Sugarcane leaves-derived polyphenols alleviate metabolic syndrome and modulate gut microbiota of ob/ob mice

Sugarcane leaves-derived polyphenols(SLP)have been demonstrated to have diverse health-promoting benefits,but the mechanism of action has not been fully elucidated.This study aimed to investigate the anti-metabolic disease effects of SLP and the underlying mechanisms in mice.In the current study,we prepared the SLP mainly consisting of three flavonoid glycosides,three phenol derivatives,and two lignans including one new compound,and further demonstrated that SLP reduced body weight gain and fat accumulation,improved glucose and lipid metabolism disorders,ameliorated hepatic steatosis,and regulated short-chain fatty acids(SCFAs)production and secondary bile acids metabolism in ob/ob mice.Notably,SLP largely altered the gut microbiota composition,especially enriching the commensal bacteria Akkermansia muciniphila and Bacteroides acidifaciens.Oral gavage with the above two strains ameliorated metabolic syndrome(MetS),regulated secondary bile acid metabolism,and increased the production of SCFAs in high-fat diet(HFD)-induced obese mice.These results demonstrated that SLP could be used as a prebiotic to attenuate MetS via regulating gut microbiota composition and further activating the secondary bile acids-mediated gut-adipose axis.

Bacteroides-derived isovaleric acid enhances mucosal immunity by facilitating intestinal IgA response in broilers

Background:The interaction between nutrition and immunity plays a vital role in nutrient digestion,absorption,and metabolism during poultry production.Recent studies showed that the gut microbiota contributes to the development of intestinal mucosal immunity.However,the mechanisms by which gut microbes regulate this process remain unclear.Methods:We compared the intestinal mucosal immunity and gut microbiota of Arbor Acre broilers AA(lower mucosal immunity)and Chinese native Wuliang Mountain Black-bone chickens(WLMB)(higher mucosal immunity)using 16S rDNA sequencing,transcriptomic analysis,and immunoglobulin A(IgA)antibody repertoire sequencing.We then combined 16S rDNA sequencing with transcriptomics to identify the key microbes and found that they were positively correlated with IgA production.Next,we transplanted candidate microbes into 1-day-old broiler to explore their role in intestinal mucosal immunity.Finally,we verified the function of candidate microbial metabolites in regulating the immune function of macrophages and the intestinal-epithelial cells(IECs)using in vitro experiments.Results:WLMB performs stronger mucosal immunity than AA,including higher IgA levels,more diverse IgA antibody repertoire,and higher bacterial affinity.Bacteroides was identified as the key microbes related to the intestinal IgA response.Bacteroides transplantation could increase IgA concentration in the duodenal contents by enhancing the expression of IgA,polymeric immunoglobin receptor(PIgR),B cell-activating factor of the TNF family(BAFF),and activation-induced cytidine deaminase(AID)in the duodenum.Additionally,Bacteroides-derived isovaleric acid promoted M2 macrophage polarization of macrophage via mTOR/PPAR-γ/STAT3 signaling pathways and regulated the immunologic function of IECs to produce cytokines,including interleukin(IL)-10,IL-4,BAFF,and transforming growth factor-beta(TGF-β),thus promoting IgA production in B cells by facilitating AID expression.Conclusion:Our study revealed that Bacteroides modulate the intestinal IgA response and maintain gut health in broilers.Bacteroides may be a promising alternative as an immunomodulatory microbial agent for developing nextgeneration probiotics for broiler production.

牙髓类杆菌的分离、培养、鉴定

试验目的是为寻找口腔内产黑色素类杆菌群中新的菌种一牙髓类杆菌（Bacteroides·endodontalis）,试验选择牙髓腔感染的成年患者80例,儿童患者（14岁以下）18例,在厌氧环境下用光滑髓针加棉捻方法收集标本,经厌氧培养,对在CDC琼脂培养基（含0.01％Vitk3及0.05％氯化血红素）上生长的产黑色素的菌落进行生化,直接血凝试验、气相色谱分析。

肿瘤粪菌疗法

<正>人类肠道含有丰富的细菌,其数量是人体细胞数量的10倍,从上往下细菌越来越多:十二指肠102~103/ml,空肠103~105/ml,回肠105~107/ml,大肠1010~1012/ml。肠道菌群(gut microbiota)的重量约占人体体重的2磅左右,其基因量约3百万个基因,是人体基因量的100倍。肠道菌群的细菌组成,在门级(phylum level)水平上。

