34 Has the Port-a-Germ changed the outcome of our cultures in our intra-abdominal infection?

Introduction The decision on appropriate empirical antibiotic therapy is complex and multifactorial, depending on the pathogenic microorganisms and the baseline characteristics of the patients. Then has the transport medium used to send our cultures changed the results of the flora in intra-abdominal infection? Material and Methods One of the theories regarding changes in the transport medium is that Enterococcus spp. is overestimated when using blood culture medium. It is a single-center observational study that prospectively included consecutive cases of secondary peritonitis from at least two quadrants, collecting epidemiological and microbiological data. Data from the peritonitis database has been collected since 2010 until our days. In 2018, the culture medium was changed, and instead of sending peritoneal fluid cultures in blood culture bottles, they were sent in the Portagerm (PORT-F) transport medium. Results The reference laboratory in Catalonia provides the hospital’s overall results regarding the microbiological findings of peritoneal fluid and bile fluid. In 2017, 82 positive cultures of peritoneal and/or bile fluid for Enterococcus spp. were reported, of which 58 patients had E. faecium. In 2022, 66 patients tested positive for Enterococcus, with 38 cases of E. faecium. In 2023, 55 patients presented with Enterococcus spp., and 21 with E. faecium. From the secondary peritonitis database between 2010 to 2017, 153 out of 629 patients (24%) had Enterococcus. This percentage has been decreasing in subsequent years, from 2018 to 2020. 910 patients with secondary peritonitis, 640 (70%) community (CP) and 270 (30%) nosocomial (PN). 61% were men with a median age of 52 + 20 years (10–101). The most common origin of CP was appendicular (38%), followed by colon (23%) and gastroduodenal (23%), and of NP the colon (59%) and small intestine (20%). A sample was taken for culture in 98% of patients. Conclusions Empirical antibiotic treatments are decided based on the overall results of each center, and adjustment policies are defined over the years. Small changes in the way samples are processed can alter the results of microorganisms in each of our centers. Understanding how samples are processed can help avoid erroneous conclusions.