What does the term "antimicrobials" apply to?
What are actinomycetes?
- Bacteria that resemble fungi due to their filamentous projections
- 85% of antibiotics are made from these
What is penecillin made from?
penicillium, a fungus
What is prophylaxis?
Prevention of post-operative wound infection
What are endogenous and exogenous bacteria?
- Endogenous - microbe comes from the patients own bacteria
- Exogenous - microbe comes from outside the patient
What is the infection cycle?
Pathogen -> Means of transmission -> Susceptible host -> SSI
What are 2 common ways to identify pathogens?
- Culture and Sensitivity
- Gram Staining
What is a culture and sensitivity test?
- grow microbes in culture to determine the infecting pathogen
- expose microbes to various antibiotics to determine which will best inhibit growth
What is an I&D?
Incision and Drainage
What is morphology?
The study of shapes of bacteria
What is selective toxicity?
Medication must act against infecting agent without harming host cells
What are prokaryotes?
- Single celled organisms
- Has a "pre-nucleus"
What are eukaryotes?
- Has a true nucleus
- Multicellular organisms
What is antibiotic resistance?
The ability of some strains to prevent or overcome the activity of an antimicrobial agent
What are the 3 ways microbes can havce antibiotic resistance?
- Manufacture enzymes that prevent the antibiotic from entering the cell
- Cell membrane may be altered to prevent entry of the antibiotic
- Target areas may be altered so the agent is no longer effective
What are aminoglycosides?
- Antibiotics that are derived from various strains of Actinomyces
- Interfere with protien synthesis
- Mostly used against Gram-negative bacteria
- Short term treatment of serious infections
- Poorly absorbed orally
- Can cause ototoxicity and nephrotoxicity
What are the 5 major categories of antibiotics?
What is ototoxicity?
Hearing and balance damage
- What is nephrotoxicity?
- Death of kidney cells/nephrons
What drugs are in the Aminoglycoside category?
- amikacin (Amikan)
- gentamicin (Garamycin)
- tobramycin (Nebcin)
- neomycin (Neobiotic)
- kanamycin (Kantrex)
What are cephlasporins?
- Broad-spectrum antibiotics derived from the fungus Cephalosporium acremonium
- Bacteriacidal, targets cell wall synthesis
- Have 4 generations
- Used for prophylaxis
- Given orally, intramuscularly, or intravenously
How is gentamycin available?
- cream or ointmet
- ophthalmic solution and ointment
- solution for injection
How is streptomycin available?
How is neomycin available?
What do 1st generation cephlasporins do?
Active against many gram positive and some gram negative bacteria
What do 2nd generation cephlasporins do?
Active against many gram negative, but few gram positive
What do 3rd generation cephlasporins do?
Wider range of effectiveness on gram-negative than 2nd generation, but very limited on gram positive
What do 4th generation cephlasporins do?
Work on gram positive and negative organisms
What are macrolides?
- Broad-spectrum antibiotics that attack protien synthesis in the ribosomes
- Includes the erythromycins
- Bactericidal for several gram positive agents, including Legionella
- Derived from Streptococcus erythreus
What are penicillins?
- First antibiotic
- Derived from penicillium
- Bactericidal on gram positive and negative
- Blocks enzymes so cell walls rupture
What is penicillinase?
An enzyme that breaks down penicillin
What are the natural penicillins?
- penicillin G (Pentids, Pfizerpen)
- benzathine penicillin G (Bicillin L-A, Permapen)
- penicillin G (Beepen-VK, Betapen-VK)
What are the Penicillinase-Resistant penicillins?
- methicillin (Staphcillin)
- cloxacillin (Cloxapen)
- dicloxacillin (Dycill, Pathocil)
- nafcillin (Nafcil, Unipen)
- oxacillin (Bactocill)
What are the Aminopenicillins (not penicillinase resistant)?
- amoxicillin (Amoxil, Polymox)
- ampicillin (Omnipen)
- bacampicillin (Spectrobid)
What are the broad spectrum penicillins?
- ticarcillin (Ticar)
- carbenicillin (Geocillin)
- mezlocillin (Mezlin)
- piperacillin (Pipracil)
What are tetracyclines?
- First broad spectrum antibiotics
- Originally obtained from cultures of Streptomyces
- Bacteriostatic against Gram positive and negative
- Interferes with protien synthesis
- Used primarily to treat acne and Rickettes
What are the tetracyclines?
- doxycycline (Vibramycin)
- tetracycline hydrachloride (Achromycin-V, Sumycin)
- minocycline (Minocin)
- oxytetracycline (Terramycin)
- chlortetracycline hydrochloride (Aureomycin)
What are oxazolidinones?
New class of synthetic antibiotics
Treats MRSA, VRE and Streptococci
Intravenously or orally
What are Quinolones?
- Antibiotics that inhibit DNA-gyrase
- Orally or intravenously
- UTI's or systemic infections
What are Sulfonamides?
- Not really antibiotics - they're antimicrobials
- Commonly known as sulfa drugs
- Lab synthesized
- UTI's, severe burns, superficial eye infections
- Orally, topically, ocassionally intravenously
What is aztreonam (Azactam)?
First drug of a new class of antibiotics called monobactams
What is systemic inflammatory response syndrome (SIRS)?
- 2 or more of the following:
- Temperature greater than 36 - 38c
- Heartrate greater than 90 bpm
- 3 - 17% mortality rate
What is sepsis?
- SIRS with the addition of an infection site confirmed by a culture
- Mortality rate 16%
What is Severe sepsis?
- Sepsis plus organ dysfunction and tissure hypoperfusion or hypotension
- Mortality rate 20%
What is Septic shock?
- Hypotension induced by sepsis despite fluid bolus or organ and tissue hypoperfusion
- Mortality rate 46%
What are the 5 ways antibiotics work?
- Inhibit cell wall synthesis
- impede protien synthesis
- alter bacterial cell wall function
- disrupt cell metabolism
- interfere with DNA/RNA synthesis