The molecular characters and antibiotic resistance of Clostridioides difficile from economic animals in China.

BACKGROUND: It has been performed worldwidely to explore the potential of animals that might be a reservoir for community associated human infections of Clostridioides difficile. Several genetically undistinguished PCR ribotypes of C. difficile from animals and human have been reported, illustrating potential transmission of C. difficile between them. Pig and calf were considered as the main origins of C. difficile with predominant RT078 and RT033, respectively. As more investigations involved, great diversity of molecular types from pig and calf were reported in Europe, North American and Australia. However, there were quite limited research on C. difficile isolates from meat animals in China, leading to non-comprehensive understanding of molecular epidemiology of C. difficile in China. RESULTS: A total of 55 C. difficile were isolated from 953 animal stool samples, within which 51 strains were from newborn dairy calf less than 7 days in Shandong Province. These isolates were divided into 3 STs and 6 RTs, of which ST11/RT126 was predominant type, and responsible for majority antibiotic resistance isolates. All the isolates were resistant to at least one tested antibiotics, however, only two multidrug resistant (MDR) isolates were identified. Furthermore, erythromycin (ERY) and clindamycin (CLI) were the two main resistant antibiotics. None of the isolates were resistant to vancomycin (VAN), metronidazole (MTZ), tetracycline (TET), and rifampin (RIF). CONCLUSIONS: In this study, we analyzed the prevalence, molecular characters and antibiotic resistance of C. difficile from calf, sheep, chicken, and pig in China. Some unique features were found here: first, RT126 not RT078 were the dominant type from baby calf, and none isolates were got from pig; second, on the whole, isolates from animals display relative lower resistant rate to these 11 tested antibiotics, compared with isolates from human in China in our previous report. Our study helps to deep understanding the situation of C. difficile from economic animals in China, and to further study the potential transmission of C. difficile between meat animals and human.

Microevolution within ST11 group Clostridioides difficile isolates through mobile genetic elements based on complete genome sequencing.

BACKGROUND: Clade 5 Clostridioides difficile diverges significantly from the other clades and is therefore, attracting increasing attention due its great heterogeneity. In this study, we used third-generation sequencing techniques to sequence the complete whole genomes of three ST11 C. difficile isolates, RT078 and another two new ribotypes (RTs), obtained from three independent hospitalized elderly patients undergoing antibiotics treatment. Mobile genetic elements (MGEs), antibiotic-resistance, drug resistance genes, and virulent-related genes were analyzed and compared within these three isolates. RESULTS: Isolates 10,010 and 12,038 carried a distinct deletion in tcdA compared with isolate 21,062. Furthermore, all three isolates had identical deletions and point-mutations in tcdC, which was once thought to be a unique characteristic of RT078. Isolate 21,062 (RT078) had a unique plasmid, different numbers of transposons and genetic organization, and harboring special CRISPR spacers. All three isolates retained high-level sensitivity to 11 drugs and isolate 21,062 (RT078) carried distinct drug-resistance genes and loss of numerous flagellum-related genes. CONCLUSIONS: We concluded that capillary electrophoresis based PCR-ribotyping is important for confirming RT078. Furthermore, RT078 isolates displayed specific MGEs, indicating an independent evolutionary process. In the further study, we could testify these findings with more RT078 isolates of divergent origins.

[Domesticated cultivation and genetic breeding of Chenopodium quinoa].

Quinoa (Chenopodium quinoa Willd, 2n=36) is an annual crop belonging to the genus Chenopodium in Amaranthaceae, and originated from the Titicaca lake of the Andes region in the South America. Due to its high nutritional values and adapted tolerance to various abiotic stresses, quinoa was considered a crop with high application potential, but improvement is still needed for the development and utilization of crop. Therefore it attains the attention of biological scientists and breeders. In recent years, with the pursuit of better health and higher quality of life, the consuming of quinoa grains has increased dramatically. Cultivation and breeding of quinoa has received more attention to ensure global food security as well. On the basis of our multiple years of experience in quinoa germplasm collection which were evolution from Andes region, the focus of this review is on the nutritional quality and application of quinoa, species origination and evolution, domestication by human, and genetic breeding progress and trends, so that a better understanding of quinoa values can be achieved. We aim to help increase farmers' income in poverty areas and ensure national food security by promoting development of quinoa industry in China.

