Evaluation of Diagnostic Methods and Rifampicin Resistance in Pulmonary Tuberculosis: A Hospital-Based Study.

Background Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis, predominantly affecting the lungs (pulmonary TB) and is a significant public health challenge in India. The study aims to analyze demographic, radiological, and clinical subgroups of pulmonary TB cases, examine the relationship between smear acid-fast bacillus (AFB examination) and cartridge-based nucleic acid amplification test (CBNAAT), evaluate CBNAAT sensitivity for Mycobacterium tuberculosis (MTB) in new and previously treated patients, and determine the proportion of rifampicin resistance. Methods This hospital-based prospective study was conducted among patients diagnosed with pulmonary TB at the Respiratory Medicine Department of a Government Hospital over 16 months (August 2019 to December 2020). The study included 150 diagnosed TB cases (new and previously treated). Data collection encompassed demographic details, clinical symptoms, comorbidities, radiological findings (chest X-ray), and microbiological results (smear AFB examination, CBNAAT). Sputum samples were subjected to Ziehl-Neelsen staining and CBNAAT for MTB detection and rifampicin resistance testing. Statistical analysis was performed using IBM SPSS Statistics version 21.0 (IBM Corp., Armonk, NY, USA). Results Of the 150 patients, 69.3% were male, and 48% were aged 21-40 years. The majority had a BMI of 18.5-24.9 kg/m² (50%) and resided in urban areas (63.3%). Common symptoms included cough (95.3%), fever (80%), and weight loss (74%). Cavitary lesions on chest X-ray were observed in 84% of patients. Smear microscopy detected MTB in 72.7% of cases, while CBNAAT detected MTB in 94% of cases. CBNAAT sensitivity for smear-positive and smear-negative samples was 93.97% and 94.12%, respectively. Rifampicin resistance was found in 3% of new cases and 6% of previously treated cases. The sensitivity of smear microscopy was 77.33%, and the sensitivity of CBNAAT was 94%. Conclusion The study underscores the high burden of pulmonary TB and the utility of CBNAAT in detecting MTB and rifampicin resistance, particularly in smear-negative samples. The findings highlight the necessity of universal drug susceptibility testing (DST) for effective TB management and the importance of addressing drug resistance to improve treatment outcomes.

Mycobacterium tuberculosis and rifampicin-resistant tuberculosis among tuberculosis presumptive patients in selected zones of Tigray, Northern Ethiopia, 2016-2019.

Introduction: Tuberculosis (TB) is the second leading cause of mortality from an infectious disease worldwide. Multidrug-resistant tuberculosis (MDR-TB), where rifampicin-resistant TB is the biggest contributor, remains a global health threat. There is scant data on MTB and rifampicin resistance (RR-MTB) using Gene Xpert MTB/RIF assay in Ethiopia. This study aimed to determine the prevalence of MTB and RR-MTB among presumptive TB patients in Tigray, Northern Ethiopia. Methods: A multi-center retrospective cross-sectional study was conducted from October 2019 to December 2019 among presumptive MTB patients from four hospitals in Tigray. Records of sputum sample results of presumptive MTB patients analyzed with Gene Xpert MTB/RIF assay from January 2016 to December 2019 were investigated. Data were extracted using a data-extraction tool from registration books and analyzed using SPSS ver.21. Statistically significant was set at p-value ≤0.05. Results: From 17,329 presumptive adult MTB patients who had submitted sputum samples for TB diagnosis, 16,437 (94.9 %) had complete records and were included in the study. More than half (60.2 %) of them were males and ages ranged from 18 to 98 years. Majority of the participants: 15,047(91.5 %) were new cases and 11,750 (71.5 %) were with unknown HIV status. Prevalence of MTB was 9.7 % (95 % CI: 9.2-10.2 %) of these, rifampicin resistant-MTB was 8.7 % (95 % CI: 7.32-10.09 %). Age (being >29 years) [p < 0.001] and new cases [AOR = 0.46; 95%CI = 0.39, 0.53, p < 0.001] were associated with low TB infection. Age groups of 18-29 years were associated with higher RR-MTB [AOR = 3.08; 95 % CI = 1.07, 8.72, p = 0.036]. Conclusion: Nearly one-tenth of the presumptive tuberculosis patients tested positive for MTB; out of these, 8.7 % were RR-MTB. The high prevalence of TB and RR-MTB at a young age and previously treated cases calls for a concerted effort to improve and monitor TB treatment to reduce the problem.

Factors influencing false-positive results of rifampicin resistance detected by Xpert MTB/RIF: A retrospective study in Zhejiang, China.

