Abstract:Objective To investigate antimicrobial resistance, gene homology and main genotypes of clinically isolated diarrheagenic Escherichia coli (DEC) in Anhui Province. Methods Antimicrobial susceptibility testing was performed with microbroth dilution method, genotyping detection and homology analysis was conducted with multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE). Results Among 268 strains of DEC, 57.1% were multidrug-resistant organisms, including 118 strains of enteroaggregative Escherichia coli (EAEC), 98 strains of enterotoxigenic Escherichia coli (ETEC) and 47 strains of enteropathogenic Escherichia coli (EPEC), resistance rates of 3 types of pathological strains to commonly used antimicrobial agents were as follows: ampicillin 83.9%, 73.5%, 78.7%, nalidixic acid 65.3%, 75.5%, 34.0%, cefazolin 53.4%, 35.7%, 34.0%, tetracycline 61.0%, 31.6%, 74.5%, compound sulfamethoxazole 63.6%, 23.5%, 46.8%, ampicillin/sulbactam 28.0%, 9.2%, 29.8%, gentamicin 34.7%, 7.1%, 34.0%, chloramphenicol 22.9%, 5.1%, 21.3%, ciprofloxacin 18.6%, 4.1%, 14.9%; two EAEC strains and 1 ETEC strain were resistant to imipenem. 55 EAEC strains were divided into 35 ST, the dominant genotype was ST10 (14.5%); 55 ETEC strains were divided into 14 ST, the dominant genotypes were ST48 (32.7%) and ST218 (16.4%); 15 EPEC strains were divided into 12 ST, the do-minating genotypes were ST28 (13.3%), ST517 (13.3%) and ST2088 (13.3%). Minimum-evolution (ME) tree analysis showed that among 55 ETEC strains, 5, 3, 2 and 2 strains isolated from Ma'anshan City were 100% homologous respectively, 5 strains isolated from Hefei City were 100% homologous; among 55 EAEC strains, 2 strains isolated from Fuyang City and 2 strains isolated from Chuzhou City were 100% homologous respectively; among 15 EPEC strains isolated from Ma'anshan City, 2 strains in 2 groups were 100% homologous. PFGE homo-logy cluster analysis results of 50 EAEC strains were as follows: 2 strains isolated from Bengbu City were 100% homologous, homology of the other strains was less than 90%; gene homology of 21 EPEC strains were all less than 75%; homology of 30 ETEC strains, 3 enteroinvasive Escherichia coli (EIEC) strains, and 5 ETEC+aEAEC strains reached 97.6% with 2 strains and 93.6% with 2 strains respectively, and the homology of the remaining strains was below 90%. Conclusion Antimicrobial resistance of clinically isolated DEC in Anhui Province is se-rious, resistance rate of EAEC is higher than that of EPEC and ETEC, resistance rate of ETEC is the lowest among the pathogenic types. Molecular typing detection found that the genotypes of clinically isolated DEC in this area are relatively scattered, among the pathogenic types, genotype of ETEC is relatively concentrated. ME tree analysis suggests that ETEC may have a regional homologous infection. In molecular typing technology, MLST can distinguish dominant genotype and aggregation, which is better than PFGE typing.

Abstract:Objective To detect the epidemiological characteristics and resistance of carbapenem-resistant Klebsiella pneumoniae (CRKP) in three general hospitals in southwest China, provide basis for the prevention and control of CRKP infection. Methods 159 strains of CRKP isolated in three tertiary first class hospitals in southwest China from January to December 2019 were collected, antimicrobial susceptibility of CRKP strains was detected by micro-broth dilution method, identification and multilocus sequence typing of carbapenemase gene were carried out by polymerase chain reaction (PCR). Clinical information of patients such as invasive procedure, antimicrobial use, laboratory examination and prognosis were compared. Results 50.9% of 159 CRKP strains were from sputum specimens. 94.3% of patients with CRKP infection had received invasive procedure, mortality of patients with bloodstream infection was 66.7%. None of strains were susceptible to carbapenems, resistance rates to levofloxacin and amikacin were 85.5% and 81.1% respectively. Carbapenemase gene was detected in all CRKP strains, detection rate of KPC-2 was 86.8%. ST11 was the most prevalent clone in southwest China. Conclusion The prevalent CRKP strains in southwest China is characterized by high drug resistance, prognosis and outcome of patients with bloodstream infection is poor, it is urgent to strengthen infection control measures and improve prevention awareness.

