Neisseria meningitidis carriage and risk factors among teenagers in Suizhou city in China.

Teenagers are important carriers of Neisseria meningitidis, which is a leading cause of invasive meningococcal disease. In China, the carriage rate and risk factors among teenagers are unclear. The present study presents a retrospective analysis of epidemiological data for N. meningitidis carriage from 2013 to 2017 in Suizhou city, China. The carriage rates were 3.26%, 2.22%, 3.33%, 3.53% and 9.88% for 2013, 2014, 2015, 2016 and 2017, respectively. From 2014 to 2017, the carriage rate in the 15- to 19-year-old age group (teenagers) was the highest and significantly higher than that in remain age groups. Subsequently, a larger scale survey (December 2017) for carriage rate and relative risk factors (population density, time spent in the classroom, gender and antibiotics use) were investigated on the teenagers (15- to 19-year-old age) at the same school. The carriage rate was still high at 33.48% (223/663) and varied greatly from 6.56% to 52.94% in a different class. Population density of the classroom was found to be a significant risk factor for carriage, and 1.4 persons/m2 is recommended as the maximum classroom density. Further, higher male gender ratio and more time spent in the classroom were also significantly associated with higher carriage. Finally, antibiotic use was associated with a significantly lower carriage rate. All the results imply that attention should be paid to the teenagers and various measures can be taken to reduce the N. meningitidis carriage, to prevent and control the outbreak of IMD.

A Cross-sectional Survey Assessing Carriage of Streptococcus pneumoniae in a Healthy Population in Xinjiang Uygur Autonomous Region of China.

The carriage rate and serotype distribution of Streptococcus pneumoniae (S. pneumoniae) in a healthy population in China remains unclear. In this study, we collected the oropharyngeal swabs from 513 individuals in Xinjiang, China. Real-time PCR targeting the lytA gene and 12 serotypes were assessed to identify S. pneumoniae carriage. The total carriage rate of S. pneumoniae was 70.4% (361/513). The most prevalent serotypes were 19B/F, 18B/C, 5, and 6A/B. The highest carriage rate of S. pneumoniae was noted in children aged 6-10 years (88.6%), which merits further attention. The co-colonization rate of two or more S. pneumoniae serotypes was 79.8% (264/331). This study aimed to investigate the baseline pneumococcal carriage rate among healthy individuals in China to improve our understanding of the epidemiology of S. pneumoniae.

Intraoperative transcutaneous electroacupoint stimulation on early postoperative fatigue in patients with Parkinson's disease undergoing deep brain stimulation surgery.

Background: In this clinical trial, we evaluated the effects of transcutaneous electroacupoint stimulation (TEAS) on postoperative fatigue (POF) in Parkinson disease (PD) patients undergoing deep brain stimulation (DBS) surgery. Methods: A total 60 PD patients undergoing DBS surgery were enrolled. They were randomized to receive either electrical stimulation [alternative frequency 2/10 Hz, dense and disperse, intensity adjusted to the maximum tolerated by the participants (6-15 mAmp)] via surface electrodes (TEAS group) or surface electrodes only without electrical stimulation (Con group) at bilateral Zusanli and Sanyinjiao acupuncture points. All participants received their assigned intervention (TEAS or Con) during the 1st stage of surgery [(except during microelectrode recording (MER)] and the entire 2nd stage of surgery. Intraoperative anesthetic requirements were adjusted based on bispectral index (BIS) monitor. POF was assessed by Christensen fatigue scales (ChrFS), along with Quality of Recovery-15 (QoR-15) and mini-mental state examination (MMSE) postoperatively over a 7-day-period. We recorded the usage of rescue analgesics and anti-emetics. Results: Fifty-nine patients' datasets were included for final analyses. Fewer patients in TEAS experienced severe POF (defined as ChrFS ≥6) at T3 than those in the Con group (TEAS vs. Con: 7 vs. 22, p < 0.001). During the 1st stage of surgery, more patients in Con group required dexmedetomidine infusion (TEAS vs. Con: 2 vs. 6; P < 0.01). Total dosages of propofol and remifanil during the 2nd stage of surgery were TEAS vs. Con: 374.7 ± 61.2 vs 421.5 ± 81.9; p < 0.001 and 572.3 ± 82.0 vs. 662 ± 148.2; P < 0.001, respectively. Postoperative rescue analgesics (TEAS vs. Con: 2 vs. 6; P < 0.001) were used less in the TEAS group. TEAS patients reported better POF, MMSE and QoR15 scores than those in the Con group during most of the assessment period. Conclusions: Intraoperative TEAS decreased the severity of POF, reduced intraoperative anesthetic requirements and facilitated post-DBS recovery in this group of PD patients.

