Cloning, purification, and functional characterization of Carocin S2, a ribonuclease bacteriocin produced by Pectobacterium carotovorum

<p>Abstract</p> <p>Background</p> <p>Most isolates of <it>Pectobacterium carotovorum subsp. carotovorum </it>(Pcc) produce bacteriocins. In this study, we have determined that Pcc strain F-rif-18 has a chromosomal gene encoding the low-molecular-weight bacteriocin, Carocin S2, and that this bacteriocin inhibits the growth of a closely related strain. Carocin S2 is inducible by ultraviolet radiation but not by mutagenic agents such as mitomycin C.</p> <p>Results</p> <p>A carocin S2-defective mutant, TF1-2, was obtained by Tn5 insertional mutagenesis using F-rif-18. A 5706-bp DNA fragment was detected by Southern blotting, selected from a genomic DNA library, and cloned to the vector, pMS2KI. Two adjacent complete open reading frames within pMS2KI were sequenced, characterized, and identified as caroS2K and caroS2I, which respectively encode the killing protein and immunity protein. Notably, carocin S2 could be expressed not only in the mutant TF1-2 but also in <it>Escherichia coli </it>DH5α after entry of the plasmid pMS2KI. Furthermore, the C-terminal domain of CaroS2K was homologous to the nuclease domains of colicin D and klebicin D. Moreover, SDS-PAGE analysis showed that the relative mass of CaroS2K was 85 kDa and that of CaroS2I was 10 kDa.</p> <p>Conclusion</p> <p>This study shown that another nuclease type of bacteriocin was found in <it>Pectobacterium carotovorum</it>. This new type of bacteriocin, Carocin S2, has the ribonuclease activity of CaroS2K and the immunity protein activity of CaroS2I.</p

DNA Polymorphisms and Biocontrol of Bacillus Antagonistic to Citrus Bacterial Canker with Indication of the Interference of Phyllosphere Biofilms

Citrus bacterial canker caused by Xanthomonas axonopodis pv. citri is a devastating disease resulting in significant crop losses in various citrus cultivars worldwide. A biocontrol agent has not been recommended for this disease. To explore the potential of bacilli native to Taiwan to control this disease, Bacillus species with a broad spectrum of antagonistic activity against various phytopathogens were isolated from plant potting mixes, organic compost and the rhizosphere soil. Seven strains TKS1-1, OF3-16, SP4-17, HSP1, WG6-14, TLB7-7, and WP8-12 showing superior antagonistic activity were chosen for biopesticide development. The genetic identity based on 16S rDNA sequences indicated that all seven native strains were close relatives of the B. subtilis group and appeared to be discrete from the B. cereus group. DNA polymorphisms in strains WG6-14, SP4-17, TKS1-1, and WP8-12, as revealed by repetitive sequence-based PCR with the BOXA1R primers were similar to each other, but different from those of the respective Bacillus type strains. However, molecular typing of the strains using either tDNA-intergenic spacer regions or 16S–23S intergenic transcribed spacer regions was unable to differentiate the strains at the species level. Strains TKS1-1 and WG6-14 attenuated symptom development of citrus bacterial canker, which was found to be correlated with a reduction in colonization and biofilm formation by X. axonopodis pv. citri on leaf surfaces. The application of a Bacillus strain TKS1-1 endospore formulation to the leaf surfaces of citrus reduced the incidence of citrus bacterial canker and could prevent development of the disease

The Requirement Analysis of Personalized Electrical Papers of Learning - in the course BCC of Authelia University

出處： Incheon National University, Kore

Understanding cellular defence in kumquat and calamondin to citrus canker caused by Xanthomonas citri subsp. citri

Histopathological assays gain physiological insights into the mechanisms by which kumquat and calamondin are resistant to citrus canker caused by Xanthomonas citri subsp. citri (Xcc). Unlike Mexican lime, which is highly susceptible to Xcc, calamondin and kumquat leaves challenged with Xcc developed rapid necrosis, resembling a hypersensitive reaction. Fluorescent microscopy examination identified fluorescent materials around the necrotic lesions in kumquat and calamondin leaves challenged with Xcc, but not in Mexican lime. The resistant cultivars inoculated with Xcc exhibited lower antioxidant enzymatic activities and accumulated less H2O2. These modifications serve as physical barriers to ward off pathogen, thereby suppressing lesion development

Dietary Patterns and the Risk of Prediabetes in Taiwan: A Cross-Sectional Study

Background: prediabetes prevention and management are the main methods used to combat the prevalence of diabetes. Exploratory factor analysis is an upcoming method that is successful in identifying dietary patterns that correlate with healthy or unhealthy outcomes. Aim: this study aims to identify dietary patterns in Taiwan that are associated with the risk of prediabetes. Methods: anthropometric, blood glucose, 3 d/24 h dietary records, and food frequency questionnaire data were collected from subjects recruited at Taipei Tzu-Chi Hospital. The following five dietary patterns were identified using factor analysis: Western, prudent, convenience, Asian traditional, and continental. This cross-sectional study compares tertiles of dietary patterns and analyzes the significance of the characteristics. Results: the Western and the prudent patterns are the major dietary patterns found in other studies. A higher factor loading in the Western pattern is significantly related to a higher risk of prediabetes. A higher factor loading in the continental pattern is significantly related to a lower risk of prediabetes. Conclusion: decreasing meat and seafood consumption while increasing egg, coffee, and milk consumption may be associated with a decreased risk for prediabetes

