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602000.9919Safety evaluation of Lactococcus lactis IDCC 2301 isolated from homemade cheese. For applications of microorganisms as probiotics in the food industry, safety evaluation has increasingly become important to ensure the health of consumers. Although people have been using various lactic acid bacteria for different purposes, some studies have reported that certain lactic acid bacteria exhibit properties of virulence and produce toxic compounds. Thus, it is necessary to examine the characteristics associated with lactic acid bacteria that are safe for use as probiotics. This research aimed to assess the safety of Lactococcus lactis IDCC 2301 isolated from homemade cheese using in vitro and in vivo assays, including antibiotic resistance, hemolytic activity, toxin production, infectivity, and metabolic activity in immune-compromised animal species. The results demonstrated that the strain was susceptible to nine antibiotics suggested by the European Food Safety Authority (EFSA). Whole-genome analysis revealed that L. lactis IDCC 2301 neither has toxigenic genes nor harbors antibiotic resistance. Moreover, L. lactis IDCC 2301 showed neither hemolytic nor β-glucuronidase activity. Furthermore, none of the D-lactate and biogenic amines were produced by L. lactis IDCC 2301. Finally, it was demonstrated that there was no toxicity and mortality using single-dose oral toxicity tests in rats. These results indicate that L. lactis IDCC 2301 can be safely used as probiotics for human consumption.202235035910
637310.9916Antibiotic resistance and multidrug-resistant efflux pumps expression in lactic acid bacteria isolated from pozol, a nonalcoholic Mayan maize fermented beverage. Pozol is a handcrafted nonalcoholic Mayan beverage produced by the spontaneous fermentation of maize dough by lactic acid bacteria. Lactic acid bacteria (LAB) are carriers of chromosomal encoded multidrug-resistant efflux pumps genes that can be transferred to pathogens and/or confer resistance to compounds released during the fermentation process causing food spoiling. The aim of this study was to evaluate the antibiotic sensibility and the transcriptional expression of ABC-type efflux pumps in LAB isolated from pozol that contributes to multidrug resistance. Analysis of LAB and Staphylococcus (S.) aureus ATCC 29213 and ATCC 6538 control strains to antibiotic susceptibility, minimal inhibitory concentration (MIC), and minimal bactericidal concentration (MBC) to ethidium bromide were based in "standard methods" whereas the ethidium bromide efflux assay was done by fluorometric assay. Transcriptional expression of efflux pumps was analyzed by RT-PCR. LAB showed antibiotic multiresistance profiles, moreover, Lactococcus (L.) lactis and Lactobacillus (L.) plantarum displayed higher ethidium bromide efflux phenotype than S. aureus control strains. Ethidium bromide resistance and ethidium bromide efflux phenotypes were unrelated with the overexpression of lmrD in L. lactics, or the underexpression of lmrA in L. plantarum and norA in S. aureus. These findings suggest that, moreover, the analyzed efflux pumps genes, other unknown redundant mechanisms may underlie the antibiotic resistance and the ethidium bromide efflux phenotype in L. lactis and L. plantarum. Phenotypic and molecular drug multiresistance assessment in LAB may improve a better selection of the fermentation starter cultures used in pozol, and to control the antibiotic resistance widespread and food spoiling for health safety.201627247772
604120.9915Gut commensal bacteria show beneficial properties as wildlife probiotics. Probiotics are noninvasive, environmentally friendly alternatives for reducing infectious diseases in wildlife species. Our aim in the present study was to evaluate the potential of gut commensals such as lactic acid bacteria (LAB) as wildlife probiotics. The LAB selected for our analyses were isolated from European badgers (Meles meles), a wildlife reservoir of bovine tuberculosis, and comprised four different genera: Enterococcus, Weissella, Pediococcus, and Lactobacillus. The enterococci displayed a phenotype and genotype that included the production of antibacterial peptides and stimulation of antiviral responses, as well as the presence of virulence and antibiotic resistance genes; Weissella showed antimycobacterial activity owing to their ability to produce lactate and ethanol; and lactobacilli and pediococci modulated proinflammatory phagocytic responses that associate with protection against pathogens, responses that coincide with the presence of immunomodulatory markers in their genomes. Although both lactobacilli and pediococci showed resistance to antibiotics, this was naturally acquired, and almost all isolates demonstrated a phylogenetic relationship with isolates from food and healthy animals. Our results show that LAB display probiotic benefits that depend on the genus, and that lactobacilli and pediococci are probably the most obvious candidates as probiotics against infectious diseases in wildlife because of their food-grade status and ability to modulate protective innate immune responses.202032026493
