Development of a Brazilian maize core collection

The aim of this study was to evaluate methods for developing a Brazilian maize core collection. For an initial survey of the active collection, passport information, as well as characterization and evaluation of accessions, were taken into consideration, these then being divided according to geographic region and kernel-type. Multiple sampling methods were evaluated. The strategy of constant sampling generated extensive alterations in extract accession frequency. The multivariate strategy with dispersion graphs and principal components associated with the Tocher method was considered efficient for identifying the most divergent genotypes. The multivariate strategy generated greater alterations in the variance of traits. The average number of traits revealed few modifications with the various sampling strategies used. Therefore, the active collection could be considered as possessing a satisfactory amount of information for most of its accessions. Moreover, the multivariate strategy generated modifications in the variance of the traits, independent of sampling intensity

Resistência antimicrobiana nos principais recursos aquícolas dos departamentos de Tumbes, Piura, San Martin e Puno

[Objective] The objective of this study was to analyze antimicrobial resistance in Peruvian aquaculture. [Methodology] An observational, descriptive study was carried out. Samples of Argopecten purpuratus, Oncorhynchus mykiss, Oreochromis niloticus and Litopenaeus vannamei were included. The bacteria Enterococcus spp., Salmonella spp., Escherichia coli, Vibrio parahaemolyticus, Aeromonas spp., and Flavobacterium psychrophilum were isolated. Antibiotic resistance was evaluated using antibiograms, and resistant samples were sequenced to identify antimicrobial resistance genes. Absolute and percentage frequencies were calculated. In addition, Wald, Clopper-Pearson, and pooled prevalence confidence intervals were estimated. [Results] In the case of A. purpuratus, 22.2% (95% CI:2.81-60.00) of the E. coli samples were resistant to oxytetracycline. Resistant samples were found in 4.44% (n=2) of the aquaculture production centers (APCs). In O. mykiss, 88.89% (95% CI:51.16-99.72) of the Enterococcus spp. were resistant to fosfomycin and oxytetracycline. Resistant samples were found in12.96% of the APCs (n=7). Regarding O. niloticus, 47.31% (95% CI: 37.16-57.46) of the E. coli samples were resistant to oxytetracycline>ampicilline>chloramphenicol>fosfomycin and azithromycin. Resistant samples were encountered in 50% of the APCs (n=19). In addition, 89.36% (95% CI:80.55-98.18) of the Enterococcus spp. were resistant to Fosfomycin> chloranphenicol and colistin> oxytetracycline>azithromycin>ampicilline; resistant samples were found in 36.84% of the APCs (n=14). In L. vannamei, 87.11% (95% CI:83.00-91.21) of the Enterococcus spp. samples were resistant to Fosfomycin> colistin> oxytetracycline> azithromycin>ampicilline and resistant samples were found in 100% of the APCs (n=33). Likewise, 35.05% (95% CI:29.74-40.23) of the V. parahaemolyticus samples were resistant to ampicilline>fosfomycin>oxytetracycline>azithromycin>eritromicine>enrofloxacin> ampicilline> chloranfhenicol. Resistant samples were found in 78.79% (n=26) of the APCs. [Conclusions] The percentage of APCs with O. niloticus and L. vannamei showed that antimicrobial resistance was high.