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  • Original Article
    YAN Jun, SHI Baoping, SU Jianhua, CHENG Luxiao, CHEN Zili, TANG Yunbo, HONG Yan, DING Ying, BIAN Xiujuan
    Journal of Microbes and Infections. 2024, 19(4): 211-218. https://doi.org/10.3969/j.issn.1673-6184.2024.04.003
    Abstract (1731) PDF (66)   Knowledge map   Save
    To investigate the clinical characteristics, drug resistance rates and risk factors of Klebsiella pneumoniae infection in elderly patients, the clinical data from 322 elderly patients with community-acquired pneumonia (CAP) who admitted to Baoshan Renhe Hospital from 2021 to 2023 were collected. The patients were divided into a Klebsiella pneumoniae-infected group (KP group, 56 patients) and a non-Klebsiella pneumoniae-infected group (NKP group, 266 patients). Multivariate logistic regression analysis was used to identify the risk factors for Klebsiella pneumoniae infection in patients. The clinical value of various indicators in assessing the risk of Klebsiella pneumoniae infection was analyzed using receiver operating characteristic (ROC) curves. The results showed that Klebsiella pneumoniae exhibited high rates of resistance to ampicillin, cefuroxime, ceftazidime and piperacillin. Multifactorial analysis showed that males, respiratory failure, solid shadows in the lungs, and high fasting glucose levels were independent risk factors for Klebsiella pneumoniae infection. The ROC curve showed that the area under the curve (AUC) for assessing the risk of infection based on male gender, respiratory failure, and elevated fasting blood glucose levels all exceed 0.6, and the AUC for the combined index of independent risk factors reached 0.762.Therefore, early identification and implementation of effective treatment and management strategies for these high-risk groups is essential in clinical practice.
  • Original Article
    MA Jiaye, LU Shuihua
    Journal of Microbes and Infections. 2024, 19(5): 280-291. https://doi.org/10.3969/j.issn.1673-6184.2024.05.003
    Tuberculosis remains a chronic infectious disease that poses a serious threat to human health and the work to control tuberculosis remains very challenging. Host-directed therapy (HDT) may represent a novel anti-tuberculosis treatment strategy worthy of attention and further exploration. The purpose of this study was to investigate the regulatory role of GPR84, a member of the G protein-coupled receptor (GPCR) family in Mycobacterium bovis Bacillus Calmette-Guérin(BCG) infection. In this study, wild-type C57BL/6 mice (WT Group) and Gpr84 gene-deficient mice (Gpr84-/- group) were used as controls to establish a high-dose BCG infection mouse model. The differences in the amount of bacteria in lungs, spleen, liver, kidney and other organs and the severity of lung pathological damage between Gpr84 gene-deficient mice and wild-type mice were evaluated by CFU assay, lung tissue HE staining and acid-fast staining. The changes of body weight and general condition of mice in the two groups were observed. The results showed that Gpr84 gene-deficient mice infected with BCG exhibited a significant decrease in body weight compared to uninfected mice. The colony-forming unit (CFU) results and acid-fast staining showed that bacterial load in lung tissues of Gpr84-/- group was higher than that of WT group, and the differences of bacterial load in spleen and liver were consistent with those in lung. HE staining revealed that the normal alveolar structure of lung tissues of Gpr84-/- group was significantly more damaged than that of WT group after BCG infection, with a higher number of lesions observed. Flow cytometric analysis of lung cells of mice indicated that in the absence of infection, the knockout of Gpr84 had no significant effect on the number of resident alveolar macrophages (AMs) and interstitial macrophages (IMs) in the lungs. And in acute infection, the proportion of AMs in the lungs of mice in Gpr84 -/-group was significantly higher than in WT group, while the proportion of IMs was significantly lower than in WT group, the proportion of mononuclear phagocytes (MNPs) Ly6Chi subpopulation was increased. The number of Ly6Clo subpopulation was decreased, and neutrophils (Neuts) infiltration was increased. The results revealed that the aggravated bacterial load and pathological damage after Gpr84 knockout may be related to the reduction of the relative ratio of IMs/AMs and the increase of the Ly6Chi MNPs subgroup, affecting its transformation to the Ly6Clo subgroup and increasing the infiltration of Neuts. Therefore, Gpr84 may serve as a potential target for host-directed therapy of tuberculosis through its role in immune regulation.
