To explore the effects of plasma jet (PJ) and plasma activated water (PAW) on the sterilization of Streptococcus mutans ( S. mutans) and compare the advantages and disadvantages of the two methods, so as to provide a basis for plasma treatment of dental caries and to enrich the treatment means of dental caries, an atmospheric pressure plasma excitation system was built, and the effects of PJ and PAW on the sterilization rate of S. mutans and the changes of temperature and pH during treatment were studied under different excitation voltage ( U _e ) and different excitation time ( t _e ). The results showed that in the PJ treatment, the difference in the survival rate of S. mutans between the treatment group and the control group was statistically significant ( P = 0.007, d=2.66) when U _e = 7 kV and t _e = 60 s, and complete sterilization was achieved at U _e = 8 kV and t _e = 120 s in the PJ treatment. In contrast, in the PAW treatment, the difference in the survival rate of S. mutans between the treatment group and the control group was statistically significant ( P = 0.029, d = 1.71) when U _e = 7 kV and t _e = 30 s, and complete sterilization was achieved with PAW treatment when U _e = 9 kV and t _e = 60 s. Results of the monitoring of temperature and pH showed that the maximum temperature rise during PJ and PAW treatment did not exceed 4.3 °C, while the pH value after PAW treatment would drop to a minimum of 3.02. In summary, the optimal sterilization parameters for PJ were U _e =8 kV and 90 s < t _e ≤ 120 s, while the optimal sterilization parameters for PAW were U _e = 9 kV and 30 s< t _e ≤ 60 s. Both treatment methods achieved non-thermal sterilization of S. mutans, where PJ required only a smaller U _e to achieve complete sterilization, while at pH < 4.7, PAW only required a shorter t _e to achieve complete sterilization, but its acidic environment could cause some chemical damage to the teeth. This study can provide some reference value for plasma treatment of dental caries.
Humans ; Streptococcus mutans ; Dental Caries/therapy* ; Sterilization ; Temperature ; Water

At the end of 2022, the World Health Organization reported an increase in group A Streptococcus (GAS) infections, such as scarlet fever, in multiple countries. The outbreak primarily affected children under 10 years old, and the number of deaths was higher than anticipated, causing international concern. This paper reviews the current state of the GAS disease outbreak, its causes, and response measures. The authors aim to draw attention from clinical workers in China and increase their awareness and vigilance regarding this epidemic. Healthcare workers should be aware of the potential epidemiological changes in infectious diseases that may arise after the optimization of control measures for coronavirus disease 2019 to ensure children's health.
Child ; Humans ; Streptococcus pyogenes ; COVID-19/epidemiology* ; Streptococcal Infections/epidemiology* ; Scarlet Fever/epidemiology* ; Epidemics ; Disease Outbreaks

Currently, the main strategy for preventing neonatal group B Streptococcus (GBS) infection is prenatal screening combined with intrapartum antibiotic prophylaxis, which has effectively reduced the incidence of neonatal GBS early-onset disease. However, the burden of GBS infection is still significant. The intrapartum antibiotic prophylaxis strategy has limitations such as inducing antibiotic resistance and inability to effectively prevent GBS late-onset disease. It is crucial to develop and evaluate other prevention strategies, while paying close attention to assessing penicillin allergy in pregnant women and how to prevent GBS infection in neonates with negative maternal GBS screening. In recent years, there has been some progress in GBS vaccines and related immunological research, and the use of specific vaccines is expected to significantly reduce GBS infection in neonates.
Female ; Humans ; Infant, Newborn ; Pregnancy ; Anti-Bacterial Agents/therapeutic use* ; Antibiotic Prophylaxis ; Infectious Disease Transmission, Vertical/prevention & control* ; Pregnancy Complications, Infectious/epidemiology* ; Streptococcal Infections/drug therapy* ; Streptococcus agalactiae

This article reviews the relevant studies on the efficacy and safety of influenza, pneumococcal and COVID-19 vaccination among tumor patients worldwide in recent years. By combing and analyzing the retrieved literature, the results show that influenza and pneumococcal vaccination can significantly reduce the morbidity and hospitalization rate of infectious diseases in tumor patients, reduce the risk of cardiovascular events and death, and significantly improve survival prognosis. COVID-19 vaccination can also protect tumor patients, especially those who have completed full dose vaccination. Authoritative guidelines and consensuses worldwide all recommend that tumor patients receive influenza, pneumococcal and COVID-19 vaccines. We should carry out relevant researches, as well as take effective measures to strengthen patient education, so that tumor patients can fully experience the health protection brought by the vaccine to this specific group.
Humans ; Influenza, Human/prevention & control* ; COVID-19 Vaccines ; COVID-19/prevention & control* ; Influenza Vaccines/therapeutic use* ; Vaccination ; Pneumococcal Vaccines/therapeutic use* ; Streptococcus pneumoniae ; Neoplasms

