{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,29]],"date-time":"2026-08-29T09:44:04Z","timestamp":1787996644908,"version":"build-2784847793"},"reference-count":26,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2021,4,19]],"date-time":"2021-04-19T00:00:00Z","timestamp":1618790400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100002347","name":"Bundesministerium f\u00fcr Bildung und Forschung","doi-asserted-by":"publisher","id":[{"id":"10.13039\/501100002347","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Cell. Infect. Microbiol."],"abstract":"<jats:p>Yeasts of the <jats:italic>Cryptococcus neoformans<\/jats:italic>\/<jats:italic>gattii<\/jats:italic> species complexes are human pathogens mostly in immune compromised individuals, and can cause infections from dermal lesions to fungal meningitis. Differences in virulence and antifungal drug susceptibility of species in these complexes indicate the value of full differentiation to species level in diagnostic procedures. MALDI-TOF MS has been reported to sufficiently discriminate these species. Here, we sought to re-evaluate sample pre-processing procedures and create a set of publicly available references for use with the MALDI Biotyper system. Peak content using four different pre-processing protocols was assessed, and database entries for 13 reference strains created. These were evaluated against a collection of 153 clinical isolates, typed by conventional means. The use of decapsulating protocols or mechanical disruption did not sufficiently increase the information content to justify the extra hands-on-time. Using the set of 13 reference entries created with the standard formic acid extraction, we were able to correctly classify 143\/153 (93.5%) of our test isolates. The majority of the remaining ten isolates still gave correct top matches; only two isolates did not give reproducible identifications. This indicates that the log score cut-off can be lowered also in this context. Ease to identify cryptococcal isolates to the species level is improved by the workflow evaluated here. The database references are freely available from <jats:uri>https:\/\/github.com\/oliverbader\/BioTyper-libraries<\/jats:uri> for incorporation into local diagnostic systems.<\/jats:p>","DOI":"10.3389\/fcimb.2021.634382","type":"journal-article","created":{"date-parts":[[2021,4,19]],"date-time":"2021-04-19T04:18:57Z","timestamp":1618805937000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":9,"title":["CryptoType \u2013 Public Datasets for MALDI-TOF-MS Based Differentiation of Cryptococcus neoformans\/gattii Complexes"],"prefix":"10.3389","volume":"11","author":[{"given":"Mareike","family":"Bernhard","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Navaporn","family":"Worasilchai","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mourine","family":"Kangogo","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Christine","family":"Bii","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Wioleta J.","family":"Trzaska","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Michael","family":"Weig","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Uwe","family":"Gro\u00df","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ariya","family":"Chindamporn","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Oliver","family":"Bader","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2021,4,19]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","first-page":"323","DOI":"10.1007\/978-1-4939-6515-1_19","article-title":"Fungal Species Identification by MALDI-ToF Mass Spectrometry","volume":"1508","author":"Bader","year":"2017","journal-title":"Methods Mol. Biol."