Comparison of fecal Campylobacter in calves and cattle of different ages and areas in Japan

To define the species of Campylobacter harboring in the intestine of calves and adult cattle and to examine their distribution among different age groups and farms, 34 calves and 60 adult cattle raised in 6 farms in 3 different areas were studied. Campylobacters were detected in the feces obtained from healthy calves (97.1%) less than 1-year-old but were much less frequently found in adult cattle (46.7%). Young calves harbored more species of Campylobacter than adult cattle. The isolation rate of campylobacters in adult cattle differed depending upon the farms examined. C. jejuni, C. hyointestinalis and C. fetus subsp. fetus were isolated from 61.8, 26.5, and 26.5% of calves, respectively. However, these 3 species were detected at the lower rates of 11.7 to 15.0% in adult cattle. C. coli, C. lari, C. fetus subsp. venerialis, C. fecalis, and other Campylobacter spp. were also detected in a few calves and adults. These results indicate that campylobacter colonization in the intestine is very common in young calves but not in adult cattle.

Effect of lactosucrose (4G-beta-D-galactosylsucrose) on fecal flora and fecal putrefactive products of cats

The effects of lactosucrose (4G-beta-D-galactosylsucrose) on fecal flora and fecal putrefactive products were studied in 3 Himalayan and 5 Persian cats fed 175 mg of lactosucrose/each/day for 2 weeks. During lactosucrose administration, the counts of lactobacilli increased significantly (p < 0.05), whereas the counts of clostridia, including Clostridium perfringens and Enterobacteriaceace decreased significantly (p < 0.05). The levels of fusobacteria and staphylococci were decreased significantly (p < 0.01) on day 7 of lactosucrose administration, while the counts of bacteroides increased significantly (p < 0.05) and day 14 of lactosucrose administration compared to pre-administration. In frequency of occurrence, bifidobacteria increased significantly (p < 0.001) during lactosucrose administration, while Spirochaetaceae and lecithinase-negative clostridia decreased significantly (p < 0.05) on day 14 of lactosucrose administration compared to pre-administration. No detectable change occurred in the counts of other organisms throughout the experimental periods. Fecal concentrations of ammonia, indole, ethylphenol, and urinary ammonia were reduced significantly (p < 0.05) on day 14 of lactosucrose administration. The water content and weight of the feces increased slightly during lactosucrose administration, but the pH values decreased slightly. The environmental ammonia and the fecal odor also decreased remarkably (p < 0.01) during administration.

Effect of left ventricular systolic pressure increase on ventricular arrhythmogenicity in old canine myocardial infarction

OBJECTIVE

The aim was to examine the effect of an increase in left ventricular systolic pressure (LVSP) on ventricular arrhythmogenicity in old canine myocardial infarction.

METHODS

Fourteen mongrel dogs of either sex weighing 11 to 15 kg were used. Studies were performed 28 d after creation of myocardial infarction by ligation of the anterior descending coronary artery. Electrical induction of ventricular arrhythmia and determinations of effective refractory period (ERP) and local intraventricular conduction delay (LIVCD) were performed using the extrastimulus technique with a cycle length of 300 ms in the normal and infarcted zones of the left ventricle. Heterogeneity of ERP (delta ERP) was determined as a difference between the longest and shortest ERP values in each site. LVSP was raised by constriction of the ascending aorta in a stepwise fashion (control, level A, level B).

RESULTS

Incidence of electrically induced ventricular arrhythmia was increased from 28.6% at control level of LVSP [130.7(SEM 7.3) mm Hg] to 42.9% at level A [190.9(6.0) mm Hg] and to 64.3% (p < 0.05) at level B [243.3(4.0) mm Hg]. delta ERP and LIVCD were greater in the infarct zone than in the normal zone at each level of LVSP (p < 0.001). delta ERP in the infarct zone increased from 18.9(4.3) ms at control level of LVSP to 20.7(6.8) ms at level A, and to 27.1(8.1) ms at level B (p < 0.001). LIVCD in the infarct zone also increased from 22.9(6.2) ms at control level of LVSP to 26.8(4.9) ms at level A (p < 0.001), and to 36.1(6.0) ms at level B (p < 0.001). delta ERP and LIVCD in the normal zone were only slightly raised by increasing the LVSP. delta ERP and LIVCD in the infarct zone were closely correlated with incidence of electrically induced ventricular arrhythmia.

