beta-Lactum resistance in aerobic commensal faecal flora

Faecal specimens from 100 healthy volunteers living in Edinburgh were examined for the presence of antibiotic-resistant bacteria. A high incidence of ampicillin resistance was found as 42% of specimens containing normally sensitive bacteria were resistant to the drug; however, only 12% of the specimens contained trimethoprim-resistant bacteria. There was no detectable resistance to the third-generation cephalosporin, ceftazidime or the 4-quinolone, ciprofloxacin. Identification of the β-lactamases produced by the ampicillin-resistant isolates demonstrated that the TEM-1 β-lactamase predominated particularly in E. coli where it was identified in 86% of isolates. Thirty-three percent of the ampicillin-resistant isolates were able to transfer their resistance to E. coli K12 strain J62-2 and analysis of these transconjugants by iso-electric focusing revealed that the TEM-1 β-lactamase was present in 100% of the transconjugants. Restriction endonuclease fingerprinting of the TEM-1 containing plasmids suggested the presence of an epidemic plasmid in the community.     

A new questionnaire for constipation and faecal incontinence

BACKGROUND: The prevalence, severity and risk factors of faecal incontinence in women in the community are incompletely characterized. AIM: To develop and validate a self-report questionnaire (faecal incontinence and constipation assessment) to address these issues. METHOD: Eighty-three women completed the instrument; 20 randomly selected patients answered the faecal incontinence and constipation assessment again 6 weeks later. A gastroenterologist also completed the faecal incontinence and constipation assessment in all 83 subjects after a detailed clinical assessment. Concurrent validity was evaluated by comparing the patient's self-report to a doctor interview for every question. Reproducibility was evaluated by a test-retest approach for every question. The severity of faecal incontinence was rated by incorporating the frequency and type of faecal incontinence, rectal urgency and use of sanitary devices. RESULTS: The questionnaire was well-understood. Reproducibility [median kappa statistic, 0.80 (interquartile range: 0.66-0.90)]; and concurrent validity [0.59 (0.47-0.67)] were acceptable. For the index question on faecal incontinence, the kappa for reproducibility and concurrent validity was 0.90 and 0.95, respectively. The faecal incontinence severity score was also valid (kappa = 0.5). CONCLUSION: The faecal incontinence and constipation assessment has excellent reproducibility and reasonable validity for assessing the presence, risk factors and severity of faecal incontinence and associated bowel disorders in women when compared against clinical assessment.     

Influence of moclobemide on ibuprofen-induced faecal blood loss

In a pharmacological screen on drug-drug interactions performed in laboratory animals moclobemide potentiated at high doses the antiphlogistic/anti-inflammatory activity of ibuprofen. Therefore, a study was undertaken to determine in healthy volunteers the faecal blood loss induced by multiple doses of ibuprofen (600 mg t.i.d.) in presence and absence of steady-state concentrations of concomitantly administered moclobemide (150 mg t.i.d.). The results show that multiple doses of moclobemide do not change faecal blood loss induced by ibuprofen. Furthermore, no clinically relevant pharmacokinetic interaction between the two drugs studied was detected.     

New reagents for detection of faecal occult blood

Imipramine hydrochloride (IPH) and desipramine hydrochloride (DPH), two widely used antidepressant drugs, are proposed as new reagents for detection of faecal occult blood. The usefulness of IPH and DPH in occult blood detection has been examined and compared with benzidine and stanoccult methods. The results show that the proposed reagents are selective and sensitive and gives reproducible results. The proposed methodology is much less subject to vegetable peroxidase, iron and vitamin C interference and can be performed on patients who are on a normal diet.     

Neuropeptide S inhibits stress-stimulated faecal output in the rat

Neuropeptide S (NPS) is a recently identified bioactive peptide that activates an orphan G-protein coupled receptor, called the NPS receptor (NPSR). In rats, NPS and NPSR constitute a novel neuropeptide system expressed both in the central nervous system and in peripheral tissues, controlling visceromotor, neuroendocrine, nociceptive and behavioural responses. To improve the knowledge of the role of the NPS–NPSR system in the gastrointestinal (GI) tract, we investigated: 1- the supraspinal effect of NPS on motor functions of the upper (gastric emptying and gastrointestinal transit) and lower (distal colonic transit and faecal output) GI tract under basal conditions, 2- during pathological states (restraint stress and corticotropin releasing factor (CRF)-induced defecation) in the rat, and 3- the receptor type involved in treatment with NPS using NPS, tachykinin NK₃ and opioid receptor antagonists (([D-Cys(tBu)⁵]NPS), SR142801 and naloxone, respectively).Intracerebroventricular injection of NPS failed to modify basal gastric emptying, gastrointestinal transit and distal colon propulsion, but significantly and dose-dependently reduced faecal pellet excretion and weight stimulated by restraint stress and CRF. The inhibitory effect of NPS on stress-induced defecation was unmodified by pre-treatment with either the tachykinin or opioid receptor antagonists, but was counteracted by a NPSR antagonist.The present study demonstrates, for the first time, that the supraspinal NPS system, which does not participate in the physiological control of GI motility, plays an inhibitory role on defecation stimulated by restraint stress and CRF. The combination of the ability of NPS to inhibit faecal output together with its known anxiolytic effect may be promising, especially in pathological conditions such as irritable bowel syndrome, where stress and the hyperactivity of the CRF system contribute to the co-morbidity of anxiety with colonic motor symptoms such as diarrhoea.     

