Streptococcus dysgalactiae subsp. dysgalactiae presents with progressive weakness in limbs: a case report and literature review

BACKGROUND

Streptococcus dysgalactiae subsp. dysgalactiae has been identified as an animal pathogen that is thought to occur only in animal populations. Between 2009 and 2022, humans infected with SDSD were reported rarely. There is a lack of details on the natural history, clinical features, and management of disease caused by this pathogen. This case outlines a human SDSD with muscle aches and progressive loss of muscle strength leading to immobility and multi-organ dysfunction syndrome.

CASE PRESENTATION

She presented with muscle pain and weakness, and later developed a sore throat, headache and fever with a maximum temperature of 40.5 °C. The muscle strength of the extremities gradually decreased to grade 1 and the patient was unable to move on his own. Next-generation blood sequencing and multi-culture confirmed the presence of Streptococcus dysgalactiae and Streptococcus dysgalactiae subsp. Dysgalactiae, respectively. A Sequential Organ Failure Assessment score of 6 indicated septicemia, and therapeutic antibiotics were prescribed empirically. After 19 days of inpatient treatment, the patient's condition greatly improved and completely recovered within a month.

CONCLUSION

Symptoms of Streptococcus dysgalactiae subsp. dysgalactiae presenting with progressive limb weakness resemble polymyositis, so a precise differential diagnosis is essential. Multidisciplinary consultation is helpful when polymyositis cannot be ruled out and facilitates the choice of an optimal treatment protocol. In the context of this case, penicillin is an effective antibiotic for Streptococcus dysgalactiae subsp. dysgalactiae infection.

All-trans Retinoic Acid-incorporated Glycol Chitosan Nanoparticles Regulate Macrophage Polarization in Pg-LPS-Induced Inflammation

OBJECTIVE

The occurrence and development of inflammation are closely correlated to the polarization of macrophages. All-trans retinoic acid (ATRA) has been proven to promote the polarization of macrophages from M1 to M2, but this lacks an effective carrier to participate in the biological response. The present study aims to determine whether retinoic acid-incorporated glycol chitosan (RA-GC) nanoparticles can regulate macrophage polarization in Porphyromonas gingivalis-lipopolysaccharide (Pg-LPS)-induced inflammation.

METHODS

Mouse 264.7 cell lines were treated with 1 µg/mL Pg-LPS to induce inflammation. After the effects of ATRA and RA-GC on the activity of macrophages were detected by CCK-8 assay, cells induced with Pg-LPS were assigned to the blank control group (GC) nanoparticles without ATRA, and experimental groups (GC nanoparticles loaded with different concentrations of ATRA: 1, 10 and 100 µg/mL). The effects of RA-GC on inflammatory cytokines tumor necrosis factor-α, interleukin (IL)-10 and IL-12 in macrophages were detected by enzyme-linked immunosorbent assay (ELISA). Subsequently, the effects of GC nanoparticles loaded with/without ATRA on macrophage polarization in an inflammatory environment were detected by RT-PCR and Western blotting.

RESULTS

The results revealed that RA-GC had no significant effect on macrophage activity. However, RA-GC could effectively inhibit the Pg-LPS-induced inflammatory factor expression in macrophages. Meanwhile, the experimental results confirmed that RA-GC could downregulate the expression of inducible nitric oxide synthase (iNOS) (a marker of M1 macrophages) and upregulate the expression of mannose receptor and Arginase-1 (a marker of M2 macrophages) in a dose-dependent manner.

CONCLUSION

The present study confirms that RA-GC can promote the M2 polarization of macrophages in an inflammatory environment, and proposes this as a promising target for the clinical treatment of Pg-LPS-related diseases.

The use of sel-ligating appliance can reduce inflammatory response to orthodontic force and keep periodontal health in orthodontic treatment

OBJECTIVE

Orthodontics, as a common way of orthodontic treatment, is usually to maintain oral health and protect periodontal tissue. The self-ligating appliance technique, since its advent in the 1930s, have been rather popular ammong the majority of orthodontists. This study was to determine that self-ligating appliance can reduce inflammation in gingival crevicular fluid (GCF) of patients receiving orthodontic treatment and keep periodontal health.

METHODS

The clinical data of 97 orthodontic patients admitted to the Department of Stomatology of Fujian Provincial Hospital, Fujian Provincial Clinical College of Fujian Medical University from March 2019 to March 2020 were analyzed retrospectively. Among them, 42 patients receiving orthodontic treatment with traditional MBT straight-wire appliance (SWA) were included in the control group (CG) and 55 patients treated with self-ligating appliance were collected as the observation group (OG). The two cohorts were compared with respect to the following aspects: curative effect, pain degree on the 1st, 2nd, 3rd, 5th and 7th day after wearing the appliance, oral related quality of life (QoL) before and after orthodontic treatment, satisfaction with the orthodontic treatment, periodontal condition, and GCF and inflammatory factor contents before, 3 months and 6 months after orthodontic treatment.

