Naučni radovi

Valorization of Invasive Faxonius limosus Shell Waste as a Biosorbent for Zn(II) and Cd(II) Removal from Aqueous Solutions

Thu, 01 Jan 2026 00:00:00 GMT

Valorization of Invasive Faxonius limosus Shell Waste as a Biosorbent for Zn(II) and Cd(II) Removal from Aqueous Solutions Vasić, Vesna; Lukić, Dragana; Subić, Teodora; Popov, Nenad; Čabarkapa, Ivana The increasing contamination of aquatic environments by heavy metals and the need for sustainable management of invasive aquatic species have stimulated interest in low-cost biosorbents derived from biological waste. In this study, minimally processed shells of the invasive crayfish Faxonius limosus were evaluated for Zn(II) and Cd(II) removal from aqueous solutions. FTIR, SEM, and BET/BJH analyses revealed an organic-mineral material containing amino, hydroxyl, amide, and carbonate functional groups with a predominantly mesoporous structure. Batch experiments showed rapid metal uptake, with equilibrium reached within approximately 60 min. The pseudo-second-order model provided the best fit to the kinetic data, while equilibrium behavior was best described by the Temkin model for Zn(II) and the Langmuir model for Cd(II). Langmuir maximum adsorption capacities were 70.69 mg/g for Zn(II) and 302.12 mg/g for Cd(II). Metal removal was influenced by both initial pH and biosorbent dose, with 2.5 g/L providing high removal efficiencies for both metals. Calcium-release experiments showed increased Ca concentrations in the presence of Zn(II) and Cd(II), supporting the involvement of the Ca-rich mineral fraction in metal removal. Overall, F. limosus shell waste represents a promising low-cost biosorbent and a sustainable valorization route for invasive biomass.

From In Vitro Screening to In Vivo Evaluation of Essential-Oil-Based Formulation Against Avian Pathogenic Escherichia coli

Thu, 01 Jan 2026 00:00:00 GMT

From In Vitro Screening to In Vivo Evaluation of Essential-Oil-Based Formulation Against Avian Pathogenic Escherichia coli Rikić, Milenko; Ružić, Zoran; Pajić, Marko; Todorović, Dalibor; Knežević, Slobodan; Kladar, Nebojša; Kovačević, Zorana Antimicrobial resistance in avian pathogenic Escherichia coli (APEC) poses a significant challenge to poultry production, highlighting the need for effective alternatives to conventional antimicrobials. This study aimed to evaluate the antibacterial activity of selected essential oils (EOs) against multidrug-resistant APEC isolates and assess the in vivo effects of an oregano–thyme EO-based formulation in experimentally infected broilers. Six EOs were screened in vitro using the broth microdilution method, and oregano and thyme EOs, showing the strongest activity (MIC 0.003% and 0.003–0.007%, respectively), were further evaluated in two combinations. The more active combination was formulated for administration via drinking water and tested in 420 Ross 308 broilers experimentally challenged with APEC. Birds were allocated to untreated control, infected untreated, EO-treated, enrofloxacin-treated, and enrofloxacin + reduced-dose EO formulation groups. Mortality did not differ significantly among groups. A binomial GLMM identified significant differences in faecal consistency among experimental groups (likelihood-ratio χ2 = 32.90, df = 4, p < 0.001), while no significant differences were observed in body weight, feed intake, or overall FCR. Significant differences were detected in AST, glucose, total bilirubin, and calcium concentrations. Overall, the EO-based formulation demonstrated antibacterial activity in vitro and was associated with changes in intestinal status following APEC challenge, while no consistent improvement in productive performance was observed. These findings support further investigation of EO-based formulations as potential non-antibiotic approaches for managing APEC-associated intestinal disturbances in broiler chickens.

