{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,22]],"date-time":"2026-10-22T02:54:25Z","timestamp":1792637665630,"version":"4.5.0"},"reference-count":21,"publisher":"American Society for Microbiology","issue":"1","license":[{"start":{"date-parts":[[2025,1,31]],"date-time":"2025-01-31T00:00:00Z","timestamp":1738281600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"},{"start":{"date-parts":[[2025,1,31]],"date-time":"2025-01-31T00:00:00Z","timestamp":1738281600000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/journals.asm.org\/non-commercial-tdm-license"}],"content-domain":{"domain":["journals.asm.org"],"crossmark-restriction":true},"short-container-title":["Infect Immun"],"published-print":{"date-parts":[[2025,1,31]]},"abstract":"<jats:title>ABSTRACT<\/jats:title>\n          <jats:sec>\n            <jats:title\/>\n            <jats:p>\n              Hypervirulent\n              <jats:italic>Klebsiella pneumoniae<\/jats:italic>\n              (hvKp) strains are considered to be relatively rare in the United States, but cases are increasingly reported. We prospectively and serially collected\n              <jats:italic>K. pneumoniae<\/jats:italic>\n              clinical isolates identified in respiratory specimens at a health system in Western Pennsylvania between 2020 and 2022. A total of 273\n              <jats:italic>K<\/jats:italic>\n              .\n              <jats:italic>pneumoniae<\/jats:italic>\n              isolates from 216 unique patients were analyzed for markers of hypervirulence by both string test for a hypermucoid phenotype and multiplex PCR to detect isolates carrying cardinal virulence genes\n              <jats:italic>rmpA<\/jats:italic>\n              ,\n              <jats:italic>rmpA2<\/jats:italic>\n              ,\n              <jats:italic>iutA<\/jats:italic>\n              , and\n              <jats:italic>iro<\/jats:italic>\n              . Of the 273 isolates, 13 (4.8%) tested positive by string test including 11 nonduplicate\n              <jats:italic>K. pneumoniae<\/jats:italic>\n              isolates, and two of these (0.7%) were positive by PCR for virulence genes\n              <jats:italic>rmpA<\/jats:italic>\n              ,\n              <jats:italic>rmpA2<\/jats:italic>\n              ,\n              <jats:italic>iutA<\/jats:italic>\n              , and\n              <jats:italic>iro<\/jats:italic>\n              . The latter two putative hvKp strains, belonging to sequence types ST23-K1 and ST86-SLV-K2, possessed pLVPK-like plasmids, and were collected from community-associated infections in individuals without known travel histories. Both putative hvKp strains and two additional string test-positive strains were resistant to killing by human serum. The hvKp strains caused significant pneumonia in mice infected by oropharyngeal aspiration, with significantly higher weight loss and increased bacterial burden in the lungs of mice infected with the KL1 (ST23) strain compared to the KL2 (ST86-SLV) strain. We also observed decreased survival of mice infected with the KL1 strain compared to the KL2 strain. These findings add to the growing body of evidence suggesting that hvKp strains, once considered endemic to Asia, may now be circulating in North America.\n            <\/jats:p>\n            <jats:sec>\n              <jats:title>IMPORTANCE<\/jats:title>\n              <jats:p>\n                Certain lineages of\n                <jats:italic>Klebsiella pneumoniae<\/jats:italic>\n                are increasingly recognized to cause severe community-associated infection, but information on their prevalence in the United States is limited. In a prospective, sequential cohort of 273\n                <jats:italic>K<\/jats:italic>\n                .