NR4A1 agonist cytosporone B attenuates neuroinflammation in a mouse model of multiple sclerosis.

Nuclear receptor subfamily 4 group A1 (NR4A1) is an orphan nuclear receptor, which is expressed in the majority of cells. NR4A1 expression in peripheral blood mononuclear cells is low during the preclinical stage of multiple sclerosis. Knockout of the Nr4a1 gene in mice can aggravate the symptoms of experimental autoimmune encephalomyelitis (EAE), which is an animal model of multiple sclerosis. In this study, we intragastrically administered the NR4A1 agonist cytosporone B (Csn-B) to mice after inducing EAE. After treatment with Csn-B, the clinical symptoms in the EAE mice were substantially attenuated compared with that in PBS-treated control mice. The percentages of CD4+ T cells and F4/80+ cells in the central nervous system were decreased. In addition, interferon-γ and interleukin-17 production by proinflammatory Th1/Th17 cells in the central nervous system and interferon-γ levels in splenocytes were decreased after Csn-B treatment. These findings suggest that the NR4A1 agonist Csn-B can alleviate nerve injury after EAE induction, and, therefore, may be useful as a potential treatment for multiple sclerosis.

[Sequence-based typing of 82 strains of serotype I Legionella pneumophila isolated from 9 provinces in China].

OBJECTIVE: To analyze the characteristics of Sequence-based Typing (SBT) of the Serotype 1 Legionella pneumophila (Lp1) isolated from environmental water in China, and then create a preliminary database. METHODS: A total of 82 strains of Lp1 isolated from environmental water in 9 provinces of China between 2005 and 2008 were genotyped by SBT method and Pulsed-field Gel Electrophoresis (PFGE) method. The results of the two different typing methods were then compared by cluster analysis, adopting BioNumerics version 5.1 software. RESULTS: By SBT method, the 82 strains of Lp1 were divided into 22 ST types, of which 17 new types and one new allele was discovered. The dominant type was ST-1 type, found in 8 provinces, accounting for 46.3% (38/82). ST-1, ST-150, ST-154, ST-159, ST-160 and ST-630 types were found in more than 2 isolated-sites; while more than 2 different ST types were found in 5 isolated-sites, as site B4, B5, B6, S3 and S8. In cluster analysis, 15 ST types were grouped into three complexes (ST-1 complex, ST-154 complex and ST-149 complex); and the other 7 ST types were not assigned complex. By PFGE method, 46 banding patterns were observed. As a result of the combination of the two methods, the 82 isolates strains could be divided into 54 molecular types, which showed a reliable accordance in the cluster analysis between the two methods. CONCLUSION: The SBT of the Lp1 in environmental water in China was unique. From the study, a preliminary SBT database was set up.

Comparison of the Pathogenicity of Neisseria meningitidis Isolates of Hyperinvasive Sequence Type 7 Belonging to Serogroups A, B, C, and X.

