Mycobacterium Tuberculosis Complex Research Articles

Optimal incubation duration of liquid cultures for assessing culture negative conversion in patients with Mycobacterium avium complex and Mycobacterium abscessus pulmonary diseases.

Mycobacterial liquid culturing typically requires six weeks or longer, primarily because of the slow growth rate of Mycobacterium tuberculosis. This study aimed to evaluate the potential of shortening the duration of mycobacterial liquid culturing in healthcare settings with high prevalence rates of non-tuberculous mycobacteria. We retrospectively analyzed the relationship between mycobacterial species and time to positive testing of liquid cultures from sputum samples using the Mycobacteria Growth Indicator Tube system over a 3.5-year period beginning in July 2020 at a university hospital in Japan. We analyzed 15,147 sputum culture samples and found a 1.1% positivity rate for Mycobacterium tuberculosis complex, while the rates for Mycobacterium avium complex and Mycobacterium abscessus were 17.6% and 2.1%, respectively. The median time to positivity was 17 days for Mycobacterium tuberculosis complex, 9 days for Mycobacterium avium complex, and 4 days for Mycobacterium abscessus. Comparing a 4-week culture period with an eight-week period, the positivity rates for Mycobacterium avium complex and Mycobacterium abscessus were 97.0% and 99.4%, respectively. In settings with a high incidence of non-tuberculous mycobacteria, the basic liquid culturing period can be safely shortened to 4 weeks without significantly compromising detection sensitivity, except for the samples that are highly suspected to contain tuberculosis, extremely slow-growing mycobacteria, smear-positive, or nucleic acid amplification testing positive.

A histopathological study in road-killed European badgers (Meles meles) from the English midlands with isolation of novel non-tuberculous atypical mycobacteria

European badgers (Meles meles) play an important role in the epidemiology of bovine tuberculosis (caused by Mycobacterium bovis) in England, but little is known about the prevalence of atypical mycobacteriosis. Badgers are also known to be infected by other infectious agents, and the relationship between mycobacteriosis and concomitant infections needs further investigation. Overall, 88 badger carcasses from the Midlands of England collected between July 2016-August 2017 were selected for histopathological examination based on the degree of autolysis (mild), mycobacterial culture results and a balanced sex ratio. Mycobacteria were cultured from 44 badgers, of which 31 were mycobacteria belonging to the M. tuberculosis complex (MTBC) (based on IS6110 PCR and Hsp64 and/or rRNA PCR and sequencing) and 13 were non-tuberculous atypical mycobacteria (NTM). Mycobacteria were not cultured from the remaining 44 animals. Histologically, the most common findings were silica-laden macrophages (85%), granulomas (53%), sarcocystosis (47%), nephritis (31%), portal/periportal hepatitis (26%), ulcerative dermatitis (18%). Culturable mycobacteriosis was associated with higher prevalence of granulomas (p < 0.001) and lower prevalence of hepatitis (p = 0.003). NTM (M. nonchromogenicum, M. avium complex, M. hassiacum, M. malmoense, M. vaccae.) infections were associated with granulomatous pneumonia, and M. malmoense was associated with pyogranulomatous and ulcerative dermatitis. In conclusion, this study describes, for the first time, histological lesions associated with NTM in badgers, the histomorphology of which was similar to those caused by MTBC. In addition, the negative relationship between mycobacteriosis and periportal hepatitis may indicate a complex relationship between mycobacteriosis and other diseases, as previously observed with tuberculosis.

Challenges in diagnosing bovine tuberculosis through surveillance and characterization of Mycobacterium species in slaughtered cattle in Kolkata

BackgroundTuberculosis in cattle is caused by Mycobacterium tuberculosis complex (MTBC) species. Apart from MTBC, different Nontuberculous Mycobacteria (NTM) species have also been isolated from cattle. The presence of NTM infection in bovines makes the diagnosis of bovine tuberculosis (bTB) a cumbersome task. Therefore, a cross sectional study was conducted to isolate and characterize different Mycobacterium spp. from a slaughterhouse situated in Kolkata, a city in the eastern part of India.ResultsOut of 258 morbid samples, 98 isolates were found to be positive for bacterial growth, and 35% (n = 34) were positive for Mycobacterium. 94% of Mycobacterial cultural isolates were NTM (n = 32), and the rest (n = 2) were found to be MTBC. Species-level identification of the isolates by hsp65 sequencing revealed that out of 32 isolates, 24 were M. fortuitum, three were M. abscessus, two each were M. chelonae and M. parascrofulaceum, and one was M. novocastrense. A phylogenetic tree with partial hsp65 gene sequences was also constructed to determine the relatedness of the unknown isolates to the reference strains.ConclusionBoth NTM species and MTBCs were identified from TB-like lesions in cattle that were slaughtered at the Kolkata abattoir. This discovery may indicate that NTM contributes to the development of lesions in cattle. Also, we recommend implication of more specific diagnostic tests for bTB.

