scholarly journals Transfer characteristics of two resistance determinants in a wild strain of Klebsiella aerogenes (V9A)

1970 ◽  
Vol 16 (2) ◽  
pp. 235-240 ◽  
Author(s):  
E. C. R. Reeve
Keyword(s):  
Escherichia Coli ◽  
Cell Attachment ◽  
Wild Strain ◽  
Klebsiella Aerogenes ◽  
Sex Factors ◽  
Chromosomal Gene ◽  
E Coli ◽  
Resistance Determinants ◽  
A Cell ◽  
Plasmid F

SUMMARYKlebsiella aerogenes strain V9A carries determinants AK and TK, giving resistance to ampicillin and tetracycline, and a plasmid FKlac, but no active sex factor. F− and I-type sex factors were able to transfer TK from V9A to Escherichia coli K12 and between strains of K12, and TK behaved as a separate plasmid with its own replicon. AK could not be transferred, except possibly by a sex factor carrying its own A determinant, but the evidence for such transfer was inconclusive. It is suggested that AK is either a chromosomal gene or is in a plasmid with a cell attachment in Klebsiella not represented in E. coli K12. AK produces a β-lactamase.

Antagonistic activity of Bacillus subtilis strains isolated from various sources

2018 ◽  
Vol 8 (2) ◽  
pp. 354-364
Author(s):  
A. N. Irkitova ◽  
A. V. Grebenshchikova ◽  
A. V. Matsyura
Keyword(s):  
Escherichia Coli ◽  
Bacillus Subtilis ◽  
Wild Strain ◽  
Fish Farming ◽  
Antagonistic Activity ◽  
Antagonistic Effect ◽  
E Coli ◽  
Long Period ◽  
Test Culture ◽  
Agar Media

<p>An important link in solving the problem of healthy food is the intensification of the livestock, poultry and fish farming, which is possible only in the adoption and rigorous implementation of the concept of rational feeding of animals. In the implementation of this concept required is the application of probiotic preparations. Currently, there is an increased interest in spore probiotics. In many ways, this can be explained by the fact that they use no vegetative forms of the bacilli and their spores. This property provides spore probiotics a number of advantages: they are not whimsical, easily could be selected, cultivated, and dried. Moreover, they are resistant to various factors and could remain viable during a long period. One of the most famous spore microorganisms, which are widely used in agriculture, is <em>Bacillus subtilis</em>. Among the requirements imposed to probiotic microorganisms is mandatory – antagonistic activity to pathogenic and conditional-pathogenic microflora. The article presents the results of the analysis of antagonistic activity of collection strains of <em>B. subtilis</em>, and strains isolated from commercial preparations. We studied the antagonistic activity on agar and liquid nutrient medias to trigger different antagonism mechanisms of <em>B. subtilis</em>. On agar media, we applied three diffusion methods: perpendicular bands, agar blocks, agar wells. We also applied the method of co-incubating the test culture (<em>Escherichia coli</em>) and the antagonist (or its supernatant) in the nutrient broth. Our results demonstrated that all our explored strains of <em>B. subtilis</em> have antimicrobial activity against a wild strain of <em>E. coli</em>, but to varying degrees. We identified strains of <em>B. subtilis</em> with the highest antagonistic effect that can be recommended for inclusion in microbial preparations for agriculture.</p><p><em><br /></em><em></em></p>

scholarly journals Impact of Feed Supplementation with Antimicrobial Agents on Growth Performance of Broiler Chickens, Clostridium perfringens and Enterococcus Counts, and Antibiotic Resistance Phenotypes and Distribution of Antimicrobial Resistance Determinants in Escherichia coli Isolates

2007 ◽  
Vol 73 (20) ◽  
pp. 6566-6576 ◽  
Author(s):  
Moussa S. Diarra ◽  
Fred G. Silversides ◽  
Fatoumata Diarrassouba ◽  
Jane Pritchard ◽  
Luke Masson ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Antimicrobial Resistance ◽  
Broiler Chickens ◽  
Antimicrobial Agents ◽  
Growth Promoters ◽  
Feed Supplementation ◽  
E Coli ◽  
Resistance Determinants ◽  
Class 1

