ABSTRACT
Background: Nocardia farcinica, a pathogen known for its strong pathogenicity, is frequently implicated in skin, central nervous system, and lung infections among immunosuppressed hosts, while intestinal nocardiosis is rare. We report the case of infectious diarrhea caused by N. farcinica in a child. Case Presentation: A 19-month-old female child was admitted to the hospital with fever and diarrhea after the consumption of oranges. The etiological agent responsible for the diarrhea was identified through the examination of fecal smears using weak acid-fast staining and conducting fecal cultures. Whole-genome sequencing was employed to analyze the causative gene. Subsequent to a 5-day treatment regimen with amoxicillin-clavulanate at a dosage of 30 mg/kg every 12 hours, the child's condition improved significantly, leading to an uncomplicated discharge. Conclusion: This case illustrates the presence of intestine virulence factors in N. farcinica capable of causing diarrhea. The utilization of weak acid-fast staining in the examination of fecal smears is crucial for the accurate diagnosis of infectious diarrhea caused by Nocardia spp.
ABSTRACT
OBJECTIVES: This study aimed to investigate the microbiological characteristics, antimicrobial resistance profiles, antibiotic choice, and outcomes of Nocardia infection in various centers over a 7-year period (from 2015 to 2021). METHODS: We retrospectively analyzed the medical records of all hospitalized patients diagnosed with Nocardia between 2015 and 2021. The isolates were identified to the species level through the sequencing of 16S ribosomal RNA or secA1 or ropB genes. The susceptibility profiles were determined using the broth microdilution method. RESULTS: Of the 130 nocardiosis cases, 99 (76.2%) were established as pulmonary infection, of which the most common underlying disease was chronic lung disease (40.4%, 40/99), including bronchiectasis, chronic obstructive pulmonary disease, and chronic bronchitis. Among 130 isolates, 12 species were identified, with the most common species being Nocardia cyriacigeorgica (37.7%) and Nocardia farcinica (20.8%). All Nocardia strains were susceptible to linezolid and amikacin, and the susceptibility rate of trimethoprim-sulfamethoxazole (TMP-SMX) was 97.7%. Of the 130 patients, 86 (66.2%) received TMP-SMX monotherapy or multidrug regimen. Furthermore, 92.3% patients who were treated achieved clinical improvement. CONCLUSION: TMP-SMX was the treatment of choice for nocardiosis, and other combination drugs with TMP-SMX therapy yielded even better results.
