Shigella dysenteriae I enterotoxin: proposed role in pathogenesis of shigellosis

1980 ◽  
Vol 239 (5) ◽  
pp. G382-G386 ◽  
Author(s):  
J. R. Mathias ◽  
G. M. Carlson ◽  
J. L. Martin ◽  
R. P. Shields ◽  
S. Formal
Keyword(s):  
Small Intestine ◽  
Action Potentials ◽  
Culture Broth ◽  
Shigella Dysenteriae ◽  
Myoelectric Activity ◽  
Bacterial Strains ◽  
Sterile Culture ◽  
Sterile Saline ◽  
New Zealand White Rabbits ◽  
Potential Complex

Bacterial strains of Shigella dysenteriae I (3818-T and 3818-O) and Shigella enterotoxin altered myoelectric activity of the small intestine in New Zealand White rabbits. These agents were compared with activity caused by sterile culture broth or sterile saline. The altered myoelectric activity was characterized by two distinct complexes: repetitive bursts of action potentials (RBAP), characteristic of invasive strains of bacteria, and the migrating action potential complex (MAPC), characteristic of noninvasive bacteria. RBAP activity was the predominant myoelectric complex observed with S. dysenteriae strain 3818-T, an invader and toxin producer; S. dysenteriae strain 3818-O, a noninvader and toxin producer; and by Shigella enterotoxin. MAPC activity was present but was significantly less in all cases. These studies of the small intestine demonstrate an alteration in myoelectric activity characterized principally by RBAP activity indicative of invasion.

Alteration of myoelectric activity of small intestine by invasive Escherichia coli

1980 ◽  
Vol 238 (1) ◽  
pp. G57-G62
Author(s):  
T. W. Burns ◽  
J. R. Mathias ◽  
J. L. Martin ◽  
G. M. Carlson ◽  
R. P. Shields
Keyword(s):  
Escherichia Coli ◽  
Small Intestine ◽  
Action Potential ◽  
Action Potentials ◽  
Myoelectric Activity ◽  
Ileal Loop ◽  
Discharge Activity ◽  
Electrode Recording ◽  
Proximal Small Intestine ◽  
Potential Complex

Invasive strains of Escherichia coli (4608-58 and TD 213 CL) altered myoelectric activity of the small intestine in New Zealand White rabbits. The altered myoelectric activity had two distinct complex patterns. The first was defined as repetitive bursts of action potentials (RBAPs) that occurred predominantly in infected ligated ileal loops. The RBAP activity is characterized by action potential discharge activity greater than 1.5 s in duration and occurring on three or more successive slow waves on the same electrode recording site. These bursts of action potentials often migrated to adjacent electrode sites. The second complex pattern, defined as the migrating action potential complex (MAPC), occurred predominantly in the uninfected small intestine orad to the ligated ileal loop. The MAPC consists of action potential discharge activity of 2.5 s or longer that propagates aborally over at least two consecutive electrode sites. These studies demonstrated an altered myoelectric pattern, the RBAP, characteristic of invasion within the infected ligated loop. The MAPC, characteristic of noninvasion, was noted in the uninfected proximal small intestine.

Alterations in motor function of the small intestine from intravenous and intraluminal cholecystokinin

1984 ◽  
Vol 247 (6) ◽  
pp. G724-G728
Author(s):  
C. A. Sninsky ◽  
M. M. Wolfe ◽  
J. E. McGuigan ◽  
J. R. Mathias
Keyword(s):  
Small Intestine ◽  
Action Potentials ◽  
Intestinal Motility ◽  
Venous Blood ◽  
Regulatory Peptides ◽  
Similar Rate ◽  
Myoelectric Activity ◽  
Blood Samples ◽  
Portal Venous Blood ◽  
The Individual

