Intestinal colonization with ESBL-producing Klebsiella pneumoniae in healthy rural villager: A genomic surveillance study in China, 2015-2017.

Background: The worldwide emergence and diffusion of extended-spectrum ß-lactamase-K. pneumoniae (ESBL-KP) is of particular concern. Although ESBL-KP can inhabit the human gut asymptomatically, colonization with ESBL-KP is associated with an increased risk of ESBL-KP infection and mortality. In this study, we investigated the prevalence and characteristics of ESBL-KP in fecal samples from healthy persons in 12 villages in Shandong Province, China. Methods: Screening for ESBL-KP in fecal samples was performed by selective cultivation. The bacterial species were identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and 16S rDNA sequence analysis. Minimum inhibitory concentrations (MICs) of 16 antibiotics were determined by the agar dilution method. Plasmid replicons, antimicrobial resistance genes and Sequence types (STs) of the isolates were determined by whole-genome sequencing (WGS). Genetic relatedness of ESBL-KP isolates was determined by the single nucleotide polymorphisms (SNP). The S1 nuclease-pulsed-field gel electrophoresis (S1-PFGE) was used to characterize the plasmids carried by ESBL-KP isolates. Conjugation assays was used to verify the transferability of bla CTX - M. Results: ESBL-KP prevalence rates increased from 12.0% in 2015 to 27.5% in 2017. The experimental results showed that 97% of isolates had multi-drug resistance. Multiple ESBL resistance genotypes were commonly detected in the isolates. STs among the ESBL-KP isolates were diverse. All 69 bla CTX-M-3-positive isolates were located on plasmids, and these genes could be transferred with plasmids between different strains. Phylogenetic analysis showed the possibility of transmission among some isolates. Conclusion: This study obtained the drug resistance patterns, the drug resistance phenotype and molecular characteristics of fecal-derived ESBL-KP in rural communities in Shandong Province, China. We report a rapid increase in occurrence of ESBL-KP among fecal samples collected from healthy rural residents of Shandong Province from 2015 to 2017. The carriage rate of multidrug-resistant bacteria in healthy residents is increasing. Thus, a need for further monitoring and possible interventions of ESBL-KP in this region is warranted.

Prevalence and transmission of mobilized colistin resistance (mcr-1) gene positive Escherichia coli in healthy rural residents in Shandong province, China.

This study was conducted to explore the prevalence and transmission of mcr-1 Escherichia coli among healthy rural residents in Shandong, China, and to provide theoretical basis for the prevention and control of spread and treatment of multi-drug resistant Escherichia coli. A total of 218 healthy residents from 3 villages in Guan County, Shandong Province, China were included in this study, and their fecal samples were collected. Colistin-resistant Escherichia coli were selected, and their drug sensitivity and plasmids' transferability were measured. After analysis, some conclusions can be drawn. The colistin-resistant Escherichia coli, most strains of which are MDROs, is common and highly transmissible in healthy residents in rural areas in China. Interventions should be implemented to prevent the spread of colistin-resistant Escherichia coli through health education and tighter regulation of antibiotics.

Emergence of NDM-1- and CTX-M-3-Producing Raoultella ornithinolytica in Human Gut Microbiota.

Raoultella ornithinolytica is an opportunistic pathogen of the Enterobacteriaceae family and has been implicated in nosocomial infections in recent years. The aim of this study was to characterize a carbapenemase-producing R. ornithinolytica isolate and three extended-spectrum ß-lactamase (ESBL)-producing R. ornithinolytica isolates from stool samples of adults in a rural area of Shandong Province, China. The species were identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and 16S rDNA sequence analysis. Antimicrobial susceptibility test showed that all four isolates were multidrug-resistant (MDR). The whole genome sequence (WGS) of these isolates was determined using an Illumina HiSeq platform, which revealed MDR-related genes. The S1 nuclease-pulsed-field gel electrophoresis (S1-PFGE) was used to characterize the plasmids carried by the R. ornithinolytica isolates. The bla NDM-1 and bla CTX-M-3 genes were probed using Southern blotting, which confirmed the location of both genes on the same plasmid with molecular weight of 336.5-398.4 kb. The transferability of bla NDM-1 and bla CTX-M was also confirmed by conjugation assays. Finally, BLAST analysis of both genes showed that mobile genetic elements were associated with the spread of drug resistance genes. Taken together, we report the presence of conjugative bla NDM-1 and bla CTX-M plasmids in R. ornithinolytica isolates from healthy humans, which indicate the possibility of inter-species transfer of drug resistance genes. To the best of our knowledge, this is the first study to isolate and characterize carbapenemase-producing R. ornithinolytica and ESBL-producing R. ornithinolytica isolates from healthy human hosts.

