1.Analysis of tellurite resistance level and resistance gene cluster in non-O157 Shiga toxin-producing Escherichia coli isolates
Xiangning BAI ; Ailan ZHAO ; Qiong MENG ; Jianguo XU ; Yanwen XIONG
Chinese Journal of Microbiology and Immunology 2012;32(7):585-588
Objective To investigate the tellurite resistance level,the presence of tellurite resistance (ter) gene cluster and their relationships in non-O157 Shiga toxin-producing Escherichia coli(STEC) isolates.Methods Tellurite resistance level was evaluated by plate dilution method and the ter gene cluster was tested by PCR.Results Only 5 of 39 non-O157 STEC isolates tested in this study were identified to have ter gene cluster,which showed relatively high levels of tellurite resistance ranging from 128 μg/ml to 512 μg/ml.In contrast,the other 34 isolates without ter gene cluster were sensitive to potassium tellurite and showed very low levels of tellurite resistance,the minimal inhibitory concentration (MIC) was <1 μg/ml for 29 isolates,8 μg/ml for 2 isolates and 2 μg/ml for 3 isolates.Conclusion Most non-O157 STEC isolates were sensitive to potassium tellurite.It could be concluded that much attention should be paid when screening the non-O157 STEC isolates using the selective medium supplemented with potassium tellurite.
2.Expression of protein tyrosine phosphatase receptor T in brains of patients with intractable epilepsy and rats after pilocarpine induced seizures
Jian ZHONG ; Zhong XU ; Hui REN ; Ailan PANG
Chinese Journal of Neurology 2012;(12):883-887
Objective To investigate the expression changes of the protein tyrosine phosphatase receptor T (PTPRT) in temporal lobe epileptic foci in the experimental animals and epileptic patients and the relationship between PTPRT and epileptogenesis.Methods After getting the epilepsy lobe tissue from the experimental and control groups,immunohistochemistry,immunofluorescence and Western blot analysis were used to assess the expression of PTPRT and its changes.Results In the temporal lobe tissue of intractable patients and control group,PTPRT was mainly expressed in the neurons.PTPRT was significantly increased in patients with intractable epilepsy (0.277 ± 0.048) than that in the control group(0.171 ±0.025 ; t =9.586,P < 0.05).PTPRT was mainly expressed in the neurons in the temporal lobe brain tissue of the rats in the control group and experimental group.Compared with control group,the expression of PTPRT in the temporal lobe tissue was increased within 24 h post-seizure,and decreased 1 and 2 weeks post-seizure,then it was increased 1 and 2 months post-seizure (A ratio:control 0.443 ± 0.039,6 h 0.840±0.032,24 h 1.113 ±0.064,7 d 0.564 ±0.039,14 d 0.570 ±0.029,30 d 0.899 ±0.034,60 d 1.011 ± 0.074,F =256.427,P < 0.05).Conclusions Through researches into the expression and function of PTPRT in the temporal lobe brain tissue of patients with intractable epilepsy and animal models,we presume that the PTPRT plays a role in the synapses reorganization and mossy fiber sprouting,and participates in the reconstruction of the neural network which leads to the intractable epilepsy.
3.Types of eae genes in non-O157 Shiga toxin-producing Escherichia coli strains
Xiangning BAI ; Yanmei XU ; Ailan ZHAO ; Juan ZHOU ; Yanwen XIONG
Chinese Journal of Microbiology and Immunology 2015;(6):414-418
Objective To analyze the subtypes of eae genes in various non-O157 Shiga toxin-pro-ducing Escherichia coli ( STEC) strains isolated in China.Methods The complete nucleotide sequences of 10 eae genes were amplified by PCR and sequenced.The BLASTn software was used to analyze the se-quences for eae gene subtyping.A phylogenetic tree was constructed based on the10 ea e gene sequences to-gether with the gene sequences of 30 different subtypes in GenBank and those of STEC strains of 7 prevalent serotypes (O157 ∶H7, O26 ∶H11, O103 ∶H2, O111 ∶H8, O145 ∶H28, O45 ∶H2 and O121 ∶H19) using MEGA 5.0.Multilocus sequence typing (MLST) was performed on the 10 STEC strains with reference to the Escherichia coli ( E.coli) MLST website ( http://mlst.warwick.ac.uk/mlst/dbs/Ecoli) for the typing of multiple loci.A minimum spanning tree ( MST) was constructed using the BioNumerics software to inves-tigate the phylogenetic relationships between the 10 eae gene-positive STEC strains in this study and hemolyt-ic uremic syndrome-associated enterohemorrhagic E.coli ( HUSEC) strains as well as all human STEC strains of O157, O26, O45, O103, O111, O121 and O145 serotypes submitted to the E.coli MLST website data-base.Results The complete nucleotide sequences of eae genes in 10 non-O157 STEC strains were 2.8 kb in length and belonged to 3 known subtypes.The predominant subtype wasβ1, accounting for 60%of the 10 STEC strains (6/10), followed byθandγ1 subtypes with two strains in each type.The eae gene sequences in certain strains were identical to those of the prevalent serotypes.Seven sequence types ( STs) were identi-fied from the 10 STEC strains carrying eae gene.Conclusion The eae genes harbored by the non-O157 STEC strains isolated from different specimens in China were diverse and had close phylogenetic relationships with the highly pathogenic and prevalent STEC strains.This study implied that the STEC strains harboring eae gene had high pathogenic potential.
