Molecular epidemiology and antimicrobial resistance patterns of carbapenem-resistant Acinetobacter baumannii isolates from patients admitted at ICUs of a teaching hospital in Zunyi, China

BackgroundCarbapenem-resistant Acinetobacter baumannii (CRAB) has emerged as a predominant strain of healthcare-associated infections worldwide, particularly in intensive care units (ICUs). Therefore, it is imperative to study the molecular epidemiology of CRAB in the ICUs using multiple molecular typing methods to lay the foundation for the development of infection prevention and control strategies. This study aimed to determine the antimicrobial susceptibility profile, the molecular epidemiology and conduct homology analysis on CRAB strains isolated from ICUs.MethodsThe sensitivity to various antimicrobials was determined using the minimum inhibitory concentration (MIC) method, Kirby-Bauer disk diffusion (KBDD), and E-test assays. Resistance genes were identified by polymerase chain reaction (PCR). Molecular typing was performed using multilocus sequence typing (MLST) and multiple-locus variable-number tandem repeat analysis (MLVA).ResultsAmong the 79 isolates collected, they exhibited high resistance to various antimicrobials but showed low resistance to levofloxacin, trimethoprim-sulfamethoxazole, and tetracyclines. Notably, all isolates of A. baumannii were identified as multidrug-resistant A. baumannii (MDR-AB). The blaOXA-51-like, adeJ, and adeG genes were all detected, while the detection rates of blaOXA-23-like (97.5%), adeB (93.67%), blaADC (93.67%), qacEΔ1-sul1 (84.81%) were higher; most of the Ambler class A and class B genes were not detected. MLST analysis on the 79 isolates identified five sequence types (STs), which belonged to group 3 clonal complexes 369. ST1145Ox was the most frequently observed ST with a count of 56 out of 79 isolates (70.89%). MLST analysis for non-sensitive tigecycline isolates, which were revealed ST1145Ox and ST1417Ox as well. By using the MLVA assay, the 79 isolates could be grouped into a total of 64 distinct MTs with eleven clusters identified in them. Minimum spanning tree analysis defined seven different MLVA complexes (MCs) labeled MC1 to MC6 along with twenty singletons. The locus MLVA-AB_2396 demonstrated the highest Simpson’s diversity index value at 0.829 among all loci tested in this study while also having one of the highest variety of tandem repeat species.ConclusionThe molecular diversity and clonal affinities within the genomes of the CRAB strains were clearly evident, with the identification of ST1144Ox, ST1658Ox, and ST1646Oxqaq representing novel findings

A Hypothesis on the Progression of Insulin-Induced Lipohypertrophy: An Integrated Result of High-Frequency Ultrasound Imaging and Blood Glucose Control of Patients

Aims: To put forward a scientific hypothesis about the progression of insulin-injection-induced lipohypertrophy (LH) according to the high-frequency ultrasonic imaging of insulin injection sites and the blood glucose control of patients. Methods: A total of 344 patients were screened for LH by means of high-frequency ultrasound scanning. The results of their ultrasound examination were described in detail and categorized into several subtypes. Seventeen patients with different subtypes of LH were followed up to predict the progression of LH. To further verify our hypothesis, the effects of different types of LH on glycemic control of patients were observed by comparing glycated hemoglobin A1c (HbA1C) and other glycemic-related indicators. Results: LH was found in 255 (74.1%) patients. According to the high-frequency ultrasonic imaging characteristics, LH can be categorized into three subtypes in general. Among all the LHs, the most common type observed was nodular hyperechoic LH (n = 167, 65.5%), followed by diffuse hyperechoic LH (n = 70, 27.5%), then hypoechoic LH (n = 18, 7.0%). At the follow-up after six months, all 10 patients with nodular hyperechoic LH had LH faded away. Of the five patients with diffuse hyperechoic LH, two had inapparent LH, and three had diffuse hyperechoic parts which had shrunk under ultrasound. No obvious changes were observed in the two cases of hypoechoic LH. Compared with the LH-free group, the mean HbA1C of the nodular hyperechoic LH group increased by 0.8% (9 mmol/mol) (95% CI:−1.394~−0.168, p = 0.005), that of the diffuse hyperechoic LH group increased by 2.0% (21 mmol/mol) (95% CI: −2.696~−1.20, p p = 0.007). Conclusions: It was hypothesized that the earlier stage of LH is nodular hyperechoic LH. If nodular LH is not found in time and the patient continues to inject insulin at the LH site and/or reuse needles, LH will develop into a diffuse type or, even worse, a hypoechoic one. Different subtypes of LH may represent differences in severity when blood glucose control is considered as an important resolution indicator. Further studies are needed to confirm our hypothesis on the progression and reversion of insulin-induced lipohypertrophy