OBJECTIVE: To compare the pathogenicity of isolates of sequence type 7 (ST-7) Neisseria meningitidis( N. meningitidis) belonging to four different serogroups (A, B, C, and X). METHODS: Four ST-7 N. meningitidis isolates serogrouped as A, B, C, and X and characterized by different capsule structures, were examined for their adhesion and invasion properties, and their ability to induce cytokine release and apoptosis in the host cell (the A549 cell line). RESULTS: Among the four ST-7 N. meningitidis isolates, the serogroup A isolate possessed the strongest adhesion and invasion ability. This isolate also induced the release of the highest levels of the pro-inflammatory mediators interleukin-6, interleukin-1ß, and interferon, and the highest apoptosis rate in the host cells. However, there was no significant difference in interleukin-8 and tumor necrosis factor-α secretion between the four isolates. Based on the findings, the serogroup X N. meningitidis isolate had the weakest pathogenicity, whereas there was almost no difference in the pathogenicity of the isolates from serogroups B and C. CONCLUSIONS: The differences in the capsular structure of the four isolates of ST-7 N. meningitidis affected their pathogenic capacities. The findings also imply that the hyperinvasive ST-7 N. meningitidis lineage may include hypoinvasive isolates.

Lower respiratory tract isolates of non-typeable Haemophilus influenzae in Western Sichuan, China: Antimicrobial susceptibility, mechanisms of ß-lactam resistance and decade changes.

OBJECTIVES: The aims of this study were to analyse the serotypes of epidemic Haemophilus influenzae and changes in mechanisms of ß-lactam resistance over the past decade. RESULTS: Haemophilus influenzae isolates in Western Sichuan from 2013-2014 were non-typeable H. influenzae (NTHi). ß-Lactam MICs for NTHi isolated during 2013-2014 were significantly higher than those from 2003-2004 (P < 0.05). Of 274 NTHi, 141 (51.5%) were ß-lactamase-positive (TEM-1 type). There were 35 amino acid (AA) substitutions in ftsI among NTHi isolated from 2013-2014. However, NTHi isolates from 2003-2004 had only nine AA substitutions. Ordered multiple classification logistic regression analysis showed that different AA substitution patterns in ftsI had different effects on ß-lactam MICs. The main factors affecting the ampicillin MIC were the mutations R517H (OR = 6.999), L389F (OR = 7.128), N526K (OR = 4.660) and D350N (OR = 0.450). The main factor influencing the amoxicillin/clavulanic acid MIC was an N526K mutation (OR = 9.349). The main factors affecting the cefuroxime MIC were the mutations S357N (OR = 37.453) and N526K (OR = 14.816). Compared with 2003-2004, gBLNAR and gBLPAR isolated from 2013-2014 increased significantly from 13.0% (7/54) and 9.3% (5/54) to 38.2% (84/220) and 45.5% (100/220), respectively (P < 0.001). In the 'others' group of ftsI gene mutations, 13 NTHi had the same ftsI gene mutation pattern and 24 AA substitutions. CONCLUSION: These results confirm that ß-lactam-resistant NTHi isolates increased rapidly. AA substitutions in ftsI were more complex and diversified in 2013-2014.

[Contamination Levels and Ecological Risk Assessment of Phthalate Esters (PAEs) in the Aquatic Environment of Key Areas of Taihu Lake].

To better understand phthalate esters (PAEs) pollution in key areas of Taihu Lake, water and sediment samples were collected for content analysis. The concentrations of ∑PAEs in water samples from wet, dry, and normal seasons ranged 1.6-11.2 µg·L-1 (mean:3.68 µg·L-1), nd-6.21 µg·L-1 (mean:1.3 µg·L-1), and nd-1.72 µg·L-1 (mean:0.48 µg·L-1), respectively. No differences were found between upstream and downstream samples. DEHP was the predominant component in water samples, whereas DBP exceeded the national surface water environmental quality standards. The total PAE concentration in the sediment ranged between 0.74 and 6.90 µg·g-1 (mean:2.64 µg·g-1), with DBP and DEHP the predominant PAEs. The risk quotient (RQ) results showed that DBP and DEHP contributed the most potentially adverse effects to the aquatic environment in the key areas. The contents of PAEs in sediment were all less than the ERLs, thus posing no significant threat to aquatic organisms. The overall level of PAEs in the study area was moderate compared to those in other areas, including rivers, lakes, and estuaries from cities worldwide. Industrial pollution and urban activities are the major sources of PAEs in the aquatic environment of key areas of Taihu Lake.

