Molecular characteristics and phylogenetic analysis of Clostridium perfringens from different regions in China, from 2013 to 2021.

Clostridium perfringens (C. perfringens) is a significant foodborne pathogen and a common cause of intestinal diseases in both animals and humans. Our study investigated MLST, phenotypic antimicrobial resistance profiles, and resistance genes among isolates from human, animal and food. 186 C. perfringens isolates were obtained from nine provinces in China between 2013 and 2021. Additionally, some specific ST complexes were analyzed by cgMLST and cgSNP to investigate genetic relatedness. MLST indicated the most prevalent STs of C. perfringens of human and animal origin were as follows: ST221 (5/147), ST62 (4/147), ST408 (4/147), and ST493 (4/147) were predominant in humans, while ST479 (5/25) was the major type in animals. Within the same ST complex, genetically unrelated relationships or potential clustering/transmission events were further recognized by cgMLST and cgSNP, illustrating that these two methods are valuable in defining outbreaks and transmission events. All tested isolates were susceptible to vancomycin and meropenem. The rates of resistance to metronidazole, penicillin, cefoxitin, moxifloxacin, and chloramphenicol were low (metronidazole: 1.08%; penicillin: 9.68%; cefoxitin: 0.54%; moxifloxacin: 6.45%; and chloramphenicol: 3.76%). Interestingly, 49.66% of human origin were clindamycin-resistant, and 18.2% were penicillin-insensitive. Importantly, the portion of MDR isolates was significantly lower than in previous reports. The study provides an overview of the epidemiological characteristics of C. perfringens with different origins and hosts in China. C. perfringens demonstrated remarkable genetic diversity and distinct molecular features compared to antibiotic-resistance profiles from other studies.

A rapid multiplex real-time PCR detection of toxigenic Clostridioides difficile directly from fecal samples.

This study developed a new single-tube multiplex real-time PCR method for detecting toxigenic C. difficile directly from fecal samples using tcdA, tcdB, cdtB, and internal gene tpi as targets, which could be performed on kinds of polymerase chain reaction device including point-of-care testing (POCT), with improved detection efficiency. The specificity, sensitivity, and repeatability of each gene was evaluated using 69 C. difficile isolates and 74 fecal samples. Results were compared with established PCR, qPCR, and ELISA methods. Interspecies specificity was 100% based on six common intestinal pathogens (Escherichia coli, Enterococcus Faecium, Enterococcus faecalis, Clostridium perfringens, Bacteroides fragilis, Clostridium botulinum). The lower detection limit (LDL) for tcdA, tcdB, and cdtB with pure C. difficile DNA was 101,100, and 100 copies/µL, respectively, the coefficients of variation among different experimental batches and within each experimental batch were both less than 3%, which shows that this method has strong repeatability. And the LDL of fecal DNA was 5 × 100, 5 × 103, and 5 × 102 colony-forming units (CFU)/g, respectively. In addition, the efficiency for detection of tcdA was compared with established PCR and real-time PCR methods, demonstrating high consistency (98.4%) and similar sensitivity. ELISA was used to confirm inconsistent results, which were identical with our method. The sensitivity and specificity for detecting toxigenic C. difficile in fecal samples were 96.49% and 94.12% compared with the toxigenic culture (TC). This method effectively identified the toxigenic and non-toxigenic strains with high specificity, sensitivity, and repeatability, and could reduce the false positive rate of tcdA, and accurately identify the typical Asian strain RT017, making it potentially contribute to the surveillance of CDI in China. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-022-03434-6.

A narrative review of Clostridioides difficile infection in China.

