Antibiotics Flashcards
What are factors that lead to infections?
Causative organism: viral, bacterial, fungal, parasite
What are factors affecting the transmission of organism?
Contact
Food, water, vector, or airborne
Vertical (perinatal)
Reservoir (human, animal, soil, water)
What are factors associated with clinical disease?
Diarrheal
Respiratory
CNS
CV
Sepsis
What is gram negative bacteria?
bacteria such as E. coli have thinner walls which allows the violet dye to escape when washed with alcohol and permits the cells to counterstain with a light red dye
What is gram positive bacteria?
Bacteria such as S. aureus have more peptidoglycans, so they retain the violet-colored dye when treated
Why can’t some bacteria be visualized by gram staining?
Some bacterial species cannot be visualized by gram stain because the lack a cell wall (such as Mycoplasma) or because they do not retain the stain (such as Chlamydia).
What bacteria is gram positive (violet)?
Staphylococci
Streptococci
Enterococci
Cornybacterium
Listeria
Clostridium
What bacteria is gram negative (pink)?
Neisseria
Moraxella
Bacteriodes
Escherichia coli
Klebsiella
Pseudomonas
Salmonella
Vibrio
What bacteria is aerobic?
M. Tuberbulosis,
Enterobacteria
Bacillus
Psuedomonas
Gonococcus
Staphylococcus
Streptococcus
What bacteria is Anaerobic?
These bacteria are more likely to cause abscesses
Clostridia
Bacteroides
Actinomyces
What bacteria are facultative?
Vibrionaceae
Enterobacteriacae
Pasteurellaceae
Lactobicillus
What antibiotics are broad spectrum?
Tetracycline
Aminoglycosides
2nd, 3rd generation cephalosporins
Amoxicillin
Azithromycin
What antibiotics are narrow spectrum?
Erythromycin
Fidaxomicin (new macrolide for C. Diff)
Clindamycin
Vancomycin
Sarecycline (new tetracycline- derived for acne)
What is antimicrobial susceptibility testing (AST)?
Measures the ability of a specific organism to grown in the presence of a particular drug in vitro
Define bacteriostatic:
Prevents the growth of bacteria
Define bactericidal:
Kills the bacteria (concentration and time dependent)
When are narrow antibiotics indicated?
When the causative organism is known
What is natural or intrinsic resistance?
Innate characteristics of bacteria that resist antibiotics. Example: e. Coli cell wall pores are too small for vanco
What is an acquired antibiotic resistance?
It is a spontaneous mutation then vertically pass along the trait to their offspring.
Resistant bacteria can also pass their genetic material to other bacteria horizontally via extra=chromosomal elements called plasmids.
What are plasmid-mediated resistant bacteria?
Bacteria that are highly-resistant that can then pass al one their resistance either vertically or horizontally.
What are the mechanisms of resistance?
Cell wall changes
Drug inactivation
Alteration of drug target molecules
Efflux pump
Generally at MIC which antibiotics are usually bacteriostatic?
Tetracyclines
Chloramphenicol
Macrolides
Spectinomyscin
Sulfonamides
Generally, at MIC, which antibiotics are most likely bactericidal?
Penicillins
Cephalosporins
Aminoglycosides
TMP-SMZ
Nitrofurans
Metronidazole
Fluoroquinolone
What is the bacteria that causes Strep throat and how is it treated?
Streptococcus pyogenese
Penicillin or amoxicillin