607630.9915Isolation and identification of mucin-degrading bacteria originated from human faeces and their potential probiotic efficacy according to host-microbiome enterotype. AIM: Mucin-degrading bacteria are known to be beneficial for gut health. We aimed to isolate human-derived mucin-degrading bacteria and identify potential probiotic characteristics and their effects on the bacterial community and short-chain fatty acid (SCFA) production according to three different enterotypes of the host. METHODS AND RESULTS: Bacteria with mucin decomposition ability from human faeces were isolated and identified by 16S rRNA sequencing and MALDI-TOF. Heat resistance, acid resistance, antibiotic resistance, and antibacterial activity were analysed in the selected bacteria. Their adhesion capability to the Caco-2 cell was determined by scanning electron microscopy. Their ability to alter the bacterial community and SCFA production of the isolated bacteria was investigated in three enterotypes. The three isolated strains were Bifidobacterium(Bif.) animalis SPM01 (CP001606.1, 99%), Bif. longum SPM02 (NR_043437.1, 99%), and Limosilactobacillus(L.) reuteri SPM03 (CP000705.1, 99%) deposited in Korean Collection for Type Culture (KCTC-18958P). Among them, Bif. animalis exhibited the highest mucin degrading ability. They exhibited strong resistance to acidic conditions, moderate resistance to heat, and the ability to adhere tightly to Caco-2 cells. Three isolated mucin-degrading bacteria incubation increased Lactobacillus in the faecal bacteria from Bacteroides and Prevotella enterotypes. However, only L. reuteri elevated Lactobacillus in the faecal bacteria from the Ruminococcus enterotype. B. longum and B. animalis increased the α-diversity in the Ruminococcus enterotype, while their incubation with other intestinal types decreased the α-diversity. Bifidobacterium animalis and L. reuteri increased the butyric acid level in faecal bacteria from the Prevotella enterotype, and L. reuteri elevated the acetic acid level in those from the Ruminococcus enterotype. However, the overall SCFA changes were minimal. CONCLUSIONS: The isolated mucin-degrading bacteria act as probiotics and modulate gut microbiota and SCFA production differently according to the host's enterotypes. SIGNIFICANCE AND IMPACT OF STUDY: Probiotics need to be personalized according to the enterotypes in clinical application.202235365862
605040.9914Vancomycin resistance factor of Lactobacillus rhamnosus GG in relation to enterococcal vancomycin resistance (van) genes. Lactobacillus rhamnosus GG (ATCC 53103) is a probiotic strain used in fermented dairy products in many countries and is also used as a food supplement in the form of freeze-dried powder. The relationship of the vancomycin resistance factor in L. rhamnosus GG and the vancomycin resistance (van) genes of Enterococcus faecalis and E. faecium were studied using polymerase chain reaction (PCR), Southern hybridization and conjugation methods. Our results show that the vancomycin resistance determinant in L. rhamnosus GG is not closely related to enterococcal van genes, since no PCR product was amplified in L. rhamnosus GG with any of the three sets of vanA primers used, and enterococcal vanA, vanB, vnH, vanX, vanZ, vanY, vanS and vanR genes did not hybridize with DNA of L. rhamnosus GG. This strain does not contain plasmids and transfer of chromosomal vancomycin resistance determinant from L. rhamnosus GG to enterococcal species was not detected. Our results are in accordance with previous findings of intrinsically vancomycin-resistant lactic acid bacteria.19989706787
602350.9914Bile-inducible efflux transporter from Bifidobacterium longum NCC2705, conferring bile resistance. Bifidobacteria are normal inhabitants of the human gut. Some strains of this genus are considered health promoting or probiotic, being included in numerous food products. In order to exert their health benefits, these bacteria must overcome biological barriers, including bile salts, to colonize and survive in specific parts of the intestinal tract. The role of multidrug resistance (MDR) transporters in bile resistance of probiotic bacteria and the effect of bile on probiotic gene expression are not fully understood. In the present study, the effect of subinhibitory concentrations of bile on the expression levels of predicted MDR genes from three different bifidobacterial strains, belonging to Bifidobacterium longum subsp. longum, Bifidobacterium breve, and Bifidobacterium animalis subsp. lactis, was tested. In this way, two putative MDR genes whose expression was induced by bile, BL0920 from B. longum and its homolog, Bbr0838, from B. breve, were identified. The expression of the BL0920 gene in Escherichia coli was shown to confer resistance to bile, likely to be mediated by active efflux from the cells. To the best of our knowledge, this represents the first identified bifidobacterial bile efflux pump whose expression is induced by bile.200919304838
