[Establishment and evaluation of a method for phages enrichment by ferric trichloride-polyvinylidene fluoride membrane filter].

Objective: To establish and evaluate a method of enriching bacteriophages in natural water based on ferric trichloride-polyvinylidene fluoride (FeCl3-PVDF)membrane filter. Methods: Based on the principle of flocculation concentration, the method of recovering bacteriophage from water sample was established by using iron ion flocculation combined with membrane filter. The titer of phage was determined by Agar double layer method. The recovery efficiency of phage was detected by phage fluorescence staining and real-time fluorescence PCR reaction. Water samples from different sources were collected for simulation experiment to evaluate the enrichment effect. At the same time, the sewage discharged from hospitals was taken as the actual water sample, and the common clinical drug-resistant bacteria were used as the host indicator bacteria to further analyze the enrichment effect of FeCl3-PVDF membrane filter rapid enrichment method on the bacteriophage in natural water samples. Results: The method of enrichment of bacteriophages in natural water by iron ion concentration 50 mg/L and PVDF membrane filter was established. The recovery rate of this method for bacteriophage was 93%-100%. Under the multi-functional microscope, it was found that the bacteriophage of the enriched water sample increased significantly and the fluorescence value of the enriched water sample determined by the enzyme labeling instrument was about 13 times as high as that before enrichment. After concentration of the actual water samples from the hospital drainage, the positive rate of bacteriophage isolation in the concentrated group and the non-concentrated group was 23% and 4%, and the fluorescence value in the concentrated group was 2-24 times as high as that of the non-concentrated group. Conclusion: The method of FeCl3-PVDF membrane filter is a simple, efficient and rapid method for enriching bacteriophages in different water samples.

[Drug resistance and genomic characteristics of a strain of O139 Vibrio cholerae isolated from human bloodstream infection].

Objective: To analyze the drug resistance and genomic characteristics of a strain of serogroup O139 Vibrio cholerae producing cholera toxin isolated from the bloodstream of a person with bacteremia. Methods: The broth dilution method and automatic drug sensitivity analyzer were used to determine the antibiotic sensitivity of the strain. The complete genome sequence of the strain was obtained by using second-generation gene sequencing and nanopore sequencing. BLAST software was used for comparison and analysis with CARD, Resfinder, ISfinder, VFDB, and other databases. The drug-resistant genes, insertion sequences and virulence genes carried by the strain were identified. MEGA 5.1 software was used to construct a genetic phylogenetic tree based on the core genomic single nucleotide polymorphisms. Results: V. cholerae SH400, as the toxigenic strain, carried multiple virulence-related genes and four virulence islands. The strain was resistant to streptomycin, tetracycline and cotrimoxazole, carrying corresponding drug-resistant genes. The strain also carried IncA/C plasmid with the size of 172914 bp and contained 10 drug-resistant genes. Combined with the genomic evolutionary relationship, this study found that the drug-resistant genes and drug-resistant plasmids carried among strains showed certain aggregation. The traditional ST type of strain SH400 was ST69, and the cgMLST type was a new type highly similar to cgST-252. Conclusion: This strain of serogroup O139 V. cholerae carries the ctxAB gene, multiple drug-resistant genes and IncA/C plasmid, and there are multiple drug-resistant islands.

[Advance on research and application of laboratory pathogen monitoring and early warning technology of bacterial infectious diseases].

Human beings are still facing the public health challenges from bacterial infectious diseases. Carrying out systematic infectious disease monitoring and early warning is the most direct solution to prevent and control infectious diseases. Etiology is an important part of infectious disease monitoring and early warning. Effective pathogen monitoring can identify pathogens, outbreaks and sources at the first time. In this study, we have reviewed the research and application of etiology monitoring and early warning technology of bacterial infectious diseases and summarized the importance and application scenarios of etiology in infectious disease monitoring and early warning, as well as the research progress of etiology monitoring and early warning technology. Based on the work of existing laboratory monitoring networks, such as Chinese Pathogen Identification Network, the development trend and prospect of infectious disease laboratory network monitoring are put forward to provide a reference for establishing and perfecting the infectious disease monitoring and early warning system.

