Escherichia Coli
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2021 ◽  
Vol 11 (1) ◽  
Surbhi Gupta ◽  
Parveen Kumar ◽  
Bhawna Rathi ◽  
Vivek Verma ◽  
Rakesh Singh Dhanda ◽  

Bence Balázs ◽  
József Bálint Nagy ◽  
Zoltán Tóth ◽  
Fruzsina Nagy ◽  
Sándor Károlyi ◽  

Abstract Multidrug resistance due to the production of extended-spectrum beta-lactamases (ESBLs) is a major problem in human as well as in veterinary medicine. These strains appear in animal and human microbiomes and can be the source of infection both in animal and in human healthcare, in accordance with the One Health theorem. In this study we examined the prevalence of ESBL-producing bacteria in food-producing animals. We collected 100 porcine and 114 poultry samples to examine the prevalence of ESBL producers. Isolates were identified using the MALDI-TOF system and their antibiotic susceptibility was tested using the disk diffusion method. ESBL gene families and phylogroups were detected by polymerase chain reactions. The prevalence of ESBL producers was relatively high in both sample groups: 72 (72.0%) porcine and 39 (34.2%) poultry isolates were ESBL producers. Escherichia coli isolates were chosen for further investigations. The most common ESBL gene was CTX-M-1 (79.3%). Most of the isolates belong to the commensal E. coli phylogroups. The porcine isolates could be divided into three phylogroups, while the distribution of the poultry isolates was more varied. In summary, ESBL-producing bacteria are prevalent in the faecal samples of the examined food-producing animals, with a dominance of the CTX-M-1 group enzymes and commensal E. coli phylogroups.

Pieter De Bruyn ◽  
Maruša Prolič-Kalinšek ◽  
Alexandra Vandervelde ◽  
Milan Malfait ◽  
Yann G.-J. Sterckx ◽  

paaR2–paaA2–parE2 is a three-component toxin–antitoxin module found in prophage CP-993P of Escherichia coli O157:H7. Transcription regulation of this module occurs via the 123-amino-acid regulator PaaR2, which forms a large oligomeric structure. Despite appearing to be well folded, PaaR2 withstands crystallization, as does its N-terminal DNA-binding domain. Native mass spectrometry was used to screen for nanobodies that form a unique complex and stabilize the octameric structure of PaaR2. One such nanobody, Nb33, allowed crystallization of the protein. The resulting crystals belong to space group F432, with unit-cell parameter a = 317 Å, diffract to 4.0 Å resolution and are likely to contain four PaaR2 monomers and four nanobody monomers in the asymmetric unit. Crystals of two truncates containing the N-terminal helix–turn–helix domain also interact with Nb33, and the corresponding co-crystals diffracted to 1.6 and 1.75 Å resolution.

mBio ◽  
2021 ◽  
Peter H. Culviner ◽  
Isabel Nocedal ◽  
Sarah M. Fortune ◽  
Michael T. Laub

Toxin-antitoxin (TA) systems are widespread genetic modules found in almost all bacteria that can regulate their growth and may play prominent roles in phage defense. Escherichia coli encodes 11 TA systems in which the toxin is a known or predicted endoribonuclease. The targets and cleavage specificities of these endoribonucleases have remained largely uncharacterized, precluding an understanding of how each impacts cell growth and an assessment of whether they have distinct or overlapping targets.

