scholarly journals Next generation sequencing and in vivo pathogenicity study of multidrug-resistance efflux pump genesoqxAB-encoding plasmids in Escherichia coli

2020 ◽  
Vol 2 (7A) ◽  
Author(s):  
Andes Lau ◽  
Huiluo Cao ◽  
Melissa Chun-Jian Liu ◽  
Man-Ki Tong ◽  
Kin-Hung Chow ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Hong Kong ◽  
Galleria Mellonella ◽  
Efflux Pump ◽  
Antibiotic Resistance Genes ◽  
Multidrug Resistant ◽  
E Coli ◽  
Pathogenic Factors ◽  
Health Deterioration

Background: Multidrug-resistant efflux pump genes oqxAB-encoding plasmids are wildly disseminated in livestock, and also identified in human samples. Giving the high presence in environment and multidrug-resistant nature of oqxAB, deeper understanding of oqxAB-encoding plasmids is necessary. Objective: To investigate the prevalence, virulence, and phylogenetic of oqxAB-encoding plasmids. Method: A total of 43 oqxAB carrying Escherichia coli were isolated from human and livestock from China and Hong Kong, these isolates were characterised by disc-diffusion susceptibility test and PCR. The 43 samples were sequenced using PacBio or Illumina platforms, and analysied with five oqxAB-encoding plasmid sequences extracted from Genbank. in vivo pathogenicity study performed by injecting E. coli J53 transconjugants containing oqxAB plasmid into Galleria mellonella larvae. Result: Among the 48 oqxAB-encoding plasmids, 27 were IncFII F18 plasmids, 12 F16 plasmids, six F33 plasmids, two F24 plasmids, and one F14 plasmid. Virulence regions in plasmids with same Inc group encoded similar set of virulence factors and antibiotic resistance genes. Co-existence of blaCTX-M, fosA3, and oqxAB genes was identified in all F33 plasmids and one F18 plasmid. in vivo pathogenicity study suggested oqxAB plasmids caused significant health deterioration in larvae but no significant increase in death. Conclusion: Our data shows similar sets of pathogenic factors are frequently co-carried by oqxAB plasmids of same Inc group, suggesting high correlation between plasmids identified from China and Hong Kong. Co-existence of fosA3, blaCTX-M, and oqxAB suggests resistance to most clinical antibiotics. in vivo test indicates oqxAB plasmid can increase pathogenicity of the host bacteria.

scholarly journals In vitro activity of antimicrobial peptide CDP-B11 alone and in combination with colistin against colistin-resistant and multidrug-resistant Escherichia coli

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kaitlin S. Witherell ◽  
Jason Price ◽  
Ashok D. Bandaranayake ◽  
James Olson ◽  
Douglas R. Call
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Peptide ◽  
Membrane Integrity ◽  
Antibiotic Resistance Genes ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Multidrug Resistant Bacteria ◽  
E Coli ◽  
Minimal Media

AbstractMultidrug-resistant bacteria are a growing global concern, and with increasingly prevalent resistance to last line antibiotics such as colistin, it is imperative that alternative treatment options are identified. Herein we investigated the mechanism of action of a novel antimicrobial peptide (CDP-B11) and its effectiveness against multidrug-resistant bacteria including Escherichia coli #0346, which harbors multiple antibiotic-resistance genes, including mobilized colistin resistance gene (mcr-1). Bacterial membrane potential and membrane integrity assays, measured by flow cytometry, were used to test membrane disruption. Bacterial growth inhibition assays and time to kill assays measured the effectiveness of CDP-B11 alone and in combination with colistin against E. coli #0346 and other bacteria. Hemolysis assays were used to quantify the hemolytic effects of CDP-B11 alone and in combination with colistin. Findings show CDP-B11 disrupts the outer membrane of E. coli #0346. CDP-B11 with colistin inhibits the growth of E. coli #0346 at ≥ 10× lower colistin concentrations compared to colistin alone in Mueller–Hinton media and M9 media. Growth is significantly inhibited in other clinically relevant strains, such as Acinetobacter baumannii, Pseudomonas aeruginosa, and Klebsiella pneumoniae. In rich media and minimal media, the drug combination kills bacteria at a lower colistin concentration (1.25 μg/mL) compared to colistin alone (2.5 μg/mL). In minimal media, the combination is bactericidal with killing accelerated by up to 2 h compared to colistin alone. Importantly, no significant red blood hemolysis is evident for CDP-B11 alone or in combination with colistin. The characteristics of CDP-B11 presented here indicate that it can be used as a potential monotherapy or as combination therapy with colistin for the treatment of multidrug-resistant infections, including colistin-resistant infections.

