1.Isolation and Identification of Staphylococcus xylosus in Nude Mice with Squamous Skin Scurfs
Zhihao KONG ; Xiaofeng WEI ; Lingzhi YU ; Liping FENG ; Qi ZHU ; Guojun SHI ; Chen WANG
Laboratory Animal and Comparative Medicine 2025;45(3):368-375
Objective To isolate pathogenic bacteria from the skin of a nude mouse exhibiting squamous skin scurfs, and perform bacterial identification, traceability analysis, and pathogenicity studies to provide a new approach for the diagnosis of pathogens in nude mice with squamous skin scurfs. MethodsSkin swab samples were collected from a nude mouse exhibiting squamous skin scurfs for nucleic acid testing, bacterial isolation and culture, biochemical identification, 16S rDNA gene amplification and sequencing, and whole genome sequencing to construct a phylogenetic tree. Fifteen BALB/c nude mice were randomized into a saline-treated control group, a high-concentration group treated with 1.8×10⁸ CFU/mL of the isolated bacterial suspension, and a low-concentration group treated with 1.8×10⁷ CFU/mL of the isolated bacterial suspension. Pathogenicity was assessed by animal infection experiments and observation of histopathological changes in skin tissue using HE staining. Results The nucleic acid test for Corynebacterium bovis was negative, excluding infection by this organism. The pathogen isolated on mannitol salt agar and blood agar, combined with Gram staining, suggested a Gram-positive Staphylococcus species. The isolated strain was identified by 16S rDNA sequencing and a fully automated microbial identification system as Staphylococcus xylosus. Phylogenetic tree analysis based on whole genome sequencing showed that the strain was most closely related to an isolate from leafy vegetables in South Korea (GenBank GCA_00207825.1). In the high-concentration group, squamous skin scurfs appeared on the head, neck, and back of nude mice on the 17th day post-infection, while in the low concentration group, similar symptoms appeared on the 20th day post-infection and gradually spread to other areas. The scaling symptoms were transient, lasting for 7 days in the high-concentration group and 3 days in the low-concentration group, after which the skin returned to normal. The infection rate was 33.33% in both the high- and low-concentration groups. No significant pathological changes were observed in the skin tissues of infected mice compared to the control group, indicating marked individual differences in the pathogenicity of the strain in nude mice. Conclusion A strain of Staphylococcus xylosus was isolated from the skin of a nude mouse exhibiting squamous skin scurfs. The strain is an opportunistic pathogen that causes transient squamous skin scurfs without significant histopathological changes, and there are individual differences in the sensitivity of nude mice to this strain. These findings can provide valuable data for pathogen identification in immunodeficient or gene knockout mice.
2.Isolation and Identification of Staphylococcus xylosus in Nude Mice with Squamous Skin Scurfs
Zhihao KONG ; Xiaofeng WEI ; Lingzhi YU ; Liping FENG ; Qi ZHU ; Guojun SHI ; Chen WANG
Laboratory Animal and Comparative Medicine 2025;45(3):368-375
Objective To isolate pathogenic bacteria from the skin of a nude mouse exhibiting squamous skin scurfs, and perform bacterial identification, traceability analysis, and pathogenicity studies to provide a new approach for the diagnosis of pathogens in nude mice with squamous skin scurfs. MethodsSkin swab samples were collected from a nude mouse exhibiting squamous skin scurfs for nucleic acid testing, bacterial isolation and culture, biochemical identification, 16S rDNA gene amplification and sequencing, and whole genome sequencing to construct a phylogenetic tree. Fifteen BALB/c nude mice were randomized into a saline-treated control group, a high-concentration group treated with 1.8×10⁸ CFU/mL of the isolated bacterial suspension, and a low-concentration group treated with 1.8×10⁷ CFU/mL of the isolated bacterial suspension. Pathogenicity was assessed by animal infection experiments and observation of histopathological changes in skin tissue using HE staining. Results The nucleic acid test for Corynebacterium bovis was negative, excluding infection by this organism. The pathogen isolated on mannitol salt agar and blood agar, combined with Gram staining, suggested a Gram-positive Staphylococcus species. The isolated strain was identified by 16S rDNA sequencing and a fully automated microbial identification system as Staphylococcus xylosus. Phylogenetic tree analysis based on whole genome sequencing showed that the strain was most closely related to an isolate from leafy vegetables in South Korea (GenBank GCA_00207825.1). In the high-concentration group, squamous skin scurfs appeared on the head, neck, and back of nude mice on the 17th day post-infection, while in the low concentration group, similar symptoms appeared on the 20th day post-infection and gradually spread to other areas. The scaling symptoms were transient, lasting for 7 days in the high-concentration group and 3 days in the low-concentration group, after which the skin returned to normal. The infection rate was 33.33% in both the high- and low-concentration groups. No significant pathological changes were observed in the skin tissues of infected mice compared to the control group, indicating marked individual differences in the pathogenicity of the strain in nude mice. Conclusion A strain of Staphylococcus xylosus was isolated from the skin of a nude mouse exhibiting squamous skin scurfs. The strain is an opportunistic pathogen that causes transient squamous skin scurfs without significant histopathological changes, and there are individual differences in the sensitivity of nude mice to this strain. These findings can provide valuable data for pathogen identification in immunodeficient or gene knockout mice.