Objective: This study aimed to explore the factors influencing false-positive results for rifampicin resistance (RIF-R) detected using Xpert MTB/RIF (Xpert). Methods: This retrospective analysis included the clinical data of patients from September 2019 to February 2023. The chi-square and rank sum tests were used to compare differences in patient characteristics between the true-positive and false-positive groups. Logistic regression was used to analyze the factors influencing false positives in the detection of RIF-R by Xpert. Results: A total of 384 patients were included. Logistic regression analysis revealed that, with mutation of probe E as the reference, mutations on probe A or C (OR = 72.68, P < 0.001), probe D (OR = 6.44, P < 0.001), and multiple probes (OR = 5.94, P = 0.002) were associated with false-positive results in Xpert detection of RIF-R. Taking probe delay ΔCt <4 as the reference, ΔCt (4-5.9) (OR = 13.54, P < 0.001), ΔCt (6-7.9) (OR = 48.08, P < 0.001) probe delays were associated with false positives in Xpert detection of RIF-R. When very low quantification is accompanied by a probe delay, the probability of false-positive RIF-R detection can reach 80 %. Conclusions: Clinicians should consider factors such as probe mutation type, probe delay, and very low quantification accompanied by probe delay when interpreting Xpert results, which can reduce the misdiagnosis of tuberculosis drug resistance.

Evaluation of Diagnostic Performance of Line Probe Assay on Smear-Negative Samples of Pulmonary Tuberculosis.

BACKGROUND: This study aims to compare the performance of line probe assay (LPA) on smear-negative samples with that of smear-positive samples for diagnosing pulmonary tuberculosis (PTB) and first-line drug sensitivity testing (FL DST). METHODS: A total of 196 sputum samples including both smear-positive (112) and negative (84) samples of patients suspected of PTB were subjected to LPA for TB detection and FL DST. TB culture followed by MPT 64 Ag was done and conventional FL DST was performed on all culture-positive isolates. Results of LPA on smear-negative were compared with smear-positive samples. RESULTS: The LPA confirmed the diagnosis of PTB in 104/112 smear-positive cases but in only 36/84 smear-negative cases. The assay had 47.36%, 72.72%, and 88.88% sensitivity and 86.96%, 95.23%, and 95.65% specificity in smear-negative cases compared to 89.09%, 95.83%, and 98.07% sensitivity and 100%, 98.36%, and 98.24% specificity in smear-positive cases for detecting Mycobacterium tuberculosis (MTB), rifampicin (RMP) resistance, and isoniazid (INH) resistance, respectively. CONCLUSION: LPA performance was better on smear-positive than smear-negative sputum samples. Further larger studies are needed to justify the use of LPA on smear-negative pulmonary samples for diagnosis.

A case report of using gauze packing to treat postoperative chest bleeding after left pneumonectomy for secondary rifampicin-resistant tuberculosis.

One patient with rifampin-resistant tuberculosis underwent emergency left pneumonectomy and thoracic gauze packing for hemoptysis due to recurrent hemoptysis after transcatheter arterial embolization. Vital signs were maintained by mechanical ventilation and medication. Tracheotomy and anti-tuberculosis treatment were performed. After half a year of follow-up, the patient's condition was stable.

Dual-centre evaluation of the FluoroType MTBDR version 2 assay for detection of Mycobacterium tuberculosis complex and resistance-conferring mutations in pulmonary and extrapulmonary samples from Denmark, Germany and Sierra Leone.

OBJECTIVES: We evaluated the ability of FluoroType MTBDR version 2 (FTv2; Hain Lifescience), a second-step real-time PCR assay, to simultaneously detect Mycobacterium tuberculosis complex (MTBC) DNA and mutations conferring resistance to rifampicin (RIF) and isoniazid (INH), in pulmonary and extrapulmonary samples from patients and compared them with corresponding cultures. METHODS: FTv2 MTBC was evaluated on 1815 and 432 samples from Denmark (DK) and Germany (DE), respectively. RIF and INH resistance mutations were assessed in the German samples and 110 samples from Sierra Leone and subsequently compared to phenotypic antimicrobial susceptibility testing and a composite reference DNA (CRD) based on the GenoType MTBDR line-probe assay and Sanger sequencing or whole-genome sequencing. RESULTS: Of the 584 (557 smear-negative) Danish and 277 (85 smear-negative) German sputum samples, 42 (16) and 246 (54) were culture positive, and 44 (18) and 222 (35) were FTv2 positive, providing an FTv2 sensitivity and specificity of 0.86 (0.63) and 0.98 (DK), 0.90 (0.65) and 1.00 (DE), respectively. The count, sensitivities, and specificities for all pulmonary samples were 1434, 0.79, and 0.99 (DK) and 347, 0.86, and 1.00 (DE), respectively; for extrapulmonary samples, 381, 0.33, 0.99 (DK) and 83, 0.50, and 1.00 (DE). The valid count, sensitivity, and specificity compared with CRD for detecting resistance mutations were RIF 355, 0.99, 0.96, and INH 340, 1.00, and 0.98, respectively. DISCUSSION: FTv2 reliably detects MTBC DNA in pulmonary and extrapulmonary samples and detects resistance mutations for INH and RIF resistance in inhA promoter, katG, and rpoB genes.

