Comparative Genomics of Lactiplantibacillus plantarum: Insights Into Probiotic Markers in Strains Isolated From the Human Gastrointestinal Tract and Fermented Foods. - Related Documents




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846201.0000Comparative Genomics of Lactiplantibacillus plantarum: Insights Into Probiotic Markers in Strains Isolated From the Human Gastrointestinal Tract and Fermented Foods. Lactiplantibacillus (Lpb.) plantarum is a versatile species commonly found in a wide variety of ecological niches including dairy products and vegetables, while it may also occur as a natural inhabitant of the human gastrointestinal tract. Although Lpb. plantarum strains have been suggested to exert beneficial properties on their host, the precise mechanisms underlying these microbe-host interactions are still obscure. In this context, the genome-scale in silico analysis of putative probiotic bacteria represents a bottom-up approach to identify probiotic biomarkers, predict desirable functional properties, and identify potentially detrimental antibiotic resistance genes. In this study, we characterized the bacterial genomes of three Lpb. plantarum strains isolated from three distinct environments [strain IMC513 (from the human GIT), C904 (from table olives), and LT52 (from raw-milk cheese)]. A whole-genome sequencing was performed combining Illumina short reads with Oxford Nanopore long reads. The phylogenomic analyses suggested the highest relatedness between IMC513 and C904 strains which were both clade 4 strains, with LT52 positioned within clade 5 within the Lpb. plantarum species. The comparative genome analysis performed across several Lpb. plantarum representatives highlighted the genes involved in the key metabolic pathways as well as those encoding potential probiotic features in these new isolates. In particular, our strains varied significantly in genes encoding exopolysaccharide biosynthesis and in contrast to strains IMC513 and C904, the LT52 strain does not encode a Mannose-binding adhesion protein. The LT52 strain is also deficient in genes encoding complete pentose phosphate and the Embden-Meyerhof pathways. Finally, analyses using the CARD and ResFinder databases revealed that none of the strains encode known antibiotic resistance loci. Ultimately, the results provide better insights into the probiotic potential and safety of these three strains and indicate avenues for further mechanistic studies using these isolates.202235663852
846610.9993Genomic Characterization of Lactiplantibacillus plantarum Strains: Potential Probiotics from Ethiopian Traditional Fermented Cottage Cheese. BACKGROUND: Lactiplantibacillus plantarum is a species found in a wide range of ecological niches, including vegetables and dairy products, and it may occur naturally in the human gastrointestinal tract. The precise mechanisms underlying the beneficial properties of these microbes to their host remain obscure. Although Lactic acid bacteria are generally regarded as safe, there are rare cases of the emergence of infections and antibiotic resistance by certain probiotics. OBJECTIVE: An in silico whole genome sequence analysis of putative probiotic bacteria was set up to identify strains, predict desirable functional properties, and identify potentially detrimental antibiotic resistance and virulence genes. METHODS: We characterized the genomes of three L. plantarum strains (54B, 54C, and 55A) isolated from Ethiopian traditional cottage cheese. Whole-genome sequencing was performed using Illumina MiSeq sequencing. The completeness and quality of the genome of L. plantarum strains were assessed through CheckM. RESULTS: Analyses results showed that L. plantarum 54B and 54C are closely related but different strains. The genomes studied did not harbor resistance and virulence factors. They had five classes of carbohydrate-active enzymes with several important functions. Cyclic lactone autoinducer, terpenes, Type III polyketide synthases, ribosomally synthesized and post-translationally modified peptides-like gene clusters, sactipeptides, and all genes required for riboflavin biosynthesis were identified, evidencing their promising probiotic properties. Six bacteriocin-like structures encoding genes were found in the genome of L. plantarum 55A. CONCLUSIONS: The lack of resistome and virulome and their previous functional capabilities suggest the potential applicability of these strains in food industries as bio-preservatives and in the prevention and/or treatment of infectious diseases. The results also provide insights into the probiotic potential and safety of these three strains and indicate avenues for further mechanistic studies using these isolates.202439596588
