{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,1]],"date-time":"2026-09-01T01:15:02Z","timestamp":1788225302865,"version":"build-2803163510"},"reference-count":20,"publisher":"American Society for Microbiology","issue":"2","license":[{"start":{"date-parts":[[2026,2,3]],"date-time":"2026-02-03T00:00:00Z","timestamp":1770076800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"},{"start":{"date-parts":[[2026,2,3]],"date-time":"2026-02-03T00:00:00Z","timestamp":1770076800000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/journals.asm.org\/non-commercial-tdm-license"}],"funder":[{"DOI":"10.13039\/100000050","name":"National Heart, Lung, and Blood Institute","doi-asserted-by":"publisher","award":["1R01HL158576-01"],"award-info":[{"award-number":["1R01HL158576-01"]}],"id":[{"id":"10.13039\/100000050","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["journals.asm.org"],"crossmark-restriction":true},"short-container-title":["Microbiol Spectr"],"published-print":{"date-parts":[[2026,2,3]]},"abstract":"ABSTRACT<\/jats:title>\n \n \n \n Accurate bacterial quantification is crucial for studying microbial pathogenesis, host-pathogen interactions, and therapeutic interventions. Two widely used methods include agar plating with colony-forming unit (CFU) enumeration and time-lapsed turbidimetry in liquid broth culture. While agar plating remains the gold standard in both\n in vitro<\/jats:italic>\n and\n in vivo<\/jats:italic>\n infection models, liquid broth turbidimetry is commonly used to assess growth kinetics, microbial fitness, antibiotic susceptibility, and bacterial genetics. While strain-specific CFU and turbidimetry (OD) calibration studies exist, a comprehensive and systematic comparison of these methods for quantifying a broad array of clinically relevant pathogens remains largely unexplored. Here, we conducted a head-to-head comparison of agar plating and liquid broth turbidimetry to quantify the growth of\n Klebsiella pneumoniae<\/jats:italic>\n ,\n Pseudomonas aeruginosa<\/jats:italic>\n , and\n Staphylococcus aureus in vitro<\/jats:italic>\n and evaluated their performance\n in vivo<\/jats:italic>\n using a murine model of\n K. pneumoniae<\/jats:italic>\n pulmonary infection. Across all pathogens tested, both methods exhibited strong correlation over a broad dynamic range (6\u20137 log\n 10<\/jats:sub>\n dilutions). Liquid broth turbidimetry demonstrated enhanced sensitivity at low bacterial densities, as well as greater precision. In the\n in vivo<\/jats:italic>\n murine pneumonia model, this method more accurately distinguished bacterial burdens at the site of infection (lung) and dissemination (spleen) between wild-type and Toll-like receptor 4 knockout mice. Overall, liquid broth turbidimetry is a reliable alternative to agar plating with a high degree of correlation for bacterial quantification and improved precision, highlighting its potential utility in studies of bacteriology and infectious diseases.\n <\/jats:p>\n <\/jats:sec>\n \n IMPORTANCE<\/jats:title>\n Accurate bacterial quantification is fundamental to microbiology research and clinical diagnostics. While agar plating is a widely used method, our study demonstrates that liquid broth turbidimetry provides accurate bacterial quantification, which is fundamental to microbiology research and clinical diagnostics. While agar plating is a widely used method, our study demonstrates that liquid broth turbidimetry provides a highly correlative and more precise approach for quantifying diverse, clinically relevant bacterial pathogens, including when dealing with low bacterial density. The enhanced sensitivity and precision may be valuable for early infection detection, monitoring treatment efficacy, and understanding microbial dynamics in research settings where accurate quantification of even low-density organisms is essential. The findings support considering liquid broth turbidimetry as a complementary or alternative method for bacterial growth quantification.