Detection of Mycobacterium bovis in Free-Ranging Sapajus nigritus, Argentina.

Mycobacterium bovis and Mycobacterium tuberculosis are the most relevant among pathogenic mycobacteria, both belonging to the M. tuberculosis complex (MTC). Samples of blood, liver, spleen, kidneys, lungs and caseous tubercles were collected from a free-ranging juvenile black capuchin monkey (Sapajus nigritus) showing non-specific signs of illness. Macroscopic findings included emaciation, a caseous lesion in a tooth and gingiva, disseminated nodules in both lungs and left kidney parenchyma and caseous nodules on the pleura and mesentery. The lesions suggested MTC infection, a diagnosis subsequently supported in the lung by bacilloscopy, immunochromatography and PCR. A multiplex PCR further validated the presence of M. bovis genes. Cases of tuberculosis in platyrrhine primates have only been reported in animals maintained in captivity. We describe for the first time the pathological and molecular findings of M. bovis infection in a free-ranging platyrrhine monkey within an area of intense human-wildlife interaction, which has important implications from a One Health perspective.

Red herrings and zebras and TB, oh my! Unexpected bone marrow presentation of Mycobacterium tuberculosis

Abstract Introduction/Objective Epithelioid granulomas are uncommon and non-specific findings in bone marrow samples, and should prompt additional testing for appropriate diagnosis and treatment, especially in the immunocompromised patient. The differential diagnosis for bone marrow granulomas includes infections, neoplasia, autoimmune disease, sarcoidosis, and drug/therapy reaction. Although bone marrow workup to delineate the cause of granulomas should include staining to rule out both infection and lymphoma, morphologic review is often inconclusive. Final diagnosis requires clinical consultation and additional testing. Methods/Case Report A 76-year-old male was admitted to the hospital from the emergency department for a level 2 trauma after being found on the ground ~3 hours after a fall. The patient reported a recent increasing frequency of falls with associated weakness, as well as an almost 30 lb weight loss over the last 3.5 months and low grade fevers over several weeks. His past medical history was significant for treatment for urothelial carcinoma with transurethral resection and BCG therapy, hypertension, coronary artery disease, and peripheral vascular disease. Imaging showed hepatosplenomgaly, suspicious for early cirrhosis, and mild peripancreatic lymphadenopathy. Initial laboratory abnormalities demonstrated mild anemia, low albumin, and mild increase in ALT, AST, and alkaline phosphotase. Initial Infectious Diseases workup was negative for causative etiology (blood cultures, tick-borne parasites, and respiratory pathogens). Patient symptoms did not improve and cytopenias worsened. A bone marrow biopsy showed multiple non-necrotizing epithelioid granulomas. Despite low clinical concern for infectious etiology, mycobacteria blood culture isolated Mycobacterium tuberculosis complex. Final results were available 112 days after specimen collection. Results (if a Case Study enter NA) NA Conclusion Although tuberculosis is commonly associated with granulomatous pathology, infection is very uncommon in North American patients who have not traveled and alternative diagnoses might initially be favored. A high suspicion for mycobacterial infections is essential for diagnosis even in low-incidence populations with no known exposure or risk factor(s).

APERFEIÇOAMENTO SOBRE O RASTREIO DA TUBERCULOSE PARA OS AGENTES COMUNITÁRIOS DE SAÚDE DA ESTRATÉGIA DE SAÚDE DA FAMÍLIA DO NASCENTE I E II EM ARARIPINA-PE.

