Abstract:Objective To understand the epidemiological and clinical characteristics of adenovirus healthcare-associated infection (HAI) in children, and provide basis for targeted prevention and treatment. Methods Medical data of children admitted to a children's hospital from January 2011 to December 2020 due to adenovirus infection were analyzed retrospectively. Children detected adenovirus in respiratory secretion over 48 hours and less than 48 hours after admission were divided into HAI group and community-associated infection group (CAI group) respectively. Epidemiological and clinical characteristics of two groups of children were compared. Results A total of 1 158 children with adenovirus pneumonia received medical treatment, including 55 (4.75%) HAI cases and 1 103 (95.25%) CAI cases. The average age of 55 children in HAI group was (2.83±0.38) years old, and the main onset age was less than 3 years old (n=36, 65.45%). In HAI group, 49.09% children had severe pneumonia, higher than 6.98% in CAI group, with statistically significant difference (P < 0.05). The case fatality rate of children in HAI group and CAI group were 1.82% and 0.18% respectively. 94.55% children in HAI group had fever. Fever duration was (10.80±0.93) days, higher than that ([6.06±0.13] days) in CAI group, with statistical difference (P < 0.001). In HAI group, 32.73% children had underlying diseases. The percentages of moderate and severe anemia (10.91%), congenital heart disease (7.27%), blood and tumor diseases (5.45%), and nervous system diseases (7.27%) were higher than that of CAI group (1.63%, 1.36%, 0.36%, and 1.09% respectively), all were statistically different (all P < 0.05). Primary diseases in children in HAI group were mainly respiratory diseases (n=39, 70.91%), and the major infectious pathogen was Mycoplasma (15, 38.46%). Conclusion Adenovirus HAI is prone to occur in infants under three years old, and can be secondary to infection caused by other respiratory pathogens such as Mycoplasma pneumoniae. Children with moderate to severe anemia, congenital heart disease, nervous system diseases and other underlying diseases are more likely to develop adenovirus HAI.

Abstract:Objective To detect the mutations of capreomycin (CM) resistance related genes of Mycobacterium tuberculosis (M.tb), explore the relationship between genotype and phenotype, and provide guidance for the clinical use of CM. Methods Sputum specimens of tuberculosis patients with positive acid-fast staining in a hospital from 2017 to 2020 were collected, from which M. tb strains were clinically isolated. Drug resistance phenotypes of the strains were identified through drug susceptibility testing (DST). DNA was extracted and underwent whole-genome sequencing (WGS) to detect mutations of CM-resistance-related genes tlyA, rrs, rpsL, eis, Rv0194 and Rv1258C. Relationship between CM and rifampicin (RIF) phenotypic resistance was explored. Results 123 M.tb strains were isolated, out of which 23 nonsynonymous mutation sites in 6 CM resistance-related genes were detected via WGS. DST showed that 52 strains were resistant to RIF and 4 strains were resistant to both CM and RIF. Nonsynonymous mutation sites (A1401G in rrs, A128G in rpsL, C3293T and T221C in Rv0194) were detected in CM-resis-tant strains. Correlation between CM and RIF resistance was statistically significant (P < 0.05). Conclusion CM resistance of M. tb may be related to the mutations of rrs gene A1401G, rpsL gene A128G and Rv0194 gene C3293T, and there may be cross resistance between CM and RIF, which can be used as a reference in formulating anti-tuberculosis treatment plan.

Abstract:Objective To understand the differences in the number of drug-resistant genes, virulence genes and plasmids among carbapenem-resistant Klebsiella pneumoniae (CRKP) from different specimen sources, and provide references for the prevention and control of CRKP infection. Methods The whole-genome sequencing data of CRKP from different specimen sources in 2011-2020 were downloaded from public database of Pathsystems Resource Integration Center (PATRIC). Drug-resistant genes, virulence genes, and plasmids were identified and analyzed with bioinformatics analysis software and compared with IBM SPSS 23.0 and R v4.2.0 software. Results A total of 2 356 CRKP whole-genome data was included. The medians (interquartile interval) of drug-resistant genes, plasmids, and virulence genes carried by CRKP strains were 18 (16, 20), 4 (3, 5), and 60 (57, 68) respectively. The number of virulence genes, plasmids, and key virulence genes (iutA, iucA, iucB, iucC, iucD, rmpA, rmpA2, iroB, iroC, iroD, iroN) carried by CRKP strains from different specimen sources was statistically significant (P < 0.05). The number of drug-resistant genes, plasmids and virulence genes carried by CRKP strains from fecal specimens was higher, with the medians (interquartile interval) of 19 (16, 21), 5 (3, 6) and 63 (61, 59) respectively. The percentage of CRKP from catheter-attached fluid carrying iutA and iuc (iucA, iucB, iucC, iucD) was higher (19.0%, 4/21). Carrying rates of rmpA and rmpA2 in CRKP from alveolar lavage fluid were the highest, 7.9% (3/38) and 15.8% (6/38) respectively. The percentage of iro (iroB, iroC, iroD, iroN) genes carried by CRKP from sterile body fluids (6.5%, 4/62) was higher than that of CRKP from other specimen types (percentage range: 0-4.9%). CRKP from blood specimen carried more virulence genes than that from other specimen sources (P=0.004). Conclusion CRKP from blood specimen carries more virulence genes than CRKP from other types of specimens, which may relate to the high clinical mortality. It is suggested to pay close attention to the evolution of CRKP strains into high virulence strain in blood specimen, and reduce the incidence of CRKP blood stream infection by strengthening healthcare-associated infection control measures.

