Intestinal Bacterial Count Research Articles

Effects of dietary antibiotic growth promoter and Saccharomyces cerevisiae fermentation product on production, intestinal bacterial community, and nonspecific immunity of hybrid tilapia (Oreochromis niloticus female × Oreochromis aureus male)1

To investigate the effects of a dietary antibiotic growth promoter (florfenicol) and a Saccharomyces cerevisiae fermentation product (DVAQUA) on growth, G:F, daily feed intake, intestinal bacterial community, and nonspecific immunity of hybrid tilapia (Oreochromis niloticus ♀ × Oreochromis aureus ♂), a 16-wk feeding trial was conducted in a recirculating aquaculture system. Four feeding regimens were evaluated: control, dietary florenicol (0.02 g/kg; 16 wk), dietary DVAQUA (0.5 g/kg; 16 wk), and sequential use of florenicol (0.02 g/kg; 8 wk), and DVAQUA (0.5 g/kg; 8 wk). Each regimen had 4 replicate tanks (0.5 × 0.5 × 0.5 m) and each tank contained 12 fish (initial BW: 46.88 ± 0.38 g). Dietary florfenicol improved growth (P = 0.089), G:F (P = 0.036), and serum complement component concentrations (P < 0.001) of hybrid tilapia. However, the compound decreased the estimated intestinal bacterial count estimated by rpoB quantitative PCR (P < 0.001) and bacterial diversity (visual band numbers, Shannon diversity index, and Shannon equitability index based on 16S rDNA V3 denaturing gradient gel electrophoresis fingerprints) compared with the control. Although sequential use of florfenicol and DVAQUA improved growth and G:F numerically to a similar extent as dietary florfenicol, and increased intestinal bacterial count to normal quantities, the sequential use of florenicol and DVAQUA decreased intestinal bacterial diversity (visual band numbers, Shannon diversity index, and Shannon equitability index) as well as serum complement component concentrations (P < 0.001) compared with their respective use and the control. These findings might be negatively related to disease control and host defense, and the sequential use of florenicol and DVAQUA should be practiced with caution. Feeding DAVQUA to the fish improved nonspecific immunity and increased intestinal bacterial count and bacterial diversity, but further research, including challenge studies, should be conducted before recommendation of DVAQUA supplementation to hybrid tilapia diets.

Effects of the antibiotic growth promoters flavomycin and florfenicol on the autochthonous intestinal microbiota of hybrid tilapia (Oreochromis niloticus ♀ × O. aureus ♂)

The 16S rDNA PCR-DGGE and rpoB quantitative PCR (RQ-PCR) techniques were used to evaluate the effects of dietary flavomycin and florfenicol on the autochthonous intestinal microbiota of hybrid tilapia. The fish were fed four diets: control, dietary flavomycin, florfenicol and their combination. After 8weeks of feeding, 6 fish from each cage were randomly chosen for the analysis. The total number of intestinal bacteria was determined by RQ-PCR. The results showed that dietary antibiotics significantly influenced the intestinal microbiota and dramatically reduced the intensity of total intestinal bacterial counts. The intensity of some phylotypes (EU563257, EU563262 and EU563255) were reduced to non-detectable levels by both dietary antibiotics, while supplementation of florfenicol to the diet also reduced the intensity of the phylotypes EU563242 and EU563262, uncultured Mycobacterium sp.-like, uncultured Cyanobacterium-like and uncultured Cyanobacterium (EU563246). Dietary flavomycin only reduced the OTU intensity of one phylotype, identified as a member of the phylum Fusobacteria. The antibiotic combination only reduced the phylotypes EU563242 and EU563262. Based on our results, we conclude that the reduced effect of florfenicol on intestinal microbiota was stronger than that of flavomycin, and when flavomycin and florfenicol were added in combination, the effect of florfenicol overshadowed that of flavomycin.

Comparative effects of dietary administered transgenic and conventional papaya on selected intestinal parameters in rat models

Transformation of agricultural crops with novel genes has significantly advanced disease-resistance breeding, including virus resistance through the expression of virus sequences. In this study, the effects of long-term, repeated exposure to transgenic papayas carrying the coat protein gene of Papaya ringspot virus and conventional non-transgenic papaya on the histology and selected biochemical parameters of the intestinal tract were compared. For 3 months, male and female Wistar rats received diets containing transgenic or non-transgenic papaya at twice the equivalent of the average daily consumption of fresh papayas. Gross and macroscopic appearance of intestinal tissues, as well as stomach tissues, was comparable (P < 0.05) as were total intestinal bacterial counts and activities of beta-glucuronidase. Activities of disaccharidases were not affected, neither were those of amylase (P < 0.05). Although significant differences were noted in the activity of Ca(2+) and Na(+)/K(+) ATPase brush border enzymes, no morphological alteration in the integrity of the intestinal mucosa was found. Overall, negligible effects on feed intake, body weight, and fecal output were observed (P < 0.05). Taken together, long-term exposure to diets formulated with transgenic papaya did not result in biologically important unintended effects.

