Mycobacterium Tuberculosis Complex Research Articles

Performance of a broth microdilution assay for routine minimum inhibitory concentration determination of 14 anti-tuberculous drugs against the Mycobacterium tuberculosis complex based on the EUCAST reference protocol.

This comparative study aimed at qualifying a broth microdilution (BMD) assay for phenotypic drug susceptibility testing (pDST) of Mycobacterium tuberculosis complex (MTBC) strains for implementation in a routine DST workflow. The assay was developed based on the EUCAST (European Committee on Antimicrobial Susceptibility Testing) reference protocol for determination of the minimum inhibitory concentration (MIC) of 14 anti-tuberculous drugs (isoniazid [INH], rifampicin [RIF], ethambutol [EMB], amikacin [AMI], moxifloxacin [MFX], levofloxacin [LFX], bedaquiline [BDQ], clofazimine [CFZ], delamanid [DLM], pretomanid [PA], para-aminosalicylic acid [PAS], linezolid [LZD], ethionamide [ETH], and cycloserine [CS]). Forty MTBC strains with various drug resistance profiles were tested to determine the agreement between MIC results and genotypic drug susceptibility testing (gDST) results derived from whole-genome sequencing (WGS). The agreement between the BMD and gDST results was solid for the majority of the drugs (average agreement 98%, range 90%-100%), including key drugs such as INH, RIF, MFX, LFX, BDQ, DLM, and PA. Ten discrepancies were identified (corresponding to 1.8% of the total number of MIC determinations) and most (8/10) were characterized by MICs equal or close to the potential critical concentration (pCC) applied in the BMD assay. Importantly, the assay can be adjusted to new drug recommendations and concentrations, tailored to local needs. We conclude that the BMD assay provides reliable results, and its implementation in our MTBC routine workflow will produce valuable data that improve our understanding and management of MTBC drug resistance.

Prevalence of non-tuberculous mycobacteria among people with acid-fast positive presumptive tuberculosis in Mali.

Non-tuberculous mycobacteria (NTM) are environmental agents that can cause opportunistic pulmonary disease in humans and animals, often misdiagnosed as tuberculosis (TB). In this study, we describe the cases of NTM identified during the first national anti-TB drug resistance survey conducted in Mali and explore associated risk factors. Sputum was collected from people presenting for pulmonary TB diagnosis from April to December 2019, regardless of age. Microscopy-positive patients were enrolled and tested using the Xpert MTB/RIF assay. A patient who tested negative for the Mycobacterium tuberculosis complex (MTBC) was tested for the presence of mycobacteria by amplification of the IS6110 and 16SrRNA (16S) genes through double quantitative real-time PCR, followed by nested PCR and Sanger sequencing of the IS6110-negative samples for NTM species identification. 1,418 sputum smear-positive patients were enrolled, including 1,199 new cases, 211 previously treated cases, and 8 whose previous treatment history was unknown. Based on the results of Xpert MTB/RIF assay and in-house PCR methods, 1,331 (93.9%) patients were positive for MTBC, 48 (3.4%) for NTM, and no species identification was possible for 39 (2.7%). Advanced age of 65 and over with an OR 8.8 (95% CI 2.3-33.2 and p = 0.001) and previous TB treatment with an OR 3.4 (95% CI 1.2-9.6 and p = 0.016) were the risk factors statistically associated with NTM detection. M. avium complex (MAC) was the predominant NTM species, detected in 20 cases. Detection of NTM in people presumed to have TB is an ongoing challenge, confounding correct TB diagnosis. Concomitant use of microscopy and GeneXpert testing among at-risk individuals could improve patient management.

Understanding the development of tuberculous granulomas: insights into host protection and pathogenesis, a review in humans and animals

