|Isolation and characterization of novel bacteriophages as a potential therapeutic option for Escherichia coli urinary tract infections

Urinary tract infections (UTIs) are mainly caused by uropathogenic Escherichia coli (UPEC), whose impact can be exacerbated by multidrug-resistant (MDR) strains. Effective control strategies are, therefore, urgently needed. Among them, phage therapy represents a suitable alternative. Here, we describe the isolation and characterization of novel phages from wastewater samples, as well as their lytic activity against biofilm and adherence of UPEC to HEp-2 cells. The results demonstrated that phage vB_EcoM-phiEc1 (ϕEc1) belongs to Myoviridae family, whereas vB_EcoS-phiEc3 (ϕEc3) and vB_EcoS-phiEc4 (ϕEc4) belong to Siphoviridae family. Phages showed lytic activity against UPEC and gut commensal strains. Phage ϕEc1 lysed UPEC serogroups, whereas phages ϕEc3 and ϕEc4 lysed only UTI strains with higher prevalence toward the O25 serogroup. Moreover, phages ϕEc1 and ϕEc3 decreased both biofilm formation and adherence, whereas ϕEc4 was able to decrease adherence but not biofilm formation. In conclusion, these novel phages showed the ability to decrease biofilm and bacterial adherence, making them promising candidates for effective adjuvant treatment against UTIs caused by MDR UPEC strains. Key points Phage with lytic activity against MDR UPEC strains were isolated and characterized under in vitro conditions. A novel method was proposed to evaluate phage activity against bacterial adherence in HEp-2 cell.. Phages represent a suitable strategy to control infections caused by MDR bacteria.

Bacteria autoaggregation: how and why bacteria stick together

Autoaggregation, adherence between identical bacterial cells, is important for colonization, kin and kind recognition, and survival of bacteria. It is directly mediated by specific interactions between proteins or organelles on the surfaces of interacting cells or indirectly by the presence of secreted macromolecules such as eDNA and exopolysaccharides. Some autoaggregation effectors are self-associating and present interesting paradigms for protein interaction. Autoaggregation can be beneficial or deleterious at specific times and niches. It is, therefore, typically regulated through transcriptional or post-transcriptional mechanisms or epigenetically by phase variation. Autoaggregation can contribute to bacterial adherence, biofilm formation or other higher-level functions. However, autoaggregation is only required for these phenotypes in some bacteria. Thus, autoaggregation should be detected, studied and measured independently using both qualitative and quantitative in vitro and ex vivo methods. If better understood, autoaggregation holds the potential for the discovery of new therapeutic targets that could be cost-effectively exploited.

The Vaginal Microbiota, Bacterial Biofilms and Polymeric Drug-Releasing Vaginal Rings

The diversity and dynamics of the microbial species populating the human vagina are increasingly understood to play a pivotal role in vaginal health. However, our knowledge about the potential interactions between the vaginal microbiota and vaginally administered drug delivery systems is still rather limited. Several drug-releasing vaginal ring products are currently marketed for hormonal contraception and estrogen replacement therapy, and many others are in preclinical and clinical development for these and other clinical indications. As with all implantable polymeric devices, drug-releasing vaginal rings are subject to surface bacterial adherence and biofilm formation, mostly associated with endogenous microorganisms present in the vagina. Despite more than 50 years since the vaginal ring concept was first described, there has been only limited study and reporting around bacterial adherence and biofilm formation on rings. With increasing interest in the vaginal microbiome and vaginal ring technology, this timely review article provides an overview of: (i) the vaginal microbiota, (ii) biofilm formation in the human vagina and its potential role in vaginal dysbiosis, (iii) mechanistic aspects of biofilm formation on polymeric surfaces, (iv) polymeric materials used in the manufacture of vaginal rings, (v) surface morphology characteristics of rings, (vi) biomass accumulation and biofilm formation on vaginal rings, and (vii) regulatory considerations.

Role of Lactobacillus in Female Infertility Via Modulating Sperm Agglutination and Immobilization

Infertility has become a common problem in recent decades. The pathogenesis of infertility is variable, but microbiological factors account for a large proportion of it. Dysbiosis of vaginal microbiota is reportedly associated with female infertility, but the influence of normal vaginal microbiota on infertility is unclear. In this review, we summarize the physiological characteristics of the vaginal tract and vaginal microbiota communities. We mainly focus on the bacterial adherence of vaginal Lactobacillus species. Given that the adherent effect plays a crucial role in the colonization of bacteria, we hypothesize that the adherent effect of vaginal Lactobacillus may also influence the fertility of the host. We also analyze the agglutination and immobilization effects of other bacteria, especially Escherichia coli, on ejaculated spermatozoa, and speculate on the possible effects of normal vaginal microbiota on female fertility.