ABSTRACT Streptococcus agalactiae (Group B streptococcus, GBS) remains a major cause of neonatal sepsis and meningitis, despite the success of intrapartum antibiotic prophylaxis. However, the rising trend of antimicrobial resistance and the emergence of hypervirulent lineages highlight the need for complementary, innovative prophylactic strategies. This study aimed to characterize the resistance and virulence repertoire of colonizing GBS isolates and to assess the antagonistic potential of selected Lactobacillus strains under conditions mimicking the vaginal niche. We performed integrated phenotypic, genotypic, and functional analysis of 31 clinical GBS isolates collected during routine pre‐partum screening, focusing on antimicrobial susceptibility, hemolytic and aggregation phenotypes, capsular serotypes, pilus island profiles, and virulence genes. The collection included MDR isolates, strains exhibiting inducible clindamycin resistance and high‐level gentamicin resistance, as well as hypervirulent ST‐17 related lineages, with marked heterogeneity in β‐hemolytic activity and aggregation phenotypes linked to specific combinations of capsule, pilus, and virulence genes. In co‐culture experiments with HeLa cells, individual Lactobacillus strains exerted strong, strain‐dependent inhibition of GBS, preserving epithelial cell viability, and impairing pathogen adhesion by up to 98%. Importantly, the multi‐strain Lactobacillus combination provided broader and more consistent antagonistic activity, including against MDR, inducible clindamycin‐resistant, hypervirulent ST‐17‐associated, and strongly hemolytic GBS isolates. Although these findings are preliminary, being derived from a limited number of isolates and an in vitro model, they support the promising potential of rationally selected multi‐strain Lactobacillus formulations as a strategy to reduce colonization by high‐risk GBS lineages and warrant further investigation.
The success of antimicrobial compounds today is diminished by the ability of microbes to develop resistance. The use of natural compounds as alternatives to antibiotics and/or antifungals is increasing. The potential use of essential oils, particularly their phenolic compounds, thymol or carvacrol, is receiving great interest. The study aims to evaluate the antimicrobial activity of the two monoterpenes against Gram-positive and -negative bacteria and various Candida spp., in planktonic form, through MIC and MBC/MFC evaluation, and sessile growth form, through crystal violet and XTT assays. In addition, Checkerboard test evaluated synergistic effects between the phenolic compounds, and phenolic compounds and antibiotics/antimycotics substances, and cytotoxicity versus three different human cell lines was evaluated through MTT assay. Results obtained showed antimicrobial activity of the phenolic compounds against bacteria and Candida spp., in both planktonic and sessile cultures. The MIC/MBC range of carvacrol and thymol was 125-250 µg/mL against all strains tested, while for Candida spp., the MIC/MFCs ranged from 250 to 2000 µg/mL. Several combinations of monoterpenes/antimicrobial compounds showed synergistic or additive effects at concentrations lower than MIC values in both planktonic and sessile forms. Carvacrol was toxic to all the tested cell lines (concentrations > 31 µg/mL); whereas thymol was toxic to only two of the tested cell lines (human urinary cell line excluded). In conclusion, although a high level of cytotoxicity against different cell lines has been demonstrated, the additive and synergistic effects shown could allow their therapeutic use at nontoxic concentrations, encouraging further studies on these substances.
To date, the presence of antibiotics resistant genes (ARGs) and virulence-related genes (VRGs) has been evidenced in several surface waters, including natural surface water and wastewater, as well as drinking water. Bottled natural mineral waters, which are by law labelled as microbiologically pure at source, from underground aquifers, natural resurgence deposits or well suction pumps, do not undergo purification treatment, and do not experience any chemical decontamination or disinfection treatment, as in the case of drinking water from municipal conduits. The present study aimed to evaluate the presence of ARGs and VRGs, as well as the composition of microbial communities, in commercially bottled natural mineral drinking water by molecular methods. The study involved the analysis of bottled drinking water from four commercial brands. Moreover, an investigation was conducted into the potential association of known mobile elements or insertion sequences with the highlighted ARGs and VRGs. Four commercial brands of drinking mineral bottled water were selected for analysis. A volume of 100 L from each brand was filtered to recover the microbes present in the water. The microbes successfully recovered on the filter, in conjunction with eventually other particles with a diameter of 0.22 μm or greater, or associated nucleic acids, underwent a process of DNA extraction using specific extraction kit. The extracted cell-DNA was subjected to shotgun sequencing. Sequence analysis revealed the presence of microbial communities associated with the water samples analyzed. Furthermore, several ARGs and VRGs were identified and, for some of them, a putative taxonomic assignment at genus level was defined. The results indicated that bottled drinking water may represent a potential reservoir of antibiotic resistance and virulence genes, which could persist and be transferred to other bacteria commonly found in the same water sample, as well as to microorganisms colonizing the human consumer. The use of the new molecular methods, such as next generation sequencing (NGS), could be useful for improving current methodologies for drinking water analysis, also considering their potential role of reservoir of antibiotic resistance and virulence genes, as well as the presence of potentially pathogenic microbes that cannot be detected by conventional cultural methods.
