Acinetobacter baumannii is a nosocomial pathogen and gram-negative coccobacillus that is responsible for opportunistic infections, pneumonia, and infections of the urinary tract, bloodstream, skin, and soft tissue. This bacterium poses a major public health problem due to inducing resistance to several drugs, isolates, multidrug treatment, and occasionally pan drugs. Drug resistance is not only a major concern caused by A. baumannii but also is considered as the main challenge in many other pathogens. Several factors such as the efflux pump are associated with antibiotic resistance, biofilm production, and genetic mutations. In this review, A. baumannii is introduced in then some of the practical works conducted on the existing efflux pump are reviewed. The importance of the efflux pump is considered in this paper in relation to the antibiotic resistance and mechanisms developed for the inhibition of these pumps as well.
1 April 2019 in TrAC Trends in Analytical Chemistry
Renal failure (RF) disease is ranked as one of the most prevalent diseases with severe morbidity and mortality. Early diagnosis of RF leads to subsequent control of disease to reduce the poor prognosis. The level of sera creatinine is considered as a significant biomarker for kidney biofunction, which is routinely detected by the Jaffe reaction. The normal range for creatinine in the blood may be 0.84‐1.21 mg/dL. Low accuracy, insufficient sensitivity, explosive and toxicity of picric acid, and pseudo‐interaction with nonspecific elements such as ammonium ions in the Jaffe method lead to the development of various techniques for precise detection of creatinine such as spectroscopic, electrochemical, and chromatography approaches and sensors based on enzymes, molecular imprinted polymer and nanoparticles, etc. Based on previously established results, they are trying to construct sensors with high accuracy, optimum sensitivity, acceptable linear/calibration range, and limit of detection, which are small in size and applicable by the patient him/herself (point‐of‐care testing). By comparing the results of research, a molecularly imprinted electrochemiluminescence‐based sensor with linear/calibration range of 5‐1 mM concentration of creatinine and the detection limit of 0.5 nM has the best detectable resolution with 2 million measurable points. In this paper, we will review the recently developed methods for measuring creatinine concentration and renal biofunction.
Parkinson's disease (PD) or simply Parkinson's is a long-term degenerative disorder of the central nervous system, which mainly affects the motor system. Consequently, the detection and quantification of related biomarkers play vital roles in the early-stage diagnosis of PD. In the present study, an innovative electrochemical immunosensor based on gold nanoparticle-modified graphene towards bioconjugation with biotinylated antibody (bioreceptor) was developed for the ultra-sensitive and specific monitoring of the alpha-synuclein (α-synuclein) protein. The synergistic effects between the gold nanoparticles (AuNPs) and graphene drastically enhanced the electrochemical activity of the resulting materials. The enhanced conductivity of the substrate together with the increase in its surface area improved the sensitivity and lowered the detection limit of the capture layer. For the first time, the α-synuclein protein was measured in human plasma samples using bioconjugated AuNP-Gr bioconjugated specific antibody with an acceptable linear range of 4 to 128 ng mL−1 and a lower limit of quantification (LLOQ) of 4 ng mL−1. Accordingly, it is expected that this diagnostic method may be produced in the near future for clinical applications and high-throughput screening of PD using point of care (POC) analysis.