Tetracycline resistance of Escherichia coli isolated from water, human stool, and fish gills from the Lake Sevan basin.

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.

Lactobacillus acidophilus INMIA 9602 Er-2 strain 317/402 probiotic regulates growth of commensal Escherichia coli in gut microbiota of familial Mediterranean fever disease subjects.

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.