Enteroaggregative Escherichia aoliisolated from Chinese diarrhea patients with high-pathogenicity island of Yersinia'xs involved in synthesis of siderophore yersiniabactin

AIM: To investigate the distribution of 12 high-pathogenicity island (HPI) genes and the relation between HPI genes and expression of yersiniabactin (Ybt) in enteroaggregative E.coli(EAggEC) isolated from Chinese diarrhea patients.METHODS: The distribution of 12 HPI genes was investigated by PCR and DNA hybridization in two prototype strains of EAggEC, EAggEC 17-2, EAggEC O42, and 6 clinical EAggEC isolates from China. The production of siderophore Ybt in HPI-positive strains was detected by reporter gene bioassay to determine the relation between HPI genes and expression of Ybt. Flow cytometry was used to detect fluorescent signal of the reporter strain that could designate production of Ybt.RESULTS: Seven strains were HPI-positive and one strain was HPI-negative. Six of the seven HPI-positive strains were inserted into asnT-tRNA site. Moreover, seven EAggEC HPI-positive strains revealed enhanced fluorescence signal but the EAggEC HPI-negative strain did not. However, there was a difference in Ybt expression condition and level among these seven EAggEC HPI-positive strains. Although UFT073 strain, the prototype strain of uropathogenic E.coli(UPEC), carried the complete HPI core part, we did not detect the expression of Ybt in it.CONCLUSION: EAggEC HPI-positive strains can express the Ybt system, but the presence of HPI core part does not mean the functional expression of Ybt.

Survival and proliferation of the lysogenic bacteriophage CTXΦ in Vibrio cholerae

The lysogenic phage CTXΦ of Vibrio cholerae can transfer the cholera toxin gene both horizontally(inter-strain) and vertically(cell proliferation). Due to its diversity in form and species, the complexity of regulatory mechanisms, and the important role of the infection mechanism in the production of new virulent strains of V.cholerae, the study of the lysogenic phage CTXΦ has attracted much attention. Based on the progress of current research, the genomic features and their arrangement, the host-dependent regulatory mechanisms of CTXΦ phage survival, proliferation and propagation were reviewed to further understand the phage's role in the evolutionary and epidemiological mechanisms of V. cholerae.

Pleiotropic Effect of tatC Mutation on Metabolism of Pathogen Yersinia enterocolitica

Objective To analyze the impact of depletion of the twin arginine translocation （TAT） system on virulence and physiology of Yersinia enterocolitica for a better understanding of its pathogenicity. Methods We constructed a △tatC：：Sp^R mutant of Yersinia enterocolitica by P1 phage mediated transduction using Escherichia coli K-12 △tatC：：Sp^R strain as a donor. Results A Pl-mediated genetic material transfer was found between the two species of enterobacteria, indicating a great potential of acquisition of antibiotic resistance in emergency of a new threatening pathogen by genetic material exchanges. Periplasmic trimethylamine N-oxidase reductase activity was detected in the wild type E enterocolitica strain and translocation of this enzyme was completely abolished by the △tatC：：Sp^R mutation. In addition, the △tatC：：Sp^R mutation showed a pleiotropic effect on the metabolism of E enterocolitica. However, the tat mutation did not seem to affect the mobility and virulence of Y. enterocolitica under the conditions used. Conclusion Unlike other pathogenic bacteria studied, the TAT system of E enterocolitica might play an important role in the pathogenic process, which is distinct from other pathogens, such as Pseudomonas aeruginosa and enterohemorrhagic E. coli O 157：H7.

