{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T00:59:52Z","timestamp":1760057992504,"version":"build-2065373602"},"reference-count":34,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2025,3,7]],"date-time":"2025-03-07T00:00:00Z","timestamp":1741305600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"University of Rijeka","award":["uniri-iskusni-biomed-23-6","uniri-iskusni-biomed-23-26"],"award-info":[{"award-number":["uniri-iskusni-biomed-23-6","uniri-iskusni-biomed-23-26"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Microorganisms"],"abstract":"<jats:p>Bloodstream infection (BSI) is a critical medical emergency associated with a high mortality rate. Rapid and accurate identification of the causative pathogen and the results of antimicrobial susceptibility testing are crucial for initiating appropriate antimicrobial therapy. The aim of this study was to evaluate the performance of a new rapid PCR Molecular Mouse System (MMS) for the identification of Gram-negative bacteria (GNB) and GNB resistance genes directly from a positive blood culture (BC). The validation of these rapid multiplex assays was carried out in a real hospital setting. A total of 80 BSI episodes were included in our study and the results were compared with culture-based methods. BC samples in which GNB had previously been detected microscopically and which originated from different hospital wards were analysed. The MMS GNB identification assay achieved a sensitivity of 98.7% and a specificity of 100% for the covered pathogens. In one BC sample, Klebsiella aerogenes was identified at the family level (Enterobacteriaceae) with MMS. However, in three polymicrobial samples, MMS identified bacteria that were not detected by culture-based methods (Klebsiella pneumoniae, K. aerogenes and Stenotrophomonas maltophilia). MMS also showed excellent overall performance in the detection of GNB resistance markers (100% sensitivity and 100% specificity). The type of extended-spectrum beta-lactamase (ESBL) resistance gene identified correctly with MMS was CTX-M-1\/9 (n = 17\/20), alone or in combination with SHV-type \u03b2-lactamase or with the different types of carbapenemase genes. MMS detected one carbapenemase gene of each type (KPC, NDM and OXA-23) and six OXA-48 genes. In addition, the colistin resistance gene mcr-1 was detected in one positive BC with Escherichia coli (E. coli). The time to result was significantly shorter for MMS than for routine culture methods. A retrospective analysis of the patients\u2019 medical records revealed that a change in empirical antimicrobial therapy would have been made in around half of the patients following the MMS results. These results support the use of MMS as a valuable complement to conventional culture methods for more rapid BSI diagnosis and adjustment of empirical therapy.<\/jats:p>","DOI":"10.3390\/microorganisms13030616","type":"journal-article","created":{"date-parts":[[2025,3,7]],"date-time":"2025-03-07T07:05:46Z","timestamp":1741331146000},"page":"616","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Evaluation of the Microbiological Performance and Potential Clinical Impact of New Rapid Molecular Assays for the Diagnosis of Bloodstream Infections"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0009-0002-8631-3472","authenticated-orcid":false,"given":"Mateo","family":"Ti\u0107ac","sequence":"first","affiliation":[{"name":"Department of Anestesiology and Intensive Care, Clinical Hospital Center Rijeka, 51000 Rijeka, Croatia"},{"name":"Department of Anesthesiology, Reanimatology, Intensive Care and Emergency Medicine, Faculty of Medicine, University of Rijeka, 51000 Rijeka, Croatia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6769-5263","authenticated-orcid":false,"given":"Tanja","family":"Grubi\u0107 Kezele","sequence":"additional","affiliation":[{"name":"Department of Clinical Microbiology, Clinical Hospital Center Rijeka, 51000 Rijeka, Croatia"},{"name":"Department of Physiology, Immunology and Pathophysiology, Faculty of Medicine, University of Rijeka, 51000 Rijeka, Croatia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Maja","family":"Abram","sequence":"additional","affiliation":[{"name":"Department of Clinical Microbiology, Clinical Hospital Center Rijeka, 51000 Rijeka, Croatia"},{"name":"Department of Microbiology and Parasitology, Faculty of Medicine, University of Rijeka, 51000 Rijeka, Croatia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6565-3377","authenticated-orcid":false,"given":"Marina","family":"Bubonja-\u0160onje","sequence":"additional","affiliation":[{"name":"Department of Clinical Microbiology, Clinical Hospital Center Rijeka, 51000 Rijeka, Croatia"},{"name":"Department of Microbiology and Parasitology, Faculty of Medicine, University of Rijeka, 51000 Rijeka, Croatia"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2025,3,7]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"200","DOI":"10.1016\/S0140-6736(19)32989-7","article-title":"Global, regional, and national sepsis incidence and mortality, 1990\u20132017: Analysis for the Global Burden of Disease Study","volume":"395","author":"Rudd","year":"2020","journal-title":"Lancet"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"e202899","DOI":"10.1001\/jamanetworkopen.2020.2899","article-title":"Prevalence of Antibiotic-Resistant Pathogens in Culture-Proven Sepsis and Outcomes Associated with Inadequate and Broad-Spectrum Empiric Antibiotic Use","volume":"3","author":"Rhee","year":"2020","journal-title":"JAMA Netw. 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