PATHOLOGICAL - Word Related Documents




#
Rank
Similarity
Title + Abs.
Year
PMID
012345
844200.9863Staphylococcus epidermidis undergoes global changes in gene expression during biofilm maturation in platelet concentrates. BACKGROUND: Staphylococcus epidermidis forms surface-attached aggregates (biofilms) when grown in platelet concentrates (PCs). Comparative transcriptome analyses were undertaken to investigate differential gene expression of S. epidermidis biofilms grown in PCs. STUDY DESIGN AND METHODS: Two S. epidermidis strains isolated from human skin (AZ22 and AZ39) and one strain isolated from contaminated PCs (ST02) were grown in glucose-supplemented Trypticase Soy Broth (TSBg) and PCs. RNA was extracted and sequenced using Illumina HiSeq. Differential expression analysis was done using DESeq, and significantly differentially expressed genes (DEGs) were selected. DEGs were subjected to Kyoto encyclopedia of genes and genomes and Gene Ontology analyses. Differential gene expression was validated with quantitative reverse transcription-PCR. RESULTS: A total of 436, 442, and 384 genes were expressed in AZ22, AZ39, and ST02, respectively. DEG analysis showed that 170, 172, and 117 genes were upregulated in PCs in comparison to TSBg, whereas 120, 135, and 89 genes were downregulated (p < .05) in mature biofilms of AZ22, AZ39, and ST02, respectively. Twenty-seven DEGs were shared by all three strains. While 76 DEGs were shared by AZ22 and AZ39, only 34 and 21 DEGs were common between ST02, and AZ22 and AZ39, respectively. Significant transcriptional expression changes were observed in genes involved in platelet-bacteria interaction, biofilm formation, production of virulence factors, and resistance to antimicrobial peptides and antibiotics. CONCLUSION: Differential gene expression in S. epidermidis is triggered by the stressful PC storage environment. Upregulation of virulence and antimicrobial resistance genes could have clinical implications for transfusion patients.202133904608
248810.9855Antibiotic resistance, putative virulence factors and curli fimbrination among Cronobacter species. This study aimed to investigate antibiotic resistance and putative virulence factors among Cronobacter sakazakii isolated from powdered infant formula and other sources. The following 9 cultures (CR1-9) were collected from our culture collection: C. sakazakii and 3 Cronobacter species: C. sakazakii ATCC® 29544™, C. muytjensii ATCC® 51329™, C. turicensis E866 were used in this study. Isolates were subjected to antibiotic susceptibility and the following virulence factors (protease, DNase, haemolysin, gelatinase, motility and biofilm formation) using phenotypic methods. All the bacteria were able to form biofilm on agar at 37 °C and were resistant to ampicillin, erythromycin, fosfomycin and sulphamethoxazole. It was observed from this study that tested strains formed weak and strong biofilm with violet dry and rough (rdar), brown dry and rough (bdar), red mucoid and smooth (rmas) colony morphotypes on Congo red agar. Rdar expresses curli and fimbriae, while bdar expresses curli. Both biofilm colony morphotypes are commonly found in Enterobacteriaceae including Salmonella species. This study also reveals a new colony morphotypes in Cronobacter species. Conclusively, there was correlation between putative virulence factors and antibiotic resistance among the tested bacteria. Further study on virulence and antibiotic resistance genes is hereby encouraged.201931404630
546520.9852The genotypic characterization of Streptococcus pluranimalium from aborted bovine fetuses in British Columbia, Canada. INTRODUCTION: Bovine abortions result in significant economic losses to dairy producers, and bacteria are among the most common causes of these abortions. In 2021, Streptococcus pluranimalium was isolated from a dairy abortion case for the first time in British Columbia (BC), Canada. This bacterium has previously been recovered from the reproductive tracts of dairy cattle and various other species, including humans. METHODS: Between 2021 and 2023, S. pluranimalium was isolated from the placenta, fetal lung, and/or fetal abomasal contents of 10 aborted dairy fetuses submitted for routine abortion diagnostics. This study was conducted to better characterize the genotype of these 10 isolates. The histopathology of the bovine abortions was examined, and the BC strains were sequenced using Nanopore technology and underwent