Aleksandr Novoslavskij

Broiler chickens are continuously exposed to microorganisms in the production environment, but the relationship between microorganisms on bird-contact surfaces and fecal microbiota remains unclear. In this exploratory observational study, shotgun metagenomic sequencing was used to compare microbial communities in feeder- and drinker-associated surface samples and individual fecal samples during one production cycle in a single commercial system housing Ross 308 broilers. The dataset comprised 22 individual fecal samples collected on days 1, 7, 19, 27, and 39 and four composite feeder- or drinker-associated environmental surface samples collected on days 1, 19, 27, and 39. Taxonomic composition, alpha and beta diversity, differential taxonomic signatures, and genus-level co-abundance patterns were evaluated. Environmental samples had greater richness and were dominated by Proteobacteria and Bacteroidetes, whereas host-associated fecal samples were dominated by Firmicutes and lactobacilli. Sample type explained 20.0% of variation in Bray–Curtis distances and 15.5% in Binary Jaccard distances (both p = 0.001). Within host-associated samples, Firmicutes increased from 51.4% on day 1 to 93.6% on day 39, while Proteobacteria decreased from 26.5% to 1.4%. Despite these taxonomic changes, host-associated communities did not form statistically distinct clusters by sampling day. Within the investigated production system, host-associated fecal microbial communities differed from those detected on the sampled feeder and drinker surfaces, while the relative abundance of dominant fecal taxa varied across sampling days. These findings are specific to the investigated production system and production cycle.

Dried plums are valued as functional foods because of their nutritional composition and health-promoting properties. However, plum drying is challenging due to the waxy fruit cuticle, which limits moisture diffusion and prolongs drying time. Although blanching is commonly used to improve drying efficiency, its effects on phenolic compounds, minerals, and microbiological quality remain insufficiently studied, particularly in regional plum cultivars. Therefore, this study evaluated the effects of hot-water and 1% citric acid blanching combined with different drying methods on the nutritional, antioxidant, and microbiological quality of dried plums of the regional cultivar “Chuyskaya krasavitsa”. Dried plums contained 16–21 g of sorbitol, 26–42 g of mono- and disaccharides, 2–2.8 g of protein, 2.2–3.9 g of ash, and 2.9–4.5 mg of vitamin C per 100 g (wet basis). The predominant amino acids were aspartic acid, glutamine, and proline, while neochlorogenic acid, hyperoside, and chlorogenic acid were the major phenolic compounds. Dried plums were also rich in potassium (1294 mg/100 g on average), whereas freeze-dried samples retained higher mineral concentrations. Pretreatment significantly affected microbiological parameters, including aerobic colony count ( p < 0.001) and yeast and mould count ( p < 0.01), as well as protein, sugar, and total phenolic contents ( p < 0.05). Citric acid blanching reduced the levels of several phenolic compounds compared with hot-water blanching and freeze-drying. These findings provide practical guidance for optimising dried plum processing while balancing nutrient retention, phenolic preservation, and microbial safety.

Lactic acid bacteria (LAB) are essential in the production of fermented dairy products, contributing to desirable sensory attributes, safety, and shelf life. Traditionally, the health-promoting properties of fermented dairy products have been associated with live probiotic LAB; however, ensuring their viability during processing, storage and gastrointestinal passage remains challenging. This has shifted scientific interest toward postbiotics—preparations consisting of inactivated microbial cells, cell components and fermentation-derived metabolites capable of resulting in health benefits without the survival of microorganisms. LAB-derived postbiotics include bioactive peptides, exopolysaccharides and cell wall fragments, which may support gut barrier function, exert immunomodulatory or antimicrobial effects and improve technological performance in dairy matrices. Their stability, predictable functionality, and favourable safety profile make them suitable alternatives or supplements to traditional probiotics. In dairy applications, postbiotics can be produced in situ during fermentation or incorporated as formulated ingredients to enhance product functionality and deliver consistent bioactivity. In addition to highlighting the technological benefits of LAB-derived postbiotics in dairy systems and assessing new regulatory frameworks, this review summarizes the current understanding of their classification, composition, and mechanisms of action. Key challenges related to definition, standardization, safety assessment and labeling are discussed to support future development of postbiotic-enriched functional dairy foods.

Escherichia coli, a major opportunistic pathogen in chickens, poses a serious threat to poultry production and public health via potential zoonotic transmission of ESBL-producing strains. Therefore, this study aimed to emphasize broilers as early carriers of ESBL E. coli and provide deeper insights into antimicrobial resistance of these bacteria. Prevalence and antimicrobial resistance (MIC) testing of ESBL E. coli in cloacal and environmental samples from one-day-old and five-day-old broilers was conducted on three different growth cycles from a conventional poultry farm in Lithuania. Confirmed prevalence of ESBL E. coli in cloacal samples ranged from 0% to 57.5%, and in environmental swabs from 0% to 25%. All 102 ESBL E. coli isolates were susceptible to meropenem, imipenem, fosfomycin, and colistin. However, 93.14% of the strains were resistant to ceftriaxone (89.06–100%, depending on bacteria isolation source), 97.06% to ciprofloxacin (95.31–100%), and 66.67% to tetracycline (26.09–100%). Additionally, 80.39% of ESBL E. coli strains exhibited multidrug resistance. In total, 23 different antimicrobial resistance profiles were confirmed, with CRO/AMS/AUG/CIP/SXT/TE and CRO/CIP being the most common, detected in 18 of the 102 strains. The detection of widespread antimicrobial-resistant ESBL E. coli in five-day-old broilers emphasizes the need to implement control strategies early in the broiler production cycle.

