Search

To determine the distribution of two important virulence factors [lipooligosaccharide (LOS) and capsular polysaccharide (CPS)] inWhole-genome sequencing was carried out for 494Nine novel and 29 previously confirmed LOS classes were identified. LOS classes A, B, and C were the most common (48.2%, 238/494) among the 494 strains. Twenty-six capsular types were identified in 448 strains. HS2, HS4c, HS5/31, HS19, and HS8/17 were the most frequent CPS genotypes (58.7%, 263/448). Strains of 17 CPS genotypes (strain number5) had one or two prevalent LOS classes (Our results describe the genetic characteristics of the important virulence factors in

Reading is a complex task that requires cognitive and emotional engagement. The integrated instruction approach, incorporating strategy instruction and literature circles, was developed to improve Chinese students’ reading comprehension, reading motivation, and strategy use in reading fiction books. The current study adopted a quasi-experimental pretest–posttest treatment–control group design. A total of 87 sixth graders (aged 11–12 years) were assigned to three groups, receiving integrated instruction (INI), literature circle (LC), or traditional Chinese instruction (TRC), respectively, over 12 weeks. A reading comprehension test, reading motivation questionnaire, and strategy questionnaire were used to measure students’ abilities before and after the quasi-experiment. Paired-samples t-tests, multivariate analysis of variance (MANOVA), and multivariate analysis of covariance (MANCOVA) were used to compare reading-related outcomes within and between groups. The results indicated that the students in the INI group significantly improved their reading comprehension, all aspects of reading motivation, and strategy use; the LC and TRC students also significantly improved some aspects of their reading motivation and strategy use, but to a lesser degree than the INI students. These findings reveal evidence-based effects of INI and LC on multiple reading outcomes in the Chinese cultural and lingual context.

In this work, metal–organic frameworks (MOFs) are utilized as effective ECL coreactant accelerator to enhance the ECL responses of N-(aminobutyl)-N-(ethylisoluminol) (ABEI). Zn-based MOFs (MOF-Zn-1) were prepared by chelating Zn ions with melamine and thiophenedicarboxylic acid (TPDA), which observably accelerated the electrocatalytic oxidation of tripropylamine (TPA). Then, ABEI-MOF-Zn-1 as a high-performance ECL emitter was synthesized via an amide reaction between ABEI and mercaptopropionic acid (MPA) modified MOF-Zn-1. Strikingly, the ABEI-MOF-Zn-1 showed the 18-fold increase in the ECL signals relative to pure ABEI by using TPA as a coreactant. Moreover, ferrocene (Fc) as a quencher was first linked with capture DNA (cDNA), and then used to modify the ABEI-MOF-Zn-1, thereby constructing a label-free ECL biosensor. After the linkage between chloramphenicol (CAP) and aptamer DNA (aptDNA), the ECL response was definitely recovered by releasing L-DNA from double-stranded DNA (dsDNA, hybridization of aptDNA and L-DNA). The resultant sensor showed a wide linear range of 1.00 nM–0.10 mM (R2 = 0.99) and a low limit of detection (LOD) down to 0.11 nM for detecting CAP. This work developed a novel pattern to design an efficient ECL enhanced emitter, coupled by expanding its potential applications in clinical diagnosis.

In this work, metal-organic frameworks (MOFs) are utilized as effective ECL coreactant accelerator to enhance the ECL responses of

Novel and distinct enhancement in electrochemiluminescence (ECL) signals of advanced organic luminophores are of importance for expanding their applications in early diagnosis. This work reported the construction of an ultrasensitive label-free ECL aptasensor for thrombin (TB) detection by grafting zinc proto-porphyrin IX (ZnP) onto an aminated zeolitic imidazole framework-8 (defined as ZnP-NH-ZIF-8 for clarity) as the luminophore. The structure and optical properties of the resulting ZnP-NH-ZIF-8 were carefully characterized. For that, there appeared to be weak ECL radiation for ZnP in dichloromethane (DCM) containing tetra-n-butylammonium perchlorate (TBAP) because of the as-formed singlet-state oxygen via the "reduction-oxidation" route. More notably, the ECL signals display 153-times enhancement for ZnP-NH-ZIF-8, thanks to the excellent catalytic kinetics for the oxygen reduction reaction (ORR). By virtue of the specific interactions of the TB aptamer (TBA) with the TB protein and the highly efficient catalysis of the ZnP-NH-ZIF-8 for ORR, the as-prepared aptasensor showed a wider linear range (0.1 fM∼1 pM) and a lower detection limit (ca. 58.6 aM). This work provides some useful guidelines for synthesis of an advanced organic luminophore with largely boosted ECL signals in ultrasensitive analysis and clinical diagnosis.