Effects of Cu2+-exchanged montmorillonite on intestinal microflora, digestibility and digestive enzyme activities of Nile tilapia

A total of 360 Nile tilapia at an average initial body weight of 3.9 g were randomly allocated to four treatments, each of which had three replicates of 30 fish per tank and used to investigate the effects of Cu2+-exchanged montmorillonite (Cu-MMT) on intestinal microflora, digestibility and digestive enzyme activities. The dietary treatments were: (i) basal diet, (ii) basal diet + 1.5 g kg−1 MMT; (iii) basal diet + 30 mg kg−1 copper as CuSO4 (equivalent to the copper in the Cu-MMT treatment group), or (iv) basal diet + 1.5 g kg−1 Cu-MMT. The results showed that supplementation with Cu-MMT significantly improved growth performance as compared with the control and fish fed with Cu-MMT had higher growth performance than those fed with MMT or CuSO4. Supplementation with Cu-MMT reduced (P < 0.05) the total intestinal aerobic bacterial counts and affected the composition of intestinal microflora with Aeromonas, Vibrio, Pseudomonas, Flavobacterium, Acinetobacter, Alcaligence, Enterobacteriaceae decreasing as compared with the control. Addition of MMT improved (P < 0.05) the apparent digestibility of dry matter and crude protein, and the activities of intestinal amylase, lipase, and alkaline phosphatase as compared with the control. Addition of Cu-MMT improved (P < 0.05) the apparent digestibilities of dry matter, crude protein, ether extract, and crude ash, and the activities of total protease, amylase, lipase, and alkaline phosphatase as compared with the control. While supplementation with CuSO4 had no (P > 0.05) effect on intestinal microflora, digestibility, and digestive enzyme activities the results showed that Cu-MMT exhibited antibacterial activity in vivo resulting in a positive effect on digestive enzyme activities, and then promoted the digestion and absorption of dietary nutrition.

Effects of Cu 2+-exchanged montmorillonite on growth performance, microbial ecology and intestinal morphology of Nile tilapia ( Oreochromis niloticus)

A total of 360 Nile tilapia at an average initial body weight of 3.9 g were randomly allocated to 4 treatments, each of which had three replicates of 30 fish/tank and used to investigate the effects of Cu 2+-exchanged montmorillonite (Cu-MMT) on growth performance, microbial ecology of the skin, gill and intestine, and intestinal morphology. The dietary treatments were: 1) basal diet, 2) basal diet + 1.5 g/kg MMT, 3) basal diet + 30 mg/kg copper as CuSO 4 (equivalent to the copper in the Cu-MMT treatment group), or 4) basal diet + 1.5 g/kg Cu-MMT. The results showed that supplementation with Cu-MMT significantly improved growth performance as compared to control and fish fed with Cu-MMT had higher growth performance than those fed with MMT or CuSO 4. Supplementation with Cu-MMT reduced ( P < 0.05) the total intestinal aerobic bacterial counts and affected the composition of intestinal microflora with a tendency of Aeromonas, Vibrio, Pseudomonas, Flavobacterium, Acinetobacter, Alcaligence, Enterobacteriaceae decreasing as compared with control. Measurements of villus and microvillus heights at different sites of the intestinal mucosa indicated that dietary addition of MMT or Cu-MMT improved intestinal mucosal morphology. However, the microbial ecology of the skin and gill was not affected by the addition of CuSO 4, MMT or Cu-MMT. Supplementation with CuSO 4 had no ( P > 0.05) effect on the growth performance, microbial ecology and intestinal morphology. The results showed that Cu-MMT exhibited antibacterial activity in vivo and protected intestinal mucosa from invasion of pathogenic bacterium and toxins, resulting in a positive effect on the growth performance.

