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Veterinary World Apr 2024Stingless bees are generally found in tropical countries, including Indonesia. In West Sumatra, stingless bees are known as , consist of several species with different...
BACKGROUND AND AIM
Stingless bees are generally found in tropical countries, including Indonesia. In West Sumatra, stingless bees are known as , consist of several species with different characteristics; however, the properties of honey produced by stingless bees have not yet been explored. This study aimed to determine the physicochemical, antioxidant, and antimicrobial activities as well as the microbiota profile of stingless bee honey from the bee species , , , and that are intensively developed in West Sumatra, Indonesia.
MATERIALS AND METHODS
Honey produced by the stingless bee species , . , , and originating in West Sumatra was examined in the present study. The physicochemical properties (Association of Official Analytical Chemists), antioxidant activity (2,2-diphenyl-1-picrylhydrazyl technique), total phenols (Folin-Ciocalteu method), antimicrobial activity (Agar-Well diffusion test), total lactic acid bacteria, and microbiota diversity were measured in stingless bee honey samples.
RESULTS
Stingless bee species significantly affected the physicochemical properties, antioxidant activity, total phenolic content, antimicrobial activity, and total lactic acid bacteria (p = 0.05), except for the crude fiber content. The carbohydrate profiles of honey produced by and were dominated by monosaccharides, whereas those of honey from and were dominated by disaccharides. In terms of antioxidant activity (half maximal inhibitory concentration [IC] value), there were no significant differences (p > 0.05) between honey from , , and , but there were significant differences (p > 0.05) between honey from . The honey of and had the highest total phenolic content (65.65 ± 14.00 and 69.78 ± 8.06, respectively). In addition, honey from the four stingless bee species showed antimicrobial activity against the pathogenic bacteria , , , and . From the principal co-ordinate analysis (PCoA) results, it can be concluded that the microbiota profiles of the four stingless bee honey samples differed.
CONCLUSION
The results showed that honey from , , , and has different physicochemical characteristics, antioxidant activity, antimicrobial activity, and microbiota diversity. By knowing the content of this stingless bee honey, the results of this study can be used as information that this stingless bee honey has the potential as a functional food that is beneficial for health.
PubMed: 38798299
DOI: 10.14202/vetworld.2024.785-795 -
Veterinary World Apr 2024Donkey and mare milk have high nutritional and functional values, but their lactic acid bacteria (LAB) content remains poorly studied and undervalued in the Algerian...
Isolation of 60 strains from fermented milk of mares and donkeys in Algeria and identification by 16S rRNA sequencing of lactobacilli: Assessment of probiotic skills of important strains and aromatic productivity power.
BACKGROUND AND AIM
Donkey and mare milk have high nutritional and functional values, but their lactic acid bacteria (LAB) content remains poorly studied and undervalued in the Algerian dairy industry. This study aimed to isolate and select LAB strains that produce antimicrobial substances during fermentation and to characterize the probiotic profiles of each extracted strain to indicate their potential for antioxidant and proteolytic activity.
MATERIALS AND METHODS
This study focuses on isolating and identifying lactic acid bacterial strains from 10 Equid-fermented milk samples collected in two regions of El Bayed Wilaya (Algeria). Identification of LAB strains was obtained by 16S rRNA sequencing. The probiotic properties of important strains and their aromatic productivity power are assessed. To evaluate their antibacterial activity against , , , and , we selected 21 strains. Different induction methods have been used to amplify the antibacterial effects against these pathogenic strains.
RESULTS
Among a total of 60 identified strains, 31 had a probiotic profile, and most were catalase-negative. Aromatic productivity power was observed in eight strains: , , , , , , , and sp1.
CONCLUSION
Our results provide insight into the considerable diversity of LAB present in fermented donkey and mare milk. To meet the expectations of the Algerian dairy industry, it is important that the probiotic skills of the nine selected strains are met. In addition, a significant number of these strains may have important probiotic activity and biotechnological potential.
PubMed: 38798294
DOI: 10.14202/vetworld.2024.829-841 -
Journal of Food Protection May 2024Listeria monocytogenes are considered to be the major foodborne pathogen worldwide. To understand the prevalence and potential risk of L. monocytogenes in retail foods,...
