Genetic characteristics of nucleoprotein of the epidemic measles virus in Xi’an, 2013-2017 / 中华实验和临床病毒学杂志

Objective@#To know the genetic characteristics of nucleoprotein(N)of wild type measles virus in Xi’an, 2013-2017.@*Methods@#We used the pharyngeal swab specimens of suspected measles cases which were tested positive for measles virus (MV) nucleic acid by Real-time RT-PCR to isolate MV strains with Vero-SLAM cells, extracted RNA of the strains, amplified the N genes of MV strains and the pharyngeal swab specimens which had lower Ct values by One-Step RT-PCR, and analyzed the result after sequencing.@*Results@#Thirty carboxyl terminal sequences of the N genes of MV endemic strains were obtained and identified as genotype H1a. The nucleotide and amino acid homology among the epidemic strains were 97.3%-100% and 96.7%-100%, among the epidemic strains and S191 were 91.3%-92.2% and 87.3%-90.0%, while among the epidemic strains and C47 were 92.2%-92.7% and 88.0%-90.7%. The nucleotide homology among the epidemic strains and wild strains of same period in Anhui, Gansu, Shandong, Henan, Jilin were higher than that in Shanxi, Sichuan, Hunan and Guangdong. The most different amino acid sites among the epidemic strains and the two vaccine strains which had high level of entropy were 422, 457 and 497, secondly 467, thirdly 500. The mutations at the 467 site only existed in 2017. dN/dS=0.199 and no positive selection site was found.@*Conclusions@#The dominant genotype of the epidemic MV strains in Xi’an was H1a in 2013-2017, the genetic diversity of viruses decreased in 2016-2017. We should strengthen the surveillance of etiology of MV to provide evidence for elimination of measles.

Study of antibacterial effect of mononuclear cells in liver lavage solution / 器官移植

Objective To evaluate the antibacterial effect of mononuclear cells(MCs)in the liver lavage solution. Methods For in vitro experiment, MCs were col ected from the liver lavage solution of SD rats and divided into the supplement of interleukin(IL)-15 and non-supplement groups. The MCs were co-cultured with Pseudomonas aeruginosa (P. aeruginosa)for 4 h and then the supernatant was collected and MCs were lysed. The bacterial load in the lysate was detected after LB plate culture. The levels of interferon(IFN)-γand tumor necrosis factor(TNF)-αin the supernatant were measured by enzyme-linked immune absorbent assay(ELISA). For in vivo experiment, 40 SD rats were administered via tracheal injection of P. aeruginosa solution at a dose of 1×109 CFU/mL and randomly divided into four groups(n=10).In the control group, physiological saline was given via gavage. In the immunosuppression group, tacrolimus(FK506)was delivered via gavage. In the MC group, MCs at a dose of 1.0×108 was given via intravenous injection after use of FK506. In the IL-15 pretreated-MC group, IL-15 pretreated-MCs at a dose of 1.0×108 were administered via intravenous injection after application of FK506. The lavage solution of pulmonary alveolus and the rat lung tissue were col ected. The bacterial load was detected after LB plate culture. The expression of IFN-γand TNF-αin the pulmonary alveolus and lung tissue were measured by ELISA and Western blot. Results Compared with MCs alone, IL-15 pretreated-MCs exhibited significantly higher antibacterial capability in vitro. The CFU was 35%of untreated MCs. The synthesis and release capabilities of IFN-γandTNF-αweresignificantlyenhanced.Comparedwiththecontrolgroup,thequantityofimmunecelsinthelungtissuewas decreased and the bacterial load in the lung tissue and the lavage solution of pulmonary alveolus was significantly increased, whereas the expression levels of IFN-γand TNF-αtended to decline in the immunosuppression group. Administration of IL-15 pretreated-MCs significantly enhanced the quantity of immune cel s in the lung tissue, decreased the bacterial load and increased the secretion of IFN-γand TNF-α. Conclusions MCs in the liver lavage solution exhibit favorable antibacterial activity.Underimmunosuppressioncondition,thedefensecapabilityofthehostagainsttheopportunisticpathogenicbacteria is significantly enhanced.