435820.9993Genomic profiling of pediococcus acidilactici BCB1H and identification of its key features for Biotechnological innovation, food technology and medicine. Lactic acid bacteria has been extensively used in food industry because of widespread properties and Pediococcus is among one of them. This study aims to conduct a comprehensive genomic analysis of Pediococcus acidilactici strain BCB1H to elucidate its genetic composition, functional elements, and potential biotechnological applications. The objectives include identifying key genomic features such as coding sequences, tRNA and rRNA genes, antibiotic resistance genes, and secondary metabolite biosynthetic gene clusters, which will highlight the adaptability and potential of P. acidilactici strain BCB1H for use in a variety of industrial and therapeutic applications. P. acidilactici strain BCB1H was analyzed using whole-genome sequencing, which used advanced sequencing technologies to obtain comprehensive genomic data. Key genomic features, such as coding sequences, tRNA and rRNA genes, antibiotic resistance genes, and secondary metabolite biosynthetic gene clusters, were identified through bioinformatics analyses. The genomic analysis of P. acidilactici strain BCB1H revealed a genome size of approximately 1.92 million base pairs with a GC content of 42.4%. The annotation identified 1,895 genes across 192 subsystems, highlighting the metabolic pathways and functional categories. Notably, specialty genes associated with carbohydrate metabolism, stress response, pathogenicity, and amino acid synthesis were identified, underscoring the versatility and potential applications in food technology and medicine. These findings shed light on the genetic makeup and functional potential of P. acidilactici strain BCB1H, highlighting its flexibility and industrial importance. The genetic traits discovered suggest its prospective use in probiotics, food preservation, and biotechnological advancements.202539971970
514830.9992Unveiling the whole genomic features and potential probiotic characteristics of novel Lactiplantibacillus plantarum HMX2. This study investigates the genomic features and probiotic potential of Lactiplantibacillus plantarum HMX2, isolated from Chinese Sauerkraut, using whole-genome sequencing (WGS) and bioinformatics for the first time. This study also aims to find genetic diversity, antibiotic resistance genes, and functional capabilities to help us better understand its food safety applications and potential as a probiotic. L. plantarum HMX2 was cultured, and DNA was extracted for WGS. Genomic analysis comprised average nucleotide identity (ANI) prediction, genome annotation, pangenome, and synteny analysis. Bioinformatics techniques were used to identify CoDing Sequences (CDSs), transfer RNA (tRNA) and ribosomal RNA (rRNA) genes, and antibiotic resistance genes, as well as to conduct phylogenetic analysis to establish genetic diversity and evolution. The study found a significant genetic similarity (99.17% ANI) between L. plantarum HMX2 and the reference strain. Genome annotation revealed 3,242 coding sequences, 65 tRNA genes, and 16 rRNA genes. Significant genetic variety was found, including 25 antibiotic resistance genes. A phylogenetic study placed L. plantarum HMX2 among closely related bacteria, emphasizing its potential for probiotic and food safety applications. The genomic investigation of L. plantarum showed essential genes, including plnJK and plnEF, which contribute to antibacterial action against foodborne pathogens. Furthermore, genes such as MurA, Alr, and MprF improve food safety and probiotic potential by promoting bacterial survival under stress conditions in food and the gastrointestinal tract. This study introduces the new genomic features of L. plantarum HMX2 about specific genetics and its possibility of relevant uses in food security and technologies. These findings of specific genes involved in antimicrobial activity provide fresh possibilities for exploiting this strain in forming probiotic preparations and food preservation methods. The future research should focus on the experimental validation of antibiotic resistance genes, comparative genomics to investigate functional diversity, and the development of novel antimicrobial therapies that take advantage of L. plantarum's capabilities.202439611087
435740.9992Comparative genomic analysis of 255 Oenococcus oeni isolates from China: unveiling strain diversity and genotype-phenotype associations of acid resistance. Oenococcus oeni, the only species of lactic acid bacteria capable of fully completing malolactic fermentation under challenging wine conditions, continues to intrigue researchers owing to its remarkable adaptability, particularly in combating acid stress. However, the mechanism underlying its superior adaptation to wine stresses still remains elusive due to the lack of viable genetic manipulation tools for this species. In this study, we conducted genomic sequencing and acid resistance phenotype analysis of 255 O. oeni isolates derived from diverse wine regions across China, aiming to elucidate their strain diversity and genotype-phenotype associations of acid resistance through comparative genomics. A significant correlation between phenotypes and evolutionary relationships was observed. Notably, phylogroup B predominantly consisted of acid-resistant isolates, primarily originating from Shandong and Shaanxi wine regions. Furthermore, we uncovered a noteworthy linkage between prophage genomic islands and acid resistance phenotype. Using genome-wide association studies, we identified key genes correlated with acid resistance, primarily involved in carbohydrates and amino acid metabolism processes. This study offers profound insights into the genetic diversity and genetic basis