Streptococcus Suis Meningitis Research Articles

Cochlear implantation for rare Streptococcus suis meningitis with hearing loss.

This study aimed to explore the diagnostic sensitivity of 3D heavily weighted T2-weighted MRI (T2MRI) and high-resolution computed tomography (HRCT) in patients with cochlear fibrosis associated with Streptococcus suis (S. suis) meningitis and the practicality of Cochlear implantation (CI) treatments. Between January 2020 and December 2022, we enrolled four patients with rare cochlear S. suis meningitis with associated hearing loss despite aggressive or non-aggressive follow-up antibiotic treatment. Clinical imaging data, surgical performances and post-surgical-electrode impedance were evaluated. Combined with HRCT and T2MRI, the cochlea had varying degrees of fibrosis and ossification in different cases. However, the electrodes were successfully and wholly inserted after intraoperative removal of the ossified and fibrotic foci. Post-surgical electrode impedance values of MP1 + 2 mode were normal in all 4 cases at initial activation. In patients with S. suis meningitis and associated cochlear fibrosis, T2MRI examination of the inner ear was more sensitive than HRCT. This research highlights the feasibility of CI treatment in S. suis meningitis patients with severe cochlear fibrosis.

Sudden sensorineural hearing loss related to Streptococcus suis meningitis

Background: Streptococcus suis meningitis is caused by Streptococcus suis, gram positive bacteria which is a pathogen mainly in pigs. It is an emerging zoonosis globally with highest incidence in Southeast Asia. The main risk factors are contact with infected pigs and consumption of raw or moderately cooked pork. Bilateral sudden sensorineural hearing loss is a remarakable symptom in this disease. Early initiation of antibiotic and systemic corticosteroids is recommended to improve clinical outcome and reduce complications. Even so, despite adequate treatment, sensorineural hearing loss related to S. suis meningitis is usually irreversible. We report two male patients consulted to otorhinolaryngology department regarding decreased hearing in both ears. Both patients was previously admitted because of altered mental status, accompanied with fever and headache. History of eating traditional Balinese pork dish before the onset was noted. Pure-tone audiometry revealed bilateral sensorineural hearing loss in both patients. Diagnosis of S. suis meningitis was established and treatment was prompted. Clinically, both patients showed improvement but evaluation audiometry showed no remarkable improvement in hearing threshold. Therefore, transmission avoidance, infection prevention, hygiene practice and educational activities are essential.

Acute multiple brain infarctions associated with Streptococcus suis infection: a case report

Streptococcus suis is one of the most common zoonotic pathogens, in humans and can cause meningitis, endocarditis, arthritis and sepsis. Human cases of Streptococcus suis infection have been reported worldwide, and most of those cases occurred in Asia. Hearing loss is the most common sequela of Streptococcus suis meningitis. Streptococcus suis infection complicated with acute cerebral infarction has rarely been reported. Therefore, to provide a reference for this disease, we reported a case of acute multiple brain infarctions associated with Streptococcus suis infection. In our report, a 69yearold male patient had Streptococcus suis meningitis and sepsis, which were associated with multiple acute cerebral infarctions in the pons and bilateral frontotemporal parietal occipital lobes. After treatment, the patient exhibited cognitive impairment, dyspraxia and irritability. There are limited case reports of cerebral infarction associated with Streptococcus suis infection, and further research is needed to determine the best treatment method.

Cochlear implantation in patients with Streptococcus suis meningitis: clinical characteristics and postoperative evaluation

Background Hearing loss is a common sequala of Streptococcus suis (S. suis) meningitis, but few have addressed cochlear implantation (CI) candidates with S. suis meningitis. Objectives To assess the clinical characteristics and CI postoperative outcomes in S. suis meningitis patients. Material and methods Eight S. suis meningitis patients underwent CI at Sun Yat-sen Memorial Hospital between 2020 and 2023. Control groups included (1) non-Suis meningitis patients (n = 12) and (2) non-meningitis patients (n = 35). Electrode impedances and neural response telemetry (NRT) thresholds were recorded at one month after surgery. The auditory performance-II (CAP) and speech intelligibility rating (SIR) were recorded at the last visit. Results CAP scores of S. suis meningitis patients were significantly lower than those of non-Suis meningitis and non-meningitis patients (p = .019; p<.001). And NRT thresholds of S. suis meningitis patients were higher than those of non-Suis meningitis and non-meningitis patients (p = .006; p = .027). Conclusions and significance It is recommended for S. suis meningitis CI candidates to undergo CI promptly after controlling infection, preferably within four to six weeks. CI users with S. suis meningitis tend to exhibit suboptimal hearing rehabilitation outcomes, possibly associated with the more severe damage on spiral ganglion cells after S. suis meningitis.