Granulomas, organized aggregates of immune cells which form in response to Mycobacterium tuberculosis (Mtb), are characteristic but not exclusive of tuberculosis (TB). Despite existing investigations on TB granulomas, the determinants that differentiate host-protective granulomas from granulomas that contribute to TB pathogenesis are often disputed. Thus, the goal of this narrative review is to help clarify the existing literature on such determinants. We adopt the a priori view that TB granulomas are host-protective organelles and discuss the molecular and cellular determinants that induce protective granulomas and those that promote their failure. While reports about protective TB granulomas and their failure may initially seem contradictory, it is increasingly recognized that either deficiencies or excesses of the molecular and cellular components in TB granuloma formation may be detrimental to the host. More specifically, insufficient or excessive expression/representation of the following components have been reported to skew granulomas toward the less protective phenotype: (i) epithelioid macrophages; (ii) type 1 adaptive immune response; (iii) type 2 adaptive immune response; (iv) tumor necrosis factor; (v) interleukin-12; (vi) interleukin-17; (vii) matrix metalloproteinases; (viii) hypoxia in the TB granulomas; (ix) hypoxia inducible factor-1 alpha; (x) aerobic glycolysis; (xi) indoleamine 2,3-dioxygenase activity; (xii) heme oxygenase-1 activity; (xiii) immune checkpoint; (xiv) leukotriene A4 hydrolase activity; (xv) nuclear-factor-kappa B; and (xvi) transforming growth factor-beta. Rather, more precise and timely coordinated immune responses appear essential for eradication or containment of Mtb infection. Since there are several animal models of infection with Mtb, other species within the Mtb complex, and the surrogate Mycobacterium marinum – whether natural (cattle, elephants) or experimental (zebrafish, mouse, guinea pig, rabbit, mini pig, goat, non-human primate) infections – we also compared the TB granulomatous response and other pathologic lung lesions in various animals infected with one of these mycobacteria with that of human pulmonary TB. Identifying components that dictate the formation of host-protective granulomas and the circumstances that result in their failure can enhance our understanding of the macrocosm of human TB and facilitate the development of novel remedies – whether they be direct therapeutics or indirect interventions – to efficiently eliminate Mtb infection and prevent its pathologic sequelae.

Same-day identification and genotypic antibiotic resistance testing of Mycobacterium tuberculosis complex and non-tuberculous mycobacteria from positive blood culture bottles – a proof of principle assessment

Background and Aims: patients suffering from systemic mycobacterial spread are at high risk of unfavorable clinical outcomes. Rapid microbiological diagnosis, however, is complicated due to the very slow cultural growth of mycobacteria. To facilitate the diagnostic workflow, we assessed a workflow allowing mass spectrometry-based identification and molecular resistance testing of mycobacteria directly from blood culture pellets. Materials and Methods: for this study, 50 blood cultures spiked with n=10 Mycobacterium tuberculosis (MTC) isolates and n=40 isolates belonging to 12 other species of non-tuberculous mycobacteria (n=13 M. abscessus complex, n=5 M. avium, n=3 M. chimaera, n=5 M. fortuitum, n=5 M. intracellulare, n=2 M. lentiflavum and n=2 M. mucogenicum, n=1 for each one of the species M. elephantis, M. hassiacum, M. marseillense, M. nebraskense and M. parascrofulaceum) were used next to two clinical cases of a disseminated infection in HIV patients. Results: the application of the MBT Sepsityper® kit allowed the correct species level identification by applying mass spectrometry as well as correct molecular resistance testing results as compared to the diagnostic reference approach applied with mycobacterial culture material. Conclusions: in conclusion, the results provide a proof-of-principle of the suitability of the assessed potential workflow in order to achieve a shortened time-to-result for the diagnosis of systemic mycobacterial infections. Future studies in high endemicity settings are desirable to assess the clinical applicability and impact of such a shortened workflow.

Immunological mechanisms involved in the protection against development of pulmonary tuberculosis in naturally infected goats

Tuberculosis (TB) is a notifiable zoonotic disease caused by bacteria of the Mycobacterium tuberculosis complex (MTBC) that affects a multitude of domestic and wild species. The main lesions caused by these mycobacteria are tuberculous granulomas, which determine the organism's immune response to the disease. Although TB pathogenesis in cattle has been extensively studied, information regarding its progression in other species of interest for the maintenance and transmission of TB such as goats remains limited. This study aimed to characterise the immune response developed in the lungs of goats naturally infected with mycobacteria of MTBC by assessing key cell populations and immunomodulatory molecules involved in defending against TB. Hence, twelve 6–12-month-old Guadarrama kid goats, initially TB-free, were selected and exposed to M. bovis through close contact with other infected goats. Only animals that tested positive by any of the TB diagnostic methods at the end of the experiment were included in the final analysis (n = 9). Gross and microscopic lesions compatible with TB (TBL) in different organs, as well as local response to TB in lungs were evaluated. Our results revealed that after five months of exposure, 44.4 % (4/9) of the M. bovis-infected animals exhibited TBL in the lungs (TBLL+), characterized by a predominance of non-cavitary necrotic granulomas. TBLL+ animals showed significantly higher presence of neutrophils, macrophages (MΦs) and lymphocytes along with greater expression of interferon (IFN)-γ. Conversely, the remaining animals did not present macroscopic or microscopic TBL in the lungs (TBLL-) (5/9). However, these goats displayed elevated expression of toll-like receptors (TLR)2 and TLR4 alongside heightened expression of pro-inflammatory cytokines, inducible nitric oxide synthase (iNOS) and interleukin (IL)-10. These results suggest the potential development of an effective immune response that may suppress or delay of TBL in infected animals. Further research is needed to elucidate how these molecules, which are involved in the defence against MTBC, confer protection and modulate their expression during infection for TB control.

