1.Construction of a recombinant Bacillus subtilis strain expressing SpaA and CbpB of Erysipelothrix rhusiopathiae and evaluation of the strain immunogenicity in a mouse model.
Zhonglin CHENG ; Hao HUANG ; Siyi CAO ; Huahui SHI ; Jiye GAO ; Jixiang LI
Chinese Journal of Biotechnology 2024;40(12):4521-4532
To construct a recombinant Bacillus subtilis strain expressing SpaA and CbpB of Erysipelothrix rhusiopathiae for oral administration, we constructed the recombinant plasmid pDG1730-CBJA by fusion PCR and seamless cloning. The plasmid was introduced into B. subtilis KC strain by natural transformation, and the recombinant strain KC-spaA-cbpB was screened out on the plate containing spectinomycin (sper) and confirmed by PCR and starch degradation test. The SpaA and CbpB expressed by KC-spaA-cbpB were detected by Western blotting and indirect immunofluorescence assay, and the genetic stability of the recombinant strain in mice was determined. The plasmid pMAD-∆sper with knockout of sper was constructed and transformed into KC-spaA-cbpB. The sper-deleted mutant strain KC-spaA-cbpB: : ∆sper was screened and identified, and its immunogenicity in a mouse model was evaluated by oral immunization. The results showed that the recombinant strain KC-spaA-cbpB was stable in mice, expressing SpaA on the cell surface and CbpB on the spore surface. KC-spaA-cbpB: : ∆sper expressed SpaA and CbpB. The mice vaccinated with the spores of KC-spaA-cbpB: : ∆sper had higher levels of SpaA and CbpB-specific IgG in the serum that those vaccinated with the wild-type spores 42 days after vaccination by gavage (P < 0.01). The protective rate of mice immunized with the recombinant spores was 67.5%. The results indicated that a recombinant B. subtilis strain expressing SpaA and CbpB of E. rhusiopathiae was successfully constructed, and the recombinant strain laid a foundation for the development of oral live vector vaccines for swine erysipelas.
Animals
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Bacillus subtilis/immunology*
;
Mice
;
Erysipelothrix/immunology*
;
Bacterial Proteins/immunology*
;
Bacterial Vaccines/genetics*
;
Erysipelothrix Infections/prevention & control*
;
Immunization
;
Mice, Inbred BALB C
;
Plasmids/genetics*
;
Immunogenicity, Vaccine
;
Administration, Oral
;
Antigens, Bacterial
2.Recent research on the epidemiology and preventive strategies of neonatal group B Streptococcus infection in the latest decade.
Meng-Yang GUO ; Wei GAO ; Lin YUAN ; Kai-Hu YAO
Chinese Journal of Contemporary Pediatrics 2023;25(5):534-540
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
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Pregnancy
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Anti-Bacterial Agents/therapeutic use*
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Antibiotic Prophylaxis
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Infectious Disease Transmission, Vertical/prevention & control*
;
Pregnancy Complications, Infectious/epidemiology*
;
Streptococcal Infections/drug therapy*
;
Streptococcus agalactiae
3.Progress of serogroup B meningococcal outer membrane vesicle vaccines.
Meng Meng YUE ; Juan XU ; Li XU ; Zhu Jun SHAO
Chinese Journal of Preventive Medicine 2022;56(9):1333-1340
This research and development of MenB meningococcal vaccines includes two technical routes: outer membrane vesicle (OMV) vaccines and recombinant protein vaccines. This article intends to review the development, production and application of MenB meningococcal OMV vaccines in order to provide a reference for the development of MenB meningococcal OMV vaccine in China.
Antigens, Bacterial
;
Humans
;
Meningococcal Infections/prevention & control*
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Meningococcal Vaccines
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Neisseria meningitidis, Serogroup B
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Serogroup
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Vaccines, Synthetic
4.Effect of intrapartum antibiotic prophylaxis of group B streptococcus infection on the incidence and bacteriological profile of early-onset neonatal sepsis.