4.The fecal bacterial community in diarrheal samples explored by 16S rRNA and PFGE analysis
Yongyun ZHOU ; Yanmay XU ; Zhigang CUI ; Dong JIN ; Ailan ZHAO ; Changyun YE ; Jianguo XU
Chinese Journal of Zoonoses 2010;(3):205-208
The purpose of this research was to understand fecal micro-flora of Enterococcus-related diarrhea feces and the clone characteristics of isolated Enterococcus strains.Primer was designed according to 16S rRNA gene and integrated DNA extracted from patients' fecal samples was used as the template to amplify the conserved sequence of 16S rRNA by PCR.After the PCR product was purified and cloned into T vector to sequence,PFGE was used to analyze 20 out of 50 Enterococcus isolates from each specimen.The 16S rRNA gene sequencing analysis indicated that these 4 portions of diarrhea feces were dominated by Enterococcus faecium (>68%) and the isolates were clonal except only one portion.Although the basic flora characteristics of diarrhea feces could be revealed by 16S rRNA gene sequencing analysis and PFGE analysis,the pathogenicity and mechanism of Enterococcus were still waiting for further experimental exploration.
5.Ebola preparedness in the Western Pacific Region, 2014
Zhen Xu ; Boris I Pavlin ; Raynal C Squires ; Thilaka Chinnayah ; Chin-Kei Lee ; Ailan Li
Western Pacific Surveillance and Response 2015;6(1):66-72
West Africa is currently experiencing the largest outbreak of Ebola virus disease (EVD) in history with intense transmission in several affected countries. For non-affected countries, the best protective measures are adequate levels of preparedness including vigilant surveillance to detect cases early and well-prepared health systems to ensure rapid containment of the virus and to avoid further spread. The World Health Organization Regional Office for the Western Pacific recently conducted two activities: a web-based EVD preparedness survey and an EVD simulation exercise to determine the overall level of EVD preparedness in the Region. The survey and exercise together demonstrate there is a good overall level of preparedness for a potential imported case of EVD in the Western Pacific Region. However, a number of areas still require further strengthening before the Region can efficiently and effectively respond to potential EVD events, including laboratory testing arrangements; clinical management and infection prevention and control; and public health intervention measures, particularly at points of entry. Importantly, the survey and exercise also highlight the unique situation in Pacific island countries and emphasize that special considerations are needed to better support these countries in EVD preparedness.
