Long-term effects of the COVID-19 pandemic on five mental and psychological disorders: in terms of the number of disease visits, drug consumption, and scale scores.

BACKGROUND: COVID-19 caused mild to severe infections in humans. The long-term epidemic environment harms people's mental health. To explore the impact of the epidemic on people's mental and psychological conditions, we surveyed in Wenzhou. METHODS: We collected the data of people who visited the First Affiliated Hospital of Wenzhou Medical University for five types of mental and psychological diseases from January 2018 to December 2021. Then, taking December 2019 as the cut-off point, the 48-month data were divided into the pre-epidemic group and the dur-epidemic group. Based on the above data, statistical analysis was done. RESULTS: From 2018 to 2021, the number of initial diagnoses, the number of disease visits, and drug consumption for these five types of mental and psychological diseases were all on the rise. Compared with the number of disease visits for all disorders in both psychiatry and neurology departments, it was found that the growth rate of these five diseases was higher than the growth rate of all disorders. We found that the number of disease visits, drug consumption, and scale scores after the COVID-19 outbreak were significantly different from those before the outbreak (P < 0.05). And the number of disease visits positively correlated with drug consumption (P < 0.0001, r = 0.9503), which verified the stability of the data. CONCLUSION: The epidemic environment has had a long-term and negative impact on people's mental and psychological conditions. Therefore, whether or not the epidemic is receding, we still need to be concerned about the impact of COVID-19 on mental and psychological health.

Tigecycline-resistant Escherichia coli ST761 carrying tet(X4) in a pig farm, China.

This study aimed to investigate the prevalence and characterization of tet(X4) in Escherichia coli isolates from a pig farm in Shanghai, China, and to elucidate tet(X4) dissemination mechanism in this swine farm. Forty-nine (80.33%) E. coli strains were isolated from 61 samples from a pig farm and were screened for the presence of tet(X). Among them, six (12.24%) strains were positive for tet(X4) and exhibited resistance to tigecycline (MIC ≥ 16 mg/L). They were further sequenced by Illumina Hiseq. Six tet(X4)-positive strains belonged to ST761 with identical resistance genes, resistance profiles, plasmid replicons, and cgMLST type except that additional ColE10 plasmid was present in isolate SH21PTE35. Isolate SH21PTE31, as a representative ST761 E. coli strain, was further sequenced using Nanopore MinION. The tet(X4) in SH21PTE31 was located on IncFIA18/IncFIB(K)/IncX1 hybrid plasmid pYUSHP31-1, highly similar to other tet(X4)-carrying IncFIA18/IncFIB(K)/IncX1 plasmids from ST761 E. coli and other E. coli lineages in China. These IncFIA18/IncFIB(K)/IncX1 plasmids shared closely related multidrug resistance regions, and could reorganize, acquire or lose resistance modules mediated by mobile elements such as ISCR2 and IS26. Phylogenetic analysis were performed including all tet(X4)-positive isolates obtained in this pig farm combined with 43 tet(X4)-positive E. coli from pigs, cow, pork, wastewater, and patients with the same ST from NCBI. The 50 tet(X4)-carrying E. coli ST761 isolates from different areas in China shared a close phylogenetic relationship (0-49 SNPs). In conclusion, clonal transmission of tet(X4)-positive E. coli ST761 has occurred in this swine farm. E. coli ST761 has the potential to become a high-risk clone for tet(X4) dissemination in China.

Elevated Serum Uric Acid Increases the Risk of Ischemic Stroke Recurrence and Its Inflammatory Mechanism in Older Adults.

