Abstract:
Probiotics have proven its efficacy in improving digestion, prevention of colon cancer and
improving lactose intolerance. However, throughout the last decade the emerging crisis of
antibiotic resistance arouse and threatened the use of probiotic, since their ability to act as reservoir
for transferable antibiotic resistance genes. This study aims at identification and characterization
of the transmissible antibiotic resistance genes in lactobacillus sp. isolated from products in the
Egyptian Market. Twenty four dairy products were collected from factories, and milk shops then
Lactobacillus sp. were isolated from samples on MRS agar. The antimicrobial susceptibility of
isolates was measured by determining the minimum inhibitory concentration against
chloramphenicol, tetracycline, and erythromycin by microbroth dilution method. Twenty four
Lactobacillus sp. isolates were recovered from samples including Lactobacillus acidophilus and
Lactobacillus casei. Lactobacillus sp. isolates showed highest resistance towards chloramphenicol
followed by erythromycin and tetracycline. Tetracycline resistance was higher in dairy products
from factories 33% (4/12) than those obtained from milk shops 30 % (3/10). The chloramphenicol
resistance transferable gene (cat) was detected in (5/22) 22.7% of chloramphenicol resistant
isolates; Transferable erythromycin resistance genes (ermB) and (ermC) genes were detected in
(3/13) 23% and (6/13) 46.15 % of erythromycin resistant isolates. The prevalence of tetracycline
resistance genes tet M, tet O, tet W, tet K, and tet L genes were 28.5%, 14.28%, 14.28%, 14.28 %
and 14.28% and (int) genees responsible for transposon mediated transfer is detected
accompanying (tetM) in L.casei isolated from raw cow milk , respectively. In conclusion,
Lactobacillus sp. in Egyptian dairy products can act as a potential reservoir for antibiotic resistance
gene which highlights the importance of screening these beneficial bacteria for antibiotic
resistance and minimizing antibiotic consumption in dairy animals.