Abstract:Objective To evaluate the administration scheme of ceftriaxone, levofloxacin and moxifloxacin based on Streptococcus spp. collected by national blood infection Bacterial Resistant Investigation Collaborative System (BRICS), provide basis for clinicians to use antimicrobial agents rationally. Methods Antimicrobial susceptibility of ceftriaxone, levofloxacin and moxifloxacin was determined by agar dilution method, probability of target attainment (PTA)and cumulative fraction of response (CFR)of different administration schemes of three antimicrobial agents was studied with Monte Carlo simulation method. Results Minimum inhibitory concentration (MIC) detection result showed that the susceptibility rates of ceftriaxone, levofloxacin and moxifloxacin to Streptococcus pneumoniae were 82.22%, 97.78% and 97.78% respectively, to other Streptococcus were 97.66%, 80.14% and 81.07% respectively. Monte Carlo simulation result showed that CFR were both ≥ 90% when ceftriaxone was used to treat streptococcus spp. infection at doses of 1 g/24 hour and 2 g/24 hour; CFR was 93% when levofloxacin was used to treat other streptococcal infection at dose of 750 mg/24 hour; CFR was < 90% when levofloxacin was used to treat Streptococcal spp. infection at dose of 500 mg/24 hour; CFR was both >90% when moxifloxacin was used to treat other streptococcal infection at doses of 400 mg/24 hour and 800 mg/24 hour, CFR was both < 90% when moxifloxacin was used to treat Streptococcus pneumoniae. Conclusion When ceftriaxone, levofloxacin and moxifloxacin are used to treat bloodstream infection caused by Streptococcus, different dosage of ceftriaxone should be selected for effective treatment according to different MIC value, therapeutic effect of levofloxacin at 750 mg/24 hours is significantly better than that at 500 mg/24 hours, moxifloxacin is not recommended for the treatment of Streptococcus spp. infection if MIC value is not within the susceptible range.

Abstract:Objective To analyze the characteristics of norovirus (NoV) healthcare-associated infection (HAI) in children. Methods Based on early active screening analysis, detection result of NoV in hospitalized children in Guangzhou Women and Children's Medical Center from January 2019 to March 2021 was analyzed by prospective study, NoV HAI in children was analyzed, genotyping was performed with reverse transcription-polymerase chain reaction (RT-PCR). Results Among 2 659 cases of HAI, there were 421 cases of gastrointestinal tract infection, 188 cases of gastrointestinal tract infection (44.7%) were conducted NoV detection; 96 cases (51.1%) were positive for NoV. There were 24 cases of NoV HAI among hospital staff, including 13 cleaners and 11 health care workers. Among children with NoV HAI, 66 were males and 30 were females; the average age was (37.6±41.10) months, and 81.3% were under 5 years old; autumn and winter had high incidence; 95.8% were transmitted by contact. 17 cases (17.7%) were asymptomatic carriers, and 79 cases of symptomatic infection were mainly change in stool shape (69.6%) and vomiting (44.3%). 20.8% of cases were related to HAI cluster epidemic. 70 cases (72.9%) of children with NoV HAI got better and 26 cases (27.1%) were cured. 90.9% of 44 NoV positive specimens were type G Ⅱ. Conclusion NoV has a great impact on children's gastrointestinal HAI and can cause cluster epidemic. Early active screening on NoV can detect disease early, isolation and preventive measures can be taken as early as possible according to the seasonal epidemic characteristic, common transmission modes, and asymptomatic infected person.

Abstract:Shelter nucleic acid testing base is the core facility to achieve rapid and large-scale nucleic acid screening and control of COVID -19 epidemic. However, due to its large number of testing institutions, complex sources and uneven levels of laboratorians, the risk of infection prevention and control is relatively high. A complete set of infection prevention and control plans and procedures during the practice in nucleic acid testing base at Zhangjiajie Institute of Aeronautical Engineering have been explored by staff: base site selection, layout, route planning, perfecting infection prevention and control organizational structure, formulating infection prevention and control system, personnel and route management and control, staff closed-loop management, training, use of personal protective equipment, biosafety management of nucleic acid testing, medical waste disposal, environmental surface disinfection, occupational exposure treatment, evacuation and terminal disinfection, medical observation of staff after finishing the mission. The measures have laid a solid foundation for the base to complete the goal of "zero missed diagnosis, zero infection, and zero transmission".

