Unlocking the secrets: exploring the influence of the aryl hydrocarbon receptor and microbiome on cancer development.

Gut microbiota regulates various aspects of human physiology by producing metabolites, metabolizing enzymes, and toxins. Many studies have linked microbiota with human health and altered microbiome configurations with the occurrence of several diseases, including cancer. Accumulating evidence suggests that the microbiome can influence the initiation and progression of several cancers. Moreover, some microbiotas of the gut and oral cavity have been reported to infect tumors, initiate metastasis, and promote the spread of cancer to distant organs, thereby influencing the clinical outcome of cancer patients. The gut microbiome has recently been reported to interact with environmental factors such as diet and exposure to environmental toxicants. Exposure to environmental pollutants such as polycyclic aromatic hydrocarbons (PAHs) induces a shift in the gut microbiome metabolic pathways, favoring a proinflammatory microenvironment. In addition, other studies have also correlated cancer incidence with exposure to PAHs. PAHs are known to induce organ carcinogenesis through activating a ligand-activated transcriptional factor termed the aryl hydrocarbon receptor (AhR), which metabolizes PAHs to highly reactive carcinogenic intermediates. However, the crosstalk between AhR and the microbiome in mediating carcinogenesis is poorly reviewed. This review aims to discuss the role of exposure to environmental pollutants and activation of AhR on microbiome-associated cancer progression and explore the underlying molecular mechanisms involved in cancer development.

Enhancement of Vitamin C's Protective Effect against Thimerosal-Induced Neurotoxicity in the Cerebral Cortex of Wistar Albino Rats: An In Vivo and Computational Study.

Vitamin C was examined to ameliorate the neurotoxicity of thimerosal (THIM) in an animal model (Wistar albino rats). In our work, oxidative and antioxidative biomarkers such as SOD, LPO, and GSH were investigated at various doses of THIM with or without concurrent vitamin C administration. Furthermore, the adverse effects of THIM on hepatic tissue and cerebral cortex morphology were examined in the absence or presence of associated vitamin C administration. Also, we studied the effect of vitamin C on the metallothionein isoforms (MT-1, MT-2, and MT-3) in silico and in vivo using the RT-PCR assay. The results showed that the antioxidant biomarker was reduced as the THIM dose was raised and vice versa. THIM-associated vitamin C reduced the adverse effects of the THIM dose. The computation studies demonstrated that vitamin C has a lower ΔG of -4.9 kcal/mol compared to -4.1 kcal/mol for THIM to bind to the MT-2 protein, which demonstrated that vitamin C has a greater ability to bind with MT-2 than THIM. This is due to multiple hydrogen bonds that exist between vitamin C and MT-2 residues Lys31, Gln23, Cys24, and Cys29, and the sodium ion represents key stabilizing interactions. Hydrogen bonds involve electrostatic interactions between hydrogen atom donors (e.g., hydroxyl groups) and acceptors (e.g., carbonyl oxygens). The distances between heavy atoms are typically 2.5-3.5 Å. H-bonds provide directed, high-affinity interactions to anchor the ligand to the binding site. The five H-bonds formed by vitamin C allow it to form a stable complex with MT, while THIM can form two H-bonds with Gln23 and Cys24. This provides less stabilization in the binding pocket, contributing to the lower affinity compared to vitamin C. The histopathological morphologies in hepatic tissue displayed an expansion in the portal tract and the hepatocytes surrounding the portal tract, including apoptosis, binucleation, and karyomegaly. The histopathological morphologies in the brain tissue revealed a significant decrease in the number of Purkinje cells due to THIM toxicity. Interestingly, THIM toxicity was associated with hemorrhage and astrogliosis. Both intracellular and vasogenic edema appeared as the concentrations of THIM rose. Finally, vitamin C ameliorated the adverse effect on the cerebral cortex in Wistar albino rats.

Care-seeking pathways and diagnostic delays in extrapulmonary TB patients.

