IntroductionAcute pancreatitis (AP) accounts for a high proportion of digestive diseases worldwide and has a high risk of infection.Pseudomonas aeruginosa, a common pathogen of hospital infections, has been observed to increase the resistance rate to several antibiotics, causing difficulties in treatments. Our study aims to investigate the impact of the multi-drug resistantPseudomonas aeruginosa(MDR-PA) infections on AP patients.MethodsAt two Chinese tertiary referral centers for AP patients infected with MDR-PA, a retrospective case-control study with a 1:2 case-control ratio was performed. Comparisons were preformed between with/without MDR-PA infections and different drug-resistance of MDR-PA infections patients, respectively. Independent risk factors of overall mortality were assessed via univariate and multivariate binary logistic regression analyses, and the distribution and antibiotic resistant rates of strains were described.ResultsMortality in AP patients with MDR-PA infections was significantly higher than in those without MDR-PA infections (7 (30.4%) vs. 4 (8.7%),P= 0.048). The rate of prophylactic use of carbapenem for 3 days (0 vs. 50%,P= 0.019) and the incidence rate of multiple organ failure (MOF) (0 vs. 57.1%,P= 0.018) were remarkably higher in the carbapenem-resistantPseudomonas aeruginosagroup compared with the carbapenem-sensitivePseudomonas aeruginosagroup. In the multivariate analysis, the severe categories of AP (OR = 13.624, 95% CIs = 1.567–118.491,P= 0.018) and MDR-PA infections (OR = 4.788, 95% CIs = 1.107–20.709,P= 0.036) were independent risk factors for mortality. The resistance rates of MDR-PA strains were low for amikacin (7.4%), tobramycin (3.7%), and gentamicin (18.5%). The resistance rates of MDR-PA strains to imipenem and meropenem were up to, 51.9% and 55.6%, respectively.ConclusionIn AP patients, severe categories of AP and MDR-PA infections were both independent risk factors for mortality. Inappropriate use of carbapenem antibiotics and MOF were related to carbapenem-resistantPseudomonas aeruginosainfections. Amikacin, tobramycin, and gentamicin are recommended for the treatment of AP patients with MDR-PA infections.