Extraintestinal pathogenic E. coli (ExPEC) are facultative pathogens that are part of the normal human intestinal flora. The ExPEC group includes uropathogenic E. coli (UPEC), neonatal meningitis E. coli (NMEC), sepsis-associated E. coli (SEPEC), and avian pathogenic E. coli (APEC). Virulence factors (VF) related to the pathogenicity of ExPEC are numerous and have a wide range of activities, from those related to bacteria colonization to those related to virulence, including adhesins, toxins, iron acquisition factors, lipopolysaccharides, polysaccharide capsules, and invasins, which are usually encoded on pathogenicity islands (PAIs), plasmids and other mobile genetic elements. Mechanisms underlying the dynamics of ExPEC transmission and the selection of virulent clones are still poorly understood and require further research. The time shift between colonization of ExPEC and the development of infection remains problematic in the context of establishing the relation between consumption of contaminated food and the appearance of first disease symptoms. What appears to be most difficult is to prove that ExPEC strains cause disease symptoms and to examine the mechanism of transition from the asymptomatic colonization of the intestines to the spreading of the bacteria outside the digestive system. A significant problem for researchers who are trying to ascribe ExPEC transmission to food, people or the environment is to draw the distinction between colonization of ExPEC and infection. Food safety is an important challenge for public health both at the production stage and in the course of its processing and distribution. Examination of the genetic similarity of ExPEC strains will allow to determine their origin from different sources. Many levels of genotyping have been proposed in which the typing of strains, plasmids and genes is compared in order to obtain a more complete picture of this complex problem. The aim of our study was to characterize E. coli strains isolated from humans, animals and food for the presence of bacterial genes encoding virulence factors such as toxins, and iron acquisition systems (siderophores) in the context of an increasing spread of ExPEC infections.

In recent years, we have witnessed increasing drug resistance among bacteria, which is associated with the use and availability of an increasing number of broad-spectrum antimicrobials, as well as with their irrational and excessive use. The present study aims to analyze changes in the drug resistance of Gram-negative Pseudomonas aeruginosa and Acinetobacter baumannii, isolated from infections in a multi-profile hospital over a five-year period (from 2017 to 2022). Among the practical results of the evaluation of these data will be the possibility to determine changes in susceptibility to the antibiotics used in the hospital. This, in turn, will help propose new therapeutic options, especially for empirical therapy, which is essential in severe infections. Analysis of the use of different antibiotic groups has made it possible to identify the causes of increasing resistance in the analyzed Gram-negative bacilli. The highest antibiotic use was observed in the hospital between 2020 and 2022, most probably due to the COVID-19 pandemic and the higher number of patients in severe condition requiring hospitalization. Unfortunately, during the period analyzed, the number of multi-resistant strains of A. baumannii was successively increasing; this seems to be related to the increased use, especially during the pandemic period, of broad-spectrum antibiotics, mainly penicillins with inhibitors, third-generation cephalosporins and carbapenems.

The pathogenicity of many bacterial strains is determined by the acquisition of virulence genes and depends on many factors. The aim of this study was to analyse the phylogenetic background, virulence patterns, and drug susceptibility of 132 E. coli isolates tested in the context of the ExPEC (Extraintestinal Pathogenic E. coli) pathotype and the correlation of these features with bacterial isolation source: food (retail meat), poultry farms (AFEC—Avian Faecal E. coli), and patients with UTI (urinary tract infection) symptoms. The drug-susceptibility results of tested E. coli isolates obtained indicate that the resistance profile—ampicillin/tetracycline/trimethoprim+sulfamethoxazole/ciprofloxacin (AMP/TE/SXT/CIP)—was most frequently observed. The multidrug resistance (MDR) phenotype was found in 31.8% of isolates from poultry farms, 36.8% of strains isolated from food, and 20% of clinical samples. The greatest similarity of virulence profiles applied to isolates derived from poultry farms and food. Most of the AFEC from poultry farms and food-derived isolates belonged to commensals from phylogroups A and B1, while among the isolates from patients with UTI symptoms, the most common was the B2 phylogroup. The collective analysis showed similarity of the three studied groups of E. coli isolates in terms of the presented patterns of antimicrobial resistance, while the virulence profiles of the isolates studied showed great diversity. The phylogroup analysis showed no similarity between the poultry/food isolates and the UTI isolates, which had significant pathogenic potential.

Human noroviruses, which belong to the enterovirus family, are one of the most common etiological agents of food-borne diseases. In recent years, intensive research has been carried out regarding the antiviral activity of plant metabolites that could be used for the preservation of fresh food, because they are safer for consumption when compared to synthetic chemicals. Plant preparations with proven antimicrobial activity differ in their chemical compositions, which significantly affects their biological activity. Our review aimed to present the results of research related to the characteristics, applicability, and mechanisms of the action of various plant-based preparations and metabolites against norovirus. New strategies to combat intestinal viruses are necessary, not only to ensure food safety and reduce infections in humans but also to lower the direct health costs associated with them.

The role of purified natural products in the prevention and treatment of countless diseases of bacterial, fungal, and viral origin cannot be overestimated. New antiviral drugs have been obtained from natural sources and transformed into preparations for prophylactic and therapeutic purposes. Flavonoids, polyphenols, saponins, proanthocyanins, polysaccharides, organic acids, proteins, polypeptides, and essential oils derived from plants, animals, or microorganisms can control and combat foodborne viral infections, including hepatitis A. The components of essential oils are characterized by numerous therapeutic and antioxidant properties and exhibit a broad spectrum of antimicrobial and antiviral activity. Due to these properties, they can be used to preserve meat, fruit, vegetables, and their products. Over the past two decades, much effort has been made to identify natural products, mostly of plant origin, to combat foodborne viruses. Natural plant extracts have several potential uses, not limited to increasing the safety of food products and improving their quality, but also as natural antiviral agents.

Uropathogenic Escherichia coli (UPEC) is the leading cause of urinary tract infections (UTIs) and a major contributor to the global antimicrobial resistance crisis. The increasing prevalence of multidrug-resistant (MDR) strains, including expanded-spectrum β-lactamases (ESBL) and carbapenemase-producing isolates, severely limits treatment options. This review provides an overview on the key molecular mechanisms of UPEC antibiotic resistance, such as enzymatic inactivation, target-site mutations, efflux pump activity, and biofilm formation. Beyond conventional antibiotics, special emphasis is placed on phytochemical strategies as promising alternatives. Flavonoids, alkaloids, terpenoids, and essential oils exhibit antibacterial, anti-adhesive, and antibiofilm properties. These natural bioactive compounds modulate motility, suppress fimbrial expression, inhibit quorum sensing, and enhance antibiotic efficacy, acting both as standalone agents and as adjuvants. Current in vitro and in vivo studies highlight the potential of plant-derived compounds and biologically based therapies to combat UPEC. However, challenges related to standardization, bioavailability, and clinical validation remain unresolved. Integrating molecular mechanistic insights with advanced phytochemical research may offers a sustainable and effective strategy for mitigating UPEC antibiotic resistance.