[Effect of admission mode of septic patients in intensive care unit on acute kidney injury and prognosis].

OBJECTIVE: To investigate the effect of intensive care unit (ICU) admission model on acute kidney injury (AKI) development and the prognosis in patients with sepsis. METHODS: Patients with sepsis admitted to the ICU of Xinjiang Uygur Autonomous Region People's Hospital from January 2019 to July 2020 were retrospectively analyzed. According to the ICU admission model, the patients were divided into emergency group (first admission or emergency transfer from relevant surgical departments) and delayed group (transferred from the general ward due to disease evolution). Patients were divided into AKI group and non-AKI group according to whether AKI was accompanied. The gender, age, underlying diseases, surgical history, heart rate, laboratory test indicators, acute physiology and chronic health evaluation II (APACHE II), sequential organ failure assessment (SOFA), organ failure and acute complications were collected. The incidence of AKI, 28-day mortality and length of ICU stay were recorded. Univariate and multivariate Logistic regression was used to analyze the risk factors of AKI in patients with sepsis. RESULTS: A total of 185 patients with sepsis were enrolled, including 96 cases in the emergency group and 89 cases in the delayed group. 119 cases of AKI occurred while 66 cases without AKI development. The incidence of AKI within 7 days and the 28-day mortality of patients in the delayed group were significantly higher than those in the emergency group [AKI incidence rate: 77.53% (69/89) vs. 52.08% (50/96), 28-day mortality: 24.72% (22/89) vs. 10.42% (10/96), both P < 0.05], and the length of ICU stay was significantly longer than that of the emergency group (days: 18.70±7.29 vs. 14.56±4.75, P < 0.05). Univariate Logistic analysis showed that there were significant differences in age, diabetes, hypertension, organ failure, heart failure, APACHE II score, SOFA score, white blood cell count (WBC), absolute neutrophil value, platelet count (PLT), blood lactate, total bilirubin, and ICU transferred from general wards between AKI group and non-AKI group. Multivariate Logistic regression analysis showed that transfer from general ward to ICU due to disease evolution was an independent risk factor for AKI in ICU sepsis patients [odds ratio (OR) = 5.165, 95% confidence interval (95%CI) was 3.911-6.823, P < 0.001]. CONCLUSIONS: Septic patients transferred from general ward to ICU due to disease evolution are more likely to develop AKI, and also had a higher mortality and longer ICU stay. It may be an independent risk factor for AKI complicated by patients with sepsis in ICU.

De novo assembly and analysis of the transcriptome of the Dermacentor marginatus genes differentially expressed after blood-feeding and long-term starvation.

BACKGROUND: The ixodid tick Dermacentor marginatus is a vector of many pathogens wide spread in Eurasia. Studies of gene sequence on many tick species have greatly increased the information on tick protective antigen which might have the potential to function as effective vaccine candidates or drug targets for eco-friendly acaricide development. In the current study, RNA-seq was applied to identify D. marginatus sequences and analyze differentially expressed unigenes. METHODS: To obtain a broader picture of gene sequences and changes in expression level, RNA-seq was performed to obtain the whole-body transcriptome data of D. marginatus adult female ticks after engorgement and long-term starvation. Subsequently, the real-time quantitative PCR (RT-qPCR) was applied to validate the RNA-seq data. RESULTS: RNA-seq produced 30,251 unigenes, of which 32% were annotated. Gene expression was compared among groups that differed by status as newly molted, starved and engorged female adult ticks. Nearly one third of the unigenes in each group were differentially expressed compared to the other two groups, and the most numerous were genes encoding proteins involved in catalytic and binding activities and apoptosis. Selected up-regulated differentially expressed genes in each group were associated to protein, lipids, carbohydrate and chitin metabolism. Blood-feeding and long-term starvation also caused genes differentially expressed in the defense response and antioxidant response. RT-qPCR results indicated 6 differentially expressed transcripts showed similar trends in expression changes with RNA-seq results confirming that the gene expression profiles in transcriptome data is in consistent with RT-qPCR validation. CONCLUSIONS: Obtaining the sequence information of D. marginatus and characterizing the expression pattern of the genes involved in blood-feeding and during starvation would be helpful in understanding molecular physiology of D. marginatus and provides data for anti-tick vaccine and drug development for controlling the tick.

Sequence identification and expression profile of seven Dermacentor marginatus glutathione S-transferase genes.

Dermacentor marginatus is a widespread tick species and a vector of many pathogens in Eurasia. Due to the medical importance of D. marginatus, control measures are needed for this tick species. Currently tick control approaches rely mostly on acaricide application, whereas wrong and irrational acaricide use may result in drug resistance and residue problems. Vaccination as an alternative approach for tick control has been proven to be effective towards some tick species. However, immunization against D. marginatus has not yet reached satisfactory protection. The effort of in silico based analysis could predict antigenicity and identify candidates for anti-tick vaccine development. We carried out an in silico analysis of D. marginatus glutathione S-transferases (DmGSTs) in order to identify blood-feeding induced GSTs as antigens that can be used in anti-tick vaccine development. Phylogenetic analysis, linear B-cell epitope prediction, homology modeling, and conformational B-cell epitope mapping on the GST models were performed to identify highly antigenic DmGSTs. Relative gene expressions of the seven GSTs were profiled through real-time quantitative PCR (RT-qPCR) to outline GSTs up-regulated during blood feeding. The phylogenetic analysis indicated that the seven GSTs belonged to four classes of GST, including one in epsilon-class, one in zeta-class, one in omega-class, and four in mu-class. Linear B-cell epitope prediction revealed mu-class GSTs share similar conserved antigenic regions. The conformational B-cell epitope mapped on the homology model of the GSTs displayed that GSTs of mu-class showed stronger antigenicity than that of other classes. RT-qPCR revealed DmGSTM1 and DmGSTM2 were positively related to blood feeding. In sum, the data suggest that DmGSTM1 and DmGSTM2 could be tested for potential anti-tick vaccine trials.

