5.Antimicrobial resistance and plasmid-mediated colistin resistance mechanism of diarrheagenic Escherichia coli recovered from foods in parts of China in 2020.
Yu Jie HU ; Yang XIAO ; Shuang Jia DONG ; Jian Yun ZHAO ; Hui LI ; Da Jin YANG ; Yin Ping DONG ; Jin XU ; Feng Qin LI
Chinese Journal of Preventive Medicine 2023;57(4):557-565
Objective: To investigate the antimicrobial resistance of food-borne diarrheagenic Escherichia coli (DEC) and the prevalence of mcr genes that mediates mobile colistin resistance in parts of China, 2020. Methods: For 91 DEC isolates recovered from food sources collected from Fujian province, Hebei province, Inner Mongolia Autonomous Region and Shanghai city in 2020, Vitek2 Compact biochemical identification and antimicrobial susceptibility testing platform was used for the detection of antimicrobial susceptibility testing (AST) against to 18 kinds of antimicrobial compounds belonging to 9 categories, and multi-polymerase chain reaction (mPCR) was used to detect the mcr-1-mcr-9 genes, then a further AST, whole genome sequencing (WGS) and bioinformatics analysis were platformed for these DEC isolates which were PCR positive for mcr genes. Results: Seventy in 91 isolates showed different antimicrobial resistance levels to the drugs tested with a resistance rate of 76.92%. The isolates showed the highest antimicrobial resistance rates to ampicillin (69.23%, 63/91) and trimethoprim-sulfamethoxazole (59.34%, 54/91), respectively. The multiple drug-resistant rate was 47.25% (43/91). Two mcr-1 gene and ESBL (extended-spectrum beta-lactamase) positive EAEC (enteroaggregative Escherichia coli) strains were detected. One of them was identified as serotype of O11:H6, which showed a resistance profile to 25 tested drugs referring to 10 classes, and 38 drug resistance genes were predicted by genome analysis. The other one was O16:H48 serotype, which was resistant to 21 tested drugs belonging to 7 classes and carried a new variant of mcr-1 gene (mcr-1.35). Conclusion: An overall high-level antimicrobial resistance was found among foodborne DEC isolates recovered from parts of China in 2020, and so was the MDR (multi-drug resistance) condition. MDR strains carrying multiple resistance genes such as mcr-1 gene were detected, and a new variant of mcr-1 gene was also found. It is necessary to continue with a dynamic monitoring on DEC contamination and an ongoing research into antimicrobial resistance mechanisms.
Humans
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Colistin/pharmacology*
;
Anti-Bacterial Agents/pharmacology*
;
Escherichia coli Infections/epidemiology*
;
Escherichia coli Proteins/genetics*
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Drug Resistance, Bacterial/genetics*
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China/epidemiology*
;
Escherichia coli
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Plasmids/genetics*
;
Microbial Sensitivity Tests
6.Study on the genotype and epidemic characteristics of diarrheagenic Escherichia coli isolated from diarrheal patients in Beijing.
Mei QU ; Xin ZHANG ; Haikun QIAN ; Bing LYU ; Ying HUANG ; Hanqiu YAN ; Zhichao LIANG ; Lei JIA ; Quanyi WANG
Chinese Journal of Epidemiology 2014;35(10):1123-1126
OBJECTIVETo understand the distribution of virulence gene and the epidemiological characteristics of diarrheagenic Escherichia(E.) coli (DEC) from diarrheal patients in Beijing.
METHODSStool specimens from diarrheal patients were cultured which were collected from the hospitals under sentinel surveillance program, during 2012-2013. DNA was examined by real-time PCR.
RESULTS253 out of 6 370 specimens were positive for DEC detection with the rate as 4.0%. A total number of 262 DEC strains were isolated. Two different pathotypes of DEC strains with mixed infection, were isolated from 9 specimens. Different pathotypes would show the following profiles: 42.8% for enteropathogenic E. coli (EPEC) including 42.0% atypical and 0.8% typical; 38.9% for enterotoxigenic E. coli (ETEC) including 24.8% st positive, 9.9% lt positive and 4.2% st and lt both positive;15.3% for enteroaggregative E. coli(EAEC);2.7% for enteroinvasive E. coli (EIEC); one strain STEC with serotype O26:K60. ETEC had obvious characteristics on age. All kinds of DEC were isolated throughout the year with seasonal fluctuation.
