{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T00:59:59Z","timestamp":1760057999889,"version":"build-2065373602"},"reference-count":52,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2025,3,4]],"date-time":"2025-03-04T00:00:00Z","timestamp":1741046400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Microorganisms"],"abstract":"<jats:p>Background: Inquilinus species are Gram-negative, non-sporulating, non-pigmented rods that are catalase-positive, indole-negative, and able to grow at various temperatures and in 1% NaCl. Infections due to Inquilinus spp. are increasingly identified, especially in patients with cystic fibrosis. Objective: This review aims to present all reported cases of Inquilinus spp. infections in humans, with an emphasis on data regarding epidemiology, antimicrobial resistance, antimicrobial treatment, and mortality. Methods: A narrative review based on a literature search of the PubMed\/MedLine and Scopus databases was performed. Results: In total, 13 articles providing data on 25 patients with Inquilinus infections were included in the analysis. The median age was 19 years, while 60% were male. Cystic fibrosis was the predominant risk factor (92%). Respiratory tract infection was the most common type of infection (96%). Inquilinus limosus was the most commonly identified species. Polymicrobial infection was very common (77.3%). Microbial identification required the use of advanced molecular techniques, such as 16s rRNA sequencing. The pathogen exhibited resistance to beta-lactams, with the exception of carbapenems. The most commonly used antimicrobials included carbapenems (68.4%), followed by quinolones (57.9%) and aminoglycosides (52.6%). Mortality was low (4%). Conclusions: Due to the potential of Inquilinus spp. to cause infection in patients with cystic fibrosis, and given the difficulties in microbial identification, clinicians and laboratory professionals should consider it in the differential diagnosis of patients with cystic fibrosis and respiratory tract infection not responding to beta-lactam treatment or with polymicrobial infections, especially when traditional techniques are used for microbial identification.<\/jats:p>","DOI":"10.3390\/microorganisms13030592","type":"journal-article","created":{"date-parts":[[2025,3,4]],"date-time":"2025-03-04T13:31:31Z","timestamp":1741095091000},"page":"592","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Inquilinus Species Infections in Humans\u2014A Narrative Review"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0009-0004-6997-7191","authenticated-orcid":false,"given":"Anastasia","family":"Vasilopoulou","sequence":"first","affiliation":[{"name":"School of Medicine, University of Crete, 71003 Heraklion, Greece"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0009-0004-1424-5436","authenticated-orcid":false,"given":"Takis","family":"Panayiotou","sequence":"additional","affiliation":[{"name":"School of Medicine, University of Crete, 71003 Heraklion, Greece"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Stella","family":"Baliou","sequence":"additional","affiliation":[{"name":"School of Medicine, University of Crete, 71003 Heraklion, Greece"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3695-0759","authenticated-orcid":false,"given":"Andreas G.","family":"Tsantes","sequence":"additional","affiliation":[{"name":"Laboratory of Hematology and Blood Bank Unit, \u201cAttikon\u201d University Hospital, School of Medicine, National and Kapodistrian University of Athens, 12462 Athens, Greece"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1082-5674","authenticated-orcid":false,"given":"Petros","family":"Ioannou","sequence":"additional","affiliation":[{"name":"School of Medicine, University of Crete, 71003 Heraklion, Greece"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2025,3,4]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1693","DOI":"10.1056\/NEJMra2216474","article-title":"Cystic Fibrosis","volume":"389","author":"Grasemann","year":"2023","journal-title":"N. Engl. J. Med."