  • Original Article
    WANG Yongkang1, CAO Heng2, LONG Gang1, 2
    Journal of Microbes and Infections. 2024, 19(5): 267-279. https://doi.org/10.3969/j.issn.1673-6184.2024.05.002
    In this study, a strain of Getah virus (GETV, GenBank: OM363683) was successfully rescued using a reverse genetics approach. Firstly, the optimized viral sequence was cloned into the low-copy plasmid pFK containing either the T7 or CMV promoter, named T7-GETV and CMV-GETV, respectively. Viral RNA was synthesized via in vitro transcription (IVT) using T7-GETV as a template, followed by RNA transfection into BHK-21 cells via liposome-mediated transfection. The viral titer was determined using 50% tissue culture infectious dose (TCID50) method and the expression of viral protein E1 was detected through western blot (WB), validating the successful rescue of GETV. Furthermore, the cytopathic effect (CPE) was observed via light microscope, and the growth characteristics of GETV were systematically analyzed using the TCID50 assay, real time fluorescent quantitative polymerase chain reaction (RT-qPCR), and WB. Additionally, based on the structure of GETV replicon, two replicative expression vectors were constructed using CMV-GETV as a template by retaining the non-structural protein genes and replacing the structural protein genes with the reporter gene mCherry or Renilla luciferase (Rluc), named pFK-GETV-mCherry and pFK-GETV-Rluc, respectively. Two control plasmids were also constructed by inserting only the reporter gene mCherry or Rluc downstream of the CMV promoter in the pFK plasmid, named pFK-mCherry and pFK-Rluc, respectively. Analysis with Image J software revealed that the average fluorescence intensity per cell of cells transfected with pFK-GETV-mCherry was approximately five times higher than that of cells transfected with pFK-mCherry. RT-qPCR results indicated that mCherry gene transcription level in cells transfected with pFK-GETV-mCherry was also approximately five times higher than that in cells transfected with pFK-mCherry, demonstrating high consistency between the two results. WB results indicated that mCherry protein expression level in cells transfected with pFK-GETV-mCherry was also higher than that in cells transfected with pFK-mCherry at the same time point. Renilla luciferase assay showed that Rluc expression efficiency in cells transfected with pFK-GETV-Rluc was about three orders of magnitude greater than that in cells transfected with pFK-Rluc. This study provides a robust reverse genetics tool for GETV research and demonstrates the ability of the GETV replicative expression vector to enhance exogenous gene expression, establishing a foundation for the development of replicative DNA vaccines.
  • Original Article
    ZHANG Meiyun1, LIU Ruijie2, ZHANG Shaoxin2, SUN Guiqin2
    Journal of Microbes and Infections. 2024, 19(6): 343-350. https://doi.org/10.3969/j.issn.1673-6184.2024.06.003
    This study aimed to analyze the distribution and drug sensitivity of pathogenic bacteria of bloodstream infections in patients hospitalized in Xinchang County Hospital of Traditional Chinese Medicine, providing a basis for the diagnosis and treatment of clinical bloodstream infections. All blood culture samples from Xinchang County Hospital of Traditional Chinese Medicine were collected from January 2019 to June 2023, and the pathogen species and drug sensitivity in vitro were analyzed statistically. A total of 1692 positive blood culture samples were obtained, primarily from the intensive care unit (ICU). The pathogens detected included 1637 aerobic (96.74%), 19 anaerobic (1.12%) and 36 fungal (2.13%) strains. The gram-negative bacteria (36.63%) were mainly Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis, and the gram-positive bacteria (63.12%) were mainly Staphylococcus hominis, Staphylococcus epidermidis, and Staphylococcus aureus. Drug sensitivity results indicated that Escherichia coli and Klebsiella pneumoniae exhibited resistance rates exceeding 70% to aztreonam but sensitivity rates exceeding 70% to cephalosporins. In contrast, Staphylococcus epidermidis, Staphylococcus aureus and Staphylococcus hominis showed resistance rates exceeding 70% to penicillin, but high sensitivity (greater than 90%) to antimicrobial agents such as linezolid and tigecycline. The positive blood culture samples are predominantly from wards housing immunocompromised patients. The primary pathogenic bacteria identified were Escherichia coli, Klebsiella pneumoniae, Staphylococcus hominis and Staphylococcus epidermidis, which are sensitive to some antibacterial drugs. However, the widespread use of antibiotics in treatment may lead to changes in drug resistance patterns. Therefore, clinical practices should emphasize the detection of pathogenic bacteria and their drug susceptibility profiles to guide the diagnosis and treatment of bloodstream infections.