CONCLUSIONDEC isolates from diarrheal patients in Beijing were dominated by EPEC and ETEC, with atypical ones accounted for the majority of EPEC. One specimen was found under mixed infection. Pathotypes DEC were found to have different age and seasonal distributions.
China ; epidemiology ; Diarrhea ; microbiology ; Enteropathogenic Escherichia coli ; genetics ; isolation & purification ; Enterotoxigenic Escherichia coli ; genetics ; isolation & purification ; Epidemics ; Escherichia coli ; genetics ; isolation & purification ; Escherichia coli Infections ; epidemiology ; microbiology ; Genotype ; Humans ; Virulence
7.Discovery of new strain of E coli O157: H7 with K antigen.
Xiao-yan ZHEN ; Zhi-yang SHI ; Hua WANG ; Yu-qing LI ; Ling GU ; Xi-ling GUO ; Xian LI ; Zheng-shi YANG
Chinese Journal of Epidemiology 2004;25(8):732-732
9.All blood, No stool: enterohemorrhagic Escherichia coli O157:H7 infection.
Journal of Veterinary Science 2008;9(3):219-231
Enterohemorrhagic Escherichia coli serotype O157:H7 is a pathotype of diarrheagenic E. coli that produces one or more Shiga toxins, forms a characteristic histopathology described as attaching and effacing lesions, and possesses the large virulence plasmid pO157. The bacterium is recognized worldwide, especially in developed countries, as an emerging food-borne bacterial pathogen, which causes disease in humans and in some animals. Healthy cattle are the principal and natural reservoir of E. coli O157:H7, and most disease outbreaks are, therefore, due to consumption of fecally contaminated bovine foods or dairy products. In this review, we provide a general overview of E. coli O157:H7 infection, especially focusing on the bacterial characteristics rather than on the host responses during infection.
Animals
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Cattle
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Cattle Diseases/blood/epidemiology
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Developing Countries
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*Enterohemorrhagic Escherichia coli
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Escherichia coli Infections/blood/*epidemiology/veterinary
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*Escherichia coli O157/genetics/pathogenicity
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Feces/microbiology
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Hemolytic-Uremic Syndrome/blood/epidemiology/veterinary
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Operon
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Shiga Toxins/analysis
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Shigella dysenteriae
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Virulence
10.Genotyping Characteristics of Human Fecal Escherichia coli and Their Association with Multidrug Resistance in Miyun District, Beijing.
Wei Wei ZHANG ; Xiao Lin ZHU ; Le Le DENG ; Ya Jun HAN ; Zhuo Wei LI ; Jin Long WANG ; Yong Liang CHEN ; Ao Lin WANG ; Er Li TIAN ; Bin CHENG ; Lin Hua XU ; Yi Cong CHEN ; Li Li TIAN ; Guang Xue HE
Biomedical and Environmental Sciences 2023;36(5):406-417
OBJECTIVE:
To explore the genotyping characteristics of human fecal Escherichia coli( E. coli) and the relationships between antibiotic resistance genes (ARGs) and multidrug resistance (MDR) of E. coli in Miyun District, Beijing, an area with high incidence of infectious diarrheal cases but no related data.
METHODS:
Over a period of 3 years, 94 E. coli strains were isolated from fecal samples collected from Miyun District Hospital, a surveillance hospital of the National Pathogen Identification Network. The antibiotic susceptibility of the isolates was determined by the broth microdilution method. ARGs, multilocus sequence typing (MLST), and polymorphism trees were analyzed using whole-genome sequencing data (WGS).
RESULTS:
This study revealed that 68.09% of the isolates had MDR, prevalent and distributed in different clades, with a relatively high rate and low pathogenicity. There was no difference in MDR between the diarrheal (49/70) and healthy groups (15/24).
CONCLUSION
We developed a random forest (RF) prediction model of TEM.1 + baeR + mphA + mphB + QnrS1 + AAC.3-IId to identify MDR status, highlighting its potential for early resistance identification. The causes of MDR are likely mobile units transmitting the ARGs. In the future, we will continue to strengthen the monitoring of ARGs and MDR, and increase the number of strains to further verify the accuracy of the MDR markers.
Humans
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Escherichia coli/genetics*
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Escherichia coli Infections/epidemiology*
;
Multilocus Sequence Typing
;
Genotype
;
Beijing
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Drug Resistance, Multiple, Bacterial/genetics*
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Anti-Bacterial Agents/pharmacology*
;
Diarrhea
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Microbial Sensitivity Tests