Nontuberculous mycobacterial and Nocardia infections mimicking pulmonary tuberculosis: a retrospective study of a general hospital patient population in China

Abstract

Purpose. In this study, we differentiated between tuberculosis (TB) and infections caused by nontuberculous mycobacteria (NTM) or Nocardia in a tertiary general hospital in China. Differences in clinical manifestations and factors between respiratory infections associated with these organisms were also investigated. Methodology. A retrospective analysis was conducted for suspected pulmonary TB patients with positive bacterial culture results under treatment at Wangjing Hospital, a tertiary general hospital, between January 2014 and June 2017. Sputum samples were submitted for liquid culture and species identification by mass spectrometry. Results. Between January 2014 and June 2017, a total of 3981 suspected TB cases were analysed, of which 151 (3.8 %) exhibited positive mycobacterial culture results. Using mass spectrometry, the 151 isolates were classified into three groups: Mycobacterium tuberculosis (MTB) (n=112; 74.2 %), NTM (n=21 13.9 %) and Nocardia (n=18; 11.9 %). The NTM and Nocardia prevalence rates were significantly higher amongst elderly patients [aged ≥65 years; odds ratio (95 % confidence interval): 3.89 (1.05–14.38) for NTM; odds ratio (95 % confidence interval): 5.10 (1.09–23.91) for Nocardia ]. In addition, treatment with immunosuppressive therapy [odds ratio (95 % confidence interval): 3.92 (1.16–13.27)] was identified as a risk factor for Nocardia infection in these patients. Conclusion. Our results demonstrated that a quarter of culture-positive ‘suspected TB patients’ harboured NTM or Nocardia infections. Notably, nearly all patients with non-TB infections presented with clinical syndromes mimicking pulmonary TB. Individuals receiving immunosuppressive therapy were at greater risk of acquiring Nocardia infections.

The species distribution and antimicrobial resistance profiles of Nocardia species in China: A systematic review and meta-analysis

“…We also aggregated the sample collected time, province and hospital involved in the included articles, and 19 articles were deleted due to duplication. Finally, 42 studies were included in present study [ 6 , 7 , 10 , 11 , 13 – 50 ], including 28 published in Chinese and 14 in English, covering 20 provinces in mainland China and involving 1008 clinical Nocardia isolates. Table 1 summarizes the characteristics of the selected articles.…”

“…Nocardia strains are frequently isolated during culture for mycobacteria in high TB burden settings, however, procedures used for decontamination of sputum specimens may be deleterious to Nocardia isolates [ 61 ]. Another factor that may limit Nocardia recovery is that egg-base L-J media is not an optimal choice for Nocardia isolation [ 11 , 62 ]. Furthermore, there are 5 antibiotics in MGIT 960 mycobacterium liquid media, which maybe unfavorable to some Nocardia species.…”

“…Different species may exhibit predilection to certain body sites. A few studies have reported the clinical features, epidemiology and antimicrobial resistance patterns of Nocardia species in China [6,[7][8][9][10][11], however, these reports harbored high degrees of variability.…”

Co-infection with Mycobacterium tuberculosis and Nocardia farcinica in a COPD patient: a case report

“…A patient with COPD may have increased susceptibility to opportunistic pathogens due to several reasons, such as changes in bronchial architecture, bacterial colonization of the lower airways, which alters ciliary motility and causes epithelial damage, the use of inhaled corticosteroid, which particularly damages the alveolar macrophages, frequent hospitalizations or antibiotic treatments, and comorbidities [ 5 , 8 ]. A literature search of the PubMed database with key terms Nocardia and tuberculosis, retrieved several cases on PN that were misdiagnosed as tuberculosis in COPD patients and cases of concurrent PN and tuberculosis in HIV patients, but co-infection with Nocardia and Mycobacterium tuberculosis in COPD patients was rarely reported [ 9 – 11 ]. The present casea was a rare case of co-infection with Nocardia and Mycobacterium tuberculosis in a COPD patient, without systemic immunosuppressive factors.…”

Co-Infektion mit Mycobacterium tuberculosisund Nocardia farcinica bei einer COPD-Patientin: ein Fallbericht

“…Veränderungen der bronchialen Struktur, eine bakterielle Besiedlung der unteren Atemwege, die die Ziliarmotilität verändert und Epithelschäden verursacht, die Verwendung von inhalativen Kortikosteroiden, die insbesondere die Alveolarmakrophagen schädigen, häufige Krankenhausaufenthalte oder Antibiotikabehandlungen und Begleiterkrankungen [5, 8]. Eine Literaturrecherche in der PubMed-Datenbank mit den Stichworten Nocardia und Tuberkulose ergab mehrere Fälle von PN, die fälschlicherweise als Tuberkulose bei COPD-Patienten diagnostiziert wurden, und Fälle von gleichzeitiger PN und Tuberkulose bei HIV-Patienten, aber eine Co-Infektion mit Nocardia und Mycobacterium tuberculosis bei COPD-Patienten wurde selten berichtet [9–11].…”