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Molina, Pablo M; Parma, A; Sanz, Marcelo E.

doi:10.1186/1471-2180-3-17

Cited by 30 publications

(11 citation statements)

References 19 publications

(13 reference statements)

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“…On all the tested surfaces in MM9 media the cytoplasmic pH decreases slightly (from 5/17 pH 8.38 to 7.78) in the course of the experiment, and the behaviour changes in LB medium, where cytoplasmic pH starts at pH 8.29 and increases over the observation time to pH 8.43. The result is not unexpected as metabolic byproducts have been demonstrated to influence E. coli's cytoplasmic pH 49,58,[68][69][70][71] . For example, glucose metabolism mainly produces organic acids as byproducts, such as acetate, lactate, formate, succinate etc.…”

Section: Discussionmentioning

confidence: 89%

“…These organic acids are capable of crossing the inner membrane in their uncharged form dissociating in the cytoplasm, which causes full or partial collapse of the pH gradient across the membrane 49,58,69 . In the case of LB medium, the alkalinisation of the media due to E. coli's metabolism has been reported and attributed to the release of the amine-containing compounds 70,71 .…”

Section: Discussionmentioning

confidence: 99%

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Comparison ofEscherichia colisurface attachment methods for single-cell,in vivomicroscopy

Wang¹,

Krasnopeeva

Lin³

et al. 2019

Preprint

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For in vivo, single-cell imaging bacterial cells are commonly immobilised via physical confinement or surface attachment. Different surface attachment methods have been used both for atomic force and optical microscopy (including super resolution), and some have been reported to affect bacterial physiology. However, a systematic comparison of the effects these attachment methods have on the bacterial physiology is lacking. Here we present such a comparison for bacterium Escherichia coli, and assess the growth rate, size and intracellular pH of cells growing attached to different, commonly used, surfaces. We demonstrate that E. coli grow at the same rate, length and internal pH on all the tested surfaces when in the same growth medium. The result suggests that tested attachment methods can be used interchangeably when studying E. coli physiology.

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Section: Discussionmentioning

confidence: 89%

Section: Discussionmentioning

confidence: 99%

Comparison ofEscherichia colisurface attachment methods for single-cell,in vivomicroscopy

Wang¹,

Krasnopeeva

Lin³

et al. 2019

Preprint

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“…On all the tested surfaces in MM9 media the cytoplasmic pH decreases slightly in the course of the experiment, and the behaviour changes in LB medium, where cytoplasmic pH increases over the observation time. The result is not unexpected, as metabolic byproducts have been demonstrated to influence E. coli's cytoplasmic pH 63,72,[79][80][81][82] . For example, glucose metabolism mainly produces organic acids as byproducts, such as acetate, lactate, formate, succinate etc.…”

Section: Discussionmentioning

confidence: 91%

“…These organic acids are capable of crossing the inner membrane in their uncharged form dissociating in the cytoplasm, which causes full or partial collapse of the pH gradient across the membrane 63,72,80 . In the case of LB medium, the alkalinisation of the media due to E. coli's metabolism has been reported and attributed to the release of the amine-containing compounds 81,82 . In both cases, however, the change does not exceed 0.6 pH units (an equivalent of 35.5 mV of proton motive force).…”

Section: Discussionmentioning

confidence: 99%

Comparison of Escherichia coli surface attachment methods for single-cell microscopy