SETTING: This study was conducted at a private tertiary hospital engaged with the TB control programme in the city of Lahore, Pakistan. OBJECTIVE: To assess the healthcare-seeking pathways, different delays and factors associated with delays among the patients who presented in the outpatient department with tuberculous lymphadenitis and pleuritis, the most common manifestations of extrapulmonary TB. DESIGN: This cross-sectional study was conducted prospectively from April 2016 to August 2017. RESULTS: The median age of the 339 patients analysed was 22 years (IQR 17-30); tuberculous lymphadenitis was predominant in females (63%), while pleuritis affected more males (64%). Overall, 62% reported seeking care from healthcare providers before diagnosis, of whom 62% sought care from private facilities, 32% visited facilities >2 times and 8% visited traditional healers. Diagnostic delay was associated with tuberculous lymphadenitis, age 15-44 years, poor socio-economic status and poor TB knowledge. CONCLUSION: There was considerable delay in the management of extrapulmonary TB patients, and the health-system delay was the major contributor, leading to increased patient suffering. Efforts towards minimising health-system delay need to be prioritised for patient screening and diagnosis, with a feasible algorithm that is workable in resource-limited settings.

CONTEXTE: Cette étude a été menée dans un hôpital tertiaire privé participant au programme de lutte contre la TB dans la ville de Lahore, au Pakistan. OBJECTIF: Évaluer les parcours de recherche de soins, les différents délais et les facteurs associés aux délais parmi les patients qui se sont présentés au service des consultations externes avec une lymphadénite et une pleurite tuberculeuses, les manifestations les plus courantes de la TB extrapulmonaire. MÉTHODE: Cette étude transversale a été menée prospectivement d'avril 2016 à août 2017. RÉSULTATS: L'âge médian des 339 patients analysés était de 22 ans (IQR 17­30) ; la lymphadénite tuberculeuse prédominait chez les femmes (63%), tandis que la pleurite touchait davantage les hommes (64%). Dans l'ensemble, 62% des patients ont déclaré avoir eu recours à des prestataires de soins de santé avant le diagnostic, dont 62% dans des établissements privés, 32% ont visité des établissements >2 fois et 8% ont consulté des guérisseurs traditionnels. Le retard de diagnostic était associé à la lymphadénite tuberculeuse, à l'âge de 15 à 44 ans, à un statut socio-économique défavorable et à un manque de connaissances sur la TB. CONCLUSION: La prise en charge des patients atteints de TB extrapulmonaire accuse un retard considérable, dont le système de santé est le principal responsable, ce qui accroît les souffrances des patients. Les efforts visant à minimiser le retard du système de santé doivent être priorisés pour le dépistage et le diagnostic des patients, avec un algorithme réalisable dans des environnements aux ressources limitées.

Experimental and theoretical investigations of the effect of bis-phenylurea-based aliphatic amine derivative as an efficient green corrosion inhibitor for carbon steel in HCl solution.

A novel bis-phenylurea-based aliphatic amine (BPUA) was prepared via a facile synthetic route, and evaluated as a potential green organic corrosion inhibitor for carbon steel in 1.0 M HCl solutions. NMR spectroscopy experiments confirmed the preparation of the targeted structure. The corrosion inhibitory behavior of the prospective green compound was explored experimentally by electrochemical methods and theoretically by DFT-based quantum chemical calculations. Obtained results revealed an outstanding performance of BPUA, with efficiency of 95.1% at the inhibitor concentration of 50 mg L-1 at 25 °C. The novel compound has improved the steel resistivity and noticeably reduced the corrosion rate from 33 to 1.7 mils per year. Furthermore, the adsorption study elucidates that the mechanism of the corrosion inhibition activity obeys Langmuir isotherm with mixed physisorption/chemisorption modes for BPUA derivatives on the steel surface. Calculated Gibb's free energy of the adsorption process ranges from -35 to -37 kJ mol-1. The SEM morphology analysis validates the electrochemical measurements and substantiates the corrosion-inhibiting properties of BPUA. Additionally, the eco-toxicity assessment on human epithelial MCF-10A cells proved the environmental friendliness of the BPUA derivatives. Density functional theory (DFT) calculations correlated the inhibitor's chemical structure with the corresponding inhibitory behavior. Quantum descriptors disclosed the potentiality of BPUA adsorption onto the surface through the heteroatom-based functional groups and aromatic rings.

6-Formylindolo(3,2-b)carbazole Dampens Inflammation and Reduces Endotoxin-Induced Kidney Injury via Nrf2 Activation.