Brain Immune Cell Infiltration and Serum Metabolomic Characteristics Reveal that Lauric Acid Promotes Immune Cell Infiltration in Brain and Streptococcus suis Meningitis in Mice.

Although naturally Streptococcus suis serotype 2 (SS2) causes meningitis resulting in death or sequela of neurological symptoms in pigs and humans, severely threatening public health in the world, it has been difficult to build up and confirm experimental meningitis mouse models with obvious neurological syndrome for about two decades, which strongly hampers the in-depth study on the control measures and mechanisms of SS2-induced meningitis. In this study, a typical meningitis mouse model of SS2 was successfully established, as confirmed by the behavioral indicators of balance beam test, suspension test, and gait analysis. With bacteria gathering in the brain, distinguishable unique features including meningeal thickening, vacuolization of the Nissl body, brain barrier damage, glial cell activation, and more infiltration of T cells, macrophages, and DCs are observed in SS2 meningitis mice with typical neurological signs. Some meningitis mice were also accompanied by identical nephritis, ophthalmia, and cochlearitis. Investigation of the metabolic features demonstrated the downregulated cholic acid and upregulated 2-hydroxyvaleric acid, tetrahydrocortisone, nicotinic acid, and lauric acid in blood serum of mice and piglets with meningitis. And feeding trials show that lauric acid can promote meningitis by promoting the infiltration of immune cells into brain. These findings demonstrated that infection of ICR (improved castle road) mice with SS2 was able to induce typical meningitis accompanied by immune cell infiltration and lauric acid upregulation. These data provide a basis for the deep study of SS2 meningitis.

Severe case of Streptococcus suis meningitis in Bali Mandara Hospital: a case report

Background: Streptococcus suis meningitis (SSM) is one of the zoonotic disease that can cause serious illness in humans. The major risk factor in many cases of SSM is associated with pig husbandry and consuming undercooked pork products. In Indonesia, especially in Bali, the cases of this acute bacterial meningitis has been strongly correlated with consuming Balinese traditional food called “red lawar”, a mixture of raw pork, fresh pork blood and traditional Balinese herbs. This study aims to report a case of SSM in Bali Mandara Hospital. Case description: A 63-year-old man admitted to the Emergency Department because of a decrease in consciousness (Glasgow coma scale 3/15). This patient was transferred from a private hospital with septic shock and suspicious to acute bacterial meningitis. He had other related symptoms like fever, headache, and cough since two days prior to admission. He also had a history of consuming “red lawar” 2 days before the symptoms appeared. Laboratory findings from cerebrospinal fluid analysis and septic marker indicate the patient had bacterial meningitis. The patient was initially started by Meropenem due to his septic shock. The broad spectrum antibiotics were then de-escalate to Ceftriaxone once the culture and sensitivity test completed and yielded Streptococcus suis. The course of Ceftriaxone as definitive therapy has been administered for 14 days and showed clinical improvement without specific sequelae related to SSM infection like hearing loss. Conclusion: Severe meningitis e.c Streptococcus suis leading to septic shock is a life threatening health condition. Adequate antibiotic therapy and multidisciplinary approach can reduce mortality and morbidity of this case.

Clinical Characteristics and Follow-up of Cases of Streptococcus suis Meningitis in Patients of Liuzhou, China.

We analyzed the clinical characteristics and outcomes of patients with Streptococcus suis meningitis in Liuzhou, China, to improve diagnostic accuracy and lower the chances of misdiagnosis. The major clinical manifestations, auxiliary examination results, treatment strategies, treatment efficacy, and follow-up results of 17 consecutively admitted patients with S. suis meningitis were evaluated. The most common clinical manifestations were fever (15/17), sensorineural hearing loss (13/17), headache (11/17), and altered mental status (8/17). In addition, 64.71% of the patients had residual symptoms of sensorineural hearing loss at discharge, and moderate disabilities occurred in 68.75% of the patients in the form of sensorineural deafness (11/17) and hemiparesis (1/17). The cerebrospinal fluid (CSF) of nine patients was used for metagenomic analysis with next-generation sequencing. The metagenomic analysis of CSF of four patients was positive, whereas blood and CSF cultures were negative. The average modified Rankin Scale (mRS) and Activities of Daily Living (ADL) scores improved significantly at the 6-month follow-up compared with those at admission (P < 0.05). There was no correlation between altered mRS and ADL scores and the CSF findings (P > 0.05). Early administration of antibiotics can prevent sensorineural hearing loss. Early CSF metagenomic analysis may be superior to blood and CSF culture.