Tuberculosis (TB), a disease formerly described as typhus, was known in the 19th century as the white plague, decimating hundreds of thousands of people around the world. TB can be caused by any of the seven species that make up the Mycobacterium tuberculosis complex: M. tuberculosis, M. bovis, M. africanum, M. canetti, M. microti, M. pinnipedi and M. caprae. M. tuberculosis is transmitted by air, from a person with pulmonary or laryngeal TB, who eliminates bacilli in the environment (source case), to another person, by inhaling aerosols from coughing, talking or sneezing. Primary pulmonary TB usually occurs after the individual's first contact with the bacillus and is therefore more common in children. Its main characteristic is a dry or productive cough. Evening fever, without chills, does not usually exceed 38.5ºC. Night sweats and anorexia are common. Tuberculosis is a serious disease, but it is curable in the vast majority of cases, as long as the treatment is followed correctly. In Brazil, treatment is standardized and free of charge, provided by the National Tuberculosis Control Program (PNCT) in Health Units. In Brazil, tuberculosis treatment is standardized and consists of two phases: intensive and maintenance. The basic regimen recommended by the Ministry of Health (BRASIL, 2019) for adults and adolescents aged 10 and over includes rifampicin, isoniazid, pyrazinamide and ethambutol (RHZE). Directly Observed Treatment (DOT) is a fundamental strategy for ensuring patient adherence to tuberculosis treatment and reducing abandonment rates. Adopted by the Ministry of Health (MoH) based on WHO recommendations, DOT consists of direct observation of drug intake by health professionals. Community health workers (CHWs) are essential for tuberculosis control, from diagnosis to the outcome of cases. Their duties include Spreading the word to their community about tuberculosis as an important current public health problem. Educate the population about airborne transmission of tuberculosis and the preventive measures that can be adopted. To be aware of the main symptoms of tuberculosis (cough, fever, weight loss and night sweats) at all meetings with the community, as well as publicizing them, and referring suspected cases to the health unit.

Rifampicin-resistant Mycobacterium tuberculosis complex in Niger: A 5-year retrospective analysis (2017–2022)

Rifampicin-resistant Mycobacterium tuberculosis complex in Niger: A 5-year retrospective analysis (2017–2022)

Mycobacterium tuberculosis complex sample processing by mechanical lysis, an essential step for reliable whole genome sequencing

Mycobacterium tuberculosis complex (MTBC) whole genome sequencing (WGS) turnaround time and WGS success rates are highly influenced by DNA extraction protocols even from cultures. Efficient mycobacterial lysis is crucial for obtaining sufficient DNA from cultures to facilitate reliable genomic drug susceptibility prediction and accurate genotyping with WGS. We compared four DNA extraction protocols from BD BACTEC™ Mycobacterial Growth Indicator Tubes (MGIT) for WGS with a focus on the lysis step: protocol A) column-based protocol without mechanical lysis; protocol B) an adapted protocol including a bead beating step; protocol C) DNA extraction from primary received cultures using bead beating: and protocol D) DNA extraction from pre MGIT-positive (enriched) cultures. Protocol B increased DNA yield approximately 60-fold, and significantly improved the sequencing success rate. The increased yield also allowed DNA extraction from primary cultures with high success rates (protocol C). Additionally, by using pre-positive enriched MGIT cultures, we demonstrated that bead beating opens the possibility of reliable WGS up to five days before a MGIT tube would be flagged positive (protocol D). The most optimal bead beating-based DNA extraction was also evaluated for Nanopore sequencing. Shortening bead beating duration to 15 s resulted in longer read lengths (N50 from 1.4 kb to 2.6 kb) while still providing efficient lysis. Furthermore, AmpureXP bead beating-based DNA capture / purification proved to be as efficient as Qiagen column-based DNA extraction, further simplifying and shortening the DNA extraction protocol. Adding a mechanical lysis step to our routine MTBC DNA extraction protocol has allowed us to reduce the turnaround time while maintaining DNA quality sequencing success rates.