[Application and reflection of laboratory-based monitoring in early warning of infectious diseases].

Despite the fact that our cognition towards infectious disease prevention, the advanced technology and the economic status of the whole society has made a great progress in the last decade, the outbreak of COVID-19 pneumonia has again enabled the public to acquire more about super-challenges of infectious diseases, epidemics and the relevant preventive measurements. In order to identify the epidemic signals in early stage or even before the onset of epidemic, the data research and utilization of a series of factors related to the occurrence and transmission of infectious diseases have played a significant role in research of prevention and control during the whole period of surveillance and early warning. Laboratory-based monitoring for the etiology has always been an important part of infectious disease warning system due to pathogens as the direct cause of such diseases. China has initially established a laboratory-based monitoring and early warning system for bacterial infectious diseases based on the Chinese Pathogen Identification Network with an aim to identify pathogens, outbreaks and sources. This network has played an essential role in early detection, tracking and precise prevention and control of bacterial infectious diseases, such as plague, cholera, and epidemic cerebrospinal meningitis. This issue focuses on the function of laboratory-based monitoring during the period of early warning, prevention, and control of bacterial infectious diseases, and conducted a wide range of researches based on the analysis of the epidemic and outbreak isolates, together with field epidemiological studies and normal monitoring systems. All of these could illustrate the effect of laboratory surveillance in the infectious disease risk assessment and epidemic investigation. At the same time, we have put forward our review and expectation of scenarios about laboratory-based monitoring and early warning technologies to provide innovative thoughts for promoting a leapfrog development of infectious disease monitoring and early warning system in China.

[Combined application of field epidemiology and laboratory etiology analysis in the investigation of a foodborne disease outbreak in Xinjiang uygur Autonomous Region, 2016].

Objectives: To analyze the causes of a foodborne outbreak in rural areas of Xinjiang between April 2 and April 5 in 2016. Methods: Cases and the relevant background information were obtained by consulting outpatient records of local health centers and regional people's hospitals and interviewing doctors and residents. All samples were collected by the laboratory test through epidemiological and food hygiene investigations. The χ2 test (Fisher's exact probability method) was used to compare differences in incidence rates. Molecular typing, virulence genes and single nucleotide polymorphisms (SNPS) were analyzed by using Pulsed Field Gel Electrophoresis (PFGE) and Whole Genome Sequencing (WGS). Results: A total of 142 cases were found in this study, with incidence rate at 5.7‰ (142/24 979). Among all cases, the main symptoms were nausea (94%), vomiting (92%) and abdominal pain (67%), and the incubation period was about 2 h (1-7.5 h). There were 16 Staphylococcus aureus isolates identified and all of them could produce A+C+E mixed enterotoxin. PFGE showed 100% homology. WGS further revealed that there were 9 and 1 strains contained by Sequence Type 1 (ST1) and ST5405, respectively. All ST1 strains were in the same clade on the genome tree. Among these, 7 strains shared close proximity (74 SNPs) and 2 strains shared close relationships as well (127 SNPs). The S. aureus isolates that caused the outbreak were introduced by a mutant isolate from the milk supply station. Conclusions: This foodborne outbreak was mainly caused by Staphylococcus aureus contamination.

[Clinical features and survival analysis of microscopic polyangiitis-associated interstitial lung disease:a retrospective study of 28 patients].

