Nanoparticle-Mediated Mucosal Vaccination: Harnessing Nucleic Acids for Immune Enhancement.

Recent advancements in in vitro transcribed mRNA (IVT-mRNA) vaccine manufacturing have attracted considerable interest as advanced methods for combating viral infections. The respiratory mucosa is a primary target for pathogen attack, but traditional intramuscular vaccines are not effective in generating protective ion mucosal surfaces. Mucosal immunization can induce both systemic and mucosal immunity by effectively eliminating microorganisms before their growth and development. However, there are several biological and physical obstacles to the administration of genetic payloads, such as IVT-mRNA and DNA, to the pulmonary and nasal mucosa. Nucleic acid vaccine nanocarriers should effectively protect and load genetic payloads to overcome barriers i.e., biological and physical, at the mucosal sites. This may aid in the transfection of specific antigens, epithelial cells, and incorporation of adjuvants. In this review, we address strategies for delivering genetic payloads, such as nucleic acid vaccines, that have been studied in the past and their potential applications.

Comparison of Colistin Susceptibility via Two Different Methods in Gram-Negative Extensive Drug-Resistance Isolates from ICU Patients.

OBJECTIVE: To compare the susceptibility of colistin by two methods in extensive drug-resistant (XDR) Gram-negative isolates from ICU patients. STUDY DESIGN: Cross-sectional comparative analysis. Place and Duration of the Study: Department of Microbiology, Combined Military Hospital Karachi, Pakistan, from August 2022 to February 2023. METHODOLOGY: A total of 100 clinical specimens received from the intensive care unit yielded growth of extensively drug-resistant gram-negative bacteria, which were evaluated for polymyxin E susceptibility. The agar dilution method was compared with the reference broth microdilution (BMD) method. Minimum inhibitory concentration (MIC) was noted for both methods. RESULTS: Comparison of the MIC method by agar dilution showed a 90% correlation with the reference method of broth microdilution. With MICs within the acceptable range of the clinical and laboratory standards institute (CLSI) recommendations, 89 isolates were susceptible to colistin, whereas only 11 remained resistant. Polymyxin E's MIC 50 and MIC 90 were determined to be 1 and 2 µg/ml, respectively, with 97% susceptibility. CONCLUSION: Agar dilution susceptibility method can be used for screening purposes for the susceptibility testing of polymyxin E. This method is reliable and can easily identify the heteroresistance. KEY WORDS: Extensively drug-resistant, Broth microdilution, Multidrug-resistant, Agar dilution, Minimum inhibitory concentration, Colony forming unit.

Long-term clinical outcomes and cost-effectiveness of catheter vs thoracoscopic surgical ablation in long-standing persistent atrial fibrillation using continuous cardiac monitoring: CASA-AF randomized controlled trial.

BACKGROUND: Long-term clinical outcomes of catheter ablation (CA) compared to thoracoscopic surgical ablation (SA) to treat patients with long-standing persistent atrial fibrillation (LSPAF) are not known. OBJECTIVE: The purpose of this study was to compare the long-term (36-month) clinical efficacy, quality of life, and cost-effectiveness of SA and CA in LSPAF. METHODS: Participants were followed up for 3 years using implantable loop recorders and questionnaires to assess the change in quality of life. Intention-to-treat analyses were used to report the findings. RESULTS: Of the 115 patients with LSPAF treated, 104 (90.4%) completed 36-month follow-up [CA: n = 57 (95%); SA: n = 47 (85%)]. After a single procedure without antiarrhythmic drugs, 7 patients (12%) in the CA arm and 5 (11%) in the SA arm [hazard ratio 1.22; 95% confidence interval (CI) 0.81-1.83; P = .41] were free from atrial fibrillation/tachycardia (AF/AT) ≥30 seconds at 36 months. Thirty-three patients (58%) in the CA arm and 26 (55%) in the SA arm (hazard ratio 1.04; 95% CI 0.57-1.88; P = .91) had their AF/AT burden reduced by ≥75%. The overall impact on health-related quality of life was similar, with mean quality-adjusted life year estimates of 2.45 (95% CI 2.31-2.59) for CA and 2.32 (95% CI 2.13-2.52) for SA. Estimated costs were higher for SA (mean £24,682; 95% CI £21,746-£27,618) than for CA (mean £18,002; 95% CI £15,422-£20,581). CONCLUSION: In symptomatic LSPAF, CA and SA were equally effective at achieving arrhythmia outcomes (freedom from AF/AT ≥30 seconds and ≥75% burden reduction) after a single procedure without antiarrhythmic drugs. However, SA is significantly more costly than CA. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT04280042.

