Study aimed to introduce the etiology and pathogen of microbial ulcerative keratitis as well as biological features, impact of microorganism. The study also introduced the diagnosis of causative agents and treatment of diseases due to common microorganism such as Staphylococcus, Streptococcus, S. pneumonia, Moraxella, Pseudomonas aeruginosa
Corneal Ulcer ; Antibiosis

Aims: Phytophthora capsici and Fusarium solani are common fungal pathogens causing severe diseases that lead to economic loss in pepper industry, especially in Sarawak. In response to the infections, chemical approach is more common; nevertheless, biological control is more favorable to control fungal pathogens. Biological control approach greatly reduces the problems associated with chemical applications and it restores balance of the natural environment. Here we present the ongoing work to study the action of antagonistic bacteria, Bacillus sp. and Pseudomonas sp., that produce volatile and non-volatile antifungal compounds against P. capsici and F. solani on pepper plants. Methodology and results: A total of seven bacterial candidates were isolated from different locations and tested for their antagonistic properties against P. capsici and F. solani in a dual culture assay and extracellular metabolite test. Extracellular hydrolytic enzymes production was also monitored and followed by genotypic indentification. Preliminary antagonism tests indicated that bacterial isolate Pep3 and Pep4 inhibit up to 50% of the growth of P. capsici and F. solani as compared to the control. Subsequent investigation on extracellular hydrolytic enzyme production revealed that both bacterial isolates are capable of secreting hydrolytic enzymes. Microscopic and genotypic analyses identified the bacterial isolates Pep3 as Bacillus amyloliquefaciens (KJ461444) and Pep4 as Pseudomonas pachastrellae (KM460937). Conclusion, significance and impact of study: B. Amyloliquefaciens (KJ461444) and P. pachastrellae (KM460937) inhibited the growth of P. capsici and F. solani thus reflecting the potential of the produced metabolites to be purified and used in combating plant pathogenic fungi.
Biological Control Agents ; Fungi ; Antibiosis

Trichoderma spp. is a kind of filamentous fungi with important biocontrol value. Twelve strains of Trichoderma spp. were isolated from the soils of different types of crops in Shaoxing, Zhejiang and Foshan, Guangdong. The antagonistic resistance to Fusarium oxysporum was compared by plate confrontation test. The further analysis of volatile secondary metabolites for two strains were carried out using HS-SPME-GC-MS analysis. The results showed that T. asperellum ZJSX5003 and GDFS1009 had fast growth ability, and the inhibition effects on F. oxysporum were 73% and 74% respectively. Six identical volatile metabolites were detected as follows 2-Methyl-1-propanol, 3-Methyl-1-butanol, 3-Methyl-3-buten-1-ol, Acetyl methyl carbinol, Butane-2,3-diol and 6-n-pentyl-2H-pyran-2-one (6-PAP). Among them, 6-PAP was validated to have a higher inhibitory effect on F. oxysporum in vitro. This study will provide basis for the development of biocontrol agents with metabolites of Trichoderma, such as 6-PAP.
Antibiosis ; Antifungal Agents ; pharmacology ; Fusarium ; drug effects ; physiology ; Gas Chromatography-Mass Spectrometry ; Trichoderma ; chemistry ; metabolism

OBJECTIVETo investigate the inhibition of Streptococcus oligofermentans (So) on Streptococcus mutans (Sm) and the producibility of hydrogen peroxide by So under the influence of glucose concentration environment.

METHODSThe inhibition between So and Sm was observed by plating method under the different glucose concentration environment. The initial synthesis rates and production of hydrogen peroxide by So were determined under the different glucose concentration environment by 4-aminoantipyine-horseradish peroxidase method at A(510).

RESULTSUnder 0, 10 and 50 mmol/L glucose environment, the inhibition of So on Sm was evident. When both Sm and So were inoculated at the same time, the ratio of inhibition area by bacterial membrane area was 0.202 ± 0.005, 0.467 ± 0.025, 0.468 ± 0.028 under 0, 10, 50 mmol/L glucose environment. When So was cultivated first and then Sm applied, the ratio was 0.394 ± 0.004, 0.811 ± 0.075 and 0.816 ± 0.007 under 0, 10 and 50 mmol/L glucose environment respectively. The inhibition under 10 and 50 mmol/L glucose environment were more significant than that under non-glucose environment. There was no significant difference between these two glucose concentrations (P > 0.05). The initial synthesis rates of H2O2 by So under the 10 mmol/L [(23.573 ± 0.263) µmo×L(-1)×min(-1)] and 50 mmol/L [(23.337 ± 0.473) µmol×L(-1)×min(-1)] glucose were higher than without glucose[(10.513 ± 0.516) µmol×L(-1)×min(-1)], P < 0.05. H2O2 was not detected in 1000 mmol/L glucose. However, the production of H2O2 by So under 0 mmol/L glucose was higher than other glucose concentrations (P < 0.05).