Bovine tuberculosis in Central Ethiopian slaughterhouses and the identification of causative mycobacteria by multiplex real-time PCR

BackgroundBovine tuberculosis (bTB) is a chronic disease caused by members of the Mycobacterium tuberculosis complex (MTBC) that ultimately leads to the development of progressive granulomatous lesions. Although the disease is widespread, especially in crossbred cattle in Ethiopia, routine investigations and surveillance are lacking. Thus, the aim of this study was to determine the prevalence, associated risk factors, and species of mycobacteria causing bTB in slaughtered cattle at four slaughterhouses in Central Ethiopia.MethodsPostmortem examination of 7,640 cattle was conducted using a cross-sectional slaughterhouse survey. A total of 388 tuberculous-like lesions (TBLs) were collected from 173 animals and cultured. Six target genes were used to differentiate mycobacterial species using multiplex real-time PCR (mRT-PCR). Multivariate logistic regression analyses and related odds ratios (ORs) were used to gauge the strength of the associations between risk factors, TBL incidence and culture growth.ResultsThe prevalence of TBL was 2.3% (95% CI = 2.0-2.6). Logistic regression analysis indicated an increased risk of TBL in crossbred cattle (OR = 11.8, 95% CI: 6.4, 21.2, p < 0.001). Animals slaughtered at Adama (OR = 3.2, 95% CI: 1.2, 7.3, p = 0.009) or Burayu (OR = 5.8, 95% CI: 3.9, 8.9, p < 0.001) had a greater risk of TBL than those slaughtered at Sululta. There were significantly more TBL-positive lesions in the lungs and lymph nodes related to the lung (OR = 7.1; 95% CI: 2.7, 24.5, p < 0.001) and the head lymph node (OR = 5.6; 95% CI: 1.8, 21.7; p = 0.006) compared to gut associated lymph nodes. Among the 173 TBL-positive animals, 36% (95% CI = 28.8, 43.2), and among the 388 TBL-positive tissues, 24.2% (95% CI = 20, 29) were culture and mRT-PCR positive. All the culture-generated isolates were positive for M. bovis in mRT-PCR. Among them, two animals had mixed infections including one zebu cattle tested positive for both M. caprae and M. bovis, and a crossbred cow tested positive for both M. tuberculosis and M. bovis in mRT-PCR. This suggests persistent transmission within the cattle population, posing a substantial public health threat.ConclusionThis study revealed an eleven-fold greater risk of bTB-related lesions in crossbred cattle compared to local zebu cattle. This finding highlights the necessity for targeted interventions, continuous vigilance, and thorough carcass inspection to mitigate public health risks.

Co-infection with Mycobacterium and 20% acid-fast Nocardia in an immunocompetent patient – A case report

Nocardiosis is an opportunistic infectious disease in immunocompromised individuals, which may be fatal and in people with healthy immune systems, which is reported as a case. Mixed infections with Nocardia and Mycobacterium tuberculosis complex (MTBC) are rare. We are reporting a case of co-infection with Nocardia spp. and MTBC in an immunocompetent patient presenting with neck swelling. Interestingly, in this case, the primary identification of Nocardia was done using 20% H2SO4 as decolorizer for Ziehl–Neelsen staining. The patient was given first-line anti-tubercular treatment for the first 2 months as an intensive phase, followed by isoniazid and rifampicin for an additional 4 months, with a total of 6 months treatment, along with linezolid (600 mg twice daily for 15 days). The patient subsequently improved.

Assessing infectiousness and the impact of effective treatment to guide isolation recommendations for people with pulmonary tuberculosis.

Determining the extent and duration of infectiousness of individuals with pulmonary tuberculosis (TB) is critical for various aspects of TB care, including decisions regarding isolation. Studies suggest considerable heterogeneity in infectiousness of people with pulmonary TB. Pre-treatment, measures of bacillary burden including sputum smear microscopy, culture time-to-positivity, and Xpert MTB/RIF cycle threshold (Ct) value, predict the risk of transmission to contacts. Index patients with smear negative disease pose lower infectious risk than those who have smear-positive disease, and household contact infection is more likely with index patients who have lower Xpert Ct values. Newer tools that enable detection of Mycobacterium tuberculosis complex (Mtb complex) from cough aerosol sampling and face mask sampling may be better predictors of contact infection risk. Clinical factors such as cough strength and frequency, and presence of cavitation on chest imaging, may also assist with risk prediction. Post-treatment, smear and culture status are poor predictors of infectiousness. While the exact duration of infectiousness post treatment initiation remains uncertain, data from human-to-guinea pig transmission studies and clinical studies suggest effective treatment results in a rapid decline in infectiousness, irrespective of smear or culture conversion. This is largely supported by early bactericidal activity and transcriptomic studies, and cough aerosol sampling studies, although a subset of patients may have persistent cough aerosol positivity. These findings can enable a more nuanced approach to isolation decision making, while further research studies are awaited.

