Anti-tubercular treatment-induced granulomatous acute interstitial nephritis.

ABSTRACT: This case emphasizes the value of meticulous observation and regular follow-up of patients receiving rifampicin therapy. The prognosis for complete improvement in renal function in such cases was excellent, with prompt recognition and discontinuation of rifampicin. Teaching patients about these possible adverse effects and encouraging immediate reporting of signs and symptoms are likely to be beneficial because acute kidney injury can manifest itself very quickly after rifampicin is started. Even if renal failure can happen with any dose of rifampicin, primary physicians must have awareness about patients on intermittent or irregular therapy and those who have previously used this medication. It is challenging to determine the prevalence of adverse reactions to common antibiotics where a state- or country-wide reporting system is absent. Along with withdrawal of the causative agent patients were treated with corticosteroids (0.5-1 mg/kg/day) for an average period of 4-12 weeks showing significant recovery of renal function.

A machine-learning based model for automated recommendation of individualized treatment of rifampicin-resistant tuberculosis.

BACKGROUND: Rifampicin resistant tuberculosis remains a global health problem with almost half a million new cases annually. In high-income countries patients empirically start a standardized treatment regimen, followed by an individualized regimen guided by drug susceptibility test (DST) results. In most settings, DST information is not available or is limited to isoniazid and fluoroquinolones. Whole genome sequencing could more accurately guide individualized treatment as the full drug resistance profile is obtained with a single test. Whole genome sequencing has not reached its full potential for patient care, in part due to the complexity of translating a resistance profile into the most effective individualized regimen. METHODS: We developed a treatment recommender clinical decision support system (CDSS) and an accompanying web application for user-friendly recommendation of the optimal individualized treatment regimen to a clinician. RESULTS: Following expert stakeholder meetings and literature review, nine drug features and 14 treatment regimen features were identified and quantified. Using machine learning, a model was developed to predict the optimal treatment regimen based on a training set of 3895 treatment regimen-expert feedback pairs. The acceptability of the treatment recommender CDSS was assessed as part of a clinical trial and in a routine care setting. Within the clinical trial setting, all patients received the CDSS recommended treatment. In 8 of 20 cases, the initial recommendation was recomputed because of stock out, clinical contra-indication or toxicity. In routine care setting, physicians rejected the treatment recommendation in 7 out of 15 cases because it deviated from the national TB treatment guidelines. A survey indicated that the treatment recommender CDSS is easy to use and useful in clinical practice but requires digital infrastructure support and training. CONCLUSIONS: Our findings suggest that global implementation of the novel treatment recommender CDSS holds the potential to improve treatment outcomes of patients with RR-TB, especially those with 'difficult-to-treat' forms of RR-TB.

Treatment for multidrug-resistant tuberculosis: A comparative analysis of programmatic outcome indicators between Buenaventura and other municipalities of Valle del Cauca, Colombia / Tratamiento para tuberculosis resistente a rifampicina o multirresistente: análisis comparativo de indicadores programáticos entre Buenaventura y otros municipios del Valle del Cauca, Colombia

Introduction. Proper management of multidrug-resistant tuberculosis is a prioritized strategy for tuberculosis control worldwide. Objective. To evaluate differences concerning demographic and clinical characteristics and programmatic indicators of Buenaventura patient cohort with confirmed diagnosis of multidrug-resistant tuberculosis, compared to those of the other municipalities from Valle del Cauca, Colombia, 2013-2016. Materials and methods. We conducted an analytical cohort study to compare records of patients older than 15 years with multidrug-resistant tuberculosis included in the Programa de Tuberculosis de Buenaventura (with para-aminosalicylic acid) versus the other municipalities of Valle del Cauca (without para-aminosalicylic). Results. Ninety-nine cases were recorded with a median age of 40 years (IQR = 26 - 53); in Buenaventura, 56% of the patients were women, while in the other municipalities, men predominated with 67%; 95% had health insurance. The most common comorbidity was diabetes (14%). Adverse reactions to antituberculosis medications in Buenaventura were 1.3 times more frequent than in the other municipalities (OR = 2.3; 95% CI = 0.993 - 5.568; p = 0.04). In Buenaventura, the mortality rate was 5% compared to the 15% reported in the other municipalities. Treatment failures were not reported in Buenaventura, but 35% did not continue with the follow-up. Treatment success was higher in Buenaventura (56 %). Conclusion. A strengthened program in Buenaventura presented better programmatic results than those from the other municipalities of Valle del Cauca. Access to molecular tests, availability of shortened treatments, and continuous monitoring to identify adverse reactions to antituberculosis medications are routes for all other control programs.