scholarly journals In Vitro and In Vivo Assessment of the Potential of Escherichia coli Phages to Treat Infections and Survive Gastric Conditions

2021 ◽  
Vol 9 (9) ◽  
pp. 1869
Author(s):  
Joanna Kaczorowska ◽  
Eoghan Casey ◽  
Gabriele A. Lugli ◽  
Marco Ventura ◽  
David J. Clarke ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Galleria Mellonella ◽  
Enterotoxigenic Escherichia Coli ◽  
E Coli ◽  
Composite Mixture ◽  
Ph Conditions ◽  
The Stability ◽  
Higher Sensitivity

Enterotoxigenic Escherichia coli (ETEC) and Shigella ssp. infections are associated with high rates of mortality, especially in infants in developing countries. Due to increasing levels of global antibiotic resistance exhibited by many pathogenic organisms, alternative strategies to combat such infections are urgently required. In this study, we evaluated the stability of five coliphages (four Myoviridae and one Siphoviridae phage) over a range of pH conditions and in simulated gastric conditions. The Myoviridae phages were stable across the range of pH 2 to 7, while the Siphoviridae phage, JK16, exhibited higher sensitivity to low pH. A composite mixture of these five phages was tested in vivo in a Galleria mellonella model. The obtained data clearly shows potential in treating E. coli infections prophylactically.

scholarly journals In Vivo Titration of Mitomycin C Action by Four Escherichia coli Genomic Regions on Multicopy Plasmids

2001 ◽  
Vol 183 (7) ◽  
pp. 2259-2264 ◽  
Author(s):  
Yan Wei ◽  
Amy C. Vollmer ◽  
Robert A. LaRossa
Keyword(s):  
Escherichia Coli ◽  
Mitomycin C ◽  
Transcriptional Activation ◽  
Efflux Pump ◽  
Wild Type ◽  
Potent Inducer ◽  
E Coli ◽  
Genomic Regions

ABSTRACT Mitomycin C (MMC), a DNA-damaging agent, is a potent inducer of the bacterial SOS response; surprisingly, it has not been used to select resistant mutants from wild-type Escherichia coli. MMC resistance is caused by the presence of any of four distinctE. coli genes (mdfA, gyrl, rob, andsdiA) on high-copy-number vectors. mdfAencodes a membrane efflux pump whose overexpression results in broad-spectrum chemical resistance. The gyrI (also called sbmC) gene product inhibits DNA gyrase activity in vitro, while the rob protein appears to function in transcriptional activation of efflux pumps. SdiA is a transcriptional activator of ftsQAZ genes involved in cell division.

scholarly journals Virulence Potential of a Multidrug-Resistant Escherichia coli Strain Belonging to the Emerging Clonal Group ST101-B1 Isolated from Bloodstream Infection

2020 ◽  
Vol 8 (6) ◽  
pp. 827 ◽  
Author(s):  
Ana Carolina M. Santos ◽  
Rosa M. Silva ◽  
Tiago B. Valiatti ◽  
Fernanda F. Santos ◽  
José F. Santos-Neto ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Bloodstream Infection ◽  
Galleria Mellonella ◽  
Multidrug Resistant ◽  
Coli Strain ◽  
Pathogenic Potential ◽  
E Coli ◽  
Antimicrobial Resistance Genes

