TB or not TB? Definitive determination of species within the Mycobacterium tuberculosis complex in unprocessed sputum from adults with presumed multidrug-resistant tuberculosis.

OBJECTIVES: Differences among Mycobacterium tuberculosis complex (MTC) species may predict drug resistance or treatment success. Thus, we optimised and deployed the genotype MTBC assay (gMTBC) to identify MTC to the species level, and then performed comparative genotypic drug-susceptibility testing to anti-tuberculosis drugs from direct sputum of patients with presumed multidrug-resistant tuberculosis (MDR-TB) by the MTBDRplus/sl reference method. METHODS: Patients with positive Xpert® MTB/RIF (Xpert) results were consented to provide early-morning-sputum for testing by the gMTBC and the reference MTBDRplus/sl. Chi-square or Fisher's exact test compared proportions. Modified Poisson regression modelled detection of MTC by gMTBC. RESULTS: Among 73 patients, 53 (73%) were male and had a mean age of 43 (95% CI; 40-45) years. In total, 34 (47%), 36 (49%) and 38 (55%) had positive gMTBC, culture and MTBDR respectively. Forty patients (55%) had low quantity MTC by Xpert, including 31 (78%) with a negative culture. gMTBC was more likely to be positive in patients with chest cavity 4.18 (1.31-13.32, P = 0.016), high-quantity MTC by Xpert 3.03 (1.35-6.82, P = 0.007) and sputum smear positivity 1.93 (1.19-3.14, P = 0.008). The accuracy of gMTBC in detecting MTC was 95% (95% CI; 86-98; κ = 0.89) compared to MTBDRplus/sl. All M. tuberculosis/canettii identified by gMTB were susceptible to fluoroquinolone and aminoglycosides/capreomycin. CONCLUSIONS: The concordance between the gMTBC assay and MTBDRplus/sl in detecting MTC was high but lagged behind the yield of Xpert MTB/RIF. All M. tuberculosis/canettii were susceptible to fluoroquinolones, a core drug in MDR-TB treatment regimens.

Performance assessment of SD Bioline TB MPT64 assay for the diagnosis of Mycobacterium tuberculosis complex in Lagos, Nigeria.

This study assessed the performance of SD Bioline MPT64 immunochromatographic test for the identification of Mycobacterium tuberculosis complex (MTBC) in Nigeria.A total of 157 mycobacterial isolates, comprising 120 (76.4%) MTBC (M. tuberculosis, 112; M. africanum, 5; M. bovis, 3) and 37 (23.6%) non-tuberculous mycobacteria (NTM) isolates from patients attending six DOTS centers in Lagos between June 2012 and July 2014 were analyzed. All the isolates were grown on Bactec MGIT960 liquid media and identified in parallel by the conventional method and MPT64 immunochromatographic test. Discrepant results were resolved using the line probe assay.The comorbid disease rates for HIV and type 2 diabetes were 20.9% and 8.2%, respectively. Compared to the conventional method, SD Bioline MPT64 identified 117 MTBC isolates correctly, producing a sensitivity of 97.5% (95% CI, 92.9-99.2) at a shorter growing median time of 11 days compared to 26 days by the conventional method. The three undetected MTBC were confirmed by the line probe assay to be M. tuberculosis strains. The test also identified all the NTM correctly producing a specificity of 100% (95% CI, 90.7-100).This study supports the integration of SD Bioline TB MPT64 antigen test into diagnostic workflow for rapid MTBC case identification in Nigeria.

Immunological and Haematological Relevance of Helminths and Mycobacterium tuberculosis Complex Coinfection among Newly Diagnosed Pulmonary Tuberculosis Patients from Bobo-Dioulasso, Burkina Faso.

