Efficacy of two low-dose oral tylosin regimens in controlling the relapse of diarrhea in dogs with tylosin-responsive diarrhea: a prospective, single-blinded, two-arm parallel, clinical field trial

Peer reviewe

Streptococcus alactolyticus is the dominating culturable lactic acid bacterium species in canine jejunum and feces of four fistulated dogs

http://www.elsevier.com/locate/issn/03781097Canine intestinal lactic acid bacterium (LAB) population in four fistulated dogs was cultured and enumerated using MRS agar. LAB levels ranging from 1.4×106 to 1.5×107 CFU ml-1 were obtained in jejunal chyme. In the fecal samples 7.0×107 and 2.0×108 CFU g-1 were detected. Thirty randomly selected isolates growing in the highest sample dilutions were identified to species level using numerical analysis of 16 and 23 S rDNA RFLP patterns (ribotyping) and 16S rDNA sequence analysis. According to these results, Streptococcus alactolyticus was the dominant culturable LAB species in both faeces and jejunal chyme. In addition, Lactobacillus murinus and Lactobacillus reuteri were detected

The effect of the macrolide antibiotic tylosin on microbial diversity in the canine small intestine as demonstrated by massive parallel 16S rRNA gene sequencing

BACKGROUND: Recent studies have shown that the fecal microbiota is generally resilient to short-term antibiotic administration, but some bacterial taxa may remain depressed for several months. Limited information is available about the effect of antimicrobials on small intestinal microbiota, an important contributor to gastrointestinal health. The antibiotic tylosin is often successfully used for the treatment of chronic diarrhea in dogs, but its exact mode of action and its effect on the intestinal microbiota remain unknown. The aim of this study was to evaluate the effect of tylosin on canine jejunal microbiota. Tylosin was administered at 20 to 22 mg/kg q 24 hr for 14 days to five healthy dogs, each with a pre-existing jejunal fistula. Jejunal brush samples were collected through the fistula on days 0, 14, and 28 (14 days after withdrawal of tylosin). Bacterial diversity was characterized using massive parallel 16S rRNA gene pyrosequencing. RESULTS: Pyrosequencing revealed a previously unrecognized species richness in the canine small intestine. Ten bacterial phyla were identified. Microbial populations were phylogenetically more similar during tylosin treatment. However, a remarkable inter-individual response was observed for specific taxa. Fusobacteria, Bacteroidales, and Moraxella tended to decrease. The proportions of Enterococcus-like organisms, Pasteurella spp., and Dietzia spp. increased significantly during tylosin administration (p < 0.05). The proportion of Escherichia coli-like organisms increased by day 28 (p = 0.04). These changes were not accompanied by any obvious clinical effects. On day 28, the phylogenetic composition of the microbiota was similar to day 0 in only 2 of 5 dogs. Bacterial diversity resembled the pre-treatment state in 3 of 5 dogs. Several bacterial taxa such as Spirochaetes, Streptomycetaceae, and Prevotellaceae failed to recover at day 28 (p < 0.05). Several bacterial groups considered to be sensitive to tylosin increased in their proportions. CONCLUSION: Tylosin may lead to prolonged effects on the composition and diversity of jejunal microbiota. However, these changes were not associated with any short-term clinical signs of gastrointestinal disease in healthy dogs. Our results illustrate the complexity of the intestinal microbiota and the challenges associated with evaluating the effect of antibiotic administration on the various bacterial groups and their potential interactions

Discounting of Evolutionary Explanations in Sociology Textbooks and Curricula

Despite being internally fragmented by clashes of paradigms, sociology textbooks and introductory courses show a remarkable similarity in their content, while they share a peculiar neglect of small scale societies, non-human social relations, as well as evolutionary explanations. The mistreatment is explained by the strong position of sociology in the nature vs. nurture debate, by paradigmatic and ideologically motivated condemnations, by the later misuse of Social Darwinism, by certain unresolved issues of evolutionary explanations of human sociality, and by epistemological critiques of evolutionary explanations. The current study assesses the extent of this avoidance in sociology by three methods: a review of major sociology textbooks, a descriptive quantitative text analysis of introductory course outlines at top ranked universities, and a keyword search in the all-time most emblematic classical books in sociology. In reaction to this mistreatment, the benefits of synthesis of sociological explanations with evolutionary thinking are discussed

Comparison between Cultured Small-Intestinal and Fecal Microbiotas in Beagle Dogs

The microbiota of the small intestine is poorly known because of difficulties in sampling. In this study, we examined whether the organisms cultured from the jejunum and feces resemble each other. Small-intestinal fluid samples were collected from 22 beagle dogs with a permanent jejunal fistula in parallel with fecal samples. In addition, corresponding samples from seven of the dogs were collected during a 4-week period (days 4, 10, 14, and 28) to examine the stability of the microbiota. In the jejunal samples, aerobic/facultative and anaerobic bacteria were equally represented, whereas anaerobes dominated in the fecal samples. Despite lower numbers of bacteria in the jejunum (range, 10(2) to 10(6) CFU/g) than in feces (range, 10(8) to 10(11) CFU/g), some microbial groups were more prevalent in the small intestine: staphylococci, 64% versus 36%; nonfermentative gram-negative rods, 27% versus 9%; and yeasts, 27% versus 5%, respectively. In contrast, part of the fecal dominant microbiota (bile-resistant Bacteroides spp., Clostridium hiranonis-like organisms, and lactobacilli) was practically absent in the jejunum. Many species were seldom isolated simultaneously from both sample types, regardless of their overall prevalence. In conclusion, the small intestine contains a few bacterial species at a time with vastly fluctuating counts, opposite to the results obtained for the colon, where the major bacterial groups remain relatively constant over time. Qualitative and quantitative differences between the corresponding jejunal and fecal samples indicate the inability of fecal samples to represent the microbiotas present in the upper gut