},{"key":"B2","doi-asserted-by":"publisher","first-page":"891","DOI":"10.1099\/00221287-147-4-891","article-title":"Hybrid genotypes in the pathogenic yeast Cryptococcus neoformans","volume":"147","author":"Boekhout","year":"2001","journal-title":"Microbiology"},{"key":"B3","doi-asserted-by":"publisher","first-page":"e16936","DOI":"10.1371\/journal.pone.0016936","article-title":"Clonality and alpha-a recombination in the Australian Cryptococcus gattii VGII population\u2013an emerging outbreak in Australia","volume":"6","author":"Carriconde","year":"2011","journal-title":"PloS One"},{"key":"B4","doi-asserted-by":"publisher","first-page":"963","DOI":"10.1093\/mmy\/myx152","article-title":"Epidemiological trends of cryptococcosis in Italy: Molecular typing and susceptibility pattern of Cryptococcus neoformans isolates collected during a 20-year period","volume":"56","author":"Cogliati","year":"2018","journal-title":"Med. Mycol."},{"key":"B5","doi-asserted-by":"publisher","first-page":"7","DOI":"10.1016\/j.bjid.2019.11.004","article-title":"Clinical and microbiological characteristics of cryptococcosis at an university hospital in China from 2013 to 2017","volume":"24","author":"Fang","year":"2020","journal-title":"Braz. J. Infect. Dis."},{"key":"B6","doi-asserted-by":"publisher","first-page":"e02306-19","DOI":"10.1128\/mBio.02306-19","article-title":"A New Lineage of Cryptococcus gattii (VGV) Discovered in the Central Zambezian Miombo Woodlands","volume":"10","author":"Farrer","year":"2019","journal-title":"mBio"},{"key":"B7","doi-asserted-by":"publisher","first-page":"e37566","DOI":"10.1371\/journal.pone.0037566","article-title":"MALDI-TOF MS enables the rapid identification of the major molecular types within the Cryptococcus neoformans\/C. gattii species complex","volume":"7","author":"Firacative","year":"2012","journal-title":"PloS One"},{"key":"B8","doi-asserted-by":"publisher","first-page":"16","DOI":"10.1016\/j.fgb.2015.02.009","article-title":"Recognition of seven species in the Cryptococcus gattii\/Cryptococcus neoformans species complex","volume":"78","author":"Hagen","year":"2015","journal-title":"Fungal Genet. Biol."},{"key":"B9","doi-asserted-by":"publisher","first-page":"e00958-17","DOI":"10.1128\/IAI.00958-17","article-title":"Differential In Vitro Cytokine Induction by the Species of Cryptococcus gattii Complex","volume":"86","author":"Herkert","year":"2018","journal-title":"Infect. Immun."},{"key":"B10","doi-asserted-by":"publisher","first-page":"73","DOI":"10.1186\/s12866-020-01752-4","article-title":"Clinical and microbiological characteristics of Cryptococcus gattii isolated from 7 hospitals in China","volume":"20","author":"Jin","year":"2020","journal-title":"BMC Microbiol."},{"key":"B11","doi-asserted-by":"publisher","first-page":"665","DOI":"10.1111\/myc.12411","article-title":"Molecular types of Cryptococcus gattii\/Cryptococcus neoformans species complex from clinical and environmental sources in Nairobi, Kenya","volume":"58","author":"Kangogo","year":"2015","journal-title":"Mycoses"},{"key":"B12","doi-asserted-by":"publisher","first-page":"17258","DOI":"10.1073\/pnas.0402981101","article-title":"A rare genotype of Cryptococcus gattii caused the cryptococcosis outbreak on Vancouver Island (British Columbia, Canada)","volume":"101","author":"Kidd","year":"2004","journal-title":"Proc. Natl. Acad. Sci. U.S.A."},{"key":"B13","doi-asserted-by":"crossref","first-page":"39","DOI":"10.1002\/9781118960226.ch2","article-title":"Criteria for Development of MALDI-TOF Mass Spectral Database","volume-title":"MALDI-TOF and Tandem MS for Clinical Microbiology","author":"Kostrzewa","year":"2017"},{"key":"B14","doi-asserted-by":"publisher","first-page":"193","DOI":"10.1038\/nrmicro2522","article-title":"Expanding fungal pathogenesis: Cryptococcus breaks out of the opportunistic box","volume":"9","author":"Kronstad","year":"2011","journal-title":"Nat. Rev. Microbiol."