6.Perinatal outcomes in pregnant women with pulmonary hypertension and concurrent congestive heart failure
Ailan XIE ; Ansu YANG ; Linzhi YAN ; Jianping WANG ; Yuhuan WANG ; Xiaowen XU
Chinese Journal of Emergency Medicine 2011;20(6):650-653
Objective To discuss the effect of the occurrence of congestive heart failure on the outcome of pregnant women with pulmonary hypertension. Methods Fifty-four pregnant patients complicated with pulmonary hypertension were admitted from January 2000 through December 2010. Among them, 34 had comorbidity of congestive heart failure. The timing and mode of pregnancy termination, and perinatal outcomes were studied, and comparison was made between those with and without heart failure. Results ① Of all 54 pregnant women with pulmonary hypertension, 34 had congestive heart failure. The incidences of congestive heart failure in patients with mild, moderate and severe degree of pulmonary hypertension were 27.78% (5/18), 73.33% (11/15) and 85.71% (18/21), respectively (P<0.05).②The rate of maternal complications was 47.06% (16/34) and maternal mortality was 17.65% (6/34) in the patients with combined pulmonary hypertension and heart failure. The rate of iatrogenic fetal loss was 29.41% ( 10/34) , preterm labor 52.94% (18/34), neonatal asphyxia 35.29% (12/34) and neonatal mortality 23.53% (8/34) in case of patients with pulmonary hypertension complicated with congestive heart failure. ③The rate of Cesarean section was 91. 18% (31/34) in the patients with combined pulmonary hypertension and heart failure. ④ The rates of iatrogenic induction, premature delivery, maternal complications and mortality, neonatal asphyxia and fetal or neonatal fatality were significantly higher in women with combined pulmonary hypertension and heart failure than those with simple pulmonary hypertension ( P < 0. 05). Conclusions The risk of heart failure increases with the severity of pulmonary hypertension. The occurrence of heart failure is the most important factor affecting the outcome of patients in pregnancy already complicated with pulmonary hypertension , and Cesarean section is the safer mode of termination of pregnancy in this cohort of women.
7.Distribution and Drug Resisance of Pathogens Isolated from Ventilator-associated Pneumonia Patients in ICU
Yan JIN ; Chuhe ZHANG ; Ailan GUO ; Feng XU ; Jinqun MA ; Dongke CHEN
Chinese Journal of Nosocomiology 2005;0(11):-
OBJECTIVE To know the distribution and drug resistance of the ventilator-associated pneumonia(VAP) bacteria in the intensive care unit(ICU),and to provide a reasonable basis for the clinical use of antibiotics. METHODS We used the Tiek Biagnostic systems to identifly microorganisms and antibiotic susceptibility.The result of the drug sensitivity test was analyzed with SPSS13.0. RESULTS A total of 538 strains were isolated from the sputum samples of the ventilator-associated pneumonia patients in the ICU over the last 4 years,in which Gram-negative bacteria were 361(the isolation rate 69.3%).Pseudomonas aeruginosa was the most common.Gram-positive bacteria were 143(the isolation rate 26.6%),in which Staphylococcus aureus was the most common.Twenty-two strain were fungi(the isolation rate 4.1%).Most of the pathogenic bacteria maintained high sensitivity rate to imipenem,vancomycin and quinupristin/daefopristin;but the drug resistance rate to other antibiotics was high and on the rise year by year. CONCLUSIONS The pathogens types of VAP was,complex,and multi-drug resistant.We should emphasize the reasonable application of the antibiotics and strengthen the monitoring of drug resistantce,and rational use of antibiotics to improve the cure rate.
8.Treatment and pathological observation of demodex canis in beagle dogs
Fuli WEN ; Hongqi XU ; Ailan XIONG ; Lei MA ; Shilan ZHANG ; Heping ZHENG
Chinese Journal of Comparative Medicine 2017;27(1):27-31
Objective Treatment and histopathological observation of demodex canis in beagle dogs .Methods Using the method of direct smear for microscopic examination of demodex canis.Histopathological observation on the skin of the parasitic parts after routine paraffin section and HE staining .Results (1) Clinical observation: The red spots and hair removal was appeared on limbs , eyes, lower abdomen and other parts of the skin of canine patients .The skin of the limbs becomes thicker and wrinkles .(2) Blood routine examination:Basically normal.(3) Microscope observation:The results showed that a large number of worms and eggs of small demodex canis could be found .(4) Histopathological observation:Hair follicles showed a large number of demodex mites and eggs.The sebaceous glands and sweat glands have normal morphology and no mites was found .A large number of eosinophils and neutrophil infiltration were seen around the hair follicles.It was also found that the formation of multifocal granuloma:the granuloma was oval shaped .(5) Treatment programme:The combination of medication and the strengthening of environmental control has been shown to be effective . Conclusions Granuloma caused by demodex canis can be divided into immune granuloma .It may not be possible to destroy the sebaceous glands after infection with small demodex canis.Whether the sebaceous gland is infected with the demodex canis may be associated with the worm species or course of disease .
9.Multilocus sequence typing analysis of enteropathogenic escherichia coli isolates in 8 provinces of China, 2006-2014.
