Colicins of Escherichia coli Lead to Resistance against the Diarrhea-Causing Pathogen Enterotoxigenic E. coli in Pigs.

Gut microbes can affect host adaptation to various environment conditions. Escherichia coli is a common gut species, including pathogenic strains and nonpathogenic strains. This study was conducted to investigate the effects of different E. coli strains in the gut on the health of pigs. In this study, the complete genomes of two E. coli strains isolated from pigs were sequenced. The whole genomes of Y18J and the enterotoxigenic E. coli strain W25K were compared to determine their roles in pig adaptation to disease. Y18J was isolated from feces of healthy piglets and showed strong antimicrobial activity against W25K in vitro. Gene knockout experiments and complementation analysis followed by modeling the microbe-microbe interactions demonstrated that the antagonistic mechanism of Y18J against W25K relied on the bacteriocins colicin B and colicin M. Compared to W25K, Y18J is devoid of exotoxin-coding genes and has more secondary-metabolite-biosynthetic gene clusters. W25K carries more genes involved in genome replication, in accordance with a shorter cell cycle observed during a growth experiment. The analysis of gut metagenomes in different pig breeds showed that colicins B and M were enriched in Laiwu pigs, a Chinese local breed, but were scarce in boars and Duroc pigs. IMPORTANCE This study revealed the heterogeneity of E. coli strains from pigs, including two strains studied by both in silico and wet experiments in detail and 14 strains studied by bioinformatics analysis. E. coli Y18J may improve the adaptability of pigs toward disease resistance through the production of colicins B and M. Our findings could shed light on the pathogenic and harmless roles of E. coli in modern animal husbandry, leading to a better understanding of intestinal-microbe-pathogen interactions in the course of evolution.

Effect of resistance exercise training on Crohn’s disease patients

Crohn’s disease (CD) is observed with increased levels of cytokines which cause inflammation in many parts of the digestive tract. Aerobic exercise contributes to the reduction of the intestine’s inflammation and increases the quality of life. Another type of exercise that shows research interest about its effects on CD symptoms is the resistance exercise (RE). The aim of the study was to review the influence of RE on CD patients. The study’s literature was collected from PubMed and Scholar databases. According to the results, the main phase of a RE training program must have a gradual increase of intensity (60%–80%) and resting periods of 15–30 seconds after each exercise, and 2–3 minutes between exercises. Also, CD patients who were in remission improved the muscle strength and quality of life via their participation in RE training program. However, the secretion of interleukin-6 in both CD and RE contributes in various physiological mechanisms setting a contradictory role in the effectiveness of RE at the disease’s inflammatory situation. So, the use of RE training in CD patients needs more research for safer participation.

Effect of resistance exercise training on Crohn’s disease patients

Crohn’s disease (CD) is observed with increased levels of cytokines which cause inflammation in many parts of the digestive tract. Aerobic exercise contributes to the reduction of the intestine’s inflammation and increases the quality of life. Another type of exercise that shows research interest about its effects on CD symptoms is the resistance exercise (RE). The aim of the study was to review the influence of RE on CD patients. The study’s literature was collected from PubMed and Scholar databases. According to the results, the main phase of a RE training program must have a gradual increase of intensity (60%–80%) and resting periods of 15–30 seconds after each exercise, and 2–3 minutes between exercises. Also, CD patients who were in remission improved the muscle strength and quality of life via their participation in RE training program. However, the secretion of interleukin-6 in both CD and RE contributes in various physiological mechanisms setting a contradictory role in the effectiveness of RE at the disease’s inflammatory situation. So, the use of RE training in CD patients needs more research for safer participation.

Effects of nitric oxide inhibition by methylene blue in cirrhotic patients with ascites.