Patients with sepsis are at a high risk of morbidity and mortality due to multiple organ injuries caused by pathological inflammation. Although sepsis is accompanied by multiple organ injuries, acute renal injury is a significant contributor to sepsis morbidity and mortality. Thus, dampening inflammation-induced renal injury may limit severe consequences of sepsis. As several studies have suggested that 6-formylindolo(3,2-b)carbazole (FICZ) is beneficial for treating various inflammatory diseases, we aimed to examine the potential protective effect of FICZ on the acute endotoxin-induced sepsis model of kidney injury. To test this, male C57Bl/6N mice were injected with FICZ (0.2 mg/kg) or vehicle 1 h prior to an injection of either lipopolysaccharides (LPS) (10 mg/kg), to induce sepsis, or phosphate-buffered saline for 24 h. Thereafter, gene expression of kidney injury and pro-inflammatory markers, circulating cytokines and chemokines, and kidney morphology were assessed. Our results show that FICZ reduced LPS-induced acute injury in kidneys from LPS-injected mice. Furthermore, we found that FICZ dampens both renal and systemic inflammation in our sepsis model. Mechanistically, our data indicated that FICZ significantly upregulates NAD(P)H quinone oxidoreductase 1 and heme oxygenase 1 via aryl hydrocarbon receptor (AhR) and nuclear factor erythroid 2-related factor 2 (Nrf2) in the kidneys to lessen inflammation and improve septic acute kidney injury. Overall, the data of our study show that FICZ possesses a beneficial reno-protective effect against sepsis-induced renal injury via dual activation of AhR/Nrf2.

Ultrastructural analysis of zinc oxide nanospheres enhances anti-tumor efficacy against Hepatoma.

Zinc oxide nanomaterial is a potential material in the field of cancer therapy. In this study, zinc oxide nanospheres (ZnO-NS) were synthesized by Sol-gel method using yeast extract as a non-toxic bio-template and investigated their physicochemical properties through various techniques such as FTIR, XR, DLS, and TEM. Furthermore, free zinc ions released from the zinc oxide nanosphere suspended medium were evaluated by using the ICP-AS technique. Therefore, the cytotoxicity of ZnO nanospheres and released Zn ions on both HuH7 and Vero cells was studied using the MTT assay. The data demonstrated that the effectiveness of ZnO nanospheres on HuH7 was better than free Zn ions. Similarly, ZnO-Ns were significantly more toxic to HuH7 cell lines than Vero cells in a concentration-dependent manner. The cell cycle of ZnO-Ns against Huh7 and Vero cell lines was arrested at G2/M. Also, the apoptosis assay using Annexin-V/PI showed that apoptosis of HuH7 and Vero cell lines by ZnO nanospheres was concentration and time-dependent. Caspase 3 assay results showed that the apoptosis mechanism may be intrinsic and extrinsic pathways. The mechanism of apoptosis was determined by applying the RT-PCR technique. The results revealed significantly up-regulated Bax, P53, and Cytochrome C, while the Bcl2 results displayed significant down-regulation and the western blot data confirmed the RT-PCR data. There is oxidative stress of the ZnO nanospheres and free Zn+2 ions. Results indicated that the ZnO nanospheres and free Zn+2 ions induced oxidative stress through increasing reactive oxygen species (ROS) and lipid peroxidation. The morphology of the HuH7 cell line after exposure to ZnO nanospheres at different time intervals revealed the presence of the chromatin condensation of the nuclear periphery fragmentation. Interestingly, the appearance of canonical ultrastructure features of apoptotic morphology of Huh7, Furthermore, many vacuoles existed in the cytoplasm, the majority of which were lipid droplets, which were like foamy cells. Also, there are vesicles intact with membranes that are recognized as swollen mitochondria.

Insight into the physiological and pathological roles of the aryl hydrocarbon receptor pathway in glucose homeostasis, insulin resistance, and diabetes development.

