Genomic mining of Vibrio parahaemolyticus highlights prevalence of antimicrobial resistance genes and new genetic markers associated with AHPND and tdh + /trh + genotypes. - Related Documents




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513001.0000Genomic mining of Vibrio parahaemolyticus highlights prevalence of antimicrobial resistance genes and new genetic markers associated with AHPND and tdh + /trh + genotypes. BACKGROUND: Acute Hepatopancreatic Necrosis Disease (AHPND) causes significant mortality in shrimp aquaculture. The infection is primarily instigated by Vibrio parahaemolyticus (Vp) strains carrying a plasmid encoding the binary toxin PirAB. Yet, comprehension of supplementary virulence factors associated with this relatively recent disease remains limited. Furthermore, the same holds for gastroenteritis in humans caused by other Vp genotypes. Additionally, given the prevalent use of antibiotics to combat bacterial infections, it becomes imperative to illuminate the presence of antimicrobial resistance genes within these bacteria. RESULTS: A subsampled number of 1,036 Vp genomes was screened for the presence of antimicrobial resistance genes, revealing an average prevalence of 5 ± 2 (SD) genes. Additional phenotypic antimicrobial susceptibility testing of three Vp strains (M0904, TW01, and PV1) sequenced in this study demonstrated resistance to ampicillin by all tested strains. Additionally, Vp M0904 showed multidrug resistance (against ampicillin, tetracycline, and trimethoprim-sulfamethoxazole). With a focus on AHPND, a screening of all Vibrio spp. for the presence of pirA and/or pirB indicates an estimated prevalence of 0.6%, including four V. campbellii, four V. owensii, and a Vibrio sp. next to Vp. Their pirAB-encoding plasmids exhibited a highly conserved backbone, with variations primarily in the region of the Tn3 family transposase. Furthermore, an assessment of the subsampled Vp genomes for the presence of known virulence factors showed a correlation between the presence of the Type 3 Secretion System 2 and tdh, while the presence of the Type 6 Secretion System 1 was clade dependent. Furthermore, a genome-wide association study (GWAS) unveiled (new) genes associated with pirA, pirB, tdh, and trh genotypes. Notable associations with the pirAB genotype included outer membrane proteins, immunoglobulin-like domain containing proteins, and toxin-antitoxin systems. For the tdh + /trh + genotypes (containing tdh, trh, or both genes), associations were found with T3SS2 genes, urease-related genes and nickel-transport system genes, and genes involved in a 'minimal' type I-F CRISPR mechanism. CONCLUSIONS: This study highlights the prevalence of antimicrobial resistance and virulence genes in Vp, identifying novel genetic markers associated with AHPND and tdh + /trh + genotypes. These findings contribute valuable insights into the genomic basis of these genotypes, with implications for shrimp aquaculture and food safety.202438355437
513110.9992Conjugative Transfer of the pVA1-Type Plasmid Carrying the pirAB(vp) Genes Results in the Formation of New AHPND-Causing Vibrio. Acute hepatopancreatic necrosis disease (AHPND) has caused sharp declines in aquaculture industries of whiteleg shrimp Penaeus vannamei in Asia and the Americas since 2010. Vibrio parahaemolyticus, V. campbellii, V. owensii, and V. punensis have been proved to cause AHPND. However, the mechanisms underlying the burgeoning number of Vibrio species that cause AHPND is not known. All of AHPND-causing Vibrio bacteria (V(AHPND)) harbor a highly homologous plasmid (designated as pVA1-type) carrying pirAB(vp) toxin genes. In this study, we demonstrate conclusively that the pVA1-type plasmid can be transferred from V(AHPND) to non-pathogenic bacteria. We constructed a pVPGX1-Cm(r) plasmid (a pVA1-type plasmid) by adding a chloramphenicol resistance gene as a marker in a donor AHPND-causing V. parahaemolyticus 20130629002S01 (Vp2S01). Horizontal transfer of this plasmid was successfully performed from the AHPND-Vp2S01 to a non-pathogenic strain of V. campbellii at the transfer efficiency of 2.6×10(-8) transconjugant/recipient, and DNase I treatment did not eliminate the transfer. The recipient V. campbellii acquired the pVA1-type plasmid and was shown to produce pirAB(vp) RNA and proteins. Challenge studies using the transconjugant caused 100% mortality in exposed groups of P. vannamei. The challenged shrimp, infected with the transconjugant bacteria, showed typical gross signs and histological lesions of AHPND. These results demonstrated the conjugative transfer of an AHPND pVA1-type plasmid. It provides timely information for explaining the increased species of AHPND-causing Vibrio bacteria and will be useful in the development of management strategies leading to the prevention and control of AHPND.201931231618
