Microorganism Classifications:
• Bacteria
• Viruses
• Fungi
• Parasites
Normal Microbial Flora —skin, upper respiratory tract, colon.
Infectious diseases involves the presence of pathogen plus clinical signs and symptoms of infection
Bacteria
• Gram positive has thick layer of peptioglycan
• Gram negative has thin peptioglycan layer and an outer membrane
Gram positive Gram negative Aerobic Anaerobic
• staphylococcus • E-Coli • staph • deep wounds
• pseudomonas • strep • abscess formation, foul smelling pus
• streptococcus • bacteroides • Clostridium perfringens
• enterococci • klebsiella
Chemotherapeutic drugs — destroys organisms that invade the body (bacteria, viruses, parasites, etc), destroys
abnormal cells within body (neoplasms or cancers)
Narrow spectrum of activity: effective against only a few microorganisms, very specific
Broad spectrum of activity: useful in treating a wide variety of infections
Anti-infectives act on specific enzyme system or biological process, many microorganisms that do not act on this
system are not affected by this particular drug
Prophylaxis: prevention of a certain disease ex: people traveling where malaria is endemic, patients undergoing GI
surgery, etc.
Laboratory Tests:
• gram stain— microscopic identification of organism
• culture— involves growing microorganism in lab
• CBC: look for elevated WBC
• serology— identifies infectious agent via antibody levels
• PCR— detects the presence of microbial DNA in sampling
Antibiotics:
• chemicals that inhibit specific bacteria
• made by: living microorganisms, synthetic manufactures, genetic engineering
• goals: eradicate causative microorganism, return host to full physiologic function
• most frequently used medication world wide, much overuse/misuse/abuse leading to— increase in adverse drug
effects, health care costs, and drug resistant infections
• bacteriostatic: prevents growth of bacteria, bactericidal: kills bacteria directly
Antimicrobial therapy
• combination therapy: treat infections caused by multiple microbes, nosocomial infections, serious infections
• duration: varies, single dose (prophylactically), 7-10 days or until patient is asymptomatic for 48-72 hours
• can increase resistance to antimicrobials
• increase cost of therapy, therapeutic effects, adverse effects, risk for superinfection
, Antimicrobial mechanisms of action:
• inhibits bacterial wall synthesis
• inhibits protein synthesis or production of abnormal bacterial proteins
• disruption of microbial cell membranes
• inhibits of reproduction of organisms
• inhibits cell metabolism and growth
Beta-Lactams
• named after beta-lactam ring in chemical structure
• specific enzymes disrupt the ring
• includes: penicillins, cephalosporins, carabapenems, and monobactams
• inhibits bacterial cell wall synthesis
• side effects: well tolerated (most part), upset stomach, diarrhea, headache and allergic skin rash can occur.
Anaphylaxis (rare)
• if patient is allergic to beta-lactam they may be allergic to other beta-lactam (except monobactams)
Penicillin
• many bacteria are resistant to penicillin but still used for syphillis and susceptible resp. and skin infections
• bactericidal
• indications: severe infections caused by sensitive organisms + broad spectrum use
• actions: destroys bacteria by weakening bacterial cell wall
• pharmacokinetics: absorbed in the GI tract, peak — 1 hr. excreted unchanged in urine and enters breast milk
• gram-positive cocci: pneumonia, meningitis, endocarditis, and pharyngitis
• gram negative cocci: meningitis
• kills spirochetes that cause syphillis
• extended use penicillin (ticarcillin + piperacillin) — used for
pseudomonas aeruginosa infections
• penicillin provide prophylaxis against bacterial endocarditis for at-risk
clients prior to dental work and other procedures
• for penicillin resistant infections use: methicillin, nafcillin, oxacillin,
deicloxacillin
• severe allergies to penicillin are at risk for allergy to cephalosporins
• anaphylactic shock— administer epinephrine and corticosteroids
• use cautiously for clients who have or are at risk for kidney dysfunction
(ill clients, older and young clients)
• do not mix penicillin w certain meds (inactivates — amino-glycosides
and birth-control pills)
Monobactams
• Aztreonam (Azactam)
• used for serious infections like meningitis, P. aeruginosa, UTI
• okay to use for patients with allergies to other betalactams
• Bacteria
• Viruses
• Fungi
• Parasites
Normal Microbial Flora —skin, upper respiratory tract, colon.