Effect of Lactobacillus rhamnosus GG supernatant on serotonin transporter expression in rats with post-infectious irritable bowel syndrome

Mucin-1, an essential transmembrane glycoprotein, was regarded as a promising biomarker for colon, breast, ovarian and lung cancers. Thus, its highly sensitive and selective detection is important to develop new analytical strategies. In this work, Zn-based metal organic frameworks with pyridine (Zn-Bp-MOFs) were synthetized via coordination to enhance the ECL responses of zinc meso-tetra(4-sulfonatophenyl) porphine (Zn-TP). The synthesized Zn-Bp-MOFs substantially accelerated the electrocatalytic reduction of K2S2O8 and excited electron amount of Zn-TP. For that, the Zn-TP linked Zn-Bp-MOFs (terminated as Zn-TP@Zn-Bp-MOFs) displayed 32-fold magnification in the ECL efficiency relative to free Zn-TP. By assembly of capture DNA (cDNA), functional luminophore effectively captured the released linked DNA (L-DNA) from double-stranded DNA (dsDNA, hybridization of aptamer DNA (aptDNA) and L-DNA) via the strong interactions between the aptDNA and mucin-1. Consequently, thionine was implanted into the groove of newly-formed dsDNA and severely quenched the ECL intensity of the emitter. The resulting biosensor showed wide linear range from 1 pg mL-1 to 10 ng mL-1 with a limit of detection (LOD) as low as 0.23 pg mL-1. Hence, such MOFs hold substantial promise to broaden their applications in photoelectric detection field.

OBJECTIVE: To investigate genetic and antibiotic resistance characteristics of Campylobacter jejuni (C. jejuni) isolated from Shenzhen. METHODS: Multilocs sequence typing and agar dilution methods were used to define the genotype and antibiotic resistance of C. jejuni, respectively. RESULTS: In total, 126 C. jejuni strains were isolated. The prevalence of C. jejuni was 5.3% in diarrheal patients. The prevalence in poultry meat (36.5%) was higher than that in cattle meat (1.1%). However, the prevalence in poultry cloacal swabs (27.0%) was lower than that in cattle stool (57.3%). Sixty-two sequence types were obtained, among which 27 of the STs and 10 alleles were previously unreported. The most frequently observed clonal complexes were ST-21 (11.9%), ST-22 (10.3%), and ST-403 (7.1%). ST-21, ST-45, ST-354, ST-403, and ST-443 complexes overlapped between isolates from patients and cattle, whereas ST-45 and ST-574 complexes overlapped between isolates from patients and poultry. All C. jejuni were resistant to at least one antibiotic. The highest resistance rate was toward ciprofloxacin (89.7%), followed by tetracycline (74.6%), and nalidixic acid (69.0%). CONCLUSION: This is the first report of the genotypes and antibiotic resistance of C. jejuni in Shenzhen. Overlapping clonal complexes were found between isolates from patients and cattle, and between patients and poultry.