3.Endo-beta-N-acetylglucosaminidase: Possible Functions and Mechanisms
Xin-Rong LU ; Yong-Liang TONG ; Wei-Li KONG ; Lin ZOU ; Dan-Feng SHEN ; Shao-Xian LÜ ; Rui-Jie LIU ; Shao-Xing ZHANG ; Yu-Xin ZHANG ; Lin-Lin HOU ; Gui-Qin SUN ; Li CHEN
Progress in Biochemistry and Biophysics 2024;51(5):985-999
Endo-beta-N-acetylglucosaminidase (ENGase) is widely distributed in various organisms. The first reported ENGase activity was detected in Diplococcus pneumoniae in 1971. The protein (Endo D) was purified and its peptide sequence was determined in 1974. Three ENGases (Endo F1-F3) were discovered in Flavobacterium meningosepticum from 1982 to 1993. After that, the activity was detected from different species of bacteria, yeast, fungal, plant, mice, human, etc. Multiple ENGases were detected in some species, such as Arabidopsis thaliana and Trichoderma atroviride. The first preliminary crystallographic analysis of ENGase was conducted in 1994. But to date, only a few ENGases structures have been obtained, and the structure of human ENGase is still missing. The currently identified ENGases were distributed in the GH18 or GH85 families in Carbohydrate-Active enZyme (CAZy) database. GH18 ENGase only has hydrolytic activity, but GH85 ENGase has both hydrolytic and transglycosylation activity. Although ENGases of the two families have similar (β/α)8-TIM barrel structures, the active sites are slightly different. ENGase is an effective tool for glycan detection andglycan editing. Biochemically, ENGase can specifically hydrolyze β‑1,4 glycosidic bond between the twoN-acetylglucosamines (GlcNAc) on core pentasaccharide presented on glycopeptides and/or glycoproteins. Different ENGases may have different substrate specificity. The hydrolysis products are oligosaccharide chains and a GlcNAc or glycopeptides or glycoproteins with a GlcNAc. Conditionally, it can use the two products to produce a new glycopeptides or glycoprotein. Although ENGase is a common presentation in cell, its biological function remains unclear. Accumulated evidences demonstrated that ENGase is a none essential gene for living and a key regulator for differentiation. No ENGase gene was detected in the genomes of Saccharomyces cerevisiae and three other yeast species. Its expression was extremely low in lung. As glycoproteins are not produced by prokaryotic cells, a role for nutrition and/or microbial-host interaction was predicted for bacterium produced enzymes. In the embryonic lethality phenotype of the Ngly1-deficient mice can be partially rescued by Engase knockout, suggesting down regulation of Engase might be a solution for stress induced adaptation. Potential impacts of ENGase regulation on health and disease were presented. Rabeprazole, a drug used for stomach pain as a proton inhibitor, was identified as an inhibitor for ENGase. ENGases have been applied in vitro to produce antibodies with a designated glycan. The two step reactions were achieved by a pair of ENGase dominated for hydrolysis of substrate glycoprotein and synthesis of new glycoprotein with a free glycan of designed structure, respectively. In addition, ENGase was also been used in cell surface glycan editing. New application scenarios and new detection methods for glycobiological engineering are quickly opened up by the two functions of ENGase, especially in antibody remodeling and antibody drug conjugates. The discovery, distribution, structure property, enzymatic characteristics and recent researches in topical model organisms of ENGase were reviewed in this paper. Possible biological functions and mechanisms of ENGase, including differentiation, digestion of glycoproteins for nutrition and stress responding were hypothesised. In addition, the role of ENGase in glycan editing and synthetic biology was discussed. We hope this paper may provide insights for ENGase research and lay a solid foundation for applied and translational glycomics.
