[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.

[Analysis on the infection source of the first local cluster epidemic caused by the VOC/Gamma variant of SARS-CoV-2 in China].

Objective: To investigate a SARS-CoV-2 epidemic reported in Rongcheng City, Weihai, Shandong Province. Methods: The SARS-CoV-2 nucleic acid positive patients and their close contacts were investigated, and the whole genome sequencing and genetic evolution analysis of 9 variant viruses were carried out. An infection source investigation and analysis were carried out from two sources of home and abroad, and three aspects of human, material and environment. Results: A total of 15 asymptomatic infections were reported in this epidemic, including 13 cases as employees of workshop of aquatic products processing company, with an infection rate of 21.67% (13/60). Two cases were infected people's neighbors in the same village (conjugal relation). The first six positive persons were processing workers engaged in the first process of removing squid viscera in the workshop of the company. The nucleic acid Ct value of the first time were concentrated between 15 and 29, suggesting that the virus load was high, which was suspected to be caused by one-time homologous exposure. The whole genome sequence of 9 SARS-CoV-2 strains was highly homologous, belonging to VOC/Gamma (Lineage P.1.15). No highly homologous sequences were found from previous native and imported cases in China. It was highly homologous with the six virus sequences sampled from May 5 to 26, 2021 uploaded by Chile. The infection source investigation showed that the company had used the squid raw materials captured in the ocean near Chile and Argentina from May to June 2021 over the last 14 days. Many samples of raw materials, products and their outer packages in the inventory were tested positive for nucleic acid. Conclusion: This epidemic is the first local epidemic caused by the VOC/Gamma of SARS-CoV-2 in China. It is speculated that the VOC/Gamma, which was prevalent in South America from May to June 2021, could be imported into China through frozen squid.

[Analysis of the epidemiological characteristics and genetic characteristics of influenza in the surveillance-year of 2021 to 2022 in Shandong Province, China].

Objective: To analyze the epidemiological characteristics, etiology and hemagglutinin (HA) gene characteristics of prevalent strains in Shandong Province from 2021 to 2022. Methods: The sentinel surveillance data of influenza-like illness (ILI) were collected in Shandong Province from 2021 to 2022. ILI specimens were detected with Real-Time PCR and virus isolation to explore the distribution of influenza viruses in different months. Three virus strains of each city were selected for gene sequencing, and the HA phylogenetic analysis was carried out. Results: In the surveillance-year from 2021 to 2022, 528 263 ILI cases were totally reported in 54 sentinel hospitals for influenza surveillance in Shandong Province. ILI visiting ratio (ILI%) was 4.07%, with the largest number in 0-4 age group (45.86%). The highly frequent season for ILI was in winter and spring, with a peak in the 52nd week, 2021 (6.62%). Totally, nucleic acid was detected in 26 754 specimens, with a positive rate of 27.10%, all of which were type B Victoria influenza. The positive rate reached a peak in the 49th week, 2021 (63.78%). A total of 295 outbreaks of ILI had been reported, in which 269 were positive for influenza virus. Most of outbreaks occurred in the primary school, with a peak in December. Gene evolution analysis showed that the HA gene in Shandong possessed high homology, 98.6% to 99.5%, with the recommended vaccine strains in 2020-2023, which was divided into two branches, V1A.3a.1 and V1A.3a.2. Conclusion: In the surveillance-year of 2021-2022, influenza is prevalent in December in Shandong Province, with a single circulating strain type. The positive rate of influenza virus and outbreak are higher than those in the previous surveillance-year. The circulating strain possesses high HA gene homology with those of the WHO vaccine recommended strains. However, the overall immune barrier of influenza virus is weak.

[Thoughts and suggestions on co-administration of seasonal influenza vaccine and COVID-19 vaccine].

In the context of the global pandemic of COVID-19, the epidemic intensity, epidemic characteristics and infection risk of influenza have presented new features. COVID-19 and influenza have simultaneously emerged in many regions of the world. COVID-19 and influenza are similar in terms of transmission mode, clinical symptoms and other aspects. There are also similarities in the mechanism of influenza virus and novel coronavirus on cells. At the same time, it is feasible and significant to do a good job in the prevention and control of COVID-19 and influenza. This paper discusses the relevant strategies and measures for the joint prevention and control of influenza and novel coronavirus from the aspects of influenza vaccination to prevent co-infection, simultaneous vaccination of influenza vaccine and novel coronavirus vaccine, etc., and puts forward corresponding thoughts and suggestions, in order to provide scientific support for the formulation of strategies on seasonal influenza vaccine and novel coronavirus vaccination.

[Molecular epidemiology of drug resistance genes and carbapenem resistance of Pseudomonas aeruginosa in rural well water].