604460.9913Phenotypic and Genetic Characterization and Production Abilities of Lacticaseibacillus rhamnosus Strain 484-A New Probiotic Strain Isolated From Human Breast Milk. Recent studies suggest that human breast milk (HBM) is a promising source of probiotic bacteria with potential applications in both medicine and the food industry. Probiotic bacteria, particularly species of the genus Lactobacillus, are classified as lactic acid bacteria (LAB). However, probiotic properties are strain-specific, as not all Lactobacillus strains exhibit health benefits or inhibit pathogens. This study evaluated the probiotic potential of a newly isolated strain, Lacticaseibacillus rhamnosus strain 484, derived from human milk. Phenotypic and genomic analyses were performed, with L. rhamnosus 1.0320 serving as a reference genome. We focused on strain safety for human use and potential health benefits. Strain 484 underwent probiotic characterization and demonstrated strong auto- and co-aggregation abilities, contributing to effective pathogenic bacteria inhibition. The strain also showed bile tolerance, antibiotic sensitivity, and lacked hemolytic and catalase activity, indicating safety and suitability profiles for oral administration. Its resistance to low pH and bile salts indicated survival during gastrointestinal transit and intestinal colonization. Notably, cell surface hydrophobicity (CSH) exceeded that of the well-known L. rhamnosus GG strain, potentially enhancing adhesion to intestinal epithelial cells. Genomic analysis confirmed no antibiotic resistance genes (ARGs) and plasmids, suggesting genetic stability. Overall, L. rhamnosus 484 appears to be a safe and promising probiotic candidate with potential applications in both medical and food-related fields, particularly for oral use in preventing and controlling common pathogens.202541019172
603470.9912Isolation and Characterization of Lactic Acid Bacteria With Probiotic Attributes From Different Parts of the Gastrointestinal Tract of Free-living Wild Boars in Hungary. Lactic acid bacteria (LAB) in the microbiota play an important role in human and animal health and, when used as probiotics, can contribute to an increased growth performance in livestock management. Animals living in their native habitat can serve as natural sources of microorganisms, so isolation of LAB strains from wild boars could provide the opportunity to develop effective probiotics to improve production in swine industry. In this study, the probiotic potential of 56 LAB isolates, originated from the ileum, colon, caecum and faeces of 5 wild boars, were assessed in vitro in details. Their taxonomic identity at species level and their antibacterial activity against four representative strains of potentially pathogenic bacteria were determined. The ability to tolerate low pH and bile salt, antibiotic susceptibility, bile salt hydrolase activity and lack of hemolysis were tested. Draft genome sequences of ten Limosilactobacillus mucosae and three Leuconostoc suionicum strains were determined. Bioinformatic analysis excluded the presence of any known acquired antibiotic resistance genes. Three genes, encoding mesentericin B105 and two different bacteriocin-IIc class proteins, as well as two genes with possible involvement in mesentericin secretion (mesE) and transport (mesD) were identified in two L. suionicum strains. Lam29 protein, a component of an ABC transporter with proved function as mucin- and epithelial cell-adhesion factor, and a bile salt hydrolase gene were found in all ten L. mucosae genomes. Comprehensive reconsideration of all data helps to select candidate strains to assess their probiotic potential further in animal experiments.202437353593