546620.9992The Trade-Off Between Sanitizer Resistance and Virulence Genes: Genomic Insights into E. coli Adaptation. BACKGROUND: Escherichia coli is one of the most studied bacteria worldwide due to its genetic plasticity. Recently, in addition to characterizing its pathogenic potential, research has focused on understanding its resistance profile to inhibitory agents, whether these be antibiotics or sanitizers. OBJECTIVES: The present study aimed to investigate six of the main serogroups of foodborne infection (O26, O45, O103, O111, O121, and O157) and to understand the dynamics of heterogeneity in resistance to sanitizers derived from quaternary ammonium compounds (QACs) and peracetic acid (PAA) using whole-genome sequencing (WGS). METHODS: Twenty-four E. coli strains with varied resistance profiles to QACs and PAA were analyzed by WGS using NovaSeq6000 (150 bp Paired End reads). Bioinformatic analyses included genome assembly (Shovill), annotation via Prokka, antimicrobial resistance gene identification using Abricate, and core-genome analysis using Roary. A multifactorial multiple correspondence analysis (MCA) was conducted to explore gene-sanitizer relationships. In addition, a large-scale analysis utilizing the NCBI Pathogen Detection database involved a 2 × 2 chi-square test to examine associations between the presence of qac and stx genes. RESULTS: The isolates exhibited varying antimicrobial resistance profiles, with O45 and O157 being the most resistant serogroups. In addition, the qac gene was identified in only one strain (S22), while four other strains carried the stx gene. Through multifactorial multiple correspondence analysis, the results obtained indicated that strains harboring genes encoding Shiga toxin (stx) presented profiles that were more likely to be sensitive to QACs. To further confirm these results, we analyzed 393,216 E. coli genomes from the NCBI Pathogen Detection database. Our results revealed a significant association (p < 0.001) between the presence of qac genes and the absence of stx1, stx2, or both toxin genes. CONCLUSION: Our findings highlight the complexity of bacterial resistance mechanisms and suggest that non-pathogenic strains may exhibit greater tolerance to QAC sanitizer than those carrying pathogenicity genes, particularly Shiga toxin genes.202540149102
468430.9991Genomic characterization and assessment of the virulence and antibiotic resistance of the novel species Paenibacillus sp. strain VT-400, a potentially pathogenic bacterium in the oral cavity of patients with hematological malignancies. BACKGROUND: Paenibacillus sp. strain VT-400, a novel spore-forming bacterium, was isolated from patients with hematological malignancies. METHODS: Paenibacillus sp. strain VT-400 was isolated from the saliva of four children with acute lymphoblastic leukemia. The genome was annotated using RAST and the NCBI Prokaryotic Genome Annotation Pipeline to characterize features of antibiotic resistance and virulence factors. Susceptibility to antibiotics was determined by the Kirby-Bauer disc diffusion method. We used a mouse model of pneumonia to study virulence in vivo. Mice were challenged with 7.5 log10-9.5 log10 CFU, and survival was monitored over 7 days. Bacterial load was measured in the lungs and spleen of surviving mice 48 h post-infection to reveal bacterial invasion and dissemination. RESULTS: Whole-genome sequencing revealed a large number of virulence factors such as hemolysin D and CD4+ T cell-stimulating antigen. Furthermore, the strain harbors numerous antibiotic resistance genes, including small multidrug resistance proteins, which have never been previously found in the Paenibacillus genus. We then compared the presence of antibiotic resistance genes against results from antibiotic susceptibility testing. Paenibacillus sp. strain VT-400 was found to be resistant to macrolides such as erythromycin and azithromycin, as well as to chloramphenicol and trimethoprim-sulphamethoxazole. Finally, the isolate caused mortality in mice infected with ≥8.5 log10 CFU. CONCLUSIONS: Based on our results and on the available literature, there is yet no strong evidence that shows Paenibacillus species as an opportunistic pathogen in immunocompromised patients. However, the presence of spore-forming bacteria with virulence and antibiotic resistance genes in such patients warrants special attention because infections caused by spore-forming bacteria are poorly treatable.201626900405
547140.9990Characterization of virulence and antimicrobial resistance genes of Aeromonas media strain SD/21-15 from marine sediments in comparison with other Aeromonas spp. Aeromonas media is a Gram-negative bacterium ubiquitously found in aquatic environments. It is a foodborne pathogen associated with diarrhea in humans and skin ulceration in fish. In this study, we used whole genome sequencing to profile all antimicrobial resistance (AMR) and virulence genes found in A. media strain SD/21-15 isolated from marine sediments in Denmark. To gain a better understanding of virulence and AMR genes found in several A. media strains, we included 24 whole genomes retrieved from the public databanks whose isolates originate from different host species and environmental samples from Asia, Europe, and North America. We also compared the virulence genes of strain SD/21-15 with A. hydrophila, A. veronii, and A. salmonicida reference strains. We detected Msh pili, tap IV pili, and lateral flagella genes responsible for expression of motility and adherence proteins in all isolates. We also found hylA, hylIII, and TSH hemolysin genes in all isolates responsible for virulence in all isolates while the aerA gene was not detected in all A. media isolates but was present in A. hydrophila, A. veronii, and A. salmonicida reference strains. In addition, we detected LuxS and mshA-Q responsible for