[Analysis of gene characteristics and core genome characteristics of carbapenem-resistant Enterobacter cloacae in rural residents of Weifang City, Shandong Province].

Objective: To investigate the drug-resistant gene characteristics and core genome characteristics of carbapenem-resistant Enterobacter cloacae (CR-ECL) in rural residents of Weifang City, Shandong Province. Methods: Fecal samples were collected from rural community residents in Weifang City, Shandong Province in 2017. Drug-resistant strains were screened using a carbapenem-resistant enterobacter chromogenic medium. CR-ECL positive strains were acquired via Matrix Assisted Laser Desorption Ionization Time of Flight Mass Spectrometry(MALDI-TOFMS) analysis. The antibiotic resistance phenotype of CR-ECL was determined using a microbroth dilution assay. Whole genome sequencing (WGS) and analysis were conducted, along with an examination of the immediate vicinity of the blaNDM gene and phylogenetic analysis of the strains. Results: A total of 628 fecal samples were collected and tested, of which 6 were CR-ECL positive (detection rate 0.96%), all exhibiting multiple drug resistance (MDR) phenotypes. Six CR-ECL strains had four MLST genotypes (ST), all of which carried multiple drug resistance genes (blaNDM-1, blaNDM-5, etc.) and virulence genes (acrA, acrB, entB, fepC, etc.). There were mobile genetic elements ISAba125, TN3-IS3000, TN3 and IS5 in the genetic environment surrounding the blaNDM gene. The phylogenetic tree showed that the multi-locus sequence typing of the core genome (cgMLST) was consistent with the single nucleotide polymorphism (SNPs) results. The cgMLST results showed that the allele differences between strains 2BC0101B and 2BC0251B, 2BG0561B and 2BI0221B were 2 and 1, respectively. The SNPs results showed that the above two pairs of bacteria also clustered together. It was found that the strains of chicken fecal samples in the National Center for Biotechnology Information (NCBI) database were located in the center of the evolutionary tree, and the local sequences could be traced back to American human sequences. Conclusion: Multidrug-resistant CR-ECL is detected in rural community residents in Weifang City, Shandong Province.

[Etiology and epidemiological characteristics of gastroenteritis virus in food-borne diarrhea from three cities in Shandong Province, 2017].

Objective: To analyze the etiology and epidemiological characteristics of gastroenteritis virus in foodborne diseases from three cities in Shandong. Methods: From January to December 2017, six sentinel hospitals in Jinan, Yantai and Linyi city of Shandong Province were selected as the research sites. Stool samples of 1 397 diarrhea patients were collected, as well as basic information and clinical symptoms. Duplex quantitative RT-PCR was used to detect Norovirus genogroupⅠ (Nov GⅠ) and genogroupⅡ (Nov GⅡ), Sapovirus (SAV) and Human astrovirus (HAstV), respectively, quantitative RT-PCR was used to detect group A Rotavirus (RVA), and quantitative PCR was used to detect Enteric adenovirus (EAdV). The specific gene of the virus were sequenced and typed. It was compared that the gastroenteritis virus rate in cases with different characteristics and the clinical symptoms difference between the virus positive and negative cases. Results: The median age (P(25), P(75)) was 23 (1, 42) , mainly male, 57.48% with 803 cased and children under 5 years old, 36.36% with 508 cases. The positive rate of gastroenteritis virus was 33.93% (474 cases), and that of Jinan, Linyi and Yantai City were 32.03% (147/459), 41.54% (189/455) and 28.57% (138/483), respectively (P<0.001). Nov GⅡ had the highest positive rate, 16.54% (231 cases), which, mainly GⅡ.P16/GⅡ.2 (48.28%, 56/116), peaked in May (24.75%, 50/202) and June (19.59%, 38/194). In patients of gastroenteritis virus positive, 44.51% (211/474) had vomiting symptoms, higher than that of patients of gastroenteritis virus negative (34.13%, 315/923). The difference was statistically significant (P<0.001). Conclusion: In Shandong Province, the majority of gastroenteritis patients were male and children under 5 years old. Nov GⅡ possessed highest epidemic intensity, and peaked in spring and summer. Viral gastroenteritis had atypical clinical symptoms.

[Prevalence and antimicrobial susceptibility of Salmonella isolated from broiler whole production process in four provinces of China].

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.

[Characteristics and drug resistance of non-O157 Shiga toxin-producing E. coli in animal feces, from Shandong Province].

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.

