Molecular characterization of antibiotics resistance genes of enterococci isolated from raw milk in Assiut city [electronic resource]

Includes bibliographic reference.

Enterococcus species are Gram-positive cocci that are characterized by being catalase negative,
facultative anaerobic bacteria, and non-spore forming. Enteroccoi is often isolated
from environmental and animal sources and inhabits the human gastrointestinal tract.
Enterococcus species, which gets its resources from the dairy industry, animals, and people,
is one of the most abundant lactic acid bacteria in raw milk. The aim of the present study is
to detect antibiotic resistance of Enterococci isolated from raw milk by phenotypic and
genotypic methods. Vitek 2 Compact System was used to identify the samples and assess
their antimicrobial susceptibility. Following that, drug resistance genes (ermB, aph (3')-IIIa,
and TetM) and one virulence gene (esp) were molecularly detected by PCR. Twenty isolates
of Enterococci were phenotypically identified by routine laboratory examination and Vitek2.
High rates of antibiotic resistance were found to erythromycin and tetracycline with
percentages of 65% and 35%, respectively. The presence of tetM and ermB in milk isolates
was found to be 100%, similarly. No detection of aph (3′)IIIa was found in milk isolates. Esp
was detected only in 5% of isolated samples. The prevalence of Enterococci among studied
samples was 11.8% (20/170). The fact that Enterococci were resistant to erythromycin and
tetracycline in our study was noteworthy since these bacteria could potentially be transmitted
to people by drinking milk that has not been properly treated.
Key words: Enterococcoi, Vitek2, Resistant genes, PCR

Summary in Arabic