quorum sensing and biofilm formation as well as the ferric uptake regulator (Fur), heme and siderophore genes responsible for iron acquisition in all A. media isolates. As for the secretory systems, we found all genes that form the T2SS in all isolates while only the vgrG1, vrgG3, hcp, and ats genes that form parts of the T6SS were detected in some isolates. Presence of bla (MOX-9) and bla (OXA-427) β-lactamases as well as crp and mcr genes in all isolates is suggestive that these genes were intrinsically encoded in the genomes of all A. media isolates. Finally, the presence of various transposases, integrases, recombinases, virulence, and AMR genes in the plasmids examined in this study is suggestive that A. media has the potential to transfer virulence and AMR genes to other bacteria. Overall, we anticipate these data will pave way for further studies on virulence mechanisms and the role of A. media in the spread of AMR genes.202236532448
546850.9990Whole-genome sequence of a putative pathogenic Bacillus sp. strain SD-4 isolated from cattle feed. OBJECTIVES: The present study describes the draft genome sequence of a novel Bacillus sp. strain SD-4 isolated from animal feed. The study aims to get a deeper insight into antimicrobial resistance and secondary metabolite biosynthetic gene clusters (BGCs) and the association between them. METHODS: The strain SD-4 was preliminarily evaluated for antibacterial activities, motility, biofilm formation, and enterotoxin production using in vitro assays. The genome of strain SD-4 was sequenced using the Illumina HiSeq 2500 platform with paired-end reads. The reads were assembled and annotated using SPAdes and PGAP, respectively. The genome was further analysed using several bioinformatics tools, including TYGS, AntiSMASH, RAST, PlasmidFinder, VFDB, VirulenceFinder, CARD, PathogenFinder, MobileElement finder, IslandViewer, and CRISPRFinder. RESULTS: In vitro assays showed that the strain is motile, synthesises biofilm, and produces an enterotoxin and antibacterial metabolites. The genome analysis revealed that the strain SD-4 carries antimicrobial resistance genes (ARGs), virulence factors, and beneficial secondary metabolite BGCs. Further genome analysis showed interesting genome architectures containing several mobile genetic elements, including two plasmid replicons (repUS22 and rep20), five prophages, and at least four genomic islands (GIs), including one Listeria pathogenicity island LIPI-1. Moreover, the strain SD-4 is identified as a putative human pathogen. CONCLUSION: The genome of strain SD-4 harbours several BGCs coding for biologically active metabolites. It also contains antimicrobial resistance genes and is identified as a potential human pathogen. These results can be used to better comprehend antibiotic resistance in environmental bacteria that are not influenced by human intervention.202235413450
543060.9990Anaerobic Gram-Negative Bacteria: Role as a Reservoir of Antibiotic Resistance. BACKGROUND: Anaerobic Gram-negative bacteria (AGNB) play a significant role as both pathogens and essential members of the human microbiota. Despite their clinical importance, there remains limited understanding regarding their antimicrobial resistance (AMR) patterns. This knowledge gap poses challenges in effectively managing AGNB-associated infections, as empirical treatment approaches may not adequately address the evolving resistance landscape. To bridge this research gap, we conducted a comprehensive study aimed at exploring the role of human AGNB as a reservoir of AMR. This can provide valuable insights for the prevention and management of anaerobic infections. METHODS: We studied the prevalence of AMR and AMR determinants conferring resistance to metronidazole (nimE), imipenem (cfiA), piperacillin-tazobactam (cepA), cefoxitin (cfxA), clindamycin (ermF), chloramphenicol (cat) and mobile genetic elements (MGEs) such as cfiA(IS) and IS1186 associated with the cfiA and nim gene expression. These parameters were studied in Bacteroides spp., Fusobacterium spp., Prevotella spp., Veillonella spp., Sutterella spp., and other clinical AGNB. RESULTS: Resistance to metronidazole, clindamycin, imipenem, piperacillin-tazobactam, cefoxitin and chloramphenicol was 29%, 33.5%, 0.5%, 27.5%, 26.5% and 0%, respectively. The presence of resistance genes, viz., nim, ermF, cfiA, cepA, cfxA, was detected in 24%, 33.5%, 10%, 9.5%, 21.5% isolates, respectively. None of the tested isolates showed the presence of a cat gene and MGEs, viz., cfiA(IS) and IS1186. The highest resistance to all antimicrobial agents was exhibited by Bacteroides spp. The association between resistant phenotypes and genotypes was complete in clindamycin, as all clindamycin-resistant isolates showed the presence of ermF gene, and none of the susceptible strains harbored this gene; similarly, all isolates were chloramphenicol-susceptible and also lacked the cat gene, whereas the association was low among imipenem and piperacillin-tazobactam. Metronidazole and imipenem resistance was seen to be dependent on insertion sequences for the expression of AMR genes. A constrained co-existence of cepA and cfiA gene in B. fragilis species was seen. Based on the absence and presence of the cfiA gene, we divided B. fragilis into two categories, Division I (72.6%) and Division II (27.3%), respectively. CONCLUSION: AGNB acts as a reservoir of specific AMR genes, which may pose a threat to other anaerobes due to functional compatibility and acquisition of these genes. Thus, AST-complying standard guidelines must be performed periodically to monitor the local and institutional susceptibility trends, and rational therapeutic strategies must be adopted to direct empirical management.202337237845
