First detection of multiple cases related to CV-A16 strain of B1c clade in Beijing in 2022.

Coxsackievirus A16 (CV-A16) is a significant etiologic agent of hand, foot, and mouth disease (HFMD) and herpangina (HA), with the capacity to progress to severe complications, including encephalitis, aseptic meningitis, acute flaccid paralysis, myocarditis, and other critical conditions. Beijing's epidemiological surveillance system, established in 2008, encompasses 29 hospitals and 16 district disease control centers. From 2019 to 2021, the circulation of CV-A16 was characterized by the co-circulation of B1a and B1b clades. Multiple cases of HFMD linked to clade B1c has not been reported in Beijing until 2022. This study enrolled 400 HFMD and 493 HA cases. Employing real-time RT-PCR, 368 enterovirus-positive cases were identified, with 180 selected for sequencing. CV-A16 was detected in 18.89% (34/180) of the cases, second only to CV-A6, identified in 63.33% (114/180). Full-length VP1 gene sequences were successfully amplified and sequenced in 22 cases, revealing the presence of clades B1a, B1b, and B1c in 14, 3, and 5 cases, respectively. A cluster of five B1c clade cases occurred between June 29 and July 17, 2022, within a 7-km diameter region in Shunyi District. Phylogenetic analysis of five complete VP1 gene sequences and two full-genome sequences revealed close clustering with the 2018 Indian strain (GenBank accession: MH780757.1) within the B1c India branch, with NCBI BLAST results showing over 98% similarity. Comparative sequence analysis identified three unique amino acid variations (P3S, V25A, and I235V). The 2022 Shunyi District HFMD cases represent the first instances of spatiotemporally correlated CV-A16 B1c clade infections in Beijing, underscoring the necessity for heightened surveillance of B1c clade CV-A16 in HFMD and HA in this region.

Evolution, recombination and geographic spreading of global Coxsackievirus A6.

BACKGROUND: The increasing incidence of hand, foot, and mouth disease (HFMD) associated with Coxsackievirus A6 (CVA6) has become a very significant public health problem. The aim of this study is to investigate the recombination, geographic transmission, and evolutionary characteristics of the global CVA6. METHODS: From 2019 to 2022, 73 full-length CVA6 sequences were obtained from HFMD patients in China and analyzed in combination with 1032 published whole genome sequences. Based on this dataset, the phylogenetic features, recombinant diversity, Bayesian phylodynamic characteristics, and key amino acid variations in CVA6 were analyzed. RESULTS: The four genotypes of CVA6, A, D, E, and F, are divided into 24 recombinant forms (RFs, RF-A - RF-X) based on differences in the P3 coding region. The eastern China region plays a key role in the dissemination of CVA6 in China. VP1-137 and VP1-138 are located in the DE loop on the surface of the CVA6 VP1 protein, with the former being a highly variable site and the latter having more non-synonymous substitutions. CONCLUSIONS: Based on whole genome sequences, this study contributes to the CVA6 monitoring, early warning, and the pathogenic mechanism by studying recombination diversity, geographical transmission characteristics, and the variation of important amino acid sites.

Genetic Features of 84 Genomes of Monkeypox Virus in Recent Circulation - Beijing Municipality, China, 2023.

The first indigenous incidence of Mpox (previously known as monkeypox) within Chinese mainland was documented in May 2023, with subsequent local and imported cases identified. A comprehensive understanding of the Mpox virus's (MPXV) characteristics within Beijing remains incomplete. In this study, 84 MPXV genomes from 82 local incidents and two imported instances, detected between May and July 2023, were analyzed. All MPXV strains fell within lineage C.1 of the West African clade, displaying limited genetic heterogeneity, encompassing 76-87 nucleotide substitutions and holding nucleotide identities between 99.996% and 100%. Phylogenetic exploration indicated that all genomes exhibited high homology to those presently prevalent in neighboring East Asian and Southeast Asian regions. Forty-six distinct haplotypes were identified among the strains, with 36.90% of genomes corresponding to four common haplotypes, suggesting repeated cross-regional introductions and restrained distribution via recurrent local transmission. These findings elucidate the genetic diversity and phylogenesis of MPXVs during their nascent transmission within Beijing and provide vital information to enhance future Mpox containment strategies.