Objective: To explore the clinical features, laboratory examination and imaging features of microscopic polyangiitis (MPA)-associated interstitial lung disease (ILD), and to perform survival analysis. Methods: The records of 28 patients with MPA-ILD who were treated at the Affiliated Hospital of Medical School of Ningbo University were reviewed retrospectively from August 2014 to November 2021. The patients' clinical features, laboratory parameters, pulmonary function test, echocardiography, chest CT scan findings and therapeutic regimen were analyzed, and the relevant data were statistically analyzed. Results: There were 18 males and 10 females, with an average age of (70.1±9.3) years. Among them, 13 patients had a history of smoking. The main clinical manifestations were cough (14/28), fever (12/28), chest tightness, shortness of breath (12/28) and hemoptysis (3/28). Sixteen patients had renal involvement, and 78.57% (22/28) and 89.28% (25/28) of the patients had elevated C-reactive protein (CRP) and ESR respectively. Sixteen (16/28) patients had increased rheumatoid factor (RF), and the positive rate of myeloperoxidase antineutrophil cytoplasmic antibodies (MPO-ANCA) was 82.12% (23/28). 96.43% (27/28) of ILDs were diagnosed before or at the same time as MPA. The chest radiological pattern was mainly usual interstitial pneumonia (UIP) or UIP-like (15/28), followed by nonspecific interstitial pneumonia (NSIP) (8/28). Compared with non-UIP-like patients, UIP or UIP-like patients were older (P=0.018), and had higher serum LDH level (P=0.041), but serum creatinine level was significantly lower (P=0.041). Univariate and multivariate survival analysis showed that inappropriate treatment (HR=9.81, 95%CI: 1.68-57.29, P=0.011) and elevated serum LDH (HR=4.11, 95%CI: 0.99-17.00, P=0.051) were independent risk factors for shortened survival of MPA-ILD, while elevated RF (HR=0.22, 95%CI: 0.06-0.91, P=0.037) was a protective factor for prolonged survival. Conclusions: MPA-ILD patients had fewer systemic vasculitis symptoms. Most of the ILD patients were diagnosed before or at the same time as MPA. The chest radiological pattern was mainly UIP or UIP-like, followed by NSIP. Early use of glucocorticoids combined with immunosuppressant or rituximab could improve the survival rate of MPA-ILD. The elevated serum LDH was an independent risk factor for shortened survival of MPA-ILD, while elevated RF was a protective factor for prolonged survival.

[Efficacy and safety of ticagrelor versus clopidogrel in Chinese patients with acute coronary syndrome treated with glycoprotein â ¡b/â ¢a receptor antagonist].

Objective: To explore the efficacy and safety of ticagrelor versus clopidogrel in acute coronary syndrome (ACS) Chinese patients using glycoprotein Ⅱb/Ⅲa inhibitor (GPI). Methods: The data from CCC-ACS (Improving Care for Cardiovascular Disease in China-ACS) project were systematically reviewed in ACS patients with GPI. The patients were divided into ticagrelor and clopidogrel groups. A logistic analysis and propensity score matching (PSM) were performed to compare occurrences of major cardiovascular events (MACE) and bleeding events between the two groups during hospitalization. Results: A total of 63 641 ACS patients were collected from 150 hospitals. Logistic regression analyses showed that there was no statistically significant difference in the reduction of MACE between ticagrelor and clopidogrel when using GPI (OR=0.881, 95%CI 0.599-1.296; P=0.521). However, major bleeding rate was higher in the ticagrelor group than that in the clopidogrel group (OR=1.401, 95%CI 1.075-1.852; P=0.013). Similar results were observed after PSM. No statistic difference in MACE between the ticagrelor and clopidogrel group (OR=0.919, 95%CI 0.613-1.376; P=0.681). Major bleeding rate was higher in the ticagrelor group (OR=1.559, 95%CI 1.130-2.150; P=0.007). Conclusion: In ACS patients with GPI, ticagrelor did not reduce MACE, but increased the major bleeding risk compared with clopidogrel.

[Genomic subtyping of nosocomial transmission of carbapenem resistant Klebsiella pneumoniae].

Objective: To analyze the genomic epidemiological subtyping of carbapenem resistant Klebsiella pneumoniae (CRKP) isolated from a Third-class A hospital in Zhengzhou. Methods: From December 4, 2019 to January 10, 2020, 67 strains of CRKP were isolated from the samples submitted by the clinical departments of a Third-class A teaching hospital in Zhengzhou for microbiological testing. Multi-locus sequence typing (MLST) and carbapenem resistance genes were identified by whole genome sequencing and sequence analysis. Based on the whole genome SNP, the phylogenetic tree was constructed, and 67 CRKP strains were divided into clonal groups. The isolation ward and date of each clone group were analyzed. Results: Sixty-seven CRKP strains were classified into four MLST types (STs), of which 64 were ST11. There were 62 ST11 strains carrying blaKPC-2 gene. Based on genome-wide SNP phylogenetic tree, 64 ST11 strains were divided into four clone groups, two of which were dominant clone groups, including 33 and 27 strains respectively; the other two clone groups only contained 2 strains respectively. There was no aggregation of the dominant clones in the isolation department and date. Conclusion: Multiple clonal groups of ST11 strain carrying blaKPC-2 gene are differentiated during spreading, and they can spread in parallel and independently in the same hospital.

