From NTM (Nontuberculous mycobacterium) to Gordonia bronchialis—A Diagnostic Challenge in the COPD Patient

Abstract

In patients with chronic obstructive pulmonary disease, respiratory infections are of various aetiology, predominantly viral and bacterial. However, due to structural and immunological changes within the respiratory system, such patients are also prone to mycobacterial and other relatively rare infections. We present the 70-year old male patient with chronic obstructive pulmonary disease (COPD) and coexisting bronchial asthma, diagnosed due to cough with purulent sputum expectoration lasting over three months. The first microbiological investigation of the sputum sample revealed the growth of mycobacteria. The identification test based on protein MPT64 production indicated an organism belonging to NTM (nontuberculous mycobacterium). However, further species identification by genetic testing verified the obtained culture as not belonging to the Mycobacterium genus. Based on observed morphology, the new characterisation identified an aerobic actinomycete, possibly a Nocardia spp. The isolated strain was recultured on standard microbiological media. The growth of colonies was observed on Columbia blood agar plates and solid Löewenstein-Jensen medium. The Gram and Zhiel-Nielsen stains revealed the presence of Gram-positive acid-fast bacilli. The extraction protocol and identification were performed in two repetitions; the result was G. bronchialis, with a confidence value of 99% and 95%, respectively. The gene sequencing method was applied to confirm the species affiliation of this isolate. The resulting sequence was checked against the 16S ribosomal RNA sequences database (Bacteria and Archaea). The ten best results indicated the genus Gordonia (99.04–100%) and 100% similarity of the 16S sequenced region was demonstrated for Gordonia bronchialis. The case described indicates that the correct interpretation of microbiological test results requires the use of advanced microbiology diagnosis techniques, including molecular identification of gene sequences. From a clinical point of view, Gordonia bronchialis infection or colonization may present a mild course, with no febrile episodes and no significant patient status deterioration and thus, it may remain undiagnosed more often than expected.

Antimicrobial treatment in invasive infections caused by Gordonia bronchialis: systematic review

“…Although pneumonia caused by G. bronchialis is the most common diagnosis in our systematic review, only three patients have a complete medical history (16,17,19). Antibiotic drugs used in the treatment of pneumonia were levofloxacin and sulfamethoxazole/ trimethoprim, as monotherapy.…”

A Patient of Spontaneous Bacterial Peritonitis in Hepatitis C Cirrhosis Caused by Gordonia terrae: A Case Report

“…12 The utilization of conventional laboratory identification methods can provide clues and tacks for the identification of G. terrae, but it can still to be mistakenly identified as Corynebacterium, Rhodococcus, Actinomyces or Mycobacterium. [13][14][15] Identification with Mycobacterium can be achieved by modified Ziehl-Neelsen staining. G. terrae is positive, while Mycobacterium presents modified Ziehl-Neelsen staining negative.…”

Gordonia sputi-associated bloodstream infection in a renal transplant patient with chronic indwelling central venous catheter: a case report and literature review

“…coronary artery bypass graft (CABG)] [2,3,7,8]. Gram-positive bacilli isolated in blood cultures of patients with clinical suspicion of infection should not be routinely dismissed as contaminating diphtheroids, especially in patients who are immunocompromised or have long-term indwelling catheters or medical devices, or when isolated in multiple culture bottles [3][4][5].…”

“…Our search identified 57 eligible articles, of which 92 documented human infections associated with Gordonia spp. were reported [1–5, 7–58] (see for details).…”

“…as other Gram-positive bacilli (e.g. Corynebacteria, Nocardia , Rhodococcus ) may delay appropriate diagnosis and treatment, including the dismissal of positive blood cultures as contaminating diphtheroids [3–5]. We report here a case of central line-associated bloodstream infection (CLABSI) due to Gordonia sputi in a renal transplant recipient that was initially misidentified as Rhodococcus spp.…”