Operational culture conditions determinate benzalkonium chloride resistance in L. monocytogenes-E. coli dual species biofilms

A previous study [Ferson, Wray and Fisher (1996) Mol. Microbiol. 22, 693–701] has shown that transposon-mediated disruption of a protein 47% identical to the Escherichia coli GABA (4-aminobutyrate) transporter abolishes the ability of nitrogen-limited culture conditions to induce expression of a GABA transport activity in Bacillus subtilis. Here it is demonstrated directly that the B. subtilis GABA permease (gabP) gene can complement the transport defect in the gabP-negative E. colistrain. Unexpectedly, the ligand-recognition profile of the B. subtilis GabP was found to differ substantially from that of the highly homologous E. coli GabP. Unlike the E. coli GabP, the B. subtilis GabP: (i) exhibits approx. equal preference for the 3-carbon (β-alanine, Km = 9.6 µM) and the 4-carbon (GABA, Km = 37 µM) amino acids, and (ii) resists inhibition by bulky, conformationally constrained compounds (e.g. nipecotic acid, guvacine), which are active against GABA transporters from brain. The present study shows additionally that the B. subtilis GabP can translocate several open-chain GABA analogues (3-aminobutyrate, 3-aminopropanoate, cis-4-aminobutenoate) across the membrane via counterflow against [3H]GABA. Thus, consistent with the idea that the ligand-recognition domain of the B. subtilis GabP is less spacious than that of the close homologue from E. coli, the former exhibits more stringent requirements than the latter for substrate recognition and translocation. These distinct functional characteristics of the E. coli and B. subtilis GABA transporters provide a basis by which to identify ligand-recognition domains within the amine-polyamine-choline transporter superfamily.

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Comparative Analysis of Genetic Determinants Encoding Cadmium, Arsenic, and Benzalkonium Chloride Resistance in Listeria monocytogenes of Human, Food, and Environmental Origin

Frontiers in Microbiology ◽

10.3389/fmicb.2020.599882 ◽

2021 ◽

Vol 11 ◽

Author(s):

Tereza Gelbicova ◽

Martina Florianova ◽

Lucie Hluchanova ◽

Alžběta Kalova ◽

Kristýna Korena ◽

...

Keyword(s):

Listeria Monocytogenes ◽

Benzalkonium Chloride ◽

Extensive Study ◽

Whole Genome Sequencing Data ◽

Production Environment ◽

Sequencing Data ◽

Genetic Determinants ◽

Cadmium Resistance ◽

Chloride Resistance ◽

Genes Encoding

Environmental adaptation of Listeria monocytogenes is a complex process involving various mechanisms that can contribute to their survival in the environment, further spreading throughout the food chain and the development of listeriosis. The aim of this study was to analyze whole-genome sequencing data in a set of 270 strains of L. monocytogenes derived from human listeriosis cases and food and environmental sources in order to compare the prevalence and type of genetic determinants encoding cadmium, arsenic, and benzalkonium chloride resistance. Most of the detected genes of cadmium (27.8%), arsenic (15.6%), and benzalkonium chloride (7.0%) resistance were located on mobile genetic elements, even in phylogenetically distant lineages I and II, which indicates the possibility of their horizontal spread. Although no differences were found in the prevalence of these genes between human and food strains, they have been detected sporadically in strains from the environment. Regarding cadmium resistance genes, cadA1C1_Tn5422 predominated, especially in clonal complexes (CCs) 121, 8, and 3 strains. At the same time, qacH_Tn6188-encoding benzalkonium chloride resistance was most frequently detected in the genome of CC121 strains. Genes encoding arsenic resistance were detected mainly in strains CC2 (located on the chromosomal island LGI2) and CC9 (carried on Tn554). The results indicated a relationship between the spread of genes encoding resistance to cadmium, arsenic, and benzalkonium chloride in certain serotypes and CCs and showed the need for a more extensive study of L. monocytogenes strains to better understand their ability to adapt to the food production environment.

