OBJECTIVETo study the molecular types of Staphylococcus aureus isolated from a severe food-poisoning and to trace the possible strains.

METHODSReal-time PCR was applied to detect nuc gene as a specific marker for S. aureus, mecA gene encoding methicillin resistance and 5 other genes encoding staphylococcal enterotoxins (sea, seb, see, sed, see). Isolates were also performed with 16S rRNA oligonucleotide sequence analyzing by DNAStar MegAlign 5.0 software and pulse-field gel electrophoresis (PFGE) by BioNumerics Version 4.0 software.

RESULTSThe nuc gene was detected from the 10 isolated strains, sea and seb genes were detected from 7 strains. There were 4 16 S rRNA types and 5 PFGE types found from all the strains.

CONCLUSIONSThree relative S. aureus strains were involved in the severe food-poisoning at least. Molecular subtyping might give a molecular epidemiological evidence and support the source tracing of an outbreak.

Bacterial Typing Techniques ; China ; Electrophoresis, Gel, Pulsed-Field ; Enterotoxins ; Humans ; Staphylococcal Food Poisoning ; epidemiology ; microbiology ; Staphylococcus aureus ; classification ; genetics ; isolation & purification

OBJECTIVETo investigate the effects of sleep deprivation on intelligence development in primary school students.

METHODSBetween June 2009 and April 2010, 316 grade 5 students aged 10-11 years were selected from four primary schools in four administrative districts of Changsha, China by stratified random sampling. The intelligence characteristics of children with varying degrees of sleep deprivation were investigated using the Chinese Wechsler Intelligence Scale for Children.

RESULTSA total of 286 valid questionnaires were received, with a response rate of 90.5%. The survey was comprised of a sleep deprivation group (sleep time <8 hours per night; n=180) and a control group (sleep time ≥8 hours per night; n=106). The sleep deprivation group had significantly lower subtest scores, verbal intelligence quotient (IQ) (VIQ), performance IQ (PIQ) and full scale IQ (P<0.05) and significantly lower verbal comprehension factor score and memory/attention factor score compared with the control group (P<0.05). Compared with the control group, the moderate sleep deprivation subgroup had significantly decreased VIQ and full scale IQ as well as verbal comprehension factor score and memory/attention factor score (P<0.05), and the severe sleep deprivation subgroup showed decreases in all scores (P<0.05). The sleep deprivation group and moderate and severe sleep deprivation subgroups had significantly higher proportions of children with VIQ-PIQ imbalance than the control group.

CONCLUSIONSSleep deprivation adversely affects intelligence development, especially VIQ, in primary school students, and the adverse effects of sleep deprivation are mainly seen in students with moderate and severe sleep deprivation.

Child ; Female ; Humans ; Intelligence ; Male ; Sleep Deprivation ; psychology

OBJECTIVETo apply pulse-field gel electrophoresis analysis(PFGE) in the analysis of cholera outbreak events and to determine the molecular epidemiological characteristics of Vibrio cholerae ( V. cholerae) isolates.

METHODSPFGE using restriction enzyme Not I was employed in the molecular subtyping of forty-one strains of V. cholerae isolated in cholera outbreak events from 2003 to 2005 in Guangzhou area and PFGE patterns were analyzed by BioNumerics Version 4.0 software to perform cluster analysis. Pattern profiles were compared by utilizing of Dice coefficient and UPGMA(unweighted pair group method with arithmetic averages). Comparison of PFGE typing results was performed with phage-biological typing and pathogenicity-associated genes typing.

RESULTSIn cholera outbreak events, PFGE could discriminate epidemiologically related and unrelated strains, having more discriminatory power than phage-biological typing and pathogenicity-associated genes-typing.

CONCLUSIONSMolecular sub-typing by PFGE could disclose the epidemiological relationships of strains from humans and the environment, providing molecular epidemiological evidence and support for the source-tracking of cholera outbreak events.

Bacterial Typing Techniques ; methods ; Cholera ; epidemiology ; microbiology ; Disease Outbreaks ; Electrophoresis, Gel, Pulsed-Field ; Humans ; Molecular Epidemiology ; Vibrio cholerae ; classification ; genetics ; isolation & purification

OBJECTIVETo apply pulse-field gel electrophoresis analysis(PFGE) in analysing a case of food poisoning caused by Vibrio parahaemolyticus.

METHODSPFGE using restriction enzyme Not I was employed in molecular subtyping of thirty strains of V. parahaemolyticus isolated from a case of food poisoning in Guangzhou city and PFGE patterns were analyzed by using BioNumerics Version 4.0 software to perform cluster analysis. Pattern profiles were compared by using the Dice coefficient and unweighted pair group method with arithmetic averages (UPGMA).

RESULTSThirty strains were of the same type of pulsotype.

CONCLUSIONSMolecular subtyping by PFGE might disclose the epidemiological relationships of the strains from humans, food and the environment, giving a strong molecular epidemiological evidence and a support for the source-tracking of outbreak events.