Relationship Between Climate Change and Marmot Plague of Marmota himalayana Plague Focus—the Altun Mountains of the Qinghai-Xizang Plateau,China,2000–2022

Introduction:Plague is a zoonotic disease that occurs naturally in specific geographic areas.Climate change can influence the populations of the plague host or vector,leading to variations in the occurrence and epidemiology of plague in animals.Methods:In this study,we collected meteorological and plague epidemiological data from the Marmota himalayana plague focus in the Altun Mountains of the Qinghai-Xizang Plateau.The data spanned from 2000 to 2022.We describe the climatic factors and plague epidemic conditions and we describe their analysis by Pearson’s correlation.Results:During the period from 2000 to 2022,the isolation rates of Yersinia pestis(Y.pestis)from marmots and fleas were 9.27%(451/4,864)and 7.17%(118/1,646),respectively.Additionally,we observed a positive rate of F1 antibody of 11.25%(443/3,937)in marmots and 18.16%(142/782)in dogs.With regards to climate,there was little variation,and a decreasing trend in blowing-sand days was observed.The temperature in the previous year showed a negative correlation with the Y.pestis isolation rate in marmots(r=−0.555,P=0.011)and the positive rate of F1 antibody in marmots(r=−0.552,P=0.012)in the current year.The average annual precipitation in the previous two years showed a positive correlation with marmot density(r=0.514,P=0.024),while blowingsand days showed a negative correlation with marmot density(r=−0.701,P=0.001).Furthermore,the average annual precipitation in the previous three years showed a positive correlation with the isolation rate of Y.pestis from marmots(r=0.666,P=0.003),and blowing-sand days showed a negative correlation with marmot density(r=−0.597,P=0.009).Conclusions:The findings of this study indicate that there is a hysteresis effect of climate change on the prevalence of plague.Therefore,monitoring climate conditions can offer significant insights for implementing timely preventive and control measures to combat plague epidemics.

Safety and Effectiveness of SA58 Nasal Spray Against COVID-19 Infection in Medical Personnel:An Open-Label,Blank-Controlled Study—Hohhot City,Inner Mongolia Autonomous Region,China,2022

Summary What is already known about this topic?The active ingredient of the SA58 Nasal Spray is a broad-spectrum neutralizing antibody with a high neutralizing capacity against different Omicron subvariants in vitro studies.What is added by this report?This study demonstrated the safety and effectiveness of SA58 Nasal Spray against coronavirus disease 2019(COVID-19)infection in medical personnel for the first time.What are the implications for public health practice?This study provides an effective approach for the public to reduce their risk of COVID-19 infection.The findings of this research have the potential to significantly reduce the risk of infection and limit human-to-human transmission in the event of a COVID-19 outbreak.

The prevalence and distribution of aminoglycoside resistance genes

Choosing the appropriate antibiotics to treat bacterial infections has grown more challenging as a result of the emergence of antibiotic-resistant bacteria.Aminoglycosides,as broad-spectrum antibiotics,are increasingly being used clinically;however,for most effective employment of aminoglycosides,a comprehensive understanding of aminoglycoside resistance genes’prevalence and dissemination is required.Therefore,to better understand the global resistance status of aminoglycoside antibiotics and the prevalence of antibiotic-resistance genes(ARGs)in various bacterial species,this systematic review gathered relevant data from multiple studies.Two primary resistance mechanisms-aminoglycoside enzymatic modification and 16S rRNA methylation-were assessed,and the prevalence of the corresponding ARGs was described.The coexistence of aminoglycoside ARGs with other ARGs was also demonstrated,as was the relationship between aminoglycoside ARGs and resistant phenotypes.The lack of effective therapeutic agents to combat resistant pathogens presents a real threat to public health.The combination of aminoglycosides with other antibiotics may provide a novel treatment strategy.

Persistent Urinary Tract Infection in Association with Community-Acquired NDM-5 Escherichia coli Clonal Group Following COVID-19 Infection-Beijing Municipality,China,2023

Summary What is already known about this topic?The hospital-acquired infections caused by New Delhi metallo-beta-lactamase(NDM)-producing strains are typically attributed to a single clonal lineage.What is added by this report?In this study,we encountered a unique case of community-acquired NDM-5 Escherichia coli urinary tract infection(UTI)following coronavirus disease 2019(COVID-19).The UTI persisted for a duration of at least 45 days.Genomic analyses revealed the presence of two NDM-5 strains,both sharing an identical chromosomal background but distinct,homologous,and recombined plasmids.