bioinformatic analysis. RESULTS: The BC strains had an average genome size of 2,313,582 base pairs and an average GC content of 38.59%. Based on whole genome phylogeny, the BC strains were clustered together and distinctly separated from other publicly available strains of this species from different regions and isolation sources. Through Clusters of Orthologous Groups analysis, the BC strains contained a larger proportion of genes associated with the mobilome. Additionally, although we identified only a few antibiotic resistance genes or virulence factors (VFs) in these strains, several of these genes were located within prophage sequences. DISCUSSION: Although the clinical and pathological significance of these bacteria in most abortion cases remains unclear, our findings underscore the importance of continued surveillance and research into uncommon pathogens to better understand their biology and potential impact on human and animal health.202540574982
846330.9850Safety assessment of five candidate probiotic lactobacilli using comparative genome analysis. Micro-organisms belonging to the Lactobacillus genus complex are often used for oral consumption and are generally considered safe but can exhibit pathogenicity in rare and specific cases. Therefore, screening and understanding genetic factors that may contribute to pathogenicity can yield valuable insights regarding probiotic safety. Limosilactobacillus mucosae LM1, Lactiplantibacillus plantarum SK151, Lactiplantibacillus plantarum BS25, Limosilactobacillus fermentum SK152 and Lactobacillus johnsonii PF01 are current probiotics of interest; however, their safety profiles have not been explored. The genome sequences of LM1, SK151, SK152 and PF01 were downloaded from the NCBI GenBank, while that of L. plantarum BS25 was newly sequenced. These genomes were then annotated using the Rapid Annotation using Subsystem Technology tool kit pipeline. Subsequently, a command line blast was performed against the Virulence Factor Database (VFDB) and the Comprehensive Antibiotic Resistance Database (CARD) to identify potential virulence factors and antibiotic resistance (AR) genes. Furthermore, ResFinder was used to detect acquired AR genes. The query against the VFDB identified genes that have a role in bacterial survivability, platelet aggregation, surface adhesion, biofilm formation and immunoregulation; and no acquired AR genes were detected using CARD and ResFinder. The study shows that the query strains exhibit genes identical to those present in pathogenic bacteria with the genes matched primarily having roles related to survival and surface adherence. Our results contribute to the overall strategies that can be employed in pre-clinical safety assessments of potential probiotics. Gene mining using whole-genome data, coupled with experimental validation, can be implemented in future probiotic safety assessment strategies.202438361650
518940.9848Genomic analysis of halophilic bacterium, Lentibacillus sp. CBA3610, derived from human feces. BACKGROUND: Lentibacillus species are gram variable aerobic bacteria that live primarily in halophilic environments. Previous reports have shown that bacteria belonging to this species are primarily isolated from salty environments or food. We isolated a bacterial strain CBA3610, identified as a novel species of the genus Lentibacillus, from a human fecal sample. In this report, the whole genome sequence of Lentibacillus sp. CBA3610 is presented, and genomic analyses are performed. RESULTS: Complete genome sequence of strain CBA3610 was obtained through PacBio RSII and Illumina HiSeq platforms. The size of genome is 4,035,571 bp and genes estimated to be 4714 coding DNA sequences and 64 tRNA and 17 rRNA were identified. The phylogenetic analysis confirmed that it belongs to the genus Lentibacillus. In addition, there were genes related to antibiotic resistance and virulence, and genes predicted as CRISPR and prophage were also identified. Genes related to osmotic stress were found according to the characteristics of halophilic bacterium. Genomic differences from other Lentibacillus species were also confirmed through comparative genomic analysis. CONCLUSIONS: Strain CBA3610 is predicted to be a novel candidate species of Lentibacillus through phylogenetic analysis and comparative genomic analysis with other species in the same genus. This strain has antibiotic resistance gene and pathogenic genes. In future, the information derived from the results of several genomic analyses of this strain is thought to be helpful in identifying the relationship between halophilic bacteria and human gut microbiota.202134162403