Genotoxicity of ultraviolet light and sunlight in the bacterium Caulobacter crescentus: Wavelength-dependence.

The ultraviolet (UV) component of sunlight can damage DNA. Although most solar UV is absorbed by the ozone layer, wavelengths > 300 nm (UVA and UVB bands) can reach the Earth's surface. It is essential to understand the genotoxic effects of UV light, particularly in natural environments. Caulobacter crescentus, a bacterium widely employed as a model for cell cycle studies, was selected for this study. Strains proficient and deficient in DNA repair (uvrA-) were used to concurrently investigate three genotoxic endpoints: cytotoxicity, SOS induction, and gene mutation, using colony-formation, the SOS chromotest, and RifR mutagenesis, respectively. Our findings underscore the distinct impacts of individual UV bands and the full spectrum of sunlight itself in C. crescentus. UVC light was highly genotoxic, especially for the repair-deficient strain. A UVB dose equivalent to 20 min sunlight exposure also affected the cells. UVA exposure caused a significant response only at high doses, likely due to activation of photorepair. Exposure to solar irradiation resulted in reduced levels of SOS induction, possibly due to decreased cell survival. However, mutagenicity is increased, particularly in uvrA- deficient cells.

Strain-specific Growth Parameters are Important to Accurately Model Bacterial Growth on Baby Spinach in Simulation Models.

Digital tools to predict produce shelf life have the potential to reduce food waste and improve consumer satisfaction. To address this need, we (i) performed an observational study on the microbial quality of baby spinach, (ii) completed growth experiments of bacteria that are representative of the baby spinach microbiota, and (iii) developed an initial simulation model of bacterial growth on baby spinach. Our observational data showed that the predominant genera found on baby spinach were Pseudomonas, Pantoea and Exiguobacterium. Rifampicin-resistant mutants (rifR mutants) of representative bacterial subtypes were subsequently generated to obtain strain-specific growth parameters on baby spinach. These experiments showed that: (i) it is difficult to select rifR mutants that do not have fitness costs affecting growth (9 of 15 rifR mutants showed substantial differences in growth, compared to their corresponding wild-type strain) and (ii) based on estimates from primary growth models, the mean (geometric) maximum population of rifR mutants on baby spinach (7.6 log10 CFU/g, at 6°C) appears lower than that of the spinach microbiota (9.6 log10 CFU/g, at 6°C), even if rifR mutants did not have substantial growth-related fitness costs. Thus, a simulation model, parameterized with the data obtained here as well as literature data on home refrigeration temperatures, underestimated bacterial growth on baby spinach. The root mean square error of the simulation's output, compared against data from the observational study, was 1.11 log10 CFU/g. Sensitivity analysis was used to identify key parameters (e.g., strain maximum population) that impact the simulation model's output, allowing for prioritization of future data collection to improve the simulation model. Overall, this study provides a roadmap for the development of models to predict bacterial growth on leafy vegetables with strain-specific parameters and suggests that additional data are required to improve these models.

Trends of Mycobacterium tuberculosis and Rifampicin resistance in Northwest Ethiopia: Xpert® MTB/RIF assay results from 2015 to 2021.

BACKGROUND: Tuberculosis (TB) remains one of the leading causes of morbidity and mortality worldwide, particularly in countries with limited resources. The emergence of drug resistance in mycobacterium tuberculosis (MTB), particularly rifampicin (RIF) resistance, hindered TB control efforts. Continuous surveillance and regular monitoring of drug-resistant TB, including rifampicin resistance (RR), are required for effective TB intervention strategies and prevention and control measures. OBJECTIVE: Determine the trend of TB and RR-TB among presumptive TB patients in Northwest Ethiopia. METHOD: A retrospective study was conducted at the University of Gondar Comprehensive Specialized Hospital (UoG-CSH). The study included TB registration logbook data from all patients who visited the hospital and were tested for MTB using the Xpert® MTB/RIF assay between 2015 and 2021. The SPSS version 26 software was used to enter, clean, and analyze the laboratory-based data. RESULTS: A total of 18,787 patient results were included, with 93.8% (17,615/18787) of them being successful, meaning they were not invalid, error, or aborted. About 10.5% (1846/17615) of the 17,615 results were MTB-positive, with 7.42% (137/1846) RIF resistant. Age, anti-TB treatment history, and diagnosis year were associated with the presence of MTB and RR-MTB. Tuberculosis (TB) prevalence was higher in productive age groups, whereas RR-TB prevalence was higher in the elderly. Regarding diagnosis year, the prevalence of TB and RR-TB showed a declining trend as the year progressed. While MTB was detected in 12.8% (471/3669) of new and 22.2% (151/679) of re-treatment presumptive TB patients, RR-MTB was detected in 8.5% (40/471) of new and 18.5% (28/151) of re-treatment TB cases. CONCLUSION: The prevalence of TB and RR-TB in the study area showed a declining trend over the years. While TB was more prevalent in productive age groups (15 to 45 years), RR-TB was more prevalent in older populations (over 45 years), than others. Moreover, patients with a history of anti-TB drug exposure were more likely to be positive for DR-TB, highlighting the need to strengthen DOT programs for proper management of TB treatment.

