Objective To investigate the antibiotic resistance and molecular epidemiology character of ?-lactamase producers among clinical isolates of Citrobacter freundii.Methods Four strains of Citrobacter freundii were detected by K-B susceptibility method and three-dimensional test.The ?-lactamase gene was identified by polymerase chain reaction(PCR) and sequencing.Results The No.29 strain of Citrobacter friundii was multiple-drug-resistant and proved to produce CMY,DHA type AmpC,TEM and SHV type of extended-spectrum ?-lactamases(ESBLs).The sequencing of corresponding DNA revealed 97% identities of the CMY-2 amino acid sequence.It was a new type of cephalosporinase.Conclusion A novel strain of Citrobacter friundii with CMY type AmpC,DHA type AmpC,TEM and SHV type ESBLs has been found in southern China and it is multiple-drug-resistant.

OBJECTIVE To investigate the phenotypical and genotypical characteristics of the ?-lactamase in the 302 strains of Gram-negative bacilli,and assess the characteristics of the drug resistance.METHODS The phenotypes of ?-lactamase were detected in the Gram-negative bacilli by disc diffusion screen test,which were further ascertained by disc diffusion confirmatory test,a cefoxitin three dimensional test,and metallo ?-lactamases double-disc synergy test.The ?-lactamases were detected by multiple PCR amplification,then DNA product was sequenced.Antibiotics susceptibility was detected by K-B method.RESULTS Among the clinical Gram-negative isolates,a total of 26.49%(80/302)strains′ ?-lactamases phenotypes were positive,ESBLs,ESBLs combined with AmpC enzyme,ESBLs combined with AmpC enzyme and MBL,and AmpC enzyme producing strains were found in 16.56%,6.62%,1.66% and 0.66%,respectively.A total of 24.83% strains′?-lactamases phenotypes were positive,strains produced ESBLs,ESBLs combined with AmpC enzyme,ESBLs combined with AmpC enzyme and MBL,and AmpC enzyme producing strains were found in 17.55%,6.95%,0.33%,and 0.33%,respectively.Drug-sensitivity test showed multi-resistant Gram-negative isolates were more sensitive to amikacin(18.75%),and heavier resistant to ampicillin(97.50%).CONCLUSIONS ?-Lactamase producing Gram-negative bacilli are resistant to multi-antibiotics.

Objective To investigate the distribution of the CTX-M- extended spectrum beta-lactamase (ESBLs) producing Esche- richia coli(ECO) and the molecular mechanism of dissemination. Methods To analyze the drug resistance of the 43 isolates, Kirby-Bauer susceptibility method was used. Multiple polymeraso chain reaction (PCR) was used to amplify the gene of ESBLs, AmpC, full length of blaCTX-M-like gene, insertion sequence (IS) ISEcp1B, IS903 , IS26 and integron I. NEST-PCR was used to detect if the beta-lactamase gene lo- cated in the integron I. The product of full length of bla-CTX-M like gone amplified by PCR was sequenced. Results Susceptibility test showed the resistance from high to low in turn was Ampicillin (97.68%), Coftriaxone (67.44 % ), piperacillin(65.12 % ), Cefotaxime (62.79 % ) ,Coftasidime(58.14% ), Cofasolin(55.81% ), Cofepime (53.49%), Cefexitin(51.16%), ciprofloxacin (44. 19% ), Aztreo- nam(41.86% ), Cefoperasone/Sulbactam ( 20.93% ), Amikacin (0% ), Imipenem (0% ), respectively. ECO was susceptive to Imipenem. CTX-M-G1 was found in 25 strains of ECO , TEM, SHV, CTX-M-G1, ISEcp1B, and integron I were found in the nine isolates. IS903 were found in ECO 3 and 5, and IS26 was found in ECO 3. In ECO 3 and 5, blaCTX-M-like was flanked upstream by ISEcp1B element that provided -35 and -10 promoter sequences and a right inverted repeat (IRR) recognized by transposase, downstream by IS903 provided an inverted re- peat, ISEcp1 B and IS903 composed the complex transpeson. Conclusion ISEcplB may drive the expression and dissemination of blaCTX-M-like gene at a high level.

