深海链霉菌Streptomyces sp.SCSIO 04777中肠道菌素的分离鉴定

目的对从印度洋深海沉积物中分离的1株深海放线菌Streptomyces sp.SCSIO 04777进行鉴定并对其抗菌活性次级代谢产物进行研究。方法通过16SrDNA序列分析并构建系统发育进化树来鉴定菌株,利用有机溶剂萃取、正相和反相硅胶层析等分离手段对海洋放线菌SCSIO 04777的发酵产物进行分离纯化,通过波谱数据分析并参阅文献对化合物进行结构鉴定。结果该放线菌被鉴定为Streptomyces sp.SCSIO04777,并从其发酵产物中分离鉴定了芳香聚酮类化合物-肠道菌素。结论首次筛选得到了1株产生肠道菌素的深海链霉菌,为肠道菌素的开发利用提供了新的菌株资源。

非肠道头孢菌素的药理作用

非肠道头孢菌素(parenteral cephalosporins)是医院最常用的抗感染药物之一,按其发明时间的先后分为第一、第二、第三和第四代.与喹诺酮类及氨基糖苷类抗生素相比,抗菌谱广,对厌氧菌有效,作用时间长,耐受性好,副反应小,除肠球菌和对甲氧苯青霉素耐药的金黄色葡萄球菌外,不易产生耐药变异体.另外,这类药物在水溶液中稳定性较好,静脉输注后,在血清和组织中能很快达到有效浓度.目前,在门诊治疗中,非肠道头孢菌素主要用于蜂窝组织炎、骨髓炎、心内膜炎、肺炎、慢性肺部感染、细菌性脑膜炎(特别是儿童)、骨盆炎及无并发症的肾盂肾炎[1～3].

关于非肠道头孢菌素临床药理作用探究

目的对非肠道头孢菌素临床药理作用进行探究。方法 210株腹泻患者菌株,对其大便进行标本培养,致病菌通过生化以及血清进行鉴定。结果通过检查,氨苄西林以及复方新诺明具有较高的耐药率,分别为94.29%、84.76%。结论由耐三代头孢菌素所产生的肠道病原菌上升速度较快,应予以相应的重视,并增强预防。

阴沟杆菌肺内感染的临床特点和药敏测定

目的 总结阴沟杆菌肺内感染的临床特点及该菌对常用抗生素的敏感性。方法分析30例阴沟杆菌下呼吸道感染的临床资料，以纸片法（K—B法）或琼脂稀释法（Etest法）测定该菌的体外药物敏感性。结果86．7％（26／30）的患者有基础疾病，其中以慢性阻塞性肺疾病最常见，60．0％（18／30）的病例为混合感染，混合菌主要为绿脓杆菌、肺炎克雷伯菌和真菌。症状为发热和咳嗽、咳痰，胸部X线表现为分布于两下肺野的支气管肺炎改变，病死率为10．0％（3／30）。药敏试验提示该菌呈现多重耐药，亚胺培南、阿米卡星、妥布霉素、环丙沙星、头孢哌酮为较敏感抗生素。结论阴沟杆菌肺内感染患者多有基础疾病，临床表现不典型，以支气管肺炎改变为主，诊断依靠病原学并结合临床及X线检查，治疗应根据药敏试验并联合应用抗生素。

Irritable bowel syndrome:Diagnosis and pathogenesis

Irritable bowel syndrome (IBS) is a common gastro-intestinal (GI) disorder that considerably reduces the quality of life. It further represents an economic burden on society due to the high consumption of healthcare resources and the non-productivity of IBS patients. The diagnosis of IBS is based on symptom assessment and the Rome Ⅲ criteria. A combination of the Rome Ⅲ criteria, a physical examination, blood tests, gastros-copy and colonoscopy with biopsies is believed to be necessary for diagnosis. Duodenal chromogranin A cell density is a promising biomarker for the diagnosis of IBS. The pathogenesis of IBS seems to be multifactorial, with the following factors playing a central role in the pathogenesis of IBS:heritability and genetics, dietary/intestinal microbiota, low-grade inflammation, and disturbances in the neuroendocrine system (NES) of the gut. One hypothesis proposes that the cause of IBS is an altered NES, which would cause abnormal GI motility, secretions and sensation. All of these abnormalities are characteristic of IBS. Alterations in the NES could be the result of one or more of the following:genetic factors, dietary intake, intestinal flora, or lowgrade inflammation. Post-infectious IBS (PI-IBS) and inflammatory bowel disease-associated IBS (IBD-IBS) represent a considerable subset of IBS cases. Patients with PI-and IBD-IBS exhibit low-grade mucosal inflammation, as well as abnormalities in the NES of the gut.

