scholarly journals Diversity of Escherichia coli from the enteric microbiota in patients with Escherichia coli bacteraemia

2019 ◽  
Author(s):  
Mia Mosavie ◽  
Oliver Blandy ◽  
Elita Jauneikaite ◽  
Isabel Caldas ◽  
Matthew J. Ellington ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Large Scale ◽  
Bloodstream Infections ◽  
Sample Type ◽  
E Coli ◽  
Rapd Pcr ◽  
Hospitalised Patients ◽  
Rapd Pattern ◽  
Chromogenic Agar ◽  
The Relationship

ABSTRACTObjectiveThe increase in Escherichia coli bloodstream infections mandates better characterisation of the relationship between commensal and invasive isolates. This study established a simple approach to characterize diversity of E. coli in the gut reservoir from patients with either E. coli bacteraemia, other Gram-negative bacteraemia, or patients without bacteraemia not receiving antibiotics. Stool or rectal swabs from patients in the three groups were cultured on selective chromogenic agar. Genetic diversity of E. coli in gut microbiota was estimated by RAPD-PCR.ResultsEnteric samples from E. coli bacteraemia patients yielded a median of one E. coli RAPD pattern (range 1-4) compared with two (range 1-5) from groups without E. coli bacteraemia. Of relevance to large-scale clinical studies, observed diversity of E. coli among E. coli bacteraemia patients was not significantly altered by sample type (rectal swab or stool), nor by increasing the colonies tested beyond ten. Overall, hospitalised patients demonstrated an apparently limited diversity of E. coli in the enteric microbiota and this was further reduced in those with E. coli bacteraemia. The reduced diversity of E. coli within the gut during E. coli bacteraemia raises the possibility that dominant strains may outcompete other lineages in patients with bloodstream infection.

scholarly journals Iron Acquisition of Urinary Tract Infection Escherichia coli Involves Pathogenicity in Caenorhabditis elegans

2021 ◽  
Vol 9 (2) ◽  
pp. 310
Author(s):  
Masayuki Hashimoto ◽  
Yi-Fen Ma ◽  
Sin-Tian Wang ◽  
Chang-Shi Chen ◽  
Ching-Hao Teng
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract ◽  
Caenorhabditis Elegans ◽  
Large Scale ◽  
Iron Acquisition ◽  
Infection Model ◽  
High Throughput Analysis ◽  
E Coli ◽  
C Elegans ◽  
Tract Infections

Uropathogenic Escherichia coli (UPEC) is a major bacterial pathogen that causes urinary tract infections (UTIs). The mouse is an available UTI model for studying the pathogenicity; however, Caenorhabditis elegans represents as an alternative surrogate host with the capacity for high-throughput analysis. Then, we established a simple assay for a UPEC infection model with C. elegans for large-scale screening. A total of 133 clinically isolated E. coli strains, which included UTI-associated and fecal isolates, were applied to demonstrate the simple pathogenicity assay. From the screening, several virulence factors (VFs) involved with iron acquisition (chuA, fyuA, and irp2) were significantly associated with high pathogenicity. We then evaluated whether the VFs in UPEC were involved in the pathogenicity. Mutants of E. coli UTI89 with defective iron acquisition systems were applied to a solid killing assay with C. elegans. As a result, the survival rate of C. elegans fed with the mutants significantly increased compared to when fed with the parent strain. The results demonstrated, the simple assay with C. elegans was useful as a UPEC infectious model. To our knowledge, this is the first report of the involvement of iron acquisition in the pathogenicity of UPEC in a C. elegans model.

SEPSIS MARKERS AND SENSITIVITY OF STAPHYLOCOCCUS AUREUS AND ESCHERICHIA COLI ISOLATES IN A GENERAL HOSPITAL SETTING

Vestnik ◽  
2021 ◽  
pp. 68-74
Author(s):  
М.Е. Рамазанов ◽  
В.Н. Сон ◽  
М.Р. Рысулы ◽  
С.Т. Турсуналиев ◽  
Е.Б. Еспенбетов
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Hospital Setting ◽  
Bloodstream Infections ◽  
High Sensitivity ◽  
Clinical Isolates ◽  
Empiric Antibiotic Therapy ◽  
E Coli ◽  
Number Of Patients ◽  
Empiric Antibiotic