Effect of Steroid on Mitochondrial Oxidative Stress Enzymes, Intestinal Microflora, and Bacterial Translocation in Rats Subjected to Temporary Liver Inflow Occlusion

Protective effects of steroids against ischemia-reperfusion (I/R) injury are well known, but there is little information about the influence of temporary inflow occlusion on intestinal barrier function or bacterial translocation. The aim of this experimental study was to investigate the effects on liver, kidney, spleen, ileal mitochondrial stress enzymes, and bacterial translocation of methylprednisolone (MP) in rats undergoing temporary liver inflow occlussion. Twenty-seven pathogen-free Wistar albino rats were randomized into three groups: group A: I/R ( n = 10); group B: I/R + MP ( n = 10); and group C: sham ( n = 7). Rats in groups A and B were subjected to 20 minutes of portal vein and hepatic artery occlusion with 3 mg/kg MP injected into group B animals intraperitoneally during the occlusion. Twenty-two hours later, all rats were sacrificed to measure mitochondrial oxidative stress enzymes in liver, kidney, spleen, and ileum. We evaluated intestinal bacterial counts, intestinal mucosal histopathology, bacterial translocation to mesenteric lymph nodes (MLN), liver, spleen, and kidney. Decreased levels of malondialdehyde and increased levels of glutathione were observed in all examined tissues of group B compared to those of group A rats. Statistically significant increases in the intestinal counts of Klebsiella spp and Proteus spp and of bacterial translocation to liver, kidney, spleen, and MLN were measured in group B with respect to group A.

Effect of acute alcohol ingestion prior to burn injury on intestinal bacterial growth and barrier function

Previous studies from our laboratory have shown that acute alcohol (EtOH) ingestion prior to burn injury enhances intestinal bacterial translocation. This study tested if increased intestinal bacterial translocation in alcohol and burn injured rats is due to an overgrowth in intestinal bacteria. We determined if the translocation was accompanied with alterations in intestinal permeability and immune cell population. Rats (225–250 g) were gavaged with alcohol to achieve a blood EtOH level in the range of 100 mg/dl prior to burn or sham injury (25% total body surface area). Two days after injury, we found that acute alcohol ingestions prior to burn injury results in a significant increase in bacterial counts in small intestine. The increase in intestinal bacterial counts accompanied a significant increase in intestinal permeability. Finally, immunohistochemical analysis revealed a substantial ( p < 0.05) loss of both T cell and dendritic cells in intestine of alcohol and burn injured rats compared with intestine of rats receiving either burn or sham injury. Altogether, results presented in this manuscript suggest that increase in intestinal bacterial growth along with alterations in intestinal permeability and immune status contribute to the increase in bacterial translocation observed in alcohol and burn injured rats.

Intestinal microflora in rats with ischemia/reperfusion liver injury

To investigate the intestinal microflora status related to ischemia/reperfusion (I/R) liver injury and explore the possible mechanism. Specific pathogen free grade Sprague-Dawley rats were randomized into three groups: Control group (n=8), sham group (n=6) and I/R group (n=10). Rats in the control group did not receive any treatment, rats in the I/R group were subjected to 20 min of liver ischemia, and rats in the sham group were only subjected to sham operation. Twenty-two hours later, the rats were sacrificed and liver enzymes and malondialdehyde (MDA), superoxide dismutase (SOD), serum endotoxin, intestinal bacterial count, intestinal mucosal histology, bacterial translocation to mesenteric lymph nodes, liver, spleen, and kidney were studied. Ischemia/reperfusion increased liver enzymes, MDA, decreased SOD, and was associated with plasma endotoxin elevation in I/R group compared to those in the sham group. Intestinal Bifidobacterium and Lactobacillus decreased and intestinal Enterobacteria and Enterococci, bacterial translocation to kidney increased in the I/R group compared to the sham group. Intestinal microvilli were lost, disrupted and the interspace between cells became wider in the I/R group. I/R liver injury may lead to disturbance of intestinal microflora and impairment of intestinal mucosal barrier function, which contributes to endotoxemia and bacterial translocation to kidney.

Intestinal bacterial overgrowth and bacterial translocation in cirrhotic rats with ascites

Background/Aims: Translocation of indigenous bacterial from the gut lumen of cirrhotic animals to mesenteric lymph nodes appears to be an important step in the pathogenesis of spontaneous bacterial peritonitis. However, the sequence of events leading to translocation remains unclear. One of the most predictable risk factors for translocation is overgrowth of gut bacterial flora. The present study was designed to compare the intestinal aerobic bacterial flora of cecal stools at the time of sacrifice between cirrhotic and normal rats and to evaluate the role of intestinal aerobic bacterial overgrowth in bacterial translocation in cirrhotic rats. Methods: Thirty-five male Sprague-Dawley rats with carbon tetrachloride-induced cirrhosis and ascites and 10 normal rats were included in this study. Cirrhotic rats were sacrificed when ill and samples of ascitic fluid, mesenteric lymph nodes and cecal stool were taken for detecting quantitatively aerobic bacteria. Results: Total intestinal aerobic bacterial count in cecal stool at the time of sacrifice was significantly increased in cirrhotic rats with bacterial translocation with or without spontaneous bacterial peritonitis compared to cirrhotic rats without bacterial translocation ( p<0.001 and p<0.001, respectively) and to normal rats ( p<0.001 and p<0.001, respectively). Of the 42 species of bacteria translocating to the mesenteric lymph nodes, 41 (97.6%) were found in supranormal numbers in the stool at the time of sacrifice. Conclusions: Carbon tetrachloride-induced cirrhotic rats with bacterial translocation have increased total intestinal aerobic bacteria count, and intestinal bacterial overgrowth appears to play an important role in bacterial translocation in this experimental model of cirrhosis in rats.