The VraSR two-component signal transduction system contributes to the damage of blood-brain barrier during Streptococcus suis meningitis

Streptococcus suis (S. suis) is an important zoonotic pathogen that can cause high morbidity and mortality in both humans and swine. As the most important life-threatening infection of the central nervous system (CNS), meningitis is an important syndrome of S. suis infection. The vancomycin resistance associated sensor/regulator (VraSR) is a critical two-component signal transduction system that affects the ability of S. suis to resist the host innate immune system and promotes its ability to adhere to brain microvascular endothelial cells (BMECs). Prior work also found mice infected with ΔvraSR had no obvious neurological symptoms, unlike mice infected with wild-type SC19. Whether and how VraSR participates in the development of S. suis meningitis remains unknown. Here, we found ΔvraSR-infected mice did not show obvious meningitis, compared with wild-type SC19-infected mice. Moreover, the proinflammatory cytokines and chemokines in serum and brains of ΔvraSR-infected mice, including IL-6, TNF-α, MCP-1 and IFN-γ, were significantly lower than wild-type infected group. Besides, blood-brain barrier (BBB) permeability also confirmed that the mutant had lower ability to disrupt BBB. Furthermore, in vivo and in vitro experiments showed that SC19 could increase BBB permeability by downregulating tight junction (TJ) proteins such as ZO-1, β-Catenin, Occludin, and Clauidn-5, compared with mutant ΔvraSR. These findings provide new insight into the influence of S. suis VraSR on BBB disruption during the pathogenic process of streptococcal meningitis, thereby offering potential targets for future preventative and therapeutic strategies against this disease.

A large cluster of human infections of Streptococcus suis in Bali, Indonesia

A cluster of 18 inpatients and 21 outpatients with a major complaint of meningitis and a history of sharing traditional delicacies of raw pork and pig blood in a village festival led to the suspicion of Streptococcus suis (S. suis) meningitis in Sibang Kaja Village, Badung, Bali, Indonesia. We conducted an investigation and case finding to prevent human fatalities. Demography and laboratory examinations of the inpatients were recorded. Bacterial culture, identification, and sensitivity tests were conducted using a VITEK 2 Compact machine (Biomeriuex®) with cerebrospinal fluid (CSF) or blood from the inpatients. The bacterial species were confirmed via PCR. A subsequent investigation was also conducted to identify the source of the meat, the presence of S. suis in slaughtered pigs, and the zoosanitary measures at pig farms and slaughterhouses. The five most common clinical signs were fever (92.3%), myalgia (46.1%), neck stiffness (25.6%), headache (23.1%), and nausea/vomiting (20.5%). S. suis was confirmed in two CSF and one blood specimens. All inpatients recovered following intravenous treatment with ceftriaxone every 12 h for 14 days and dexamethasone every 6 h for 4 days, while the outpatients were treated with 500 mg of amoxicillin three times daily for 7 days. The veterinary and environmental investigation identified the source of the pork for the festival, confirmed the presence of S. suis in the slaughtered pigs, and elucidated the sanitary measures applied at the pig farms and slaughterhouses. We conclude that infections of S. suis in humans can spread in cluster phenomena following the sharing of high-risk food. A prompt and early response, as well as early treatment of patients, is paramount in case finding to enable a favourable outcome of full recovery. Additionally, the implementation of the “One Health” approach provides a comprehensive picture of the management of S. suis infection in humans.

The value of next-generation sequencing for the diagnosis of Streptococcus suis meningitis.

The aim of this study was to investigate the value of next-generation sequencing for the diagnosis of Streptococcus suis meningitis. Patients with meningitis in the Department of Neurology of the Hainan General Hospital were recruited and divided into a next-generation sequencing group and a control group. In the next-generation sequencing group, we used the next-generation sequencing method to detect the specific pathogenic bacteria in the patients. In the control group, we used the cerebrospinal fluid bacterial culture method to detect the specific pathogenic bacteria in the patients. A total of 28 participants were recruited for this study, with 14 participants in each group. The results showed similarities in both the average age and average course of the disease between the two groups (p>0.05). The white blood cell count, percentage of neutrophils, and level of C-reactive protein in the next-generation sequencing group were significantly higher than those in the control group (p<0.05). There were similarities in both the temperature and intracranial pressure between the two groups (p>0.05). In the next-generation sequencing group, all patients (100%) were detected as having had the S. suis meningitis infection by next-generation sequencing, while only 6 (43%) patients in the control group had been detected as having the S. suis meningitis infection by cerebrospinal fluid bacterial culture. The positive detection rate of S. suis by the next-generation sequencing method was significantly higher compared with using a cerebrospinal fluid bacterial culture. Therefore, the next-generation sequencing method is valuable for the diagnosis of S. suis meningitis and is worthy of clinical application.