\n                <jats:italic>pneumoniae<\/jats:italic>\n                respiratory isolates, we identified two of them as genetically defined hypervirulent\n                <jats:italic>K. pneumoniae<\/jats:italic>\n                . The isolates were from local residents who developed community-onset pneumonia, suggesting that hypervirulent\n                <jats:italic>K. pneumoniae<\/jats:italic>\n                may already be present in the community.\n              <\/jats:p>\n            <\/jats:sec>\n          <\/jats:sec>","DOI":"10.1128\/iai.00486-24","type":"journal-article","created":{"date-parts":[[2024,12,11]],"date-time":"2024-12-11T19:15:18Z","timestamp":1733944518000},"update-policy":"https:\/\/doi.org\/10.1128\/asmj-crossmark-policy-page","source":"Crossref","is-referenced-by-count":13,"title":["Prevalence and features of hypervirulent\n            <i>Klebsiella pneumoniae<\/i>\n            in respiratory specimens at a US hospital system"],"prefix":"10.1128","volume":"93","author":[{"given":"Christi L.","family":"McElheny","sequence":"first","affiliation":[{"name":"Center for Innovative Antimicrobial Therapy, Division of Infectious Diseases, University of Pittsburgh School of Medicine","place":["Pittsburgh, USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alina","family":"Iovleva","sequence":"additional","affiliation":[{"name":"Center for Innovative Antimicrobial Therapy, Division of Infectious Diseases, University of Pittsburgh School of Medicine","place":["Pittsburgh, USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nathalie","family":"Chen","sequence":"additional","affiliation":[{"name":"Center for Innovative Antimicrobial Therapy, Division of Infectious Diseases, University of Pittsburgh School of Medicine","place":["Pittsburgh, USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Dominic","family":"Woods","sequence":"additional","affiliation":[{"name":"Center for Innovative Antimicrobial Therapy, Division of Infectious Diseases, University of Pittsburgh School of Medicine","place":["Pittsburgh, USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Akansha","family":"Pradhan","sequence":"additional","affiliation":[{"name":"Center for Innovative Antimicrobial Therapy, Division of Infectious Diseases, University of Pittsburgh School of Medicine","place":["Pittsburgh, USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jonah L.","family":"Sonnabend","sequence":"additional","affiliation":[{"name":"Center for Innovative Antimicrobial Therapy, Division of Infectious Diseases, University of Pittsburgh School of Medicine","place":["Pittsburgh, USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Aidan R.","family":"Matunis","sequence":"additional","affiliation":[{"name":"Center for Innovative Antimicrobial Therapy, Division of Infectious Diseases, University of Pittsburgh School of Medicine","place":["Pittsburgh, USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nathan J.","family":"Raabe","sequence":"additional","affiliation":[{"name":"Center for Innovative Antimicrobial Therapy, Division of Infectious Diseases, University of Pittsburgh School of Medicine","place":["Pittsburgh, USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6812-6043","authenticated-orcid":true,"given":"Janet S.","family":"Lee","sequence":"additional","affiliation":[{"name":"Division of Pulmonary and Critical Care Medicine, Washington University School of Medicine","place":["St. Louis, USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Giraldina","family":"Trevejo-Nu\u00f1ez","sequence":"additional","affiliation":[{"name":"Center for Innovative Antimicrobial Therapy, Division of Infectious Diseases, University of Pittsburgh School of Medicine","place":["Pittsburgh, USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7284-0103","authenticated-orcid":true,"given":"Daria","family":"Van Tyne","sequence":"additional","affiliation":[{"name":"Center for Innovative Antimicrobial Therapy, Division of Infectious Diseases, University of Pittsburgh School of