  • Review
    LI Yuanyuan1, LIU Xin1, XU Tingshuang2
    Journal of Microbes and Infections. 2024, 19(5): 305-313. https://doi.org/10.3969/j.issn.1673-6184.2024.05.006
    Ubiquitination plays an important role in many biological processes, including viral infections, and can be reversed by deubiquitinating enzymes (DUBs). Although some studies have found that DUBs can either inhibit or enhance viral infection through various mechanisms, the role of DUBs in viral regulation is still unknown and needs to be further explored. Ubiquitin specific protease (USP) belongs to cysteine protease and is one of the important members of deubiquitination enzyme family. USP family members affect viral replication through positive or negative regulatory mechanisms in a variety of ways. For example, USP4, USP8, USP13, USP15 and USP49 have antiviral effects, while USP1, USP7, USP33 and UL36USP negatively regulate the antiviral immune response of the body. This review aims to comprehensively summarize the regulatory mechanisms and research progress of USP family members in antiviral immune response, which not only reveals the complex role of these proteases in virus-host interactions, but also provides valuable molecular targets and theoretical basis for the development of novel antiviral strategies. With the deepening of research, the multifaceted nature of USPs in virus infection and prevention and control will gradually become clear, offering new solutions to global public health challenges.
  • Original Article
    ZHU Qin1, 3, SU Yu2, YANG Yongyu2, XIE Li2, CHEN Hong1, 3, YANG Le2, BU Fan2, DENG Qiang2, WU Jian2, JIANG Wei1, 3
    Journal of Microbes and Infections. 2024, 19(5): 257-266. https://doi.org/10.3969/j.issn.1673-6184.2024.05.001
    Chronic infection with the hepatitis B virus (HBV) is a significant contributor to severe liver diseases, including cirrhosis and hepatocellular carcinoma, thereby posing a substantial global health concern. This investigation employed an HBV transgenic mouse model harboring mutations in the basal core promoter (BCP) region to assess the model’s virological characteristics and hepatic damage. The extent of liver fibrosis was determined using sirius red staining of liver tissue. Furthermore, whole-genome transcriptomic analysis of liver tissue was conducted. The study revealed that 12-week-old HBV transgenic mice with BCP region mutations exhibited increased HBV DNA replication levels and spontaneous liver fibrosis. Differential gene expression analysis identified 729 upregulated and 325 down-regulated genes within the HBV-Tg cohort, which predominantly associated with the extracellular matrix, peroxisome proliferator-activated receptor (PPAR) pathway, and cytochrome P450 pathway. Protein-protein interaction (PPI) network analysis indicated that pivotal genes were implicated in collagen synthesis, inflammatory response, cell cycle regulation, and apoptosis. The pathological alterations observed in this murine model align with the progression of chronic liver disease, thus providing a robust and effective model for elucidating the mechanisms underlying HBV infection-related hepatic pathology.
  • Original Article
    ZHANG Shuang1, 2, ZHANG Yan1, LYU Lijing1, WANG xueliang1, HU Caixia1
    Journal of Microbes and Infections. 2024, 19(4): 204-210. https://doi.org/10.3969/j.issn.1673-6184.2024.04.002
    Abstract (143) PDF (73)   Knowledge map   Save
    This paper aimed to identify the differences in the diversity and composition of intestinal fungal flora between the plaque psoriatic patients and the healthy individuals. It obtained the fresh fecal samples from the psoriatic (P) patients and the healthy controls (C) during January 2021 to December 2021 in the dermatology clinic, the Fourth Hospital of Hebei Medical University. Fecal samples were processed and internal transcribed spacer (ITS) was sequenced using the Illumina NovaSeq PE250 platform by UPARSE software. Results showed that although a slight elevation was found in the richness and diversity of the intestinal fungi for the psoriasis group, there was no statistical difference between the two groups by the alpha diversity analysis (P>0.05). A significant separation was detected between P and C groups with the partial least squares discriminant analysis (PLS-DA). The species diversity analysis showed that there were more than 10 species with significant different abundance between two groups. Phaffomycetaceae, Psathyrellaceae, Wickerhamomyces, Papiliotrema_flavescens in group P, and Saccharomycopsis, Saccharomycopsis fibuliger, Cutaneotrichosporon_cyanovorans, Cutaneotrichosporon, Aspergillus_conicus, Penicillium sumatraense, Mrakia blollopis, Hyphopichia, Talaromyces_duclauxii in the group C, were found with higher abundance, respectively. The composition of intestinal fungal flora in the plaque psoriatic patients is significantly different compared with the healthy controls.