CONCLUSIONSThe capability of the inhibition of So on Sm was affected by glucose environment and was much stronger under certain glucose concentrations (10, 50 mmol/L).

Antibiosis ; Dose-Response Relationship, Drug ; Glucose ; metabolism ; Hydrogen Peroxide ; metabolism ; Streptococcus ; growth & development ; metabolism ; physiology ; Streptococcus mutans ; growth & development ; metabolism

Altered bowel flora is currently thought to play a role in a variety of disease conditions, and the use of Bifidobacterium spp. and Lactobacillus spp. as probiotics has been demonstrated to be health-promoting, even if the success of their administration depends on the applied bacterial strain(s) and the targeted disease. In the last few decades, specific probiotics have been shown to be effective in the treatment or the prevention of acute viral gastroenteritis, pediatric post-antibiotic-associated diarrhea, some pediatric allergic disorders, necrotizing enterocolitis in preterm infants, inflammatory bowel diseases and postsurgical pouchitis. The potential application of probiotics is continuously widening, with new evidence accumulating to support their effect on the prevention and treatment of other disease conditions, including several oral diseases, such as dental caries, periodontal diseases and oral malodor, as well as genitourinary and wound infections. Considering the increasingly widespread ability of pathogens to generate persistent biofilm-related infections, an even more attractive proposal is to administer probiotics to prevent or counteract biofilm development. The response of biofilm-based oral, intestinal, vaginal and wound infections to probiotics treatment will be reviewed here in light of the most recent results obtained in this field.
Antibiosis ; physiology ; Bacterial Infections ; prevention & control ; Bifidobacterium ; physiology ; Biofilms ; growth & development ; Humans ; Lactobacillus ; physiology ; Mucous Membrane ; microbiology ; Probiotics ; therapeutic use

Epicoccum purpurascens stain 5615 AUMC was investigated for its biocontrol activity against root rot disease caused by Pythium irregulare. E. purpurascens greenhouse pathogenicity tests using three leguminous plants indicated that the fungus was nonpathogenic under the test conditions. The germination rate of the three species of legume seeds treated with a E. purpurascens homogenate increased significantly compared with the seeds infested with P. irregulare. No root rot symptoms were observed on seeds treated with E. purpurascens, and seedlings appeared more vigorous when compared with the non-treated control. A significant increase in seedling growth parameters (seedling length and fresh and dry weights) was observed in seedlings treated with E. purpurascens compared to pathogen-treated seedlings. Pre-treating the seeds with the bioagent fungus was more efficient for protecting seeds against the root rot disease caused by P. irregulare than waiting for disease dispersal before intervention. To determine whether E. purpurascens produced known anti-fungal compounds, an acetone extract of the fungus was analyzed by gas chromatography mass spectrometry. The extract revealed a high percentage of the cinnamic acid derivative (trimethylsiloxy) cinnamic acid methyl ester. The E. purpurascens isolate grew more rapidly than the P. irregulare pathogen in a dual culture on potato dextrose agar nutrient medium, although the two fungi grew similarly when cultured separately. This result may indicate antagonism via antibiosis or competition.
Acetone ; Agar ; Antibiosis ; Cinnamates ; Fabaceae ; Fungi ; Gas Chromatography-Mass Spectrometry ; Germination ; Glucose ; Pythium ; Seedlings ; Seeds ; Solanum tuberosum ; Sprains and Strains

