Principles of Infectious disease Flashcards
What is the systematic approach for selecting antimicrobial agents
Confirm presence of infection
identify pathogen
select presumptive therapy
therapeutic steps
What does a left shift indicate
Bands (premature neutrophils) in blood > 10%
Bacterial infection
How to confirm presence of infection
H&P exam predisposing factors signs and symptoms - fever - wbc count - esr - crp - procalcitonin - pain and inflammation - disease specific signs and symptoms
what is the range for CRP
.5 - 1 normal
1 - 1.5 moderate inflammation
>10 infection
What is bacteria classified as
Susceptible
intermediate
resistent
What should peak dosage be
2 - 4 x MIC
What factors increase antibiotic resistance
Overuse low dose prolonged exposure inappropriate antibiotics day care
What are requirements for antimicrobial activity
penetrate cell
reach target
kill organism
What are mechanisms of resistance
decreased permeability - porin channels close
drug efflux - pump abx out
drug inactivation - enzymes attack abx
altered target - change ribosomes with CH3 so no binding
what are gram + cocci
Staph
Strep
Enterococcus
What are gram - cocci & cocco-bacilli
H. flu
Neisseria
Moraxella catarrhalis
What are Enterobacteriacea
EKP - e. coli - klebsiella - proteus ESP - enterobacter - serratia - providencia
What are anaerobes
bacteroides fragilis
What is PA
pseudomonas aeruginosa
How to identify pathogen
Stains
Serologies
Culture and sensitivity
What are the stains
Gram Stain - G+ purple (peptidoglycan) - G- pink Acid-fast - mycobacteria - nocardia India Ink - cryptococcus
What are gram stains routinely performed on
CSF for meningitis
Urethral smears for STI
abscesses or effusions
What is the gold standard for identifying bacteria
Cultures
What are the types of antibody and antigen detection
Immunoflorescence
Latex agglutination
Enzyme-linked Immunoassay
What is identified through immunoflorescence
CMV RSV Varicella Treponema pallidum Borrelia burgdorferi
What is identified through Latex agglutination
Meningococcus in CSF
Legionella pneumophelia
What is identified through Enzyme-linked immunoassay
HIV Herpes RSV Preumococcus N. gonorrhea Haemophilus pylori
What is identified through PCR
Anthrax
What are host factors to consider when selecting therapy
drug allergies age pregnancy renal and hepatic function site of infection underlying disease states concomitant drug therapy
What are drug factors to consider when selecting therapy
antimicrobial activity spectrum of activity pharmacokinetics pharmacodynamics tissue penetration adverse effects cost convenience
What does bactericidal mean
kills organisms
What does bacteriostatic mean
inhibit growth of bacteria but does not kill. Lets body immune system kill bacteria
How prevent bacterial growth
destroy cell wall
inhibit protein synthesis
What is MIC
Minimum inhibitory concentration
lowest antimicrobial concentration that prevents visible growth
What are the susceptibility testing methods
macrodilution microdilution kirby-Bauer disk diffusion E-test Automated
What are the automated susceptibility testing methods
Vitek
Microscan
What are concentration and time-dependent effects
MIC
concentration-dependent killing rate
postantibiotic effect
Which 2 bacteria should have 2 abx used on them at same time
Enterococcus
Pseudomonas aeruginosa
What are typical pathogens for Acute Otitis Media
S. pneumoniae
H. flu
M. catarrhalis
What are typical pathogens for Sinusitis
S. pneumoniae
H. flu
M. catarrhalis
What are typical pathogens for Meningitis
S. pneumoniae
H. flu
N. meningitidis
What are typical pathogens for Chronic Bronchitis
C. pneumoniae M. Pneumoniae S. pneumoniae H. flu M. catarrhalis
What are typical pathogens for Pneumonia
M. Pneumoniae S. pneumoniae H. flu Pseudomonas Staph aureus
What are typical pathogens for Bowel perf-appendicitis
E. coli Klebsiella Enterococcus Pseudomonas Bacteriodes Fragilis
What are typical pathogens for Urinary Tract Infections
E. Coli
Klebsiella
Proteus
Enterococcus
What are typical pathogens for Osteomyelitis
Staph
What do staph affect
skin
soft tissue
What do Strep effect
Respiratory tract infections
What do enterococcus effect
GI
wounds
What do Neisseria effect
meningitis
What do H flu and moraxella catarrhalis effect
sinusitis
bronchitis
acute otis media
What do EKP effect
many
UTI
GI
What do ESP effect
GI
What do pseudomonas aeruginosa effect
pneumonia
various
What do anaerobes effect
GI
aspiration pneumonia
