Abstract: Objective To investigate the prevalence and pathogenic characteristics of Yersinia enterocolitica infection in children with diarrhea under 5 years of age in western Yunnan, and to provide a basis for the prevention and treatment of infectious diarrhea in children. Methods Feces were collected from under five-year-old children with diarrhea in the First Affiliated Hospital of Dali University from 2020 to 2021. Clinical information of the cases was also collected. Yersinia enterocolitica was isolated from the samples after cold enrichment on selective culture plates, and the pathogenic characteristics of Yersinia enterocolitica were analyzed by biological type and serotype and virulence gene detection. Results A total of 397 feces were collected. Seven strains of Yersinia enterocolitica were isolated in three samples, and the prevalence of Yersinia enterocolitica infection was 0.76% (3/397). Among the three positive samples, two Yersinia frederiksenii or Yersinia intermedia were isolated in specimen No. 212 , and five Yersinia enterocolitica were detected in specimens No. 24 and 226. Two Yersinia enterocolitica isolated from one sample were biological type 1A, and the virulence gene test results were ail-/ystA-/ ystB+ /yadA-/virF-, which were non-pathogenic Yersinia enterocolitica. Three Yersinia enterocolitica isolated from the other sample were biological type 3, serotype O∶3 (rfbc+), and virulence gene detection results were ail+/ystA+/ystB-/yadA+ /virF+, which were pathogenic Yersinia enterocolitica. While pathogenic Yersinia enterocolitica was detected from feces of children with diarrhea at 11 months of age with a infection rate of 0.50%(2/397). Conclusion Sporadic infection of pathogenic Yersinia enterocolitica was found in under five-year-old children in western Yunnan Province. It is necessary to strengthen the monitoring and research of Yersinia enterocolitica.

Objective To establish an extensively drug-resistant Acinetobacter baumannii (XDR-AB) infection model using Caenorhabditis elegans (C.elegans),and evaluate the effect of efflux pump inhibitors(EPIs) on reversal of ciprofloxacin resistance in XDR-AB.Methods XDR-AB infection model of C.elegans was established,six EPIs(CCCP,PAβN,NMP,omeprazole,reserpine,and verapamil)combined with ciprofloxacin were used to treat the infected model,the survival rate of C.elegans was recorded to evaluate the in vivo activities of drugs,toxicity test and in vitro drug susceptibility test were also performed.Results Lethal effect of different concentrations of XDR-AB on C.elegans was varied,5 × 106 CFU/mL of XDR-AB was selected to infect C.elegans.C.elegans survival test showed that survival curves of C.elegans infected with XDR-AB for 3 hours and curves of control group (polymixin B was added) were not significantly different (x2 =3.154,P＞0.05);compared with control group,survival curves of C.elegans infected with XDR-AB for 6 hours or 9 hours were significantly different (both P＜0.001),but 6 hours and 9 hours were not significantly different(x2 =0.669,P＞0.05),6 hours was chosen as the duration of infection,36 hours was appropriate for the duration of antimicrobial therapy.Ciprofloxacin with EPIs for infection model revealed that low concentration of PAβN,NMP,omeprazole,and reserpine could improve the survival rate of C.elegans by 30％-40％,15％-20％,20％-30％,and 20％ respectively,high concentration of verapamil could improve the survival rate of infected C.elegans by about 30％.In vitro susceptibility test and toxicity test results showed that ciprofloxacin combined respectively with CCCP,omeprazole,and verapamil could reduce minimum inhibitory concentration(MIC) to the original 1/4,combined respectively with PAβN,NMP,and reserpine could reduce MIC to the original 1/2,CCCP had the best bacterial inhibitory effect in vitro,but the toxicity was large,and was not suitable for the study of pharmacodynamics in vivo.Conelusion The infection model of C.elegans XDR-AB is initially and successfully established,which is used to evaluate the efficiency of six EPIs for reversing ciprofloxacin resistance.