Escherichia coli EC121 is a multidrug-resistant (MDR) strain isolated from a bloodstream infection of an inpatient with persistent gastroenteritis and T-zone lymphoma that died due to septic shock. Despite causing an extraintestinal infection, previous studies showed that it did not have the usual characteristics of an extraintestinal pathogenic E. coli. Instead, it belonged to phylogenetic group B1 and harbored few known virulence genes. To evaluate the pathogenic potential of strain EC121, an extensive genome sequencing and in vitro characterization of various pathogenicity-associated properties were performed. The genomic analysis showed that strain EC121 harbors more than 50 complete virulence genetic clusters. It also displays the capacity to adhere to a variety of epithelial cell lineages and invade T24 bladder cells, as well as the ability to form biofilms on abiotic surfaces, and survive the bactericidal serum complement activity. Additionally, EC121 was shown to be virulent in the Galleria mellonella model. Furthermore, EC121 is an MDR strain harboring 14 antimicrobial resistance genes, including blaCTX-M-2. Completing the scenario, it belongs to serotype O154:H25 and to sequence type 101-B1, which has been epidemiologically linked to extraintestinal infections as well as to antimicrobial resistance spread. This study with E. coli strain EC121 shows that clinical isolates considered opportunistic might be true pathogens that go underestimated.

Carbapenemases and Extended-Spectrum β-Lactamase–Producing Multidrug-Resistant Escherichia coli Isolated from Retail Chicken in Peshawar: First Report from Pakistan

2018 ◽  
Vol 81 (8) ◽  
pp. 1339-1345 ◽  
Author(s):  
KAFEEL AHMAD ◽  
FARYAL KHATTAK ◽  
AMJAD ALI ◽  
SHAISTA RAHAT ◽  
SHAZIA NOOR ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Nalidixic Acid ◽  
Resistance Genes ◽  
Antibiotic Resistance Genes ◽  
Multidrug Resistant ◽  
E Coli ◽  
Extended Spectrum ◽  
Amoxicillin Clavulanate ◽  
Synergy Test

ABSTRACT We report the prevalence of extended-spectrum β-lactamases and carbapenemases in Escherichia coli isolated from retail chicken in Peshawar, Pakistan. One hundred E. coli isolates were recovered from retail chicken. Antibiotic susceptibility testing was carried out against ampicillin, chloramphenicol, kanamycin, nalidixic acid, cephalothin, gentamicin, sulfamethoxazole-trimethoprim, and streptomycin. Phenotypic detection of β-lactamase production was analyzed through double disc synergy test using the antibiotics amoxicillin-clavulanate, cefotaxime, ceftazidime, cefepime, and aztreonam. Fifty multidrug-resistant isolates were screened for detection of sul1, aadA, cmlA, int, blaTEM, blaSHV, blaCTX-M, blaOXA-10, blaVIM, blaIMP, and blaNDM-1 genes. Resistance to ampicillin, nalidixic acid, kanamycin, streptomycin, cephalothin, sulfamethoxazole-trimethoprim, gentamicin, cefotaxime, ceftazidime, aztreonam, cefepime, amoxicillin-clavulanate, and chloramphenicol was 92, 91, 84, 73, 70, 67, 53, 48, 40, 39, 37, 36, and 23% respectively. Prevalence of sul1, aadA, cmlA, int, blaTEM, blaCTX-M, blaIMP, and blaNDM-1 was 78% (n = 39), 76% (n = 38), 20% (n = 10), 90% (n = 45), 74% (n = 37), 94% (n = 47), 22% (n = 11), and 4% (n = 2), respectively. blaSHV, blaOXA-10, and blaVIM were not detected. The coexistence of multiple antibiotic resistance genes in multidrug-resistant strains of E. coli is alarming. Hence, robust surveillance strategies should be developed with a focus on controlling the spread of antibiotic resistance genes via the food chain.

scholarly journals New topoisomerase inhibitors: Evaluating the potency of gepotidacin and zoliflodacin in fluoroquinolone-resistant Escherichia coli upon tolC inactivation and differentiating their efflux pump substrate nature.

