Escherichia coli producing extended-spectrum beta-lactamase (ESBL) are antimicrobial- -resistant Enterobacteriaceae important in the livestock production sector, especially dairy cows because these antimicrobial-resistant bacteria can be transferred to consumers via consumption. If antimicrobials are continually used in dairy farms, this may result in antimicrobial resistance. Therefore, investigation of antimicrobial resistance and finding new alternative methods for inhibiting ESBL-producing E. coli is essential. Hence, the aim of this study was to examine the ability of selected antimicrobials to inhibit E. coli ATCC 25922, control bacteria and ESBL-producing E. coli isolated from dairy farms. We also investigated the capacity of polyphenol extract from 10 varieties of medicinal plants to inhibit ESBL-producing E. coli using a broth microdilution method. It was found that control bacteria were susceptible to all antimicrobial agents, i.e., ampicillin, cefotaxime, ciprofloxacin, chloramphenicol, gentamycin, imipenem, nalidixic acid, tetracycline, and sulfamethoxazole/ trimethoprim. However, ESBL-producing E. coli exhibited both susceptibility and resistance to selected antimicrobials. The polyphenol extracted from Psidium guajava Linn at the lowest concentration was 4.5 mg/mL, which could inhibit control bacteria, but at the same concentration could not inhibit ESBL-producing E. coli. These phenomena indicated that ESBL-producing E. coli had both susceptibility and resistance to antimicrobials. Polyphenol, which could inhibit non-resistant E. coli, could not inhibit ESBL-producing E. coli.

The aim of this study was to investigate the effect of aqueous extract from Scutellaria baicalensis Georgi roots (SB) on blood parameters and immune response during an experimental trichinellosis. A total of 60 mice infected with 200 Trichinella spiralis larvae were assigned into two groups. One of them served as a control and the second received SB extract orally from day 5 before infection to day 28 after infection (dpi). Blood was sampled at 7, 14, 21 dpi. Lymphocytes obtained from the spleen and mesenteric lymph nodes (MLN) at 7, 14, 21, and 28 dpi were counted, CD4+ and CD8+ subpopulations were analyzed by flow cytometry, and lymphocyte proliferation was estimated with colorimetric (MTT) assay. The intensity of intestinal and muscle invasion was also studied. SB caused a remarkable elevation of banded neutrophils in the blood at 7 dpi. SB increased ConA-stimulated splenocyte proliferation and CD4+ and CD8+ splenocyte subsets at 14 and 21 dpi, whereas MLN lymphocyte subset stimulation involved only CD4+ at 14 dpi. After administration of SB a downward trend in the number of T. spiralis larvae in the muscle was observed. These results suggest that Scutellaria baicalensis root extract stimu- lates murine cellular immune response during intestinal phase of T. spiralis infection.