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1859","DOI":"10.1001\/jama.2023.8120","article-title":"Cystic Fibrosis: A Review","volume":"329","author":"Ong","year":"2023","journal-title":"JAMA"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"727","DOI":"10.1055\/s-0039-1698464","article-title":"Microbiology of Cystic Fibrosis Airway Disease","volume":"40","author":"Blanchard","year":"2019","journal-title":"Semin. Respir. Crit. Care Med."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"715","DOI":"10.1055\/s-0039-1694021","article-title":"Cystic Fibrosis: Pathophysiology of Lung Disease","volume":"40","author":"Bergeron","year":"2019","journal-title":"Semin. Respir. Crit. Care Med."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"S2","DOI":"10.1258\/jrsm.2008.s18002","article-title":"Identification and Management of Unusual Pathogens in Cystic Fibrosis","volume":"101","author":"Elborn","year":"2008","journal-title":"J. R. Soc. Med."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"3851","DOI":"10.1128\/JCM.37.12.3851-3855.1999","article-title":"Novel Bacterium Isolated from a Lung Transplant Patient with Cystic Fibrosis","volume":"37","author":"Pitulle","year":"1999","journal-title":"J. Clin. Microbiol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"2062","DOI":"10.1128\/JCM.40.6.2062-2069.2002","article-title":"Characterization of Unusual Bacteria Isolated from Respiratory Secretions of Cystic Fibrosis Patients and Description of Inquilinus Limosus Gen. Nov., Sp. Nov","volume":"40","author":"Coenye","year":"2002","journal-title":"J. Clin. Microbiol."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Akinnurun, O.M., Riedel, T., M\u00fcller, S., Bunk, B., and Schr\u00f6ttner, P. (2024). Current Knowledge on Inquilinus Limosus, a Scarcely Researched Human Pathogen. BMC Microbiol., 24.","DOI":"10.1186\/s12866-024-03617-6"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"317","DOI":"10.1016\/j.diagmicrobio.2006.05.005","article-title":"Early-Onset Prosthetic Valve Endocarditis Caused by Inquilinus sp.","volume":"56","author":"Kiratisin","year":"2006","journal-title":"Diagn. Microbiol. Infect. Dis."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"619","DOI":"10.1002\/ppul.21003","article-title":"Mucoid Inquilinus Limosus in a Young Adult with Cystic Fibrosis","volume":"44","author":"Hayes","year":"2009","journal-title":"Pediatr. Pulmonol."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1220","DOI":"10.1016\/j.healun.2015.06.013","article-title":"Bacteremic Inquilinus Limosus Empyema in an Australian Lung Transplant Patient with Cystic Fibrosis","volume":"34","author":"Goeman","year":"2015","journal-title":"J. Heart Lung Transplant."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"446","DOI":"10.1016\/j.diagmicrobio.2016.09.006","article-title":"Inquilinus Limosus in Pulmonary Disease: Case Report and Review of the Literature","volume":"86","author":"McHugh","year":"2016","journal-title":"Diagn. Microbiol. Infect. Dis."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"E21","DOI":"10.1002\/ppul.24043","article-title":"Potential Pathogenicity of Inquilinus Limosus in a Pediatric Patient with Cystic Fibrosis","volume":"53","author":"Poore","year":"2018","journal-title":"Pediatr. Pulmonol."},{"key":"ref_14","first-page":"101487","article-title":"Familial Cluster of Inquilinus Limosus Infection among Three Brothers with Cystic Fibrosis","volume":"34","author":"Watson","year":"2021","journal-title":"Respir. Med. Case Rep."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"156","DOI":"10.1016\/j.ijmmb.2021.11.010","article-title":"Inquilinus Limosus Isolated from a Patient with Chronic Cystic Fibrosis. First Report in Mexico and Evidence That Co-Infection with Pseudomonas aeruginosa Promotes the Accelerated and Increased Formation of Extracellular Neutrophil Traps","volume":"40","author":"Bustamante","year":"2022","journal-title":"Indian J. Med. Microbiol."