The aryl hydrocarbon receptor (AhR) is a ligand-activated transcriptional factor that mediates the toxicities of several environmental pollutants. Decades of research have been carried out to understand the role of AhR as a novel mechanism for disease development. Its involvement in the pathogenesis of cancer, cardiovascular diseases, rheumatoid arthritis, and systemic lupus erythematosus have long been known. One of the current hot research topics is investigating the role of AhR activation by environmental pollutants on glucose homeostasis and insulin secretion, and hence the pathogenesis of diabetes mellitus. To date, epidemiological studies have suggested that persistent exposure to environmental contaminants such as dioxins, with subsequent AhR activation increases the risk of specific comorbidities such as obesity and diabetes. The importance of AhR signaling in various molecular pathways highlights that the role of this receptor is far beyond just xenobiotic metabolism. The present review aims at providing significant insight into the physiological and pathological role of AhR and its regulated enzymes, such as cytochrome P450 1A1 (CYP1A1) and CYP1B1 in both types of diabetes. It also provides a comprehensive summary of the current findings of recent research studies investigating the role of the AhR/CYP1A1 pathway in insulin secretion and glucose hemostasis in the pancreas, liver, and adipose tissues. This review further highlights the molecular mechanisms involved, such as gluconeogenesis, hypoxia-inducible factor (HIF), oxidative stress, and inflammation.

The miniature CRISPR-Cas12m effector binds DNA to block transcription.

CRISPR-Cas are prokaryotic adaptive immune systems. Cas nucleases generally use CRISPR-derived RNA guides to specifically bind and cleave DNA or RNA targets. Here, we describe the experimental characterization of a bacterial CRISPR effector protein Cas12m representing subtype V-M. Despite being less than half the size of Cas12a, Cas12m catalyzes auto-processing of a crRNA guide, recognizes a 5'-TTN' protospacer-adjacent motif (PAM), and stably binds a guide-complementary double-stranded DNA (dsDNA). Cas12m has a RuvC domain with a non-canonical catalytic site and accordingly is incapable of guide-dependent cleavage of target nucleic acids. Despite lacking target cleavage activity, the high binding affinity of Cas12m to dsDNA targets allows for interference as demonstrated by its ability to protect bacteria against invading plasmids through silencing invader transcription and/or replication. Based on these molecular features, we repurposed Cas12m by fusing it to a cytidine deaminase that resulted in base editing within a distinct window.

Diverse role of endocannabinoid system in mammalian male reproduction.

Endocannabinoid system (ECS) is known for its modulatory role in numerous physiological processes in the body. Endocannabinoids (eCBs) are endogenous lipid molecules which function both centrally and peripherally. The ECS is best studied in the central nervous system (CNS), immune system as well as in the metabolic system. The role of ECS in male reproductive system is emerging and the presence of a complete enzymatic machinery to synthesize and metabolize eCBs has been demonstrated in male reproductive tract. Endocannabinoid concentrations and alterations in their levels have been reported to affect the functioning of spermatozoa. A dysfunctional ECS has also been linked to the development of prostate cancer, the leading cause of cancer related mortality among male population. This review is an attempt to provide an insight into the significant role of endocannabinoids in male reproduction and further summarize recent findings that demonstrate the manner in which the endocannabinoid system impacts male sexual behavior and fertility.

Characterization of Genomic Variants Associated with Resistance to Bedaquiline and Delamanid in Naive Mycobacterium tuberculosis Clinical Strains.

The role of mutations in genes associated with phenotypic resistance to bedaquiline (BDQ) and delamanid (DLM) in Mycobacterium tuberculosis complex (MTBc) strains is poorly characterized. A clear understanding of the genetic variants' role is crucial to guide the development of molecular-based drug susceptibility testing (DST). In this work, we analyzed all mutations in candidate genomic regions associated with BDQ- and DLM-resistant phenotypes using a whole-genome sequencing (WGS) data set from a collection of 4,795 MTBc clinical isolates from six countries with a high burden of tuberculosis (TB). From WGS analysis, we identified 61 and 163 unique mutations in genomic regions potentially involved in BDQ- and DLM-resistant phenotypes, respectively. Importantly, all strains were isolated from patients who likely have never been exposed to these medicines. To characterize the role of mutations, we calculated the free energy variation upon mutations in the available protein structures of Ddn (DLM), Fgd1 (DLM), and Rv0678 (BDQ) and performed MIC assays on a subset of MTBc strains carrying mutations to assess their phenotypic effect. The combination of structural and phenotypic data allowed for cataloguing the mutations clearly associated with resistance to BDQ (n = 4) and DLM (n = 35), only two of which were previously described, as well as about a hundred genetic variants without any correlation with resistance. Significantly, these results show that both BDQ and DLM resistance-related mutations are diverse and distributed across the entire region of each gene target, which is of critical importance for the development of comprehensive molecular diagnostic tools.

