Rapid and extensive SARS-CoV-2 Omicron variant infection wave revealed by wastewater surveillance in Shenzhen following the lifting of a strict COVID-19 strategy.

Wastewater-based epidemiology (WBE) has emerged as a promising tool for monitoring the spread of COVID-19, as SARS-CoV-2 can be shed in the faeces of infected individuals, even in the absence of symptoms. This study aimed to optimize a prediction model for estimating COVID-19 infection rates based on SARS-CoV-2 RNA concentrations in wastewater, and reveal the infection trends and variant diversification in Shenzhen, China following the lifting of a strict COVID-19 strategy. Faecal samples (n = 4337) from 1204 SARS-CoV-2 infected individuals hospitalized in a designated hospital were analysed to obtain Omicron variant-specific faecal shedding dynamics.

[Genetic characterization and drug resistance analysis of Salmonella Kentucky ST314 in Shenzhen in 2010-2021].

Objective: To understand the prevalence, genetic characteristics and drug resistance features of Salmonella Kentucky ST314 in Shenzhen.

Methods: Whole genome sequencing of 14 strains of Salmonella Kentucky ST314 collected from 2010-2021 by the Foodborne Disease Surveillance Network of Shenzhen Center for Disease Control and Prevention for phylogenetic evolutionary analysis, drug resistance gene and plasmid detection; drug susceptibility experiments were performed by micro-broth dilution method.

Results: A total of 57 strains of Salmonella Kentucky were collected from the foodborne disease surveillance network, 14 of which were ST314.

Pathogenetic detection, retrospective and pathogenicity analysis of a fatal case of Vibrio vulnificus in Shenzhen, China.

We report a 36-year-old male patient died of V. vulnificus-induced septicaemia and multiple organ failure syndrome after oyster consumption at a restaurant. We isolated and identified V.

Emergence of chromosomally located bla and qnrS1 in Salmonella enterica serotype Kentucky ST198 in China.

Highly fluoroquinolone-resistant Salmonella enterica serotype Kentucky has become widespread in recent years, largely associated with the spread of sequence type 198 (ST198), which often leads to multidrug resistance. Research on the genomic epidemiology of Salmonella Kentucky in China is currently uncommon. In this study, we analysed the genomic epidemiology and antimicrobial resistance characteristics of Salmonella Kentucky ST198 collected from foodborne disease surveillance in Shenzhen, China, during 2010-2021, using whole-genome sequencing and antibiotic susceptibility testing.

Epidemiological and genomic analyses of human isolates of between 2005 and 2021 in Shenzhen, China.

() is an important food-borne zoonotic pathogen that causes swine streptococcosis, which threatens human health and brings economic loss to the swine industry. Three-quarters of human infections are caused by serotype 2. A retrospective analysis of human cases in Shenzhen, a megacity in China, with high pork consumption, between 2005 and 2021 was conducted to understand its genomic epidemiology, pathogen virulence, and drug resistance characteristics.

Population dynamics and antimicrobial resistance of Derby ST40 from Shenzhen, China.

subsp. serovar Derby ( Derby) is one of the most common serotypes responsible for salmonellosis in humans and animals. The two main sequence types (ST) observed in China are ST40 and ST71, with ST40 presently being the most common in Shenzhen.

Outbreak dynamics of foodborne pathogen Vibrio parahaemolyticus over a seventeen year period implies hidden reservoirs.

Controlling foodborne diseases requires robust outbreak detection and a comprehensive understanding of outbreak dynamics. Here, by integrating large-scale phylogenomic analysis of 3,642 isolates and epidemiological data, we performed 'data-driven' outbreak detection and described the long-term outbreak dynamics of the leading seafood-associated pathogen, Vibrio parahaemolyticus, in Shenzhen, China, over a 17-year period. Contradictory to the widely accepted notion that sporadic patients and independent point-source outbreaks dominated foodborne infections, we found that 71% of isolates from patients grouped into within-1-month clusters that differed by ≤6 single nucleotide polymorphisms, indicating putative outbreaks.

A Novel Molecular Method for Simultaneous Identification of 57 K-Serogroups Using Probe Melting Curve Analysis.

