Đánh giá hoạt lực của cao sen (nelumbo nucifera gaertn) trên vi khuẩn Escherichia coli gây tiêu chảy heo con trong phòng thí nghiệm

Abstract

Diarrhea is one of common symptom in piglets. This symptom is caused by many factors, one of them is E.coli. We studied more than 136 piglets at two different pig farms in Long Ho district, there were 78 piglets with diarrhea accounting for 57,35%. Isolation, cultivation and identification of E.coli from 46 diarrhea fecal samples, the result showed that the proportion of infected samples was 100% , with average density of E.coli was 140,95 x 10⁶ CFU/gram feces. Testing the susceptibility of E.coli to antibiotics by antimicrobial susceptibility testing methods presented that E.coli was susceptible to Norfloxacin (60,00%) and Enrofloxacin (50,00%), resistant to Streptomycin (60,00%) and Florfenicol (50,00%). Different parts of Nelumbo nucifera gaertn were extracted in ethanol to make jelly. The extracted jelly was used to study the resistance to E.coli by Kirby-Bauer method (Bauer et al., 1959; Bauer et al., 1966; Hudzicki, 2014). The experiment was set into three treatments: NT1: extracted jelly of lotus young leaves, NT2: extracted jelly of lotus older leaves, NT3: extracted jelly of lotus seed-pod, ĐC (-): negative control treatment (-) without extracted jelly and ĐC (+): possitive control treatment (+) with Amoxcixillin. The results showed that the resistance to E.coli of NT1, NT1 and NT3 at MIC = 128µg/ml was 25.5 ± 0.33, 14.6 ± 0.18; 7.0 ± 0.81, respectively. The resistance of extracted jelly of lotus young leaves was lower than commercial antibiotics like amoxicillin (MIC = 64µg/ml).