scholarly journals Genomic signatures of host adaptation in group B Salmonella enterica ST416/ST417 from harbour porpoises

2021 ◽  
Vol 52 (1) ◽  
Author(s):  
Arnar K. S. Sandholt ◽  
Aleksija Neimanis ◽  
Anna Roos ◽  
Jenny Eriksson ◽  
Robert Söderlund
Keyword(s):  
Salmonella Enterica ◽  
Core Genome ◽  
Opportunistic Infections ◽  
Environmental Cues ◽  
Loss Of Function ◽  
Tissue Samples ◽  
Clonal Population ◽  
Genomic Signatures ◽  
Group B ◽  
Close Relatives

AbstractA type of monophasic group B Salmonella enterica with the antigenic formula 4,12:a:- (“Fulica-like”) has been described as associated with harbour porpoises (Phocoena phocoena), most frequently recovered from lung samples. In the present study, lung tissue samples from 47 porpoises found along the Swedish coast or as bycatch in fishing nets were analysed, two of which were positive for S. enterica. Pneumonia due to the infection was considered the likely cause of death for one of the two animals. The recovered isolates were whole genome sequenced and found to belong to sequence type (ST) 416 and to be closely related to ST416/ST417 porpoise isolates from UK waters as determined by core-genome MLST. Serovars Bispebjerg, Fulica and Abortusequi were identified as distantly related to the porpoise isolates, but no close relatives from other host species were found. All ST416/417 isolates had extensive loss of function mutations in key Salmonella pathogenicity islands, but carried accessory genetic elements associated with extraintestinal infection such as iron uptake systems. Gene ontology and pathway analysis revealed reduced secondary metabolic capabilities and loss of function in terms of signalling and response to environmental cues, consistent with adaptation for the extraintestinal niche. A classification system based on machine learning identified ST416/417 as more invasive than classical gastrointestinal serovars. Genome analysis results are thus consistent with ST416/417 as a host-adapted and extraintestinal clonal population of S. enterica, which while found in porpoises without associated pathology can also cause severe opportunistic infections.

scholarly journals Steroid hormones sulfatase inactivation extends lifespan and ameliorates age-related diseases

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Mercedes M. Pérez-Jiménez ◽  
José M. Monje-Moreno ◽  
Ana María Brokate-Llanos ◽  
Mónica Venegas-Calerón ◽  
Alicia Sánchez-García ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Caenorhabditis Elegans ◽  
Protein Aggregation ◽  
Steroid Hormones ◽  
Sensory Neurons ◽  
Environmental Cues ◽  
Steroid Sulfatase ◽  
Loss Of Function ◽  
C Elegans ◽  
Age Related

AbstractAging and fertility are two interconnected processes. From invertebrates to mammals, absence of the germline increases longevity. Here we show that loss of function of sul-2, the Caenorhabditis elegans steroid sulfatase (STS), raises the pool of sulfated steroid hormones, increases longevity and ameliorates protein aggregation diseases. This increased longevity requires factors involved in germline-mediated longevity (daf-16, daf-12, kri-1, tcer-1 and daf-36 genes) although sul-2 mutations do not affect fertility. Interestingly, sul-2 is only expressed in sensory neurons, suggesting a regulation of sulfated hormones state by environmental cues. Treatment with the specific STS inhibitor STX64, as well as with testosterone-derived sulfated hormones reproduces the longevity phenotype of sul-2 mutants. Remarkably, those treatments ameliorate protein aggregation diseases in C. elegans, and STX64 also Alzheimer’s disease in a mammalian model. These results open the possibility of reallocating steroid sulfatase inhibitors or derivates for the treatment of aging and aging related diseases.

scholarly journals Active and Passive Intranasal Immunizations with Streptococcal Surface Protein C5a Peptidase Prevent Infection of Murine Nasal Mucosa-Associated Lymphoid Tissue, a Functional Homologue of Human Tonsils