CONCLUSIONS

Increasing the LVSP enhances ventricular arrhythmogenicity and pre-existing electrophysiologic abnormalities of the heart in the presence of old myocardial infarction. Thus a rise in LVSP from any cause in the old myocardial infarction can be a trigger of life threatening ventricular arrhythmias.

Evaluation of the anaerobic method for the analysis of fecal microflora of beagle dogs

The plate-in-bottle method of Mitsuoka et al. (1969) for the counting of fecal bacteria in beagle dogs was superior to an anaerobic jar method. Comparisons of three nonselective media, such as medium 10 supplemented with 10% cecal extract of dogs (designated as M10C), M10 with 10% fecal extract of dogs (M10F), and M10, by the plate-in-bottle method indicated that the visible bacterial counts for M10C were higher than those for M10 and M10F. The high percentage (18.4%) of numbers of the extremely oxygen-sensitive anaerobes to the fecal total counts by using the plate-in-bottle method with M10C was also observed.

Effect of dietary fat and fiber on fecal flora, bacterial metabolites, and fecal properties in Japanese volunteers

The effects of dietary fat and dietary fiber (DF) levels in diet on fecal flora, activities of three fecal enzymes, putrefactive metabolites, fecal mutagenicity and fecal properties were studied in eight healthy volunteers. They were given low fat and low DF diet (LF: fat energy ratio was 13.9%, and DF intake was 9.0 g/day) for 10 days, high fat and low DF diet (HF: fat energy ratio was 52.7%, and DF intake was 7.1 g/day) for 10 days, and high fat and high DF diet (HFF: fat energy ratio was 52.0%, and DF intake was 24.8 g/day) for 10 days. No change of fecal flora at the bacterial group level was observed throughout the experimental period, except that the population of lactobacilli showed a tendency to increase in HF period. Fecal activities of beta-glucuronidase, beta-glucosidase and nitroreductase and some putrefactive products were unchanged between LF and HF, while these values decreased in HFF period. No significant change of fecal properties was observed between LF and HF, while by HFF supplementation fecal weight increased and fecal pH value was lower than that in LF and HF. Excretions of iron, zinc and calcium in feces did not increase by high DF supplementation.

Impact of the advances in age on the gastrointestinal microflora of beagle dogs

The gastrointestinal microflora of male beagle dogs in two different age groups; I) less than month 12 of age, and II) more than year 11 of age, was compared. No detectable difference occurred on the microflora of stomach, duodenum, jejunum, and ileum in both dogs. Large bowel (cecum, colon and rectum) microflora in both dogs yielded the different microbial populations. In all regions of large bowel, the levels of bacteroides, eubacteria, peptostreptococci, bifidobacteria, lactobacilli, and staphylococci in the elderly dogs were lower than those in the younger animals, whereas the numbers of Clostridium perfringens and streptococci in the elderly animals were higher than those in the youngers. The high incidence of lecithinase-negative clostridia was observed with advances in age, but not that of spiral shaped rods. The result of this study shows that the advances in age of beagle dogs yield some changes in the microbial population of large bowel in the animals.

Taxonomic study of the Lactobacillus acidophilus group, with recognition of Lactobacillus gallinarum sp. nov. and Lactobacillus johnsonii sp. nov. and synonymy of Lactobacillus acidophilus group A3 (Johnson et al. 1980) with the type strain of Lactobacillus amylovorus (Nakamura 1981)

Biochemical properties and DNA-DNA reassociation studies of Lactobacillus acidophilus strains isolated from humans and animals indicate that these include six genomospecies. Two new species can be differentiated from the established species of the genus Lactobacillus: L. gallinarum sp. nov. (type strain, ATCC 33199) and L. johnsonii sp. nov. (type strain, ATCC 33200). Furthermore, it was clarified that L. acidophilus group A3 (Johnson et al. 1980) is synonymous with L. amylovorus.