589780.9912Characterization of microbiota in Arapaima gigas intestine and isolation of potential probiotic bacteria. AIMS: The aim of this study was to determine the intestinal microbiota of pirarucu (Arapaima gigas) in different growth stages (adult and fingerlings) and to isolate and identify potential probiotic bacteria. METHODS AND RESULTS: High-throughput sequencing analysis of the intestinal contents revealed that the majority of sequences belonged to the Proteobacteria, Fusobacteria and Firmicutes phyla. At the genus level, the greatest number of sequences belonged to Bradyrhizobium in adult fish, while Cetobacterium was the most abundant in juvenile fish. Twenty-three lactic-acid bacteria (LABs) were isolated on MRS agar from healthy juvenile fish. The isolates were tested in vitro for probiotic properties. Two isolates (identified as strains of Lactococcus lactis subsp. lactis and Enterococcus faecium) displayed antagonism against all 10 pathogens tested, were nonhaemolytic and maintained good viability for at least 3 weeks when supplemented to fish diets. The presence of a number of antibiotic resistance genes (ARGs), conferring resistance to erythromycin, tetracycline and chloramphenicol, was investigated by PCR. CONCLUSIONS: The absence of ARGs investigated the potential to antagonize pathogens, and favourable growth and survival characteristics indicate that these autochthonous isolates have the potential to be considered probiotics, which will be studied in future in vivo experiments. SIGNIFICANCE AND IMPACT OF THE STUDY: This study has demonstrated, for the first time, the normal microbiota in the A. gigas intestine during different life stages and the presence of LAB strains. It also demonstrated LAB antibiotic resistance and antagonistic behaviour against pathogens isolated from the same fish.201728833934
358290.9912Investigating the transmissibility of tet(W) in bifidobacteria exposed to acid and bile stress. Transfer of antibiotic resistance genes from probiotic bacteria to pathogens poses a safety concern. Orally administered probiotics are exposed to stressful conditions during gastrointestinal transit. In this study, filter mating experiments were performed to investigate the potential role of exposure of Bifidobacterium isolates to acid and bile stress on the transfer of a tetracycline resistance gene, tet(W), to Enterococcus faecalis ATCC 51299. No E. faecalis transconjugants were obtained after mating with either stressed or unstressed Bifidobacterium, thereby suggesting that tet(W) could not be transferred as a result of exposure to gastrointestinal stresses.201829662736
6056100.9912Virulence, antibiotic resistance and biogenic amines of bacteriocinogenic lactococci and enterococci isolated from goat milk. The present study aimed to investigate the virulence, antibiotic resistance and biogenic amine production in bacteriocinogenic lactococci and enterococci isolated from goat milk in order to evaluate their safety. Twenty-nine bacteriocinogenic lactic acid bacteria (LAB: 11 Lactococcus spp., and 18 Enterococcus spp.) isolated from raw goat milk were selected and subjected to PCR to identify gelE, cylA, hyl, asa1, esp, efaA, ace, vanA, vanB, hdc1, hdc2, tdc and odc genes. The expression of virulence factors (gelatinase, hemolysis, lipase, DNAse, tyramine, histamine, putrescine) in different incubation temperatures was assessed by phenotypic methods, as well as the resistance to vancomycin, gentamicin, chloramphenicol, ampicillin and rifampicin (using Etest®). The tested isolates presented distinct combinations of virulence related genes, but not necessarily the expression of such factors. The relevance of identifying virulence-related genes in bacteriocinogenic LAB was highlighted, demanding for care in their usage as starter cultures or biopreservatives due to the possibility of horizontal gene transfer to other bacteria in food systems.201424960293
6030110.9911Molecular identification and probiotic potential characterization of lactic acid bacteria isolated from the pigs with superior immune responses. Lactic acid bacteria (LAB) belong to a significant group of probiotic bacteria that provide hosts with considerable health benefits. Our previous study showed that pigs with abundant LAB had more robust immune responses in a vaccination experiment. In this study, 52 isolate strains were isolated from the pigs with superior immune responses. Out of these, 14 strains with higher antibacterial efficacy were chosen. We then assessed the probiotic features of the 14 LAB strains, including such as autoaggregation, coaggregation, acid resistance, bile salt resistance, and adhesion capability, as well as safety aspects such as antibiotic resistance, hemolytic activity, and the presence or absence of virulence factors. We also compared these properties with those of an opportunistic pathogen EB1 and two commercial probiotics (cLA and cLP). The results showed that most LAB isolates exhibited higher abilities of aggregation, acid and bile salt resistance, adhesion, and antibacterial activity than the two commercial