underlying adaptation mechanisms to acid stress in O. oeni.IMPORTANCEThis study provides valuable insights into the genetic basis of acid resistance in Oenococcus oeni, a key lactic acid bacterium in winemaking. By analyzing 255 isolates from diverse wine regions in China, we identified significant correlations between strain diversity, genomic islands, and acid resistance phenotypes. Our findings reveal that certain prophage-related genomic islands and specific genes are closely linked to acid resistance, offering a deeper understanding of how O. oeni adapts to acidic environments. These discoveries not only advance our knowledge of microbial stress responses but also pave the way for selecting and engineering acid-resistant strains, enhancing malolactic fermentation efficiency and wine quality. This research underscores the importance of genomics in improving winemaking practices and addressing challenges posed by high-acidity wines.202540261018
514950.9992Complete genome sequence and comparative genomic analysis of Enterococcus faecalis EF-2001, a probiotic bacterium. Enterococcus faecalis is a common human gut commensal bacterium. While some E. faecalis strains are probiotic, others are known to cause opportunistic infections, and clear distinction between these strains is difficult using traditional taxonomic approaches. In this study, we completed the genome sequencing of EF-2001, a probiotic strain, using our in-house hybrid assembly approach. Comparative analysis showed that EF-2001 was devoid of cytolysins, major factors associated with pathogenesis, and was phylogenetically distant from pathogenic E. faecalis V583. Genomic analysis of strains with a publicly available complete genome sequence predicted that drug-resistance genes- dfrE, efrA, efrB, emeA, and lsaA were present in all strains, and EF-2001 lacked additional drug-resistance genes. Core- and pan-genome analyses revealed a higher degree of genomic fluidity. We found 49 genes specific to EF-2001, further characterization of which may provide insights into its diverse biological activities. Our comparative genomic analysis approach could help predict the pathogenic or probiotic potential of E. faecalis leading to an early distinction based on genome sequences.202133771633
838360.9991Novel insights into carbohydrate utilisation, antimicrobial resistance, and sporulation potential in Roseburia intestinalis isolates across diverse geographical locations. Roseburia intestinalis is one of the most abundant and important butyrate-producing human gut anaerobic bacteria that plays an important role in maintaining health and is a potential next-generation probiotic. We investigated the pangenome of 16 distinct strains, isolated over several decades, identifying local and time-specific adaptations. More than 50% of the genes in each individual strain were assigned to the core genome, and 77% of the cloud genes were unique to individual strains, revealing the high level of genome conservation. Co-carriage of the same enzymes involved in carbohydrate binding and degradation in all strains highlighted major pathways in carbohydrate utilization and reveal the importance of xylan, starch and mannose as key growth substrates. A single strain had adapted to use rhamnose as a sole growth substrate, the first time this has been reported. The ubiquitous presence of motility and sporulation gene clusters demonstrates the importance of these phenotypes for gut survival and acquisition of this bacterium. More than half the strains contained functional, potentially transferable, tetracycline resistance genes. This study advances our understanding of the importance of R. intestinalis within the gut ecosystem by elucidating conserved metabolic characteristics among different strains, isolated from different locations. This information will help to devise dietary strategies to increase the abundance of this species providing health benefits.202540089923
514170.9991Flavobacterium flabelliforme sp. nov. and Flavobacterium geliluteum sp. nov., Two Multidrug-Resistant Psychrotrophic Species Isolated From Antarctica. Despite unfavorable Antarctic conditions, such as cold temperatures, freeze-thaw cycles, high ultraviolet radiation, dryness and lack of nutrients, microorganisms were able to adapt and surprisingly thrive in this environment. In this study, eight cold-adapted Flavobacterium strains isolated from a remote Antarctic island, James Ross Island, were studied using a polyphasic taxonomic approach to determine their taxonomic position. Phylogenetic analyses based on the 16S rRNA gene and 92 core genes clearly showed that these strains formed two distinct phylogenetic clusters comprising three and five strains, with average nucleotide identities significantly below 90% between both proposed species as well as between their closest phylogenetic relatives. Phenotyping revealed a unique pattern of biochemical and physiological characteristics enabling differentiation from the closest phylogenetically related Flavobacterium spp. Chemotaxonomic analyses showed that type strains P4023(T) and P7388(T) were characterized by the major polyamine sym-homospermidine and a quinone system containing predominantly menaquinone MK-6. In the polar lipid profile phosphatidylethanolamine, an