Wang

Krasnopeeva

Lin

et al. 2019

Sci Rep

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for in vivo, single-cell imaging bacterial cells are commonly immobilised via physical confinement or surface attachment. Different surface attachment methods have been used both for atomic force and optical microscopy (including super resolution), and some have been reported to affect bacterial physiology. However, a systematic comparison of the effects these attachment methods have on the bacterial physiology is lacking. Here we present such a comparison for bacterium Escherichia coli, and assess the growth rate, size and intracellular pH of cells growing attached to different, commonly used, surfaces. We demonstrate that E. coli grow at the same rate, length and internal pH on all the tested surfaces when in the same growth medium. The result suggests that tested attachment methods can be used interchangeably when studying E. coli physiology. Microscopy has been a powerful tool for studying biological processes on the cellular level, ever since the first discovery of microorganisms by Antonie van Leeuwenhoek back in 17th century 1. Recently employed single-cell imaging allowed scientists to study population diversity 2 , physiology 3 , sub-cellular features 4 , and protein dynamics 5 in real-time. Single cell imaging of bacteria is particularly dependent on immobilisation, as majority of bacteria are small in size and capable of swimming. Immobilisation methods vary depending on the application, but typically fall into one of the two categories: use of physical confinement or attachment to the surface via specific molecules. The former group includes microfluidic platforms capable of mechanical trapping 6,7 , where some popular examples include the "mother machine" 8 , CellASIC 9 or MACS 10 devices, and porous membranes such as agarose gel pads 2,11-13. Physical confinement methods, while higher in throughput, can have drawbacks. For example, agarose gel pads do not allow fast medium exchange, and when mechanically confining bacteria the choice of enclosure dimensions should be done carefully in order to avoid influencing the growth and morphology with mechanical forces 14. Furthermore, mechanically confined bacteria cannot be used for studies of bacterial motility or energetics via detection of bacteria flagellar motor rotation 15-17. Chemical attachment methods rely on the interaction of various adhesive molecules, deposited on the cover glass surface, with the cell itself. Adhesion can be a result of electrostatic (polyethylenimine (PEI) 18,19 , poly-L-lysine (PLL) 15,17,19) or covalent interactions (3-aminopropyltriethoxysilane (APTES) 19), or a combination, such as with polyphenolic proteins (Cell-Tak) 19. Time scales on which researchers perform single-cell experiments vary. For example, scanning methods, like atomic force microscopy (AFM) or confocal laser scanning microscopy (CLSM) 19,20 , require enough time to probe each point of the sample, and stochastic approaches of super resolution microscopy (e.g. PALM and STORM) use low activation rate of fluorophores to achieve a single fluorophore localisati...

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“…From the study of Loo et al (2013), thirty-seven (18.5%) vegetable samples were contaminated with Shiga-toxin producing E. coli indicating Shiga-toxin producing E. coli showing higher rate of survival. The survival of several types of Shiga-toxin producing E. coli which are the E. coli O157: H7 and also non-O157: H7 were studied in Argentina (Molina et al, 2003). Several types of Shiga-toxin producing E. coli non-O157 strains were used which were the E. coli O26: H11, O88: H21, O111: H¯, O113: H21, O116: H21, O117: H7, O171: H2 and OX3: H21.…”

Section: Discussionmentioning

confidence: 99%

Prevalence and antibiotic profile of Shiga-toxin producing Escherichia coli and Escherichia coli O157: H7 in beef and buffalo

Kwan¹,

Chang²,

Loo³

et al. 2018

Food Res.

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Shiga-toxin producing Escherichia coli bacteria are well known to be the pathogenic bacteria that cause traveler diarrhea. E. coli O157: H7 from the group of Shiga-toxin producing E. coli cause even severe infection which can lead to fatality for humans. In this study, local beef and Indian buffalo were selected to determine the presence of Shiga-toxin producing E. coli and E. coli O157: H7 using Most Probable Number-Polymerase Chain Reaction (MPN-PCR) method. Among 108 samples, eight (7.41%) samples from local beef and Indian buffalo were detected a positive on E. coli O157: H7 while thirteen (12.04%) samples were detected positive for Shiga-toxin producing E. coli gene. Out of 108 samples, eleven isolates of E. coli O157: H7 were successfully isolated in order to carry out the antibiotic susceptibility test. Shiga-toxin producing E. coli isolates were found susceptible to ceftazidime (100%), moxifloxacin (83.33%), sulphamethoxazole (66.67%), ampicillin (50%), amoxycillin (50%), ciprofloxacin (50%), erythromycin (33.33%) and penicillin G (33.33%). E. coli O157: H7 isolates were susceptible toward erythromycin (100%), ceftazidime (100%), ciprofloxacin (100%) and moxifloxacin (100%), sulphamethoxazole (60%), ampicillin (20%), amoxycillin (20%), and penicillin G (0%). The safety of both local beef and Indian buffalo was challenged by the presence of both Shiga-toxin producing E. coli and E. coli O157: H7. Better and safer ways of removing the pathogen from local beef and Indian buffalo should be researched more deeply.

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Cited by 30 publications

References 19 publications

Comparison ofEscherichia colisurface attachment methods for single-cell,in vivomicroscopy

Comparison ofEscherichia colisurface attachment methods for single-cell,in vivomicroscopy

Comparison of Escherichia coli surface attachment methods for single-cell microscopy

Prevalence and antibiotic profile of Shiga-toxin producing Escherichia coli and Escherichia coli O157: H7 in beef and buffalo

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