BASI74, a Virulence-Related sRNA in Brucella abortus

Brucella spp. are intracellular pathogens that infect a wide variety of mammals including humans, posing threats to the livestock industry and human health in developing countries. A number of genes associated with the intracellular trafficking and multiplication have so far been identified in Brucella spp. However, the sophisticated post-transcriptional regulation and coordination of gene expression that enable Brucella spp. to adapt to changes in environment and to evade host cell defenses are not fully understood. Bacteria small RNAs (sRNAs) play a significant role in post-transcriptional regulation, which has already been confirmed in a number of bacteria but the role of sRNAs in Brucella remains elusive. In this study, we identified several different sRNAs in Brucella spp., and found that over-expression of a sRNA, tentatively termed BASI74, led to alternation in virulence of Brucella in macrophage infection model. The expression level of BASI74 increased while Brucella abortus 2308 was grown in acidic media. In addition, BASI74 affected the growth ratio of the Brucella cells in minimal media and iron limiting medium. Using a two-plasmid reporter system, we identified four genes as the target of BASI74. One target gene, BABI1154, was predicted to encode a cytosine-N4-specific DNA methyltransferase, which protects cellular DNA from the restriction endonuclease in Brucella. These results show that BASI74 plays an important role in Brucella survival in macrophage infection model, speculatively by its connection with stress response or impact on restriction-modification system. Our study promotes the understanding of Brucella sRNAs, as well as the mechanism by which sRNAs use to influence Brucella physiology and pathogenesis

One month follow-up of carotid endarterectomy with in-hospital preoperative aspirin monotherapy and postoperative dual antiplatelet therapy in asymptomatic and symptomatic patients: A multi-center study

Background: There is currently no consensus regarding the optimal perioperative antiplatelet strategy for carotid artery surgery. This multicentre study aimed to analyse the association between preoperative aspirin monotherapy following postoperative dual antiplatelet therapy (DAPT) and the risk for stroke and death after carotid endarterectomy (CEA). Methods: This cohort study included 821 patients with carotid artery stenosis who underwent CEA. Primary outcomes included any stroke or death up to the one-month postoperative follow-up. Multilevel multivariate regression analyses and descriptive statistics were performed. Results: Patients were predominantly male (53 %), with a mean age of 66.2 years. The primary outcome occurred in 1.6 % of patients. Univariate and multivariate analyses revealed that patients with chronic obstructive pulmonary disease (COPD) exhibited a high risk for stroke or death (P = 0.011). The occurrence of any local complications in the neck was accompanied by an increase in diastolic blood pressure (DBP) (P = 0.007). Patients with a high systolic blood pressure (SBP) (P = 0.002) experienced a longer operative duration. The length of hospital stay was longer in the patients with COPD (P = 0.020), minor stroke (P = 0.011), and major stroke (P = 0.001). A positive linear correlation was found between SBP and operative duration in the overall population (β 0.4 [95 % confidence interval (CI) 0.1–0.7]; P = 0.002). The resultant curve for DBP and any local complications in the neck exhibited a two-stage change and one breakpoint in the entire population (k = 68 mmHg, <68; odds ratio [OR] 0.9 [95 % CI 0.7–1.1], P = 0.461; ≥68: OR 1.1 [95 % CI 1.0–1.1], P = 0.003). Conclusions: Preoperative aspirin monotherapy and postoperative DAPT were safe and effective antiplatelet treatments for patients who underwent CEA