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Evaluation of bacterial proliferation with a microfluidic-based device: Antibiochip

10.1101/792358 ◽

2019 ◽

Author(s):

Valentina Gallo ◽

Alessia Ruiba ◽

Massimo Zanin ◽

Paolo Begnamino ◽

Sabina Ledda ◽

...

Keyword(s):

Laboratory Medicine ◽

Culture Conditions ◽

Inhibition Of Proliferation ◽

Standard Methods ◽

E Coli ◽

Bacterial Proliferation ◽

Microbial Cultures ◽

Novel Approach ◽

Microbial Strains ◽

The Relationship

AbstractThe measurement of the proliferation (and the relevant inhibition of proliferation) of microbes is used in different settings, from industry to laboratory medicine. Thus, in this study, the capacity of the Antibiochip (ELTEK spa), a microfluidic-based device, to measure the amount of E. coli in certain culture conditions, was evaluated. An Antibiochip is composed of V-shaped microchannels, and the amount of microparticles (such as microbes) is measured by the surface of the pellet after centrifugation. In the present study, different geometries, volumes and times were analyzed. When the best conditions were identified, serial dilutions of microbial cultures were tested to validate the linearity of the results. Then, with the use of wild E. coli strains isolated from medical samples, the relationship between bacterial susceptibility to antibiotics (gentamicin, amikacin and ceftriaxone) measured by standard methods and that measured by the Antibiochip was evaluated. In this report, the good quality performances of the methods, their linearity and the capacity to identify susceptible microbial strains after 60 minutes of incubation are shown. These results represent a novel approach for ultrarapid antibiograms in clinics.

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Detection of benzalkonium chloride resistance in community environmental isolates of staphylococci

Journal of Medical Microbiology ◽

10.1099/jmm.0.073072-0 ◽

2014 ◽

Vol 63 (5) ◽

pp. 735-741 ◽

Cited By ~ 14

Author(s):

Gui-Xin He ◽

Michael Landry ◽

Huizhong Chen ◽

Conner Thorpe ◽

Dennis Walsh ◽

...

Keyword(s):

Antimicrobial Resistance ◽

Resistance Gene ◽

Environmental Samples ◽

Benzalkonium Chloride ◽

Cetyltrimethylammonium Bromide ◽

Gene Analysis ◽

Environmental Isolates ◽

Chloride Resistance ◽

Resistant Strains

We isolated a total of 653 strains from 64 community environmental samples in Massachusetts, USA. Among these isolates, 9.65 % (63 strains) were benzalkonium chloride (BC)-resistant staphylococci. All BC-resistant strains were collected from surfaces upon which antibacterial wipes or antibacterial sprays containing 0.02–0.12 % BC had frequently been used in the fitness centres. However, isolates from surfaces upon which antibacterial wipes or antibacterial sprays had not been used were all sensitive to BC. All BC-resistant strains were also resistant to erythromycin, penicillin and ampicillin. In addition, 51 strains showed resistance to cetyltrimethylammonium bromide (CTAB), 15 strains showed resistance to chloramphenicol, 12 strains showed resistance to ciprofloxacin and four strains showed resistance to meticillin. Resistance gene analysis demonstrated that 41 strains contained qacA/B, 30 strains had qacC, 25 strains contained qacG, 16 strains had qacH and eight strains contained qacJ. These data indicate that application of BC is associated with environmental staphylococcal antimicrobial resistance.