Chinese Journal of Contemporary Pediatrics 2022;24(1):49-53
OBJECTIVES:
To study the effect of intrapartum antibiotic prophylaxis (IAP) of group B streptococcus (GBS) infection on the incidence and bacteriological profile of early-onset neonatal sepsis (EONS).
METHODS:
A retrospective analysis was performed on the medical data of 494 pregnant women with positive GBS screening results and 526 neonates born by these women. According to whether the pregnant woman received IAP, the neonates were divided into two groups: IAP (n=304) and control (n=222). The two groups were compared in terms of clinical indices, incidence rate of EONS, and distribution of pathogenic bacteria in blood culture.
RESULTS:
Compared with the control group, the IAP group had a significantly lower proportion of children with abnormal clinical manifestations (P<0.001) and a significantly lower incidence rate of EONS (P=0.022). In the IAP group, Escherichia coli (2.3%) was the most common type of pathogenic bacteria in blood culture of the neonates with EONS, while GBS (3.2%) was the most common type of pathogenic bacteria in the control group. The IAP group had a significantly higher detection rate of ampicillin-resistant Escherichia coli than the control group (P=0.029).
CONCLUSIONS
Although IAP can significantly reduce the incidence rate of EONS in neonates born to pregnant women with positive GBS screening results, the infection rate of ampicillin-resistant Escherichia coli may increase after IAP treatment. Therefore, it is needed to enhance the monitoring of blood culture results of neonates with EONS and timely adjust treatment plan according to drug susceptibility test results.
Anti-Bacterial Agents/therapeutic use*
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Antibiotic Prophylaxis
;
Child
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Female
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Humans
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Incidence
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Infant, Newborn
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Infectious Disease Transmission, Vertical/prevention & control*
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Neonatal Sepsis/prevention & control*
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Pregnancy
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Pregnancy Complications, Infectious
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Retrospective Studies
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Streptococcal Infections/prevention & control*
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Streptococcus agalactiae
5.Application and reflection of laboratory-based monitoring in early warning of infectious diseases.
Hai Jian ZHOU ; Zhi Gang CUI ; Biao KAN
Chinese Journal of Preventive Medicine 2022;56(4):401-404
Despite the fact that our cognition towards infectious disease prevention, the advanced technology and the economic status of the whole society has made a great progress in the last decade, the outbreak of COVID-19 pneumonia has again enabled the public to acquire more about super-challenges of infectious diseases, epidemics and the relevant preventive measurements. In order to identify the epidemic signals in early stage or even before the onset of epidemic, the data research and utilization of a series of factors related to the occurrence and transmission of infectious diseases have played a significant role in research of prevention and control during the whole period of surveillance and early warning. Laboratory-based monitoring for the etiology has always been an important part of infectious disease warning system due to pathogens as the direct cause of such diseases. China has initially established a laboratory-based monitoring and early warning system for bacterial infectious diseases based on the Chinese Pathogen Identification Network with an aim to identify pathogens, outbreaks and sources. This network has played an essential role in early detection, tracking and precise prevention and control of bacterial infectious diseases, such as plague, cholera, and epidemic cerebrospinal meningitis. This issue focuses on the function of laboratory-based monitoring during the period of early warning, prevention, and control of bacterial infectious diseases, and conducted a wide range of researches based on the analysis of the epidemic and outbreak isolates, together with field epidemiological studies and normal monitoring systems. All of these could illustrate the effect of laboratory surveillance in the infectious disease risk assessment and epidemic investigation. At the same time, we have put forward our review and expectation of scenarios about laboratory-based monitoring and early warning technologies to provide innovative thoughts for promoting a leapfrog development of infectious disease monitoring and early warning system in China.
Bacterial Infections/epidemiology*
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COVID-19
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Communicable Diseases/epidemiology*
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Disease Outbreaks/prevention & control*
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Epidemics
;
Humans
;
Laboratories
6.Advance on research and application of laboratory pathogen monitoring and early warning technology of bacterial infectious diseases.
