“Pathology of Bacterial Infection”

นายแพทย ดร.ณตพล ศุภณัฐเศรษฐกุล ภาควิชาพยาธิวิทยา คณะแพทยศาสตร มหาวิทยาลัยนเรศวร

11 กรกฎาคม พ.ศ. 2555

TOPICS

 Introduction  Bacterial pathogenesis  Classification of bacterial diseases  Diseases and pathology

1 Introduction - First observed by Antonie van Leeuwenhoek in 1676 by using a single-lens microscope “animalcules” - Bacteria are prokaryotes, have a cell membrane but lack of nuclear membrane. - Classification of bacteria - Morphology - Staining - Living environment - Biochemical method - Molecular method - Pathogenicity

http://cellbiology.med.unsw.edu.au/units/images/Bacterial_morphology_diagram.png

2 Gram Postive cocci in cluster

Gram staining

Gram negative bacilli

Acid-fast staining : - Ziehl-Neelsen stain - Kinyoun stain

Acid fast bacilli (AFB)

http://www.ihcworld.com/royellis/gallery/images/zn.jpg

3 Introduction

Living environment : Aerobic, Anaerobic, Facultative anaerobic, Microaerophilic, Obligate intracellular

Biochemical method : substrate, enzyme, product

Molecular method : DNA, RNA, using PCR method

Pathogenicity : เชื้อประจําถิ่น (normal flora), เชื้อกอโรค (pathogen)

Bacterial Pathogenesis การติดเชื้อ (Infection) หมายถึง กระบวนการที่เชื้อโรค เขาไปเจริญเติบโตอยูในเนื้อเยื่อของ host

- การติดเชื้อที่ไมปรากฎอาการ (Subclinical infection)

- ระยะที่เกิดอาการของโรคติดเชื้อ (Clinical illness)

- การติดเชื้อแบบไมแสดงอาการ หรือ แบบแอบแฝง (Latent infection)

4 ปจจัยที่เกี่ยวของกับการเกิดโรคติดเชื้อ Pathogenicity หมายถึง ความสามารถของเชื้อที่จะทํา ใหเกิดโรคใน host

Virulence factors : Exotoxin, Endotoxin, Antiphagocytic factor (capsule), Enzyme (hyaluronidase, collagenase, deoxyribonuclease, hemolysin)

Host factor : Immunity, Inflammation, stress, occupation, hereditary

ปจจัยอื่นที่มีผลตอการติดเชื้อ : 1. Tissue affinity 2. Microbial adherence 3. Invasion of the host 4. Infective dose 5. Portal of entry 6. Communicability via mode of transmission (direct contact, airborne, foodborne and water borne, animal vector or zoonoses)

5 Classification of Bacterial Diseases

 Type of bacteria : Streptococcus, Neisseria, Mycobacterium etc.  Host status : Childhood, Immunocompetent, Immunocompromised, Opportunistic, Nosocomial  Organs and systems involved : CVS, STD, UTI  Duration of infection : Acute, Chronic, Sub-acute  Mode of transmission : Vector-borne, airborne

6 Bacterial infection

 Classification  Pyogenic gram positive cocci  Bacterial infections of childhood  Sexually transmitted bacterial diseases  Enteropathogenic bacterial diseases  Clostridial infection  Bacterial infection with animal reservoirs  Bacterial infection with immunocompromised host  Filamentous bacterial infection  Mycobacterial infection  Chlamydial infection  Rickettsial infection  Mycoplasma infection

7 Pyogenic gram positive cocci

 Staphylococcus  Streptococcus

Staphylococcus aureus

- gram-positive cocci that form grapelike clusters and cause…

- skin lesions (furuncles (boils), carbuncles, impetigo, and scalded skin syndrome)

- abscess, pneumonia,endocarditis,osteomyelytis, food poisoning, toxic shock syndrome, sepsis

8 - is a major cause of infection of persons with severe burns and surgical wounds.