Prevalence of Rifampicin resistance tuberculosis among presumptive tuberculosis patients in Egypt-2021: a national health facility-based survey.

BACKGROUND: The magnitude of MDR-TB cases was noticeable in Egypt. However, the last national survey was 11-years ago. The current survey was conducted to determine the prevalence of rifampicin resistance among sputum smear-positive pulmonary tuberculosis patients in Egypt. METHODS: A national health facility-based cross-sectional study was conducted in 14 randomly selected governorates in Egypt between August 2020 and September 2021. All presumptive TB cases, either new or previously treated according to WHO definitions, with no gender, age, or nationality limitations, and provided informed consent were included in the study. Each patient completed a case report form (CRF). The CRF included socio-demographic and clinical data. Sputum samples were collected according to standard techniques and cultured on Lowenstein-Jensen (L-J) medium. Gene X-pert test was carried out first on the samples for simultaneous identification of MTB and rifampicin resistance. The prevalence of RR was calculated using crude, cluster, and weighted methods. Factors associated with RR were analyzed by bivariate and multivariate techniques. RESULTS: Among the total 849 presumptive TB patients enrolled in the study, 710 (83.6%) patients were subjected to Gene X-pert testing (MTB/RIF). The crude prevalence of RR was 3.32% (95% CI: 1.89-4.76%) among the new cases and 9.46% (95% CI: 2.63-16.29%) among the retreated cases with an overall estimate of 3.99%; (95% CI: 2.51-5.47%). By cluster analysis the overall prevalence of RR was 5.01% (95% CI: 2.90-7.13). Factors associated with the prevalence of RR were co-morbidity with bronchial asthma, drug abuse and history of contact with a family member with TB. CONCLUSION: The prevalence of RR among either new or retreated cases TB patients was lower than the previous Egyptian rates in 2010-2012. The strongest predictor associated with RR was comorbidity with bronchial asthma.

Treatment outcomes of retreated patients with isoniazid/rifampicin resistant pulmonary tuberculosis.

BACKGROUND: About 8% of TB cases worldwide are estimated to have rifampicin-susceptible, isoniazid-resistant tuberculosis (Hr-TB), ranging from 5 to 11% regions. However, Hr-TB has not received much attention while comparing to be given high priority to the management of rifampicin-resistant tuberculosis (RR-TB). This study aimed to compare the differences of treatment effects for Hr-TB and RR-TB, so as to intensify the treatment and management of Hr-TB. METHODS: A retrospective study was used to collect bacteriologically positive retreated patients with isoniazid/rifampicin resistant pulmonary tuberculosis, who were conducted at 29 tuberculosis control institutions in China from July 2009 to June 2021. We assessed effectiveness and safety of retreated patients with isoniazid/ rifampicin resistant pulmonary tuberculosis. RESULTS: A total of 147 with either positive smear or cultures were enrolled, and 80 cases were in Hr-TB group and 67 cases were in RR-TB group. There was no significant difference in terms of age, sex, body mass, type of retreatment and comorbid diabetes between the two groups (P > 0.05). The rate of number of lesions involving lung fields ≥ 3 in Hr-TB group 75.9% (60/79) was significantly higher than RR-TB group 56.7% (38/67) (χ2 = 6.077, P = 0.014). There was no statistically significant difference (P = 0.166) with regard to the treatment outcomes of the two groups, the cure rates were 54.7% (41/75) and 53.6% (30/56), respectively, and the failure rate in Hr-TB group 22.7% (17/75) was 10% higher than RR-TB group 10.7% (6/56). The rate of negative sputum smear at the end of the second month (65.7%) in the Hr-TB group was significantly lower than that in the RR-TB group (85.7%) (P = 0.025). There were no significant differences in the incidences of serious adverse reactions and chest X-ray changes between the two groups (P > 0.05). During the 5-year follow-up, recurrence in the Hr-TB group (7 cases, 14.9%) was no significantly lower than that in the RR-TB group (4 cases, 11.8%) (P = 0.754). CONCLUSION: The treatment of retreated Hr-TB patients was difficult and could be statistically similar or considerably worse than RR-TB. It's urgent to conduct further evaluation of the treatment status quo to guide the guideline development and clinical practice of Hr-TB patients.

Occurrence and determinants of seizures and their impact on tuberculous meningitis: a prospective evaluation.