454070.9990Unveiling potential virulence determinants in Vibrio isolates from Anadara tuberculosa through whole genome analyses. The genus Vibrio includes pathogenic bacteria able to cause disease in humans and aquatic organisms, leading to disease outbreaks and significant economic losses in the fishery industry. Despite much work on Vibrio in several marine organisms, no specific studies have been conducted on Anadara tuberculosa. This is a commercially important bivalve species, known as "piangua hembra," along Colombia's Pacific coast. Therefore, this study aimed to identify and characterize the genomes of Vibrio isolates obtained from A. tuberculosa. Bacterial isolates were obtained from 14 A. tuberculosa specimens collected from two locations along the Colombian Pacific coast, of which 17 strains were identified as Vibrio: V. parahaemolyticus (n = 12), V. alginolyticus (n = 3), V. fluvialis (n = 1), and V. natriegens (n = 1). Whole genome sequence of these isolates was done using Oxford Nanopore Technologies (ONT). The analysis revealed the presence of genes conferring resistance to β-lactams, tetracyclines, chloramphenicol, and macrolides, indicating potential resistance to these antimicrobial agents. Genes associated with virulence were also found, suggesting the potential pathogenicity of these Vibrio isolates, as well as genes for Type III Secretion Systems (T3SS) and Type VI Secretion Systems (T6SS), which play crucial roles in delivering virulence factors and in interbacterial competition. This study represents the first genomic analysis of bacteria within A. tuberculosa, shedding light on Vibrio genetic factors and contributing to a comprehensive understanding of the pathogenic potential of these Vibrio isolates.IMPORTANCEThis study presents the first comprehensive report on the whole genome analysis of Vibrio isolates obtained from Anadara tuberculosa, a bivalve species of great significance for social and economic matters on the Pacific coast of Colombia. Research findings have significant implications for the field, as they provide crucial information on the genetic factors and possible pathogenicity of Vibrio isolates associated with A. tuberculosa. The identification of antimicrobial resistance genes and virulence factors within these isolates emphasizes the potential risks they pose to both human and animal health. Furthermore, the presence of genes associated with Type III and Type VI Secretion Systems suggests their critical role in virulence and interbacterial competition. Understanding the genetic factors that contribute to Vibrio bacterial virulence and survival strategies within their ecological niche is of utmost importance for the effective prevention and management of diseases in aquaculture practices.202438189292
178980.9990Genomic and phylogenetic analysis of a multidrug-resistant Burkholderia contaminans strain isolated from a patient with ocular infection. OBJECTIVES: The genus Burkholderia comprises rod-shaped, non-spore-forming, obligately aerobic Gram-negative bacteria that is found across diverse ecological niches. Burkholderia contaminans, an emerging pathogen associated with cystic fibrosis, is frequently isolated from contaminated medical devices in hospital settings. The aim of this study was to understand the genomic characteristics, antimicrobial resistance profile and virulence determinants of B. contaminans strain SBC01 isolated from the eye of a patient hit by a cow's tail. METHODS: A hybrid sequence of isolate SBC01 was generated using Illumina HiSeq and Oxford Nanopore Technology platforms. Unicycler was used to assemble the hybrid genomic sequence. The draft genome was annotated using the NCBI Prokaryotic Genome Annotation Pipeline. Antimicrobial susceptibility testing was performed by VITEK®2. Antimicrobial resistance and virulence genes were identified using validated bioinformatics tools. RESULTS: The assembled genome size is 8 841 722 bp with a G+C content of 66.33% distributed in 19 contigs. Strain SBC01 was found to possess several antimicrobial resistance and efflux pump genes. The isolate was susceptible to tetracyclines, meropenem and ceftazidime. Many genes encoding potential virulence factors were identified. CONCLUSION: Burkholderia contaminans SBC01 belonging to sequence type 482 (ST482) is a multidrug-resistant strain containing diverse antimicrobial resistance genes, revealing the risks associated with infections by new Burkholderia spp. The large G+C-rich genome has a myriad of virulence factors, highlighting its pathogenic potential. Thus, while providing insights into the antimicrobial resistance and virulence potential of this uncommon species, the present analysis will aid in understanding the evolution and speciation in the Burkholderia genus.202133965629