[Pollution Characteristics and Health Risk Assessment of VOCs Fugitively Emitted from Typical Brewers].

Food processing plants are an important industrial source of volatile organic compounds (VOCs). Research on the unorganized emissions of VOCs to the surrounding environment from food processing plants is still quite scarce. The purpose of this study was to investigate the concentration characteristics, odor pollution, and health risk of the VOCs fugitively emitted from the brewing industry. The concentration characteristics of VOCs fugitively emitted from a typical vinegar factory and a typical distillery were detected via portable gas chromatography-mass spectrometry. The thresholds of the diluted multiple and sensory methods were also used for analyzing the VOCs. In addition, the assessment of health risk was conducted according to the US EPA evaluation model. The results show that the concentrations of the total VOCs emitted from the vinegar factory and the distillery were 0.968 mg·m-3 and 0.293 mg·m-3, respectively. Ethyl acetate and acetic acid were the main VOCs in the atmosphere of the vinegar plant, accounting for 76.3% and 13.5% of the total VOCs, respectively. The VOCs of the distillery were mainly characterized by ethanol and ethyl acetate, which accounted for 56.3% and 30.4% of the total VOCs, respectively. Oxygen-containing VOCs were the most important component of the studied brewing industry source. The total odor indices of the VOCs emitted from the vinegar factory and the distillery were both higher than 1, which indicates that their unorganized emission of VOCs have odor pollution to the atmosphere. The odor concentrations of the vinegar factory and the distillery were also higher than the standard limit of malodorous pollutants. The results of the health risk assessment show that the carcinogenic risk indices of VOCs were 2.45×10-6 and 5.25×10-6, respectively, which exceeded the suggested risk value by the EPA but were lower than the OSHA and ICRP values.

[Comparison on the levels of human serum antibody against Neisseria meningitidis serogroup C measured using serum bactericidal assay and ELISA].

OBJECTIVE: To analyze the levels of human serum antibody against Neisseria meningitidis serogroup C measured by serum bactericidal assay (SBA) and ELISA. METHODS: SBA and a modified ELISA were applied to measure the serum bactericidal titer and the specific concentration of immunoglobulin G (IgG) against meningococcal serogroup C in sera samples. Seventy-five sera were from healthy adults without undertaking vaccination while another 429 and 388 pre- and post-vaccinated sera were from 143 infants and 194 young children immunized with conjugate vaccine or polysaccharide vaccine, respectively. Correlation between serum bactericidal titer and the concentration of specific IgG against meningococcal serogroup C was analyzed. RESULTS: The concentration of meningococcal serogroup C specific IgG in healthy adults showed a strong correlation (r=0.814 33, P<0.001) with serum bactericidal titer through linear regression analysis. Weak correlation was observed between SBA titers and IgG concentration in pre vaccinated sera of infants and children (conjugate/polysaccharide vaccine) (infants: r=0.140 64, P>0.100/r=0.2899, P<0.05; children: r=0.540 40, P<0.05/r=0.194 36, P<0.05). After immunization with 2-dose conjugate vaccine in infants and 1-dose in children, a strong correlation between the two panels of results was observed (r=0.809 38, P<0.001 and r=0.837 23, P<0.001 respectively). However after immunization with polysaccharide vaccine, the correlation between serum bactericidal titer and concentration of specific IgG was weak (r<0.50000). CONCLUSION: Among healthy adults and post vaccinated infants or young children immunized with conjugate vaccine, the concentration of specific IgG was comparable to the serum bactericidal titer against meningococcal serogroup C. However, it was not unfavorable to use ELISA as the principal means of measuring serum antibody responses to polysaccharide vaccine for infants under 1 year old.

[Molecular typing of Legionella pneumophila isolates from China with pulsed field gel electrophoresis].