probiotics. Out of the 14 strains, only LS1 and LS9 carried virulence genes and none had hemolytic activity. We selected three LAB strains (LA6, LR6 and LJ1) with superior probiotic properties and LS9 with a virulence gene for testing their safety in vivo. Strains EB1, cLA and cLP were also included as control bacteria. The results demonstrated that mice treated LAB did not exhibit any adverse effects on weight gain, organ index, blood immune cells, and ileum morphology, except for those treated with LS9 and EB1. Moreover, the antimicrobial effect of LR6 and LA6 strains was examined in vivo. The results indicated that these strains could mitigate the inflammatory response, reduce bacterial translocation, and alleviate liver, spleen, and ileum injury caused by Salmonella typhimurium infection. In addition, the LR6 treatment group showed better outcomes than the LA6 treatment group; treatment with LR6 substantially reduced the mortality rate in mice. The study results provide evidence of the probiotic properties of the LAB isolates, in particular LR6, and suggest that oral administration of LR6 could have valuable health-promoting benefits.202438585699
6070120.9910Probiotic bacteria of wild boar origin intended for piglets - An in vitro study. Using probiotics represents a potential solution to post-weaning diarrheal diseases in piglets on commercial farms. The gastrointestinal tract of wild boars serves as a promising reservoir of novel lactic acid bacteria with suitable probiotic characteristics. In this study, we isolated eight bacterial strains from the intestinal content of wild boars identified as representatives of the species Bifidobacterium apri, Lactobacillus amylovorus, and Ligilactobacillus salivarius. These isolates underwent in vitro analysis and characterisation to assess their biological safety and probiotic properties. Analysis of their full genome sequences revealed the absence of horizontally transferrable genes for antibiotic resistance. However, seven out of eight isolates harboured genes encoding various types of bacteriocins in their genomes, and bacteriocin production was further confirmed by mass spectrometry analysis. Most of the tested strains demonstrated the ability to inhibit the growth of selected pathogenic bacteria, produce exopolysaccharides, and stimulate the expression of interleukin-10 in porcine macrophages. These characteristics deem the isolates characterised in this study as potential candidates for use as probiotics for piglets during the post-weaning period.202439296628
6049130.9910Probiotic Properties and Antioxidant Activity In Vitro of Lactic Acid Bacteria. The properties of probiotics such as lactic acid bacteria (LAB) have been widely studied over the last decades. In the present study, four different LAB species, namely Lactobacillus gasseri ATCC 33323, Lacticaseibacillus rhamnosus GG ATCC 53103, Levilactobacillus brevis ATCC 8287, and Lactiplantibacillus plantarum ATCC 14917, were investigated in order to determine their ability to survive in the human gut. They were evaluated based on their tolerance to acids, resistance to simulated gastrointestinal conditions, antibiotic resistance, and the identification of genes encoding bacteriocin production. All four tested strains demonstrated high resistance to simulated gastric juice after 3 h, and the viable counts revealed declines in cell concentrations of less than 1 log cycle. L. plantarum showed the highest level of survival in the human gut, with counts of 7.09 log CFU/mL. For the species L. rhamnosus and L. brevis, the values were 6.97 and 6.52, respectively. L. gasseri, after 12 h, showed a 3.96 log cycle drop in viable counts. None of the evaluated strains inhibited resistance to ampicillin, gentamicin, kanamycin, streptomycin, erythromycin, clindamycin, tetracycline, or chloramphenicol. With regard to bacteriocin genes, the Pediocin PA gene was identified in Lactiplantibacillus plantarum ATCC 14917, Lacticaseibacillus rhamnosus GG ATCC 53103, and Lactobacillus gasseri ATCC 33323. The PlnEF gene was detected in Lactiplantibacillus plantarum ATCC 14917 and Lacticaseibacillus rhamnosus GG ATCC 53103. The Brevicin 174A and PlnA genes were not detected in any bacteria. Moreover, the potential antioxidant activity of LAB's metabolites was evaluated. At the same time, the possible antioxidant activity of metabolites of LAB was first tested using the free radical DDPH(•) (a, a-Diphenyl-β-Picrylhydrazyl) and then evaluated with regard to their radical scavenging activity and inhibition against peroxyl radical induced DNA scission. All strains showed antioxidant activity; however, the best antioxidant activity was achieved by L. brevis (94.47%) and L. gasseri (91.29%) at 210 min. This study provides a comprehensive approach to the action of these LAB and their use in the food industry.202337317238