Chinese Journal of Preventive Medicine 2022;56(4):525-532
Human beings are still facing the public health challenges from bacterial infectious diseases. Carrying out systematic infectious disease monitoring and early warning is the most direct solution to prevent and control infectious diseases. Etiology is an important part of infectious disease monitoring and early warning. Effective pathogen monitoring can identify pathogens, outbreaks and sources at the first time. In this study, we have reviewed the research and application of etiology monitoring and early warning technology of bacterial infectious diseases and summarized the importance and application scenarios of etiology in infectious disease monitoring and early warning, as well as the research progress of etiology monitoring and early warning technology. Based on the work of existing laboratory monitoring networks, such as Chinese Pathogen Identification Network, the development trend and prospect of infectious disease laboratory network monitoring are put forward to provide a reference for establishing and perfecting the infectious disease monitoring and early warning system.
Bacterial Infections/prevention & control*
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Communicable Diseases/epidemiology*
;
Disease Outbreaks/prevention & control*
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Humans
;
Laboratories
;
Technology
7.Application of nanodrug carriers in the prevention and treatment of infection around orthopedic prosthesis.
Zhenyao PAN ; Yan WANG ; Jiaojiao LI ; Jialong CHEN
Journal of Biomedical Engineering 2019;36(5):862-869
Despite the continuous improvement in perioperative use of antibiotics and aseptic techniques, the incidence of infection continues to rise as the need for surgery increasing and brings great challenges to orthopedic surgery. The rough or porous structure of the prosthesis provides an excellent place for bacterial adhesion, proliferation and biofilm formation, which is the main cause of infection. Traditional antibiotic therapy and surgical debridement are difficult to determine whether the infected focus have been removed completely and whether the infection will recur. In recent years, nanotechnology has shown obvious advantages in biomaterials and drug delivery. Nano drug carriers can effectively achieve local antimicrobial therapy, prevent surgical infection by local sustained drug release or intelligent controlled drug release under specific stimuli, and reduce the toxic side effects of drugs. The unique advantages of nanotechnology provide new ideas and options for the prevention and treatment of periprosthetic infection. At present, the application of nano-technology in the prevention and treatment of infection can be divided into the addition of nano-drug-loaded materials to prosthesis materials, the construction of drug-loaded nano-coatings on the surface of prosthesis, the perfusable nano-antimicrobial drug carriers, and the stimulation-responsive drug controlled release system. This article reviews the methods of infection prevention and treatment in orthopaedic surgery, especially the research status of nanotechnology in the prevention and treatment of periprosthetic infection.
Anti-Infective Agents
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administration & dosage
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Bacterial Adhesion
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Drug Carriers
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Humans
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Nanotechnology
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Orthopedics
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Prosthesis-Related Infections
;
prevention & control
8.Cefoxitin plus levofloxacin for prevention of severe infection after transrectal prostate biopsy.
Rong-Bing LI ; Xiao-Fei WEN ; Yue-Min WANG ; Wei-Hua CHEN ; Xue-Lei WANG ; Ji-Ling WEN ; Lin-Jie SHEN
National Journal of Andrology 2018;24(4):322-326
ObjectiveTo evaluate the effect of cefoxitin prophylactic in reducing the incidence of severe infection after transrectal prostate biopsy (TRPB).
METHODSThis retrospective study included 155 cases of TRPB with a 5-day administration of oral levofloxacin at 200 mg bid (the control group) and another 167 cases with a 3-day administration of oral levofloxacin at the same dose plus intravenous cefoxitin at 2.0 g 2 hours before TRPB (the experimental group) according to the distribution characteristics of drug-resistance bacteria in our department. The patients of the control and experimental groups were aged (68.68 ± 8.12) and (68.72 ± 7.51) years, with PSA levels of (19.78 ± 21.57) and (21.15 ± 42.63) μg/L, involving (11.68 ± 1.44) and (11.77±1.02) biopsy cores, respectively. Comparisons were made between the two groups of patients in the incidence rate of severe infection, which was defined as lower urinary track symptoms plus the systemic inflammatory response syndrome (SIRS) within 7 days after TRPB.