Introducción. El manejo adecuado de la tuberculosis multirresistente es una estrategia priorizada para el control de la tuberculosis en el mundo. Objetivo. Evaluar las diferencias entre las características demográficas y clínicas, y los indicadores programáticos de los pacientes con diagnóstico confirmado de tuberculosis pulmonar resistente a rifampicina o multirresistente en Buenaventura, frente a la cohorte de los demás municipios del Valle del Cauca entre 2013 y 2016. Materiales y métodos. Se desarrolló un estudio analítico de cohortes para comparar los registros de pacientes mayores de 15 años con tuberculosis multirresistente, del Programa de Tuberculosis de Buenaventura (con ácido paraaminosalicílico), frente a los demás municipios del Valle del Cauca (sin ácido paraaminosalicílico). Resultados. Se registraron 99 casos con una mediana de edad de 40 años (RIC = 26- 53); en Buenaventura, el 56 % eran mujeres; en los demás municipios, predominaron los hombres (67 %); el 95 % de los evaluados tenía aseguramiento en salud. La comorbilidad más frecuente fue diabetes (14 %). Las reacciones adversas a medicamentos antituberculosos en Buenaventura fueron 1,3 veces más frecuentes que en los demás municipios (OR = 2,3; IC95 %: 0,993 - 5,568; p = 0,04). En Buenaventura falleció el 5 % de los casos frente al 15 % reportado en los demás municipios. No hubo fracasos con el tratamiento en Buenaventura, pero se reportó un 35 % de pérdida del seguimiento. El éxito del tratamiento fue mayor en Buenaventura en el 56 %. Conclusión. El programa fortalecido de Buenaventura presentó mejores resultados programáticos que los demás municipios del Valle del Cauca. El acceso a pruebas moleculares, la disponibilidad de tratamientos acortados y el seguimiento continuo para identificar reacciones adversas a medicamentos antituberculosos son un derrotero para todos los programas de control.

Cryo-EM structures of a mycobacterial ABC transporter that mediates rifampicin resistance.

Drug-resistant Tuberculosis (TB) is a global public health problem. Resistance to rifampicin, the most effective drug for TB treatment, is a major growing concern. The etiological agent, Mycobacterium tuberculosis (Mtb), has a cluster of ATP-binding cassette (ABC) transporters which are responsible for drug resistance through active export. Here, we describe studies characterizing Mtb Rv1217c-1218c as an ABC transporter that can mediate mycobacterial resistance to rifampicin and have determined the cryo-electron microscopy structures of Rv1217c-1218c. The structures show Rv1217c-1218c has a type V exporter fold. In the absence of ATP, Rv1217c-1218c forms a periplasmic gate by two juxtaposed-membrane helices from each transmembrane domain (TMD), while the nucleotide-binding domains (NBDs) form a partially closed dimer which is held together by four salt-bridges. Adenylyl-imidodiphosphate (AMPPNP) binding induces a structural change where the NBDs become further closed to each other, which downstream translates to a closed conformation for the TMDs. AMPPNP binding results in the collapse of the outer leaflet cavity and the opening of the periplasmic gate, which was proposed to play a role in substrate export. The rifampicin-bound structure shows a hydrophobic and periplasm-facing cavity is involved in rifampicin binding. Phospholipid molecules are observed in all determined structures and form an integral part of the Rv1217c-1218c transporter system. Our results provide a structural basis for a mycobacterial ABC exporter that mediates rifampicin resistance, which can lead to different insights into combating rifampicin resistance.

Pharmacokinetics of olverembatinib (HQP1351) in the presence of a strong CYP3A4 inhibitor (itraconazole) or inducer (rifampin) in healthy volunteers.