[Serotype identification and antibiotic susceptibility of Shiga toxin-producing Escherichia coli in the Weishan area in Shandong Province, China].

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.

Epidemic characteristics and spatio-temporal patterns of scrub typhus during 2006-2013 in Tai'an, Northern China.

Tai'an, a famous cultural tourist district, is a new endemic foci of scrub typhus in northern China. Frequent reports of travel-acquired cases and absence of effective vaccine indicated a significant health problem of scrub typhus in Tai'an. Thus, descriptive epidemiological methods and spatial-temporal scan statistics were used to describe the epidemic characteristics and detect the significant clusters of the high incidence of scrub typhus at the town level in Tai'an. Results of descriptive epidemiological analysis showed a total of 490 cases were reported in Tai'an with the annual average incidence ranging from 0·48 to 2·27/100 000 during 2006-2013. Females, the elderly and farmers are the high-risk groups. Monthly changes of scrub typhus cases indicated an obvious epidemic period in autumn. Spatial-temporal distribution analysis, showed significant clusters of high incidence mainly located in eastern and northern Tai'an. Our study suggests that more effective, targeted measures for local residents should be implemented in the eastern and northern areas of Tai'an in autumn. Meanwhile, it may prove beneficial for health policy makers to advise travellers to take preventive measures in order to minimize the risk of infection of scrub typhus in Tai'an.

[Detection rate, antimicrobial resistance and molecular types of Klebsiella pneumoniae from stool samples of outpatients with diarrhea-syndrome in Tai'an].

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 (χ(2)=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.

[Spatial analysis of autumn-winter type scrub typhus in Shandong province, 2006-2014].

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, eastern 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.

[Meta-analysis on epidemiology of iatrogenic-borne methicillin-resistant Staphylococcus aureus].

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 3(rd), 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. aureus, 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.

Time-series analysis on human brucellosis during 2004-2013 in Shandong Province, China.

Human brucellosis is a re-emerging bacterial anthropozoonotic disease, which remains a public health concern in China with the growing number of cases and more widespread natural foci. The purpose of this study was to short-term forecast the incidence of human brucellosis with a prediction model. We collected the annual and monthly laboratory data of confirmed cases from January 2004 to December 2013 in Shandong Diseases Reporting Information System (SDRIS). Autoregressive integrated moving average (ARIMA) model was fitted based on the monthly human brucellosis incidence from 2004 to 2013. Finally, monthly brucellosis incidences in 2014 were short-term forecasted by the obtained model. The incidence of brucellosis was increasing from 2004 to 2013. For the ARIMA (0, 2, 1) model, the white noise diagnostic check (x(2) = 5.58 P = 0.35) for residuals obtained was revealed by the optimum goodness-of-fit test. The monthly incidences that fitted by ARIMA (0, 2, 1) model were closely consistent with the real incidence from 2004 to 2013. And forecasting incidences from January 2014 to December 2014 were, respectively, 0.101, 0.118, 0.143, 0.166, 0.160, 0.172, 0.169, 0.133, 0.122, 0.105, 0.103 and 0.079 per100 000 population, with standard error 0.011-0.019 and mean absolute percentage error (MAPE) of 58.79%.

Expression and immunohistochemical localization of aquaporin-1 in male reproductive organs of the mouse.

Aquaporin-1 (AQP-1), a six-transmembrane domain protein, is found to be responsible for water transport. The purpose of this study was to investigate the expression of AQP-1 mRNA and protein in the testis, epididymis, vas deferens, ventral prostate, and seminal vesicle from mature mice by using reverse transcription polymerase chain reaction (RT-PCR) and Western blotting, and the cellular localization of AQP-1 by immunohistochemistry. RT-PCR revealed that AQP-1 mRNA was expressed in all organs we examined. Western blotting displayed a 29-kDa band and a 35- to 45-kDa band corresponding to non-glycosylated and/or glycosylated AQP-1 in those organs. The immunohistochemical evidence showed that AQP-1 was mainly located on the plasma membrane of epithelial cells of the rete testis, vas deferens, ventral prostate, seminal vesicle and the non-ciliated cells of the proximal and distal efferent ducts. However, AQP-1 was absent from spermatogenic cells lining the seminiferous epithelium and from the spermatozoa in the lumen of the distal efferent duct. These findings provide valuable information on the expression of AQP-1 in male reproductive organs and suggest that AQP-1 is involved in water transport to regulate water homeostasis in male reproductive physiology.