Rapid, cost-effective, and sensitive diagnostic assays are essential for global tuberculosis (TB) control, especially in high TB burden, resource-limited settings. The current study was designed to ...evaluate diagnostic accuracy of Truenat MTB-Rif Dx (MolBio) in children less than 18 years of age, with symptoms suggestive of TB. Gastric aspirate, induced sputum, and broncho-alveolar lavage samples were subjected simultaneously to AFB-smear, GeneXpert MTB/RIF, liquid culture (MGIT-960) and Truenat MTB-Rif Dx. The index-test results were evaluated against microbiological reference standards (MRS). Truenat MTB-Rif Dx had a sensitivity of 57.1%, specificity of 92% against MRS. The sensitivity and specificity of the Truenat MTB-RIF Dx compared with liquid culture was 58.7% and 87.5% while GeneXpert MTB/RIF was 56% and 91.4%. The performance of both GeneXpert MTB/RIF and Truenat MTB-Rif Dx are comparable. Result of our study demonstrates that Truenat MTB-Rif can aid in early and efficient diagnosis of TB in children.
Emerging evidence indicates that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-infected individuals are at an increased risk for coinfections; therefore, physicians need to be ...cognizant about excluding other treatable respiratory pathogens. Here, we report coinfection with SARS-CoV-2 and other respiratory pathogens in patients admitted to the coronavirus disease (COVID) care facilities of an Indian tertiary care hospital. From June 2020 through January 2021, we tested 191 patients with SARS-CoV-2 for 33 other respiratory pathogens using an fast track diagnostics respiratory pathogen 33 (FTD-33) assay. Additionally, information regarding other relevant respiratory pathogens was collected by reviewing their laboratory data. Overall, 13 pathogens were identified among patients infected with SARS-CoV-2, and 46.6% (89/191) of patients had coinfection with one or more additional pathogens. Bacterial coinfections (41.4% 79/191) were frequent, with Staphylococcus aureus being the most common, followed by Klebsiella pneumoniae. Coinfections with SARS-CoV-2 and Pneumocystis jirovecii or Legionella pneumophila were also identified. The viral coinfection rate was 7.3%, with human adenovirus and human rhinovirus being the most common. Five patients in our cohort had positive cultures for Acinetobacter baumannii and K. pneumoniae, and two patients had active Mycobacterium tuberculosis infection. In total, 47.1% (90/191) of patients with coinfections were identified. The higher proportion of patients with coinfections in our cohort supports the systemic use of antibiotics in patients with severe SARS-CoV-2 pneumonia with rapid de-escalation based on respiratory PCR/culture results. The timely and simultaneous identification of coinfections can contribute to improved health of COVID-19 patients and enhanced antibiotic stewardship during the pandemic. IMPORTANCE Coinfections in COVID-19 patients may worsen disease outcomes and need further investigation. We found that a higher proportion of patients with COVID-19 were coinfected with one or more additional pathogens. A better understanding of the prevalence of coinfection with other respiratory pathogens in COVID-19 patients and the profile of pathogens can contribute to effective patient management and antibiotic stewardship during the current pandemic.
To assess diagnostic value of polymerase chain reaction (PCR) in endometrial aspirates (EAs) in comparison with conventional tests for diagnosis of female genital tuberculosis (TB) and to find ...agreement between EA PCR done for endometrial TB and laparoscopic findings of pelvic TB in women with unexplained infertility.
Prospective observational cohort study.
Tertiary care hospital.
A total of 732 infertile females screened and 385 enrolled to undergo procedure to obtain EAs.
EAs were tested by conventional tests (histopathology, acid-fast bacilli, Lowenstein-Jensen staining, liquid culture) and PCR for Mycobacterium tuberculosis. Patients with positive conventional tests were started on antitubercular treatment (ATT). Patients with negative conventional tests underwent laparohysteroscopy irrespective of PCR results to assess changes of tubercular infection in the pelvis. Peritoneal washings were also sent for liquid culture and PCR for TB, and suspicious lesions were biopsied at laparohysteroscopy. Findings at laparoscopy upgraded the diagnosis in these women. EAPCR results were analyzed to find agreement with the findings at laparoscopy.
Conventional tests were positive in 8 of 385 (2%) patients. PCR was positive in 58.1% (n = 224) of endometrial samples, with sensitivity of 62.5% (95% confidence interval CI, 24.49-91.48), specificity of 41.91% (95% CI, 36.88-47.07), positive predictive value of 2.23% (95% CI, 1.31-3.78), negative predictive value of 98.14% (95% CI, 95.53-99.24), and a diagnostic accuracy of 42.34% (95% CI, 37.35-47.45) with conventional tests. A total of 265 patients underwent laparoscopy, of whom 165 were PCR positive and 100 were PCR negative. Laparoscopic findings suggestive of TB were found in 39.3% of patients who were PCR positive and 9% of patients who were PCR negative. Kappa agreement was 0.25, suggesting fair agreement between PCR and laparoscopy.