The serotyping of , which is crucial to the surveillance and detection of outbreaks of vibriosis infection, has been widely used in many countries. In this study, we developed a molecular assay, named multiplex ligation reaction based on probe melting curve analysis (MLMA), for simultaneous identification of 57 K-serogroups. Based on the previous genomes of 418 strains including 39 K-serogroups and the 18 K-serogroups sequences from public databases, we obtained 57 K-serogroups specific gene sequences for designing primers and probes.

Integrated Whole-Genome Sequencing Infrastructure for Outbreak Detection and Source Tracing of Serotype Enteritidis.

As an important foodborne pathogen, serotype Enteritidis is recognized as one of the most common causes of human salmonellosis globally. Outbreak detection for this highly homogenous serotype, however, has remained challenging. Rapid advances in sequencing technologies have presented whole-genome sequencing (WGS) as a significant advancement for source tracing and molecular typing of foodborne pathogens.

[Rapid identification of 15 common S. enterica Salmonella serovars by multiplex real-time PCR].

Objective: Multiplex real-time PCR for the identification of 15 Salmonella serovars was developed.

Methods: Through the Salmonella genome comparison, 12 membrane proteins STM4497 gene can be used to identify 15 Salmonella serovars, and these 12 genes were respectively listed as A-L genes. Then primers were designed according to A-L gene conserved sequences, and then multiplex real-time PCR was established assessed with the evaluation of the limit detection, sensitivity, specificity, and repeatability.

Synthesis of FePcS-PMA-LDH Cointercalation Composite with Enhanced Visible Light Photo-Fenton Catalytic Activity for BPA Degradation at Circumneutral pH.

(1) Background: Iron tetrasulfophthalocyanine with a large nonlinear optical coefficient, good stability, and high catalytic activity has aroused the attention of researchers in the field of photo-Fenton reaction. Further improvement of the visible light photo-Fenton catalytic activity under circumneutral pH conditions for their practical application is still of great importance. (2) Methods: In this paper, iron tetrasulfophthalocyanine (FePcS) and phosphomolybdic acid (PMA) cointercalated layered double hydroxides (LDH) were synthesized by the ion-exchange method.

Quantitative detection of gold nanoparticles in soil and sediment.

Ever-growing application of engineering nanoparticles in many sectors of the society requires efficient methods to extract them from soil and sediment, for the sake of environmental protection. In this study, we develop a new method which uses sodium pyrophosphate solution (TSPP, NaPO) as extratant to extract gold nanoparticle (AuNPs) from soil and sediment under optimized parameters through vortexing, water bath oscillation, ultrasonic bath and precipitation. SP-ICP-MS was used for the detection of number concentration, mass concentration and size distribution of AuNPs in soil.

Whole-Genome Analysis of Salmonella enterica Serovar Enteritidis Isolates in Outbreak Linked to Online Food Delivery, Shenzhen, China, 2018.

In July 2018, an outbreak of 10 cases of Salmonella enterica serovar Enteritidis infection occurred in Shenzhen, China. Outbreak investigation complemented by whole-genome sequencing traced the source to food ordered online. Our investigation highlights the role of online food delivery platforms as a new mode of foodborne disease transmission.

Characterization of a Novel Diarrheagenic Strain of Associated With Food Poisoning in China.

is commonly considered to be an opportunistic pathogen causing urinary tract infections (UTIs) in humans. However, some strains of were found to be associated with food poisoning outbreaks, with the pathogenic mechanism still unclear. In our study, we described a novel strain of C02011 isolated from patients' specimens in a food poisoning in China.

Multiplex ligation reaction based on probe melting curve analysis: a pragmatic approach for the identification of 30 common Salmonella serovars.

Background: While Salmonella serotyping is of paramount importance for the disease intervention of salmonellosis, a fast and easy-to-operate molecular serotyping solution remains elusive. We have developed a multiplex ligation reaction based on probe melting curve analysis (MLMA) for the identification of 30 common Salmonella serovars.

Methods: Serovar-specific primers and probes were designed based on a comparison of gene targets (wzx and wzy encoding for somatic antigen biosynthesis; fliC and fljB for flagellar antigens) from 5868 Salmonella genomes.

Simultaneous Identification of Clinically Common Serotypes Using Probe Melting Curve Analysis.

The dynamic nature of epidemiology has presented a unique challenge for disease intervention strategies. Despite the continued rise of disease incidence and outbreaks of vibriosis, as well as the global emergence of pandemic clones and serovariants with enhanced virulence, there is a paucity of molecular methods for the serotyping of strains to improve disease surveillance and outbreak investigations. We describe the development of a multiplex ligation reaction based on probe melting curve analysis (MLMA) for the simultaneous identification of 11 clinically most common serotypes spanning a 10-year period.