Background Pediatric chronic intestinal pseudo-obstruction (PIPO) is a rare disease characterized by symptoms and radiological signs suggestive of intestinal obstruction, in the absence of lumen-occluding lesions. It results from an extremely severe impairment of propulsive motility. The intestinal endocrine system (IES) jointly with the enteric nervous system (ENS) regulates secreto-motor functions via different hormones and bioactive messengers/neurotransmitters. The neurotransmitter 5-hydroxytryptamine (5-HT) (or serotonin) is linked to intestinal peristalsis and secretory reflexes. Gut microbiota and its interplay with ENS affect 5-HT synthesis, release, and the subsequent serotonin receptor activation. To date, the interplay between 5-HT and gut microbiota in PIPO remains largely unclear. This study aimed to assess correlations between mucosa associated microbiota (MAM), intestinal serotonin-related genes expression in PIPO. To this purpose, biopsies of the colon, ileum and duodenum have been collected from 7 PIPO patients, and 7 age-/sex-matched healthy controls. After DNA extraction, the MAM was assessed by next generation sequencing (NGS) of the V3-V4 region of the bacterial RNA 16 S, on an Illumina Miseq platform. The expression of genes implicated in serotoninergic pathway ( TPH1, SLC6A4, 5-HTR3 and 5-HTR4 ) was established by qPCR, and correlations with MAM and clinical parameters of PIPO have been evaluated. Results Our results revealed that PIPO patients exhibit a MAM with a different composition and with dysbiosis, i.e. with a lower biodiversity and fewer less connected species with a greater number of non-synergistic relationships, compared to controls. qPCR results revealed modifications in the expression of serotonin-related intestinal genes in PIPO patients, when compared to controls. Correlation analysis do not reveal any kind of connection. Conclusions For the first time, we report in PIPO patients a specific MAM associated to underlying pathology and an altered intestinal serotonin pathway. A possible dysfunction of the serotonin pathway, possibly related to or triggered by an altered microbiota, may contribute to dysmotility in PIPO patients. The results of our pilot study provide the basis for new biomarkers and innovative therapies targeting the microbiota or serotonin pathways in PIPO patients.
The present study discusses current literature regarding the relationship between gut microbiota, CIPO patients and intestinal motility, suggesting that future studies could be important for better comprise the causes of intestinal motility dysfunction in CIPO patients. Chronic intestinal pseudo-obstruction (CIPO) is a rare clinical syndrome characterized by severe impairment of gastrointestinal (GI) motility and its symptoms are suggestive of partial or complete intestinal obstruction in absence of any lesion restricting the intestinal lumen. Diagnosis and therapy of CIPO patients still represent a significant challenge for clinicians, despite their efforts to improve diagnostic workup and treatment strategies for this disease. Motility in the GI tract is controlled by the enteric nervous system (ENS), CIPO patients could be affected by alterations of the ENS. Furthermore, a recent pilot study has also highlighted, for the first time, a specific intestinal mucosa associated microbiota, and an altered expression of intestinal serotonin-related genes in CIPO patients. The purpose of this review is to better understand what is currently known about the relationship between CIPO patients and intestinal microbiota, with a focus on the role of the enteric nervous system (ENS) and the intestinal endocrine system (IES) in intestinal motility, underling the importance of further studies to deeply understand the causes of gut motility dysfunction in these patients.
