The potential risks of animal plague in natural foci of Meriones unguiculatus in the Inner Mongolia plateau predicted by Maximum Entropy model / 中华地方病学杂志

Objective@#To forecast the risk distribution of inter-animal plague in Meriones unguiculatus effectively and provide scientific evidence for prevention and control of inter-animal plague, through studying the correlation between meteorological and environmental factors and inter-animal plague in Meriones unguiculatus.@*Methods@#Positive data of plague bacterial culture in 30 epidemic source areas of Meriones unguiculatus in the Inner Mongolia plateau from 2005 to 2018, including detecting time, number of bacteria, latitude and longitude or detailed location, host type, were from the Chinese Disease Prevention and Control System Plague Prevention Management Information System and related professional institutions for plague prevention and treatment. Logistic regression was used to explore the relationship between the inter-animal plague and climate-related risk factors. The Maximum Entropy (Maxent) model was used to predict the habitat distributions of inter-animal plague, and the receiver operating characteristic (ROC) curve was used to validate the model.@*Results@#There were 11 climatic factors including annual mean temperature, isothermality, temperature seasonality, mean temperature of driest quarter, mean temperature of warmest quarter, mean temperature of coldest quarter, annual precipitation, precipitation seasonality, globcover, normalized difference vegetation index and slope, were related to the outbreak of plague among Meriones unguiculatus and included in the model (OR = 1.302, 0.455, 0.957, 0.930, 4.864, 0.179, 0.986, 1.126, 0.992, 0.981, 0.721, P < 0.01). The increase of annual mean temperature, mean temperature of warmest quarter and precipitation seasonality will increase the risk of animal plague in the plague foci of Meriones unguiculatus; the increase of isothermality, temperature seasonality, mean temperature of driest quarter, mean temperature of coldest quarter, annual precipitation, globcover, normalized difference vegetation index, and slope will reduce the risk of animal plague in the plague foci of Meriones unguiculatus. The areas under the curve (AUCs) of the Maxent model training data and test data were 0.988 and 0.985, the prediction effect of the model was better. The habitat distribution of Meriones unguiculatus plague mainly concentrated in the central and northern Ulanqab plateau, Ordos plateau, and eastern Hetao plain.@*Conclusions@#The use of Maxent model and climate data can predict the potential risks and spatial distribution of animal plague in Meriones unguiculatus; the results are accurate and reliable.

The potential risks of animal plague in natural foci of Meriones unguiculatus in the Inner Mongolia plateau predicted by Maximum Entropy model / 中华地方病学杂志

Objective To forecast the risk distribution of inter-animal plague in Meriones unguiculatus effectively and provide scientific evidence for prevention and control of inter-animal plague,through studying the correlation between meteorological and environmental factors and inter-animal plague in Meriones unguiculatus.Methods Positive data of plague bacterial culture in 30 epidemic source areas of Merioncs unguiculatus in the Inner Mongolia plateau from 2005 to 2018,including detecting time,number of bacteria,latitude and longitude or detailed location,host type,were from the Chinese Disease Prevention and Control System Plague Prevention Management Information System and related professional institutions for plague prevention and treatment.Logistic regression was used to explore the relationship between the inter-animal plague and climate-related risk factors.The Maximum Entropy (Maxent) model was used to predict the habitat distributions of inter-animal plague,and the receiver operating characteristic (ROC) curve was used to vzlidate the model.Results There were 11 climatic factors including annual mean temperature,isothermality,temperature seasonality,mean temperature of driest quarter,mean temperature of warmest quarter,mean temperature of coldest quarter,annual precipitation,precipitation seasonality,globcover,normalized difference vegetation index and slope,were related to the outbreak of plague among Meriones unguiculatus and included in the model (OR =1.302,0.455,0.957,0.9130,4.864,0.179,0.986,1.126,0.992,0.981,0.721,P ＜ 0.01).The increase of annual mean temperature,mean temperature of warmest quarter and precipitation seasonality will increase the risk of animal plague in the plague foci of Meriones unguiculatus;the increase of isothermality,temperature seasonality,mean temperature of driest quarter,mean temperature of coldest quarter,annual precipitation,globcover,normalized difference vegetation index,and slope will reduce the risk of animal plague in the plague foci of Meriones unguiculatus.The areas under the curve (AUCs) of the Maxent model training data and test data were 0.988 and 0.985,the prediction effect of the model was better.The habitat distribution of Meriones unguiculatus plague mainly concentrated in the central and northem Ulanqabplateau,Ordos plateau,and eastern Hetao plain.Conclusions The use of Maxent model and climate data can predict the potential risks and spatial distribution of animal plague in Meriones unguiculatus;the results are accurate and reliable.