OBJECTIVE: To analyze the molecular types of Legionella (L.) pneumophila strains isolated in China, and to develop the PulseNet-China Database of L. pneumophila. METHODS: Pulsed field gel electrophoresis (PFGE) was used to analyze 262 L. pneumophila strains collected from 11 provinces between 2004 and 2009 in China. Different kinds of genomic DNA in different L. pneumophila strains were isolated and separated after digesting with Asc I. BioNumerics software was used to analysis the PFGE fingerprints. RESULTS: L. pneumophila strains isolated in China were quite different regarding their PFGE patterns. There were 108 PFGE types among the 262 strains tested in this study. The similarity value of these strains was in the range of 16% - 100% and the same types were discovered in different provinces and years. CONCLUSION: L. pneumophila strains isolated in China were with high genetic variations. There might be different clones existed in China. The development of PulseNet China Database was thus of great significance in monitoring the L. pneumophila strains in the future.

[Molecular typing of Klebsiella pneumonia by pulse-field gel electrophoresis in combination with multilocus sequence typing].

OBJECTIVE: To type Klebsiella pneumonia through methods including pulse-field gel electrophoresis (PFGE) in combination with multilocus sequence typing. METHODS: Four selected different EPs, referring to the Standard Operating Procedure of PulseNet China, were used. The single colony of Klebsiella pneumonia was quantified after enriched culture. Embedding organisms in agarose and genome DNA were lysed with Proteinase K and then digested by restriction endonuclease XbaI, to produce agarose gel. Fingerprint was obtained through PFGE and bands were marked with their molecular weights and then analyzed by BioNumerics software. Using MLST to analyze the strains that were highly similar, by PFGE typing RESULTS: By comparing the four results from each EPs, fk3 (switch time from 6s to 36s, total run time is 18.5 hours) seemed to be better than the others. 59 strains of Klebsiella pneumonia were divided into 47 PFGE types and 19 PFGE clusters. The highly similar strains could be typed into ST-340, ST-342, ST-343, ST-344, ST-345 by MLST. Among them, ST-342, ST-343, ST-344, ST-345 types were all new MLST types that were reported in China. CONCLUSION: Highly similar Klebsiella pneumonias typed by PFGE could also be typed by MLST.

[Study on the bactericidal antibody against Neisseria meningitidis serogroup C strains after immunization with a divalent polysaccharide (A plus C) vaccine].

OBJECTIVE: To optimize the serum bactericidal assay (SBA), detect and analyze the bactericidal antibody level against Neisseria meningitidis serogroup C strains after divalent polysaccharide (A plus C) vaccine immunization. METHODS: Two Neisseria meningitidis serogroup C strains, vaccine candidate strain (C11) and epidemic strain (053442), were selected as targets. The national Neisseria meningitidis standardized serum was used as reference serum. Pel-Freez infant rabbit complements was available. The optimized SBA method was used to detect bactericidal antibody against strain C11 and 053442 for 122 pairs of sera before and after immunization with a divalent polysaccharide (A and C) vaccine. RESULTS: The strain C11 and 053442 both could be used as targeted strain for SBA. The optimized concentration of targeted strain was achieved when a whole-cell suspension of 0.35 A at 600 nm was diluted 4 x 10(4) times. Before immunization, SBA geometric mean titers (GMT) of 122 sera against strain C11 and 053442 were 1:1.75 and 1:2.63 respectively, and the protective rates were 9.8% and 17.2% respectively. After immunization, the GMTs and the protective rates of 122 sera both rose significantly (P<0.01), the GMTs against strain C11 and 053442 were 1:483.73 and 1:412.57 respectively. The protective rates against strain C11 and 053442 were 100% and 95.9% respectively. CONCLUSION: Immunization with a divalent polysaccharide (A and C) vaccine could elevate remarkably the population SBA titer against Neisseria meningitidis serogroup C strains of different subtypes, but the surveillance of vaccine effect against different targeted strains remains necessary.

[Distribution and molecular epidemiologic characterizes of insertion sequence IS1301 in neisseria meningitidis isolated from China].