},{"key":"B15","doi-asserted-by":"publisher","first-page":"804","DOI":"10.2307\/1555045","article-title":"Proposal to conserve the name Cryptococcus gattii against C. hondurianus and C. bacillisporus (Basidiomycota, Hymenomycetes, Tremenomycetidae)","volume":"51","author":"Kwon-Chung","year":"2002","journal-title":"Taxon"},{"key":"B16","doi-asserted-by":"publisher","first-page":"1004","DOI":"10.1093\/mmy\/myy161","article-title":"Molecular types of Cryptococcus neoformans and Cryptococcus gattii in Western Australia and correlation with antifungal susceptibility","volume":"57","author":"Lee","year":"2019","journal-title":"Med. Mycol"},{"key":"B17","doi-asserted-by":"publisher","first-page":"3050","DOI":"10.1128\/JCM.00651-11","article-title":"Rapid identification of Cryptococcus neoformans and Cryptococcus gattii by matrix-assisted laser desorption ionization-time of flight mass spectrometry","volume":"49","author":"McTaggart","year":"2011","journal-title":"J. Clin. Microbiol."},{"key":"B18","doi-asserted-by":"publisher","first-page":"189","DOI":"10.3201\/eid0902.020246","article-title":"Molecular typing of IberoAmerican Cryptococcus neoformans isolates","volume":"9","author":"Meyer","year":"2003","journal-title":"Emerg. Infect. Dis."},{"key":"B19","doi-asserted-by":"publisher","first-page":"387","DOI":"10.1128\/CMR.00001-12","article-title":"The Cryptococcus neoformans capsule: a sword and a shield","volume":"25","author":"O\u2019Meara","year":"2012","journal-title":"Clin. Microbiol. Rev."},{"key":"B20","doi-asserted-by":"publisher","first-page":"2472","DOI":"10.1128\/JCM.00737-12","article-title":"Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry-Based Method for Discrimination between Molecular Types of Cryptococcus neoformans and Cryptococcus gattii","volume":"50","author":"Posteraro","year":"2012","journal-title":"J. Clin. Microbiol."},{"key":"B21","doi-asserted-by":"publisher","first-page":"e1004285","DOI":"10.1371\/journal.ppat.1004285","article-title":"Cryptococcus gattii VGIII isolates causing infections in HIV\/AIDS patients in Southern California: identification of the local environmental source as arboreal","volume":"10","author":"Springer","year":"2014","journal-title":"PloS Pathog."},{"key":"B22","doi-asserted-by":"publisher","first-page":"303","DOI":"10.3314\/mmj.54.303","article-title":"Prevalence and Antifungal Susceptibility of Cryptococcus neoformans Isolated from Pigeon Excreta in Chon Buri Province, Eastern Thailand","volume":"54","author":"Tangwattanachuleeporn","year":"2013","journal-title":"Med. Mycol. J."},{"key":"B23","doi-asserted-by":"publisher","first-page":"474","DOI":"10.1128\/JCM.02635-15","article-title":"Does the Capsule Interfere with Performance of Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry for Identification of Cryptococcus neoformans and Cryptococcus gattii","volume":"54","author":"Thomaz","year":"2016","journal-title":"J. Clin. Microbiol."},{"key":"B24","doi-asserted-by":"publisher","first-page":"328","DOI":"10.3109\/13693786.2011.602126","article-title":"Correlation of antifungal susceptibility and molecular type within the Cryptococcus neoformans\/C. gattii species complex","volume":"50","author":"Trilles","year":"2012","journal-title":"Med. Mycol."},{"key":"B25","doi-asserted-by":"publisher","first-page":"5194","DOI":"10.1038\/ncomms6194","article-title":"\u2018Division of labour\u2019 in response to host oxidative burst drives a fatal Cryptococcus gattii outbreak","volume":"5","author":"Voelz","year":"2014","journal-title":"Nat. Commun."},{"key":"B26","doi-asserted-by":"publisher","first-page":"680","DOI":"10.1093\/mmy\/myw130.","article-title":"Diversity and Antifungal Drug Susceptibility of Cryptococcus Isolates in Thailand","volume":"55","author":"Worasilchai","year":"2017","journal-title":"Med. Mycol."}],"container-title":["Frontiers in Cellular and Infection Microbiology"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fcimb.2021.634382\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2021,4,19]],"date-time":"2021-04-19T04:19:01Z","timestamp":1618805941000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fcimb.2021.634382\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,4,19]]},"references-count":26,"alternative-id":["10.3389\/fcimb.2021.634382"],"URL":"https:\/\/doi.org\/10.3389\/fcimb.2021.634382","relation":{},"ISSN":["2235-2988"],"issn-type":[{"value":"2235-2988","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,4,19]]},"article-number":"634382"}}