- Virulence factors, which are controlled by an autoinducing peptide, include: * surface proteins involved in adherence to host cells

* Anti-phagocytosis: polysaccharide capsule

9 * enzymes that degrade host proteins, phospho- lipid membrane involved in abscess formation

* toxins that lyse host cells: Exotoxins - scalded skin syndrome Enterotoxins - food poisoning Endotoxin and toxic shock syndrome toxin – hypotension (shock) with multi-organ failure especially in a woman using tampon

10 SSSS

Staphylococcus

Streptococcus Species

Streptococci are gram-positive cocci that grow in pairs or chains

11 Streptococcal infection

 3 types according to hemolytic pattern on bloody agar: -  hemolytic streptococci (incomplete hemolysis) eg. S. pneumoniae, S. viridans, S. mutans

-  hemolytic streptococci (complete hemolysis) eg. S. pyogenes (group A), S. agalactiae (group B)

-  hemolytic streptococci (non-hemolytic) eg. S. faecalis (group D)

S. pneumoniae is the most important -hemolytic streptococcus and is the major cause of community-acquired pneumonia (lobar pneumonia) and meningitis in adults.

S. viridans causes an infective bacterial endocarditis

S. pyogenes (-hemolytic streptococcus gr. A) referred to as flesh eating bacteria – cause a rapidly progressive necrotizing fasciitis.

12 S. pyogenes also causes :

Pharyngitis Scarlet fever (most common in children 3 -15 years old) Erysipelas (rapidly spreading erythematous cutaneous swelling skin lesion) Rheumatic fever Poststreptococcal glomerulonephritis

Acute pharyngitis and tonsillitis

Erysipelas

13 Scarlet fever

strawberry tongue

circumoral pallor

Pathogenesis of RHD

14 Figure 11-20 Infective (bacterial) endocarditis. A, Endocarditis of mitral valve (subacute, caused by Streptococcus viridans). The large, friable vegetations are denoted by arrows. B, Acute endocarditis of congenitally bicuspid aortic valve (caused by Staphylococcus aureus) with extensive cuspal destruction and ring abscess (arrow).

Downloaded from: StudentConsult (on 22 December 2009 03:19 AM) © 2005 Elsevier

เชื้อที่เปนสาเหตุของ Bacterial meningitis

 Streptococcus pneumoniae 50%  Neisseria meningitidis 25%  Group B streptococci 15%  Listeria monocytogenes 10%  Haemophilus influenzae <10% (type b)

From Harrison ed. 16th

15 Bacterial infection of Childhood

 Diphtheria  Pertussis  Haemophilus influenza infection

Diphtheria

- is caused by gram-positive rod with clubbed ends Corynebacterium diphtheriae and is prevented by immunization with a formalin-fixed toxoid in the DPT vaccine.

16 Tracheal colonization may lead to

- Diphtheria toxin (exotoxin) - Mucosal erosion - Formation of a suffocating pharyngeal fibrinosuppurative exudate (pseudomembrane)  obstruct airway - Toxin-mediated damage to the heart, nerves, liver, or kidneys

Diphtheria

17 Whooping Cough (Pertussis)

- is caused by the gram-negative coccobacillus Bordetella pertussis

- Acute, highly communicable illness with violent coughing followed by a loud inspiratory “whoop” - Laryngotracheobronchitis may include mucosal erosion, hyperemia, and copious mucopurulent exudates - pertussis toxin (exotoxin) paralyzes the cilia, impair pulmonary defense

Haemophilus influenzae

- is a gram-negative coccobacilli, which is a major cause of life-threatening epiglottitis, laryngotracheobronchitis, pneumonia and meningitis in young children.

18 Sexually Transmitted Diseases (STDs)

 Gonorrhea  Chancroid  Syphilis

Neisseria gonorrhoeae

- is an encapsulated, gram-negative diplococcus that causes urethritis, pharyngitis, or proctitis, depending on sexual practices.

- Cause arthritis in reproductive age

- may cause urethral strictures and chronic infections of the epididymis, prostate, and seminal vesicles.

19 - may infect the fallopian tubes (salpingitis), resulting in tubo-ovarian abscesses and scars, sterility, and ectopic pregnancy.

- Perinatal ophthalmic infection was a major cause of blindness before prophylactic administration of silver nitrate to neonates became routine.

20 Chancroid (soft chancre)

 Haemophilus ducreyi (gram negative bacilli)  Clinical feature: - Painful multiple genital ulcer and dirty-based ulcer - 50% inguinal lymphadenitis

21 Chancroid (soft chancre)

Treponema pallidum (Syphilis)

- is a microaerophilic spirochete with an axial periplasmic flagella wound around a slender, helical protoplasm, all of which is covered by an outer membrane.

