5.1 Facility-level interventions

Antibiograms

Facility-level interventions are guided by data collected on the antimicrobial susceptibility profile of bacterial isolates in a hospital. This is usually provided in the form of a hospital antibiogram, which is expected to be updated annually. A hospital antibiogram is a collection of data, usually in the form of a table, that summarises the percentage of individual bacterial pathogens susceptible to different antimicrobial agents.

A typical hospital antibiogram is shown in Table 1. The first rows list the bacteria, separating them into Gram-positive and Gram-negative. The row below that shows the number of patients in the facility who had the organism and were included in the antibiogram; only the first isolate from each patient is included. Antimicrobials tested and the organisms’ susceptibilities are listed in the remaining rows.

Table 1 An example of an annual hospital antibiogram (modified from Truong et al., 2021).
Hospital antibiogram annual report on percentages of susceptibility rates to selected antibioticsGram-negative               Gram-positive                    
EcKpPaMSSAMRSASpEspp.
Total isolates221553244650931247295
Penicillin 97
Ampicillin4187
Ampicillin/sulbactam5472
Piperacillin/tazobactam949592
Ceftriaxone857997
Cefepime887991
Meropenem1009987
Ciprofloxacin777541
Oxacillin1000
CTX76839694
Nitrofurantoin973599
Gentamicin919390
Vancomycin89

Footnotes  

(Ec = E. coli; Kp = Klebsiella pneumoniae; Pa = Pseudomonas aeruginosa; Sp = Streptococcus pneumoniae; Espp. = Enterococcus spp.)

Activity 5: Looking at an antibiogram

Timing: Allow about 5 minutes

Read the antibiogram in Table 1 and answer the following questions:

  1. How many people had Pseudomonas aeruginosa infections?
  2. Of these, what percentage of isolates were susceptible to ciprofloxacin?
  3. How would you use the antibiogram to select an antimicrobial for empirical treatment of Pseudomonas aeruginosa in this hospital?
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Answer

  1. Pseudomonas aeruginosa was isolated in 446 people. It was tested for susceptibility to a number of antibiotics.
  2. Of the Pseudomonas aeruginosa cultures tested against ciprofloxacin, only 41 per cent were susceptible to the antibiotic.
  3. The hospital antibiogram shows a high rate of resistance to ciprofloxacin, so this is not an appropriate choice for empirical therapy; your empirical antibiotic choice should consider antimicrobials with susceptibility higher than 75%. In this example you might choose cefepime, meropenem, gentamicin or piperacillin/tazobactam, because Pseudomonas aeruginosa isolates from this hospital in the last year have been at least 87 per cent susceptible to these antimicrobials.

A short article on the FutureLearn platform includes more information about antibiograms, including how to create them [Tip: hold Ctrl and click a link to open it in a new tab. (Hide tip)] .

5 Interventions

Antimicrobial timeouts