2005 ◽  
Vol 73 (12) ◽  
pp. 7878-7886 ◽  
Author(s):  
Hae-Sun Park ◽  
P. Patrick Cleary
Keyword(s):  
Nasal Mucosa ◽  
Lymphoid Tissue ◽  
Streptococcal Infection ◽  
Surface Protein ◽  
Effective Vaccine ◽  
Infection Model ◽  
Loss Of Function ◽  
Intranasal Immunization ◽  
Endemic Disease ◽  
Group B

ABSTRACT C5a peptidase, also called SCPA (surface-bound C5a peptidase), is a surface-bound protein on group A streptococci (GAS), etiologic agents for a variety of human diseases including pharyngitis, impetigo, toxic shock, and necrotizing fasciitis, as well as the postinfection sequelae rheumatic fever and rheumatic heart disease. This protein is highly conserved among different serotypes and is also expressed in human isolates of group B, C, and G streptococci. Human tonsils are the primary reservoirs for GAS, maintaining endemic disease across the globe. We recently reported that GAS preferentially target nasal mucosa-associated lymphoid tissue (NALT) in mice, a tissue functionally analogous to human tonsils. Experiments using a C5a peptidase loss-of-function mutant and an intranasal infection model showed that this protease is required for efficient colonization of NALT. An effective vaccine should prevent infection of this secondary lymphoid tissue; therefore, the potential of anti-SCPA antibodies to protect against streptococcal infection of NALT was investigated. Experiments showed that GAS colonization of NALT was significantly reduced following intranasal immunization of mice with recombinant SCPA protein administered alone or with cholera toxin, whereas a high degree of GAS colonization of NALT was observed in control mice immunized with phosphate-buffered saline only. Moreover, administration of anti-SCPA serum by the intranasal route protected mice against streptococcal infection. These results suggest that intranasal immunization with SCPA would prevent colonization and infection of human tonsils, thereby eliminating potential reservoirs that maintain endemic disease.

Histopathologic lesions in conventional pigs experimentally infected with Haemophilus parasuis serovar 5

2015 ◽  
Vol 43 (02) ◽  
pp. 91-96 ◽  
Author(s):  
R.-L. Austin-Busse ◽  
A. Ladinig ◽  
G. Balka ◽  
S. Zoels ◽  
M. Ritzmann ◽  
...  
Keyword(s):  
Clinical Signs ◽  
Control Group ◽  
Post Inoculation ◽  
Haemophilus Parasuis ◽  
Tissue Samples ◽  
Group A ◽  
Pathologic Lesions ◽  
Group B ◽  
Kidney Lesions ◽  
Challenge Group

Summary Objective: In the present study various tissues of pigs were investigated for the presence of histopathologic lesions after an experimental infection with Haemophilus (H.) parasuis serovar 5. Material and methods: Conventional pigs (n = 36) were divided into a control group B (n = 9) and a challenge group A (n = 27), which was infected intratracheally. Pigs that did not die prior to study termination were euthanized on day 14 post inoculation. Postmortem samples of the lung, heart, liver, kidney, spleen, left tarsal joint capsule and brain were collected. Results: All but one pig with detectable histopathologic lesions (n = 11) showed typical macroscopic changes. Histopatho logic examination of all tissue samples identified pyelitis (n = 10), synovitis (n = 7) and meningitis (n = 7) and all those animals were euthanized prior to study termination. No histopathologic lesions were found in pigs of the control group. The correlations between pyelitis and meningitis, pyelitis and synovitis and synovitis and meningitis were significant (p < 0.001). No significant correlation could be observed between the histopathologic and the clinical examination of the joints. The investigation of samples from the joints by PCR was not significantly correlated with the observed synovitis. The clinical observation of neurologic signs was significantly correlated with meningitis (p = 0.03). A significant correlation (p < 0.001) could be detected between meningitis and the detection of H. parasuis by PCR in brain samples. Conclusions: H. parasuis constantly causes clinical signs and pathologic lesions as soon as it infects the brain while it can infect the joints without causing histopathologic lesions. Pigs with histopathologic lesions do not always show typical clinical signs. Only few studies described the finding of kidney lesions in pigs with Glässer’s disease and this is the first study to describe a pyelitis in pigs experimentally infected with H. parasuis. The observed pyelitis mainly occurred in acute cases.