Abstract:Objective To explore the indications and opportunities applicable for hand hygiene (HH) monitoring of cleaners in medical institutions through risk identification and clustering analysis method, provide tools and stan-dards for the monitoring of HH compliance of cleaners. Methods The workflow and behavior of 50 cleaners were observed anonymously by random sampling method, 10 experts were selected to judge the workflow, risk belts were defined with risk identification tools, HH indications were determined by cluster analysis. Results Risk scores of 17 types of work behavior of cleaners met the standard of cluster analysis and had HH indications, the highest risk score was mopping object surface of each bed, toilet, corridor, and so on in the ward one by one (4.50±0.53) as well as wiping the sink, handrail, wall, windowsill, and so on (4.50±0.53). Cluster analysis showed that tool preparation, cleaning and disinfection, personal protection, medical waste and environmental sorting were 5 main behavior nodes. After further inductive analysis, it is determined that HH indications of cleaners were "one before and five after", that is, before cleaning and disinfection, after preparing tools, after cleaning and disinfection, after taking off personal protective equipment, after transferring medical waste and after environmental sorting. Conclusion The establishment of "one before and five after" HH monitoring indication system for cleaners in medical institutions not only provides applicable quantitative reference indication for HH training of cleaners, but also provides a reference tool for monitoring and intervention of HH of cleaners.

Abstract:Objective To understand the direct economic loss of lower respiratory tract (LRT) healthcare-associa-ted infection (HAI). Methods 50 patients with LRT HAI in a tertiary general hospital in Fuyang City from May 1, 2018 to May 31, 2020 were selected as case group, a 1:1 matching study was adopted, 50 inpatients who had no LRT HAI and no other sites HAI during the same period, had the same initial diagnosis at admission and discharge were in control group, direct economic loss caused by LRT HAI was compared. Results The median of total hospitalization expense and average daily hospitalization expense in case group were 64 858.5 Yuan and 2 128.6 Yuan respectively; in control group were 26 728.0 Yuan and 1 477.5 Yuan respectively. The direct economic loss caused by LRT HAI was 38 130.5 Yuan/case, mainly expense of medicine, other (material), diagnosis and treatment, and nursing, expense of medicine was the highest. Except for the operation expense, the other medical expenses in case group were all higher than those in control group, differences were all significant (all P < 0.05). Compared with control group, the main increased expenses in case group were antimicrobial agents, inflammatory indicators and imaging examination. Differences of median were 2 962.0, 180.0, 444.0 and 1 288.5 Yuan respectively, differences were all significant (all P < 0.01). Length of hospitalization stay in case group and control group were (29.3±15.2) days and (14.9±7.5) days respectively, there was significant difference between two groups (P < 0.001). Conclusion Direct economic loss caused by LRT HAI is serious, the total expense and daily average hospitalization expense increased, and length of hospital stay is prolonged, much attention should be paid, prevention and control measures should be taken as early as possible.

Abstract:Objective To explore and analyze features of clinical manifestations and auxiliary examination results of patients with Chlamydia psittaci (C. psittaci) pneumonia, and improve the understanding of the disease. Methods Clinical data of 9 patients with C. psittaci pneumonia diagnosed by metagenomic next-generation sequencing (mNGS) in a hospital from June 2019 to August 2021 were retrospectively analyzed. Results Among 9 patients, 7 were males and 2 were females, including a pregnant woman who was 36⁺² weeks pregnancy; patients were aged 25-70 years, with a median age of 63 years; the main clinical manifestations were high fever (n=9), cough (n=9) and expectoration (n=7). Eight patients' leukocyte count was normal, 9 patients' lymphocyte count decreased, 9 patients' C-reactive protein (CRP) increased, 9 patients' erythrocyte sedimentation rate (ESR) increased, 4 patients' procalcitonin (PCT) was normal, 6 patients' aspartate aminotransferase (AST) and alanine aminotransferase (ALT) increased. Chest CT of all patients showed patchy or patchy consolidation. After confirmed by mNGS of blood and bronchoalveolar lavage fluid, monotherapy of doxycycline, moxifloxacin, levofloxacin, and azithromycin were administered for 14-21 days, all patients were cured and discharged from hospital. Conclusion C. psittaci pneumonia has a variety of clinical manifestations and is difficult to be diagnosed, mNGS test can quickly identify the etiology, facilitate the timely initiation of specific anti-infective therapy, reduce antimicrobial use, and improve the prognosis.