Cholecystokinin has been found within the lumen of the gastrointestinal tract; however, its effect on intestinal motility has not been studied. We examined the effect of intraluminal and intravenous infusion of the octapeptide of cholecystokinin (CCK-OP) on myoelectric activity in the intestine of rabbits. CCK-OP was infused intraluminally at 1,000 ng X kg-1 X h-1, and portal venous blood samples were obtained hourly for plasma immunoreactive CCK. CCK-OP was also infused intravenously at a similar rate, and hourly peripheral venous blood samples were obtained for plasma immunoreactive CCK. Myoelectric activity was monitored in a 12-cm ligated ileal segment and the proximal adjacent small intestine after the infusion of intraluminal or intravenous CCK-OP. Intraluminal infusion of CCK-OP caused a significant increase (P less than 0.01) in both migrating action potential complexes (MAPC) and repetitive bursts of action potentials (RBAP) (3.1 +/- 0.8 MAPC/h and 4.6 +/- 1.3 RBAP/h). In contrast, intravenous CCK-OP induced only repetitive bursts of action potentials (8.3 +/- 1.7 RBAP/h, P less than 0.01). In summary, alterations in intestinal motility may vary according to the route of administration of the individual peptide. Furthermore, results from these studies suggest that intraluminal release of regulatory peptides may be important in the modulation of intestinal motility.

Effect of toxigenic Escherichia coli on myoelectric activity of small intestine.

1978 ◽  
Vol 235 (3) ◽  
pp. E311 ◽  
Author(s):  
T W Burns ◽  
J R Mathias ◽  
G M Carlson ◽  
J L Martin ◽  
R P Shields
Keyword(s):  
Escherichia Coli ◽  
Small Intestine ◽  
Culture Filtrate ◽  
Intestinal Motility ◽  
Myoelectric Activity ◽  
E Coli ◽  
Small Intestinal Motility ◽  
Rabbit Small Intestine ◽  
Small Intestinal ◽  
Potential Complex

When exposed to cholera toxin (CT), distal ileal loops of the rabbit small intestine showed an alteration in myoelectric activity. This alteration was defined as the migrating action potential complex (MAPC). The purpose of this study was to determine, using myoelectric recording techniques, the effects of live toxigenic Escherichia coli (TEC) on motility. Live TEC, live nontoxigenic E. coli (NTEC), and culture filtrates of these organisms were studied. Live TEC and its filtrate induced MAPC activity similar to that of CT. Live TEC induced a mean of 3.8 MAPCs/h, significantly greater than induced by live NTEC. TEC filtrate induced a mean of 14.2 MAPCs/h, significantly greater than NTEC filtrate. Heating the TEC filtrate to 100 degrees C before use resulted in a significant decrease of MAPC activity. This experiment demonstrated that live TEC and its culture filtrate altered ileal myoelectric activity. The effect may have been mediated by a heat-labile enterotoxin. This study suggests that alterations in small intestinal motility may be important in the pathogenesis of TEC diarrhea.

Influence of microbial species on small intestinal myoelectric activity and transit in germ-free rats

2001 ◽  
Vol 280 (3) ◽  
pp. G368-G380 ◽  
Author(s):  
Einar Husebye ◽  
Per M. Hellström ◽  
Frank Sundler ◽  
Jie Chen ◽  
Tore Midtvedt
Keyword(s):  
Small Intestine ◽  
Intestinal Microflora ◽  
Burst Activity ◽  
Intestinal Transit ◽  
Myoelectric Activity ◽  
Regular Spike ◽  
Spike Burst ◽  
Germ Free ◽  
Microbial Species ◽  
Small Intestinal

The effect of an intestinal microflora consisting of selected microbial species on myoelectric activity of small intestine was studied using germ-free rat models, with recording before and after specific intestinal colonization, in the unanesthetized state. Intestinal transit, neuropeptides in blood (RIA), and neuromessengers in the intestinal wall were determined. Clostridium tabificum vp 04 promoted regular spike burst activity, shown by a reduction of the migrating myoelectric complex (MMC) period from 30.5 ± 3.9 min in the germ-free state to 21.2 ± 0.14 min ( P < 0.01). Lactobacillus acidophilus A10 and Bifidobacterium bifidum B11 reduced the MMC period from 27.9 ± 4.5 to 21.5 ± 2.1 min ( P < 0.02) and accelerated small intestinal transit ( P < 0.05). Micrococcus luteus showed an inhibitory effect, with an MMC period of 35.9 ± 9.3 min compared with 27.7 ± 6.3 min in germ-free rats ( P < 0.01). Inhibition was indicated also for Escherichia coli X7gnotobiotic rats. No consistent changes in slow wave frequency were observed. The concentration of neuropeptide Y in blood decreased after introduction of conventional intestinal microflora, suggesting reduced inhibitory control. Intestinal bacteria promote or suppress the initiation and aboral migration of the MMC depending on the species involved. Bacteria with primitive fermenting metabolism (anaerobes) emerge as important promoters of regular spike burst activity in small intestine.

