A total of 25 fast-growing rhizobium isolates from variety of legumiuous plants in Hainan Province, a tropical region of China, and 7 representative strains of genera Rhizobium, Sinorhizobium and Agrobacterium were characterized by numerical taxonomy. The results indicated that rhizobium isolates from Hainan were taxonomically heterogenous. At thesimilarity level of 70%, 13 strains from Hainan formed a distinct group which could use wider range of carbon and nitrogen sources, and were more resistent to antibiotics and chemicals than known rhizobium species. 2 strains could not fall into any group, and the others fell into different known species respectively. There were no correlations between hosts and the taxonomic positions of their symbionts. The rhizobium isolates from the same host genus or speceis could fall into different groups.

Objective To understand the breeding situation of Acaroid mites in indoor environments of kindergartens in Wuhu City so as to provide the evidence for its prevention and control. Methods From March to June and September to De?cember in 2014 dust samples were collected from 15 kindergartens of 3 ranks every month. Acaroid mites in the samples were isolated identified and counted. Results Totally 360 samples were selected and 169 samples 46.94% had mite infestation. Pyroglyphidae accounted for the most in the population with the breeding rate of 45.00%. Totally 18 504 mites were found and Dermatophagoides farina and Dermatophagoides pteronyssinus were the dominant species with the composition ratios of 30.21%5 590 mites and 17.83% 3 300 mites respectively. The third?ranked kindergartens were in the most serious situation con?cerning with 81.67% 98/120 of the breeding rate of Acaroid mites. The differences were statistically significant among the kin?dergartens with different ranks F=6.048 χ2=73.523 both P<0.05 . There were no significant differences about the Aca?roid mite population among different grades in kindergartens F=0.132 χ2 =2.377 both P>0.05 . Conclusion Acaroid mites in the kindergartens in Wuhu City were in serious condition and the population and species composition of Acaroid mite community is influenced by the human behavior and indoors environments.

Objective To characterize the population dynamics and spatial distribution of Aleuroglyphus ovatus in the flour warehouse,so as to provide the basic evidence for improving the sampling guidelines that are essential for effective pest monitor?ing and management. Methods The samples from flour warehouses of four localities were collected,examined and counted for A. ovatus in every month in Wuhu City. The dispersion pattern target,Iwao m*/-x regression analysis and Taylor power method were used for analyzing the spatial distribution pattern of A. ovatus in the flour warehouses. Results The peaks of population dynamics of A. ovatus were discovered in July and September,respectively. The indexes of dispersion were as follows:I>0, CA>0,m*/-x >1. At the same time,the parameters in the equation of Iwao:m*=5.471+1.022-x (r=0.999)and Taylor:lgS2=0.697+1.111 lg-x (r=0.987)showed that the spatial distribution pattern of A. ovatus was assembled. Conclusion The peaks of population dynamics of A. ovatus in the flour warehouse are bimodal pattern ,and the spatial distribution pattern of A. ovatus is assembled.

Objective To observe the Tyrophagus palmarum and its hypopus in feed of Tenebrio molitor. Methods Feed samples were collected from T. molitor farms,and T. palmarum and its hypopus were separated from the samples by the vibra?tion sieve method and floating method. The glass specimens were prepared and T. palmarum and its hypopus were observed un?der an optical microscope. Results Under the light microscope,the skin of T. palmarum was smooth and bright,the color of legs and chelicerae was relatively dark,the length of dorsal seta d2 was 3?4 times longer than d1 and la;Theω1 in tarsus of legⅠ,Ⅱwas short rod,and its top was not tapered;the sucker plate in tarsus of legⅣlocated in the middle of the section. The hypopus was oblate,and there were two pairs of legs in front which extended to body. The rear end of hypopus became pointless and round,wrapping around a transparent and ossification skin. Conclusion Light microscopy shows the morphological charac?teristics of T. palmarum and its dormant body,providing the basis for identifying the hypopus.