Olverembatinib (HQP1351) is a BCR-ABL1 tyrosine kinase inhibitor with promising clinical activity. It is approved in China for the treatment of patients with chronic myeloid leukemia harboring drug-resistant mutations, such as T315I. In vitro studies suggested that metabolism of olverembatinib is primarily mediated by cytochrome P450 (CYP3A4). The effects of CYP3A4 inhibition and induction on the pharmacokinetics of olverembatinib were evaluated in an open-label, 2-part, fixed-sequence study in healthy volunteers. In Part 1 of this study, 16 participants received a single oral dose of olverembatinib (20 mg) and the oral CYP3A4 inhibitor itraconazole (200 mg). In Part 2, 16 participants received a single oral dose of olverembatinib (40 mg) and the oral CYP3A4 inducer rifampin (600 mg). To measure pharmacokinetic parameters, serial blood samples were collected after administration of olverembatinib alone and combined with itraconazole or rifampin. Coadministration of olverembatinib with itraconazole increased the peak plasma concentration of olverembatinib, its area under the time-concentration curve (AUC)0-last, and AUC0-inf by 75.63%, 147.06%, and 158.66%, respectively. Coadministration with rifampin decreased these same variables by 61.27%, 74.21%, and 75.19%, respectively. These results confirm that olverembatinib is primarily metabolized by CYP3A4 in humans, suggesting that caution should be exercised with concurrent use of olverembatinib and strong CYP3A4 inhibitors or inducers.

Diagnostic Accuracy of FluoroCycler XT MTBDR Assay for Detection of Rifampicin and Isoniazid-resistant Mycobacteria tuberculosis in Clinical Isolates from Kenya.

BACKGROUND: Drug-resistant tuberculosis (DR-TB) poses a major global challenge to public health and therapeutics. It is an emerging global concern associated with increased morbidity and mortality mostly seen in the low- and middle-income countries. Molecular techniques are highly sensitive and offer timely and accurate results for TB drug resistance testing, thereby positively influencing patient management plan. METHODS: The study was carried out at the National Tuberculosis Reference Laboratory (NTRL) in Kenya in the period between January and October 2022. A total of 243 Mycobacterium tuberculosis (M.tb) clinical isolates were included in the study. These isolates comprised of 50 isolates with mutations in rpoB, 51 isolates with katG mutations, 51 isolates with mutations in inhA, and 91 M.tb isolates lacking mutations in these genes based on Genotype MTBDRplus results. DNA from the isolates was extracted using the FluoroLyse extraction kit. Real-time polymerase chain reaction targeting the rpoB, InhA, and katG genes was performed using the FluoroType MTBDR amplification mix. Isolates with discordant results between Genotype MTBDRplus and FluoroCycler® MTBDR assays underwent targeted sequencing for the respective genes, then, sequences were analyzed for mutations using Geneious version 11.0 software. RESULTS: The sensitivity of the Fluorocycler XT MTBDR assay for the detection of mutations that confer drug resistance was 86% (95% confidence interval [CI] 73.0-94.0) for rpoB, 96% (95% CI 87-100) for katG and 92% (95% CI 81-98) for inhA. The assay's specificity was 97% (95% CI 93-99) for rpoB, 98% (95% CI 96-100) for katG, and 97% (95% CI 93-99) for inhA. CONCLUSION: The diagnostic accuracy of FluoroType MTBDR for the detection of mutations conferring resistance to rifampicin and isoniazid was high compared with that of Genotype MTBDRplus and demonstrates its suitability as a replacement assay for Genotype MTBDRplus.

Affecting Factors Unfavorable Treatment Outcomes of Rifampicin-resistant/Multidrug-resistant Tuberculosis Patients Treated with Long-term Regimen.

BACKGROUND: Drug-resistant tuberculosis (DR-TB) poses a significant threat to global TB control and remains a major public health issue. This study aims to evaluate treatment outcomes and identify risk factors for unfavorable outcomes in patients with multi-DR-TB (MDR-TB) treated at a major reference hospital in Istanbul. METHODS: We conducted a retrospective analysis of 413 patients with rifampicin-resistant and MDR-TB who received treatment between January 1, 2013, and December 31, 2023, at the University of Health Sciences Süreyyapasa Chest Diseases Training and Research Hospital. Patients were treated following the World Health Organization and national guidelines, with regimens tailored to individual drug resistance profiles and side effect management. Demographic data, comorbidities, microbiological follow-up, drug resistance patterns, treatment regimens, and radiological findings were analyzed. RESULTS: Treatment success was achieved in 350 patients (84.74%). Thirty-two patients (7.74%) were lost to follow-up, and 32 patients (7.74%) died. Logistic regression analysis identified several factors associated with unfavorable treatment outcomes: comorbidities (odds ratio [OR]: 7.555, P = 0.001), quinolone resistance (OR: 3.695, P = 0.030), and bronchiectasis (OR: 4.126, P = 0.013). Additional significant factors included male gender (P = 0.007), foreign-born status (P = 0.013), age over 35 years (P = 0.002), previous treatment history (P = 0.058), and drug side effects (P = 0.012). CONCLUSION: The long-term regimen for MDR-TB was found to be highly successful, with an 84.74% treatment success rate. Effective treatment regimens, close patient follow-up, early recognition of side effects, and comprehensive management are crucial for achieving successful outcomes. Identifying and addressing risk factors such as comorbidities, drug resistance, and specific patient demographics can further improve treatment success rates. This study underscores the importance of tailored treatment strategies and robust patient management in combating MDR-TB.