Transforming bacterial disease surveillance and investigation using whole-genome sequence to probe the trace

Two decades have passed since the first bacterial whole-genome sequencing, which provides new opportunity for microbial genome. Consequently, considerable genetic diversity encoded by bacterial genomes and among the strains in the same species has been revealed. In recent years, genome sequencing techniques and bioinformatics have developed rapidly, which has resulted in transformation and expedited the application of strategy and methodology for bacterial genome comparison used in dissection of infectious disease epidemics. Bacterial whole-genome sequencing and bioinformatic computing allow genotyping to satisfy the requirements of epidemiological study in disease control. In this review, we outline the significance and summarize the roles of bacterial genome sequencing in the context of bacterial disease control and prevention. We discuss the applications of bacterial genome sequencing in outbreak detection, source tracing, transmission mode discovery, and new epidemic clone identification. Wide applications of genome sequencing and data sharing in infectious disease surveillance networks will considerably promote outbreak detection and early warning to prevent the dissemination of bacterial diseases.

PulseNet China,a model for future laboratory-based bacterial infectious disease surveillance in China

Surveillance is critical for the prevention and control of infectious disease.China’s real-time web-based infectious disease reporting system is a distinguished achievement.However,many aspects of the current China Infectious Disease Surveillance System do not yet meet the demand for timely outbreak detection and identification of emerging infectious disease.PulseNet,the national molecular typing network for foodborne disease surveillance was first established by the Centers for Disease Control and Prevention of the United States in 1995 and has proven valuable in the early detection of outbreaks and tracing the pathogen source.Since 2001,the China CDC laboratory for bacterial pathogen analysis has been a member of the PulseNet International family;and has been adapting the idea and methodology of PulseNet to develop a model for a future national laboratory-based surveillance system for all bacterial infectious disease.We summarized the development progress for the PulseNet China system and discussed it as a model for the future of China’s national laboratory-based surveillance system.

Chinese Pathogen Identification Net:A Laboratory Network for Surveillance and Response of Bacterial Infectious Diseases

Infectious diseases are a sustained threat to social development and public health.Bacterial infectious diseases,including plague,cholera,anthrax,brucellosis,typhoid fever,meningitis,and even those caused by antimicrobial-resistant bacteria,have been prevalent around the world for a long time,and still trigger outbreaks and long-term epidemics in different countries or regions nowadays(1),and trans-regional spread of diseases has frequently exhibited epidemic patterns.

Cholera Caused by a New Clone of Serogroup O1 Vibrio cholerae-Beijing Municipality,China,June 2021

Several lineages have been identified in the population of serogroup O1 Vibrio cholerae(V.cholerae)(1-3).The strains,which were responsible for the ongoing seventh cholera pandemic,were in Lineage 2.Nearly all the V.cholerae strains in this lineage carried genes coding cholera toxin(ctxAB)(1-2).Lineage 3b consists of strains isolated from different continents and the vast majority of strains in this lineage lack the ctxAB genes.

Genetic source tracking of an anthrax outbreak in Shaanxi province,China

Background:Anthrax is an acute zoonotic infectious disease caused by the bacterium known as Bacillus anthracis.From 26 July to 8 August 2015,an outbreak with 20 suspected cutaneous anthrax cases was reported in Ganquan County,Shaanxi province in China.The genetic source tracking analysis of the anthrax outbreak was performed by molecular epidemiological methods in this study.Methods:Three molecular typing methods,namely canonical single nucleotide polymorphisms(canSNP),multiple-locus variable-number tandem repeat analysis(MLVA),and single nucleotide repeat(SNR)analysis,were used to investigate the possible source of transmission and identify the genetic relationship among the strains isolated from human cases and diseased animals during the outbreak.Results:Five strains isolated from diseased mules were clustered together with patients’isolates using canSNP typing and MLVA.The causative B.anthracis lineages in this outbreak belonged to the A.Br.001/002 canSNP subgroup and the MLVA15-31 genotype(the 31 genotype in MLVA15 scheme).Because nine isolates from another four provinces in China were clustered together with outbreak-related strains by the canSNP(A.Br.001/002 subgroup)and MLVA15 method(MLVA15-31 genotype),still another SNR analysis(CL10,CL12,CL33,and CL35)was used to source track the outbreak,and the results suggesting that these patients in the anthrax outbreak were probably infected by the same pathogen clone.Conclusions:It was deduced that the anthrax outbreak occurred in Shaanxi province,China in 2015 was a local occurrence.