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Impact of Preinoculation Culture Conditions on the Behavior of Escherichia coli O157:H7 Inoculated onto Romaine Lettuce (Lactuca sativa) Plants and Cut Leaf Surfaces

Journal of Food Protection ◽

10.4315/0362-028x-72.7.1553 ◽

2009 ◽

Vol 72 (7) ◽

pp. 1553-1559 ◽

Cited By ~ 24

Author(s):

CHRISTOPHER G. THEOFEL ◽

LINDA J. HARRIS

Keyword(s):

Escherichia Coli ◽

High Standard ◽

Culture Conditions ◽

Escherichia Coli O157 ◽

Late Stationary Phase ◽

Romaine Lettuce ◽

Preparation Methods ◽

E Coli ◽

Leaf Surfaces ◽

Inoculum Preparation

Inoculum preparation methods can impact growth or survival of organisms inoculated into foods, thus complicating direct comparison of results among studies. The objective of this study was to evaluate preinoculation culture preparation for impact on Escherichia coli O157:H7 inoculated onto leaves of romaine lettuce plants and cut leaf surfaces. E. coli O157:H7 was grown quiescently or shaken at 15, 25, or 37°C to different growth phases in tryptic soy or M9 minimal salts broth or agar. Cells were harvested, washed, and suspended in 0.1% peptone, Milli Q water, or well water and refrigerated for 0 or 18 h. Prepared inoculum was spotted onto cut romaine lettuce (10 μl; 3 × 104 CFU/10 g) or onto romaine lettuce plants (20 μl; 3 × 106 CFU per leaf). Cut lettuce was sealed in 100-cm2 bags (made from a commercial polymer film) and incubated at 5 or 20°C. Lettuce plants were held at 23°C for 24 h. For all tested conditions, levels of E. coli O157:H7 increased at 20°Concut lettuce and decreased on cut lettuce stored at 5°C or on leaves of lettuce plants. At 20°C, preinoculation culture conditions had little impact on growth of E. coli O157:H7 on cut lettuce. However, survival at 5°C was significantly better (P < 0.05) for cultures grown at 15 or 37°C in minimal medium and to late stationary phase. Impact of preinoculation handling on survival on lettuce plants was less clear due to relatively high standard deviations observed among samples.

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Regulation of P-Fimbrial Phase Variation Frequencies in Escherichia coli CFT073

Infection and Immunity ◽

10.1128/iai.01989-06 ◽

2007 ◽

Vol 75 (7) ◽

pp. 3325-3334 ◽

Cited By ~ 30

Author(s):

Nicola Holden ◽

Makrina Totsika ◽

Lynn Dixon ◽

Kirsteen Catherwood ◽

David L. Gally

Keyword(s):

Escherichia Coli ◽

Phase Transition ◽

Regulatory Region ◽

Phase Variation ◽

Culture Conditions ◽

Host Tissue ◽

Clinical Isolates ◽

E Coli ◽

K 12 ◽

First Time

ABSTRACT Adherence of uropathogenic Escherichia coli to host tissue is required for infection and is mediated by fimbriae, such as pyelonephritis-associated pili (Pap). Expression of P fimbriae is regulated by phase variation, and to date, phase transition frequencies have been measured only for pap regulatory region constructs integrated into the E. coli K-12 chromosome. The aim of this work was to measure P phase transition frequencies in clinical isolates for the first time, including frequencies for the sequenced strain E. coli CFT073. P fimbriation and associated phase transition frequencies were measured for two E. coli clinical isolates and compared with levels for homologous pap constructs in E. coli K-12. Fimbriation and off-to-on transition frequencies were always higher in the clinical isolate. It was concluded that the regulatory inputs controlling papI expression are likely to be different in E. coli CFT073 and E. coli K-12 as (i) phase variation could be stimulated in E. coli K-12 by induction of papI and (ii) the level of expression of a papI::gfp + fusion was higher in E. coli CFT073 than in E. coli K-12. Furthermore, phase transition frequencies for the two E. coli CFT073 pap clusters were shown to be different depending on the culture conditions, indicating that there is a hierarchy of expression depending on signal inputs.

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Mechanical Stimuli Affect E. Coli Heat Stable Enterotoxin (ST)-Cyclic GMP Signaling in a Human Enteroid Intestine-Chip Diarrhea Model

10.1101/772608 ◽

2019 ◽

Author(s):

Laxmi Sunuwar ◽

Jianyi Yin ◽

Magdalena Kasendra ◽

Katia Karalis ◽

James Kaper ◽

...