4.Glycyrrhizic Acid Showed Therapeutic Effects on Severe Pulmonary Damages in Mice Induced by Pneumonia Virus of Mice Infection
Yun LIU ; Tingting FENG ; Wei TONG ; Zhi GUO ; Xia LI ; Qi KONG ; Zhiguang XIANG
Laboratory Animal and Comparative Medicine 2024;44(3):251-258
Objective In this study,inbred BALB/c mice infected with the pneumonia virus of mice(PVM)were used to establish an animal model of viral pneumonia,and the changes in the pro-inflammatory alarmin molecule,high mobility group box 1 protein(HMGB1),during PVM infection were observed,as well as the in vivo intervention effects of the HMGB1 inhibitor,glycyrrhizic acid(GA),on PVM-induced lung injury.Methods Three-week-old female BALB/c mice were randomly divided into three groups,each consisting of 6 mice.One group,uninfected by PVM,served as the control group(Control).The other two groups were inoculated intranasally with PVM at a dose of 1×104 50%tissue culture infective dose(TCID50)/25 μL,and subsequently treated with GA saline solution(GA group)or plain saline solution(normal saline,NS group)via gavage for 15 consecutive days.During this period,changes in body weight and appearance were monitored in each group.At the end of the experiment,lung tissue samples were collected from all groups.The distribution of PVM and HMGB1 proteins in the lung tissues was analyzed using hematoxylin-eosin staining and immunohistochemistry.The expression levels of HMGB1 and its Toll-like receptor 4(TLR-4),advanced glycosylation end-product-specific receptor(AGER),and inflammatory cytokines such as interleukin(IL)-1β,IL-2,and tumor necrosis factor-α(TNF-α)in lung tissues of mice were measured using real time fluorescence quantitative PCR.Results Compared with the Control group,the NS group showed a significant weight loss after 6 days(P<0.05).Histopathological tests revealed pronounced inflammatory lesions in their lungs.Immunohistochemistry results showed that HMGB1 was released from the nucleus to the cytoplasm,and real time fluorescence quantitative PCR results indicated that the expression levels of HMGB1,IL-1β,and IL-2 were significantly upregulated(P<0.05).In the GA group,there was no significant change in the clinical symptoms or body weight.However,compared with the NS group,the pathological damages of lung tissues in the GA group were significantly reduced,and the expression levels of HMGB1,IL-1 β,IL-2,and interferon-γ(IFN-γ)in lung tissues were also significantly decreased(P<0.05),although the expression level of AGER was significantly increased(P<0.05).Conclusion PVM infection can cause significant inflammatory pathological lung damages in mice,and GA can effectively alleviate the damages.Its therapeutic effect may be related to the activation of HMGB1 signaling pathway.