2020 ◽  
Author(s):  
Sabine Schuster ◽  
Martina Vavra ◽  
Raphael Köser ◽  
John W. A. Rossen ◽  
Winfried V. Kern
Keyword(s):  
Escherichia Coli ◽  
Efflux Pump ◽  
Multidrug Resistant ◽  
Quinolone Resistance ◽  
Topoisomerase Inhibitors ◽  
E Coli ◽  
Sequence Types ◽  
Substrate Nature

Inactivating tolC in multidrug-resistant Escherichia coli with differing sequence types and quinolone resistance-determining mutations reveals remarkably potentiated activity of the first-in-class topoisomerase inhibitors gepotidacin and zoliflodacin. Differences between both structurally unrelated compounds in comparison to fluoroquinolones regarding the selectivity of E. coli RND-type transporters, efflux inhibitors, and AcrB porter domain mutations were demonstrated. The findings should reinforce efforts to develop efflux bypassing drugs and provide AcrB targets with critical relevance for this purpose.

scholarly journals Peptidoglycan sensing prevents quiescence and promotes quorum-independent growth of uropathogenic Escherichia coli

2019 ◽  
Author(s):  
Eric C. DiBiasio ◽  
Hilary J. Ranson ◽  
James R. Johnson ◽  
David C. Rowley ◽  
Paul S. Cohen ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Structural Integrity ◽  
Recurrent Infection ◽  
Multidrug Resistant ◽  
Quiescent State ◽  
E Coli ◽  
Tract Infections ◽  
Patients Experience

AbstractThe layer of peptidoglycan surrounding bacteria provides structural integrity for the bacterial cell wall. Many organisms, including human cells and diverse bacteria, detect peptidoglycan fragments that are released as bacteria grow. Uropathogenic Escherichia coli (UPEC) strains are the leading cause of human urinary tract infections (UTIs) and many patients experience recurrent infection after successful antibiotic treatment. The source of recurrent infections may be persistent bacterial reservoirs in vivo that are in a quiescent state and, thus, are not susceptible to antibiotics. Here, we show that multiple UPEC strains require a quorum to proliferate in vitro with glucose as the sole carbon source; at low density, the bacteria remain viable but enter a quiescent, non-proliferative state. Of all clinical UPEC isolates tested to date, 35% (51/145) enter this quiescent state, including archetypal strains CFT073 (from classic endemic lineage ST73) and JJ1886 (from recently emerged, multidrug-resistant pandemic lineage ST131). We further show that quorum-dependent UPEC quiescence is prevented and reversed by small molecules, called proliferants, that stimulate growth, such as L-lysine, L-methionine, and peptidoglycan (PG) stem peptides, including an isolated PG pentapeptide from Staphylococcus aureus. Together, our results indicate that (i) uptake of L-lysine and (ii) PG peptide sensing by UPEC modulate the quorum-regulated decision to proliferate and further demonstrate that PG fragments are important for intra- and interspecies signaling in pathogenic E. coli.

scholarly journals The cnf1 gene is associated to an expanding Escherichia coli ST131 H30Rx/C2 sublineage and confers a competitive advantage for host colonization

2021 ◽  
Author(s):  
Landry Laure TSOUMTSA MEDA ◽  
Luce LANDRAUD ◽  
Serena PETRACCHINI ◽  
Stéphane DESCORPS-DECLERE ◽  
Emeline PERTHAME ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Gastrointestinal Tract ◽  
Antibiotic Resistance Genes ◽  
Multidrug Resistant ◽  
Clinical Strain ◽  
Host Colonization ◽  
E Coli ◽  
Clonal Distribution ◽  
Cytotoxic Necrotizing Factor 1 ◽  
Sequence Types