Remote monitoring of atrial fibrillation recurrence using mHealth technology (REMOTE-AF).

Aims: This proof-of-concept study sought to evaluate changes in heart rate (HR) obtained from a consumer wearable device and compare against implantable loop recorder (ILR)-detected recurrence of atrial fibrillation (AF) and atrial tachycardia (AT) after AF ablation. Methods and results: REMOTE-AF (NCT05037136) was a prospectively designed sub-study of the CASA-AF randomized controlled trial (NCT04280042). Participants without a permanent pacemaker had an ILR implanted at their index ablation procedure for longstanding persistent AF. Heart rate and step count were continuously monitored using photoplethysmography (PPG) from a commercially available wrist-worn wearable. Photoplethysmography-recorded HR data were pre-processed with noise filtration and episodes at 1-min interval over 30 min of HR elevations (Z-score = 2) were compared with corresponding ILR data. Thirty-five patients were enrolled, with mean age 70.3 ± 6.8 years and median follow-up 10 months (interquartile range 8-12 months). Implantable loop recorder analysis revealed 17 out of 35 patients (49%) had recurrence of AF/AT. Compared with ILR recurrence, wearable-derived elevations in HR ≥ 110 beats per minute had a sensitivity of 95.3%, specificity 54.1%, positive predictive value (PPV) 15.8%, negative predictive value (NPV) 99.2%, and overall accuracy 57.4%. With PPG-recorded HR elevation spikes (non-exercise related), the sensitivity was 87.5%, specificity 62.2%, PPV 39.2%, NPV 92.3%, and overall accuracy 64.0% in the entire patient cohort. In the AF/AT recurrence only group, sensitivity was 87.6%, specificity 68.3%, PPV 53.6%, NPV 93.0%, and overall accuracy 75.0%. Conclusion: Consumer wearable devices have the potential to contribute to arrhythmia detection after AF ablation. Study Registration: ClinicalTrials.gov Identifier: NCT05037136 https://clinicaltrials.gov/ct2/show/NCT05037136.

Advances in Nanoparticle-Enhanced Thermoelectric Materials from Synthesis to Energy Harvesting: A Review.

This comprehensive review analysis examines the domain of composite thermoelectric materials that integrate nanoparticles, providing a critical assessment of their methods for improving thermoelectric properties and the procedures used for their fabrication. This study examines several approaches to enhance power factor and lattice thermal conductivity, emphasizing the influence of secondary phases and structural alterations. This study investigates the impact of synthesis methods on the electrical characteristics of materials, with a particular focus on novel techniques such as electrodeposition onto carbon nanotubes. The acquired insights provide useful guidance for the creation of new thermoelectric materials. The review also compares and contrasts organic and inorganic thermoelectric materials, with a particular focus on the potential of inorganic materials in the context of waste heat recovery and power production within industries. This analysis highlights the role of inorganic materials in improving energy efficiency and promoting environmental sustainability.

Novel hemoperfusion adsorbents based on collagen for efficient bilirubin removal - A thought from yellow skin of patients with hyperbilirubinemia.

