week1day3 Flashcards
what are the three different types of anaerobes? which ones have catalase? and what are the examples?
1) obligate anaerobes-lack SOD and catalase - Clostridium, majority of perio bacteria
2) Facultative anaerobe - (grows with or w/o O2) - E.coli Streptococcus
3) Fastidious Anaerobes - May have low levels of SOD and may or may not have catalase - Bacteroides Fragilis
What is a consideration when selecting an antibiotic for B. fragilis?
It has beta-lactamases, and it confers the resistance to penicillin
What is a species of bacteriodes we studied? Is it pathogenic only?
B. fragilis. Its a “friendly” commensal that remains a normal resident until something changes in host (like a surgery). Then it will become pathogenic
What are the four gram- bacteria commonly found in infections?
Bacteroides, Prevotella, Porphyromonas, Fusobacterium
What is a species of bacteriodes we studied? Is it pathogenic only?
B. fragilis. Its a “friendly” commensal that remains a normal resident until something changes in host (like a surgery). Then it will become pathogenic
How does P.fragilis infect?
P. fragilis produces endotoxin. it has beta -lactamases. They confer resistance to penicillin.
What is the bacteria species of Prevotella that we studied? Where is it found?
P.melaninogenica, found in oral pharynx
which bacteria is a diagnostic marker for OSCC?
P. melaninogenica is found to predict 80%of oral squamous cell carcinomas
Which two bacterial species play a prominent role in adult periodontitis?
P.melaninogenica, P.intermedia
In which kinds of infections does P. melaninogenica become important?
oral and pulmonary infections (Asthma, COPD)
What species of porphymonas did we study?
P. gingivalis
What three types of disease is Fusobacterium nucleatum important in?
important in oral infections, lung abscesses, and other pulmonary infections, also ANUG
Which bacteria is associated with ANUG? What is unique about ANUG?
Fusobacterium nucleatum. ANUG is one of the only conditions that have 1 organism as a main player, since most other conditions are polymicrobial
What are the four different species of Clostridium? G- or g+?
C. Perfringens
C. difficile
C. Tetani
C. Botulinum
How does C. Perfringens cause the disease? What disease?
It causes GAS gangrene
It produces alpha toxin
What disease does C. Difficile cause? How?
Pseudomembranous colitis (inflammation in colon) Antibiotics associated diarrhea
What disease can C. Tetanus cause? How? get infected?
Tetanus. It releases neurotoxin -> muscle spasm/paralysis
Bacteria can be in soil, enters through a deep cut. Also via mother to fetus
What are the three types of C. Botulinum toxin?
1) Food - home canned goods
2) Wound - deep cut - through environment
3) Infant - bacterial spores
Why should we not give babies raw honey?
Clostridium botulinum toxin - can cause botulism - “floppy baby syndrome”
What are the three different actinomyces types? What are the treatment options?
Oral -normal flora, becomes pathogenic if trauma: like extraction
Cervicofacial -(sulfur granules)-> pyogenic abscesses
Abdominal - especially if ulcer
Treat with surgical draining and penicillin/ampicillin
What are the two main pathogenic Niseria species? What is a way we can differentiate between them?
Neisseria meningitidis -Ferments both glucose and maltose
and Neisseria gonorrhoeae - only ferments glucose
What are the two key virulence factors of Neisseria meningitis?
- Evade the immune system → IgA protease and polysaccharide capsule
- Overstimulate immune system → lipooligosaccharide
What does overstimulation of immune system caused by N. Meningitis manifest in?
Fever, Septic shock, Disseminated intravascular coagulation
Which bacteria would cause severe infection if someone’s complement doesn’t work?
N. Meningitis