Analysis of Intestinal Microbiota of Type 2 Diabetes Patients of by Two Fingerprint Technologies / 现代检验医学杂志

Objective To explore the characteristics of intestinal Microbiota in T2DM patients by two molecular fingerprint technologies,and investigate the correlation of intestinal microbiota and T2DM,and evaluate the application value of two fin-gerprint technologies.Methods Fecal samples of 8 healthy groups and 7 diabetes patients were collected.Then the total DNA of gut microbiota was extracted.Through the analysis of products by two molecular fingerprints of ERIC-PCR and DGGE-PCR,ecological characteristics of diversity and similarity of gut microbiota were obtained in healthy groups and dia-betes patients.Results Compared to healthy groups,the number of bands and Shannon-Wiener index of gut microbiota in di-abetes patients was decreased but no statistical significance.The similarity in patients group was declining(P <0.05),and the construction of gut microbiota was inclined to differ.Two fingerprint technologies of ERIC and DGGE could directly re-flect the diversity of gut microbiota and were the modern molecular biological techniques without depending on cultivation. ERIC was simple and convenient,had a better reflection of microbial diversity,but gel band cutting and regarded asa proper approach with higher diffraction efficiency and excellent repetition to studysequencing couldn’t be performed since there were more influencing factors on the experiment.DGGE could better reflect the ecological characteristics such as microbial diversity and similarity,and selecting bands,gel band cutting and sequencing could be done.Conclusion The composition and construction of gut microbiota in diabetes patients were changed,which suggests the occurrence of the disease had the correlation with gut microbiota.ERIC and DGGE is regarded as a proper approach with higher diffraction efficiency and ex-cellent repetition to study intestinal microbiota,but also gel band cutting,sequencing,bacteria identification can be performed by DGGE,both can be used in combination.

Ocular pathogen or commensal: a PCR-based study of surface bacterial flora in normal and dry eyes.

PURPOSE: To compare the bacterial population of the ocular surface of normal and dry eye subjects using conventional culture and 16S rDNA PCR. METHODS: Ninety-one subjects were classified as normal (n = 57) or dry eye (n = 34) by using tear break-up time, McMonnies survey, goblet cell density, and meibomian gland assessment. Conventional bacterial culture and broad-range 16S rDNA PCR, cloning, and DNA sequencing were used for bacterial identification. Repeated sampling was performed in a subset of subjects over a 3-month period. The association between goblet cell loss and bacterial counts in a subgroup of subjects was assessed. RESULTS: Most of the bacteria identified by culture were coagulase negative staphylococci, whereas molecular methods demonstrated a considerable number of additional bacteria. Atypical ocular surface bacteria including Rhodococcus erythropolis, Klebsiella oxytoca, and Erwinia sp., were identified in cases of overt inflammation and, surprisingly, on the normal ocular surface. The same bacteria remained on the ocular surface after repeated sampling. Increased bacterial flora was associated with reduced goblet cell density. CONCLUSIONS: Molecular analysis revealed a diverse ocular surface bacterial population. In addition to the normal flora, various potentially pathogenic bacteria were identified. The detection of known pathogens in both normal and dry eyes, with minimal signs of infection, presents a diagnostic dilemma. It remains unknown whether their presence is associated with inflammation and reduced goblet cell density or whether they adversely affect the ocular surface predisposing it to abnormal microbial colonization. In the absence of overt clinical infection, it is unknown whether such results should prompt intervention with therapy.

False identification of Coccidioides immitis: do molecular methods always get it right?

rRNA sequence analysis of a partial region of the 18S and 5.8S-internal transcribed spacer 2 (ITS2) region of Chrysosporium keratinophilum highlights its potential molecular misidentification as Coccidioides immitis. Molecular identification of medically important fungi should not be based solely on sequence analysis of the 18S rRNA gene but should be confirmed by sequence analysis of an additional rRNA gene locus, such as the ITS region(s).