金定鸭盲肠厌氧菌的研究

正常生理条件下,动物肠道中寄居着大量的微生物,构成了肠道正常菌群。正常菌群对动物宿主的生长、发育和衰老,对营养物质的吸收和消化,对于宿主的免疫应答和对各种致病因素的抗性等,都起着不可忽视的作用。金定鸭是我国著名的蛋用鸭,平均年产蛋300枚、蛋质好、用途广。该鸭种适应性强。

几种拟杆菌质粒提取方法的比较

本文介绍了4种拟杆菌质粒的提取方法,并对它们做了比较,根据作者的体会,指出了每种方法的特点和操作时应注意的问题。

丹酚酸B对小鼠体内抗氧化和肠道微生物群落的影响

为研究丹酚酸B的体内抗氧化性和对小鼠肠道微生物群落的影响,本实验对昆明小鼠灌胃不同剂量丹酚酸B溶液,将小鼠分为丹酚酸B低剂量组(30 mg/kg mb)、丹酚酸B中剂量组(60 mg/kg mb)、丹酚酸B高剂量组(120 mg/kg mb)。42 d后,记录小鼠的体质量变化;计算心脏、肝脏、肾脏、脾脏的脏器指数;检测血液和肝脏的抗氧化指标。结果显示在小鼠肝脏中,中剂量、高剂量和阳性对照组相对于正常组脏器指数显著降低(P<0.05)。肾脏中,高剂量组相对于正常组脏器指数显著降低(P<0.05);阳性对照组相对于正常组极显著降低(P<0.01)。抗氧化指标检测结果显示,和正常组相比较,中剂量组血清中丙二醛(malondialdehyde,MDA)含量显著降低(P<0.05),高剂量组和VC组血清中MDA含量极显著降低(P<0.01),高剂量组肝脏中MDA含量显著降低(P<0.05)。高剂量组和VC组血清中GSH含量显著增加(P<0.05)。通过高通量测序技术分析可知,小鼠肠道菌群结构以拟杆菌门(Bacteroidetes)、厚壁菌门(Firmicutes)、变形菌门(Proteobacteria)、疣微菌门(Verrucomicrobia)、放线菌门(Actinobacteria)为各组的优势菌门。根据LEfSe分析发现相对正常组,3组给药组中Bacteroides vulgatus和Parabacteroides distasonis两个菌种相对丰度显著增加(P<0.05),相对丰度随药物浓度增加而降低。丹酚酸B可以提高小鼠体内抗氧化能力,改善小鼠肠道环境,增加有益菌,该发现为丹酚酸B治疗心血管疾病提供新的研究思路。

痤疮型多囊卵巢综合征患者肠道菌群分析

目的以基于16S rDNA高通量测序技术分析痤疮型多囊卵巢综合征患者的肠道菌群结构特征。方法以痤疮综合评分系统(GAGS)评价患者痤疮程度,收集健康女性(HC,n=10)、多囊卵巢综合征女性(NA-PCOS,n=10)和中重度痤疮多囊卵巢综合征女性(MSA-PCOS,n=10)新鲜粪便,扩增细菌16S rDNA V3-V4片段并对其进行测序,分析受试者肠道菌群的组成特征及其与临床参数之间的相关性。结果与对照组相比,PCOS患者肠道菌群多样性降低(P<0.05),粪便中Bacteroides相对丰度显著高于健康组(P<0.001),Prevotella和Faecalibacteruim显著减少(P<0.05);MSA-PCOS患者肠道菌群中Bacteroides相对丰度显著高于NA-PCOS患者(P<0.01);Bacteroides与睾酮、炎症因子、血脂异常呈正相关(P<0.05)。结论肠道菌群紊乱可能加剧PCOS患者代谢和内分泌紊乱进而导致痤疮皮损加重。

Role of intestinal flora imbalance in pathogenesis of pouchitis

Objective: To discuss the role of intestinal flora imbalance in the pathogenesis of pouchitis. Methods: The puochitis rat model was established and the faeces sample and the mucous membrane sample were collected regularly, in which the bacterial nucleic acids were extracted for quantitative analysis of the intestinal flora in the samples through using the real-time quantitative PCR technique and high energy sequencing technology. Results: The disorder phenomenon of the intestinal flora appeared at the 7th day of the experiment, and the pouchitis was presented at the 21 th day of the experiment. At the 31 th day of the experiment, compared to control group and non-pouchitis group, the quantity of Bifidobacterium and the Lactobacillusof the pouchitis model rats in the mucous membrane sample and the faeces sample were significantly decreased(P<0.05), and the Bacteroidetes, Faecalibacterium prausnitzii and 桛 Clostridium leptum subgroup in the mucous membrane of pouchitis were significantly decreased(P<0.05). The Clostridium coccoides group was the main flora in the mucous membrane of pouchitis, the bacterial diversity of non-puochitis group and control group was significantly higher than that of the puochitis group(P<0.05). Conclusions: The intestinal flora imbalance is one of the factors that cause the incidence of the pouhitis; this study provides a clue of the pathogenesis and treatment direction of the intestinal inflammatory disease.