OBJECTIVES: To investigate the potential relationship between age and Streptococcus pneumoniae vaccination coverage in kindergarten children, and to provide a basis for guiding vaccination and developing new protein vaccines. METHODS: The stratified cluster random sampling method was used to select 1 830 healthy children from six kindergartens in Shunde District, Foshan City, China, and nasopharyngeal swabs were collected for the isolation and identification of Streptococcus pneumoniae. The logistic regression model based on restricted cubic spline was used to analyze the dose-response relationship between age and Streptococcus pneumoniae vaccination coverage. RESULTS: The rate of nasal Streptococcus pneumoniae carriage was 22.46% (411/1 830) among the kindergarten children, with the predominant serotypes of 6B, 19F, 15A, 23A, 34, and 23F. The coverage rates of 10-valent pneumococcal conjugate vaccine (PCV10) and 13-valent pneumococcal conjugate vaccine (PCV13) were 53.0% and 57.9%, respectively, and there was a significant non-linear dose-response relationship between age and the coverage rates of PCV10 and PCV13 (P<0.05), with a higher coverage rate of PCV10 (88.0%) and PCV13 (91.1%) in the children aged 2 years. There was a significant non-linear dose-response relationship between age and the coverage rates of pilus islet 1 (PI-1) and pilus islet 2 (PI-2) (P<0.05), with a lower vaccination coverage rate for PI-1 (37.7%) and PI-2 (16.1%). The coverage rates of PI-1 (13.0%-58.5%) and PI-2 (6.0%-29.4%) were lower in all age groups. The virulence genes lytA (99.5%) and ply (99.0%) associated with candidate protein vaccines showed higher vaccination coverage rates. CONCLUSIONS There is a significant non-linear dose-response relationship between the age of kindergarten children and the coverage rates of PCV10 and PCV13 serotypes, and kindergarten children aged 2 years have a relatively high coverage rate of PCV. The high prevalence of the virulence genes lytA and ply shows that they are expected to become candidate virulence factors for the development of a new generation of recombinant protein vaccines.
Humans ; Child ; Infant ; Streptococcus pneumoniae/genetics* ; Pneumococcal Infections/epidemiology* ; Vaccination Coverage ; Pneumococcal Vaccines ; Serogroup ; Vaccination ; Nasopharynx ; Carrier State/epidemiology*

OBJECTIVE: To establish and modify quantitative real-time polymerase chain reaction (qPCR)-based serotyping assays to distinguish 97 pneumococcal serotypes. METHODS: A database of capsular polysaccharide ( cps) loci sequences was generated, covering 97 pneumococcal serotypes. Bioinformatics analyses were performed to identify the cps loci structure and target genes related to different pneumococcal serotypes with specific SNPs. A total of 27 novel qPCR serotyping assay primers and probes were established based on qPCR, while 27 recombinant plasmids containing serotype-specific DNA sequence fragments were constructed as reference target sequences to examine the specificity and sensitivity of the qPCR assay. A panel of pneumococcal reference strains was employed to evaluate the capability of pneumococcal serotyping. RESULTS: A total of 97 pneumococcal serotyping assays based on qPCR were established and modified, which included 64 serotypes previously reported as well as an additional 33 serotypes. Twenty-seven novel qPCR serotyping target sequences were implemented in the pneumococcal qPCR serotyping system. A total of 97 pneumococcal serotypes, which included 52 individual serotypes and 45 serotypes belonging to 20 serogroups, could not be identified as individual serotypes. The sensitivity of qPCR assays based on 27 target sequences was 1-100 copies/µL. The specificity of the qPCR assays was 100%, which were tested by a panel of 90 serotypes of the pneumococcal reference strains. CONCLUSION A total of 27 novel qPCR assays were established and modified to analyze 97 pneumococcal serotypes.
Real-Time Polymerase Chain Reaction ; Serotyping ; Streptococcus pneumoniae/genetics* ; Serogroup

Aminopeptidase A (Pep A) is a metal-dependent enzyme that specifically hydrolyze peptides with the N-terminal amino acids glutamic acid (Glu) and aspartic acid (Asp). A possible application of PepA is the hydrolysis of Glu/Asp-rich food proteins such as wheat gluten and casein, increasing the flavor and solubility of food protein. In the present study, the gene encoding a Pep A from Lactococcus lactis ssp. lactis IL1403 was synthesized and introduced into Pichia pastoris GS115 (His4). Lc-Pep A was successfully expressed and secreted to the culture medium, followed by identification and purification to homogeneity. Characteristics study demonstrated that Lc-Pep A could specifically hydrolyze the substrates Glu-pNA and Asp-pNA with similar catalytic activity, and this was further confirmed by the kinetics parameters measured. Additionally, Lc-Pep A showed a broad thermostability and pH stability with an optimum temperature of 60 ℃ and an optimum pH of 8.0. The enzyme activity of Lc-Pep A was activated by metal ions Co²⁺, Mn²⁺, and Zn²⁺ but was strongly inhibited by Ni²⁺and Cu²⁺. The routine proteinase inhibitor had no effect on the activity of Lc-Pep A. However, Lc-Pep A was strongly inhibited by the metallopeptidase inhibitor, EDTA, and disulfide bond-reducing agents. The study may facilitate production and application of Lc-Pep A.
Glutamyl Aminopeptidase ; Lactococcus lactis/genetics* ; Biological Transport ; Culture Media ; Glutamic Acid