547090.9990Antimicrobial resistance genes, virulence markers and prophage sequences in Salmonella enterica serovar Enteritidis isolated in Tunisia using whole genome sequencing. Salmonella Enteritidis causes a major public health problem in the world. Whole genome sequencing can give us a lot of information not only about the phylogenetic relatedness of these bacteria but also in antimicrobial resistance and virulence gene predictions. In this study, we analyzed the whole genome data of 45 S. Enteritidis isolates recovered in Tunisia from different origins, human, animal, and foodborne samples. Two major lineages (A and B) were detected based on 802 SNPs differences. Among these SNPs, 493 missense SNPs were identified. A total of 349 orthologue genes mutated by one or two missense SNPs were classified in 22 functional groups with the prevalence of carbohydrate transport and metabolism group. A good correlation between genotypic antibiotic resistance profiles and phenotypic analysis were observed. Only resistant isolates carried the respective molecular resistant determinants. The investigation of virulence markers showed the distribution of 11 Salmonella pathogenicity islands (SPI) out of 23 previously described. The SPI-1 and SPI-2 genes encoding type III secretion systems were highly conserved in all isolates except one. In addition, the virulence plasmid genes were present in all isolates except two. We showed the presence of two fimbrial operons sef and ste previously considered to be specific for typhoidal Salmonella. Our collection of S. Enteritidis reveal a diversity among prophage profiles. SNPs analysis showed that missense mutations identified in fimbriae and in SPI-1 and SPI-2 genes were mostly detected in lineage B. In conclusion, WGS is a powerful application to study functional genomic determinants of S. Enteritidis such as antimicrobial resistance genes, virulence markers and prophage sequences. Further studies are needed to predict the impact of the missenses SNPs that can affect the protein functions associated with pathogenicity.202235909609
4553100.9990Horizontal gene transfer contributes to virulence and antibiotic resistance of Vibrio harveyi 345 based on complete genome sequence analysis. BACKGROUND: Horizontal gene transfer (HGT), which is affected by environmental pollution and climate change, promotes genetic communication, changing bacterial pathogenicity and drug resistance. However, few studies have been conducted on the effect of HGT on the high pathogenicity and drug resistance of the opportunistic pathogen Vibrio harveyi. RESULTS: V. harveyi 345 that was multidrug resistant and infected Epinephelus oanceolutus was isolated from a diseased organism in Shenzhen, Southern China, an important and contaminated aquaculture area. Analysis of the entire genome sequence predicted 5678 genes including 487 virulence genes contributing to bacterial pathogenesis and 25 antibiotic-resistance genes (ARGs) contributing to antimicrobial resistance. Five ARGs (tetm, tetb, qnrs, dfra17, and sul2) and one virulence gene (CU052_28670) on the pAQU-type plasmid p345-185, provided direct evidence for HGT. Comparative genome analysis of 31 V. harveyi strains indicated that 217 genes and 7 gene families, including a class C beta-lactamase gene, a virulence-associated protein D gene, and an OmpA family protein gene were specific to strain V. harveyi 345. These genes could contribute to HGT or be horizontally transferred from other bacteria to enhance the virulence or antibiotic resistance of 345. Mobile genetic elements in 71 genomic islands encoding virulence factors for three type III secretion proteins and 13 type VI secretion system proteins, and two incomplete prophage sequences were detected that could be HGT transfer tools. Evaluation of the complete genome of V. harveyi 345 and comparative genomics indicated genomic exchange, especially exchange of pathogenic genes and drug-resistance genes by HGT contributing to pathogenicity and drug resistance. Climate change and continued environmental deterioration are expected to accelerate the HGT of V. harveyi, increasing its pathogenicity and drug resistance. CONCLUSION: This study provides timely information for further analysis of V. harveyi pathogenesis and antimicrobial resistance and developing pollution control measurements for coastal areas.201931640552
4685110.9990Antimicrobial Susceptibility Profile and Whole-Genome Analysis of a Strong Biofilm-Forming Bacillus Sp. B87 Strain Isolated from Food. Members of the Bacillus cereus group are considered to be foodborne pathogens commonly associated with diarrheal and emetic gastrointestinal syndromes. Biofilm formation is a major virulence determinant of various pathogenic bacteria, including the B. cereus strains, since it can protect the bacteria against antimicrobial agents and the host immune response. Moreover, a biofilm allows the exchange of genetic material, such as antimicrobial resistance genes, among the different bacterial strains inside the matrix. The aim of the current study was to genotypically and phenotypically characterize Bacillus sp. B87, a strain that was isolated from food and which exhibited strong biofilm-forming capacity. Based on the analysis of the phylogenetic relationship, the isolate was phylogenetically mapped close to Bacillus pacificus. Antimicrobial susceptibility testing revealed that the isolate was resistant to tetracycline and β-lactam antimicrobial agents, which corresponded with the genotypic characterization using the whole-genome analysis. The genome of Bacillus sp. B87 carried the three-component non-hemolytic enterotoxin (NHE), which is a type of enterotoxin that causes diarrheal symptoms. In addition, the genome also contained several genes that participate in biofilm formation, including the pelDEA(DA)FG operon. These findings expand our understanding of antimicrobial resistance and virulence in Bacillus species based on the link between genotypic and phenotypic characterization.202235208707
