Objective To understand the infection of Salmonella (S.) in patients with diarrhea and outbreaks caused by Salmonella to identify the serotypes, resistance to antibiotics and PFGE types of the strains from the surveillance program in Guangdong province. Methods S. strains from patients with diarrhea were detected, and all the positive strains collected in routine and outbreak surveillance programs, were tested by serum agglutination, antibiotic susceptibility and PFGE.Results 71 S. strains were isolated from 1922 stool samples in 2008, with positive rate as 3.7%.85 S. strains were isolated from 2110 stool samples in 2009, with positive rate as 4.0%. All the 156 strains were divided into 37 serotypes, with S. serotype typhimurium and enteritidis as the most common serotypes. 10 incidents of food poisoning were detected, of which 4 were caused by enteritidis and 3 by typhimurium. A suspected outbreak by enteritidis was discovered and under epidemiological investigation. The findings indicated that 2 of the 4 patients from this outbreak were infected with identical enteritidis isolates. 80% of the 229 isolates were found susceptible to cephalosporins and quinoione and 59.3% of them were muitiresistant to the antibiotics. Conclusion S. enteritidis and S. typhimurium were the most common serotypes that caused infectious diarrhoea and food poisoning in Guangdong province.

Objective To study the serotypes,virulence features and molecular characteristics of Vibrio parahaemaolyticus isolated in food poisoning cases and surveillance program on diarrhea patients in Guangdong,2009.Methods 95 Vibrio parahaemolyticus strains from food poisoning cases and 15 strains from surveillance program on diarrhea patients were serotyped and detected for tdh(thermostable direct hemolysin,tdh)and trh(tdh-related hemolysin gene,trh)by PCR.81 sero-variant Vibrio parahaemolyticus strains were selected through PFGE subtyping.Results There were 15 Vibrio parahaemolyticus strains isolated from surveillance program on diarrhea patients and 95 strains were isolated from 11 Vibrio parahaemolyticus-caused food poisoning cases in 2009.Among these strains,O3:K6(46.67％ and 44.21％)and O4:K8(33.33％ and 28.42％)were the dominant serotypes,but not the 7 food-borne strains.There were 93(84.54％)tdh +trh-,13(11.81％)tdh-trh-,and 3(3.65％)tdh+ trh + strains.The similarity value was between 57.7％ to 100.0％ of the 81 strains after PFGE sub-typing method and 36 PFGE subtypes were identified.PFGE001 and PFGE029 appeared to be the dominant subtypes.Conclusion O3:K6 and O4:K8 were the most dominant serotypes in Vibrio parahaemolyticus-caused diarrhea and food poisoning cases in Guangdong and tdh were detected in most of the strains.Dominant PFGE subtypes were causing both sporadic and outbreak cases in different areas in Guangdong province.

Objective To understand the distribution,molecular characteristics and virulence genes of the O1 and O139 Vibrio cholerae isolates from the Pearl River Estuary water.Methods Vibrio cholerae isolates collected from the Pearl River estuary waters from January 2009 to December 2010,were tested by PCR for eight virulence-related genes,including cholera toxin(ctxA),zonula occludens toxin(zot),accessory cholera enterotoxin(ace),hemolysin(hlyA),toxin-coregulated pilus (tcpA),outer membrane protein(ompU),and the regulatory protein genes(tcpⅠ,toxR).Genetic relation was assessed by pulsed-field gel electrophoresis(PFGE)and the patterns were clustered by BioNumerics.Results From 1152 aquatic samples,69 isolates were identified,including 41 Inaba,18 Ogawa and 10 O139.All the isolates showed ctxA negative,while the hlyA and toxR genes were positive in all the isolates.34.15％(14/41)of the Inaba strains were hlyA + toxR + ompU + ace + zot + tcpI+,while 66.67％(12/18)belonged to Ogawa strains and 70％(7/10)of the O139 strains were hlyA + toxR+.Through PFGE analysis,the O1 isolates formed three clusters in this study.The patterns of O1 isolates differed widely,with the similarity as 72.8％-100.0％,while the patterns of O139 isolates having the similarity of 69.9％-95.5％.Conclusion The non-toxigenic O1 and O139 V.cholerae had a wide distribution in the environment of Pearl River estuary water during the nonepidemic period of cholera.All the aquatic isolates presented diversities on the related virulent genes.

OBJECTIVETo study the responses of different pancreatic cancer cells to stimulations by nerve growth factor (NGF) and explore the role of Trk-A in such responses.

METHODSFive pancreatic cancer cell lines (MIA-PaCa-2, PANC-1, SW-1990, AsPC-1, and BxPC-3) were exposed to different concentrations of NGF (0, 4, 20, 100, and 500 ng/ml). MTT and Matrigel invasion method were used to observe the changes in the cell proliferation and invasion ability. Trk-A expression in these cells was detected by PCR and Western blotting, and the relations of Trk-A expression to the cell proliferative and invasive abilities following NGF treatment were analyzed.