Clostridioides difficile is the predominant pathogen responsible for antimicrobial associated diarrhea (AAD) and health care facility-associated infectious diarrhea. The role of C. difficile in China and its impact on public health have gained attention in recent years. Most clinical C. difficile isolates in China belong to multilocus sequence type clade 1 with sequence types (STs) 3, 35 and 54 predominating. Of note, the proportion of C. difficile isolates from clade 4, especially ST37 (PCR ribotype 17), is much higher in China than in other areas. In China, the antimicrobial-resistance profile of C. difficile is similar to that of other countries, demonstrating a higher resistance rate to erythromycin, clindamycin, and fluoroquinolones (ciprofloxacin, levofloxacin, and moxifloxacin). In general, susceptibility to vancomycin and metronidazole of clinical C. difficile in China is high, however, some resistance to metronidazole have recently been reported. Preclinical research on C. difficile in animals in China is limited, and different studies have reported varied isolation rates and antimicrobial resistance profiles. The diverse molecular types of C. difficile in China merit further epidemiological, genomic and evolutionary investigation. While the use of probiotics in preventing C. difficile infection (CDI) have received both support and opposition, the discovery of new probiotics and new formulations are showing promising results in combating the threat posed by CDI.

Anterior Cervical Discectomy and Fusion Combined with Foraminotomy Assisted by High-Definition 3-Dimensional Exoscope in the Treatment of Cervical Spondylotic Radiculopathy Secondary to Bony Foraminal Stenosis.

OBJECTIVE: To evaluate the outcomes of cervical spondylotic radiculopathy secondary to bony foraminal stenosis treated with anterior cervical discectomy and fusion (ACDF) combined with anterior cervical foraminotomy (ACF) assisted by High-Definition 3-Dimensional Exoscope. METHODS: In this retrospective study, a total of 19 consecutive patients (12 males and seven females, with an average of 49.2 years, range from 40 to 59 years) with spondylotic radiculopathy caused by bony foraminal stenosis underwent ACDF combined with ACF assisted by High-Definition 3-Dimensional Exoscope in our hospital between January 2019 and December 2019 were included in this study. All patients signed the consent form before the surgery. The patient baseline information such as gender, age, body mass index (BMI), surgery time, blood loss, hospital stay, lesion segment, side, follow-up time and postoperative complications were recorded. The Japanese Orthopedic Association (JOA), Neck Disability Index (NDI), and Visual Analogue Scale (VAS) were measured and compared before surgery, 1 months and final follow-up after surgery. The radiographic outcomes were evaluated using the C2 -C7 angel, disc height, foraminal height, superior diagonal distance, inferior diagonal distance, and foraminal area. RESULTS: The involved levels included C4 -C5 (six cases), C5 -C6 (10 cases), C6 -C7 (three cases). The mean duration of the surgery, mean blood loss, mean hospital stay, and mean follow-up were 100 ± 11.10 min, 19.4 ± 7.05 mL, 7.1 ± 0.99 days, and 12.1 ± 2.25 months, respectively. The average preoperative JOA score was 11.9 ± 1.31, then improved to 15.7 ± 0.73 (t = -13.45, P < 0.001) and 16.2 ± 0.74 (t = -14.39, P < 0.001) at 1 month after operation and at last follow-up, respectively. The average preoperative NDI score was 27.3 ± 3.36, then decreased to 5.1 ± 1.79 (t = 20.63, P < 0.001) and 4.5 ± 1.21 (t = 25.53, P < 0.001) 1 month after operation and at last follow-up, respectively. The average preoperative VAS score was 6.7 ± 0.93, then decreased to 2.4 ± 0.69 (t = 15.05, P < 0.001) and 1.9 ± 0.78 (t = 16.40, P < 0.001) 1 month after operation and at last follow-up, respectively. As compared with the condition before surgery, there was a significant improvement in the C2 -C7 angel, disc height, foraminal height, and foraminal area (P < 0.05). None of the patients developed postoperative vascular injury, nerve injury, loosening and rupture of the internal fixation, displacement of interbody fusion cage, and pseudarthrosis. CONCLUSION: ACDF combined with ACF assisted by High-Definition 3-Dimensional Exoscope is effective and safe for the treatment of CSR caused by secondary to bony foraminal stenosis.

DIP2A is involved in SOD-mediated antioxidative reactions in murine brain.