scholarly journals Salmonella enterica subspecies houtenae as an opportunistic pathogen in a case of meningoencephalomyelitis and bacteriuria in a dog

2020 ◽  
Vol 16 (1) ◽  
Author(s):  
Melissa N. Andruzzi ◽  
Mary L. Krath ◽  
Sara D. Lawhon ◽  
Beth Boudreau
Keyword(s):  
Salmonella Enterica ◽  
Bacterial Infections ◽  
Opportunistic Infections ◽  
Treatment Success ◽  
Immunosuppressive Treatment ◽  
Clinical Signs ◽  
Opportunistic Pathogen ◽  
First Case ◽  
Disease Diagnostics ◽  
Infectious Disease Diagnostics

Abstract Background We report the first case of canine Salmonella meningoencephalomyelitis and second case of canine Salmonella bacteriuria, as well as the first reported case of Salmonella enterica subspecies houtenae in a dog. Case presentation Immunosuppressive treatment in a dog for a relapse of steroid-responsive meningitis and arteritis (SRMA) allowed for the opportunistic establishment of a bacteremia with Salmonella enterica subsp. houtenae, ultimately causing meningoencephalomyelitis and subclinical bacteriuria. The bacterial infections were treated with a four-month course of amoxicillin; clinical treatment success was determined by serial negative urine cultures and lack of clinical signs correlated to the meningoencephalomyelitis. Conclusions Both the bacteriuria and meningoencephalomyelitis represented opportunistic infections in a dog immunosuppressed for SRMA. The clinical course of this infectious meningoencephalitis emphasizes the importance of differentiating relapse of initial disease from opportunistic infection occurring in a compromised central nervous system. The novel Salmonella species identified in this case acts as a reminder that infectious disease diagnostics should not be curbed by anecdotal prediction of routine pathogenic suspects.

Bacterial Persisters and Infection: Past, Present, and Progressing

2019 ◽  
Vol 73 (1) ◽  
pp. 359-385 ◽  
Author(s):  
Bridget Gollan ◽  
Grzegorz Grabe ◽  
Charlotte Michaux ◽  
Sophie Helaine
Keyword(s):  
Immune Responses ◽  
Environmental Cues ◽  
Antibiotic Exposure ◽  
Scientific Communities ◽  
Clonal Population ◽  
Vast Array ◽  
Host Immune Responses ◽  
History Of ◽  
Harsh Conditions

Persisters are nongrowing, transiently antibiotic-tolerant bacteria within a clonal population of otherwise susceptible cells. Their formation is triggered by environmental cues and involves the main bacterial stress response pathways that allow persisters to survive many harsh conditions, including antibiotic exposure. During infection, bacterial pathogens are exposed to a vast array of stresses in the host and form nongrowing persisters that survive both antibiotics and host immune responses, thereby most likely contributing to the relapse of many infections. While antibiotic persisters have been extensively studied over the last decade, the bulk of the work has focused on how these bacteria survive exposure to drugs in vitro. The ability of persisters to survive their interaction with a host is important yet underinvestigated. In order to tackle the problem of persistence of infections that contribute to the worldwide antibiotic resistance crisis, efforts should be made by scientific communities to understand and merge these two fields of research: antibiotic persisters and host-pathogen interactions. Here we give an overview of the history of the field of antibiotic persistence, report evidence for the importance of persisters in infection, and highlight studies that bridge the two areas.

scholarly journals Geography Shapes the Population Genomics of Salmonella enterica Dublin

