Phylogeny, Resistome, and Virulome of Escherichia coli Causing Biliary Tract Infections

Snapshot of resistome, virulome and mobilome in aquaculture

Aquaculture environments can be hotspots for resistance genes through the surrounding environment. Our objective was to study the resistome, virulome and mobilome of Gram-negative bacteria isolated in seabream and bivalve molluscs, using a WGS approach. Sixty-six Gram-negative strains (Aeromonadaceae, Enterobacteriaceae, Hafniaceae, Morganellaceae, Pseudomonadaceae, Shewanellaceae, Vibrionaceae, and Yersiniaceae families) were selected for genomic characterization. The species and MLST were determined, and antibiotic/disinfectants/heavy metals resistance genes, virulence determinants, MGE, and pathogenicity to humans were investigated. Our study revealed new sequence-types (e.g. Aeromonas spp. ST879, ST880, ST881, ST882, ST883, ST887, ST888; Shewanella spp. ST40, ST57, ST58, ST60, ST61, ST62; Vibrio spp. ST206, ST205). >140 different genes were identified in the resistome of seabream and bivalve molluscs, encompassing genes associated with β-lactams, tetracyclines, aminoglycosides, quinolones, sulfonamides, trimethoprim, phenicols, macrolides and fosfomycin resistance. Disinfectant resistance genes qacE-type, sitABCD-type and formA-type were found. Heavy metals resistance genes mdt, acr and sil stood out as the most frequent. Most resistance genes were associated with antibiotics/disinfectants/heavy metals commonly used in aquaculture settings. We also identified 25 different genes related with increased virulence, namely associated with adherence, colonization, toxins production, red blood cell lysis, iron metabolism, escape from the immune system of the host. Furthermore, 74.2 % of the strains analysed were considered pathogenic to humans. We investigated the genetic environment of several antibiotic resistance genes, including blaTEM-1B, blaFOX-18, aph(3″)-Ib, dfrA-type, aadA1, catA1-type, tet(A)/(E), qnrB19 and sul1/2. Our analysis also focused on identifying MGE in proximity to these genes (e.g. IntI1, plasmids and TnAs), which could potentially facilitate the spread of resistance among bacteria across different environments. This study provides a comprehensive examination of the diversity of resistance genes that can be transferred to both humans and the environment, with the recognition that aquaculture and the broader environment play crucial roles as intermediaries within this complex transmission network.

Comparison of phylogenetic and virulence factors between Escherichia coli isolated from biliary tract infections and uropathogenic Escherichia coli

Escherichia coli is a gram-negative intestinal commensal that can also cause various infections, including urinary tract infections, biliary tract infections, neonatal meningitis, and septicemia. Although the characteristics of uropathogenic E. coli and the mechanisms of urinary tract infection have been well studied, the genetic distinctions among E. coli isolates from different types of infections have not yet been determined. This study compared the phylogenetic and virulence factors of E. coli isolates from bacteremic biliary tract infections with those from bacteremic urinary tract infections. The phylogenetic B2 group was the most prevalent in both pathogenic groups (68 % in biliary pathogenic isolates and 85 % in uropathogenic isolates), but the frequency pattern of the phylogenetic group was different. Half of the uropathogenic isolates belonged to ST95 and ST131 (51 %). Among the biliary pathogenic isolates, ST131 was the most prevalent, while the remaining half belonged to other STs outside the four major STs. The frequency of some virulence factors, such as papC, papG2, hlyA, tcpC, fyuA, kpsMT2, sat, and traT, was lower in the biliary pathogenic isolates than in the uropathogenic isolates. The frequency of phylogenetic groups and STs in MLST differed between E. coli isolates from bacteremic biliary tract infections and urinary tract infections. Additionally, some virulence factors, including adhesion and toxin gene groups, showed lower frequencies in the biliary pathogenic group than in the uropathogenic group. Studying the differences in E. coli pathovars from different infection sites is important for developing pathovar-specific targeted therapies such as vaccine therapy.

Affective lability and social functioning in severe mental disorders

Social functioning is impaired in severe mental disorders despite clinical remission, illustrating the need to identify other mechanisms that hinder psychosocial recovery. Affective lability is elevated and associated with an increased clinical burden in psychosis spectrum disorders. We aimed to investigate putative associations between affective lability and social functioning in 293 participants with severe mental disorders (schizophrenia- and bipolar spectrum), and if such an association was independent of well-established predictors of social impairments. The Affective Lability Scale (ALS-SF) was used to measure affective lability covering the dimensions of anxiety-depression, depression-elation and anger. The interpersonal domain of the Social Functioning Scale (SFS) was used to measure social functioning. Correlation analyses were conducted to investigate associations between affective lability and social functioning, followed by a hierarchical multiple regression and follow-up analyses in diagnostic subgroups. Features related to premorbid and clinical characteristics were entered as independent variables together with the ALS-SF scores. We found that higher scores on all ALS-SF subdimensions were significantly associated with lower social functioning (p < 0.005) in the total sample. For the anxiety-depression dimension of the ALS-SF, this association persisted after controlling for potential confounders such as premorbid social functioning, duration of untreated illness and current symptoms (p = 0.019). Our results indicate that elevated affective lability may have a negative impact on social functioning in severe mental disorders, which warrants further investigation. Clinically, it might be fruitful to target affective lability in severe mental disorders to improve psychosocial outcomes.