The ecological balance of intestinal microbiota plays an important role in digestion,absorp-tion,metabolism,immunity and protection against pathogens.Intestinal microbiota can not only regulate the innate immunity of the body,but also can stimulate the immune response by the bacteria itself and its metabo-lites.The imbalance intestinal microbiota may lead to abnormal immune mechanism,and then participate in the occurrence and development of the tumor,especially colorectal cancer.

Objective To explore the spatial distribution and spatial clustering of brucellosis in Zibo,2013-2015.Methods Spatial autocorrelation analysis was used to analyze the surveillance data of brucellosis at town level.Township as a spatial analysis unit,spatial distribution of brucellosis in small scale in Zibo City was analyzed.Results The global Moran's I indexes of brucellosis were not significantly different in 2013-2015.According to local Moran's Ⅰ statistic,the high-high regions were Xindian Street and Jiangjunlu Street in 2013.The high-high regions were Tangfang Town,Jinshan Town,Luocun Town,Zhaili Town,Xihe Town and Longquan Town in 2014.The high-high region was Wangcun Town in 2015.Condusions Our study has showed that the spatial distribution of brucellosis is local clustered in Zibo.The detection of hotspots could provide guidance for formulating regional prevention and control strategies.

Objective: To determine the serotypes and drug resistance profiles of Shiga toxin-producing Escherichia coli (STEC) in animal stools from the Weishan area in Shandong Province, China. To provide the basis for further study. Methods: Five hundred animal stool samples (from pigs, cattle, sheep, dogs and birds) were collected from the Weishan area and STEC strains were isolated from these samples. Strains were serotyped by a serum agglutination test, and their drug resistance profiles were determined through antimicrobial sensitivity experiments. In this study, PCR was used to detect tetracycline resistance genes (tetA, tetB, tetC, tetD) and beta-lactam resistance genes (blaSHV-1, blaCTX-M, blaTEM). Results: Sixteen strains of STEC were isolated from animal stool samples. Thirteen strains were isolated from pig stool samples, two from bovine stool samples and one from a sheep stool sample. Two of the strains were identified as E. coli O157:H7, and other 14 strains were non-O157 STEC of different serotypes. Antimicrobial sensitivity experiments showed that 15 of the strains were multidrug resistant. The rates of resistance were as follows: nalidixic acid (12/16 strains), sulfisoxazole (11/16), trimethoprim and sulphame-thoxazole (11/16), doxycycline (9/16), azithromycin (9/16), tetracycline (9/16), chloramphenicol (8/16) and streptomycin (8/16). Therefore, nalidixic acid showed the highest rate of resistance among the strains, followed by trimethoprim and sulphame-thoxazole, and sulfisoxazole. Resistance to cefepime or imipenem was not detected. In total, three types of drug resistance genes (tetA, tetB and tetC) were detected among the 16 strains. Conclusion The results showed that STEC strains isolated from animals in the Weishan area were of a range of serotypes. The 16 strains of STEC isolated from animal stools in this area were resistant to a number of antibiotics, with many strains displaying multidrug resistance.

Objective To study the molecular-biologic characteristics and epidemiological status of iatrogenic related Community-acquired methicillin-resistant Staphylococcus (S.) aureus (CA-MRSA) in China through Meta-analysis.Methods Data through systematic searching for peer-reviewed articles published before December 3rd,2015 from 4 main electronic databases including China National Knowledge Infrastructure (CNKI),Wanfang Data,PubMed and Web of Science Core Collection was collected,for this Meta-analysis.PRISMA guidelines were followed and the proportion of MRSA,CA-MRSA,hospital-acquired MRSA (HA-MRSA) and panton-valentine leucocidin (PVL) gene in certain populations were quantitatively analyzed by Stata 13.0 software.Results Average proportion of CA-MRSA from S.aureus was 12％ (95％CI:8％-16％).CA-MRSA in MRSA was 18％ (95％CI:12％-24％).42.1％ (95％CI:20.4％-63.7％) of the CA-MRSA carried a PVL gene,and the number was higher than general MRSA (t =-2.99,P=0.011).Conclusion CA-MRSA was in lower proportion than HA-MRSA,both seen in general MRSA and in S.aureu.s,but under higher proportion of carrying the PVL gene.Transmission of CA-MRSA could be prevented within the general population through conducting effective surveillances and preventive programs.

