Background: Foodborne outbreaks caused by Campylobacter jejuni have become a significant public health problem worldwide. Applying genomic sequencing as a routine part of foodborne outbreak investigation remains in its infancy in China. We applied both traditional PFGE profiling and genomic investigation to understand the cause of a foodborne outbreak in Hangzhou in December 2018. Method: A total of 43 fecal samples, including 27 sick patients and 16 canteen employees from a high school in Hangzhou city in Zhejiang province, were recruited. Routine real-time fluorescent PCR assays were used for scanning the potential infectious agents, including viral pathogens (norovirus, rotavirus, adenovirus, and astrovirus), and bacterial pathogens (Salmonella, Shigella, Campylobacter jejuni, Vibrio parahaemolyticus and Vibrio cholerae). Bacterial selection medium was used to isolate and identify the positive bacteria identified by molecular test. Pulsed field gel electrophoresis (PFGE), and next generation sequencing (NGS) were applied to fifteen recovered C. jejuni isolates to further understand the case linkage of this particular outbreak. Additionally, we retrieved reference genomes from the NCBI database and performed a comparative genomics analysis with the examined genomes produced in this study. Results: The analyzed samples were found to be negative for the queried viruses. Additionally, Salmonella, Shigella, Vibrio parahaemolyticus and Vibrio cholera were not detected. Fifteen C. jejuni strains were identified by the real-time PCR assay and bacterial selection medium. These C. jejuni strains were classified into two genetic profiles defined by the PFGE. Out of fifteen C. jejuni strains, fourteen have a unified consistent genotype belonging to ST2988, and the other strain belongs to ST8149, with a 66.7% similarity in comparison with the rest of the strains. Moreover, all fifteen strains harbored bla_OXA-61 and tet(O), in addition to a chromosomal mutation in gyrA (T86I). The examined fourteen strains of ST2988 from CC354 clone group have very minimal genetic difference (3~66 SNPs), demonstrated by the phylogenomic investigation. Conclusion: Both genomic investigation and PFGE profiling confirmed that C. jejuni ST2988, a new derivative from CC354, was responsible for the foodborne outbreak Illustrated in this study.

Non-toxigenic Vibrio cholerae isolates have been found associated with diarrheal disease globally, however, the global picture of non-toxigenic infections is largely unknown. Among non-toxigenic V. cholerae, ctxAB negative, tcpA positive (CNTP) isolates have the highest risk of disease. From 2001 to 2012, 71 infectious diarrhea cases were reported in Hangzhou, China, caused by CNTP serogroup O1 isolates. We sequenced 119 V. cholerae genomes isolated from patients, carriers and the environment in Hangzhou between 2001 and 2012, and compared them with 850 publicly available global isolates. We found that CNTP isolates from Hangzhou belonged to two distinctive lineages, named L3b and L9. Both lineages caused disease over a long time period with usually mild or moderate clinical symptoms. Within Hangzhou, the spread route of the L3b lineage was apparently from rural to urban areas, with aquatic food products being the most likely medium. Both lineages had been previously reported as causing local endemic disease in Latin America, but here we show that global spread of them has occurred, with the most likely origin of L3b lineage being in Central Asia. The L3b lineage has spread to China on at least three occasions. Other spread events, including from China to Thailand and to Latin America were also observed. We fill the missing links in the global spread of the two non-toxigenic serogroup O1 V. cholerae lineages that can cause human infection. The results are important for the design of future disease control strategies: surveillance of V. cholerae should not be limited to ctxAB positive strains. Non-toxigenic Vibrio cholerae isolates are associated with diarrheal disease globally. Among them, ctxAB negative, tcpA positive (CNTP) isolates have the highest risk of disease because they may be able to colonize the human intestine. By population genomic analysis of 850 previously published genomes and 119 newly sequenced genomes in this study, we found that most of CNTP isolates can be attributed into two distinctive lineages, L3b and L9. Both lineages are not only circulating in local regions causing endemic disease, but have been spreading worldwide over the past 100 years. Central Asia is the most likely origin of the L3b lineage, and the strains spread to China on at least three occasions. The L3b strains were also exported from China to other parts of the world, and one of the migrations are related to the groups that circulated in Latin America. Within Hangzhou, a modernized city in China, aquatic food products are the most likely medium of CNTP strains, and a spread pattern from rural aquafarms to the urban areas was observed. This work filled the missing links in the global spread of two non-toxigenic serogroup O1 V. cholerae lineages that can cause human infection. The results suggest that in future disease control efforts, the sampling of V. cholerae should not be limited to the apparently toxic isolates, and that a more thorough and unbiased sampling framework is needed.

The fractal dimension of retinal arteries and veins is a measure of the complexity of the vascular tree. We hypothesized that retinal fractal dimension would be associated with brain volume and white matter integrity in HIV-infected women. Nested case-control within longitudinal cohort study. Women were recruited from the Brooklyn site of the Women’s Interagency HIV study (WIHS); 34 HIV-infected and 21 HIV-uninfected women with analyzable MRIs and retinal photographs were included. Fractal dimension was determined using the SIVA software program on skeletonized retinal images. The relationship between predictors (retinal vascular measures) and outcomes (quantitative MRI measures) were analyzed with linear regression models. All models included age, intracranial volume, and both arterial and venous fractal dimension. Some models were adjusted for blood pressure, race/ethnicity, and HIV-infection. The women were 45.6 ± 7.3 years of age. Higher arterial dimension was associated with larger cortical volumes, but higher venous dimension was associated with smaller cortical volumes. In fully adjusted models, venous dimension was significantly associated with fractional anisotropy (standardized β = -0.41, p = 0.009) and total gray matter volume (β = -0.24, p = 0.03), and arterial dimension with mean diffusivity (β = -0.33,.p = 0.04) and fractional anisotropy (β = 0.34, p = 0.03). HIV-infection was not associated with any retinal or MRI measure. Higher venous fractal dimension was associated with smaller cortical volumes and lower fractional anisotropy, whereas higher arterial fractal dimension was associated with the opposite patterns. Longitudinal studies are needed to validate this finding.

Introduction: With the large-scale use of antibiotics, the detection rate and mortality of carbapenem resistant Escherichia coli (CR-EC) have gradually increased. This study investigated the molecular characteristics and prevalence of CR-EC in order to supplement the isolated data of CR-EC in Hangzhou, China. Methodology: The minimal inhibitory concentration was determined by microbroth dilution method. The drug resistance genes were detected by polymerase chain reaction. The transferability of plasmid was verified by the conjugation test and genetic homology was detected by pulsed-field gel electrophoresis. The whole genome was sequenced (WGS) using the Illumina MiSeq technology. Results: A total of 8 non-duplicated CR-EC isolates were collected, and all exhibited a multidrug-resistant phenotype. Two different New Delhi metallo-β-lactamase (NDM) variants, blaNDM-5 and blaNDM-13, were found with detection rates of 62.5% and 12.5%, respectively. The success rate of conjugation was 100% (6/6). Homology analysis showed that there was no widespread cloning outbreak of CR-EC, and blaNDM-5-ST410 was prevalent in the local area as a dominant group. WGS also indicated the rate of occurrence of resistance genes carrying resistance for more types of antibiotics, as well as exposed potential virulence risks. Conclusions: This was a survey on the prevalence and molecular characteristics of CR-EC in Hangzhou. blaNDM-like production combined with extended spectrum beta-lactamase (ESBLs) and/or AmpC was the main resistance mechanism of CR-EC in this area. The dominant blaNDM-5-ST410 requires enhanced attention. The horizontal transformation of plasmids, complex drug resistance, and potential virulence risks also need close attention.