Teaching plan of bilingual teaching
双语教学教案
Gannan Medical College
Department of pathogenic Biology
Teacher
（教师）
Date
（日期）
Grade
（年级）
Speciality
专业
Lecture type
(授课类型)
Clinical medical
(临床医学)
Theory Course
(理论课)
Subject
（课程）
Class hour
（学时）
4 hours
Medical Microbiology
医学微生物学
chapters and sections
(授课章节)
Chapter 10 Pyogenic bacterium
Objective and request
教学目的和要求
1. Master the pathogenicity of Staphylococcus and Streptococcus.
2. Master the following concepts :
Coagulase; SPA ; M protein; .LTA; Streptolysin
3. Understand the pathogenicity of Pneumococcus, Meningococcus and Neisseria
gonorrhoeae.
Emphasis and difficulty
授课重点、难点
Reference teaching material
参考教材
Teaching aid
媒体与教具
1. The pathogenicity of Staphylococcus
2. The pathogenicity of Streptococcus
1．周正任主编.《医学微生物学》第 6 版
2．Medical microbiology(21 edition, Jawetz, Melnick, and Adelberg)
Powerpoint
Teach contents（教学内容）
Chapter 10
Pyogenic bacterium
Section1. Staphylococcus
I. Biological characteristics
1.Morphology:
Gram positive cocci, arranged in irregular, grape – like clusters
special structure
2.Culture
blood agar----- haemolysis
Colony : 1~2 mm, circular, smooth, shiny surface, opaque, various pigments
3. Classification:
Major properties of three species of staphylococci
Main property
Staph. aureus
Staph. Epidermidis
Staph saprophyticus
Pigmentation
Golden yellow
White
Citrine
1
Coagulase
Hemolysin
SPA
Pathogenicity
+
+
+
+++
-/+
-
4. Antigenic structure:
(1) SPA (staphylococcal protein A)
i) cell wall protein
ii) it combines nonspecifically with the Fc-portion of human IgG
iii) antiphagocytosis
iv) coagglutination
5. Resistance:
(1) resistant to dry; heat (80℃,30min); salt(10~15%)
(2) sensitivity to: basic-dyes(crystal violet); antibiotics and sulfonamides (antibiotic resistance)
II. Pathogenicity
1.pathogenic factor
1).Invasiveness
(1)Surface structure: SPA
(2)Enzyme
Coagulase:.
(1).Extracellular coagulase
(2).Bound coagulase2)Toxin---exotoxin
(1).Staphylolysin:
(2) .Leukocidin:
(3) Enterotoxin:Protein;
(4).Toxic shock syndrome toxin-1 (TSST-1):
(5).Epidermolytic toxin:
2. pathogensis
1) purulent infection
(1) local infection
(2) organ infection: pneumonia meningitis.
(3) Systemic infection: Septicemia; pyemia
2) toxin diseases
(1) Food poisoning (enterotoxin)
(2) TSS (Toxic shock syndrome)
(3). SSSS(staphylococcal scalded skin syndrome):
3) Staphylococcal enteritis:
III. Immunity
IV. Laboratory diagnosis
specimen:
isolation and identification: blood agar
2
coagulose test
Enterotoxin test and animal test
V. Treatment
Section 2. Streptococcus
I.Biological characteristics
1.Morphology & cultural properties:
(1) G+ ,cocci, arranged in chains,
no special structure(capsule of hyaluronic acid in the early period).
(2).high nutritive requirement (blood & serum)
blood agar:
* hemolyze erythrocytes in vitro in varying degrees
*faculation/obligate anaerobe
2.Classsification:
(1) Hemolytic activity:
(i)α-hemolytic streptococcus
(ii)β-hemolytic streptococcus (or pyogenic streptococcus)
(iii)γ-streptococcus
(2) Antigenic structure:
3.Resistance
*heat labile: 60℃,30 min
*antibiotics sencitivity: panicillin G ,etc.
II. phathogenicity
1. Pathogenic substances (invasiveness & exotoxin):
(1).Invasiveness
(i).surface structure
*LTA(lipoteichoic acid): adhere to sensitive cell
* M-protein : ◆anti-phagocytotic
◆M-Ag Ab: ypersensitivity(glomerulonephritis)
◆Common antigen---heart muscle cell(rheumatic fever)
(ii).enzyme
*Hyaluronidase (spreading factor):
* Streptokinase (SK ):
* Streptodornase (SD):
(2).Toxins---exotoxin
(i) Streptolysin (hemolysin)
Streptolysin O (SLO); Streptolysin S(SLS)
(ii) Erythrogenic toxin (or pyrogenic toxin /scarlet fever toxin)
2. Diseases of streptococcal infection
-hemolytic streptococci)
3
(1). local purulent infections:
(2). systemic infection
(3) poststerptococcal diseases (hypersensitive disease)
IV.Immunity
V. Laboratory diagnosis
1. Isolation & identification of pathogen
. ASO test: ASO titer > 1: 400 units, help to diagnose rheumatic fever.
VI. Prevention & treatment
*Treat the pharyngitis and tonsillitis in time, avoid the post streptococcal diseases.
*Antibiotics and chemical agents: penicillin G for the first choice
Section 3. Pneumococcus
1. Belong to the Streptococcus ( Streptococcus pneumoniae ),
2.G+, diplococcus, lancet shape,
arranged in pair, capsule of polysaccharide
3.Blood agar, 0.1% glucose, 5~15%CO2
4.small colony, α- haemolysis, smooth colony (virulent strain)
‘draughtsman’colony(incubation over 24 hour)
5.Pathogenic factor: capsule( antiphagocytosis)(S→R); pneumolysin
6.Disease: pneumonia , bacteraemia; meningtis
7.Treatment: sensitive to a wide range of antimicrobia agent. eg.Penicillins*,
Section 4. Neisseria
Common biological characteristics
1.Gram negative cocci, kidney-shaped, in pairs have capsules and pili
2.Need enriched medium (chocolate blood agar )
3. 5~10%CO2
4.Resistance: very weak “fragile”, extremely sensitive to drying, heat, cold…
Neisseria meningitidis
I. biological characteristics
II.Pathogenicity and immunity
1. Pathogenicity:
(1) Human is the only natural host for pathogenic meningococci.
(2) Pathogenic factor:
*Pili– attach to nasopharyngeal mucosa
*capsule – antiphagocytosis
*endotoxin –
2.Pathogenesis:
epidemic cerebrospinal meningitis
4
clinical typing: common, outbreak,septicemic type
3.Immunity:
group-specific antibody, cross-immunity between groups.
III. Laboratory diagnosis
1. specimen: spinal fluid, blood, nasopharyngeal swabs .
2.
- diplococci, within white cells)
3. isolation and identification:
4. serologic test : to detect the unknown Ag with given Ab
IV. Prevention and treatment
1. Polysaccharide vaccine (group A, C)
2. Penicillin; cefotaxime; chloramphenicol
Neisseria gonorrhoeae
1. Pathogenic factors:
* Pilli: attach to epithelial cells (urinary-gentital, RBC)
* IgA 1-protease: break down surface IgA antibodies.
*Outer membrane protein (OMP):
2. Diseases:
*Gonorrhea (STD: sexually transmitted disease)
*ophthalmia neonatorum→blindness
3. Laboratory diagnosis:
Specimen: purulent secretion of genitourinary tract
Isolation and identification: direct smear, culture, biochemical tests
4. Prevention and treatment
*penicillin----- Gonorrhea
*silver nitrate
question
思考题
Try to describe pathogenicity of 5 pathogenic cocci
5