Molecular epidemiology and phylodynamic analysis of enterovirus 71 in Beijing, China, 2009-2019.

BACKGROUND: Enterovirus 71(EV71)-associated hand, foot and mouth disease (HFMD) decreased dramatically in Beijing from 2009 to 2019. This study was to investigate the epidemiological characteristics, evolutionary dynamics, geographic diffusion pathway, and other features of EV71 in Beijing, China. METHODS: We conducted a retrospective study of EV71-associated HFMD and its causative agent in Beijing, China, from 2009 to 2019. Phylogenetic and phylogeographic methods based on the EV71 genome were used to determine the evolution features, origin, and spatiotemporal dynamics. Positive selection sites in the VP1 gene were identified and exhibited in the tertiary structure. Bayesian birth-death skyline model was used to estimate the effective reproductive number (Re). RESULTS: EV71-associated HFMD decreased greatly in Beijing. From 2009 to 2019, EV71 strains prevalent in Beijing shared high homology in each gene segment and evolved with a rate of 4.99*10- 3 substitutions per site per year. The genetic diversity of EV71 first increased and peaked in 2012 and then decreased with fluctuations. The time to the most recent common ancestor (TMRCA) of EV71 in Beijing was estimated around 2003 when the EV71 strains were transmitted to Beijing from east China. Beijing played a crucial role in seeding EV71 to central China as well. Two residues (E145Q/G, A293S) under positive selection were detected from both the VP1 dataset and the P1 dataset. They were embedded within the loop of the VP1 capsid and were exposed externally. Mean Re estimate of EV71 in Beijing was about 1.007. CONCLUSION: In recent years, EV71 was not the primary causative agent of HFMD in Beijing. The low Re estimate of EV71 in Beijing implied that strategies for preventing and controlling HFMD were performed effectively. Beijing and east China played a crucial role in disseminating EV71 to other regions in China.

Clinical, epidemiological, and virological features of Mpox in Beijing, China - May 31-June 21, 2023.

The first locally acquired case in the Chinese mainland was reported on May 31, 2023, lagging behind other countries. In this study, we aimed to examine the early clinical and epidemiological characteristics of the earliest cases of Mpox in Beijing, China. Additionally, we investigated the sequence and transmission patterns of the Mpox virus (MPXV). We analyzed 37 reported cases of Mpox in Beijing from May 31, 2023 to June 21, 2023. The age range of the subjects was 24-51 years. Thirty-six cases (97.3%) were identified in men who have sex with men (MSM), and 19 cases (51.4%) tested positive for the human immunodeficiency virus. Thirty-three cases were symptomatic, while four were asymptomatic. Skin lesions were observed in 32 cases (97.0%), fever in 26 (78.8%), and swollen lymph nodes in 17 (51.5%). Rash typically appeared in the genital or perianal area 1-3 days before fever onset, with a minimum incubation period of 2 days. For individuals with skin rashes, the skin lesion samples showed 100% positivity and low Ct values. There were high oropharyngeal swab (75.8%) and blood (84.6%) positivity rates. All MPXV strains belonged to the B.1.3 branch of the West African lineage. These strains carried 76-86 nucleotide substitutions compared with the reference human MPXV genome, and genetic diversity was observed. Our findings provide the first insights into the landscape of early transmission of Mpox in Beijing and help inform policy formulation in the Chinese mainland.

Phylogenetics and phylogeographic characteristics of coxsackievirus A16 in hand foot and mouth disease and herpangina cases collected in Beijing, China from 2019 to 2021.

