scholarly journals The tva(A) Gene from Brachyspira hyodysenteriae Confers Decreased Susceptibility to Pleuromutilins and Streptogramin A in Escherichia coli

2019 ◽  
Vol 63 (9) ◽  
Author(s):  
Ana B. García-Martín ◽  
Sybille Schwendener ◽  
Vincent Perreten
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Minor Effect ◽  
Content Type ◽  
Brachyspira Hyodysenteriae ◽  
Resistance Phenotype ◽  
E Coli ◽  
Direct Association ◽  
A Minor

ABSTRACT The tva(A) gene suspected to confer resistance to pleuromutilins in Brachyspira hyodysenteriae was tested for functionality in Escherichia coli AG100A and Staphylococcus aureus RN4220. Expression of the cloned tva(A) gene conferred decreased susceptibility to pleuromutilin (P) and streptogramin A (SA) antibiotics in E. coli and had a minor effect in S. aureus. The finding provides evidence of the direct association of tva(A) with the PSA resistance phenotype.

scholarly journals Screening of Escherichia coli Species Biodiversity Reveals New Biofilm-Associated Antiadhesion Polysaccharides

mBio ◽  
2011 ◽  
Vol 2 (3) ◽  
Author(s):  
Olaya Rendueles ◽  
Laetitia Travier ◽  
Patricia Latour-Lambert ◽  
Thierry Fontaine ◽  
Julie Magnus ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Bacterial Adhesion ◽  
Bioactive Molecules ◽  
Bacterial Biofilms ◽  
Gram Positive ◽  
Content Type ◽  
E Coli ◽  
Species Biodiversity

ABSTRACTBacterial biofilms often form multispecies communities in which complex but ill-understood competition and cooperation interactions occur. In light of the profound physiological modifications associated with this lifestyle, we hypothesized that the biofilm environment might represent an untapped source of natural bioactive molecules interfering with bacterial adhesion or biofilm formation. We produced cell-free solutions extracted fromin vitromature biofilms formed by 122 naturalEscherichia coliisolates, and we screened these biofilm extracts for antiadhesion molecules active on a panel of Gram-positive and Gram-negative bacteria. Using this approach, we showed that 20% of the tested biofilm extracts contained molecules that antagonize bacterial growth or adhesion. We characterized a compound, produced by a commensal animalE. colistrain, for which activity is detected only in biofilm extract. Biochemical and genetic analyses showed that this compound corresponds to a new type of released high-molecular-weight polysaccharide whose biofilm-associated production is regulated by the RfaH protein. We demonstrated that the antiadhesion activity of this polysaccharide was restricted to Gram-positive bacteria and that its production reduced susceptibility to invasion and provided rapid exclusion ofStaphylococcus aureusfrom mixedE. coliandS. aureusbiofilms. Our results therefore demonstrate that biofilms contain molecules that contribute to the dynamics of mixed bacterial communities and that are not or only poorly detected in unconcentrated planktonic supernatants. Systematic identification of these compounds could lead to strategies that limit pathogen surface colonization and reduce the burden associated with the development of bacterial biofilms on medical devices.IMPORTANCEWe sought to demonstrate that bacterial biofilms are reservoirs for unknown molecules that antagonize bacterial adhesion. The use of natural strains representative ofEscherichia colispecies biodiversity showed that nonbiocidal antiadhesion polysaccharides are frequently found in mature biofilm extracts (bacterium-free suspensions which contain soluble molecules produced within the biofilm). Release of an antiadhesion polysaccharide confers a competitive advantage upon the producing strain against clinically relevant pathogens such asStaphylococcus aureus. Hence, exploring the biofilm environment provides a better understanding of bacterial interactions within complex communities and could lead to improved control of pathogen colonization.

scholarly journals Evidence for Recent Acquisition and Successful Transmission ofblaCTX-M-15in Salmonella enterica in South Korea

2013 ◽  
Vol 57 (5) ◽  
pp. 2383-2387 ◽  
Author(s):  
Min-Su Kang ◽  
Yong-Kuk Kwon ◽  
Jae-Young Oh ◽  
Mi-Jin Kim ◽  
Douglas R. Call ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
South Korea ◽  
Salmonella Enterica ◽  
Content Type ◽  
Successful Transmission ◽  
Resistance Phenotype ◽  
E Coli ◽  
Genetic Structures

ABSTRACTWe identified two distinctblaCTX-M-bearing and five distinctblaCMY-2-bearing genetic structures located on plasmids fromSalmonella entericaandEscherichia coliisolates (n= 35) collected from chickens in South Korea. AllSalmonellaplasmids shared a common replicon,blaCTX-M-15transposon, and core resistance phenotype, whileE. coli blaCTX-M-15plasmids included four distinct replicons.