Objective To investigate the distribution of high pathogenicity island(HPI)in multiple-drug-resistance gram-negative bacilli and analyze the protein sequence.Methods To amplify thefyuA-irp2 gene cluster of the 84 isolates by multiple polymerase chain reaction(PCR),the product was subsequently sequenced.Results The positive rate ofirpl,irp2,irp3,irp4 and fyuA was 40.48％,41,67％,5.95％,O％and 16.67％,respectively.Theamino sequence offyuA comefromEC06748,Kp7151 and PAE7 was usedto compare with AL590842,there are 100％identities.Amino sequence ofirp2 come from Kp49 and Kp51 have 99％identities with AAA27636.1,but amino sequence of irp2 come from EC04 and EC07 only have 90％identities with 1176840.The GenBank accession number is FJ211852 and FJ211851.Amino sequence ofirpl come fromKp 10,Kp49 and Kp51 have 99％identities with AL590842。and amino sequence ofirp3 come from EC03,Kp51,Kp10 and Kp49 have 97％identities with CAA73128.There are the same mutation among the same species,and different mutation among different species.Conclusion There was different extant mutant lost in thefy～t-i,v2 gene cluster in multiple-drug-resistanee gram-negative bacilli.

Objective: To understand the current status of acquired immunodeficiency syndrome (AIDS) knowledge, attitudes, and practices of college students in Tianjin City and to further investigate the associated factors of high risk sexual behaviors, so as to provide a scientific and theoretical basis for accurate prevention and treatment of AIDS. Methods: A stratified cluster random sample of 64 697 students in 56 colleges and universities in Tianjin City in November to December 2022 was investigated about the current status of AIDS knowledge, attitudes and practices. Information was collected using online survey via Questionnaire Star. Descriptive analysis was used for the current status of AIDS knowledge, attitudes and practices among college students. Chi square test and multiple Logistic regression analysis were used to analyze the influencing factors of high risk sexual behavior among college students. Results: The AIDS awareness rate of college students in Tianjin City reached 87.33%. The sexual openness rate was 70.73 %. Among the 3 463 students who had sex during the past year, 42.13% of students reported high risk sexual behavior. Multivariate Logistic regression showed that female, having a romantic partner, having received sex education and prevention and treatment knowledge of AIDS were negatively associated with high risk sexual behavior ( OR =0.66, 0.59, 0.81, 0.59, P <0.05). Being in sophomore year, non heterosexuality (homosexuality, bisexuality, not knowing), prejudice against AIDS, and misunderstanding the testing methods for AIDS showed positive correlations with highrisk sexual behavior ( OR =1.22, 2.49, 2.30, 3.17, 1.43, 1.22 , P <0.05). Conclusions The awareness rate of AIDS in college students in Tianjin is high, but high risk sexual behaviors are still at a high level. Further targeted knowledge education and behavioral interventions are needed to scientifically prevent the spread of AIDS.

BACKGROUND:Studies have shown that nucleotide binding oligomerization domain-like receptor protein 3(NLRP3)inflammasome,interleukin-18,and interleukin-1β levels can induce an inflammatory cascade response to release inflammatory factors,affect metabolic stress,and damage endothelial cells involved in the development and progression of diabetic foot ulcers,which can provide a reference for early infections. OBJECTIVE:To investigate the predictive effect of peripheral blood mononuclear cell NLRP3 inflammasome,interleukin-18 and interleukin-1β levels on early infection after flap repair of diabetic foot ulcers. METHODS:A total of 147 patients with diabetic foot ulcers were selected and divided into infection group and non-infection group according to whether they were infected within 1 week after operation.Logistic regression was used to analyze the relationship between NLRP3 inflammasome,interleukin-18 and interleukin-1β levels in peripheral blood mononuclear cells and early postoperative infections,and to evaluate their predictive values. RESULTS AND CONCLUSION:In 147 patients with diabetic foot ulcers,35 cases(23.81%)were infected within 1 week after operation,and 47 strains of pathogenic bacteria were isolated,including 25 strains of Gram-positive bacteria(53.19%)and 22 strains of Gram-negative bacteria(46.81%).Univariate analysis showed that Wagner grade,presence of comorbid diabetic nephropathy,operation time,peripheral blood NLRP3 mRNA,Caspase-1 mRNA,ASC mRNA,interleukin-18 and interleukin-1β levels were risk factors for early postoperative infections(all P＜0.05).Multivariate analysis suggested that Wagner grade,NLRP3 mRNA,Caspase-1 mRNA,ASC mRNA,high interleukin-18,interleukin-1β were independent risk factors(all P＜0.05).Receiver operator characteristic curve results showed that the area under the receiver operator characteristic curve of NLRP3 mRNA,Caspase-1 mRNA,ASC mRNA,interleukin-18 and interleukin-1β for early postoperative infections in patients with diabetic foot ulcers was 0.823,0.705,0.676,0.811 and 0.853,respectively,and the area under the curve of combined predictive efficacy was 0.915.To conclude,patients with diabetic foot ulcers are mainly affected by Gram-positive bacteria,and the levels of NLRP3 inflammasome,interleukin-18 and interleukin-1β in peripheral blood mononuclear cells are independent risk factors for early postoperative infections.The combined prediction efficacy of these indicators is better and deserves further in-depth study.