Abstract:Objective To explore the key genes in the occurrence and development of tuberculous ulcer(TU)through bioinformatics, and provide new ideas for the study of TU. Methods Datasets of previous acquired gene sequencing and GSE83456 downloaded from gene expression omnibus (GEO) were selected. Common differentially expressed genes were screened by R software and performed enrichment analysis via gene ontology (GO) as well as Kyoto encyclopedia of genes and genomes (KEGG). Protein-protein interaction (PPI) network was constructed and visualized by STRING and Cytoscape software. Key genes were screened out by cytoHubba plug-in, then verified by gene set enrichment analysis (GSEA). 60 patients with TU in a hospital from July 2021 to March 2022 and 60 healthy physical examination persons during the same period were selected. Key genes in serum were verified by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Results 19 common differentially expressed genes were screened out, mainly enriched in antiviral immune response, monocyte chemotaxis regulation, interferon-β function, NOD-like receptor signaling pathway, and infectious diseases, etc. GBP1 was screened out as a key gene after PPI analysis, and verified to be highly correlated with TU by GSEA. qRT-PCR confirmed that GBP1 expression was high in the serum of TU patients, and decreased significantly after 2 weeks treatment (both P < 0.001). Conclusion GBP1 may be a biomarker for TU diagnosis and potential target for treatment.

Abstract:Objective To analyze the clinical infection characteristics and resistance mechanisms of carbapenem-resistant Enterobacterales (CRE), provide reference for clinical prevention and treatment of CRE infection. Methods Clinically isolated CRE strains and patients information in a tertiary first-class hospital from July 2021 to June 2022 were collected. Antimicrobial resistance genes were detected by polymerase chain reaction. Induced antimicrobial resistance of mcr-9 positive strains was detected by inducing test. Results A total of 167 CRE strains were collected, mainly Klebsiella pneumoniae (38.9%) and Enterobacter cloacae (35.3%). CRE strains demonstrated multiple drug resistance phenotype, with 3 strains (1.8%) exhibiting polymyxin B resistance. Most CRE strains harboured bla_NDM (52.1%, n=87) and bla_KPC (34.7%, n=58). Patients with CRE infection were divided into NDM group and KPC group according to carbapenemase. Univariate analysis showed that in terms of influencing factors as stay in ICU ≥7 days, endotracheal intubation, and use of carbapenems before infection, KPC group was higher than NDM group, however, curing rate was lower than NDM group (P < 0.05). Multivariate logistic regression analysis showed that gastric intubation, pulmonary diseases and malignant tumor were independent influencing factors for the prognosis of patients with CRE infection of different carbapenemase genes (P < 0.05). Polymyxin B resistant strains all carried mgrB point mutation. 7 (4.2%) CRE strains harboured mcr-9, most of which also harboured bla_NDM. MIC values of 4 mcr-9 positive CRE strains after polymyxin B induction were higher than those before induction. Conclusion CRE in this area mainly harbour bla_NDM and bla_KPC, and a few also harbour mcr-9 and bla_NDM, showing multiple drug resistance. Clinical prevention and control should be strengthened to prevent its clinical transmission.