DNA relatedness among Erysipelothrix rhusiopathiae strains representing all twenty-three serovars and Erysipelothrix tonsillarum

The levels of relatedness among strains of Erysipelothrix rhusiopathiae (serovars 1 through 23 and type N) were estimated by performing DNA-DNA hybridization experiments with the type strains of E. rhusiopathiae and Erysipelothrix tonsillarum, which are the two Erysipelothrix species that have been described. Two distinct DNA relatedness groups were identified. The group 1 strains, representing serovars 1, 2, 4 through 6, 8, 9, 11, 12, 15 through 17, 19, and 21 and type N, exhibited more than 73% hybridization with the type strain of E. rhusiopathiae but less than 24% hybridization with the type strain of E. tonsillarum. Group 2 included serovar 3, 7, 10, 14, 20, 22, and 23 strains, and these strains exhibited more than 66% hybridization with the type strain of E. tonsillarum but less than 27% hybridization with the type strain of E. rhusiopathiae. Strains representing serovars 13 and 18 exhibited low levels of hybridization (16 to 47%) with both of the type strains, indicating that these serovars may be members of a new genomic species. The members of the E. rhusiopathiae and E. tonsillarum groups resembled each other in many phenotypic characteristics, but differed in their ability to produce acid from saccharose and in their pathogenicity for swine. Our results confirm that the genus Erysipelothrix contains two main genomic species, E. rhusiopathiae and E. tonsillarum, which can be differentiated into serovars.

Impact of Bifidobacterium longum on human fecal microflora

The effects of Bifidobacterium longum feedings for five weeks on the fecal microflora, water contents, pH values, ammonia concentration, and beta-glucuronidase activity were investigated in five healthy human volunteers. Although numbers of major bacterial groups of the fecal microflora were not changed by the bifidobacteria feedings, a remarkably decreasing number of lecithinase-negative clostridia was observed. The percentage of lecithinase-negative clostridia and bacteroides to the total bacterial numbers isolated were decreased during the feedings and numbers of C. paraputrificum and C. innocuum were reduced. A significant reduction of fecal pH values for the last week of the feeding was observed. Ammonia concentration and beta-glucuronidase activity in the feces during the feedings were significantly lower than those before or after the feedings. The oral supplement of B. longum may be introduced to improve the fecal properties such as fecal ammonia concentration and beta-glucuronidase activity, but not the composition of fecal flora.

Effect of Bilateral Stellectomy on Electrical Instability of the Atrium in the Dog with Hypokalemia

To investigate the effect of sympathetic nerve activity on electrical instability of the atrium in the presence of hypokalemia, open chest electrophysiological study was performed before and after bilateral stellectomy (BS) in 15 dogs with hypokalemia (hypokalemia group) and in 15 dogs with normokalemia (control group). Hypokalemia was created by infusion of 5.0 g/kg of polystyrene sulfonic acid calcium into the colon. Serum level of potassium was significantly lower in the hypokalemia group (2.94 +/- 0.52 mEq/L) than in the control group (4.86 +/- 0.51 mEq/L, P less than 0.01) before BS. There was no significant change in serum level of potassium in the two groups after BS. Incidence of electrically induced atrial fibrillation (AF) was significantly higher in the hypokalemia group (80%) than in the control group (13%, P less than 0.001) before BS. It was significantly reduced in the hypokalemia group (40%, P less than 0.05), but not in the control group (6%) after BS. Dispersion of effective refractory period of the atrium (delta ERP) was significantly greater in the hypokalemia group (26.1 +/- 2.8 msec) than in the control group (22.0 +/- 3.3 msec, P less than 0.005) before BS. It was significantly decreased to 23.1 +/- 3.2 msec in the hypokalemia group (P less than 0.001) and to 20.6 +/- 2.5 msec in the control group (P less than 0.01) after BS. Maximum conduction delay in the atrium (MaxCD) was 36.1 +/- 3.5 msec before and 36.2 +/- 4.1 msec after BS in the hypokalemia group and 31.1 +/- 4.2 msec before and 32.3 +/- 4.9 msec after BS in the control group. There was a significant difference in MaxCD between the two groups before BS. Atrial fibrillation threshold (AFT) was significantly lower in the hypokalemia group (3.9 +/- 0.7 mA) than in the control group (13.8 +/- 3.1 mA, P less than 0.001) before BS. It was significantly increased both in the hypokalemia group (6.5 +/- 1.3 mA, P less than 0.001) and in the control group (15.0 +/- 2.7 mA, P less than 0.005) after BS. It is concluded that sympathetic nerve activity may play some role in the increase in electrical instability of the atrium in the presence of hypokalemia.