Background: Serum uric acid (UA) has been reported to be associated with ischemic stroke and inflammation. However, whether or not UA is related to the recurrence of ischemic stroke, and whether inflammation plays a role in the relationship between them remain inconclusive. Objective: We sought to explore the relationship between UA and the recurrence of ischemic stroke and to define the role of neutrophil-to-lymphocyte ratio (NLR) in the aforementioned relationship. Methods: A total of 8,995 patients were included in this study. Basic information and blood samples were collected, and whether or not each participant experienced ischemic stroke recurrence within 3 years was documented. Patients were stratified into three groups according to their UA level, as follows: ≤ 266, 267-339, and ≥ 340 µmol/L. COX regression and restricted cubic spline regression models were used to evaluate the clinical correlation between UA and ischemic stroke recurrence, mediation analysis and interaction and joint analysis were used to evaluate the role of NLR in the association of UA and ischemic stroke recurrence, and sensitivity and subgroup analyses were performed to test the robustness of the data. Results: Ischemic stroke recurrence was related to male sex, older age, higher UA level, higher NLR, hypertension, diabetes, and cardiovascular disease. Following adjustment for potential confounders, a high level of UA (≥ 340 µmol/L) increased the risk of recurrence by 92.6% in patients with previous ischemic stroke. We also found that NLR affects the association between UA and the recurrence of ischemic stroke in older adults, suggesting that patients with high NLR and high UA levels are at greater risk for ischemic stroke recurrence. Conclusion: UA level is non-linearly associated with recurrence, and NLR has an additive interaction between UA and ischemic stroke recurrence.

Association Between Serum Lactate Dehydrogenase Level and Hematoma Expansion in Patients with Primary Intracerebral Hemorrhage: A Propensity-Matched Analysis.

OBJECTIVE: The present study aimed to explore whether a higher serum lactate dehydrogenase (sLDH) level on admission is associated with hematoma expansion (HE) in patients with primary intracerebral hemorrhage (ICH). METHODS: This single-center prospective observational study of patients with primary ICH aged 19 years or older was conducted at the Dehua County Hospital from January 2018 to May 2021. Clinical data and demographic information and outcomes were collected and analyzed. The association between increased sLDH levels and HE was assessed in univariate and multivariate analyses. Propensity-score matching (PSM) analysis was implemented to reduce baseline differences between the groups. RESULTS: Of 609 patients with ICH screened, 360 who met all eligibility criteria were enrolled in the study (mean age, 59.83 ± 12.64 years; 60.28% female patients), of whom 69 (19.17%) developed early HE. sLDH levels were statistically higher in the HE group compared with the non-HE group (236.0 [222.30-275.50] U/L vs. 209.6 [179.30-253.8] U/L; P < 0.001). Multivariable analysis showed that higher sLDH levels were still statistically associated with HE (odds ratio [OR], 0.08; 95% confidence interval, 0.03-0.210; P < 0.001). After PSM, the matched HE group had a significantly higher sLDH level than did the matched non-HE group (236.0 [222.0-279.10] vs. 216.30 [173.0-278.7] U/L; P = 0.003). The area under the curve of 0.704 (95% confidence interval, 0.654-0.751; P < 0.0001) (sensitivity, 92.75%; specificity, 52.58%), and the optimal cutoff value for sLDH level as a predictor for HE in patients with primary ICH was determined as 211.0U/L. The area under the curve of the logistic regression model based on these predictors (the TsL (time from onset to initial computed tomography,sLDH) modelbased on these predictors: sLDH, time from onset to initial computed tomography) was 0.817, with a sensitivity of 84.06% and specificity of 72.51% for HE. The TsL model produced the best ability to predict HE compared with single sLDH. sLDH levels were statistically correlated with poor outcome. CONCLUSIONS: The current PSM analysis study shows that increased serum LDH level is statistically associated with HE. Our findings indicate that the TsL model constructed by sLDH and time from onset to initial computed tomography markedly enhances the prediction of HE after ICH.

Multiple Mechanisms of Tigecycline Resistance in Enterobacteriaceae from a Pig Farm, China.