Abstract:Objective To investigate the clinical characteristics of patients with Klebsiella variicola (K. variicola) infection, and provide theoretical basis for the prevention and control of the pathogen in clinical practice. Methods 70 patients infected with K. variicola identified by whole-genome sequencing in a hospital between January 2013 and July 2018 were collected retrospectively. 70 patients with Klebsiella pneumoniae (K. pneumoniae) infection during the same period were randomly selected as control. Clinical data of two groups were analyzed. Results 70 patients with K. variicola infection were aged 1 day-95 years, median age was 51 years old, 6 (8.6%) of whom were infants less than 1 year old. The underlying diseases were mainly cardiovascular diseases (16, 22.9%), followed by diabetes mellitus (11, 15.7%) and tumor (9, 12.6%). The main infection sites were respiratory system (34, 48.6%), blood stream (8, 11.4%) and intra-abdominal cavity (8, 11.4%). 20 patients (28.6%) were with low or suppressed immunity due to tumor radio-/chemotherapy, glucocorticoid or immunosuppressive therapy. Resistance rates of K. variicola to commonly used antimicrobial agents were low (all < 40%), and lower than that of K. pneumoniae (all P < 0.001). Conclusion Clinical characteristics of patients with K. variicola infection are similar to patients with K. pneumoniae infection. It is necessary to be alert to the epidemic transmission of this bacteria in infants and population with low immunity. At present, antimicrobial resistance rate of K. variicola is low, but it is still necessary to standardize clinical rational use of antimicrobial agents, so as to prevent the emergence of antimicrobial resistant strains.

Abstract:Objective To analyze the disease burden and epidemic characteristics of major pathogens causing acute respiratory infection (ARI) in children in Guangzhou City. Methods In 2017.01-2022.06, 18 542 hospitalized children with ARI in a hospital in Guangzhou City were taken as the research objects. Serum IgM antibodies against 8 common pathogens, including respiratory syncytial virus (RSV), adenovirus (ADV), influenza virus A (IFV-A), influenza virus B (IFV-B), parainfluenza virus (PIV), Legionella pneumophila (LP), Mycoplasma pneumo-niae (MP) and Chlamydia pneumoniae (CP), were detected by indirect immunofluorescence method. SPSS 22.0 software was used for statistical analysis. Results The average length of hospital stay of 18 542 children with ARI was 7 days, and the median of total hospitalization expense was 5 870.93 Yuan. The total hospitalization expense of children in the -1-year-old group was the highest. Among 18 542 children, 10 214 were infected with at least one pathogen, with a detection rate of 55.09%. Detection rate in boys (52.31%) was lower than that in girls (59.77%). The total detection rate and co-infection rate in 2017-2019 were higher than those in 2020-2021, and those in elder group were higher than in younger group. 4 973 children were co-infected, mostly with IFV-A+IFV-B+MP (n=1 033) and IFV-A+IFV-B (n=1 022). The top three pathogens with the highest detection rates were IFV-B (27.27%), MP (25.47%) and IFV-A (21.24%). Detection rate of RSV decreased with the increase of age, and detection rate of LP, CP and MP increased with the increase of age. Detection rate of ADV peaked in children in the -3-year-old group, while detection rates of IFV and PIV were the highest in the -5-year-old group. CP and RSV occurred frequently in summer and autumn, however, detection rates of the other 6 pathogens showed no obvious seasonal dependence. Conclusion Pathogens causing ARI in children in Guangzhou City have different age di-stribution and seasonal epidemic characteristics. Measures should be taken to reduce the incidence of pneumonia in younger children, so as to ease their disease burden of ARI.

Abstract:Objective To investigate the clinical characteristics of patients with pyogenic liver abscess (PLA) under different immune status, and analyze the influencing factors for poor prognosis. Methods Clinical data of 104 patients with PLA admitted to Meng Chao Hepatobiliary Hospital of Fujian Medical University from November 2017 to November 2021 were analyzed retrospectively. Patients were divided into immunocompromised group and immunocompetent group based on their basic immune status, and compared in the aspects of general conditions, laboratory and imaging results, complications, treatment plans as well as disease outcomes. According to the treatment results, 104 PLA patients were divided into good prognosis group and poor prognosis group. Risk factors for poor prognosis were analyzed with multivariate logistic regression. Results A total of 104 patients were recruited, including 70 immunocompetent patients and 34 immunocompromised patients. Serum procalcitonin level, detection rate of Klebsiella pneumoniae, and length of hospital stay of patients in immunocompromised group were higher than those in immunocompetent group. Serum albumin level was lower than that in immunocompetent group (all P < 0.05). The top two pathogens detected in both groups were Klebsiella pneumoniae and Escherichia coli. Poor prognosis rates (ineffective treatment, including death) in immunocompromised group and immunocompetent group were 26.5% and 7.1% respectively, with statistically significant difference (P < 0.05). There was no significant difference in clinical manifestations, complications, treatment plans, in-hospital case fatality rates and other indicators between two groups (P>0.05). Multivariate logistic regression analysis showed that combination of immunosuppressive underlying disease (OR=8.041, P=0.008), abscess diameter≥10 cm (OR=12.896, P=0.005), septic shock (OR=7.714, P=0.041) were independent risk factors for poor prognosis of PLA patients. Conclusion When PLA patients is combined with underlying diseases of low immunity, infection is more severe, and the nutritional status is worse, indicating longer length of hospital stay and poor prognosis. For immunocompromised PLA patients, more active treatment strategies and focused monitoring are required.