The effect of helminthiasis on host immunity is a neglected area of research, particularly in tuberculosis (TB) infection. This study aimed to evaluate the effect of helminthiasis on immunological and haematological parameters in newly diagnosed TB patients in Bobo-Dioulasso. After all biological analyses, we formed three subpopulations: group 1 (n = 82), as control, were participants without helminthic or Mycobacterium tuberculosis complex infection (Mtb-/Helm-), group 2 (n = 73) were TB patients without helminthic infection (Mtb+/Helm-), and group 3 (n = 22) were TB patients with helminthic infection (Mtb+/Helm+). The proportion of helminth coinfection was 23.16% (22/95) in TB patients, and Schistosoma mansoni infection was found in 77.3% (17/22) cases of helminthiasis observed in this study. A low CD4 T cell count and a low CD4:CD8 ratio were significantly associated with concomitant infection with helminths and the Mtb complex (Mtb+/Helm+) compared to the other groups (p < 0.05). However, there was no statistically significant difference in the CD8 median among the three participating groups (p > 0.05). Lymphopenia, monocytosis, thrombocytosis, and hypochromic microcytic anaemia were the haematological defects observed in the Mtb+/Helm+ and Mtb+/Helm- patients. Exploring these types of immune-haematological biomarkers would be a valuable aid in diagnosing and a better follow-up and monitoring of the tuberculosis-helminthiasis coinfection.

Use of Whole Genome Sequencing for Mycobacterium tuberculosis Complex Antimicrobial Susceptibility Testing: From Sequence Data to Resistance Profiles.

Whole genome sequencing of Mycobacterium tuberculosis complex (MTBC) isolates has been shown to provide accurate predictions for resistance and susceptibility for many first- and second-line anti-tuberculosis drugs. However, bioinformatic pipelines and mutation catalogs to predict antimicrobial resistances in MTBC isolates are often customized and detailed protocols are difficult to access. Here, we provide a step-by-step workflow for the processing and interpretation of short-read sequencing data and give an overview of available analysis pipelines.

Specific identification of Mycobacterium bovis by Loop-Mediated Isothermal Amplification (LAMP) targeting the Region of Difference 12 (RD12) of the M. tuberculosis complex.

Bovine tuberculosis is a prevalent zoonotic disease that causes high risks for production animals, dairy producers and consumers, together with significant economic losses. Thus, methods for easy, fast and specific detection of Mycobacterium bovis in small and medium-sized livestock under field conditions are very required. In this work, a Loop-Mediated Isothermal Amplification LAMP-PCR targeting the Region of Difference 12 (RD12) of M. bovis genome was designed for the purpose of identification. A set of six primers designed for the isothermal amplification of five different genomic fragments led to the specific identification of M. bovis from other mycobacterial species. A basic colorimetric reaction was clearly observed at first sight under natural light, indicating positive identification of M. bovis in a maximum of 30 min of isothermal amplification at 65 °C. The limit of detection was near 50 fg of M. bovis genomic DNA, corresponding approximately to 10 copies of the genome. •The proposed LAMP-PCR amplification of M. bovis genomic DNA might be performed by untrained laboratory personnel.•Specific identification of M. bovis LAMP is possible in 30 min at 65.. C using a simple water bath.•The basic colorimetric reaction for M. bovis identification could be observed with the naked eye under natural light.

Molecular epidemiology of tuberculosis in the Somali region, eastern Ethiopia.

Background: Tuberculosis (TB) is one of the leading causes of morbidity and mortality in low-income countries like Ethiopia. However, because of the limited laboratory infrastructure there is a shortage of comprehensive data on the genotypes of clinical isolates of Mycobacterium tuberculosis (M. tuberculosis) complex (MTBC) in peripheral regions of Ethiopia. The objective of this study was to characterize MTBC isolates in the Somali region of eastern Ethiopia. Methods: A cross-sectional study was conducted in three health institutions between October 2018 and December 2019 in the capital of Somali region. A total of 323 MTBC isolates (249 from pulmonary TB and 74 from extrapulmonary TB) were analyzed using regions of difference 9 (RD 9)-based polymerase chain reaction (PCR) and spoligotyping. Results: Of the 323 MTBC isolates, 99.7% (95% CI: 99.1-100%) were M. tuberculosis while the remaining one isolate was M. bovis based on RD 9-based PCR. Spoligotyping identified 71 spoligotype patterns; 61 shared types and 10 orphans. A majority of the isolates were grouped in shared types while the remaining grouped in orphans. The M. tuberculosis lineages identified in this study were lineage 1, 2, 3, 4, and 7 with the percentages of 7.4, 2.2, 28.2, 60.4, and 0.6%, respectively. Most (87.9%) of the isolates were classified in clustered spoligotypes while the remaining 12.1% isolates were singletons. The predominant clustered spoligotypes identified were SIT 149, SIT 21, SIT 26, SIT 53, and SIT 52, each consisting of 17.6, 13.3, 8.4, 7.4, and 5%, respectively. Lineage 3 and lineage 4, as well as the age group (15-24), were associated significantly with clustering. Conclusion: The MTBC isolated from TB patients in Somali region were highly diverse, with considerable spoligotype clustering which suggests active TB transmission. In addition, the Beijing spoligotype was isolated in relatively higher frequency than the frequencies of its isolation from the other regions of Ethiopia warranting the attention of the TB Control Program of the Somali region.