The use of lactic acid bacteria (LAB) in the fermentation process to produce fermented foods has a long history. Furthermore, LAB are beneficial microorganisms known for their health-promoting characteristics. During fermentation, LAB have the capacity to produce significant amounts of bioactive substances, such as peptides, bacteriocins, lactic acid, exopolysaccharides (EPSs), enzymes, and others. Lactococcus lactis as one of the best-known and well-characterized species of LAB serves as a model organism for studying LAB. For a very long time, L. lactis has been used in milk fermentation, both in well-monitored industrial settings and on a small scale in traditional operations. Furthermore, L. lactis is a vital microorganism in the dairy food fermentation industry due to its role in acidification, flavor development, and the creation of various dairy products, including cheese, fermented butter, and others. The novelty of this review is the comprehensive and organized presentation of the main benefits of the use of L. lactis in milk fermentation processes including technological and safety features relevant for the dairy industry, probiotic potential, the ability to produce bioactive compounds (e.g., bacteriocins, GABA), and the recent development of such bacteria research methods like whole genome sequencing (WGS).

Campylobacter jejuni is known as one of the main causative agents of gastroenteritis in humans worldwide, and the rise of antimicrobial resistance (AMR) in Campylobacter is a growing public health challenge of special concern. Whole-genome sequencing (WGS) was used to characterize genetic determinants of AMR in 53 C. jejuni isolates from dairy cattle, broiler products, wild birds, and humans in Lithuania. The WGS-based study revealed 26 C. jejuni AMR markers that conferred resistance to various antimicrobials. Genetic markers associated with resistance to beta-lactamases, tetracycline, and aminoglycosides were found in 79.3%, 28.3%, and 9.4% of C. jejuni isolates, respectively. Additionally, genetic markers associated with multidrug resistance (MDR) were found in 90.6% of C. jejuni isolates. The WGS data analysis revealed that a common mutation in the quinolone resistance-determining region (QRDR) was R285K (854G > A) at 86.8%, followed by A312T (934G > A) at 83% and T86I (257C > T) at 71.7%. The phenotypic resistance analysis performed with the agar dilution method revealed that ciprofloxacin (CIP) (90.6%), ceftriaxone (CRO) (67.9%), and tetracycline (TET) (45.3%) were the predominant AMR patterns. MDR was detected in 41.5% (22/53) of the isolates tested. Fifty-seven virulence genes were identified in all C. jejuni isolates; most of these genes were associated with motility (n = 28) and chemotaxis (n = 10). Additionally, all C. jejuni isolates harbored virulence genes related to adhesion, invasion, LOS, LPS, CPS, transportation, and CDT. In total, 16 sequence types (STs) and 11 clonal complexes (CC) were identified based on core-genome MLST (cgMLST) analysis. The data analysis revealed distinct diversity depending on phenotypic and genotypic antimicrobial resistance of C. jejuni.

The vicinity of small apiaries to the farms makes honey and bee pollen prone to the contamination with clostridial spores. The possible presence of Clostridium difficile (C. difficile) spores in bee products may pose a risk especially to elderly who perceive them as natural remedies in health problems including functional bowel abnormalities. The aim of the study was to evaluate the prevalence of C. difficile spores in 120 samples of honey and 44 samples of bee pollen harvested in Northeastern Europe. All incubation procedures were performed in anaerobic conditions. The 10 g samples were subsequently pre-enriched in Cooked Meat Medium (CMM) and Brain Heart Infusion-supplement (BHIS) broths. Sporulated forms were seeded on supplemented C. difficile blood agar. Rapid immunoenzymatic tests targeted at glutamate dehydrogenase (GDH) detection and polymerase chain reaction (PCR) targeted at tpi gene detection were also performed. Based on microbiological culture 32 (20%) out of 164 samples were selected for culture on blood agar. The growth of ground-glass colonies was noted towards 13 (8%) samples. The presence of C. difficile was not confirmed by immunoenzymatic rapid tests towards any sample selected. Neither PCR assay targeted to tpi gene showed positive samples. This is the first report reviewing the possibility of native to Europe Apis mellifera (A. mellifera) bee products contamination with C. difficile. The samples of A. mellifera bee products produced in small apiaries in Northeastern Europe did not show the presence of C. difficile spores.

The occurrence, seasonal variation and genetic diversity of Campylobacter spp. in pigeons and crows over a 1-year period were evaluated. Campylobacter spp. were isolated from 166 (34.6 %) out of 480 wild bird faecal samples. The occurrence of Campylobacter spp. in faecal samples was higher among crows (39.2 %) than pigeons (30.0 %), (P < 0.05). Campylobacter jejuni was the most common species detected among wild bird faecal samples (98.2 %). Meanwhile, Campylobacter coli prevalence in wild bird faecal samples was low—6 %. The Simpson’s diversity index of C. jejuni flaA RFLP types was lower in pigeons (D = 0.88) compared with C. jejuni isolates detected in crows (D = 0.97). Obtained results revealed that C. jejuni are widely prevalent among crows and pigeons, indicating these wild birds as potential infection sources to humans. Further studies are required to determine crows and pigeons role in zoonotic transmission of Campylobacter.