Idea Transcript
Pathology of Bacterial Infection Komson Wannasai M.D., FRCPath. Pathology, Medicine, CMU
1
วัตถุประสงค์ • เมื่อสิ้นสุดการเรียนการสอน นักศึกษาสามารถ – – – –
อธิบาย host defense mechanism ต่อการติดเชื้อแบคทีเรียได้ อธิบายกลไกการตอบสนองของเนื้อเยื่อต่อการติดเชื้อแบคทีเรียได้ อธิบายพยาธิกําเนิดของโรคติดเชื้อแบคทีเรียที่พบบ่อยได้ อธิบายอาการและอาการแสดงทางคลินิกของโรคติดเชื้อแบคทีเรียที่พบ บ่อยได้ – อธิบายพยาธิสภาพของโรคติดเชื้อแบคทีเรียที่พบบ่อยได้ – ประยุกต์ความรู้พื้นฐานกับทางคลินิกได้ 2
Bacteria • Prokaryotes: unicellular without nucleus • Structures: – Cell wall – Cytoplasm • Coiled DNA (chromosome) • Ribosome
– +/- Capsule, flagellae or pili
• Nutrient : Aerobic, facultative aerobe or anaerobic 3
4
5
Types of bacteria • Filamentous bacteria: true branching • True bacteria: multiplied by simple binary fission • Spirochetes: spiral, divided by transverse binary fission • Mycoplasmas: lack rigid cell wall • Rickettsiae and chlamydia
6
Classification of infectious agent by site of multiplication in host IA
IEA
All virus
* Mycoplasma Actinomyces * All bacteria except * Nocardia * Fungi Pseudomomas * Protozoa Salmonella typhi * Parasites
All rickettsiae All chlamydiae Protozoa
EA
Mycobacteria
Fungi Protozoa
Metazoa
7
Classification of infectious agent by site of multiplication in host Taxonomic
Site of Propagation
Examples
Disease
Bacteria
Obligate intracellular
Chlamydia trachomatis Streptococcus pneumoniae Mycobacterium tuberculosis Candida albicans
Trachoma, urethritis Pneumonia
Histoplasmosis
Facultative intracellular
Histoplasma capsulatum Trypanosoma gambiense Trypanosoma cruzi
Obligate intracellular
Leishmania donovani
Kala-azar
Extracellular
Wuchereria bancrofti Filariasis
Intracellular
Trichinella spiralis
Viruses
Obligate intracellular
Extracellular Facultative intracellular Fungi
Extracellular Facultative intracellular
Protozoa
Helminths
Extracellular
Poliovirus
Poliomyelitis
Tuberculosis Thrush
Sleeping sickness Chagas disease
Trichinosis
8
Normal Flora • The agents live on or within the body without causing disease, and play and important role in protecting the host from pathogenic agents. • Most of them are bacteria 9
10
Virulent of bacteria • • • • •
Bacterial adhesion on host cells Bacterial invasion into host cells Avoidance of host defense mechanisms Toxins Enzymes 11
Encapsulated bacteria • • • •
Haemophilus influenzae Streptococcus pneumoniae Neisseria meningitidis Klebseilla pneumoniae
Pt. loss of humoral defense 12
Host’s defense mechanisms • By organs • By mechanisms 1. 2. 3. 4.