In Vitro Antimycobacterial Activity of Human Lactoferrin-Derived Peptide, D-hLF 1-11, against Susceptible and Drug-Resistant Mycobacterium tuberculosis and Its Synergistic Effect with Rifampicin.

Tuberculosis is a highly contagious disease caused by the Mycobacterium tuberculosis complex (MTBC). Although TB is treatable, multidrug-resistant, extensively drug-resistant, and totally drug-resistant forms of M. tuberculosis have become a new life-threatening concern. New anti-TB drugs that are capable of curing these drug-resistant strains are urgently needed. The purpose of this study is to determine the antimycobacterial activity of D-enantiomer human lactoferricin 1-11 (D-hLF 1-11) against mycobacteria in vitro using a 3-(4,5-dimethylthiazol-2-yl)-2,5-dephenyltetrazolium bromide colorimetric assay, resazurin microplate assay, and microscopic observation drug susceptibility assay. Three previously described antimicrobial peptides, protegrin-1, AK 15-6, and melittin, with potent anti-TB activity, were included in this study. The findings suggest that D-hLF 1-11 can inhibit the growth of M. tuberculosis with a minimum inhibitory concentration of 100−200 µg/mL in susceptible, isoniazid (INH)-monoresistant, rifampicin (RF)-monoresistant, and MDR strains. The peptide can also inhibit some nontuberculous mycobacteria and other MTBC in similar concentrations. The antibiofilm activity of D-hLF 1-11 against the biofilm-forming M. abscessus was determined by crystal violet staining, and no significant difference is observed between the treated and untreated biofilm control. The checkerboard assay was subsequently carried out with M. tuberculosis H37Rv and the results indicate that D-hLF 1-11 displays an additive effect when combined with INH and a synergistic effect when combined with RF, with fractional inhibitory concentration indices of 0.730 and 0.312, respectively. The red blood cell hemolytic assay was initially applied for the toxicity determination of D-hLF 1-11, and negligible hemolysis (<1%) was observed, despite a concentration of up to 4 mg/mL being evaluated. Overall, D-hLF 1-11 has potential as a novel antimycobacterial agent for the future treatment of drug-sensitive and drug-resistant M. tuberculosis infections.

Identification of the Mycobacterial Strains Isolated From Clinical Specimens Using hsp65 PCR-RFLP Method.

OBJECTIVES: It is important to identify mycobacteria at the species level, to distinguish pathogen from non-pathogenic species, to choose the appropriate treatment regimen and to collect epidemiological data. For the identification of mycobacteria, which are time-consuming and laborious with traditional methods, faster, more sensitive and reliable methods are needed. This study aims to investigate the suitability of the hsp65 Polymerase chain reaction-restriction fragment polymorphism (PCR-RFLP) method for routine laboratory use. METHODS: In this study, 141 mycobacterial isolates were obtained from 1632 samples, which were sent to the Medical Microbiology Laboratory. RESULTS: In the culture, mycobacteria were identified as 138 M. tuberculosis complex (MTBC) and three non-tuberculosis mycobacteria (NTM) by conventional methods. Using the hsp65 PCR-RFLP method, 137 isolates were identified as MTBC, four isolates as NTM. An isolate that was evaluated as MTBC because it was PNB sensitive by the conventional method was determined as NTM with the hsp65 method. In the identification of non-tuberculosis mycobacteria with the hsp65 PCR-RFLP method, one isolate was identified as M. abcessus and three isolates were identified as M. avium complex. CONCLUSION: In our study, it was concluded that the hsp65 PCR-RFLP method, which allows identification of mycobacteria, including NTMs, is a method that is cheap, easy and suitable for routine use to provide rapid information to the clinic. The scope of the agar and database used in the method is effective in the definition of the correct species.

