Infectious Diseases II

for eradication of the microorganism

Selecting the most appropriate antibiotic according to an assessment of the following:

What genotypic resistance mechanisms may be suggested by the phenotypic representation of

the AST?

ii.

How may the underlying resistance mechanisms affect the choice of antimicrobial therapy?

iii.

The PK characteristics of the medication and patient characteristics that may affect the

antimicrobial’s PK

iv.

The likelihood that the considered antimicrobial agent will reach its PD targets for optimal

therapy at the local site of infection

Selecting the antimicrobial according to a balance of antimicrobial stewardship principles,

adverse effects profile, allergies, and cost

the site of infection is questionable, or the correlation of PK and PD target attainment is not available,

additional interventions may be required. Optimization of therapy should be tried through one or more

of the following: using a higher dose, using administration strategies that may optimize PK/PD (i.e.,

extended- or continuous-infusion β-lactams), or combination therapy.

three greatest threats to human health.

The NHSN for the CDC reports recent resistance rates among commonly encountered pathogens. More

than 3000 U.S. hospitals participate in this national surveillance program, with as many as 100,000–

300,000 pathogens reported and about 70% of the reporting from critical care sites. See Table 8 for

selected resistance rates in different hospital-acquired infections.

with the reports from previous years.

The CDC reports on antimicrobial-resistant threats and classifies them as urgent or serious.

An urgent antimicrobial-resistant threat indicates a situation requiring immediate and aggressive

action because of high mortality and limited treatment options. These threats include:

ii.

A serious antimicrobial-resistant threat signifies a need for prompt and sustained action to

prevent further resistance development. These threats include:

Resistant pathogens consistently correlate with worse clinical outcomes, which is partially explained by

the higher likelihood of empiric treatment with a resistant antibiotic.