Quantification of MDR-TB drug JBD0131 and its metabolite in plasma via UPLC-MS/MS: application in first-in-human study.

Aim: JBD0131, a novel anti-multidrug-resistant tuberculosis (MDR-TB) drug, can target and inhibit the synthesis of mycolic acids, which are crucial components of the cell wall of the Mycobacterium tuberculosis complex. To support the results of this clinical trial in healthy subjects, development of a specific and accurate quantification method for detecting JBD0131 and its metabolite DM131 in human plasma is needed.Materials & methods: Samples with prior added stabilizer were pretreated by protein precipitation method and the extracts weresubjected to ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The m/z transitions for the precursor/product ion pairs were 402.1/273 for JBD0131, 333.1/273 for DM131 and 386.1/257 for the internal standard (IS).Results: This method showed good linearity from 1 to 2000ng/ml for JBD0131 and 0.25 to 500ng/ml for DM131 and was validated in terms of selectivity, linearity, accuracy, precision, matrix effect, recovery of pretreament and stability.Conclusion: This method was sensitive and specific for measuring the plasma concentrations of JBD0131 and its metabolites. And it was applied for the investigation of the pharmacokinetics of JBD0131 and DM131 in a clinical trial.

Molecular identification of Mycobacterium bovis in patients with tuberculosis attending a tertiary care hospital in South India

Background: Mycobacterium (M.) bovis is a member of Mycobacterium tuberculosis complex (MTBC). Clinical infection caused by M. bovis is indistinguishable from other MTBC and could pose a potential challenge for control of TB epidemic due to its zoonotic nature. Availability of reliable molecular diagnostic methods such as Genotype MTBC based on line probe assay (LPA) paves way for reliable differentiation of M. bovis from other MTBC. Objective: To determine the proportion of Mycobacterium bovis among the Mycobacterium tuberculosis complex isolates from patients with tuberculosis. Methods: In our study, we analysed MGIT positive cultures and performed Line probe assay (LPA) for identification of MTBC isolates. Total of 206 patient samples were taken, 104 pulmonary and 102 from extrapulmonary sites. Results: M.tuberculosis/ M.canettii was isolated in all pulmonary specimens (100%). Among 102 extrapulmonary samples, 99 % was identified as M.tuberculosis/ M.canettii, and 1 % as M. bovis BCG. Conclusion: Our study suggests that zoonotic TB by M. bovis may not be as prevalent in India and hence may not constitute a significant risk to public health in India. Keywords: TB; M. bovis; line probe assay.

The In-Vitro Activity of Manuka Honey and Indian Costus (Saussurea Costus) on the Growth of Bacteria that Cause Pulmonary Tuberculosis

The Mycobacterium Tuberculosis complex is a group of species of Mycobacteria involved in a serious bacterial disease which infects the respiratory system and organs. Multi-drug resistant (MDR) strains have been produced as a result of the fast emergence of resistance against first-line anti-tuberculosis medicines in recent years worldwide. The objective of this study is to determine alternatives to anti-mycobacterial antibiotics, such as Manuka honey and Indian costus. MTB isolates (???? = 15) were evaluated for their susceptibility to Manuka honey graded as +15 and Indian costus by using different concentrations. Among the TB isolates (???? = 15) tested, four (27%) isolates were resistant at 15% v/v honey, while, at 18% v/v of Manuka honey, two (13%) isolates were found to be resistant. Resistance was not seen at honey concentrations of 20% v/v. On the other hand, Indian costus had a slight effectiveness at concentrations of 20% and 25%, affecting only two and five isolates of Mycobacteria, respectively; however, all isolates were inhibited at a concentration of 33% v/v of Indian costus. The present study clearly demonstrates that supposed alternatives (Manuka honey graded as +15 and Indian costus) possess significant anti-mycobacterial activity in vitro; however, further clinical trials should be performed to corroborate our initial findings.