PCR as a stand-alone diagnostic test for endometrial TB is not justified to confirm diagnosis and initiate ATT. The addition of laparohysteroscopy improves diagnostic yield for genital TB. Referring patients with a suspicion of female genital TB to tertiary care for 1-time laparoscopy is better than initiating ATT solely on the basis of PCR results.
An effective regimen for treatment of tuberculosis (TB) is comprised of multiple drugs that inhibit a range of essential cellular activities in Mycobacterium tuberculosis. The effectiveness of a ...regimen is further enhanced if constituent drugs act with synergy. Here, we report that faropenem (a penem) or biapenem, doripenem, or meropenem (carbapenems), which belong to the β-lactam class of antibiotics, and rifampin, one of the drugs that forms the backbone of TB treatment, act with synergy when combined. One of the reasons (carba)penems are seldom used for treatment of TB is the high dosage levels required, often at the therapeutic limits. The synergistic combination of rifampin and these (carba)penems indicates that (carba)penems can be administered at dosages that are therapeutically relevant. The combination of faropenem and rifampin also limits the frequency of resistant mutants, as we were unable to obtain spontaneous mutants in the presence of these two drugs. The combinations of rifampin and (carba)penems were effective not only against drug-sensitive Mycobacterium tuberculosis but also against drug-resistant clinical isolates that are otherwise resistant to rifampin. A combination of doripenem or biapenem and rifampin also exhibited synergistic activity against Mycobacterium abscessus. Although the MICs of these three drugs alone against M. abscessus are too high to be of clinical relevance, their concentrations in combinations are therapeutically relevant; therefore, they warrant further evaluation for clinical utility to treat Mycobacterium abscessus infection, especially in cystic fibrosis patients.
Newer molecular diagnostics have brought paradigm shift in early diagnosis of tuberculosis TB. WHO recommended use of GeneXpert MTB/RIF Xpert for Extra-pulmonary EP TB; critics have since questioned ...its efficiency.
The present study was designed to assess the performance of GeneXpert in 761 extra-pulmonary and 384 pulmonary specimens from patients clinically suspected of TB and compare with Phenotypic, Genotypic and Composite reference standards CRS.
Comparison of GeneXpert results to CRS, demonstrated sensitivity of 100% and 90.68%, specificity of 100% and 99.62% for pulmonary and extra-pulmonary samples. On comparison with culture, sensitivity for Rifampicin Rif resistance detection was 87.5% and 81.82% respectively, while specificity was 100% for both pulmonary and extra-pulmonary TB. On comparison to sequencing of rpoB gene Rif resistance determining region, RRDR, sensitivity was respectively 93.33% and 90% while specificity was 100% in both pulmonary and extra-pulmonary TB. GeneXpert assay missed 533CCG mutation in one sputum and dual mutation 517 & 519 in one pus sample, detected by sequencing. Sequencing picked dual mutation 529, 530 in a sputum sample sensitive to Rif, demonstrating, not all RRDR mutations lead to resistance.
Current study reports observations in a patient care setting in a high burden region, from a large collection of pulmonary and extra-pulmonary samples and puts to rest questions regarding sensitivity, specificity, detection of infrequent mutations and mutations responsible for low-level Rif resistance by GeneXpert. Improvements in the assay could offer further improvement in sensitivity of detection in different patient samples; nevertheless it may be difficult to improve sensitivity of Rif resistance detection if only one gene is targeted. Assay specificity was high both for TB detection and Rif resistance detection. Despite a few misses, the assay offers major boost to early diagnosis of TB and MDR-TB, in difficult to diagnose pauci-bacillary TB.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Parental underestimation of the severity and risks of their child's obesity and parents' potential implicit weight bias contribute to the reluctance to consider bariatric surgery for their adolescent ...children with obesity. Despite evidence for safety and efficacy of bariatric surgery in adolescents, pediatric providers may be hesitant or uncomfortable to discuss the benefits and refer patients for surgical evaluation. Understanding these barriers is an essential step toward effective long-term care in this patient population.
We hypothesized that parental views on bariatric surgery are primarily influenced by personal experiences with bariatric surgery, their implicit bias, understanding of health risks of obesity, and counseling by pediatric providers.
Data were collected and analyzed at an academic medical center in the United States.
After a retrospective chart review of 192 adolescents with obesity, a telephone survey of patients' parents was conducted.
Parents of 71.4% of patients who received outpatient weight loss counseling had accurate recollection of that event. Only 12.8% of parents who were referred to lifestyle programs successfully enrolled. Neither prior personal exposure to bariatric surgery nor enrollment of the child in a lifestyle program increased parents' likelihood to consider bariatric surgery for their child (P = .10 and .70, respectively). Most parents (84.6%) who were counseled by their pediatric provider about bariatric surgery would consider it, compared with only 34.5% of the parents who did not receive counseling (P < .001).
Counseling by pediatric providers, not involvement in lifestyle programs or exposure to bariatric surgery, increased parents' willingness to consider bariatric surgery for their child. Given the current recommendations to incorporate bariatric surgery as a treatment modality in severe adolescent obesity, earlier counseling about the role of surgery by pediatric providers is essential. More detailed provider education on the current state of bariatric surgery in the treatment of severe adolescent obesity is also necessary.