Objective: To summarize the mid-term effect of modified extended Morrow procedure in patients with hypertrophic obstructive cardiomyopathy (HOCM) combining sub aortic valve obstruction and mid left ventricular obstruction. Methods: We studied 34 consecutive HOCM patients with sub aortic and midventricular obstruction who received modiifed extended Morrow procedure with extracorporeal circulation in our hospital from 1996-11 to 2015-01. Transthoracic echocardiography was conducted at pre-, post-operation and follow-up period to evaluate the changes of mid-ventricular gradient, subarctic gradient and each heart valve function. Results: The average follow-up time was (25.7 ± 14.9) months, 2 patients lost contact and no death occurred. In rest 32 patients, the mid ventricular gradient decreased from (60.3 ± 29.4) mmHg to (21.0 ± 19.8) mmHg, subaortic valve gradient decreased from (77.9 ± 26.2) mmHg to (11.6 ± 6.5) mmHg, the maximum ventricular septal thickness dropped from (25.2 ± 4.9) mm to (17.9 ± 7.2) mm, left atrial diameter reduced from (41.1 ± 7.8) mm to (37.6 ± 6.4) mm, left ventricular end-diastolic diameter increased from (39.8 ± 5.1) mm to (42.2 ± 4.3) mm, allP<0.05; there were 5 patients without obviously improved mid ventricular gradient because of insufifcient resection of septal myocardium in mid-ventricle. The post-operative NYHA classiifcation was improved,P<0.01, mitral valve regurgitation degree was decreased,P<0.01 and SAM phenomenon was disappeared. Complications included 3 (8.8%) patients of III atrio-ventricular block, 1 (2.9%) patient of re-admission due to poorly healed sternum combining pneumonia Conclusion: Modified extended Morrow procedure may relieve sub aortic valve and mid ventricular obstruction, therefore improve left ventricular diastolic function and prognosis in relevant patients.

Objective: In this study, we analyze the regulation mechanisms of the expression of ampD in AmpC β-lactamase and the regulation mechanism of β-N-acetylglucosaminidase (NagZ) in Yersinia enterocolitica. Methods: We construct the mutation strains of Yersinia enterocolitica AmpD (AmpD1-3) gene (ampD1-3), Low-Molecular-Mass Penicillin-Binding Proteins (LMM PBPs) gene (pbp4, pbp5a, pbp5b, pbp7), NagZ gene (nagZ), and ampR gene by deleting and complementing genes, and induce them by cefoxitin. We determined the activity of AmpC β-lactamase activity (U) of mutant strains (basal level and induce level) by using cephalothiophene hydrolysis method, the promoter activity of AmpC β-lactamase ((relative light unit (RLU)) was detected by the luxCDABEreporter system, and the activity of β-N-acetylglucosaminidase (nmol/L) was determined by by using 4-nitrophenyl N-acetyl-β-D-glucosaminide as the chromogenic substrate. Results: AmpD1 (Basal level: (3.29±1.58) U; Induced level: (4.08±1.75) U) was the most potent one. The YEΔ5b, YEΔ4Δ5b, YEΔ5aΔ5b and YEΔ5bΔ7 of ampC promoter activity increase significantly, whichYEΔ4Δ5b is the highest one (Basal level: (106 903.16±61 910.61) RLU; Induced level: (205 427.45±45 352.17) RLU). The YEΔ4Δ5bΔ7 of ampC promoter activity is the highest among triple mutant strain (Basal level: (304 108.04±99 274.53) RLU; Induced level: (531 440.21±68 891.02) RLU). Quadruple deletion strain YEΔ4Δ5aΔ5bΔ7 have the highest ampC promoter activity (Basal level: (1 013 810.99±260 955.96) RLU; Induced level: (1 230 214.59±205 526.79) RLU). After the deletion of nagZ gene, there is no significant change in β-lactamase activity of YEΔD1D2D3ΔZ, while β-lactamase activity of YEΔ4Δ5aΔ5bΔ7ΔZ shows a significant decrease (Basal level: (0.30±0.20) U; Induced level: (0.29±0.21) U), which basically drops to the wild strain level. Conclusion This is the first report of ampC multi-step upregulation mechanism driven by three AmpD homologues in Yersinia enterocolitica. The AmpC regulation mode with the function of single PBP4, PBP5a or PBP7 is relatively low, which work in coordination with PBP5b. Yersinia enterocolitica have both NagZ-depend and NagZ-independent mechanisms for β-lactamase expression.