7200 A Unique Case Of Hypercalcemia From Primary Hyperparathyroidism With Thymoma And Concurrent Pulmonary Tuberculosis

Abstract Disclosure: S. Jing Hang Randy: None. L. Huiling: None. Background: Several case reports have reported the rare association of thymoma with primary hyperparathyroidism. We describe a unique case of hypercalcemia with such association but was also found to have concurrent pulmonary tuberculosis. Clinical Case: A 50-year-old Indian female with a significant history of anterior mediastinal mass underwent median sternotomy with mass resection and was found to have peri-operative hypercalcemia. Her only complaint was chronic cough. Initial investigations showed high adjusted calcium 2.78 mmol/L (2.15– 2.50 mmol/L), normal phosphate 1.1 mmol/L (0.8– 1.4 mmol/L) and high PTH 24.7 pmol/L (1.6– 6.9 pmol/L). Apart from the mediastinal mass, a whole-body CT scan showed multiple prominent mediastinal lymph nodes with non-specific subcentimetre lung nodules. The post-operative finding was a Type AB thymoma with necrotizing granulomatous inflammation in adjacent station I lymph node. Differentials for patient’s hypercalcemia included primary hyperparathyroidism, malignancies such as lymphomas and infectious causes in particular tuberculosis. Her 25-OH Vitamin D was low at 9 ug/L (30 - 100 ug/L), 1,25-dihydroxyvitamin D was elevated at 205 pg/mL (18-64 pg/mL) while creatinine, ALP, serum ACE and PTHrP were unremarkable. She was subsequently admitted for worsening hypercalcemia, fever and left pleural effusion with generalized lymphadenopathy where she underwent an Endobronchial Ultrasound-guided Transbronchial Needle Aspirate of station IV lymph nodes before being started on tuberculosis treatment. The AFB culture showed Mycobacterium Tuberculosis Complex thereafter. Parathyroid sonography revealed a 2.2cm x 0.9cm x 0.8cm lobulated hypoechoic lesion posterior to the inferior pole of left thyroid lobe. However, a confirmatory sestamibi scan could only be done 6 weeks post-thymectomy given the raw surgical bed, with a possibility of false-negative result for cervical parathyroid adenoma given a recent thymectomy. It subsequently showed a hyperfunctioning left inferior parathyroid nodule with no other suspicious focal uptake in the neck or mediastinum. Patient underwent a focused left parathyroidectomy. Histology showed features consistent with parathyroid adenoma. A stepwise trajectory of her calcium normalization was observed with hydration, intravenous zoledronic acid for her osteoporosis, tuberculosis treatment, adjuvant radiation therapy for her thymoma with margins involvement, and parathyroidectomy. Conclusion: This case illustrates the challenges faced while considering localizing scans for primary hyperparathyroidism with recent thymectomy given the common embryological origin of inferior parathyroid and thymus. It also demonstrates the possible co-existence of separate pathologies in hypercalcemia and the need to exercise prudent clinical judgement to further evaluate for these various etiologies. Presentation: 6/2/2024

A-252 Evaluation of the Use of One-tube Blood Collection and Automated Specimen Processing System for LIAISON® QuantiFERON®-TB Gold Plus Testing at a Large Regional Reference Laboratory

Abstract Background LIAISON® QuantiFERON®-TB Gold Plus (QFT-Plus) is an in vitro diagnostic assay for the indirect detection of infection caused by Mycobacterium tuberculosis complex (MTBC). QFT-Plus testing consists of four tubes (controls and TB antigens) and detects interferon-γ (IFN-γ) released by host cells when exposed to MTBC peptide antigens using chemiluminescence immunoassay (CIA) technology. Patient’s blood can be collected directly into four QFT-Plus tubes or into a single lithium heparin tube. If the one-tube collection process is utilized, blood must be aliquoted into each of the four QFT-Plus tubes prior to testing. In this study, we evaluated the workflow and feasibility of lithium-heparin blood collection and pre-analytical processing using the Copan Universe system for QFT-Plus testing on the LIAISON XL analyzer. Methods Whole blood collected into a 6 mL lithium heparin tube was mixed using a tube rotator prior to processing on the Copan UniVerse, which aliquots 0.9 mL blood into each of four QFT-Plus tubes and label the tubes with patient information. The lithium heparin tube is mixed again immediately prior to aliquoting into each QFT-Plus tube. Different methods of mixing (vortexing vs pipetting) were assessed for efficiency and performance. Walkaway feasibility was also assessed by testing aliquoting efficiency when loading 6, 9, 12 and 18 blood samples at a time. Visual inspection of the QFT-Plus tubes to check accuracy of labels was performed prior to incubation and validation of readability of the barcode labels through the analyzer was performed. Results Of 44 blood samples that were pipet mixed, 26 (59.1%), 15 (34.1%) and 3 (6.8%) showed no, slight and moderate hemolysis, respectively. None were grossly hemolyzed. Vortex mixing showed similar results with 61.3% (19/31) and 38.7% (12/31) showed no or slight hemolysis. However, bubble formation, which may interfere with pipetting by the UniVerse, was observed in several tubes when the samples were vortex mixed. The UniVerse appropriately aliquoted 0.9 mL blood and labeled 280 tubes. Only 1 (0.4%) tube had &amp;lt;0.9 mL volume detected. It takes about 20 minutes to aliquot 12 patient samples into four QFT-Plus tubes. Walkaway was possible when loading 18 patients’ samples at a time without negative downstream impact on pipetting or appropriate mixing of samples for QFT-Plus testing. All QFT-Plus tubes were labeled accurately with barcodes and accession numbers which were all read and processed through the analyzer. Conclusions Implementation of lithium-heparin blood collection for centralized QFT-Plus testing was feasible when used in conjunction with the Copan UniVerse, which allowed for high throughput specimen processing and mitigated the risk of sample mislabeling.