ornithine lipid and two unidentified lipids lacking a functional group were detected as major lipids. These characteristics along with fatty acid profiles confirmed that these species belong to the genus Flavobacterium. Thorough genomic analysis revealed the presence of numerous cold-inducible or cold-adaptation associated genes, such as cold-shock proteins, proteorhodopsin, carotenoid biosynthetic genes or oxidative-stress response genes. Genomes of type strains surprisingly harbored multiple prophages, with many of them predicted to be active. Genome-mining identified biosynthetic gene clusters in type strain genomes with a majority not matching any known clusters which supports further exploratory research possibilities involving these psychrotrophic bacteria. Antibiotic susceptibility testing revealed a pattern of multidrug-resistant phenotypes that were correlated with in silico antibiotic resistance prediction. Interestingly, while typical resistance finder tools failed to detect genes responsible for antibiotic resistance, genomic prediction confirmed a multidrug-resistant profile and suggested even broader resistance than tested. Results of this study confirmed and thoroughly characterized two novel psychrotrophic Flavobacterium species, for which the names Flavobacterium flabelliforme sp. nov. and Flavobacterium geliluteum sp. nov. are proposed.202134745033
436080.9991Comparative Genomics Reveals Novel Species and Insights into the Biotechnological Potential, Virulence, and Resistance of Alcaligenes. Alcaligenes is a cosmopolitan bacterial genus that exhibits diverse properties which are beneficial to plants. However, the genomic versatility of Alcaligenes has also been associated with the ability to cause opportunistic infections in humans, raising concerns about the safety of these microorganisms in biotechnological applications. Here, we report an in-depth comparative analysis of Alcaligenes species using all publicly available genomes to investigate genes associated with species, biotechnological potential, virulence, and resistance to multiple antibiotics. Phylogenomic analysis revealed that Alcaligenes consists of at least seven species, including three novel species. Pan-GWAS analysis uncovered 389 species-associated genes, including cold shock proteins (e.g., cspA) and aquaporins (e.g., aqpZ) found exclusively in the water-isolated species, Alcaligenes aquatilis. Functional annotation of plant-growth-promoting traits revealed enrichment of genes for auxin biosynthesis, siderophores, and organic acids. Genes involved in xenobiotic degradation and toxic metal tolerance were also identified. Virulome and resistome profiles provide insights into selective pressures exerted in clinical settings. Taken together, the results presented here provide the grounds for more detailed clinical and ecological studies of the genus Alcaligenes.202337761923
463890.9991Comprehensive Scanning of Prophages in Lactobacillus: Distribution, Diversity, Antibiotic Resistance Genes, and Linkages with CRISPR-Cas Systems. Prophage integration, release, and dissemination exert various effects on host bacteria. In the genus Lactobacillus, they may cause bacteriophage contamination during fermentation and even regulate bacterial populations in the gut. However, little is known about their distribution, genetic architecture, and relationships with their hosts. Here, we conducted prophage prediction analysis on 1,472 genomes from 16 different Lactobacillus species and found prophage fragments in almost all lactobacilli (99.8%), with 1,459 predicted intact prophages identified in 64.1% of the strains. We present an uneven prophage distribution among Lactobacillus species; multihabitat species retained more prophages in their genomes than restricted-habitat species. Characterization of the genome features, average nucleotide identity, and landscape visualization presented a high genome diversity of Lactobacillus prophages. We detected antibiotic resistance genes in more than 10% of Lactobacillus prophages and validated that the occurrence of resistance genes conferred by prophage integration was possibly associated with phenotypic resistance in Lactobacillus plantarum. Furthermore, our broad and comprehensive examination of the distribution of CRISPR-Cas systems across the genomes predicted type I and type III systems as potential antagonistic elements of Lactobacillus prophage. IMPORTANCE Lactobacilli are inherent microorganisms in the human gut and are widely used in the food processing industries due to their probiotic properties. Prophages were reportedly hidden in numerous Lactobacillus genomes and can potentially contaminate entire batches of fermentation or modulate the intestinal microecology once they are released. Therefore, a comprehensive scanning of prophages in Lactobacillus is essential for the safety evaluation and application development of probiotic candidates. We show that prophages are widely distributed among lactobacilli; however, intact prophages are more common in multihabitat species and display wide variations in genome feature, integration site, and genomic organization. Our data of the prophage-mediated antibiotic resistance genes (ARGs) and the resistance phenotype of lactobacilli provide evidence for deciphering the putative role of prophages as vectors of the ARGs. Furthermore, understanding the association between prophages and CRISPR-Cas systems is crucial to appreciate the coevolution of phages and Lactobacillus.202134060909