Objective: To analyze molecular epidemiological characteristics of drug resistance genes and carbapenem resistance of Pseudomonas aeruginosa (PA) in rural well water. Methods: According to Citation of Natural Mineral Water Inspection (GB 8538-2016), a total of 112 well water samples were tested in Juye county of Shandong province, and PFGE and drug susceptibility test were conducted for the identified PA strains. After PCR identification of carbapenem resistance genes, S1-PFGE and Southern blotting were used to determine the location of drug resistance genes, and combined experiments were used to determine gene transferability. Results: The detection rate of PA in rural well water samples in Juye county of Shandong province was 54.46% (61/112). The 61 strains could be divided into 56 PFGE types. There were 2 strains with 100.00% consistent band types, and there was no obvious predominant band type. The results of drug susceptibility experiments showed that 93.44% (57/61) were multi-drug resistant strains, and there were 2 strains carrying blaVIM-2, both of which were located on the plasmid, and both of them were transferred horizontally with the plasmid. Conclusion: PA carrying carbapenem resistance genes was detected in well water of rural communities in Juye country, and there is the possibility of horizontal transmission of such resistance genes.

[Genomic investigation of human Streptococcus suis infection in Shandong Province].

To investigate Streptococcus suis (S.suis) isolated from patients in Shandong province using genomic epidemiology and pathogenologic analysis. To provide the foundation to establish reasonable and accurate prevention and control measures of human S. suis infection. Molecular typing, whole genome phylogenetic tree, virulence gene typing, antibiotic resistance profile and mobile genetic elements carrying antibiotic resistance genes of isolated S. suis strains were investigated. The pathogenicity of isolated strains was also evaluated by comparing their capacity to induce pro-inflammatory cytokine production in vitro. S. suis infections in Shandong province were predominantly due to serotype 2 and sequence type 1 strains. The major symptoms were meningitis. The studied strains could be divided into five lineages. All strains belong to highly pathogenic type in Shandong province,Strains from lineage 2 possessed higher capacity to stimulate pro-inflammatory cytokine production than other strains did, even though other strains belong to highly pathogenic strains. In addition, multiple antibiotic resistance genes and corresponding mobile genetic elements werewidespread in S. suis strains from Shandong province, except strains from lineage 3. High diversities in genome, evolutionary path and pathogenicity of S. suis strains from Shandong province were revealed. It was necessary to surveillant the S. suis strain in genomic level.

[Multi locus sequence typing and antibiotic susceptibility of extended-spectrum beta-lactamases producing Enterobacteriaceae in rural residents in villages with pig-breeding farms in Shandong province].

Objective: To analyze the antimicrobial resistance and multilocus sequence typing (MLST) results of extended-spectrum ß-lactamase (ESBLs)-producing Escherichia coli in rural residents in villages with pig breeding farms in a county of Shandong province. Methods: Antimicrobial susceptibility testing was performed with agar dilution method by using 360 ESBLs-producing E. coli strains from fresh stool samples of rural residents in villages with pig breeding farms in a county of Shandong. PCR was conducted to amplify the CTX-M, TEM, SHV genes and capillary electrophoresis was used to screen positive strains in July, 2016. MLST was performed for molecular typing analysis, and eBURST v3.0 software was used for cluster analysis. Results: Among 360 strains of ESBLs-producing E. coli, the resistance rates to cefotaxime, tetracycline, trimethoprim-sulfamethoxazole and florfenicol were 100.0% (360/360), 82.2% (296/360), 81.1% (292/360) and 80.3% (289/360), respectively. The positive rate of CTX-M gene was 99.2% (357/360), in which the positive rate of CTX-M-9 was 35.6% (128/360) and the positive rate of CTX-M-1 was 24.4% (88/360). The positive rate of TEM gene was 26.9% (97/360). A total of 132 STs were identified through MLST. The predominant ST was ST10, accounting for 12.5% (45/360). Cluster analysis showed that CC10 was the most important clone group, including 39 ST clones, involving 148 strains (41.1%). Conclusions: The drug resistances of ESBLs-producing E. coli to cefotaxime, tetracycline, trimethoprim-sulfamethoxazole and flurfenicol are serious in this rural area. There is a small-scale clustering of CC10 and transmission mode from animals to humans might exist.

[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.

[Human papillomavirus infection and vaccination].

Human papillomavirus (HPV) is an infection that can be sexually transmitted and result in health consequences. Persistent high-risk HPV infection can lead to various cancers and is the essential cause of cervical cancer. HPV vaccine can prevent the HPV infection and thus the incidence of cervical cancer. In this review we introduced the prevalence of HPV infection and vaccination, and the prevention and early detection of cervical cancer. We also introduced the present knowledge and awareness of HPV infection and HPV vaccine in Chinese. Propaganda all over China should be performed on HPV vaccination to improve the vaccination rate, thus preventing the incidence of cervical cancer.

[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.

[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.

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.

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%.