Increased endogenous nitric oxide production has been proposed as an important mediator of the peripheral arterial vasodilation and the hyperdynamic circulation in cirrhosis, whereas a decreased intrahepatic production of nitric oxide has been implicated in the pathogenesis of portal hypertension. The present study investigated the possible beneficial effects of methylene blue, which is a potent inhibitor of guanylate cyclase and nitric oxide synthase, on hyperdynamic circulation and renal function in cirrhotic patients with ascites together with the effects on portal hemodynamics. Twenty patients were evaluated at baseline and during 2 consecutive 4-hr periods after the administration of methylene blue at a dose of 3 mg/kg (10 patients) or placebo (10 patients). Mean arterial pressure, heart rate, cardiac output, systemic vascular resistance, plasma active renin, plasma aldosterone, plasma antidiuretic hormone, serum urea, serum creatinine, serum sodium, urinary flow rate, glomerular filtration rate, effective renal plasma flow, portal flow volume, and portal vein velocity were not modified by methylene blue or placebo. Urinary sodium excretion, fractional sodium excretion and serum nitric oxide levels were significantly decreased 4 hr after methylene blue administration (P < 0.05), to return toward basal levels over a further 4-hr period. It is concluded that methylene blue, at the dose used in the present study, has no effect on systemic and portal hemodynamics in cirrhotic patients with ascites. The reduction in renal sodium excretion, in the absence of changes in renal function and hemodynamics, suggests, at least partly, a direct antinatriuretic effect of methylene blue.

Effects of somatostatin, terlipressin and somatostatin plus terlipressin on portal and systemic hemodynamics and renal sodium excretion in patients with cirrhosis.

BACKGROUND AND AIM: Terlipressin and somatostatin are the most preferable agents for the control of variceal bleeding in cirrhotic patients. The present study evaluated the hemodynamic effects of somatostatin, terlipressin and somatostatin plus terlipressin in cirrhotic patients with portal hypertension, as well as the effect of each regimen on renal sodium excretion. METHODS: Twenty-four patients with esophageal varices were randomly assigned to receive either an intravenous infusion of a placebo (n = 12) or somatostatin 250 microg/h after an initial bolus of 250 microg (n = 12) for 60 min. Thereafter, each patient received an intravenous injection of terlipressin 2 mg while the intravenous infusion of either somatostatin or placebo was maintained. Portal and systemic hemodynamic parameters, assessed by Doppler sonography, and urinary sodium excretion were evaluated at baseline, 60 min after placebo or somatostatin, and 30 min after terlipressin. RESULTS: Placebo had no effect on the patients studied. After terlipressin, portal vein velocity, portal flow volume and cardiac output (CO) significantly decreased (0.09 vs 0.15 m/s, 0.56 vs 1 L/min and 6.4 vs 7.6 L/min, respectively [values are medians]), while mean arterial pressure (MAP) and systemic vascular resistance significantly increased (103.3 vs 89.9 mmHg and 1541 vs 1108dyn.s/cm(5), respectively). Fractional sodium excretion significantly increased in patients without ascites (0.43 vs 0.16%) while it did not change in patients with ascites. Somatostatin did not alter portal hemodynamics whereas it significantly reduced MAP, heart rate (HR) and CO (86.9 vs 98.6 mmHg, 65 vs 73 bpm and 8.4 vs 9.1 L/min, respectively) and, in patients with ascites, sodium excretion (0.13 vs 0.23%). The addition of terlipressin to somatostatin induced similar changes to those observed after terlipressin alone. The magnitude of increase in MAP was significantly higher in patients receiving terlipressin alone than in those receiving somatostatin plus terlipressin (15 vs 5.3%), while CO was conversely affected (-28.5 vs-20.9%). CONCLUSIONS: Combined treatment with somatostatin and terlipressin does not exert an additive portal hypotensive effect in cirrhotic patients as compared to terlipressin alone, whereas somatostatin alone may impair systemic hemodynamics. Compared with somatostatin, terlipressin exerts a more beneficial effect on renal sodium excretion in patients with or without ascites.