ABSTRACT The effects of feed supplementation with the approved antimicrobial agents bambermycin, penicillin, salinomycin, and bacitracin or a combination of salinomycin plus bacitracin were evaluated for the incidence and distribution of antibiotic resistance in 197 commensal Escherichia coli isolates from broiler chickens over 35 days. All isolates showed some degree of multiple antibiotic resistance. Resistance to tetracycline (68.5%), amoxicillin (61.4%), ceftiofur (51.3%), spectinomycin (47.2%), and sulfonamides (42%) was most frequent. The levels of resistance to streptomycin, chloramphenicol, and gentamicin were 33.5, 35.5, and 25.3%, respectively. The overall resistance levels decreased from day 7 to day 35 (P < 0.001). Comparing treatments, the levels of resistance to ceftiofur, spectinomycin, and gentamicin (except for resistance to bacitracin treatment) were significantly higher in isolates from chickens receiving feed supplemented with salinomycin than from the other feeds (P < 0.001). Using a DNA microarray analysis capable of detecting commonly found antimicrobial resistance genes, we characterized 104 tetracycline-resistant E. coli isolates from 7- to 28-day-old chickens fed different growth promoters. Results showed a decrease in the incidence of isolates harboring tet(B), bla TEM, sulI, and aadA and class 1 integron from days 7 to 35 (P < 0.01). Of the 84 tetracycline-ceftiofur-resistant E. coli isolates, 76 (90.5%) were positive for bla CMY-2. The proportions of isolates positive for sulI, aadA, and integron class 1 were significantly higher in salinomycin-treated chickens than in the control or other treatment groups (P < 0.05). These data demonstrate that multiantibiotic-resistant E. coli isolates can be found in broiler chickens regardless of the antimicrobial growth promoters used. However, the phenotype and the distribution of resistance determinants in E. coli can be modulated by feed supplementation with some of the antimicrobial agents used in broiler chicken production.

scholarly journals Preparation of Sticky Escherichia coli through Surface Display of an Adhesive Catecholamine Moiety

2013 ◽  
Vol 80 (1) ◽  
pp. 43-53 ◽  
Author(s):  
Joseph P. Park ◽  
Min-Jung Choi ◽  
Se Hun Kim ◽  
Seung Hwan Lee ◽  
Haeshin Lee
Keyword(s):  
Escherichia Coli ◽  
Cell Surface ◽  
Communication Systems ◽  
Cell Attachment ◽  
Surface Display ◽  
Content Type ◽  
E Coli ◽  
Material Surfaces ◽  
Mussel Adhesive ◽  
Adhesive Proteins

ABSTRACTMussels attach to virtually all types of inorganic and organic surfaces in aqueous environments, and catecholamines composed of 3,4-dihydroxy-l-phenylalanine (DOPA), lysine, and histidine in mussel adhesive proteins play a key role in the robust adhesion. DOPA is an unusual catecholic amino acid, and its side chain is called catechol. In this study, we displayed the adhesive moiety of DOPA-histidine onEscherichia colisurfaces using outer membrane protein W as an anchoring motif for the first time. Localization of catecholamines on the cell surface was confirmed by Western blot and immunofluorescence microscopy. Furthermore, cell-to-cell cohesion (i.e., cellular aggregation) induced by the displayed catecholamine and synthesis of gold nanoparticles on the cell surface support functional display of adhesive catecholamines. The engineeredE. coliexhibited significant adhesion onto various material surfaces, including silica and glass microparticles, gold, titanium, silicon, poly(ethylene terephthalate), poly(urethane), and poly(dimethylsiloxane). The uniqueness of this approach utilizing the engineered stickyE. coliis that no chemistry for cell attachment are necessary, and the ability of spontaneousE. coliattachment allows one to immobilize the cells on challenging material surfaces such as synthetic polymers. Therefore, we envision that mussel-inspired catecholamine yielded stickyE. colithat can be used as a new type of engineered microbe for various emerging fields, such as whole living cell attachment on versatile material surfaces, cell-to-cell communication systems, and many others.

scholarly journals Dissemination of the blaNDM-5 Gene via IncX3-Type Plasmid among Enterobacteriaceae in Children

mSphere ◽  
2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Dongxing Tian ◽  
Bingjie Wang ◽  
Hong Zhang ◽  
Fen Pan ◽  
Chun Wang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Drug Resistance ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Klebsiella Pneumoniae ◽  
Pediatric Patients ◽  
Transmission Mechanism ◽  
Klebsiella Aerogenes ◽  
Content Type ◽  
E Coli