Effect of low-fat, high-fat, and fiber-supplemented high-fat diets on colon cancer risk factors in feces of healthy subjects

Normal healthy volunteers (n = 8) received low- and high-fat (14% and 53% energy/day, respectively) and dietary fiber-supplemented high-fat diets (fiber 25 g/day, fat 52% energy/day) for 10 days each. Colon cancer risk factors in feces were measured by colonic nuclear aberration assay, the Ames Salmonella test using strain TA100, and measurement of bile acids and calcium soaps. Nuclear aberrations in colonic epithelium increased during the high-fat diet period and then decreased during the fiber-supplemented high-fat diet period. There were no significant differences in the mutagenicity on Salmonella TA100 or in the concentration of bile acids during the high-fat diet period. Bile acids decreased during the fiber supplementation period. The marked increase in calcium soaps during the high-fat diet period indicates an increase in long-chain fatty acids in the fecal lipid component and conversion of these fatty acids to insoluble calcium soaps when enough calcium is present.

Quantitative fluorometric assay for rapid enzymatic characterization of Bifidobacterium longum and related bifidobacteria

The quantitative, semi-automated assay described here is an alternative characterization method allowing for highly sensitive and specific detection of bifidobacterial enzymes. Twenty strains of Bifidobacterium longum, including the type strain ATCC 15707, and type strains of 15 other Bifidobacterium species were enzymatically characterized using 20 4-methylumbelliferyl conjugated substrates. Enzyme activities were determined by directly measuring the intensity of fluorescence derived from 4-methylumbelliferone, a fluorescent metabolic by-product. For this method, a Titertek Fluoroskan II fluorometer was used. Enzymes included glycosidases, an esterase, phosphatase, sulphatase, and neuraminidase. B. longum showed strong activity (greater than 1,000 absolute fluorescence units, afu) for alpha-L-Arabinopyranosidase and alpha-L-Arabinofuranosidase, beta-D-Fucosidase, alpha- and beta-D-Galactosidase, alpha-D-Glucosidase, and alpha-D-Mannosidase. No activity (less than or equal to 50 afu) was observed for beta-D-Cellobiosidase, alpha- and beta-L-Fucosidase, beta-D-Glucuronidase, beta-D-Mannosidase, Neuraminidase and Sulphatase. Enzymatic activity profiles in other bifidobacteria were different according to the species. This assay is simple and rapid (6 hr). Special cultural requirements are unnecessary. Results are objective and quantitative. This assay may be a useful tool for bifidobacterial taxonomy.

Influence of sympathetic nerve activity on ventricular arrhythmogenicity in the dog with chronic hypokalemia