Signatures of transmission in within-host Mycobacterium tuberculosis complex variation: a retrospective genomic epidemiology study

Mycobacterium tuberculosis complex (MTBC) species evolve slowly, so isolates from individuals linked in transmission often have identical or nearly identical genomes, making it difficult to reconstruct transmission chains. Finding additional sources of shared MTBC variation could help overcome this problem. Previous studies have reported MTBC diversity within infected individuals; however, whether within-host variation improves transmission inferences remains unclear. Here, we aimed to quantify within-host MTBC variation and assess whether such information improves transmission inferences. We conducted a retrospective genomic epidemiology study in which we reanalysed publicly available sequence data from household transmission studies published in PubMed from database inception until Jan 31, 2024, for which both genomic and epidemiological contact data were available, using household membership as a proxy for transmission linkage. Wequantified minority variants (ie, positions with two or more alleles each supported by at least five-fold coverage and with a minor allele frequency of 1% or more) outside of PE and PPE genes, within individual samples and shared across samples. We used receiver operator characteristic (ROC) curves to compare the performance of a general linear model for household membership that included shared minority variants and one that included only fixed genetic differences. We identified three MTBC household transmission studies with publicly available whole-genome sequencing data and epidemiological linkages: a household transmission study in Vitória, Brazil (Colangeli etal), a retrospective population-based study of paediatric tuberculosis in British Columbia, Canada (Guthrie etal), and a retrospective population-based study in Oxfordshire, England (Walker etal). We found moderate levels of minority variation present in MTBC sequence data from cultured isolates that varied significantly across studies: mean 168·6minority variants (95% CI 151·4-185·9) for the Colangeli etal dataset, 5·8 (1·5-10·2) for Guthrie etal (p<0·0001, Wilcoxon rank sum test, vsColangeli etal), and 7·1 (2·4-11·9) for Walker etal (p<0·0001, Wilcoxon rank sum test, vs Colangeli etal). Isolates from household pairs shared more minority variants than did randomly selected pairs of isolates: mean 97·7shared minority variants (79·1-116·3) versus 9·8 (8·6-11·0) in Colangeli etal, 0·8 (0·1-1·5) versus 0·2(0·1-0·2) in Guthrie etal, and 0·7 (0·1-1·3) versus 0·2 (0·2-0·2) in Walker etal (allp<0·0001, Wilcoxon rank sumtest). Shared within-host variation was significantly associated with household membership (odds ratio 1·51 [95% CI 1·30-1·71], p<0·0001), for one standard deviation increase in shared minority variants. Models that included shared within-host variation versus models without within-host variation improved the accuracy of predicting household membership in all three studies: area under the ROC curve 0·95versus 0·92for the Colangeli etal study, 0·99versus 0·95for the Guthrie etal study, and 0·93versus 0·91for the Walker etal study. Within-host MTBC variation persists through culture of sputum and could enhance the resolution of transmission inferences. The substantial differences in minority variation recovered across studies highlight the need to optimise approaches to recover and incorporate within-host variation into automated phylogenetic and transmission inference. National Institutes of Health.