Abstract:Objective To assess the performance of three metagenomic-next generation sequencing (mNGS) platforms. Methods 18 reference and 8 clinical specimens were performed mNGS by three platforms (A, B and C). Sensitivity, specificity, negative predictive value and positive predictive value were analyzed. Results For reference, sensitivity of platform A, B and C were 97.8%, 100%, and 45.1%; specificity were 50.0%, 100% and 100%; negative predictive value were 25.0%, 100% and 3.8%; positive predictive value were 87.3%, 75.2% and 93.2%. As for clinical specimens, sensitivity of platform A, B and C were 87.0%, 82.6% and 87.0%; positive predictive value were 90.9%, 65.5% and 60.6%. Conclusion This research enriches the data in domestic mNGS platform, and provides suggestions for the development of new diagnostic technologies for infectious diseases.

Abstract:Objective To analyze pathogens detected in blood culture of elderly inpatients in a hospital and antimicrobial resistance of main pathogens. Methods Clinical data, pathogenic distribution and antimicrobial susceptibility testing results of elderly inpatients aged ≥60 whose specimens were performed blood culture in a hospital from Ja-nuary 2018 to December 2021 were retrospectively analyzed. Results A total of 8 138 blood culture specimens were detected, out of which 1 067 were positive, with blood culture positive rate of 13.11%. A total of 1 097 pathogenic strains were detected, including 837 Gram-negative bacterial strains, accounting for 76.30%. The top three detected pathogens were Escherichia coli, Klebsiella pneumoniae and Staphylococcus aureus, accounting for 41.84%, 15.41% and 3.83%, respectively. The most detected pathogens in blood culture were from intensive care unit (214, 19.51%). Resistance rates of Escherichia coli and Klebsiella pneumoniae to piperacillin/tazobactam, ce-foperazone/sulbactam, carbapenems, amikacin and tegacyclin were 3.80% and 8.59%, 4.24% and 7.32%, < 1% and < 6%, 2.46% and 4.27%, 0 and 1.85%, respectively. Detection rate of methicillin-resistant Staphylococcus aureus (MRSA) was 21.95%. Minocycline-, vancomycin-, teicoplanin-, and linezolid-resistant Staphylococcus aureus were not detected. Conclusion The positive rate of blood culture from elderly patients is high. Major pathogens are Gram-negative bacteria, most of which are Escherichia coli and Klebsiella pneumoniae. Antimicrobial resistance varies in different pathogens. Blood culture should be performed in time to rationally use antimicrobial agents according to antimicrobial susceptibility testing results.

Abstract:Objective To explore imipenem-based in vitro and in vivo antibacterial methods against clinically isolated multidrug-resistant Acinetobacter baumannii (MDR-AB). Methods The minimal inhibitory concentrations (MICs) and combined MICs of seven clinically isolated MDR-AB strains against 5 antimicrobial agents (imipenem [IMP], fosfomycin [FOS], amikacin [AMI], tigecycline [TGC], and polymyxin B [PB]) were detected using broth microdilution and checkerboard methods. Fractional inhibitory concentration index (FICI) was calculated. Bactericidal effect of imipenem combined with fosfomycin was determined by time-bactericidal curve. The strains AB6624 and AB0153 were selected to construct the in vitro biofilm model, and biofilm was semi-quantitatively detected by crystal violet staining. Killing effect of imipenem combined with fosfomycin on biofilm bacteria was observed with laser scanning confocal microscopy. Effects of imipenem alone or in combination with fosfomycin on bacterial reactive oxygen species expression were detected by flow cytometry. Wax moth infection model was constructed, and survival rates of wax moth treated with imipenem and fosfomycin alone or in combination were recorded. Results Imipenem combined with fosfomycin had synergistic effect on 5 MDR-AB strains. After combined treatment of imipenem and fosfomycin, colony numbers of AB6624 and AB0153 at 4 and 8 hour were lower than those with single-drug-treatment group by more than 2log₁₀ CFU/mL. The combined use of imipenem and fosfomycin inhibited the formation of AB0153 biofilm and destroyed its structure. It also increased the intracellular ROS level in AB0153, with statistically significant difference (P < 0.05). Compared with control group, imipenem combined with fosfomycin treatment group improved the survival rate of wax moth (median survival time 96 hours), with statistically significant difference (P=0.022). Conclusion Imipenem combined with fosfomycin has synergistic effect on MDR-AB, and may play a role by inhibiting biofilm formation and increasing intracellular ROS level of bacteria.