Phylogenetic Analysis of Serogroup O5 Vibrio cholerae that Caused Successive Cholera Outbreaks——Guangdong Province,China,2020-2021

Introduction:Gastroenteritis caused by non-O1/non-O139 Vibrio cholerae exhibited an increasing trend in recent years in China.Whole genome sequence(WGS)data could play an important role both in the identification of the outbreaks and in the determination of the serogroup.Here,we present the employment of WGS data in the investigation of two outbreaks caused by non-O1/non-O139 V.cholerae in Guangdong,China,2020-2021.Methods:We obtained the whole genome sequence of 66 V.cholerae strains isolated in two outbreaks with next generation sequencing technology.We retrieved the publicly available WGS data of non-O1/non-O139 V.cholerae from public database.We used a pipeline integrated in China Pathogen Identification Net(PIN)to complete the phylogenetic analysis.Results:Two outbreaks caused by non-O1/non-O139 V.cholerae were identified using WGS data.These V.cholerae strains were determined as serogroup O5.Type 3 and 6 secretion systems were detected in these serogroup O5 strains.These serogroup O5 strains belonged to sequence type(ST)88.Conclusions:Our analysis indicated the risk of non-O1/non-O139 V.cholerae leading to outbreaks of diarrheal diseases.The application of genomic data played an important role in the identification of the serogroup of non-O1/non-O139 V.cholerae in the lack of antiserum,which gave an example of the application of genome data in disease surveillance and public health emergency response.

Performing Laboratory Network Surveillance to Monitor the Emergence and Spread of Infectious Diseases

Laboratory systems are one of the pillars in the infrastructure for infectious disease control and prevention——surveillance,early warning,and emergency response capacities are a priority to public health.Laboratory based monitoring provides essential support for infection diagnosis,pathogen identification,spread tracking,and outbreak warning,especially for emerging infections caused by newly recognized pathogens and clusters of unknown diseases.

Trans-Regional and Cross-Host Spread of mcr-Carrying Plasmids Revealed by Complete Plasmid Sequences——44 Countries,1998−2020

Background:The surveillance of antimicrobial resistance genes(ARGs)and bacteria is one critical approach to prevent and control antimicrobial resistance(AMR).Next-generation sequencing(NGS)is a powerful tool in monitoring the emergence and spread of ARGs and resistant bacteria.The horizontal transfer of ARGs across host bacteria mediated by plasmids is a challenge in NGS surveillance for resistance because short-read sequencing can hardly generate the complete plasmid genome sequence,and the correlation between ARGs and plasmids are difficult to determine.Methods:The complete genome sequences of 455 mcr-carrying plasmids(pMCRs),and the data of their host bacteria and isolation regions were collected from the NCBI database.Genes of Inc types and ARGs were searched for each plasmid.The genome similarity of these plasmids was analyzed by pangenome clustering and genome alignment.Results:A total of 52 Inc types,including a variety of fusion plasmids containing 2 or more Inc types were identified in these pMCRs and carried by complex host bacteria.The cooccurrence of ARGs in pMCRs was generally observed,with an average of 3.9 ARGs per plasmid.Twenty-two clusters with consistent or highly similar sequences and gene compositions were identified by the pangenome clustering,which were characterized with distributions in different countries/regions,years or host bacteria in each cluster.Discussion:Based on the complete plasmid sequences,distribution of mcr genes in different Inc type plasmids,their co-existence with other AMRs,and transmission of one pMCR across regions and host bacteria can be revealed definitively.Complete plasmid genomes and comparisons in the laboratory network are necessary for spread tracing of ARG-carrying plasmids and risk assessment in AMR surveillance.