846150.9846Complete genome sequence provides information on quorum sensing related spoilage and virulence of Aeromonas salmonicida GMT3 isolated from spoiled sturgeon. Foodborne bacteria can pose a threat to the public health due to their spoilage and virulence potential, which can be regulated by quorum sensing (QS) system. In the study, we isolated a spoilage bacteria strain Aeromonas salmonicida GMT3 from refrigerated sturgeon. The complete genome of A. salmonicida GMT3 was sequenced, and the QS related genes were assigned. QS signal molecules N-acyl-homoserine lactones (AHLs) and AI-2 were detected. Genes regulating the spoilage-related metabolic pathways, including protease and lipase secretion, amines metabolism, sulfur metabolism, motility and biofilm formation were analyzed. Furthermore, genes encoding for several virulence factors, e.g. hemolysin, aerolysin, type II secretion system (T2SS), type VI secretion system (T6SS), antibiotic and multidrug resistance were also identified. In addition, the spoilage and virulence phenotypes associated with QS including protease, swimming and swarming activity, biofilm and hemolytic activity were detected. This study provided new insights into spoilage and virulence mechanisms correlated with QS of A. salmonicida GMT3, which might promote development of new approaches for spoilage and virulence control based on QS target.202439614553
253960.9846Comparative Genome Analysis of Canine Frederiksenia canicola Isolates. Background/Objectives: The One Health approach is crucial for managing and controlling the spread of antimicrobial resistance. Frederiksenia canicola is a recently identified bacterial species that seems to be a component of the oral microbiota of dogs; however, its pathogenic nature is questionable. Methods: In this study, the antibacterial susceptibility of F. canicola isolates was determined using the disk diffusion and broth microdilution methods. Genome-wide comparative analyses were performed to identify the genetic factors driving virulence and antimicrobial drug resistance (e.g., virulence factors, antimicrobial resistance genes (ARGs) and prophage-related sequences). Results: Most of the F. canicola isolates lacked virulence-associated genes. F. canicola is likely resistant to clindamycin, lincomycin and neomycin, but susceptible to penicillin, erythromycin and enrofloxacin. Antimicrobial resistance genes were not found in the F. canicola genomes, but prophage-related sequences were identified, suggesting its potential in the transfer of genes associated with drug resistance between bacteria in the oral microbiome. Conclusions: F. canicola is presumably a commensal organism with low virulence potential, as evidenced by the absence of virulence-associated genes. As F. canicola can colonize a wide range of hosts, including humans, further investigation with a greater number of isolates is needed to better understand the role of F. canicola in disease development and the spread of drug resistance.202439766625
907370.9845EpitoCore: Mining Conserved Epitope Vaccine Candidates in the Core Proteome of Multiple Bacteria Strains. In reverse vaccinology approaches, complete proteomes of bacteria are submitted to multiple computational prediction steps in order to filter proteins that are possible vaccine candidates. Most available tools perform such analysis only in a single strain, or a very limited number of strains. But the vast amount of genomic data had shown that most bacteria contain pangenomes, i.e., their genomic information contains core, conserved genes, and random accessory genes specific to each strain. Therefore, in reverse vaccinology methods it is of the utmost importance to define core proteins and core epitopes. EpitoCore is a decision-tree pipeline developed to fulfill that need. It provides surfaceome prediction of proteins from related strains, defines core proteins within those, calculate their immunogenicity, predicts epitopes for a given set of MHC alleles defined by the user, and then reports if epitopes are located extracellularly and if they are conserved among the core homologs. Pipeline performance is illustrated by mining peptide vaccine candidates in Mycobacterium avium hominissuis strains. From a total proteome of ~4,800 proteins per strain, EpitoCore predicted 103 highly immunogenic core homologs located at cell surface, many of those related to virulence and drug resistance. Conserved epitopes identified among these homologs allows the users to define sets of peptides with potential to immunize the largest coverage of tested HLA alleles using peptide-based vaccines. Therefore, EpitoCore is able to provide automated identification of conserved epitopes in bacterial pangenomic datasets.202032431712