  • Original Article
    MEN Xin1, AN Ruifang2, GUO Encheng3, LIU Dong3
    Journal of Microbes and Infections. 2024, 19(4): 193-203. https://doi.org/10.3969/j.issn.1673-6184.2024.04.001
    Abstract (97) PDF (168)   Knowledge map   Save
    The purpose of this study was to compare the structural composition of vaginal microbial community between women with vulvovaginal candidiasis and healthy women, and to analyze the relevance between dominant bacteria and vulvovaginal candidiasis. A total of 18 patients with vulvovaginal candidiasis (VVC group) and 27 healthy women (NC group) were recruited. The VVC group received clotrimazole treatment, while the NC group received no treatment. The vaginal secretions of the NC group were collected once, and those of the VVC group were collected four times (before treatment and on the 10th, 30th, 60th days after treatment). Total DNA in the vaginal secretions samples was extracted respectively. The bacterial diversity in the vaginal secretions samples was analyzed using high-throughput sequencing technology. Changes in the bacterial community in the VVC group of the vaginal secretions samples before and after treatment were discussed, and the difference in the bacterial community was compared with the NC group. The results showed that the dominant vaginal bacteria in the VVC group were primarily Lactobacillus iners, while Lactobacillus crispatus dominated in the NC group. After treatment with clotrimazole, no significant difference was observed in the vaginal microbiota composition of the VVC group compared to pre-treatment. This study confirms that vaginal bacterial community composition of patients with vulvovaginal candidiasis is significantly different from that of healthy women. Clotrimazole treatment for vulvovaginal candidiasis can not promote the transformation of vaginal dominant bacterial community to a healthy state.
  • Case Analysis
    XIE Yunqi1, 2, YUAN Yunsheng3, LIN Xiaohua3, HUANG Lei3, RAO Liying1, 2, LIU Zhenyi1, 2, SUO Zhijun3, YU Zhijian1, 2, CHEN Zhong1, 2
    Journal of Microbes and Infections. 2024, 19(4): 227-231. https://doi.org/10.3969/j.issn.1673-6184.2024.04.005
    Cryptococcus is an opportunistic pathogen that causes cryptococcal meningitis in immunocompromised patients. Cryptococcus mainly causes subacute or chronic infection, but the acute course is rare. This article introduced a case of progressive exacerbation of meningitis caused by acute infection of Cryptococcus neoformans in a diabetic patient, and to understand the factors affecting the poor prognosis of cryptococcal meningitis.
  • Review
    ZHANG Ting1, WU Jianhua2, TANG Jinmo2, WANG Min1, 2
    Journal of Microbes and Infections. 2024, 19(4): 237-243. https://doi.org/10.3969/j.issn.1673-6184.2024.04.007
    This study aimed to investigate the changes of serum interleukin-21 (IL-21) levels in patients with chronic hepatitis B (CHB) under the conditions of virological response, hepatitis B E antigen (HBeAg) seroconversion and viral relapse after treatment with nucleoside (acid) analogues (NAs). It searched PubMed, Cochrane Library, Embase, Web of Science, Springer Link, CNKI, CBM, Wanfang, WIP, Duxiu, and other databases from January 2010 to October 2024. Literature screening, data extraction and quality evaluation were carried out according to the inclusion criteria, and Meta-analysis was conducted by Review Manager 5.4 software. The level of IL-21 in HBV DNA complete response group was significantly higher than that in HBV DNA incomplete response group (RR = 24.94, 95% CI [20.09, 29.80 ], Z = 10.07, P<0.01), and the level of IL-21 in HBeAg negative group was significantly higher than that in HBeAg positive group (RR = 34.22, 95% CI [29.01, 39.44]Z=12.86,P<0.01), IL-21 was significantly higher in the virological sustained response group than in the virological relapse group (RR =-13.07, 95% CI [-15.51, -10.62], Z=10.47, P<0.01). Serum IL-21 can be used as an effective biomarker to evaluate the therapeutic effect of patients, to assist in the adjustment of antiviral therapy and to evaluate the prognosis of patients.