Autism spectrum disorders (ASDs) are highly associated with oxidative stress. We have recently shown that Disconnected-interacting protein homolog 2 A (DIP2A) functions in ASD pathophysiology by regulating cortactin acetylation for spine development and synaptic transmission. However, its role is not fully understood in the context of its abundant expression in mitochondria. In this paper, we found that DIP2A was involved in superoxide dismutase (SOD)-mediated antioxidative reactions. In mice, DIP2A knockout inhibited SOD activity and increased reactive oxygen species (ROS) levels in the cerebral cortex. In vitro gain-of-function experiments further confirmed the positive role of DIP2A in scavenging ROS upon oxidative stress. Moreover, DIP2A knockout caused irregular mitochondrial morphology in the cerebral cortex and impaired mitochondrial metabolism with an over consumption of lipids for energy supply. Taken together, these results revealed unrecognized functions of DIP2A in antioxidative protection, providing another possible explanation for DIP2A-mediated ASD pathophysiology.

The CT Image Changes in Ankylosing Spondylitis from Fracture to Andersson Lesions: A Case Report and Literature Review.

BACKGROUND: Ankylosing spondylitis with Andersson lesions is not rare, but its potential pathogenesis and natural course remain unclear. CASE DESCRIPTION: We describe a case of CT image changes in ankylosing spondylitis from fracture to Andersson lesions. A 40-year-old man with a 23-year history of ankylosing spondylitis presented with acute back pain after a slight fall, and the CT showed a T12 fracture; the patient refused surgery for 12 months. The process from fracture to Andersson lesions was characterized by CT, including the subsequent interbody bone graft with internal fixation and successful bone fusion at the last follow-up. Histopathologic analysis showed degenerative fibrocartilage tissue calcification, necrotic intervertebral disc tissue, fibrovascular hyperplasia, and focal accumulation of inflammatory cells. CONCLUSION: Aseptic inflammation and persistent instability caused by a fracture contributed in the course from fracture to Andersson lesions in ankylosing spondylitis. CT can accurately track the pathological process, and interbody fusion via the posterior pedicle lateral approach can achieve satisfactory effectiveness, good fusion and kyphosis correction.

[Changes of cerebral cortical metabolomics in rats following benzo[a]pyrene exposure].

OBJECTIVE: To analyze the changes in endogenous small molecule metabolites after benzo[a]pyrene (B[a]P) exposure in rat cerebral cortex and explore the mechanism of B[a]P neurotoxicity. METHODS: Five-day-old SD rats were subjected to gavage administration of 2 mg/kg B[a]P for 7 consecutive weeks. After the exposure, the rats were assessed for spatial learning ability using Morris water maze test, ultrastructural changes of the cortical neurons under electron microscope, and metabolite profiles of the cortex using GC/MS. The differential metabolites between the exposed and control rats were identified with partial least squares discriminant analysis (PLS-DA) and the metabolic pathways related with the differential metabolites were analyzed using Cytoscape software. RESULTS: Compared with the control group, the rats exposed to B[a]P showed significantly increased escape latency (P<0.05) and decreased time spent in the target area (P<0.05). The exposed rats exhibited widened synaptic cleft, thickened endplate membrane and swollen cytoplasm compared with the control rats. Eighteen differential metabolites (VIP>1, P<0.05) in the cortex were identified between the two groups, and 9 pathways associated with B[a]P neurotoxicity were identified involving amino acid metabolism, tricarboxylic acid cycle and Vitamin B3 (niacin and nicotinamide) metabolism. CONCLUSION: B[a]P can cause disturbance in normal metabolisms and its neurotoxicity is possibly related with disorders in amino acid metabolism, tricarboxylic acid cycle and vitamin metabolism.

Synthesis, crystal structures and antitumor activity of two platinum(II) complexes with methyl hydrazinecarbodithioate derivatives of indolin-2-one.