Представлены результаты проспективного обследования 80 больных ГКБ №7 с бактериемией с октября 2019 года по февраль 2021 года из различных отделений госпиталя. Производилась оценки показателей маркеров сепсиса - пресепсина, прокальцитонина и С-реактивного белка (СРБ) в крови больных в динамике эмпирической терапии антимикробными препаратами (АМП). Наибольшее число больных с выявленной бактериемией находилось в отделении ОАРИТ - 39 пациентов, у 25 из них был диагностирован сепсис по шкале СЕПСИС III, вызванный известными патогенами Staphylococcus aureus (46,6%) и Escherichia coli (36,6%). Для эмпирического лечения применялись различные антибиотики: ампенициллин, амикацин, меропенем, цефотаксим, метрид, ципрофлоксацин, ципрокс, цефлокс, цефазолин, цефтриаксон, левофлоксацин. Уровни прокальцитонина составляют для больных с клиническими изолятами E. coli 20,8±3,1нг/мл, а для изолятов St. aureus 15,7±1,8 нг/мл. После терапии АМП наблюдается значительное снижение показателей до 1,43±0,6 и 2,3±0,9 нг/мл., что позволяет признать эффективность эмпирической антибиотикотерапии при инфекциях кровотока. Высокая чувствительность клинических изолятов Escherichia coli отмечена к препаратам группы карбапенемов - имипенему и меропенему (90,9%), низкая к эртапенему (72,7%). 100% чувствительность все изоляты показали по отношению к АМП из группы глицилциклинов - тигециклину, который структурно сходен с тетрациклинами. Высокой резистеностью клинические изоляты Staphylococcus aureus обладают к пенициллину (92,9%), липопептиду природного происхождения даптомицину (85,8%) и препарату из группы линкозамидов - клиндамицину (64,3%). The results of a prospective examination of 80 patients with bacteremia from October 2019 to February 2021 from various departments of the hospital are presented. The largest number of patients with detected bacteremia were in the OARIT department - 39 patients, 25 of them were diagnosed with sepsis according to the SEPSIS III scale, caused by known pathogens Staphylococcus aureus (46.6%) and Escherichia coli (36.6%). For empirical treatment, various antibiotics were used: ampenicillin, amikacin, meropenem, cefotaxime, metrid, ciprofloxacin, ciprox, ceflox, cefazolin, ceftriaxone, levofloxacin. Procalcitonin levels for patients with clinical E. coli isolates are 20.8 ± 3.1 ng / ml, and for St. aureus 15.7 ± 1.8 ng / ml. After AMP therapy, there is a significant decrease in indicators to 1.43 ± 0.6 and 2.3 ± 0.9 ng / ml, which makes it possible to recognize the effectiveness of empiric antibiotic therapy for bloodstream infections. High sensitivity of clinical isolates of Escherichia coli was noted to drugs of the carbapenem group - imipenem and meropenem (90.9%), low to ertapenem (72.7%). All isolates showed 100% sensitivity to AMPs from the glycylcycline group - tigecycline, which is structurally similar to tetracyclines. Clinical isolates of Staphylococcus aureus are highly resistant to penicillin (92.9%), natural lipopeptide daptomycin (85.8%), and a drug from the lincosamide group - clindamycin (64.3%).

scholarly journals Antibiotic Susceptibility and Genotype Patterns of Escherichia coli, Klebsiella pneumonia and Pseudomonas aeruginosa Isolated from Urinary Tract Infected Patients

2010 ◽  
Vol 59 (3) ◽  
pp. 207-212 ◽  
Author(s):  
M.I. ABOU-DOBARA ◽  
M.A. DEYAB ◽  
E.M. ELSAWY ◽  
H.H. MOHAMED
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Urinary Tract ◽  
Antibiotic Susceptibility ◽  
Susceptibility Testing ◽  
Random Amplified Polymorphic Dna ◽  
Test Methods ◽  
Klebsiella Pneumonia ◽  
E Coli ◽  
Rapd Pcr

