scholarly journals Streptococcus suis Research: Progress and Challenges

Pathogens ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 707 ◽  
Author(s):  
Mariela Segura
Keyword(s):  
Antimicrobial Resistance ◽  
Close Contact ◽  
Streptococcus Suis ◽  
Control Measures ◽  
Health Concern ◽  
Research Progress ◽  
Economic Losses ◽  
Swine Industry ◽  
Host Animal ◽  
Prophylactic Use

Streptococcus suis is considered among the top bacterial pathogens leading to important economic losses to the swine industry, with the incidence of disease increasing as the prophylactic use of antimicrobial is being vanished worldwide. S. suis is also a zoonotic agent afflicting people in close contact with infected pigs or pork meat. Besides, in some Asian countries, it is considered a major public health concern for the general population as well. Antimicrobial resistance is one of the most important global health challenges, and in the absence of preventive measures (such as effective vaccines), S. suis remains a risk for increased antimicrobial resistance and transmission of resistance genes to other bacteria beyond the host animal species. The studies in this Special Issue have evidenced the importance of swine population demographics and management on disease control, progress in molecular tools to better understand the epidemiology of S. suis infections in swine and humans, and the mechanisms involved in different aspects of the immuno-pathogenesis of the disease. The importance of reducing the prophylactic use of antimicrobials in livestock productions and the development of alternative control measures, including vaccination, are herein discussed.

scholarly journals Non-serotype 2 isolates from healthy pigs are a potential zoonotic reservoir of Streptococcus suis genetic diversity and antimicrobial resistance

2021 ◽  
Author(s):  
Nattinee Kittiwan ◽  
Jessica K Calland ◽  
Evangelos Mourkas ◽  
Matthew D Hitchings ◽  
Susan Murray ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Antimicrobial Resistance ◽  
Resistance Genes ◽  
Close Contact ◽  
Streptococcus Suis ◽  
Invasive Disease ◽  
Economic Losses ◽  
Swine Industry ◽  
Integrative And Conjugative Elements ◽  
Antimicrobial Resistance Genes

Streptococcus suis is a leading cause of bacterial meningitis in SE Asia, with frequent zoonotic transfer to humans associated with close contact with pigs. A small number of invasive lineages are responsible for endemic infection in the swine industry causing considerable global economic losses. A lack of surveillance and a rising trend in clinical treatment failure has raised concerns of growing antimicrobial resistance (AMR) among invasive S. suis. The source-sink dynamics between healthy and disease isolates is poorly understood and, in this study, we sample and sequence a collection of isolates predominantly from healthy pigs in Chiang Mai province, Northern Thailand. Pangenome comparisons with a selection of invasive serotype 2 isolates identified increased genetic diversity and more frequent AMR carriage in isolates from healthy pigs. Multiple antimicrobial resistance genes were identified conferring resistance to aminoglycosides, lincosamides, tetracycline and macrolides. All isolates were non-susceptinle to three or more different antimicrobial classes, and 75% of non-serotype 2 isolates were non-susceptible to 6 or more classes (compared to 37.5% of serotype 2 isolates). Antimicrobial resistance genes were found on integrative and conjugative elements (ICE) previously observed in other species, suggesting mobile gene pool which can be accessed by invasive disease isolates.

scholarly journals Research and Technological Advances Regarding the Study of the Spread of Antimicrobial Resistance Genes and Antimicrobial-Resistant Bacteria Related to Animal Husbandry

2019 ◽  
Vol 16 (24) ◽  
pp. 4896
Author(s):  
Na Li ◽  
Chong Liu ◽  
Zhiguo Zhang ◽  
Hongna Li ◽  
Tingting Song ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Resistance Genes ◽  
High Throughput Sequencing ◽  
Animal Husbandry ◽  
Control Measures ◽  
Research Progress ◽  
Future Research ◽  
Resistant Bacteria ◽  
Technological Advances ◽  
Antimicrobial Resistance Genes