Hemoperfusion is a well-developed method for removing bilirubin from patients with hyperbilirubinemia. The performance of adsorbents is crucial during the process. However, most adsorbents used for bilirubin removal are not suitable for clinical applications, because they either have poor adsorption performance or limited biocompatibility. Patients with hyperbilirubinemia usually have distinctive yellow skin, indicating that collagen, a primary component of the skin, may be an effective material for absorbing bilirubin from the blood. Based on this idea, we designed and synthesized collagen (Col) and collagen-polyethyleneimine (Col-PEI) microspheres and employed them as hemoperfusion adsorbents for bilirubin removal. The microspheres have an efficient adsorption rate, higher bilirubin adsorption capacity, and competitive adsorption of bilirubin in the bilirubin/bovine serum albumin (BSA) solution. The maximum adsorption capacities of Col and Col-PEI microspheres for bilirubin are 150.2 mg/g and 258.4 mg/g, respectively, which are higher than those of most traditional polymer microspheres. Additionally, the microspheres exhibit excellent blood compatibility originating from collagen. Our study provides a new collagen-based strategy for the hemoperfusion treatment of hyperbilirubinemia.

Left Atrial Function Predicts Atrial Arrhythmia Recurrence Following Ablation of Long-Standing Persistent Atrial Fibrillation.

BACKGROUND: Left atrial (LA) function following catheter or surgical ablation of de-novo long-standing persistent atrial fibrillation (AF) and its impact on AF recurrence was studied in patients participating in the CASA-AF trial (Catheter Ablation vs. Thoracoscopic Surgical Ablation in Long Standing Persistent Atrial Fibrillation). METHODS: All patients underwent echocardiography preablation, 3 and 12 months post-ablation. LA structure and function were assessed by 2-dimensional volume and speckle tracking strain measurements of LA reservoir, conduit, and contractile strain. Left ventricular diastolic function was measured using transmitral Doppler filling velocities and myocardial tissue Doppler velocities to derive the e', E/e', and E/A ratios. Continuous rhythm monitoring was achieved using an implantable loop recorder. RESULTS: Eighty-three patients had echocardiographic data suitable for analysis. Their mean age was 63.6±9.7 years, 73.5% were male, had AF for 22.8±11.6 months, and had a mean LA maximum volume of 48.8±13.8 mL/m2. Thirty patients maintained sinus rhythm, and 53 developed AF recurrence. Ablation led to similar reductions in LA volumes at follow-up in both rhythm groups. However, higher LA emptying fraction (36.3±10.6% versus 27.9±9.9%; P<0.001), reservoir strain (22.6±8.5% versus 16.7±5.7%; P=0.001), and contractile strain (9.2±3.4% versus 5.6±2.5%; P<0.001) were noted in the sinus rhythm compared with AF recurrence group following ablation at 3 months. Diastolic function was better in the sinus rhythm compared with the AF recurrence group with an E/A ratio of 1.5±0.5 versus 2.2±1.2 (P<0.001) and left ventricular E/e' ratio of 8.0±2.1 versus 10.3±4.1 (P<0.001), respectively. LA contractile strain at 3 months was the only independent predictor of AF recurrence. CONCLUSIONS: Following ablation for long-standing persistent AF, improvement in LA function was greater in those who maintained sinus rhythm. LA contractile strain at 3 months was the most important determinant of AF recurrence following ablation. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT02755688.

The Electronic Properties of Cadmium Naphthalene Diimide Coordination Complex.