Coxsackievirus A16 (CV-A16) is a significant pathogen responsible for causing hand foot and mouth disease (HFMD) and herpangina (HA). This study aimed to investigate the recent evolution and spread of CV-A16 by monitoring HFMD and HA cases in 29 hospitals across 16 districts in Beijing from 2019 to 2021. The first five cases of HFMD and the first five cases of HA each month in each hospital were included in the study. Real-time reverse transcription polymerase chain reaction was used to identify CV-A16, CV-A6, and EV-A71. From each district, two to four CV-A16 positive samples with a relatively long sampling time interval every month were selected for sequencing. A total of 3344 HFMD cases and 2704 HA cases were enrolled in this study, with 76.0% (2541/3344) of HFMD and 45.4% (1227/2704) of HA cases confirmed to be infected by enterovirus. Among the EV-positive samples, CV-A16 virus was detected in 33.61% (854/2541) of HFMD cases and 13.4% (165/1227) of HA cases, with the predominant cluster being B1a. Both B1a and B1b had a co-circulation of local and imported strains, with different origin time (1993 vs. 1995), different global distribution (14 countries vs. 10 countries), and different transmission centers but mainly distributed in the southern and eastern regions of Beijing. Strengthening surveillance of HFMD in southern and eastern regions will improve the prevention and control efficiency of enterovirus infections.

Comparative genomics analysis of Acinetobacter baumannii multi-drug resistant and drug sensitive strains in China.

The incidence of multidrug-resistant Acinetobacter baumannii has posed a major challenge for clinical treatment. There is still a significant gap in understanding the mechanism causing multi-drug resistance (MDR). In this study, the genomes of 10 drug sensitive and 10 multi-drug resistant A.baumannii strains isolated from a hospital in China were sequenced and compared. The antibiotic resistance genes, virulence factors were determined and CRIPSR-Cas system along with prophages were detected. The results showed that MDR strains are significantly different from the drug sensitive strains in the CARD entries, patterns of sequences matching up to plasmids, VFDB entries and CRISPR-Cas system. MDR strains contain unique CARD items related to antibiotic resistance which are absent in sensitive strains. Furthermore, sequences from genomes of MDR strains can match up with plasmids from more diversified bacteria genera compared to drug sensitive strains. MDR strains also contain a lower level of CRISPR genes and larger amount of prophages, along with higher levels of spacer sequences. These findings provide new experimental evidences for the study of the antibiotic resistance mechanism of A. baumannii.

Identification of altered exosomal microRNAs and mRNAs in Alzheimer's disease.

Alzheimer's disease (AD) is a progressive neurodegenerative disease characterized by decreased memory and cognitive functions. Exosomes carry a variety of important information such as proteins, lipids, DNA and RNA of mother cells. It is reported that exosomes play critical roles in nervous system physiology and neurodegenerative diseases. However, the functions of exosomes in AD progression are not fully elucidated. In this study, we detected the expression pattern of mRNAs and miRNAs in exosomes derived from the AD and health mice. A total of 1320 mRNAs and 29 miRNAs were differentially expressed in exosomes between the two groups. Subsequently, the downregulation of Chi3l1 and upregulation of Rhog in AD mice were verified by qRT-PCR. Meanwhile, the downregulation of miR-148a-5p and upregulation of miR-27a-5p in AD group were also tested by qRT-PCR. The functions of differentially expressed mRNAs and potential target genes of miRNAs were determined by GO and KEGG analysis. According to the ceRNA hypothesis, we established an integrated ceRNA network of circRNA-lncRNA-miRNA-mRNA. In conclusion, exosomal lncRNAs, mRNAs, circRNAs and miRNAs were identified to participate in the progression of AD which might be possible biomarkers and therapeutic targets for AD.

Transcriptome Characterization and Identification of Molecular Markers (SNP, SSR, and Indels) in the Medicinal Plant Sarcandra glabra spp.

Sarcandra glabra has significant metabolically active bioingredients of pharmaceutical importance. The deficiency of molecular markers for S. glabra is a hindrance in molecular breeding for genetic improvement. In this study, 57.756 million pair-end reads were generated by transcriptome sequencing in S. glabra (Thunb.) Nakai and its subspecies S. glabra ssp. brachystachys. A total of 141,954 unigenes with 646.63 bp average length were assembled. A total of 25,620 simple sequence repeats, 726,476 single nucleotide polymorphisms, and 42,939 insertions and deletions were identified, and the associated unigenes and differentially expressed genes were characterized. This work enhanced the molecular marker resources and will facilitate molecular breeding and gene mining in S. glabra spp.

Proteomic Analyses of Acinetobacter baumannii Clinical Isolates to Identify Drug Resistant Mechanism.