Objective: To determine the prevalence and antimicrobial susceptibility of Salmonella isolated from broiler production process in 4 provinces of China. Methods: Using convenience sampling method, 238 sample sites from broiler whole production process were chosen in Henan, Jiangsu, Heilongjiang and Shandong provinces in 2012. A total of 11 592 samples were collected and detected to analyze prevalence baseline, including 2 090 samples from breeding chicken farms and hatcheries, 1 421 samples from broiler farms, 5 610 samples from slaughterhouses and 2 471 samples from distribution and retail stores. All Salmonella strains were isolated through selective enrichment, and were serotyped according to Kauffmann-White scheme. The antimicrobial susceptibilities of selected Salmonella strains were determined by the broth microdilution method and fourteen antimicrobial agents were examined. Results: During incubation course, the average prevalence of Salmonella was 5.5% in feces of breeding hens, feces of chicks, and hatching eggs, 123 Salmonella strains were isolated. During cultivation course, the prevalence of Salmonella was 8.0% in feces from broiler farms, soil, feed, and workers, 114 Salmonella strains were isolated. During slaughter course, the prevalence of Salmonella was 24.9% in swabs pre-slaughter, dressed broiler carcasses, pre-cooled broiler carcasses, water from precooling pool, cutter and chipping boards, frozen chicken portions, and workers, 1 438 Salmonella strains were isolated. During distribution and sale course, the prevalence of Salmonella was 20.9% in transport carts, frozen chicken portions, retail chicken portions and workers, 551 Salmonella strains were isolated. The dominant Salmonella serotypes were Salmonella Enteritidis (n=1 229) and Salmonella Indiana (n=621). Among 1 231 examined strains, 97.2% Salmonella isolates were resistant to at least one antimicrobial, 69.9% Salmonella strains were multi-drug resistant isolates. Conclusion Our findings indicated that Salmonella contamination was common and serious in commercial broiler whole production process in China, especially in the course of defeathering, precooling and selling. The environment of broiler farm is the important source of Salmonella contamination. Additionally, antibiotic resistance of Salmonella was serious for common antimicrobials and multi-drug resistant strains existed widespread, which can pose potential risk on public health and clinical therapy.

Objective To discuss the spatial-temporal distribution and epidemic trends of autumn-winter type scrub typhus in Shandong province,and provide scientific evidence for further study for the prevention and control of the disease.Methods The scrub typhus surveillance data during 2006-2014 were collected from Shandong Disease Reporting Information System.The data was analyzed by using software ArcGIS 9.3 (ESRI Inc.,Redlands,CA,USA),GeoDa 0.9.5-i and SatScan 9.1.1.The Moran' s I,log-likelihood ratio (LLR),relative risk (RR) were calculated and the incidence choropleth maps,local indicators of spatial autocorrelation cluster maps and space scaning cluster maps were drawn.Results A total of 4 453 scrub typhus cases were reported during 2006-2014,and the annual incidence increased with year.Among the 17 prefectures (municipality) in Shandong,13 were affected by scrub typhus.The global Moran' s I index was 0.501 5 (P＜0.01).The differences in local Moran' s I index among 16 prefectures were significant (P＜0.01).The "high-high" clustering areas were mainly Wulian county,Lanshan district and Juxian county of Rizhao,Xintai county of Tai' an,Gangcheng and Laicheng districts of Laiwu,Yiyuan county of Zibo and Mengyin county of Linyi.Spatial scan analysis showed that an eastward moving trend of high-risk clusters and two new high-risk clusters were found in Zaozhuang in 2014.The centers of the most likely clusters were in the south central mountainous areas during 2006-2010 and in 2012,eastem hilly areas in 2011,2013 and 2014,and the size of the clusters expanded in 2008,2011,2013 and 2014.One spatial-temporal cluster was detected from October 1,2014 to November 30,2014,the center of the cluster was in Rizhao and the radius was 222.34 kilometers.Conclusion A positive spatial correlation and spatial agglomerations were found in the distribution of autumn-winter type scrub typhus in Shandong.Since 2006,the epidemic area of the disease has expanded and the number of high-risk areas has increased.Moreover,the eastward moving and periodically expanding trends of high-risk clusters were detected.