2021 ◽  
Shan-Shan Peng ◽  
Yingjie Li ◽  
Qiuhong Chen ◽  
Qi Hu ◽  
Ying He ◽  

Abstract Enterotoxigenic Escherichia coli (ETEC) is closely associated with diarrhoea in children in resource-limited countries and of travellers’ diarrhoea. This study aims to investigate the change of ileal mucosal microbiome and ileal protein expression as well as their correlation in pigs by E. coli K88 (ETEC). Seven weaned male pigs were orally given 1 ×109 CFU of ETEC (ETEC, n = 7), and the other seven received saline (CON, n = 7). Ileal tissues were obtained 48 h after the ETEC challenge for both proteomic and mucosal microbiomic analyses. Nine proteins were altered in expression level in the ETEC group, including decreased expression of FABP1 and FABP6 involved in bile acid circulation. TLR-9 mediated pathway was also affected at transcription level with increased expression of SIGIRR and MyD88. Correlation analysis revealed correlations between the ileal proteins and mucosal bacterial taxa, including the positive correlation between Lactobacilli and PPP3CA (r = 0.9, p < 0.001), and negative correlation between Prevotella with CTNND1 (r = -0.7, p < 0.01). In conclusion, ETEC infection caused inflammation and impaired the circulation of bile acids, and the mucosal microbiome may affect the expression of intestinal proteins. Further studies are needed for exact roles of these affected processes in the pathogenesis of ETEC-triggered diarrhoea.

2021 ◽  
Vol 74 (1) ◽  
Hye-Ri Jung ◽  
Koeun Kim ◽  
Young Ju Lee

Abstract Background This study was conducted to analyze the genetic characteristics of 41 β-lactam-resistant Escherichia coli isolates, which are one of the common causes of environmental mastitis, isolated from the bulk tank milk of 290 dairy farms in five factories operated by three dairy companies in Korea. Results Analysis of the phenotypic and genotypic characteristics of β-lactam-resistant E. coli isolates revealed differences between factories even within the same company. Isolates from factory A1 and C1 showed high resistance to cephalothin (76.9 and 100%, respectively), which is a first-generation cephalosporins, whereas resistance to tetracycline was showed by only the isolates from factories B1 (60.0%), C2 (66.7%), and C3 (100%). Although all the 41 β-lactam-resistant E. coli isolates were positive for blaOXA-1, blaTEM-1 was highly prevalent in isolates from factories C2 (100%) and C3 (100%). Among 17 isolates resistant to both β-lactams and aminoglycosides, the most common multilocus sequence type was ST399 (13isolates, 76.5%). Furthermore, 2 (11.8%) and 12 (70.6%) isolates belonged to the phylogenetic groups B2 and D, respectively, which are invasive strains that cause intestinal infections, respectively. The predominant serogroup was O15 (70.6%), which is a globally distributed extraintestinal pathogen. Interestingly, one isolate from factory A1 belonged to O157 and carried six virulence genes, simultaneously. Conclusions Although E. coli isolates were isolated from bulk tank milk, and not the clinical mastitis samples, the presence of the phylogenetic groups B2 and D, and the serogroups O15 and O157, which harbor antimicrobial resistance genes and virulence factors, can pose a threat to public health.

Antibiotics ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1137
Valery S. Sonola ◽  
Abdul S. Katakweba ◽  
Gerald Misinzo ◽  
Mecky I. N. Matee

We investigated antibiotic resistance profiles of Escherichia coli among 960 samples obtained from chickens (236), humans (243), rodents (101) and soil (290). E. coli was isolated from 650 (67.7%) samples. Isolation frequency varied significantly between chickens, humans, rodents and soil samples, being 81.6%, 86.5%, 79.2% and 31.0%, respectively (p < 0.001). Resistance rates were particularly higher against imipenem (79.8%), cefotaxime (79.7%) and tetracycline (73.7%) and moderate against amoxicillin-clavulanate (49.4%). Overall, 78.8% of the isolates were multidrug-resistant (MDR) among which, 38.8%, 25.1%, 12.9% and 2.5% exhibited resistance to three, four, five and six different classes of antibiotics, respectively. Multidrug-resistant E. coli were observed in 27.7%, 30.3%, 10.8% and 10.0% of the isolates from chickens, humans, rodents and soil samples, respectively. Our results show high levels of antimicrobial resistance including MDR in E. coli isolated from chickens, humans, rodents and soil samples in Karatu, Northern Tanzania. Comprehensive interventions using a one-health approach are needed and should include improving (i) awareness of the community on judicious use of antimicrobial agents in humans and animals, (ii) house conditions and waste management and (iii) rodent control measures.

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