Physical defenses Humoral defenses Cellular defenses Inflammatory response 13
Host defense: Respiratory tract • Mucocilliary action • Macrophages
14
Host defense: GI tract • Stomach acidity • Mucous layer • Lytic pancreatic enzymes and bile detergents • Secreted IgA antibody • Normal flora in colon 15
16
Host defense: Urinary tract • • • • • •
Continuous urine flow Vesico-ureteral orifice Vesico-urethral orifice Obstruction/reflux Ascending infection Female>male 10 times
17
Host defense: Skin • Keratinization • Turn over • Secretion from sweat and sebaceous glands • Dryness • Normal flora 18
19
Humoral defenses (secretion) • Non immunologically specific – Gastric secretion, vitrous humor – Antibactericidal activity: lysozyme in tear – Complement system: opsonin, chemoattractant for neutrophils, bactericidal activity – Fibronectin and surfactant: active phagocytosis
• Immunologically specific – Antibody (Ig: Immunoglobulin) produced by B-lymphocyte 20
Cellular defenses • Non immunologically specific – Phagocytosis: • Macrophage (monocyte, histiocyte) • Neutrophil
• Immunologically specific – T-lymphocytes • CD4 (helper): memory, activate B cell and phagocytosis • CD8 (suppresser): direct cytotoxic to tumor cells and virus infected cells • Natural killer cell (NK): Ab dependent cellular 21 cytotoxicity
Result of infection • No disease • Disease – Acute, subacute, chronic (carrier, reactivation) – Mild to severe – Complication
• Recovery or death 22
Tissue damage by infectious agents IA
EA
Cell swelling Cell necrosis Inclusion body formation Giant cell formation
Locally acting enzyme
Latent viral infection Reactivation Oncogenesis
Destroy cells and tissue Protect agents Local vasculitis Toxin
23
Tissue change by host response • Acute inflammation • Chronic inflammation • Suppurative inflammation
24
Inflammatory response • General – EA: phagocytosis (PMN, macrophages) • acute inflammation with neutrophils – IEA: can survive in macrophages • macrophages or granuloma – IA: T-lymphocyte • inflammation with lymphocytes 25
Acute inflammation – EA (bacteria): neutrophils – IA (virus): lymphocytes – IEA (Mycobacteria): macrophages
26
www.courses.washington.edu 27
Chronic inflammation • Chronic granulomatous inflammtion – IEA esp. Mycobacterium – Granuloma (group of epithelioid histiocytes)
• Macrophages proliferation – IEA in low immune patient
• Lymphocytes and plasma cells – IA, EA 28
www.pathpedia.com
29
30 library.med.utah.edu
Suppurative inflammation Pus, abscess: neutrophils, fibrin, cell debris
• Acute suppuration – Agents resist to phagocytosis (encapsulated agents)
• Chronic suppuration
– Primary: Actinomyces, Nocardia – Secondary: After acute suppuration 31
ntp.niehs.nih.gov 32
Bacteremia, sepsis and septic shock • Bacteremia (transient and severe) • Definition of the stages of sepsis*
Bacteria Toxin
Mediator Inflammation
Vascular injury Heart failure Myocardial depression Organs failure DIC (disseminated intravascular coagulation)
33
Definition and stage of sepsis • Systemic inflammatory response syndrome (SIRS) – 2 or more of • • • •
Temperature: > 38 °C or < 36 °C Heart rate: >90/min Respiratory rate: >20/min WBC count: > 12,000 or < 4000 … or >10% immature form
• Sepsis: bacteremia/source of infection + SIRS • Septic shock: sepsis + shock (hypotension despite fluid resuscitation plus hypoperfusion abnormality) 34
Hospital infection • • • •
Poor defenses High virulence bacteria Per-cutaneous line Surgical wound
• • • •
High mortality rate Prolonged hospital stay A need for potent antibiotic Source of infection 35
Hospital infection • • • • •
UTI Surgical wound infection Lower respiratory tract infection Bacteremia Others
• • • •
E.coli, GNB enteric bacteria S.aureus, S.epidermidis, S.pyogenes P.aeruginosa Candida
42% 24% 11% 5% 18%
36
Common Bacterial infections
37
Common Bacterial infections • Gram positive bacteria -cocci
-bacilli
• Gram negative bacteria -cocci
-bacilli
• Mycobacteria • Spirochete 38
Gram positive cocci Staphylococcus aureus
Streptococcus pyogenes
Streptococcus pneumoniae
Acute inflammation (skin*,pharyngitis, tonsilitis, pneumonia, endocarditis, osteomyelitis) Toxic shock syndrome Scalded skin syndrome Food poisoning Acute inflammation esp. pharyngitis* Erysipelas Scarlet fever Post streptococcal syndrome* Acute rheumatic fever Acute glomerulonephritis Pneumonia*, sinusitis, meningitis
39
STAPHYLOCOCCI Staphylococcus aureus – Gram-positive cocci in groups – Toxic shock syndrome (TSST) • Usually occurs in tampon-using menstruating women • Clinical findings – Fever, hypotension – Desquamating, sunburn-like rash
– Other infections • • • •
Folliculitis, furuncle, carbuncle, hidradenitis suppurativa Postsurgical wound infection (most common pathogen) Infective endocarditis (IVDU) Pneumonia: multiple small abscesses
Staphylococcus epididermidis – Colonization on indwelling catheters
(hospital aquired)
40
Furuncle or boil • Focal suppurative inflammation of the skin and subcutaneous tissue • Moist, hairy areas (face, axillae, groin, legs, and submammary folds) • Single hair follicle infection (folliculitis) deepening abscess.