Keyword(s):

Epithelial Cell ◽

Animal Studies ◽

Culture Conditions ◽

Cyclic Stretch ◽

Mechanical Forces ◽

Mechanical Stimuli ◽

E Coli ◽

Cell Height ◽

Heat Stable ◽

Static Conditions

ABSTRACTModeling host-pathogen interactions with human intestinal epithelia using enteroid monolayers on permeable supports (such as Transwells) represents an alternative to animal studies or use of colon cancer-derived cell lines. However, the static monolayer model does not expose epithelial cells to mechanical forces normally present in the intestine, including luminal flow and serosal blood flow (shear force) or peristaltic forces. To determine the contribution of mechanical forces in the functional response of human small intestine to a pathogen virulence factor, human jejunal enteroids were cultured as monolayers in microengineered fluidic-based Organ-Chips (Intestine-Chips), exposed to enterotoxigenic E. coli heat-stable enterotoxin A (ST), and evaluated under conditions of static fluid, apical and basolateral flow, and flow plus repetitive stretch. Application of flow increased epithelial cell height, transcription of the cyclic nucleotide transporting protein MRP4, and apical and basolateral secretion of cGMP under baseline, unstimulated conditions. Addition of ST under flow conditions increased apical and basolateral secretion of cGMP relative to static conditions, but did not enhance intracellular cGMP accumulation. Cyclic stretch did not have any significant effect beyond that contributed by flow. This study demonstrates that fluid flow application initiates changes in intestinal epithelial cell characteristics relative to static culture conditions under both baseline conditions and with exposure to ST enterotoxin, and suggests that further investigations of application of these mechanical forces will provide insights into physiology and pathophysiology that more closely resembles intact intestine than study under static conditions.

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Effects of biocide exposure on P. Aeruginosa, E. coli and A. Baumannii complex isolates from hospital and household environments

Infectio ◽

10.22354/in.v21i4.687 ◽

2017 ◽

Vol 21 (4) ◽

Author(s):

Daniel Felipe Vásquez-Giraldo ◽

Gerardo Andrés Libreros-Zúñiga ◽

María Del Pilar Crespo-Ortiz

Keyword(s):

Escherichia Coli ◽

Benzalkonium Chloride ◽

Inhibitory Concentration ◽

Minimum Bactericidal Concentration ◽

Multidrug Resistant ◽

Environmental Isolates ◽

E Coli ◽

Acinetobacter Baumannii Complex ◽

Cleaning And Disinfection ◽

Reference Strains

Background: Bacterial responses to biocide exposure and its effects on survival and persistence remain to be studied in greater detail.Aim: To analyse the viability and survival of environmental isolates from household and hospital settings after biocide exposure.Methods: The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of chlorhexidine (CHxG), benzalkonium chloride (BAC) and triclosan (TC) were determined in isolates of Pseudomonas aeruginosa, Acinetobacter baumannii complex and Escherichia coli collected from hospital and households environments. Viability was monitored after exposure and removal of biocides using agar cultures and flow cytometry.Findings: P. aeruginosa isolates showed greater tolerance for all biocides tested whereas A. baumannii complex and E. coli were less tolerant.When compared with reference strains, biocide tolerance was up to 8 to 13-fold higher for TC and BAC respectively. Flow cytometry showed that biocide exposure may induce viable but non-growing states in P. aeruginosa and E. coli isolates before becoming fully replicative. Changes in the susceptibility profile in one isolate of A. baumannii complex were observed after biocide exposure.Discussion: Bacteria isolates from hospital and households were able to recover after biocide exposure at bactericidal concentrations favouring persistence and spread of biocide-tolerant strains. This study reinforces that cleaning compliance should be monitored by non-culture based tests. Novel formulations in cleaning and disinfection protocols should be revisited in hospitals harbouring P. aeruginosa and A. baumannii multidrug resistant isolates.

