Publications by authors named "Zoltan Urshev"

During the last few decades, the main focus of numerous studies has been on the human breast milk microbiota and its influence on the infant intestinal microbiota and overall health. The presence of lactic acid bacteria in breast milk affects both the quantitative and qualitative composition of the infant gut microbiota. The aim of this study was to assess the most frequently detected cultivable rod-shaped lactobacilli, specific for breast milk of healthy Bulgarian women and fecal samples of their infants over the first month of life, in 14 mother-infant tandem pairs.

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is a major cause of bacterial spot disease in various crops. The present study was focused on the pathosystem pepper ( L.) - 269p (wild strain).

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The present study was focused on the pathosystem pepper plants ( L.)-phytopathogenic bacterium (wild strain 269p)-bacteriophage BsXeu269p/3 and the possibility of bacteriophage-mediated biocontrol of the disease. Two new model systems were designed for the monitoring of the effect of the phage treatment on the infectious process in vivo.

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Article Synopsis
  • Yersiniosis is the third most reported foodborne illness in the EU, prompting a study on healthy pigs in Bulgaria to assess the prevalence of pathogenic Yersinia.
  • A total of 601 pigs were tested, revealing that 6.7% of their tonsils and feces contained pathogenic Yersinia, specifically bioserotype 4/O:3, with significant genetic homogeneity among isolates.
  • The bacteria were mostly susceptible to several antibiotics but resistant to ampicillin, indicating a low prevalence in healthy pigs while still posing a potential risk for pork contamination for consumers.
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Bacteriophages have greatly engaged the attention of scientists worldwide due to the continuously increasing resistance of phytopathogenic bacteria to commercially used chemical pesticides. However, the knowledge regarding phages is still very insufficient and must be continuously expanded. This paper presents the results of the isolation, characterization, and evaluation of the potential of 11 phage isolates as natural predators of a severe phytopathogenic bacterium-.

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Introduction: The gram-negative bacterium Porphyromonas gingivalis is a major causative agent of periodontitis in adults. It is also associated with disorders of the cardiovascular and endocrine systems, rheumatoid arthritis, pancreatic cancer, and Alzheimer's disease. Lactic acid bacteria (LAB) present in the oral cavity or introduced as probiotic preparations can support successful treatment of periodontitis due to their antagonism with the pathogen.

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The urgent need of research of new approaches to control bacterial disease on economical important crops, focuses our attention on bacteriophages as alternative biocontrol agents. Thus, the purpose of this paper is to present the isolation and initial characterization of three bacteriophages (SfXv124t/1, 2 and 3) isolated from rhizosphere soil of a healthy tomato plant in Bulgaria that are capable to lyse three phytopathogenic bacteria. The initial characterization includes determination of: their host range, plaque morphology, optimal storage temperature of pure phage lysates, their sensitivity to UV light, thermal inactivation, optimal multiplicity of infection (MOI) and virion morphology.

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In lactobacilli the aggregation phenotype is linked to their ability to colonize the intestinal and urogenital tracts and to counteract pathogenic bacteria. In all available complete genome sequences of Lactobacillus delbrueckii ssp. bulgaricus there are at least two genes putatively related to aggregation, one of which is annotated as aggregation-promoting factor (apf).

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Pulsed-field gel electrophoresis (PFGE) is a highly discriminative molecular typing method that is used for epidemiological studies and investigation of outbreaks caused by different pathogens, including phytopathogenic Xanthomonas species. Bacterial spot (BS) is the most common and one of the most destructive diseases of tomato and pepper plants in Bulgaria. Several Xanthomonas species are known to cause BS, but the global distribution and genetic diversity of these species are not well understood.

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Lactobacillus delbrueckii subsp. bulgaricus LBB.B5 originates from homemade Bulgarian yogurt and was selected for its ability to form a strong association with Streptococcus thermophilus The genome sequence will facilitate elucidating the genetic background behind the contribution of LBB.

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Among cultures, the principle component of yoghurt and cheese starters, a minority of strains forms the group of 'H'-strains which show an unusually high acidification rate, grow faster and coagulate milk 3-5 hours earlier than the typical cultures. A large-scale screening study was performed to select 'H'-strains of from more than 100 samples of home-made yoghurt, industrial yoghurt starters and single cultures, maintained in the LBB culture collection. Only four strains - LBB.

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The aim of this study was to characterize genetically Bulgarian Erwinia amylovora strains using pulsed-field gel electrophoresis (PFGE) analysis. Fifty E. amylovora strains isolated from different hosts, locations, as well as in different years were analysed by PFGE after XbaI, SpeI, and XhoI digestion of the genomic DNA.

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A new Lactococcus lactis subsp. lactis B84, capable of utilizing starch as a sole carbon source and producing L(+)-lactate, was isolated from spontaneously fermented rye sourdough. Aiming at maximum lactic acid productivity, the components of the media and the cultivation conditions were varied.

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The neutral exopolysaccharide produced by Lactobacillus delbrueckii ssp. bulgaricus LBB.B332 in skimmed milk was found to be composed of d-glucose, d-galactose, and l-rhamnose in a molar ratio of 1:2:2.

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The neutral exopolysaccharide produced by Lactobacillus delbrueckii ssp. bulgaricus LBB.B26 in skimmed milk was found to be composed of d-glucose and d-galactose in a molar ratio of 2:3.

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