6019140.9910Effects of Lactobacillus pentosus combined with Arthrospira platensis on the growth performance, immune response, and intestinal microbiota of Litopenaeus vannamei. Litopenaeus vannamei is one of the most productive shrimp species in the world. However, shrimp farming is suffering from adverse environmental conditions and disease outbreaks. Typically, Lactobacillus pentosus and Arthrospira platensis are used as substitutes for some antibiotics. In the present study, we assessed the effects of dietary supplements along with living bacteria or cell-free extracts of L. pentosus combined with A. platensis on the growth performance, immune response, intestinal microbiota, and disease resistance of L. vannamei against Vibrio alginolyticus. Shrimp fed L. pentosus live bacteria combined with A. platensis showed the best growth performance and lowest feed conversion rate. The supplementation diet with L. pentosus live bacteria and A. platensis could significantly enhance the trypsin activity in shrimp after the feeding trial. Given the lowest feed conversion rate in shrimp fed L. pentosus live bacteria combined with A. platensis, we reasonably speculated that the decrease in feed conversion rate may be related to the increase in trypsin activity. In addition, dietary cell-free extracts of L. pentosus combined with A. platensis enhanced the expression of immune-related genes after the feeding trial or challenge test. Moreover, results of the bacterial challenge test indicated that the shrimp fed cell-free extracts of L. pentosus combined with A. platensis diet resulted in the highest survival rate, which suggested that cell-free extracts of L. pentosus and A. platensis could improve the disease resistance against V. alginolyticus by up-regulating the expressions of immune-related genes. Dietary L.pentosus or A. platensis, or their combination, reduced the abundance of harmful bacteria, including Proteobacteria in shrimp intestine, which suggested that L. pentosus and A. platensis could improve the growth performance and health of shrimp by regulating the structure of the intestinal microbiota. The findings of this study demonstrated that L. pentosus live bacteria and A. platensis exerted synergistic effects on the growth performance and digestion in shrimp, while cell-free extracts of L. pentosus and A. platensis showed synergistic effects on the immune response and disease resistance of shrimp against V. alginolyticus.202234883257
158150.9910Homology- and cross-resistance of Lactobacillus plantarum to acid and osmotic stress and the influence of induction conditions on its proliferation by RNA-Seq. In this study, homology- and cross-resistance of Lactobacillus plantarum L1 and Lactobacillus plantarum L2 to acid and osmotic stress were investigated. Meanwhile, its proliferation mechanism was demonstrated by transcriptomic analysis using RNA sequencing. We found that the homologous-resistance and cross-resistance of L. plantarum L1 and L. plantarum L2 increased after acid and osmotic induction treatment by lactic acid and sodium lactate solution in advance, and the survival rate of live bacteria was improved. In addition, the count of viable bacteria of L. plantarum L2 significantly increased cultivated at a pH 5.0 with a 15% sodium lactate sublethal treatment, compared with the control group. Further study revealed that genes related to membrane transport, amino acid metabolism, nucleotide metabolism, and cell growth were significantly upregulated. These findings will contribute to promote high-density cell culture of starter cultures production in the fermented food industry.202133945164
474160.9910Novel antibiotic resistance profiles in bacteria isolated from oil fly larvae Helaeomyia petrolei living in the La Brea Tar Pits. Larvae from the petroleum oil fly, Helaeomyia petrolei, live in the asphaltene and polyaromatic hydrocarbon rich asphalt seeps of Rancho La Brea, Los Angeles, California. These larvae pass high amounts of viscous asphalt through their digestive system, and their gut microbiota is exposed to these extreme conditions. Environmental stress response mechanisms can co-select for antibiotic resistance, and in the current study we used 16S rRNA and genomic sequencing along with the Comprehensive Antibiotic Resistance Database (CARD) tools to characterize antibiotic resistance profiles from six bacteria previously isolated from the oil fly larval intestinal tract, linking phenotypic and genotypic resistance profiles. The isolates contain a core set of antibiotic resistance determinants along with determinants that are rarely found in these species. Comparing these oil fly isolates to the phenotypic prevalence data generated by the CARD Resistance Gene Identifier revealed sixteen instances where the oil fly bacteria appeared to carry a resistance not seen in related taxa in the database, suggesting a novel suite of resistance families in the oil fly isolates compared to other members of the same taxa. Results highlight the functional duality of genes that simultaneously code for antibiotic resistance and survival under extreme conditions, and expand our understanding of the ecological and evolutionary role of antibiotic resistance genes in environmental habitats.202439718641
