Bioaerosol sampling of patients with suspected pulmonary tuberculosis: a study protocol

Abstract

Background: Tuberculosis (TB) is transmitted in bioaerosols containing Mycobacterium tuberculosis (Mtb). Despite being central to ongoing TB transmission, no routine diagnostic assay exists to measure Mtb in bioaerosols. Furthermore, published studies of Mtb in bioaerosol samples have been limited to individuals with sputum-positive pulmonary TB. Notably, TB diagnosis is based on clinical symptoms and sputum laboratory findings. This is despite the fact that approximately half of all patients commencing TB treatment are sputum-negative, resulting in a high proportion of presumptive treatments. Here, we propose to use a sensitive air sampling protocol to investigate the prevalence of Mtb-containing bioaerosols in both sputum-positive and sputum-negative TB suspects, at the same time evaluating the potential to identify unrecognized transmitters of TB. Methods: Our parallel-group design will identify viable Mtb in bioaerosols produced by individuals attending a TB clinic in South Africa. Sampling will be performed on eligible individuals presenting with symptoms indicative of TB and repeated at 14 days if initially positive. Participants will be prospectively classified into three distinct groups based on National TB Control Program (NTBCP) criteria: Group A, TB notification with sputum-based laboratory confirmation; Group B, TB notification with empiric diagnosis; and Group C, individuals not notified. Group C individuals with detectable Mtb bioaerosol will be monitored until resolution of clinical and laboratory status. Collection of bioaerosol specimens will be via two consecutive sampling modalities: (1) direct sampling following a specific respiratory manoeuvre; and (2) indirect sampling during passive respiratory activity. Bioaerosol specimens will be analyzed for viable Mtb using DMN-trehalose staining and live-cell fluorescence microscopy. Mtb genomes and mycobacterial and host lipids will be detected using droplet digital PCR and mass spectrometry analyses, respectively. The primary objective is to determine the prevalence of Mtb bioaerosols in all TB clinic attendees and in each of the groups. Secondary objectives are to investigate differences in prevalence of Mtb bioaerosol by HIV status and current isoniazid preventive therapy (IPT) use; we will also determine the impact of anti-TB chemotherapy on Mtb-containing bioaerosol production. Discussion: Respiratory bioaerosol has a potential role in non-invasive TB diagnosis, infectivity measurement and treatment monitoring.

Capture and visualization of live Mycobacterium tuberculosis bacilli from tuberculosis patient bioaerosols

“…(ii) The bacillary counts and morphological phenotypes presented here are not augmented with clinical metadata (chest radiography scores, HIV status, etc.). Our intention in this study was to establish the technological platform for bioaerosol sample capture and analysis-as described in our recently published protocol [34], current and planned work involves the application of the RASC to carefully designed clinical cohorts. (iii) The criteria used to classify DMN-tre + organisms as "putative Mtb" are potentially restrictive, especially given that prevailing assumptions about the size and shape of clinical Mtb isolates are heavily influenced by the commonly applied staining methods (almost never supported by confirmatory molecular or microbiological data) as well as knowledge of Mtb morphology from growth in vitro in defined culture, in some cases in intracellular infection models or under applied stress conditions.…”

Rapid detection of airborne protein from Mycobacterium tuberculosis using a biosensor detection system

“…7 The mixture contained in breath is not as complicated as those in sputum, serum and urine, and can be used for screening, early auxiliary diagnosis and disease monitoring of TB. 8,9 It has been confirmed that there is cultivable MTB in the exhaled breath of TB patients and it is feasible and reproducible to collect exhaled breath for detection. 10 Collecting exhaled breath condensate (EBC) is a common method for exhaled breath sample collection.…”

Analysis of Deep Learning Techniques for Tuberculosis Disease

“…because it does not have to be delivered by medical professionals. In a sampling bag, users blow in and set the BAP with a breath-filled sampling bag and a disposable unit containing the purpose of biological detection of particulates by aerosol [8]. The BAP sample pack collection and the system detect all bioaerosol particles immediately in the sampling bag and indicates whether the patient's disease is favorable or not.…”