Antibiotic resistance of clinical isolates of Clostridioides difficile in China and its association with geographical regions and patient age.

It is known that antibiotic usage is associated with the development of Clostridioides difficile infection (CDI), especially clindamycin, third-generation cephalosporins, and fuoroquinolones. Antibiotic resistance rates to many antibiotics varies a lot by study. We performed a study focused on antibiotic resistance in clinical isolates of C. difficile from more widespread geographic regions across China. Of 319 C. difficile isolates tested against 11 antibiotics, 313 (98.1%) were resistant to at least one antibiotic. The highest rate of resistance was to ciprofloxacin, clindamycin, and erythromycin across all age groups, similar to previous studies. However, all isolates were susceptible to metronidazole and vancomycin. Overall the resistance rate to tested antibiotics was lower than other reports in China except for chloramphenicol and meropenem. Genotype ST37/RT017 in clade 4 was resistant to more antibiotics than other types. Unexpectedly, RT078 isolates in this study were susceptible to almost all tested antibiotics. In addition, the proportion of multi-drug resistant (MDR) isolates observed (17%) in this study was much lower than several European studies (up to 55%) and a previous study in China (78%). Although isolates from patients aged between 65 and 85 were more resistant to antibiotics in comparison to other age groups, MDR isolates were still detected in children below 2-years of age. The highest percentage of MDR isolates was determined in South China, an area that is most developed economically. The clade 4, RT017 (ST37) has been associated with outbreaks in Europe and North America and is responsible for most C. difficile infections (CDIs) in Asia. In addition, RT017 is often clindamycin and fluoroquinolone resistant. This study provided a relatively comprehensive description of antibiotic resistance of C. difficile in China, and further elucidates the epidemiology and antibiotic resistance of clinical isolates of C. difficile in China at a national level.

miR-29a inhibits adhesion, migration, and invasion of osteosarcoma cells by suppressing CDC42.

Osteosarcoma is one of the most common tumors of the bone in children and adolescents worldwide. The relapse and metastasis of osteosarcoma are a major therapeutic challenge. Recently, several metastasis regulators, including miRNAs, kinases, and lncRNAs, were reported in osteosarcoma. Identifying novel regulators of metastasis will be useful to explore novel biomarkers for osteosarcoma. The present study showed miR-29a overexpression significantly inhibited HOS and MG-63 cell adhesion, invasion, and migration. About 70% of the wound area was repaired by migrating cells after 24 h in the control group, and only 50% of the wound area was repaired in the miR-29a overexpression group. The numbers of invading cells were decreased by 40% and 50% in HOS and MG-63 cells transfected with miR-29a, respectively, compared with the negative control group. Moreover, the present study validated that CDC42 was a direct target of miR-29a in OS cells. In conclusion, miR-29a may serve as a therapeutic target for osteosarcoma.

SUMO-specific protease 2 (SENP2) functions as a tumor suppressor in osteosarcoma via SOX9 degradation.

Osteosarcoma (OS) is the most common primary bone malignancy in children and adolescents, the pathogenesis of which remain largely unknown. Small ubiquitin-like modifier (SUMO)-Specific Protease 2 (SENP2) has been reported to serve as a tumor suppressor in hepatocellular carcinoma cells. The aim of the present study was to investigate the critical role of SENP2 in OS cells. Using reverse transcription-quantitative polymerase chain reaction and western blot assays, it was observed that SENP2 was significantly downregulated in clinical OS tissues compared with adjacent normal samples. Ectopic expression of SENP2 resulted in the suppression of proliferation, migration and invasion in OS cells, whereas SENP2 knockdown by CRISPR-Cas9-based gene editing had the opposite effect. SENP2 is associated with the proteasome-dependent ubiquitination and degradation of SRY-box-9 (SOX9). SOX9 silencing impaired SENP2-depletion-induced accelerated cell growth and migration. Together, these results suggest that SOX9 is a critical downstream effector of the tumor suppressor SENP2 in OS.