516280.9845Genomic identification and characterization of Streptococcus oralis group that causes intraamniotic infection. BACKGROUND: Intraamniotic infection is a cause of spontaneous preterm labor. Streptococcus mitis is a common pathogen identified in intraamniotic infection, with the possible route of hematogenous dissemination from the oral cavity or migration from the vaginal canal. However, there are a few reports on Streptococcus oralis, a member of the S. mitis group, as a cause of pathogen in intraamniotic infection. We reported herein whole genome sequencing and comparative genomic analysis of S. oralis strain RAOG5826 that causes intraamniotic infection. RESULTS: Streptococcus mitis was initially identified from amniotic fluid, vaginal swab, and fetal blood of a patient presenting with preterm prelabor rupture of membranes with intraamniotic infection by the use of conventional microbiological methods (biochemical phenotype, MALDI-ToF, 16 S rRNA). Subsequently, this strain was later identified as S. oralis RAOG5826 by whole-genome hybrid sequencing. Genes involved in macrolide and tetracycline resistance, namely ermB and tet(M), and mutations in penicillin-binding protein were present in the genome. Moreover, potential virulence genes were predicted and compared with other Streptococcal species. CONCLUSION: We reported a comprehensive genomic analysis of S. oralis, which causes intraamniotic infection. S. mitis was initially identified by conventional microbiological identification. However, whole-genome hybrid sequencing demonstrates S. oralis with complete profiles of antimicrobial resistance genes and potential virulence factors. This study highlights the limitations of traditional techniques and underscores the importance of genomic sequencing for accurate diagnosis and tailored antimicrobial treatment. The study also suggests that S. oralis may be an underestimated pathogen in intraamniotic infection.202541023353
519090.9845Genomic Analysis of Cronobacter condimenti s37: Identification of Resistance and Virulence Genes and Comparison with Other Cronobacter and Closely Related Species. Cronobacter condimenti are environmental commensals that have not been associated with any clinical infections. To date, they are the least understood and described Cronobacter species within the genus. The objective of this study was to use a draft genome sequence (DGS) of the Cronobacter condimenti strain s37 to screen for genes encoding for antibiotic resistance, virulence, response to environmental stress, and biofilm formation. The strain was isolated in Poland from commercial small radish sprouts. This is the second genome of this species available in the GenBank database. The comparative genome analysis (cgMLST) of C. condimenti s37 with other Cronobacter spp. including the pathogenic species C. sakazakii and the plant-associated closely related genera Franconibacter and Siccibacter was also performed. The assembled and annotated genome of the C. condimenti s37 genome was 4,590,991 bp in length, with a total gene number of 4384, and a GC content of 55.7%. The s 37 genome encoded for genes associated with resistance to stressful environmental conditions (metal resistance genes: zinc, copper, osmotic regulation, and desiccation stress), 17 antimicrobial resistance genes encoding resistance to various classes of antibiotics and 50 genes encoding for the virulence factors. The latter were mainly genes associated with adhesion, chemotaxis, hemolysis, and biofilm formation. Cg-MLST analysis (3991 genes) revealed a greater similarity of C. condimenti s37 to S. turicensis, F. pulveris, and C. dublinensis than to other species of the genus Cronobacter. Studies on the diversity, pathogenicity, and virulence of Cronobacter species isolated from different sources are still insufficient and should certainly be continued. Especially the analysis of rare strains such as s37 is very important because it provides new information on the evolution of these bacteria. Comparative cgMLST analysis of s37 with other Cronobacter species, as well as closely related genera Franconibacter and Siccibacter, complements the knowledge on their adaptability to specific environments such as desiccation.202439201307
