Rationale: Monitoring and controlling cardiac myocyte activity with optogenetic tools offer exciting possibilities for fundamental and translational cardiovascular research. Genetically encoded voltage indicators may be particularly attractive for minimal invasive and repeated assessments of cardiac excitation from the cellular to the whole heart level. Objective: To test the hypothesis that cardiac myocyte–targeted voltage-sensitive fluorescence protein 2.3 (VSFP2.3) can be exploited as optogenetic tool for the monitoring of electric activity in isolated cardiac myocytes and the whole heart as well as function and maturity in induced pluripotent stem cell–derived cardiac myocytes. Methods and Results: We first generated mice with cardiac myocyte–restricted expression of VSFP2.3 and demonstrated distinct localization of VSFP2.3 at the t-tubulus/junctional sarcoplasmic reticulum microdomain without any signs for associated pathologies (assessed by echocardiography, RNA-sequencing, and patch clamping). Optically recorded VSFP2.3 signals correlated well with membrane voltage measured simultaneously by patch clamping. The use of VSFP2.3 for human action potential recordings was confirmed by simulation of immature and mature action potentials in murine VSFP2.3 cardiac myocytes. Optical cardiograms could be monitored in whole hearts ex vivo and minimally invasively in vivo via fiber optics at physiological heart rate (10 Hz) and under pacing-induced arrhythmia. Finally, we reprogrammed tail-tip fibroblasts from transgenic mice and used the VSFP2.3 sensor for benchmarking functional and structural maturation in induced pluripotent stem cell–derived cardiac myocytes. Conclusions: We introduce a novel transgenic voltage-sensor model as a new method in cardiovascular research and provide proof of concept for its use in optogenetic sensing of physiological and pathological excitation in mature and immature cardiac myocytes in vitro and in vivo.

Heavy metal pollution is a direct consequence of the extensive utilization of heavy metals in various industrial processes. The persistence and nondegradability of heavy metals cause them to bioaccumulate in nature, and when they come in direct contact with the pristine environment, they not only contaminate it severely but also pose dire consequences to the health of all living forms on earth, including humans. Chromium (Cr) is one of the heavy metals which has been extensively used in various industrial processes such as mining, alloy manufacturing, tanning of hides and skins, pigment production, etc. However, it is regarded as a priority pollutant due to its highly toxic, teratogenic, mutagenic, and carcinogenic nature, and the U.S. Environmental Protection Agency (EPA) also categorized it into group "A" human carcinogen. In contrast to water-soluble hexavalent chromium (Cr 6+), its reduced form, trivalent chromium (Cr 3+), is relatively benign and readily precipitated at environmental pH. Thus, bioremediation of Cr 6+ through microorganisms including bacteria, yeast, and algae provides a promising approach to decontaminate a metal-polluted environment. This review describes an overview of the microbial reduction of Cr 6+ , resistance mechanism, and the antioxidant profiling exhibited by these microorganisms when exposed to Cr 6+. It also describes the pilot-scale study of the successive use of bacterial, fungal, and algal strains and the subsequent use of microbially purified water for the cultivation of plant growth. Multiple metal-resistant microorganisms are a good bioresource for green chemistry to eradicate environmental Cr 6+. Key Points • Hexavalent chromium (Cr 6+) is highly toxic for living organisms including humans. • Microbial Cr resistance is mediated at the genetic, proteomic, and molecular levels. • Successive use of microorganisms is the best strategy to exterminate Cr 6+ from the environment.

Coronary artery disease (CAD) is one of the leading public health problems associated with mortality and morbidity in the world. It is a complex disorder influenced by both genetic and environmental factors. Atherosclerosis and elevated levels of plasma cholesterol contribute to increased risk for CAD. Other risk factors include age, hypertension, obesity, diabetes, smoking, and family history. Previous genetic studies have identified multiple polymorphisms in various genes to be associated with the risk of CAD in different populations. We aimed to examine the association of MRAS/rs9818870 and C12orf43/rs2258287 polymorphisms with the risk of CAD in a Pakistani sample. A total of 200 samples (100 cases and 100 controls) was analyzed by Allele-specific PCR. Genotypes were determined by agarose gel electrophoresis. In the current study, locus C12orf43/rs2258287 was found to be associated with the risk of CAD in the studied Pakistani cohort (OR 0.18; CI 0.08-0.37; p = 0.0001) while no association was observed for MRAS/rs9818870 (OR 1.34; CI 0.65-2.76; p = 0.42). In conclusion, the rs2258287 SNP may play an important role in the progression of CAD in the Pakistani subjects. However, future studies should be done on a larger sample size to fully establish its exact role in CAD.