Antibiotics were a huge advance for the field of medicine because they decreased the risk of people getting sick due to harmful bacteria. However, bacteria quickly learned to “fight back” against these powerful medicines. Antibiotic-resistant bacteria, increasingly frequent nowadays, cannot be killed by antibiotics, making infections with these organisms very dangerous. Some common infections have become extremely difficult or even impossible to cure, leading to an alarming public health problem. In this article, we will discuss how helpful “predator bacteria” might be useful in fighting antibiotic-resistant infections. The bacterium we chose to study is called Bdellovibrio bacteriovorus, it lives in the healthy human gut and is capable of preying on other bacteria. In the future, might this bacterium be an effective treatment for dangerous bacterial infections? We think so!
Several studies have shown fluctuations in the maternal microbiota at various body sites (gut, oral cavity, and vagina). The skin microbiota plays an important role in our health, but studies on the changes during pregnancy are limited. Quantitative and qualitative variations in the skin microbiota in pregnant woman could indeed play important roles in modifying the immune and inflammatory responses of the host. These alterations could induce inflammatory disorders affecting the individual’s dermal properties, and could potentially predict infant skin disorder in the unborn. The present study aimed to characterize skin microbiota modifications during pregnancy. For this purpose, skin samples were collected from 52 pregnant women in the first, second, and third trimester of non-complicated pregnancies and from 17 age- and sex-matched healthy controls. The skin microbiota composition was assessed by next generation sequencing (NGS) of the V3–V4 region of the bacterial rRNA 16S. Our results indicate that from the first to the third trimester of pregnancy, changes occur in the composition of the skin microbiota, microbial interactions, and various metabolic pathways. These changes could play a role in creating more advantageous conditions for fetal growth.
INTRODUCTION: In the treatment of upper GI endoscopy-negative patients with heartburn and epigastric pain or burning, antacids, antireflux agents, and mucosal protective agents are widely used, alone or as add-on treatment, to increase response to proton-pump inhibitors, which are not indicated in infancy and pregnancy and account for significant cost expenditure. METHODS: In this randomized, controlled, double-blind, double-dummy, multicenter trial assessing the efficacy and safety of mucosal protective agent Poliprotect (neoBianacid, Sansepolcro, Italy) vs omeprazole in the relief of heartburn and epigastric pain/burning, 275 endoscopy-negative outpatients were given a 4-week treatment with omeprazole (20 mg q.d.) or Poliprotect (5 times a day for the initial 2 weeks and on demand thereafter), followed by an open-label 4-week treatment period with Poliprotect on-demand. Gut microbiota change was assessed. RESULTS: A 2-week treatment with Poliprotect proved noninferior to omeprazole for symptom relief (between-group difference in the change in visual analog scale symptom score: [mean, 95% confidence interval] -5.4, -9.9 to -0.1; -6.2, -10.8 to -1.6; intention-to-treat and per-protocol populations, respectively). Poliprotect's benefit remained unaltered after shifting to on-demand intake, with no gut microbiota variation. The initial benefit of omeprazole was maintained against significantly higher use of rescue medicine sachets (mean, 95% confidence interval: Poliprotect 3.9, 2.8-5.0; omeprazole 8.2, 4.8-11.6) and associated with an increased abundance of oral cavity genera in the intestinal microbiota. No relevant adverse events were reported in either treatment arm. DISCUSSION: Poliprotect proved noninferior to standard-dose omeprazole in symptomatic patients with heartburn/epigastric burning without erosive esophagitis and gastroduodenal lesions. Gut microbiota was not affected by Poliprotect treatment. The study is registered in Clinicaltrial.gov (NCT03238534) and the EudraCT database (2015-005216-15).
Rheumatoid Arthritis (RA) is a chronic systemic autoimmune disease. Modifications of gut microbiota seem to be associated with the disease, but the impact of gut microbiota on therapies' outcome remains unclear. A role of T cells in RA pathogenesis has been addressed, particularly on the Th17/Treg cells balance. Our study aimed to evaluate in early RA (ERA) patients compared to a control group, fecal gut microbiota composition, short-chain fatty acids concentrations, and the levels of circulating Th17/Treg and their own cytokines, before and after 3 months of standard treatment (Methotrexate (MTX) plus glucocorticoids). Fecal microbiota characterization was carried out on 19 ERA patients and 20 controls matched for sex and age. Significant decreased biodiversity levels, and a partition on the base of the microbiota composition, between the ERA patients at baseline compared to controls, were observed. The co-occurrent analysis of interactions revealed a characteristic clustered structure of the microbial network in controls that is lost in ERA patients where an altered connection between microbes and clinical parameters/metabolites has been reported. Microbial markers such as Acetanaerobacterium elongatum, Cristiansella massiliensis, and Gracilibacter thermotolerans resulted significantly enriched in control group while the species Blautia gnavus emerged to be more abundant in ERA patients. Our results showed an alteration in Th17/Treg balance with higher Th17 levels and lower Treg levels in ERA group respect to control at baseline, those data improved after therapy. Treatment administration and the achievement of a low disease activity/remission appear to exert a positive pressure on the structure of intestinal microbiota with the consequent restoration of biodiversity, of the structure of microbial network, and of the abundance of taxa that became closer to those presented by the subject without the disease. We also found an association between Blautia gnavus and ERA patients characterized by a significant reduction of propionic acid level. Furthermore significant differences highlighted at baseline among controls and ERA patients are no more evident after treatment. These data corroborate the role played by gut microbiota in the disease and suggest that therapy aimed to restore gut microbiota would improve treatment outcome.