OBJECTIVE: To assess the incidence of seizures and the factors contributing to poor outcomes in patients with tuberculous meningitis (TBM). METHODS: In this prospective observational study, 129 patients with TBM were enrolled at the Department of Neurology, King George's Medical University, Uttar Pradesh, India, from April 2021 to April 2023. Detailed clinical history, neurological examinations, baseline laboratory tests, contrast-enhanced Magnetic resonance imaging (MRI) and electroencephalography (EEG) were obtained for all patients. Patients received anti-tuberculous therapy and, if necessary, anti-epileptic treatment. Patients were followed for 6 months, with outcomes evaluated using the Modified Rankin Scale (MRS). RESULTS: Of the 129 patients, 48 (37.2%) reported seizures. Advanced TBM stage (p = 0.040, OR = 2.50 95% CI:1.02-6.07), cortical involvement (p = .0.013, OR = 2.58 95% CI:1.20-5.51) and spike-wave discharges in the EEG (p = 0.001) were significantly associated with seizure occurrence. After multivariate analysis, only cortical involvement (p = 0.031, OR = 2.34, 95% CI:1.08-5.08) emerged as independent predictor of for seizures. Focal to bilateral seizures (p = 0.008, OR = 9.41, 95% CI: 1.76-74.04), status epilepticus (p = 0.002, OR = 8.00, 95% CI: 1.86-34.32), and rifampicin resistance (p = 0.022, OR = 9.25, 95% CI: 1.43-59.50) were significantly associated with poor outcomes at the 6-month mark. CONCLUSION: Seizures were significantly associated with advanced stage of the disease, cortical involvement on neuro-imaging and epileptiform pattern on EEG. Additionally, focal to bilateral seizures and status epilepticus adversely affected the outcome.

Diagnóstico de tuberculosis con ensayo Xpert® MTB/RIF en la región oriental de Cuba / Diagnosis of tuberculosis withXpert® MTB/RIF test in the easternregion of Cuba / Diagnosis of tuberculosis withXpert® MTB/RIF test in the easternregion of Cuba / Diagnóstico de tuberculose com ensaio Xpert® MTB/RIF na região leste de Cuba

Introducción: La infección por tuberculosis repercute en el mundo a pesar de los años de estudio y avances tecnológicos en su diagnóstico. El ensayo Xpert® MTB/RIF permite, en gran medida, la identificación del bacilo de Koch en cualquier muestra patológica, y lo hace con una alta sensibilidad, especificidad y rapidez con respecto a otros métodos. Objetivo: Realizar el diagnóstico de tuberculosis con ensayo Xpert® MTB/RIF. Método: Se realizó un estudio transversal en 46 muestras analizadas (n=46) de las provincias orientales de Cuba con ensayo Xpert® MTB/RIF, entre abril y septiembre de 2023, por el Centro Provincial de Higiene, Epidemiología y Microbiología de Holguín. Las variables estudiadas fueron: provincia de procedencia, edad, sexo, tipo de muestra, factores de riesgo, resultado al ensayo y resistencia a la rifampicina. Resultados: Santiago de Cuba y Guantánamo fueron las provincias que mayor cantidad de casos reportaron, con 14 casos cada una (30,4 porciento). El sexo masculino fue el de mayor incidencia, 33 casos (71,7 porciento), independientemente de la provincia. El grupo de edad de 25 a 34 años fue el de mayor prevalencia, con el 26,1 porciento. Los grupos de riesgos más afectados fueron: los fumadores (37,0 porciento), los reclusos (32,6 porciento), los adultos mayores de 60 años (26,6 porciento) y los alcohólicos (23,9 porciento). Conclusiones: La introducción del GeneXpert en su diagnóstico es muy efectivo, por su alta sensibilidad y especificidad con relación a los estudios tradicionales, como son la baciloscopia y el cultivo, además de la rapidez en la obtención del resultado.Informa también sobre la resistencia a la rifampicina, atribuible al gen rpoβ lo que resulta muy oportuno en momentos en que la multidrogorresistencia aumenta aceleradamente.(AU)

Introduction: Tuberculosis infection affects the world despite years of study and technological advances in its diagnosis.The Xpert® MTB/RIF test allows, to a largeextent, the identification of Koch bacillus in any pathological sample, and does so with high sensitivity, specificity and speed compared too ther methods. Objective: To diagnose tuberculosis with the Xpert® MTB/RIF test. Method: A cross-sectional study was carried out on 46 analyzed samples (n 46) from the eastern provinces of Cuba with the Xpert® MTB/RIF test, between April and September 2023, by the Centro Provincial de Higiene, Epidemiología y Microbiología de Holguín (Provincial Center of Hygiene, Epidemiology and Microbiology of Holguín).The variables studied were: province of origin, age, sex, type of sample, risk factors, test resultand resistance to rifampicin. Results: Santiago de Cuba and Guantánamo were the provinces that reported the highest number of cases, with 14 cases each(30.4 percent).The maleshad the highest incidence, 33 cases (71.7 percent), regardless of the province.The age group of 25 to 34 years was the one with the highest prevalence, with 26.1 percent.The most affected risk groups were: smokers (37.0 percent), prisoners (32.6 percent), adults over 60 years of age (26.6 percent) and alcoholics (23.9 percent). Conclusions: The introduction of GeneXpert in tuberculosis diagnosis is very effective, due to its high sensitivity and specificity in relation to traditional studies, such as smear microscopy and culture, in addition to the speed in obtaining the result. It also reports on resistance to rifampicin, attributable to the rpoβ gene, which is timely at a moment when multidrug resistance is increasing rapidly.(AU)