  • Original Article
    YANG Junying1, LI Hanzhang1, REN Wei2, WANG Tao1, MENG Cheng1, ZHANG Shuangli1
    Journal of Microbes and Infections. 2024, 19(5): 292-299. https://doi.org/10.3969/j.issn.1673-6184.2024.05.004
    To provide a theoretical basis for the early diagnosis and treatment of brucellosis in Honghe Prefecture, Yunnan Province, this study analyzed the clinical characteristics of confirmed cases of brucellosis in Yunnan region, and compared these cases with the reported cases in the literature. The clinical data of 36 patients with brucella infection confirmed by positive blood culture admitted from Jan. 2018 to Dec. 2022 were retrospectively analyzed. Based on the clinical characteristics and diagnosis, they were divided into classic fever of unknown origin (FOU) group and non classic fever of unknown origin (non-FOU) group, and the epidemiological and clinical characteristics of the two groups were analyzed. The results demonstrated that, 91.67% patients lived mainly in rural areas; the acute stage is mainly, accounting for 88.89%, fever is one of the most common clinical symptoms, accounting for 94.44%, and 80.56% were complicated with liver injury. Comparing the epidemiological characteristics, clinical features, laboratory test results, and clinical outcomes of the two groups of patients, the non-FUO group had a significantly higher misdiagnosis rate than the FUO group (94.74% vs. 64.71%, P=0.023); the proportion of fever accompanied by chills in the FUO group was significantly higher than that in the non-FUO group (77.78% vs. 22.22%, P=0.000). There was no statistical difference between the two groups in the remaining data (P>0.05). It was concluded that, brucellosis have a high misdiagnosis rate, and patients with non-FUO are more likely to be misdiagnosed as other diseases. Incidents of Brucella infection in the Honghe of Yunnan are sporadic throughout the year, and doctors need to attach great importance to inquiring about epidemiological history and relevant laboratory tests to reduce the missed diagnosis and misdiagnosis rate of the disease.
  • Original Article
    CAI Xia, CAI Qiliang
    Journal of Microbes and Infections. 2024, 19(5): 300-304. https://doi.org/10.3969/j.issn.1673-6184.2024.05.005
    To enhance the efficiency and safety of laboratory animal management in medical and life science research, this study have developed a novel individually ventilated cage (IVC) system that integrates remote locking and position detection functions. As life science research advances, the demand for experimental animals increases, posing challenges for traditional IVC systems due to issues like cage misplacement from improper handling. The new IVC system, integrated with software, employs clear lighting cues and system alarms to effectively differentiate cage statuses in complex operational contexts, providing instant feedback and significantly reducing the likelihood of mishandling. Its reservation management and locking capabilities prevent mishaps when multiple groups share the IVC system, further boosting efficiency and safety in laboratory management. This IVC system with remote locking and position detection functions not only increases the accuracy of operations, but also provides a higher level of safety and reliability for laboratory animal management. It offers important support for medical and life science research and the management of biosafety laboratories.
  • Review
    YANG Mei, TAN Quanhui, TANG Zhenghao
    Journal of Microbes and Infections. 2024, 19(6): 378-384. https://doi.org/10.3969/j.issn.1673-6184.2024.06.008
    Hepatitis B virus (HBV) infection is one of the major global public health problems, with nearly 887 000 deaths from HBV-associated disease each year. Due to the persistent presence of covalently closed circular DNA (cccDNA) in the nuclei of liver cells, patients infected with HBV are prone to chronic infection, which increases the risk of developing cirrhosis and hepatocellular carcinoma. Therefore, closely monitoring cccDNA levels during the treatment of HBV infection plays an important role in assessing the condition of patients with chronic hepatitis B. In contrast, cccDNA testing requires invasive liver puncture to obtain, which is difficult to be widely performed in the clinical work. Existing studies have shown that serum HBV RNA can reflect the levels of cccDNA in patients. This article provides a review of the advances in the application of serum HBV RNA detection during the antiviral treatment process in patients with chronic hepatitis B.
  • Review
    WANG Yutong, WANG Xinyu, LIN Nuo, FANG Bo, ZHANG Keying, SUN Guiqin
    Journal of Microbes and Infections. 2024, 19(5): 314-320. https://doi.org/10.3969/j.issn.1673-6184.2024.05.007
    Elizabethkingia meningoseptica (EM) can cause meningitis, sepsis, lung infection, eye infection, catheter-related bloodstream infection and surgical site infection. EM is one of the important pathogens of nosocomial infection. The infection mechanisms of EM include invasion of host cells,production of proteases,biofilms,etc,and EM can produce related virulence factors to damage the immune system. In addition,EM carries multiple drug resistance genes and is resistant to commonly used antibiotics in clinical practice. This article reviews the infection types,clinical features and infection mechanisms of EM, which would provide a reference for the diagnosis and clinical treatment of EM infection.