To examine the influence of sympathetic nerve activity on ventricular arrhythmogenicity in the dog with chronic hypokalemia, an electrophysiologic study was performed before and after bilateral stellectomy (BS) in 10 dogs with chronic hypokalemia (2.8 +/- 0.1 mEq/L), which was created by feeding a low-potassium diet and by administering furosemide over a four-week period, and the results were compared with those obtained from 10 dogs with normokalemia (4.7 +/- 0.3 mEq/L) from being fed an ordinary diet over a four-week period. Before BS the incidence of electrically induced ventricular arrhythmias was higher in the hypokalemic than in the normokalemic dogs. After BS it was decreased considerably in the hypokalemic but not in the normokalemic dogs. Heterogeneity of effective refractory period (delta ERP), which was determined as the difference between the longest and shortest effective refractory periods in three sites of the right and left ventricles, was greater in the hypokalemic than in the normokalemic dogs before BS. The delta ERP decreased slightly in the two groups both before and after BS. There was, however, no significant difference in delta ERP in the two groups both before and after BS. Ventricular fibrillation threshold (VFT) was significantly lower in the hypokalemic dogs than in the normokalemic dogs before BS (p less than 0.005). VFT was elevated in the two groups after BS. Percent increase in VFT after BS was significantly greater in the hypokalemic than in the normokalemic dogs. In conclusion, sympathetic nerve activity may play an important role in the increase in ventricular arrhythmogenicity in the presence of chronic hypokalemia.

Effects of sympathetic and parasympathetic stimulation on the induction of atrial flutter in dogs with aseptic pericarditis

To study the effects of sympathetic stimulation (SS) and vagal stimulation (VS) on the induction of atrial flutter (AF) and its cycle length, aseptic pericarditis was produced surgically in 17 adult mongrel dogs. Programmed atrial stimulation was used to induce AF and to determine the effective refractory periods (ERP) and maximum conduction delay (maxCD) of the atrium. These tests were performed before and during stimulation of the right cervical vagus nerve and the right stellate ganglion. Results showed: (1) AF could be induced in animals with short ERP and large maxCD before SS; (2) ERP was significantly shortened, maxCD was significantly increased by VS; (3) During SS, ERP was slightly shortened, but there were no changes in maxCD and the induction rate of AF; (4) The cycle length of AF was shortened by SS, however, the cycle length of AF was shortened more notably by VS than by SS. From these findings, a shortening of the ERP and an increase in maxCD appear to be related to an increased AF induction rate by VS.

Effect of Konjac mannan on intestinal microbial metabolism in mice bearing human flora and in conventional F344 rats

The effects of dietary Konjac mannan (KM), a frequent ingredient of traditional Japanese foods, on intestinal microbial metabolism and microflora composition were investigated using two laboratory animal models, namely, conventional F344 rats and C3H/He male mice bearing human flora. Dietary KM led to a significant reduction in faecal beta-glucuronidase, nitroreductase and azoreductase activities, and in the production of phenol and indole in the faeces of conventional F344 rats. In the C3H/He male mice bearing human flora, faecal beta-glucuronidase and nitroreductase activities were significantly reduced by KM ingestion, as were the amounts of the putrefactive products, p-cresol and indole, in the faeces. Slight differences in intestinal microflora composition between control and KM diet groups were noted. The results indicate that, in C3H/He male mice bearing human flora, dietary KM may modify microbial metabolism without causing significant alterations in intestinal microflora composition.

Proposal of two subspecies of Fusobacterium necrophorum (Flügge) Moore and Holdeman: Fusobacterium necrophorum subsp. necrophorum subsp. nov., nom. rev. (ex Flügge 1886), and Fusobacterium necrophorum subsp. funduliforme subsp. nov., nom. rev. (ex Hallé 1898)

The biological and biochemical properties, DNA base compositions, and levels of DNA-DNA homology of two biovars of Fusobacterium necrophorum were examined. Some differences were found between the two biovars in biological and biochemical properties. The G + C contents of DNAs from biovar A strains VPI 2891T (T = type strain), NCTC 10576, N167, Fn47, and Fn43, were 32, 30, 29, 28, and 31 mol%, respectively. The G + C contents of DNAs from biovar B strains Fn524T, 606, Fn49, Fn45, and 1260 were 30, 31, 27, 31, and 30 mol%, respectively. Labeled DNA from biovar A strain VPI 2891T exhibited 100 to 80% relatedness to DNAs from biovar A strains and 59 to 51% relatedness to DNAs from biovar B strains. Labeled DNA from biovar B strain Fn524T exhibited 100 to 81% relatedness to DNAs from biovar B strains and 71 to 60% relatedness to DNAs from biovar A strains. Therefore, the names Fusobacterium necrophorum subsp. necrophorum subsp. nov., nom. rev. (ex Flügge 1886), and Fusobacterium necrophorum subsp. funduliforme subsp. nov., nom. rev. (ex Hallé 1898), are proposed for Fusobacterium necrophorum biovars A and B, respectively. The type strain of F. necrophorum subsp. necrophorum is strain VPI 2891 (= JCM 3718 = ATCC 25286), and the type strain of F. necrophorum subsp. funduliforme is strain Fn524 (= JCM 3724).

