Surface characterization, electrochemical properties and in vitro biological properties of Zn-deposited TiO2 nanotube surfaces.

In this work, to improve antibacterial, biocompatible and bioactive properties of commercial pure titanium (cp-Ti) for implant applications, the Zn-deposited nanotube surfaces were fabricated on cp-Ti by using combined anodic oxidation (AO) and physical vapor deposition (PVD-TE) methods. Homogenous elemental distributions were observed through all surfaces. Moreover, Zn-deposited surfaces exhibited hydrophobic character while bare Ti surfaces were hydrophilic. Due to the biodegradable behavior of Zn on the nanotube surface, Zn-deposited nanotube surfaces showed higher corrosion current density than bare cp-Ti surface in SBF conditions as expected. In vitro biological properties such as cell viability, ALP activity, protein adsorption, hemolytic activity and antibacterial activity for Gram-positive and Gram-negative bacteria of all surfaces were investigated in detail. Cell viability, ALP activity and antibacterial properties of Zn-deposited nanotube surfaces were significantly improved with respect to bare cp-Ti. Moreover, hemolytic activity and protein adsorption of Zn-deposited nanotube surfaces were decreased. According to these results; a bioactive, biocompatible and antibacterial Zn-deposited nanotube surfaces produced on cp-Ti by using combined AO and PVD techniques can have potential for orthopedic and dental implant applications.

Rapid Molecular Diagnosis of Group A Streptococcus with a Novel Loop Mediated Isothermal Amplification Method.

BACKGROUND: Group A Streptococcus (GAS) is the most common bacterial cause of acute tonsillopharyngitis. In this study, it was aimed to evaluate the performance of a novel Loop Mediated Isothermal Amplification (LAMP) method in the rapid diagnosis of GAS in samples taken from children with a prediagnosis of acute bacterial tonsillopharyngitis by comparing it with culture and rapid antigen test (RAT) methods. METHODS: A total of 100 throat swab samples taken from children at the pediatrics outpatient clinic with suspected tonsillopharyngitis were included in the study. Throat swab samples were analyzed by RAT, throat culture, and LAMP method. GAS suspected colonies were identified with MALDI-TOF MS system. The isothermal amplification reaction for LAMP was conducted by a novel LAMP instrument. RESULTS: According to the results of throat cultures; 53 of them were positive and 47 were negative in terms of GAS. Six (11.32%) of the culture positive samples were found to be negative by the RAT (sensitivity; 88.68%, specificity 100%). While the antigen test was positive, no culture negative sample was detected. One of the culture positive samples was found negative by LAMP. In two samples, while throat culture was negative, it was observed that LAMP was positive (sensitivity; 98.11%, specificity; 95.74%). In one of these samples, the bacteria grown in the culture were identified as Streptococcus dysgalactiae by mass spectrophotometry. CONCLUSIONS: In this study, it was determined that the LAMP method used in the diagnosis of throat infections caused by GAS has high sensitivity and specificity. We believe that the instrument is easy to use, low cost, portable, and adaptable to point of care tests. There are very few studies in the literature regarding the use of the instrument in this field, and it should be evaluated in terms of its usability in daily practice with new studies.

Optimization of isothermal amplification method for Mycobacteriumtuberculosisdetection and visualization method for fieldwork

Background/aim: Tuberculosis is still one of the most contagious diseases around the world. Key factors of tuberculosis control are rapid diagnostic, efficient treatment, and prevention of contamination by surveillance and monitoring. However, culture is the gold standard method for laboratory diagnosis of tuberculosis; the results are several weeks to obtain. In order to prevent contamination of tuberculosis, diagnosis must be made in short time and treatment should be started as soon as possible. The aim of this study is to optimize the loop-mediated isothermal amplification (LAMP) method, which provides a much faster and more sensitive result than the polymerase chain reaction (PCR) method and allows the replication of target nucleic acid sequences under isothermal conditions without the need for laboratory infrastructure. Materials and methods: Sputum samples were homogenized with 5% trypsin solution in CaCl2 to obtain DNA.DNA was purified using QIAGEN QIAamp DNA mini kit. LAMP primers were design using Primer explorer V5 program according to IS6110 gene of Mycobacterium tuberculosis. NEB Bst 3.0 DNA polymerase kit was used for LAMP reactions. Besides, LAMP reactions were compared with TaqMan based RT-PCR method using NEB's Taq polymerase kit. Finally, for visualization of LAMP products, lateral flow dipsticks that produced by Milenia Biotec, colorimetric 2X LAMP master mix that produced by NEB and 2% w/v agarose gel electrophoresis methods were used. Results: Optimum amplification temperature for LAMP was found to be 71.4 °C. The detection limit of the method was 102 CFU/mL and sensitivity was determined 100% compared to five different Mycobacterium species. Conclusion: The current study indicated that the LAMP-LFD and colorimetric LAMP protocol optimized with sputum samples can be reliable used as a rapid, sensitive and specific assay in the diagnosis of tuberculosis in the field.

Detection of Potato ring rot Pathogen Clavibacter michiganensis subsp. sepedonicus by Loop-mediated isothermal amplification (LAMP) assay.

Clavibacter michiganensis subsp. sepedonicus (CMS) is an important bacterial plant pathogen causing potato ring rot disease. Rapid diagnosis of CMS is crucial because of the economic losses caused by serious harvest losses. Although there are serological tests used in the rapid diagnosis of CMS, they are not widely used because of their low sensitivity. The DNA-based PCR methods, which are highly sensitive, do not have the possibility of on-site diagnosis, especially since they require serious laboratory infrastructure. In recent years, scientists have been working on alternative amplification methods to develop DNA-based point of care (POC) diagnostic methods. Accordingly, the loop-mediated isothermal amplification (LAMP) method, which was developed in the early 2000s, provides an important convenience for DNA-based tests to use in the field. Due to the unique design of primers, more amplification products could be create in a shorter time than conventional amplification methods without needing a temperature cycle, and it can be applied with the aid of a simple heater without requiring a laboratory environment. In this study, efficient LAMP method for the detection of CMS has optimized. For device-independent detection of LAMP products, colorimetric method and LFD has used.