8392100.9991Identification of variable genomic regions related to stress response in Oenococcus oeni. The lactic acid bacterium Oenococcus oeni is the most important species involved in malolactic fermentation due to its capability to survive in presence of ethanol and in the acidic environment of wine. In order to identify novel genes involved in adaptation to wine, a new approach using genome-wide analysis based on stress-related genes was performed in strain O. oeni PSU-1, and 106 annotated stress genes were identified. The in silico analysis revealed the high similarity of all those genes through 57 O. oeni genomes; however, seven variable regions of genomic plasticity could be determined for their different presence observed among these strains. Regions 3 and 5 had the typical hallmarks of horizontal transfer, suggesting that the strategy of acquiring genes from other bacteria enhanced the fitness of O. oeni strains. Certain genes related to stress resistance were described in these regions, and similarities of putative acquired regions with other lactic acid bacteria species were found. Some genomic fragments present in all the strains were described and another new genomic island harbouring a threonine dehydrogenase was found. The association of selected sequences with adaptation to wine was assessed by screening 31 O. oeni strains using PCR of single genes, but no sequences were found to be exclusive to highly performing malolactic fermentation strains. This study provides new information about the genomic variability of O. oeni strains contributing to a further understanding of this species and the relationship of its genomic traits with the ability to adapt to stress conditions.201729195994
4663110.9991Pan-genomics of Ochrobactrum species from clinical and environmental origins reveals distinct populations and possible links. Ochrobactrum genus is comprised of soil-dwelling Gram-negative bacteria mainly reported for bioremediation of toxic compounds. Since last few years, mainly two species of this genus, O. intermedium and O. anthropi were documented for causing infections mostly in the immunocompromised patients. Despite such ubiquitous presence, study of adaptation in various niches is still lacking. Thus, to gain insights into the niche adaptation strategies, pan-genome analysis was carried out by comparing 67 genome sequences belonging to Ochrobactrum species. Pan-genome analysis revealed it is an open pan-genome indicative of the continuously evolving nature of the genus. The presence/absence of gene clusters also illustrated the unique presence of antibiotic efflux transporter genes and type IV secretion system genes in the clinical strains while the genes of solvent resistance and exporter pumps in the environmental strains. A phylogenomic investigation based on 75 core genes depicted better and robust phylogenetic resolution and topology than the 16S rRNA gene. To support the pan-genome analysis, individual genomes were also investigated for the mobile genetic elements (MGE), antibiotic resistance genes (ARG), metal resistance genes (MRG) and virulence factors (VF). The analysis revealed the presence of MGE, ARG, and MRG in all the strains which play an important role in the species evolution which is in agreement with the pan-genome analysis. The average nucleotide identity (ANI) based on the genetic relatedness between the Ochrobactrum species indicated a distinction between individual species. Interestingly, the ANI tool was able to classify the Ochrobactrum genomes to the species level which were assigned till the genus level on the NCBI database.202032428556
4639120.9990Genomic and Phenotypic Characterization of Mastitis-Causing Staphylococci and Probiotic Lactic Acid Bacteria Isolated from Raw Sheep's Milk. Dairy products play a crucial role in human nutrition as they provide essential nutrients. However, the presence of diverse microorganisms in these products can pose challenges to food safety and quality. Here, we provide a comprehensive molecular characterization of a diverse collection of lactic acid bacteria (LAB) and staphylococci isolated from raw sheep's milk. Whole-genome sequencing, phenotypic characterization, and bioinformatics were employed to gain insight into the genetic composition and functional attributes of these bacteria. Bioinformatics analysis revealed the presence of various genetic elements. Important toxin-related genes in staphylococci that contribute to their pathogenic potential were identified and confirmed using phenotypic assays, while adherence-related genes, which are essential for attachment to host tissues, surfaces in the dairy environment, and the creation of biofilms, were also present. Interestingly, the Staphylococcus aureus isolates belonged to sequence type 5, which largely consists of methicillin-susceptible isolates that have been involved in severe nosocomial infections. Although genes encoding methicillin resistance were not identified, multiple resistance genes (RGs) conferring