Thirty nine isolates of Escherichia coli, twenty two isolates of Klebsiella pneumoniae and sixteen isolates of Pseudomonas aeruginosa isolated from urinary tract infected patients were analyzed by antimicrobial susceptibility typing and random amplified polymorphic DNA (RAPD)-PCR. Antibiotic susceptibility testing was carried out by microdilution and E Test methods. From the antibiotic susceptibility, ten patterns were recorded (four for E. coli, three for K. pneumoniae and three for P. aeruginosa respectively). Furthermore, genotyping showed seventeen RAPD patterns (seven for E. coli, five for K. pneumoniae and five for P. aeruginosa respectively). In this study, differentiation of strains of E. coli, K. pneumoniae and P. aeruginosa from nosocomial infection was possible with the use of RAPD.

scholarly journals Bacterial genotypic and patient risk factors for adverse outcomes in Escherichia coli bloodstream infections: a prospective molecular-epidemiological study

2021 ◽  
Author(s):  
Elita Jauneikaite ◽  
Kate Honeyford ◽  
Oliver Blandy ◽  
Mia Mosavie ◽  
Max Pearson ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Length Of Stay ◽  
Single Agent ◽  
Bloodstream Infections ◽  
Outcome Data ◽  
Sequence Type ◽  
Adverse Outcomes ◽  
Beta Lactam ◽  
E Coli ◽  
Sequence Types

Background Escherichia coli bloodstream infections have increased rapidly in the UK, for reasons that are unclear. The relevance of highly fit, or multi-drug resistant lineages such as ST131 to overall E. coli disease burden remains to be fully determined. We set out to characterise the prevalence of E. coli multi-locus sequence types (MLST) and determine if these were associated with adverse outcomes in an urban population of E. coli bacteraemia patients. Methods We undertook whole genome sequencing of E. coli blood isolates from all patients with diagnosed E. coli bacteraemia in north-west London from July 2015 to August 2016 and assigned multi-locus sequence types to all isolates. Isolate sequence types were linked to routinely collected antimicrobial susceptibility, patient demographic, and clinical outcome data to explore relationships between the E. coli sequence types, patient factors, and outcomes. Findings A total of 551 E. coli genomes were available for analysis. More than half of these cases were caused by four E. coli sequence types: ST131 (21%), ST73 (15%), ST69 (9%) and ST95 (8%). E. coli genotype ST131-C2 was associated with non-susceptibility to quinolones and third-generation cephalosporins, and also to amoxicillin, augmentin, gentamicin and trimethoprim. An association between the ST131-C2 lineage and longer length-of-stay was detected, although multivariable regression modelling did not demonstrate an association between E. coli sequence type and mortality. However, a number of unexpected associations were identified, including gentamicin non-susceptibility, ethnicity, and sex that might influence mortality and length-of-stay, requiring further research. Interpretation Although E. coli sequence type was associated with antimicrobial non-susceptibility patterns and length-of-stay, we did not find that E. coli sequence type was associated with increased mortality. Where ST131 is prevalent, caution is required when pairing beta-lactam agents with gentamicin or using single agent aminoglycosides.

Contribution of SOS Genes to H2O2-induced Apoptosis-like Death in Escherichia Coli

2021 ◽  
Author(s):  
Heesu Kim ◽  
Dong Gun Lee
Keyword(s):  
Oxidative Stress ◽  
Escherichia Coli ◽  
Treatment Strategies ◽  
Sos Response ◽  
Bacterial Dna ◽  
E Coli ◽  
New Treatment ◽  
Induced Apoptosis ◽  
And Function ◽  
The Relationship

Abstract Hydrogen peroxide (H2O2) is a debriding agent that damages the microbial structure and function by generating various reactive oxygen species (ROS). H2O2-produced hydroxyl radical (OH∙) also exert oxidative stress on microorganisms. The spread of antibiotic resistance in bacteria is a serious issue worldwide, and greater efforts are needed to identify and characterize novel antibacterial mechanisms to develop new treatment strategies. Therefore, this study aimed to clarify the relationship between H2O2 and Escherichia coli and to elucidate a novel antibacterial mechanism(s) of H2O2. Following H2O2 exposure, increased levels of 8-hydroxyldeoxyguanosine and malondialdehyde indicated that H2O2 accelerates oxidation of bacterial DNA and lipids in E. coli. As oxidative damage worsened, the SOS response was triggered. Cell division arrest and resulting filamentation were identified in cells, indicating that LexA was involved in DNA replication. It was also verified that RecA, a representative SOS gene, helps self-cleavage of LexA and acts as a bacterial caspase-like protein. Our findings also showed that dinF is essential to preserve E. coli from H2O2-induced ROS, and furthermore, demonstrated that H2O2-induced SOS response and SOS genes participate differently in guarding E. coli from oxidative stress. As an extreme SOS response is considered apoptosis-like death (ALD) in bacteria, additional experiments were performed to examine the characteristics of ALD. DNA fragmentation and membrane depolarization appeared in H2O2-treated cells, suggesting that H2O2 causes ALD in E. coli. In conclusion, our investigations revealed that ALD is a novel antibacterial mode of action(s) of H2O2 with important contributions from SOS genes.