The extensive use of antimicrobials in animal farms poses serious safety hazards to both the environment and public health, and this trend is likely to continue. Antimicrobial resistance genes (ARGs) are a class of emerging pollutants that are difficult to remove once introduced. Understanding the environmental transfer of antimicrobial-resistant bacteria (ARB) and ARGs is pivotal for creating control measures. In this review, we summarize the research progress on the spread and detection of ARB and ARG pollution related to animal husbandry. Molecular methods such as high-throughput sequencing have greatly enriched the information about ARB communities. However, it remains challenging to delineate mechanisms regarding ARG induction, transmission, and tempo-spatial changes in the whole process, from animal husbandry to multiple ecosystems. As a result, future research should be more focused on the mechanisms of ARG induction, transmission, and control. We also expect that future research will rely more heavily on metagenomic -analysis, metatranscriptomic sequencing, and multi-omics technologies

scholarly journals Field Study on the Immunological Response and Protective Effect of a Licensed Autogenous Vaccine to Control Streptococcus suis Infections in Post-Weaned Piglets

Vaccines ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 384 ◽  
Author(s):  
Lorelei Corsaut ◽  
Marty Misener ◽  
Paisley Canning ◽  
Guy Beauchamp ◽  
Marcelo Gottschalk ◽  
...  
Keyword(s):  
Field Study ◽  
Immunological Response ◽  
Streptococcus Suis ◽  
Vaccination Program ◽  
Economic Losses ◽  
Control Group ◽  
Vaccine Formulation ◽  
Weaned Piglets ◽  
Swine Industry ◽  
Autogenous Vaccine

Streptococcus suis is one of the most important bacterial pathogens in weaned piglets and responsible for serious economic losses to the swine industry. Currently, mostly autogenous vaccines composed of killed bacteria (bacterins) are available. However, immunological and protective data from field studies are missing. We report for the first time a comparative field study on the immunological response induced by an autogenous vaccine applied to either piglets or sows in a farm with recurrent S. suis problems. (I) Piglets from non-vaccinated sows received an autogenous bacterin during the first week and at three weeks of age. (II) Sows received the vaccine at five and three weeks pre-farrowing and piglets were non-vaccinated. Levels, isotype profile and opsonophagocytosis capacity of the serum antibodies induced by vaccination were evaluated. Vaccination of piglets failed to induce an active immune response. Vaccination of sows induced a significant increase in anti-S. suis antibodies, mainly composed of IgG1. However, isotype switching was modulated by the S. suis serotype included in the vaccine formulation. Despite this antibody increase in vaccinated sows, transfer of maternal immunity to piglets was not different from the control group (i.e., piglets from non-vaccinated sows). Notably, levels of maternal antibodies in piglets were already very high with marked opsonophagocytosis capacity at one week of age, independently of the vaccination program. However, their levels decreased by three weeks of age, indicating possible absence of antibodies in the post-weaning high-risk period. These observations correlated with lack of clinical protection in the farm. Overall, a piglet or a sow vaccination program herein mostly failed to induce lasting protection in nursery piglets. An improvement of vaccine formulation or an optimized program may be required.

Norfloxacin Sub-Inhibitory Concentration Affects Streptococcus suis Biofilm Formation and Virulence Gene Expression

2020 ◽  
Author(s):  
Baobao Li ◽  
Li Yi ◽  
Jinpeng Li ◽  
Shenglong Gong ◽  
Xiao Dong ◽  
...  
Keyword(s):  
Gene Expression ◽  
Biofilm Formation ◽  
Inhibitory Concentration ◽  
Mrna Level ◽  
Virulence Gene ◽  
Streptococcus Suis ◽  
Economic Losses ◽  
Swine Industry ◽  
Virulence Gene Expression ◽  
Viable Bacteria

Streptococcus suis (S. suis) is a major pathogen causing economic losses to the swine industry. Norfloxacins are usually used at sub-MIC (Minimum Inhibitory Concentration) doses to prevent S. suis infection. This study demonstrates the effect of norfloxacin sub-MIC on biofilm formation and virulence gene expression in S. suis.It was found that 1/4 MIC of norfloxacin increased biofilm formation in S. suis, the biofilms formed contained a higher number of viable bacteria. Additionally, bacterial growth rates were inhibited at 1/2 MIC of norfloxacin. Furthermore, the mRNA level of S. suis virulence gene cps, ef, sly, fpbs, gdh and gapdh increased by real-time PCR, while the virulence gene mrp decreased at 1/4 MIC. In conclusion, Norfloxacin sub-MICs affects biofilm formation and virulence gene expression in S. suis. These findings suggest that investigating the effect of the administration of antibiotics sub-MICs on bacterial biofilms and infection may lead to the development of future antibiotic treatments modalities.

scholarly journals Amentoflavone AmelioratesStreptococcus suis-Induced InfectionIn VitroandIn Vivo