Abstract:Objective To understand the real situation of healthcare-associated infection (HAI) quality control indexes of medical institutions (MIs) through comparison of process and outcome data reported by MIs on HAI monitoring data platform in Guizhou Province. Methods Process and outcome data of HAI management quality control indexes reported by MIs participating in HAI monitoring platform of Guizhou Province from January 1 to December 31, 2019 were collected by retrospective survey and statistically analyzed. Results Process and outcome data of HAI monitoring of 12 MIs in Guizhou Province were collected. HAI incidences were 1.03% and 1.15%; HAI prevalence rates were 1.37% and 2.31%; antimicrobial agents usage rates were 50.33% and 48.65%; inpatients' pathogen examination rates before antimicrobial treatment were 13.90% and 37.70%; surgical site infection rates of class I incision were 0.13% and 0.29%; incidences of catheter-related bloodstream infection (CRBSI) were 0.06 ‰ and 0.50‰; incidences of catheter-associated urinary tract infection (CAUTI) were 1.11 ‰ and 1.60 ‰. Referring to the detection rates of carbapenem-resistant Acinetobacter baumannii (CRPA) and carbapenem-resistant Klebsiella pneumoniae (CRKP), and inpatients' antimicrobial usage rates in 12 MIs, all process data were higher than outcome data with statistical difference (all P < 0.05). Conclusion Process data of HAI monitoring is more accurate than outcome data. All regions should actively promote the reporting of process data, and improve the authenticity of HAI management quality control indexes.

Abstract:Objective To evaluate the contamination of public environment and medical staff's personal protective equipment (PPE) by SARS-CoV-2 Omicron variant. Methods Public area, PPE removal area and PPE of a designated COVID -19 treatment hospital were sampled. Real time fluorescence quantitative polymerase chain reaction was adopted to detect SARS-CoV-2 nucleic acid and Ct value was reported. Factors related to positive SARS-CoV-2 nucleic acid results of PPE were analyzed. Results A total of 100 environmental specimens from ward public area were collected and the overall positive rate was 30.00%. Positive rates of elevator floor in PPE removal area (60.00%), corridor public area floor (60.00%), and the elevator button in PPE removal area (40.00%) were the highest. SARS-CoV-2 nucleic acid detection rates in the first-level and second-level PPE removal areas were 18.33% and 1.67%. SARS-CoV-2 nucleic acid was detected from 48.33% staff's PPE, 35.00%, 21.67% and 8.33% of which were detected from soles of outer shoe covers, outer gloves and protective clothing. Univariate analysis showed that PPE of doctors and medical staff performing high-risk manipulation had high positive rate of nucleic acid (all P < 0.05). Conclusion Omicron variant contaminated the ward public area, the first-level PPE removal area and PPE to different degrees. Personal protection as well as regular environmental cleaning and disinfection can reduce the infection risk of medical staff.

Abstract:Objective To understand medical staff's feeling of fitness and comfort when wearing different brands of medical protective masks. Methods Fever clinic staff including doctors, nurses, medical technicians and hospital service workers were selected. Quantitative fit test of four brands of folding medical protective masks were conducted. Staff's subjective feeling on mask fitness during different body movements was investigated. Discomfort fee-lings of medical staff at the beginning and 4 hours after wearing masks were tested, including pressure sense of nose bridge, skin itching, facial skin damage, mouth abrasion, tightening of ears and facial compression of masks. Mask deformation after 4 hours usage was also investigated. Results A total of 98 staff in fever clinic were investigated on the wearing fitness and comfort of medical protective masks. Compared with quantitative fit test results, the conformity rates of actual fit of subjective feeling was 77.42%, and non-actual fit was 56.86%. In different tested movements except loud speaking, conformity rates of the actual fit of subjective feeling were higher than 90%, however, conformity rates of actual non-fit movement were low, all below 30%. The main problems reflected by the subjective feeling of wearing masks were inappropriate size, uncomfortable headband tension, and pressure on nose bridge. Overall proportion of person with discomfort feeling was about 40%. After wearing masks for 4 hours, proportion of persons with discomfort feeling from headband tension and pressure on nose bridge increased. Conclusion When choosing medical protective masks, it is necessary to consider not only the fit test data, but also subjective feelings like comfort level, so as to improve the compliance and correctness in wearing medical protective masks as well as the satisfaction level of medical personnel.

