Publications (4) View all
-
Article: Molecular diversity among natural populations of Lactobacillus paracasei and Lactobacillus plantarum/paraplantarum strains isolated from autochthonous dairy products
[show abstract] [hide abstract]
ABSTRACT: The diversity of 87 Lactobacillus paracasei and Lactobacillus plantarum/paraplantarum strains, pre-viously identified from different autochthonous dairy products, was investigated by phenotypic and genotypic approaches. The increased resolution obtained using phe-notypic and genotypic characterization allowed the level of strain heterogeneity detection to be widened. Phenotypic diversity was evaluated by studying biochemical charac-teristics of technological interest, including antimicrobial and proteinase activities, resistance to nisin, aggregation ability, production of exopolysaccharides, acetoin and diacetyl, citrate utilization, and antibiotic susceptibility. Genotypic diversity was generally evaluated by PCR amplification of repetitive bacterial DNA element finger-printing using the (GTG) 5 primer [(GTG) 5 -PCR]. More-over, in cases where strains were not discriminated by (GTG) 5 -PCR combined with phenotypic analysis, pulsed-field gel electrophoresis (PFGE) analysis was performed. The results indicate that L. plantarum/paraplantarum and L. paracasei natural isolates from artisanal dairy products are a gold mine in terms of diversity of strains and could be potentially interesting to dairy companies for the formu-lation of functional starter cultures in the production of innovative foods.European Food Research and Technology 01/2012; 234:627-638. · 1.57 Impact Factor -
Article: Molecular typing and antimicrobial resistance of Salmonella Enteritidis isolated from poultry, food, and humans in Serbia.
[show abstract] [hide abstract]
ABSTRACT: Molecular typing and resistotyping coupled with gyrA single nucleotide polymorphism (SNP) of 60 Salmonella Enteritidis (SE) isolates originated from poultry, food, and humans in Serbia is described. Molecular fingerprinting was performed by randomly amplified polymorphic DNA (RAPD) using four primers, and the diversity index (D) was 0.688. In combination with resistotyping and gyrA SNP, D increased to 0.828. A total of 23 genetic groups were obtained. When four RAPD primers were combined, epidemic isolates from a fast-food restaurant outbreak were clustered in a distinctive genetic group. Among 60 SE strains, three had multiple resistances to three or more antibiotics. Nine strains were resistant to nalidixic acid (NAL; a non-fluorinated quinolone). The mutations in quinolone resistance-determining region (QRDR) found in NAL-resistant strains were attributed to Asp(87) → Asn in six strains, Asp(87) → Gly in one strain, and Ser(83) → Phe in one strain. One NAL-resistant strain had no mutations in QRDR, suggesting another mechanism of resistance.Folia Microbiologica 03/2011; 56(1):66-71. · 0.68 Impact Factor -
Article: Variation in specificity of the PrtP extracellular proteinases in Lactococcus lactis and Lactobacillus paracasei subsp. paracasei.
[show abstract] [hide abstract]
ABSTRACT: Comparison of cell-wall-bound extracellular proteinases (CEPs) from Lactobacillus paracasei (LBP) ssp. paracasei natural isolates BGHN14, BGAR75 and BGAR76 with Lactococcus lactis (LCL) ssp. cremoris Wg2, in their action on alpha(S1)-, beta- and kappa-casein was done. The CEPs of LBP strains were able to degrade alpha(S1)- and beta-caseins and their caseinolytic specificity depended on the type of buffer used. These CEPs, compared with LCL Wg2, differ in four amino acid residues in small segments predicted to be involved in substrate binding. The most striking features of this comparison are the presence of Ala instead of Ser(329) and the presence of Thr instead of Asn(256) and Ala(299), in the subtilisin-like region of the CEP in LBP natural isolates. Additional conservative amino acid substitution Leu to Ile(364) was found.Folia Microbiologica 02/2009; 54(3):188-94. · 0.68 Impact Factor -
Article: Casitone-dependent transcriptional regulation of the prtP and prtM genes in the natural isolate Lactobacillus paracasei subsp. paracasei.
[show abstract] [hide abstract]
ABSTRACT: The prtP-prtM intergenic region of Lactobacillus paracasei subsp. paracasei BGHN 14 was cloned and sequenced. The nucleotide sequence of the prtP-prtM intergenic region in BGHN 14, containing divergently orientated P(prtP) and P(prtP) promoters, was shorter by 35 bp in comparison with that in lactococci. The nucleotide sequence involved in casitone-dependent transcriptional regulation of the lactococcal prt genes was not found in the BGHN14. The activity of P(prtM) in L. lactis NZ9000 was very low and insignificantly changed in the presence of casitone, whereas P(prtP) was completely inactive. When L. casei ATCC393(T) was used as host, both P(prtP) and P(prtM) were active and strongly regulated by casitone. The results strongly indicate that the mechanisms of the casitone-dependent regulation of the prt genes in BGHN14 and lactococci are different.Folia Microbiologica 02/2007; 52(6):577-84. · 0.68 Impact Factor
