Analysis of Phenotypic and Genotypic Susceptibility to Clarithromycin and Amikacin of Mycobacterium abscessus Complex Strains Isolated from Cystic Fibrosis Patients

Mycobacterium; Amikacin; ClarithromycinMicobacteria; Amikacina; ClaritromicinaMicobacteri; Amikacina; ClaritromicinaMycobacterium abscessus complex infections are ever on the rise. To curb their increasing evolution, we performed an in-depth study of 43 clinical isolates of cystic fibrosis patients obtained from 2009 to 2020. We identified their subspecies, uncovered their genotypic resistance profiles, characterised their antibiotic-resistant genes, and assessed their phenotypic antibiotic susceptibilities. The phenotypic and genotypic methods showed total agreement in terms of resistance to clarithromycin and amikacin. Of the 43 clinical strains, 28 belonged to M. abscessus subsp. abscessus (65.1%), 13 to M. abscessus subsp. massiliense (30.2%), and 2 to M. abscessus subsp. bolletii (4.6%). The resistant rates for clarithromycin and amikacin, the two main drugs against M. abscessus complex pulmonary infections, were 64.2% and 14.2%, respectively. We found three strains of M. abscessus subsp. abscessus that showed heteroresistance in the rrl and rrs genes, and these strains also presented double-resistance since they were macrolide- and aminoglycoside-resistant. M. abscessus subsp. abscessus showed a high minimum inhibitory concentration (MIC) and a resistant percentage larger than or equal to 88% to cefoxitin, ciprofloxacin, moxifloxacin, doxycycline, imipenem, and trimethoprim-sulfamethoxazole. These results show a panorama of the high resistance of Mycobacterium abscessus complex to current drugs for cystic fibrosis patients. Thus, other treatment methods are urgently needed.This research received funding from the Fundació Hospital Universitari Vall Hebron—Institut de Recerca

Epidemiology and diagnosis of pleural tuberculosis in a low incidence country with high rate of immigrant population : A retrospective study

Background: The confirmatory diagnosis of pleural tuberculosis (pTB) remains challenging. The aim of this study was to describe the clinical and epidemiological characteristics of pTB patients and assess the yield of different diagnostic procedures in a low burden country with a high rate of immigrant population. Methods: All adult patients with pTB between 2007 and 2014 were studied retrospectively. Results: One hundred and three out of 843 patients with tuberculosis had pTB. Fifty-three (54.1%) were male, and the median age was 45 years (range 18-87 years). Fifty-two (50.49%) patients were immigrants. A confirmed diagnosis was reached in 16 patients (15.5%) by microbiological studies of pleural effusion. Lung involvement was demonstrated by sputum smear microscopy in 13/49 (26.5%), sputum GeneXpert MTB/RIF test in 13/20 (65%), and sputum culture in 16/37 (43.2%). High-resolution computed tomography (CT) showed lung involvement in 47.7% of the patients. The cure rate was 91.3% at the 1-year follow-up. Three patients died, all of them within the first month after diagnosis. Conclusions: The detection of lung involvement increased by two-fold when lung CT was used; this correlated with the likelihood of finding a positive microbiological result on sputum sample testing. Pleural microbiological studies had a low diagnostic yield, and sputum could have a complementary role

Polyresistant Mycobacterium bovis Infection in Human and Sympatric Sheep, Spain, 2017-2018.