2018 ◽  
Vol 84 (24) ◽  
Author(s):  
Xue Shen ◽  
Xiaodi Niu ◽  
Gen Li ◽  
Xuming Deng ◽  
Jianfeng Wang
Keyword(s):  
Bacterial Resistance ◽  
Cell Model ◽  
Streptococcus Suis ◽  
Chinese Herbs ◽  
Economic Losses ◽  
Swine Industry ◽  
Necrosis Factor Alpha ◽  
Content Type ◽  
Anti Inflammatory

ABSTRACTStreptococcus suis, an important zoonotic pathogen, has caused considerable economic losses in the swine industry and severe public health issues worldwide. The development of a novel effective strategy for the prevention and therapy ofS. suisis urgently needed. Here, amentoflavone, a natural biflavonoid compound isolated from Chinese herbs that has negligible anti-S. suisactivity, was identified as a potent antagonist of suilysin (SLY)-mediated hemolysis without interfering with the expression of SLY. Amentoflavone effectively inhibited SLY oligomerization, which is critical for its pore-forming activity. The treatment with amentoflavone reducedS. suis-induced cytotoxicity in macrophages (J774 cells). Furthermore,S. suis-infected mice that received amentoflavone exhibited lower mortality and bacterial burden. Additionally, amentoflavone significantly decreased the production of tumor necrosis factor alpha (TNF-α), interleukin-1β (IL-1β), and IL-6 in anS. suis-infected cell model. Analyses of signaling pathways demonstrated that amentoflavone reducedS. suis-induced inflammation inS. suisserotype 2 (SS2)-infected cells by regulating the p38, Jun N-terminal protein kinase 1 and 2 (JNK1/2), and NF-κB pathways. The antivirulence and anti-inflammatory properties of amentoflavone againstS. suisinfection provide the possibility for future pharmaceutical application of amentoflavone in the treatment ofS. suisinfection.IMPORTANCEThe widespread use of antibiotics in therapy and in the prevention ofStreptococcus suisinfection in the swine industry raises concerns for the emergence of a resistant strain. The use of antivirulence agents has potential benefits, mainly because of the reduced selective pressure for the development of bacterial resistance. In this study, we found that amentoflavone is an effective agent againstS. suisserotype 2 (SS2) infection bothin vitroandin vivo. Our results demonstrated that amentoflavone is a promising anti-infective therapeutic forS. suisinfections, due to its antivirulence and anti-inflammatory effects without antibacterial activity, with fewer side effects than conventional antibacterial agents.

scholarly journals Engineering Antigens to Assemble into Polymer Particle Vaccines for Prevention of Streptococcus suis Infection

Vaccines ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 1386
Author(s):  
Zennia Jean C. Gonzaga ◽  
Shuxiong Chen ◽  
Mélanie Lehoux ◽  
Mariela Segura ◽  
Bernd H. A. Rehm
Keyword(s):  
Immune Responses ◽  
Streptococcus Suis ◽  
Polymer Particle ◽  
Economic Losses ◽  
Infection Model ◽  
Swine Industry ◽  
Humoral Immune ◽  
Humoral Immune Responses ◽  
Flight Mass Spectrometry ◽  
Negative Surface

Streptococcus suis is a zoonotic pathogen affecting pigs and humans. This bacterium causes severe economic losses in the swine industry and poses a serious threat to public health and food safety. There is no effective commercial vaccine available for pigs or humans. In this study, we applied the biopolymer particle (BP) vaccine technology to incorporate seven conserved S. suis antigens (38 kDa protein (38), enolase (Enol), SSU1915, SSU1355, SSU0185, SSU1215, and SSU1773 (SSU1 and SSU2)). Two combinations of these antigens (38 and Enol; all SSU antigens designated as SSU1 and SSU2) were engineered to mediate production of BPs coated with either antigens 38 and Enol or SSU1 and SSU2 inside recombinant Escherichia coli. The isolated and purified empty BPs, 38-BP-Enol and SSU1-BP-SSU2, showed size ranges of 312–428 nm and 292–344 nm with and without the QuilA® adjuvant, respectively, and all showed a negative surface charge. Further characterization of purified BPs confirmed the presence of the expected antigen-comprising fusion proteins as assessed by tryptic peptide fingerprinting analysis using quadrupole time-of-flight mass spectrometry and immunoblotting. Vaccination with 38-BP-Enol and SSU1-BP-SSU2 formulated with and without QuilA® adjuvant induced significant antigen-specific humoral immune responses in mice. Antigen-coated BPs induced significant and specific Ig (IgM + IgG) and IgG immune responses (1.0 × 106–1.0 × 107) when compared with mice vaccinated with empty BPs. Functionality of the immune response was confirmed in challenge experiments using an acute murine S. suis infection model, which showed 100% survival of the 38-BP-Enol and SSU1-BP-SSU2 vaccinated mice compared to 70% survival when vaccinated with empty BPs. Overall, our data suggest that S. suis antigen-coated BPs could be developed into particulate vaccines that induce protective immunity against S. suis infections.