Objective:To investigate the isolation rate, antimicrobial resistance phenotype, and molecular type characteristics of Klebsiella pneumoniae from infectious diarrhea outpatients in Tai’an. Methods:A total of 866 stool samples were collected from infectious diarrhea cases in sentinel hospitals in 6 counties of Tai’an from 2013 to 2017. The strains were isolated from stool samples of the cases and identified by biochemical test. Micro broth dilution method was used to detect the drug resistance of the strains. The molecular typing was conducted by using pulsed field gel electrophoresis (PFGE).Results:The detection rate of Klebsiella pneumoniae in the stool samples was 7.97 % (69/866), with significant differences among the 6 counties ( χ2=39.627, P=0.000). Sixty- eight out of the 69 strains were resistant to 15 antibiotics with resistance rate 98.55 %(68/69). The resistance to ampicillin (AMP) was highest (84.06 %) (58/69), followed by sulfamethoxazole (SOX) (72.46 %)(50/69). There were 40 drug resistance profiles, and the predominant resistance profile was AMP-SOX detected ( n=10). The multi-drug resistant (MDR) strains accounted for 33.33 % (23/69). The 69 strains could be divided into 65 PFGE patterns, and no predominant PFGE pattern or cluster was observed. Conclusions:Klebsiella pneumoniae was detected in the stool samples of diarrhea- syndrome outpatients, indicating the risk for community-acquired infection; the strains were resistant to multiplex antibiotics, with wide drug-resistance profiles and high multi-drug resistance rates. The PFGE patterns were diverse, which showed no correlation with drug resistance profiles. Our study indicated that it necessary to strengthen the surveillance and detection of Klebsiella pneumoniae from diarrhea outpatients, which could facilitate the prevention of the emergence and spread of drug resistance strains and the protection of susceptible population.

OBJECTIVETo investigate the molecular epidemiological characteristics and antibiotic resistance profiles of Vibrio cholerae O139 in Shandong province.

METHODSA total of 13 strains of V. cholerae O139 (9 clinical strains and 4 environmental strains) isolated from cholera epidemics in Shandong province since 1997 were recovered and confirmed with serum agglutination and biochemical reaction. Pulsed-field gel electrophoresis (PFGE) was carried out for molecular subtyping. Virulence genes and drug resistance related genes were detected by PCR. Antibiotic susceptibility tests were performed using micro-broth dilution method.

RESULTSThirteen strains of V. cholerae O139 were differentiated into seven pulsetypes. One clinical strain and two environmental strains isolated from Jining in 2013 were clustered into the pulsetype namely KZGN11O139. CN0077, and an identical PFGE pattern of KZGN11O139. CN0002 was found among three clinical strains from Jinan in 2005, Jining in 2005 and Heze in 2009. Other pulsotypes were unique in China and found only in Shandong province. Because of deletion of ctxAB and tcpI, the PFGE patterns of two strains isolated from Yantai in 2000 and 2004 were different from other 11 strains which harbored ctxAB, tcpA, tcpI, rtxA, hlyA and toxR. All strains contained one or more drug resistance related genes such as intI 1, intI 4 and sxt, and were resistant to two kinds of antibiotics at least. Among the 12 kinds of antibiotics, the resistant ratioes to kamamycin, trimethoprim-sulfamethoxazole, ampicillin and gentamicin were 11/13, 9/13, 7/13 and 7/13, respectively.

CONCLUSIONMolecular subtyping indicates possible epidemiological links among V.cholerae O139 in Shandong province, and almost all strains were toxigenic and drug resistant.