Isolation and identification of Withaphysalins from Physalis minima / 中国药科大学学报

@#To investigate the chemical constituents of Physalis minima L. , compounds were isolated by chromatographic methods from Physalis minima L. . Their structures were determined on the basis of spectral analysis. Five compounds were isolated and identified as Withaphysalin P(I), 14, 18-di-O-acetylwithaphysalin C(II), Withaphysalin Q(III), Withaphysalin 1(IV)and Withaphysalin 2(V). Compounds IV and V are new compounds, orderly named as Withaphysalin T and Withaphysalin U.

Surveillance for diarrheagenic Escherichia coli in Shanghai, 2012-2013 / 中华流行病学杂志

<p><b>OBJECTIVE</b>To understand the distribution of diarrheagenic Escherichia (E.) coli in population in Shanghai and discuss the practice model of cooperation in enteric infectious disease prevention and control between public health institution and hospital.</p><p><b>METHODS</b>Sentinel hospitals were assigned, standard detection and identification of diarrheagenic E. coli were conducted, incidence curve of diarrheagenic E. coli infection was drawn and epidemiologic survey and laboratory detection were conducted for suspect diarrheagenic E. coli infection outbreaks.</p><p><b>RESULTS</b>A total of 7 204 stool specimens were collected from diarrhea patients in 4 hospitals during 2012-2013, in which 712 (9.9% ) were diarrheagenic E. coli positive, including 351 enteropathogenic E. coli (EPEC) strains, 292 enterotoxigenic E. coli (ETEC) strains, 32 enteroinvasive E. coli(EIEC) strains and 6 Shiga toxin-producing E. coli (STEC/EHEC) strains, as well as 31 mixed strains. EPEC infection mainly occurred in children aged 1-5 years; and all of these infections were caused by aEPEC. The incidence peak of ETEC infection was during August, the positive rate was >20%. The ETEC infection mainly occurred in infants aged 1-28 days in 2012 and in people aged 20-60 years in 2013 (P<0.05). ST was the major type (59.6%), followed by LT (27.8%) and ST/LT (12.6%). EIEC infection increased in children obviously in 2013 (P<0.01). No EHEC O157:H7 case was detected, but two EHEC O26:H11 (eae-hlyA-stx1a) cases in children were reported for the first time in Shanghai. The survey result indicated that the multidrug-resistant ETEC (STh-CS21-CFA/I-ClyA-EatA-ST2332-SHNL0005) strain causing outbreak in 15 newborns in Shanghai in 2012 was in the same clone as the strain detected in Zigong in Sichuan province.</p><p><b>CONCLUSION</b>Significant change has occurred in diarrheagenic E. coli distribution in Shanghai in recent years, ETEC has potential risk to cause outbreak of hospital acquired infection in neonates and food borne infection. The active surveillance on ETEC and other enteric pathogens by both public health institutions and hospitals need to be improved.</p>

Study on the molecular epidemiology and antibiotic resistance of Salmonella enterica serovar Pomona / 中华流行病学杂志