Survival of Escherichia coli on Lettuce under Field Conditions Encountered in the Northeastern United States

2017 ◽  
Vol 80 (7) ◽  
pp. 1214-1221 ◽  
Author(s):  
Daniel L. Weller ◽  
Jasna Kovac ◽  
Sherry Roof ◽  
David J. Kent ◽  
Jeffrey I. Tokman ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Microbial Contamination ◽  
Field Conditions ◽  
Risk Assessments ◽  
Most Probable Number ◽  
Northeastern United States ◽  
Probable Number ◽  
E Coli ◽  
The Relationship ◽  
Sample Time

ABSTRACT Although wildlife intrusion and untreated manure have been associated with microbial contamination of produce, relatively few studies have examined the survival of Escherichia coli on produce under field conditions following contamination (e.g., via splash from wildlife feces). This experimental study was performed to estimate the die-off rate of E. coli on preharvest lettuce following contamination with a fecal slurry. During August 2015, field-grown lettuce was inoculated via pipette with a fecal slurry that was spiked with a three-strain cocktail of rifampin-resistant nonpathogenic E. coli. Ten lettuce heads were harvested at each of 13 time points following inoculation (0, 2.5, 5, and 24 h after inoculation and every 24 h thereafter until day 10). The most probable number (MPN) of E. coli on each lettuce head was determined, and die-off rates were estimated. The relationship between sample time and the log MPN of E. coli per head was modeled using a segmented linear model. This model had a breakpoint at 106 h (95% confidence interval = 69, 142 h) after inoculation, with a daily decrease of 0.70 and 0.19 log MPN for 0 to 106 h and 106 to 240 h following inoculation, respectively. These findings are consistent with die-off rates obtained in similar studies that assessed E. coli survival on produce following irrigation. Overall, these findings provide die-off rates for E. coli on lettuce that can be used in future quantitative risk assessments.

Distribution of Coliphages in Various Foods

1986 ◽  
Vol 49 (12) ◽  
pp. 944-951 ◽  
Author(s):  
J. E. KENNEDY ◽  
C. I. WEI ◽  
J. L. OBLINGER
Keyword(s):  
Escherichia Coli ◽  
Food Samples ◽  
Fecal Coliforms ◽  
Bacterial Indicators ◽  
Processed Meats ◽  
E Coli ◽  
Plate Counts ◽  
The Relationship

The distribution of coliphages in various foods and the relationship between the incidences of coliphages and bacterial indicators were investigated. A total of 120 food samples comprising twelve products and including fresh meats, shellfish, vegetables and processed meats, were analyzed for indigenous coliphages using Escherichia coli hosts C, C-3000 and B. Bacterial analyses included enumeration of E. coli, fecal coliforms and coliforms, as well as aerobic plate counts and Salmonella analyses. Coliphages were detected (≥10 PFU/100 g) in 56% of samples and eleven of twelve products. Coliphages, E. coli, fecal coliforms and coliforms were recovered at a level of at least 30 organisms per 100 g in 43, 43, 68 and 81% of samples, with overall mean recoveries of 13, 19, 93 and 4300 organisms/100 g, respectively. Highest and lowest recoveries of coliphages and E. coli were from fresh meats and vacuum-packaged processed meats, respectively. Significant nonparametric correlations between coliphages, E. coli, fecal coliforms and coliforms were found among all food samples.

scholarly journals Extraintestinal pathogenic Escherichia coli in Saudi Arabia: A review of antimicrobial resistance and molecular epidemiology

