Surveillance for diarrheagenic Escherichia coli in Shanghai, 2012-2013 / 中华流行病学杂志

<p><b>OBJECTIVE</b>To understand the distribution of diarrheagenic Escherichia (E.) coli in population in Shanghai and discuss the practice model of cooperation in enteric infectious disease prevention and control between public health institution and hospital.</p><p><b>METHODS</b>Sentinel hospitals were assigned, standard detection and identification of diarrheagenic E. coli were conducted, incidence curve of diarrheagenic E. coli infection was drawn and epidemiologic survey and laboratory detection were conducted for suspect diarrheagenic E. coli infection outbreaks.</p><p><b>RESULTS</b>A total of 7 204 stool specimens were collected from diarrhea patients in 4 hospitals during 2012-2013, in which 712 (9.9% ) were diarrheagenic E. coli positive, including 351 enteropathogenic E. coli (EPEC) strains, 292 enterotoxigenic E. coli (ETEC) strains, 32 enteroinvasive E. coli(EIEC) strains and 6 Shiga toxin-producing E. coli (STEC/EHEC) strains, as well as 31 mixed strains. EPEC infection mainly occurred in children aged 1-5 years; and all of these infections were caused by aEPEC. The incidence peak of ETEC infection was during August, the positive rate was >20%. The ETEC infection mainly occurred in infants aged 1-28 days in 2012 and in people aged 20-60 years in 2013 (P<0.05). ST was the major type (59.6%), followed by LT (27.8%) and ST/LT (12.6%). EIEC infection increased in children obviously in 2013 (P<0.01). No EHEC O157:H7 case was detected, but two EHEC O26:H11 (eae-hlyA-stx1a) cases in children were reported for the first time in Shanghai. The survey result indicated that the multidrug-resistant ETEC (STh-CS21-CFA/I-ClyA-EatA-ST2332-SHNL0005) strain causing outbreak in 15 newborns in Shanghai in 2012 was in the same clone as the strain detected in Zigong in Sichuan province.</p><p><b>CONCLUSION</b>Significant change has occurred in diarrheagenic E. coli distribution in Shanghai in recent years, ETEC has potential risk to cause outbreak of hospital acquired infection in neonates and food borne infection. The active surveillance on ETEC and other enteric pathogens by both public health institutions and hospitals need to be improved.</p>

Multilocus sequence typing analysis of enteropathogenic escherichia coli isolates in 8 provinces of China, 2006-2014 / 中华预防医学杂志

<p><b>OBJECTIVE</b>To investigate the molecular typing feature of enteropathogenic Escherichia coli (EPEC) strains isolated from different reservoirs in eight provinces of China from 2006 to 2014.</p><p><b>METHODS</b>According 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).</p><p><b>RESULTS</b>Among 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.</p><p><b>CONCLUSION</b>A 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.</p>

Types of eae genes in non-O157 Shiga toxin-producing Escherichia coli strains / 中华微生物学和免疫学杂志

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.

Analysis of tellurite resistance level and resistance gene cluster in non-O157 Shiga toxin-producing Escherichia coli isolates / 中华微生物学和免疫学杂志

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.

The fecal bacterial community in diarrheal samples explored by 16S rRNA and PFGE analysis / 中国人兽共患病学报

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.

Visual acuity test for children under 5 years of age / 中华全科医师杂志

The visual acuity testa were performed in 8219 children(16 438 eyes)under 5 years of age with sound and light toys,electric torch and a retinoscope.The general ocular examination and mydriatic optometry were also performed for the ametropia.In 8219 children 61 were found to have dominant strabismus,including 59 cases of concomitant strabismus and 2 paralytic strabismus.AbnormaJ refraction was detected in 404 children(739 eye)accounting for 4.92%,including 68 cases of anisometropia (0.83%).In 16 438 eyes 621(3.78%)were moderate or hyper-presbyopia;53(0.32%)were myopia;65 (0.40%)were mixed astigmatism.The vision acuity test described above is a simple and convenient method suitable for children under 5 who are not able to read the conventional test chart.

Building and put the emergency nursing program for burst group accidents into practice / 中国实用护理杂志

Objective To find out the weakness in the emergency nursing for burst group accidents, and then building a normative nursing program which have included framework and 4 stages. Methods Using the method of Fish-Bone Drawing to analyzed the nursing courses in 22 burst accidents within the past 4 years retrospectively. Results After using the normative nursing program, nurses have known their own working targets and responsibility, which can apply the nursing care effectively and orderly. Conclusion The application of emergency nursing program is a kind of quick and proper nursing method, which can improve the patients' prognosis effectively.

Molecular typing of Shiga-toxin producing Escherichia coli O157:H7 isolated in China with pulsed field gel electrophresis / 中华流行病学杂志

<p><b>OBJECTIVE</b>To type and group the Shiga-toxin producing Escherichia coli O157:H7 strains isolated recent years in China to understand the epidemiological features caused by the pathogen.</p><p><b>METHODS</b>Pulsed field gel electrophoresis of large restriction fragments of bacterial chromosomal DNA was used.</p><p><b>RESULTS</b>The 51 isolates of E. coli O157:H7 collected in recent years in China could be divided into 8 Pulsed Field Gel Electrophoresis (PFGE) types based on the size and number of restriction fragments and patterns, that were digested by XbaI. Strains isolated from Ningxia province showed only two types- PFGE1 and PFGE2. Strains isolated in Xuzhou of Jiangsu province had 6 PFGE types. Isolates identified between 1986 - 1988 belonged to PFGE7. Strains isolated from patients in 1999 - 2000 were PFGE5 and PFGE3. Strains isolated from stool samples of domestic animal, food and vegetable were PFGE3 - 6, of which the predominant type was PFGE5. All of the 5 strains isolated from patients with diarrhea and hemolytic uremic syndrome (HUS) belonged to PFGE type 5, which was the dominant type of the isolates from stool samples of domestic animal and samples of food and vegetable contaminated.</p><p><b>CONCLUSION</b>Data suggested that the cluster patients with diarrhea and HUS might have been related to the pathogens from domestic animas and contaminated food or vegetables. The distribution of PFGE types also varied in different provinces of China.</p>