We isolated eight tigecycline-resistant Enterobacteriaceae strains from a pig farm in Shanghai, China, including Escherichia coli (n = 1), Proteus cibarius (n = 1), and Enterobacter hormaechei (n = 6). Two of them (E. coli and P. cibarius) were positive for tet(X). E. coli SH19PTE6 contained an IncFIA18/IncFIB(K)/IncX1 hybrid plasmid pYUSHP6-tetX, highly similar to other tet(X)-bearing hybrid plasmids from E. coli in China. In P. cibarius SH19PTE4, tet(X) was located within a new chromosomal integrative and conjugative element (ICE), ICEPciChn2, belonging to the SXT/R391 ICE family. All tigecycline-resistant E. hormaechei isolates carried the tet(A) variant; cloning and transfer of this tet(A) variant into various hosts increased their MICs for tigecycline (4- to 8-fold). Tigecycline resistance observed on a pig farm is mediated by the tet(A) variant and tet(X) via a plasmid or ICE. The rational use of antibiotics such as doxycycline and surveillance of tigecycline resistance in livestock are warranted. IMPORTANCE As a last-resort antimicrobial agent to treat serious infections, the emergence and spread of tigecycline resistance in Enterobacteriaceae and Acinetobacter have raised global concerns. Multiple mechanisms mediate tigecycline resistance in Enterobacteriaceae, such as the monooxygenase Tet(X), mutations in Tet proteins, and overexpression of efflux pumps. Although tigecycline is not approved for animals, tigecycline resistance has been observed in Escherichia coli, Proteus cibarius, and Enterobacter hormaechei isolates on a pig farm, mediated by the tet(A) variant and tet(X) via a plasmid or ICE. The heavy use of tetracyclines such as doxycycline in food-producing animals in China may be the reason for the emergence and transmission of tigecycline resistance.

Chromosomally Located fosA7 in Salmonella Isolates From China.

This study aimed to investigate the prevalence of fosfomycin fosA7 in Salmonella enterica isolates from food animals and retail meat products in China and the impact of fosA7 on bacterial fitness. A total of 360 Salmonella isolates collected from 11 provinces and cities in China were detected for fosA7. All fosA7-positive Salmonella isolates were determined minimum inhibitory concentrations (MICs) and sequenced by Illumina Hiseq. The fosA7 gene of S. Derby isolate HA2-WA5 was knocked out. The full length of fosA7 was cloned into vector pBR322 and then transformed into various hosts. MICs of fosfomycin, growth curves, stability, and fitness of fosA7 were evaluated. The fosA7 gene was identified in S. Derby (ST40, n = 30) and S. Reading (ST1628, n = 5). MICs to fosfomycin of 35 fosA7-positive isolates were 1 to 32 mg/L. All fosA7 were located on chromosomes of Salmonella. The deletion of fosA7 in HA2-WA5 decreased fosfomycin MIC by 16-fold and slightly affected its fitness. The acquisition of plasmid-borne fosA7 enhanced MICs of fosfomycin in Salmonella (1,024-fold) and Escherichia coli (16-fold). The recombinant plasmid pBR322-fosA7 was stable in Salmonella Typhimurium, S. Pullorum, S. Derby, and E. coli, except for Salmonella Enteritidis, and barely affected on the growth of them but significantly increased biological fitness in Salmonella. The spread of specific Salmonella serovars such as S. Derby ST40 will facilitate the dissemination of fosA7. fosA7 can confer high-level fosfomycin resistance and enhance bacterial fitness in Salmonella if transferred on plasmids; thus, it has the potential to be a reservoir of the mobilized fosfomycin resistance gene.

Multiple PCR assay based on the cigR gene for detection of Salmonella spp. and Salmonella Pullorum/Gallinarum identification.

Salmonella spp. are important zoonotic pathogens that are responsible for severe diseases in both animals and humans. Salmonella enterica subsp. enterica serovar Gallinarum biovar Gallinarum (S. Gallinarum) and biovar Pullorum (S. Pullorum) are typical infectious pathogens detected in the chicken industry that have caused great economic losses. To facilitate their detection and prevent contamination, we developed a rapid multiple PCR method, which can simultaneously detect Salmonella spp. and further identify the biovars S. Pullorum/Gallinarum. This PCR detection method is based on the cigR gene, which is conserved among Salmonella spp. but has a 42-bp deletion in S. Pullorum/Gallinarum. The specificity and sensitivity of the PCR assay was evaluated with 41 different strains: 34 Salmonella strains, including 5 S. Pullorum/Gallinarum strains, and 7 non-Salmonella strains. The lower limit of detection was 8.15 pg of S. Pullorum (S06004) genomic DNA and 20 cfu in PCR, which shows a great sensitivity. In addition, this method was applied to detect or identify Salmonella from processing chicken liver and egg samples, and the results corresponded to those obtained from serotype analysis using the conventional slide agglutination test. Overall, the new cigR-based PCR assay is efficient and practical for Salmonella detection and S. Pullorum/Gallinarum identification and will greatly reduce the workload of epidemiologic investigation.

