[Metagenomic Analysis of Antibiotic Resistant Bacteria and Resistance Genes in a Pharmaceutical and Chemical Wastewater Treatment Plant].

Wastewater treatment plants hold a vast pool of antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs). The aim of this study is to analyze the ARB and ARGs in a pharmaceutical and chemical wastewater treatment plant using a metagenomic technique. The results of taxonomic annotation revealed that bacteria were the predominant domain. The most abundant phyla and genus was Proteobacteria and Hyphomicrobium, respectively. A total of 74 categories of ARGs were predicted using CARD with the most dominant types being sav 1866, dfrE, and mfd. Furthermore, a network analysis was conducted to investigate the co-occurrence patterns between ARGs and microbial taxa. ARGs were found to be highly connected to microbial taxa at the genus level. With respect to the antibiotic resistance mechanisms, antibiotic-specific efflux pumps appeared to be the most common mechanisms. Among these, resistance-nodulation-cell division (RND) was the major type. The most important functional pathway of this microbial community was metabolic correlation. Interestingly, there were many genes related to human diseases, among which bacterial infectious diseases were the main ones. On the one hand, these data further confirmed that pharmaceutical and chemical wastewater treatment plants are rich in ARB and ARGs. The accumulation of ARGs increases the potential environmental risks, and hence it is necessary to strengthen the active monitoring of ARB and ARGs in pharmaceutical and chemical wastewater treatment plants. On the other hand, research on ARB and ARGs offers important information for the selection of deep processing technology to effectively remove ARB and ARGs.

Synthesis and characterization of Ni(III)N3S2 complexes as active site models for the oxidized form of nickel superoxide dismutase.

Nickel complexes, [Ni(H2BA(R)TPP)](ClO4)2 (R = Ph for 1 or iPr for 2), supported by a pentadentate ligand H2BA(R)TPP were synthesized and oxidized to form Ni(III) species having a N3S2 coordination environment to mimic the active site of the oxidized form of nickel superoxide dismutase (NiSODox). The Ni(III) species 2(+) exhibited a rhombic signal with g values at 2.15, 2.12 and 2.02 similar to that of NiSODox. DFT calculations revealed that 2(+) has an unpaired electron primarily located in the dz2 orbital of the Ni(III) center, which strongly overlaps with the pz orbital of the axial pyridine nitrogen of H2BA(Pr)TPP.

The effect of myopia on retinal nerve fibre layer measurement: a comparative study of spectral-domain optical coherence tomography and scanning laser polarimetry.

BACKGROUND/AIM: To evaluate the effect of myopia on retinal nerve fibre layer (RNFL) thickness measurement by using spectral domain optical coherence tomography (Cirrus HD OCT) and scanning laser polarimetry with enhanced corneal compensator (GDx ECC). METHODS: One hundred and forty-nine eyes of 149 myopic subjects were recruited and subdivided into three groups according to their refractive errors: high myopia group (spherical equivalent (SE) ≤ -6 D); moderate group (-3 D ≥ SE > -6 D); low group (-0.5D ≥ SE > - 3 D). RNFL thickness was measured by Cirrus High Definition (HD) OCT and GDx ECC. Associations between RNFL thickness and axial length/SE were evaluated by using Pearson correlation analysis. RESULTS: Average RNFL thickness measured with Cirrus OCT correlated significantly with axial length (r = -0.322, p < 0.001) and SE (r = 0.291, p < 0.001). No significant correlation was detected between axial length (r = -0.068, p = 0.407)/SE (r = 0.109, p = 0.187) and RNFL thickness measured with GDx ECC. CONCLUSION: Average RNFL thickness measured with Cirrus HD OCT decreases as the degree of myopia increases while no such correlation was detected in GDx ECC. Histological studies are warranted to further our understanding of the relationship between RNFL thickness and myopia.

[Preliminary study on bacterial culture through near-natural pure culture technique].

Based on the ecological features of mutual benefits of different microbes in natural environment, near-natural pure culture technique which was an improvement of conventional pure culture method had been put forward. The key point of this new method was to make hole petri dishes covered with millipore membranes. When these covered dishes being used to culture microorganisms, it could provide incubated microbes active materials from native environment, maintain free communicating with outside microbes, and improve their recovery and culturability of some bacteria. To some degree, this technique enhanced their strengths and overcome their weaknesses of mixed culture method and conventional pure culture method so as to increase microbial culturability and even possibly obtain some nonculturable microorganisms.