Objective To indentify the risk factors of hemorrhage of cerebral arteriovenous malformations (AVMs) in children,and further conclude the treatment strategies and safety of these patients by endovascular embolization.Methods The clinical data of 56 patients with AVMs aged 3-14 years,admitted to our hospital from June 2005 to June 2015,were retrospectively analyzed.The risk factors of hemorrhage of these patients were identified by univariate and multivariate analyses;and the treatment strategies by endovascular embolization were analyzed.Results Univariate analysis indicated that small size of malformation vascular mass was the independent risk factor of hemorrhage for patients with AVMs in children (OR=0.292,95％CI:0.106-0.805,P=0.017).For 56 patients treated by endovascular embolization,a total of 121 feeding pedicles were embolized,and the mean obliteration rate of AVMs was 79％ (20％-100％).Finally,only 9 patients (7.9％) suffered embolization-related complications,such as headache,facial paralysical,hemianopsia,and activity obstacle;however,no patients suffered severe disability or death.After a follow-up of 2 months to 36 months (mean=17 months),all childem had favorable outcome,and none suffered intracerebral hemorrhage or recurrent AVMs.Conclusions Small size of malformation vascular mass is the independent risk factor of hemorrhage of patients with AVMs in children.The endovascular embolization of patients with intracranial AVM in children is efficacy and safe with few complications.

Objective To illuminate the epidemic characteristics of Yersiniosis among children in the central city of Beijing and the accuracy of current clinical diagnosis towards Yersiniosis. Methods Etiological surveillance of diarrheal patients, a total of 3 493 cases, was performed in a children hospital in central area of Beijing from 2011 to 2018 continuously. Collected the epidemiological and clinical information of the cases, analyzed the clinical and etiological diagnosis for Yersiniosis and bacterial dysentery and compared the distribution of Yersiniosis cases with the different symptoms. Results A total of 3 493 acute diarrhea cases distributed from the age of 6 months to 13 years old, M (P25, P75) was 1.50 (0.75, 3.17) years old. The 28 cases were isolated Yersinia enterocolitica (isolation rate of 0.80%) and they could be diagnosed as Yersiniosis by etiology. The isolation peaked in May and February. A total of 85.71% (24/28) of Yersiniosis cases were under 5?year old. The children of 3-4 age group had the highest isolation rate (1.52%) while the rate (0.18%) of 0-1 age group was the lowest (P=0.025). The Yersinia enteroclitica isolation rates of diarrheal patients with the symptoms including mucus feces, fever, white blood cell (WBC) and red blood cell (RBC) in feces were higher than the patients without these symptoms (P＞0.05). The 9 of 28 Yersiniosis cases by etiology diagnosis were clinical diagnosed as bacillary dysentery. Conclusion The infants and young children under 5?year old were the main population of Yersiniosis adolescent patients under 14?year old. The typical symptoms characterized with mucus stool, fever, WBC and RBC by routine microscopic examination. The preliminary clinical diagnosis of Yersiniosis is easily confused with bacterial dysentery.

Objective To illuminate the epidemic characteristics of Yersiniosis among children in the central city of Beijing and the accuracy of current clinical diagnosis towards Yersiniosis. Methods Etiological surveillance of diarrheal patients, a total of 3 493 cases, was performed in a children hospital in central area of Beijing from 2011 to 2018 continuously. Collected the epidemiological and clinical information of the cases, analyzed the clinical and etiological diagnosis for Yersiniosis and bacterial dysentery and compared the distribution of Yersiniosis cases with the different symptoms. Results A total of 3 493 acute diarrhea cases distributed from the age of 6 months to 13 years old, M (P25, P75) was 1.50 (0.75, 3.17) years old. The 28 cases were isolated Yersinia enterocolitica (isolation rate of 0.80%) and they could be diagnosed as Yersiniosis by etiology. The isolation peaked in May and February. A total of 85.71% (24/28) of Yersiniosis cases were under 5?year old. The children of 3-4 age group had the highest isolation rate (1.52%) while the rate (0.18%) of 0-1 age group was the lowest (P=0.025). The Yersinia enteroclitica isolation rates of diarrheal patients with the symptoms including mucus feces, fever, white blood cell (WBC) and red blood cell (RBC) in feces were higher than the patients without these symptoms (P＞0.05). The 9 of 28 Yersiniosis cases by etiology diagnosis were clinical diagnosed as bacillary dysentery. Conclusion The infants and young children under 5?year old were the main population of Yersiniosis adolescent patients under 14?year old. The typical symptoms characterized with mucus stool, fever, WBC and RBC by routine microscopic examination. The preliminary clinical diagnosis of Yersiniosis is easily confused with bacterial dysentery.