To obtain biocontrol fungus for Alternaria panax,the antifungal effects of one strain of endophytic fungi isolated from leaves of healthy ginseng were screened and evaluated by using dual-culture method,and the taxonomic assignment of the screened strain was identified based on the morphological characters and ITS sequence analysis. The results of dual-culture showed that one of the endophytes marked as FS-01 had good antifungal effects and the inhibitory rates of FS-01 strain to A. panax was( 60. 21±0. 12) %.The hyphae junction of the both strains,A. panax dissolved,broke and winded,while the hyphae of FS-01 strain remained normal. The inhibitory rates of non-sterilized FS-01 strain fermentation liqud was( 13. 94±0. 21) %. Strain FS-01 identified as Chaetomium globosum.
Alternaria ; pathogenicity ; Antibiosis ; Chaetomium ; classification ; isolation & purification ; Endophytes ; isolation & purification ; Fungicides, Industrial ; Panax ; microbiology ; Plant Diseases ; prevention & control

In order to find new source of antifungal agents, eleven cultivable endophytic fungi were isolated from the roots,stems and leaves of Chelidonium majus by traditional method. Seven of them were identified as Colletotrichum(L1, L2, L3, S1, S3, S4, S5), and three of them were identified as Fusarium(R1,R2,R3) by morphological features and molecular biological technology. The antifungal activity test showed that all the tested fungi displayed some inhibitory activity against five common plant pathogens(C. gloeosporioides, Curvularia lunata, Pyricularia oryza, Alternaria alternate and A. brassicae), and their inhibition rate of some test items were over 60%. Among them, R1, S2, S3 and S4 were more potent than others. This study enriches the understanding of endophytes from Ch. majus and provides a basis for the study of new microbial fungicides.
Alternaria ; pathogenicity ; Antibiosis ; Ascomycota ; pathogenicity ; Chelidonium ; microbiology ; Colletotrichum ; chemistry ; isolation & purification ; Endophytes ; chemistry ; isolation & purification ; Fusarium ; chemistry ; isolation & purification

Leaf blight is the main disease of Asarum. At present, chemical treatment is main measure for disease control, and there is no report on biological control. In order to achieve the biological control of Asarum leaf blight, the biocontrol strains with antagonistic effect on Asarum leaf blight were screened. The rhizosphere bacteria of healthy Asarum plants were isolated by soil dilution method, and the isolated strains were screened by the methods of antagonistic antifungal and fermentation liquid antifungal, then the strains were identified and the control effect in vivo was determined. Abiocontrol bacterial strains S2-31 which with high antagonism to leaf blight was obtained from more than 100 isolated strains. The inhibitory rates of antagonistic antifungal and fermentation liquid antifungal reached 92.47% and 60.56%, respectively. It was identified by morphology and 16 S rDNA sequence analysis, and the strain was identified as Brevibacillus laterosporus. The results of indoor potted experiment showed that the control effect was 79.87%, 71.44% and 66.82% on the 3 rd, 5 th and 7 th day after inoculation, respectively, which indicated that S2-31 could reduce the disease index and control the development of Asarum leaf blight.
Antibiosis ; Asarum/microbiology* ; Biological Control Agents ; DNA, Ribosomal ; Firmicutes ; Fungi/pathogenicity* ; Plant Diseases/prevention & control* ; Rhizosphere ; Soil Microbiology

To reveal the colonization characteristics in host of endophytic biocontrol bacteria NJ13 isolated from Panax ginseng, this study obtained the marked strain NJ13-R which was double antibiotic resistant to rifampicin and streptomycin through enhancing the method of inducing antibiotic. The colonization characteristics in ginseng and its biocontrol efficiency against Alternaria spot of ginseng in the field were studied. The results showed that the strain could colonize in root, stem and leaf of ginseng and the colonization amount was positive correlated with inoculation concentration. Meanwhile, the strain could infect and then transfer in different tissues of ginseng The colonization amount of strain in roots and leaves of ginseng increased first and then decreased. However, the tendency of colonization amount of strain in stems was ascend at first and then descend slowly, and was more than that in roots and leaves along with time, which had a preference to specific tissue of its host. In field experiment, the endophytic bacteria NJ13 was proved to be effective in controlling Alternaria leaf spot of ginseng. The biocontrol efficiency of fermentation broth at the concentration of 0.76 x 10(8) cfu x mL(-1) reached 75.62%, which was close to the controlling level (73.06%) of 0.67 mg x L(-1) 50% cyprodinil WG.
Alternaria ; physiology ; Antibiosis ; Bacillus ; growth & development ; isolation & purification ; physiology ; Endophytes ; growth & development ; isolation & purification ; physiology ; Panax ; growth & development ; microbiology ; Plant Diseases ; microbiology