MaxEnt Modeling of Dermacentor marginatus (Acari: Ixodidae) Distribution in Xinjiang, China.

Dermacentor marginatus Sulkzer is a common tick species found in the Xinjiang Uygur Autonomous Region (XUAR) of China, and is a vector for a variety of pathogens. To determine the potential distribution of this tick species in Xinjiang, a metadata containing 84 D. marginatus presence records combined with four localities from field collection were used for MaxEnt modeling to predict potential distribution of this tick species. Identification of tick samples showed 756 of 988 (76%) were D. marginatus. MaxEnt modeling results indicated that the potential distribution of this tick species was mainly confined to northern XUAR. Highly suitable areas included west side of Altay mountain, west rim of Junggar basin, and Yili River valley in the study area. The model showed an AUC value of 0.838 ± 0.063 (SD), based on 10-fold cross-validation. Although tick presence records used for modeling were limited, this is the first regional tick distribution model for D. marginatus in Xinjiang. The model will be helpful in assessing the risk of tick-borne diseases to human and animals in the region.

Caracterization of glutathione S-transferase of Dermacantor marginatus and effect of the recombinant antigen as a potential anti-tick vaccine.

Dermacentor marginatus is one of the main tick species in northwestern China, and is a vector of various tick-borne pathogens. Tick control method largely depends on chemical agents, but the disadvantages of using such approach would cause environmental damage and the risk of developing tick resistance to acaricides. Vaccination of tick protective antigen is an eco-friendly approach which is an alternative and promising method to mitigate tick infestation in livestock. In the study, a mu-class glutathione S-transferase (GST) sequence of D. marginatus was cloned and the recombinant protein (rDmGST) was expressed. Transcriptional level of the GST was measured together with native GST activity of the tick. Finally, A vaccine trial on rabbits against D. marginatus was proceeded to evaluate the anti-tick effect of rDmGST. Results reveled that the CDs of the D. margiantus glutathione S-transferase mu 1 gene has 669 base pair nucleotide sequence encoding a 223 amino acid. The deduced GST protein sequence had over 95 % similarity with that of D. variabilis. The rDmGST was efficiently expressed soluble and purified by His trap affinity chromatography. Enzyme activity of native GST and transcriptional profiles of the GST showed up-regulation in different stages and organs of D. marginaus during blood feeding. Polyclonal antibody reacted with rDmGST in Western blotting. Tick challenge on rDmGST inoculated rabbits showed reductions in adult female engorgement rate, total egg mass and egg hatching rate with an overall vaccine efficacy of 43.69 %. The results of the experiment indicated the GST has potential value to be an effective protective antigen of D. marginatus.

Development and application of Real-time PCR assay for detection of Theilera annulata infection in cattle in Xinjiang Uygur Autonomous Region, China.

Theileria annulata (T. annulata), the causative agent of tropical theileriosis, is a protozoan parasite that also causes lymphoproliferative diseases in cattle. Development of reliable and fast methods are necessary in the epidemiological investigation of T. annulata in ticks and animals. Real-time PCR possesses merits of rapidity, accuracy, reliability, automation and ease of standardization, which is widely used for the detection of blood borne parasites. In this study, species-specific primers and TaqMan probe were designed on the basis of the 18s rRNA gene sequence of T. annulata, and the real-time PCR assay was developed by optimizing the reaction parameter. The performance of real-time PCR was assessed by testing 47 blood samples from cattle and comparing with the results from conventional PCR. The results show that this real-time PCR assay could specifically detect 10 copies DNA of T. annulata, which is 10-fold sensitivity more than conventional PCR. No cross-reactions were observed with Babesia bovis, Babesia bigemina, Trypanosoma evansi and Theileria equi. Of the 47 field samples collected from Xinjiang Uygur Autonomous Region, China, 36.17% were detected by real-time PCR, and 25.53% were found positive for T. annulata infection by conventional PCR. These results indicated that the real-time PCR assay is a useful approach for detecting T. annulata infections and has potential as an alternative tool for ecological and epidemiological surveillance of ovine theileriosis.

Seroepidemiologic studies on Babesia equi and Babesia caballi infections in horses in Jilin province of China.

The prevalence of equine piroplasmosis caused by Babesia equi and Babesia caballi in northeast China has remained unknown, although the People's Republic of China is recognized as an endemic country for the diseases. In the present study, we investigated the prevalence of equine piroplasmosis in Jilin province, a part of northeast China. A total of 111 serum samples were taken from horses in eastern Jilin, and examined for diagnosis of B. equi and B. caballi infections by the enzyme-linked immunosorbent assays with recombinant antigens, equi merozoite antigen-1 and P48, respectively. Of the 111 samples, 38 (34%) and 36 (32%) samples were sero-positive for B. equi infection and B. caballi infection, respectively. In addition, 14 (12%) samples were sero-positive for both B. equi and B. caballi infections. These results indicate that equine piroplasmosis is widespread and therefore a cause for serious concern in northeast China.