scholarly journals Microbial Production of Glyceric Acid, an Organic Acid That Can Be Mass Produced from Glycerol

2009 ◽  
Vol 75 (24) ◽  
pp. 7760-7766 ◽  
Author(s):  
Hiroshi Habe ◽  
Yuko Shimada ◽  
Toshiharu Yakushi ◽  
Hiromi Hattori ◽  
Yoshitaka Ano ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Growth Parameters ◽  
Operating Time ◽  
Enantiomeric Excess ◽  
Gluconobacter Oxydans ◽  
Acetic Acid Bacteria ◽  
Culture Broth ◽  
Glyceric Acid ◽  
Bacterial Strains ◽  
Biotechnological Production

ABSTRACT Glyceric acid (GA), an unfamiliar biotechnological product, is currently produced as a small by-product of dihydroxyacetone production from glycerol by Gluconobacter oxydans. We developed a method for the efficient biotechnological production of GA as a target compound for new surplus glycerol applications in the biodiesel and oleochemical industries. We investigated the ability of 162 acetic acid bacterial strains to produce GA from glycerol and found that the patterns of productivity and enantiomeric GA compositions obtained from several strains differed significantly. The growth parameters of two different strain types, Gluconobacter frateurii NBRC103465 and Acetobacter tropicalis NBRC16470, were optimized using a jar fermentor. G. frateurii accumulated 136.5 g/liter of GA with a 72% d-GA enantiomeric excess (ee) in the culture broth, whereas A. tropicalis produced 101.8 g/liter of d-GA with a 99% ee. The 136.5 g/liter of glycerate in the culture broth was concentrated to 236.5 g/liter by desalting electrodialysis during the 140-min operating time, and then, from 50 ml of the concentrated solution, 9.35 g of GA calcium salt was obtained by crystallization. Gene disruption analysis using G. oxydans IFO12528 revealed that the membrane-bound alcohol dehydrogenase (mADH)-encoding gene (adhA) is required for GA production, and purified mADH from G. oxydans IFO12528 catalyzed the oxidation of glycerol. These results strongly suggest that mADH is involved in GA production by acetic acid bacteria. We propose that GA is potentially mass producible from glycerol feedstock by a biotechnological process.

Bioactivity of Some Natural and Semisynthetic Coumarin Derived Compounds

2021 ◽  
Vol 19 (6) ◽  
pp. 129-138
Author(s):  
Yasser Fakri Mustafa ◽  
Moath Kahtan Bashir ◽  
Mahmood Khudhayer Oglah ◽  
Raghad Riyadh Khalil ◽  
Eman Tareq Mohammed
Keyword(s):  
Pathogenic Fungi ◽  
Salmonella Typhi ◽  
Positive Influence ◽  
Shigella Dysenteriae ◽  
Klebsiella Pneumonia ◽  
Bacterial Strains ◽  
Cancerous Cell ◽  
Free Hydroxyl ◽  
Antibacterial And Antifungal ◽  
Diffusion Assay

