title: Cluster and sporadic cases of herbaspirillum species infections in patients with cancer.
abstract: BACKGROUND
  Herbaspirillum species are gram-negative Betaproteobacteria that inhabit the rhizosphere. We investigated a potential cluster of hospital-based Herbaspirillum species infections.
  
  
  METHODS
  Cases were defined as Herbaspirillum species isolated from a patient in our comprehensive cancer center between 1 January 2006 and 15 October 2013. Case finding was performed by reviewing isolates initially identified as Burkholderia cepacia susceptible to all antibiotics tested, and 16S ribosomal DNA sequencing of available isolates to confirm their identity. Pulsed-field gel electrophoresis (PFGE) was performed to test genetic relatedness. Facility observations, infection prevention assessments, and environmental sampling were performed to investigate potential sources of Herbaspirillum species.
  
  
  RESULTS
  Eight cases of Herbaspirillum species were identified. Isolates from the first 5 clustered cases were initially misidentified as B. cepacia, and available isolates from 4 of these cases were indistinguishable. The 3 subsequent cases were identified by prospective surveillance and had different PFGE patterns. All but 1 case-patient had bloodstream infections, and 6 presented with sepsis. Underlying diagnoses included solid tumors (3), leukemia (3), lymphoma (1), and aplastic anemia (1). Herbaspirillum species infections were hospital-onset in 5 patients and community-onset in 3. All symptomatic patients were treated with intravenous antibiotics, and their infections resolved. No environmental source or common mechanism of acquisition was identified.
  
  
  CONCLUSIONS
  This is the first report of a hospital-based cluster of Herbaspirillum species infections. Herbaspirillum species are capable of causing bacteremia and sepsis in immunocompromised patients. Herbaspirillum species can be misidentified as Burkholderia cepacia by commercially available microbial identification systems.
authors.affiliation: Department of Infectious Diseases, Infection Control and Employee Health, The University of Texas MD Anderson Cancer Center, Houston.
authors.forename: Roy F
authors.initials: RF
authors.lastname: Chemaly
authors.affiliation: Epidemic Intelligence Service, Scientific Education and Professional Development Program Office Division of Healthcare Quality Promotion, Centers for Disease Control and Prevention, Atlanta, Georgia.
authors.forename: Raymund
authors.initials: R
authors.lastname: Dantes
authors.affiliation: Department of Infectious Diseases, Infection Control and Employee Health, The University of Texas MD Anderson Cancer Center, Houston.
authors.forename: Dimpy P
authors.initials: DP
authors.lastname: Shah
authors.affiliation: The University of Texas School of Public Health, Houston.
authors.forename: Pankil K
authors.initials: PK
authors.lastname: Shah
authors.affiliation: Texas Department of State Health Services, Austin.
authors.forename: Neil
authors.initials: N
authors.lastname: Pascoe
authors.affiliation: Department of Infectious Diseases, Infection Control and Employee Health, The University of Texas MD Anderson Cancer Center, Houston.
authors.forename: Ella
authors.initials: E
authors.lastname: Ariza-Heredia
authors.affiliation: Department of Infectious Diseases, Infection Control and Employee Health, The University of Texas MD Anderson Cancer Center, Houston.
authors.forename: Cheryl
authors.initials: C
authors.lastname: Perego
authors.affiliation: Epidemic Intelligence Service, Scientific Education and Professional Development Program Office Division of Healthcare Quality Promotion, Centers for Disease Control and Prevention, Atlanta, Georgia.
authors.forename: Duc B
authors.initials: DB
authors.lastname: Nguyen
authors.affiliation: Department of Infectious Diseases, Infection Control and Employee Health, The University of Texas MD Anderson Cancer Center, Houston.
authors.forename: Kim
authors.initials: K
authors.lastname: Nguyen
authors.affiliation: Division of Healthcare Quality Promotion, Centers for Disease Control and Prevention, Atlanta, Georgia.
authors.forename: Farhad
authors.initials: F
authors.lastname: Modarai
authors.affiliation: Division of Healthcare Quality Promotion, Centers for Disease Control and Prevention, Atlanta, Georgia.
authors.forename: Heather
authors.initials: H
authors.lastname: Moulton-Meissner
authors.affiliation: Division of Healthcare Quality Promotion, Centers for Disease Control and Prevention, Atlanta, Georgia.
authors.forename: Judith
authors.initials: J
authors.lastname: Noble-Wang
authors.affiliation: Department of Laboratory Medicine, The University of Texas MD Anderson Cancer Center, Houston.
authors.forename: Jeffrey J
authors.initials: JJ
authors.lastname: Tarrand
authors.affiliation: Department of Pediatrics and Communicable Diseases, University of Michigan, Ann Arbor.
authors.forename: John J
authors.initials: JJ
authors.lastname: LiPuma
authors.affiliation: Division of Healthcare Quality Promotion, Centers for Disease Control and Prevention, Atlanta, Georgia.
authors.forename: Alice Y
authors.initials: AY
authors.lastname: Guh
authors.affiliation: Division of Healthcare Quality Promotion, Centers for Disease Control and Prevention, Atlanta, Georgia.
authors.forename: Tara
authors.initials: T
authors.lastname: MacCannell
authors.affiliation: Department of Infectious Diseases, Infection Control and Employee Health, The University of Texas MD Anderson Cancer Center, Houston.
authors.forename: Issam
authors.initials: I
authors.lastname: Raad
authors.affiliation: Department of Infectious Diseases, Infection Control and Employee Health, The University of Texas MD Anderson Cancer Center, Houston.
authors.forename: Victor
authors.initials: V
authors.lastname: Mulanovich
mesh_terms: D000293:Adolescent; D000368:Aged; D020562:Betaproteobacteria; D016956:Burkholderia cepacia; D002675:Child, Preschool; D016000:Cluster Analysis; D003428:Cross Infection / Q000453:epidemiology* / Q000382:microbiology*; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D016521:Electrophoresis, Gel, Pulsed-Field; D005260:Female; D005838:Genotype; D016905:Gram-Negative Bacterial Infections / Q000453:epidemiology* / Q000382:microbiology*; D042803:Herbaspirillum / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D008297:Male; D008875:Middle Aged; D058889:Molecular Typing; D009369:Neoplasms / Q000150:complications*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012189:Retrospective Studies; D017422:Sequence Analysis, DNA
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S
keywords: Herbaspirillum; cancer; immunocompromised; misdiagnosis; outbreak