The computational simulations for electronic properties of cadmium (Cd) coordinated L-alanine NDI ligand (H2-l-ala NDI) based complex are the focus of this research. For the first time, the Cd-NDI complex (monomer) has been produced using water as the solvent; this is a new approach to synthesizing the Cd-NDI complex that has not been reported yet. Along with crystallography and Hirsch field analysis, CAM-B3LYP/LANL2DZ and B3LYP/LANL2MB basis sets were used, and in-depth characterisation of the Cd-NDI complex by following DFT and TD-DFT hypothetical simulations. Hyperpolarizabilities, frontier molecular orbitals (FMOs), the density of states (DOS), dipole moment (µ), electron density distribution map (EDDM), transition density matrix (TDM), molecular electrostatic potential (MEP), electron-hole analysis (EHA), and electrical conductivity (σ) have all been studied regarding the Cd-NDI complex. The vibrational frequencies and types of interaction are studied using infrared (IR) and non-covalent interaction (NCI) analysis with iso-surface. In comparison to the Cd-NDI complex with 2.61, 2.42 eV Eg (using CAM-B3LYP/LANL2DZ and B3LYP/LANL2MB basis sets, respectively) and 376 nm λmax, (in case of B3LYP/LANL2MB λmax is higher), H2-l-ala NDI have 3.387 eV Eg and 375 nm λmax, metal-ligand coordination in complex dramatically altered charge transfer properties, such as narrowing band gap (Eg). Based on the electronic properties analysis of Cd-NDI complex, it is predicted that the Cd-NDI complex will have a spectacular (nonlinear optical) NLO response. The Cd-NDI complex is discovered to be advantageous for the creation of future nanoscale devices due to the harmony between the Cd metal and H2-l-ala NDI, in addition to their influences on NLO characteristics.

Genetic engineering of bacteriophages: Key concepts, strategies, and applications.

Bacteriophages are the most abundant biological entity in the world and hold a tremendous amount of unexplored genetic information. Since their discovery, phages have drawn a great deal of attention from researchers despite their small size. The development of advanced strategies to modify their genomes and produce engineered phages with desired traits has opened new avenues for their applications. This review presents advanced strategies for developing engineered phages and their potential antibacterial applications in phage therapy, disruption of biofilm, delivery of antimicrobials, use of endolysin as an antibacterial agent, and altering the phage host range. Similarly, engineered phages find applications in eukaryotes as a shuttle for delivering genes and drugs to the targeted cells, and are used in the development of vaccines and facilitating tissue engineering. The use of phage display-based specific peptides for vaccine development, diagnostic tools, and targeted drug delivery is also discussed in this review. The engineered phage-mediated industrial food processing and biocontrol, advanced wastewater treatment, phage-based nano-medicines, and their use as a bio-recognition element for the detection of bacterial pathogens are also part of this review. The genetic engineering approaches hold great potential to accelerate translational phages and research. Overall, this review provides a deep understanding of the ingenious knowledge of phage engineering to move them beyond their innate ability for potential applications.

Variation in optimal hemodynamic atrio-ventricular delay of biventricular pacing with different endocardial left ventricular lead locations using precision hemodynamics.

INTRODUCTION: It is not known whether the optimal atrioventricular (AVopt ) delay varies between left ventricular (LV) pacing site during endocardial biventricular pacing (BiVP) and may therefore needs consideration. METHODS: We assessed the hemodynamic AVopt in patients with chronic heart failure undergoing endocardial LV lead implantation. AVopt was assessed during atrio-BiVP with a "roving LV lead." Up to four locations were studied: mid-lateral wall, mid-septum (or a close alternative), site of greatest hemodynamic improvement, and LV lead implant site. The AVopt was compared to a fixed AV delay of 180 ms. RESULTS: Seventeen patients were included (12 male, aged 66.5 ± 12.8 years, ejection fraction 26 ± 7%, 16 left bundle branch block or high percentage of right ventricular pacing [RVP], QRS duration 167 ± 27 ms). In most locations (62/63), AVopt increased systolic blood pressure during BiVP compared with RVP (relative improvement 6 mmHg, interquartile range [IQR] 4-9 mmHg). Compared to a fixed AV delay, the hemodynamic improvement at AVopt was higher (1 mmHg, IQR 0.2-2.6 mmHg, p < .001). Within most patients (16/17), we observed a difference in AVopt between pacing sites (median paced AVopt 209 ms, IQR 117-250). Within this range, the hemodynamic impact of these differences was small (median loss 0.6 mmHg, IQR 0.1-2.6 mmHg). CONCLUSION: Within a patient, different endocardial LV lead locations have slightly different hemodynamic AVopt which are superior to a fixed AV delay. The hemodynamic consequence of applying an optimum from a different lead location is small.

Functionalization of ampicillin and gentamicin with biogenic copper nanoparticles (CuNPs) remodel antimicrobial and cytotoxic outcome against MDR clinical isolates.