Review article: faecal transplantation therapy for gastrointestinal disease

Aliment Pharmacol Ther 2011; 34: 409–415

Summary

Background Evidence is emerging regarding the relationship between a dysbiosis of the human gut microbiota and a number of gastrointestinal diseases as well as diseases beyond the gut. Probiotics have been investigated in many gastrointestinal disease states, with variable and often modest outcomes. Faecal transplantation is an alternative approach to manipulate the gut microbiota. Aim To review the use of faecal transplantation therapy for the management of gastrointestinal disorders. Methods Available articles on faecal transplantation in the management of gastrointestinal disorders were identified using a Pubmed search and bibliographies of review articles on the subject were collated. Results A total of 239 patients who had undergone faecal transplantation were reported. Seventeen of 22 studies of faecal transplantation were in fulminant or refractory Clostridium difficile. Studies of faecal transplantation are heterogeneous regarding the patients, donors, screening, methods of administration and definition of response. Faecal transplantation for C. difficile has been demonstrated to be effective in 145/166 (87%) patients. Small numbers of patients are reported to have undergone successful faecal transplantation for irritable bowel syndrome and inflammatory bowel disease. Conclusions Faecal transplantation has been reported with good outcomes for fulminant and refractory C. difficile. No adverse effects of faecal transplantation have been reported. However, there are no level 1 data of faecal transplantation and reports to date may suffer from reporting bias of positive outcomes and under‐reporting of adverse effects. This therapy holds great promise, where a dysbiosis of the gut microbiota is responsible for disease and further studies are necessary to explore this potential.     

Metabolic adaptation of rat faecal microflora to cyclamate in vitro

Previous studies have demonstrated that the rat faecal microflora maintained in vitro under conditions of continuous flow possesses bacteriological and metabolic characteristics similar to those of the native bacterial population of the caecum. Addition of sodium cyclamate (75 mm) to the culture concurrent with the progressive dilution of the growth medium promoted metabolism of cyclamate to cyclohexylamine (sulphamatase activity) within 4 wk. The maximum formation of cyclohexylamine was attained in about 8 wk and was equivalent to a 2–3% molar conversion of cyclamate to cyclohexylamine. The recovery of viable cells from the culture and the total microscopic count decreased during the adaptation period, although the relative proportions of the major bacterial types remained unchanged. Concurrent with the increase in sulphamatase activity, other enzyme functions (as assessed by the API-zym system) decreased markedly. The ability to hydrolyse cyclamate to cyclohexylamine developed independently of other bacterial biotransformation enzymes in vitro, and was not associated with any gross taxonomic changes. These studies demonstrate the suitability of continuous culture systems for investigating the metabolic activity of the rat gut flora.     

Review article: faecal occult blood testing for colorectal cancer

Major health organizations recommend colorectal cancer screening using faecal occult blood tests, sigmoidoscopy or both for patients 50 years of age or older who are at average risk for colorectal cancer. However, no specific recommendations have been made regarding choice of test from among the tests currently or soon to be available. Therefore, to aid clinicians in rationally choosing a particular test for faecal occult blood, published data are reviewed regarding the performance characteristics, strengths and weaknesses of the various faecal occult blood tests. New studies suggest that immunochemical tests (e.g. HemeSelect) or a combination of sensitive guaiac tests and immunochemical tests (e.g. Hemoccult Sensa and HemeSelect) are the most sensitive, specific tests for detecting colorectal carcinoma and colorectal polyps ≥ 1 cm.     

Dapagliflozin modulates the faecal microbiota after myocardial infarction in non-diabetic mice

The gut microbiota seems to be a major modulator of cardiovascular diseases, such as myocardial infarction. Dapagliflozin, a sodium glucose cotransporter 2 inhibitor (SGLT2i), is an antidiabetic agent that was recently utilized in patients with cardiovascular diseases. This study aims to investigate the effects of dapagliflozin on the faecal microbiota of postinfarction non-diabetic mice. A total of 19 male mice were randomly divided into three groups, where two groups were enduced with myocardial infarction (MI) by left anterior descending ligation. One day after the surgery, each group was administered normal saline (15 mL/kg/day, 0.9%) or dapagliflozin (1.5 mg/kg/day) for 4 weeks. Echocardiography was obtained on day 28 post MI. Masson's trichrome staining was used to determine the degree of fibrosis. Faecal samples were collected to assess the microbiome by 16S ribosomal RNA gene sequencing. We found that dapagliflozin significantly improved cardiac function in the non-diabetic myocardial infarction mice model after the 28-day treatment, especially in ejection fraction and fractional shortening (p < 0.01). Enterotypes were composed of Muribaculaceae and Lactobacillaceae after dapagliflozin treatment, while Muribaculaceae and Erysipelotrichaceae were the main enterotypes post-MI. Dapagliflozin increased the abundance of beneficial bacteria like Lactobacillaceae, while decreasing the abundance of beneficial bacteria like Bifidobacteriaceae. It was interesting to discover that Proteobacteria (especially Desulfovibrionaceae) were enriched after the dapagliflozin treatment for myocardial infarction. Dapagliflozin increased the abundance of the main beneficial bacteria. In post-myocardial infarction treatments, using dapagliflozin could positively contribute to the improvement of cardiac function and alter the structure of faecal microbiota.