22 -Primary syphilis: occurs approximately 3 weeks after contact with an infected individual, features a single firm, non-tender, raised, red lesion (chancre) located at the site of treponemal invasion on the penis, cervix, vaginal wall, or anus.

- Secondary syphilis: occurs 2 to 10 weeks after the primary chancre, is characterized by a diffuse rash, particularly of the palms and soles, that may be accompanied by white oral lesions, fever, lymphadenopathy, headache, arthritis.

23 24 - Tertiary syphilis: occurs years after the primary lesion, is characterized by 1. Active inflammatory lesions of the aorta, heart (syphilitic aortitis with aneurysm), and central nervous system (neurosyphilis with paralysis and seizure)

2. Quiescent lesions (gummas) involving the liver, bones, brain and skin ลักษณะรอยโรคเปนจุดขาว และนิ่ม เรียกวา gummas - Congenital syphilis : Trans-placental to fetus

25 Tertiary syphilis

syphilitic aortitis with aneurysm

Enteropathogenic Bacterial infection

 Salmonella  Shigella  Cholera  E. coli

26 SALMONELLA SPECIES

S. enteritidis - contaminated chicken and beef are important causes of food poisoning.

S. typhi, gram negative bacilli, is spread from person-to-person via the fecal-oral route, causes Typhoid fever (systemic infectious disease)

 Salmonella typhi (Typhoid fever) - septicemia, fever, abdominal pain - bacterial replication in macrophages of Peyer patches of terminal ileum  nodule - ulcer along the intestine mucous bloody diarrhea shock

27 Shigella

 ทําใหเกิดกลุมอาการ “บิด” (Dysentery) : cramping, tenemus, mucus bloody diarrhea  Shigella boydii, S. flexneri, S. dysenteriae  Shiga toxin  Fecal – oral route

VIBRIO CHOLERAE

- Gram negative, comma shape with flagella

- is a non-invasive, toxin- producing bacteria that causes severe watery diarrhea

- Cholera toxin increase levels of intracellular cAMP, and cause massive secretion of chloride, sodium, and water.

28 Mechanism of cholera

Escherichia coli

 Gram negative bacilli

 Normal flora in lower intestines (colon)

 Cause several intestinal and extra-intestinal infections eg. urinary tract infections (UTI), meningitis, pneumonia, abdominal pain and diarrhea

29 * Enterotoxigenic E.coli produce cholera- like toxin (ETEC) * Enterohemorrhagic E.coli produce shiga- like toxin, E. coli O157: H7 causes hemolytic uremic syndrome (EHEC) * Enteropathogenic strains attach and efface epithelium, do not invade (EPEC) * Enteroinvasive strains like shigellosis All cause “Traveler’s Diarrhea”

Helicobacter pylori

 Curvilinear gram negative bacilli  Causes chronic gastritis, peptic ulcer  Clinical symptoms: epigastric pain, nausea, vomiting  Associated with gastric carcinoma and lymphoma

30 Helicobacter pylori

Clostridial Infection

 Clostridium perfringens  Clostridium tetani  Clostridium botulinum  Clostridium difficile

31 Clostridium Species

- gram-positive, box-shaped bacilli that grow under anaerobic conditions and produce spores frequently present in the soil.

C. perfringens invade traumatic and surgical wounds and cause gas gangrene, food poisoning (necrotizing enterocolitis)

C. difficile overgrows other intestinal flora in antibiotic- treated patients, releases multiple toxins, and causes a pseudomembranous colitis

C. Tetani - proliferates in puncture wounds and in the umbilical stump of newborn infants in developing countries, releases a potent neurotoxin, called tetanospasmin, that causes convulsive contractions of skeletal muscles (lockjaw). - Tetanus toxoid (formalin-fixed neurotoxin) is part of the diphtheria, pertussis; and tetanus (DPT) immunization.