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"302","DOI":"10.1002\/ppul.22820","article-title":"Continuous Infusion Meropenem and Ticarcillin-Clavulanate in Pediatric Cystic Fibrosis Patients","volume":"49","author":"Zobell","year":"2014","journal-title":"Pediatr. Pulmonol."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1425","DOI":"10.1099\/jmm.0.46466-0","article-title":"Clonal Analysis of Inquilinus Limosus Isolates from Six Cystic Fibrosis Patients and Specific Serum Antibody Response","volume":"55","author":"Schmoldt","year":"2006","journal-title":"J. Med. Microbiol."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"993","DOI":"10.3201\/eid1406.071355","article-title":"Inquilinus Limosus and Cystic Fibrosis","volume":"14","author":"Bittar","year":"2008","journal-title":"Emerg. Infect. Dis."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"3938","DOI":"10.1128\/JCM.43.8.3938-3943.2005","article-title":"Clinical and Microbiological Features of Inquilinus Sp. Isolates from Five Patients with Cystic Fibrosis","volume":"43","author":"Chiron","year":"2005","journal-title":"J. Clin. Microbiol."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"642","DOI":"10.3201\/eid2903.221564","article-title":"Inquilinus limosus Bacteremia in Lung Transplant Recipient after SARS-CoV-2 Infection","volume":"29","author":"Farfour","year":"2023","journal-title":"Emerg. Infect. Dis."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"2195","DOI":"10.1016\/S0140-6736(20)32542-3","article-title":"Cystic Fibrosis","volume":"397","author":"Shteinberg","year":"2021","journal-title":"Lancet Lond. Engl."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"937","DOI":"10.1126\/science.1223012","article-title":"A Periciliary Brush Promotes the Lung Health by Separating the Mucus Layer from Airway Epithelia","volume":"337","author":"Button","year":"2012","journal-title":"Science"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"83","DOI":"10.2147\/IDR.S80341","article-title":"Discrepancy in MALDI-TOF MS Identification of Uncommon Gram-Negative Bacteria from Lower Respiratory Secretions in Patients with Cystic Fibrosis","volume":"8","author":"AbdulWahab","year":"2015","journal-title":"Infect. Drug Resist."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"299","DOI":"10.1128\/CMR.00068-09","article-title":"The Changing Microbial Epidemiology in Cystic Fibrosis","volume":"23","author":"Lipuma","year":"2010","journal-title":"Clin. Microbiol. Rev."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"e00215-21","DOI":"10.1128\/cmr.00215-21","article-title":"Practical Guidance for Clinical Microbiology Laboratories: Updated Guidance for Processing Respiratory Tract Samples from People with Cystic Fibrosis","volume":"37","author":"Saiman","year":"2024","journal-title":"Clin. Microbiol. Rev."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"e02422-21","DOI":"10.1128\/jcm.02422-21","article-title":"Distribution of Achromobacter Species in 12 French Cystic Fibrosis Centers in 2020 by a Retrospective MALDI-TOF MS Spectrum Analysis","volume":"60","author":"Garrigos","year":"2022","journal-title":"J. Clin. Microbiol."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"376","DOI":"10.1016\/j.jcf.2019.08.006","article-title":"Changing Epidemiology of the Respiratory Bacteriology of Patients with Cystic Fibrosis-Data from the European Cystic Fibrosis Society Patient Registry","volume":"19","author":"Hatziagorou","year":"2020","journal-title":"J. Cyst. Fibros."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"3361","DOI":"10.1128\/JCM.00569-08","article-title":"Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry for Identification of Nonfermenting Gram-Negative Bacilli Isolated from Cystic Fibrosis Patients","volume":"46","author":"Degand","year":"2008","journal-title":"J. Clin. Microbiol."