Acinetobacter baumannii is one of the main causes of nosocomial infections. Increasing numbers of multidrug-resistant Acinetobacter baumannii cases have been reported in recent years, but its antibiotic resistance mechanism remains unclear. We studied 9 multidrug-resistant (MDR) and 10 drug-susceptible Acinetobacter baumannii clinical isolates using Label free, TMT labeling approach and glycoproteomics analysis to identify proteins related to drug resistance. Our results showed that 164 proteins exhibited different expressions between MDR and drug-susceptible isolates. These differential proteins can be classified into six groups: a. proteins related to antibiotic resistance, b. membrane proteins, membrane transporters and proteins related to membrane formation, c. Stress response-related proteins, d. proteins related to gene expression and protein translation, e. metabolism-related proteins, f. proteins with unknown function or other functions containing biofilm formation and virulence. In addition, we verified seven proteins at the transcription level in eight clinical isolates by using quantitative RT-PCR. Results showed that four of the selected proteins have positive correlations with the protein level. This study provided an insight into the mechanism of antibiotic resistance of multidrug-resistant Acinetobacter baumannii.

Roles of the Hcp family proteins in the pathogenicity of Salmonella typhimurium 14028s.

The type VI secretion system (T6SS) is a new secretion system that is widely distributed among Gram-negative bacteria. The core component hemolysin-coregulated protein (Hcp) can be used as both its structural protein and secretory protein or chaperone protein. Studies on Hcp are important to elucidate the overall virulence mechanism of T6SS. Salmonella typhimurium is an important foodborne pathogen. There are three copies of hcp genes identified in S. Typhimurium 14028s. This study aimed to characterize the functions of the three Hcp family proteins and to elucidate the interactions among them. The hcp gene deletion mutants were constructed by λ Red-based recombination system. Effects of hcp mutation on the pathogenicity of 14028s were studied by bacterial competition assays, Dictyostelium discoideum assays and mouse model. The three Hcp family proteins were found to play different roles. Hcp1 can affect the transcription of rpoS and type 2 flagellar gene and influence the motility of 14028s. It is also involved in the intracellular survival of 14028s in Dictyostelium discoideum; Hcp2 is involved in the early proliferative capacity of 14028s in mice and can prevent its excessive proliferation; Hcp3 did not show direct functions in these assays. Hcp1 can interact with Hcp2 and Hcp3. Deletion of one hcp gene can result in a transcription level variation in the other two hcp genes. Our findings elucidated the functions of the three Hcp family proteins in S.Typhimurium and illustrated that there are interactions between different Hcp proteins. This study will be helpful to fully understand how T6SS actions in an organism.

An outbreak of acute respiratory infection at a training base in Beijing, China due to human adenovirus type B55.

BACKGROUND: Twelve students experienced symptoms of acute respiratory infection (ARI) at a training base in Beijing from August 26 to August 30, 2015. We investigated the cause of this ARI outbreak. METHODS: In partnership with the local center for disease control, we collected a total of twelve pharyngeal swab specimens as well as demographic information for the affected patients. We used multiplex real-time PCR to screen for sixteen common respiratory viruses in these samples. To isolate HAdV, we inoculated Hep-2 cells with the human adenovirus (HAdV)-positive samples and then carried out sequencing and phylogenetic analysis of the hexon, fiber, and penton genes of the isolated adenoviruses. In addition, we analyzed the entire genome of one strain isolated from the index case to identify single-nucleotide substitutions. RESULTS: We identified ten HAdV-positive students using multiplex real-time PCR. None of the students were co-infected with other viruses. We successfully isolated seven HAdV strains from the pharyngeal swab specimens. The coding sequences of the hexon, fiber, and penton genes of these seven HAdV strains were identical, suggesting that they represented seven strains from a single virus clone. One HAdV isolate obtained from the index case, BJDX-01-2015, was selected for whole genome analysis. From this isolate, we obtained a 34,774-nucleotide sequence. The genome of BJDX-01-2015 clustered with HAdV-B55 in phylogenetic analyses and had 99.97% identity with human adenovirus 55 isolate HAdV-B/CHN/BJ01/2011/55 (GenBank accession no. JX491639). CONCLUSIONS: We identified HAdV-B55 as the strain associated with the August 2015 ARI outbreak at a training base in Beijing. This was the first reported outbreak in Beijing due to HAdV-B55. Continuous surveillance of respiratory adenoviruses is urgently needed to understand the epidemiological and evolutionary features of HAdV-B55, and an epidemiological modeling approach may provide further insights into this emerging public health threat. Furthermore, the clinical laboratory data from this outbreak provides important reference for the clinical diagnosis and may ultimately aid in informing the development of strategies to control and prevent respiratory tract infections caused by HAdV-B55.