A couple of natural coumarins was identified in the seeds of two apples’ cultivars commonly known as Granny Smith and Red Delicious. The effect of the phenolic hydroxyl moieties found in these products was evaluated on the bioactivity. This evaluation included the structural alteration of these moieties into less hydrophilic ones to explore the significance of the parent moieties on the biological activity. The investigated biopotentials were antioxidant, antiproliferative, antibacterial, and antifungal effects. The antioxidant potential was investigated by detecting the ability of the natural and semisynthetic coumarins to trap the free hydroxyl and DPPH radicals. The antiproliferative potential was assessed via an MTT-depended assay versus eight cancerous-cell lines, included HeLa, SK-OV-3, AR42J, MCF-7, AB12, KYSE-30, LC540, and AMN3. The antibacterial potential was tested versus six common pathogenic bacterial strains via a well-defined disc diffusion assay. These pathogens were Escherichia coli, Salmonella typhi, Klebsiella pneumonia, Haemophilus influenzae, Shigella dysenteriae, and Pseudomonas aeruginosa. The antifungal potential was also screened by utilizing a similar microbiological technique versus three pathogenic fungi, involved Candida albicans, Aspergillus flavus, and Aspergillus niger. It is concluded that the investigated chemical moiety has a positive influence on the antioxidant and antiproliferative potentials of the natural derivatives, and a negative one on their antibacterial and antifungal potentials.

Gastrointestinal myoelectric activity in conscious guinea pigs

1985 ◽  
Vol 249 (1) ◽  
pp. G92-G99 ◽  
Author(s):  
J. J. Galligan ◽  
M. Costa ◽  
J. B. Furness
Keyword(s):  
Small Intestine ◽  
Guinea Pigs ◽  
Mammalian Species ◽  
Gastric Antrum ◽  
Slow Waves ◽  
Cycle Period ◽  
Myoelectric Activity ◽  
Phase 3 ◽  
Fed State ◽  
Intestinal Slow Waves

Myoelectric activity was recorded from the gastric antrum and small intestine of conscious, unrestrained guinea pigs using bipolar Ag-Ag chloride electrodes that had been previously implanted under pentobarbital sodium/Innovar anesthesia. In fasted guinea pigs, the migrating myoelectric complex (MMC) was recorded from the small intestine and was observed to propagate aborally at a speed that declined with distance from the pylorus (range of speeds of the front of phase 3: 17.5 cm/min in the duodenum to 4.1 cm/min in the ileum). The complex was not disrupted by feeding but occurred less frequently in the freely fed state (82-min cycle period in the fasted state versus 139 min in the fed state). The complex started in the duodenum and was accompanied by a brief (6.3 +/- 0.9 min) period of inhibition of antral myoelectric activity. Slow waves were also recorded from the gastric antrum (10.3 +/- 1.3/min) and the small intestine. The frequency of intestinal slow waves was uniform along the length of the bowel (26.2 +/- 1.3/min in the duodenum to 24.7 +/- 1.3/min in the ileum). It is concluded that the guinea pig is similar to other mammalian species, so far examined, in its pattern of gastrointestinal myoelectric activity.

Effect of secretin on electrical activity of small intestine

1975 ◽  
Vol 229 (2) ◽  
pp. 484-488 ◽  
Author(s):  
AK Mukhopadhyay ◽  
LR Johnson ◽  
EM Copeland ◽  
NW Weisbrodt
Keyword(s):  
Small Intestine ◽  
Small Bowel ◽  
Electrical Activity ◽  
Slow Wave ◽  
Intravenous Infusion ◽  
Action Potentials ◽  
Slow Waves ◽  
Wave Frequency ◽  
Conscious Dogs ◽  
Total Percentage

The effect of intravenously administered secretin (0.5, 2.0, 6.0 U/kg-h) and intraduodenal acidification (13.2 meq/h HCl) on the electrical activity of the small bowel of three conscious dogs with gastric and duodenal cannulas was observed. Electrical activity was recorded in fasted as well as fed conditions through silver wire electrodes implanted along the entire length of the small bowel. Intravenous infusion of secretin in all dosages and in all dogs delayed the onset of the interdigestive myoelectric complex and reduced the total percentage of slow waves with superimposed spike potentials. Intraduodenal acidification also inhibited the interdigestive myoelectric complex, which developed incompletely with fewer action potentials on slow waves. Secretin did not produce any alteration in the fed pattern of activity, slow-wave frequency, or the caudal migration of the interdigestive myoelectric complex. The present study indicates that the nuerohumoral mechanisms responsible for initiation of the interdigestive myoelectric complex may be different from those responsible for its caudal migration.