Psychosocial determinants of irritable bowel syndrome

From a pure motor disorder of the bowel,in the past few years,irritable bowel syndrome (IBS) has become a multifactorial disease that implies visceral hypersensitivity,alterations at the level of nervous and humoral communications between the enteric nervous system and the central nervous system,alteration of the gut microflora,an increased intestinal permeability and minimum intestinal inflammation.Psychological and social factors can interfere with the communication between the central and enteric nervous systems,and there is proof that they are involved in the onset of IBS and influence the response to treatment and outcome.There is evidence that abuse history and stressful life events are involved in the onset of functional gastrointestinal disorders.In order to explain clustering of IBS in families,genetic factors and social learning mechanisms have been proposed.The psychological features,such as anxiety,depression as well as the comorbid psychiatric disorders,health beliefs and coping of patients with IBS are discussed in relation to the symptoms and outcome.

Rifaximin in the treatment of inflammatory bowel disease

The gut microbiota plays a role in promoting and maintaining inflammation in inflammatory bowel diseases （IBD）, hence the rationale for the use of antibiotics in the treatment of those disorders. Antibiotics, however, may induce untoward effects, especially during longterm therapy. Rifaximin α polymer is an antibacterial agent that is virtually unabsorbed after oral administration and is devoid of systemic side effects. Rifaximin has provided promising results in inducing remission of Crohn＇s disease （up to 69% in open studies and significantly higher rates than placebo in double blind trials） and ulcerative colitis （76% in open studies and significantly higher rates than placebo in controlled studies） and might also have a role in maintaining remission of ulcerative colitis and pouchitis. The potential therapeutic activity of rifaximin in IBD deserves to be further investigated and confirmed in larger, controlled studies. The optimal dosage still needs to be better defined.

Probiotics in hepatology

The paper provides a basic review of intestinal microflora and its importance in liver diseases. The intestinal microflora has many important functions, above all to maintain the microbial barrier against established as well as potential pathogens. Furthermore, it influences the motility and perfusion of the intestinal wall, stimu- lates the intestinal immune system and therefore also the so-called common mucosal immune system, reducing bacterial translocation and producing vitamins. Immune homeostasis at mucosal level results from a controlled response to intestinal luminal antigens. In liver cirrhosis, there are many changes in its function, mostly an increase in bacterial overgrowth and translocation. In this review, probiotics and their indications in hepatology are generally discussed. According to recent knowledge, these preparations are indicated in clinical practice only for cases of hepatic encephalopathy. Probiotics are able to decrease the permeability of the intestinal wall, and decrease bacterial translocation and endotoxemia in animal models as well as in clinical studies, which is extremely important in the prevention of complications of liver cirrhosis and infection after liver transplantation. Probiotics could limit oxidative and inflammatory liver damage and, in some situations, improve the histological state, and thus non-alcoholic steatohepatitis could be considered as another possible indication.

Effects of severe acute pancreatitis on gut bacteria/endotoxin translocation in pigs

Objective： To set up a swine model of severe acute pancreatitis（SAP） and to observe its relationship with the gut-originated bacteria/endotoxin translocation. Methods： Forty pigs weighing 17-22 kg were randomly diyided into SAP group （n=34） and sham-SAP group （n=6）. By injecting 1 ml/kg of combined solution of 5% sodium taurocholate and 8 000-10 000 benzoyl arginine ethyl ester（BAEE） units trypsin per milliliter into pancreas via pancreatic duct, SAP was induced under anesthesia. Endotoxin samples from vena cava were determined by chromogenic limulus amebocyte lysate （LAL） technique. Both portal and central vena blood samples were collected before and 72 h after the induction of SAP and cultured for both aerobic and anaerobic bacterial growth. Animals were sacrificed at the end of experiments by injecting 20 ml of 10% KCl intravenously and tissue specimens of mesenteriolum and mesocolon lymph nodes, lung, pulmonary portal lymph nods and pancreas were taken immediately after animal death, and homogenized for bacteriological studies. Results： Systemic plasma endotoxin levels increased rapidly 6 h post induction of SAP（PIS） with a peak at 48 h PIS （P〈0.01）. The magnitude of bacterial translocation in both portal and systemic blood and remote systemic organs as well were recovered PIS. Conclusion： （1） A swine model of SAP was established; （2）The early endotoxemia PIS seamed probable originated from gut endotoxin translocation; （3）The magnitude of bacterial translocation in both portal and systemic blood and the remote systemic organs as well were recovered at 72h PIS.