Coexistence of bla OXA-58 and tet(X) on a Novel Plasmid in Acinetobacter sp. From Pig in Shanghai, China.

The purpose of this study was to characterize the complete sequence of a novel plasmid carrying tigecycline resistance gene tet(X) and carbapenemase gene bla OXA-58 from a swine Acinetobacter sp. strain SH19PTT10. Minimal inhibitory concentration (MIC) was performed using microbroth dilution method. The isolate SH19PTT10 was highly resistant (16 mg/L) to tigecycline, and also exhibited resistance to ampicillin, streptomycin, tetracycline, chloramphenicol, florfenicol, ciprofloxacin, and sulfamethoxazole/trimethoprim. Although SH19PTT10 harbored bla OXA-58, it was susceptible to cefotaxime and meropenem. The genome sequence of SH19PTT10 was determined using PacBio single-molecule real-time sequencing. Plasmid pYUSHP10-1 had a size of 174,032 bp and showed partial homology to several plasmids found in Acinetobacter isolates. It contained two repA genes, putative toxin-antitoxin systems (HipA/HipB, RelE/RelB, and BrnT/BrnA), partitioning genes (parA and parB), and heavy metal resistance-associated genes (copA/copB, nrp, and czcA/czcD) but the transfer region or proteins was not found. pYUSHP10-1 carried 16 resistance genes, mainly clustered in two mosaic multiresistance regions (MRRs). The first MRR contained sul3, qacI-aadA1-clmA1-aadA2-blaCARB-2-dfrA16 cassette, aac(3)-IId, and bla OXA-58. The bla OXA-58 gene was associated with ISAba3, as previously described. The second MRR is the tet(X) region (ISAcsp12-aph(3')-Ia-IS26-ΔxerD-tet(X)-res-ISCR2-sul2) related to the corresponding region in other tet(X)-bearing plasmids. The pdif sites, as well as mobile elements, play an important role in mobilization of DNA modules and plasmid evolution. Coexistence of numerous resistance genes on a single plasmid may contribute to the dissemination of these genes under pressure posed by different agents, which may explain the presence of clinically crucial resistance genes tet(X) and bla OXA-58 in livestock. Thus, rational drug use and continued surveillance of tet(X) and bla OXA-58 in livestock are warranted.

Admission Neutrophil-Lymphocyte Ratio Predicts Rebleeding Following Aneurismal Subarachnoid Hemorrhage.

OBJECTIVE: The relationship between neutrophil-lymphocyte ratio (NLR) and the occurrence of rebleeding in aneurysmal subarachnoid hemorrhage (aSAH) is poorly understood. Our study aimed to investigate the association between NLR on admission and rebleeding following aSAH. METHODS: Clinical and laboratorial data from patients with aSAH were retrospectively collected, including leukocyte, neutrophil, lymphocyte, and NLR. Univariate and multivariate analyses were performed to assess for the association of NLR with rebleeding. We performed propensity-score matching analyses to correct imbalances in patient characteristics between the rebleeding group and nonrebleeding group. RESULTS: Rebleeding occurred in 30 of 716 (4.19%) patients with aSAH in this cohort. Patients with rebleeding had significantly higher NLR comparing with patients without rebleeding (11.27 vs. 5.5; P < 0.05) in the univariate analysis. In the multivariate analysis, NLR was considered as a risk factor of rebleeding (odds ratio, 0.283; 95% confidence interval, 0.130-0.620; P = 0.002), as well as Fisher grade (odds ratio, 0.353, 95% confidence interval, 0.151-0.824; P = 0.016). The area under the curve of the NLR and combined NLR-Fisher grade model was 0.702 and 0.744 (sensitivity was 39.94%, and specificity was 100%) for predicting rebleeding, respectively. After propensity-score matching, the optimal cutoff value for NLR as a predictor for rebleeding following aSAH was determined as 5.4 (sensitivity was 83.33%, and the specificity was 63.33%). CONCLUSIONS: Higher NLR predicts the occurrence of rebleeding and poor outcome, and NLR combined with Fisher grade significantly improves the prediction of rebleeding following aSAH.