Quality Analysis of Different Specification Grades of Astragalus membranaceus var. mongholicus (Huangqi) from Hunyuan, Shanxi.

Background: Huangqi is a famous Chinese medicinal material whose Dao-di producing area is Hunyuan, Shanxi. Huangqi produced in Hunyuan, Shanxi, were divided into several different specifications and grades according to the diameters and different positions of root system. Objective: This article investigates the quantitative characteristics of chemical compositions in different specifications and grades of Astragalus membranaceus var. mongholicus roots, aiming to elucidate the correlation between specifications and/or grades and chemical compositions in Huangqi. Methods: Based on the field investigation, samples of Huangqi collected from Hunyuan, Shanxi, were divided into different specifications and grades. The content of seven flavonoids and five saponins in Astragalus membranaceus var. mongholicus roots of different specifications and grades were determined simultaneously by HPLC-diode-array detection-evaporative light-scattering detection (HPLC-DAD-ELSD). Results: Huangqi was processed by traditional methods, and its commercial specification was classified by different parts of the root system, such as ge-da-tou, hong-lan-qi, zheng-bai-qi, fu-bai-qi, mao-wei-zi, and qi-jian. The total content of seven flavonoids and five saponins in ge-da-tou, qi-jian were lower. The total content of seven flavonoids in hong-lan-qi was much higher, while that of five saponins was much lower. The total content of seven flavonoids in lateral roots or fibrous roots were higher, and that of five saponins was lower, such as zheng-bai-qi, fu-bai-qi, and mao-wei-zi. According to the root diameters, Huangqi was classified to special grade, grade I, grade II, grade III, grade IV, or grade V. Among six grades of Huangqi, the total content of seven flavonoids in grade III, grade IV, and grade V were lower, while the total content of five saponins in them were much higher. Conclusions: There is an obvious difference on the distribution pattern of contents of seven flavonoids and five saponins in Huangqi of different specifications and grades, which provide a certain scientific basis for the quality evaluation of Huangqi. Highlights: The content of seven flavonoids and five saponins in Huangqi were determined by HPLC-DAD-ELSD. The relationship between the commercial specification grades and chemical components of Dao-di herbs Astragalus membranaceus var. mongholicus (Huangqi ) from Hunyuan, Shanxi were revealed, which provided a chemical basis for the classification of commercial specification grades of dao-herbs Astragalus membranaceus var. mongholicus (Huangqi ) from Hunyuan, Shanxi.

The taxonomic relevance of flower colour for Epimedium (Berberidaceae), with morphological and nomenclatural notes for five species from China.

Morphological variations, particularly flower colour, could be considered as an evolutionarily and ornamentally significant taxonomic criterion for Epimedium. Our extensive field investigation based on population studies revealed abundant intraspecific variations in flower colour. Five species, (i.e., E.acuminatum Franch., E.leptorrhizum Stearn, E.pauciflorum K.C.Yen, E.mikinorii Stearn, and E.glandulosopilosum H.R.Liang) were found to possess polymorphic flower colour, which is first described and illustrated here. Moreover, all these species were found to be polymorphic in other diagnostic characters, such as the type of rhizome, the number and arrangement of stem-leaves, and/or their indumentum, which have not been adequately described in previous studies. Therefore, their morphological descriptions have been complemented and/or revised. We also provide notes on the morphology and nomenclature for each species. Additionally, a key to the species in China has been provided. The present study could serve as a basis for understanding their taxonomy and helping their utilisation as an ornamental plant.

