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.

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.

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 .

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

OBJECTIVETo 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.

METHODSSentinel 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.

RESULTSA 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.

CONCLUSIONSignificant 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.

Adult ; Child, Preschool ; China ; epidemiology ; Diarrhea ; microbiology ; Disease Outbreaks ; Enteropathogenic Escherichia coli ; isolation & purification ; Enterotoxigenic Escherichia coli ; isolation & purification ; Escherichia coli Infections ; epidemiology ; Humans ; Incidence ; Infant ; Infant, Newborn ; Middle Aged ; Sentinel Surveillance ; Young Adult