Biocontrol potential of endophytic bacterium Bacillus altitudinis GS-16 against tea anthracnose caused by Colletotrichum gloeosporioides.

Background: As one of the main pathogens causing tea anthracnose disease, Colletotrichum gloeosporioides has brought immeasurable impact on the sustainable development of agriculture. Given the adverse effects of chemical pesticides to the environment and human health, biological control has been a focus of the research on this pathogen. Bacillus altitudinis GS-16, which was isolated from healthy tea leaves, had exhibited strong antagonistic activity against tea anthracnose disease. Methods: The antifungal mechanism of the endophytic bacterium GS-16 against C. gloeosporioides 1-F was determined by dual-culture assays, pot experiments, cell membrane permeability, cellular contents, cell metabolism, and the activities of the key defense enzymes. Results: We investigated the possible mechanism of strain GS-16 inhibiting 1-F. In vitro, the dual-culture assays revealed that strain GS-16 had significant antagonistic activity (92.03%) against 1-F and broad-spectrum antifungal activity in all tested plant pathogens. In pot experiments, the disease index decreased to 6.12 after treatment with GS-16, indicating that strain GS-16 had a good biocontrol effect against tea anthracnose disease (89.06%). When the PE extract of GS-16 treated mycelial of 1-F, the mycelial appeared deformities, distortions, and swelling by SEM observations. Besides that, compared with the negative control, the contents of nucleic acids, protein, and total soluble sugar of GS-16 group were increased significantly, indicating that the PE extract of GS-16 could cause damage to integrity of 1-F. We also found that GS-16 obviously destroyed cellular metabolism and the normal synthesis of cellular contents. Additionally, treatment with GS-16 induced plant resistance by increasing the activities of the key defense enzymes PPO, SOD, CAT, PAL, and POD. Conclusions: We concluded that GS-16 could damage cell permeability and integrity, destroy the normal synthesis of cellular contents, and induce plant resistance, which contributed to its antagonistic activity. These findings indicated that strain GS-16 could be used as an efficient microorganism for tea anthracnose disease caused by C. gloeosporioides.

Plant Virome Analysis by the Deep Sequencing of Small RNAs of Fritillaria thunbergii var. chekiangensis and the Rapid Identification of Viruses.

Thunberg fritillary (Fritillaria thunbergii), a perennial used in traditional Chinese herbal medicine, is a members of the family Liliaceae. The degeneration of germplasm is a severe problem in the production of Fritillaria thunbergii var. chekiangensis. However, no information about viral infections of F. thunbergii var. chekiangensis has been reported. In this study, we sequenced the small RNAs of F. thunbergii var. chekiangensis from leaves and bulbs, and viruses were identified using a phylogenetic analysis and BLAST search for sequence. In addition, multiplex reverse transcriptase-polymerase chain reaction (RT-PCR) was used to rapidly detect viruses in this variety. Our study first reported that five viruses infected F. thunbergii var. chekiangensis. Among them, fritillary virus Y (FVY), lily mottle virus (LMoV), Thunberg fritillary mosaic virus (TFMV), and hop yellow virus (HYV) had been reported in F. thunbergii, while apple stem grooving virus was first reported in the genus Fritillaria. A multiplex RT-PCR method was developed to rapidly test the four viruses FVY, LMoV, TFMV, and HYV in F. thunbergii var. chekiangensis. Our results provide a better understanding of the infection of F. thunbergii var. chekiangensis by viruses and a basic reference for the better design of suitable control measures.

Distribution of Microbes and Drug Susceptibility in Patients with Diabetic Foot Infections in Southwest China.

OBJECTIVE: To investigate the microbial distribution and drug susceptibility among diabetic foot ulcers (DFUs) with different Wagner grades and between acute and chronic DFUs. Methods. We enrolled 428 DFU patients who were hospitalized and treated in the Southwest Hospital. We collected deep ulcer secretion for microbial culture and drug susceptibility tests and analyzed the results. We reexamined 67 patients with poor anti-infection efficacy and analyzed microbial species. Results: The 354 positive samples included 201 cases (56.8%) of single-pathogen infections and 153 cases (43.2%) of multiple-pathogen infections before antibiotic therapy. A total of 555 strains were cultivated, including 205 (36.9%) strains of gram-positive organisms (GPOs), 283 (51.0%) gram-negative bacilli (GNB), and 67 (12.1%) fungal strains. In terms of distribution, patients with different Wagner grades had different bacterial composition ratios (P < 0.01). Patients with Wagner grades 3-5 mainly had GNB. The specimens from chronic ulcer wounds were primarily GNB (54.2%), whereas fungi accounted for 14.4% of the infections; the distribution was significantly different from that of acute ulcers (P < 0.01). The susceptibility tests showed that the Staphylococcus genus was more susceptible to vancomycin, linezolid, and tigecycline. Tobramycin was the most effective drug (97%) for the treatment of Escherichia coli, followed by ertapenem (96.4%), imipenem (93.5%), and cefotetan (90%). Most of the remaining GNB were susceptible to antibiotics such as carbapenems, aminoglycosides, fluoroquinolones, ceftazidime, cefepime, and piperacillin-tazobactam (>63.2%). After antibiotic therapy, the positive rate of microbial culture was 52.2%, and the proportion of GNB and fungi increased to 68.9% and 20%. CONCLUSION: The distribution and types of bacteria in diabetic foot infection (DFI) patients varied with the different Wagner classification grades, courses of the ulcers, and antibiotic therapy. Multidrug resistance were increased, and the clinical treatment of DFIs should select the most suitable antibiotics based on the pathogen culture and drug susceptibility test results.