The aim of this work was to optimize and characterize nanocomposite films based on gellan gum methacrylate (GG-MA) and silver nanoparticles (AgNPs) for application in the field of wound dressing. The films were produced using the solvent casting technique coupled with a photocuring process. The UV irradiation of GG-MA solutions containing glycerol as a plasticizer and different amounts of silver nitrate resulted in the concurrent crosslinking of the photocurable polymer and a reduction of Ag ions with consequent in situ generation of AgNPs. In the first part of the work, the composition of the films was optimized, varying the concentration of the different components, the GG-MA/glycerol and GG-MA/silver nitrate weight ratios as well as the volume of the film-forming mixture. Rheological analyses were performed on the starting solutions, whereas the obtained films were characterized for their mechanical properties. Colorimetric analyses and swelling studies were also performed in order to determine the AgNPs release and the water uptake capacity of the films. Finally, microbiological tests were carried out to evaluate the antimicrobial efficacy of the optimized films, in order to demonstrate their possible application as dressings for the treatment of infected hard-to-heal wounds, which is a demanding task for public healthcare.
Violacein is a natural pigment, a pyrrolidone, and a bisindole derived from the condensation of two tryptophan molecules, which gives a blue violet color to several gram-negative violacein-producing bacteria. Violacein production provides a competitive advantage against antagonistic species or predators. In addition, the compound has antibacterial, antifungal, antiviral, and antioxidant activities. Several studies on colon, breast, and head and neck cancer lines have already demonstrated the anti-proliferative potential of violacein. Bladder cancer is one of the most common types of cancer in urology. The therapeutic approach is mainly based on surgery, chemotherapy, and immunotherapy. The aim of the present study was to evaluate the anti-proliferative activity of violacein against the human bladder cancer cell lines, HTB4 (T24) and HTB9 (5637), using low-grade and high-grade transitional cell carcinoma models, respectively, which has never been assayed before. For this purpose, the potential violacein anti-proliferative effect on T24 and 5637 cells was evaluated by studying the cell viability, proliferation, cell cycle, and caspase-3 activation. The results showed that violacein had anti-proliferative activity in the two cell lines, which was greater for the second-stage bladder cancer cell line (5637), and a different mode of action against the two cell lines.
Chronic intestinal pseudo-obstruction (CIPO) is a rare clinical syndrome characterized by severe impairment of gastrointestinal (GI) motility, and its symptoms are suggestive of partial or complete intestinal obstruction in the absence of any lesion restricting the intestinal lumen. Diagnosis and therapy of CIPO patients still represent a significant challenge for clinicians, despite their efforts to improve diagnostic workup and treatment strategies for this disease. The purpose of this review is to better understand what is currently known about the relationship between CIPO patients and intestinal microbiota, with a focus on the role of the enteric nervous system (ENS) and the intestinal endocrine system (IES) in intestinal motility, underling the importance of further studies to deeply understand the causes of gut motility dysfunction in these patients.
Sleep plays a fundamental role in maintaining good psycho-physical health, it can influence hormone levels, mood, and weight. Recent studies, focused on the interconnection between intestinal microbiome and sleep disorders, have shown the growing importance of a healthy and balanced intestinal microbiome for the hosts health. Normally, gut microbiota and his host are linked by mutualistic relationship, that in some conditions, can be compromised by shifts in microbiota's composition, called dysbiosis. Both sleep problems and dysbiosis of the gut microbiome can lead to metabolic disorders and, in this review, we will explore what is present in literature on the link between sleep pathologies and intestinal dysbiosis.