A Case of Streptococcus Suis Meningitis with Visual Impairment And Hearing Loss Diagnosed by Metagenomic Next-Generation Sequencing

A Case of Streptococcus Suis Meningitis with Visual Impairment And Hearing Loss Diagnosed by Metagenomic Next-Generation Sequencing

PBI-003 - Don’t bring home that bacon: a report of two simultaneous cases of Streptococcus suis meningitis

PBI-003 - Don’t bring home that bacon: a report of two simultaneous cases of Streptococcus suis meningitis

Role of Bacterial and Host DNases on Host-Pathogen Interaction during Streptococcus suis Meningitis.

Streptococcus suis is a zoonotic agent causing meningitis in pigs and humans. Neutrophils, as the first line of defense against S. suis infections, release neutrophil extracellular traps (NETs) to entrap pathogens. In this study, we investigated the role of the secreted nuclease A of S. suis (SsnA) as a NET-evasion factor in vivo and in vitro. Piglets were intranasally infected with S. suis strain 10 or an isogenic ssnA mutant. DNase and NET-formation were analyzed in cerebrospinal fluid (CSF) and brain tissue. Animals infected with S. suis strain 10 or S. suis 10ΔssnA showed the presence of NETs in CSF and developed similar clinical signs. Therefore, SsnA does not seem to be a crucial virulence factor that contributes to the development of meningitis in pigs. Importantly, DNase activity was detectable in the CSF of both infection groups, indicating that host nucleases, in contrast to bacterial nuclease SsnA, may play a major role during the onset of meningitis. The effect of DNase 1 on neutrophil functions was further analyzed in a 3D-cell culture model of the porcine blood–CSF barrier. We found that DNase 1 partially contributes to enhanced killing of S. suis by neutrophils, especially when plasma is present. In summary, host nucleases may partially contribute to efficient innate immune response in the CSF.

TRIM32 Drives Pathogenesis in Streptococcal Toxic Shock-Like Syndrome and Streptococcus suis Meningitis by Regulating Innate Immune Responses.

Streptococcus suis is an emerging zoonotic agent that causes streptococcal toxic shock-like syndrome (STSLS) and meningitis in humans, with high mortality and morbidity. The pathogenesis of both STSLS and central nervous system (CNS) infections caused by S. suis is not well understood. TRIM32, a member of the tripartite motif (TRIM) protein family, has been reported to regulate host inflammatory responses. In this study, we showed that TRIM32 deficiency significantly reduced the level of bacteremia and the production of proinflammatory cytokines following severe S. suis infection, protecting infected mice from STSLS. The influence of TRIM32 gene deletion on a range of processes known to be involved in S. suis meningitis was also examined. Both levels of bacterial loads and indications of brain hemorrhage were reduced in infected Trim32-/- mice compared with infected wild-type (WT) controls. We also found that TRIM32 deficiency increased the permeability of the blood-brain barrier (BBB) and the recruitment of inflammatory monocytes during the early course of S. suis infection, potentially limiting the development of S. suis meningitis. Our results suggest that TRIM32 sensitizes S. suis-induced infection via innate immune response regulation.

The inflammatory response and neuronal injury in Streptococcus suis meningitis

BackgroundMany of the currently used models of bacterial meningitis have limitations due to direct inoculation of pathogens into the cerebrospinal fluid or brain and a relatively insensitive assessment of long-term sequelae. The present study evaluates the utility of a Streptococcus (S.) suis intranasal infection model for the investigation of experimental therapies in meningitis.MethodsWe examined the brains of 10 piglets with S. suis meningitis as well as 14 control piglets by histology, immunohistochemistry and in-situ tailing for morphological alterations in the hippocampal dentate gyrus and microglial activation in the neocortex.ResultsIn piglets with meningitis, the density of apoptotic neurons was significantly higher than in control piglets. Moreover, scoring of microglial morphology revealed a significant activation of these cells during meningitis. The slight increase in the density of dividing cells, young neurons and microglia observed in piglets suffering from meningitis was not statistically significant, probably because of the short time frame between onset of clinical signs and organ sampling.ConclusionsThe morphological changes found during S. suis meningitis are in accordance with abnormalities in other animal models and human autopsy cases. Therefore, the pig should be considered as a model for evaluating effects of experimental therapeutic approaches on neurological function in bacterial meningitis.