Developmental anatomy of anomalous structure and classification of commercial specifications and grades of the Astragalus membranaceus var. mongholicus.

The Daodi herb, Huangqi from Shanxi, is derived from the root of Astragalus membranaceus (Fisch.) Bge. var. mongholicus (Bge.) Hsiao. Huangqi was divided into different commercial specifications and grades in producing area according to macroscopic features. Developmental anatomy of anomalous structure of the perennial fresh main root of A. membranaceus var. mongholicus was investigated using conventional paraffin section to explore the relationship between anomalous structure and classification of commercial specifications and grades of Huangqi. The results of developmental anatomy showed that parenchyma cells in secondary phloem and secondary xylem of the perennial fresh main root regained meristematic ability, and resulted in anomalous structure. Several layers of additional periderm could sometimes be found in the secondary phloem near the initial periderm, which was called rhytidome. Additional periderm could sometimes be observed in the center of secondary xylem, which was described as "rotten heart." The area of rhytidome and "rotten heart" increased gradually with increasing age. The results of different commercial specifications and grades of Huangqi revealed rhytidome and "rotten heart" mainly existed in Ge-Da-Tou, Er-Dao-Tou, Hong-Lan-Qi, Special Class, First Class, and Second Class. The additional periderm in secondary phloem of Ge-Da-Tou, Er-Dao-Tou, Hong-Lan-Qi, and Special Class could reach five layers; however, that of First Class and Second Class was three layers at most. In summary, this study demonstrated the rules of the development of rhytidome and "rotten heart" in A. membranaceus var. mongholicus. The relationship between anomalous structure and different commercial specifications and grades of Daodi herb Huangqi, was clarified. RESEARCH HIGHLIGHTS: The rhytidome and the development of "rotten heart" have not been reported in Astragalus membranaceus var. mongholicus. At present article, we demonstrated the developmental anatomy of the rhytidome and "rotten heart" existed in the secondary phloem and secondary xylem of the root of A. membranaceus var. mongholicus respectively. The rhytidome and "rotten heart" is different among six commercial specifications and grades of Huangqi.

Genotyping of Salmonella with lineage-specific genes: correlation with serotyping.

BACKGROUND: The bacterial genus Salmonella encompasses a large number of serotypes that are genetically very similar but biologically quite different, especially in pathogenic properties and host specificity. Serotyping has been used for the classification, identification, and epidemiological investigation due to its excellent discriminating power, but it cannot distinguish the different pathogenic lineages within a polyphyletic serotype. Additionally, very few institutions have the comprehensive set of antisera for typing. Therefore various studies have been performed to explore alternative assays to differentiate Salmonella isolates, such as the search for genes that can be used as potential molecular substitutes for serotyping. However, the genes tested so far have often given inconsistent results. METHODS: In this study, the discriminating power of seven genes to differentiate 309 Salmonella strains representing 26 serotypes was evaluated and the results were compared with those of other methods. RESULTS: The seven newly selected genes have a good power to differentiate different serovars. The tree based on the concatenated sequences of these genes revealed phylogenetic relationships of the bacteria consistent with that of the whole genome tree. CONCLUSION: Individual Salmonella lineages each have specific genes that can be used to differentiate Salmonella isolates on a phylogenetic basis.

Protective Efficacy of the Conserved NP, PB1, and M1 Proteins as Immunogens in DNA- and Vaccinia Virus-Based Universal Influenza A Virus Vaccines in Mice.

The conventional hemagglutinin (HA)- and neuraminidase (NA)-based influenza vaccines need to be updated most years and are ineffective if the glycoprotein HA of the vaccine strains is a mismatch with that of the epidemic strain. Universal vaccines targeting conserved viral components might provide cross-protection and thus complement and improve conventional vaccines. In this study, we generated DNA plasmids and recombinant vaccinia viruses expressing the conserved proteins nucleoprotein (NP), polymerase basic 1 (PB1), and matrix 1 (M1) from influenza virus strain A/Beijing/30/95 (H3N2). BALB/c mice were immunized intramuscularly with a single vaccine based on NP, PB1, or M1 alone or a combination vaccine based on all three antigens and were then challenged with lethal doses of the heterologous influenza virus strain A/PR/8/34 (H1N1). Vaccines based on NP, PB1, and M1 provided complete or partial protection against challenge with 1.7 50% lethal dose (LD50) of PR8 in mice. Of the three antigens, NP-based vaccines induced protection against 5 LD50 and 10 LD50 and thus exhibited the greatest protective effect. Universal influenza vaccines based on the combination of NP, PB1, and M1 induced a strong immune response and thus might be an alternative approach to addressing future influenza virus pandemics.