Aims: Streptococcus pneumoniae is one the world’s foremost bacterial pathogens that cause massive global mortality and morbidity in young children and immunocompromised adults especially in developing countries. Biofilms have been increasingly recognized as an important prerequisite to disease. Individual S. pneumoniae strains differ markedly in their virulence phenotypes, but genetic heterogeneity has complicated attempts to identify any association between a given clonal lineage and propensity to cause a particular disease type. This study investigated serotype 19 S. pneumoniae from blood and ear isolates for biofilm formation capacity in relation to isolate source, pH and ferric oxide [Fe(III)] supplementation. Methodology and results: Viable count and density biofilm assays, microscopy and multi locus sequence typing (MLST) were applied to investigate biofilm formation capacity and genetic diversity of serotype 19 S. pneumoniae from blood and ear isolates. Generally, blood isolates were observed to produce more biofilms at both pH 7.4 and 6.8 compared to the ear isolates. The supplementation of Fe(III) was also found to support biofilm growth. Upon MLST typing of the isolates, marked differences in biofilm formation within the same sequence types (ST) of ST199 and ST177 was observed. This strongly indicated that strains within the same sequence type show differences in biofilm formation capacity. Conclusion, significance and impact of study This study showed that despite belonging to the same serotype, serotype 19, S. pneumoniae blood and ear isolates showed high diversity in biofilm formation ability in relation to pH and Fe(III) supplementation. Additionally, pneumococcal isolates from sequence types ST199 and ST177 also gave rise to differences in biofilm formation ability within the same sequence type (ST). The diversity of biofilm formation within serotype 19 seen in this study is significant to further inform of vaccination strategies against pneumococcal infections, in that due to variations in biofilm formation capacity within the same ST. It is possible that within serotype 19 may show variable vaccination or drug treatment responses. This also indicates that the current treatment strategy which employs specific serotype selection as for PCV14 and PCV7 pneumococcal vaccines may not produce the desired therapeutic results.
Streptococcus pneumoniae--immunology ; Biofilms--radiation effects

Aims: Maternal vaginal Group B Streptococcus (GBS) colonization is considered a risk factor for preterm delivery and, consequently, neonatal infections. Previous studies have portrayed the important roles of these virulence factors, including hemolytic pigment, hyaluronidase (HylB), serine-rich protein (Srr) and bacterial surface adhesion of GBS (BsaB) in mediating GBS colonization and intrauterine ascending infection, causing preterm delivery. This study aimed to investigate the association between mRNA expression of virulence genes in GBS isolates obtained from symptomatic pregnant women and preterm delivery. Methodology and results: GBS isolates were obtained from high vaginal swabs of 40 symptomatic pregnant women of gestational age of less than 37 weeks. RNA was extracted from these GBS isolates and RT-qPCR was performed to determine the relative mRNA expression of GBS virulence genes, including CylE (encode enzyme required for the biosynthesis of the hemolytic pigment), HylB, Srr-1 and BsaB. Socio-demographic details and obstetric history were not found to be associated with the delivery outcomes of these women. The GBS isolates from symptomatic pregnant women who delivered prematurely showed a higher expression of CylE gene and a trend towards an elevated expression of HylB gene compared to women with term delivery. Meanwhile the expression of both Srr-1 and BsaB genes was similar between symptomatic pregnant women who had term or preterm delivery. Conclusion, significance and impact of study The results suggest that following vaginal colonization, both CylE and HylB genes are likely to contribute to intrauterine ascending infection and inflammation, leading to preterm delivery in humans. These virulence factors may be targeted for the pre-clinical stages of vaccine development or therapeutic intervention.
Streptococcus agalactiae--isolation & ; purification ; Pregnant Women

More than 100 serotypes of Streptococcus pneumonia have been identified, which has been one bottleneck problem for pneumococcal disease diagnosis, surveillance, development of pneumococcal vaccine and effectiveness evaluation of pneumococcal vaccines. Three categories of approaches for pneumococcal serotyping will be discussed including phenotyping based on anti-serum, biochemical typing based on pneumococcal capsular characteristics and genotyping based on pneumococcal capsular locus sequences. We reviewed the development and applications of different serotyping of pneumococcus to provide guidance for pneumococcal disease prevention and control.
Humans ; Serotyping/methods* ; Pneumococcal Infections/prevention & control* ; Pneumococcal Vaccines ; Streptococcus pneumoniae/genetics* ; Pneumonia