Pathogenic Foodborne Bacteria in the Game Meat of Hunted Large Ungulates—A Systematic Review and Meta-Analysis

Thu, 01 Jan 2026 00:00:00 GMT

Pathogenic Foodborne Bacteria in the Game Meat of Hunted Large Ungulates—A Systematic Review and Meta-Analysis Fredriksson-Ahomaa, Maria; Bonardi, Silvia; Futoma-Koloch, Bozena; Sakaridis, Ioannis; Petrović, Jelena; Van Damme, Inge Zoonotic bacterial pathogens are a major concern for food safety, yet information regarding their occurrence in game meat remains fragmented. This systematic review synthesizes available data on Salmonella spp., Shiga toxin-producing Escherichia coli (STEC), Listeria spp., Yersinia spp., and Campylobacter spp. in game meat from hunted wild ungulates. Relevant studies published between 2004 and 2024 were identified through structured database searches and screened using predefined criteria. Data on host species, diagnostic methods, prevalence estimates, isolate characterization, and antimicrobial resistance (AMR) were extracted. Pooled prevalence estimates were determined, stratified by detection methods (culture-based and PCR-based) and animal groups (suids and ruminants). A total of 46 publications (170 studies; 223 prevalence estimates) were included. Substantial heterogeneity was observed across the studies. PCR-based methods yielded higher detection rates than culture, though the magnitude of the difference varied between pathogens. Pathogen occurrence was generally higher in meat from suids, except for STEC, which was more prevalent in the game meat of ruminants. Although many strains appeared to have lower pathogenic potential compared with those typically implicated in human disease, the presence of specific virulence-associated genes, serogroups, and sequence types linked to human infections indicates that game meat may act as a potential source of infection. AMR was reported in a limited number of studies. Overall, this review highlights substantial methodological variability and important data gaps, particularly regarding virulence-associated genes, genomic characterization, and AMR. More comprehensive studies spanning a broader range of ecological and production contexts are needed to strengthen the evidence base for the microbiological safety of game meat.

Natural antimicrobial effect of donkey milk using screening microbiological tests

Thu, 01 Jan 2026 00:00:00 GMT

Natural antimicrobial effect of donkey milk using screening microbiological tests Vidaković Knežević, Suzana; Vranešević, Jelena; Knežević, Slobodan; Dončić, Stefan; Pajić, Marija; Milanov, Dubravka Donkey milk has been used since ancient times and is well known for its many beneficial properties. The aim of this study was to confirm the antimicrobial activity of donkey milk using a commercial screening assay and standard microbiological methods. The antimicrobial activity of donkey milk, along with cow, sheep, and goat milks, was initially tested by Delvotest® SP NT, a test based on the rapid growth and acid production of Bacillus stearothermophilus. This test showed false positive results to antibiotics in donkey milk, while all other milk samples were negative. This indicates the presence of natural antimicrobial agents in donkey milk. Further, the antimicrobial activity of all milk samples was evaluated using agar diffusion assay, against Staph ylococcus aureus (ATCC 25923), Bacillus subtilis subsp. spizizenii (ATCC 6633), Listeria monocytogenes 4e (ATCC 19118), Kocuria rhizophila (ATCC 9341), Escherichia coli (ATCC 25922) and Salmonella Typhimuri um (ATCC 14028). Only donkey milk showed small inhibition zones of Bacillus subtilis subsp. spizizenii and Salmonella Typhimurium at pH 6 and 8, respectively. To check the ability of foodborne pathogens to survive and grow in milk, all milk samples (donkey, cow, sheep, and goat milks) were contaminated at two levels ( 10 CFU/mL and 400 CFU/mL) with Salmonella Typhimurium and stored under different conditions (at 37 ? for 4 hours and at 4 ? for 24 hours). The highest number of Salmonella Typhimurium cells was recorded in cow milk, regardless of storage conditions. In this study, donkey milk demonstrated significant antibacterial activity against Salmonella Typhimurium in all storage conditions, which may be attributed to its naturally high content of lysozyme and lactoferrin.