  • Case Analysis
    ZHOU Xianyuan, HUANG Yingfeng, JIA Ashao, YU Mengqiu, DENG Li
    Journal of Microbes and Infections. 2024, 19(4): 232-236. https://doi.org/10.3969/j.issn.1673-6184.2024.04.006
    Abstract (63) PDF (106)   Knowledge map   Save
    There are few reports on bloodstream infections caused by Aeromonas dhakensis. This article presented a case report of a patient with liver cirrhosis who developed Aeromonas dhakensis bloodstream infection. The patient exhibited symptoms such as fever, cellulitis, necrotizing fasciitis, rhabdomyolysis, and lesions resembling pyoderma gangrenosum, and suffered septic shock. The disease progressed rapidly with a poor prognosis. During the species identification process, methods such as the bioMérieux VITEK 2 Compact identified the isolate as either Aeromonas hydrophila or Aeromonas caviae. The Bruker mass spectrometer identified it as Aeromonas hydrophila, noting that the intragenus protein fingerprint was similar and could not be differentiated from other species. Additionally, 16S rRNA sequencing failed to unequivocally distinguish the species. All these methods including the bioMérieux VITEK 2 Compact, Bruker mass spectrometer, and 16S rRNA sequencing were unable to provide accurate identification. However, gyrB sequencing and metagenomic next-generation sequencing (mNGS) were able to yield definitive species results. Through the comprehensive application of multiple methods, this study provides a clear identification result for clinical diagnosis.
  • Original Article
    LIU Wanling1, XIU Lei2, HU Wei1, 2, ZHANG Wenhong1, WU Jing1, 2
    Journal of Microbes and Infections. 2024, 19(4): 219-226. https://doi.org/10.3969/j.issn.1673-6184.2024.04.004
    SHROOM2 is an actin-binding protein involved in the regulation of cell motility and actin cytoskeleton remodeling. Schistosome eggs can induce granuloma formation, leading to organized immune aggregates around the eggs. This study unexpectedly observed that Shroom2-deficient mice exhibited a significantly higher mortality rate after infection with Schistosoma japonicum compared to wild-type mice. This study aimed to investigate the disease progression in Shroom2 knockout mice after infection with Schistosoma japonicum, revealing the potential role of the Shroom2 gene in the immune response to schistosome infection and granuloma formation around the eggs. It used CRISPR/Cas9 technology to generate Shroom2 knockout (KO) mice. Both C57BL/6 wild-type (WT) and KO mice were infected with Schistosoma japonicum cercariae (30±2 cercariae/mouse) via abdominal skin exposure. The mice were monitored daily, and the number of deaths was recorded. At the fifth and the seventh weeks post-infection, mice were sacrificed for blood routine analysis and liver histopathology with hematoxylin-eosin (HE) staining. KO mice showed a significant increase in mortality during the acute phase of schistosome infection, accompanied by severe liver pathology and abnormal blood parameters. These findings suggest that the Shroom2 gene plays a critical role in regulating the host immune response, and its deficiency may increase susceptibility to pathogens, accelerating disease progression.
  • Case Analysis
    MIN Yan1, XU Jie2, LIU Moyan2, LI jixia1
    Journal of Microbes and Infections. 2024, 19(6): 361-366. https://doi.org/10.3969/j.issn.1673-6184.2024.06.005
    This paper reports a case of pulmonary infection caused by Corynebacterium striatum in an elderly patient. The patient, male, 93 years old, was treated with piperacillin-tazobactam, imipenem-cilastatin and levofloxacin due to “aspiration pneumonia” two months ago. The patient’s pulmonary infection was difficult to control, and meropenem was upgraded for anti-infection, but the effect was not good. After empiric antifungal treatment with fluconazole, the pulmonary infection continued to persist and the symptoms worsened. Sputum culture result suggested Corynebacterium striatum (++++), and linezolid showed a large diameter inhibitory zone against the bacteria. Considering the previous treatment plan was not satisfactory, fluconazole was discontinued and the regimen was adjusted to meropenem combined with linezolid for anti-infection. Ten days after the adjustment of the antimicrobial agents, the patient’s symptoms of cough and sputum production gradually improved. Subsequently, meropenem was de-escalated to levofloxacin combined with linezolid for anti-infection. After 2 days of de-escalation therapy, the patient’s pulmonary infection improved, and the antimicrobial agents were discontinued, resulting in successful treatment of the pulmonary infection.
  • Case Analysis
    QIU Meibing, LAN Qiuhui, NIE Yijun, YANG Tong
    Journal of Microbes and Infections. 2024, 19(6): 367-372. https://doi.org/10.3969/j.issn.1673-6184.2024.06.006
    This study analyzed the clinical characteristics of severe pneumonia in children caused by Whipple disease to enhance pediatricians’ understanding and treatment of this condition. A retrospective analysis was conducted on the clinical data of two cases of severe Whipple disease-related pneumonia admitted to Liuzhou People’s Hospital from 2020 to 2021, along with a review of relevant domestic and international literature. Patient 1 was a female aged 41 months, Patient 2 was a male aged 5 months. Both patients presented primarily with fever, cough, and shortness of breath. C-reactive protein and procalcitonin levels were elevated in both cases, and computed tomography scans indicated varying degrees of patchy shadows and bronchial wall thickening in the lungs. Metagenomic next-generation sequencing was performed on the bronchoalveolar lavage fluid of the patients. In sample 1, Staphylococcus aureus and Tropheryma whipple were detected, while sample 2 revealed Tropheryma whipple and Acinetobacter baumannii. Both patients received assisted ventilation via a ventilator and were treated with a combination of meropenem and sulfamethoxazole-trimethoprim for infection. Both patients eventually improved and were discharged. The results indicate that Whipple disease can cause severe pneumonia in infants and young children, primarily presenting with fever, cough, and shortness of breath, and may be associated with other bacterial infections. It is crucial to employ metagenomic next-generation sequencing technology for pathogen detection early on to confirm the diagnosis and provide timely targeted anti-infection treatment.