Epidemiological projections point to acquisition of ever-expanding multidrug resistance (MDR) by Escherichia coli, a commensal of the digestive tract acting as a source of urinary tract pathogens. We performed a high-throughput genetic screening of predominantly clinical E. coli isolates from wide geographical origins. This revealed a preferential distribution of the Cytotoxic Necrotizing Factor 1 (CNF1)-toxin encoding gene, cnf1, in four sequence types encompassing the pandemic E. coli MDR lineage ST131. This lineage is responsible for a majority of extraintestinal infections that escape first-line antibiotic treatment and has known enhanced capacities to colonize the gastrointestinal tract (GIT). Statistical modeling uncovered a dominant global expansion of cnf1-positive strains within multidrug-resistant ST131 subclade H30Rx/C2. Despite the absence of phylogeographical signals, cnf1-positive isolates adopted a clonal distribution into clusters on the ST131-H30Rx/C2 phylogeny, sharing a similar profile of virulence factors and the same cnf1 allele. Functional analysis of the cnf1-positive clinical strain EC131GY ST131-H30Rx/C2, established that a cnf1-deleted EC131GY is outcompeted by the wildtype strain in a mouse model of competitive infection of the bladder while both strains behave similarly during monoinfections. This points for positive selection of cnf1 during UTI rather than urovirulence. Wildtype EC131GY also outcompeted the mutant when concurrently inoculated into the gastrointestinal tract, arguing for selection within the gut. Whatever the site of selection, these findings support that the benefit of cnf1 enhancing host colonization by ST131-H30Rx/C2 in turn drives a worldwide dissemination of the cnf1 gene together with extended spectrum of antibiotic resistance genes.

scholarly journals Characterization of proteobacterial plasmid integron-encoded qac efflux pump sequence diversity and quaternary ammonium compound antiseptic selection in E. coli grown planktonically and as biofilms

2021 ◽  
Author(s):  
Carmine J. Slipski ◽  
Taylor R. Jamieson-Datzkiw ◽  
George G. Zhanel ◽  
Denice C. Bay
Keyword(s):  
Escherichia Coli ◽  
Quaternary Ammonium ◽  
Susceptibility Testing ◽  
Efflux Pump ◽  
Multidrug Resistant ◽  
Quaternary Ammonium Compound ◽  
Ammonium Compound ◽  
E Coli ◽  
Susceptibility Patterns

Qac efflux pumps from proteobacterial multidrug-resistant plasmids are integron-encoded and confer resistance to quaternary ammonium compound (QAC) antiseptics, however, many are uncharacterized and misannotated. A survey of >2000 plasmid-encoded qac identified 37 unique qac sequences that correspond to one of five representative motifs: QacE, QacEΔ1, QacF/L, QacH/I, and QacG. Antimicrobial susceptibility testing of each cloned qac member in Escherichia coli , highlighted distinctive antiseptic susceptibility patterns that were most prominent when cells grew as biofilms.

scholarly journals Synergy between Florfenicol and Aminoglycosides against Multidrug-Resistant Escherichia coli Isolates from Livestock

Antibiotics ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 185 ◽  
Author(s):  
Shukho Kim ◽  
Jung Hwa Woo ◽  
So Hyun Jun ◽  
Dong Chan Moon ◽  
Suk-Kyung Lim ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Synergistic Effect ◽  
Antimicrobial Agents ◽  
Alternative Therapy ◽  
Multidrug Resistant ◽  
Combination Regimen ◽  
E Coli ◽  
Effective Combination

The increasing prevalence of antimicrobial resistance and the laborious development of novel antimicrobial agents have limited the options for effective antimicrobial therapy. The combination of previously used antimicrobial agents represents an alternative therapy for multidrug-resistant (MDR) pathogens. The objective of this study was to investigate the synergistic effect of a florfenicol (FFL)-based combination with other antimicrobial agents against MDR Escherichia coli isolates from livestock using checkerboard assays and murine infection models. The FFL/amikacin (AMK) and FFL/gentamicin (GEN) combinations showed synergy against 10/11 and 6/11 MDR E. coli isolates in vitro, respectively. The combination of FFL with aminoglycosides (AMK or GEN) exhibited a better synergistic effect against MDR E. coli isolates than the cephalothin (CEF)/GEN or FFL/CEF combinations. The combination of FFL with AMK or GEN could reduce the emergence of resistant mutants in vitro. The FFL/AMK combination showed a higher survival rate of mice infected with MDR E. coli isolates than FFL or AMK alone. In summary, the combination of FFL with aminoglycosides (AMK or GEN) is highly effective against MDR E. coli isolates both in vitro and in vivo. Our findings may contribute to the discovery of an effective combination regimen against MDR E. coli infections in veterinary medicine.

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