resistance to aminoglycosides, macrolides, and fluroquinolones were found. In contrast, LAB had few inherently present RGs and no virulence genes, suggesting their likely safe status as food additives in dairy products. LAB were also richer in bacteriocins and carbohydrate-active enzymes, indicating their potential to suppress pathogens and effectively utilize carbohydrate substrates, respectively. Additionally, mobile genetic elements, present in both LAB and staphylococci, may facilitate the acquisition and dissemination of genetic traits, including RGs, virulence genes, and metabolic factors, with implications for food quality and public health. The molecular and phenotypic characterization presented herein contributes to the effort to mitigate risks and infections (e.g., mastitis) and enhance the safety and quality of milk and products thereof.202337762186
5151130.9990Comparative Genome Analysis of Bacillus amyloliquefaciens Focusing on Phylogenomics, Functional Traits, and Prevalence of Antimicrobial and Virulence Genes. Bacillus amyloliquefaciens is a gram-positive, nonpathogenic, endospore-forming, member of a group of free-living soil bacteria with a variety of traits including plant growth promotion, production of antifungal and antibacterial metabolites, and production of industrially important enzymes. We have attempted to reconstruct the biogeographical structure according to functional traits and the evolutionary lineage of B. amyloliquefaciens using comparative genomics analysis. All the available 96 genomes of B. amyloliquefaciens strains were curated from the NCBI genome database, having a variety of important functionalities in all sectors keeping a high focus on agricultural aspects. In-depth analysis was carried out to deduce the orthologous gene groups and whole-genome similarity. Pan genome analysis revealed that shell genes, soft core genes, core genes, and cloud genes comprise 17.09, 5.48, 8.96, and 68.47%, respectively, which demonstrates that genomes are very different in the gene content. It also indicates that the strains may have flexible environmental adaptability or versatile functions. Phylogenetic analysis showed that B. amyloliquefaciens is divided into two clades, and clade 2 is further dived into two different clusters. This reflects the difference in the sequence similarity and diversification that happened in the B. amyloliquefaciens genome. The majority of plant-associated strains of B. amyloliquefaciens were grouped in clade 2 (73 strains), while food-associated strains were in clade 1 (23 strains). Genome mining has been adopted to deduce antimicrobial resistance and virulence genes and their prevalence among all strains. The genes tmrB and yuaB codes for tunicamycin resistance protein and hydrophobic coat forming protein only exist in clade 2, while clpP, which codes for serine proteases, is only in clade 1. Genome plasticity of all strains of B. amyloliquefaciens reflects their adaption to different niches.202134659348
8382140.9990Transcriptional and Functional Analysis of Bifidobacterium animalis subsp. lactis Exposure to Tetracycline. Commercial probiotic bacteria must be tested for acquired antibiotic resistance elements to avoid potential transfer to pathogens. The European Food Safety Authority recommends testing resistance using microdilution culture techniques previously used to establish inhibitory thresholds for the Bifidobacterium genus. Many Bifidobacterium animalis subsp. lactis strains exhibit increased resistance to tetracycline, historically attributed to the ribosomal protection gene tet(W). However, some strains that harbor genetically identical tet(W) genes show various inhibition levels, suggesting that other genetic elements also contribute to observed differences. Here, we adapted several molecular assays to confirm the inhibition of B. animalis subsp. lactis strains Bl-04 and HN019 and employed RNA sequencing to assess the transcriptional differences related to genomic polymorphisms. We detected specific stress responses to the antibiotic by correlating ATP concentration to number of viable genome copies from droplet digital PCR and found that the bacteria were still metabolically active in high drug concentrations. Transcriptional analyses revealed that several polymorphic regions, particularly a novel multidrug efflux transporter, were differentially expressed between the strains in each experimental condition, likely having phenotypic effects. We also found that the tet(W) gene was upregulated only during subinhibitory tetracycline concentrations, while two novel tetracycline resistance genes were upregulated at high concentrations. Furthermore, many genes involved in amino acid metabolism and transporter function were upregulated, while genes for complex carbohydrate utilization, protein metabolism, and clustered regularly interspaced short palindromic repeat(s) (CRISPR)-Cas systems were downregulated. These results provide high-throughput means for assessing antibiotic resistances of two highly related probiotic strains and determine the genetic network that contributes to the global tetracycline response.IMPORTANCEBifidobacterium animalis subsp. lactis is widely used in human food and dietary supplements. Although well documented to be safe, B. animalis subsp. lactis strains must not contain transferable antibiotic resistance elements. Many B. animalis subsp. lactis strains have different resistance measurements despite being genetically similar, and the reasons for this are not well understood. In the current study, we sought to examine how genomic differences between two closely related industrial B. animalis subsp. lactis strains contribute to different resistance levels. This will lead to a better understanding of resistance, identify future targets for analysis of transferability, and expand our understanding of tetracycline resistance in bacteria.201830266728