5816120.9990Comparison of virulence and resistance genes in Mannheimia haemolytica and Pasteurella multocida from dairy cattle with and without bovine respiratory disease. Mannheimia haemolytica and Pasteurella multocida are two of the main bacterial pathogens associated with bovine respiratory disease (BRD). BRD represents one of the most significant health challenges in the cattle industry, causing substantial economic losses through animal morbidity and mortality while raising serious welfare concerns. The objectives of this project were to (i) characterize virulence factor (VF) and antimicrobial resistance (AMR) genes in M. haemolytica and P. multocida isolates from dairy cattle of different ages with and without BRD using whole-genome sequencing (WGS); (ii) evaluate associations between microbial genetic elements and animal disease status; and (iii) assess the accuracy of genome-based predictions for the antimicrobial resistance phenotype. Using a case-control study, AMR and VF genes were characterized from 149 P. multocida and 68 M. haemolytica isolates from preweaned calves, weaned heifers, and cows with and without BRD. The large genetic diversity observed in both bacterial species prevented the identification of unique genetic markers associated with disease status or age group. AMR genes (22 genes) from 12 antimicrobial classes were identified in P. multocida isolates, while 11 AMR genes for seven antimicrobial classes were identified in M. haemolytica isolates. Additionally, 28 and 15 virulence genes were identified in P. multocida and M. haemolytica, respectively. The ability of WGS-based predictions to predict phenotypic antimicrobial resistance showed variable accuracy across different antimicrobials, achieving moderate levels of agreement overall. Findings from this project demonstrate that identifying genomic markers based on gene presence/absence lacks discriminatory power within this population for identifying unique genotypes associated with disease status in these genomically diverse organisms. IMPORTANCE: This case-control study provides key microbial ecological advances by elucidating the role of bacteria in the bovine respiratory disease complex in dairy cattle. Previous research has identified specific virulence factors in both bacterial genomes that resulted in disease. Our results challenge this perception and are of high impact, revealing that the pan-genome of both bacteria did not differentiate among the clinical cases or age groups, and a specific pathogenic pathotype was not evident in the isolates from this study, and it did not emerge when including additional public whole-genome sequences to increase the analytical power of the analysis (the first study to use this approach to evaluate bovine respiratory disease in cattle). In addition to these novel discoveries, this study describes the first population-scale genomic comparison of both Mannheimia haemolytica and Pasteurella multocida genomes collected from affected and healthy dairy cattle from different age groups and from multiple farms.202540522106
5158130.9990Distinct adaptation and epidemiological success of different genotypes within Salmonella enterica serovar Dublin. Salmonella Dublin is a host-adapted, invasive nontyphoidal Salmonella (iNTS) serovar that causes bloodstream infections in humans and demonstrates increasing prevalence of antimicrobial resistance (AMR). Using a global dataset of 1303 genomes, coupled with in vitro assays, we examined the evolutionary, resistance, and virulence characteristics of S. Dublin. Our analysis revealed strong geographical associations between AMR profiles and plasmid types, with highly resistant isolates confined predominantly to North America, linked to IncC plasmids co-encoding AMR and heavy metal resistance. By contrast, Australian isolates were largely antimicrobial-susceptible, reflecting differing AMR pressures. We identified two phylogenetically distinct Australian lineages, ST10 and ST74, with a small number of ST10 isolates harbouring a novel hybrid plasmid encoding both AMR and mercuric resistance. Whereas the ST10 lineage remains globally dominant, the ST74 lineage was less prevalent. ST74 exhibited unique genomic features including a larger pan genome compared to ST10 and the absence of key virulence loci, including Salmonella pathogenicity island (SPI)-19 which encodes a type VI secretion system (T6SS). Despite these genomic differences, the ST74 lineage displayed enhanced intracellular replication in human macrophages and induced less pro-inflammatory responses compared with ST10, suggesting alternative virulence strategies that may support systemic dissemination of ST74. The Vi antigen was absent in all ST10 and ST74 genomes, highlighting challenges for serotyping and vaccine development, and has implications for current diagnostic and control strategies for S. Dublin infections. Collectively, this study represents the most comprehensive investigation of S. Dublin to date and, importantly, has revealed distinct adaptations of two genotypes within the same serovar, leading to different epidemiological success. The regional emergence and evolution of distinct S. Dublin lineages highlight the need to understand the divergence of intra-serovar virulence mechanisms which may impact the development of effective control measures against this important global pathogen.202540560760
