Rapid culture-based diagnosis of pulmonary tuberculosis in developed and developing countries

Abstract

Culturing Mycobacterium tuberculosis remains the gold standard for the laboratory diagnosis of pulmonary tuberculosis, with 9 million new cases and 1.5 million deaths mainly in developing countries. Reviewing data reported over 20 years yields a state-of-the-art procedure for the routine culture of M. tuberculosis in both developed and developing countries. Useful specimens include sputum, induced sputum, and stools collected in quaternary ammonium preservative-containing sterile cans. The usefulness of other non-invasive specimens remains to be evaluated. Specimens can be collected in a diagnosis kit also containing sampling materials, instructions, laboratory requests, and informed consent. Automated direct LED fluorescence microscopy after auramine staining precedes inoculation of an egg-lecithin-containing culture solid medium under microaerophilic atmosphere, inverted microscope reading or scanning video-imaging detection of colonies and colonies identification by recent molecular methods. This procedure should result in a diagnosis of pulmonary tuberculosis as fast as 5 days. It may be implemented in both developed and developing countries with automated steps replaceable by manual steps depending on local resources.

Resuscitation-promoting factors are important determinants of the pathophysiology inMycobacterium tuberculosisinfection

“…It enables drug susceptibility testing, typing for outbreak investigations and advanced "omic" studies (Asmar & Drancourt, 2015;Hayer et al, 2013;Ryu, 2015). Despite advances in the molecular detection of Mtb, culture remains the gold standard for diagnosis (Asmar & Drancourt, 2015).…”

“…Despite advances in the molecular detection of Mtb, culture remains the gold standard for diagnosis (Asmar & Drancourt, 2015). It is more sensitive and is unencumbered by dead bacilli (Asmar & Drancourt, 2015). Nevertheless, culture sensitivity can be low, particularly for extrapulmonary samples (Sandgren et al, 2013), so improving culture performance would have undoubted clinical benefits.…”

Mycobacteria fecal shedding in wild boars (Sus scrofa), South-eastern France

“…The lymph nodes are the most frequently used sample for the research of mycobacteria in animals 17–19 but this invasive sampling made by well trained staff, is almost limited to dead animals. Therefore, the analysis of feces is an emerging method in wild animals 13,20–22 on the model of what has been reported for the routine diagnosis in human patients 23 .…”

Rapid method for detecting and differentiating Mycobacterium tuberculosis complex and non-tuberculous mycobacteria in sputum by fluorescence in situ hybridization with DNA probes

“…However, AFB staining methods do not easily differentiate between Mycobacterium species and the closely related Nocardia species, which may also be found in respiratory samples. The correct identification of mycobacteria from sputumderived cultures at the species level in resource-limited tuberculosis-endemic settings relies on the observation of colony characteristics and additional biochemical, immunological, or molecular biological tests (Asmar and Drancourt, 2015;Pai and Schito, 2015;UNITAID, 2016). Culture-based identification, however, requires good quality sputum samples and is time-consuming, because it requires 2-6 weeks to produce results and is laborintensive.…”