www.soc.ucsb.edu 41
Carbuncle • A deep suppurative infection • Beneath the deep subcutaneous fascia burrows superficially erupt in multiple adjacent skin sinuses 42 missinglink.ucsf.edu • Upper back and posterior neck
STREPTOCOCCI Streptococcus pyogenes - Gram-positive cocci in chains - Acute suppurative pharyngitis and tonsillitis
- Impetigo - Rash usually begins on the face - Vesicles and pustules rupture to form honeycolored, crusted lesions. - Presence of bullae indicates superinfection with Staphylococcus aureus. - Post streptococcal syndrome • Acute rheumatic fever • Acute glomerulonephritis – Necrotizing fasciitis 43
Impetigo: honey-colored crust
Acute suppurative tonsillitis
44
STREPTOCOCCI • Erysipelas – Middle-aged persons in warm climates – Exotoxins from superficial infection with S. pyogenes – Rapidly spreading erythematous cutaneous swelling – Face, body or an extremity – Sharp, well-demarcated, serpiginous border rash – “Butterfly” distribution on the face
mydermpath.com
45
STREPTOCOCCI • Scarlet fever – Particular strains produce an erythrogenic toxin. – Desquamating, sandpaperlike erythematous rash – Develops on the skin and tongue ("strawberry" tongue) – Increased risk for developing poststreptococcal glomerulonephritis
www.skincareguide.ca
46
www.essexchronicle.co.uk
A 32‐year‐old male with necrotizing fasciitis on foot (Pus / Gram)
47
STREPTOCOCCI Streptococcus pneumoniae (pneumococci) – Gram positive lancet-shaped diplococci – Lobar pneumonia
• Complete or almost complete consolidation of a lobe of lung • Acute suppurative inflammation – Infiltration of neutrophils within alveolar spaces • Fever, cough, dyspnea
– Acute suppurative meningitis
• Inflammation of meninges (pia matter) • Fever, headache, stiff neck • CSF: high protein, low sugar
48
Bronchopneumonia
Lobar pneumonia
49 .