Variation in rhizosphere microbiota correlates with edaphic factor in an abandoned antimony tailing dump.

The distribution pattern of root-associated bacteria in native plant growth in tailing dumps with extreme conditions remains poorly understood and largely unexplored. Herein we chose a native plant, Bidens bipinnata, growing on both an Sb tailing dump (WKA) and adjacent normal soils (WKC) to in-depth understand the distribution pattern of root-associated bacteria and their responses on environmental factors. We found that the rhizosphere microbial diversity indices in the tailing dump were significantly different from that in the adjacent soil, and that such variation was significantly related with soil nutrients (TC, TOC, TN) and metal(loid) concentrations (Sb and As).

Clonal Expansion of Biofilm-Forming Typhimurium ST34 with Multidrug-Resistance Phenotype in the Southern Coastal Region of China.

To disclose the antibiotics susceptibility and wide adaptability of commonly occurring genotypes of Typhimurium, the antibiotic resistance and biofilm formation of different multi-locus sequence typing (MLST) types of a collection of 240 . Typhimurium isolates (33 food and 207 clinical ones) during 2010-2014 in Shenzhen were analyzed. Among these strains, 167 was ST34 (69.

Simultaneous Identification of Ten Bacterial Pathogens Using the Multiplex Ligation Reaction Based on the Probe Melting Curve Analysis.

Pathogenic Vibrio spp., Aeromonas spp. and Plesiomonas shigelloides are associated with human gastroenteritis and wound infections, as well as fish diseases.

Phenotypic and Genotypic Characterization of Clinical Enterotoxigenic Escherichia coli Isolates from Shenzhen, China.

Background: Enterotoxigenic Escherichia coli (ETEC) is one of the major causes of infectious diarrhea in developing countries. This study aimed to characterize the prevalence and phenotypic and genotypic features of ETEC isolates from Shenzhen, China.

Methods: ETEC isolates were obtained from acute diarrheal patients and evaluated for enterotoxin, classical colonization factors (CFs), serotypes, antimicrobial susceptibility, and multilocus sequencing typing (MLST).

Feasibility of Using Multiple-Locus Variable-Number Tandem-Repeat Analysis for Epidemiology Study of Vibrio parahaemolyticus Infections.

Vibrio parahaemolyticus causes foodborne gastroenteritis, which is often associated with the consumption of raw or undercooked shellfish. Molecular typing can provide critical information for detecting outbreaks and for source attribution. In this study, we describe the development and evaluation of an optimized multiple-locus variable-number tandem-repeat (VNTR) analysis (MLVA) for the characterization of V.

Comparative Screening of Digestion Tract Toxic Genes in Proteus mirabilis.

Proteus mirabilis is a common urinary tract pathogen, and may induce various inflammation symptoms. Its notorious ability to resist multiple antibiotics and to form urinary tract stones makes its treatment a long and painful process, which is further challenged by the frequent horizontal gene transferring events in P. mirabilis genomes.

The evaluation and application of multilocus variable number tandem repeat analysis (MLVA) for the molecular epidemiological study of Salmonella enterica subsp. enterica serovar Enteritidis infection.

Background: Salmonella enterica subsp. enterica serovar Enteritidis (S. Enteritidis) is one of the most prevalent Salmonella serotypes that cause gastroenteritis worldwide and the most prevalent serotype causing Salmonella infections in China.

[Epidemiologic and etiologic characteristics of diarrheagenic Escherichia coli infection in population in Shenzhen].

Objective: To understand the epidemiologic and etiologic characteristics of diarrheagenic Escherichia (E.) coli infections in Shenzhen.

Methods: Stool samples were collected from acute diarrheal patients in four sentinel hospitals in Shenzhen and diarrheagenic E.

Risk Factors for Vibrio parahaemolyticus Infection in a Southern Coastal Region of China.

Objectives: The objectives of the study were to identify dietary and medical risk factors for Vibrio parahaemolyticus (VP) infection in the coastal city Shenzhen in China.

Methods: In April-October 2012, we conducted a case-control study in two hospitals in Shenzhen, China. Laboratory-confirmed VP cases (N = 83) were matched on age, sex, and other social factors to healthy controls (N = 249).