Bacterial Typing Techniques ; methods ; China ; Electrophoresis, Gel, Pulsed-Field ; methods ; Foodborne Diseases ; microbiology ; Humans ; Vibrio parahaemolyticus ; classification ; genetics ; isolation & purification

Adult ; Female ; Humans ; Hypertension, Portal ; diagnosis ; etiology ; genetics ; Liver Cirrhosis ; complications ; diagnosis ; genetics ; Male ; Middle Aged ; Models, Statistical ; Nitric Oxide Synthase ; genetics ; Polymorphism, Genetic ; Prognosis ; Prospective Studies

OBJECTIVETo apply multiplex polymerase chain reaction (MPCR) assay and sequencing in study of the carrying status of four pathogenicity-related genes of Vibrio cholerae (V.cholerae) and the variation of ctxA.

METHODSPrimers targeting cholera toxin sub-unit A gene (ctxA), toxin-coregulated pilus gene (tcpA), accessory cholera enterotoxin gene (ace), zonula occludens toxin gene (zot) were designed and the MPCR method was applied to detect the pathogenicity-related genes of 276 strains of V.cholerae isolates. The amplified fragments of ctxA gene were sequenced and the genetic homology of the amplified fragments of ctxA was analyzed.

RESULTSOf the 276 strains of V.cholerae, 93.9% strains from human sources belong to the pathogenicity-related genes type A (ctxA(+)tcpA(+)ace(+)zot(+) type) and 6.1% belong to pathogenicity-related genes type C (ctxA(-)tcpA(-)ace(-)zot(-) type). Type A strains from clinical sources were isolated from patients with mild to severe symptom and carriers, among which 68.5% were isolated from patients with mild symptom and 21.9% from carriers. All 63.6% of type C strains from clinical sources were isolated from patients with mild symptom and 36.4% from carriers. The proportion of type C strains that caused mild symptom was higher than that of type A strains. Of the 78 strains isolated from the environment, 9.0% strains belong to pathogenicity-related type A and 35.9% belong to the pathogenicity-related genes type B (ctxA(-)tcpA(-)ace(+)zot(+) type), while 55.1% belong to pathogenicity-related genes type C. The sequencing results showed little genetic variation among the amplified fragments for ctxA.

CONCLUSIONMPCR disclosed the polymorphic status of pathogenicity-related gene patterns in V.cholerae isolates of Guangzhou, providing effective means for further study on evolution of pathogenicity-related genes among V.cholerae isolates from human and environmental sources. This study also offers significant guidance for effective prevention, control and warning against cholera epidemic in local area.

China ; Cholera Toxin ; genetics ; DNA, Bacterial ; Genes, Bacterial ; genetics ; Genotype ; Humans ; Polymerase Chain Reaction ; Sequence Analysis ; Vibrio cholerae ; classification ; genetics ; isolation & purification

Objective To analyze epidemiological characters of an outbreak of rotavirus diarrhea in Daxing county, Guangxi province. Methods Rotavirus-positive specimens were identified by ELBA kit. G/P typing assays were confirmed with multiplex seminested RT-PCR. Full-length VP7 genes of 4 positive specimens were amplified and analyzed. Results 30 cases of Rotavirus-positive were identified from 64 specimens. The attack rate was 46.9% , and G/P typing was G1P[8]. A change of VP7 amino acid residue is at positions 68.Conclusion G1P[8] rotavirus is the etiologic agents of this diarrhea outbreak. In addition, adults were included in this outbreak.

Objective::To observe the effect of sanggenone C (SanC) on the proliferation and differentiation of mouse MC3T3-E1 osteoblasts induced by dexamethasone (DEX), and to explore its mechanism. Method::Molecular docking was conducted between SanC and Runt-associated transcription factor 2(Runx2) protein structure obtained by homologous modeling. MC3T3-E1 cells were jointly treated by different concentrations of SanC (8, 16, and 32 μmol·L^-1) and 1 μmol·L^-1 DEX, and then cell counting kit-8(CCK-8) method was used to detect the effect of SanC on the proliferation of MC3T3-E1 osteoblasts. The alkaline phosphatase (ALP) activity of MC3T3-E1 osteoblasts was determined by reagent kit and the formation of mineralized bone nodules were detected by alizarin red staining. Real-time fluorescent quantitative polymerase chain reaction (Real-time PCR) was used to detect the mRNA expression of Runx2, ALP and Osterix. The protein expression of Runx2 was detected by Western blot. Result::The docking score of SanC and Runx2 was -9.78.As compared with the normal group, DEX group significantly reduced the cell survival rate (P<0.01), and the greatest difference occurred on the seventh day. As compared with DEX group, SanC could significantly promote the cell proliferation of MC3T3-E1 (P<0.01), in which 32 μmol·L^-1 SanC had the largest difference in proliferation rate on seventh day. As compared with the normal group, the expression of Runx2, ALP and Osterix mRNA increased to a certain extent in DEX group(P<0.01). As compared with DEX group, the expression levels of Runx2, ALP and Osterix mRNA were up-regulated in different concentration groups of SanC in a dose-dependent manner (P<0.01). As compared with the normal group, the expression of Runx2 protein in DEX group decreased significantly (P<0.05), and as compared with DEX group, the expression of Runx2 protein in cells under the intervention of SanC increased significantly (P<0.01). Conclusion::SanC can promote the proliferation, differentiation and mineralization of MC3T3-E1 osteoblasts, and the mechanism may be related to the up-regulation of Runx2 expression.