Oldest evidence of tuberculosis in Argentina: A multidisciplinary investigation in an adult male skeleton from Saujil, Tinogasta, Catamarca (905-1030 CE).

The Mycobacterium tuberculosis complex (MTC) has affected South American populations since ca. 200 years BCE. In Argentina, possible cases date from ca. 1000-1400 Common Era (CE). This paper describes the oldest (905-1030 CE) confirmed case of tuberculosis (TB) in a young adult male from Lomitas de Saujil (Tinogasta, Catamarca, Argentina). Osteolytic lesions on the bodies of the lower spine were macroscopically and radiographically identified. Bilateral new bone formation was seen on the visceral vertebral third of several ribs and in long bones, compatible with hypertrophic osteoarthropathy. Representative rib and hand bones gave profiles for MTC-specific C27-C32 mycocerosic acid lipid biomarkers; these were strongest in one heavily-lesioned lower rib, which also had MTC-diagnostic C76-C89 mycolic acids and positive amplification of MTC-typical IS6110 aDNA fragments. During the first millennium CE, the intense social interaction, the spatial circumscription of villages among the pre-Hispanic societies in the mesothermal valleys of Catamarca and the fluid contacts with the Eastern lowlands, valleys and puna, were factors likely to favor disease transmission. It is proposed that TB arrived from northern Chile and dispersed towards the northeast into the Yocavil valley, where several cases of TB infection were macroscopically identified for a later chronology.

In vitro Antimycobacterial, Apoptosis-Inducing Potential, and Immunomodulatory Activity of Some Rubiaceae Species.

Tuberculosis (TB), a disease caused by microorganisms of the Mycobacterium tuberculosis complex, infects almost one-third of the world's population. The TB epidemic has been further exacerbated by the emergence of multi, extensively, and totally-drug-resistant (MDR, XDR, and TDRTB) strains. An effective immune response plays a crucial role in determining the establishment of TB infection. Therefore, the modulation of the immune system has been considered as a vital approach for the treatment or control of various immune-related diseases such as TB. In this study, the antimycobacterial, immunomodulatory, and apoptosis-inducing effects of six Rubiaceae species were evaluated. A twofold serial dilution method was used to determine the minimum inhibitory concentration values of the plant extracts. The effect of the extracts on the activity of 15-lipoxygenase was investigated. The levels of six different cytokines, IL-2, IL-4, IL-5, IL-10, IFN-γ, and TNF-α, were measured in LPS-activated U937 cell line while the apoptosis-inducing effect of the extracts was evaluated using an annexin V/PI assay using a flow cytometer. The results obtained revealed that all the six extracts tested had antimycobacterial activity against M. tuberculosis H37Rv, M. tuberculosis ATCC 25177, and Mycobacterium bovis ATCC 27299 strains, with MIC values ranging from 39 to 312 µg/mL. The extracts of Cremaspora triflora and Cephalanthus natalensis were the most active against M. tuberculosis (MIC = 39 µg/mL), followed by Pavetta lanceolata and Psychotria zombamontana against M. bovis (MIC = 78 µg/mL). The extracts of P. zombamontana and Psychotria capensis had remarkable IC50 values of 4.32 and 5.8 µg/mL, respectively, better than that of quercetin. The selected extracts promoted Th1/Th2 balances in an in vitro model at the tested concentration which may suggest the therapeutic value of the plant in diseases where inflammation is a significant factor such as TB. The addition of the crude extracts of C. triflora, P. capensis, and P. zombamontana at the tested concentrations to the cell culture medium induced apoptosis in a time- and dose-dependent manner. This interesting preliminary result generated from this study encourages further investigations of these extracts owing to the LOX-inhibitory effect, immunomodulatory, and apoptotic-inducing properties in addition to their antimycobacterial properties.

Recent technological advancements in tuberculosis diagnostics - A review.