Diagnostics Evaluation of Smart Sure™ Mycobacterium tuberculosis Screening Kit and Smart Sure™ Multidrug-resistant Tuberculosis Detection Kit on Nonsputum Specimens at a Tertiary Care Center of North India.

BACKGROUND: Tuberculosis (TB) is caused due to the infection of Mycobacterium tuberculosis (MTB) and it can infect the various parts of the human body. The disease is highly prevalent and is the second most common cause of death worldwide after COVID-19. Apart from sputum specimen, it is exceedingly difficult to diagnose due to its paucibacillary nature. The current study was intended to evaluate the accuracy of Smart Sure™ MTB and multidrug-resistant-TB (MDR-TB) kits (Genetix Biotech Asia Pvt. Ltd., India) with Xpert ultra and Mycobacterium growth indicator tube (MGIT) culture on nonsputum specimens from TB suspects. METHODS: A total of 205 nonsputum specimens were received between October 2023 and May 2024 at Intermediate Reference Laboratory, Department of Medicine, All India Institute of Medical Sciences, New Delhi, India. Xpert ultra and Smart Sure™ MTB and MDR-TB tests were done directly on samples. However, processed specimens were used for MGIT culture and drug-susceptibility testing (DST). Invalid and MGIT contaminated specimens were excluded from the final calculation. RESULTS: Overall, sensitivity and specificity of Smart Sure™ MTB screening kit was 71.59% and 98.28%, respectively, with Xpert ultra and 68.35% and 90.83%, respectively, with MGIT culture. While comparing with both Xpert ultra and MGIT-DST to detect rifampicin (RIF) resistant, Smart Sure™ MDR-TB kits showed sensitivity of 75.0% and 100% of specificity. However, for isoniazid (INH) resistance, Smart Sure™ MDR-TB kits showed 100% of sensitivity and specificity with MGIT-DST. CONCLUSION: For the detection of MTB and its drug-resistance patterns (RIF and INH) in the specimens other than sputum, Smart Sure™ MTB and MDR-TB kits could play a vital role in TB endemic countries. While comparing the set-ups and skilled staffs, it required almost same as compared with previously approved WHO diagnostics used in resource-limited countries.

[Skin disease caused by Mycobacterium marinum:a case report].

Mycobacterium marinum infection often affects the extremities, causing single or multiple skin lesions. With the improvement of molecular detection technology and the clinical application of NGS pathogen detection, the diagnosis rate of Mycobacterium marinum skin disease is gradually increasing. This article reported the case of a 54-year-old man who was stung by a marine fish and gradually developed swelling and nodules on his right hand and right upper limb. He was diagnosed with Mycobacterium marinum infection by detection of the tuberculosis resistance gene dissolution curve of the pus and the identification of the bacteria. Oral rifampicin combined with clarithromycin and minocycline was given for anti-infection treatment. During follow-up, the abscesses and nodules gradually shrank and eventually disappeared. By presenting the diagnosis and treatment of this case, the understanding of this disease among clinicians can be improved to avoid misdiagnosis and missed diagnosis.

Rifampicin tolerance and growth fitness among isoniazid-resistant clinical Mycobacterium tuberculosis isolates from a longitudinal study.

Antibiotic tolerance in Mycobacterium tuberculosis reduces bacterial killing, worsens treatment outcomes, and contributes to resistance. We studied rifampicin tolerance in isolates with or without isoniazid resistance (IR). Using a minimum duration of killing assay, we measured rifampicin survival in isoniazid-susceptible (IS, n=119) and resistant (IR, n=84) isolates, correlating tolerance with bacterial growth, rifampicin minimum inhibitory concentrations (MICs), and isoniazid-resistant mutations. Longitudinal IR isolates were analyzed for changes in rifampicin tolerance and genetic variant emergence. The median time for rifampicin to reduce the bacterial population by 90% (MDK90) increased from 1.23 days (IS) and 1.31 days (IR) to 2.55 days (IS) and 1.98 days (IR) over 15-60 days of incubation, indicating fast and slow-growing tolerant sub-populations. A 6 log10-fold survival fraction classified tolerance as low, medium, or high, showing that IR is linked to increased tolerance and faster growth (OR = 2.68 for low vs. medium, OR = 4.42 for low vs. high, p-trend = 0.0003). High tolerance in IR isolates was associated with rifampicin treatment in patients and genetic microvariants. These findings suggest that IR tuberculosis should be assessed for high rifampicin tolerance to optimize treatment and prevent the development of multi-drug-resistant tuberculosis.