8438100.9845Virulence of Bacteria Colonizing Vascular Bundles in Ischemic Lower Limbs. BACKGROUND: We documented previously the presence of bacterial flora in vascular bundles, lymphatics, and lymph nodes of ischemic lower limbs amputated because of multifocal atheromatic changes that made them unsuitable for reconstructive surgery and discussed their potential role in tissue destruction. The question arose why bacterial strains inhabiting lower limb skin and considered to be saprophytes become pathogenic once they colonize deep tissues. Bacterial pathogenicity is evoked by activation of multiple virulence factors encoded by groups of genes. METHODS: We identified virulence genes in bacteria cultured from deep tissue of ischemic legs of 50 patients using a polymerase chain reaction technique. RESULTS: The staphylococcal virulence genes fnbA (fibronectin-binding protein A), cna (collagen adhesin precursor), and ica (intercellular adhesion) were present in bacteria isolated from both arteries and, to a lesser extent, skin. The IS256 gene, whose product is responsible for biofilm formation, was more frequent in bacteria retrieved from the arteries than skin bacteria. Among the virulence genes of Staphylococcus epidermidis encoding autolysin atlE, icaAB (intercellular adhesion), and biofilm insert IS256, only the latter was detected in arterial specimens. Bacteria cultured from the lymphatics did not reveal expression of eta and IS256 in arteries. The Enterococcus faecalis asa 373 (aggregation substance) and cylA (cytolysin activator) frequency was greater in arteries than in skin bacteria, as were the E. faecium cyl A genes. All Pseudomonas aeruginosa virulence genes were present in bacteria cultured from both the skin and arteries. Staphylococci colonizing arterial bundles and transported to tissues via ischemic limb lymphatics expressed virulence genes at greater frequency than did those dwelling on the skin surface. Moreover, enterococci and Pseudomonas isolated from arterial bundles expressed many virulence genes. CONCLUSIONS: These findings may add to the understanding of the mechanism of development of destructive changes in lower limb ischemic tissues by the patient's, but not hospital-acquired, bacteria, as well as the generally unsatisfactory results of antibiotic administration in these cases. More aggressive antibiotic therapy targeted at the virulent species should be applied.201626431369
8364110.9844Trimeric autotransporter adhesins in members of the Burkholderia cepacia complex: a multifunctional family of proteins implicated in virulence. Trimeric autotransporter adhesins (TAAs) are multimeric surface proteins exclusively found in bacteria. They are involved in various biological traits of pathogenic Gram-negative bacteria including adherence, biofilm formation, invasion, survival within eukaryotic cells, serum resistance, and cytotoxicity. TAAs have a modular architecture composed by a conserved membrane-anchored C-terminal domain and a variable number of stalk and head domains. In this study, a bioinformatic approach has been used to analyze the distribution and architecture of TAAs among Burkholderia cepacia complex (Bcc) genomes. Fifteen genomes were probed revealing a total of 74 encoding sequences. Compared with other bacterial species, the Bcc genomes contain a large number of TAAs (two genes to up to eight genes, such as in B. cenocepacia). Phylogenetic analysis showed that the TAAs grouped into at least eight distinct clusters. TAAs with serine-rich repeats are clearly well separated from others, thereby representing a different evolutionary lineage. Comparative gene mapping across Bcc genomes reveals that TAA genes are inserted within conserved synteny blocks. We further focused our analysis on the epidemic strain B. cenocepacia J2315 in which seven TAAs were annotated. Among these, three TAA-encoding genes (BCAM019, BCAM0223, and BCAM0224) are organized into a cluster and are candidates for multifunctional virulence factors. Here we review the current insights into the functional role of BCAM0224 as a model locus.201122919579
7730120.9843Cerebral 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