Effect of corn fiber residue supplementation on fecal properties, flora, ammonia, and bacterial enzyme activities in healthy humans

Effects of corn fiber residue (5 g/day for 10 days) on fecal weight, moisture, pH, fecal flora, ammonia content, and on the activities of beta-glucuronidase and beta-glucosidase were investigated in six healthy subjects. Corn fiber residue was remnant of hemicellulose extraction from corn fiber by calcium hydroxide. Fecal weight showed a tendency to increase, and fecal pH did not change during corn fiber residue supplementation. No remarkable changes in the fecal flora at the bacterial group level were observed. Fecal ammonia content and beta-glucuronidase activity per gram of wet feces decreased slightly but the daily output did not change. Fecal beta-glucosidase activities per gram of wet feces increased significantly (p less than 0.05) and the daily output also tended to increase during corn fiber residue supplementation.

Isolation and identification of clostridia from the intestine of laboratory animals

Quantitative and qualitative examination of faecal clostridia from laboratory mice, rats, hamsters and rabbits was carried out by using selective as well as nonselective culture techniques. The 364 isolates were identified where possible, to species level on the basis of physiological and biochemical characteristics. Most isolates from mice and rabbits were identified, i.e. 79.4% and 76.5%, respectively, while only 25.4% and 28.6% of isolates from rats and hamsters were characterized as described species. The most common species of the 16 identified were: C. coccoides, C. cocleatum and C. innocuum from mice; C. cocleatum, C. cochlearium and C. irregularis from rats; C. cocleatum and C. irregularis from hamsters; and C. aminovalericum and C. irregularis from rabbits. Unidentified Clostridium spp. were isolated from each animal species tested and were tentatively classified into 26 groups. None of these groups was found in more than one animal species in this study.

Arrhythmogenic properties of the ventricular myocardium in cardiomyopathic Syrian hamster, BIO 14.6 strain

STUDY OBJECTIVE

Incidence of spontaneous cardiac arrhythmias and inducibility of ventricular arrhythmias in the cardiomyopathic hamster, BIO 14.6 strain, were examined.

DESIGN

A 3 min electrocardiogram (ECG) was recorded weekly to 50 weeks of age. Programmed ventricular stimulation was then performed with single and double ventricular premature stimuli during both sinus rhythm and ventricular pacing, and with brief bursts of ventricular pacing to induce ventricular arrhythmias.

EXPERIMENTAL MATERIAL

19 male cardiomyopathic and 10 age matched normal hamsters from 16 to 50 weeks were used for recording the 3 min ECG; 11 cardiomyopathic and 10 normal hamsters aged 50 to 55 weeks were used for the induction of ventricular arrhythmias.

MEASUREMENTS AND MAIN RESULTS

Spontaneous and sporadic ventricular premature contractions were documented in 8.3% of 218 ECGs from the cardiomyopathic hamsters between the ages of 30 and 46 weeks, whereas no ventricular arrhythmia was recorded in normal hamsters throughout the entire follow up period. Non-sustained ventricular tachycardia (NSVT) was induced in 7/11 cardiomyopathic hamsters by single ventricular premature stimulus. Either NSVT or ventricular fibrillation was induced in all cardiomyopathic hamsters with a significantly prolonged intraventricular conduction delay and refractory period. In contrast, neither NSVT nor ventricular fibrillation was induced in normal hamsters.

CONCLUSION

This study provides the first evidence of the high arrhythmogenicity of the ventricles in cardiomyopathic hamsters.