Action potential generation in the small intestine of W mutant mice that lack interstitial cells of Cajal

1996 ◽  
Vol 271 (3) ◽  
pp. G387-G399 ◽  
Author(s):  
J. Malysz ◽  
L. Thuneberg ◽  
H. B. Mikkelsen ◽  
J. D. Huizinga
Keyword(s):  
Small Intestine ◽  
Action Potentials ◽  
Interstitial Cells Of Cajal ◽  
Interstitial Cells ◽  
K Channel ◽  
Pacemaker Activity ◽  
Channel Blockade ◽  
Auerbach’S Plexus ◽  
Cells Of Cajal ◽  
Auerbach's Plexus

The small intestine of W/Wv mice lacks both the network of interstitial cells of Cajal (ICC), associated with Auerbach's plexus, and pacemaker activity, i.e., it does not generate slow-wave-type action potentials. The W/Wv muscle preparations showed a wide variety of electrical activities, ranging from total quiescence to generation of action potentials at regular or irregular frequency with or without periods of quiescence. The action potentials consisted of a slow component with superimposed spikes, preceded by a slowly developing depolarization and followed by a transient hyperpolarization. The action potentials were completely abolished by L-type Ca2+ channel blockers. W/Wv mice responded to K+ channel blockade (0.5 mM Ba2+ or 10 mM tetraethylammonium chloride) with effects on amplitude, frequency, rate of rise, and duration of the action potentials. In quiescent tissues from W/Wv mice, K+ channel blockade evoked the typical spikelike action potentials. Electron microscopy identified few methylene blue-positive cells in the W/Wv small intestine associated with Auerbach's plexus as individual ICC. Numbers of resident macrophage-like cells (MLC) and fibroblast-like cells (FLC) were significantly changed. Neither FLC nor MLC were part of a network nor did they form specialized junctions with neighboring cells as ICC do. Hence no cell type had replaced ICC at their normal morphological position associated with Auerbach's plexus. ICC were present in W/Wv mice at the deep muscular plexus in normal organization and numbers, indicating that they are not dependent on the Kit protein and do not take part in generation of pacemaker activity.

Myoelectric effects of vasoactive intestinal peptide on rabbit small intestine

1983 ◽  
Vol 244 (1) ◽  
pp. G46-G51
Author(s):  
C. A. Sninsky ◽  
M. M. Wolfe ◽  
J. L. Martin ◽  
B. A. Howe ◽  
T. M. O'Dorisio ◽  
...  
Keyword(s):  
Vasoactive Intestinal Peptide ◽  
Venous Blood ◽  
Intestinal Secretion ◽  
Similar Rate ◽  
Myoelectric Activity ◽  
Rabbit Ileum ◽  
Blood Samples ◽  
Rabbit Small Intestine ◽  
The Mean ◽  
Potential Complex

Myoelectric recording techniques were used to study the motility of rabbit ileum during infusions of vasoactive intestinal peptide (VIP). VIP was infused intravenously at a rate of 300 pmol X kg-1 X h-1, and peripheral venous blood samples were obtained hourly for VIP assay. VIP was also infused intraluminally at a similar rate, and hourly portal vein blood samples were obtained for VIP assay. Alterations in motility were observed after both intravenous and intraluminal infusions of VIP. These alterations in motility consisted of the migrating action potential complex and repetitive bursts of action potentials. The VIP infusion rate used and the mean peripheral plasma VIP level of 267 +/- 29 pg/ml attained during intravenous VIP infusion were similar to those that induced intestinal secretion in other animal species. Portal venous VIP levels (93 +/- 21 pg/ml) were unchanged during the intraluminal infusion of VIP. These studies show that intravenous infusion of VIP causes alterations in motility of rabbit ileum. These alterations in motility with concomitant secretion of water and electrolytes may contribute to the diarrhea induced by VIP infusion. In addition, intraluminal infusion of VIP also induced alterations in myoelectric activity, which suggested that this peptide has a luminal effect as well as a hormonal effect.

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