The present study reports the functionalization of antibiotic-conjugated Alternanthera pungens and Trichodesma indicum copper nanoparticles (CuNPs). Initially, antibiotic profiling of multi-drug resistant (MDR) clinical isolates against five antibiotics was verified and then gentamicin and ampicillin conjugates of CuNPs were prepared. Biosynthesized nanostructures were characterized through UV-visible spectroscopy, Fourier-transformed infrared spectroscopy, X-ray diffraction and scanning electron microscope. Biogenic synthesized CuNPs displayed highest antibacterial activity (24.0-31.3 mm inhibition zones) when capped with gentamicin as compared to the ampicillin-conjugated NPs which showed resistance against most of the bacterial species. A. pungens-derived conjugates of gentamicin (CuAp-GNT) along with the vehicle revealed 4.86 ± 0.20% and 4.25 ± 2.96% hemolytic potential and highest MDA production in S. typhimurium (3.18 ± 1.52 µg/mL and 6.31 ± 3.49 µg/mL) and K. pneumoniae (2.99 ± 0.90 µg/mL and 4.06 ± 1.20 µg/mL). Similarly, CuAp-GNT also showed highest DNA protection ability by displaying 1342.99 ± 11.87 band intensity. All-inclusive, CuAp showed more promising effects when conjugated with gentamicin indicating that capping of gentamicin with the active components of the plant-based copper nanostructures increases the antibacterial capacity of the drug. Hence, conjugation of antibiotics with bio-based sources offers great potential for identifying potent drug leads.

Fused Deposition Modeling and Characterization of Heat Shape Memory Poly(lactic) Acid-Based Porous Vascular Scaffold.

Shape memory polymers have received widespread attention from researchers because of their low density, shape variety, responsiveness to the environment, and transparency. This study deals with heat-shape memory polymers (SMPs) based on polylactic acid (PLA) for designing and fabricating a novel porous vascular scaffold to treat vascular restenosis. The solid isotropic material penalization method (SIMP) was applied to optimize the vascular scaffolds. Based on the torsional torque loading of Hyperworks Optistruct and the boundary conditions, the topological optimization model of a vascular scaffold unit was established. Forward and reverse hybrid modeling technology was applied to complete the final stent structure's assembly. The glass transition temperature for the present SMPs is 42.15 °C. With the increase in temperature, the ultimate tensile strength of the SMPs is reduced from 29.5 MPa to 11.6 MPa. The maximum modulus at room temperature was around 34 MPa. Stress relaxation curves show that the material classification is a "thermoset" polymer. The superb mechanical properties, the transition temperature of the SMPs, and the recovery ratio made it a feasible candidate for a vascular scaffold. A circular tube based on the shape memory polymers was presented as an example for analyzing the recovery ratio in an unfolding state. A higher recovery ratio was obtained at a temperature of 65 °C with a tube thickness of 2 mm. Finally, the proposed porous vascular scaffold was successfully fabricated, assessed, and compared with the original and previously developed vascular scaffolds. The proposed scaffold structure regains its initial shape with a recovery ratio of 98% (recovery temperature of 47 °C) in 16 s. The tensile strength, Young's modulus, and bending strength of the proposed scaffold were 29.5 MPa, 695.4 MPa, and 6.02 MPa, respectively. The results showed that the proposed scaffold could be regarded as a potential candidate for a vascular implantation.

Mr.Vc v2: An updated version of database with increased data of transcriptome and experimental validated interactions.

