One in Three Carbapenem-Resistant Pseudomonas Isolates Resists Ceftazidime-Avibactam

The pooled prevalence of resistance was 32.93 percent, with a 95 percent confidence interval of 27.50 to 38.37 percent, based on 31 independent reports covering 12,091 isolates, of which 3,469 were resistant.

The review was conducted in accordance with the PRISMA guidelines. The researchers searched PubMed, EMBASE, SCOPUS, Web of Science and Google Scholar for observational studies reporting ceftazidime-avibactam resistance in carbapenem-resistant P. aeruginosa clinical isolates. In total, 36 studies published between 2016 and 2025, encompassing 13,231 isolates, entered the systematic review. After removing three reports nested within larger datasets, 33 independent reports remained, and the 31 reports containing at least one resistant isolate contributed to the pooled estimate. The analysis was carried out in STATA version 17 using a random-effects model.

The pooled estimate came with very high statistical heterogeneity, quantified at I² of 97.95 percent with a p value below 0.001, and a 95 percent prediction interval stretching from 2.0 to 63.8 percent. The authors themselves caution that the extreme heterogeneity, the low certainty of the evidence and the uneven geographical representation of the underlying studies warrant cautious interpretation of the pooled figures. Publication bias was assessed with funnel plots and Egger’s and Begg’s tests, and sources of heterogeneity were explored through subgroup analysis and meta-regression.

Regional variation was striking. Africa showed the highest pooled resistance at 69.15 percent, based on three strata and 338 isolates, with a confidence interval of 46.25 to 92.04 percent. Latin America followed at 37.25 percent, Asia, including Asia-Pacific and South Pacific collections, at 34.07 percent, and Europe at 32.84 percent. North America recorded the lowest regional estimate at 14.31 percent. At the country level, the highest estimates came from Egypt at 88.33 percent and Pakistan at 77.26 percent.

Time also appeared to matter. Meta-regression suggested that resistance increased by about 2.4 percentage points per year of isolate collection, with a p value of 0.041. The authors describe this as a tendency rather than a definitive trend, and the estimate is a statistical association across studies of differing designs and settings rather than a direct measurement of resistance dynamics within any single surveillance program.

Carbapenem-resistant P. aeruginosa remains a significant public health threat and was associated with an estimated 11,800 deaths globally in 2019, according to the background cited in the review.

The authors conclude that strengthened, standardized surveillance, particularly in under-represented regions, and antimicrobial stewardship are needed to preserve the efficacy of ceftazidime-avibactam. The uneven geographic distribution of the included studies means that the regional estimates rest on very different amounts of data, and the African figure in particular is drawn from only three strata and 338 isolates, so it should be read with corresponding uncertainty.

As a systematic review and meta-analysis of observational studies, the work aggregates what has already been reported rather than generating new laboratory or clinical data. Its value lies in quantifying the scale of the problem across regions and over time, and in flagging where surveillance gaps leave the true burden least certain. The authors note that the pooled estimate of about one in three resistant isolates should be interpreted in light of the wide prediction interval, which indicates that individual settings could plausibly see resistance anywhere from very low to well above the pooled average.

Subject of Research: Global prevalence of ceftazidime-avibactam resistance among carbapenem-resistant Pseudomonas aeruginosa clinical isolates

Article Title: Global burden of CAZ-AVI resistance among carbapenem-resistant Pseudomonas aeruginosa clinical isolates: a systematic review and meta-analysis

Article References: Wada, F. W., Alemu, A. K., Boltena, M. T., Gebremedhn, A. T., Hailegebrel, E. A., Tadele, M., & Adane, H. T. (2026). Global burden of CAZ-AVI resistance among carbapenem-resistant Pseudomonas aeruginosa clinical isolates: a systematic review and meta-analysis. BMC Infectious Diseases. https://doi.org/10.1186/s12879-026-14741-1

Image Credits: AI Generated

DOI: 10.1186/s12879-026-14741-1

Keywords: ceftazidime-avibactam, carbapenem-resistant Pseudomonas aeruginosa, antimicrobial resistance, systematic review, meta-analysis, CRPA, surveillance, drug resistance, public health, antimicrobial stewardship, Global, burden