Objective:To understand the characteristics and differences of diarrhea-related symptoms caused by different pathogens, and the clinical features of various pathogens causing diarrhea.Methods:Etiology surveillance program was conducted among 20 provinces of China from 2010 to 2016. The acute diarrhea outpatients were collected from clinics or hospitals. A questionnaire was used to survey demographics and clinical features. VFeces samples were taken for laboratory detection of 22 common diarrhea pathogens, to detect and analyze the clinical symptom pattern characteristics of the patient’s.Results:A total of 38 950 outpatients were enrolled from 20 provinces of China. The positive rates of Rotavirus and Norovirus were the highest among the five diarrhea-causing viruses (Rotavirus: 18.29%, Norovirus: 13.06%). In the isolation and culture of 17 diarrhea-causing bacterial, Escherichia coli showed the highest positive rates (6.25%). The clinical features of bacterial diarrhea and viral diarrhea were mainly reflected in the results of fecal traits and routine examination, but pathogenic Vibrio infection was similar to viral diarrhea. Conclusion:Infectious diarrhea presents different characteristics due to various symptoms which can provide a basis for clinical diagnosis.

Objective:To study the differential expressions of piRNAs in the seminal plasma of men and the role of piRNAs in spermatogenesis.Methods:We sequenced the seminal plasma samples collected from 187 male infertility patients and 58 normal healthy men,obtained differentially expressed piRNAs,and detected the relative expressions of piRNAs in different types of sperm by RT-qPCR to explore their significance in the diagnosis of male infertility.Using histopathology,RNA-protein pull-down and Western blot,we investigated the action mechanism of piRNAs in spermatogenesis in the mouse model.Results:RT-qPCR of the seminal plasma samples revealed a high expression of hsa_piR_000478 in teratozoospermia and ROC curve analysis showed an auxiliary signifi-cance of hsa_piR_000478 in the diagnosis of the disease(AUC=0.7549).Transfection of hsa_piR_000478 and its homologous se-quence piR_mmu_54800729 into the seminiferous tubules of the mouse model significantly decreased sperm motility,increased the per-centage of morphologically abnormal sperm and destroyed the testicular structure.Molecular biological experiments exhibited a close correlation between piRNAs and the energy metabolism-related pathway,which elevated the level of cell glycolysis and interfered with normal spermatogenesis.Conclusion:hsa_piR_000478 has an auxiliary significance in the diagnosis of male infertility,and piRNAs may interfere with spermatogenesis by affecting the glycolysis-related pathway in the spermatogenic microenvironment of the testis.

Objective:To investigate the impact of ionizing radiation(IR)on the structure and function of the testis and pro-vide some strategies for the prevention and treatment of IR-induced damage(IRD).Methods:Using radiation dose simulation,se-men analysis,hormone testing,electron microscopy and single-cell transcriptome sequencing,we assessed and analyzed a case of IRD.We established a mouse model of IRD to validate the results of single-cell sequencing,and investigated the specific biological mecha-nisms of IRD and potential strategies for its intervention.Results:IR at 1-2 Gy significantly reduced sperm concentration and mo-tility,which gradually recovered after 12 months but the percentage of morphologically normal sperm remained low.It also caused im-balanced levels of various steroid hormones,decreased testosterone and dehydroepiandrosterone sulfate,increased progesterone,prolac-tin,luteinizing hormone,and follicle-stimulating hormone.Electron microscopy revealed damages to the testis structure,including loss of germ cells,atrophy of the seminiferous tubules,nuclear membrane depression of the spermatocytes,mitochondrial atrophy and de-formation,and reduction of mitochondrial cristae.Single-cell sequencing indicated significant changes in the function of the Leydig cells and macrophages and disrupted lipid-related metabolic pathways after IRD.Administration of L-carnitine to the mouse model im-proved lipid metabolism disorders and partially alleviated IRD to the germ cells.Conclusion:Ionizing radiation can cause disorders of testicular spermatogenesis and sexual hormones and inhibit lipid metabolism pathways in Leydig cells and macrophages.Improving lipid metabolism can alleviate IRD to germ cells.