Search

Paramesh Ramulu Lambadi,1,* Tarun Kumar Sharma,1,* Piyush Kumar,1 Priyanka Vasnani,2 Sitaramanjaneya Mouli Thalluri,2 Neha Bisht,1 Ranjana Pathania,1,2 Naveen Kumar Navani1,21Department of Biotechnology, 2Centre of Nanotechnology, Indian Institute of Technology, Roorkee, Uttarakhand, India*These authors contributed equally to this workAbstract: Infectious diseases cause a huge burden on healthcare systems worldwide. Pathogenic bacteria establish infection by developing antibiotic resistance and modulating the host’s immune system, whereas opportunistic pathogens like Pseudomonas aeruginosa adapt to adverse conditions owing to their ability to form biofilms. In the present study, silver nanoparticles were biofunctionalized with polymyxin B, an antibacterial peptide using a facile method. The biofunctionalized nanoparticles (polymyxin B-capped silver nanoparticles, PBSNPs) were assessed for antibacterial activity against multiple drug-resistant clinical strain Vibrio fluvialis and nosocomial pathogen P. aeruginosa. The results of antibacterial assay revealed that PBSNPs had an approximately 3-fold higher effect than the citrate-capped nanoparticles (CSNPs). Morphological damage to the cell membrane was followed by scanning electron microscopy, testifying PBSNPs to be more potent in controlling the bacterial growth as compared with CSNPs. The bactericidal effect of PBSNPs was further confirmed by Live/Dead staining assays. Apart from the antibacterial activity, the biofunctionalized nanoparticles were found to resist biofilm formation. Electroplating of PBSNPs onto stainless steel surgical blades retained the antibacterial activity against P. aeruginosa. Further, the affinity of polymyxin for endotoxin was exploited for its removal using PBSNPs. It was found that the prepared nanoparticles removed 97% of the endotoxin from the solution. Such multifarious uses of metal nanoparticles are an attractive means of enhancing the potency of antimicrobial agents to control infections.Keywords: polymyxin B, silver nanoparticles, biofunctionalization, nosocomial pathogen, biofilm inhibition, endotoxin removal

Indro Neil Ghosh,1,* Supriya Deepak Patil,1,* Tarun Kumar Sharma,1,2 Santosh Kumar Srivastava,1 Ranjana Pathania,1 Naveen Kumar Navani11Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand, 2Center for Biodesign and Diagnostics, Translational Health Science and Technology Institute, Gurgaon Haryana, India*These authors contributed equally to this workAbstract: Silver has long been advocated as an effective antimicrobial. However, toxicity issues with silver have led to limited use of silver in nanoform, especially for food preservation. With the aim of exploring combinatorial options that could increase the antibacterial potency of silver nanoparticles and reduce the effective dosage of silver, we evaluated the extent of synergy that a combination of silver nanoparticles and an essential oil representative (cinnamaldehyde) could offer. A battery of gram-positive and gram-negative bacterial strains was utilized for antibacterial assays, and extents of synergism were calculated from fractional inhibitory concentration indices. The activity of nanoparticles was greatly enhanced when utilized in the presence of cinnamaldehyde. We observed combinatorial effects that were strongly additive against all the bacterial strains tested, and genuine synergy was found against spore forming Bacillus cereus and Clostridium perfringens – bacterial strains associated with release of cytotoxins in contaminated food and known for their persistence. Bacterial kill curve analysis revealed a very fast bactericidal action when a combination of two agents was used. The electron and atomic force microscopy also revealed extensive damage to the bacterial cell envelop in the presence of both agents. We also performed hemolysis assays to investigate and approximate the extent of toxicity exhibited by the two agents, and observed no adverse effect at the concentrations required for synergy. This study shows that safe levels of silver in nanoform in combination with essential oil component cinnamaldehyde can be effectively used for controlling the spore-forming bacterial species.Keywords: antibacterial activity, bacterial food spoilage, erythrocyte toxicity, essential oil, in vitro, synergy, toxin producing spore-forming bacteria

Tarun K Sharma,1 Stephen A Vernon 1Worcestershire Acute Hospitals NHS Trust, 2University Hospital, Nottingham, UKAbstract: Optometrists are increasing their roles into the field of clinical management. Making management decisions and treating patients increases the risk of litigation. Guidelines have been developed to assist in the clinical care of patients and are being increasingly used in litigation cases to assist in the decision making process. This article outlines the status of litigation as it relates to current optometric and ophthalmic practice, and discusses clinical management in the context of guidelines. In some countries, including the UK, optometrists are becoming the principal providers of primary eye care in the community, with their role expanding beyond traditional refractive practice into the realm of the treatment of medical conditions. The delivery of health care in the modern era is becoming increasingly challenging as a result of improving patient knowledge via the Internet, and a commensurate rise in patient expectations. In addition, close scrutiny by the media and those in the legal profession has appeared to drive an increase in claims against practitioners. Practitioners are vulnerable to litigation when patients consider that their care has fallen below acceptable standards. This article discusses the current status of guidelines with respect to potential litigation in the context of clinical care as it relates to expanding roles within optometric practice.Keywords: guidelines, litigation, optometrists

Background: Tuberculous meningitis (TBM) is the most devastating manifestation of extra-pulmonary tuberculosis. About 33% of TBM patients die due to very late diagnosis of the disease. Conventional diagnostic methods based on signs and symptoms, cerebrospinal fluid (CSF) smear microscopy or liquid culture suffer from either poor sensitivity or long turnaround time (up to 8 weeks). Therefore, in order to manage the disease efficiently, there is an urgent and unmet need for a rapid and reliable diagnostic test., Methods: In the current study, to address the diagnostic challenge of TBM, a highly rapid and sensitive structural switching electrochemical aptasensor was developed by combining the electrochemical property of methylene blue (MB) with the molecular recognition ability of a ssDNA aptamer. To demonstrate the clinical diagnostic utility of the developed aptasensor, a blinded study was performed on 81 archived CSF specimens using differential pulse voltammetry., Results: The electrochemical aptasensor developed in the current study can detect as low as 10 pg HspX in CSF background and yields a highly discriminatory response ( P <0.0001) for TBM and not-TBM categories with ~95% sensitivity and ~97.5% specificity and has the ability to deliver sample-to-answer in ≤30 minutes., Conclusion: In summary, we demonstrate a new aptamer-based electrochemical biosensing strategy by exploiting the target-induced structural switching of H63 SL-2 M6 aptamer and electroactivity of aptamer-tagged MB for the detection of HspX in CSF samples for the diagnosis of TBM. Further, the clinical utility of this sensor could be extended for the diagnosis of other forms of tuberculosis in the near future., Competing Interests: Disclosure The aptamer used in this study is a proprietary reagent and is deposited in the Indian Patent Office as part of Indian Patent application number 201611001550; the patent was transferred to a Translational Health Science and Technology Institute (THSTI) spinoff, AptaBharat Innovation Pvt. Ltd. (ABIPL), for further development of aptamer-based diagnostics. RD is employed by AptaBharat Innovation Pvt. Ltd (ABIPL) and TKS is employed by THSTI. TKS is also the founder of THSTI spinoff, ABIPL and owns 87% stakes in ABIPL. The authors report no other conflicts of interest in this work.