Characterization of dominant and cellulolytic bacterial communities along the gut of silver carp Hypophthalmichthys molitrix during cyanobacterial blooms

Silver carp is one of the most important planktivorous fish in Chinese aquaculture and plays a significant role controlling cyanobacterial blooms. A balanced gut microbiota is crucial for growth and health of the host because of its important roles in immune defense, digestion of complex carbohydrates, and production of enterocytes. In our study, the dominant bacterial and cellulolytic bacterial （Clostridium 1, Clostridium 111, Clostridium XIVab, and Fibrobacter） communities in the contents and mucus of the silver carp gut （foregut, midgut, and hindgut） were analyzed by denaturing gradient gel electrophoresis and quantitative polymerase chain reaction （qPCR） analyses. The results revealed that the dominant and cellulolytic bacterial communities were significantly different among gut regions as well as in contents and mucus. Bacterial diversity and richness in contents and mucus increased along the gut and were higher in contents than those in local mucus. A sequence analysis of gut samples exhibited the conservative phylotypes of Proteobacteria, Actinobacteria, and Firmicutes. The gut of silver carp harbored an abundance of cellulolytic bacteria, particularly Clostridium XIVab. The foregut segment had the highest proportions of the four cellulolytic bacteria, followed by the midgut and hindgut. However, the proportions of cellulolytic species in the silver carp gut was much lower than those in the terrestrial vertebrate gastrointestinal tract. We conclude that gut bacteria could help silver carp obtain energy from cyanobacteria, which may be why silver carp can maintain high growth rates during cyanobacterial blooms.

Suspected Resistance against Moxidectin in Sheep Strongylid Nematodes in Austria

Loss of efficacy due to resistance development against anthelmintics in livestock parasites is a growing concern worldwide. The aim of the present study was to determine the efficacy of moxidectin, a frequently-used macrocyclic lactone, against gastrointestinal nematodes of sheep in Austria. Individual faecal samples were collected from 243 adult sheep from 16 flocks in Styria and Salzburg before deworming and egg excretion （EPG （eggs per gram） of faeces） was determined using a modified McMaster technique. The animals were randomly assigned to a treatment group which received 0.2 mg/kg of body weight of moxidectin （Cydectin , Zoetis Schweiz GmbH, Zurich, Switzerland）, and an untreated control group. Fourteen days after deworming a FECRT （faecal egg count reduction test） for detection of anthelmintic resistance was performed. Before deworming, the infection rate for gastrointestinal strongylids was 94.7%, with EPG values of 0-5,800. The FECRT showed reduction rates between 93.08% and 99.78% and was sufficient in 15/16 flocks. The lower confidence interval was 70.0-100%. In 3/16 flocks this value was below the minimum for sufficient efficacy （70.0%, 79.0%, 85.0%）, and in two flocks the value （90,0%） was near the limit. These results indicated a （suspected） reduced efficacy of moxidectin in 5/16 examined flocks.

美替拉酮对放线菌Streptomyces sp.LXF-80代谢途径的影响

目的渤海海泥来源放线菌Streptomyces sp.LXF-80可以生产罕见的包含α-吡喃酮的三环骈合聚酮化合物肠道菌素(Enterocin)。美替拉酮是1种细胞色素P450氧化酶的抑制剂,本实验试图利用美替拉酮影响肠道菌素的生合成过程,表达获得新的聚酮类化合物。方法向LXF-80的发酵培养基中添加酶抑制剂,结合HPLC分析确定最优条件,并进行大规模发酵和目标产物的分离。结果从添加美替拉酮的LXF-80发酵提取物中共分离获得3个化合物,包括Enterocin(1)、5-deoxyenterocin(2)以及3-epi-5-deoxyenterocin(3)。结论实验结果证明美替拉酮的添加,影响了菌株聚酮类化合物的生合成过程,得到2个肠道菌素的形成过程中的中间体化合物2和3。

Outcomes and prognostic factors of fecal microbiota transplantation in patients with slow transit constipation:results from a prospective study with long-term follow-up