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"457","DOI":"10.3201\/eid1103.041078","article-title":"Inquilinus Limosus in Patients with Cystic Fibrosis, Germany","volume":"11","author":"Wellinghausen","year":"2005","journal-title":"Emerg. Infect. Dis."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"414","DOI":"10.1016\/j.eimc.2012.11.013","article-title":"Chronic Colonization of Inquilinus limosus in a Patient with Cystic Fibrosis: First Report in Spain","volume":"31","year":"2013","journal-title":"Enferm. Infecc. Microbiol. Clin."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"25","DOI":"10.1002\/vms3.1040","article-title":"Oral Flora of Domestic Cats in Hong Kong: Identification of Antibiotic-Resistant Strains","volume":"9","author":"Cheung","year":"2023","journal-title":"Vet. Med. Sci."},{"key":"ref_32","first-page":"53176","article-title":"Identification of Rare Bacterial Pathogens by 16S rRNA Gene Sequencing and MALDI-TOF MS","volume":"113","author":"Gunzer","year":"2016","journal-title":"J. Vis. Exp. JoVE"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"2182","DOI":"10.1128\/JCM.00492-13","article-title":"Identification of Rare Pathogenic Bacteria in a Clinical Microbiology Laboratory: Impact of Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry","volume":"51","author":"Seng","year":"2013","journal-title":"J. Clin. Microbiol."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"14","DOI":"10.1016\/j.mimet.2012.10.014","article-title":"Use of MALDI-TOF Mass Spectrometry for Identification of Bacteria That Are Difficult to Culture","volume":"92","author":"Biswas","year":"2013","journal-title":"J. Microbiol. Methods"},{"key":"ref_35","first-page":"567","article-title":"Identification of Inquilinus limosus in Cystic Fibrosis: A First Report in Italy","volume":"37","author":"Cicatiello","year":"2014","journal-title":"New Microbiol."},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Magalh\u00e3es, A.P., Lopes, S.P., and Pereira, M.O. (2016). Insights into Cystic Fibrosis Polymicrobial Consortia: The Role of Species Interactions in Biofilm Development, Phenotype, and Response to In-Use Antibiotics. Front. Microbiol., 7.","DOI":"10.3389\/fmicb.2016.02146"},{"key":"ref_37","first-page":"217","article-title":"Isolation of Alginate-Producing Mutants of Pseudomonas Fluorescens, Pseudomonas putida and Pseudomonas mendocina","volume":"125","author":"Govan","year":"1981","journal-title":"J. Gen. Microbiol."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"2404","DOI":"10.1016\/j.carres.2007.07.012","article-title":"Exopolysaccharides Produced by Inquilinus limosus, a New Pathogen of Cystic Fibrosis Patients: Novel Structures with Usual Components","volume":"342","author":"Herasimenka","year":"2007","journal-title":"Carbohydr. Res."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"105742","DOI":"10.1016\/j.micpath.2022.105742","article-title":"Intracellular Replication of Inquilinus limosus in Bronchial Epithelial Cells","volume":"171","author":"Lamberti","year":"2022","journal-title":"Microb. Pathog."},{"key":"ref_40","doi-asserted-by":"crossref","unstructured":"Lopes, S.P., Azevedo, N.F., and Pereira, M.O. (2014). Emergent Bacteria in Cystic Fibrosis: In Vitro Biofilm Formation and Resilience under Variable Oxygen Conditions. BioMed Res. Int., 2014.","DOI":"10.1155\/2014\/678301"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"340","DOI":"10.1016\/j.jcf.2016.01.004","article-title":"Microbial Colonization and Lung Function in Adolescents with Cystic Fibrosis","volume":"15","author":"Hector","year":"2016","journal-title":"J. Cyst. Fibros. Off. J. Eur. Cyst. Fibros. Soc."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"773","DOI":"10.1083\/jcb.201203170","article-title":"Neutrophil Extracellular Traps: Is Immunity the Second Function of Chromatin?","volume":"198","author":"Brinkmann","year":"2012","journal-title":"J. Cell Biol."