Binding of Fibronectin to SsPepO Facilitates the Development of Streptococcus suis Meningitis.

SsPepO is an important virulence in Streptococcus suis. In this study, we showed that SsPepO contributes to the human fibronectin-mediated adherence ability of S. suis to human brain microvascular endothelial cells. The addition of an antifibronectin antibody or an arginine-glycine-aspartic acid peptide that blocks fibronectin binding to integrins significantly reduced adherence of the wild-type but not the SspepO mutant strain, indicating the importance of the SsPepO-fibronectin-integrin interaction for S. suis cellular adherence. By analyzing Evans blue extravasation in vivo, we showed that the interaction between SsPepO and human fibronectin significantly increased permeability of the blood-brain barrier. Furthermore, the SspepO mutant caused lower bacterial loads in the brain than wild-type S. suis in models of meningitis. These data demonstrate that SsPepO is a fibronectin-binding protein, which plays a contributing role in the development of S. suis meningitis.

Case of Streptococcus suis meningitis in a French cooker and review

Case of Streptococcus suis meningitis in a French cooker and review

Interaction of fibrinogen and muramidase-released protein promotes the development of Streptococcus suis meningitis

Muramidase-released protein (MRP) is as an important virulence marker of Streptococcus suis (S. suis) serotype 2. Our previous works have shown that MRP can bind human fibrinogen (hFg); however, the function of this interaction in S. suis meningitis is not known. In this study, we found that the deletion of mrp significantly impairs the hFg-mediated adherence and traversal ability of S. suis across human cerebral microvascular endothelial cells (hCMEC/D3). Measurement of the permeability to Lucifer yellow in vitro and Evans blue extravasation in vivo show that the MRP-hFg interaction significantly increases the permeability of the blood–brain barrier (BBB). In the mouse meningitis model, wild type S. suis caused higher bacterial loads in the brain and more severe histopathological signs of meningitis than the mrp mutant at day 3 post-infection. Western blot analysis and immunofluorescence observations reveal that the MRP-hFg interaction can destroy the cell adherens junction protein p120-catenin of hCMEC/D3. These results indicate that the MRP-hFg interaction is important in the development of S. suis meningitis.

Comparative genomic analysis shows that Streptococcus suis meningitis isolate SC070731 contains a unique 105 K genomic island

Streptococcus suis (SS) is an important swine pathogen worldwide that occasionally causes serious infections in humans. SS infection may result in meningitis in pigs and humans. The pathogenic mechanisms of SS are poorly understood. Here, we provide the complete genome sequence of S. suis serotype 2 (SS2) strain SC070731 isolated from a pig with meningitis. The chromosome is 2,138,568bp in length. There are 1933 predicted protein coding sequences and 96.7% (57/59) of the known virulence-associated genes are present in the genome. Strain SC070731 showed similar virulence with SS2 virulent strains HA9801 and ZY05719, but was more virulent than SS2 virulent strain P1/7 in the zebrafish infection model. Comparative genomic analysis revealed a unique 105K genomic island in strain SC070731 that is absent in seven other sequenced SS2 strains. Further analysis of the 105K genomic island indicated that it contained a complete nisin locus similar to the nisin U locus in S. uberis strain 42, a prophage similar to S. oralis phage PH10 and several antibiotic resistance genes. Several proteins in the 105K genomic island, including nisin and RelBE toxin–antitoxin system, contribute to the bacterial fitness and virulence in other pathogenic bacteria. Further investigation of newly identified gene products, including four putative new virulence-associated surface proteins, will improve our understanding of SS pathogenesis.

Severe cochlear inflammation and vestibular syndrome in an experimental model of Streptococcus suis infection in mice

Hearing impairment is a common and frequently permanent sequel of Streptococcus suis meningitis in humans. Nevertheless, mechanisms underlying the development of cochlear damage have not been addressed so far. In the present work, we characterized a mouse model of suppurative labyrinthitis and meningitis induced by a systemic infection with S. suis and studied the impact of the injected bacterial dosage on the progression of such inflammatory events. We observed that high infection doses of bacteria lead to sustained bacteremia, with an increase in the permeability of the blood-labyrinth and blood-brain barriers, causing suppurative labyrinthitis and meningitis, respectively. However, in mice infected with a low dose of S. suis, bacteria disappeared quickly from blood, hence, cochlear inflammation and meningitis were not consistent features. This model of S. suis infection seems ideal to evaluate novel drugs that may help alleviate the negative consequences of such important sequelae of S. suis-induced meningitis and labyrinthitis.