[Laboratory testing and tracing analysis of a typhoid epidemic in Jiangyin city, Jiangsu Province].

To conduct outbreak identification and transmission factor analysis of typhoid epidemic occurred in Xinqiao town, Jiangyin city from June to September 2016. A total of 14 strains of Salmonella typhi isolated from confirmed cases were collected, and 65 external environment samples and 13 food samples related to the outbreak were taken. Real-time PCR was used to detect specific gene of Salmonella typhi in the samples. Conventional method was used to isolate strains. The strains isolated from both the samples and patients in the epidemic were subjected to antimicrobial susceptibility testing and PFGE molecular characteristics. Salmonella typhi strain was isolated from one external sample (well water of a deli processing plant). The results of drug susceptibility showed that 15 strains were resistant to nalidixic acid. A total of 15 strains of Salmonella typhi were divided into 2 molecular patterns by pulsed field gel electrophoresis. The fingerprints of PFGE from the 13 patients and the environmental isolate were completely consistent, and there was one band difference from the other patient isolate. Combined with the epidemiological investigation and laboratory test results, it was determined that the outbreak was caused by genetic clone of the same Salmonella typhi. Food processing plant should be one of the key links.

[Daclatasvir-sofosbuvir combination therapy for chronic hepatitis C virus infection: progress in clinical studies].

All-oral, pan-genotypic combination of direct-acting antiviral agents is currently clinically prescribed trends in the management of chronic hepatitis C virus infection. The combination of daclatasvir and sofosbuvir has proven strong antiviral activity across all common genotypes in clinical trials and real world studies. Furthermore, it can be safely used in patients with advanced liver disease, HCV/HIV co-infection, or HCV recurrence after liver transplantation, more patients will gain clinical benefits. We aim to summarize the clinical progress about this combination.

Risks of undernutrition and malnutrition in hospitalized pediatric patients with spinal cord injury.

STUDY DESIGN: Prospective study. OBJECTIVES: To describe the nutritional risk/status of Chinese children with spinal cord injury (SCI) at admission and determine the relationship between nutritional risk/status and demography/SCI characteristics. SETTING: China Rehabilitation Research Center, Beijing, China. METHODS: Baseline clinical data, appetite level, anthropometric measurements and Screening Tool for the Assessment of Malnutrition in Pediatrics (STAMP) scores were obtained for pediatric SCI patients. The relationships among the demographic/SCI characteristics and STAMP score and z-scores of weight-for-age (WAZ), height-for-age (HAZ) and body mass index-for-age (BAZ) were assessed. The risk of undernutrition was compared with actual nutritional status. RESULTS: Forty-five children including 12 boys and 33 girls were included. The risks of undernutrition using the STAMP tool and malnutrition were 51.1% and 55.6%, respectively. Children with different demographic characteristics had similar nutritional status and risk of malnutrition. The risk of undernutrition was associated with nutritional status, including WAZ (P<0.001), HAZ (P=0.001), BAZ (P<0.001) and appetite level (P<0.001). Compared with nutritional status, STAMP had a sensitivity of 100%, a specificity of 73.3% and an overall agreement of 82.2%. As the duration of SCI increased, the risks of overweight and stunting increased. CONCLUSIONS: Nutritional screening in all pediatric SCI patients should be performed periodically. The decreasing trends in nutritional status and appetite level after SCI require special attention. The STAMP may be an alternative method for assessing nutritional status in Chinese children with SCI.

[Molecular epidemiology of carbapenem resistant Klebsiella pneumoniae in a hospital in Beijing].