A-264 Validation of a Novel Real-Time PCR Assay for Identification of Mycobacterium species Isolates Recovered from Clinical Culture

Abstract Background Historically, clinical mycobacteriology laboratories used the nucleic acid hybridization-based AccuProbe assay manufactured by Hologic, Inc., to rapidly rule in or rule out Mycobacterium tuberculosis (MTB) and members of the M. avium-intracellulare complex (MAC). The clinical value of this test was in its ability to rapidly rule in/out MTB from positive broth cultures and allow the initiation of appropriate antimicrobial therapy and infection prevention practices. Recent discontinuation of this commercial assay left a gap in testing available for the rapid identification of these organisms, which allowed us to develop an in-house real-time PCR test. Methods A replacement assay was developed by Labcorp R &amp; D based on real-time PCR amplification of extracted nucleic acids from positive culture growth. Aliquots from positive AFB VersaTREK broth cultures were heat inactivated, and nucleic acids were extracted using the MagNA Pure 24 (MP24) instrument (Roche). Real-time PCR using published primer probe sets (Rocchetti, et al 2016) was performed on the QuantStudio™ 7 (QS7) instrument (Applied Biosystems®). The assay was designed with three independent primer/probe sequence targets: one for MTB Complex (IS6110), one for MAC (ITS), and one pan-target for the Mycobacterium genus (16s rRNA). Results Procedural verification was performed using 100 residual clinical specimens previously identified using the Hologic AccuProbe® assay. Categorical concordance was 97% (97/100). The three discrepant results were identified as MAC positive by PCR; however, these were not identified as MAC on the predicate assay. Analytical sensitivity for the PCR assay was established to be 1,000 CFU/mL for each target. Analytical specificity was assessed in vitro for nine Mycobacterium species, with no cross-reactivity observed. In vitro analysis of target detection in the presence of yeast (Candida glabrata) was also performed, and we saw no inhibition. Analysis of the primer/probe sets for all targets was performed in silico using XploreDB database of microbial genomes, with confirmed 100% matches for both MAC and MTB genomes compared to hundreds of species. By comparison, the PAN-Myco primer set showed decreased performance, having three mismatches (two on forward primer and one on the probe). As this target sequence is used as an Internal Control (IC) this was not problematic for overall assay performance. The assay demonstrated excellent precision (%CV) for each target: MTB = 0.74%, MAC = 1.10%, PAN-Myco = 3.19%. Conclusions Utilizing the depth of molecular methodologies available in our laboratories, we developed a rapid method for identification of MAC and MTB from positive broth cultures, which had excellent performance compared to the predicate assay. The PCR ID LDT test is now available and allows testing to continue with no interruption in patient care.