ABSTRACT The continuous emergence of novel New Delhi metallo-β-lactamase-5 (NDM-5)-producing Enterobacteriaceae isolates is receiving more and more public attention. Twenty-two NDM-5-producing strains were identified from 146 carbapenemase-producing Enterobacteriaceae (CRE) strains isolated from pediatric patients between January and March 2017, indicating that the blaNDM-5 gene has spread to children. All 22 isolates, including 16 Klebsiella pneumoniae strains, four Klebsiella aerogenes strains, and two Escherichia coli strains, showed significantly high resistance to β-lactam antibiotics (except aztreonam) but remained susceptible to tigecycline and colistin. K. pneumoniae and K. aerogenes strains were respectively defined as homologous clonal isolates by pulsed-field gel electrophoresis (PFGE). Multilocus sequence typing (MLST) results confirmed the genetic relatedness with all K. pneumoniae strains belonging to sequence type (ST) 48. Two E. coli isolates (ST617 and ST1236) were considered genetically unrelated. Twenty-two blaNDM-5 plasmids were positive for the IncX3 amplicon and showed almost identical profiles after digestion with HindIII and EcoRI. Four representative strains (K. pneumoniae K725, K. aerogenes CR33, E. coli Z214, and E. coli Z244) were selected for further study. Plasmids harboring blaNDM-5 showed strong stability in both clinical isolates and transconjugants, without apparent plasmid loss after 100 serial generations. S1-PFGE followed by Southern blot analysis demonstrated that the blaNDM-5 gene was located on an ∼46-kb plasmid. Plasmid sequences of pNDM-K725, pNDM-CR33, and pNDM-Z214 were almost identical but were slightly different from that of pNDM-Z244. Compared with pNDM-Z244, ΔISAba125 and partial copies of IS3000 were missing. The genetic backgrounds of the blaNDM-5 gene in four strains were slightly different from that of the typical pNDM_MGR194. This study comprehensively characterized the horizontal gene transfer of the blaNDM-5 gene among different Enterobacteriaceae isolates in pediatric patients, and the IncX3-type plasmid was responsible for the spread. IMPORTANCE The emergence of CRE strains resistant to multiple antibiotics is considered a substantial threat to human health. Therefore, all the efforts to provide a detailed molecular transmission mechanism of specific drug resistance can contribute positively to prevent the further spread of multidrug-resistant bacteria. Although the new superbug harboring blaNDM-5 has been reported in many countries, it was mostly identified among E. coli strains, and the gene transfer mechanism has not been fully recognized and studied. In this work, we identified 22 blaNDM-5-positive strains in different species of Enterobacteriaceae, including 16 Klebsiella pneumoniae strains, four Klebsiella aerogenes strains, and two Escherichia coli strains, which indicated the horizontal gene transfer of blaNDM-5 among Enterobacteriaceae strains in pediatric patients. Moreover, blaNDM-5 was located on a 46-kb IncX3 plasmid, which is possibly responsible for this widespread horizontal gene transfer. The different genetic contexts of the blaNDM-5 gene indicated some minor evolutions of the plasmid, based on the complete sequences of the blaNDM-5 plasmids. These findings are of great significance to understand the transmission mechanism of drug resistance genes, develop anti-infection treatment, and take effective infection control measures.

scholarly journals Iha: a Novel Escherichia coli O157:H7 Adherence-Conferring Molecule Encoded on a Recently Acquired Chromosomal Island of Conserved Structure

2000 ◽  
Vol 68 (3) ◽  
pp. 1400-1407 ◽  
Author(s):  
Phillip I. Tarr ◽  
Sima S. Bilge ◽  
James C. Vary ◽  
Srdjan Jelacic ◽  
Rebecca L. Habeeb ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Epithelial Cells ◽  
Vibrio Cholerae ◽  
Shiga Toxin ◽  
Escherichia Coli O157 ◽  
Chromosomal Gene ◽  
Gene Encoding ◽  
Tellurite Resistance ◽  
E Coli ◽  
Dna Library