Introdução: A infecção tuberculosa afeta o mundo apesar de anos de estudo e avanços tecnológicos no seu diagnóstico.O ensaio Xpert® MTB/RIF permite, em grande medida, a identificação do bacilo de Koch em qualquer amostra patológica, e fá-lo com elevada sensibilidade, especificidade e rapidez em comparação com outros métodos. Objetivo: Diagnosticar tuberculose com o ensaio Xpert® MTB/RIF. Método: Foi realizado um estudo transversal em 46 amostras analisadas (n 46) das províncias orientais de Cuba com o ensaio Xpert® MTB/RIF, entre abril e setembro de 2023, pelo Centro Provincial de Higiene, Epidemiologia e Microbiologia de Holguín.As variáveis estudadas foram: província de origem, idade, sexo, tipo de amostra, fatores de risco, resultado de exame e resistência à rifampicina. Resultados: Santiago de Cuba e Guantánamo foram as províncias que notificaram o maior número de casos, com 14 casos cada (30,4 porcento).O sexo masculino teve a maior incidência, 33 casos (71,7 porcento), independentemente da província.A faixa etária de 25 a 34 anos foi a que apresentou maior prevalência, com 26,1 porcento.Os grupos de risco mais acometidos foram: fumantes (37,0 porcento), presidiários (32,6 porcento), adultos acima de 60 anos (26,6 porcento) e alcoolistas (23,9 porcento). Conclusões: A introdução do GeneXpert no seu diagnóstico é muito eficaz, devido à sua alta sensibilidade e especificidade em relação aos estudos tradicionais, como baciloscopia e cultura, além da rapidez na obtenção do resultado.Também relata a resistência à rifampicina, atribuível ao gene rpoβ, que é muito oportuna numa altura em que a resistência a múltiplos medicamentos está a aumentar rapidamente.(AU)

Prevalence of isoniazid resistance in cases of rifampicin resistance detected on GeneXpert MTB/RIF assay.

Background: The fight against tuberculosis in our country has taken a new shape with the inclusion of rapid nucleic acid amplification tests like GeneXpert MTB/RIF assay which rapidly detects Mycobacterium tuberculosis and rifampicin resistance. Rifampicin resistance detected on GeneXpert has been considered as a sine qua non for the presence of isoniazid resistance and hence classified as multidrug-resistant tuberculosis (MDR-TB). However treatment of rifampicin-resistant, isoniazid-monoresistance, and MDR-TB are different. Our study was done with the aim of identification of the prevalence of isoniazid resistance on culture, in cases which had rifampicin resistance on GeneXpert. Methods: Pulmonary samples of patients of presumptive tuberculosis were subjected to GeneXpert testing and liquid MGIT (mycobacterium growth indicator tube) culture. On detection of rifampicin resistance on MTB/RIF assay, the patients were included in our study and cultures were followed-up for sensitivity to isoniazid. A total of 76 patients were included. Results: 76 patients of rifampicin resistance on GeneXpert MTB/RIF assay were followed-up for the sensitivity of isoniazid on culture media. Out of the 76 cases, 62 (81.57%) were found to have isoniazid resistance. Out of the 14 patients, the cultures showed no growth in 6, and in the rest, isoniazid was found to be sensitive. Conclusion: GeneXpert MTB/RIF assay is an excellent modality for the detection of M. tuberculosis and rifampicin resistance. The decision to exclude isoniazid from the treatment regimen in patients with rifampicin resistance should be made only after conducting further molecular/phenotypic tests.

Diagnostic Utility of Cartridge-Based Nucleic Acid Amplification Test (CBNAAT) on Induced Sputum Versus Gastric Aspirate Samples for the Diagnosis of Paediatric Pulmonary Tuberculosis.