Robbins 9th ed
50
www.microscopyu.com
51
www.medicalexhibits.com
52
STREPTOCOCCI • Viridans Streptococci – Infective endocarditis
(infection of heart valve)
• Previous heart abnormalities • Vegetation on heart valves
53
Gram positive bacilli Non spore forming
Corynebacterium diphtheriae Diphetheria Actinomyces israeii Actinomycosis Nocardia asteroides Nocardiasis Gardnerella vaginalis Vaginitis, urinary tract infection
Spore forming
Clostridium
Food poisoning (C.perfringen A, C, D) Necrotizing enteritis (C. perfringen C) Gas gangrene, myonecrosis (C.perfringen A) Tetanus (C.tetani) Botulism (C.botulinum) Pseudomembranous enterocolitis (C.difficile)
54
Corynebacterium diphtheriae • Slender gram-positive rod with clubbed ends • Proliferate at the site of attachment – Mucosa of the nasopharynx, oropharynx, larynx, or trachea
• “Diphtheria” – Diphtherial toxin (exotoxin): stop prot. synthesis – Acute necrotozing tracheobronchitis with DIRTY MEMBRANE (pseudomembrane) respiratory tract obstruction 55 – Toxin: Myocarditis isolated myofiber necrosis
56
commons.wikimedia.org
en.wikipedia.org
Nocardia spp. • Nocardiasis/nocardiosis • gram-positive bacteria that grow in distinctive branched chains • Opportunistic infections in immunocompromised people • Nocardia asteroides: respiratory infections – Pneumonia and lung abscess +/- brain infection
• Nocardia brasiliensis: skin
57
thunderhouse4-yuri.blogspot.com
jpkc.gdmc.edu.cn
58 lookfordiagnosis.com
Actinomyces israelii • Actinomycosis • Chronic suppurative and granulomatous inflammation in deep organ with or without SULFER GRANULES • Head and neck • Intraabdomen • Pelvis • Lungs
medicalpicturesinfo.com
59
pathmicro.med.sc.edu
CLOSTRIDIAL INFECTION • Clostridium species – Gram-positive bacilli – Anaerobic conditions – Produce spores
60
CLOSTRIDIAL INFECTION • C. perfringens – Cellulitis and myonecrosis of traumatic and surgical wounds (gas gangrene)
• C. tetani
– Tetanus – Proliferates in puncture wounds and in the umbilical stump of newborn infants – Tetanospasmin and tetanolysin – Convulsive contractions of skeletal muscles (lockjaw) 61
62
usmlepathslides.tumblr.com
63
CLOSTRIDIAL INFECTION • C. botulinum – – – –
Grows in inadequately sterilized canned foods Potent neurotoxin Blocks synaptic release of acetylcholine Severe paralysis of respiratory and skeletal muscles (botulism)
• C. difficile
– Overgrows other intestinal flora in antibiotictreated people – Pseudomembranous colitis
64
65
Gram negative cocci • Neisseria meningitidis: Meningococcemia • Neisseria gonorrhea: Gonorrhea • Acute pyogenic (bacterial) meningitis • Etiology: age group • Neonate; Gr B Streptococcus, E. coli • Infants or children; H. influenzae,
N. meningitidis • Adults; S. pneumoniae, N. meningitidis 66
NEISSERIA N.meningitidis (MENINGOCOCCI)
‘MENINGOCOCCEMIA’ : endotoxin severe sepsis, wide spread hemorrhage ‘Waterhouse Friderichsen syndrome” (bilateral adenal gland hemorrhage)
N.gonorrhoeae (GONOCOCCI)
‘Gonorhoea’ (flow of seeds) Ophthalmia neonatorum
67
5minuteconsult.com
68
Ophthalmia neonatorum
69
Gram negative bacilli Bordetella pertussis Escherichia coli
Haemophilus influenzae Haemophilus ducryi Helicobacter pylori Psuedomonas aeruginosa Burkholderia pseudomalei Shigella Salmonella Typhi Salmonella Entertitidis Vibrio cholera
Pertussis Diarrhea Urinary tract infection Pneumonia Meningitis Acute inflammation of head and neck Chancroid Gastritis Pneumonia, skin infection Melioidosis Dysentery Typhoid fever Enterocolitis Cholera
70
71
72
Helicobacter pylori
‘Gastritis’ CA stomach MALToma 73
Bordetella pertussis
‘WHOOPING COUGH’ (ACUTE LARYNGOTRACHEOBRONCHITIS) lymphocytes in lesion and peripheral lymphocytosis 74
HEMOPHILUS INFECTION - H.influenza – Acute inflammation of respiratory tract, sinus, middle ears and facial tissue – Non-capsulated and encapsulated bacteria
- H.ducryi – Chancroid (sexually transmitted disease)
75
Klebsiella pneumoniae • Most frequent cause of gramnegative bacterial pneumonia • Debilitated and malnourished people, particularly chronic alcoholics • Thick and gelatinous sputum
76
Escherichia coli 1. Diarrhea and dysentary –
2. 3. 4. 5.