[Analysis of antibodies of poliviruses in persistent populations in Beijing, 2012].

OBJECTIVE: To analyze the polio immunity level of persistent population in Beijing, 2012. METHODS: A total of 1 676 subjects residing more than 6 months in Beijing were selected by stratified random cluster sampling design in 2012. Demographic characteristics, history of oral poliovirus vaccine (OPV) immunization were investigated by questionnaire. All 5 ml blood sample were collected for testing of polio neutralizing antibody using the method of microcell neutralization. The positive rate and the geometric mean titer (GMT) of polio neutralizing antibody type I, II and III were analyzed in different groups. RESULTS: The positive rate of type I, II and III were 98.2% (1 645/1 676), 98.1% (1 644/1 676), 97.6% (1 635/1 676); The GMT were 1:130.2, 1: 113.4 and 1: 79.7. Three types of positive rates in<15 years group (99.7% (664/666), 99.8% (665/666), 99.5% (663/666)) were higher than those of ≥ 15 years group (97.1% (981/1 010), 96.9% (979/1 010), 96.2% (972/1 010)), the differences were significant (all the values of P < 0.01); The GMT in<15 years group (1:325.9, 1:250.5, 1:190.7) were higher than that of ≥ 15 years group (1: 71.1, 1: 67.2, 1: 44.8), the difference was significant (all the values of P < 0.01). The positive rate (99.0%-100%) and GMT (1: 128.8-1: 300.7) in vaccination information confirmed population were higher. The highest positive rate (all were 100%) and GMT(1: 409.7-1: 636.7) were observed in children who vaccinated three times. CONCLUSION: The polio antibody of healthy population was at a high level in Beijing in 2012; Especially the age groups of < 15 years which were covered by vaccines.Immunization barrier had been formed firmly to interrupt the transmission of wild poliovirus and vaccine-derived poliovirus.

Comparative genomic analysis between typhoidal and non-typhoidal Salmonella serovars reveals typhoid-specific protein families.

BACKGROUND: The genus Salmonella contains more than 2600 serovars. While most cause a self-limiting gastroenteritis, four serovars, S. Typhi, S. Paratyphi A, B and C, elicit typhoid, a potentially fatal systemic infection. Because of the prevalence in certain regions, such as South Asia, and the disease severity of typhoidal Salmonella infections, comprehensive studies are needed to elucidate the pathogenesis of diseases caused by these typhoidal serovars. RESULTS: We performed comparative genomic analyses on eight human typhoidal strains and 27 non-human typhoidal Salmonella strains to elucidate their evolutionary relationships and identify the genes specific to the four typhoidal serovars. Our results indicate that Salmonella may have an open pan-genome. A core-genome based phylogeny demonstrated that divergence between S. Paratyphi A and S. Typhi took place not long ago and S. Paratyphi B shared a recent common ancestor with S. Paratyphi C. Of great interest, the divergence between S. Paratyphi B and S. Paratyphi C was shown to be more recent than that between S. Paratyphi A and S. Typhi. Alignment and comparisons of the genomes identified unique complements of protein families to each of the typhoidal serovars. Most of these protein families are phage related and some are candidate virulence factors. Importantly, we found 88 protein families specific to two to three of the four typhoidal serovars. All but two of the 88 genes are present in S. Typhi, with a few in the three paratyphoidal serovars but none in the non-human typhoidal serovars. Most of these genes are predicted to encode hypothetical proteins and some are known to code for virulence factors such as Vi polysaccharide related proteins. CONCLUSIONS: By comprehensive genomic comparisons, we identified protein families specific to the human typhoidal serovars, which will greatly facilitate investigations on typhoid pathogenesis.