OBJECTIVE: To research the distribution and molecular epidemiology of insertion sequence IS1301 in Neisseria (N.) meningitidis strains in China, so as to provide scientific and available evidence for a new method of genotyping in N. meningitidis strains with IS1301. METHODS: Examined the IS1301 by PCR in 219 N.meningitidis strains from 16 provinces and 3 cities during 2007 and 2008 in China, productions of amplification were sent for sequencing. The positive N. meningitidis strains were analyzed by pulse field gel electrophoresis (PFGE) and nucleic acid blotting hybridization(Southern blot) by electrophoresis. RESULTS: The positive rates with IS1301 were 15.53%, 11.11%, 20.75%,6.17% and 28.57% for four serotypes (A, B, C, N) respectively. The sequence comparability between the amplification productions and No.Z49092.1 N. meningitidis which registered in GenBank was 94%-100%. There were two types of clusters divided by cladogram analysis. There appeared large IS1301 sequence difference between the serotype C and others. The number of IS1301 replica ranged from 6-17 per strain at least. The number of IS1301 replica changed in the same type of PFGE N. meningitidis respectively. CONCLUSION: Typing by IS1301 combined with PFGE could comprehend the homology and genetic polymorphism of N.meningitidis epidemic strains at the molecular level.

[Detection of Haemophilus influenzae by multiplex polymerase chain reaction method].

OBJECTIVE: To develop a rapid method for detecting Haemophilus influenzae by multiplex polymerase chain reaction (M-PCR). METHODS: Primers (Hi) were designed for amplification of p6 gene coding P6 protein of Haemophilus influenzae, which was used to identify Haemophilus influenzae species. Primers (Hi-cap) were designed for amplification of bexA gene which coding capsular polysaccharide (cap) synthesis was used for detecting whether Haemophilus influenzae isolates possess bexA gene relating to cap synthesis. Twelve primers (Hia-Hif) were designed for amplification of cap synthesis gene to identify the cap-type of Haemophilus influenzae. Other relative enteric pathogenic bacteria were amplified by M-PCR to serve as controls. 200 strains isolated from patients were identified. Results from M-PCR were compared to two methods including V and X factors grow requirement test and standard slide agglutination serotyping (SAST). RESULTS: The results indicated that the M-PCR assay was high specificity and sensitivity and might be valuable for differential diagnosis of Haemophilus influenzae. The sensitivity of detection was 0.935 pg. 189 strains out of the 200 belonged to Haemophilus influenzae isolates, and one isolate was cap-type f. An agreement results were seen among the V and X factors grow requirement test, SAST and M-PCR methods. CONCLUSION: M-PCR method showed satisfactory sensitivity, specificity and stability for detecting and identifying Haemophilus influenzae, and could be used in clinic diagnosis, surveillance and rapid diagnosis for plague of Haemophilus influenzae.

[Establishment and application of TaqMan Real-Time PCR in detection and serogrouping of Neisseria meningitidis].

OBJECTIVE: To establish TaqMan Real-Time PCR method for detection and identification of Neisseria meningitidis. METHODS: Seven sets of primers and FAM-labeled probes targeting different genes of Neisseria meningitidis were designed and synthesized. ctrA gene was used for identification of N. meningitidis species. Six serogruops (A, B, C, X, Y, W135) of N. meningitidis were detected with following genes: sacB (A), siaD (B), siaD (C), xcbB (X), synF (Y) and synG (W135) respectively. Sensitivity and specificity of Real-Time PCR were assessed for different primers and probes. 121 cerebrospinal fluid (CSF) specimens from suspected N. meningitidis invasive meningitis cases were detected by latex agglutination test and Real-Time PCR assay simultaneously. RESULTS: 79 N. meningitidis isolates of different serogroups could be detected and identified by seven sets of primers and probes in this study. Real-Time PCR seemed more sensitive than standard PCR by 10(1)-10(3) times. The respective sensitivities for ctrA, sacB, siaD (B), siaD (C), xcbB, synF and synG were 8, 8, 80, 8, 8, 80, 8 genome DNA copies in each reaction. Of the 121 CSF specimens, 11 were positive for Real-Time PCR and 6 for latex agglutination test. CONCLUSION: Real-Time PCR could rapidly detect and identify N. meningitidis of different serogroups and seemed more sensitive. It could be widely used for diagnose of invasive meningitis caused by N. meningitidis.