Mr.Vc is a database of curated Vibrio cholerae transcriptome data and annotated information. The main objective is to facilitate the accessibility and reusability of the rapidly growing Vibrio cholerae omics data and relevant annotation. To achieve these goals, we performed manual curation on the transcriptome data and organized the datasets in an experiment-centric manner. We collected unknown operons annotated through text-mining analysis that would provide more clues about how Vibrio cholerae modulates gene regulation. Meanwhile, to understand the relationship between genes or experiments, we performed gene co-expression analysis and experiment-experiment correlation analysis. In additional, functional module named "Interactions" which dedicates to collecting experimentally validated interactions about Vibrio cholerae from public databases, MEDLINE documents and literature in life science journals. To date, Mr.Vc v2, which is significantly increased from the previous version, contains 107 microarray experiments, 106 RNA-seq experiments, and 3 Tn-seq projects, covering 56,839 entries of DEGs (Differentially Expressed Genes) from transcriptomes and 7,463 related genes from Tn-seq, respectively. and a total of 270,129 gene co-expression entries and 11,990 entries of experiment-experiment correlation was obtained, in total 1,316 entries of interactions were collected, including 496 protein-chemical signaling molecule interactions, 472 protein-protein interactions, 306 TF (Transcription Factor)-gene interactions and 42 Vibrio cholerae-virus interactions, most of which obtained from 402 literature through text-mining analysis. To make the information easier to access, Mr.Vc v2 is equipped with a search widget, enabling users to query what they are interested in. Mr.Vc v2 is freely available at http://mrvcv2.biownmc.info.

Correlation Of Glomerular Filtration Rate (Gfr) Estimation Formulae With Measured Gfr In Pediatric Oncology Patients.

Background: In patients with malignancy accurate assessment of renal function is important for administration of chemotherapeutic medicines. Measurement of GFR by inulin, EDTA clearance, iohexol and 24 hrs urinary creatinine clearance (Crcl) is cumbersome so creatinine based GFR formulas have been developed for assessment of kidney function and there are variety of GFR formulas available for clinical use. Objective was to determine the correlation of estimated GFR by creatinine-based estimation formulae with measured GFR by 24-hours creatinine clearance. Methods: A cross sectional study was conducted in which all patients who underwent measured GFR (mGFR) assessment at Oncology Unit of NICH between 1st January to 31st December 2019 were enrolled in the study. Estimated Glomerular filtration rate (eGFR) of all these patients was calculated by three formulae Original Schwartz (OS), Updated Schwartz (US) and simple height independent equation (SHID). Correlation was made with mGFR by Crcl taken as gold standard using Pearson's correlation and Linear regression analysis. Bland Altman analysis was also done to see the agreement between eGFR with mGFR. Results: Total sixty (60) patients were enrolled with mean age of 8.2±3.6 years. All three eGFR formulae exhibited a statistically significant positive correlation with mGFR (p-value <0.01). Linear regression analysis also showed a statistically significant relation between mGFR and eGFRs however, the developed regression models for all three formulae showed a low R2 values. Bland-altman analysis revealed that useful level of agreement does not exist between mGFR and eGFR by OS however, SHID and US were found to be in agreement with mGFR by Crcl. Conclusion: SHID and US equations give a good estimate of GFR and may be used in children with malignancies to estimate GFR.

Effectiveness And Safety Of Direct Acting Antiviral Agents In Thalassaemic Patients With Chronic Hepatitis C.

BACKGROUND: Pakistan has the highest prevalence of Β-Thalassemia major in children and Chronic Hepatitis C (HCV) infection is a common transfusion transmitted infection. After the emergence of new generations of Antiviral drugs labelled as Direct Acting Antivirals (DAAs), substantial eradication of HCV has been reported as 90-95% with fewer side effects as compared to older regimen of Peginterferon with or without Ribavirin. The main objective of this study was to assess the Rapid virological response (RVR) at 4th week, End of treatment response (ETR) at 12th week and sustained viral response (SVR) at 24th week achieved by using direct acting antiviral and to assess their safety. Methods: Retrospective descriptive study was conducted from July 2018 to July 2020 at National Institute of Child Health. All ß-thalassemia major paediatric patients with HCV infection and age between 3-14 years were included. Demographic data, liver function test, HCV PCR, and response of antiviral therapy was recorded and analyzed. Safety was determined by adverse effects reported in records and efficacy was documented by clearance of HCV-RNA to see ETR and SVR. RESULTS: Total 21 patients were treated. Mean age was 7.67±3yr and 12 (57%) were male. Mean weight was 19.3±3.2kg. RVR and ETR was achieved in all (100%) and SVR was achieved in 20/21 (95%) patients. Headache in 2(9.5%) and generalized body ache was found in 1 (4.25%) patient. Conclusion: Combined Sofosbuvir and Daclatasvir were found to be effective and safe for treating HCV in Thalassaemia Major Children.