Early diagnosis and on-time effective treatment are indispensable for Tuberculosis (TB) control - a life threatening infectious communicable disease. The conventional techniques for diagnosing TB normally take two to three weeks. This delay in diagnosis and further increase in detection complexity due to the emerging risks of XDR-TB (Extensively drug Resistant-TB) and MDR-TB (Multidrug Resistant-TB) are evoking interest of researchers in the field of developing rapid TB detection techniques such as biosensing and other point-of-care (POC) techniques. Biosensing technologies along with the collaboration with nanotechnology have enormous potential to boost the MTB detection and for overall management in clinical diagnosis. A diverse range of portable, sensitive and rapid biosensors based on different signal transducer principles and with different biomarkers detection capabilities have been developed for TB detection in the early stages. Further, a lot of progress has been achieved over the years in developing various point-of-care diagnostic tools including non-molecular methods and molecular techniques. The objective of this study is to present a succinct review of the available TB detection techniques that are either in use or under development. The focus of this review is on the current developments occurred in nano-biosensing technologies. A synopsis of ameliorations in different non-molecular diagnostic tools and progress in the field of molecular techniques along with the role of emerging Lab-on-Chip technology for diagnosing and mitigating the TB consequences have also been presented.

Utility of MPT64 Antigen Detection for Rapid Confirmation of Mycobacterium tuberculosis Complex.

BACKGROUND: Rapid differentiation of the Mycobacterium tuberculosis complex (MTBC) and mycobacteria other than tuberculosis (MOTT) is crucial to facilitate early and effective treatment of the patients. Clinical presentation of MTBC and MOTT is not always very clear and routine conventional methods are time consuming. MATERIALS AND METHODS: In the present study, the MPT64 protein detection-based immunochomatographic test (SD Bioline Kit, Standard Diagnostics, Inc., Korea) was compared with the conventional biochemical method. RESULTS: The sensitivity, specificity, positive predictive, and negative predictive values of the SD AgMPT64 kit were found to be 100, 96.4, 98.72, and 100%, respectively. CONCLUSIONS: Our results have demonstrated that the SD bioline kit is a rapid, reliable method and it can be used in the Revised National Tuberculosis Control Program (RNTCP) of India, for the appropriate management of tuberculosis.

Rapid Immunochromatographic Test for the Identification and Discrimination of Mycobacterium tuberculosis Complex Isolates from Non-tuberculous Mycobacteria.

BACKGROUND: A new rapid Immunochromatographic test (ICT) kit (SDBioline TB Ag MPT64RAPID(®)) developed by Standard Diagnostics, South Korea was evaluated for rapid differentiation of M. tuberculosis from non tuberculous mycobacteria (NTM). It detects MPT 64 antigen in M. tuberculosis isolates using mouse monoclonal MPT 64 antibody. The kit was assessed for routine identification of the Acid Fast Bacilli(AFB) isolated in our laboratory. MATERIALS AND METHODS: Two hundred eight culture isolates of Mycobacteria were tested using ICT test kit for detection of MPT 64 antigen from liquid and solid culture. H37Rv strain was employed as the positive reference control. Any negative result was referred for confirmation by Gen Probe Accu Probe assay for MTB Complex (Gen-Probe, San Diego, Calif.). Speciation of NTM was performed using genotypic Mycobacterium CM assay (Hain's life sciences, Germany). RESULTS: Of the 208 culture positive isolates tested, 182 (87.5%) were found positive for Mycobacterium tuberculosis Complex and remaining 26 (12.5%) were considered as NTM. These results were further confirmed by Gen Probe Accu probe assay that served as the reference method for detection of MTBC. H37Rv reference strain was taken as a control for ICT test and molecular tests. The reference strain showed the presence of MPT64 antigen band in the ICT test. Similar bands were formed in all MTBC (182) isolates tested, proving 100 per cent sensitivity and no bands were detected in 48 (100%) NTM isolates tested, proving 100 per cent specificity of the ICT kit. CONCLUSION: Tuberculosis is a global pandemic. Rapid identification of Mycobacteria as MTB complex or non-tuberculous Mycobacteria from culture is important for treatment of infected cases and drug susceptibility testing of the culture isolate. MPT 64 TB antgen detection using SD Bioline Immunochromatographic test is a simple and cost effective method for differentiation of Mycobacterial cultures as MTB complex from non- tuberculous Mycobacteria.

A simple and efficient multiplex PCR assay for the identification of Mycobacterium genus and Mycobacterium tuberculosis complex to the species level.