RESULTS

OG had significantly higher therapeutic efficacy of orthodontic treatment than CG (P<0.05). At the initial stage of treatment, the pain degree in OG was obviously lower than that in CG (P<0.05). Compared with CG, the plaque index (PLI), sulcus bleeding index (SBI), gingival recession (GR), periodontal probing depth (PPD) and clinical attachment loss (CAL) were better in OG after orthodontic treatment, and the differences were statistically significant (P<0.05). The contents of GCF, prostaglandin E2 (PGE₂), tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) in OG were lower than those in CG after orthodontic treatment, with significant differences between the two groups (P<0.05). Oral related QoL and orthodontic satisfaction were higher in OG, and the differences were statistically significant (P<0.05).

CONCLUSIONS

Compared with traditional SWA, the self-ligating appliance in orthodontic treatment contributes to higher efficacy and satisfaction, less local inflammatory reaction, and significantly improved periodontal condition and oral health of patients.

[Inhibition and Remediation of Methylmercury Contaminated Soil by Use of Modified Montmorillonite]

Montmorillonite was modified by 3-mercaptopyl trimethoxysilane and chitosan. The modified montmorillonite was characterized by XRD technology. The effects of thiol montmorillonite and chitosan montmorillonite on the inhibition and remediation of methylmercury contaminated soil under different water conditions were studied using laboratory simulation. XRD results showed that both thiol and chitosan were successfully loaded on the montmorillonite. The results of simulation tests showed that the addition of the remediation material to soil contaminated with methylmercury produced a better remediation effect. Compared with the blank control, the content of methylmercury in the soil was reduced by 82.10% (thiol montmorillonite) and 45.20% (chitosan montmorillonite), respectively, in the flooded condition. Under dry/wet alternation, the content of methyl mercury in soil decreased by 66.70% (thiol montmorillonite) and 49.79% (chitosan montmorillonite), respectively. Under drought conditions, the content of methylmercury in soil decreased by 44.66% (thiol montmorillonite), and the concentration of methylmercury in soil decreased by 54.37% after adding chitosan montmorillonite for 4 weeks. Compared with single modified montmorillonite, the repair effect of combined modified montmorillonite and lime treatment was not improved significantly.

[Characteristics of Stable Mercury Isotopic Compositions in the Food Web of the Caohai Lake]

Caohai Plateau Wetland is a National Nature Reserve. The characteristics of stable mercury isotopic compositions in the food web were studied by comprehensively analyzing the concentrations of Hg species (MeHg, THg), δ¹³ C, and δ¹⁵N, and the isotopic compositions of Hg in different aquatic organisms. The main results are as follows:all samples of the food web show mass-dependent fractionation (MDF) and mass-independent fractionation (MIF) and a negative δ²⁰² Hg(-0.93‰±1.32‰, n=14)and positive △¹⁹⁹ Hg(0.79‰±0.76‰, n=14). The δ¹⁹⁹ Hg values are significantly positively correlated with δ¹⁵N (r=0.65, P<0.05) and the δ²⁰² Hg values also exhibit a positive correlation with δ¹⁵N, except for Myriophyllum spicatum(δ¹⁵N=-1.88‰), indicating that the bioaccumulation of mercury leads to an enrichment with heavier isotopes. The △¹⁹⁹ Hg values increase with δ¹⁵N(r=0.67, P<0.05). Nevertheless, the △¹⁹⁹ Hg values correlate with% MeHg (r=0.58, P<0.05), indicating that the increase of the MIF level in the samples with the food web might be related to% MeHg.

[Mercury Distribution of Benthonic Animals and Response to Mercury in Sediments in Caohai Wetland, Guizhou Province]

Caohai wetland is a National Nature Reserve. Benthic animals were collected from the deep-water area in the middle of Caohai Lake and the shallow-water area in the surrounding marshes, and mercury and methyl mercury distributions in the benthic animals were analyzed and discussed. The risk of mercury pollution was evaluated. The concentrations of total mercury and methyl mercury in the benthonic animals were in the range of 0.51-46.55 ng·g^-1 with an average of 7.82 ng·g^-1 and 0.04-27.71 ng·g^-1 with an average of 4.31 ng·g^-1, respectively. This was lower than reports from other natural reserves. By contrast, the total mercury and methyl mercury in the benthic animals in summer were higher than in other seasons, which was consistent with the characteristics of methyl mercury distribution in sediments but opposite to the spatial distribution characteristics of total mercury in sediments. The methyl mercury contents in Cipangopaludina cathayensis were positively correlated with the content of methyl mercury in the sediments (r=0.52, P<0.05). The results showed methylation and the bioavailability of mercury in sediments from the shallow-water area were obviously higher than those from the deep-water area in the middle of Caohai Lake. The difference in organic matter content of the sediment or the wet-dry alternation (flooding-receding-flooding) in the surrounding shallow marshes was suspected to be associated with the obvious difference. The high enrichment coefficient of total mercury and methyl mercury in benthic animals were sufficient to raise the risk of mercury contamination in the aquatic food chain in the wetland.