Implementing universal rifampicin testing for TB in Pakistan: results and implications for the TB response.

SETTING: A large specialised chest hospital in Pakistan.OBJECTIVE: To study outcomes of comprehensive Xpert® MTB/RIF and universal rifampicin testing.DESIGN: A hospital-based, 3-year retrospective record review of registered TB patients.RESULTS: During the study, 11 744 TB patients were registered when the number of annual notifications remained stagnant. Xpert use increased dramatically in adults with pulmonary TB (PTB) from less than 1% tested with Xpert alone in 2016, to 81.6% by 2018. Significant increases were seen in bacteriologically confirmed PTB in adults from 64% to 77.3% (P < 0.001). No remarkable changes were seen in testing and confirmation of PTB in children or extrapulmonary TB. Significantly lower (P < 0.001) rifampicin resistance (RR) was observed among those with smear-negative compared to those with smear-positive results among new (1.0% vs. 5.1%) and previously treated PTB cases (2.0% vs. 14.4%). Most importantly, a significant decline in RR was observed among previously treated individuals, from 15.4% (95%CI 12.2-19.0) to 8.6% (95%CI 6.6-11.0) during the study. A decrease in RR was also documented in newly diagnosed PTB patients, but this was not statistically significant.CONCLUSION: Universal rifampicin testing is feasible in adult PTB patients; a decline in RR was seen among previously treated individuals with PTB.

Primary drug resistance in extra-pulmonary tuberculosis: a hospital-based prospective study from Pakistan.

SETTING: Tertiary level specialised tuberculosis (TB) hospital.OBJECTIVE: To determine the prevalence of antimicrobial resistance in new extra-pulmonary tuberculosis (EPTB) cases.DESIGN: Prospective cross-sectional study. Presumptive EPTB patients with enlarged lymph nodes or pleural effusion having no history of TB treatment were enrolled. Specimens were tested for smear, Xpert® MTB/RIF and culture. Indirect drug susceptibility testing (DST) was performed using MGIT 960 and line-probe assays (LPA).RESULTS: Among 671 cases, 255 were bacteriologically confirmed and 185 DSTs were performed. Multidrug resistance (MDR-TB) was reported in 2.2% (95%CI 0.6-5.4), any resistance to rifampicin (RMP) in 2.7% (95%CI 0.9-6.2), isoniazid (INH) in 7.6% (95%CI 4.1-12.4), ethambutol in 1.1% (95%CI 0.1-3.9), pyrazinamide in 2.2% (95%CI 0.9-5.5) and fluoroquinolones (FQ) in 6.0% (95%CI 3.0-10.4). The sensitivity and specificity of LPA-DST was 100% and >98.8% respectively for RMP, INH and FQ. Among 82 cases with RMP of the results available for all three methods used, five were reported to be resistant on Xpert but all five were susceptible on MGIT 960 and four on MTBDRplus.CONCLUSION: Prevalence of RMP resistance in new EPTB cases is 2.7% (95%CI 0.9-6.2). Caution is warranted for RMP resistance detected using Xpert in EPTB samples with a very low bacterial load.

Synthesis of a novel hexaazatriphenylene derivative for the selective detection of copper ions in aqueous solution.

A hexaazatriphenylene (HAT) derivative, naphtho[2,3-h]naphtho[2',3':7,8]quinoxalino[2,3-a]naphtho[2',3':7,8]quinoxalino[2,3-c]phenazine-5,10,15,20,25,30-hexaone (NQH) was synthesized, characterized, and found to have novel properties in being selective toward the detection of copper (Cu2+) ions. The capability of NQH to be employed as a colorimetric, chemo-fluorescence and electrochemical sensor for the detection of Cu2+ was demonstrated by performing UV-Vis absorbance, fluorescence intensity, and cyclic voltammetry (CV) measurements. The interaction between NQH and Cu2+ was initially observed with an obvious color change from yellow to brown upon the addition of Cu2+ ions to NQH. The interaction was also confirmed by UV-Vis absorbance, fluorescence intensity, and mass spectroscopy (MS/MS) measurements. UV absorbance, fluorescence and CV of NQH toward Cu2+ showed good linearity with a detection limit of 3.32 µM, 2.20 µM and 0.78 µM, respectively, which are lower than the toxicity levels of copper in drinking water (20-30 µM) set by the U.S. Environmental Protection Agency (EPA) and World Health Organization (WHO). A 1 : 2 stoichiometry complexation between NQH and Cu2+ was confirmed by Job's plot and MS/MS. In addition, the selectivity and sensitivity of the NQH compound towards Cu2+ ions were further confirmed by performing CV on a screen printed flexible and planar electrochemical sensor.