Emergence of 16S rRNA Methylase Gene rmtB in Salmonella Enterica Serovar London and Evolution of RmtB-Producing Plasmid Mediated by IS26.

This study aimed to characterize 16S rRNA methylase genes among Salmonella and to elucidate the structure and evolution of rmtB-carrying plasmids. One hundred fifty-eight Salmonella isolates from one pig slaughterhouse were detected as containing 16S rRNA methylase genes; two (1.27%) Salmonella London isolates from slaughtered pigs were identified to carry rmtB. They were resistant to gentamicin, amikacin, streptomycin, ampicillin, tetracycline, florfenicol, ciprofloxacin, and sulfamethoxazole/trimethoprim. The complete sequences of RmtB-producing isolates were obtained by PacBio single-molecule real-time sequencing. The isolate HA1-SP5 harbored plasmids pYUHAP5-1 and pYUHAP5-2. pYUHAP5-1 belonged to the IncFIBK plasmid and showed high similarity to multiple IncFIBK plasmids from Salmonella London in China. The rmtB-carrying plasmid pYUHAP5-2 contained a typical IncN-type backbone; the variable region comprising several resistance genes and an IncX1 plasmid segment was inserted in the resolvase gene resP and bounded by IS26. The sole plasmid in HA3-IN1 designated as pYUHAP1 was a cointegrate of plasmids from pYUHAP5-1-like and pYUHAP5-2-like, possibly mediated by IS26 via homologous recombination or conservative transposition. The structure differences between pYUHAP1 and its corresponding part of pYUHAP5-1 and pYUHAP5-2 may result from insertion, deletion, or recombination events mediated by mobile elements (IS26, ISCR1, and ISKpn43). This is the first report of rmtB in Salmonella London. IncN plasmids are efficient vectors for rmtB distribution and are capable of evolving by reorganization and cointegration. Our results further highlight the important role of mobile elements, particularly IS26, in the dissemination of resistance genes and plasmid evolution.

Isolation and characterization of virulent phages infecting Shewanella baltica and Shewanella putrefaciens, and their application for biopreservation of chilled channel catfish (Ictalurus punctatus).

The growth of Shewanella spp., mainly S. baltica and S. putrefaciens, is responsible for the spoilage of chilled fresh fish. Phages are an alternative tool to control bacterial growth. In this study, virulent phages infecting 4 S. baltica and 6 S. putrefaciens strains were isolated and characterized. Transmission electron microscopy revealed that 6 out of 10 phages (3 phages infecting S. baltica and 3 phages infecting S. putrefaciens) belonged to Myoviridae, while the other 4 phages (1 phage infecting S. baltica and 3 phages infecting S. putrefaciens) belonged to Siphoviridae. Phage SppYZU01 and SppYZU05 showed the broadest host range, being lytic towards all the 4 S. baltica strains and 5 out of the 6 S. putrefaciens strains, respectively. The genome sequence of SppYZU01 had no similarity with known genome sequences, while that of SppYZU05 was 88.5% similar to the genome of a virulent S. putrefaciens-infecting phage (Spp001). According to the host range and lytic activity, 3 phages, including SppYZU01, SppYZU05, and SppYZU06, were combined into a cocktail (designated as SPMIX3-156). SPMIX3-156 showed potential as an antimicrobial agent to control S. baltica and S. putrefaciens strain growth in catfish matrices. Bacterial growth in the catfish muscle juice inoculated with 104 colony-forming units (CFU)/mL of Shewanella strains was partially inhibited by 105 plaque-forming units (PFU)/mL of SPMIX3-156 at both 25 °C and 4 °C. The catfish fillets inoculated with Shewanella strains were used as a model to evaluate the biopreservative effects of SPMIX3-156. Total viable counts of fillet samples treated with 107 PFU/mL of SPMIX3-156 were reduced by 3.21 and 2.75 log units after 1 day at 25 °C and 10 day at 4 °C, respectively, compared to those of untreated samples. Fillet quality indices, including pH, total volatile basic nitrogen, and sensory value of the SPMIX3-156-treated samples, considerably improved compared to those of the control samples at both 4 °C and 25 °C. Our results suggest that SPMIX3-156 is a promising biological agent against S. baltica and S. putrefaciens, and may have a potential use in chilled fish fillet biopreservation.

