A Rare Strain Actinomadura geliboluensis Was First Isolated from the Bronchoalveolar Lavage Fluid of a Patient with Pneumonia

Abstract

Background: Actinomadura geliboluensis was first isolated in 2012 in Gelibolu, Canakkale, Turkey, and has not been reported to be isolated from humans until now. We have isolated it from the bronchoalveolar lavage fluid (BLF) of a patient with pneumonia and found its drug resistance. It is the first time that Actinomadura geliboluensis has been isolated from humans since its discovery and naming. This case may provide new ideas and methods for the clinical diagnosis and treatment of pulmonary actinomycosis.

Case description: The patient was a 75-year-old male who was hospitalized in a township hospital and failed to improve after penicillin treatment. After admission to our hospital, the patient was treated with piperacillin/tazobactam according to clinical guidelines for 14 days. Actinomadura geliboluensis was isolated from the patient's BLF and was identified by 16S rRNA sequencing. This report shows the biological characteristics and in vitro drug susceptibility testing, as well as the genomics analysis based on next-generation sequencing (NGS). The results demonstrated that Actinomadura geliboluensis was easy to be mistakenly identified as Actinomyces dental caries by using the Merieux ANC identification card. Based on the MIC test, Actinomadura geliboluensis was susceptible to tetracyclines, quinolones and sulfonamides, but resistant to carbapenems, penicillins and cephalosporins. The K-B test results showed Actinomadura geliboluensis was highly sensitive to piperacillin/tazobactam. Genomic analysis based on NGS showed that the Actinomadura geliboluensis belongs to Planobispora rosea EF-Tu mutants conferring resistance to inhibitor GE2270A, AAC(3)-VIIa, vanRO, chrB, and mexY.

Conclusion: Actinomycetes is generally sensitive to Penicillin but Actinomadura geliboluensis is not. In vitro drug susceptibility test is needed to support individualized drug use to avoid delay in the disease.

Keywords: Actinomadura geliboluensis; antibiotic resistance; genomics; next generation sequencing; pulmonary actinomycosis.

Figure 1

Chest CT image. The township hospital chest CT (A) lung window and (B) longitudinal window shows the left lower lung showed a mass of high-density shadow with vague edge, adjacent to the pleural retraction, and slightly dilated bronchioles in it. The admission chest CT (C) lung window and (D) longitudinal window shows the left lower lung showed a mass of high-density shadow with vague edge, adjacent to the pleural retraction, and slightly dilated bronchioles in it. The discharged chest CT (E) lung window and (F) longitudinal window shows the left lower lung showed stripped-like, patchy high-density shadow with clear boundary, adjacent to the pleural stretch, slightly dilated bronchioles, and more anterior absorption of the lesion.

Figure 2

(A) Colony morphology of Actinomadura geliboluensis after 3 days of culture on Columbia blood plate medium (ultra-micrograph with 4× magnification); (B) weak acid-fast staining (with 2000× magnification) of Actinomadura geliboluensis colonies after slide blotting; (C) Gram staining (with 1000× magnification) of growth in liquid medium of Actinomadura geliboluensis.

Figure 3

Protein fingerprints detected by MALDI TOF.

Figure 4

The timeline shows the entire diagnosis and treatment process of this case.