Clinical Interpretation of Repeated Isolation of Leclercia adecarboxylata from Sputum Specimens in an Elderly Patient with Limited Systemic Inflammatory Response: A Case Report.
- 1Department of Clinical Laboratory, Lianyungang Maternal and Child Health Hospital, Affiliated Lianyungang Maternal and Child Health Hospital of Kangda College of Nanjing Medical University, Lianyungang, Jiangsu, People's Republic of China.
Abstract
Background
Leclercia adecarboxylata is an uncommon Gram-negative bacillus traditionally regarded as an environmental organism or opportunistic pathogen. The clinical significance of respiratory isolation remains uncertain because sputum cultures may represent contamination, colonization, or true infection.Case presentation
An 87-year-old man with neurological disease and abnormal pulmonary imaging developed cough, sputum production, impaired sputum clearance, and decreased oxygen saturation after prolonged immobilization. Laboratory tests showed a white blood cell count of 3.70 × 10⁹/L and a procalcitonin level of 0.070 ng/mL, indicating a limited systemic inflammatory response. The initial sputum specimen met quality criteria and showed predominant growth of L. adecarboxylata, which was again isolated from a second specimen 2 days later. The isolate was susceptible to multiple antimicrobial agents, including ceftriaxone. Because repeated isolation did not establish pathogenicity, antimicrobial therapy was not escalated solely on the basis of culture results. Respiratory symptoms and imaging abnormalities improved after comprehensive management, but the specific contribution of L. adecarboxylata could not be confirmed.Conclusion
Repeated isolation of uncommon bacteria from sputum specimens may provide clinically relevant information but does not independently establish infection. We propose a conceptual three-category interpretation framework comprising possible contamination, clinically relevant airway persistence, and confirmed infection. This hypothesis-generating model is intended to support cautious clinical interpretation rather than serve as a validated diagnostic tool, and its generalizability requires further evaluation in larger studies.
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BibTeX
@article{zhang2026clinical,
title = {{Clinical Interpretation of Repeated Isolation of Leclercia adecarboxylata from Sputum Specimens in an Elderly Patient with Limited Systemic Inflammatory Response: A Case Report.}},
author = {Pengfei Zhang and Lili Wei and Yaozhi Qi and Baocheng Zhou},
journal = {Infection and drug resistance},
year = {2026},
month = oct,
doi = {10.2147/idr.s643222},
url = {https://europepmc.org/article/MED/42928864},
note = {CC BY-NC},
}
RIS
TY - JOUR
TI - Clinical Interpretation of Repeated Isolation of Leclercia adecarboxylata from Sputum Specimens in an Elderly Patient with Limited Systemic Inflammatory Response: A Case Report.
AU - Pengfei Zhang
AU - Lili Wei
AU - Yaozhi Qi
AU - Baocheng Zhou
PY - 2026
DA - 2026/10/21
JO - Infection and drug resistance
DO - 10.2147/idr.s643222
UR - https://europepmc.org/article/MED/42928864
AB - Background Leclercia adecarboxylata is an uncommon Gram-negative bacillus traditionally regarded as an environmental organism or opportunistic pathogen. The clinical significance of respiratory isolation remains uncertain because sputum cultures may represent contamination, colonization, or true infection.Case presentation An 87-year-old man with neurological disease and abnormal pulmonary imaging developed cough, sputum production, impaired sputum clearance, and decreased oxygen saturation after prolonged immobilization. Laboratory tests showed a white blood cell count of 3.70 × 10⁹/L and a procalcitonin level of 0.070 ng/mL, indicating a limited systemic inflammatory response. The initial sputum specimen met quality criteria and showed predominant growth of L. adecarboxylata, which was again isolated from a second specimen 2 days later. The isolate was susceptible to multiple antimicrobial agents, including ceftriaxone. Because repeated isolation did not establish pathogenicity, antimicrobial therapy was not escalated solely on the basis of culture results. Respiratory symptoms and imaging abnormalities improved after comprehensive management, but the specific contribution of L. adecarboxylata could not be confirmed.Conclusion Repeated isolation of uncommon bacteria from sputum specimens may provide clinically relevant information but does not independently establish infection. We propose a conceptual three-category interpretation framework comprising possible contamination, clinically relevant airway persistence, and confirmed infection. This hypothesis-generating model is intended to support cautious clinical interpretation rather than serve as a validated diagnostic tool, and its generalizability requires further evaluation in larger studies.
SN - 1178-6973
ER -