Search

This study focused on assessing the microbiological and chemical contamination of air, soil and leachate in uncontrolled refuse storage areas in central Poland. The research included an analysis of the number of microorganisms (culture method), endotoxin concentration (gas chromatography-mass spectrometry), heavy metals level (atomic absorption spectrometry), elemental characteristics (elemental analyser), cytotoxicity assessment against A-549 (human lung) and Caco-2 (human colon adenocarcinoma) cell lines (PrestoBlue™ test) and toxic compound identification (ultra-high-performance liquid chromatography-quadrupole time-of-flight ultrahigh-resolution mass spectrometry). Microbial contamination differed depending on the dump and the group of tested microorganisms. The number of bacteria was: 4.3 × 10 2 - 1.8 × 10 3 CFU m -3 (air); 1.1 × 10 3  - 1.2 × 10 6 CFU mL -1 (leachate); 1.0 × 10 6 - 3.9 × 10 6 CFU g -1 (soil). Respectively, for air and soil the number of fungi was: 2.2 × 10 2 - 4.6 × 10 2 CFU m -3 ; 1.8 × 10 2 - 3.9 × 10 3 CFU g -1 . Metal levels (Fe, Mn, Pb, Zn, Al, Hg, Cd, Cu, Cr) were higher than in the control sample; however, the average concentrations did not exceed the permissible standards. The cytotoxicity of soil and leachate samples depended on the dump, sample and cell line tested. The leachates were more cytotoxic than soil extracts. Compounds belonging to pesticides, surfactants and biocides, chemicals and/or polymer degradation products, medicinal drugs and insect repellents were found. The detection of potential pathogens in the air, soil and leachate, the presence of toxic compounds and the confirmation of the cytotoxic effect of leachate and soil on human cell lines justify the need for further research on the risks posed by illegal dumps. These studies should aim at developing a unified assessment method and a method to minimise the risk of contaminants spreading in the environment, including harmful biological agents., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Commercial preparations of 6-phytase A alone and in combination with phytase B were used in rye breadmaking. Determination of bioavailability of myo-inositol phosphates from bread was performed by an in vitro digestion method followed by the measurement of an uptake by Caco-2 cells in culture. In bread supplemented with a combination of 6-phytase A and phytase B, a significant reduction in phytate content was observed from 3.62 μmol/g in the control to 0.7 μmol/g. Bioavailability of phytate estimated by an in vitro method simulating digestion in the human alimentary tract was 9% in the bread supplemented with phytase B, 7% (6-phytase A) and 50% in the control bread. In cell culture, the bioaccessibilities of inositol triphosphates from bread baked with the addition of 6-phytase A was higher by 36% as compared to the samples baked with phytase B and by 32% in breads baked with combination of both phytases. [ABSTRACT FROM AUTHOR]

Bacillus cereus sensu lato comprises Gram-positive spore-forming bacteria producing toxins associated with foodborne diseases. Three pore-forming enterotoxins, nonhemolytic enterotoxin (Nhe), hemolysin BL (Hbl), and cytotoxin K (CytK), are considered the primary factors in B. cereus sensu lato diarrhea. The aim of this study was to determine the potential risk of enterotoxicity among soil B. cereus sensu lato isolates representing diverse phylogroups and originated from different geographic locations with various climates (Burkina Faso, Kenya, Argentina, Kazakhstan, and Poland). While nheA - and hblA -positive isolates were present among all B. cereus sensu lato populations and distributed across all phylogenetic groups, cytK-2 -positive strains predominated in geographic regions with an arid hot climate (Africa) and clustered together on a phylogenetic tree mainly within mesophilic groups III and IV. The highest in vitro cytotoxicity to Caco-2 and HeLa cells was demonstrated by the strains clustered within phylogroups II and IV. Overall, our results suggest that B. cereus sensu lato pathogenicity is a comprehensive process conditioned by many intracellular factors and diverse environmental conditions. IMPORTANCE This research offers a new route for a wider understanding of the dependency between pathogenicity and phylogeny of a natural bacterial population, specifically within Bacillus cereus sensu lato , that is widely distributed around the world and easily transferred into food products. Our study indicates differences in the phylogenetic and geographical distributions of potential enterotoxigenic B. cereus sensu lato strains. Hence, these bacilli possess a risk for human health, and rapid testing methods for their identification are greatly needed. In particular, the detection of the CytK enterotoxin should be a supporting strategy for the identification of pathogenic B. cereus sensu lato ., (Copyright © 2020 Drewnowska et al.)

Background: The relationship of diffusely adherent Escherichia coli (DAEC) with pediatric inflammatory bowel disease (IBD) has not been previously studied. Diffusely adherent E. coli are a common cause of long-lasting childhood diarrhea and we postulated that they may induce inflammation of the intestinal mucosa, contributing to the development of IBD in susceptible children., Objectives: The aim of the study was to investigate the relationship between DAEC and pediatric IBD, including Crohn's disease (CD) and ulcerative colitis (UC). Diffusely adherent E. coli isolates were also assessed regarding their pathogenicity., Material and Methods: Diffusely adherent E. coli were screened among 130 E. coli strains isolated from intestinal biopsy specimens from 26 children with IBD using polymerase chain reaction (PCR) with primers specific to the pathotype and adherence assays to HEp-2 cells. Diffusely adherent E. coli were further analyzed for their ability to adhere to and invade polarized Caco-2 cells. The immunomodulatory effect of DAEC on the secretion of tumor necrosis factor α (TNF-α) by human monocyte-derived macrophages (MDM) was assessed using an immunoenzymatic assay., Results: Diffusely adherent E. coli were recovered from 18 (69.2%) of the 26 intestinal biopsy specimens from both CD and UC patients. Most DAEC isolates carried AfaE3 adhesin, adhered to and were internalized by Caco-2 cells, and induced secretion of elevated levels of TNF-α., Conclusions: The study demonstrated the internalization of DAEC by intestinal epithelial cells and their ability to induce secretion of increased level of TNF-α in a Caco-2/macrophage compartmentalized culture. This indicated that the pathovar should be considered a pathobiont inducing inflammation of the intestinal mucosa in pediatric patients with IBD.

148 enterococcal strains: E.faecalis (108), E.faecium (35), E.gallinarum (3), E.casseliflavus (1) and E.durans (1) from various clinical specimens were investigated for their ability to adhere to Caco-2 and HEp-2 cell lines, and also for the presence of the esp gene, biofilm formation, production of haemolysins, DNAse and lipase. Several types of enterococcal adhesion to both cell lines were noted. An aggregative adherence was the most frequent among E.faecalis and E.faecium isolates. Other species presented various adhesive types. The occurrence of virulence factors in the whole group of strains was as follows: esp gene in 53.4%, biofilm in 45.3%, haemolysins in 15.5%, DNAse in 12.2% and lipase in 33.1% of enterococcal isolates. It appears that the adherence of the enterococci studied was not significantly associated with the presence of virulence factors.