Objective: To reveal the molecular epidemiological characteristics of Carbapenem-Resistant Klebsiella pneumoniae (CRKP) isolated from a three level teaching hospital in Beijing. Methods: Pulsed field gel electrophoresis (PFGE) was carried out to subtyping 375 CRKP isolated in that hospital between May 2010 and October 2015. Fifteen strains were chose based on the PFGE patterns to be analyzed by multi-locus sequence typing (MLST) and detection of carbapenem-resistance genes. One strain (A1502) was selected for whole genome sequencing and analyzing. Results: The 375 CRKP were divided into 140 PFGE types, among which five types contained more than five strains. The dominant types were distributed in different time periods and wards. Among the 15 strains tested by MLST and carbapenem-resistance genes detection, 13 were ST11 strains carrying KPC-2 gene. By genome-based typing, A1502 was clustered together with strains from other hospitals of Beijing but far from the strains from Shanghai and Hangzhou. Conclusion: The CRKP epidemic clone (ST11 clone carrying KPC-2) has been spreading within single hospital and across different hospitals in Beijing.

[Clinical characteristics analysis of 120 cases of pediatric spinal cord injury without radiologic abnormality].

OBJECTIVE: To study the epidemiologic characteristics of pediatric spinal cord injury without radiologic abnormality. METHODS: A retrospective analysis was performed and 120 cases of children with spinal cord injury without radiologic abnormality were admitted in China Rehabilitation Research Center from January 2005 to December 2014.The gender, age, causes of injury, injury condition and complication were analyzed. All cases were divided into two groups (0-7 years old and 8-13 years old) according to age. RESULTS: One hundred and twenty cases included 31 boys (25.8%) and 89 girls (74.2%). Most of the children were 0-7 years old (96 cases, 80.0%). The top 3 causes of spinal cord injury were sports activities (60 cases, 50.0%), traffic accident (25 cases, 29.2%) and other trauma (11 cases, 12.5%). Seventy-one cases were low-energy injury (59.2%) and 49 cases were high-energy trauma (40.8%), most of low-energy injury were completely injured (56 cases, 78.9%). The complication rate was 59.2% and the top 3 complications were urinary infection (35 cases, 29.2%), hydronephrosis (12 cases, 10.0%) and pressure ulcers (10 cases, 8.3%). CONCLUSION: It is needed to pay more attention to pediatric spinal cord injury without radiologic abnormality caused by low-energy injury, especially children aged 0-7 years old with history of slight injury, and be careful about spinal cord injury without radiologic abnormality result from high-energy damage.

Multilocus variable-number tandem-repeat analysis of Neisseria meningitidis serogroup C in China.

This study characterized Neisseria meningitidis serogroup C strains in China in order to establish their genetic relatedness and describe the use of multilocus variable-number tandem-repeat (VNTR) analysis (MLVA) to provide useful epidemiological information. A total of 215 N. meningitidis serogroup C strains, obtained from 2003 to 2012 in China, were characterized by MLVA with different published schemes as well as multilocus sequence typing. (i) Based on the MLVA scheme with a combination of five highly variable loci, 203 genotypes were identified; this level of discrimination supports its use for resolving closely related isolates. (ii) Based on a combination of ten low variable loci, clear phylogenetic relationships were established within sequence type complexes. In addition, there was evidence of microevolution of VNTR loci over the decade as strain lineages spread from Anhui to other provinces, the more distant the provinces from Anhui, the higher the genetic variation.

[Study of the urban-impact on microbial communities and their virulence factors and antibiotic resistance genomes in the Nandu River, Haikou].