BACKGROUND: Tuberculosis (TB) in children is neglected, mainly due to a lack of sensitive diagnostic tools. Paediatric TB is now a global priority. More paediatric TB cases are being recorded as a result of the introduction of Xpert® Mycobacterium tuberculosis (MTB)/rifampicin (RIF) (Cepheid Inc., Sunnyvale, USA). This study was undertaken to evaluate the performance of Xpert MTB/RIF in the diagnosis of pulmonary TB in children. METHODS: We recruited 70 paediatric patients with probable pulmonary TB and their gastric aspirate (GA), and induced sputum (IS) samples were collected between January 2021 and June 2022 in Saifai, Etawah, Uttar Pradesh, at the Microbiology Department of the Uttar Pradesh University of Medical Sciences (U.P.U.M.S.). All samples were subjected to smear examination, Bacterial Activation of Continuous Temperature and Environmental Control - Mycobacterial Growth Indicator Tube (BACTEC-MGIT) culture, and Xpert MTB/RIF. RESULTS:  The specimens included 70 GAs and 70 IS samples. The total number of specimens were 140 and we collected GA as well as IS from each of the patient enrolled in the study. When compared to microscopy, GeneXpert provides a quicker and earlier detection of paediatric TB. The sensitivity of the cartridge-based nucleic acid amplification test (CBNAAT) against mycobacterial growth indicator tube (MGIT) was 75.0% for GA samples and 63.64% for IS samples. CONCLUSION: Paediatric TB, owing to its paucibacillary nature and difficulty in the collection of samples, makes the diagnosis difficult by conventional methods. Our study shows that smear and culture yield in GA samples are superior to those of IS samples and the sensitivity of Xpert MTB/RIF assay is also significantly different in GA and IS samples, but a combination of GA and IS yielded the best results.

Prevalence of rifampicin resistant pulmonary tuberculosis using geneXpert assay in Ethiopia, a systematic review and meta-analysis.

Background: Drug-resistant tuberculosis continues to be a global public health threat. Ethiopia is one of the high-burden countries for tuberculosis and multi-drug resistant tuberculosis. The estimated annual incidents of tuberculosis were 119 per 100,000 populations in 2021 and the prevalence of multi-drug resistance tuberculosis is about 0.7% among newly diagnosed cases in Ethiopia. On time detection of rifampicin resistance is essential for the management of the disease and earlier treatment initiation. Among the different diagnostic tests; Xpert is widely used for the rapid detection of Mycobacterium tuberculosis and rifampicin resistant in the country. The prevalence of rifampicin resistance-pulmonary tuberculosis varied from locality to locality and the estimated national prevalence of rifampicin resistance pulmonary tuberculosis is not available in the country. Therefore, the aim of this meta-analysis was to summarize the results of available studies and generate pooled prevalence estimate of rifampicin resistance pulmonary tuberculosis in Ethiopia. Methods: Literature search was carried out using PubMed and Scopus public databases. Original articles conducted in Ethiopia and those containing a prevalence report of rifampicin resistance pulmonary tuberculosis diagnosed by Xpert Mycobacterium tuberculosis/rifampicin resistance assay were included in the meta-analysis. All retrospective and prospective studies published until May 2022 were screened in the study. The methodological qualities of included article were assessed using Joanna Briggs Institute quality assessment tool for cross-sectional studies. Random effect model was used to determine the pooled prevalence of rifampicin resistance pulmonary tuberculosis. Subgroup analysis and regression were carried out across regional states and study designs. Heterogeneity across studies was assessed using I2 test. The data were analyzed using STATA version 14. Result: A total of 1570 titles were identified and 34 studies met the inclusion criteria. Of the total 17,292 pulmonary tuberculosis patients who were identified from the included articles, 1669 were rifampicin resistance pulmonary tuberculosis. The pooled prevalence of rifampicin resistant among pulmonary tuberculosis patients diagnosed with Xpert Mycobacterium tuberculosis/rifampicin resistance assay was 9.67% (95% CI: 8.11-11.24). The highest pooled prevalence was from Oromia11.84% (95% CI: 4.49-19.2%) and the lowest rifampicin resistance was identified in Amhara Regional State, 8.51% (95% CI: 5.96-11.06%). The pooled prevalence rates of rifampicin resistant among pulmonary tuberculosis patients were 10.18% (95% CI: 6.85-13.51) and 9.57% (95% CI: 7.68-11.47) in prospective and retrospective types of cross-sectional studies. Conclusion: Our study showed that the pooled prevalence of rifampicin resistance among pulmonary tuberculosis patients was 9.67%. This showed that the occurrence of rifampicin resistance pulmonary tuberculosis among Mycobacterium tuberculosis patients remains high in Ethiopia. Regional state wise, rifampicin resistance variation was small. Further meta-analysis of factors associated with rifampicin resistance among pulmonary tuberculosis patients as well as among extrapulmonary Mycobacterium tuberculosis cases should be carried out.

Incidence of Rifampicin Resistance in Periprosthetic Joint Infection: A Single-Centre Cohort Study on 238 Patients.