Two new platinum(II) complexes 7a and 7b with methyl hydrazinecarbodithioate derivatives of indolin-2-one have been prepared and characterized by single-crystal X-ray diffraction, NMR spectroscopy and mass spectrometry. Antiproliferative activity of the two complexes and their ligands 6a and 6b against HCT-116, MCF-7 and MDA-MB-231 cell lines was determined by the MTS assay. Complexes 7a and 7b exhibited stronger antiproliferative activity against three cell lines than compounds 6a and 6b (IC50, 1.89-5.60 versus 6.52-35.13 µM). Moreover, treatment of HCT-116 cells with the complexes resulted in an obvious sub-G1 peak by cell cycle profile analysis, and an increase of cleaved PARP1 and caspases 3, 7, and 9 by immunoblotting analysis. Live cell imaging showed that nucleus shrinkage and condensation started to appear when MCF-7 cells were treated with 7a for 8 h. Fluorescent spectrophotometric analysis revealed that the complexes physically associated with calf thymus DNA. Competitive DNA binding assays uncovered that the complexes non-covalently bind to DNA. Taken together, our results indicated that the two new platinum(II) complexes 7a and 7b non-covalently bind to DNA with high affinity and exhibit cytotoxicity against cancer cells by inducing apoptosis.

In vivo and in vitro effect of hepatocarcinoma lymph node metastasis by upregulation of Annexin A7 and relevant mechanisms.

We unveiled the association of Annexin A7 with vascular endothelial growth factor-C (VEGF-C) and the effect of upregulation of Annexin A7 in Hca-F and Hca-P cells on inhibiting hepatocarcinoma (HCC) lymph node metastasis (LNM) in vitro and in vivo. A total of 200 inbred 615 mice were randomly divided into four equal groups inoculated with Hca-F, Hca-P, FAnxa7-upregulated, and PAnxa7-upregulated cells, respectively. The primary tumor, popliteal, inguinal, and iliac lymph nodes were prepared for immunohistochemical (IHC) staining, real-time quantitative polymerase chain reaction (qRT-PCR) analysis, Western blot, and hematoxylin-eosin (H&E) staining. There was over 50 % increase both in the number of FAnxa7-upregulated and PAnxa7-upregulated cells migrated through the filter compared to their controls (FAnxa7-control, Hca-F and PAnxa7-control, Hca-P). However, no significant differences were noted in invasion ability between them (all P > 0.05). Tumor lymph vessels were significantly reduced in FAnxa7-upregulated and PAnxa7-upregulated tumors when compared with Hca-F and Hca-P tumors (all P < 0.05). Blood vessel density did not differ significantly between FAnxa7-upregulated and PAnxa7-upregulated tumors and Hca-F and Hca-P tumors. Enzyme-linked immunosorbent assay (ELISA) for VEGF-C showed that upregulating Annexin A7 decreased VEGF-C secretion in FAnxa7-upregulated and PAnxa7-upregulated cells (P < 0.05). The IHC staining result showed that the level of serum Annexin A7 was found to be statistically higher in all experimental groups than that in the control group (P < 0.05). The present results indicated that alterations in serum Annexin A7 expression may be of prognostic relevance in HCC lymphatic metastasis.

Annexin A7 gene is an important factor in the lymphatic metastasis of tumors.

In the tumor malignancy progression, lymph node metastasis (LNM) is recognized as an important factor. In this study, RNA interference (RNAi) was employed to down-regulate ANXA7 gene in Hca-F cells, a hepatocarcinoma cell line with high LNM rate. There was no significant effect on cell proliferation ability, but cell division, motility, and invasion abilities were markedly inhibited. By contrast, up-regulating the expression of ANXA7 gene in Hca-P cells with lower LNM rate, cell migration ability was improved and the percentage of cells in S phase was significantly decreased in vitro. Here, we reported that the expression of Ech1, GSN and JNK1 genes, which were relevant to tumor lymphatic metastasis, had been inhibited due to down-regulation ANXA7 gene and promoted due to up-regulation ANXA7 gene by western blot analysis. These results indicated that ANXA7 is a critical factor in the development of lymphatic metastasis in hepatocarcinoma progression.