The main etiologic agent of tuberculosis (TB) in livestock is Mycobacterium bovis; human TB cases caused by M. bovis are rare. Analysis of a TB outbreak caused by polyresistant M. bovis involving a human and sympatric sheep in Spain suggests local circulation of drug-resistant M. bovis strains among livestock.This work was supported by the Department of Agriculture, Livestock, Fisheries and Food of the Government of Catalonia and by the Spanish Ministry of Agriculture, Fisheries and Food. The Institute of Agrifood Research and Technology is supported by Centres de Recerca de Catalunya Programme/Generalitat de Catalunya.S

Polyresistant Mycobacterium bovis Infection in Human and Sympatric Sheep, Spain, 2017–2018

The main etiologic agent of tuberculosis (TB) in livestock is Mycobacterium bovis; human TB cases caused by M. bovis are rare. Analysis of a TB outbreak caused by polyresistant M. bovis involving a human and sympatric sheep in Spain suggests local circulation of drug-resistant M. bovis strains among livestock.info:eu-repo/semantics/publishedVersio

Safety of Rifampicin at High Dose for Difficult-to-Treat Tuberculosis: Protocol for RIAlta Phase 2b/c Trial

Rifampicin; Tuberculosis; Vulnerable populationRifampicina; Tuberculosis; Población vulnerableRifampicina; Tuberculosi; Població vulnerablePrevious clinical trials for drug-susceptible tuberculosis (DS-TB) have shown that first-line treatment with doses of rifampicin up to 40 mg/kg are safe and increase the early treatment response for young adults with pulmonary tuberculosis. This may lead to a shorter treatment duration for those persons with TB and a good baseline prognosis, or increased treatment success for vulnerable subgroups (age > 60, diabetes, malnutrition, HIV, hepatitis B or hepatitis C coinfection, TB meningitis, stable chronic liver diseases). Here, we describe the design of a phase 2b/c clinical study under the hypothesis that rifampicin at 35 mg/kg is as safe for these vulnerable groups as for the participants included in previous clinical trials. RIAlta is an interventional, open-label, multicenter, prospective clinical study with matched historical controls comparing the standard DS-TB treatment (isoniazid, pyrazinamide, and ethambutol) with rifampicin at 35 mg/kg (HR35ZE group) vs. rifampicin at 10 mg/kg (historical HR10ZE group). The primary outcome is the incidence of grade ≥ 3 Adverse Events or Severe Adverse Events. A total of 134 participants will be prospectively included, and compared with historical matched controls with at least a 1:1 proportion. This will provide a power of 80% to detect non-inferiority with a margin of 8%. This study will provide important information for subgroups of patients that are more vulnerable to TB bad outcomes and/or treatment toxicity. Despite limitations such as non-randomized design and the use of historical controls, the results of this trial may inform the design of future more inclusive clinical trials, and improve the management of tuberculosis in subgroups of patients for whom scientific evidence is still scarce. Trial registration: EudraCT 2020-003146-36, NCT04768231.This study is part of the European South American TB Research Collaborative Network (EUSAT-RCS), a project that has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 823890. A.S.M. is supported by a Juan Rodés (JR18/00022) postdoctoral fellowship from ISCIII

Usefulness of FDG PET/CT in the management of tuberculosis

Tuberculosis; Positron emission tomography (PET); FDGTuberculosis; Tomografía por emisión de positrones (PET); FDGTuberculosi; Tomografia per emissió de positrons (PET); FDGBACKGROUND: The aim of our study is to describe the FDG-PET/CT findings in patients with tuberculosis and to correlate them with the patient's prognosis. METHODS: We retrospectively collected data from patients with tuberculosis, who had an FDG-PET/CT performed prior to treatment initiation from 2010 to 2015. RESULTS: Forty-seven out of 504 patients with active tuberculosis diagnosis (9.33%) underwent an FDG-PET/CT. The reasons for performing the FDG-PET/CT were: characterization of a pulmonary nodule (24; 51.1%), study of fever of unknown origin (12; 25.5%), study of lymph node enlargement (5; 10.6%) and others (6; 12.8%). Median age was 64 (IQR 50-74) years and 31 (66%) patients were male. Twenty-six (55.3%) patients had an immunosuppressant condition. According to the FDG-PET/CT, 48.6% of the patients had more than 1 organ affected and 46.8% had lymph node involvement. Median SUVmax of the main lesion was 5 (IQR 0.28-11.85). We found an association between the FDG accumulation and the size of the main lesion with a correlation coefficient of 0.54 (p<0.002). Patients with an unsuccessful outcome had a higher ratio SUVmax main lesion / SUVmean liver (1.92 vs 7.67, p<0.02). CONCLUSIONS: In our cohort, almost half of the patients had more than 1 organ affected and 46.8% of them had lymph node involvement. FDG uptake was associated with the size of the main lesion and seems to be related to the treatment outcome. The extent of its potential to be used as an early predictor of treatment success still needs to be defined