A highly sensitive printed humidity sensor based on a functionalized MWCNT/HEC composite for flexible electronics application.

A novel functionalized multi-walled carbon nanotube (FMWCNT)/hydroxyethyl cellulose (HEC) composite-based humidity sensor was successfully developed for humidity monitoring applications. FMWCNTs were synthesized by covalently functionalizing multi-walled carbon nanotubes (MWCNTs) in a mixture of sulfuric and nitric acid to enhance their hydrophilicity. The FMWCNTs were characterized using transmission electron microscopy, Raman spectroscopy, Fourier transform infrared spectroscopy and dispersion analysis to verify the presence of functional hydroxyl and carboxyl groups. A FMWCNT/HEC (1 : 6 w/w) composite ink was formulated using the solution blending technique with 2.5 wt% FMWCNTs. A multi-layered humidity sensor was fabricated using additive print manufacturing processes on a flexible polyethylene terephthalate (PET) substrate. Screen printing and gravure printing processes were used to deposit the bottom silver (Ag) electrode and FWMCNT/HEC sensing layers, respectively. The capability of the fabricated humidity sensor was investigated by measuring its resistive response towards relative humidity (RH) varying from 20% RH to 80% RH. As the RH was increased from 20% RH to 80% RH in steps of 10% RH at 25 °C, it was observed that the resistance of the printed sensor increased linearly. The printed sensor demonstrated resistance changes as high as ≈290% at 80% RH, when compared to its base resistance at 20% RH. A sensitivity and a response time of 0.048/%RH and ≈20 s were obtained for the printed sensor, respectively. The results thus demonstrated the feasibility of employing additive print manufacturing processes to develop a highly sensitive sensor for humidity monitoring applications.

Sputum smear microscopy in the Xpert® MTB/RIF era.

A balanced perspective is advocated for the assessment and application of the most recent and the oldest diagnostic methods for pulmonary tuberculosis (TB)-the molecular Xpert® MTB/RIF assay and microscopy for acid-fast bacilli. We discuss their respective merits and shortcomings and identify threats that may hamper their use in TB control. Neither test on its own provides all the information needed for diagnosis and treatment monitoring. Considering all aspects important for both individual patient care and disease control, neither seems 'better' than the other. The required advancement of microscopy had already been hampered before the introduction of the GeneXpert technology by unsuccessful and probably misguided attempts to decentralise culture-based diagnosis and drug susceptibility testing. It seems evident that systematic replacement of microscopy by Xpert is not a viable option for the foreseeable future. Instead, the two methods should complement each other to arrive at a comprehensive, accessible and continuous service for a maximum number of patients. This will intrinsically prioritise targeting the most potent transmitters with the worst prognosis, simultaneously offering optimised prospects for efficient TB control. New microscopy and Xpert applications are expected to ultimately make control programmes independent of culture-based methods in diagnosis, treatment monitoring and outcome assessment.

Systematic case finding for tuberculosis in HIV-infected people who inject drugs: experience from Pakistan.

SETTING: Pakistan is a high tuberculosis (TB) burden country, moving from low human immunodeficiency virus (HIV) prevalence to a concentrated epidemic driven primarily by people who inject drugs (PWID). The Antiretroviral Treatment Adherence Unit (AAU) in Islamabad, Pakistan, is a residential facility that offers combined treatment for opioid dependence and HIV. OBJECTIVE AND DESIGN: This retrospective study was conducted to assess TB prevalence among HIV-infected PWID referred to the AAU and to evaluate the diagnostic value of cough as a screening symptom. A single sputum sample was collected regardless of symptoms, and examined using smear, Xpert® MTB/RIF and culture. RESULTS: Of 888 PWID, 71.5% submitted a sputum sample. More TB cases were detected using Xpert (n = 25) than with smear (n = 10) or culture (n = 20). A TB prevalence of 6141 per 100 000 was estimated based on seven cases already identified as being on anti-tuberculosis treatment and 32 newly diagnosed bacteriologically confirmed TB cases. Both cough and smoking (10 pack-years) were associated with increased TB prevalence. Only half of the TB cases reported cough. Rifampicin resistance was reported among 10% (3/29) of newly identified cases. CONCLUSION: TB prevalence in HIV-infected PWID was 15 times higher than in the general adult population. As a screening symptom, cough has low diagnostic value.