Medicine","place":["Pittsburgh, USA"]},{"name":"Center for Evolutionary Biology and Medicine, University of Pittsburgh School of Medicine","place":["Pittsburgh, USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9620-2525","authenticated-orcid":false,"given":"Yohei","family":"Doi","sequence":"additional","affiliation":[{"name":"Center for Innovative Antimicrobial Therapy, Division of Infectious Diseases, University of Pittsburgh School of Medicine","place":["Pittsburgh, USA"]},{"name":"Departments of Microbiology, Fujita Health University School of Medicine","place":["Toyoake, Japan"]},{"name":"Departments of Infectious Diseases, Fujita Health University School of Medicine","place":["Toyoake, Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"235","reference":[{"key":"e_1_3_5_2_2","doi-asserted-by":"publisher","DOI":"10.1128\/CMR.00001-19"},{"key":"e_1_3_5_3_2","doi-asserted-by":"publisher","DOI":"10.1128\/JCM.00776-18"},{"key":"e_1_3_5_4_2","doi-asserted-by":"publisher","DOI":"10.1128\/AAC.00519-19"},{"key":"e_1_3_5_5_2","doi-asserted-by":"publisher","DOI":"10.3201\/eid2708.210234"},{"key":"e_1_3_5_6_2","doi-asserted-by":"publisher","DOI":"10.1186\/s12879-022-07558-1"},{"key":"e_1_3_5_7_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.cmi.2020.05.012"},{"key":"e_1_3_5_8_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.diagmicrobio.2022.115784"},{"key":"e_1_3_5_9_2","doi-asserted-by":"publisher","DOI":"10.1128\/JCM.00731-18"},{"key":"e_1_3_5_10_2","volume-title":"Performance standards for antimicrobial susceptibility testing","year":"2022","unstructured":"Clinical and Laboratory Standards Institute. 2022. Performance standards for antimicrobial susceptibility testing. 32nd ed. Berwyn, PA.","edition":"32"},{"key":"e_1_3_5_11_2","doi-asserted-by":"publisher","DOI":"10.1128\/aac.00030-23"},{"key":"e_1_3_5_12_2","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pcbi.1005595"},{"key":"e_1_3_5_13_2","doi-asserted-by":"publisher","DOI":"10.1186\/1471-2164-9-75"},{"key":"e_1_3_5_14_2","doi-asserted-by":"publisher","DOI":"10.1038\/s41467-021-24448-3"},{"key":"e_1_3_5_15_2","doi-asserted-by":"publisher","DOI":"10.1093\/nar\/gkad326"},{"key":"e_1_3_5_16_2","doi-asserted-by":"publisher","DOI":"10.1099\/mgen.0.000685"},{"key":"e_1_3_5_17_2","doi-asserted-by":"publisher","DOI":"10.1172\/jci.insight.135591"},{"key":"e_1_3_5_18_2","doi-asserted-by":"publisher","DOI":"10.1017\/S0950268816002442"},{"key":"e_1_3_5_19_2","doi-asserted-by":"publisher","DOI":"10.1093\/jac\/dky492"},{"key":"e_1_3_5_20_2","doi-asserted-by":"publisher","DOI":"10.1093\/jac\/dkw137"},{"key":"e_1_3_5_21_2","doi-asserted-by":"publisher","DOI":"10.1128\/mbio.01949-23"},{"key":"e_1_3_5_22_2","doi-asserted-by":"publisher","DOI":"10.1093\/infdis\/jiae003"}],"container-title":["Infection and Immunity"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/journals.asm.org\/doi\/pdf\/10.1128\/iai.00486-24","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.asm.org\/doi\/pdf\/10.1128\/iai.00486-24","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,1,31]],"date-time":"2025-01-31T14:00:56Z","timestamp":1738332056000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.asm.org\/doi\/10.1128\/iai.00486-24"}},"subtitle":[],"editor":[{"given":"Andreas J.","family":"B\u00e4umler","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"editor"}]}],"short-title":[],"issued":{"date-parts":[[2025,1,31]]},"references-count":21,"journal-issue":{"issue":"1","published-print":{"date-parts":[[2025,1,31]]}},"alternative-id":["10.1128\/iai.00486-24"],"URL":"https:\/\/doi.org\/10.1128\/iai.00486-24","relation":{},"ISSN":["0019-9567","1098-5522"],"issn-type":[{"value":"0019-9567","type":"print"},{"value":"1098-5522","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,1,31]]},"assertion":[{"value":"2024-12-11","order":3,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}],"article-number":"e00486-24"}}