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Urinary tract infections (UTIs) are one of the most commonly presented infections among men and women as they acquire it at least once in their lifetime and disease can recur. In recent era, one of the challenges faced by humans is progressively increasing dissemination of antimicrobial resistance among pathogens causing UTIs and other diseases. A hospital-based investigation was carried out including 200 UTI patients affirmed by clinicians. Samples selected based on initial screening by nitrite test were cultured and gram-stained. 161 isolates of gram-negative bacteria were characterized based on morphological and biochemical analysis. Antibiotic susceptibility testing was done by Kirby-Bauer disc diffusion method against 16 selected antibiotics. Genotyping was done for blaTEM and blaCTX-M by PCR. Out of the 161 isolated gram-negative bacteria, E. coli (N=116, 72%) was the most common followed by Klebsiella oxytoca (N=22, 13%), Klebsiella pneumoniae (N=14, 9%), Proteus mirabilis (N=6, 4%) and Proteus vulgaris (N=3, 2%). Antibiotic susceptibility testing revealed that isolated gram-negative pathogens were highly sensitive to Amikacin, Fosfomycin, Imipenem and Meropenem where as high level of resistance was observed against Ampicillin, Amoxicillin, Cefotaxime, Nalidixic acid and Norfloxacin. The blaTEM and blaCTX-M genotyping showed that around half of the isolates were positive for either or both of these genes. blaCTX-M (57%) was described as being more common as compared to blaTEM (45%). Pertinent to the rapidly evolving drug resistance patterns amongst pathogenic bacteria, conducting monitoring and surveillance studies to provide updates to physicians regarding latest and emerging trends of drug resistance is crucial globally.

Human skin microflora plays important role in the functioning of skin and is modulated by several intrinsic and extrinsic factors including hygiene practices. During Covid-19 pandemic, focus has been particularly directed towards improving hygiene. We explored the skin microflora of healthcare workers in local population of Multan, Pakistan. A total of 44 samples of skin were collected from healthy workers along with the administration of questionnaire regarding hygiene practices. After isolation, bacteria were characterized by morphology, staining andbiochemical tests. Majority of the workers was 20-30 years old females. Most of them reported to wear gloves during practice, wash hands 8-10 times a day, use sanitizer 8-10 times a week and took bath 12-15 times a month. Isolated microflora (n=110) included Staphylococcus aureus (62%), Escherichia coli (16%), Pseudomonas spp. (9%), Proteus spp. (5%), Enterobacter spp. (5%) and Klebsiella spp. (3%). Presence of pathogens, although in small numbers, emphasizes the necessity of disseminating knowledge regarding adoption and maintenance of hygienic practices, specifically among healthcare workers.

Prevalence and multidrug resistance among bacteria in catheter-associated urinary tract infections (CAUTIs) has been on the rise in recent times. Hence, the prevalence rate and antibacterial susceptibility of bacteria in CAUTIs in ICU patients was evaluated. A total of 120 patients admitted to the ICU of Nishtar Hospital, Multan, were recruited for this study. Both gram-positive and gram-negative bacterial isolates were characterized based on biochemical tests including catalase test, oxidase test, indole test, TSI test, citrate test, coagulase test and growth on 6.5% NaCl agar. The prevalence of bacterial species was Escherichia coli (32%), Staphylococcus aureus (26%), Pseudomonas spp. (18%), Proteus spp. (14%) and Enterococcus spp. (2%). A considerable degree of resistance against commonly prescribed antibiotics was observed. Gram negative bacteria showed resistance to ciprofloxacin, piperacillin-tazobactam and amikacin as well as susceptibility to imipenem, tigecycline and polymixin. Gram positive bacteria showed resistance to antibiotics such as piperacillin-tazobactam, ampicillin, gentamicin, oxacillin and ceftazidime suggesting the ineffectiveness of these antibiotics for treating bacterial infections among CAUTI patients and demonstrating the latest trends in antimicrobial drug resistance profile in local population.