Clinical characterization of brucellosis in children from non-pastoral areas: a report of five cases.

BACKGROUND: Brucellosis is a global public health concern and occurs mainly in young adults and the elderly, with children having a lower incidence, thus often leading to delayed treatment. This study aimed to describe the epidemiologic features and clinical characteristics of brucellosis in children. METHODS: In this retrospective study, the clinical data of five children diagnosed with brucellosis in Anhui Provincial Children's Hospital between January 1, 2021 and December 30, 2022 were analyzed. RESULTS: All five cases were from non-pastoral areas, among which three have a history of livestock exposure and originated from the countryside. All patients had medium-high grade fever, mostly accompanied by night sweats and malaise, and three had joint pains. Laboratory tests showed that their white blood cell count was normal or mildly raised, with lymphocytes as the predominant cell population. Four patients had anemia, four had aspartate aminotransferase and alanine aminotransferase abnormality, and two had elevated ferritin levels. All blood samples were positive for Brucella culture, one of which had positive bone marrow culture, and all had positive serology test results. All patients were treated with rifampicin, in combination with sulfamethoxazole or doxycycline for 6 weeks following diagnosis. Four children had a good prognosis, but one child had recurrent joint pain. CONCLUSIONS: The epidemiologic history of children from non-pastoral areas with brucellosis is often unclear; clinical manifestations and laboratory tests lack specificity; and they are easily delayed diagnosis. Clinicians should remain vigilant regarding the possibility of this disease in children with fever of unknown origin. The epidemiological history should be investigated in detail to improve the diagnostic ability of brucellosis. We recommend emphasizing serological testing. Children with brucellosis who receive timely diagnosis and standardized treatment can expect a favorable prognosis.

Unveiling the complexity of rifampicin drug susceptibility testing in Mycobacterium tuberculosis: comparative analysis with next-generation sequencing.

Introduction. The discordance between phenotypic and molecular methods of rifampicin (RIF) drug susceptibility testing (DST) in Mycobacterium tuberculosis poses a significant challenge, potentially resulting in misdiagnosis and inappropriate treatment.Hypothesis/gap statement. A comparison of RIF phenotypic and molecular methods for DST, including whole genome sequencing (WGS), may provide a better understanding of resistance mechanisms.Aim. This study aims to compare RIF DST in M. tuberculosis using two phenotypic and molecular methods including the GeneXpert RIF Assay (GX) and WGS for better understanding.Methodology. The study evaluated two phenotypic liquid medium methods [Lowenstein-Jensen (LJ) and Mycobacterium Growth Indicator Tube (MGIT)], one targeted molecular method (GX), and one WGS method. Moreover, mutational frequency in ponA1 and ponA2 was also screened in the current and previous RIF resistance M. tuberculosis genomic isolates to find their compensatory role.Results. A total of 25 RIF-resistant isolates, including nine from treatment failures and relapse cases with both discordant and concordant DST results on LJ, MGIT and GX, were subjected to WGS. The phenotypic DST results indicated that 11 isolates (44%) were susceptible on LJ and MGIT but resistant on GX. These isolates exhibited multiple mutations in rpoB, including Thr444>Ala, Leu430>Pro, Leu430>Arg, Asp435>Gly, His445>Asn and Asn438>Lys. Conversely, four isolates that were susceptible on GX and MGIT but resistant on LJ were wild type for rpoB in WGS. However, these isolates possessed several novel mutations in the PonA1 gene, including a 10 nt insertion and two nonsynonymous mutations (Ala394>Ser, Pro631>Ser), as well as one nonsynonymous mutation (Pro780>Arg) in PonA2. The discordance rate of RIF DST is higher on MGIT than on LJ and GX when compared to WGS. These discordances in the Delhi/CAS lineages were primarily associated with failure and relapse cases.Conclusion. The WGS of RIF resistance is relatively expensive, but it may be considered for isolates with discordant DST results on MGIT, LJ and GX to ensure accurate diagnosis and appropriate treatment options.