5.Establishment of a qPCR method to detect Staphylococcus xylosus and its application
Lingzhi YU ; Liping FENG ; Zhihao KONG ; Qi ZHU ; Xiaofeng WEI
Acta Laboratorium Animalis Scientia Sinica 2024;32(1):73-79
Objective To establish and evaluate a method for rapid and sensitive S.xylosus detection using qPCR(real-time quantitative PCR).Methods A gehM gene fragment was selected as the target for S.xylosus.A set of specific primers was synthesized and a qPCR method was established to detect S.xylosus.A S.xylosus standard strain and other non-target strains were chosen for analysis.DNA of S.xylosus was diluted 10-fold to determine its sensitivity.Clinical samples were tested,and positive products were sequenced.The result were compared with those of bacterial culture.Results S.xylosus had a specific amplification curve,whereas other non-S.xylosus species did not,indicating that the primers were specific for S.xylosus.Sensitivity was 100 fg/μL DNA.Repeatability within and between groups was less than 3%.A total of 60 clinical samples were analyzed,of which five samples had a typical S curve.qPCR products were sequenced and BLAST searched.The similarity of the gene sequences was 99.63%,indicating that the sample was positive for the S.xylosus gehM gene with a positivity rate of 8.3%.However,the positivity rate of bacterial culture was 6.7%.The positivity rate of qPCR was slightly higher than that of the culture.Conclusions The established qPCR method is rapid with high sensitivity and specificity,and can be used to detect S.xylosus.
6.A review of the studies on genomics of Candida auris
Huai-Yuan SUN ; Jia-Jia FENG ; Wei-Hua KONG ; Kun JIANG ; Li-Kai LIN
Chinese Journal of Infection Control 2024;23(11):1456-1462
Candida auris(C.auris)is a fungus with multidrug resistance.Current genomic studies indicate that C.auris shares similarities in genome size and evolution with other resistant yeast species.There are differences in genome size and structural variations among different geographical clades of C.auris,which may be related to differences in phenotype and drug resistance.C.auris exhibits resistance to multiple antifungal agents,including triazole,amphotericin B,and echinocandins.Genomic studies have found that resistance of C.auris may be related to factors such as membrane transport protein and mutation in the ergosterol pathway,its resistance can change fur-ther during evolution.In this paper,the relevant studies are reviewed,with a view to understanding the mechanism of drug resistance of C.auris,and providing important basis for formulating prevention and control strategies as well as treatment programs of C.auris.
7.Therapeutic effect of ursodeoxycholic acid-berberine supramolecular nanoparticles on ulcerative colitis based on supramolecular system induced by weak bond.
Shan GAO ; Feng GAO ; Jing-Wei KONG ; Zhi-Jia WANG ; Hao-Cheng ZHENG ; Xin-Qi JIANG ; Shu-Jing XU ; Shan-Lan LI ; Ming-Jun LU ; Zi-Qi DAI ; Fu-Hao CHU ; Bing XU ; Hai-Min LEI
China Journal of Chinese Materia Medica 2023;48(10):2739-2748
Ulcerative colitis(UC) is a recurrent, intractable inflammatory bowel disease. Coptidis Rhizoma and Bovis Calculus, serving as heat-clearing and toxin-removing drugs, have long been used in the treatment of UC. Berberine(BBR) and ursodeoxycholic acid(UDCA), the main active components of Coptidis Rhizoma and Bovis Calculus, respectively, were employed to obtain UDCA-BBR supramolecular nanoparticles by stimulated co-decocting process for enhancing the therapeutic effect on UC. As revealed by the characterization of supramolecular nanoparticles by field emission scanning electron microscopy(FE-SEM) and dynamic light scattering(DLS), the supramolecular nanoparticles were tetrahedral nanoparticles with an average particle size of 180 nm. The molecular structure was described by ultraviolet spectroscopy, fluorescence spectroscopy, infrared spectroscopy, high-resolution mass spectrometry, and hydrogen-nuclear magnetic resonance(H-NMR) spectroscopy. The results showed that the formation of the supramolecular nano-particle was attributed to the mutual electrostatic attraction and hydrophobic interaction between BBR and UDCA. Additionally, supramolecular nanoparticles were also characterized by sustained release and pH sensitivity. The acute UC model was induced by dextran sulfate sodium(DSS) in mice. It was found that supramolecular nanoparticles could effectively improve body mass reduction and colon shortening in mice with UC(P<0.001) and decrease disease activity index(DAI)(P<0.01). There were statistically significant differences between the supramolecular nanoparticles group and the mechanical mixture group(P<0.001, P<0.05). Enzyme-linked immunosorbent assay(ELISA) was used to detect the serum levels of tumor necrosis factor-α(TNF-α) and interleukin-6(IL-6), and the results showed that supramolecular nanoparticles could reduce serum TNF-α and IL-6 levels(P<0.001) and exhibited an obvious difference with the mechanical mixture group(P<0.01, P<0.05). Flow cytometry indicated that supramolecular nanoparticles could reduce the recruitment of neutrophils in the lamina propria of the colon(P<0.05), which was significantly different from the mechanical mixture group(P<0.05). These findings suggested that as compared with the mechanical mixture, the supramolecular nanoparticles could effectively improve the symptoms of acute UC in mice. The study provides a new research idea for the poor absorption of small molecules and the unsatisfactory therapeutic effect of traditional Chinese medicine and lays a foundation for the research on the nano-drug delivery system of traditional Chinese medicine.