BACKGROUND: Rifampicin is a pillar in the treatment of periprosthetic joint infection (PJI). However, rifampicin resistance is an increasing threat to PJI treatment. This study explores the incidence of rifampicin-resistant bacteria over time in a Swedish tertiary referral centre and the association of rifampicin resistance with infection-free survival after PJI. METHODS: The study included 238 staphylococcal PJIs treated between 2001 and 2020 for which susceptibility data for rifampicin were available. Data on causative bacteria, rifampicin resistance, treatment, and outcome were obtained. Kaplan-Meier survival analysis and Cox regression modelling estimated the infection-free cumulative survival and adjusted hazard ratios (HRs) for the risk of treatment failure. RESULTS: Rifampicin-resistant causative bacteria were identified in 40 cases (17%). The proportion of rifampicin-resistant agents decreased from 24% in 2010-2015 to 12% in 2016-2020. The 2-year infection-free survival rates were 78.6% (95% CI, 66.4-93.1%) for the rifampicin-resistant group and 90.0% (95% CI, 85.8-94.4%) for the rifampicin-sensitive group. Patients with PJI caused by rifampicin-resistant bacteria had an increased risk of treatment failure (adjusted HR, 4.2; 95% CI, 1.7-10.3). CONCLUSIONS: The incidence of PJI caused by rifampicin-resistant bacteria did not increase over the past 20 years. The risk of treatment failure in PJI caused by rifampicin-resistant bacteria is more than four times that caused by rifampicin-sensitive bacteria, highlighting the importance of limiting the development of rifampicin resistance.

Integrating Molecular Diagnostics and GIS Mapping: A Multidisciplinary Approach to Understanding Tuberculosis Disease Dynamics in South Africa Using Xpert MTB/RIF.

An investigation was carried out to examine the use of national Xpert MTB/RIF data (2013-2017) and GIS technology for MTB/RIF surveillance in South Africa. The aim was to exhibit the potential of using molecular diagnostics for TB surveillance across the country. The variables analysed include Mycobacterium tuberculosis (Mtb) positivity, the mycobacterial proportion of rifampicin-resistant Mtb (RIF), and probe frequency. The summary statistics of these variables were generated and aggregated at the facility and municipal level. The spatial distribution patterns of the indicators across municipalities were determined using the Moran's I and Getis Ord (Gi) statistics. A case-control study was conducted to investigate factors associated with a high mycobacterial load. Logistic regression was used to analyse this study's results. There was striking spatial heterogeneity in the distribution of Mtb and RIF across South Africa. The median patient age, urban setting classification, and number of health care workers were found to be associated with the mycobacterial load. This study illustrates the potential of using data generated from molecular diagnostics in combination with GIS technology for Mtb surveillance in South Africa. Spatially targeted interventions can be implemented in areas where high-burden Mtb persists.

Rifampicin-resistant RpoB S522L Vibrio vulnificus exhibits disturbed stress response and hypervirulence traits.

Rifampicin resistance, which is genetically linked to mutations in the RNA polymerase ß-subunit gene rpoB, has a global impact on bacterial transcription and cell physiology. Previously, we identified a substitution of serine 522 in RpoB (i.e., RpoBS522L ) conferring rifampicin resistance to Vibrio vulnificus, a human food-borne and wound-infecting pathogen associated with a high mortality rate. Transcriptional and physiological analysis of V. vulnificus expressing RpoBS522L showed increased basal transcription of stress-related genes and global virulence regulators. Phenotypically these transcriptional changes manifest as disturbed osmo-stress responses and toxin-associated hypervirulence as shown by reduced hypoosmotic-stress resistance and enhanced cytotoxicity of the RpoBS522L strain. These results suggest that RpoB-linked rifampicin resistance has a significant impact on V. vulnificus survival in the environment and during infection.

Frequency of rifampicin-resistant mycobacterium tuberculosis by GeneXpert MTB/RIF assay and its correlates among 2605 probable tuberculosis patients in upper Egypt.

RATIONALE: GeneXpert MTB/RIF (Mycobacterium tuberculosis/rifampicin) assay is a method for detecting rifampicin resistance (RR-MTB) in suspected samples in less than 2 hours with high sensitivity and specificity yield. This study aimed to use the GeneXpert MTB/RIF assay to determine the frequency of RR-MTB and to study the possible influencing correlates associated with positive results. SUBJECTS AND METHODS: This is a retrospective cross-sectional study of patients who visited TB clinic in 5 years (2016-2021). According to the data sheet of the patients, all the collected specimens were divided into 2 parts one for diagnosis by Ziehl-Neelsen stain and the other part for GeneXpert analysis. GeneXpert was also used to look for evidence of RR. RESULTS: Out of the 2605 total samples screened, 718 (27.6%) tested positive for MTB on GeneXpert assay; of them 633 (88.4%) were sensitive to Rifampicin, 83 (11.6%) were resistant to Rifampicin and 2 cases were undetermined. Factors contributing to RR-MTB were: smoker/ex-smoker, with 2.5 times more risk (p = 0.013.0, p = 0.001); recurrence cases had a 4-fold increased risk (p < 0.001); patients with very low M. tuberculosis detected on the GeneXpert MTB/RIF test were 8 times more likely to have RR-TB (P = 0.004). CONCLUSION: This study disclosed a high-rate MTB in Egyptian probable TB cases. Smoking, recurrence and cases with a very low M. tuberculosis burden noticed on the GeneXpert MTB/RIF test had augmented risk of RR-TB.