Effect of oral supplementation of lactobacilli on bacterial translocation in acute liver injury induced by d-galactosamine

Background/Aim: Bacterial infections and sepsis are frequent complications of acute liver injury, with a high share in the mortality and morbidity of this condition. Bacterial translocation from the gut may play an important role in the high rate of infections observed. In this experiment the effect of different oral supplementation on bacterial translocation was evaluated in acute liver injury induced by d-galactosamine in the rat. Methods: Rats were given oral supplements of lactulose, neomycin, Lactobacillus reuteri R2LC, and Lactobacillus plantarum DSM 9843 for 1 week. Liver injury was induced by intraperitoneal administration of 1.1 g/kg d-galactosamine. Twentyfour hours later, rats were sacrificed and liver enzymes and histology, intestinal bacterial count and microflora, intestinal mucosal histology, DNA and RNA content, bacterial translocation to blood, mesenteric lymph nodes, and liver, and serum endotoxin were studied or measured. Results: Lactulose was highly effective in prevention of liver injury and bacterial translocation. Neomycin and Lactobacillus plantarum DSM 9843 showed a moderate effect in prevention of liver injury and bacterial translocation. Intestinal bacterial count and micrflora were affected by different treatment modalities. No endotoxin concentration was found in any of the experimental groups. Both lactobacilli could significantly improve the mucosal proliferative state. Conclusions: Oral supplementation of lactulose with anti-endotoxin effect could successfully prevent the liver injury and the subsequent bacterial translocation in acute liver injury induced by administration of d-galactosamine in the rat. This effect was irrespective of the intestinal bacterial alteration or mucosal proliferative state.

Effect of erythromycin on microbial antagonisms: a study in gnotobiotic mice associated with a human fecal flora.

The effect of erythromycin base was studied on intestinal resistance to colonization of gnotobiotic mice inoculated with a human fecal flora and challenged with six microbial strains potentially pathogenic for immunocompromised patients. Fecal concentrations of erythromycin were greater than 1,000 micrograms/g in the human donor and in mice. Total intestinal bacterial counts were not significantly different in the human donor and in the recipient mice and were not affected by erythromycin treatment. Strains of various species from the dominant flora (greater than 10(9) colony-forming units/g) and resistant to greater than 1,000 micrograms of erythromycin/ml were present before and persisted during treatment. Strains sensitive to such concentrations - particularly all enterobacteria-were eliminated. Treatment did not reduce colonization resistance against Candida albicans, Clostridium perfringens, and erythromycin-sensitive Escherichia coli. It reduced but did not eliminate some colonization resistance against Pseudomonas aeruginosa, Clostridium difficile, and erythromycin-resistant E coli.

Experimental feline panleucopenia in the conventional cat.

Coventional kittens, 12-27 weeks old, were inoculated with cell-cultured feline panleucopenia virus and killed sequentially between day 3 and day 24 after inoculation. All developed a non-fatal mild disease between days 2 and 9, characterized by lymphopenia, neutropenia, listlessness, depression and the development of neutralizing antibodies to the virus. Small intestinal bacterial counts were reduced during the period of maximal clinical disease, presumably a result of decreased food intake. There was involution of the thymus with marked depletion of lymphocytes between days 3 and 12. Depletion of lymphocytes also characterized the lesions in the lymph nodes between days 3 and 8. At the same time crypt lesions with spotty distribution were in the small intestinal and colonic mucosa. The changes were loss of crypt epithelial cells with compensatory attenuation of the remaining epithelium. Electron microscopically, the number and size of microvilli and secretory granules were reduced but there was no change indicating lethal cell injury. There were no virus particles. The findings point to an early and transient cellular damage by the virus. Intestinal alkaline phosphatase activity disappeared from the luminal surface of the attenuated crypt epithelial cells. Otherwise, intestinal alkaline and acid phosphatase activity were not altered in inoculated cats.

On the Logarithmic Transformation of Intestinal Bacterial Counts

On the Logarithmic Transformation of Intestinal Bacterial Counts