An epidemiological surveillance study (2021-2022): detection of a high diversity of Clostridioides difficile isolates in one tertiary hospital in Chongqing, Southwest China.

BACKGROUND: Clostridioides difficile is a bacterium that causes antibiotic-associated infectious diarrhea and pseudomembranous enterocolitis. The impact of C. difficile infection (CDI) in China has gained significant attention in recent years. However, little epidemiological data are available from Chongqing, a city located in Southwest China. This study aimed to investigate the epidemiological pattern of CDI and explore the drug resistance of C. difficile isolates in Chongqing. METHODS: A case-control study was conducted to investigate the clinical infection characteristics and susceptibility factors of C. difficile. The features of the C. difficile isolates were evaluated by testing for toxin genes and using multi-locus sequence typing (MLST). The susceptibility of strains to nine antibiotics was determined using agar dilution technique. RESULTS: Out of 2084 diarrhea patients, 90 were tested positive for the isolation of toxigenic C. difficile strains, resulting in a CDI prevalence rate of 4.32%. Tetracycline, cephalosporins, hepatobiliary disease, and gastrointestinal disorders were identified as independent risk factors for CDI incidence. The 90 strains were classified into 21 sequence types (ST), with ST3 being the most frequent (n = 25, 27.78%), followed by ST2 (n = 10, 11.11%) and ST37 (n = 9, 10%). Three different toxin types were identified: 69 (76.67%) were A+B+CDT-, 12 (13.33%) were A-B+CDT-, and 9 (10%) were A+B+CDT+. Although substantial resistance to erythromycin (73.33%), moxifloxacin (62.22%), and clindamycin (82.22%), none of the isolates exhibited resistance to vancomycin, tigecycline, or metronidazole. Furthermore, different toxin types displayed varying anti-microbial characteristics. CONCLUSIONS: The strains identified in Chongqing, Southwest China, exhibited high genetic diversity. Enhance full awareness of high-risk patients with HA-CDI infection, particularly those with gastrointestinal and hepatocellular diseases, and emphasize caution in the use of tetracycline and capecitabine. These findings suggest that a potential epidemic of CDI may occur in the future, emphasizing the need for timely monitoring.

Cloning and Biochemical Characterization of a Hyaluronate Lyase from Bacillus sp. CQMU-D.

Hyaluronidase (HAase) can enhance drug diffusion and dissipate edema by degrading hyaluronic acid (HA) in the extracellular matrix into unsaturated HA oligosaccharides in mammalian tissues. Microorganisms are recognized as valuable sources of HAase. In this study, a new hyaluronate lyase (HAaseD) from Bacillus sp. CQMU-D was expressed in Escherichia coli BL21, purified, and characterized. The results showed that HAaseD belonged to the polysaccharide lyase (PL) 8 family and had a molecular weight of 123 kDa. HAaseD could degrade chondroitin sulfate (CS) -A, CS-B, CS-C, and HA, with the highest activity toward HA. The optimum temperature and pH value of HAaseD were 40°C and 7.0, respectively. In addition, HAaseD retained stability in an alkaline environment and displayed higher activity with appropriate concentrations of metal ions. Moreover, HAaseD was an endolytic hyaluronate lyase that could degrade HA to produce unsaturated HA oligosaccharides. Together, our findings indicate that HAaseD from Bacillus sp. CQMU-D is a new hyaluronate lyase and with excellent potential for application in industrial production.

To Explore the Application of PDCA in Hemodialysis Center and Its Effect on the Maintenance of Internal Fistula.

Background: The survey found that in recent years, with the incidence of chronic kidney disease (CKD) increasing, some patients with CKD even progressed to end-stage renal disease. Luckily, progressive hemodialysis technology and nursing level can improve the quality of life and prognosis of patients. Objective: To explore the application of plan-do-check-adjust (PDCA) cycle in the management of nurses in hemodialysis center and its effect on the maintenance of internal fistula in patients. Methods: In this study, a randomized controlled trail (RCT) was used to select 90 patients who underwent maintenance hemodialysis in the hemodialysis center of our hospital from January 2018 to June 2021 as objects. They were divided into a PDCA group (with PDCA nursing management) and routine group (with routine nursing management) by random number table with each of 45 cases for 6 months to compare the differences of the internal fistula complications, internal fistula maintenance quality, patients' microinflammatory state, and satisfaction with nursing, as well as nursing staff's operational and theoretical performance between the two groups. Results: There was no significant difference in CRP, IL-1, TNF-α, and IL-6 levels between the two groups before intervention (P > 0.05); after that, these levels in the PDCA group were lower than those in the routine group, with statistically significant difference (P < 0.05); before intervention, there was no statistically significant difference in the qualification rate of blood flow, the awareness rate of health education, and the incidence of nursing defects between the two groups (P > 0.05); after that, the qualification rate of blood flow and the awareness rate of health education among nurses in PDCA group were higher than those in routine group, while the incidence of nursing defect accidents in the PDCA group was lower than that in routine group, and the differences were statistically significant (P < 0.05); before intervention, there was no significant difference in the complication rate between the two groups (P > 0.05); after that, the complication rate of the PDCA group was lower than that of the routine group, and the differences were statistically significant (P < 0.05); after intervention, the theoretical assessment and practical skills assessment scores of the PDCA group were higher than those of the routine group, and the differences were statistically significant (P < 0.05); after intervention, the nursing satisfaction of the PDCA group was higher than that of the routine group, and the differences were statistically significant (P < 0.05). Conclusion: The application of PDCA approach in the management of nurses in hemodialysis centers can effectively improve the quality of internal fistula management and improve the practical and theoretical level of nurses, as well as reduce the microinflammation of patients.

A preferable approach to clone hLIF cDNA from the genomic DNA

Complementary DNA (cDNA) is valuable for investigating protein structure and function in the research of life science, but it is difficult to obtain by traditional reverse transcription. In this study, we employed a novel strategy to clone the human leukemia inhibitory factor (hLIF) gene cDNA from genomic DNA directly isolated from the mucous membrane of mouth. The hLIF sequence can be acquired within a few hours by means of amplification of each exon and splicing using overlap-PCR. Thus, the new approach developed in this study is simple, time- and cost-effective, and it is not limited to particular gene expression levels of each tissue.

Novel polymorphisms of goat growth hormone and growth hormone receptor genes and their effects on growth traits.

In this study, the polymorphisms of growth hormone (GH) gene 5' promoter region and intron 8, exons 4 and 10 of growth hormone receptor (GHR) gene were analyzed in Xinong Saanen goats (SG) and Boer goats (BG). Two alleles (A and B) and three genotypes (AA, AB and BB) were detected at P1 locus of GH gene, and two alleles (G and T) and two genotypes (GG and GT) were detected at P4 locus of GHR gene by PCR-SSCP analysis. In addition, two single nucleotide polymorphisms (SNPs)-A73C (P1 locus) and G114T (P4 locus), were identified by DNA sequencing. The frequencies of alleles A and B in the two goat breeds were 0.61-0.62, and 0.39-0.38, respectively, and the frequencies of alleles G and T in the two goat breeds were 0.82-0.86, and 0.18-0.14, respectively. The SNP loci were in Hardy-Weinberg disequilibrium in both goat breeds (P<0.05). Polymorphisms of GH and GHR genes were shown to be associated with growth traits in BG breed. AA and GG genotypes were associated with superior growth traits in 1-, 2- and 3-month old individuals. Hence, AA and GG genotypes are suggested to be a molecular marker for superior growth traits in BG breed.