Anaplasma bovis Infection in Fever and Thrombocytopenia Patients——Anhui Province,China,2021

Summary What is already known about this topic?The genus Anaplasma contains seven recognized bacterial species,mainly transmitted by tick bites.The two species,A.phagocytophilum and A.capra,are known commonly to cause diseases in humans.What is added by this report?Anaplasma bovis was initially thought to be only an animal agent until the first patient case was reported in 2019.This study investigated another two patients who became sick within one month in the same township and were infected with A.bovis in Anhui Province.

Human Plague Case Diagnosed in Ningxia Tracked to Animal Reservoirs—Inner Mongolia Autonomous Region,China,2021

Summary What is already known about this topic?There were a total of 4 and 3 human plague cases that occurred in the Inner Mongolia Autonomous Region in 2019 and 2020,respectively,with 1 and 2 deaths in 2019 and 2020 respectively,which indicated that plague still poses a significant threat to human health especially for farmers,shepherds,or residents living in native plague foci.What is added by this report?On August 14,2021,1 patient from the Otog Qi(County)in the Inner Mongolia sought treatment in Yinchuan City(the capital of Ningxia Hui Autonomous Region).

不同社交距离下口罩对气溶胶化新冠病毒替代物的过滤效率

The coronavirus disease 2019(COVID-19)pandemic is an unpreedented global event.It has become clear that COVID-19 is transmitted by virus-containing droplets(>5μm)and aerosols(<5μm),and that all human exhalatory activities(e.g.,breathing,speaking,singing,shouting,coughing,and sneezing)result in the emission of suspended droplets/aerosols of various sizes.As an example,COVID-19 patients exhale millions of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)RNA copies into the air per hour[1].SARS-CoV-2-laden aerosols play a profound role in disease transmission,as they can linger and remain viable in the air for a long duration(~16 h)[2]and travel a long distance(~4.8 m)due to their smaller size[3].

Co-Localization of Sampling and Sequencing for Zoonotic Pathogen Identification in the Field Monitoring Using Mobile Laboratories

Introduction:Accurate etiological detection is needed to evaluate the risk of zoonotic diseases.Metagenomic next-generation sequencing(mNGS)can be used to monitor pathogens in animal species and identify potential zoonotic threats.The current sampling model for zoonotic pathogen monitoring in wild animals requires samples to be transferred from the field to a laboratory for further detection.Methods:We constructed a zoonotic pathogen survey model using a set of mobile laboratories.Results:The monitoring in this study was preplanned to detect Yersinia pestis,but the mNGS unexpectedly identified Bartonella spp.in the rodent samples,thus exposing the threat of bartonellosis to humans in this region.The co-localization of sampling and sequencing(CLOSS)model we tested required no long-distance transferring of samples and expands the regional coverage of zoonotic surveys by using a mobile laboratory.Discussion:Using this mNGS technique will enable detection of more zoonotic pathogens beyond the preplanned monitoring targets.This may increase the surveillance efficiency compared with that of the previous workflow and expand the application of the mobile laboratories for infectious diseases identification and surveillance in the field.

Dissemination of Antibiotic Resistance Genes Among Patients with Diarrhea — Freetown, Sierra Leone, 2018

What is already known about this topic?Antibiotic resistance(AR)is a serious public health threat worldwide.However,the AR and antibiotic resistance genes(ARGs)data from West Africa,especially from Sierra Leone,are limited.What is added by this report?The study revealed ARGs’common dissemination,and multiplex antibiotic resistance genes in one sample.Genes blaNDM and blaOXA-48-like were first discovered in Sierra Leone.What are the implications for public health practice?Basic information is provided for AR research and surveillance and highlights that effective AR surveillance among diarrhea patients is necessary for Sierra Leone and West Africa.