6725170.9910Honeybee (Apis mellifera) resistance to deltamethrin exposure by Modulating the gut microbiota and improving immunity. Honeybees (Apis mellifera) are important economic insects and play important roles in pollination and maintenance of ecological balance. However, the use of pesticides has posed a substantial threat to bees in recent years, with the more widely used deltamethrin being the most harmful. In this study, we found that deltamethrin exposure significantly reduced bee survival in a dose-dependent manner (p = 0.025). In addition, metagenomic sequencing further revealed that DM exposure significantly reduced the diversity of the bee gut microbiota (Chao1, p < 0.0001; Shannon, p < 0.0001; Simpson, p < 0.0001) and decreased the relative abundance of core species of the gut microbiota. Importantly, in studies of GF-bees, we found that the colonization of important gut bacteria such as Gilliamella apicola and Lactobacillus kunkeei significantly increased bee resistance to DM (survival rate increased from 16.7 to 66.7%). Interestingly, we found that the immunity-genes Defensin-2 and Toll were significantly upregulated in bees after the colonization of gut bacteria. These results suggest that gut bacteria may protect against DM stress by improving host immunity. Our findings provide an important rationale for protecting honeybees from pollutants from the perspective of gut microbes.202236208825
6043180.9910Histamine and cholesterol lowering abilities of lactic acid bacteria isolated from artisanal Pico cheese. AIMS: This study was designed to select lactic acid bacteria with histamine- and cholesterol-reducing abilities to be used as potential probiotics. METHODS AND RESULTS: Thirty strains of lactic acid bacteria isolated from an artisanal raw milk cheese were screened for their abilities to degrade histamine, reduce cholesterol and hydrolyse bile salts. Strains were also screened for safety and probiotic traits, such as resistance to gastrointestinal conditions, adhesion to Caco-2 cells, resistance to antibiotics and presence of virulence genes. Two Lactobacillus paracasei strains presented high cholesterol- and histamine-lowering abilities, tested negative for the presence of virulence genes and showed susceptibility to most important antibiotics. These strains were also shown to possess desirable in vitro probiotic properties, revealed by tolerance to gastrointestinal conditions and high adhesion to intestinal cells. CONCLUSIONS: Among the screened strains, Lb. paracasei L3C21M6 revealed the best cholesterol and histamine reducing abilities together with desirable probiotic and safety features to be used in food applications. SIGNIFICANCE AND IMPACT OF THE STUDY: The strain L3C21M6 is a good candidate for use as a probiotic with histamine-degrading activity and cholesterol lowering effect. In addition, this strain could be use in dairy foods to prevent histamine food poisoning.202032500572
7730190.9910Cerebral Intraparenchymal Hemorrhage Changes Patients' Gut Bacteria Composition and Function. Gut bacteria consists of 150 times more genes than humans that are vital for health. Several studies revealed that gut bacteria are associated with disease status and influence human behavior and mentality. Whether human brain injury alters the gut bacteria is yet unclear, we tested 20 fecal samples from patients with cerebral intraparenchymal hemorrhage and corresponding healthy controls through metagenomic shotgun sequencing. The composition of patients' gut bacteria changed significantly at the phylum level; Verrucomicrobiota was the specific phylum colonized in the patients' gut. The functional alteration was observed in the patients' gut bacteria, including high metabolic activity for nutrients or neuroactive compounds, strong antibiotic resistance, and less virulence factor diversity. The changes in the transcription and metabolism of differential species were more evident than those of the non-differential species between groups, which is the primary factor contributing to the functional alteration of patients with cerebral intraparenchymal hemorrhage.202235372117