Related Experiment Video
Updated: Aug 30, 2026

Genotyping of Staphylococcus aureus by Ribosomal Spacer PCR (RS-PCR)
Published on: November 4, 2016
Occurrence of Enterococci in Mastitic Cow's Milk and their Antimicrobial Resistance
Hanna Różańska1, Aleksandra Lewtak-Piłat2, Maria Kubajka1
1Department of Microbiology, 24-100 Puławy, Poland.
Introduction:
The aim of the study was to evaluate the occurrence of enterococci in inflammatory secretions from mastitic bovine udders and to assess their antimicrobial resistance.
Material And Methods:
A total of 2,000 mastitic milk samples from cows were tested in 2014-2017. The isolation of enterococci was performed by precultivation in buffered peptone water, selective multiplication in a broth with sodium azide and cristal violet, and cultivation on Slanetz and Bartley agar. The identification of enterococci was carried out using Api rapid ID 32 strep kits. The antimicrobial susceptibility was evaluated using the MIC technique.
Results:
Enterococci were isolated from 426 samples (21.3%). Enterococcus faecalis was the predominant species (360 strains), followed by E. faecium (35 isolates), and small numbers of others. The highest level of resistance was observed to lincomycin, tetracycline, quinupristin/dalfopristin (Synercid), erythromycin, kanamycin, streptomycin, chloramphenicol, and tylosin. Single strains were resistant to vancomycin and ciprofloxacin. All isolates were sensitive to daptomycin. E. faecalis presented a higher level of resistance in comparison to E. faecium, except to nitrofurantoin.
Conclusion:
The results showed frequent occurrence of enterococci in mastitic cow's milk and confirmed the high rate of their antimicrobial resistance.
More Related Videos
08:58Isolation and Identification of Waterborne Antibiotic-Resistant Bacteria and Molecular Characterization of their Antibiotic Resistance Genes
Published on: March 3, 2023
09:44Characterization of a Pathogenic Escherichia coli Strain Derived from Oreochromis spp. Farms Using Whole-Genome Sequencing
Published on: December 23, 2022
Related Concept Videos
Antibiotic Selection
Surface Membrane Barriers
The outer layer of the skin, the epidermis, is a robust barrier comprising layers of closely packed keratinized cells. This dense arrangement prevents microbes from penetrating the body. The periodic shedding of epidermal cells...
Antimicrobial Effectiveness
Development of Antibiotic Resistance
Mechanism of Antibiotic Resistance in MRSA
Clinical Significance of Antibiotic Resistance