Investigation of the microbial quality and the occurrence of Shiga-like-toxin-producingEscherichia coliand methicillin resistantStaphylococcus aureusin traditional cheeses produced in northwest of Iran

2019 ◽  
Vol 49 (3) ◽  
pp. 407-417 ◽  
Author(s):  
Mohammad Yousefi ◽  
Maryam Farshidi ◽  
Mahmood Alizadeh Sani ◽  
Laleh Payahoo ◽  
Ali Ehsani
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Microbial Quality ◽  
Content Type ◽  
Total Coliforms ◽  
E Coli ◽  
Maximum Value ◽  
Northwest Of Iran ◽  
Pcr Method

PurposeThis paper aims to evaluate the microbial quality of some traditional cheese samples (sheep, cow and koopeh cheeses) consumed in northwest of Iran, and to detect Shiga-like-toxin-producingEscherichia coli(STEC) and methicillin-resistantStaphylococcus aureus(MRSA) in cheese samples by polymerase chain reaction (PCR) method.Design/methodology/approachAlmost half of the project was based on counting the population of Staphylococcus aureus, total coliforms, Escherichia coli, and total aerobic mesophilic bacteria, also the other section was related to the isolation and the detection of the STEC and MRSA in cheese samples. The findings were compared with standard maximum and threshold values.FindingsThe results revealed that 36.99, 30.14 and 100% of cheeses exceeded the standard threshold value ofE. coli(102), total coliforms (104) andS. aureus(102). However, total coliforms, in any of the cheese samples examined, did not reach the maximum value and only 24.66% of samples exceeded the maximum value ofE. coli. Also, no significant difference (p> 0.05) in counts of each bacterial group examined in sheep, cow and koopeh cheeses was observed. The colony PCR method demonstrated the existence of 19 MRSA and 2 STEC isolates.Originality/valueThis research showed a general overview of the bacterial quality of cheeses in northwest of Iran.

scholarly journals No Decrease in Susceptibility to NVC-422 in Multiple-Passage Studies with Methicillin-Resistant Staphylococcus aureus, S. aureus, Pseudomonas aeruginosa, and Escherichia coli

2012 ◽  
Vol 56 (5) ◽  
pp. 2753-2755 ◽  
Author(s):  
Louisa D'Lima ◽  
Lisa Friedman ◽  
Lu Wang ◽  
Ping Xu ◽  
Mark Anderson ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Fusidic Acid ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Cross Resistance ◽  
Methicillin Resistant ◽  
Content Type ◽  
E Coli ◽  
Resistant Strains

ABSTRACTTwenty-five serial passages ofEscherichia coli,Pseudomonas aeruginosa, andStaphylococcus aureusand 50 passages of methicillin-resistantStaphylococcus aureusresulted in no significant increase in NVC-422 MICs, while ciprofloxacin MICs increased 256-fold forE. coliand 32-fold forP. aeruginosaandS. aureus. Mupirocin, fusidic acid, and retapamulin MICs for MRSA increased 64-, 256-, and 16-fold, respectively. No cross-resistance to NVC-422 was observed with mupirocin-, fusidic acid-, and retapamulin-resistant strains.

scholarly journals mcr-9, an Inducible Gene Encoding an Acquired Phosphoethanolamine Transferase in Escherichia coli, and Its Origin

2019 ◽  
Vol 63 (9) ◽  
Author(s):  
Nicolas Kieffer ◽  
Guilhem Royer ◽  
Jean-Winoc Decousser ◽  
Anne-Sophie Bourrel ◽  
Mattia Palmieri ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Lipid A ◽  
Acquired Resistance ◽  
Regulatory System ◽  
Amino Acid Identity ◽  
Gene Encoding ◽  
Content Type ◽  
E Coli ◽  
K 12 ◽  
A Minor