  • Original Article
    WANG Manxi1, LIU Na1, DONG Nihua1, WANG Yongkang2, CAO Heng1, LONG Gang1, 2
    Journal of Microbes and Infections. 2024, 19(6): 321-331. https://doi.org/10.3969/j.issn.1673-6184.2024.06.001
    This study constructed a full-length infectious clone of tick-borne encephalitis virus (TBEV), providing an essential tool for in-depth investigation of TBEV replication and pathogenesis. Firstly, prokaryotic promoters within the full-length TBEV sequence were predicted, and synonymous mutations were introduced to eliminate the activity of these promoters, thereby reducing the bacterial toxicity of the cDNA. Subsequently, considering sequence complexity and cloning efficiency, the TBEV cDNA sequence was divided into two fragments for synthesis, which were then cloned into the pFK vector using homologous recombination technology. Viral RNA generated by in vitro transcription was transfected into cells. Viral RNA replication was successfully detected by real-time fluorescence quantitative polymerase chain reaction (RT-qPCR) using TBEV E protein-specific primers. Meanwhile, Western blot analysis with a TBEV NS1 protein-specific antibody confirmed viral protein expression. 50% tissue culture infectious dose (TCID50) assays demonstrated a significant increase in viral titers at 48 h post-transfection. Finally, plaque assays in BHK-21 cells at 96 h post-infection validated the infectivity of second-generation viruses. Results showed that plaque numbers markedly increased with the decreasing viral dilution, and both viral RNA levels and protein expression escalated over time, indicating the infectivity and intracellular replication capacity of second-generation viruses. These results provide a novel tool for TBEV research, and a general strategy for constructing infectious clones.
  • Review
    FENG Jiawei1, SONG Zhenyu1, MING Chaochang2, CAO Qianqian3, HUANG Jincheng4, WANG Qingkai1, WANG Donghui1, JIN Yi4
    Journal of Microbes and Infections. 2024, 19(4): 244-256. https://doi.org/10.3969/j.issn.1673-6184.2024.04.008
    This Meta-analysis aimed to clarify the microbial distribution of periprosthetic joint infection (PJI) and to explore therapeutic strategies for specific pathogens associated with PJI. PubMed, CNKI (China National Knowledge Infrastructure), and Wanfang databases were searched for relevant literature up to November 8, 2022. Studies reporting on the distribution of PJI pathogens and their antimicrobial susceptibility were included. Data on pathogen distribution and antibiotic resistance profiles were collected. Studies meeting the criteria underwent quality assessment used the Joanna Briggs Institute (JBI) critical appraisal tool for analytical cross-sectional studies. Meta-analysis was conducted using STATA 17 software. A total of 25 studies were included, consisting of 22 retrospective studies and 3 randomized controlled trials. Among these 25 studies, the overall prevalence of Gram-positive bacteria was 76% (95% CI is [0.72, 0.80], P<0.01), Gram-negative bacteria was 18% (95% CI is [0.15, 0.21], P<0.01), fungi was 3% (95% CI is [0.02, 0.04], P<0.01), and mycobacteria was 2% (95% CI is [0.01, 0.03], P<0.01). Coagulase-negative Staphylococci and Staphylococcus aureus are the two main pathogens contributing to periprosthetic joint infections. Clinical practice should optimize more effective utilization of existing drugs, mitigate the development of bacterial resistance, and seek new drug targets to expand the range of antibiotic options for periprosthetic joint infections.