Abstract:Objective To analyze the effect of healthcare failure mode and effect analysis (HFMEA) based control management for preventing multidrug-resistant organism (MDRO) healthcare-associated infection (HAI) outbreak. Methods A multi-disciplinary team (MDT) for management implementation was set up to retrospectively analyze patients admitted to the intensive care unit (ICU) of a hospital from June to December 2020. HFMEA model was used to assess the risk of MDRO HAI outbreak prevention and control, causes of high-risk failure mode was analyzed, targeted preventive measures were formulated and implemented from January 2021. Staff's hand hygiene, wearing and taking off isolation clothing, as well as MDRO HAI occurred in patients before and after implementation were compared. Results After the implementation of HFMEA, the risk coefficient of potential failure mode of MDRO HAI in ICU decreased significantly. Compared with before implementation, Staff's compliance rate of hand hygiene increased by 10.98%-14.12%; staff's compliance rate in wearing isolation clothing when contacting MDRO-infected patients and patients' bed units increased by 8.61%-15.21%; correct rate of wearing and taking off isolation clothing increased by 10.73%-18.43%; HAI rate in ICU, daily MDRO HAI rate, incidence of ventilator-associated pneumonia (VAP), incidence of central venous catheter-related bloodstream infections (CRBSI), and catheter-associated urinary tract infection (CAUTI) decreased. Conclusion Prospective assessment of HFMEA as well as intervention of MDRO HAI prevention and control measures can effectively reduce the incidence of MDRO HAI, thus preventing the outbreak of MDRO HAI.

Abstract:Objective To reduce infection risks and achieve best protective effect via selection of suitable masks for medical staff through qualitative fit test of 3M FT-30 medical protective mask. Methods From April 1 to 22, 2022, 567 medical staff engaged in medical technology, nursing and logistics work in a hospital were selected for qualitative fit test of medical protective masks organized by department of healthcare-associated infection. 3M FT-30 fit test equipment and qualitative method were applied to test subjects' fit level in wearing medical protective masks. Results All 567 medical staff in the hospital were sensitive to bitter, sensitivity rate was 100%. 567 medical staff underwent fit test with medical protective masks (folding type) produced by Winner Medical Company, out of which 28 failed(failure rate 4.94%). Staff with thin/fat faces or prominent facial features could not wear masks closely, thus were prone to air leakage and failure in test. After changing masks of two other brands, staff failed in the first test were tested again. 11 of them passed with medical protective masks (head-mounted) from Zhende Medical Supplies Co., Ltd. 16 medical staff with thin face, pointed chin and collapsed nose passed the test with Siwo D920 medical protective mask. 1 medical staff failed with medical protective masks from all three brands. There were statistical differences in test failure rates when subjects wore medical protective masks of the same type and batch for different movements during test (all P < 0.05). Conclusion Qualitative fit test for masks can help medical staff select suitable medical protective masks based on test results, improve their protection awareness and reduce infection risks.

Abstract:Clostridioides difficile infection (CDI) is a clinical problem that deserves more attention. Its clinical manifestations range from mild /moderate diarrhea to fulminant colitis, even death.At present, the first-line drugs for treating CDI mainly include metronidazole, vancomycin, etc. But because of the high recurrence rate after treatment, it is urgent to find new treatment scheme for CDI. In recent years, nutrients like protein, amino acid, carbohydrate, trace elements and plant extracts have been reported to be beneficial to the treatment of CDI.This article reviews the research on the adjuvant treatment of CDI with food-derived substances such as nutrients and plant extracts, in order to provide reference for the adjuvant treatment of CDI.

Abstract:Corynebacterium striatum is an opportunistic pathogen, clinical infection caused by which increases gradually in recent years. It shows the trend of multiple drug resistance, and may lead to death if not treated in time. According to the latest research progress, this article reviews its pathogenic characteristics, pathogenesis, epidemiological characteristics, laboratory tests, status and mechanisms of drug resistance, as well as treatment and prevention of infection.