Objective: To explore the changes in bacterial community structure, antibiotic resistance genome, and pathogen virulence genome in river water before and after the river flowing through Haikou City and their transmission and dispersal patterns and to reveal anthropogenic disturbance's effects on microorganisms and resistance genes in the aquatic environment. Methods: The Nandu River was divided into three study areas: the front, middle and rear sections from the upstream before it flowed through Haikou City to the estuary. Three sampling sites were selected in each area, and six copies of the sample were collected in parallel at each site and mixed for 3 L per sample. Microbial community structure, antibiotic resistance, virulence factors, and mobile genetic elements were analyzed through bioinformatic data obtained by metagenomic sequencing and full-length sequencing of 16S rRNA genes. Variations in the distribution of bacterial communities between samples and correlation of transmission patterns were analyzed by principal co-ordinates analysis, procrustes analysis, and Mantel test. Results: As the river flowed through Haikou City, microbes' alpha diversity gradually decreased. Among them, Proteobacteria dominates in the bacterial community in the front, middle, and rear sections, and the relative abundance of Proteobacteria in the middle and rear sections was higher than that in the front segment. The diversity and abundance of antibiotic resistance genes, virulence factors, and mobile genetic elements were all at low levels in the front section and all increased significantly after flow through Haikou City. At the same time, horizontal transmission mediated by mobile genetic elements played a more significant role in the spread of antibiotic-resistance genes and virulence factors. Conclusions: Urbanization significantly impacts river bacteria and the resistance genes, virulence factors, and mobile genetic elements they carry. The Nandu River in Haikou flows through the city, receiving antibiotic-resistant and pathogen-associated bacteria excreted by the population. In contrast, antibiotic-resistant genes and virulence factors are enriched in bacteria, which indicates a threat to environmental health and public health. Comparison of river microbiomes and antibiotic resistance genomes before and after flow through cities is a valuable early warning indicator for monitoring the spread of antibiotic resistance.

[Population structure of food-borne Staphylococcus aureus in China].

Objective: To understand the population structure of food-borne Staphylococcus (S.) aureus in China. Methods: Whole genome sequencing was used to analyze 763 food-borne S. aureus strains from 16 provinces in China from 2006 to 2020. Multilocus sequence typing (MLST), staphylococcal protein A gene (spa) typing, and staphylococcal chromosome cassettemec (SCCmec) typing were conducted, and minimum spanning tree based on ST types (STs) was constructed by BioNumerics 7.5 software. Thirty-one S. aureus strains isolated from imported food products were also included in constructing the genome phylogenetic tree. Results: A total of 90 STs (20 novel types) and 160 spa types were detected in the 763 S. aureus isolates. The 72 STs (72/90, 80.0%) were related to 22 clone complexes. The predominant clone complexes were CC7, CC1, CC5, CC398, CC188, CC59, CC6, CC88, CC15, and CC25, accounting for 82.44% (629/763) of the total. The STs and spa types in the predominant clone complexes changed over the years. The methicillin-resistant S. aureus (MRSA) detection rate was 7.60%, and 7 SCCmec types were identified. The ST59-t437-Ⅳa (17.24%, 10/58), ST239-t030-Ⅲ (12.07%, 7/58), ST59-t437-Ⅴb (8.62%, 5/58), ST338-t437-Ⅴb (6.90%, 4/58) and ST338-t441-Ⅴb (6.90%, 4/58) were the main types in MRSA strains. The genome phylogenetic tree had two clades, and the strains with the same CC, ST, and spa types clustered together. All CC7 methicillin sensitive S. aureus strains were included in Clade1, while 21 clone complexes and all MRSA strains were in Clade2. The MRSA strains clustered according to the SCCmec and STs. The strains from imported food products in CC398, CC7, CC30, CC12, and CC188 had far distances from Chinese strains in the tree. Conclusions: In this study, the predominant clone complexes of food-borne strains were CC7, CC1, CC5, CC398, CC188, CC59, CC6, CC88, CC15, and CC25, which overlapped with the previously reported clone complexes of hospital and community-associated strains in China, suggesting that close attention needs to be paid to food, a vehicle of pathogen transmission in community and food poisoning.

Caecal transcriptome analysis of colonized and non-colonized chickens within two genetic lines that differ in caecal colonization by Campylobacter jejuni.