  • Original Article
    KONG Yu1, SHI Yibing1, CAI Xia2
    Journal of Microbes and Infections. 2024, 19(6): 351-360. https://doi.org/10.3969/j.issn.1673-6184.2024.06.004
    This study aims to investigate the disinfection and sterilization effects of common disinfectants on common pathogens on smooth and porous surfaces in the environment, providing a basis for blocking the transmission routes of pathogens in the environment and formulating practical and effective disinfection technology pathways. In this experiment, the suspension quantitative sterilization method was used to detect the sterilization effects of 75% ethanol, 1% hydrogen peroxide, and 500 mg/L chlorine-containing disinfectant on common laboratory environmental bacteria (Escherichia coli and Staphylococcus aureus) in different scenarios such as smooth and porous surfaces. In smooth scenarios, 1% hydrogen peroxide disinfectant showed significantly better disinfection effects than 75% ethanol and chlorine-containing disinfectant. When the action time was 1~5 minutes, its logarithmic reduction value was greater than 5, meeting the disinfection qualification requirements. On porous surfaces, when the action time of chlorine-containing disinfectant was 1~5 minutes, it showed high logarithmic reduction values (≥4) against different pathogens. Field experiments also found that the disinfection effect of chlorine-containing disinfectant was better than that of 1% hydrogen peroxide and 75% ethanol. Chlorine-containing disinfectant has a good disinfection effect and acts quickly, making it suitable for rapid disinfection of different surface structures in various scenarios. However, it is not environmentally friendly. When choosing a rapid disinfectant, a comprehensive assessment must be made based on its harmfulness to the environment, among other factors.
  • Case Analysis
    HUANG Yingfeng, ZHOU Xianyuan, ZHANG Chi, CHEN Pingping, JIA Ashao, DENG Li
    Journal of Microbes and Infections. 2024, 19(6): 373-377. https://doi.org/10.3969/j.issn.1673-6184.2024.06.007
    Tuberculous meningitis (TBM) is the most common and severe form of central nervous system tuberculosis, characterized by high mortality and morbidity rates. However, its diagnosis and treatment remain challenging, posing a significant threat to global health. Clinically, the high fatality and disability rates associated with TBM are attributed to multiple factors, including nonspecific clinical manifestations, lack of rapid and sensitive diagnostic tests for early detection, frequent misdiagnosis due to coinfection with other pathogens, the emergence of multidrug-resistant tuberculosis (MDR-TB), and limited blood-brain barrier penetration of antitubercular drugs. This article summarized a case of TBM incidentally diagnosed during COVID-19 screening. A patient presenting with coma underwent cerebrospinal fluid (CSF) smear examination and related laboratory tests. A positive result of acid-fast staining of CSF prompted a rapid clinical diagnosis of TBM. Although molecular diagnostic techniques for TBM demonstrate superior sensitivity and specificity, traditional CSF acid-fast smear microscopy retains unique advantages, such as simplicity, rapid turnaround time and low cost, making it a critical diagnostic tool in resource-limited settings. This study recommends integrating smear microscopy, molecular testing, and culture techniques in clinical practice to establish a stepwise diagnostic framework for TBM.
  • Original Article
    LI Xurong1, LIU Yan2, ZHANG Chubin1, WANG Jie2, ZHANG Wei1, LIU Qianqian1, ZHOU Zhe1, XU Yuzhen1, SHAO Lingyun1, ZHAO Xin’guo3, YANG Qingluan1, PU Yonglan2
    Journal of Microbes and Infections. 2024, 19(6): 332-342. https://doi.org/10.3969/j.issn.1673-6184.2024.06.002
    In order to understand the T cell immune status of active tuberculosis (ATB) patients, the study compared the expression levels of T cell immune molecules and the proportion of T cell functional subsets between ATB patients and healthy controls (HC). A total of 21 ATB patients and 10 HC were enrolled from December 2020 to May 2021. Peripheral blood samples were collected from the participants, and flow cytometry was performed for surface and intracellular staining to investigate the proportion and functional status of peripheral blood T cells. Fisher’s exact probability test and non-parametric Mann-Whitney U test were used to analyze the data. The result showed that the proportion of Tfh in CD4 T cells was significantly lower in ATB patients than that in HC group (P<0.05), and the proportions of naive T cells, progenitor exhausted T cells in CD8 T cells were lower in ATB patients compared to HC, while terminal exhausted T cells were higher (P<0.05). The expression of CD62L on CD4 T cells was significantly lower in the ATB group (P=0.01). The expression of TIM-3 and CD127 on CD8 T cells as well as T-bet and TCF1 in CD8 T cells in the ATB group were also significantly lower than those in the HC group, while KLRG1, PD1, TIGIT, and CD69 were higher (P<0.05). In conclusion, T cells from active tuberculosis patients exhibit a unique immune phenotype characterized by reduced pro-inflammatory capacity and increased anti-inflammatory capacity, meanwhile exacerbated differentiation towards an exhausted phenotype in CD8 T cells.