RESULTSNGF at 100 ng/ml most obviously stimulated the cell proliferation, and PANC-1 cells showed the highest while AsPC-1 cells showed the least sensitivity to 100 ng/ml NGF stimulation. Matrigel invasion test showed that NGF enhanced the invasiveness of PANC-1 and MIA-PaCa-2 cells but produced only limited effect on AsPC-1 cells; the effect of NGF was completely inhibited by the Trk-A inhibitor CEP701. The expression levels of Trk-A mRNA and protein were the highest in PANC-1 cells and the lowest in AsPC-1 cells.

CONCLUSIONNGF can enhance the proliferation and invasiveness of pancreatic cancer cells, and this effect is possibly mediated by Trk-A protein.

Cell Line, Tumor ; Cell Movement ; drug effects ; Cell Proliferation ; drug effects ; Humans ; Neoplasm Invasiveness ; Nerve Growth Factor ; pharmacology ; Pancreatic Neoplasms ; metabolism ; pathology ; Receptor, trkA ; genetics ; metabolism

OBJECTIVETo prepare a DNA Microarray that can detect 8 common species of food borne bacterial pathogens in south China.

METHODSAll the 70mer oligo probes were designed on the characteristic genome loci of the 8 species of food borne bacterial pathogens. Eight subarrays corresponding to the 8 food borne bacterial pathogens were spotted onto the slide and integrated into a pan-array on the chip. A number of identified and known bacterial samples from the storage bank were selected for the validation test.

RESULTSBased on the PPR ranking, for LM sub-array, the PPR of the 3 Listeria bacteria LM, Lin and Liv was 68.8%, 51.8% and 59.6%, respectively, while that of the non-Listeria bacterial samples was all below 43%. For VC sub-array, the PPR of VC sample was 54.1% and that of the non-VC bacterial samples was lower than 17.2%. For VP sub-array, the PPR was 66.7% for VP sample and below 24.2% for non-VP bacterial samples. For Sal sub-array, the PPR was 55.9% for Sal sample and below 50.5% for non-Sal bacterial samples. For Shi sub-array, the PPR of Shi sample and the non-Shi bacterial samples was 53.8% and below 36.6%, respectively. For SA sub-array, the PPR of SA sample and non-SA bacterial samples was 65.2% and below 22.7%, respectively. For CJ sub-array, the PPR of the 2 Campylobacter bacteria CJ and CC were 88.2% and 58.8%, respectively, and that of the non-Campylobacter bacterial samples was lower than 35.3%. For EC sub-array, the PPR of EC sample was 47.9%, and that of the non-EC bacterial samples was lower than 41.6%. Evaluation of the Biosafood-8 chip developed in this study by 18 biological samples from different origins demonstrated its good specificity and accuracy in the identification of the pathogens.

CONCLUSIONThe chip we developed can clearly differentiate the target food borne pathogenic bacteria and non-target bacteria and allows specific and accurate identification of the species of the tested bacteria isolates.

Bacteria ; classification ; isolation & purification ; China ; Food Contamination ; analysis ; Food Microbiology ; Oligonucleotide Array Sequence Analysis ; methods

OBJECTIVEIn order to better understand the nature of Salmonella infection in diarrheal patients in Guangdong province, the study analyzed the serum types, antibiotic resistance and molecular determinants of the isolated Salmonella strains.

METHODSIn year 2010, 8405 diarrhea patients from 16 surveillant hospital in Guangzhou, Zhongshan, Dongguan, Zhuhai, Maoming, Yangjiang and Jiangmen cities in Guangdong province, were recruited in the study. A total of 8405 fecal specimen were collected and subjected to Salmonella isolation and culture. The isolated Salmonella strains were further analyzed via serotyping, antimicrobial susceptibility testing, and PFGE. The χ(2) test was applied to compare the differences between the isolated Salmonella strains in different seasons and districts. BioNumerics software was used to analyze the PFGE results in order to determine the correlation between different Salmonella strains.

