Metabolic and genomic analysis deciphering biocontrol potential of endophytic Streptomyces albus RC2 against crop pathogenic fungi.

Plant diseases caused by phytopathogenic fungi are one of the leading factors affecting crop loss. In the present study, sixty-one Streptomyces strains were screened for their antifungal activity against relevant wide range fungal pathogens prominent in Vietnam, namely Lasiodiplodia theobromae, Fusarium fujikuroi, and Scopulariopsis gossypii. Endophytic strain RC2 was the most effective strain in the mycelial inhibition of the tested fungi. Based on phenotypic characteristics, 16S rDNA gene analysis, and genomic analysis, strain RC2 belonged to Streptomyces albus. An ethyl acetate extract of S. albus RC2 led to the strong growth inhibition of S. gossypii Co1 and F. fujikuroi L3, but not L. theobromae N13. The crude extract also suppressed the spore germination of S. gossypii Co1 and F. fujikuroi L3 to 92.4 ± 3.2% and 87.4% ± 1.9%, respectively. In addition, the RC2 extract displayed potent and broad-spectrum antibacterial activity against Escherichia coli, Pseudomonas aeruginosa, and the phytopathogenic bacteria Ralstonia solanacearum and Xanthomonas oryzae. The genome of strain RC2 was sequenced and revealed the presence of 15 biosynthetic gene clusters (BGCs) with similarities ≥ 45% to reference BGCs available in the antiSMASH database. The UPLC-HRMS analysis led to the identification of 8 other secondary metabolites, which have not been reported in S. albus. The present study indicated that RC2 could be a potent biocontrol agent against phytopathogenic fungi. Further attention should be paid to antifungal metabolites without functional annotation, development of product prototypes, and greenhouse experiments to demonstrate effective control of the plant diseases.

Non-invasive assessment of physiological stress in captive common palm civets (Paradoxurus hermaphroditus) in Vietnam

Common Palm Civet (Paradoxurus hermaphroditus) is a rare mammal appearing in South and Southeast Asia, first described in 1777. An expensive coffee is made of beans eaten and rejected by civets. In Vietnam, the animals are increasingly captured and kept captive to sell these beans, which has adversely affected their population. Because of the detrimental effects of stress, studying stress responses is important for this wildlife conservation. The stress response of the Common Palm Civet was investigated through the concentration of glucocorticoid hormones in feces under different conditions such as translocation and forced-pairing during the breeding season, among others. This is a non-invasive method for measuring glucocorticoid hormones in captive Common Palm Civet in Vietnam. Our results validated that fecal glucocorticoid metabolites (FGM) accurately reflect circulating glucocorticoid stress hormones in Common Palm Civet. FGM increased under adrenocorticotropic hormone stimulation and during the breeding season (April and NovemberDecember). FGM during estrus and parturition was high as well in female civets. Stress response was also observed in case of forced-pairing or residence change. These data could be useful for research and the conservation of this species.

Screening of Endophytic Bacteria Isolated from Weed Plant to Biocontrol Stem Rot Disease on Pitaya (Hylocereus undatus)

Abstract Endophytic bacteria from weed are emerging as valuable alternatives for biochemical pesticides in sustainable agriculture. This study aims to discover the antagonistic effects of some endophytic bacteria isolated from weed (Lactuca indica) against A. alternata, a casual of stem end rot disease of pitaya. A total of 14 endophytic bacteria were isolated and four of them presented in vitro antagonistic activity against A. alternata. Of four, strain L115 significantly inhibited the pathogenic growth with a mean inhibition diameter of 12.67 ± 0.02 mm, while the other three (strain L110, L111, and L114) showed a weak inhibition. The results indicated that strain L115 could belong to the Bacillaceae family while the other three (strain L110, L111, and L114) had characteristics of the Pseudomonadaceae family. Interestingly, strain L115 showed positive results for phosphate solubilization, indole acetic acid (IAA), and biofilm production, whereas three other strains presented weak capabilities for phosphate solubilization, biofilm production and IAA production. In addition, the filtrate of strain L115 presented antifungal activity on biocontrol tests in vitro. Especially, strain L115 significantly increased seedling biomass of pitaya and tomato compared to the control. Hence, these results suggest strain L115 has the potential to be used as biocontrol agents against A. alternata. More studies should be done in the future to evaluate their efficiency in field conditions.