8440130.9843A Genome-Wide Knockout Screen in Human Macrophages Identified Host Factors Modulating Salmonella Infection. A genome-scale CRISPR knockout library screen of THP-1 human macrophages was performed to identify loss-of-function mutations conferring resistance to Salmonella uptake. The screen identified 183 candidate genes, from which 14 representative genes involved in actin dynamics (ACTR3, ARPC4, CAPZB, TOR3A, CYFIP2, CTTN, and NHLRC2), glycosaminoglycan metabolism (B3GNT1), receptor signaling (PDGFB and CD27), lipid raft formation (CLTCL1), calcium transport (ATP2A2 and ITPR3), and cholesterol metabolism (HMGCR) were analyzed further. For some of these pathways, known chemical inhibitors could replicate the Salmonella resistance phenotype, indicating their potential as targets for host-directed therapy. The screen indicated a role for the relatively uncharacterized gene NHLRC2 in both Salmonella invasion and macrophage differentiation. Upon differentiation, NHLRC2 mutant macrophages were hyperinflammatory and did not exhibit characteristics typical of macrophages, including atypical morphology and inability to interact and phagocytose bacteria/particles. Immunoprecipitation confirmed an interaction of NHLRC2 with FRYL, EIF2AK2, and KLHL13.IMPORTANCESalmonella exploits macrophages to gain access to the lymphatic system and bloodstream to lead to local and potentially systemic infections. With an increasing number of antibiotic-resistant isolates identified in humans, Salmonella infections have become major threats to public health. Therefore, there is an urgent need to identify alternative approaches to anti-infective therapy, including host-directed therapies. In this study, we used a simple genome-wide screen to identify 183 candidate host factors in macrophages that can confer resistance to Salmonella infection. These factors may be potential therapeutic targets against Salmonella infections.201931594818
6029140.9841Characterization of Potential Virulence, Resistance to Antibiotics and Heavy Metals, and Biofilm-Forming Capabilities of Soil Lignocellulolytic Bacteria. Soil bacteria participate in self-immobilization processes for survival, persistence, and production of virulence factors in some niches or hosts through their capacities for autoaggregation, cell surface hydrophobicity, biofilm formation, and antibiotic and heavy metal resistance. This study investigated potential virulence, antibiotic and heavy metal resistance, solvent adhesion, and biofilm-forming capabilities of six cellulolytic bacteria isolated from soil samples: Paenarthrobacter sp. MKAL1, Hymenobacter sp. MKAL2, Mycobacterium sp. MKAL3, Stenotrophomonas sp. MKAL4, Chryseobacterium sp. MKAL5, and Bacillus sp. MKAL6. Strains were subjected to phenotypic methods, including heavy metal and antibiotic susceptibility and virulence factors (protease, lipase, capsule production, autoaggregation, hydrophobicity, and biofilm formation). The effect of ciprofloxacin was also investigated on bacterial susceptibility over time, cell membrane, and biofilm formation. Strains MKAL2, MKAL5, and MKAL6 exhibited protease and lipase activities, while only MKAL6 produced capsules. All strains were capable of aggregating, forming biofilm, and adhering to solvents. Strains tolerated high amounts of chromium, lead, zinc, nickel, and manganese and were resistant to lincomycin. Ciprofloxacin exhibited bactericidal activity against these strains. Although the phenotypic evaluation of virulence factors of bacteria can indicate their pathogenic nature, an in-depth genetic study of virulence, antibiotic and heavy metal resistance genes is required.202336944321
5774150.9841The correlation between the presence of quorum sensing, toxin-antitoxin system genes and MIC values with ability of biofilm formation in clinical isolates of Pseudomonas aeruginosa. INTRODUCTION: Pseudomonas aeruginosa is a Gram-negative bacterium that considered as important opportunistic human pathogen. One of the mechanisms that help bacteria to tolerate survival in adverse conditions and resistance to antibiotics is biofilm formation through quorum sensing (QS) signals and toxin-antitoxin (TA) systems. QS and TA are two systems that have important roles in biofilm formation. QS is a global regulatory mechanism that enable bacteria to communicate with each other by production of auto inducers (AI) molecules in population. Because of importance biofilm formation