5147140.9989Multiscale comparative pathogenomic analysis of Vibrio anguillarum linking serotype diversity, genomic plasticity and pathogenicity. Vibrio anguillarum is a major marine fish pathogen causing high mortality and potential zoonotic risks. Understanding its genomic diversity, virulence factors, and antibiotic resistance is crucial for aquaculture disease management. In this study, a comparative pan-genomic analysis of 16 V. anguillarum strains was conducted to examine core and accessory genome diversity, virulence factors, and antibiotic resistance mechanisms. The phylogenetic analysis was conducted using six core genes and SNPs to evaluate evolutionary relationships and pathogenic traits. The core genome contained 2,038 unique ORFs, while the accessory genome had 5,197 cloud genes, confirming an open pangenome. This study identified 118 pathogenic genomic islands, antibiotic resistance genes (tetracycline, quinolone, and carbapenem), and virulence factors, including type VI secretion system (T6SS) components and RTX toxins (hcp-2, vipB/mglB, rtxC). Core genes such as ftsI uncovered substantial evolutionary divergence among species, identifying more than 150 distinct SNPs. Phylogenetic analysis showed serotype-specific clustering, with O1 strains displaying genetic homogeneity, whereas O2 and O3 exhibited divergence, suggesting distinct evolutionary adaptations influencing pathogenicity and ecological interactions. These findings provide primary insights for developing molecular markers and targeted treatments for aquaculture pathogens.202540854641
1783150.9989Multi-locus sequence typing and genetic diversity of antibiotic-resistant genes and virulence-associated genes in Burkholderia pseudomallei: Insights from whole genome sequencing of animal and environmental isolates in Thailand. Burkholderia pseudomallei is a Gram-negative bacillus and the etiological agent of melioidosis in humans and animals. The disease is highly endemic in northern Australia and Southeast Asia. Comprehensive genomic data are essential for understanding the bacteria's dissemination and genetic relationships among strains from different geographical regions. In this study, we conducted antimicrobial susceptibility testing and whole-genome sequencing of 54 B. pseudomallei isolates obtained from environmental and animal sources in southern Thailand between 2011 and 2018. Their genomics were determined of antibiotic-resistant genes (ARGs), virulence-associated genes, mobile genetic elements (MGEs), sequence types (STs), and single nucleotide polymorphisms (SNPs) to evaluate their epidemiological relatedness. Remarkably, all 54 isolates displayed sensitivity to antimicrobial agents typically used for melioidosis treatment. We identified nine distinct sequence types: ST392, ST51, ST409, ST508, ST376, ST1721, ST389, ST395, and ST289. Oxacillinase genes and the resistance nodulation family of efflux pumps (RND) were identified as contributors to antimicrobial resistance. Phylogenetic analysis demonstrated close genetic relations with other strains isolated from Southeast Asia. Furthermore, 172 virulence-associated genes were identified among the isolates, suggesting variations in clinical presentations. These findings underscore the importance of ongoing molecular genetic surveillance of B. pseudomallei for effective healthcare management and reducing melioidosis mortality.202439216325
5129160.9989Complete genome sequences of Vibrio parahaemolyticus strains L2171 and L2181 associated with AHPND in Penaeus vannamei postlarvae by hybrid sequencing. Vibrio parahaemolyticus strains L2171 and L2181 were isolated from a Penaeus vannamei shrimp hatchery. Both strains carry the pVA plasmid harboring the PirAB genes encoding the binary PirAB toxins that cause the acute hepatopancreatic necrosis disease (AHPND) in cultured shrimp. The strains also harbor multidrug resistance (MDR) and a repertoire of virulence factor genes. Our goal was to determine their complete genome sequences and perform a comprehensive analysis of their genetic characteristics. Therefore, the genomes of two strains, which are highly virulent to shrimp were sequenced by Illumina and the PacBio platforms. These data contribute to a better understanding of V. parahaemolyticus and its role as a pathogen in commercially important species such as farmed shrimp, providing valuable insights for disease management in aquaculture.202540677256