LATENT TUBERCULOSIS IN PATIENTS WITH CROHN'S DISEASE IN A UNIVERSITY HOSPITAL IN NORTHEASTERN BRAZIL: A RETROSPECTIVE STUDY.

BACKGROUND: Among chronic condition problems, tuberculosis still represents a serious public health problem globally. OBJECTIVE: To investigate latent tuberculosis infection in patients with Crohn's disease. Retrospective, descriptive cross-sectional study of quantitative analysis. METHODS: The research was conducted on diagnosed cases of Crohn's disease at the University Hospital located in a city in Northeastern Brazil. All cases of patients with Crohn's disease undergoing isoniazid or rifampicin therapy for latent tuberculosis (LTBI) were included in the study. The data obtained were subsequently subjected to statistical analysis using the Statistical Package for the Social Sciences (SPSS) program. RESULTS: We analyzed 235 medical records, and it was observed that 56% were male, with a mean age of 42.7. Among these, 54% declared themselves as brown, 31% had completed high school, and 47% were residents of the city of Teresina. Regarding the clinical and epidemiological characteristics of the studied patients classified as having ILTB, 34% of the medical records were diagnosed by tuberculin test, 48.51% were investigated by x-ray examination, and the recent location affected the colon with 27%. CONCLUSION: Overall, the health profile of the participants in this study aligns with findings previously established in the literature, particularly studies conducted in other Brazilian states, as well as in other developing countries.

EFFICACY AND SAFETY OF SILVER NANOCOMPOSITES ON RIFAMPICIN-RESISTANT M. TUBERCULOSIS STRAINS.

BACKGROUND: Control of rifampicin-resistant tuberculosis (RR-MTB) requires novel technologies for restoring the anti-TB efficacy of priority drugs. We sought to evaluate the ability of nanotechnology application in the recovery of the anti-tuberculosis efficacy of rifampicin. METHODS: Nanocomposite- standard dose of rifampicin and 20 nm silver nanoparticles (AgNPs) suspension solution of 6 different concentrations: 0.25%; 0.5%; 1%; 2.5%; 5%; and 10%, were supplemented to 70 rifampicin-resistant mycobacterium tuberculosis (RR-MTB) isolates. The control arm consisted of 35 RR-MTB isolates and AgNPs suspension with identical concentrations. The inhibitory effect of nanocomposites was evaluated by MTB growth rate using the BACTECTM MGIT 960TM. The safety assessment of single-use AgNPs was conducted in experimental animals. RESULTS: The suppression process of AgNPs on RR-MTB isolates started with 2,5% nanocomposite solution application and full suppression was achieved in 5% and 10% nanocomposite solutions. A standard dose of rifampicin and a 2.5% solution of AgNPs increased the minimal inhibitory effect on RR-MTB by 10% (total 80%) vs the isolated use of a 2.5% solution of AgNPs (70%). An experiment on animals revealed the complete safety of a single injection of ultra-high doses of AgNPs. CONCLUSION: The study showed the potentiating effect of AgNPs in overcoming the resistance of MTB to rifampicin providing a scientific basis for further research.

Infection by a multidrug-resistant Corynebacterium diphtheriae strain: prediction of virulence factors, CRISPR-Cas system analysis, and structural implications of mutations conferring rifampin resistance.

Cases of diphtheria, even in immunized individuals, are still reported in several parts of the world, including in Brazil. New outbreaks occur in Europe and other continents. In this context, studies on Corynebacterium diphtheriae infections are highly relevant, both for a better understanding of the pathogenesis of the disease and for controlling the circulation of clones and antimicrobial resistance genes. Here we present a case of cutaneous infection by multidrug-resistant Corynebacterium diphtheriae and provide its whole-genome sequencing. Genomic analysis revealed resistance genes, including tet(W), sul1, cmx, rpoB2, rbpA and mutation in rpoB. We performed phylogenetic analyzes and used the BRIG to compare the predicted resistance genes with those found in genomes from other significant isolates, including those associated with some outbreaks. Virulence factors such as spaD, srtBC, spaH, srtDE, surface-anchored pilus proteins (sapD), nonfimbrial adhesins (DIP0733, DIP1281, and DIP1621), embC and mptC (putatively involved in CdiLAM), sigA, dtxR and MdbA (putatively involved) in post-translational modification, were detected. We identified the CRISPR-Cas system in our isolate, which was classified as Type II-U based on the database and contains 15 spacers. This system functions as an adaptive immune mechanism. The strain was attributed to a new sequence type ST-928, and phylogenetic analysis confirmed that it was related to ST-634 of C. diphtheriae strains isolated in French Guiana and Brazil. In addition, since infections are not always reported, studies with the sequence data might be a way to complement and inform C. diphtheriae surveillance.