},{"key":"ref_43","doi-asserted-by":"crossref","unstructured":"Mart\u00ednez-Alem\u00e1n, S.R., Campos-Garc\u00eda, L., Palma-Nicolas, J.P., Hern\u00e1ndez-Bello, R., Gonz\u00e1lez, G.M., and S\u00e1nchez-Gonz\u00e1lez, A. (2017). Understanding the Entanglement: Neutrophil Extracellular Traps (NETs) in Cystic Fibrosis. Front. Cell. Infect. Microbiol., 7.","DOI":"10.3389\/fcimb.2017.00104"},{"key":"ref_44","first-page":"943","article-title":"Draft Genome Sequence of Inquilinus limosus Strain MP06, a Multidrug-Resistant Clinical Isolate","volume":"46","author":"Pino","year":"2015","journal-title":"Braz. J. Microbiol. Publ. Braz. Soc. Microbiol."},{"key":"ref_45","doi-asserted-by":"crossref","unstructured":"Gradel, K.O., Jensen, U.S., Sch\u00f8nheyder, H.C., \u00d8stergaard, C., Knudsen, J.D., Wehberg, S., S\u00f8gaard, M., and Danish Collaborative Bacteraemia Network (DACOBAN) (2017). Impact of Appropriate Empirical Antibiotic Treatment on Recurrence and Mortality in Patients with Bacteraemia: A Population-Based Cohort Study. BMC Infect. Dis., 17.","DOI":"10.1186\/s12879-017-2233-z"},{"key":"ref_46","first-page":"CD002007","article-title":"Single versus Combination Intravenous Anti-Pseudomonal Antibiotic Therapy for People with Cystic Fibrosis","volume":"6","author":"Holland","year":"2021","journal-title":"Cochrane Database Syst. Rev."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"4124","DOI":"10.1128\/JCM.01121-14","article-title":"When Does 2 plus 2 Equal 5? A Review of Antimicrobial Synergy Testing","volume":"52","author":"Doern","year":"2014","journal-title":"J. Clin. Microbiol."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"1295","DOI":"10.1164\/rccm.202102-0461OC","article-title":"A Randomized Clinical Trial of Antimicrobial Duration for Cystic Fibrosis Pulmonary Exacerbation Treatment","volume":"204","author":"Goss","year":"2021","journal-title":"Am. J. Respir. Crit. Care Med."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"204","DOI":"10.1016\/j.jcf.2015.09.002","article-title":"Causes of Death in French Cystic Fibrosis Patients: The Need for Improvement in Transplantation Referral Strategies!","volume":"15","author":"Martin","year":"2016","journal-title":"J. Cyst. Fibros."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"190","DOI":"10.1186\/s12931-024-02778-2","article-title":"Acute Respiratory Failure Due to Pulmonary Exacerbation in Children with Cystic Fibrosis Admitted in a Pediatric Intensive Care Unit: Outcomes and Factors Associated with Mortality","volume":"25","author":"Drummond","year":"2024","journal-title":"Respir. Res."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"1017","DOI":"10.1513\/AnnalsATS.201804-268OC","article-title":"Mortality in Adults with Cystic Fibrosis Requiring Mechanical Ventilation. Cross-Sectional Analysis of Nationwide Events","volume":"16","author":"Siuba","year":"2019","journal-title":"Ann. Am. Thorac. Soc."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"482","DOI":"10.1016\/j.jcf.2012.12.006","article-title":"Chronic Stenotrophomonas maltophilia Infection and Mortality or Lung Transplantation in Cystic Fibrosis Patients","volume":"12","author":"Waters","year":"2013","journal-title":"J. Cyst. Fibros."}],"container-title":["Microorganisms"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-2607\/13\/3\/592\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T16:47:08Z","timestamp":1760028428000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-2607\/13\/3\/592"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,3,4]]},"references-count":52,"journal-issue":{"issue":"3","published-online":{"date-parts":[[2025,3]]}},"alternative-id":["microorganisms13030592"],"URL":"https:\/\/doi.org\/10.3390\/microorganisms13030592","relation":{},"ISSN":["2076-2607"],"issn-type":[{"type":"electronic","value":"2076-2607"}],"subject":[],"published":{"date-parts":[[2025,3,4]]}}}