Campylobacter jejuni is one of the most common causes of human bacterial enteritis worldwide. The molecular mechanisms of the host responses of chickens to C. jejuni colonization are not well understood. We have previously found differences in C. jejuni colonization at 7-days post-inoculation (pi) between two genetic broiler lines. However, within each line, not all birds were colonized by C. jejuni (27.5% colonized in line A, and 70% in line B). Therefore, the objective of the present experiments was to further define the differences in host gene expression between colonized and non-colonized chickens within each genetic line. RNA isolated from ceca of colonized and non-colonized birds within each line was applied to a chicken 44K Agilent microarray for the pair comparison. There were differences in the mechanisms of host resistant to C. jejuni colonization between line A and line B. Ten times more differentially expressed genes were observed between colonized and non-colonized chickens within line B than those within line A. Our study supports the fact that the MAPK pathway is important in host response to C. jejuni colonization in line B, but not in line A. The data indicate that inhibition of small GTPase-mediated signal transduction could enhance the resistance of chickens to C. jejuni colonization and that the tumour necrosis factor receptor superfamily genes play important roles in determining C. jejuni non-colonization in broilers.

Effects of cold stress on growth performance, serum biochemistry, intestinal barrier molecules, and adenosine monophosphate-activated protein kinase in broilers.

The homeostasis dysfunctions caused by cold stress remain a threat to intestinal health, particularly for young broiler chickens. We hypothesized that adenosine monophosphate-activated protein kinase (AMPK) was involved in the regulation of cold stress on intestinal health. This study aimed to examine the effect of cold stress for 72 h on growth performance, serum biochemistry, intestinal barrier molecules, and AMPK in broilers. A total of 144 10-day-old male Arbor Acres broilers were subjected to temperature treatments (control 28  ±â€¯1 °C vs cold stress 16 ±â€¯1 °C) for 72 h. Growth performance was monitored, serum was collected for the analysis of physiological parameters, and jejunal mucosa was sampled for the determination of tight junction (TJ) proteins, heat shock proteins, and AMPK signaling molecules. Results showed that 72 h cold treatment reduced average BW gain and increased the feed conversion ratio of the broilers (P < 0.05). Cold stress for 72 h increased blood endotoxin, aspartate aminotransferase, glucose, and low-density lipoprotein cholesterol levels (P < 0.05). Moreover, 72 h cold treatment up-regulated jejunal Occludin, zonula occludin 1, inducible nitric oxide synthase, heat shock factor 1, and AMPKα1 gene expression (P < 0.05) but had no obvious effect on total AMPK protein expression (P > 0.05). In conclusion, cold stress significantly reduced the growth performance of broiler chickens. The intestinal barrier function might be impaired, and enhanced bacterial translocation might occur. The unregulated gene expression of TJ proteins implied the remodeling of intestinal barrier. The change of AMPK suggested the possible relationship between intestinal energy metabolism and barrier function under cold stress.

Significant histopathology in Chinese chronic hepatitis B patients with persistently high-normal alanine aminotransferase.

Current guidelines recommend antiviral therapy for chronic hepatitis B (CHB) patients with elevated alanine aminotransferase (ALT) and high viral load. Scant histological data exist for CHB patients with persistently normal ALT (PNALT) because disease progression is thought to be rare. To identify potential predictors of significant histology in the presence of PNALT, we compared the clinical characteristics and histology of Chinese CHB PNALT patients to those in patients with elevated ALT. Percutaneous liver biopsy was performed in 522 CHB patients with Chinese ethnicity who had not had antiviral treatment. Differences in age, ALT, viral load, hepatitis B e antigen (HBeAg) status and liver histology were compared between eligible PNALT (252) and elevated ALT (270) patients. Of the PNALT patients, 38.5% had normal liver histology, 25.4% had significant necroinflammation and/or fibrosis and 8.4% had established cirrhosis. Furthermore, histopathological differences between patients with high-normal ALT (0.5-1.0 x the upper limit of normal (ULN)) and low-normal ALT (≤ 0.5 x ULN) were evaluated. There was a significantly greater prevalence of histopathology in the high-normal group (40.0%) than in the low-normal group (16.6%) (P < 0.001). Multiple logistic regression identified that significant histopathology findings in PNALT patients correlated with age (P < 0.001) and ALT level (P < 0.001), with age >40 years and ALT >0.5 x ULN predicting significant histopathology. Our data indicate that liver biopsy is recommended in CHB patients >40 years of age, particularly when their ALT is 0.5-1.0 x ULN. The findings above provide evidence for indication of antiviral therapy in patients with PNALT and significant histopathological change.