Molecular detection and characterization of Coxiella burnetii in aborted samples of livestock in China.

Coxiella burnetii is the causative agent of zoonotic Q fever. Animals are the natural reservoirs of C. burnetii, and domestic livestock represent the major sources of human infection. C. burnetii infection in pregnant females may causes abortion during late pregnancy, whereby massive shedding of C. burnetii with abortion products becomes aerosolized and persists in the environment. Therefore, monitoring and surveillance of this infection in livestock is important for the prevention of the C. burnetii transmission. Previous serological surveys have shown that C. burnetii infection is endemic in livestock in China. However, few data are available on the diagnosis of C. burnetii as a cause of abortion by molecular methods in livestock. To get a better understanding of the impact of C. burnetii infection on domestic livestock in China, a real-time PCR investigation was carried out on collected samples from different domestic livestock suffering abortion during 2021-2023. A total of 338 samples collected from eight herds of five livestock species were elected. The results showed that 223 (66 %) of the collected samples were positive for C. burnetii DNA using real-time PCR. For the aborted samples, 82 % (128/15) of sheep, 81 % (34/42) of goats, 44 % (15/34) of cattle, 69 % (18/26) of camels, and 50 % (17/34) of donkeys were positive for C. burnetii. Besides, 44 % (8/18) and 4 % (1/25) of asymptomatic individuals of sheep and donkey were also positive for C. burnetii. In addition, the positive samples were further confirmed by amplification and sequencing of the C. burnetii-specific isocitrate dehydrogenase (icd) gene. Phylogenetic analysis based on specific gene fragments of icd genes revealed that the obtained sequences in this study were clustered into two different groups associated with different origin of hosts and geographic regions. This is the first report confirming that C. burnetii exists in aborted samples of sheep, goats, cattle, donkeys and camels in China. Further studies are needed to fully elucidate the epidemiology of this pathogen in livestock as well as the potential risks to public health.

[Effects of different fertilization patterns on soil improvement and vegetation restoration of desertified grassland in northwest Liaoning Province, China]. / 不同培肥模式对辽西北沙化草地土壤改良与植被恢复的影响.

Improving soil fertility is one of the key approaches for ecological restoration of the wind-sand area in northwest Liaoning Province. Taking wind-sand area in northwest Liaoning Province as test object, we conducted a fertilization experiment with treatments of inorganic fertilizer (nitrogen, phosphorus and potassium fertilizers), organic fertilizer, combined application of organic and inorganic fertilizers, and organic fertilizer combined with a biologically organic matrix (γ-polyglutamic acid), and no fertilizer as control. We measured soil organic matter content and extractable cations concentrations, vegetation coverage, and biomass under different fertilization treatments and determine the suitable fertilization mode. The results showed that compared to the control, inorganic fertilizer rapidly increased vegetation coverage and biomass, but high levels of inorganic fertilizer (150 kg N·hm-2) led to soil acidification and Ca2+ leaching. Organic fertilizer increased soil organic matter content, exchangeable K+, Ca2+, and Mg2+ contents, as well as coverage and biomass vegetation, especially combined with γ-polyglutamic acid. Overall, the combination of low levels of inorganic fertilizer (50 kg N·hm-2) and moderate levels of organic fertilizer (30000 kg·hm-2) was the best fertilization practice for the rapid and stable restoration of grassland in wind-sand area. Moreover, the extra addition of γ-polyglutamic acid (60 kg·hm-2)could effectively improve soil fertility.

Therapeutic Window of Intravenous Immunoglobulin (IVIG) and its correlation with IVIG-resistant in Kawasaki Disease: a retrospective study

Abstract Objective: To investigate the optimal timing of initial intravenous immunoglobulin (IVIG) treatment in Kawasaki disease (KD) patients. Methods: KD patients were classified as the early group (day 1-4), conventional group (day 5-7), conventional group (day 8-10), and late group (after day 10). Differences among the groups were analyzed by ANOVA and Chi-square analysis. Predictors of IVIG resistance and the optimal cut-off value were determined by multiple logistic regression analyses and receiver operating characteristic (ROC) curve analysis. Results: There were no significant differences in IVIG resistance among the 4 groups (p = 0.335). The sensitivity analysis also confirmed no difference in the IVIG resistance between those who started the initial IVIG ≤ day 7 of illness and those who received IVIG >day 7 of illness (p = 0.761). In addition, patients who received IVIG administration more than 7 days from the onset had a higher proportion of coronary artery abnormalities (p = 0.034) and longer length of hospitalization (p = 0.033) than those who started IVIG administration less than 7 days. The optimal cut-off value of initial IVIG administration time for predicting IVIG resistance was >7 days, with a sensitivity of 75.25% and specificity of 82.41%. Conclusions: IVIG therapy within 7 days of illness is found to be more effective for reducing the risk of coronary artery abnormalities than those who received IVIG >day 7 of illness. IVIG treatment within the 7 days of illness seems to be the optimal therapeutic window of IVIG. However, further prospective studies with long-term follow-up are required.