in P. aeruginosa infections, here, we studied frequency of QS and TA genes among clinical isolates of P. aeruginosa with ability of biofilm formation. MATERIALS AND METHODS: One hundred and forty clinical isolates of P. aeruginosa were collected from Tehran and Ilam hospitals. The isolates were identified by biochemical tests. Biofilm formation was evaluated by microplate method. After DNA extraction by boiling method, the frequency of QS genes (lasIR, rhlIR), and TA genes (mazEF, relBE, hipBA, ccdAB and mqsR) were analyzed by PCR. RESULTS: Our results showed that maximum resistance is related to aztreonam (72.85%) antibiotic. Most of isolates were able to produce biofilm (87.15%) and the majority of them formed strong biofilm (56.42%). PCR results showed that frequency of mazEF, relBE, hipBA, ccdAB, mqsR, lasIR and rhlIR genes were 85.71, 100, 1.42, 100, 57.14, 93.57 and 83.57 percent, respectively. CONCLUSION: Clinical isolates of P. aeruginosa had high ability to form biofilm, and QS and TA system genes among these isolates were very high (except hipBA genes). There are significaut correlation between biofilm for mation and present of QS and TA system genes.201425870745
6004160.9841Contact Lens Wear Alters Transcriptional Responses to Pseudomonas aeruginosa in Both the Corneal Epithelium and the Bacteria. PURPOSE: Healthy corneas resist colonization by virtually all microbes, yet contact lens wear can predispose the cornea to sight-threatening infection with Pseudomonas aeruginosa. Here, we explored how lens wear changes corneal epithelium transcriptional responses to P. aeruginosa and its impact on bacterial gene expression. METHODS: Male and female C57BL/6J mice were fitted with a contact lens on one eye for 24 hours. After lens removal, corneas were immediately challenged for 4 hours with P. aeruginosa. A separate group of naïve mice was similarly challenged with bacteria. Bacteria-challenged eyes were compared to uninoculated naïve controls, as was lens wear alone. Total RNA sequencing determined corneal epithelium and bacterial gene expression. RESULTS: Prior lens wear profoundly altered the corneal response to P. aeruginosa, including upregulated pattern recognition receptors (tlr3, nod1); downregulated lectin pathway of complement activation (masp1); amplified upregulation of tcf7, gpr55, ifi205, and wfdc2 (immune defense); and further suppression of efemp1 (corneal stromal integrity). Without lens wear, P. aeruginosa upregulated mitochondrial and ubiquinone metabolism genes. Lens wear alone upregulated axl, grn, tcf7, and gpr55 (immune defense) and downregulated Ca2+-dependent genes necab1, snx31, and npr3. P. aeruginosa exposure to prior lens wearing versus naïve corneas upregulated bacterial genes of virulence (popD), its regulation (rsmY, PA1226), and antimicrobial resistance (arnB, oprR). CONCLUSIONS: Prior lens wear impacts corneal epithelium gene expression, altering its responses to P. aeruginosa and how P. aeruginosa responds to it favoring virulence, survival, and adaptation. Impacted genes and associated networks provide avenues for research to better understand infection pathogenesis.202539932472
9019170.9841Deleting qseC downregulates virulence and promotes cross-protection in Pasteurella multocida. QseC, a histidine sensor kinase of the QseBC two-component system, acts as a global regulator of bacterial stress resistance, biofilm formation, and virulence. The function of QseC in some bacteria is well understood, but not in Pasteurella multocida. We found that deleting qseC in P. multocida serotype A:L3 significantly down-regulated bacterial virulence. The mutant had significantly reduced capsule production but increased resistance to oxidative stress and osmotic pressure. Deleting qseC led to a significant increase in qseB expression. Transcriptome sequencing analysis showed that 1245 genes were regulated by qseC, primarily those genes involved in capsule and LPS biosynthesis and export, biofilm formation, and iron uptake/utilization, as well as several immuno-protection related genes including ompA, ptfA, plpB, vacJ, and sodA. In addition to presenting strong immune protection against P. multocida serotypes A:L1 and A:L3 infection, live ΔqseC also exhibited protection against P. multocida serotype B:L2 and serotype F:L3 infection in a mouse model. The results indicate that QseC regulates capsular production and virulence in P. multocida. Furthermore, the qseC mutant can be used as an attenuated vaccine against P. multocida strains of multiple serotypes.202134801081