Analysis of epidemiological characteristics of four natural-focal diseases in Shandong Province, China in 2009-2017: A descriptive analysis.

BACKGROUND: Natural-focal diseases are serious diseases that endanger human health. They threaten about 100 million people in Shandong Province, and cause illness in thousands of people each year. However, information on the epidemiological characteristics of natural-focal diseases in Shandong Province has been limited. The purpose of the study was to describe and analyze the epidemiological characteristics of natural-focal diseases in Shandong Province, 2009-2017. METHODS: We describe the incidence and distribution of four natural-focal diseases in Shandong Province using surveillance data from 2009-2017. RESULTS: From 2009-2017, 11123 cases of four natural-focal diseases including 257 deaths were reported in Shandong Province, China. The four natural-focal diseases were severe fever with thrombocytopenia syndrome (SFTS), human granulocytic anaplasmosis (HGA), typhus, and scrub typhus. The high-risk groups of the four diseases were farmers and the elderly. The incidence rate of scrub typhus was significantly higher in females. However, this difference was not seen in the other three diseases. The four diseases were mainly clustered in the middle-southern part of Shandong Province and the Shandong Peninsula. The annual incidence of SFTS and scrub typhus increased, typhus was relatively stable, and HGA declined. However, the range of SFTS expanded, while HGA shrunk, and typhus and scrub typhus were unchanged. The epidemic period of SFTS and HGA was from May to October, typhus was from October to November, and scrub typhus was from September to November. The fatality rates of SFTS, typhus, scrub typhus, and HGA were 9.19%, 0%, 0.01%, and 2.24%, respectively. CONCLUSIONS: Our study described and analyzed the prevalence of natural-focal diseases in Shandong Province, and confirmed that age was closely related to the SFTS fatality rate. This study may help to improve the understanding of the prevalence of natural-focal diseases in Shandong Province in recent years and to better develop accurate prevention and control strategies for natural-focal diseases.

Characterization of extended-spectrum ß-lactamase-producing Escherichia coli harboring mcr-1 and toxin genes from human fecal samples from China.

AIM: To characterize extended-spectrum ß-lactamase-producing Escherichia coli harboring the colistin resistance gene mcr-1 from human fecal samples collected in 2012 in a rural area of Shandong province, PR China. MATERIALS & METHODS: Whole-genome sequencing and antimicrobial susceptibility testing was performed on 25 mcr-1-positive isolates to determine carriage of antibiotic resistance and virulence genes, diversity and antibiotic resistance profiles. RESULTS: The isolates were highly genetically diverse and carried a large variety of different antibiotic resistance genes. The multidrug-resistance rate was high (96%). Virulence genes associated with intestinal pathogenic E. coli were carried by 32% of the isolates. CONCLUSION: Further monitoring of the epidemiological situation is necessary to ensure a preparedness for potential emergence of novel, difficult-to-treat strains and awareness of available treatment options.

[Breakfast practice of students in four cities in China].

In order to investigate the breakfast practice of Chinese students in four cities, and to provide scientific basis for developing School Breakfast Program, self-administrated questionnaire is administrated among 7,617 elementary and junior students in Guangzhou, Shanghai, Jinan and Haerbin. The results showed that 18.9% junior students and 16.6% elementary students did not have breakfast everyday and, the nutrition of their breakfasts is inadequate. It is suggested that further recognition should be given to the improvement of the breakfast of the students.