Evaluation of a novel line probe assay to detect resistance to pyrazinamide, a key drug used for tuberculosis treatment.

OBJECTIVES: The development of rapid molecular diagnostic assays for pyrazinamide (PZA) resistance is considered technically challenging as mutations are highly diverse, scattered along the full length of the pncA gene and not all are associated with PZA resistance. We evaluated the performance of the novel Genoscholar PZA-TB II line probe assay (PZA-LPA2; NIPRO Corporation, Japan). METHODS: To evaluate the applicability of the PZA-LPA2 in clinical settings, we compared the performance of the PZA-LPA2 to a composite reference standard pncA Sanger and Illumina sequencing plus phenotypic susceptibility testing on a panel of 87 Mycobacterium tuberculosis isolates from World Health Organization (WHO) drug resistance surveys, harbouring mutations previously classified as associated or not associated with resistance according to data from peer-reviewed literature. In addition, the PZA-LPA2 was challenged against a selection of isolates with lineage-specific and non-resistance-associated mutations, for which the frequency among clinical isolates is unknown, and tested directly on 59 sputum extracts. RESULTS: For the survey isolates, the PZA-LPA2 reached an overall agreement with the composite reference of 97.6% (80/82) or 94.3% (82/87) excluding or including heteroresistance, respectively. The PZA-LPA2 failed on 8.5% (5/59) of clinical samples; among valid results, 100% (14/14) sensitivity and 100% (7/7) specificity was reached relative to pncA Sanger sequencing. CONCLUSIONS: The PZA-LPA2 represents a valid and rapid alternative for indirect PZA susceptibility testing. Preliminary findings on clinical samples show promise for direct testing. Further studies are needed to assess the clinical risk of missing heteroresistance and falsely detecting lineage-specific, silent and nonassociated mutations.

Gastric specimens for diagnosing tuberculosis in adults unable to expectorate in Rawalpindi, Pakistan.

Setting: Adult pulmonary tuberculosis (TB) patients unable to expectorate quality sputum represent a diagnostic challenge. A private hospital in Pakistan routinely performs gastric aspiration in adults with difficulties expectorating. Objective: To assess the usefulness of gastric specimens (GS) in diagnosing pulmonary TB (PTB) and drug-resistant TB in adult presumptive TB patients unable to expectorate, and to compare the diagnostic yield and sensitivity of smear, culture and the Xpert® MTB/RIF assay. Design: This was a comparative cross-sectional study based on retrospective record review. Results: Of 900, 885 and 877 GS tested by smear, Xpert and culture, respectively, interpretable results were obtained for respectively 900 (100%), 859 (97.1%) and 754 (86.0%), with a diagnostic yield of respectively 23.6%, 30.3% and 24.9%. The yield was significantly higher for Xpert in previously treated patients. There were 313 patients with definite TB, defined as positive on Xpert and/or culture. The 82.8% sensitivity of Xpert was significantly higher than that of smear (61.0%) and culture (67.8%). Conclusion: GS obtained by aspiration under routine programme conditions is useful for detecting TB and drug-resistant TB in adult patients unable to expectorate. Xpert, with its rapid testing, high proportion of interpretable results and better sensitivity, can substantially improve the diagnosis of bacteriologically confirmed TB and rifampicin resistance.