Animals
;
Mice
;
Colitis, Ulcerative/drug therapy*
;
Ursodeoxycholic Acid/adverse effects*
;
Berberine/pharmacology*
;
Interleukin-6
;
Tumor Necrosis Factor-alpha/pharmacology*
;
Drugs, Chinese Herbal/pharmacology*
;
Colon
;
Nanoparticles
;
Dextran Sulfate/adverse effects*
;
Disease Models, Animal
;
Colitis/chemically induced*
8.Investigation of ABO and RhD blood groups in childbearing age people in rural areas of Yunnan Province.
Zheng Yuan XIE ; Guang CAO ; Tao WANG ; Cai KONG ; Yi Xiao LI ; Wei Lei ZU ; Zi Gao ZHAO ; Han Feng YE
Chinese Journal of Preventive Medicine 2023;57(1):52-57
The participants in this study were 20-49 years old rural childbearing age people who received the National Free Preconception Health Examination Project (NFPHEP) in Yunnan Province during 2013 to 2019. The proportion of ABO and RhD blood groups among different ethnic groups and different areas were calculated. The proportion of 2 748 131 participants with blood group A phenotype was highest (32.60%), followed by O (30.60%), B (27.33%) and AB (9.47%). In the RhD blood system, the proportion of the RhD positivity (RhD+) and RhD negativity (RhD-) group were 99.29% and 0.71% respectively. The proportions blood groups were significantly different among ethnic groups and areas (all P<0.001). Among 18 ethnic groups with more than 3 000 participants, Yao (42.75%), Bouyei (40.58%) and Dai (40.37%) ethnic groups had higher proportion of blood group O phenotype than other ethnic groups. Wa ethnic groups had highest proportion of the A (40.15%) and AB phenotypes (11.23%). Miao ethnic group (34.70%) and Lahu ethnic group (34.42%) had higher proportion of blood group B phenotype than other ethnic groups. Wa ethnic group had the highest proportion of RhD-group (1.88%). In all 16 prefectures of Yunnan, the proportion of blood group O phenotype was highest in Xishuangbanna Dai Autonomous Prefecture (40.27%). Baoshan city (36.39%), Lincang city (36.22%) and Dali Bai autonomous prefecture (36.06%) had higher proportion of blood group A phenotype than other regions. Diqing Tibetan Autonomous Prefecture (30.83%) and Qujing city (30.48%) had higher proportion of blood group B phenotype than other areas, while Zhaotong city had a highest proportion of blood group AB phenotype (11.19%). The proportion of RhD-group was highest in Honghe hani and Yi nationality autonomous prefecture(1.37%). The A RhD+(39.36%), A RhD-(0.78%), AB RhD+(11.03%), AB RhD-(0.20%) and O RhD-(0.48%) blood groups were higher proportion in Wa ethnic group than in other ethnic groups (P<0.001).
Adult
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Humans
;
Middle Aged
;
Young Adult
;
Blood Group Antigens
;
China
;
Ethnicity
;
Rural Population
9.Epidemiological characteristics of a 2019-nCoV outbreak caused by Omicron variant BF.7 in Shenzhen.
