Impacto do uso de antibióticos na microbiota do solo
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Data
2016-12-09
Autores
Gallego, Jefferson Cerquera [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
Devido ao grande número de antibióticos de uso veterinário que estão sendo liberados no solo através da urina e dejetos fecais dos animais de produção, algumas pesquisas têm verificado o impacto desses antibióticos na microbiota do solo. O presente estudo teve como objetivo avaliar o impacto dos antibióticos sobre a microbiota do solo em condições de microcosmos, de um solo de pastagem de bovinos e um solo de floresta, submetidos à presença de três antibióticos utilizados na produção animal, sendo estes, ampicilina, enrofloxacina e estreptomicina, nas concentrações de 0, 30 e 100 mg/kg de solo seco. A concentração de 0 mg/kg foi usada como controle. Os solos foram incubados em frascos de vidro de tampa rosca e mantidos a temperatura ambiente no escuro para reproduzir as condições reais encontradas na natureza. Foram avaliadas atividade respiratória microbiana, atividade da enzima desidrogenase e contagem de unidades formadoras de colônias (UFC) para estabelecer se existia ou não inibição do crescimento bacteriano nos dias 0, 1, 20 e 35. Os resultados mostram um aumento considerável nas UFC nos solos que receberam a ampicilina em ambas às concentrações durante o primeiro dia com relação ao controle. No dia 35 estas contagens se tornaram semelhantes ao controle ou menores. Os solos que receberam enrofloxacina e estreptomicina tiveram uma contagem menor que o controle inicialmente e com o tempo essas UFC aumentaram. A atividade respiratória microbiana e a atividade da enzima desidrogenase também confirmam esse achado. Esses resultados sugerem que os micro-organismos estão utilizando algum composto da ampicilina para o aumento das colônias e que os outros antibióticos diminuem a população microbiana do solo, especialmente a estreptomicina. Provavelmente alguns micro-organismos estejam sendo selecionados.
Due to the large number of veterinary antibiotics that are being released into the soil through urine and fecal waste of livestock, some research has linked the impact of those antibiotics in soil microflora. In the current study was evaluated the impact of antibiotics in the soil microbial community under microcosms conditions, cattle pasture soil and a forest soil under the presence of three antibiotics used in animal husbadry; ampicilin, enrofloxacyn and streptomycin, using a concentration of 0, 30 e 100 mg/kg dry soil. The concentration of 0mg/kg was used as control. The soils were incubated in screw cap glass jars and kept at room temperature in the dark to reproduce actual conditions found in nature. It was evaluated the microbial respiratory activity as well as the activity of dehydrogenase enzyme and colony forming units (CFU) to establish whether there was inhibition of bacterial growth or not at day 0, 1, 20 and 35. The results show a considerable increase in CFU in soils that received both concentrations of ampicillin during the first day compared with control. At day 35 these counting became similar to control or lower. The soils that received enrofloxacin and streptomycin, initially had lower countings than the control and over time these CFU increased. The microbial respiratory activity and the activity of dehydrogenase also confirmed these findings. These results suggest that some microorganisms are using a compound of ampicillin to grow. The other antibiotics decrease the soil microbial population, especially streptomycin. Probably some microorganisms are being selected.
Due to the large number of veterinary antibiotics that are being released into the soil through urine and fecal waste of livestock, some research has linked the impact of those antibiotics in soil microflora. In the current study was evaluated the impact of antibiotics in the soil microbial community under microcosms conditions, cattle pasture soil and a forest soil under the presence of three antibiotics used in animal husbadry; ampicilin, enrofloxacyn and streptomycin, using a concentration of 0, 30 e 100 mg/kg dry soil. The concentration of 0mg/kg was used as control. The soils were incubated in screw cap glass jars and kept at room temperature in the dark to reproduce actual conditions found in nature. It was evaluated the microbial respiratory activity as well as the activity of dehydrogenase enzyme and colony forming units (CFU) to establish whether there was inhibition of bacterial growth or not at day 0, 1, 20 and 35. The results show a considerable increase in CFU in soils that received both concentrations of ampicillin during the first day compared with control. At day 35 these counting became similar to control or lower. The soils that received enrofloxacin and streptomycin, initially had lower countings than the control and over time these CFU increased. The microbial respiratory activity and the activity of dehydrogenase also confirmed these findings. These results suggest that some microorganisms are using a compound of ampicillin to grow. The other antibiotics decrease the soil microbial population, especially streptomycin. Probably some microorganisms are being selected.
Descrição
Palavras-chave
Antibióticos veterinários, Comunidades microbianas, Microcosmos, Solo, Veterinary antibiotics, Microbial community, Microcosms, Soil