Contexte: Les patients adultes atteints de tuberculose pulmonaire (TB) incapables d'expectorer des crachats de qualité posent un problème en matière de diagnostic. Un hôpital privé du Pakistan réalise en routine l'aspiration gastrique chez les adultes qui ont du mal à expectorer.Objectif: Evaluer l'utilité des échantillons gastriques (GS) chez des patients adultes présumés atteints de TB incapables d'expectorer, pour le diagnostic de la TB pulmonaire et pharmacorésistante et pour comparer le rendement diagnostique et la sensibilité du frottis, de la culture et du test Xpert® MTB/RIF.Schéma: Etude comparative transversale basée sur une revue rétrospective des dossiers.Résultats: Un total de 900, 885 et 877 GA ont été testés respectivement par frottis, Xpert et culture et des résultats interprétables ont été obtenus chez 900 (100%), 859 (97,1%) et 754 (86,0%) patients avec un rendement diagnostique respectivement de 23,6%, 30,3% et 24,9%. Le rendement a été significativement plus élevé pour l'Xpert chez les patients déjà traités. Il y avait 313 patients avec une TB, définie comme la positivité de l'Xpert et/ou de la culture. La sensibilité de l'Xpert de 82,8% a été significativement plus élevée que le frottis (61,0%) et la culture (67,8%).Conclusion: Le GS aspiré sous des conditions de routine de programme est utile pour détecter la TB et la TB pharmacorésistante chez des patients adultes incapables d'expectorer. L'Xpert avec un test rapide, la proportion élevée de résultats interprétables et une meilleure sensibilité, peuvent substantiellement améliorer le diagnostic de la TB confirmée par bactériologie et la résistance à la rifampicine.

Marco de referencia: El diagnóstico de la tuberculosis (TB) pulmonar se dificulta en los pacientes adultos que no pueden suministrar muestras de esputo de buena calidad. En un hospital privado del Pakistán se practica de manera sistemática la aspiración gástrica en los adultos con dificultad para expectorar.Objetivo: Evaluar la utilidad del aspirado gástrico (GS) para el diagnóstico de la TB pulmonar farmacorresistente, en los pacientes con presunción de TB que tienen dificultad para expectorar y comparar el rendimiento diagnóstico y la sensibilidad de la baciloscopia, el cultivo y la prueba Xpert® MTB/RIF.Método: Un estudio transversal comparativo a partir del examen retrospectivo de las historias clínicas.Resultados: Se examinaron 900 muestras de GS mediante baciloscopia, 885 con la prueba Xpert y 877 por cultivo; se obtuvieron resultados interpretables en 900 (100%), 859 (97,1%) y 754 muestras (86,0%), con un rendimiento diagnóstico de 23,6%, 30,3% y 24,9%, respectivamente. El rendimiento fue significativamente superior con la prueba Xpert en los pacientes con antecedente de tratamiento. El diagnóstico definitivo de TB, definido como un resultado positivo de la prueba Xpert, el cultivo o ambos, se estableció en 313 pacientes. La prueba Xpert exhibió una sensibilidad de 82,8%, que fue significativamente más alta que la sensibilidad de la baciloscopia (61,0%) y la del cultivo (67,8%).Conclusión: El examen de las muestras de GS en el marco del programa corriente es útil para detectar la TB y la TB farmacorresistente en los pacientes adultos que no pueden expectorar. La prueba Xpert que ofrece un diagnóstico rápido, alta proporción de resultados interpretables y mejor sensibilidad puede mejorar notablemente el diagnóstico con confirmación bacteriológica de la TB y la resistencia a rifampicina.

Fluoroquinolone consumption and -resistance trends in Mycobacterium tuberculosis and other respiratory pathogens: Ecological antibiotic pressure and consequences in Pakistan, 2009-2015.

OBJECTIVE/BACKGROUND: Fluoroquinolones (FQs) are important anti-tuberculous drugs for the treatment of multidrug-resistant (MDR) tuberculosis. Resistance to FQs leads to fewer options for treatment of tuberculosis (TB), and infection with such strains may also require longer treatment duration. Trends of resistance in Mycobacterium tuberculosis (MTB) are indicators of MTB-resistance evolution. Drivers of such resistance need to be understood and studied to inform preventive strategies. METHODS: Here, we present FQ-resistance rates and trends in Pakistan from 2010 to 2015 and compare rates with FQ-consumption data and rates in other community pathogens. RESULTS: Our results reveal a recent decrease in FQ-resistance rates in MTB, but an increase in resistance for Haemophilus influenzae and Shigella spp. Correlation of FQ resistance with FQ consumption at the population level was weak for MTB, although strong associations were noted for H. influenzae and Shigella spp. CONCLUSION: We discuss the possible reasons for the decrease in resistance rates in TB, putative drivers of resistance other than volume of FQ consumption, and the possible impact of the National Tuberculosis Programme and drug regulatory activities.