2019 ◽  
Vol 11 (8) ◽  
pp. 2220-2231 ◽  
Author(s):  
Gavin J Fenske ◽  
Anil Thachil ◽  
Patrick L McDonough ◽  
Amy Glaser ◽  
Joy Scaria
Keyword(s):  
Population Structure ◽  
Salmonella Enterica ◽  
Core Genome ◽  
Population Genomics ◽  
Negative Impact ◽  
Antibiotic Resistance Genes ◽  
Virulence Plasmid ◽  
Ancestral State ◽  
Secretion Systems ◽  
Data Set

Abstract Salmonella enterica serotype Dublin (S. Dublin) is a bovine-adapted serotype that can cause serious systemic infections in humans. Despite the increasing prevalence of human infections and the negative impact on agricultural processes, little is known about the population structure of the serotype. To this end, we compiled a manually curated data set comprising of 880 S. Dublin genomes. Core genome phylogeny and ancestral state reconstruction revealed that region-specific clades dominate the global population structure of S. Dublin. Strains of S. Dublin in the UK are genomically distinct from US, Brazilian, and African strains. The geographical partitioning impacts the composition of the core genome as well as the ancillary genome. Antibiotic resistance genes are almost exclusively found in US genomes and are mediated by an IncA/C2 plasmid. Phage content and the S. Dublin virulence plasmid were strongly conserved in the serotype. Comparison of S. Dublin to a closely related serotype, S. enterica serotype Enteritidis, revealed that S. Dublin contains 82 serotype specific genes that are not found in S. Enteritidis. Said genes encode metabolic functions involved in the uptake and catabolism of carbohydrates and virulence genes associated with type VI secretion systems and fimbria assembly respectively.

scholarly journals Usefulness of High-Quality Core Genome Single-Nucleotide Variant Analysis for Subtyping the Highly Clonal and the Most Prevalent Salmonella enterica Serovar Heidelberg Clone in the Context of Outbreak Investigations

2015 ◽  
Vol 54 (2) ◽  
pp. 289-295 ◽  
Author(s):  
S. Bekal ◽  
C. Berry ◽  
A. R. Reimer ◽  
G. Van Domselaar ◽  
G. Beaudry ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Salmonella Enterica ◽  
Core Genome ◽  
Phage Type ◽  
Epidemiological Data ◽  
Single Nucleotide Variant ◽  
High Quality ◽  
Typing Method ◽  
Single Nucleotide ◽  
Content Type

Salmonella entericaserovar Heidelberg is the second most frequently occurring serovar in Quebec and the third-most prevalent in Canada. Given that conventional pulsed-field gel electrophoresis (PFGE) subtyping for commonSalmonellaserovars, such asS. Heidelberg, yields identical subtypes for the majority of isolates recovered, public health laboratories are desperate for new subtyping tools to resolve highly clonalS. Heidelberg strains involved in outbreak events. As PFGE was unable to discriminate isolates from three epidemiologically distinct outbreaks in Quebec, this study was conducted to evaluate whole-genome sequencing (WGS) and phylogenetic analysis as an alternative to conventional subtyping tools. Genomes of 46 isolates from 3 Quebec outbreaks (2012, 2013, and 2014) supported by strong epidemiological evidence were sequenced and analyzed using a high-quality core genome single-nucleotide variant (hqSNV) bioinformatics approach (SNV phylogenomics [SNVphyl] pipeline). Outbreaks were indistinguishable by conventional PFGE subtyping, exhibiting the same PFGE pattern (SHEXAI.0001/SHEBNI.0001). Phylogenetic analysis based on hqSNVs extracted from WGS separated the outbreak isolates into three distinct groups, 100% concordant with the epidemiological data. The minimum and maximum number of hqSNVs between isolates from the same outbreak was 0 and 4, respectively, while >59 hqSNVs were measured between 2 previously indistinguishable outbreaks having the same PFGE and phage type, thus corroborating their distinction as separate unrelated outbreaks. This study demonstrates that despite the previously reported high clonality of this serovar, the WGS-based hqSNV approach is a superior typing method, capable of resolving events that were previously indistinguishable using classic subtyping tools.