Listeria monocytogenes are considered to be the major foodborne pathogen worldwide. To understand the prevalence and potential risk of L. monocytogenes in retail foods, a total of 1243 retail foods in 12 food categories were sampled and screened for L. monocytogenes from 2020 to 2022 in Huzhou, China. A total of 46 out of 1234 samples were confirmed to be L. monocytogenes positive with a total rate of 3.7%. The contamination rate of seasoned raw meat (15.2%) was the highest, followed by raw poultry meat and raw livestock meat (9.9%) and salmon sashimi (9.5%). The L. monocytogenes isolates belonged to four serotypes, 1/2a,1/2b, 1/2c, and 4b, with the most prevalent serotype being 1/2a (47.9%). All isolates were grouped into 15 sequence types (STs) belonging to 14 clonal complexes (CCs) via multilocus sequence typing (MLST). The most prevalent ST was ST9/CC9 (23.9%), followed by ST3/CC3 (19.6%) and ST121/CC121 (17.4%). Notably, 11 STs were detected from ready-to-eat (RTE) foods, some of them have been verified to be strongly associated with clinical origin listeriosis cases, such as ST3, ST2, ST5, ST8, and ST87. Listeria pathogenicity islands 1 (LIPI-1) and LIPI-2 were detected in approximately all L. monocytogenes isolates, whereas the distribution of both LIPI-3 genes and LIPI-4 genes exhibited association with specific ST, with LIPI-3 in ST3 and ST288, and LIPI-4 in ST87. The strains carrying LIPI-3 and LIPI-4 virulence genes in this study were all isolated from RTE foods. Antimicrobial susceptibility tests showed that >90% of isolates were susceptible to PEN, AMP, ERY, CIP, SXT, VAN, CHL, and GEN, indicating the antibiotic treatment might be still efficient for most of the L. monocytogenes strains. However, for the three clinical first-line antibiotics (PEN, AMP, and GEN), we also observed three and four strains showing MIC values greater than the susceptibility standards for PEN and AMP, respectively, and one strain showing resistance to GEN.
PubMed: 38797247
DOI: 10.1016/j.jfp.2024.100307 -
Pharmaceutics May 2024In recent decades, ionic liquids (ILs) have garnered research interest for their noteworthy properties, such as thermal stability, low or no flammability, and negligible...
In recent decades, ionic liquids (ILs) have garnered research interest for their noteworthy properties, such as thermal stability, low or no flammability, and negligible vapour pressure. Moreover, their tunability offers limitless opportunities to design ILs with properties suitable for applications in many industrial fields. This study aims to synthetise two series of methylimidazolium ILs bearing long alkyl chain in their cations (C9, C10, C12, C14, C16, C18, C20) and with tetrafluoroborate (BF) and the 1,3-dimethyl-5-sulfoisophthalate (DMSIP) as counter ions. The ILs were characterised using H-NMR and MALDI-TOF, and their thermal behaviour was investigated through DSC and TGA. Additionally, the antimicrobial, anticancer, and cytotoxic activities of the ILs were analysed. Moreover, the most promising ILs were incorporated at different concentrations (0.5, 1, 5 wt%) into polyvinyl chloride (PVC) by solvent casting to obtain antimicrobial blend films. The thermal properties and stability of the resulting PVC/IL films, along with their hydrophobicity/hydrophilicity, IL surface distribution, and release, were studied using DSC and TGA, contact angle (CA), SEM, and UV-vis spectrometry, respectively. Furthermore, the antimicrobial and cytotoxic properties of blends were analysed. The in vitro results demonstrated that the antimicrobial and antitumor activities of pure ILs against t , , strains, and the breast cancer cell line (MCF7), respectively, were mainly dependent on their structure. These activities were higher in the series containing the BF anion and increased with the increase in the methylimidazolium cation alkyl chain length. However, the elongation of the alkyl chain beyond C16 induced a decrease in antimicrobial activity, indicating a cut-off effect. A similar trend was also observed in terms of in vitro biocompatibility. The loading of both the series of ILs into the PVC matrix did not affect the thermal stability of PVC blend films. However, their T decreased with increased IL concentration and alkyl chain length. Similarly, both the series of PVC/IL films became more hydrophilic with increasing IL concentration and alkyl chain. The loading of ILs at 5% concentration led to considerable IL accumulation on the blend film surfaces (as observed in SEM images) and, subsequently, their higher release. The biocompatibility assessment with healthy human dermal fibroblast (HDF) cells and the investigation of antitumoral properties unveiled promising pharmacological characteristics. These findings provide strong support for the potential utilisation of ILs in biomedical applications, especially in the context of cancer therapy and as antibacterial agents to address the challenge of antibiotic resistance. Furthermore, the unique properties of the PVC/IL films make them versatile materials for advancing healthcare technologies, from drug delivery to tissue engineering and antimicrobial coatings to diagnostic devices.
PubMed: 38794304
DOI: 10.3390/pharmaceutics16050642 -
Microorganisms May 2024Lactoperoxidase (LP) is an important enzyme of the salivary and mammary glands. It has been proven to increase the shelf life of raw milk by inhibiting the growth of...