Abstract:Objective To analyze the clinical features, diagnosis and treatment methods of Chlamydia psittaci (C. psittaci) pneumonia, and improve the understanding of the disease. Methods Clinical data of patients with C. psittaci pneumonia diagnosed with metagenomic next-generation sequencing (mNGS) in a hospital from September 2019 to August 2021 were retrospectively analyzed, clinical features, diagnosis and treatment of the disease was summarized. Results Among 8 patients, 7 were males and 1 was female, aged 45-83 years. All patients started with high fever, accompanied by cough, fatigue, and general muscle pain, 6 of whom had a definite history of poultry contact. All patients had increased C-reactive protein (CRP) and lactate dehydrogenase (LDH) as well as abnormal coagulation function; 5 patients had decreased lymphocyte count; 6 patients had increased alanine aminotransferase and aspartate aminotransferase as well as decreased blood sodium. Chest imaging showed that manifestation of unilateral lung was more common, lesions mainly occurred in the right lung (n=5), less in both lungs (n=1). Five patients showed lung consolidation with bronchial inflation sign, 1 patient was with lung consolidation, ground-glass opacity and cavity formation respectively. Seven patients showed congestion and edema of bronchial mucosa under bronchoscopy. Eight patients were clearly diagnosed as C. psittaci pneumonia by mNGS, and were treated with doxycycline, azithromycin and moxifloxacin, all patients were cured and discharged from hospital. Conclusion C. psittaci pneumonia is usually characterized by high fever with pulmonary consolidation patches, application of mNGS detection of bronchoalveolar lavage fluid of patient can quickly and accurately diagnose C. psittaci pneumonia. Early treatment with doxycycline, azithromycin or moxifloxacin is effective in C. psittaci pneumonia.

Abstract:Objective To construct a Nomogram model for individualized prediction of risk of pulmonary infection (PI) in patients with non-small cell lung cancer (NSCLC) during chemotherapy period, and validate the prediction efficiency of the model. Methods 218 patients with NSCLC who were treated in a hospital from February 2018 to January 2021 were selected as the research objects, according to whether they had PI after chemotherapy, they were divided into PI group (n=56) and pulmonary non-infection group (n=162), LASSO and logistic regression analysis were used to screen the independent risk factors for PI in NSCLC patients during chemotherapy, and a Nomogram prediction model was constructed. Results 218 NSCLC patients were included in study, 56 patients had PI during chemotherapy, incidence of PI was 25.69%. LASSO and logistic regression analysis showed that age ≥ 60 years old, diabetes mellitus, combined chemotherapy drugs, chemotherapy cycle >2 times, albumin content after chemotherapy < 30 g/L, KPS score < 80 points before chemotherapy were independent predictors of PI in NSCLC patients during chemotherapy (all P < 0.05). Based on 6 independent predictors, the Nomogram model was constructed to predict the risk of PI in NSCLC patients during chemotherapy. Validation result showed that the C -index of the training set and validation set were 0.819 (95%CI: 0.788-0.850) and 0.802 (95%CI: 0.778-0.829) respectively. The calibration curve trend of two sets was relatively close to the diagonal (ideal curve), the area under the ROC curve (AUC) were 0.807 (95%CI: 0.775-0.839) and 0.797 (95%CI: 0.773-0.821) respectively. When the decision curve showed that the threshold probability was 1%-90%, there was a relatively high net profit value. Conclusion Nomogram model based on independent predictors of PI in NSCLC patients du-ring chemotherapy has good prediction efficiency, which is helpful to screen high-risk patients as early as possible and improvement of treatment plans.

Abstract:Objective To understand the cognition status and related influencing factors of health care workers' (HCWs) knowledge towards coronavirus disease 2019 (COVID -19) in a stomatology medical institution, provide thought for the prevention and control training of outbreaks of infectious diseases. Methods A survey was conducted among HCWs of different posts in a stomatology medical institutions at a given time period by means of network questionnaire, survey results were analyzed. Results A total of 1 945 questionnaires were received, the average score of HCWs' knowledge on prevention and control of COVID -19 was 12.43 points (full score: 16 points); scores of knowledge, attitude and practice (KAP) among HCWs of different age, gender, professional title and work department were statistically significant (all P < 0.05), while scores of working years was not significantly different (P>0.05), the correct rates of knowledge on diagnostic criteria of suspected COVID -19 patients, environmental disinfection measures, personal protection and judgment of close contact were all low. Conclusion Stomatology medical institution can adopt intuitive flowchart for screening confirmed and suspected cases, pay attention to evidence-based research on the impact of stacking and wearing of personal protective equipment as well as air disinfection measures, and organize multi-form and multi-level training.