Cytokines Levels and Anti-tuberculosis Drug Resistance among HIV Seropositive Patients in Ibadan, Southwest, Nigeria

Susceptibility to TB disease rises on mutations in cytokine receptors which ultimately lead to defective signaling and alter the immune surveillance and bacterial killing. Therefore, this study was undertaken to investigate the association between cytokines and anti-TB drug resistances. A total of 217 people living with human immunodeficiency virus at University College Hospital, Ibadan were recruited. Venous blood and sputum samples were collected. Sputum samples were cultured for Mycobacterium tuberculosis complex and characterized using standard methods. Anti-TB drug resistance was detected using phenotypic and genotypic methods. Cytokines levels (IL-10 and IFN-Y) were estimated using ELISA method. Association between cytokines and anti-TB drug resistance was determined using linear regression analysis. There were 105(48.4%) males and 112(51.6%) females with a mean age of 42.95 ± 8.286 years and a range of 28-65 years. The prevalence of TB among PLHIV was found to be 19.1% with male having higher rate than female (P&lt;0.05), and highest rate among aged ≥40. There was no significant association between cytokines (IL-10 and IFN-y) and sex of the subjects (P&gt;0.05). However, females had higher IFN-y level of 231.06±61.81 IU/ml when compared to 227.53±57.92 IU/ml obtained from males. The prevalence of multi-drug resistance TB was 11.9% with Rifampicin resistance having the highest rate of 5.5%. There was no significant association between cytokines (IL-10 and IFN-y) and sex, but age group &gt;40 years had higher IL-10 and IFN-y level of 226.53±52.39 IU/ml and 232.41±66.63 IU/ml respectively. There was an association between high cytokines levels and anti-TB drug resistance (P&lt;0.05). Highest cytokines levels; IL-10 (401.00±7.07 IU/ml) and IFN-Y (401.00±7.07 IU/ml) were recorded in Levofloxacin resistance. There was an association between high cytokines levels and genotypic anti- TB drug resistance (P&lt;0.05) with highest cytokines levels; IL-10 (400.12±12.37 IU/ml) and IFN-Y (472.87±31.93 IU/ml) recorded in Rifampicin resistance. This entire study revealed that there is high prevalence of MDR-TB among PLHIV, with Rifampicin monoresistance having the highest resistance rate among the drugs tested, and pro and inflammatory cytokines (IL-10 and IFN-y) play significant role in the development of Multi Drug Resistant-Tuberculosis among people living with HIV.

Clonal Diversity and Spatial Dissemination of Drug-resistant Mycobacterium tuberculosis Complex among HIV Seropositive Patients in Southwest Nigeria

Mycobacterium tuberculosis complex display relatively static genomes and 99.9% nucleotide sequence identity. Studying the evolutionary history of such monomorphic bacteria is a difficult and challenging task. Therefore, this study was undertaken to investigate the clonal diversity and spatial dissemination of drug-resistant M. tuberculosis complex among HIV seropositive clients in Southwest Nigeria. A total of two-hundred and seventeen (217) consented HIV positive (case subjects) and fifty (50) non-HIV positive controls were recruited for this study. Two Sputum samples were collected from each participant in two consecutive days. The samples were divided into two parts: one part was decontaminated using NAOH-NALC method and aseptically cultured for Mycobacteria on Lowenstein-Jensen (LJ) medium with and without pyruvate. Mycobacterial isolates were characterized using conventional and molecular methods. Anti-TB drug sensitivity test was done using 1% proportion conventional method on LJ. MTBC isolates were sequenced using Genetic Analyzer 3130xl sequencer. Genetic relatedness and clonal diversity (phylogenetic analysis) of MTBC isolates were done using Bio- Edit software and MEGA 6. Out of 217 HIV positive participants, 105(48.4%) were male, while 112(51.6%) were female. Twenty-six (26(52.0%)) of the control subjects were male, while 24(48.0%) were females. The overall prevalence of TB among PLHIV was found to be 19.1%. The prevalence of NTM among PLHIV was found to be 2.8% with M. intracellulare being the predominant organism isolated. Participants’ age was found to be significantly associated with TB (P&lt;0.05), however there was no significant association between TB and sex of the participants (P&lt;0.05). The prevalence of culture confirmed drug-resistant TB (DR-TB) among PLHIV was found to be 11.9%, with Rifampicin having the highest monoresistance rate of 5.5%. The overall prevalence of MDR-TB among PLHIV was found to be 9.2%. The phylogenetic analysis of M. tuberculosis strains revealed same clone of all isolates. All PLHIV should be screened for drug-resistant TB especially MDR-TB as the prevalence of primary MDR-TB is high among them. Further study like 3R gene-based studies of adaptation and evolution is needed to facilitate further epidemiological studies of these bacteria.