Pharmacokinetics of extended-release clarithromycin in patients with Mycobacterium ulcerans infection.

Clarithromycin extended-release (CLA-ER) was used as companion drug to rifampicin (RIF) for Mycobacterium ulcerans infection in the intervention arm of a WHO drug trial. RIF enhances CYP3A4 metabolism, thereby reducing CLA serum concentrations, and RIF concentrations might be increased by CLA co-administration. We studied the pharmacokinetics of CLA-ER at a daily dose of 15 mg/kg combined with RIF at a dose of 10 mg/kg in a subset of trial participants, and compared these to previously obtained pharmacokinetic data. Serial dried blood spot samples were obtained over a period of ten hours, and analyzed by LC-MS/MS in 30 study participants-20 in the RIF-CLA study arm, and 10 in the RIF-streptomycin study arm. Median CLA Cmax was 0.4 mg/L-and median AUC 3.9 mg*h/L, following 15 mg/kg CLA-ER. Compared to standard CLA dosed at 7.5 mg/kg previously, CLA-ER resulted in a non-significant 58% decrease in Cmax and a non-significant 30% increase in AUC. CLA co-administration did not alter RIF Cmax or AUC. Treatment was successful in all study participants. No effect of CLA co-administration on RIF pharmacokinetics was observed. Based on our serum concentration studies, the benefits CLA-ER over CLA immediate release are unclear.

Targeted next-generation sequencing of Mycobacterium tuberculosis from patient samples: lessons learned from high drug-resistant burden clinical settings in Bangladesh.

Lack of appropriate early diagnostic tools for drug-resistant tuberculosis (DR-TB) and their incomplete drug susceptibility testing (DST) profiling is concerning for TB disease control. Existing methods, such as phenotypic DST (pDST), are time-consuming, while Xpert MTB/RIF (Xpert) and line probe assay (LPA) are limited to detecting resistance to few drugs. Targeted next-generation sequencing (tNGS) has been recently approved by WHO as an alternative approach for rapid and comprehensive DST. We aimed to investigate the performance and feasibility of tNGS for detecting DR-TB directly from clinical samples in Bangladesh. pDST, LPA and tNGS were performed among 264 sputum samples, either rifampicin-resistant (RR) or rifampicin-sensitive (RS) TB cases confirmed by Xpert assay. Resistotypes of tNGS were compared with pDST, LPA and composite reference standard (CRS, resistant if either pDST or LPA showed a resistant result). tNGS results revealed higher sensitivities for rifampicin (RIF) (99.3%), isoniazid (INH) (96.3%), fluoroquinolones (FQs) (94.4%), and aminoglycosides (AMGs) (100%) but comparatively lower for ethambutol (76.6%), streptomycin (68.7%), ethionamide (56.0%) and pyrazinamide (50.7%) when compared with pDST. The sensitivities of tNGS for INH, RIF, FQs and AMGs were 93.0%, 96.6%, 90.9%, and 100%, respectively and the specificities ranged from 91.3 to 100% when compared with CRS. This proof of concept study, conducted in a high-burden setting demonstrated that tNGS is a valuable tool for identifying DR-TB directly from the clinical specimens. Its feasibility in our laboratory suggests potential implementation and moving tNGS from research settings into clinical settings.

Risk assessment and transmission of fluoroquinolone resistance in drug-resistant pulmonary tuberculosis: a retrospective genomic epidemiology study.

Fluoroquinolone resistance is a major challenge in treating Multidrug-Resistant Tuberculosis globally. The GenoType MTBDRsl Ver 2.0, endorsed by the WHO, was used to characterize fluoroquinolone resistance. The fluoroquinolone resistance rates in the MDR-TB, Rifampicin-Resistant TB, and non-MDR-TB were 33%, 16.5%, and 5.4%, respectively. The most common mutation found in fluoroquinolone-resistant isolates was D94G (49.5%) in the gyrA gene. Of the 150 MDR-TB isolates, the prevalence of Extensively Drug-Resistant Tuberculosis and pre-XDR-TB was 1.33% and 30%, respectively. Among the 139 RR-TB isolates, pre-XDR-TB prevalence was 15.8%. The fluoroquinolone resistance rates were 5.12% among the 1230 isoniazid-monoresistant isolates. The study found that MDR-TB and RR-TB have higher risk of fluoroquinolone resistance than non-MDR tuberculosis. Rifampicin-resistant isolates with a mutation at codon S450L have a higher risk (RR = 12.96; 95%CI: 8.34-20.13) of developing fluoroquinolone resistance than isolates with mutations at other codons in the rpoB gene. Isoniazid-resistant isolates with a mutation at codon S315T have a higher risk (RR = 2.09; 95%CI: 1.25-3.50) of developing fluoroquinolone resistance. The study concludes that rapid diagnosis of fluoroquinolone resistance before starting treatment is urgently needed to prevent the spread and increase of resistance and to achieve better treatment outcomes in areas where it is higher.