Evaluation of Multiplex loop-mediated isothermal amplification assay for the detection of Mycobacterium tuberculosis complex from clinically suspected cases of pulmonary tuberculosis

Tuberculosis (TB) is the second leading cause of death from a single infectious agent worldwide. Bangladesh ranks 7th among the 30 high TB burdened countries in the world. Accurate detection of Mycobacterium tuberculosis complex (MTBC) is challenging for developing countries as most of the resource poor settings are not suitable to perform molecular techniques.The purpose of the study was to compare the multiplex TB-LAMP assay with MTB/NTM qPCR, culture, Z-N staining, and fluorescence microscopy in order to assess the effectiveness of the LAMP assay for detecting cases of pulmonary tuberculosis.This research work was done from March 2022 to February 2023. Fulfilling the inclusion criteria 130 sputum samples were collected. TB-LAMP assay, qPCR, culture in L-J media, Z-N staining and fluorescence microscopy were performed.Out of 130 samples qPCR detected MTBC in 56.92% cases and TB-LAMP detected 53.85%. MTBC was detected by culture 46.15%, by Fluorescence microscopy 40.77% and Z-N staining 36.92%. TB-LAMP detected 16.93% more cases than Z-N staining and 13.08% more cases than fluorescence microscopy. The sensitivity, specificity, positive, and negative predictive values of multiplex-LAMP assay were 95%, 81.4%, 81.4% and 95% respectively considering culture as a gold-standard. MTBC negative culture samples (18.57%) showed positivity by LAMP assay as well as by qPCR. This study detected 7.69% non-tuberculous mycobacteria (NTM) by qPCR. All NTM positive samples were negative by TB-LAMP.TB-LAMP is an easy to perform, cost-effective, reliable assay with high sensitivity and specificity. World Health Organization recommended TB-LAMP as a rapid molecular test for rapid detection of tuberculosis and as replacement of microscopy in resource poor settings/hard to reach areas. Bangladesh being a high TB burden country it is essential to implement TB-LAMP to achieve End TB Strategy by 2035.

Mycobacteria that cause tuberculosis have retained ancestrally acquired genes for the biosynthesis of chemically diverse terpene nucleosides.

Mycobacterium tuberculosis (Mtb) releases the unusual terpene nucleoside 1-tuberculosinyladenosine (1-TbAd) to block lysosomal function and promote survival in human macrophages. Using conventional approaches, we found that genes Rv3377c and Rv3378c, but not Rv3376, were necessary for 1-TbAd biosynthesis. Here, we introduce linear models for mass spectrometry (limms) software as a next-generation lipidomics tool to study the essential functions of lipid biosynthetic enzymes on a whole-cell basis. Using limms, whole-cell lipid profiles deepened the phenotypic landscape of comparative mass spectrometry experiments and identified a large family of approximately 100 terpene nucleoside metabolites downstream of Rv3378c. We validated the identity of previously unknown adenine-, adenosine-, and lipid-modified tuberculosinol-containing molecules using synthetic chemistry and collisional mass spectrometry, including comprehensive profiling of bacterial lipids that fragment to adenine. We tracked terpene nucleoside genotypes and lipid phenotypes among Mycobacterium tuberculosis complex (MTC) species that did or did not evolve to productively infect either human or nonhuman mammals. Although 1-TbAd biosynthesis genes were thought to be restricted to the MTC, we identified the locus in unexpected species outside the MTC. Sequence analysis of the locus showed nucleotide usage characteristic of plasmids from plant-associated bacteria, clarifying the origin and timing of horizontal gene transfer to a pre-MTC progenitor. The data demonstrated correlation between high level terpene nucleoside biosynthesis and mycobacterial competence for human infection, and 2 mechanisms of 1-TbAd biosynthesis loss. Overall, the selective gain and evolutionary retention of tuberculosinyl metabolites in modern species that cause human TB suggest a role in human TB disease, and the newly discovered molecules represent candidate disease-specific biomarkers.

Review on Tuberculosis

Abstract: Tuberculosis (TB) is an airborne irresistible infection brought about by creatures of the Mycobacterium tuberculosis complex. Tuberculosis (TB) stays perhaps of the deadliest irresistible infection liable for a great many passings yearly across the world. Disease with M. tuberculosis can develop from control in the host, in which the microbes are segregated inside granulomas (dormant TB disease), to an infectious state, wherein the patient will show side effects that can incorporate hack, fever, night sweats and weight reduction. Just dynamic pneumonic TB is infectious. In this paper we present an overall outline of TB including the pathogenesis, conclusion, and treatment rules. In readiness of this review, we scanned PubMed for applicable articles on TB. Moreover, we looked through the sites of global establishments like the World Wellbeing Association (WHO) and the US Communities for Infectious prevention and Avoidance (CDC) for related reports and clinical rules. This paper brings been composed with the expectation to the table for general schooling to wellbeing experts, strategy creators, patients and people in general.