<\/jats:p>\n <\/jats:sec>","DOI":"10.1128\/spectrum.01807-25","type":"journal-article","created":{"date-parts":[[2025,12,26]],"date-time":"2025-12-26T12:34:16Z","timestamp":1766752456000},"update-policy":"https:\/\/doi.org\/10.1128\/asmj-crossmark-policy-page","source":"Crossref","is-referenced-by-count":1,"title":["Performance of time-lapsed turbidimetry and agar plating as bacterial quantification methods"],"prefix":"10.1128","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-8335-4538","authenticated-orcid":true,"given":"Angelika","family":"Dewicki","sequence":"first","affiliation":[{"name":"Division of Pediatric Infectious Diseases, Department of Pediatrics, University of Pittsburgh School of Medicine","place":["Pittsburgh, USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Matthew","family":"Henkel","sequence":"additional","affiliation":[{"name":"Division of Pediatric Infectious Diseases, Department of Pediatrics, University of Pittsburgh School of Medicine","place":["Pittsburgh, USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Norie","family":"Sugitani","sequence":"additional","affiliation":[{"name":"Division of Pediatric Infectious Diseases, Department of Pediatrics, University of Pittsburgh School of Medicine","place":["Pittsburgh, USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alexander","family":"Applegate","sequence":"additional","affiliation":[{"name":"Division of Pediatric Infectious Diseases, Department of Pediatrics, University of Pittsburgh School of Medicine","place":["Pittsburgh, USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5380-9837","authenticated-orcid":true,"given":"Brian T.","family":"Campfield","sequence":"additional","affiliation":[{"name":"Division of Pediatric Infectious Diseases, Department of Pediatrics, University of Pittsburgh School of Medicine","place":["Pittsburgh, USA"]},{"id":[{"id":"https:\/\/ror.org\/011htkb76","id-type":"ROR","asserted-by":"publisher"}],"name":"University of Pittsburgh Medical Center (UPMC) Children\u2019s Hospital of Pittsburgh","place":["Pittsburgh, USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"235","reference":[{"key":"e_1_3_4_2_2","doi-asserted-by":"publisher","DOI":"10.1017\/s002217240001158x"},{"key":"e_1_3_4_3_2","doi-asserted-by":"publisher","DOI":"10.1038\/srep38828"},{"key":"e_1_3_4_4_2","doi-asserted-by":"publisher","DOI":"10.1177\/1087057107304478"},{"key":"e_1_3_4_5_2","doi-asserted-by":"publisher","DOI":"10.2217\/fmb-2022-0097"},{"key":"e_1_3_4_6_2","doi-asserted-by":"publisher","DOI":"10.1086\/595011"},{"key":"e_1_3_4_7_2","doi-asserted-by":"publisher","DOI":"10.1111\/j.1469-0691.2011.03570.x"},{"key":"e_1_3_4_8_2","unstructured":"CDC. 2019. Antibiotic resistance threats in the United States 2019. Atlanta GA U.S. Department of Health and Human Services"},{"key":"e_1_3_4_9_2","doi-asserted-by":"publisher","DOI":"10.1186\/s12866-014-0222-6"},{"key":"e_1_3_4_10_2","doi-asserted-by":"publisher","DOI":"10.3389\/fimmu.2025.1558252"},{"key":"e_1_3_4_11_2","doi-asserted-by":"publisher","DOI":"10.1128\/IAI.00298-20"},{"key":"e_1_3_4_12_2","doi-asserted-by":"publisher","DOI":"10.1053\/j.gastro.2012.05.053"},{"key":"e_1_3_4_13_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.immuni.2011.10.018"},{"key":"e_1_3_4_14_2","doi-asserted-by":"publisher","DOI":"10.1164\/rccm.201905-0973OC"},{"key":"e_1_3_4_15_2","doi-asserted-by":"publisher","DOI":"10.1183\/09031936.00076510"},{"key":"e_1_3_4_16_2","doi-asserted-by":"publisher","DOI":"10.1128\/AEM.66.4.1706-1710.2000"},{"key":"e_1_3_4_17_2","doi-asserted-by":"publisher","DOI":"10.1021\/acssynbio.6b00198"},{"key":"e_1_3_4_18_2","doi-asserted-by":"publisher","DOI":"10.3791\/63849"},{"key":"e_1_3_4_19_2","doi-asserted-by":"publisher","DOI":"10.3389\/fmicb.2022.988728"},{"key":"e_1_3_4_20_2","doi-asserted-by":"publisher","DOI":"10.21769\/BioProtoc.4410"},{"key":"e_1_3_4_21_2","doi-asserted-by":"publisher","DOI":"10.1111\/j.1472-765x.2004.01448.x"}],"container-title":["Microbiology Spectrum"],"original-title":[],"contributor":[{"given":"Rafael M.","family":"Cant\u00f3n","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"reviewer"}]}],"language":"en","link":[{"URL":"https:\/\/journals.asm.org\/doi\/pdf\/10.1128\/spectrum.01807-25","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.asm.org\/doi\/pdf\/10.1128\/spectrum.01807-25","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,1]],"date-time":"2026-09-01T00:45:35Z","timestamp":1788223535000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.asm.org\/doi\/10.1128\/spectrum.01807-25"}},"subtitle":[],"editor":[{"given":"Monika","family":"Kumaraswamy","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"editor"}]}],"short-title":[],"issued":{"date-parts":[[2026,2,3]]},"references-count":20,"journal-issue":{"issue":"2","published-print":{"date-parts":[[2026,2,3]]}},"alternative-id":["10.1128\/spectrum.01807-25"],"URL":"https:\/\/doi.org\/10.1128\/spectrum.01807-25","relation":{},"ISSN":["2165-0497"],"issn-type":[{"value":"2165-0497","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,2,3]]},"assertion":[{"value":"2025-06-13","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2025-11-26","order":2,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2025-12-26","order":3,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}],"article-number":"e01807-25"}}