Digital healthcare: the future.

Digital healthcare offers a huge range of possibilities and may improve the quality of patient care. The traditional paradigm of clinical history, examination, differential diagnosis and treatment may be improved by tools such as machine learning, mobile applications and sensors, wearables, and telehealth. The recent pandemic has accelerated the move towards this future, however, important concerns remain. These include ensuring that new technologies are assessed effectively and are introduced thoughtfully, data are unified into care records, and, ultimately, digital tools are underpinned with appropriate clinical support. Patients must benefit without worsening workload for the clinician. Old barriers may be overcome but new challenges will be faced, in particular, ensuring the promise of better care for those who lack access to smart phones and the internet will be crucial. Clinicians must continue to advocate for patients and their colleagues as we embrace the future of digital healthcare.

ChromagarTM Col-Apse for Detection of Colistin Resistance in Clinical Isolates of Multidrug Resistant Gram Negative Bacilli.

OBJECTIVE: To determine the diagnostic accuracy of CHROMagarTM COL-APSE, for detection of colistin resistance in clinical isolates of multi drug resistant (MDR) gram negative bacilli (GNB). STUDY DESIGN: Cross-sectional validation study. PLACE AND DURATION OF STUDY: Department of Microbiology, Armed Forces Institute of Pathology (AFIP), Rawalpindi, Pakistan from February 2019 to August 2019. METHODOLOGY: Total 96 MDR-GNB in clinical isolates were included. Isolates were identified using gram stain, catalase, oxidase, API 20E and API 20NE. After taking approval from Institutional Ethical Review Committee, colistin susceptibility was determined simultaneously by CHROMagarTM COL-APSE (using 1x105 CFU/ml inoculum) and Broth Micro Dilution (BMD) Minimum Inhibitory Concentration (MIC) method as per CLSI. EUCAST guidelines were followed for interpretation of susceptibility profile. Results were validated with gold standard test, i.e. BMD. RESULTS: Out of 96 MDR clinical isolates, the distribution was K. pneumoniae n=63, E. coli n=18, A. baumannii n=11, C. freundii n=3, and E. cloacae n=1. The sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of CHROMagarTM COL-APSE for detection of colistin resistance, keeping BMD-MIC method as gold standard, was 97.96%, 97.87%, 97.96%, 97.87% and 97.92%, respectively. CONCLUSION: CHROMagarTM COL-APSE can be used as screening agar by direct streaking of specimen as well as diagnostic for detection of colistin resistance by the use of standardised inoculum. It can be used as a critical time saving method for colistin resistance detection in absence of expertise or manpower required for BMD as well as the cost required for genetic sequencing to detect MCR genes. Key Words: Multi drug resistant (MDR), Gram negative bacilli (GNB), Colistin resistance, CHROMagarTM COL-APSE.

Invasive fungal disease in critically ill and Immunocompromised patients.

OBJECTIVE: To study the frequency and type of invasive fungal disease in critically ill and immunocompromised patients. Method: The prospective, cross-sectional, descriptive study was conducted at the Armed Forces Institute of Pathology, Rawalpindi, Pakistan, from January 2017 to December 2020, and comprised pathological samples from immunocompromised and critically ill patients for fungal culture. Data regarding demographics, comorbidities, results of direct microscopy and fungal culture was recorded. Data was analysed using SPSS 22. RESULTS: Of the 8285 patients' specimens, 4722(57%) belonged to males and 3563(43%) to females. The mean age of the patients was 48.32±5.42 years (range: 14-98 years). Out of total 8285, 3465(41.82%) were related to blood, 2640(32%) endobronchial washing, 837(10%) sputum, 623(7.5%) tissue, 332(4%) body fluids, 288(3.5%) bronchoalveoar lavage and 100(1.2%) cerebrospinal fluid. Aspergillus flavus (20.7%) and candida albicans (14.5%) were the two most commonly isolated fungal species. CONCLUSIONS: A high index of suspicion for invasive fungal disease should be maintained in immunocompromised and critically ill patients.

