First report of cavitary pneumonia due to community-acquired Acinetobacter pittii, study of virulence and overview of pathogenesis and treatment

BMC Infectious Diseases

Case Report

Albert Sotto¹  Romaric Larcher²  Erik Arnaud²  Alix Pantel³  Jean-Philippe Lavigne³ 

[1] Department of Infectious Diseases, Caremeau University Hospital, 29 place du Professeur Debre, Nimes, France;Department of Internal Medicine, Caremeau University Hospital, 29 place du Professeur Debre, Nimes, France;Department of Microbiology, Caremeau University Hospital, 29 place du Professeur Debre, Nimes, France;

关键词: Community-acquired pneumonia;    Cavitary pneumonia;    Cavitation;    Acinetobacter pittii;    Acinetobacter calcoaceticus-baumannii;    Virulence;    Biofilm;   

DOI  :  10.1186/s12879-017-2589-0

 received in 2017-04-06, accepted in 2017-07-03,  发布年份 2017

来源: Springer

【 摘 要 】

BackgroundAcinetobacter pittii is a nosocomial pathogen rarely involved in community-acquired infections. We report for the first time that A. pittii can be responsible for cavitary community-acquired pneumonia and study its virulence, and discuss its pathogenesis and treatment options.Case presentationA 45-year-old woman with a history of smoking and systemic lupus was admitted to Nimes University Hospital (France) with coughing and sputum lasting for three weeks. Thoracic CT scanner showed cavitary pneumonia. Broncho-alveolar lavage cultures found community-acquired Acinetobacter calcoaceticus-baumannii complex. The clinical outcome was favourable after twenty-one days of antimicrobial treatment by piperacillin/tazobactam and amikacin then cefepime. Multilocus sequence typing (MLST) analyses identified an A. pittii ST249. Despite the atypical clinical presentation with an unexpected partial destruction of lung parenchyma, we found very low virulence potential of the A. pittii strain with nematode killing assays and biofilm formation test. The median time required to kill 50% of the nematodes was 7 ± 0.3 days for A. pittii ST249, 7 ± 0.2 days for A. baumanii NAB ST2 and 8 ± 0.2 days for E. coli OP50, (p > 0,05). A. pittii ST249 showed significantly slower biofilm formation than A. baumanii NAB ST2: BFI = 8.83 ± 0.59 vs 3.93 ± 0.27 at 2 h (p < 0.0001), BFI = 6.3 ± 0.17 vs 1.87 ± 0.12 at 3 h (p < 0.0001) and BFI = 3.67 ± 0.41 vs 1.7 ± 0.06 after 4 h of incubation (p < 0.01).ConclusionsCommunity-acquired A. pittii should be considered as possible cause of sub-acute cavitary pneumonia particularly in a smoking and/or immunocompromised patient despite its low virulence potential.

【 授权许可】

CC BY   
© The Author(s). 2017