Background and aim:Gutmicrobiotamay contribute to regulate colonicmotility,which is involved in the etiology of constipation.Fecalmicrobiota transplantation(FMT)has been demonstrated to restore intestinal homeostasis.The aimof this study was to evaluate the clinical outcomes and prognostic factors of FMT for the treatment of slow transit constipation(STC).Methods:Fifty-two patients with STC received standardized FMT and were followed up for 6 months.Bowel habit,colonic transit time,constipation-related symptoms(PAC-SYM score),quality of life(PAC-QOL score),treatment satisfaction scores and adverse events were monitored.The primary efficacy endpoint was the proportion of patients having on average three or more complete spontaneous bowel movements(CSBMs)per week.Results:The primary efficacy endpoint was achieved in 50.0%,38.5%and 32.7%of patients over week intervals 3–4,9–12 and 21–24,respectively(P<0.01 for all comparisons).Significant improvements were also observed in other bowel movement assessments,colonic transit time,constipation-related symptoms and quality of life;but all improvements diminished at weeks 12 and 24.Incompleteness of evacuation served as the only factor associated with efficacy.No serious treatmentrelated adverse events were observed.Conclusion:This study suggested FMT was effective and safe for STC,while a late loss of efficacy was also observed.A lower degree of sensation of incompleteness predicted a better outcome.

Changes in peripheral blood inflammatory factors(TNF-α and IL-6) and intestinal flora in AIDS and HIV-positive individuals

Objective:In this study,we investigated the changes in peripheral blood inflammatory factors and intestinal flora in acquired immune deficiency syndrome(AIDS)and human immunodeficiency virus(HIV)-positive individuals(AIDS/HIV patients),and explored the relationships among intestinal flora,peripheral blood inflammatory factors,and CD4^+T lymphocytes.Methods:Thirty blood and stool samples from an AIDS group and a control group were collected.The levels of tumor necrosis factor-α(TNF-α)and interleukin-6(IL-6)were determined by enzyme-linked immunosorbent assay(ELISA),and the number of CD4^+T lymphocytes by a FACSCount automated instrument.Quantitative real-time polymerase chain reaction(qRT-PCR)was used to determine the messenger RNA(mRNA)levels of Bifidobacterium,Lactobacillus,Escherichia coli,Enterococcus faecalis,and Enterococcus faecium.Correlations among intestinal flora,inflammatory factor levels,and CD4^+T lymphocyte values were evaluated using the Spearman correlation coefficient.Results:The levels of TNF-αand IL-6 in the AIDS group were higher than those in the control group,while the number of CD4^+T lymphocytes was lower.The amounts of Bifidobacterium and Lactobacillus in the AIDS group were significantly lower than those in control group,while the amounts of E.coli,E.faecalis,and E.faecium were much higher.The amounts of Bifidobacterium and Lactobacillus were negatively correlated with the content of TNF-αand IL-6 and the CD4^+T lymphocyte count,while those correlations were reversed for E.coli,E.faecalis,and E.faecium.Conclusions:The intestinal microbiota of AIDS/HIV patients were disordered,and there was a correlation between the amount of intestinal flora and the number of CD4^+T lymphocytes and the levels of TNF-αand IL-6.

Effect of feeding Lactobacillus plantarum P-8 on the faecal microbiota of broiler chickens exposed to lincomycin

Poultry and eggs are nutritious and healthy foods that contain high-quality proteins and low levels of fat compared with other meats. Recent studies have shown that poultry performance is closely associated with colonic health. Antibiotics are commonly used in the poultry industry to control diseases and enhance survival rates. However, antibiotic use can also result in host gut dysbiosis and immune dysregulation. Such imbalances compromise poultry health and growth performance. Thus, our study investigated the effect of Lactobacillus(L.) plantarum P-8 on the gut microbiome of chickens co-inoculated with the antibiotic lincomycin. Principal coordinate analysis showed that L. plantarum P-8 treatment shifted the faecal bacterial population structure. At the metagenomic level, the Clusters of Orthologous Groups(COGs) functional categories of P, C, N and A were overrepresented in the probiotic group. Additionally, the relative gene abundances of metabolic pathways involved in flagellar assembly,bacterial chemotaxis, nitrogen metabolism, sulfur metabolism, cofactor and vitamin biosynthesis were also higher in the probiotic group than the control; in contrast genes related to galactose degradation,carbon fixation, multiple sugar transport systems and ribosomes were underrepresented in the probiotic group. Our data suggest that feeding L. plantarum P-8 has the potential to improve metabolic activity and nutrient utilization of poultry. Furthermore, the faecal antibiotic resistomes of the two groups could be separated using principal components analysis, indicating that the probiotic treatment may modulate the intestinal antibiotic resistance gene pool by changing the population structure of the gut microbiota.This study has provided interesting insights into the application of probiotics in the poultry industry.