Factors associated with incomplete tuberculosis preventive treatment: a retrospective analysis of six-years programmatic data in Cambodia.

Tuberculosis (TB) preventive treatment (TPT) effectively prevents the progression from TB infection to TB disease. This study explores factors associated with TPT non-completion in Cambodia using 6-years programmatic data (2018-2023) retrieved from the TB Management Information System (TB-MIS). Out of 14,262 individuals with latent TB infection (LTBI) initiated with TPT, 299 (2.1%) did not complete the treatment. Individuals aged between 15-24 and 25-34 years old were more likely to not complete the treatment compared to those aged < 5 years old, with aOR = 1.7, p = 0.034 and aOR = 2.1, p = 0.003, respectively. Individuals initiated with 3-month daily Rifampicin and Isoniazid (3RH) or with 6-month daily Isoniazid (6H) were more likely to not complete the treatment compared to those initiated with 3-month weekly Isoniazid and Rifapentine (3HP), with aOR = 2.6, p < 0.001 and aOR = 7, p < 0.001, respectively. Those who began TPT at referral hospitals were nearly twice as likely to not complete the treatment compared to those who started the treatment at health centers (aOR = 1.95, p = 0.003). To improve TPT completion, strengthen the treatment follow-up among those aged between 15 and 34 years old and initiated TPT at referral hospitals should be prioritized. The national TB program should consider 3HP the first choice of treatment.

Predicting the incidence of rifampicin resistant tuberculosis in Yunnan, China: a seasonal time series analysis based on routine surveillance data.

BACKGROUND: Rifampicin resistant tuberculosis (RR-TB) poses a growing threat to individuals and communities. This study utilized a seasonal autoregressive integrated moving average (SARIMA) model to quantitatively predict the monthly incidence of RR-TB in Yunnan Province which could guide government health administration departments and the centers for disease control and prevention (CDC) in preventing and controlling the RR-TB epidemic. METHODS: The study utilized routine surveillance reporting data from the infectious Disease Network Surveillance and Reporting System. Monthly incidence rates of RR-TB were collected from January 2019 to December 2022. A time series SARIMA model was used to predict the number of monthly RR-TB cases in Yunnan Province in 2023, and the model was validated using time series plots, seasonal and non-seasonal differencing, autocorrelation and partial autocorrelation analysis, and white noise tests. RESULTS: From 2019 to 2022, the incidence of RR-TB decreases as the incidence of all TB decreases (P < 0.05). There was no significant change in the proportion of RR-TB among all TB cases, which remained within 2.5% (P>0.05). The time series decomposition shows that it presented obvious seasonality, periodicity and randomness after being decomposed. Time series analysis was performed on the original series after 1 non-seasonal difference and 1 seasonal difference, the ADF test showed P < 0.05. According to ACF and PACF, the SARIMA (1, 1, 1) (1, 1, 0)12 model was chosen and statistically significant model parameter estimates (P < 0.05). The predicted seasonal trend of RR-TB incidence in 2019 to 2023 was similar to the actual data. The percentage accuracy in the prediction excesses 80% in 2019 to 2022 and is all within 95% CI. However there was a certain gap between the actual incidence and the predicted value in 2023, and the acutual incidence had increased by 12.4% compared to 2022. The percentage of accuracy in the prediction was only 70% in 2023. CONCLUSIONS: We found the incidence of RR-TB was based on that of all TB in Yunnan. The SARIMA model successfully predicted the seasonal incidence trend of RR-TB in Yunnan Province in 2019 to 2023, but the prediction precision could be influenced by factors such as new infectious disease outbreaks or pandemics, social issues, environmental challenges or other unknown risks. Hence CDCs should pay special attention to the post epidemic effects of new infectious disease outbreaks or pandemics, carry out monitoring and early warning, and better optimize disease prediction models.