2020 ◽  
Vol 19 (2) ◽  
pp. 447-453
Author(s):  
Abdulaziz Alqasim
Keyword(s):  
Escherichia Coli ◽  
Saudi Arabia ◽  
Antimicrobial Resistance ◽  
Molecular Epidemiology ◽  
Bloodstream Infections ◽  
Epidemiological Studies ◽  
Colistin Resistance ◽  
E Coli ◽  
Extended Spectrum ◽  
Pathogenic Escherichia Coli

Extra-intestinal pathogenic Escherichia coli (ExPEC) is commonly associated with causing urinary tract and bloodstream infections. Over the past two decades, the antimicrobial resistance of ExPEC has increasingly been reported [1]. Given that Saudi Arabia annually hosts mass religious events, such as Hajj, this review investigated several aspects of antimicrobial resistance of ExPEC in this country including the current prevalence of resistance and molecular epidemiology of ExPEC isolates. Generally, the overall prevalence of antibiotic resistance of ExPEC in Saudi Arabia is on increase. The current emergence of colistin resistance in ExPEC represents a major challenge to public health. Local molecular epidemiological studies have shown the dominance of E. coli sequence type 131 (E. coli ST131) over other major ExPEC STs. This is an important observation given that this clone has been associated with high multidrug resistance and extended-spectrum β-lactamases carriage. To reduce the burden of this resistance in the future, it would be crucial to avoid uncontrolled use of antibiotics in either clinical settings or animal food industry. Keywords: Extra-intestinal pathogenic Escherichia coli, Antimicrobial resistance, ST131, Saudi Arabia, Colistin resistance, Extended-spectrum β-lactamases

scholarly journals Purification and separation of holo- and apo-forms of Saccharopolyspora erythraea acyl-carrier protein released from recombinant Escherichia coli by freezing and thawing

1993 ◽  
Vol 294 (2) ◽  
pp. 521-527 ◽  
Author(s):  
S A Morris ◽  
W P Revill ◽  
J Staunton ◽  
P F Leadlay
Keyword(s):  
Escherichia Coli ◽  
Large Scale ◽  
Acyl Carrier Protein ◽  
Saccharopolyspora Erythraea ◽  
Carrier Protein ◽  
Freezing And Thawing ◽  
Acyl Carrier Proteins ◽  
Expression Plasmid ◽  
E Coli ◽  
Protein Dimer

Saccharopolyspora erythraea acyl-carrier protein, highly expressed from a T7-based expression plasmid in Escherichia coli, can be selectively released from the cells in near-quantitative yield by a single cycle of freezing and thawing in a neutral buffer. Electrospray mass spectrometry was used to confirm that the recombinant S. erythraea acyl-carrier protein over-expressed in E. coli is present predominantly as the holo-form, with variable amounts of apo-acyl-carrier protein, holo-acyl-carrier protein dimer and holo-acyl-carrier protein glutathione adduct. The holo- and apo-acyl-carrier proteins are both readily purified on a large scale from the freeze-thaw extracts and can be separated from one another by octyl-Sepharose chromatography. The holo-acyl-carrier protein obtained in this way was fully active in supporting the synthesis of acyl-acyl-carrier protein by extracts of S. erythraea.

scholarly journals Characterization of the β-lactamase specified by the resistance factor R-1818 in Escherichia coli K12 and other Gram-negative bacteria

1971 ◽  
Vol 123 (4) ◽  
pp. 501-505 ◽  
Author(s):  
J. W. Dale
Keyword(s):  
Escherichia Coli ◽  
Host Species ◽  
Host Bacterium ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
E Coli ◽  
R Factor ◽  
Relationship Of ◽  
The Relationship

1. The amino acid composition of the β-lactamase from E. coli (R-1818) was determined. 2. The R-1818 β-lactamase is inhibited by formaldehyde, hydroxylamine, sodium azide, iodoacetamide, iodine and sodium chloride. 3. The Km values for benzylpenicillin, ampicillin and oxacillin have been determined by using the R-factor enzyme from different host species. The same values were obtained, irrespective of the host bacterium. 4. The molecular weight of the enzyme was found to be 44600, and was the same for all host species. 5. The relationship of R-1818 and R-GN238 β-lactamases is discussed.

Sign in / Sign up

Export Citation Format

Share Document