Analiza antropologică a resturilor scheletice dintr-un mormânt triplu de inhumaţie din perioada medio-bizantină de la Nufăru – Curtea şcolii, jud. Tulcea

Recent preventive archaeological excavations carried out in the courtyard of a local school in the village of Nufăru have led to the documentation of a Middle Byzantine inhumation cemetery comprising 191 funerary complexes. Among the individual burials, which are exclusive within the cemetery, our attention was drawn to a multiple burial containing the skeletal remains of three individuals: two adult females (a young adult ‑ approximately 34.6 years old, and a middle adult – approximately 43.3 years old) framing the skeleton of a subadult. The skeletal remains of the subadult belong to a child of approximately 10.0 years old. Beyond the issues raised by this less common practice in the Dobrudja funerary archaeology landscape regarding burial rituals, determining the cause of death for these three individuals becomes essential for the anthropologist. In the case of the middle adult, death most likely occurred due to a blow inflicted with a sharp object, such as a sword, in the cervical region. However, the situation is not as clear regarding the other two deceased individuals. Several atypical pathognomonic manifestations (hypervascularization and resorptive lesions on the bodies of all vertebrae, except for the cervical ones) observed in the child’s skeleton seem to indicate an infection with one of the species of the Mycobacterium tuberculosis complex. These macroscopically observed changes need to be confirmed by genetic analyses. As for the cause of death of the young adult, it remains a mystery despite numerous osteological (cribra orbitalia, osteoarthritis, spinal disc herniation, periostitis, vertebral compression fracture, osteomas, osteochondritis dissecans) and dental (caries, dental calculus, dental enamel hypoplasia, ante‑mortem tooth loss, congenital absences) pathological changes noted. Other pathological manifestations identified in the case of the middle adult include: cribra orbitalia, caries, dental calculus, dental abscesses, ante‑mortem tooth loss, congenital absences, osteoarthritis, spinal disc herniation, periostitis, Colles’ fracture, and osteochondritis dissecans. In the case of the child, cribra orbitalia, caries, dental calculus, and periostitis were also observed.

A high titer antibody response against P22 protein immunocomplex is not correlated with protection in naturally tuberculosis-infected goats

Caprine livestock are significant reservoirs of the Mycobacterium tuberculosis complex (MTBC), contributing to tuberculosis (TB) transmission among animals and humans. The P22 protein immunocomplex (P22PI), derived from bovine tuberculin, shows immunostimulating capacity and is used for TB diagnosis. This study assessed the immunogenicity and protective efficacy of P22PI in two groups of goats: 24 naïve goats (12 immunised, 12 controls) from a TB-free herd, and 24 infected goats (12 immunised, 12 controls), referred to as pre-infected animals, from a M. bovis-infected herd. Both were exposed for 5 months to M. bovis-naturally infected goats. Reactors to single and comparative intradermal tuberculin (SIT and SCIT, respectively) tests and interferon-gamma release assay (IGRA) significantly increased (p < 0.05) in both groups 5 months’ post-exposure, with no significant differences between immunised and control animals. However, immunised animals exhibited a significantly higher (p < 0.05) antibody response against P22PI. Most naïve animals (83.3%) and all pre-infected animals developed TB-compatible lesions, with extensive necrosis in the lungs and associated lymph nodes, compared to 50% and 83.3% of control animals, respectively. These findings suggest that while P22PI stimulates an intense antibody response under the conditions of the present study, it does not confer protection against TB and may exacerbate disease severity.

Overexpression of outer membrane protein A (OmpA) increases aminoglycoside sensitivity in mycobacteria

BackgroundTuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb) complex infection, is a leading cause of death worldwide from a single infectious agent. The emergence of drug resistance Mtb clinical strains makes the situation more serious. The role of Mtb outer membrane protein A (OmpA) in antimicrobial resistance remains unclear. This study aimed to evaluate the effect of OmpA expression on mycobacterial drug resistance. In this study, a Mycobacterium smegmatis (Ms) strain overexpressing OmpA (Ms-OmpA) and a Mycobacterium bovis (Mb) strain overexpressing OmpA (Mb-OmpA) were constructed, and their susceptibility to anti-TB drugs was determined by performing the minimal inhibitory concentrations (MICs), the plate assay and the macrophage infection assays.ResultsThe streptomycin MIC of the overexpressing strain was 2-fold lower than those of the wide-type (Ms) and empty plasmid strains (pMV-261) as well as amikacin and gentamicin. Moreover, both the plate and the macrophage infection assays indicate that overexpression of OmpA increases streptomycin sensitivity in Mycobacteria. The other aminoglycosides like amikacin and gentamicin have the same phenotypes as streptomycin on the plates for the virulent strain Mb-OmpA. The porin inhibitor spermidine can increase streptomycin tolerance in the overexpressing strain, and overexpressing OmpA can increase the intracellular accumulation of hydrophilic ethidium bromide, which indicates that porin protein OmpA contributes to aminoglycosides sensitivity in Mycobacteria.ConclusionsIn this study, we have characterized the contribution of OmpA in the antimicrobial resistance phenotype of Mycobacteria, which may provide valuable insights for understanding antibiotic resistance and designing new strategies for TB treatment.

Population-level frequency of fluoroquinolone resistance by whole-genome sequencing drug predictions in Mycobacterium tuberculosis complex isolates in England from 2017-2023.

Fluoroquinolones are an important component of anti-tuberculosis treatment and identifying fluoroquinolone resistance is essential. We present the first survey of fluoroquinolone resistance in England from sequencing of over 16,000 unselected isolates. Fluoroquinolone resistance was 1.4% overall and 23.9% in multidrug-resistant TB. Routine sequencing allows resistance surveillance and should be widely adopted.

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.

Pathogen and host determinants of extrapulmonary tuberculosis among 1035 patients in Frankfurt am Main, Germany, 2008–2023

ObjectivesExtrapulmonary tuberculosis (EPTB) presents with nonspecific symptoms that can pose a significant diagnostic challenge. Various factors, including age, sex, and HIV status, have been associated with an increased risk of developing EPTB. However, the influence of the lineage of the infecting Mycobacterium tuberculosis complex (Mtbc) strain remains controversial. MethodsBetween 2008 and 2023, comprehensive clinical data from 1035 cases, along with whole genome sequencing data of the respective Mtbc strains, have been collected. To examine the association between Mtbc lineage and EPTB, we calculated crude and adjusted OR using logistic regression and performed propensity score matching with a subset of the cohort. ResultsOf the 1035 patients, 272 had exclusively extrapulmonary disease and 138 had both pulmonary and extrapulmonary disease. Patients infected with a lineage one strain had the highest odds of developing EPTB in the univariate analysis (OR, 3.30; 95% CI, 1.97–5.49). However, Mtbc lineage was not a significant predictor in the multivariable model, whereas the odds of developing extrapulmonary disease were higher among patients born in the South-East Asian Region (adjusted OR, 6.00; 95% CI, 3.41–10.69) and the Eastern Mediterranean Region (adjusted OR, 5.95; 95% CI, 3.61–9.96) compared with those born in the European Region. Furthermore, female sex and age were significant positive predictors for EPTB. DiscussionOur results demonstrate that host factors, such as geographic origin, age, and sex are stronger predictors for EPTB than infection with an Mtbc strain of a particular lineage. Further investigation of this host-pathogen interaction is needed.

Validation and implementation of whole-genome sequencing-based analytical methods for molecular surveillance and relatedness analysis of Mycobacterium tuberculosis complex isolates at a national reference laboratory

Whole genome sequencing-based methodologies have become extremely relevant for the molecular surveillance of human pathogens and are being increasingly introduced into national reference laboratory services. In this study, we describe the validation and implementation of core-genome Multi-Locus Sequence Typing (cgMLST) and whole genome single-nucleotide polymorphism (wgSNP) analysis at the Irish Mycobacteria Reference Laboratory, as a replacement for Mycobacterial Interspersed Repetitive Unit-Variable Number Tandem Repeat (MIRU-VNTR) typing. Concordance of clustering, discriminatory power, and ease-of-use of both WGS analytical methods were evaluated. Although wgSNP analysis (MTBseq) was the most discriminatory method (p < 0,001), we recommend cgMLST (SeqSphere+), as the first-line approach for molecular typing of Mycobacterium tuberculosis isolates in the context of routine surveillance work due to its ease of use and decreased turnaround time, while reserving wgSNP-analysis for a more in-depth cluster analysis of new isolates that show a distance of ≤12 alleles to any other isolate(s) in the cgMLST database.

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.

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.

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).