Inconceivable Hypokalemia: A Case Report of Acute Severe Barium Chloride Poisoning.

Barium is a heavy divalent alkaline earth metal that has been known as a muscle poison. Barium can cause human toxicity, which may lead to significant hypokalemia and have serious consequences. This paper reports a case of unprecedented barium intoxication in which the patient, who suffered from depression, swallowed at least 3.0 g barium chloride to commit suicide. On admission, the patient presented with nausea, vomiting, stomach burning feeling, dizziness, and weakness. Emergency biochemical testing showed that the patient was suffering from severe hypokalemia (K+ 1.7 mmol/L). His electrocardiogram (ECG) prompted atrioventricular blocking, ventricular tachycardia, prolongation of PR interval, ST segment depression with U waves, and T wave inversion. Intravenous potassium supplements were given immediately to correct hypokalemia and regular monitoring of vital signs and fluid balance was arranged. After all-out rescue of our hospital personnel, the condition of the patient is currently stable and he is gradually recovering. This case exemplifies the weaknesses of the management of toxic substances and the lack of mental health education for young people. We hope to get more attention for the supervision of toxic substances and the healthy development of young people.

Adjuvant effect of ethanol extract of Semen Cuscutae on the immune responses to ovalbumin in mice.

An ethanol extract of Semen Cuscutae (EESC) was evaluated for its adjuvant potentials on the cellular and humoral immune responses of ICR mice against ovalbumin (OVA). ICR mice were immunized subcutaneously with OVA 100 microg alone or with OVA 100 microg dissolved in saline containing aluminum hydroxide gel (Alum) (200 microg), Quil A (10 or 50 microg) or EESC (100, 200 or 400 microg) on Days 1 and 15. Two weeks later (Day 28), concanavalin A (Con A)-, pokeweed (PWM)- and OVA-stimulated splenocyte proliferation and OVA-specific antibody in serum were investigated. EESC significantly enhanced the Con A-, PWM-, and OVA-induced splenocyte proliferation in OVA-immunized mice at a dose of 200 microg (P<0.05 or P<0.025). OVA-specific IgG, IgG1 and IgG2b antibody levels in serum were significantly enhanced by EESC compared with OVA control group (P<0.025). Moreover, enhancing effects of EESC on these OVA-specific antibody responses to OVA in mice were more significant than those of Alum and Quil A (P<0.025). In conclusion, the results suggest that EESC is effective on Th1 and Th2 cell functions, and could be safely used as adjuvant.

Adjuvant effect of Panax notoginseng saponins on the immune responses to ovalbumin in mice.

In this study, the haemolytic activities of Panax notoginseng saponins (PNS) and its adjuvant potentials on the cellular and humoral immune responses of ICR mice against ovalbumin (OVA) were evaluated. We determined the haemolytic activity of PNS using 0.5% rabbit red blood cell. PNS showed a slight haemolytic effect, with its haemolytic percents being 11.59 and 3.60% at the concentrations of 500 and 250 microg/ml, respectively. Furthermore, the adjuvant potential of PNS at three dose levels on the cellular and humoral immune responses of ICR mice against ovalbumin were investigated. ICR mice were immunized subcutaneously with OVA 100 microg alone or with OVA 100 microg dissolved in saline containing aluminum hydroxide gel (Alum) (200 microg), Quil A (10 and 50 microg) or PNS (50, 100 or 200 microg) on days 1 and 15. Two weeks later (day 28), concanavalin A (Con A)-, pokeweed (PWM)- and OVA-stimulated splenocyte proliferation and OVA-specific antibodies in serum were measured. PNS significantly enhanced the Con A-, PWM-, and OVA-induced splenocyte proliferation in the OVA-immunized mice at a dose of 100 microg (P < 0.05 or P < 0.025). OVA-specific IgG, IgG1 and IgG2b antibody levels in serum were significantly enhanced by PNS compared with OVA control group (P < 0.025). Moreover, enhancing effect of PNS on the OVA-specific IgG2b antibody responses to OVA in mice were more significant than that of Quil A (P < 0.025). In conclusion, the results suggest that PNS could be safely used as adjuvant with low or non-haemolytic effect.

Haemolytic activities and immunologic adjuvant effect of Panax notoginseng saponins.

AIM: To evaluate haemolytic activities and adjuvant effect of Panax notoginseng saponins (PNS). METHODS: The haemolytic potential of PNS and its effects on the humoral and cellular immune responses to mice subcutaneously immunized with ovalbumin (OVA) were examined. ICR mice were immunized with OVA 100 microg alone, the mixture of OVA 100 microg and aluminoid 2 mg, or mixture of OVA 100 microg and PNS 50, 100, or 200 microg on the first and fifteenth day. Two weeks later (d 28), antigen-specific antibody in serum and concanavalin A (Con A)-, pokeweed (PWM)-, and phytohaemagglutinin (PHA)-stimulated splenocyte proliferation were investigated. RESULTS: Haemolytic percents of PNS-treated red blood cell were 11.6 % and 3.6 % at concentrations of 500 and 250 mg/L, respectively. Con A-, PWM- and PHA-stimulated splenocyte proliferation in the mice immunized with OVA/PNS (100 microg) was higher than that in the OVA control group (P<0.01). Mice immunized with OVA and PNS (50, 100, 200 microg) showed significantly higher serum OVA-specific IgG antibody titers (P<0.01) in comparison with the control group that received OVA alone. CONCLUSION: PNS possesses immunologic adjuvant activities and low-haemolytic effect.