ABSTRACT The mechanisms used by Shiga toxin (Stx)-producingEscherichia coli to adhere to epithelial cells are incompletely understood. Two cosmids from an E. coliO157:H7 DNA library contain an adherence-conferring chromosomal gene encoding a protein similar to iron-regulated gene A (IrgA) ofVibrio cholerae (M. B. Goldberg, S. A. Boyko, J. R. Butterton, J. A. Stoebner, S. M. Payne, and S. B. Calderwood, Mol. Microbiol. 6:2407–2418, 1992). We have termed the product of this gene the IrgA homologue adhesin (Iha), which is encoded by iha. Iha is 67 kDa in E. coliO157:H7 and 78 kDa in laboratory E. coli and is structurally unlike other known adhesins. DNA adjacent toiha contains tellurite resistance loci and is conserved in structure in distantly related pathogenic E. coli, but it is absent from nontoxigenic E. coli O55:H7, sorbitol-fermenting Stx-producing E. coli O157:H−, and laboratory E. coli. We have termed this region the tellurite resistance- and adherence-conferring island. We conclude that Iha is a novel bacterial adherence-conferring protein and is contained within an E. coli chromosomal island of conserved structure. Pathogenic E. coli O157:H7 has only recently acquired this island.

Verotoxin-Producing Escherichia coli in Spain: Prevalence, Serotypes, and Virulence Genes of O157:H7 and Non-O157 VTEC in Ruminants, Raw Beef Products, and Humans

2003 ◽  
Vol 228 (4) ◽  
pp. 345-351 ◽  
Author(s):  
Jorge Blanco ◽  
Miguel Blanco ◽  
Jesus E. Blanco ◽  
Azucena Mora ◽  
Enrique A. Gonzalez ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Virulence Factor ◽  
Intestinal Mucosa ◽  
Virulence Genes ◽  
Chromosomal Gene ◽  
E Coli ◽  
Beef Products

In Spain, as in many other countries, verotoxin-producing Escherichia coli (VTEC) strains have been frequently isolated from cattle, sheep, and foods. VTEC strains have caused seven outbreaks in Spain (six caused by E. coli O157:H7 and one by E. coli O111:H– [nonmotile]) in recent years. An analysis of the serotypes indicated serological diversity. Among the strains isolated from humans, serotypes O26:H11, O111:H–, and O157:H7 were found to be more prevalent. The most frequently detected serotypes in cattle were O20:H19, O22:H8, O26:H11, O77:H41, O105:H18, O113:H21, O157:H7, O171:H2, and OUT (O untypeable):H19. Different VTEC serotypes (e.g., O5:H–, O6:H10, O91:H–, O117:H–, O128:H–, O128:H2, O146:H8, O146:H21, O156:H–, and OUT:H21) were found more frequently in sheep. These observations suggest a host serotype specificity for some VTEC. Numerous bovine and ovine VTEC serotypes detected in Spain were associated with human illnesses, confirming that ruminants are important reservoirs of pathogenic VTEC. VTEC can produce one or two toxins (VT1 and VT2) that cause human illnesses. These toxins are different proteins encoded by different genes. Another virulence factor expressed by VTEC is the protein intimin that is responsible for intimate attachment of VTEC and effacing lesions in the intestinal mucosa. This virulence factor is encoded by the chromosomal gene eae. The eae gene was found at a much less frequency in bovine (17%) and ovine (5%) than in human (45%) non-O157 VTEC strains. This may support the evidence that the eae gene contributes significantly to the virulence of human VTEC strains and that many animal non-O157 VTEC strains are less pathogenic to humans.

Expression of Psychrophilic Genes in Mesophilic Hosts: Assessment of the Folding State of a Recombinant α-Amylase

1998 ◽  
Vol 64 (3) ◽  
pp. 1163-1165 ◽  
Author(s):  
Georges Feller ◽  
Olivier Le Bussy ◽  
Charles Gerday
Keyword(s):  
Escherichia Coli ◽  
Enzyme Stability ◽  
Expression System ◽  
Wild Strain ◽  
Culture Temperature ◽  
E Coli ◽  
System A ◽  
Irreversible Denaturation ◽  
The Antarctic ◽  
Folding State

