

1. In all pus forming lesions

• Gram stain and culture of pus

2. In all systemic infections

• Blood culture

3. In infections of other tissues

• Culture of relevant tissue or exudate

50. Diagnosis

Gram Stain: Gram positive cocci in clusters

Yellowish colonies , b-hemolytic on Blood agar

Catalase and coagulase positive

Mannitol fermenter

51. Antibiotic sensitivity pattern

Very variable and not predictable

Very imp. In Pt. Management

Mechanisms

• 1.B lactamase production - plasmid mediated

• • Has made S. aureus resistant to penicillin group of antibiotics -90% of S. aureus (Gp A)

• • B lactamase stable penicillins (cloxacillin, oxacillin, methicillin)used

• 2. Alteration of penicillin binding proteins

• • (Chromosomal mediated)

• • Vancomycin is the drug of choice

• • MRSA, NRSA, VISA

52.

Tested in lab using methicillin

Referred to as methicillin resistant S. aureus (MRSA)

Emerging problem in the world

In Sri Lanka prevalence varies from 20- 40% in hospitals

Drug of choice - vancomycin

In Japan emergence of VIRSA (vancomycin intermediate resistant S. aureus)

No effective antibiotics discovered -We might have to discover

53. 2. Staphylococcus epidermidis

Skin commensal

Has predilection for plastic material

Ass. With infectionof IV lines, prosthetic heart valves,shunts

Causes urinary tract infection in cathetarised patients

Has variable ABS pattern , highly resistant

Treatment should be aided with ABST

Hospital acquired

Novobiocin sensitive

54. 3. Stapylococcus saprophyticus

Skin commensal

Imp. Cause of UTI in sexually active young women

Usually sensitive to wide range of antibiotics

55. GRAM POSITIVE COCCI S. aureus hemolytic mannitol yellow + - Staphylococcus (Clusters) Streptococcus (pairs & chains) Catalase BETA:Bacitracin S. pyogenes (group A) CAMP/ HippurateS.agalactiae (group B) Hemolysis Coagulase S.epidermidis nonhemolytic (usually) mannitol white ALPHA:Optochin /Bile SolubilityS. pneumoniae GAMMA:BileEsculin6.5%NaClGroup D* Enterococcus BileEsculin6.5%NaClGroup D* Non- Enterococcus (*can also be alpha hemolytic) Note:S. viridans isIs alpha hemolytic and negative for all the tests below below + + + + + + + - - Summary Figure (Identification Scheme)