5496170.9989Genome-Wide Analysis of Escherichia coli Isolated from Dairy Animals Identifies Virulence Factors and Genes Enriched in Multidrug-Resistant Strains. The gastrointestinal tracts of dairy calves and cows are reservoirs of antimicrobial-resistant bacteria (ARB), which are present regardless of previous antimicrobial therapy. Young calves harbor a greater abundance of resistant bacteria than older cows, but the factors driving this high abundance are unknown. Here, we aimed to fully characterize the genomes of multidrug-resistant (MDR) and antimicrobial-susceptible Escherichia coli strains isolated from pre-weaned calves, post-weaned calves, dry cows, and lactating cows and to identify the accessory genes that are associated with the MDR genotype to discover genetic targets that can be exploited to mitigate antimicrobial resistance in dairy farms. Results indicated that both susceptible and resistant E. coli isolates recovered from animals on commercial dairy operations were highly diverse and encoded a large pool of virulence factors. In total, 838 transferrable antimicrobial resistance genes (ARGs) were detected, with genes conferring resistance to aminoglycosides being the most common. Multiple sequence types (STs) associated with mild to severe human gastrointestinal and extraintestinal infections were identified. A Fisher's Exact Test identified 619 genes (ARGs and non-ARGs) that were significantly enriched in MDR isolates and 147 genes that were significantly enriched in susceptible isolates. Significantly enriched genes in MDR isolates included the iron scavenging aerobactin synthesis and receptor genes (iucABCD-iutA) and the sitABCD system, as well as the P fimbriae pap genes, myo-inositol catabolism (iolABCDEG-iatA), and ascorbate transport genes (ulaABC). The results of this study demonstrate a highly diverse population of E. coli in commercial dairy operations, some of which encode virulence genes responsible for severe human infections and resistance to antibiotics of human health significance. Further, the enriched accessory genes in MDR isolates (aerobactin, sit, P fimbriae, and myo-inositol catabolism and ascorbate transport genes) represent potential targets for reducing colonization of antimicrobial-resistant bacteria in the calf gut.202337887260
5157180.9989Genomic insights and phenotypic characterization of three multidrug resistant Cupriavidus strains from the cystic fibrosis lung. AIMS: We aimed to investigate phenotypic and genomic traits of three Cupriavidus spp. isolates recovered from people with cystic fibrosis (PWCF). These bacteria are recognized as emerging pathogens in PWCF. METHODS AND RESULTS: Using short and long sequencing reads, we assembled three hybrid complete genomes for the genus Cupriavidus, adding to the 45 published currently, describing multipartite genomes and plasmids. The isolates likely represent three different species, and they carry a cumulative total of 30 antibiotic resistance genes with high homology to well-characterized resistance determinants from other bacteria. Multidrug resistance to antibiotics used in CF management was observed in all three isolates. However, two treatments were active across all isolates: cefotaxime and piperacillin/tazobactam. Biofilm formation was only seen at physiological temperatures (37°C) and lost at 20°C and all isolates had low lethality in Galleria mellonella larvae. Isolates demonstrated variable motility, with one non-motile isolate carrying a disrupted flhD transcriptional regulator, abolishing flagella expression. CONCLUSIONS: Our Cupriavidus spp. isolates showed considerable genomic and phenotypic variability that may impact their virulence and treatment in PWCF, where multidrug resistance will negate treatments and biofilm formation and motility play key roles in infection establishment, as seen in CF pathogens like Pseudomonas aeruginosa. More detailed investigation of clinical Cupriavidus isolates is needed for full understanding of the risk they pose to PWCF.202540246707
5813190.9989CRISPR-Cas System: An Adaptive Immune System's Association with Antibiotic Resistance in Salmonella enterica Serovar Enteritidis. Several factors are involved in the emergence of antibiotic-resistant bacteria and pose a serious threat to public health safety. Among them, clustered regularly interspaced short palindromic repeat- (CRISPR-) Cas system, an adaptive immune system, is thought to be involved in the development of antibiotic resistance in bacteria. The current study was aimed at determining not only the presence of antibiotic resistance and CRISPR-Cas system but also their association with each other in Salmonella enteritidis isolated from the commercial poultry. A total of 139 samples were collected from poultry birds sold at the live bird markets of Lahore City, and both phenotypic and genotypic methods were used to determine antimicrobial resistance. The presence of the CRISPR-Cas system was determined by PCR, followed by sequencing. All isolates of S. enteritidis (100%) were resistant to nalidixic acid, whereas 95% of isolates were resistant to ampicillin. Five multidrug-resistant isolates (MDR) such as S. enteritidis isolate (S. E1, S. E2, S. E4, S. E5, and S. E8) were found in the present study. The CRISPR-Cas system was detected in all of these MDR isolates, and eight spacers were detected within the CRISPR array. In addition, an increased expression of CRISPR-related genes was observed in the standard strain and MDR S. enteritidis isolates. The association of the CRISPSR-Cas system with multiple drug resistance highlights the exogenous acquisition of genes by horizontal transfer. The information could be used further to combat antibiotic resistance in pathogens like Salmonella.202235386307