ABSTRACT α-Amylase from the antarctic psychrophile Alteromonas haloplanktis is synthesized at 0 ± 2°C by the wild strain. This heat-labile α-amylase folds correctly when overexpressed in Escherichia coli, providing the culture temperature is sufficiently low to avoid irreversible denaturation. In the described expression system, a compromise between enzyme stability and E. coli growth rate is reached at 18°C.

scholarly journals Interaction between complement subcomponent C1q and bacterial lipopolysaccharides

1989 ◽  
Vol 257 (3) ◽  
pp. 865-873 ◽  
Author(s):  
A Zohair ◽  
S Chesne ◽  
R H Wade ◽  
M G Colomb
Keyword(s):  
Escherichia Coli ◽  
Chemical Modification ◽  
Essential Role ◽  
Wild Strain ◽  
E Coli ◽  
Diethyl Pyrocarbonate ◽  
Direct Binding ◽  
Bacterial Lipopolysaccharides ◽  
K 12

The heptose-less mutant of Escherichia coli, D31m4, bound complement subcomponent C1q and its collagen-like fragments (C1qCLF) with Ka values of 1.4 x 10(8) and 2.0 x 10(8) M-1 respectively. This binding was suppressed by chemical modification of C1q and C1qCLF using diethyl pyrocarbonate (DEPC). To investigate the role of lipopolysaccharides (LPS) in this binding, biosynthetically labelled [14C]LPS were purified from E. coli D31m4 and incorporated into liposomes prepared from phosphatidylcholine (PC) and phosphatidylethanolamine (PE) [PC/PE/LPS, 2:2:1, by wt.]. Binding of C1q or its collagen-like fragments to the liposomes was estimated via a flotation test. These liposomes bound C1q and C1qCLF with Ka values of 8.0 x 10(7) and 2.0 x 10(7) M-1; this binding was totally inhibited after chemical modification of C1q and C1qCLF by DEPC. Liposomes containing LPS purified from the wild-strain E. coli K-12 S also bound C1q and C1qCLF, whereas direct binding of C1q or C1qCLF to the bacteria was negligible. Diamines at concentrations which dissociate C1 into C1q and (C1r, C1s)2, strongly inhibited the interaction of C1q or C1qCLF with LPS. Removal of 3-deoxy-D-manno-octulosonic acid (2-keto-3-deoxyoctonic acid; KDO) from E. coli D31m4 LPS decreases the binding of C1qCLF to the bacteria by 65%. When this purified and modified LPS was incorporated into liposomes, the C1qCLF binding was completely abolished. These results show: (i) the essential role of the collagen-like moiety and probably its histidine residues in the interaction between C1q and the mutant D31m4; (ii) the contribution of LPS, particularly the anionic charges of KDO, to this interaction.

Determinants of β-lactam resistance in meningitis-causingEnterobacteriaceaein Brazil

2010 ◽  
Vol 56 (5) ◽  
pp. 399-407 ◽  
Author(s):  
L. N. Andrade ◽  
L. A.R. Minarini ◽  
A. Pitondo-Silva ◽  
E. C. Clímaco ◽  
I. C.V. Palazzo ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Insertion Sequence ◽  
Genetic Relationships ◽  
Mlst Database ◽  
High Genetic Diversity ◽  
Mlst Analysis ◽  
E Coli ◽  
Resistance Determinants ◽  
Class 1 ◽  
Encoding Genes

This study analyzed resistance determinants in extended-spectrum β-lactamase (ESBL)-producing enterobacteria and the epidemiology of 11 Escherichia coli isolates obtained from meningitis patients in a region of Brazil from 2000 to 2005. ESBL-encoding genes and their genetic environment were investigated by PCR and sequencing. The gene blaCTX-M-2was identified in 3 different enterobacteria (E. coli, Serratia marcescens , and Proteus mirabilis ) downstream of the insertion sequence ISCR1 (localized in class 1 integrons), but not as part of the resistance cassettes region. Multilocus sequence typing (MLST) was used to investigate genetic relationships between the 11 E. coli isolates in this study and strains associated with meningitis in the E. coli MLST database. MLST analysis indicated high genetic diversity among isolates, and no significant genetic relationship was identified with meningitis-causing E. coli in the database. The results in this report reinforce the need to be attentive to meningitis suspected to be due to ESBL-producing enterobacterial isolates, especially where ESBL epidemiology is well known.

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