The adhesion and aggregation are characteristic attributes of probiotic strains belonging to Lactobacillaceae genus. Due to these properties the host organisms can avoid colonisation of the intestinal tract by enteropathogenic bacteria. The presented research includes a comparison of the properties of various strains belonging to different Lactobacillaceae species and isolated from different sources The aim of this study was to investigate the ability of Lactocaseibacillus rhamnosus, Lactiplantibacillus plantarum, and Lactobacillus strains (L. acidophilus, L. gasseri, L. ultunensis) from probiotic products and clinical specimens to direct and competitive adherence to Caco-2 and HT-29 cell lines. Furthermore, the ability of lactobacilli and enteropathogenic bacteria, E. coli, E. faecalis, and S. Typhimurium, to auto- and co-aggregation was also investigated.The results showed that all tested strains adhered to Caco-2 and HT-29 cell lines. Though, the factor of adhesion depended on the species and origin of the strain. L. rhamnosus strains showed a lowest degree of adherence as compared to L. plantarum and Lactobacillus sp. strains. On the other side both, L. rhamnosus and L. acidophilus strains reduced the pathogenic bacteria in competition adherence test most effectively. All tested lactobacilli strains were characterised by auto- and co-aggregation abilities, to various degrees. The properties of Lactobacillaceae strains analysed in this study, like adhesion abilities, competitive adherence, auto- and co-aggregation, may affect the prevention of colonisation and elimination of pathogenic bacteria in gastrointestinal tract.

Ciprofloxacin (CP) has a confirmed cytotoxic action on some cancerous cells, but in high, non-pharmacological concentrations. Considering features of natural fatty acids, such as biocompatibility, biodegradability and their increased cellular uptake by cancer cells, it seems that combining them with a drug could improve its bioavailability, and thus cytotoxicity. Therefore, the aim of this study was coupling of CP with saturated and unsaturated fatty acids, and evaluation of their cytotoxicity, apoptosis-inducing effects and inhibition of IL-6 release in human primary (SW480) and metastatic (SW620) colon cancer, metastatic prostate cancer (PC3) and normal (HaCaT) cell lines. The PC3 cell line was the most sensitive to the presence of the obtained conjugates. The value of IC50 for oleic acid conjugate (4) was 7.7 μM, and it was 12 times lower than for CP alone (101.4 μM). The studied derivatives induced late apoptosis in all cancer cell lines, but not in normal cells. The most potent apoptosis inducer was conjugate 4, that resulted in the highest percentage of PC3 cells in late apoptosis (81.5% ± 3.9), followed by elaidic acid amide 5 (75% ± 4.8). The strongest pro-apoptic effects on SW480 cells were demonstrated by conjugates of DHA (8) and sorbic (2) acids, whereas in SW620 cell lines, compounds 2 and 5 appeared to be the most effective. To establish the mechanism of cytotoxic action of derivatives 2, 4, 5, the level of interleukin-6 (IL-6) was measured. The compounds with the highest cytotoxic potential significantly decreased the release of IL-6 by cancer cells. Additionally, all conjugates were evaluated for their in vitro antimicrobial activity. Short chain amides - crotonic (1) and sorbic (2) - were the most active against Staphyloccoci. The second-mentioned amide has shown both strong antistaphylococcal and antitumor properties.

Free living, cosmopolitan amoebae from Acanthamoeba genus present a serious risk to human health. As facultative human parasites, these amoebae may cause Acanthamoeba keratitis (AK). Acanthamoeba keratitis is a severe, vision-threatening corneal infection with non-specific symptoms. The number of reported AK cases worldwide has been increasing every year. Moreover, 90% of Acanthamoeba keratitis cases are related to contact lens use. Wearing and storage contact lenses not in accordance with the physicians and manufacturers recommendations are the primary key risk factors of this disease. Amoebae can easily adhere to the contact lens surface and transmit to the corneal epithelium. Preventing amoebae adhesion to the contact lens surface could significantly decrease the number of AK infections. Until now, the effective therapy against AK is still under development. Currently proposed therapies are mainly limited to the chlorhexidine digluconate combined with propamidine isethionate or hexamidine applications, which are insufficient and very toxic to the eye. Due to lack of effective treatment, looking for new potential preventive agents is crucial to decrease the number of Acanthamoeba keratitis infections, especially among contact lens users. Nanoparticles have been already included in several novel therapies against bacteria, viruses, fungi, and protist. However, their anti-amoebic potential has not been fully tested yet. The aim of this study was to assess silver nanoparticles (AgNPs) and platinum nanoparticles (PtNPs) anti-amoebic activity and influence on the amoebae adhesion to the surface of four different groups of contact lenses—classified according to the Food and Drugs Administration (FDA) guidelines. The obtained results show that both tested nanoparticles were effective against Acanthamoeba trophozoites and decreased the amoebae adhesion to the contact lens surface. AgNPs showed better anti-amoebic activity to cytotoxicity dependence and reduced amoebae adhesion in a wider spectrum of the tested contact lenses. Our studies also confirmed that ionization next to hydration of the contact lens material is a crucial parameter influencing the Acanthamoeba adhesion to the contact lens surface. In conclusion, silver nanoparticles might be considered as a novel preventive agent against Acanthamoeba keratitis infection.