<p><b>OBJECTIVE</b>To study the epidemiological characteristics and antibiotic resistance of Salmonella enterica serovar Pomona (S. Pomona).</p><p><b>METHODS</b>Antimicrobial susceptible testing (AST) and pulsed field gel electrophoresis (PFGE) methods were used to analyze on S. Pomona strains that were isolated from diarrhea cases through the diarrhea network monitoring program, environment and food samples in Shanghai as well as from reptiles in Guangxi Zhuang Autonomous Region.</p><p><b>RESULTS</b>4 553 clinic Salmonella (S.) strains were isolated from the Shanghai network laboratories from 2005 to 2012. The top 10 serotypes would include 20 serotypes all belonged to A-F groups, while S. Pomona was next to S. Wandsworth, according to the non- A-F groups. Young children seemed to be susceptible to S. Pomona, and might cause bloody stools and super-infection. The top 10 serotypes from 1 805 foodborne Salmonella strains were significantly more extensive than those from the human S. Pomona strains, followed by those rare serotypes which were mostly isolated from turtle, sea-shellfish and reptiles. Antibiotic resistance of S. Pomona strains from other sources were significantly more severe than those from human samples, and belonged to A and B clones by means of PFGE. Clone A strains were non-epidemic strains which showed multi-drug resistance (MDR) to antimicrobials. Clone B was the main epidemic-causing strain that not resistant to drugs, which consisting B- I from young-age-groups and B-II were from the seniors. B-I strains were homologous to those from shellfish, tortoises and lizards, while B-II strains only showing homology to those from shellfish. One S. Pomona strain-MDR, isolated from human was homologous to 8 antimicrobials.</p><p><b>CONCLUSION</b>S. Pomona was a quite common serotype among those rare serotypes, which showed higher pathogenicity to infants while genetic evolution might take place when comparing them with the strains isolated from the clinics in 2005. Surveillance programs should be intensified along with the early warnings systems on infections which were from seafood and reptiles.</p>

Development of a real time PCR assay for rapid detection of Vibrio parahaemolyticus from seafood

A real time PCR assay for the detection of Vibrio parahaemolyticus in seafood samples was developed using a novel specific target and a competitive internal amplification control (IAC). The specificity of this assay was evaluated using 390 bacterial strains including V. parahaemolyticus, and other strains belonging to Vibrio and non-Vibrio species. The real time PCR assay unambiguously distinguished V. parahaemolyticus with a detection sensitivity of 4.8 fg per PCR with purified genomic DNA or 1 CFU per reaction by counting V. parahaemolyticus colonies. The assays of avoiding interference demonstrated that, even in the presence of 2.1 μg genomic DNA or 10(7) CFU background bacteria, V. parahaemolyticus could still be accurately detected. In addition, the IAC was used to indicate false-negative results, and lower than 94 copies of IAC per reaction had no influence on the detection limit. Ninety-six seafood samples were tested, of which 58 (60.4%) were positive, including 3 false negative results. Consequently, the real time PCR assay is effective for the rapid detection of V. parahaemotyticus contaminants in seafood.

Screening of specific target sequences for the PCR detection of Staphylococcus aureus by automatic genomic comparison / 生物工程学报

The aim of this study was to establish a fast and accurate method for developing specific DNA sequences and PCR primers for the detection of Staphylococcus aureus. An automatic C++ program for genomic comparison was used to identify specific DNA sequences from the genome of S. aureus MRSA 252. Four primer pairs were obtained from 9 specific target sequences by comparison of 2656 coding sequences with our local genome database, and 2 pairs of primers were confirmed to be specific to S. aureus by PCR evaluation against 137 bacterial strains, including 11 species of Staphylococcus. Furthermore, the DNA detection sensitivity of primer SA3 was 13.7 fg/microL and the cell sensitivity for this primer was 9.25 x 10(2) CFU/mL. This method has overcome the limitations of specific target mining in conventional assays, and it could be easily and widely used for other foodborne pathogens.

Development of single base extension-tags microarray for the detection of food-borne pathogens / 生物工程学报

We developed single base extension-tags (SBE-tags) microarray to detect eight common food-borne pathogens, including Staphylococcus aureus, Vibrio parahaemolyticus, Listeria monocytogenes, Salmonella, Enterobacter sakazaki, Shigella, Escherichia coli O157:H7 and Campylobacter jejuni. With specific PCR primers identified and integrated for eight food-borne pathogens, target sequences were amplified and purified as template DNA of single base extension-tags reaction. The products were hybridized to microarrays and scanned for fluorescence intensity. The experiment showed a specific and simultaneous detection of eight food-borne pathogens. The system limits is 0.1 pg for a genomic DNA and 5x10(2) CFU/mL for Salmonella typhimurium cultures. The single base extension-tags assay can be used to detect food-borne pathogens rapidly and accurately with a high sensitivity, and provide an efficient way for diagnosis and control of disease caused by food-borne pathogens.