Lactoperoxidase (LP) is an important enzyme of the salivary and mammary glands. It has been proven to increase the shelf life of raw milk by inhibiting the growth of bacteria, especially , , , and spp. The aim of this work was to verify the use of LP to extend the shelf life of meat products. In vitro experiments showed inhibitory effects on the selected bacteria ( (ATCC 33090), (CP054440.1), and (ATCC 13525) due to a prolongation of the lag phase of growth curves. A lower increase in viable counts ( < 0.05) was also found by testing pork cubes' surface treated with LP solution (5%) + and stored for 7 days at 15 °C. LP has also been studied at concentrations of 0.25 and 0.50% in meat products (pork ham and pâté) during refrigerated storage (4 °C for 28 days). Lower viable counts were observed throughout the storage experiment, especially for 0.50% LP ( < 0.05). Meat products containing LP also showed lower levels of oxidation (MAD) ( < 0.05). According to these results, LP could extend the shelf life of a wider range of products.
PubMed: 38792839
DOI: 10.3390/microorganisms12051010 -
Microorganisms May 2024The study used whole-genome sequencing (WGS) and bioinformatics analysis for the genomic characterization of 60 isolates of obtained from the beef production chain...
The study used whole-genome sequencing (WGS) and bioinformatics analysis for the genomic characterization of 60 isolates of obtained from the beef production chain (cattle farms, abattoirs, and retail outlets) in Gauteng province, South Africa. The sequence types (STs), clonal complexes (CCs), and the lineages of the isolates were determined using in silico multilocus sequence typing (MLST). We used BLAST-based analyses to identify virulence and antimicrobial genes, plasmids, proviruses/prophages, and the CRISPR-Cas system. The study investigated any association of the detected genes to the origin in the beef production chain of the isolates. Overall, in 60 isolates of , there were seven STs, six CCs, forty-four putative virulence factors, two resistance genes, one plasmid with AMR genes, and three with conjugative genes, one CRISPR gene, and all 60 isolates were positive for proviruses/prophages. Among the seven STs detected, ST204 (46.7%) and ST2 (21.7%) were the most prominent, with ST frequency varying significantly ( < 0.001). The predominant CC detected were CC2 (21.7%) and CC204 (46.7%) in lineages I and II, respectively. Of the 44 virulence factors detected, 26 (across Pathogenicity Islands, LIPIs) were present in all the isolates. The difference in the detection frequency varied significantly ( < 0.001). The two AMR genes ( and ()) detected were present in all 60 (100%) isolates of The only plasmid, NF033156, was present in three (5%) isolates. A CRISPR-Cas system was detected in six (10%), and all the isolates carried proviruses/prophages. The source and sample type significantly affected the frequencies of STs and virulence factors in the isolates of The presence of and () genes in all isolates obtained from the three industries of the beef production chain can potentially cause therapeutic implications. Our study, which characterized recovered from the three levels in the beef production chain, is the first time genomics was performed on this type of data set in the country, and this provides insights into the health implications of
PubMed: 38792832
DOI: 10.3390/microorganisms12051003 -
Microorganisms May 2024() poses a significant threat to food safety due to its ability to cause severe human illness and its resistance to various antibiotics and environmental conditions....
() poses a significant threat to food safety due to its ability to cause severe human illness and its resistance to various antibiotics and environmental conditions. This study investigated the prevalence, serotype distribution, virulence gene profiles, and antimicrobial resistance patterns of in ready-to-eat (RTE) food products from Romania. A total of 8151 samples were analyzed, including various processed dairy, bovine, poultry, pork, and fish products. Bacterial isolation was conducted using the classical standard method, followed by confirmation through biochemical and molecular testing. Among the isolated strains, serotypes 1/2a, 1/2b, and 1/2c were identified, with a prevalence of 75% for serotype 1/2a. Additionally, virulence genes specific to listeriolysin O (A) and regulatory factor A (A) were detected in all isolates. Antimicrobial susceptibility testing revealed varying resistance patterns among the strains. Trimethoprim-sulfamethoxazole and oxacillin showed the highest prevalence of resistance at 26.92% and 23.07%, respectively. However, all strains remained susceptible to ciprofloxacin, levofloxacin, and moxifloxacin. Notably, 23.07% of the isolates exhibited multidrug resistance, with the most common pattern being resistance to oxacillin, penicillin, and tetracycline. Analysis of antimicrobial resistance genes identified tetracycline resistance genes, particularly (C), (M), and (K), in a significant proportion of isolates. The presence of C and D genes was also notable, indicating potential mechanisms of resistance. These results emphasize the necessity for ongoing surveillance of in RTE foods and emphasize the importance of thorough monitoring of antimicrobial resistance to guide public health strategies within the European Union.
PubMed: 38792784
DOI: 10.3390/microorganisms12050954 -
Microorganisms Apr 2024The search for natural food additives makes propolis an exciting alternative due to its known antimicrobial activity. This work aims to investigate propolis' behavior as...