scholarly journals Source Tracking Based on Core Genome SNV and CRISPR Typing of Salmonella enterica Serovar Heidelberg Isolates Involved in Foodborne Outbreaks in Québec, 2012

2020 ◽  
Vol 11 ◽  
Author(s):  
Khadidja Yousfi ◽  
Valentine Usongo ◽  
Chrystal Berry ◽  
Rufaida H. Khan ◽  
Denise M. Tremblay ◽  
...  
Keyword(s):  
Salmonella Enterica ◽  
Core Genome ◽  
Source Tracking ◽  
Foodborne Outbreaks

Core genome sequence analysis to characterize Salmonella enterica serovar Rissen ST469 from a swine production chain

2019 ◽  
Vol 304 ◽  
pp. 68-74 ◽  
Author(s):  
Teerarat Prasertsee ◽  
Phongsakorn Chuammitri ◽  
Manu Deeudom ◽  
Nipa Chokesajjawatee ◽  
Pannita Santiyanont ◽  
...  
Keyword(s):  
Sequence Analysis ◽  
Genome Sequence ◽  
Salmonella Enterica ◽  
Core Genome ◽  
Swine Production ◽  
Production Chain ◽  
Genome Sequence Analysis

scholarly journals Pathological and microbiological impact of a gentamicin-loaded biocomposite following limited or extensive debridement in a porcine model of osteomyelitis

2020 ◽  
Vol 9 (7) ◽  
pp. 394-401
Author(s):  
Sophie A. Blirup-Plum ◽  
Thomas Bjarnsholt ◽  
Henrik E. Jensen ◽  
Kasper N. Kragh ◽  
Bent Aalbæk ◽  
...  
Keyword(s):  
Bone Tissue ◽  
Porcine Model ◽  
Drill Hole ◽  
Post Mortem ◽  
Tissue Samples ◽  
Group A ◽  
Extensive Debridement ◽  
Group B ◽  
The Right ◽  
Surrounding Bone

Aims CERAMENT|G is an absorbable gentamicin-loaded biocomposite used as an on-site vehicle of antimicrobials for the treatment of chronic osteomyelitis. The purpose of the present study was to investigate the sole effect of CERAMENT|G, i.e. without additional systemic antimicrobial therapy, in relation to a limited or extensive debridement of osteomyelitis lesions in a porcine model. Methods Osteomyelitis was induced in nine pigs by inoculation of 104 colony-forming units (CFUs) of Staphylococcus aureus into a drill hole in the right tibia. After one week, the pigs were allocated into three groups. Group A (n = 3) received no treatment during the study period (19 days). Groups B (n = 3) and C (n = 3) received limited or extensive debridement seven days postinoculation, respectively, followed by injection of CERAMENT|G into the bone voids. The pigs were euthanized ten (Group C) and 12 (Group B) days after the intervention. Results All animals presented confirmatory signs of bone infection post-mortem. The estimated amount of inflammation was substantially greater in Groups A and B compared to Group C. In both Groups B and C, peptide nucleic acid fluorescence in situ hybridization (PNA FISH) of CERAMENT|G and surrounding bone tissue revealed bacteria embedded in an opaque matrix, i.e. within biofilm. In addition, in Group C, the maximal measured post-mortem gentamicin concentrations in CERAMENT|G and surrounding bone tissue samples were 16.6 μg/ml and 6.2 μg/ml, respectively. Conclusion The present study demonstrates that CERAMENT|G cannot be used as a standalone alternative to extensive debridement or be used without the addition of systemic antimicrobials. Cite this article: Bone Joint Res 2020;9(7):394–401.

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