Hong LI ; Xiangning BAI ; Ailan ZHAO ; Yanwen XIONG ; Yanmei XU
Chinese Journal of Preventive Medicine 2015;49(4):339-343
OBJECTIVETo investigate the molecular typing feature of enteropathogenic Escherichia coli (EPEC) strains isolated from different reservoirs in eight provinces of China from 2006 to 2014.
METHODSAccording to the time, place, reservoir, and PFGE pattern of the EPEC strains isolated from stools of humans with diarrhea, animal feces, and foods in eight provinces of China between 2006 and 2014, 149 EPEC strains were selected and characterized by multilocus sequence typing (MLST) using seven housekeeping genes provided by E.coli MLST database. Strain analysis demonstrated 56 different sequence types (STs). SeqMan II, MEGA 5.05, and eBURST V3 were applied to analyze the genetic relationships of domestic and forein existing 392 strains (243 EPEC strains included in the E.coli MLST database and 149 EPEC strains comprised in the present study).
RESULTSAmong the 56 different STs, the prevalent ST was ST-40, which included 19 (19/149, 12.8%) isolates. Nineteen new STs were identified. Eleven new alleles were detected in six house-keeping genes (adk, fumC, gyrB, icd, mdh, and purA). Six STs were simultaneously detected among EPEC strains isolated from patients with diarrhea and animals. And these EPEC strains were all aEPEC strains. Two STs were simultaneously identified among EPEC strains isolated from patients with diarrhea and foods. Also, these EPEC strains were all aEPEC strains. 33 out of 173 STs were divided into five major clone complexes by eBURST, STC-29, STC-10, STC-20, STC-28, and STC-517. The remaining EPEC strains included in the other 140 STs were part of the other clone complexes or just were singletons.
CONCLUSIONA high degree of phylogenetic heterogeneity was observed among the EPEC strains isolated in eight provinces of China. The EPEC strains with same STs of human isolates isolated from animal feces and foods were all aEPEC strains.
Animals ; China ; Diarrhea ; Enteropathogenic Escherichia coli ; Escherichia coli ; Escherichia coli Proteins ; Feces ; Humans ; Multilocus Sequence Typing ; Phylogeny
10.Epidemiological characteristics of patients with severe fever with thrombocytopenia syndrome in Dongyang City
CHEN Kang ; WU Ailan ; MA Jingjing ; WU Zhenhua ; XU Yuechen ; ZHANG Jing ; JIN Xujing ; CAO Hui ; CHEN Shuang
Journal of Preventive Medicine 2024;36(1):47-50
Objective :
To investigate the epidemiological characteristics of severe fever with thrombocytopenia syndrome (SFTS) in Dongyang City, Zhejiang Province from 2017 to 2022, so as to provide insights into SFTS prevention and control.
Methods:
Data pertaining to patients with SFTS in Dongyang City from 2017 to 2022 were collected from Notifiable Infectious Disease Reporting System of Chinese Disease Prevention and Control Information System. The epidemiological and clinical characteristics of patients with SFTS were descriptively analyzed, and the trends in incidence of SFTS was evaluated using annual percent change (APC).
Results:
A total of 32 SFTS cases were reported in Dongyang City from 2017 to 2022, with mean annual incidence of 0.63/105, and 8 cases died, with a fatality rate of 25.00%. The incidence of SFTS appeared a tendency towards a rise from 2017 to 2022 (APC=40.697%, P<0.05). The male to female ratio of SFTS cases was 0.78∶1, and farmer was the predominant occupation (31 cases, 96.88%). SFTS predominantly occurred among individuals at ages of 51 to 69 years (20 cases, 62.50%), and the incidence peaked during the period between March and May and between July and August (28 cases, 87.50%). SFTS cases were reported in 11 out of the 18 townships (streets) in Dongyang City, with the highest number found in Zuocun Township (8 cases, 28.13%), and had the lowest platelet count of (41.46±5.19)×109 platelets/L, with the lowest count of (3.00 to 67.00) ×109 platelets/L. All the SFTS cases had a history of mountain forest and farmland activities 2 weeks prior to onset of the disease, and 5 cases (15.63%) had a history of tick bites.
Conclusions
The incidence of SFTS appeared a tendency towards a rise in Dongyang City from 2017 to 2022, and SFTS was highly prevalent in spring and summer, with high incidence among farmers. Intensified health education of SFTS is recommended among residents in high-incidence areas.