Yan Peng CHENG ; Dong Feng KONG ; Jia ZHANG ; Zi Quan LYU ; Zhi Gao CHEN ; Hua Wei XIONG ; Yan LU ; Qing Shan LUO ; Qiu Ying LYU ; Jin ZHAO ; Ying WEN ; Jia WAN ; Fang Fang LU ; Jian Hua LU ; Xuan ZOU ; Zhen ZHANG
Chinese Journal of Epidemiology 2023;44(3):379-385
Objective: To explore the epidemiological characteristic of a COVID-19 outbreak caused by 2019-nCoV Omicron variant BF.7 and other provinces imported in Shenzhen and analyze transmission chains and characteristics. Methods: Field epidemiological survey was conducted to identify the transmission chain, analyze the generation relationship among the cases. The 2019-nCoV nucleic acid positive samples were used for gene sequencing. Results: From 8 to 23 October, 2022, a total of 196 cases of COVID-19 were reported in Shenzhen, all the cases had epidemiological links. In the cases, 100 were men and 96 were women, with a median of age, M (Q1, Q3) was 33(25, 46) years. The outbreak was caused by traverlers initial cases infected with 2019-nCoV who returned to Shenzhen after traveling outside of Guangdong Province.There were four transmission chains, including the transmission in place of residence and neighbourhood, affecting 8 persons, transmission in social activity in the evening on 7 October, affecting 65 persons, transmission in work place on 8 October, affecting 48 persons, and transmission in a building near the work place, affecting 74 persons. The median of the incubation period of the infection, M (Q1, Q3) was 1.44 (1.11, 2.17) days. The incubation period of indoor exposure less than that of the outdoor exposure, M (Q1, Q3) was 1.38 (1.06, 1.84) and 1.95 (1.22, 2.99) days, respcetively (Wald χ2=10.27, P=0.001). With the increase of case generation, the number and probability of gene mutation increased. In the same transmission chain, the proportion of having 1-3 mutation sites was high in the cases in the first generation. Conclusions: The transmission chains were clear in this epidemic. The incubation period of Omicron variant BF.7 infection was shorter, the transmission speed was faster, and the gene mutation rate was higher. It is necessary to conduct prompt response and strict disease control when epidemic occurs.
Male
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Humans
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Female
;
SARS-CoV-2
;
COVID-19/epidemiology*
;
Disease Outbreaks
;
Epidemics
;
China/epidemiology*
10.Epididymis cell atlas in a patient with a sex development disorder and a novel NR5A1 gene mutation.
Jian-Wu SHI ; Yi-Wen ZHOU ; Yu-Fei CHEN ; Mei YE ; Feng QIAO ; Jia-Wei TIAN ; Meng-Ya ZHANG ; Hao-Cheng LIN ; Gang-Cai XIE ; Kin Lam FOK ; Hui JIANG ; Yang LIU ; Hao CHEN
Asian Journal of Andrology 2023;25(1):103-112
This study aims to characterize the cell atlas of the epididymis derived from a 46,XY disorders of sex development (DSD) patient with a novel heterozygous mutation of the nuclear receptor subfamily 5 group A member 1 (NR5A1) gene. Next-generation sequencing found a heterozygous c.124C>G mutation in NR5A1 that resulted in a p.Q42E missense mutation in the conserved DNA-binding domain of NR5A1. The patient demonstrated feminization of external genitalia and Tanner stage 1 breast development. The surgical procedure revealed a morphologically normal epididymis and vas deferens but a dysplastic testis. Microfluidic-based single-cell RNA sequencing (scRNA-seq) analysis found that the fibroblast cells were significantly increased (approximately 46.5%), whereas the number of main epididymal epithelial cells (approximately 9.2%), such as principal cells and basal cells, was dramatically decreased. Bioinformatics analysis of cell-cell communications and gene regulatory networks at the single-cell level inferred that epididymal epithelial cell loss and fibroblast occupation are associated with the epithelial-to-mesenchymal transition (EMT) process. The present study provides a cell atlas of the epididymis of a patient with 46,XY DSD and serves as an important resource for understanding the pathophysiology of DSD.
Male
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Humans
;
Epididymis
;
Disorder of Sex Development, 46,XY/genetics*
;
Disorders of Sex Development
;
Mutation
;
Mutation, Missense
;
Steroidogenic Factor 1/genetics*

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