AIM To evaluate the effect of Lactobacillus rhamnosus GG supernatant (LGG-s) on the expression of serotonin transporter (SERT) in rats with post-infectious irritable bowel syndrome (PI-IBS). METHODS Campylobacter jejuni 81-176 (1010 CFU/mL) was used to induce intestinal infection to develop a PI-IBS model. After evaluation of the post-infectious phase by biochemical tests, DNA agarose gel electrophoresis, abdominal withdrawal reflex (AWR) test, and the intestinal motility test, four PI-IBS groups received different concentrations of LGG-s for 4 wk. The treatments were maintained for 1.0, 2.0, 3.0 or 4.0 wk during the experiment, and the colons and brains were removed for later use each week. SERT mRNA and protein levels were detected by real-time PCR and Western blot, respectively. RESULTS The levels of SERT mRNA and protein in intestinal tissue were higher in rats treated with LGG-s than in control rats and PI-IBS rats gavaged with PBS during the whole study. Undiluted LGG-s up-regulated SERT mRNA level by 2.67 times compared with the control group by week 2, and SERT mRNA expression kept increasing later. Double-diluted LGG-s was similar to undiluted-LGG-s, resulting in high levels of SERT mRNA. Triple-diluted LGG-s up-regulated SERT mRNA expression level by 6.9-times compared with the control group, but SERT mRNA expression decreased rapidly at the end of the second week. At the first week, SERT protein levels were basically comparable in rats treated with undiluted LGG-s, double-diluted LGG-s, and triple-diluted LGG-s, which were higher than those in the control group and PBS-treated PI-IBS group. SERT protein levels in the intestine were also comparable in rats treated with undiluted LGG-s, double-diluted LGG-s, and triple-diluted LGG-s by the second and third weeks. SERT mRNA and protein levels in the brain had no statistical difference in the groups during the experiment. CONCLUSION LGG-s can up-regulate SERT mRNA and protein levels in intestinal tissue but has no influence in brain tissue in rats with PI-IBS.

Mycoplasma pneumoniae (M. pneumoniae) is one of the most important pathogens that cause respiratory tract infection in children and adults. In this study, we describe a rapid and sensitive colorimetric loop mediated isothermal amplification (LAMP) method to detect M. pneumoniae. The specificity and sensitivity of this assay were detected with 21 common respiratory pathogens and 39 M. pneumoniae DNA. The sensitivity of LAMP was 100% among 39 M. pneumoniae isolates and the specificity was 100% among 9 members of other Mycoplasma and 12 common respiratory pathogens. The lowest detectable limit (LDL) of this assay was 102 copies, which detected by a series of standard M. pneumoniae DNA. To evaluate the clinical applicability of the LAMP assay, a total of 80 clinical samples were examined by conventional PCR, real-time PCR and the LAMP assays, respectively. The positive rates were 15.0%, 32.5% and 26.3%, respectively. This colorimetric LAMP assay demonstrated a high level of sensitivity comparable with that of conventional PCR for the detection of M. pneumoniae. It is a valuable method for simple, cost-effective and rapid detection of M. pneumoniae in the rural areas and basic clinical of China.

Ganglioside mimicry by C. jejuni lipo-oligosaccharides (LOS) could induce the production of autoantibodies against gangliosides and the development of Guillain-Barré syndrome (GBS). The LOS biosynthesis region exhibits significant variation with different strains. Using PCR amplifications of genes from published LOS loci and sequencing the LOS biosynthesis loci, the eight GBS-associated C. jejuni strains from HeBei could be classified into four classes. The expression of sialylated LOS structures (class A) or non-sialylated LOS structures(class F, H and P) in the C. jejuni LOS is considered to be two different factors for the induction of GBS.

* These two authors contribute equally to this paper. In order to identify the proteins associated with Helicobacter pylori colonization in mice, we used 2-dimensional gel electrophoresis (2-DE) to analyze the membrane- and soluble-cellular proteins extracted from H. pylori strain 26695 and the mouse-passaged homolog 88-3887. We defined 2- and 3-fold changes in protein expression as the threshold values for differential expression in the membrane-protein and whole-cell-protein fractions, respectively. The differentially expressed proteins were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF/TOF). A total of 29 proteins, including 16 mem- brane- or membrane-associated proteins (13 upregulated, 3 downregulated) and 13 cellular proteins (10 upregulated, 3 downregulated) were differentially expressed between the strains 26695 and 88-3887. Among the upregulated proteins, 10 proteins had been previously shown to be associated with the mouse colonization, and 13 upregulated proteins were shown to be associated with the adaptation of H. pylori in murine hosts for the first time in this study. The identified proteins were classified as proteins related to metabolism, stress response, virulence, or adhesion. The data presented in this report indicated that there were subsets of upregulated proteins in mouse-adapted H. pylori. In particular, the adhesins, virulence factors, and stress- response proteins are likely to contribute to colonization in mice.