Infectious diseases involves the presence of pathogen plus clinical signs and symptoms of infection
Bacteria
• Gram positive has thick layer of peptioglycan
• Gram negative has thin peptioglycan layer and an outer membrane
Gram positive Gram negative Aerobic Anaerobic
• staphylococcus • E-Coli • staph • deep wounds
• pseudomonas • strep • abscess formation, foul smelling pus
• streptococcus • bacteroides • Clostridium perfringens
• enterococci • klebsiella
Chemotherapeutic drugs — destroys organisms that invade the body (bacteria, viruses, parasites, etc), destroys
abnormal cells within body (neoplasms or cancers)
Narrow spectrum of activity: effective against only a few microorganisms, very specific
Broad spectrum of activity: useful in treating a wide variety of infections
Anti-infectives act on specific enzyme system or biological process, many microorganisms that do not act on this
system are not affected by this particular drug
Prophylaxis: prevention of a certain disease ex: people traveling where malaria is endemic, patients undergoing GI
surgery, etc.
Laboratory Tests:
• gram stain— microscopic identification of organism
• culture— involves growing microorganism in lab
• CBC: look for elevated WBC
• serology— identifies infectious agent via antibody levels
• PCR— detects the presence of microbial DNA in sampling
Antibiotics:
• chemicals that inhibit specific bacteria
• made by: living microorganisms, synthetic manufactures, genetic engineering
• goals: eradicate causative microorganism, return host to full physiologic function
• most frequently used medication world wide, much overuse/misuse/abuse leading to— increase in adverse drug
effects, health care costs, and drug resistant infections
• bacteriostatic: prevents growth of bacteria, bactericidal: kills bacteria directly
Antimicrobial therapy
• combination therapy: treat infections caused by multiple microbes, nosocomial infections, serious infections
• duration: varies, single dose (prophylactically), 7-10 days or until patient is asymptomatic for 48-72 hours
• can increase resistance to antimicrobials
• increase cost of therapy, therapeutic effects, adverse effects, risk for superinfection
, Antimicrobial mechanisms of action:
• inhibits bacterial wall synthesis
• inhibits protein synthesis or production of abnormal bacterial proteins
• disruption of microbial cell membranes
• inhibits of reproduction of organisms
• inhibits cell metabolism and growth
Beta-Lactams
• named after beta-lactam ring in chemical structure
• specific enzymes disrupt the ring
• includes: penicillins, cephalosporins, carabapenems, and monobactams
• inhibits bacterial cell wall synthesis
• side effects: well tolerated (most part), upset stomach, diarrhea, headache and allergic skin rash can occur.
Anaphylaxis (rare)
• if patient is allergic to beta-lactam they may be allergic to other beta-lactam (except monobactams)
Penicillin
• many bacteria are resistant to penicillin but still used for syphillis and susceptible resp. and skin infections
• bactericidal
• indications: severe infections caused by sensitive organisms + broad spectrum use
• actions: destroys bacteria by weakening bacterial cell wall
• pharmacokinetics: absorbed in the GI tract, peak — 1 hr. excreted unchanged in urine and enters breast milk
• gram-positive cocci: pneumonia, meningitis, endocarditis, and pharyngitis
• gram negative cocci: meningitis
• kills spirochetes that cause syphillis
• extended use penicillin (ticarcillin + piperacillin) — used for
pseudomonas aeruginosa infections
• penicillin provide prophylaxis against bacterial endocarditis for at-risk
clients prior to dental work and other procedures
• for penicillin resistant infections use: methicillin, nafcillin, oxacillin,
deicloxacillin
• severe allergies to penicillin are at risk for allergy to cephalosporins
• anaphylactic shock— administer epinephrine and corticosteroids
• use cautiously for clients who have or are at risk for kidney dysfunction
(ill clients, older and young clients)
• do not mix penicillin w certain meds (inactivates — amino-glycosides
and birth-control pills)
Monobactams
• Aztreonam (Azactam)
• used for serious infections like meningitis, P. aeruginosa, UTI
• okay to use for patients with allergies to other betalactams