PURPOSE: The Mycobacterium tuberculosis complex comprises M. tuberculosis, M. bovis, M. bovis bacillus Calmette-Guérin (BCG) and M. africanum, and causes tuberculosis in humans and animals. Identification of Mycobacterium spp. and M. tuberculosis complex to the species level is important for practical use in microbiological laboratories, in addition to optimal treatment and public health. MATERIALS AND METHODS: A novel multiplex PCR assay targeting a conserved rpoB sequence in Mycobacteria spp., as well as regions of difference (RD) 1 and RD8, was developed and evaluated using 37 reference strains and 178 clinical isolates. RESULTS: All mycobacterial strains produced a 518-bp product (rpoB), while other bacteria produced no product. Virulent M. tuberculosis complex strains, M. tuberculosis, M. bovis and M. africanum, produced a 254-bp product (RD1), while M. bovis BCG, M. microti and nontuberculous mycobacteria produced no RD1 region product. Additionally, M. tuberculosis and M. africanum produced a 150-bp product (RD8), while M. bovis and M. bovis BCG produced a 360-bp product (deleted form of RD8). M. microti and nontuberculous mycobacteria produced no RD8 region product. This assay identified all Mycobacterium spp. and all M. tuberculosis complex strains to the species level. CONCLUSION: The multiplex PCR assay of the present study could be implemented as a routine test in microbiology laboratories, and may contribute to more effective treatment and surveillance of tuberculosis stemming from the M. tuberculosis complex.

Role of GenoType(®) Mycobacterium Common Mycobacteria/Additional Species Assay for Rapid Differentiation Between Mycobacterium tuberculosis Complex and Different Species of Non-Tuberculous Mycobacteria.

BACKGROUND: Mycobacterium tuberculosis complex (MTBC) and non-tuberculous mycobacteria (NTM) may or may not have same clinical presentations, but the treatment regimens are always different. Laboratory differentiation between MTBC and NTM by routine methods are time consuming and cumbersome to perform. We have evaluated the role of GenoType(®) Mycobacterium common mycobacteria/additional species (CM/AS) assay for differentiation between MTBC and different species of NTM in clinical isolates from tuberculosis (TB) cases. MATERIALS AND METHODS: A total of 1080 clinical specimens were collected from January 2010 to June 2012. Diagnosis was performed by Ziehl-Neelsen staining followed by culture in BacT/ALERT 3D system (bioMerieux, France). A total of 219 culture positive clinical isolates (BacT/ALERT(®) MP cultures) were selected for differentiation by p-nitrobenzoic acid (PNB) sensitivity test as and BIO-LINE SD Ag MPT64 TB test considering as the gold standard test. Final identification and differentiation between MTBC and different species of NTM were further confirmed by GenoType(®) Mycobacterium CM/AS assay (Hain Lifescience, Nehren, Germany). RESULTS: Out of 219 BacT/ALERT(®) MP culture positive isolates tested by PNB as 153 MTBC (69.9%) and by GenoType(®) Mycobacterium CM/AS assay as 159 (72.6%) MTBC and remaining 60 (27.4%) were considered as NTM species. The GenoType(®) Mycobacterium CM/AS assay was proved 99.3% sensitive and 98.3% specific for rapid differentiation of MTBC and NTM. The most common NTM species were; Mycobacterium fortuitum 20 (33.3%) among rapid growing mycobacteria and Mycobacterium intracellulare 11 (18.3%) among slow growing mycobacteria. CONCLUSION: The GenoType(®) Mycobacterium assay makes rapid and accurate identification of NTM species as compared with different phenotypic and molecular diagnostic tool and helps in management of infections caused by different mycobacteria.

Identification of Mycobacterium tuberculosis complex by polymerase chain reaction of Exact Tandem Repeat-D fragment from mycobacterial cultures.

This study evaluated an in-house polymerase chain reaction (PCR) for rapid identification of the Mycobacterium tuberculosis complex (MTBC) using the MTBC-specific Exact Tandem Repeat D (ETR-D) as the amplification target. In a prospective study, 801 clinical isolates identified as MTBC and 15 nontuberculous mycobacteria were analyzed. Mycobacterial DNA was extracted from automated broth cultures or from egg-based media. The amplification of the ETR-D showed to a sensitivity of 99.6% and a specificity of 100% for the correct identification of MTBC; improved extractions protocols led to 100% sensitivity. The main utility of this technique is the simplicity, rapidity, low cost and accuracy.