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This study aimed to evaluate antimicrobial resistance, virulence, and the genetic diversity of Aeromonas isolated from migratory birds from Guangxi Province, Guangdong Province, Ningxia Hui Autonomous Region, Jiangxi Province, and Inner Mongolia in China. A total of 810 samples were collected, including fresh feces, cloacal swabs, and throat swabs. The collected samples were processed and subjected to bacteriological examination. The resistance to 21 antibiotics was evaluated. A phylogenetic tree was constructed using concatenated gltA-groL-gyrB-metG-PPSA-recA sequences. Eight putative virulence factors were identified by PCR and sequencing, and a biofilm formation assay was performed using a modified microtiter plate method. In total, 176 Aeromonas isolates were isolated including A. sobria, A. hydrophila, A. veronii, and A. caviae. All isolates showed variable resistance against all 16 tested antibiotic discs, and only one antibiotic had no reference standard. Six kinds of virulence gene markers were discovered, and the detection rates were 46.0% (hlyA), 76.1% (aerA), 52.3% (alt), 4.5% (ast), 54.0% (fla), and 64.2% (lip). These strains were able to form biofilms with distinct magnitudes; 102 were weakly adherent, 14 were moderately adherent, 60 were non-adherent, and none were strongly adherent. Our results suggest that migratory birds carry highly virulent and multidrug-resistant Aeromonas and spread them around the world through migration, which is a potential threat to public health.

The aim of the experiment was to study the nutrient composition and fermentation quality of mixed silage of corn straw and potato starch residue in different proportions. Using the corn stalk and potato starch residue as raw materials, the experiment adopted a two-factor experimental design, taking different mixing ratios of raw materials (CKB1, CKB2, CKB3) and different mixing ratios after adding bacteria (AB1, AB2, AB3) as treatments. The conventional nutrition and fermentation quality of mixed silage was analyzed after 30 days. The results showed that the interaction of different raw material ratios and bactericides had significant effects on pH values, lactic acid, acetic acid, acid detergent fiber and ammonia nitrogen/total nitrogen content of silage (P<0.05). Under the same mixing ratio of raw materials, the addition of bactericides could increase the lactic acid content of silage (P<0.05), and decrease the pH value, acetic acid and ammonia nitrogen/total nitrogen content (P<0.05). Under the same treatment, the concentration of crude protein and soluble carbohydrate and relative feeding value of silage decreased, while the concentration of neutral detergent fiber, acid detergent fiber and crude ash increased. The concentration of dry matter, crude ash, soluble carbohydrate, pH value, crude protein, neutral detergent fiber and acid detergent fiber and their relative feeding value were significantly affected by different raw material ratios (P<0.05). The study indicates that potato starch residue to corn straw is 7:3, and the better silage effect is obtained by adding bactericide. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate antimicrobial resistance, virulence, and the genetic diversity of Aeromonas isolated from migratory birds from Guangxi Province, Guangdong Province, Ningxia Hui Autonomous Region, Jiangxi Province, and Inner Mongolia in China. A total of 810 samples were collected, including fresh feces, cloacal swabs, and throat swabs. The collected samples were processed and subjected to bacteriological examination. The resistance to 21 antibiotics was evaluated. A phylogenetic tree was constructed using concatenated gltA-groL-gyrB-metG-PPSA-recA sequences. Eight putative virulence factors were identified by PCR and sequencing, and a biofilm formation assay was performed using a modified microtiter plate method. In total, 176 Aeromonas isolates were isolated including A. sobria, A. hydrophila, A. veronii, and A. caviae. All isolates showed variable resistance against all 16 tested antibiotic discs, and only one antibiotic had no reference standard. Six kinds of virulence gene markers were discovered, and the detection rates were 46.0% (hlyA), 76.1% (aerA), 52.3% (alt), 4.5% (ast), 54.0% (fla), and 64.2% (lip). These strains were able to form biofilms with distinct magnitudes; 102 were weakly adherent, 14 were moderately adherent, 60 were non-adherent, and none were strongly adherent. Our results suggest that migratory birds carry highly virulent and multidrug-resistant Aeromonas and spread them around the world through migration, which is a potential threat to public health. [ABSTRACT FROM AUTHOR]

We collected the experimental dataset of a spring-maize in Hetao irrigation district (Bayannaoer, Inner Mongolia) during 2012 and 2013, as well as the crop data observed in related agrometeorological stations to investigate the impacts of light and temperature variation on maize development during the seedling stage to derive adequate light and temperature indices for different suitability. Furthermore, polynomial fitting was applied to interpolate the temperature indices for each day of the whole seedling period to draw the dynamics of the temperature indices and to better characterize its influence on maize development during the seedling stage. The results suggested that the emergence and development rates increased by 11% and 12%, respectively when the average temperature increased 1 °C during the sowing-emergence period and emergence-jointing period, and the biological lowest temperature was 7.4 and 11.9 °C, respectively. The optimum temperature at the sowing-emergence stage ranged from 16.0 to 18.0 °C, and the leaf area index at the three-leaf stage reached 0.0172 and above. The optimum temperature at the emergence-jointing stage ranged from 21.6 to 23.0 °C, and the photosynthesis/growth of plant tissue was positively correlated with the temperature. The leaf area index in the jointing period could reach 2.15 and the plant height was 120 cm. At the emergence-jointing stage, when the sunshine percentage ≥74%, or the daily sunshine hours ≥11.0 h • d-1, or the total sunshine hours ≥540 h, the dry mass of plant tissue could reach more than 34 g. [ABSTRACT FROM AUTHOR]

We collected the experimental dataset of a spring-maize in Hetao irrigation district (Bayannaoer, Inner Mongolia) during 2012 and 2013, as well as the crop data observed in related agrometeorological stations to investigate the impacts of light and temperature variation on maize development during the seedling stage to derive adequate light and temperature indices for different suitability. Furthermore, polynomial fitting was applied to interpolate the temperature indices for each day of the whole seedling period to draw the dynamics of the temperature indices and to better characterize its influence on maize development during the seedling stage. The results suggested that the emergence and development rates increased by 11% and 12%, respectively when the average temperature increased 1 °C during the sowing-emergence period and emergence-jointing period, and the biological lowest temperature was 7.4 and 11.9°C , respectively. The optimum temperature at the sowing-emergence stage ranged from 16.0 to 18.0°C , and the leaf area index at the three-leaf stage reached 0.0172 and above. The optimum temperature at the emergence-jointing stage ranged from 21.6 to 23.0°0C , and the photosynthesis/growth of plant tissue was positively correlated with the temperature. The leaf area index in the jointing period could reach 2.15 and the plant height was 120 cm. At the emergence-jointing stage, when the sunshine percentage 74%, or the daily sunshine hours ≥11.0 h . d-1 , or the total sunshine hours ≥540 h, the dry mass of plant tissue could