Immunogenicity of Mycobacterial Extracellular Vesicles Isolated From Host-Related Conditions Informs About Tuberculosis Disease Status

Tuberculosis (TB) still represents a major global health problem affecting over 10 million people worldwide. The gold-standard procedures for TB diagnosis are culture and nucleic acid amplification techniques. In this context, both lipoarabinomannan (LAM) urine test and rapid molecular tests have been major game changers. However, the low sensitivity of the former and the cost and the prohibitive infrastructure requirements to scale-up in endemic regions of the latter, make the improvement of the TB diagnostic landscape a priority. Most forms of life produce extracellular vesicles (EVs), including bacteria despite differences in bacterial cell envelope architecture. We demonstrated that Mycobacterium tuberculosis (Mtb), the causative agent of TB, produces EVs in vitro and in vivo as part of a sophisticated mechanism to manipulate host cellular physiology and to evade the host immune system. In a previous serology study, we showed that the recognition of several mycobacterial extracellular vesicles (MEV) associated proteins could have diagnostic properties. In this study, we pursued to expand the capabilities of MEVs in the context of TB diagnostics by analyzing the composition of MEVs isolated from Mtb cultures submitted to iron starvation and, testing their immunogenicity against a new cohort of serum samples derived from TB+ patients, latent TB-infected (LTBI) patients and healthy donors. We found that despite the stringent condition imposed by iron starvation, Mtb reduces the number of MEV associated proteins relative to iron sufficient conditions. In addition, TB serology revealed three new MEV antigens with specific biomarker capacity. These results suggest the feasibility of developing a point-of-care (POC) device based on selected MEV-associated proteins

Impact of the COVID-19 pandemic on tuberculosis management in Spain

Coronavirus SARS-CoV-2; COVID-19; 2019-nCoV; Impacte; TuberculosiCoronavirus SARS-CoV-2; COVID-19; 2019-nCoV; Impacto; TuberculosisCoronavirus SARS-CoV-2; COVID-19; 2019-nCoV; Impact; TuberculosisBackground The impact of COVID-19 on the diagnosis and management of tuberculosis (TB) patients is unknown. Methods Participating centres completed a structured web-based survey regarding changes to TB patient management during the COVID-19 pandemic. The study also included data from participating centres on patients aged ≥18 diagnosed with TB in 2 periods: March 15 to June 30, 2020 and March 15 to June 30, 2019. Clinical variables and information about patient household contacts were retrospectively collected. Results A total of 7 (70%) TB units reported changes in their usual TB team operations. Across both periods of study, 169 patients were diagnosed with active TB (90 in 2019, 79 in 2020). Patients diagnosed in 2020 showed more frequent bilateral lesions in chest X-ray than patients diagnosed in 2019 ( P = 0.004). There was a higher percentage of latent TB infection and active TB among children in households of patients diagnosed in 2020, compared with 2019 ( P = 0.001). Conclusions The COVID-19 pandemic has caused substantial changes in TB care. TB patients diagnosed during the COVID-19 pandemic showed more extended pulmonary forms. The increase in latent TB infection and active TB in children of patient households could reflect increased household transmission due to anti-COVID-19 measures.This research did not receive any specific grant from funding agencies in the public, commercial or not-for-profit sectors.MLA was supported by a postdoctoral grant “Rio Hortega” and ASM was supported by a postdoctoral grant “Juan Rodés” (JE18/00022) from the Instituto de Salud Carlos III through the Spanish Ministry of economy and competitiveness