scholarly journals Glyconanoparticles as tools to prevent antimicrobial resistance

2021 ◽  
Author(s):  
Laura Morelli ◽  
Laura Polito ◽  
Barbara Richichi ◽  
Federica Compostella
Keyword(s):  
Antimicrobial Resistance ◽  
Control Measures ◽  
New Drugs ◽  
Health Concern ◽  
Global Public Health ◽  
Infection Control Measures ◽  
Microbial Infections ◽  
New Antibiotics ◽  
Improved Sanitation ◽  
Alternative Delivery

AbstractThe increased phenomenon of antimicrobial resistance and the slow pace of development of new antibiotics are at the base of a global health concern regarding microbial infections. Antibiotic resistance kills an estimated 700,000 people each year worldwide, and this number is expected to increase dramatically if efforts are not made to develop new drugs or alternative containment strategies. Increased vaccination coverage, improved sanitation or sustained implementation of infection control measures are among the possible areas of action. Indeed, vaccination is one of the most effective tools of preventing infections. Starting from 1970s polysaccharide-based vaccines against Meningococcus, Pneumococcus and Haemophilus influenzae type b have been licensed, and provided effective protection for population. However, the development of safe and effective vaccines for infectious diseases with broad coverage remains a major challenge in global public health. In this scenario, nanosystems are receiving attention as alternative delivery systems to improve vaccine efficacy and immunogenicity. In this report, we provide an overview of current applications of glyconanomaterials as alternative platforms in the development of new vaccine candidates. In particular, we will focus on nanoparticle platforms, used to induce the activation of the immune system through the multivalent-displacement of saccharide antigens. Graphical abstract

scholarly journals Antimicrobial Resistance of Aeromonas Species Isolated from Cultured Indian Major Carp, Labeo rohita: Possible Public Health Concern

2021 ◽  
Vol 12 (5) ◽  
pp. 506-515
Author(s):  
Chethurajupalli Lavanya ◽  
◽  
Tambireddy Neeraja ◽  
P. Hari Babu ◽  
T. V. Ramana ◽  
...  
Keyword(s):  
Public Health ◽  
Antimicrobial Resistance ◽  
Freshwater Fish ◽  
Labeo Rohita ◽  
Health Concern ◽  
Economic Losses ◽  
Aeromonas Species ◽  
Biochemical Tests ◽  
Pathogenic Potential ◽  
Risk Sources

In India, Labeo rohita is widely cultured and consumed freshwater fish. Aeromonads are etiological agents of major bacterial fish diseases like furunculosis, haemorrhagic septicaemia, skin ulcers, fin/tail rot and dropsy, causing significant economic losses in carp culture. Aeromonas species are widely distributed in aquatic environment which is considered as important vehicle of Aeromonas infections to fish and humans. Some of the Aeromonas spp. causes gastroenteritis, septicaemia, peritonitis, meningitis and eye infections in humans. In the present study Aeromonas species were isolated from diseased freshwater fish Labeo rohita collected from two districts viz., West Godavari and SPSR Nellore of Andhra Pradesh, India. A Total of 12 Aeromonas spp. were isolated and identified by biochemical tests. A. veronii bv. veronii (35%) was dominant when compared to other Aeromonas spp. Further, Antimicrobial resistance and multiple Antimicrobial resistance (MAR) of all Aeromonas spp. were tested against 17 antibiotics being frequently used for human diseases. The Antimicrobial resistance of all the 12 Aeromonas spp. have shown significantly high (p<0.05) resistance (100%) to ampicillin, amoxyclave and oxytetracycline except A. cavernicola when compared to other antibiotics. The MAR index of Aeromonas spp. ranged from 0.18-0.76, which indicates origination of isolated Aeromonas spp. from high risk sources of contamination. A. hydrophila, A. veronii bv. sobria, A. veronii bv. veronii, A. schubertii and A. jandaei isolated in this study were found to be pathogenic to humans also. The results revealed the pathogenic potential of Aeromonas infections in freshwater fish culture and emerging threats to public health.