Abstract:Objective To design an aerosol bacterial retention testing to evaluate bacterial retention capacity of air inlet filter of infusion device using challenging aerosol of Staphylococcus aureus. Methods Staphylococcus aureus suspension was diluted to 10⁸ CFU/mL, aerosol was produced by aerosol bacterial retention testing system, positive control branch and 75 air filters from 5 manufacturers (A-E) were tested, membrane filtration method was adopted to collect liquid specimen in the liquid impact sampler, bacteria growth and count was observed. Results After the testing, the collected fluid of positive control branch and 60 specimens from 12 batches of 5 manufacturers (A-D) were without bacteria growth and met the requirements; bacterial colonies of 15 specimens from 3 branches of ma-nufacturer E was >100 CFU, which did not meet the requirements. The air filter of manufacturer E was made of glass fiber with a pore diameter of 5 μm. Conclusion The designed aerosol bacterial retention testing system can successfully retain the bacteria in the air inlet filter of infusion devices.

Abstract:Objective To analyze the role of active screening in the prevention and control of multidrug-resistant organism (MDRO) infection in intensive care unit (ICU) through active screening on patients in ICU. Methods Patients who were admitted to the emergency ICU of a hospital from January 1, 2017 to December 31, 2020 were selected, patients who didn't conduct active screening from 2017 to 2018 were in control group, those who underwent active screening from 2019 to 2020 were in intervention group. Infection status, MDRO infection and adverse medical events of two groups of patients were compared. Results A total of 1 834 patients were in control group, incidence of healthcare-associated infection (HAI) was 7.91%; 1 636 patients were in intervention group, HAI rate was 5.26%; there was significant difference between two groups (P=0.002). 58 patients (3.16%) in control group and 33 patients (2.02%) in intervention group had MDRO infection, there was significant difference between two groups (P=0.035). Case infection rates of carbapenem-resistant Acinetobacter baumannii (CRAB), multidrug-resistant/pandrug-resistant Pseudomonas aeruginosa (MDR/PDR-PA) and extended-spectrum β-lactamases(ESBLs)-producing bacteria in intervention group were all lower than those in control group (all P < 0.05). MDRO respiratory tract infection rates in control group and intervention group were 2.84% and 1.77% respectively, there was significant difference between two groups (P=0.038). The average total hospitalization days and ICU hospita- lization days in intervention group were both lower than those in control group (both P < 0.05). Incidence of adverse medical events in patients with MDRO infection in intervention group was lower than that in control group (6.06% vs 25.86%), difference was statistically significant (P=0.006). There was no significant difference in positive rate of active screening and that of bacterial culture (P=0.067), the sensitivity and specificity of active screening were 87.13% and 97.29% respectively. Conclusion Implementation of active screening can early identify MDRO car-riers, understand MDRO infection and colonization as early as possible, reduce HAI rate and MDRO infection rate of ICU patients, and reduce hospitalization days and incidence of adverse medical events.

Abstract:Aspergillus flavus belongs to Aspergillaceae and is second only to Aspergillus fumigatus inducing Aspergillosis, it occurs more often in lung, sinuses and eye, while renal pelvis infection is rare. In this case, acute renal failure was caused by Aspergillus flavus infection of the renal pelvis. Amphotericin B was used locally and systemically, with good therapeutic effect and recovery of renal function.

Abstract:Organ transplant recipients are high risk population for COVID -19, and vaccination is an effective prevention and control method to reduce the infection rate and severe disease rate of such patients. This paper introduces the clinical prognosis of COVID -19 in solid organ transplant recipients, comprehensively analyze the related mechanisms of immune response and research progress of intensified immunization in this population, and put forward immunization strategies for these patients.

Abstract:In recent years, with the widely application of carbapenems, carbapenem-resistant Enterobacterales (CRE) infection is increasingly prevalent in children, and are often associated with poor clinical outcomes. Due to the specific pharmacokinetic/pharmacodynamic (PK/PD) characteristics of children, most anti-CRE antimicrobial agents lack clinical application experience in children, and pediatricians face huge challenge in the treatment of CRE. In this paper, the existing knowledge of CRE infection in children is collected, epidemiology, antimicrobial resis-tance mechanisms and the latest treatment strategies are reviewed, so as to provide a reference for clinical medication.