The search for natural food additives makes propolis an exciting alternative due to its known antimicrobial activity. This work aims to investigate propolis' behavior as a nitrite substitute ingredient in cooked ham (a ready-to-eat product) when confronted with pathogenic microorganisms of food interest. The microbial evolution of , , , and inoculated at known doses was examined in different batches of cooked ham. The design of a challenge test according to their shelf life (45 days), pH values, and water activity allowed the determination of the mesophilic aerobic flora, psychotropic, and acid lactic bacteria viability. The test was completed with an organoleptic analysis of the samples, considering possible alterations in color and texture. The cooked ham formulation containing propolis instead of nitrites limited the potential growth (δ < 0.5 log) of all the inoculated microorganisms until day 45, except for , which in turn exhibited a bacteriostatic effect between day 7 and 30 of the storage time. The sensory analysis revealed the consumer's acceptance of cooked ham batches including propolis as a natural additive. These findings suggest the functionality of propolis as a promising alternative to artificial preservatives for ensuring food safety and reducing the proliferation risk of foodborne pathogens in ready-to-eat products.
PubMed: 38792741
DOI: 10.3390/microorganisms12050914 -
Microorganisms Apr 2024Higher plants produce secondary metabolites expressing antimicrobial effects as a defense mechanism against opportunistic microorganisms living in close proximity with...
Higher plants produce secondary metabolites expressing antimicrobial effects as a defense mechanism against opportunistic microorganisms living in close proximity with the plant. Fermentation leads to bioconversion of plant substrates to these bioactive compounds and their subsequent release via breakdown of plant cell walls. Fermented feed products have recently started to become implemented in the pig industry to reduce overall disease pressure and have been found to reduce events such as post-weaning diarrhea. In this study, we investigate the antimicrobial potential of fermented soybean- and rapeseed-based pig feed supplements with and without added seaweed. The antimicrobial effect was tested in a plate well diffusion assay against a range of known human and livestock pathogenic bacteria. Further, we investigate the metabolite profiles based on liquid-chromatography mass-spectrometry (LC-MS) analysis of the fermented products in comparison to their unfermented constituents. We observed a pronounced release of potential antimicrobial secondary metabolites such as benzoic acids when the plant material was fermented, and a significantly increased antimicrobial effect compared to the unfermented controls against several pathogenic bacteria, especially Typhimurium, , , and a strain of atopic dermatitis causing CC1. In conclusion, fermentation significantly enhances the antimicrobial properties of rapeseed, soybean, and seaweed, offering a promising alternative to zinc oxide for controlling pathogens in piglet feed. This effect is attributed to the release of bioactive metabolites effective against pig production-relevant bacteria.
PubMed: 38792720
DOI: 10.3390/microorganisms12050891 -
International Journal of Environmental... Apr 2024Using whey, a by-product of the cheese-making process, is important for maximizing resource efficiency and promoting sustainable practices in the food industry. Reusing...
Using whey, a by-product of the cheese-making process, is important for maximizing resource efficiency and promoting sustainable practices in the food industry. Reusing whey can help minimize environmental impact and produce bio-preservatives for foods with high bacterial loads, such as Mexican-style fresh cheeses. This research aims to evaluate the antimicrobial and physicochemical effect of CFS from 21/1 produced in a conventional culture medium (MRS broth) and another medium using whey (WB medium) when applied in Mexican-style fresh cheese inoculated with several indicator bacteria (, serovar Typhimurium, , and ). The CFSs (MRS or WB) were characterized for organic acids concentration, pH, and titratable acidity. By surface spreading, CFSs were tested on indicator bacteria inoculated in fresh cheese. Microbial counts were performed on inoculated cheeses during and after seven days of storage at 4 ± 1.0 °C. Moreover, pH and color were determined in cheeses with CFS treatment. Lactic and acetic acid were identified as the primary antimicrobial metabolites produced by the 21/1 fermentation in the food application. A longer storage time (7 days) led to significant reductions ( < 0.05) in the microbial population of the indicator bacteria inoculated in the cheese when it was treated with the CFSs (MRS or WB). serovar Typhimurium was the most sensitive bacteria, decreasing 1.60 ± 0.04 log CFU/g with MRS-CFS, whereas WB-CFS reduced the microbial population of to 1.67 log CFU/g. and were the most resistant at the end of storage. The cheese's pH with CFSs (MRS or WB) showed a significant reduction ( < 0.05) after CFS treatment, while the application of WB-CFS did not show greater differences in color (ΔE) compared with MRS-CFS. This study highlights the potential of CFS from 21/1 in the WB medium as an ecological bio-preservative for Mexican-style fresh cheese, aligning with the objectives of sustainable food production and guaranteeing food safety.
Topics: Cheese; Lacticaseibacillus casei; Whey; Food Microbiology; Hydrogen-Ion Concentration; Food Preservation; Mexico; Fermentation
PubMed: 38791776
DOI: 10.3390/ijerph21050560