To investigate the protein expression profiles of the major food-borne pathogen Campylobacter jejuni NCTC11168.Membrane and soluble cellular proteins were extracted from the genome-sequenced C. jejuni strain NCTC11168. Protein expression profiles were determined using two-dimensional gel electrophoresis (2-DE). All the detected spots on the 2-DE map were subjected to matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF/TOF) analysis.A total of 537 and 333 spots were detected from the whole cell and membrane-associated proteins of C. jejuni NCTC11168 cultured on Columbia agar medium at 42 °C by 2-DE and Coomassie Brilliant Blue staining, respectively. Analyses of whole cell and membrane-associated proteins included 399 and 133 spots, respectively, which included 182 and 53 functional proteins identified by MALDI-TOF/TOF analysis.The comprehensive expression protein profiles of C. jeuni NCTC11168 obtained in this study will be useful for elucidating the roles of these proteins in further pathogenesis investigation.

AIM: To investigate the non-Helicobacter pylori (H. pylori) bacterial flora concurrent with H. pylori infection. METHODS: A total of 103 gastric biopsy specimens from H. pylori positive patients were selected for bacterial culture. All the non-H. pylori bacterial isolates were identified by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). RESULTS: A total of 201 non-H. pylori bacterial isolates were cultivated from 67 (65.0%) of the 103 gastric samples, including 153 isolates identified successfully at species level and 48 at genus level by MALDI-TOF MS. The dominant species were Streptococcus, Neisseria, Rothia and Staphylococcus, which differed from the predominantly acid resistant species reported previously in healthy volunteers. The prevalence of non-H. pylori bacteria was higher in non-ulcer dyspepsia group than in gastric ulcer group (100% vs 42.9%, P < 0.001). Six bacterial species with urease activity (Staphylococcus epidermidis, Staphylococcus warneri, Staphylococcus capitis, Staphylococcus aureus, Brevibacterium spp. and Klebsiella pneumoniae) were also isolated. CONCLUSION: There is a high prevalence of the non-H. pylori bacteria concurrent with H. pylori infection, and the non-H. pylori bacteria may also play important as-yet-undiscovered roles in the pathogenesis of stomach disorders.

AIM: To investigate the relationship between urinary peptide changes and Helicobacter pylori (H. pylori) infection using urinary peptidome profiling. METHODS: The study was performed in volunteers (n = 137) who gave informed consent. Urinary peptides were enriched by magnetic beads based weak cation exchange chromatography and spectrums acquired by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS). ClinProTools bioinformatics software was used for statistical analysis and the recognition of peptide patterns. The marker peptides were identified by LTQ Obitrap XL tandem MS. RESULTS: Approximately 50 proteins or peptides which loaded onto the magnetic beads were detected by MALDI-TOF MS. By optimizing the parameters of the model, the Genetic Algorithm model had good recognition capability (97%) and positive predictive value (94%). Based on the model, 2 markers with molecular masses of 6788 and 1912 Da were found that differentiated between H. pylori positive and negative volunteers. The m/z 1912 sequence was parsed as SKQFTSSTSYNRGDSTF. The peptide was identified as isoform 1 of the fibrinogen α chain precursor, whose concentration in urine was markedly higher in H. pylori infected volunteers than in H. pylori non-infected ones. CONCLUSION: The appearance of urinary fibrinogen degradation products is caused by an active H. pylori-induced process.

Objective During 2003-2005, an outbreak of meningitis due to Neisseria meningitidis serogroup C occurred in China. With the aim to find strain clues result in the final epidemics, the ancestral strain 053442, a clinical isolate, and a carrier strain 053426 with different gene type were analyzed. Methods Clinical strain 053442 and carrier strain 053426 were cultured on GC agar plates under the same condition. Two-dimensional electrophoresis was performed using the pH 3–10 nonlinear IPG strips of 24 cm length, and all the protein spots were identified by matrix-assisted laser desorption/ionization time of flight spectrometry. Results 502 and 380 protein spots were identified in 053426 and 053442 respectively, relating to 266 and 202 different genes covering a wide range of cellular functions. The express volume and number of proteins involved in energy metabolism, protein synthesis and amino acid biosynthesis in 053426 were higher than in 053442. Virulence factor Opa, Opc and a series of proteins involved in pilus assembly and retraction were identified in 053442, which appear to be of primary importance in colonization and invasion of human cells. Compared to 053442, virulence protein species were less in 053426, with lower express volumes too. No Opa and Opc were detected in 053426. Conclusions The different protein expression profiles of the clinical strain 053442 and carrier strain 053426 in the present study provide some clues of the different pathogenicity of the two strains, which may account for result in the final epidemics.