Understanding cellular defence in kumquat and calamondin to citrus canker caused by Xanthomonas citri subsp. citri

Histopathological assays gain physiological insights into the mechanisms by which kumquat and calamondin are resistant to citrus canker caused by Xanthomonas citri subsp. citri (Xcc). Unlike Mexican lime, which is highly susceptible to Xcc, calamondin and kumquat leaves challenged with Xcc developed rapid necrosis, resembling a hypersensitive reaction. Fluorescent microscopy examination identified fluorescent materials around the necrotic lesions in kumquat and calamondin leaves challenged with Xcc, but not in Mexican lime. The resistant cultivars inoculated with Xcc exhibited lower antioxidant enzymatic activities and accumulated less H2O2. These modifications serve as physical barriers to ward off pathogen, thereby suppressing lesion development

Association between heme oxygenase one and sepsis development in patients with moderate-to-critical COVID-19: a single-center, retrospective observational study

Abstract Background Heme oxygenase one (HO-1) is considered a poor prognostic factor for survival in patients with severe-to-critical coronavirus disease (COVID-19), but the clinical correlation between heme catabolism biomarkers and COVID-19-related sepsis is unknown. The etiopathogenetic hypothesis of HO-1 response during sepsis in patients with poor prognosis should be clarified. This study aimed to investigate sepsis development within 48 h following moderate-to-critical COVID-19 and examined heme/HO-1 catabolism biomarkers associated with sepsis. We also studied the HO-1 and traditional prognostic factors for predicting survival in patients with COVID-19. Methods This retrospective observational study included patients unvaccinated for COVID-19 with moderate-to-critical COVID-19 (n = 156) who had been admitted to Taipei Tzu Chi Hospital in 2021. All COVID-19 patients were diagnosed by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) reverse transcriptase polymerase chain reaction. For analysis of heme catabolism in SARS-CoV-2-induced sepsis, we excluded patients with co-infection and severe anemia. Heme catabolism biomarkers were compared between groups of patients with COVID-19 and sepsis (sepsis) and those with COVID-19 without sepsis (no sepsis), and a control group comprising 100 healthy individuals. All clinical and laboratory data were collected retrospectively and blood specimens were collected from Biobank. Multivariable logistic regression analysis was used to compare all variables between the sepsis and no-sepsis groups. Cox regression analysis was used to determine predictors of survival in patients with COVID-19. Results There were 71 and 85 patients with and without sepsis, respectively. Heme and HO-1 levels differed significantly between the sepsis, no sepsis, and control groups. In multivariate analysis, confusion, blood urea nitrogen, respiration, blood pressure in patients aged > 65 years (CURB-65) (adjusted odds ratio [aOR] 5.331, 95% confidence interval [CI] 2.587–10.987; p < 0.001), albumin (aOR 0.139, 95% CI 0.003–0.636; p = 0.01), d-dimer (aOR 1.001, 95% CI 1.000–1.002; p = 0.032), and HO-1 (aOR 1.116, 95% CI 1.055–1.180; p < 0.001) were significantly associated with 48-h sepsis episodes after adjusting for other confounding factors. HO-1 levels were also significantly associated with 48-h Sequential Organ Failure Assessment Score (SOFA) scores. However, HO-1 did not significantly increase the hazard of in-hospital mortality in moderate-to-critical COVID-19 by Cox regression analysis. Conclusions HO-1 levels increased with sepsis development within 48 h of admission for COVID-19 after adjusting for other risk factors, but no significant association was observed between HO-1 and COVID-19 mortality. We suppose that HO-1 may have protective effect in early sepsis, but further clinical multicenter prospective studies are needed

Chromosomal Gain of 3q and Loss of 11q Often Associated with Nodal Metastasis in Early Stage Cervical Squamous Cell Carcinoma

Cervical cancer remains a health problem among women worldwide. Delineation of genetic changes is critical to understanding the molecular basis of tumor progression, as well as for identifying genetic markers for early identification of patients at high risk for a poor outcome. Methods: To provide comparative genomic hybridization data for cervical squamous cell carcinoma in Taiwan, and to gain further insight into genetic markers associated with lymph node metastasis of this disease, we performed comparative genomic hybridization analysis of 30 consecutive cases of cervical squamous cell carcinoma (24 stage IB and 6 stage IIB). Results: The results disclosed that higher staged tumors or those with lymph node metastasis had more chromosomal imbalances. The commonly recurrent chromosomal imbalances were gains of 3q (46.7%), 1q (36.7%) and 8q (20.0%) and losses of 11q (36.7%), 3p (33.3%), 6q (23.3%), and 2q (20.0%). The frequencies of these chromosomal imbalances in stage IB and IIB tumors did not differ significantly. However, when compared with tumors without lymph node metastasis, the loss of 11q14-q22 (5/9 vs. 3/21, p = 0.019) and gains of 3q11-q22 and 3q26-qter (6/9 vs. 5/21, p = 0.026) were significantly more prevalent in tumors with lymph node metastasis. Conclusion: The results suggest that certain tumor-associated genes residing on 3q and 11q warrant further investigation to elucidate their role in the progression of this disease