RESULTSThe positive rate of the surveillant Salmonella in Guangdong province was 3.58% (301/8405) in 2010; with the gender ratio at 1.34:1 (166/124). Salmonella infection was found in all age groups, and most in infants, accounting for 57.48% (173/301). The isolated rates of Salmonella were separately 3.48% (61/1751), 4.97% (134/2695), 3.08% (73/2370) and 2.08% (33/1589) in the four seasons; and the difference was statistically significant (χ(2) = 27.29, P < 0.01). The isolated rates of Salmonella in different regions were as follows: Zhuhai 15.43% (25/162), Maoming 7.53% (18/239), Dongguan 6.51% (39/599), Yangjiang 3.64% (14/385), Zhongshan 3.03% (70/2309), Guangzhou 2.90% (126/4349) and Jiangmen 2.49% (9/362). The difference between regions was statistically significant (χ(2) = 100.75, P < 0.01). Except one strain of the isolated Salmonella cannot be serotyped, the other 300 strains were divided into 42 serotypes, of which Salmonella typhimurium and Salmonella enteritidis were dominant, account for 45.18% (136/301) and 10.96% (33/301) respectively. Although over 85% of Salmonella were sensitive to cephalosporin, ACSSuT resistance patterns (defined as resistance to at least ampicillin, chloramphenicol, streptomycin, sulfamethoxazole and tetracycline) reached 34.88% (105/301), the highest resistant rate was found in serotype Salmonella typhimurium, as high as 65.44% (89/136). 136 strains of Salmonella typhimurium were divided into 51 PFGE types, showed great genetic diversity. 33 strains of Salmonella enteritidis were divided into 18 PFGE types. The strains with same PFGE pattern may have different drug-resistant patterns, and vice versa.

CONCLUSIONSalmonella typhimurium and Salmonella enteritidis were the dominant serotypes causing infectious diarrhea in Guangdong province. Cephalosporin was the primary choice in clinical medicine. However, Salmonella typhimurium was resistant to drug most seriously in Guangdong province. There was no significant correlation between Salmonella resistance patterns and PFGE type.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Anti-Bacterial Agents ; pharmacology ; Bacterial Typing Techniques ; Child ; Child, Preschool ; China ; epidemiology ; Diarrhea ; microbiology ; Drug Resistance, Bacterial ; Female ; Humans ; Infant ; Male ; Microbial Sensitivity Tests ; Middle Aged ; Salmonella Infections ; epidemiology ; microbiology ; prevention & control ; Salmonella enteritidis ; classification ; isolation & purification ; Salmonella typhimurium ; classification ; isolation & purification ; Serotyping ; Young Adult

ObjectiveTo observe the effect of ethyl acetate extract of Acanthopanacis Senticosi Radix et Rhizoma seu Caulis on high-fat diet-induced apolipoprotein E gene knockout （ApoE^-/-） mice， and explore its mechanism of treating atherosclerosis by regulating intestinal flora. MethodThirty-two 8-week-old male ApoE^-/- mice were randomly divided into model group， rosuvastatin group （10 mg·kg^-1）， high-， low-dose groups of ethyl acetate extract of Acanthopanacis Senticosi Radix et Rhizoma seu Caulis （75， 25 mg·kg^-1）， with 8 mice in each group. Eight C57BL/6 mice were used as blank group. After 8 weeks of continuous administration， blood was taken to determine the blood lipid level. Enzyme-linked immunosorbent assay （ELISA） was used to detect the contents of related indexes in serum of mice. Hematoxylin-eosin （HE） staining was used to observe the formation of aortic plaque in mice. Cecal contents were collected and 16S rRNA amplicon sequencing was used to detect intestinal flora. ResultCompared with the blank group， the plaque area of the model group was significantly increased with inflammatory infiltration， the contents of triglyceride （TG）， total cholesterol （TC）， low-density lipoprotein cholesterol （LDL-C）， inflammatory factors and inducible nitric oxide synthase （iNOS） were increased， while the content of high-density lipoprotein cholesterol （HDL-C） was decreased. Compared with the model group， rosuvastatin group and high- and low-dose groups of ethyl acetate extract of Acanthopanacis Senticosi Radix et Rhizoma seu Caulis could improve the deposition of aortic plaque， reduce the contents of TG， TC， LDL-C， inflammatory factors and iNOS， and increase the content of HDL-C. Compared with the blank group， the relative abundances of Firmicutes and Proteobacteria in the model group increased， while the relative abundance of Bacteroidetes decreased. Alpha and Beta diversity analysis showed that samples of each group could be significantly isolated， and the total number and abundance of intestinal flora species in the model group were low. Compared with the model group， ethyl acetate extract of Acanthopanacis Senticosi Radix et Rhizoma seu Caulis could increase the relative abundance of beneficial bacteria and decrease the relative abundance of pathogenic bacteria. ConclusionEthyl acetate extract of Acanthopanacis Senticosi Radix et Rhizoma seu Caulis was mainly composed of flavonoids， which can treat atherosclerosis by regulating the intestinal flora and improve the pathological changes in the aorta of ApoE^-/- mice induced by high-fat diet. The mechanism may be related to its ability to reduce the level of inflammatory factors， improve antioxidant capacity and repair the disorder of intestinal flora structure.