4359150.9990Whole-genome sequencing of Alcaligenes sp. strain MMA: insight into the antibiotic and heavy metal resistant genes. Introduction: A wide range of pollutants, including the likes of xenobiotics, heavy metals, and antibiotics, are characteristic of marine ecosystems. The ability of the bacteria to flourish under high metal stress favors the selection of antibiotic resistance in aquatic environments. Increased use and misuse of antibiotics in medicine, agriculture, and veterinary have posed a grave concern over antimicrobial resistance. The exposure to these heavy metals and antibiotics in the bacteria drives the evolution of antibiotic and heavy metal resistance genes. In the earlier study by the author Alcaligenes sp. MMA was involved in the removal of heavy metals and antibiotics. Alcaligenes display diverse bioremediation capabilities but remain unexplored at the level of the genome. Methods: To shed light on its genome, the Alcaligenes sp. strain MMA, was sequenced using Illumina Nova Seq sequencer, which resulted in a draft genome of 3.9 Mb. The genome annotation was done using Rapid annotation using subsystem technology (RAST). Given the spread of antimicrobial resistance and the generation of multi-drug resistant pathogens (MDR), the strain MMA was checked for potential antibiotic and heavy metal resistance genes Further, we checked for the presence of biosynthetic gene clusters in the draft genome. Results: Alcaligenes sp. strain MMA, was sequenced using Illumina Nova Seq sequencer, which resulted in a draft genome of 3.9 Mb. The RAST analysis revealed the presence of 3685 protein-coding genes, involved in the removal of antibiotics and heavy metals. Multiple metal-resistant genes and genes conferring resistance to tetracycline, beta-lactams, and fluoroquinolones were present in the draft genome. Many types of BGCs were predicted, such as siderophore. The secondary metabolites of fungi and bacteria are a rich source of novel bioactive compounds which have the potential to in new drug candidates. Discussion: The results of this study provide information on the strain MMA genome and are valuable for the researcher in further exploitation of the strain MMA for bioremediation. Moreover, whole-genome sequencing has become a useful tool to monitor the spread of antibiotic resistance, a global threat to healthcare.202337251338
4637160.9990What Differentiates Probiotic from Pathogenic Bacteria? The Genetic Mobility of Enterococcus faecium Offers New Molecular Insights. Enterococcus faecium is a lactic acid bacterium with applications in food engineering and nutrigenomics, including as starter cultures in fermented foods. To differentiate the E. faecium probiotic from pathogenic bacteria, physiological analyses are often used but they do not guarantee that a bacterial strain is not pathogenic. We report here new findings and an approach based on comparison of the genetic mobility of (1) probiotic, (2) pathogenic, and (3) nonpathogenic and non-probiotic strains, so as to differentiate probiotics, and inform their safe use. The region of the 16S ribosomal DNA (rDNA) genes of different E. faecium strains native to Pernambuco-Brazil was used with the GenBank query sequence. Complete genomes were selected and divided into three groups as noted above to identify the mobile genetic elements (MGEs) (transposase, integrase, conjugative transposon protein and phage) and antibiotic resistance genes (ARGs), and to undertake pan-genome analysis and multiple genome alignment. Differences in the number of MGEs were found in ARGs, in the presence and absence of the genes that differentiate E. faecium probiotics and pathogenic bacteria genetically. Our data suggest that genetic mobility appears to be informative in differentiating between probiotic and pathogenic strains. While the present findings are not necessarily applicable to all probiotics, they offer novel molecular insights to guide future research in nutrigenomics, clinical medicine, and food engineering on new ways to differentiate pathogenic from probiotic bacteria.202032762606