Altered intrinsic brain activities in patients with acute eye pain using amplitude of low-frequency fluctuation: a resting-state fMRI study.

OBJECTIVE: Many previous studies have reported that pain symptoms can lead to significant brain function and anatomical changes, whereas the intrinsic brain activity changes in acute eye pain (EP) patients remain unknown. Using the amplitude of low-frequency fluctuation (ALFF) method, this study aimed to evaluate the spontaneous brain activity alterations and their relationships with clinical features in acute EP patients. PARTICIPANTS AND METHODS: A total of 20 patients with EP (15 males and 5 females) and 20 healthy controls (HCs; 15 males and 5 females) closely matched in age, sex, and education underwent resting-state functional magnetic resonance imaging scans. The ALFF method was applied to assess spontaneous brain activity changes. The ALFF values of the EP patients were distinguished from those of the HCs using a receiver operating characteristic curve. Pearson's correlation analysis was used to investigate the relationships between the mean ALFF signal values from many brain regions and the clinical features in EP patients. RESULTS: Compared with the HCs, acute EP patients had significantly lower ALFF in the left and right precentral/postcentral gyrus and left precuneus. In contrast, acute EP patients showed higher ALFF values in the right and left parahippocampal gyri and left caudate. However, no relationship was observed between the mean ALFF signal values from the different areas and clinical manifestations in the acute EP patients. CONCLUSION: We demonstrated that acute EP patients showed abnormal intrinsic brain activities in the precentral/postcentral gyrus and limbic system, which might provide useful information for explaining neural mechanisms in EP patients.

A Genetically Modified attenuated Listeria Vaccine Expressing HPV16 E7 Kill Tumor Cells in Direct and Antigen-Specific Manner.

Attenuated Listeria monocytogenes (L. monocytogenes, LM) induces specific CD8+ and CD4+ T cell responses, and has been identified as a promising cancer vaccine vector. Cervical cancer is the third most common cancer in women worldwide, with human papillomavirus (HPV), particularly type 16, being the main etiological factor. The therapeutic HPV vaccines are urgently needed. The E7 protein of HPV is necessary for maintaining malignancy in tumor cells. Here, a genetically modified attenuated LM expressing HPV16 E7 protein was constructed. Intraperitoneal vaccination of LM4Δhly::E7 significantly reduced tumor size and even resulted in complete regression of established tumors in a murine model of cervical cancer. We provided evidence that recombinant LM strains could enter the tumor tissue and induce non-specific tumor cell death, probably via activation of reactive oxygen species and increased intracellular Ca2+ levels. LM4Δhly::E7 effectively triggered a strong antigen-specific cellular immunity in tumor-bearing mice, and elicited significant infiltration of T cells in the intratumoral milieu. In summary, these data showed LM4Δhly::E7 to be effective in a cervical cancer model and LM4Δhly::E7 induced an antitumor effect by antigen-specific cellular immune responses and direct killing of tumor cells, indicating a potential application against cervical cancer.

Development of a double-monoclonal antibody sandwich ELISA: Tool for chicken interferon-γ detection ex vivo.

The aim of the present work was to develop reagents to set up a chicken interferon-γ (ChIFN-γ) assay. Four monoclonal antibodies (mAbs) specific for ChIFN-γ were generated to establish sandwich ELISA based on 2 different mAbs. To improve the detection sensitivity of ChIFN-γ, a double-monoclonal antibody sandwich ELISA was developed using mAb 3E5 as capture antibody and biotinylated mAb 3E3 as a detection reagent. The results revealed that this ELISA has high sensitivity, allowing for the detection of 125 to 500 pg/mL of recombinant ChIFN-γ, and also has an excellent capacity for detecting native ChIFN-γ. This ELISA was then used to detect ChIFN-γ level in chickens immunized with a Newcastle disease virus (NDV) vaccine, the immunized chicken splenocytes were stimulated by NDV F protein as recall antigen. From our results, it appears that the sensitivity range of this sandwich ELISA test is adequate to measure the ex vivo release of ChIFN-γ.