32 C. botulinum - grows in inadequately sterilized canned foods and releases a potent neurotoxin (inhibit acetyl choline exocytosis) that causes a severe paralysis of respiratory and skeletal muscles (botulism) - หนอไมปบ

33 Clostridium infection

Pseudomembranous colitis

34 Animal reservoirs or insect vector

 Plaque (กาฬโรค): flea ในสัตวจําพวกหนู  Anthrax : goat, sheep, cattle  Leptospirosis : rodent

Plague

 Caused by Yersinia pestis (gram negative intracellular bacilli)  Infected by flea bite  The Black Death pandemic (1347-1350) : 34,000,000 deaths in Europe  3 syndromes : - bubonic plague - septicemic plague - pneumonic plague

35 Anthrax

- Infected by contact with soil or inhalation of spores of Bacillus anthrasis (gram positive bacilli) - cutaneous anthrax (95%) - inhalational anthrax

- cause vasculitis and hemorrhagic necrosis of skin, lung and gastrointestinal tract

- Bioterrorism weapon

Leptospirosis  Leptospira interrogans, spirochete  Reservoir ไดแก หนู หมู วัว ควาย สุนัข แมว  โรคฉี่หนู, ตามแหลงน้ําขัง ชาวไร ชาวนา ลุยน้ํา  เขาสูรางกายโดยไชผานผิวหนังที่มีรอยถลอก  Leptospiremic phase: คลายไขหวัดใหญ (ไข, ปวดศีรษะ, ปวดเมื่อยกลามเนื้อ)  Leptospiuric phase: Aseptic meningitis  Severe Leptospirosis: jaundice, GI bleeding, hepatomegaly, renal failure, death

36 Leptospira spp.

With Immunocompromised host

 Pseudomonas aeruginosa: gram negative bacilli  Nosocomial infection, highly antibiotic resistant  Opportunistic infection  Predispose factors: severe burn, diabetes mellitus, urinary catheterization, cystic fibrosis, neutropenia  Associated with pneumonia, wound infections, UTI, hemorrhagic necrosis of skin and lungs, rapidly progress to sepsis

37 Filamentous Bacterial Infection

 Actinomycosis  Actinomyces spp.  Actinomycotic mycetoma  Nocardiosis  Nocardia spp.  Lobar pneumonia

Mycetoma

 หรือเรียกวา Madura foot, โรคเทาชาวนา เปนโรคติดเชื้อเรื้อรังที่เกิดไดจาก ทั้งแบคทีเรีย และจากเชื้อราบางชนิดที่อาศัยอยูในดิน ซึ่งเขาสูรางกายทาง บาดแผล (minor trauma) โดยเฉพาะบริเวณเทา จะมีลักษณะเปนกอนแข็ง บวมตะปุมตะปา มีรูเปด (sinus) ซึ่งจะมีหนอง และโคโลนีของเชื้อ (grains, granules) ที่มีสี และขนาดตาง ๆ กันปะปนออกมา  Actinomycotic mycetoma เกิดจากเชื้อแบคทีเรีย เชน Actinomadura madurae, A. pelletieri, Streptomyces somaliensis เปนตน  Eumycotic mycetoma เกิดจากเชื้อรา เชน Pseudallescheria boydii, Madurella grisea, M. mycetomatis เปนตน

38 Actinomycotic mycetoma

 Lesions are composed of suppurating abscesses and sulfur granules (grains)

 Microscopic : organisms surrounded by neutrophils, histiocytes, giant cells

 Special stains (GMS): filamentous shaped bacteria

Actinomycotic mycetoma

39 Sulfur granules

Mycetoma เปนโรคที่เกิดจากการ ติดเชื้อที่ผิวหนังเรื้อรัง ทําใหเห็น เปนตะปุมตะปาและมีหนองไหล ในหนองและเนื้อเยื่อที่ติดเชื้อจะมี sulfur granules สีเหลือง ซึ่งเปน colonies ของเชื้อ

Actinomycotic mycetoma

Cluster of filamentous bacteria Filamentous bacteria by GMS

40 Nocardiosis

 Opportunistic infection in immunocompromised host  Nocardia asteroides - organisms found in soil - transmitted by inhaled organisms - lobar pneumonia or abscess - s/s : fever, cough, dyspnea

Nocardiosis

 Microscopic : neutrophil, macrophage, necrosis, organisms and may be giant cells

 Special stains : modified acid fast stain (red filament or branching)

41 Nocardia spp. (Modified AFB stain)

Mycobacterial Infection

 Mycobacterium tuberculosis  Mycobacterium leprae (โรคเรื้อน, Leprosy)

42 Tuberculosis (วัณโรค)

- is caused by the aerobic, non-spore-forming, non-motile bacillus Mycobacterium tuberculosis, which has a waxy coat that stains red with acid-fast stain.