Antimicrobial susceptibility pattern and genotypic characterisation of quinolone and ceftriaxone resistant genes among Salmonella typhi from various regions of Pakistan.

OBJECTIVE: To determine the current antibiotic resistance patterns and identification of quinolone and ceftriaxone resistant genes among Salmonella enterica subspecies serovar Typhi. METHODS: The prospective study was conducted from September 2018 to March 2019 and comprised samples collected from major hospitals and laboratories in Karachi, Quetta, Lahore, Kharia, Rawalpindi, Islamabad and Peshawar after approval from the institutional ethics review board of Hazara University, Mansehra, Pakistan. Antimicrobial susceptibility of isolates collected from the health facilities was checked using the Kirby Bauer disc diffusion method in line with the Clinical and Laboratory Standards Institute guidelines at the Department of Microbiology, Armed Forces Institute of Pathology (AFIP), Rawalpindi, Pakistan. All isolates were subjected for identification of genes responsible for quinolone and ceftriaxone resistance using polymerase chain reaction followed by gel-electrophoresis. RESULTS: Among the 96 isolates, phenotypically, ceftriaxone was found resistant in 31(32.29%) and ciprofloxacin in 95(99%). Genotypically, blaCTX-M-15 (beta lactamase, CTX as its acronym, -M from Munich) gene for ceftriaxone resistance was found in all phenotypically resistant 31(32.29%) isolates, while QnrS (Quinolone resistance, S group), GyrA (DNA gyrase subunit A), and GyrB (DNA gyrase subunit B) genes responsible for ciprofloxacin resistance were found in different frequencies (percentages given in table 2). CONCLUSIONS: The spread of extensively drug-resistant Salmonella enterica subspecies serovar Typhi strain to many big cities calls for urgent preventive measures.

Novel aggregated multiposition noncontact mapping of atrial tachycardia in humans: From computational modeling to clinical validation.

BACKGROUND: A novel aggregated multiposition noncontact mapping (AMP-NCM) algorithm is proposed to diagnose cardiac arrhythmias. OBJECTIVE: The purpose of this study was to computationally determine an accuracy threshold and to compare the accuracy and clinical utility of AMP-NCM to gold standard contact mapping. METHODS: In a cellular automata model, the number of catheter positions and chamber coverage were varied to establish accuracy requirements for clinically relevant AMP-NCM. This guided the clinical study protocol. In a prospective cohort of patients with atrial tachycardia (AT), noncontact mapping (NCM) recordings from a single position (SP) and multiple positions were compared to contact mapping with a high-density multipolar catheter using morphology and timing differences of reconstructed signals. Identification of AT mechanisms and ablation targets using both AMP-NCM and contact mapping were randomly evaluated by 5 blinded reviewers. RESULTS: AMP-NCM accuracy was asymptotic at 60 catheter positions in computational modeling. Twenty patients (age 65 ± 12 years; 19 male) with 26 ATs (5 focal, 21 reentrant) were studied. Morphologic correlation of signals derived from AMP-NCM was significantly better than those from SP-NCM compared to contact signals (median 0.93 vs 0.76; P <.001). AMP-NCM generated maps more rapidly than contact mapping (3 ± 1 minutes vs 13 ± 6 minutes; P <.001) and correctly diagnosed AT mechanisms in 25 of 26 maps (96%). Overall, 80% of arrhythmia mechanisms were correctly identified using AMP-NCM by blinded reviewers. CONCLUSION: Once 60 catheter positions were achieved, AMP-NCM successfully diagnosed mechanisms of AT and identified treatment sites equal to gold standard contact mapping in 3 minutes of procedural time.