L'objectif de la présente étude était de développer des réactifs afin de mettre au point une épreuve de détection de l'interféron-γ de poulet (ChIFN-γ). Quatre anticorps monoclonaux (AcMo) spécifiques pour ChIFN-γ ont été produits afin d'avoir un ELISA sandwich reposant sur deux AcMo différents. Afin d'améliorer la sensibilité de détection de ChIFN-γ, un test ELISA sandwich a deux anticorps monoclonaux a été développé utilisant l'AcMo 3E5 comme anticorps de capture et l'AcMo 3E3 biotinylé comme réactif de détection. Les résultats ont démontré que ce test ELISA possède une sensibilité élevée, permettant la détection de 125 à 500 pg/mL de ChIFN-γ recombinant, et ayant également une excellente capacité à détecter le ChIFN-γ original. Ce test ELISA a par la suite été utilisé pour détecter les quantités de ChIFN-γ chez des poulets immunisés avec un vaccin contre la maladie de Newcastle (NDV), les cellules de la rate des poulets immunisés ont été stimulées par la protéine F du NDV comme antigène de rappel. À partir de nos résultats, il semble que la plage de sensibilité de ce test ELISA sandwich est adéquate pour mesurer la libération ex vivo de ChIFN-γ.(Traduit par Docteur Serge Messier).

Evaluation of Immunogenicity and Protective Efficacy Elicited by Mycobacterium bovis BCG Overexpressing Ag85A Protein against Mycobacterium tuberculosis Aerosol Infection.

Mycobacterium bovis bacillus Calmette-Guérin (BCG) is currently the only vaccine available for preventing tuberculosis (TB), however, BCG has varying success in preventing pulmonary TB. In this study, a recombinant BCG (rBCG::Ag85A) strain overexpressing the immunodominant Ag85A antigen was constructed, and its immunogenicity and protective efficacy were evaluated. Our results indicated that the Ag85A protein was successfully overexpressed in rBCG::Ag85A, and the Ag85A peptide-MHC complexes on draining lymph node dendritic cells of C57BL/6 mice infected with rBCG::Ag85A were detectable 4 h post-infection. The C57BL/6 mice infected with this strain had stronger antigen-specific interferon-gamma (IFN-γ) responses and higher antibody titers than those immunized with BCG, and the protective experiments showed that rBCG::Ag85A can enhance protection against Mycobacterium tuberculosis (M. tuberculosis) H37Rv infection compared to the BCG vaccine alone. Our results demonstrate the potential of rBCG::Ag85A as a candidate vaccine against TB.

Prevalence, characteristics, and antimicrobial resistance patterns of Salmonella in retail pork in Jiangsu province, eastern China.

Salmonella is commonly isolated from raw pork and is a leading cause of foodborne illness. Because China has the highest rate of pork consumption and the largest number of pig breeding facilities in the world, an epidemiological analysis of Salmonella species from pork in China is warranted. In this study, pork samples (n = 1,096) were collected from 20 major free markets in four cities of Jiangsu province from August 2010 to December 2012. A total of 163 Salmonella isolates were recovered from 154 Salmonella-positive samples. Among 14 Salmonella serovars identified, Derby (47.9%) was most prevalent, followed by Typhimurium (10.4%), Meleagridis (9.2%), Anatum (8.6%), and London (6.7%). Antimicrobial sensitivity testing revealed that 134 (82.2%) of the isolates were resistant to at least one antimicrobial agent, and 41 (25.2%) were resistant to more than three antimicrobials. The highest resistance was to tetracycline (66.3% of isolates) followed by ampicillin (39.9%), trimethoprim-sulfamethoxazole (31.3%), and nalidixic acid (30.1%). Multilocus sequence typing analysis revealed 14 sequence type (ST) patterns; ST40 was the most common (77 isolates) followed by ST64 (19 isolates). Our research revealed a high prevalence of Salmonella in retail pork. Diversity among the Salmonella isolates was high in terms of serovar and genotype, and multidrug resistance was prevalent. Multilocus sequence type was generally associated with serovar and provided a reliable prediction of the most common Salmonella serovars.