Dysentery: mucous bloody diarrhea, cramping, tenesmus
Urinary tract infection Pneumonia Meningitis Sepsis 77
Genitourinary tract infection • Bacteria: acute inflammation, abscess, fibrosis and obstruction • Urethritis, cystitis, ureteritis, pyelonephritis • Vaginitis, cervicitis, endometritis, salpingitis, pelvic inflammatory disease • Prostatitis, epididymitis, orchitis 78
79
Mycobacteria • M.tuberculosis – – – –
Primary tuberculosis Secondary tuberculosis Disseminated tuberculosis Miliary tuberculosis
• M.leprae
– Tuberculoid leprosy – Lepromatous leprosy
• M.avium-intracellulare complex 80
Tuberculosis • Mycobacterium tuberculosis • Staining; acid-fast stain, weakly positive with Gram stain • Person-to-person transmission of airborne droplets – Primary tuberculosis – Secondary tuberculosis – Miliary tuberculosis
81
Primary tuberculosis • Early stage (0-3wk) – Endocytosis by macrophage – Proliferate in macrophage
• Late stage (>3wk) – Differentiation of T-cell – Mature T-cell produce -IFN – -IFN activate macrophage 82
83
84
85
Secondary tuberculosis • Reactivation or re-exposure (reinfection) • Apex of upper lobe, high oxygen tension • Cavity • Less prominent lymph node 86
Robbin’s
87
5th
edition
Robbin’s
88
5th
edition
Robbin’s 5th edition
89
Clinical manifestations • 5-10% of infected healthy people • Chronic cough, hemoptysis, lowgrade fever, night sweat, fatigue, weight loss • Extrapulmonary manifestations: immunocompromised hosts, elderly, AIDS 90
Leprosy • • • •
Hansen disease
Mycobacterium laprae
Obligate intracellular organism Person-to-person transmission through aerosols • Immunity 91
Leprosy • Tuberculoid leprosy
– Scaly skin with anesthesia – Granulomatous inflammation – Paucibacillary lesion
• Lepromatous leprosy – – – –
Thickening skin or nodules, cool area anesthesia Aggregation of foamy macrophages Multibacillary lesion
• Borderline leprosy
92
Skin lesion with irregular-shaped, elevated hyperpigmented margins and depressed pale 93 center
carryseats.com 94
Papular or nodular lesion leonine facies
95
96 www.epathologies.com
M.avium-intracellularae complex - Immunocompromised hosts - PROLIFERATION OF MACROPHAGES - LUNG, BOWEL, LIVER, SPLEEN, LYMPH NODE, BONE MARROW 97
98
Spirochete • Tryponema pallidum: Syphilis – – – –
Primary Secondary Tertiary Congenital
• Leptospira interogans: Leptospirosis 99
Primary syphilis • 3 weeks after contact • Chancre; heal in 3 to 6 weeks • Hematologic and lymphatic dissemination
100
Chancre: painless ulceration (sore) most commonly formed during the primary stage of syphilis
www.your-doctor.net
textbookofbacteriology.net
101
Secondary syphilis • 75% of untreated patient • 2-10 wks after primary • Widespread mucocutaneous lesion; oral palm, sole • Lymphadenopathy • Condyloma latum 102
103
Condyloma latum
104
Tertiary syphilis • One-third of untreated patient • > 5 years • Cardiovascular; dilatation of aortic root, arch, aortic insufficiency • Neurosyphilis; tabes dorsalis, generalized brain parenchymal disease • Gumma: a form of granuloma – Soft, non-cancerous growth displaying firm, necrotic center surrounded by inflamed tissue, which forms an amorphous proteinaceous mass.
105
escholarship.org
106
Obliterative endarteritis
107
Congenital syphilis • • • •
Transplacental transmission Abortion or stillbirth Infantile; rash, periostitis Childhood; Hutchinson teeth, interstitial keratitis, eighth nerve deafness 108
Hutchinson teeth 109
condyloma lata
110
Thank You For Your Patience
111