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Influence of Culture Conditions on Expression of the 40-Kilodalton Porin Protein of Vibrio anguillarum Serotype O2

Applied and Environmental Microbiology ◽

10.1128/aem.64.1.138-146.1998 ◽

1998 ◽

Vol 64 (1) ◽

pp. 138-146 ◽

Cited By ~ 13

Author(s):

Michelle L. Davey ◽

Robert E. W. Hancock ◽

Lucy M. Mutharia

Keyword(s):

Bacterial Species ◽

Vibrio Anguillarum ◽

Immunoblot Analysis ◽

Culture Conditions ◽

Ionic Concentration ◽

Antigenic Determinants ◽

E Coli ◽

Porin Protein ◽

Outer Membrane Porin ◽

Terminal Amino

ABSTRACT Vibrio anguillarum serotype O2 strains express a 40-kDa outer membrane porin protein. Immunoblot analysis revealed that antigenic determinants of the V. anguillarum O2 40-kDa porin were conserved within bacterial species of the genusVibrio. The relative amounts of the V. anguillarum O2 40-kDa porin were enhanced by growth of V. anguillarum O2 in CM9 medium containing 5 to 10% sucrose or 0.1 to 0.5 M NaCl. In contrast, the levels of the porin were significantly reduced when cells were grown at 37°C, and a novel 60-kDa protein was also observed. However, the osmolarity or ionic concentration of the growth medium did not influence expression of the 60-kDa protein. Growth in medium containing greater than 0.6 mM EDTA reduced production of the V. anguillarum O2 40-kDa porin and enhanced levels of a novel 19-kDa protein. Thus, expression of the V. anguillarum O2 40-kDa porin was osmoregulated and possibly coregulated by temperature. The N-terminal amino acid sequence of theV. anguillarum O2 40-kDa protein and the effect of environmental factors on the cellular levels of the porin suggested that the V. anguillarum O2 40-kDa porin was functionally similar to the OmpC porin of Escherichia coli. However, pore conductance assays revealed that the V. anguillarum O2 40-kDa porin was a general diffusion porin with a pore size in the range of that of the OmpF porin of E. coli.

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Clinical Application of Silver Nanoparticles Coated by Benzalkonium Chloride

Coatings ◽

10.3390/coatings11111382 ◽

2021 ◽

Vol 11 (11) ◽

pp. 1382

Author(s):

Shakeel Ahmed Ansari ◽

Asim Muhammed Alshanberi

Keyword(s):

Silver Nanoparticles ◽

Surface Modification ◽

Benzalkonium Chloride ◽

Experimental Conditions ◽

E Coli ◽

Neem Leaves ◽

Potential Applications ◽

Research Findings ◽

Bioactive Agents ◽

Biomedical Fields

The present study investigates the surface modification of AgNPs (synthesized by neem leaves) by benzalkonium chloride (BAC). It was observed that 22 × 109 CFU were formed at 0.25 mM AgNPs concentration. However, it was reduced to 14 × 109 CFU for BAC-coated AgNPs at similar experimental conditions. The enzymatic activity of β-glucosidase was significantly enhanced from 0.0625 mM to 0.5 mM concentration of AgNPs, as well as BAC–AgNPs. However, there was no further change of activity beyond this concentration. ZOI of AgNPs and BAC–AgNPs was measured against E. coli, B. subtilis, P. aeruginosa, and S pneumoniae at 0.25 mM and 0.50 mM concentrations of these bioactive agents. ZOI was 3.45 cm and 3.56 cm for AgNPs and BAC–AgNPs at 0.25 mM of these bioactive agents, respectively, against E. coli. However, these values were 4.28 cm and 4.40 cm, respectively, against B. subtilis. ZOI was obtained at 3.36 cm and 3.47 cm, respectively, against P. aeruginosa under similar experimental concentrations. However, ZOI was achieved at 3.44 cm and 3.62 cm, respectively, against S. pneumonia, under similar experimental conditions. Hence, such research findings can be exploited for potential applications in numerous environmental and biomedical fields.

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