No abstract

Misuse of antibiotics has recently been considered a global issue because of its harmful effects on human health. Since conventional methods have numerous limitations, it is necessary to develop fast, simple, sensitive, and reproducible methods for the detection of antibiotics. Among numerous recently developed methods, aptasensors are fascinating because of their good specificity, sensitivity and selectivity. These kinds of biosensors combining aptamer with colorimetric applications of gold nanoparticles to recognize small molecules are becoming more popular owing to their advantageous features, for example, low cost, ease of use, on-site analysis ability using naked eye and no prerequisite for modern equipment. In this review, we have highlighted the recent advances and working principle of gold nanoparticles based colorimetric aptasensors as promising methods for antibiotics detection in different food and environmental samples (2011–2020). Furthermore, possible advantages and disadvantages have also been summarized for these methods. Finally, the recent challenges, outlook, and promising future perspectives for developing novel aptasensors are also considered.

At present, fluorescence recovery after photobleaching (FRAP) data are interpreted using various types of reaction-diffusion (RD) models: the model type is usually fixed first, and corresponding model parameters are inferred subsequently. In this article, we describe what we believe to be a novel approach for RD modeling without using any assumptions of model type or parameters. To the best of our knowledge, this is the first attempt to address both model-type and parameter uncertainties in inverting FRAP data. We start from the most general RD model, which accounts for a flexible number of molecular fractions, all mobile, with different diffusion coefficients. The maximal number of possible binding partners is identified and optimal parameter sets for these models are determined in a global search of the parameter-space using the Simulated Annealing strategy. The numerical performance of the described techniques was assessed using artificial and experimental FRAP data. Our general RD model outperformed the standard RD models used previously in modeling FRAP measurements and showed that intracellular molecular mobility can only be described adequately by allowing for multiple RD processes. Therefore, it is important to search not only for the optimal parameter set but also for the optimal model type.

The emerging threat of multi-drug resistance (MDR) in a wide range of diseases is a major public health problem, which prolongs treatment, imposes disabilities and reduces the expected life span. MDR is common in urinary tract infections (UTI). Due to recent dramatic change in antimicrobial activity spectrum, we evaluated the current spectrum of antimicrobials activity in UTIs. We observed 33% infection rate in cultures and positive cultures were followed by the Kirby-Bauer technique for sensitivity testing. We evaluated that females are 3.71 folds more infected than males. We observed Escherichia coli (E. coli) as the most frequent and Pseudomonas aeruginosa (P. aeruginosa) as the least (9.1%). Further, we noted that E. coli infection in males is 4.75 times of males. Moreover, Klebsiella pneumoniae (K. pneumoniae) and E. coli are 2.33 and 7.67 times more prevalent than P. aeruginosa respectively. Our sensitivity results indicate that E. coli and K. pneumoniae are resistant to the most tested antimicrobials. However, P. aeruginosa is susceptible to only few of the tested drugs which include Amikacin, Piperacillin+Tazobactam (in combination), and Ceftriaxone. We conclude, due to MDR strains we need to imitate the current strategies and propose neoadjuvant and other therapies like applied in cancer.