[Objetivo] El objetivo fue analizar la resistencia antimicrobiana en la acuicultura peruana. [Metodología] Se realizó un estudio observacional, descriptivo. Se incluyeron muestras de las especies Argopecten purpuratus, Oncorhynchus mykiss, Oreochromis niloticus y Litopenaeus vannamei. Se aislaron bacterias del género Enterococcus spp., Salmonella spp. y Aeromonas spp., y especies de Escherichia coli, Vibrio parahaemolyticus, y Flavobacterium psychrophilum. La resistencia antimicrobiana fue evaluada mediante antibiograma y las muestras resistentes fueron secuenciadas para identificar genes de resistencia antimicrobiana. Se calculó la frecuencia absoluta y porcentual, además, se estimaron los intervalos de confianza de Wald, de Clopper-Pearson, y prevalencia agrupada. [Resultados] Respecto a A. purpuratus, el 22,2 % (IC95%:2,81-60,00) de las muestras de E. coli fueron resistentes a oxitetraciclina. Estas pertenecían al 4,44 % (n=2) de los centros de producción acuícola (CPA). En O. mykiss, el 88,89% (IC95%:51,16-99,72) de las muestras de Enterococcus spp. fueron resistentes a fosfomicina y oxitetraciclina. Estas pertenecían al 12,96 % de los CPA (n=7). En referencia a O. niloticus, el 47,31 % (IC95%: 37,16-57,46) de las muestras de E. coli fueron resistentes oxitetraciclina>ampicilina>cloranfenicol>fosfomicina y azitromicina. Estas pertenecían al 50 % de los CPA (n=19). Además, 89, 36% (IC95 %:80,55-98,18) de las muestras de Enterococcus spp. fueron resistentes a fosfomicina>cloranfenicol y colistina>oxitetraciclina>azitromicina>ampicilina; estas pertenecían al 36,84 % de los CPA (n=14). En L. vannamei, el 87,11 % (IC95%:83,00-91,21) de las muestras de Enterococcus spp. fueron resistentes a fosfomicina>colistina>oxitetraciclina>azitromicina>eritromicina>enrofloxacino> ampicilina>cloranfenicol y estas pertenecían al 100 % de los CPA (n=33). Asimismo, 35,05 % (IC95%: 29,74-40,23) de las muestras de V. parahaemolyticus fueron resistentes a ampicilina>fosfomicina>colistina>oxitetraciclina>azitromicina. Estas pertenecían al 78,79 % (n=26) de los CPA. [Conclusiones] El porcentaje de CPA de O. niloticus y L. vannamei, mostraron mayor resistencia antimicrobiana del estudio.[Objetivo] O objetivo foi analisar a resistência antimicrobiana na aquicultura peruana. [Metodologia] Foi realizado um estudo observacional, descritivo. Foram incluídas amostras das espécies Argopecten purpuratus, Oncorhynchus mykiss, Oreochromis niloticus e Litopenaeus vannamei.   Foram isoladas bactérias dos gêneros Enterococcus spp., Salmonella spp., Aeromonas spp., e espécies de Escherichia coli, Vibrio parahaemolyticus e Flavobacterium psychrophilum. A resistência antimicrobiana foi avaliada por meio de antibiograma, e amostras resistentes foram sequenciadas para identificar genes de resistência antimicrobiana. Foram calculadas as frequências absoluta e percentual, além dos intervalos de confiança de Wald, Clopper-Pearson e as prevalências agrupadas. [Resultados] Em relação a A. purpuratus, 22,2% (IC 95%: 2,81-60,00) das amostras de E. coli foram resistentes à oxitetraciclina. Estes pertenciam a 4,44 % (n=2) dos centros de produção aquícola (CPA). Em O. mykiss, 88,89% (IC 95%: 51,16-99,72) das amostras de Enterococcus spp. foram resistentes à fosfomicina e oxitetraciclina.  Estas pertenciam a 12,96% das CPAs (n=7). Em relação a O. niloticus, 47,31 % (IC 95%: 37,16-57,46) das amostras de E. coli foram resistentes à oxitetraciclina>ampicilina>cloranfenicol>fosfomicina e azitromicina. Estas pertenciam a 50% das CPAs (n=19). Além disso, 89,36% (IC95%: 80,55-98,18) das amostras de Enterococcus spp. foram resistentes a fosfomicina>cloranfenicol e colistina>oxitetraciclina>azitromicina>ampicilina; estas pertenciam a 36,84% das CPAs (n=14). Em L. vannamei, 87,11% (IC 95%: 83,00-91,21) das amostras de Enterococcus spp foram resistentes à fosfomicina>colistina>oxitetraciclina>azitromicina>eritromicina>enrofloxacina> ampicilina>cloranfenicol e pertenciam a 100% das CPAs (n=33). Além disso, 35,05% (IC 95%: 29,74-40,23) das amostras de V. parahaemolyticus foram resistentes à ampicilina>fosfomicina>colistina>oxitetraciclina>azitromicina. Estas pertenciam a 78,79% (n=26) das CPAs. [Conclusões] A porcentagem de CPA de O. niloticus e L. vannamei, mostrou maior resistência antimicrobiana do estudo