Antimicrobial resistance in Pseudomonas aeruginosa bacteraemia, percent of resistance testing by month
Last updated on Thursday, 29 May 2025 at 02:24pm
Summary
- Topic
- P-aeruginosa
- Category
- testing
- API name
p-aeruginosa_testing_bacteraemiaPercentTestedRollingMonth
Rationale
Timely monitoring of susceptibility test results for Pseudomonas aeruginosa (P. aeruginosa) supports the government’s 5-year action plan on confronting antimicrobial resistance (AMR; for example, resistance to antibiotics). Antimicrobials presented in this metric have been selected due to their clinical importance when treating serious P. aeruginosa infections.
Definition
This metric shows the rolling monthly average of the percent of P. aeruginosa bacteraemia (bacteria found in patient blood specimens), reported by English laboratories, with susceptibility test results for ciprofloxacin, gentamicin, piperacillin with tazobactam, amikacin, carbapenems or ceftazidime.
Methodology
A national database maintained by UKHSA (the AMR module of SGSS – Second Generation Surveillance System) contains voluntary laboratory data from approximately 98% of hospital microbiology laboratories in England. Data on susceptibility of pathogens was obtained from SGSS for this metric. Patients may have more than one positive culture (type of laboratory test undertaken on blood specimens) result reported to SGSS, so cultures from the same patient for the same pathogen in a 14-day rolling period are deduplicated to only retain one result representing that episode of bacteraemia per patient. If susceptibility to the antimicrobial was tested for in any culture during the episode, it will be counted in this metric. This metric is calculated by dividing the total number of P. aeruginosa bacteraemia episodes by the number of P. aeruginosa bacteraemia episodes with susceptibility test results for ciprofloxacin, gentamicin, piperacillin with tazobactam, amikacin, carbapenems or ceftazidime by month, and averaging the result for each month with the previous two months, to create a three-month rolling average. Results are multiplied by 100 to be viewed as a percentage.
Carbapenems comprise meropenem or imipenem.
Caveats
Data used for this indicator are from routine voluntary laboratory surveillance schemes, therefore total numbers of P. aeruginosa bacteraemia presented in this indicator differ from those presented in the mandatory surveillance scheme indicators.
Combining patient results into one infection episode is limited by the provision of key identifiers by reporting laboratories, so some episodes may be counted more than once if these identifiers enabling grouping and de-duplication are not provided or are provided incorrectly.
The data reflects microbiology results reported to the UK Health Security Agency's routine laboratory surveillance system antimicrobial testing module (SGSS AMR;). Not all laboratories in England were able to report during the indicator time period. As a result, a zero value does not necessarily reflect a lack of testing but could be a lack of reporting in an area.
Hospital microbiology laboratories have reported antimicrobial susceptibility test results as ‘susceptible’,’susceptible, increased exposure’ or ‘resistant’. These categories were defined as follows as per the European Committee on Antimicrobial Susceptibility Testing (EUCAST). Breakpoints can change over time, and this has implications for interpretation of resistance trends spanning breakpoint changes; please see ESPAUR 2023/24 report box 2.3 for further information. SGSS is a live reporting database, and therefore data is subject to change and may differ from other published outputs.