[Distributions, Sources and Pollution Assessment of Hg in Sediment of Douhe Reservoir in Tangshan City]

Sediment cores from Douhe reservoir in Tangshan City were sampled in August 2013, in order to evaluate the mercury (Hg) pollution degree and its possible sources. Agriculture soils surrounding the Douhe reservoir and sediments from an upstream reservoir (Daheiting) were also collected. Total mercury (THg), methylmercury (MeHg), dissolved mercury in pore water (DHg) and organic matter (OM) in sediment of Douhe reservoir were analyzed, while, only THg in the agriculture soils and upstream reservoir sediments was determined. Finally, the geoaccumulation index method was applied to evaluate the Hg pollution status in soils and reservoir sediments. The results showed that THg content in sediment of Douhe reservoir ranged from 19 to 97 ng·g^-1. dw, MeHg (dw) from 0.02 to 1.27 ng·g^-1, and the contents of both THg and MeHg were higher in the upper layers than the deeper layers, indicating that Hg in sediments was increasing in recent years by the exogenetic loadings. THg (dw) in soils offshore the Douhe reservoir, which is close to a large coal-fired power plant, averaged at 22 ng·g^-1. Among the three sediment cores of Douhe reservoir, the central point had the highest THg, followed by the western site, and the eastern site had the lowest THg. While, THg content (dw) in sediments of Daheiting reservoir was much higher, with a mean of 176 ng·g^-1. Combining all the above information, we concluded that Hg in Douhe reservoir was mainly derived from the Daheiting reservoir and the mercury atmospheric deposition from the nearby coal-fired power plant contributed a less content. THg and MeHg in the sediments of Douhe reservoir were positively correlated with OM, indicating that OM in sediments had good ability of adsorbing THg and MeHg, and also played an important role in Hg methylation. The geoaccumulation index (I_geo) showed that the Hg pollution status deceased in this order:central of Daheting, Daba of Daheting, central of Douhe, western of Douhe, eastern of Douhe, soils surrounding Douhe. Central and western sites in Douhe belonged to moderate pollution and the eastern site belonged to slight pollution. While, sediments of Daheiting reservoir, affected by the iron ore mining activities, were in the moderate and strong pollution status.

[Geochemical cycling of mercury in the sediment of Hongfeng Reservior]

Spatial and temporal distributions of total and methyl mercury and controlling factors were investigated based on cold vapor atomic fluorescence detection. Total mercury levels in the whole sediments are (0.392 +/- 0.070) microg/g, without significant variations between different seasons, but generally increase toward the sediment-water interface. Total mercury levels are higher compared to data reported in other uncontaminated reservoirs and Wujiangdu Reservoir. This indicates there are mercury contaminations in Hongfeng Reservoir. Methyl mercury concentrations are highest in spring, without significant variations in other seasons. The peak values of methyl mercury typically appear in the upper 8 cm of the sediment profiles which are also the zones of sulfate-reducing bacteria activities. The seasonal variation and maximum peak value distributions of methyl mercury in sediment are mainly controlled by seasonally migration of oxic/anoxic boundary layer. Total mercury concentrations in the pore water and partition coefficients for THg in solid phase and water phase are mainly controlled by temperature or redox potential. Total mercury concentrations in the pore water have no relationship with total mercury concentrations in solid phase. However, the methyl mercury concentrations in the pore water have a strong relationship with those in solid phase (r = 0.70, p < 0.001). The methyl mercury concentrations in solid phase and pore water are controlled by solid/water partition coefficient, as well as methyl mercury production.

Chemokine expression in rat stab wound brain injury

A traumatic injury to the adult mammalian central nervous system (CNS) results in reactive astrogliosis and the migration of hematogenous cells into the damaged neural tissue. Chemokines, a novel class of chemoattractant cytokines, are now being recognized as mediators of the inflammatory changes that occur following injury. The expression of MCP-1 (macrophage chemotactic peptide-1), a member of the beta family of chemokines, has recently been demonstrated in trauma in the rat brain (Berman et al.: J Immunol 156:3017-3023, 1996). Using a stab wound model for mechanical injury, we studied the expression of two other beta chemokines: RANTES (Regulated on Activation, Normal T cell Expressed and Secreted) and MIP-1 beta (macrophage inflammatory protein-1 beta) in the rat brain. The stab wound injury was characterized by widespread gliosis and infiltration of hematogenous cells. Immunohistochemical staining revealed the presence of RANTES and MIP-1 beta in the injured brain. RANTES and MIP-1 beta were both diffusely expressed in the necrotic tissue and were detected as early as 1 day post-injury (dpi). Double-labeling studies showed that MIP-1 beta, but not RANTES, was expressed by reactive astrocytes near the lesion site. In addition, MIP-1 beta staining was also detected on macrophages at the site of injury. The initial expression of the chemokines closely correlated with the appearance of inflammatory cells in the injured CNS, suggesting that RANTES and MIP-1 beta may play a role in the inflammatory events of traumatic brain injury. This study also demonstrates for the first time MIP-1 beta expression in reactive astrocytes following trauma to the rat CNS.