Flashcards in Bacteria 2 Deck (80):
2 examples of common upper respiratory infections caused by normal flora?
1) Ottis media
What causes upper respiratory infections via normal flora?
Blockage of sinus ostia, estachian tube by virally induced or allergic inflammation
What causes invasive Upper respiratory disease in neonates?
E. coli and Group B Strep
What causes IURD in children 1-5?
H. influenzae type B
What cause IURD in adolscents and young adults?
What causes IURD in all age groups?
What is the key to pathogenicity for bacteria?
Where does the pathogenesis begin?
Upper respiratory infection
What happens after the initial Upper respiratory infection?
Invasion of bacteria into deep tissues and bloodstream
What happens when the bacteria is disseminated in the body?
What leads to vascular leakage?
Endothelial and macrophage activation by LPS
Vascular leakage leads to what?
Disseminated intravascular coagulation (DIC)
Infections with encapsulated organisms require what that Staph and strep infections don't?
Antibodies or complement
What is a splenic condition that increases susceptibility to encapsulated organisms?
Where is Pneumococcus found?
Normal Upper respiratory flora
What does Pneumococcus look like?
Gram + diplococcus
Pneumococcus virulence factors?
Capsule and PspC (Pneumococcal surface protein C)
Disease caused by Pneumococcus?
Sepsis and meningitis
Where is N. meningitidis?
What does N. meningitides look like?
Gram -, diplococcus
Virulence factors of N. meningitides?
Capsule and LPS
Disease caused by N. meningitides?
DIC, sepsis, meningitis
Where is N. gonorrhea found?
What does N. gonorrhea look like?
Gram - diplococcus
Virulence factors of N. gonorrhea?
Capsule and LOS
Diseases of N. gonorrhea?
Where is H. influenza found?
Normal flora, type B exogenous
What does H. influenza look like?
Gram - pleomorphic
Virulence factors of H. influenza?
Capsule and LPS
Disease caused by H. Influenzae?
Sepsis and meningitis
What does invasive disease lead to?
What is found on bacterial capsule that causes Sepsis or DIC?
LPS or PspC
Why do encapsulted bacteria and meningitis go to CSF?
No complement for opsonization
In sepsis what does LPS stimulate?
Toll Like Receptors to induce systemic cytokine secretion and endothelial cell activation
What is DIC?
Systemic coagulation caused by bacteria
What limits Gonococci's ability to cause DIC?
They have LOS instead of LPS
Most common caused of community acquired pneumonia ?
What special attachment does Strep pneumoniae have on its polysaccharide capsule?
What virulence factor of Strep Pneumoniae inhibits alternate complement pathway?
Who is the pneumococcal conjugate vaccine for?
Children younger than 5 and adults with risk factors
Who is the pneumococcal polysaccharide vaccine for?
Children two years or older
What is one of the main nutritional requirements for Neisseria?
Where is Neiserria found?
Not normal flora, exogenous
Incubation time N. meningitides?
Less than a week
What is N. meningitidis susceptible to?
What causes the petechial rash in N. meningitidis?
Microhemorrhages in capillaries
What is Waterhouse Friderichsen syndrome?
Hemorrhage into adrenals
Are vaccinations effective for meningococcal disease?
Yes, doesn't cover group B though which is biggest in neonates
Why do N. meningitidis vaccines not work in neonates?
Neonates cannot respond to capsular antigen vaccine
How does N. Gonorrhea differ from N. Meningitidis?
Different capsule allows different behavior
Where does N. Gonorrhea attach?
Columnar and transitional epithelia mucous membranes of genital tract, rectum, and nasopharynx
N. Gonorrhea IgA protease allows for what?
Evasion of mucosal immunity
Why has it been difficult to make a vaccine for N. Gonorrhea?
What is a defining characteristic of H. influenza?
What can make H. influenza dangerous?
Encapsulation and endotoxin
What is the window of vulnerability for invasive disease of Type B?
3 months to 3 years due to bad protective antibody response to type B capsular antigens
What is a good way to vaccinate toddlers and infants with Type B?
Conjugate capsule with protein
What causes Diphtheria?
What causes the membrane formation of Diphtheria?
Local epithelial necrosis which releases exotoxin A
What is characteristic of Whooping Cough?
What does the exotoxin of Whooping Cough do?
Leads to local ciliary paralysis
What does the DPT vaccine do for cases of Whooping Cough?
Gives immunization to Exotoxin
What is the Pertussis vaccine called?
Tdap for 10 years and older, DTaP for children younger than 7 years
What does Diphtheria look like?
Gram + rod
What does the exotoxin do in Diphtheria?
Inhibits protein synthesis and leads to fatty myocardial changes
Biggest reason for death with Diphtheria?
What type of infection are UTIs generally?
Gram negative infections
What are the 2 main types of gram - infections?
1)Spread of organisms that have colonized GI tract
2) Contamination of tissues and materials from hospital environment
Cause of most uncomplicated UTIs in absence of obstruction?
What causes suppurative infections of abdominal cavity?
Secondary to obstruction, perforation, and trauma
What is Klebsiella pneumonia associated with?
Aspiration in hospital setting
Characteristic of Klebsiella and Enterobacter in septicemia?
Association with thick mucoid capsule
Defining characterstic of proteus marabilis?
Staghorn pyelonephritis due to chronic pyelonephritis
What does Serrate marcescens cause?
Pneumonia and UTIs
What defines Pseudomonas aeruginosa histologically?
Blue haze around blood vessels
What is the common pathogenic organism in cystic fibrosis?
Outbreak of Legionella associated with?
Community outbreaks associated with contaminated aerosolized water supplies
Biggest problem with Legionella?
Fibrinopurulent necrosis of pulmonary tissue
How does helicobacter pylori survive in the stomach?
Urease creates protective layer of ammonia around organism