ABSTRACT The plasmid-located mcr-9 gene, encoding a putative phosphoethanolamine transferase, was identified in a colistin-resistant human fecal Escherichia coli strain belonging to a very rare phylogroup, the D-ST69-O15:H6 clone. This MCR-9 protein shares 33% to 65% identity with the other plasmid-encoded MCR-type enzymes identified (MCR-1 to -8) that have been found as sources of acquired resistance to polymyxins in Enterobacteriaceae. Analysis of the lipopolysaccharide of the MCR-9-producing isolate revealed a function similar to that of MCR-1 by adding a phosphoethanolamine group to lipid A and subsequently modifying the structure of the lipopolysaccharide. However, a minor impact on susceptibility to polymyxins was noticed once the mcr-9 gene was cloned and produced in an E. coli K-12-derived strain. Nevertheless, we showed here that subinhibitory concentrations of colistin induced the expression of the mcr-9 gene, leading to increased MIC levels. This inducible expression was mediated by a two-component regulatory system encoded by the qseC and qseB genes located downstream of mcr-9. Genetic analysis showed that the mcr-9 gene was carried by an IncHI2 plasmid. In silico analysis revealed that the plasmid-encoded MCR-9 shared significant amino acid identity (ca. 80%) with the chromosomally encoded MCR-like proteins from Buttiauxella spp. In particular, Buttiauxella gaviniae was found to harbor a gene encoding MCR-BG, sharing 84% identity with MCR-9. That gene was neither expressed nor inducible in its original host, which was fully susceptible to polymyxins. This work showed that mcr genes may circulate silently and remain undetected unless induced by colistin.

scholarly journals Feeding the Probiotic Enterococcus faecium Strain NCIMB 10415 to Piglets Specifically Reduces the Number of Escherichia coli Pathotypes That Adhere to the Gut Mucosa

2013 ◽  
Vol 79 (24) ◽  
pp. 7896-7904 ◽  
Author(s):  
Carmen Bednorz ◽  
Sebastian Guenther ◽  
Kathrin Oelgeschläger ◽  
Bianca Kinnemann ◽  
Robert Pieper ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Enterococcus Faecium ◽  
Specific Effect ◽  
Control Group ◽  
Content Type ◽  
Probiotic Group ◽  
E Coli ◽  
Gut Mucosa ◽  
A Minor ◽  
Gut Microorganisms

ABSTRACTFeed supplementation with the probioticEnterococcus faeciumfor piglets has been found to reduce pathogenic gut microorganisms. SinceEscherichia coliis among the most important pathogens in pig production, we performed comprehensive analyses to gain further insight into the influence ofE. faeciumNCIMB 10415 on porcine intestinalE. coli. A total of 1,436E. colistrains were isolated from three intestinal habitats (mucosa, digesta, and feces) of probiotic-supplemented and nonsupplemented (control) piglets.E. colibacteria were characterized via pulsed-field gel electrophoresis (PFGE) for clonal analysis. The high diversity ofE. coliwas reflected by 168 clones. Multilocus sequence typing (MLST) was used to determine the phylogenetic backgrounds, revealing 79 sequence types (STs). Pathotypes ofE. coliwere further defined using multiplex PCR for virulence-associated genes. While these analyses discerned only a few significant differences in theE. colipopulation between the feeding groups, analyses distinguishing clones that were uniquely isolated in either the probiotic group only, the control group only, or both groups (shared group) revealed clear effects at the habitat level. Interestingly, extraintestinal pathogenicE. coli(ExPEC)-typical clones adhering to the mucosa were significantly reduced in the probiotic group. Our data show a minor influence ofE. faeciumon the overall population ofE. coliin healthy piglets. In contrast, this probiotic has a profound effect on mucosa-adherentE. coli. This finding further substantiates a specific effect ofE. faeciumstrain NCIMB 10415 in piglets against pathogenicE. coliin the intestine. In addition, these data question the relevance of data based on sampling fecalE. colionly.

scholarly journals In Vitro Activity of Fenticonazole against Candida and Bacterial Vaginitis Isolates Determined by Mono- or Dual-Species Testing Assays

2019 ◽  
Vol 63 (7) ◽  
Author(s):  
Maurizio Sanguinetti ◽  
Emilia Cantón ◽  
Riccardo Torelli ◽  
Fabio Tumietto ◽  
Ana Espinel-Ingroff ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Candida Glabrata ◽  
Candida Parapsilosis ◽  
Bacterial Species ◽  
In Vitro Activity ◽  
Content Type ◽  
E Coli ◽  
Time Kill