scholarly journals The E3 Ubiquitin Ligase TRIM25 Inhibits Tembusu Virus Replication in vitro

2021 ◽  
Vol 8 ◽  
Author(s):  
Han Kaikai ◽  
Dongmin Zhao ◽  
Yuzhuo Liu ◽  
Qingtao Liu ◽  
Xinmei Huang ◽  
...  
Keyword(s):  
Ubiquitin Ligase ◽  
Egg Production ◽  
Molecular Mechanisms ◽  
E3 Ubiquitin Ligase ◽  
Control Measures ◽  
Neurological Dysfunction ◽  
Health Concern ◽  
Economic Losses ◽  
Tembusu Virus

Duck Tembusu virus (DTMUV) is a newly emerging pathogenic flavivirus that has caused significant economic losses to the duck industry in China since 2010 due to egg production losses and neurological dysfunction. DTMUV is a public health concern because the infection spreads rapidly among birds. Retinoic acid-inducible gene-I (RIG-I)serves as an innate immune sensor and plays a key role in host antiviral defenses. Tripartite motif-containing protein 25 (TRIM25), an E3 ubiquitin ligase, is pivotal for RIG-I ubiquitination and activation. In addition, TRIM25 acts as an interferon-stimulated gene and mediates the antiviral activity. However, the effect of duck TRIM25 on DTMUV has not been assessed. Herein, we reportthe antiviral function of TRIM25 against DTMUV. First, we constructed the pcDNA3.1-c-myc-duTRIM25 plasmid. TRIM25 has a 2052 bp open reading frame that encodes a predicted 684 amino acid protein consisting of a RING finger domain, a B-box domain, a coiled-coil domain, and a PRY/SPRY domain. The protein sequence identity with chicken, mouse, and human TRIM25 is 69.7, 47.8, and 48.3%, respectively. TRIM25 was upregulated in BHK-21 cells, duck embryo fibroblasts, and 293T cellsupon DTMUV infection. The expression of viral RNA and proteins was significantly lower in cells over expressing TRIM25 than in control cells. Furthermore, siRNA-mediated silencing of TRIM25 increased the production of viral progeny. These results help elucidate the molecular mechanisms underlying the host response to DTMUV infection and suggest potential control measures for DTMUV outbreaks.

scholarly journals Seroprevalences of classical swine fever virus and porcine reproductive and respiratory syndrome virus in pigs in Hunan Province, China

2020 ◽  
Author(s):  
Haoyang Yu ◽  
Luhua Zhang ◽  
Yunfeng Cai ◽  
Tao Peng ◽  
Lei Liu ◽  
...  
Keyword(s):  
Average Rate ◽  
Classical Swine Fever ◽  
Control Measures ◽  
Hunan Province ◽  
Economic Losses ◽  
Respiratory Syndrome Virus ◽  
Growth Stages ◽  
Serum Samples ◽  
Swine Industry ◽  
Effective Prevention

Abstract Background: Classical swine fever (CSF) and porcine reproductive and respiratory syndrome (PRRS) are responsible for major economic losses and represent a threat to the swine industry worldwide. Routine surveillance serology for CSF and PRRS will be critical to maintain the health status of sow farms in Hunan Province, which is one of the top pig production provinces in China.The objective of our study was to investigate the seroprevalence of CSF virus (CSFV) and PRRS virus (PRRSV) in Hunan Province from 2017 to 2019 using ELISA. The cohort pig serum samples were collected from vaccinated and unvaccinated sow farms in eight cities in Hunan Province. Results: CSFV and PRRSV seropositivity showed significant differences among parts of Hunan Province in China. Interestingly, our findings show that the level of CSFV antibody in piglet sera decreases gradually with increasing piglet age, whereas PRRSV-specific antibodies may appear in various growth stages in unvaccinated animals. Meanwhile, the average rate of CSFV antibody seropositivity was 82.2%, while the rate of PRRSV antibody seropositivity was slightly higher (84.4%) in the immunized group.Conclusions: The results from this study suggest that a serological investigation of these two major infectious diseases (CSF and PRRS) among pigs at various growth stages will provide a basis for the further development of more effective prevention and control measures.

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