Characterization of Erythromycin and Tetracycline Resistance in Lactobacillus fermentum Strains

Abstract

Lactobacillus fermentum colonizing gastrointestinal and urogenital tracts of humans and animals is widely used in manufacturing of fermented products and as probiotics. These bacteria may function as vehicles of antibiotic resistance genes, which can be transferred to pathogenic bacteria. Therefore, monitoring and control of transmissible antibiotic resistance determinants in these microorganisms is necessary to approve their safety status. The aim of this study was to characterize erythromycin and tetracycline resistance of L. fermentum isolates and to estimate the potential transfer of resistance genes from lactobacilli to the other Gram-positive and Gram-negative bacteria. Among six L. fermentum strains isolated from human feces and commercial dairy products, five strains demonstrated phenotypic resistance to tetracycline. PCR screening for antibiotic resistance determinants revealed plasmid-located tetracycline resistance genes tet(K) and tet(M) in all strains and erythromycin resistance genes erm(B) in the chromosome of L. fermentum 5-1 and erm(C) in the plasmid of L. fermentum 3-4. All tested lactobacilli lacked conjugative transposon Tn916 and were not able to transfer tetracycline resistance genes to Staphylococcus aureus, Staphylococcus epidermidis, Listeria monocytogenes, Acinetobacter baumannii, Citrobacter freundii, and Escherichia coli by filter mating. Staphylococcus haemolyticus did not accept erythromycin resistance genes from corresponding Lactobacillus strains. Thus, in the present study, L. fermentum was not implicated in the spread of erythromycin and tetracycline resistance, but still these strains pose the threat to the environment and human health because they harbored erythromycin and tetracycline resistance genes in their plasmids and therefore should not be used in foods and probiotics.

Lactobacillus commensals autochthonous to human milk have the hallmarks of potent probiotics

“…The safety standards of the European Food Safety Authority (EFSA) [82] and the generally recognized as safeGenerally Recognized as Safe (GRAS) designation of the US Food and Drug Administration (FDA) [83] demand stringent safety assessments of candidate probiotics [84]. In furtherance of this, virulence traits such as haemolysis and gelatinase were checked through functional assaying and found to be absent in NPL-99.…”

Antibiotics susceptibility patterns of Citrobacter freundii isolated from pa-tients with urinary tract infection in Al-Najaf governorate – Iraq

“…The most of isolates in this study showed an obvious resistance to chloramphenicol antibiotic. The target modifying may also contribute to chloramphenicol resistance, the efflux pump that is throwing away this antibiotic, causing decreasing of antibiotic concentration inside the bacterial cell (Anisimova and Yarullina 2018). The bacterial cell that has an ability to resisting the tetracycline antibiotic by many mechanisms such as hydrolyzing enzymes encoding by tet(X) genes, efflux pumps (A-E) types (Leski et al, 2016).…”

Whole genome sequence data of Lactobacillus fermentum HFD1, the producer of antibacterial peptides

“…For the genotyping, the genomic DNA of isolate was purified by using diaGene bacterial DNA extraction kit (Dia-M, Russia) from 10 ml of 24 h old culture grown under static anaerobic conditions. Then the gene of 16S rRNA was amplified by using universal 16S rRNA bacterial primers 27F (5′-GAG TTT GAT CCT GGC TCA G-3′) and 1392R (5′ ACG TT CC TG TA GA TT-3′) and Q5 DNA polymerase and sequenced (Evrogen JSC, Moscow) [15] , [16] , [17] , [18] . Species were identified on the basis of 16S rRNA gene sequences similarity obtained by its alignment with NCBI database using BLAST algorithm ( https://www.ncbi.nlm.nih.gov/BLAST ).…”