ABSTRACT We determined the in vitro activity of fenticonazole against 318 vaginitis isolates of Candida and bacterial species and selected 28 isolates for time-kill studies. At concentrations equal to 4× MIC, fenticonazole reached the 99.9% killing endpoint by ∼10 h for Staphylococcus aureus, Streptococcus agalactiae, and Escherichia coli and by ∼17 h for Candida albicans and Candida parapsilosis; and at concentrations equal to 8× MIC, by ∼19 and ∼20 h for Candida glabrata and Candida tropicalis, respectively. At concentrations equal to 2× MIC, fenticonazole required ∼20 h to reach the above endpoint against C. albicans in mixed culture with S. aureus, S. agalactiae, or E. coli versus ∼17 h against C. albicans in pure culture. Supra-MICs are achievable in topically treated patients’ vaginal surfaces.

scholarly journals Draft Genome Sequences of Enterohemorrhagic Escherichia coli O103:H2 Strains Isolated from Feces of Feedlot Cattle

2017 ◽  
Vol 5 (19) ◽  
Author(s):  
Lance W. Noll ◽  
Jay N. Worley ◽  
Xun Yang ◽  
Pragathi B. Shridhar ◽  
Jianfa Bai ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Draft Genome ◽  
Genomic Analysis ◽  
Feedlot Cattle ◽  
Enterohemorrhagic Escherichia Coli ◽  
Genome Sequences ◽  
Content Type ◽  
E Coli ◽  
Virulence Potential ◽  
A Minor

ABSTRACT The enterohemorrhagic pathotype represents a minor proportion of the Escherichia coli O103 strains shed in the feces of cattle. We report here the genome sequences of 43 strains of enterohemorrhagic E. coli (EHEC) O103:H2 isolated from feedlot cattle feces. The genomic analysis will provide information on the genetic diversity and virulence potential of bovine EHEC O103.

scholarly journals Draft Genome Sequences of Enteropathogenic Escherichia coli O103 Strains Isolated from Feces of Feedlot Cattle

2017 ◽  
Vol 5 (21) ◽  
Author(s):  
Lance W. Noll ◽  
Jay N. Worley ◽  
Xun Yang ◽  
Pragathi B. Shridhar ◽  
Jianfa Bai ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Genetic Diversity ◽  
Draft Genome ◽  
Feedlot Cattle ◽  
Enteropathogenic Escherichia Coli ◽  
Genome Sequences ◽  
Content Type ◽  
E Coli ◽  
Virulence Potential ◽  
A Minor

ABSTRACT Enteropathogenic Escherichia coli (EPEC) pathotype represents a minor proportion of E. coli O103 strains shed in the feces of feedlot cattle. The draft genome sequences of 13 strains of EPEC O103 are reported here. The availability of the genome sequences will help in the assessment of genetic diversity and virulence potential of bovine EPEC O103.

scholarly journals Antimicrobial Activities of Ceftaroline and Comparator Agents against Bacterial Organisms Causing Bacteremia in Patients with Skin and Skin Structure Infections in U.S. Medical Centers, 2008 to 2014

2016 ◽  
Vol 60 (4) ◽  
pp. 2558-2563 ◽  
Author(s):  
Helio S. Sader ◽  
Robert K. Flamm ◽  
Rodrigo E. Mendes ◽  
David J. Farrell ◽  
Ronald N. Jones
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Klebsiella Pneumoniae ◽  
Antimicrobial Susceptibility ◽  
Antimicrobial Activities ◽  
Methicillin Resistant ◽  
Content Type ◽  
Skin Structure ◽  
E Coli ◽  
Medical Centers

ABSTRACTWe evaluated the antimicrobial susceptibility of 1,454 organisms consecutively collected from patients with bacteremia associated with skin and skin structure infections. The most common organisms obtained wereStaphylococcus aureus(670 organisms [46.1%]),Escherichia coli(200 organisms [13.8%]), β-hemolytic streptococci (βHS) (138 organisms [9.5%]), andKlebsiella pneumoniae(109 organisms [7.5%]). The susceptibility rates for ceftaroline were 97.9% forS. aureus(95.9% among methicillin-resistantS. aureus[MRSA]), 100.0% for βHS, 86.5% forE. coli, and 89.0% forK. pneumoniae. Ceftaroline and tigecycline provided the best overall coverage.

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