China ; Cholera ; Cholera Toxin ; Drug Resistance, Bacterial ; Electrophoresis, Gel, Pulsed-Field ; Epidemics ; Humans ; Molecular Epidemiology ; Polymerase Chain Reaction ; Vibrio cholerae O139 ; Virulence

Objective: To understand the infection status, characteristics and drug resistance of non-O157 Shiga toxin-producing E. coli (STEC) in animal feces in Shandong Province. Methods: From 2015 to 2016, convient sampling method was used to collect 1 022 fresh feces of animals in Weishan county and Laizhou city, and 24 non-O157 STEC were isolated. The serotypes of non-O157 STEC strains were confirmed through serum agglutination test. The susceptibility was explored through the antimicrobial sensitivity experiments. ESBLs activity was confirmed by double-disc diffusion. PCR method was used to detect the resistance genes. PFGE typing was operated to assess the relatedness and variability of the strains. The multi-locus sequence typing (MLST) was adopted to get the allelic profile and ST sequence of strains. Analysis was made on the evolutionary relationship between different ST groups was made through CLC Sequence Viewer and Counting Express. Results: A total of 24 non-O157 STEC were isolated from animal feces. 23 strains were from pig feces, and 1 strain was from cow feces, and the serotypes were more dispersed. All of the 24 strains carried stx2 genes. The highest resistance rate was sulfamethoxazole(22 strains), the mount of cotrimoxazole and nalidixic acid was 18 strains, chloramphenicol was 13 strains, tetracycline was 19, and there was a phenomenon of multiple drug resistance. The drug resistance spectrum was sulfamethoxazole tetracycline-compound novammin-naphthidine-chloramphenicol. All strains were sensitive to cefepime and imipenem. The ESBLs confirmatory test showed that 4 strains of non O157 STEC produced beta lactamase. PCR detected 7 resistance genes, and 4 tetracycline resistance genes (Tet A, Tet B, tetC and tetD) were detected. The beta lactamase resistance genes (blaSHV-1, bla CTX-M, bla TEM) were all negative. 24 strains were divided into 15 PFGE types, and their clustering results were more dispersed and no dominant PFGE type. There were 11 kinds of MLST types, most of them are ST540 and ST5133 types, each of which was 4 strains, and clustered into 1 MLST genomes. Conclusion The serotypes of non-O157 STEC in animal feces O157 STEC were dispersed, and the resistant rate to common antibiotic was high. MLST typing results presents obvious polymorphism. Surveillance and manage ment of these strains should be strengthened.

Objective To explore the spatial and temporal characteristics of human brucellosis in Shandong province and to provide scientific basis for the development of related regional public health strategies.Methods 1 802 diagnosed cases of human brucellosis patients were selected based on the data that was collected by Diseases Reporting Information System between year 2004 and 2012 in Shandong province.Methods on spatial thematic mapping,spatial autocorrelation analysis,spatial clustering analysis,and temporal clustering analysis were applied to describe the temporal and spatial distribution on human brucellosis cases.Results The incidence rate of human brucellosis increased from 0.038 2/100 000 (35 cases) to 0.620 5/100 000 (598 cases),with annual average incidence rate as 0.211 1/100 000 and the incidence was evidently increased.The value of M (0.375 3) showed that this disease was seasonal,with the epidemic months between March and June,accounting for 56.27％ (1 014/1 802).The Global Moran' s I index was 0.198 901 (P=0.000 120),showing that there was a positive correlation between space and the incidence of brucellosis.The incidence rates in 2006,2007,2009 and 2012 and the space distribution appeared a positive correlation (P＜0.05) in Shandong province.The local Moran's I index showed that there were 8 “High-High” (HH) clustering areas,which were proved to have statistical significance (P＜0.05).Local indicators of spatial association (LISA) revealed that southwest and north districts of Shandong were highly clustered districts of brucellosis and the areas paralleled to the areas that having higher incidence rates.There were two spatial clustering areas in this study,one as the center of Juanchen with radiation radius at 33.83 km whose RR was 9.78 (P＜0.05) and the other was the center of Binchen with radiation radius at 62.78 km with RR as 4.99 (P＜0.05).All the 8 HH counties (districts) were included in the two cluster regions.Conclusion Incidence of human brucellosis showed an obvious increase in Shandong during year 2004-2012.Months with epidemics were between March and June.The incidence of brucellosis in counties (districts) was non-randomly distributed.A positive spatial correlation and the feature of clusters was noticed.