Normal Values and Associated Factors in Highresolution Anorectal Manometry in Healthy Vietnamese Adults / Valores normais e fatores associados na manometria anorretal de alta resolução em adultos vietnamitas saudáveis

Abstract Introduction The present study aims to identify normal high-resolution anorectal manometry (HRAM) values and related factors in healthy Vietnamese adults. Methods The present cross-sectional study was conducted at the Viet Duc hospital, Hanoi, Vietnam, during April and May 2019. Healthy volunteers were recruited to participate in the study. Anorectal measurement values from the digestive tract, including pressure, were recorded. Results A total of 76 healthy volunteers were recruited. The mean functional anal canal length was 4.2 ± 0.5 cm, while the mean anal high-pressure zone length was 3.4 ± 0.5 cm. Themean defecation index was 1.4 ± 0.8, with values ranging from 0.3 to 5.0. The mean threshold volume to elicit the rectoanal inhibitory reflex (RAIR) was 18.1 mL. The mean rectal sensation values were 32.4mL, 81.6mL, and 159 mL for first sensation, desire to defecate, and urge to defecate, respectively. Dyssynergic patterns occurred in ~ 50% of the study participants and included mainly types I (27.6%) and III (14.6%). There were significant differences between male and female patients in terms of maximum anal squeeze pressure, maximum anal cough pressure, maximum anal strain pressure, maximum rectal cough pressure, and maximum rectal strain pressure (all p<0.01). Conclusions The present study establishes normal HRAM values in healthy Vietnamese adults, particularly regarding normal values of anorectal pressure and rectal sensation. Further studies that include larger sample sizes should be conducted to further confirm the constants and their relationships.

Resumo Introdução O presente estudo tem como objetivo identificar valores normais de manometria anorretal de alta resolução e fatores relacionados em adultos vietnamitas saudáveis. Métodos O presente estudo transversal foi conduzido no hospital Viet Duc, Hanói, Vietnã, durante abril e maio de 2019. Voluntários saudáveis foram recrutados para participar do estudo. Valores de medição anorretal, incluindo pressão do trato digestivo, foram registrados. Resultados Um total de 76 voluntários saudáveis foram recrutados. O comprimento funcional médio do canal anal foi de 4,2 ± 0,5 cm, enquanto o comprimento médio da zona anal de alta pressão foi de 3,4 ± 0,5 cm. O índice médio de defecação foi de 1,4 ± 0,8, com valores variando de 0,3 a 5,0. O volume limite médio para eliciar o reflexo inibitório retoanal (RAIR, sigla em inglês) foi de 18,1 mL. Os valores médios da sensação retal foram 32,4mL, 81,6mL e 159 mL para a primeira sensação, o desejo de defecar e a urgência de defecar, respectivamente. Os padrões dissinérgicos ocorreram em aproximadamente 50% dos participantes do estudo e incluíram principalmente os tipos I (27,6%) e III (14,6%). Houve diferenças significativas entre homens e mulheres na pressão de compressão anal máxima, pressão de tosse anal máxima, pressão de distensão anal máxima, pressão de tosse retal máxima e pressão de distensão retal máxima (todos p<0,01). Conclusões O presente estudo estabelece valores normais de HRAM em adultos vietnamitas saudáveis, particularmente no que diz respeito aos valores normais de pressão anorretal e sensação retal. Mais estudos que incluam tamanhos de amostra maiores devemser realizados a fim de confirmar melhor as constantes e suas relações.