Objective To compare the effects of three kinds of Oncomelania hupensis RNA extraction methods,namely a modified SDS method,TRIzol reagent method,and CTAB method,so as to obtain an economical and efficient method for RNA extraction from O. hupensis. Methods The modified SDS method,TRIzol reagent method and CTAB method were applied to ex-tract the RNA from O. hupensis. A nucleic acid protein analyzer was used to measure the concentration and purity of RNA. The yields were calculated by the concentration of the products. The purity was indicated by A260/A280 and A260/A230. The quality of RNA was inspected by 1% agarose gel electrophoresis. The β-acting gene was selected as the target gene for RT-PCR analysis. Re-sults The RNA yields obtained by using the three kinds of extraction methods were significantly different(F = 16895.85,P <0.01)according to the analysis of variance. The LSD test showed that the yields obtained by using the modified SDS method were the highest,and those obtained by the CTAB method were the lowest. The purity of RNA extracted by the CTAB method was su-perior to that by the other two methods,and the A260/A280 and A260/A230 ratios of the CTAB method were in the range from 1.8-2.0 and 2.0-2.2. The A260/A230 ratios of the other two methods were both lower than 2.0. The RNA extracted by the modified SDS meth-od had the better integrity. The electrophoresis results showed that the 28S rRNA band,18S rRNA band and 5S rRNA band were clear,and there was no obvious smear between each band. The RNA obtained by the TRIzol reagent method had no 28S rRNA band,and that obtained by the CTAB method had no 28S rRNA and 5S rRNA bands. The β-acting gene of the RNA ex-tracted by all the three methods could be amplified by RT-PCR. The costs and time-consuming of the modified SDS method were less than those of the other two methods. Conclusion The modified SDS method is an economic and efficient method,and it is suitable for extracting the RNA of O. hupensis,especially for large sample preparation.

Objective To optimize the extraction methods of mitochondrial genome DNA(mtDNA)of Oncomelania hupen-sis. Methods The pyrolysis,protein K variable-temperature digestion and high-concentration potassium acetate purification were applied to optimize the high-concentration-salt precipitation method,and then the optimized method was compared with two common extraction methods,the sucrose density gradient centrifugation method and traditional high-concentration-salt pre-cipitation method. The mtDNA samples were identified by using spectrophotometry,agarose gel electrophoresis and the amplifi-cation products of COX1. The nuclear DNA contamination was tested by the amplification products of ITS. Results The concen-tration and yield of the improved method was significantly higher than those of the traditional method(F=3032.65,10185.00, both P<0.01). The mtDNA samples extracted were essentially free of nuclear DNA and protein,meeting PCR,sequence analy-sis and other molecular biology research requirements. Conclusions The improved high-concentration-salt precipitation meth-od for isolating mtDNA is simple,and it has high yield and low cost. The extracted mtDNA can meet relevant analysis require-ments.

Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)-induced cytokine storms constitute the primary cause of coronavirus disease 19(COVID-19)progression,severity,criticality,and death.Gluco-corticoid and anti-cytokine therapies are frequently administered to treat COVID-19,but have limited clinical efficacy in severe and critical cases.Nevertheless,the weaknesses of these treatment modalities have prompted the development of anti-inflammatory therapy against this infection.We found that the broad-spectrum anti-inflammatory agent inosine downregulated proinflammatory interleukin(IL)-6,upregulated anti-inflammatory IL-10,and ameliorated acute inflammatory lung injury caused by mul-tiple infectious agents.Inosine significantly improved survival in mice infected with SARS-CoV-2.It indirectly impeded TANK-binding kinase 1(TBK1)phosphorylation by binding stimulator of interferon genes(STING)and glycogen synthase kinase-3β(GSK3β),inhibited the activation and nuclear trans-location of the downstream transcription factors interferon regulatory factor(IRF3)and nuclear factor kappa B(NF-κB),and downregulated IL-6 in the sera and lung tissues of mice infected with lipopoly-saccharide(LPS),H1N1,or SARS-CoV-2.Thus,inosine administration is feasible for clinical anti-inflammatory therapy against severe and critical COVID-19.Moreover,targeting TBK1 is a promising strategy for inhibiting cytokine storms and mitigating acute inflammatory lung injury induced by SARS-CoV-2 and other infectious agents.