8439180.9840Comparative genomics analysis and virulence-related factors in novel Aliarcobacter faecis and Aliarcobacter lanthieri species identified as potential opportunistic pathogens. BACKGROUND: Emerging pathogenic bacteria are an increasing threat to public health. Two recently described species of the genus Aliarcobacter, A. faecis and A. lanthieri, isolated from human or livestock feces, are closely related to Aliarcobacter zoonotic pathogens (A. cryaerophilus, A. skirrowii, and A. butzleri). In this study, comparative genomics analysis was carried out to examine the virulence-related, including virulence, antibiotic, and toxin (VAT) factors in the reference strains of A. faecis and A. lanthieri that may enable them to become potentially opportunistic zoonotic pathogens. RESULTS: Our results showed that the genomes of the reference strains of both species have flagella genes (flaA, flaB, flgG, flhA, flhB, fliI, fliP, motA and cheY1) as motility and export apparatus, as well as genes encoding the Twin-arginine translocation (Tat) (tatA, tatB and tatC), type II (pulE and pulF) and III (fliF, fliN and ylqH) secretory pathways, allowing them to secrete proteins into the periplasm and host cells. Invasion and immune evasion genes (ciaB, iamA, mviN, pldA, irgA and fur2) are found in both species, while adherence genes (cadF and cj1349) are only found in A. lanthieri. Acid (clpB), heat (clpA and clpB), osmotic (mviN), and low-iron (irgA and fur2) stress resistance genes were observed in both species, although urease genes were not found in them. In addition, arcB, gyrA and gyrB were found in both species, mutations of which may mediate the resistance to quaternary ammonium compounds (QACs). Furthermore, 11 VAT genes including six virulence (cadF, ciaB, irgA, mviN, pldA, and tlyA), two antibiotic resistance [tet(O) and tet(W)] and three cytolethal distending toxin (cdtA, cdtB, and cdtC) genes were validated with the PCR assays. A. lanthieri tested positive for all 11 VAT genes. By contrast, A. faecis showed positive for ten genes except for cdtB because no PCR assay for this gene was available for this species. CONCLUSIONS: The identification of the virulence, antibiotic-resistance, and toxin genes in the genomes of A. faecis and A. lanthieri reference strains through comparative genomics analysis and PCR assays highlighted the potential zoonotic pathogenicity of these two species. However, it is necessary to extend this study to include more clinical and environmental strains to explore inter-species and strain-level genetic variations in virulence-related genes and assess their potential to be opportunistic pathogens for animals and humans.202235761183
5892190.9840Virulence characteristics and epidemiology of Yersinia enterocolitica and Yersiniae other than Y. pseudotuberculosis and Y. pestis isolated from water and sewage. AIMS: To determine the species, bio-sero-phagetypes, antimicrobial drug resistance and also the pathogenic potential of 144 strains of Yersinia spp. isolated from water sources and sewage in Brazil. METHODS AND RESULTS: The 144 Yersinia strains were characterized biochemically, serologically and had their antibiotic resistance and phenotypic virulence markers determined by microbiological and serological standard techniques. The Y. enterocolitica strains related to human diseases were also tested for the presence of virulence genes, by the PCR technique. The isolates were classified as Y. enterocolitica, Y. intermedia, Y. frederiksenii, Y. kristensenii and Yersinia biochemically atypical. The 144 isolates belonged to various bio-serogroups. Half of the strains showed resistance to three or more drugs. The Y. enterocolitica strains related to human diseases exhibited phenotypic virulence characteristics and virulence genes. CONCLUSIONS: Water from various sources and sewage are contaminated with Yersinia spp. in Brasil. Among these bacteria, virulent strains of Y. enterocolitica were found, with biotypes and serogroups related to human diseases. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first documented description of the occurrence of pathogenic Y. enterocolitica in water sources and sewage in Brazil. The occurrence of virulence strains of Y. enterocolitica shows that the environment is a potential source of human infection by this species in this country.200415139914