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Previously, we reported a positive effect the probiotic formulation, Lactobacillus acidophilus INMIA 9602 Er-2 strain 317/402 (Narine strain), had on the blood characteristics of patients with familial Mediterranean fever disease (FMF). The aim of this investigation was to evaluate the effect of the Narine probiotic on growth characteristics in the predominant commensal Escherichia coli isolates from the gut microbiota in FMF-positive study participants. Bacterial growth of 192 prevalent commensal E. coli isolates found in the volunteer participants' guts was evaluated using Verhulst's logistic function. This study showed that the duration of the preparatory growth phase for the E. coli isolates collected from FMF-positive volunteers was significantly shorter, whereas the duration of the logarithmic growth phase was significantly longer (P < 0·03) than that of the isolates collected from healthy participants. The Narine probiotic formulation caused a significant extension (P < 0·001) of the preparatory growth phase in the commensal E. coli isolated from FMF subjects a month after the Narine probiotic administration was terminated. The data suggest that the mathematical model characterizes the growth of commensal E. coli isolates from FMF-positive participants and it can be useful in a decision-making process on the practical use of probiotics during FMF., Significance and Impact of the Study: This is the first study to demonstrate the effects of Narine, containing the probiotic Lactobacillus acidophilus, on the growth of gut commensal Escherichia coli from study participants with familial Mediterranean fever disease (FMF). Verhulst's logistic function was demonstrated to act as a possible tool for the evaluation and quantification of effects produced by the probiotic formulation in FMF participants., (© 2017 The Society for Applied Microbiology.)

Unlabelled: DNA protective and antioxidant activity of Bacillus amyloliquefaciens B-1895 and Bacillus subtilis KATMIRA1933 were evaluated by Escherichia coli-based Lux biosensors. Two biosensor strains of E. coli, MG1655 (pColD-lux) and MG1655 (pSoxS-lux), which react on DNA damage and superoxide-anion radical activity, were used. SOS-response and Sox-response were stimulated by addition of dioxidine (2,3-Quinoxalinedimethanol,1,4-dioxide) and paraquat (N,N'-dimethyl-4,4'-bipyridinium dichloride) respectively. Preparations of both Bacillus fermentates demonstrated DNA protective and antioxidant (superoxide scavenging) activity (up to 60·19%). The strain К1933 is, in general, characterized by higher DNA protective activity (28·85%), with parameters of antioxidant activity of both bacilli strains being statistically not significantly different. Sporogenous potential probiotic micro-organisms with antioxidant and DNA protective activities can become an effective tool for compensation of various negative oxidative stress processes in humans., Significance and Impact of the Study: In humans, oxidative stress is a cause or an important component of many serious diseases, as well as being one of the age influencing factors. Environmental stresses lead to the increase in levels of reactive oxygen species (ROS). Oxidative DNA damage is a side effect of nonspecific inflammation. These human health challenging factors trigger the search for health-promoting bacteria capable of production of antioxidants and DNA-protectors. In this study, two Bacillus strains of interest were shown to produce noticeable DNA protective and antioxidant activities., (© 2015 The Society for Applied Microbiology.)

Vitamin A deficiency (VAD) is an overwhelming public health problem that affects hundreds of millions of people worldwide. A definitive solution to VAD has yet to be identified. Because it is an essential nutrient, vitamin A or its carotenoid precursor β-carotene can only be obtained from food or supplements. In this study, we wanted to establish whether β-carotene produced in the mouse intestine by bacteria synthesizing the provitamin A carotenoid could be delivered to various tissues within the body. To achieve this, we took advantage of the Escherichia coli MG1655*, an intestine-adapted spontaneous mutant of E. coli MG1655, and the plasmid pAC-BETA, containing the genes coding for the 4 key enzymes of the β-carotene biosynthetic pathway (geranylgeranyl pyrophosphate synthase, phytoene synthase, phytoene desaturase, and lycopene cyclase) from Erwinia herbicola. We engineered the E. coli MG1655* to produce β-carotene during transformation with pAC-BETA (MG1655*-βC) and gavaged wild-type and knockout mice for the enzyme β-carotene 15,15'-oxygenase with this recombinant strain. Various regimens of bacteria administration were tested (single vs. multiple and low vs. high doses). β-Carotene concentration was measured by HPLC in mouse serum, liver, intestine, and feces. Enumeration of MG1655*-βC cells in the feces was performed to assess efficiency of intestinal colonization. We demonstrated in vivo that probiotic bacteria could be used to deliver vitamin A to the tissues of a mammalian host. These results have the potential to pave the road for future investigations aimed at identifying alternative, novel approaches to treat VAD.

Using the phasmid vector pSL5, the genomic DNA fragment of T. aquaticus YT1 which contained the thermostable DNA polymerase (Taq-polymerase) gene was cloned. The BglII fragment of this genome locus was subcloned in the BamHI site of the pUC19 plasmid. To optimize the Taq-polymerase gene expression in E. coli cells, the gene was cloned in the correct reading frame regarding the initiation ATG codon of the pPR-TGATG-1 expression vector. The gene expression in this vector was controlled by the phage lambda PR promoter and the temperature-sensitive phage lambda repressor. We used PCR to amplify the short 5'-end fragment of the Taq-polymerase gene coding for the part into which an artificial SacI site was introduced. This site has been used for cloning the PCR product into the pPR-TGATG-1 vector, and the missing gene part was cloned into the KpnI site of the PCR product from the natural cloned gene. The cells of the E. coli PVG-A1 strain, which was obtained in the end, expressed efficiently the Taq-polymerase gene at the nonpermissive temperature. The content of the recombinant Taq-polymerase in the cells was about 1-2% of total proteins. The purified nearly homogeneous Taq-polymerase amplified efficiently in the PCR DNA fragments up to 5.5 kb long and was useful in DNA sequencing the by Sanger method. The half-life of the purified Taq polymerase was about 60 min at 95 degrees C, it was active for at least 65 standard PCR circles. The specific activity of recombinant enzyme preparations was about 180-200,000 units per mg of protein. The E. coli PVG-A1 strain enables one to isolate up to 500,000 units of purified enzyme from 2 l of bacterial culture.

Gene ent-A has been cloned on phage vector pSL5 with the use of the gene library of S. aureus FR1722(H). It is located within DNA fragment Hind III having 2,500 nucleotide pairs.

The ecological state of Lake Sevan, the largest drinking water reservoir for the South Caucasus, formed under the influence of climatic and social changes. This study assesses the bacteriological quality of water in the rivers of the Lake Sevan basin and tetracycline-resistant bacteria isolated from fish and people living near the rivers of the Lake Sevan basin in Armenia in autumn 2019 and spring 2020. No differences have been shown for the tetracycline resistance of the investigated E. coli isolated from the human gut and the Masrik, Argichi, and Gavaraget Rivers. Horizontal gel electrophoresis revealed the same plasmid bands in most of the investigated E. coli with the same tetracycline resistance from the different sources of the Argichi River (obtained from people/fish/water sources where the fish were caught). The results also showed that most of the waters carried Edwardsiella spp. Erwinia spp. Morganella spp. and Proteus spp. in addition to E. coli ; the coliform index did not exceed the standard level of 5 × 104 CFU mL-1 there. These findings highlight the importance of multidisciplinary studies of bacteria from "interacting" ecosystems, which might serve as a basis for the suggestion of microbial antibiotic resistance as another indicator of water pollution. [ABSTRACT FROM AUTHOR]