Effects of Global Warming on the Growth and Proliferation of Attached <i>Sargassum horneri</i> in the Aquaculture Area near Gouqi Island, China

With global warming, in recent years, golden tides have frequently occurred off the coasts of China. Sargassum horneri, which attach to aquaculture rafts, can float and form small-scale golden tides after falling off. Temperature will affect the growth and reproduction of algae. In order to explore whether the temperature is the potential influence factor of the golden tide outbreak, in this study, the effects of global warming on the growth and proliferation of S. horneri in the mussel aquaculture area of Gouqi Island will be discussed. Samples of the macroalgae were collected monthly from August 2021 to July 2022 at various stages of its life cycle, and the relationship between algal growth and temperature was analyzed based on the concept of effective accumulated temperature, combined with the parameters of sea surface temperature, photosynthetic rate, growth rate, and growth cycle. Based on the continuous temperature variation observed, the growth cycle could be divided into five stages: the decreasing temperature period (October to November), the low-temperature adaptation period (December), the second suitable low-temperature period (January to February), and the high-temperature decay period (February to May). The effective accumulated temperature stored by S. horneri from 2021 to 2022 was 2772.4 °C·d; compared with previous studies, it decreased by about 800 °C·d. The winter temperature in 2022 was higher than the average temperature in the previous 5 years, allowing the macroalgae to enter the reproductive period in advance. This had a significant impact on the blooming time of golden tides and led to an earlier outbreak and extinction. Therefore, in the future, we can set up a monitoring system for the early warning of golden tides according to the change of SST in winter

Reduced Drought Tolerance by CRISPR/Cas9-Mediated <i>SlMAPK3</i> Mutagenesis in Tomato Plants

Drought stress is one of the most destructive environmental factors that affect tomato plants adversely. Mitogen-activated protein kinases (MAPKs) are important signaling molecules that respond to drought stress. In this study, <i>SlMAPK3</i> was induced by drought stress, and the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (CRISPR/Cas9) system was utilized to generate <i>slmapk3</i> mutants. Two independent T1 transgenic lines and wild-type (WT) tomato plants were used for analysis of drought tolerance. Compared with WT plants, <i>slmapk3</i> mutants exhibited more severe wilting symptom, higher hydrogen peroxide content, lower antioxidant enzymes activities, and suffered more membrane damage under drought stress. Furthermore, knockout of <i>SlMAPK3</i> led to up- or down-regulated expressions of drought stress-responsive genes including <i>SlLOX</i>, <i>SlGST</i>, and <i>SlDREB</i>. The results suggest that <i>SlMAPK3</i> is involved in drought response in tomato plants by protecting cell membranes from oxidative damage and modulating transcription of stress-related genes

Chrysophanol Alleviates Metabolic Syndrome by Activating the SIRT6/AMPK Signaling Pathway in Brown Adipocytes

Chrysophanol, a primary active ingredient of Cassia mimosoides Linn or Rhei radix et rhizoma, has various pharmacological properties, including anticancer, antidiabetic, and anti-inflammatory, as well as blood lipid regulation. However, whether chrysophanol can mitigate obesity, and its underlying mechanisms remains unclear. This study investigated whether chrysophanol effects energy metabolism in high-fat diet- (HFD-) induced obese mice and fat-specific Sirtuin 6- (SIRT6-) knockout (FKO) mice, targeting the SIRT6/AMPK signaling pathway in brown and white fat tissue. Our results showed that chrysophanol can effectively inhibit lipid accumulation in vitro and reduce mice’s body weight, improve insulin sensitivity and reduced fat content of mice, and induce energy consumption in HFD-induced obese mice by activating the SIRT6/AMPK pathway. However, a treatment with OSS-128167, an SIRT6 inhibitor, or si-SIRT6, SIRT6 target specific small interfering RNA, in vitro blocked chrysophanol inhibition of lipid accumulation. Similar results were obtained when blocking the AMPK pathway. Moreover, in the HFD-induced obese model with SIRT6 FKO mice, histological analysis and genetic test results showed that chrysophanol treatment did not reduce lipid droplets and upregulated the uncoupling protein 1 (UCP1) expression. Rather, it upregulated the expression of thermogenic genes and activated white fat breakdown by inducing phosphorylation of adenosine 5′-monophosphate- (AMP-) activated protein kinase (AMPK), both in vitro and in vivo. OSS-128167 or si-SIRT6 blocked chrysophanol’s upregulation of peroxisome proliferator-activated receptor-γ coactivator-1α (Pgc-1α) and Ucp1 expression. In conclusion, this study demonstrated that chrysophanol can activate brown fat through the SIRT6/AMPK pathway and increase energy consumption, insulin sensitivity, and heat production, thereby alleviating obesity and metabolic disorders