A/45-49 GENERAL PATHOLOGY OF INFECTIOUS DISEASES (Tamer) Flashcards

Question

how can Viral Poteins cause injury ?

Answer 1

**1) lyis of host cell** due to interfering replicaiton **2) immune cell-mediated killing** infected cells are recognized and attacked by cytotoxic t-cells **3)** **alteration of apoptosis** by viral proteins * adenovirus induce cell apoptosis -microbe elimination (good) * some release anti-apoptotic proteins - viral replication (not good) **4) transformaiton** of infected cell resulting in **cancer** * EBV * HBV * HCV * HPV **5)** **inhibition** of host's DNA,RNA, protein synthesis **6) insert into plasma membrane** causing it's damage **7) secondary infections**

Answer 2

1) **adherence to host molecules - ** adhesins aid bacteria to bind host cells -on gram +(bind fibronectin,prevent phagocytosis) * fimbria * lipoteichoic acid * M protein * F protein - on gram - * fimbria/pilli for adhesion - ------------------------------------------------------------------------------ 2) **virulence of intracellular bacteria** ability to **enter** the cell by opsonization and endocytosis ability to **survive** by inhibition of ,escape from ,resistance to phagolysosomes and lysosmal products - ------------------------------------------------------------------------------ 3) **bacterial toxins** *_-Endotoxin_* LPS (lipid-A) of gram - bacteria promote cell activation and inflammatory repsonse involving IL-1, TNF, kinins ,septic shock *_-Exotoxin_* * **Enzymes** * **A-B toxins** -alter intracellular signaling/regulatory pathways * **Superantigens**-massive stimulation of T-cells leading to SIRS, toxic shock syndrome * **Neurotoxins** - inhibit release of NT's , paralysis * **Enterotoxins**-nausea , vomting

Answer 3

- tissue injury caused by host's own immune response against tissue injury. e. g. - TB causes GRANULOMATOUS reaction that prevents spread of bacilli, but on the other hand tissue damage and fibrosis. - antibodies against bacterial M protein can also attack cardiac proteins leading to rheumatic fever

Answer 4

1) Culture 2) Serological tests 3) Stain in direct smear/sliders 4) PCR, QR-PCR - gonorrhea , Chlamydia, TB 5) In situ hybridization - CMV, EBV 6) Immunohistochemistry on slides /smears 7) EM: EBV, Helico.B , Herpes ,

Answer 5

most bacteria

Answer 6

Mycobacteria , Nocardiae

Answer 7

Fungi , Legionella , Pneumocystis

Answer 8

Fungi ,Amebae

Answer 9

Campylobacter, protozoa

Answer 10

bacteria present in blood , confirmed by culture , may be transient

Answer 11

SIRS --\> SEPSIS --\> SEVERE SEPSIS --\>SEPTIC SHOCK

Answer 12

response to a wide variety of clinical insults which can be infectious as in sepsis or non-infectious (burns,pancreatitis)

Answer 13

clinical evidence of infection and systemic response including two or more of the following conditions : 1) Temperature \> 38 C , 36 C 2) HR \> 90 BPM 3) Respiratory rate \> 20 breaths/min , PaCO2 \< 32 mmHg 4) WBC \> 12,000 cells/mm3 or WBC \< 4000 cells mm3 or WBC \> 10% immature forms

Answer 14

Sepsis **+ organ dysfunction** that results in - hypotension - lactic acidosis - oliguria - confusion - hepatic dysfunction

Answer 15

Severe sepsis + **hypotension** _depsite fluid resuscitation_

Answer 16

septic shock that lasts \>1 hour , with no response to fluid adminstration,medication

Answer 17

- weak host defense - type and duration of hospitalization (higher rate in ICU) - operative procedure - indwelling urinary catheters , intravascular devices

Answer 18

**35% of sepsis** incidents include : * E.coli * Pseudomonas * Klebsiella

Answer 19

**39%** of sepsis incidents include : * S.aureus * S.epidermidis * Enterococci * Pneumococci

Answer 20

**a mix** of microorganisms (gram +/- etc...)

Answer 21

**5%** of sepsis incidents

Answer 22

- **Endotoxin** (LPS, lipid -A) - all GRAM - - **Peptidoglycan -** all bacteria - **Lipoteichoic acid** - Gram + - **Pore-forming exotoxins** - a-hemolysin , streptolysin-o - **Superantigens** -TSST1 , enterotoxins A-F - **Enzymes -**PLC , IL-1B cnonvertase

Answer 23

- complement system - monocytes - endothelial cells - neutrophils - factor XII

Answer 24

**TNF-α , IL-1** these further stimulate **IL-6** producing cells

Answer 25

-NO * Vasodilation * Regional Vasoconstriction * Capillary shunting - Tissue Factor * coagulopathies ,microthrombi - TNF-α * reduced stroke volume * reduced Ejection Fraction

Answer 26

**microvascular insufficiency** * dramatic fall in systemic vascular resistance * ****severe myocardial depression * severe hypotension -all of these changes lead to **Tissue hypoxia** and finally **Multi-Organ Failure**

Answer 27

1) Peripheral vasculature - **NO** and **TF** lead to * vasodilation , * Coagulopathy (DIC) , * Refractory hypotension , * shunting 2) Myocardium -altered **Ca+2 influx** and decreased contractility lead to * **myocardial depression** * **arrhythmias** 3) Lung - due to increased endothel permability and neutrophils activation/migration * **ARDS** *

Answer 28

- _Kidney_ - due to renal hypoperfusion * **Acute tubular Necrosis** _-Liver -_ due to hypoperfusion and acidosis * **Zonal necrosis** * **hepatic failure** * **jaundice** **_-_**_Gut_ - due to hypoperfusion and acidosis * **Breach of endothelial integrity** **** **** **-**

Answer 29

**Encephalopathy** due to hypoperfusion and acidosis

Answer 30

- treating the underlying non-infective disease - preserve vital organ perfusion and tissue oxygenation - treat underlying infection - avoid complications

Answer 31

- **Transcervically** (ascending infections) - **Transplancentally** (hematogenic infections)

Answer 32

- infection spreads from **cervicovaginal cana**l (inhaled by fetus) or **during birth** (when passing through birth canal) - mostly bacterial infection that lead to **inflammation** of **placental** membrane and **umbilical cord** - later gives rise to **pneumonia** , **meningitidis**, **sepsis**

Answer 33

-**direct tranfusion from Chorionic vill**i during delivery leads to "TORCH" * *T**oxoplasma * *O**ther * *R**ubella virus * *C**ytomegallovirus * *H**erpesvirus - *_Early_* in gestation: growth restriction, mental retardation, cardiac abnormalities - *_Later_*: inflammatory tissue injury (pneumonia, myocarditis)