Pulmonary tuberculosis

 Caused by M. tuberculosis  Classified 2 types - Primary pulmonary tuberculosis - Secondary pulmonary tuberculosis

43 Primary pulmonary tuberculosis

 Primary infection at lungs composed of “Ghon complex” - Lung infection  Ghon focus - Infection of hila lymph node  Most of infected persons healed scar  Clinical : non specific

Primary pulmonary tuberculosis

44 Secondary pulmonary tuberculosis  Reactivation of latent infection or exogenous reinfection when host resistance is weakened

 Classically involves the apex of the upper lobes of one or both lungs

 Because of the pre-existence of hypersensitivity, severe lung damage and cavitation is readily occurred

Secondary pulmonary tuberculosis

45 Secondary pulmonary tuberculosis

 Clinical feature: - remittent low grade fever, night sweat, anorexia, weight loss, increasing amounts of sputum, hemoptysis, pleuritic pain

- lymphatic or hematogenous spread to other organs e.g. liver, spleen, pancreas  miliary TB

Miliary TB

46 Caseous granulomas

47 Diagnostic test for TB

 Special stains - AFB : reddish bacilli - Gram stain : indistinct gram positive bacilli  Culture  PCR

48 Mycobacterium avium-intracellulare Complex (MAC)

 Common in immunocompromised host e.g. AIDS (CD4+ < 60 cells/mm3), leukemia  MAC is common in soil, water, dust  Widely disseminated Infection including lung, GI, lymph node, spleen  Hallmark of MAC infection : abundant acid-fast bacilli within macrophages

Mycobacterium avium-intracellulare Complex (MAC)

49 Chlamydial Infection

 Chlamydia trachomatis  Chlamydia psittaci (ไขนกแกว ติดจากสัตวปก)  Chlamydia pneumonia (ปอดบวม ชนิด atypical pneumonia)

Chlamydia trachomatis

is an obligate intracellular, gram negative bacilli that causes : - non-gonococcal urethritis (หนองในเทียม), - lymphogranuloma venereum (ฝมะมวง), - epididymitis, prostatitis, PID - trachoma (ริดสีดวงตา)

50 Chlamydia trachomatis

- Non-gonococcal urethritis (NGU, หนองในเทียม) a mucopulrulent discharge containing neutrophils with an absence of gram-stained organisms

- lymphogranuloma venereum (LGV, ฝมะมวง) a chronic ulcerative lesion of the inguinal lymph nodes with granulomatous inflammation

Lymphogranuloma venereum

51 Trachoma

Rickettsial Infection

 Spotted fever group  Typhus group  Scrub typhus group

52 Rickettsiae

- are obligate intracellular bacteria, poorly stained gram negative bacilli, causes : spotted fevers (Rickettsia rickettsii and others) Rocky Mountain spotted fever (RMSF) murine typhus (R. typhi), scrub typhus (Orienta tsutsugamushi)

- แมลงที่เปนพาหะไดแก เห็บ (tick), ไร (mite), หมัด (flea), เหา (louse), ไรออน (chigger)

Rickettsia infection

 Pathology - infect vascular endothelial cells especially in lungs and brain - destroy arteriole and capillary causing necrotizing vasculitis, hypovolemic shock, pulmonary edema, renal failure, CNS manifestation and coma

 Eschar at the infected sites : spotted fever & scrub typhus

53 Eschar

Mycoplasma infection

 Mycoplasma pneumoniae  เปนแบคทีเรียที่มีขนาดเล็กที่สุดที่กอโรคในคนได  ไมมีผนังเซลล มีแตเยื่อหุมเซลล เซลลยืดหยุนได  30-50% of Community acquired pneumonia (CAP)  Interstitial (atypical) pneumonia in children and young adults and also causes pharyngitis, sinusitis, laryngotracheobronchitis

54 References

 รองศาสตราจารย นายแพทย สุภรณ พงศะบุตร, บรรณาธิการ, “ตําราเรียน พยาธิวิทยาทั่วไป” ภาควิชา พยาธิวิทยา และนิติเวชศาสตร คณะแพทยศาสตร มหาวิทยาลัยนเรศวร, กุมภาพันธ 2551 หนา 91-240.  ผูชวยศาสตราจารยนงลักษณ สุวรรณพินิจ., “แบคทีเรียที่ เกี่ยวของกับโรค, พิมพครั้งที่ 3.” Noble print, 2547.  Kumar V., Abbas AK., Fausto N., “Robbins and Cotran Pathologic Basis of Disease, 7th edition.” Elsevier Saunders, 2005.

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