Mixed/polyclonal infections due to different genotypes are reported in Tuberculosis. The current study was designed to understand the fate of mixed infections during the course of treatment and ...follow-up and its role in disease pathogenesis. Sputum samples were collected on 0,1,2,3,6,12 and 24 months from 157 treatment-naïve patients, cultures subjected to Drug-Susceptibility-testing (MGIT 960), spoligotyping, MIRU-VNTR and SNP genotyping. All isolated colonies on thin layer agar (7H11) were subjected to spoligotyping. One thirty three baseline cultures were positive (133/157, 84.7%), 43(32.3%) had mixture of genotypes. Twenty-four of these patients (55.8%) showed change in genotype while six showed different drug-susceptibility patterns while on treatment. Twenty-three (53.5%) patients with polyclonal infections showed resistance to at least one drug compared to 10/90 (11.1%) monoclonal infections (P<0.0001). Eight patients had recurrent TB, two with a new genotype and two with altered phenotypic DST. The coexistence of different genotypes and change of genotypes during the same disease episode, while on treatment, confirms constancy of polyclonal infections. The composition of the mixture of genotypes and the relative predominance may be missed by culture due to its limit of detection. Polyclonal infections in TB could be a rule rather than exception and challenges the age-old dogma of reactivation/reinfection.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Abstract Bacteria employ quorum sensing as a remarkable mechanism for coordinating behaviors and communicating within their communities. In this study, we introduce a MATLAB Graphical User Interface ...(GUI) that offers a versatile platform for exploring the dynamics of quorum sensing. Our computational framework allows for the assessment of quorum sensing, the investigation of parameter dependencies, and the prediction of minimum biofilm thickness required for its initiation. A pivotal observation from our simulations underscores the pivotal role of the diffusion coefficient in quorum sensing, surpassing the influence of bacterial cell dimensions. Varying the diffusion coefficient reveals significant fluctuations in autoinducer concentration, highlighting its centrality in shaping bacterial communication. Additionally, our GUI facilitates the prediction of the minimum biofilm thickness necessary to trigger quorum sensing, a parameter contingent on the diffusion coefficient. This feature provides valuable insights into spatial constraints governing quorum sensing initiation. The interplay between production rates and cell concentrations emerges as another critical facet of our study. We observe that higher production rates or cell concentrations expedite quorum sensing, underscoring the intricate relationship between cell communication and population dynamics in bacterial communities. While our simulations align with mathematical models reported in the literature, we acknowledge the complexity of living organisms, emphasizing the value of our GUI for standardizing results and facilitating early assessments of quorum sensing. This computational approach offers a window into the environmental conditions conducive to quorum sensing initiation, encompassing parameters such as the diffusion coefficient, cell concentration, and biofilm thickness. In conclusion, our MATLAB GUI serves as a versatile tool for understanding the diverse aspects of quorum sensing especially for non-biologists. The insights gained from this computational framework advance our understanding of bacterial communication, providing researchers with the means to explore diverse ecological contexts where quorum sensing plays a pivotal role.
There is an unmet need for tools that permit diagnosis of Tuberculosis (TB) that are affordable, low-tech, and can differentiate Mycobacterium tuberculosis (M.tb) from non-tuberculous mycobacteria ...(NTM). In this study, we have developed a strip-based assay to detect the activity of a unique Carbapenem Resistance Factor A (CrfA) enzyme present only in M.tb. The strip comprises of PVDF (Polyvinylidene fluoride) membrane that has an immobilized anti-CrfA antibody to capture the CrfA enzyme from M.tb lysate. Lysate of mycobacteria is applied to the strip, washed, and incubated in the presence of chromogenic reporter dye which is a substrate for CrfA. A change in the color of the dye that is readily visible to the naked eye is the readout. We evaluated lysates from M.tb and various NTMs namely, M. abscessus, M. chelonae, M. avium, M. obuense, M. paraintracellulare, M. kansasi, including the patient-derived sputum samples. The strip assay selectively identified only those samples containing M.tb. Based on this evidence, this new assay enables the identification and differentiation of M.tb from NTMs in patient sputum samples. As this tool can be simple to use, therefore has the potential to serve the unmet need for diagnosis of TB and NTM infections in resource-limited settings.
•Misdiagnosis of chronic pulmonary tuberculosis due to failures in recognizing non-tuberculous mycobacteria.•A unique marker CrfA enzyme in Mycobacterium tuberculosis Complex species is absent in non-tuberculous mycobacteria.•A novel strip-based CrfA activity assay to differentiate Mycobacterium tuberculosis Complex from non-tuberculous mycobacteria is described.•Positive Acid-Fast Bacilli staining and a positive CrfA activity assay confirms Mycobacterium tuberculosis complex species.•Positive Acid-Fast Bacilli staining and a negative CrfA activity assay confirms non-tuberculous mycobacterial species.
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