No pārtikas produktiem izolētu E.coli virulences gēnu, serogrupu un antibiotiku jutīguma izpēte - Jakovele, Alise (Latvijas Universitāte, 2016)
Šajā pētījumā 72 E.coli paraugiem, kas izolēti no gaļas produktiem un diedzētiem graudiem, tika noteikta vtx1, vtx2 un eaeA gēnu klātbūtne, serogrupu sadalījums un antibiotiku rezistence. 91.67% paraugi nesaturēja nevienu no virulences gēniem, 8.33% saturēja intimīna gēnu (eaeA), no tiem 2,78% saturēja arī vtx1. Serogrupēšanas rezultātā tika atklāts, ka 29,17% paraugu nav konstatētas verotoksīnus producējošas serogrupas, 44,43% tika konstatēta O121 serogrupa, 9,71% - O103, 12,50% - pašaglutinējoši, 1,39% - serogrupas O26, O145 un O142. Kopumā 35 paraugi tika izolēti no diedzētiem graudiem un sēklām, 37 - no gaļas produktiem. 85,70% paraugu, kas izolēti no diedzētiem graudiem pieder pie serogrupas O121, kas ir statistiski nozīmīgi (p< 0.001), salīdzinot ar paraugiem, kas izolēti no gaļas produktiem, kuriem serogrupu sadalījums bija heterogēns. Antibiotiku rezistence tika noteikta ar MIC metodi pret 14 antibiotikām. No 72 paraugiem rezistenti pret vismaz vienu antibiotiku bija 17 paraugi (23,60%), kas visi bija izolēti gaļas produktiem. Visvairāk paraugu bija rezistenti pret tetraciklīnu (10 paraugi), ampicīnu (8 paraugi) un sulfametoksazolu (7 paraugi). Divi no paraugiem bija multirezistenti, kas bija rezistenti pret četrām antibiotiku klasēm. Tie bija pozitīvi arī uz mcr- 1 gēnu, kas nosaka kolistīna rezistenci.

In this research 72 E.coli samples, that were isolated from meat products and sprouted grain, were tested on presence of vtx1, vtx2 and eaeA genes antibiotic resistance and serogrouped. 91.67 % did not contain any of virulence genes, 8.33% contained intimin gene (eaeA), from those 2,78% contained additionally vtx1 gene. As a result of serogrouping 29,17% from samples did not contain verotoxin producing serogroups, 44,43% belonged to O121 serogroup, 9,71% - O103, 12,50% were self – agglutinating, 1,39% - belonged to serogroups O26, O145 and O142. Overall 35 samples were isolated from sprouted grain, 37 – from meet products. 85,70% from samples that were isolated from sprouted grain belonged to serogroup O121, which is statistically significant (p< 0.001) in comparison with samples isolated from meat, which had heterogenous division of serogroups. Antibiotic resistance was detected with MIC method against 14 diffrent antibiotics. From all 72 samples resistant against at least one antibiotic were 17 samples (23,60%), all of which were isolated from meat. The most samples were resistant against tetracycline (10 samples), ampicillin (8 samples), and sulfamethoxazole (7 samples). Two of the samples were multiresistant, they had resistance against four antibiotic classes. They contained mcr – 1 gene, that determines resistance against colistin.
Investigation of virulence genes, serogroups and antibiotic resistance of E.coli isolated from food
Keywords: Bioloģija; VTEC; vtx; eae; serogrupas; antibiotiku rezistence