Objective To explore the potential influencing factors and complex pathways affecting rehabilitation effect for children with autism spectrum disorder(ASD)from the perspective of parental efficacy in doctor-patient communication,and to provide evidence for improving the quality of rehabilitation service for children with ASD. Methods An anonymous face-to-face questionnaire survey was conducted to collect general demographic information of parents of children with ASD at designated rehabilitation institutions in Gansu province.The data included paren-tal efficacy in doctor-patient communication,parental compliance of treatment and children's rehabilitation out-comes were collected.A structural equation model was used to explore the impact mechanism of parental commu-nication efficacy on the rehabilitation outcomes of children with ASD. Results Data from 519 parents at 37 rehabilitation institutions across 13 cities/counties in Gansu province were collect-ed.Significant positive correlations were found between parental efficacy in doctor-patient communication,doc-tor-patient relationships,parental compliance with treatment and rehabilitation outcomes for children with ASD(P＜0.05).Through structural equation model analysis,the standardized direct effect of children with ASD from parents'doctor-patient communication efficacy was 0.151(P=0.023).The mediating effect of doctor-patient rela-tionship and parental compliance with treatment were 0.160(P=0.001)and 0.111(P=0.001),respectively,with a chained mediating effect of 0.035(P=0.001).The pathway"parental efficacy in doctor-patient communica-tion → doctor-patient relationship → ASD child's rehabilitation outcome"accounted for the highest proportion of the total mediating effect,at 52.29%. Conclusion Parental doctor-patient communication efficacy may positively impact on the rehabilitation outcomes of chil-dren with ASD directly,and indirectly through the doctor-patient relationship and parental compliance with treat-ment.Rehabilitation institutions should focus on fostering parental communication skills and enhancing high-quality and humanized rehabilitation services.

Objective: To analyze the epidemiological history, clinical manifestations, treatment and the short-term prognosis of 31 cases of 2019 novel coronavirus(2019-nCoV) infection in children from six provinces (autonomous region) in northern China. Methods: A retrospective analysis of the epidemiological history, clinical symptoms, signs, laboratory examinations, chest imaging, treatment and the short-term prognosis of 31 cases of 2019-nCoV was conducted. The patients were diagnosed between January 25th, 2020 and February 21st, 2020 in 21 hospitals in 17 cities of six provinces(autonomous region) of Shaanxi, Gansu, Ningxia, Hebei, Henan and Shandong. Results: The age of the 31 children with 2019-nCoV infection was 7 years and 1 month (6 months -17 years). Nine cases (29%) were imported cases. Other 21 cases (68%) had contact with confirmed infected adults. One case (3%) had contact with asymptomatic returnees from Wuhan. Among the 31 children, 28 patients (90%) were family cluster cases. The clinical types were asymptomatic type in 4 cases (13%), mild type in 13 cases (42%), and common type in 14 cases (45%). No severe or critical type existed. The most common symptom was fever (n=20, 65%), including 1 case of high fever, 9 cases of moderate fever, 10 cases of low fever. Fever lasted from 1 day to 9 days. The fever of fifteen cases lasted for ≤3 d, while in other 5 cases lasted > 3 d. Other symptoms included cough (n=14, 45%), fatigue (n=3, 10%) and diarrhea (n=3, 9%). Pharyngalgia, runny nose, dizziness, headache and vomiting were rare. In the early stage, the total leukocytes count in peripheral blood decreased in 2 cases (6%), the lymphocytes count decreased in 2 cases (6%), and the platelet count increased in 2 cases (6%).Elevation of C-reactive protein (10%, 3/30), erythrocyte sedimentation rate(19%,4/21), procalcitonin(4%,1/28), liver enzyme(22%, 6/27) and muscle enzyme (15%, 4/27) occurred in different proportions. Renal function and blood glucose were normal. There were abnormal chest CT changes in 14 cases, including 9 cases with patchy ground glass opacities and nodules, mostly located in the lower lobe of both lungs near the pleural area. After receiving supportive treatment, the viral nucleic acid turned negative in 25 cases within 7-23 days. Among them, 24 children (77%) recovered and were discharged from hospital. No death occurred. Conclusions In this case series, 2019-nCoV infections in children from six provinces (autonomous region) in northern China are mainly caused by close family contact. Clinical types are asymptomatic, mild and common types. Clinical manifestations and laboratory examination results are nonspecific. Close contact history of epidemiology, nucleic acid detection and chest imaging are important bases for diagnosis. After general treatment, the short-term prognosis is good.