To analyze multilocus sequence typing (MLST) of methicillin-resistant Staphylococcus aureus (MRSA) strains in 2000 and 2005, and get a primary knowledge of MLST Characterization of MRSA.Sequence analysis was conducted on seven allelic genes of 29 methicillin-resistant Staphylococcus aureus strains and 2 methicillin-sensitive Staphylococcus aureus (MSSA) strains and the allelic profiles were gained from internet database.All 12 MRSA strains in 2000 were sequence type (ST) 239 and 10 MRSA strains in 2005 were ST239, while 7 MRSA strains in 2005 were new types, ST5 (41.18%, 7/17). ST6 and ST630 were allelic profiles of 2 MSSA strains. ST239 was the most prevalent allelic profile (75.86%, 22/29), while ST5 was the second prevalent allelic profile (24.14%, 7/29) among all isolates.ST239 and ST5 are the most prevalent MRSA clones in this research. MRSA strains have different allelic profile from MSSA strains. MLST might provide an unambiguous method for assigning MRSA and MSSA isolates to known clones or assigning them as novel clones via the internet. Further studies need to be taken by increasing strains.

In order to identify the proteins associated with Helicobacter pylori colonization in mice, we used 2-dimensional gel electrophoresis (2-DE) to analyze the membrane- and soluble-cellular proteins extracted from H. pylori strain 26695 and the mouse-passaged homolog 88-3887. We defined 2- and 3-fold changes in protein expression as the threshold values for differential expression in the membrane-protein and whole-cell-protein fractions, respectively. The differentially expressed proteins were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF/TOF). A total of 29 proteins, including 16 membrane- or membrane-associated proteins (13 upregulated, 3 downregulated) and 13 cellular proteins (10 upregulated, 3 downregulated) were differentially expressed between the strains 26695 and 88-3887. Among the upregulated proteins, 10 proteins had been previously shown to be associated with the mouse colonization, and 13 upregulated proteins were shown to be associated with the adaptation of H. pylori in murine hosts for the first time in this study. The identified proteins were classified as proteins related to metabolism, stress response, virulence, or adhesion. The data presented in this report indicated that there were subsets of upregulated proteins in mouse-adapted H. pylori. In particular, the adhesins, virulence factors, and stress-response proteins are likely to contribute to colonization in mice.

This study was to simultaneously identify Campylobacter jejuni and Campylobacter coli isolates in China by Multi-PCR assay and to study the prevalence of six virulence and toxin genes on them.A multi-PCR method with three sets of primers specifically designed for application of a 16S rRNA as a universal control, mapA, ceuE based on the specific sequence of C. jejuni and C. coli, was applied to detect 65 Campylobacter isolates from China. Another two separately PCR Primers were directed towards the hippuricase gene (hipO) characteristic of C.jejuni and glyA gene characteristic of C. coli were performed for further confirmation. The presence of the cadF, virB11, flaA, cdtA, cdtB, cdtC genes among these 65 strains were investigated by PCR.From multi-PCR detection, 42 isolates belonged to C. jejuni, other 23 isolates belong to C. coli. Data showing the identification were 100% in concordance with the separated PCR for hipO and glyA amplification. The efficiency (100%) of identification by these three primers multi-PCR method was higher than the biochemical test (83.1%). The cadF and flaA genes were detected from 100% (65/65) of the isolates and the PCR product of each gene were identical with each isolate. Only 10.8% (7/65) of the isolates were positive for virB11. The cdtA gene was found in 92% (60/65) of the isolates. 97.6% (41/42) of C. jejuni had cdtB gene, whereas no PCR product with this primers for all the C. coli isolates. cdtC was presented in all the isolates but the lengths of PCR products were different. For C. jejuni, it was 555 bp, for C. coli, it was about 465 bp.This three primers simultaneous multi-PCR method seemed to be useful for the identification of C. jejuni and C. coli isolates from China since cadF and flaA genes were widely spread in Campylobacter isolates in this country. The present report on virB11 was similar to previous reports from other countries, but the distribution of cdt gene cluster in Campylobacter species isolated from China might be different.