4715170.9990Genomic and stress resistance characterization of Lactiplantibacillus plantarum GX17, a potential probiotic for animal feed applications. Lactobacilli, recognized as beneficial bacteria within the human body, are celebrated for their multifaceted probiotic functions, including the regulation of intestinal flora, enhancement of body immunity, and promotion of nutrient absorption. This study comprehensively analyzed the genotypic and phenotypic characteristics of Lactiplantibacillus plantarum (L. plantarum) strains isolated from the intestines of healthy chicks and assessed their potential as probiotics. The assembled genome consists of 29,521,986 bp, and a total of 1,771 coding sequences (CDSs) were predicted. Based on the entire genome sequence analysis, 50 stress resistance genes and seven virulence factors were identified. The results of the phenotypic experiments showed that the strain had good resistance to high temperature, low temperature, acid, alkali, salt, artificial gastrointestinal fluid, and strong antioxidant capacity. Additionally, transcriptomic analysis confirmed that under stress conditions, the expression levels of key genes were significantly upregulated. Therefore, the phenotypic characteristics of L. plantarum GX17 align well with its genotypic features, demonstrating promising probiotic properties. This strain holds great potential as a probiotic candidate, and further investigation into its beneficial effects on human health is warranted. IMPORTANCE: In humans, Lactiplantibacillus plantarum may synergize with host microbiota to ameliorate dysbiosis-related pathologies, enhance immunomodulation, and facilitate micronutrient bioavailability. For livestock, its application could improve feed conversion ratios, suppress enteric pathogens through competitive exclusion, and mitigate antibiotic overuse, "a critical strategy in One Health frameworks." Further investigations into strain-specific mechanisms (e.g., postbiotic metabolites, quorum sensing regulation) are warranted to translate these genomic-phenotypic advantages into sustainable health solutions across species.202540919934
5150180.9990Cultivation and Genomic Characterization of the Bile Bacterial Species From Cholecystitis Patients. The microbes in human bile are closely related to gallbladder health and other potential disorders. Although the bile microbial community has been investigated by recent studies using amplicon or metagenomic sequencing technologies, the genomic information of the microbial species resident in bile is rarely reported. Herein, we isolated 138 bacterial colonies from the fresh bile specimens of four cholecystitis patients using a culturome approach and genomically characterized 35 non-redundant strains using whole-genome shotgun sequencing. The bile bacterial isolates spanned 3 classes, 6 orders, 10 families, and 14 genera, of which the members of Enterococcus, Escherichia-Shigella, Lysinibacillus, and Enterobacter frequently appeared. Genomic analysis identified three species, including Providencia sp. D135, Psychrobacter sp. D093, and Vibrio sp. D074, which are not represented in existing reference genome databases. Based on the genome data, the functional capacity between bile and gut isolates was compared. The bile strains encoded 5,488 KEGG orthologs, of which 4.9% were specific to the gut strains, including the enzymes involved in biofilm formation, two-component systems, and quorum-sensing pathways. A total of 472 antibiotic resistance genes (ARGs) were identified from the bile genomes including multidrug resistance proteins (42.6%), fluoroquinolone resistance proteins (12.3%), aminoglycoside resistance proteins (9.1%), and β-lactamase (7.2%). Moreover, in vitro experiments showed that some bile bacteria have the capabilities for bile salt deconjugation or biotransformation (of primary bile acids into secondary bile acids). Although the physiological or pathological significance of these bacteria needs further exploration, our works expanded knowledge about the genome, diversity, and function of human bile bacteria.202134790179
6094190.9990Genomic characterization and computational phenotyping of nitrogen-fixing bacteria isolated from Colombian sugarcane fields. Previous studies have shown the sugarcane microbiome harbors diverse plant growth promoting microorganisms, including nitrogen-fixing bacteria (diazotrophs), which can serve as biofertilizers. The genomes of 22 diazotrophs from Colombian sugarcane fields were sequenced to investigate potential biofertilizers. A genome-enabled computational phenotyping approach was developed to prioritize sugarcane associated diazotrophs according to their potential as biofertilizers. This method selects isolates that have potential for nitrogen fixation and other plant growth promoting (PGP) phenotypes while showing low risk for virulence and antibiotic resistance. Intact nitrogenase (nif) genes and operons were found in 18 of the isolates. Isolates also encode phosphate solubilization and siderophore production operons, and other PGP genes. The majority of sugarcane isolates showed uniformly low predicted virulence and antibiotic resistance compared to clinical isolates. Six strains with the highest overall genotype scores were experimentally evaluated for nitrogen fixation, phosphate solubilization, and the production of siderophores, gibberellic acid, and indole acetic acid. Results from the biochemical assays were consistent and validated computational phenotype predictions. A genotypic and phenotypic threshold was observed that separated strains by their potential for PGP versus predicted pathogenicity. Our results indicate that computational phenotyping is a promising tool for the assessment of bacteria detected in agricultural ecosystems.202133911103