Molecular characterization of rpoB gene mutations in isolates from tuberculosis patients in Cubal, Republic of Angola

Angola; Rifampicina; Mutaciones rpoBAngola; Rifampicina; Mutacions rpoBAngola; Rifampicin; rpoB mutationsBackground The importance of Mycobacterium tuberculosis strains with disputed rpoB mutations remains to be defined. This study aimed to assess the frequency and types of rpoB mutations in M. tuberculosis isolates from Cubal, Angola, a country with a high incidence of tuberculosis. Methods All isolates included (n = 308) were analyzed using phenotypic drug susceptibility testing and GenoType MTBDRplus assay. DNA sequencing of the rpoB gene and determination of rifampicin MIC by macrodilution method were additionally performed on isolates yielding discordant results (n = 12) and those in which the mutation detected was not characterized (n = 8). Results In total, 85.1% (74/87) of rifampicin-resistant strains had undisputed rpoB mutations -S450L (49), D435V (15), H445D (3), H445Y (2), Q432ins (1), L449M plus S450F (1), S450F (1), S450W (1) and S450Y (1)-; 10.3% (9/87) had disputed rpoB mutations—L430P plus S493L (1), N437del (1), H445L (3), D435Y (2), L452P (2)-, 2.3% (2.3%) showed no rpoB mutations and 2.3% (2/87) showed heteroresistance—D435Y plus L452P and L430P plus S493L-. Conclusion Disputed rpoB mutations were common, occurring in 10.3% of rifampicin resistant isolates. Current phenotyping techniques may be unable to detect this resistance pattern. To increase their sensitivity, a lower concentration of RIF could be used in these tests or alternatively, rpoB mutations could be screened and characterized in all M. tuberculosis strains.This work was supported by Probitas Foundation. Thanks to the financial support received from Probitas Foundation it was possible not only purchase the equipment and reagents to launch the study but to strengthen the capacity of the laboratory and local staff

Adherence and Toxicity during the Treatment of Latent Tuberculous Infection in a Referral Center in Spain

Latent tuberculosis infection; Toxicity; Tuberculosis screeningInfecció tuberculosa latent; Toxicitat; Cribratge de tuberculosiInfección tuberculosa latente; Toxicidad; Cribado de tuberculosisThe screening and treatment of latent tuberculosis infection (LTBI) in countries with a low incidence of TB is a key strategy for the elimination of tuberculosis (TB). However, treatment can result in adverse events (AEs) and have poor adherence. This study aimed to describe treatment outcomes and AEs for LTBI patients at two departments in Vall d'Hebron University Hospital in Barcelona, Spain. A retrospective study was conducted on all persons treated for LTBI between January 2018 and December 2020. Variables collected included demographics, the reason for LTBI screening and treatment initiation, AEs related to treatment, and treatment outcome. Out of 261 persons who initiated LTBI treatment, 145 (55.6%) were men, with a median age of 42.1 years. The indications for LTBI screening were household contact of a TB case in 96 (36.8%) persons, immunosuppressive treatment in 84 (32.2%), and recently arrived migrants from a country with high TB incidence in 81 (31.0%). Sixty-three (24.1%) persons presented at least one AE during treatment, and seven (2.7%) required definitive discontinuation of treatment. In the multivariate analysis, AE development was more frequent in those who started LTBI treatment due to immunosuppression. Overall, 226 (86.6%) completed treatment successfully. We concluded that LTBI screening and treatment groups had different risks for adverse events and treatment outcomes. Persons receiving immunosuppressive treatment were at higher risk of developing AEs, and recently arrived immigrants from countries with a high incidence of TB had greater LTFU. A person-centered adherence and AE management plan is recommended.A.M.L. was supported by a postdoctoral grant “Juan Rodés” (JE21/00027) from the Instituto de Salud Carlos through the Ministry of Economy and Competitiveness, Spain