RESULTSThe incidence rate of postoperative severe infection was significantly lower in the experimental group than in the control (0.6% [1/167] vs 5.8% [9/155], P < 0.05). Blood cultures revealed positive E-coli strains in 6 cases in the control group, including 5 ESBL-positive and 4 quinolone-resistant and amikacin-sensitive cases, all sensitive to cefoxitin, cefoperazone/sulbactam and imipenem. The only one case of severe infection was shown to be negative in blood culture.
CONCLUSIONSPreoperative intravenous administration of cefoxitin according to the specific distribution characteristics of drug-resistance bacteria can significantly reduce the incidence of severe infection after TRPB.
Aged ; Anti-Bacterial Agents ; therapeutic use ; Biopsy ; adverse effects ; methods ; Cefoxitin ; therapeutic use ; Drug Resistance, Bacterial ; Escherichia coli ; isolation & purification ; Escherichia coli Infections ; microbiology ; prevention & control ; Humans ; Levofloxacin ; therapeutic use ; Male ; Middle Aged ; Postoperative Complications ; blood ; prevention & control ; Prostate ; pathology ; Retrospective Studies
9.Transforming bacterial disease surveillance and investigation using whole-genome sequence to probe the trace.
Biao KAN ; Haijian ZHOU ; Pengcheng DU ; Wen ZHANG ; Xin LU ; Tian QIN ; Jianguo XU
Frontiers of Medicine 2018;12(1):23-33
Two decades have passed since the first bacterial whole-genome sequencing, which provides new opportunity for microbial genome. Consequently, considerable genetic diversity encoded by bacterial genomes and among the strains in the same species has been revealed. In recent years, genome sequencing techniques and bioinformatics have developed rapidly, which has resulted in transformation and expedited the application of strategy and methodology for bacterial genome comparison used in dissection of infectious disease epidemics. Bacterial whole-genome sequencing and bioinformatic computing allow genotyping to satisfy the requirements of epidemiological study in disease control. In this review, we outline the significance and summarize the roles of bacterial genome sequencing in the context of bacterial disease control and prevention.We discuss the applications of bacterial genome sequencing in outbreak detection, source tracing, transmission mode discovery, and new epidemic clone identification. Wide applications of genome sequencing and data sharing in infectious disease surveillance networks will considerably promote outbreak detection and early warning to prevent the dissemination of bacterial diseases.
Bacteria
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genetics
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Bacterial Infections
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epidemiology
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microbiology
;
transmission
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Bacterial Typing Techniques
;
Disease Outbreaks
;
prevention & control
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Genome, Bacterial
;
Genotype
;
Humans
;
Population Surveillance
;
Whole Genome Sequencing
10.Spontaneous Bacterial Peritonitis.
The Korean Journal of Gastroenterology 2018;72(2):56-63
Spontaneous bacterial peritonitis (SBP) is defined as bacterial infections that occur in patients with cirrhosis and ascites without any significant intraperitoneal infection, accounting for approximately 10–30% of bacterial infections in hospitalized patients. SBP develops in patients with liver cirrhosis because bacterial translocations are increased by changes in the intestinal bacteria and mucosal barriers. In addition, the decreased host immune response cannot remove the bacteria and their products. The most common cause of SBP is Gram-negative bacteria, such as Escherichia coli and Klebsiella species, and infections by Gram-positive bacteria are increasing. SBP is diagnosed by the presence of >250 polymorphonuclear leukocyte/mm³ in ascites after paracentesis. If SBP is diagnosed, empirical antibiotic therapy should be started immediately. Empirical antibiotic treatment should distinguish between community acquired infections and nosocomial infections. Cirrhotic patients with gastrointestinal bleeding or low ascitic protein concentrations should consider primary prevention and those who recover from SBP should consider secondary prevention. This review describes the pathophysiology, diagnosis, treatment, and prevention of SBP.
Ascites
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Bacteria
;
Bacterial Infections
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Community-Acquired Infections
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Cross Infection
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Diagnosis
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Escherichia coli
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Fibrosis
;
Gram-Negative Bacteria
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Gram-Positive Bacteria
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Hemorrhage
;
Humans
;
Klebsiella
;
Liver Cirrhosis
;
Paracentesis
;
Peritonitis*
;
Primary Prevention
;
Secondary Prevention

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