Molecular structures of the stem tuber anthocyanins of colored potatoes and their coloring effects on the tubers.

This paper summarized the important achievements about the general characteristics of the molecular structures of the stem tuber anthocyanins of Colored potatoes and the basic coloring effects of the anthocyanins on the tubers. The various coloration patterns of the skins and/or flesh of Colored potato tubers result from the accumulation of the anthocyanins in the periderms, phelloderms and/or peripheral cortices of the tubers, and the tuber colors are fundamentally determined by the matching profiles of the six naturally occurring anthocyanidins, i.e., cyanidin, delphinidin, malvidin, pelargonidin, peonidin and petunidin. Generally, the tuber anthocyanidins hold an O-glycosidic bond-linked rutinosyl at the C3 site, and either a glucosyl linked by an O-glycosidic bond or no substituent group may exist at the C5 site simultaneously. Furthermore, an E-monoacyl frequently exists at the C3-rutinosyls or at the C5-glucosyls of most tuber anthocyanins, and the phenolic acids acylating the tuber anthocyanins are often p-coumaric, ferulic and caffeic acids. The popular names of the p- coumaric acid derivatives of the malvidin, pelargonidin, peonidin and petunidin of the tubers are Malvanin, Pelanin, Peonanin and Petanin, respectively. This review provides a reference for the exploration of the mechanism of the tuber coloration and the identification of the molecular structures of the stem tuber anthocyanins of Colored potatoes.

[Role of endotoxin translocation on mesenteric lymph reperfusion aggravating multiple organ injury in SMAO shock rats].

OBJECTIVE: To investigate the role of mesenteric lymph reperfusion (MLR) aggravates multiple organs injury in superior mesenteric artery occlusion (SMAO) shock and its mechanism. METHODS: Twenty four Wistar rats were randomly divided into 4 groups (n = 6): Sham group (only anesthetized and operated), MLR group rats performed 1 h occlusion of mesenteric lymph duct (MLD), then followed by 2 h of reperfusion, SMAO group (rats performed 1 h occlusion of superior mesenteric artery (SMA) and then followed by 2 h of reperfusion), SMAO + MLR group (rats performed 1 h occlusion of SMA and MLD and then followed by 2 h of reperfusion). The blood sample was taken out from abdominal aortic for plasma and the liver, kidney, myocardium, lung tissues in fixed position were prepared for making homogenate after reperfusion of 2 h respectively. And the levels of endotoxin (ET) in plasma and homogenates were determined with kinetic turbidimetric technique of tachypleus amebocyte lysate, the contents of lipopolysaccharide-binding protein (LBP), lipopolysaccharide receptor (CD14) and tumor necrosis factor-alpha (TNF-alpha) in homogenates were determined with enzyme-linked immunosorbent assay method. RESULTS: The indices have no statistics difference between sham group and MLR group. The ET levels of the plasma and hepatic, renal, myocardial, pulmonary homogenates in SMAO and SMAO + MLR groups were significant higher than that of sham and MLR groups, and these indices in SMAO + MLR were increased significantly than those in SMAO group. The CD14, LBP and TNF-alpha contents of the hepatic, renal, myocardial and pulmonary homogenates in SMAO and SMAO + MLR groups were significant higher than those in sham and MLR groups, and these indices in SMAO+ MLR were higher than SMAO group significantly. CONCLUSION: The mechanism of MLR aggravates multiple organs injury in SMAO shock may be associated with enterogenous ET through intestinal lymphatic pathway to translocate, activate the LBP/CD14 as endotoxin sensitizing system and promote inflammatory response.