Gut microbiome composition can predict the response to nivolumab in advanced hepatocellular carcinoma patients

BACKGROUND Immunotherapy has revolutionized the clinical outcomes of intractable cancer patients.Little is known about the intestinal nonpathogenic bacterial composition of hepatocellular carcinoma(HCC)patients treated by immunotherapy.AIM To determine whether there is a correlation between gut bacterial composition and prognosis in HCC patients.METHODS From September 2019 to March 2020,we prospectively collected fecal samples and examined the gut microbiome of 8 advanced HCC patients treated with nivolumab as a second-or third-line systemic treatment.Fecal samples were collected before the start of immunotherapy.Fecal samples of patients with progression during treatment were collected at the time of progression,and fecal samples of patients who showed good response to nivolumab were collected after 5-7 mo as follow-up.Metagenomic data from 16S ribosomal RNA sequencing were analyzed using CLC Genomics Workbench.Microbiome data were analyzed according to therapeutic response.RESULTS All 8 patients were male,of which 6 had underlying chronic hepatitis B.A higher Shannon index was found in the responders than in the non-responders after nivolumab therapy(P=0.036).The unweighted beta diversity analysis also showed that the overall bacterial community structure and phylogenetic diversity were clearly distinguished according to therapeutic response.There was no significant difference in the diversity or composition of the patient gut microbiome according to the immunotherapy used.Several taxa specific to therapeutic response were designated as follows:Dialister pneumosintes,Escherichia coli,Lactobacillus reteri,Streptococcus mutans,Enterococcus faecium,Streptococcus gordonii,Veillonella atypica,Granulicatella sp.,and Trchuris trichiura for the nonresponders;Citrobacter freundii,Azospirillum sp.and Enterococcus durans for the responders.Of note,a skewed Firmicutes/Bacteroidetes ratio and a low Prevotella/Bacteroides ratio can serve as predictive markers of non-response,whereas the presence of Akkermansia species predicts a good response.CONCLUSION The current presumptive study suggests a potential role for the gut microbiome as a prognostic marker for the response to nivolumab in treatment of HCC patients.

Suppression of colorectal tumorigenesis by recombinant Bacteroides fragilis enterotoxin-2 in vivo

AIM To evaluate the impact of recombinant Bacteroides fragilis enterotoxin-2 (BFT-2, or Fragilysin) on colorectal tumorigenesis in mice induced by azoxymethane/dextran sulfate sodium (AOM/DSS). METHODS Recombinant proBFT-2 was expressed in Escherichia coli strain Rosetta (DE3) and BFT-2 was obtained and tested for its biological activity via colorectal adenocarcinoma cell strains SW-480. Seventy C57BL/6J mice were randomly divided into a blank (BC; n = 10), model (AD; n = 20), model + low-dose toxin (ADLT; n = 20, 10 mu g), and a model + high-dose toxin (ADHT; n = 20, 20 mu g) group. Mice weight, tumor formation and pathology were analyzed. Immunohistochemistry determined Ki-67 and Caspase-3 expression in normal and tumor tissues of colorectal mucosa. RESULTS Recombinant BFT-2 was successfully obtained, along with its biological activity. The most obvious weight loss occurred in the AD group compared with the ADLT group (21.82 +/- 0.68 vs 23.23 +/- 0.91, P < 0.05) and the ADHT group (21.82 +/- 0.68 vs 23.57 +/- 1.06, P < 0.05). More tumors were found in the AD group than in the ADLT and ADHT groups (19.75 +/- 3.30 vs 6.50 +/- 1.73, P < 0.05; 19.75 +/- 3.30 vs 6.00 +/- 2.16, P < 0.05). Pathology showed that 12 mice had adenocarcinoma and 6 cases had adenoma in the AD group. Five mice had adenocarcinoma and 15 had adenoma in the ADLT group. Four mice had adenocarcinoma and 16 had adenoma in the ADHT group. The incidence of colorectal adenocarcinoma in both the ADHT group and the ADHT group was reduced compared to that in the AD group (P < 0.05, P < 0.05). The positive rate of Ki-67 in the ADLT group and the ADHT group was 50% and 40%, respectively, both of which were lower than that found in the AD group (94.44%, P < 0.05, P < 0.05). Caspase-3 expression in the ADLT group and the ADHT group was 45% and 55%, both of which were higher than that found in the BC group (16.67%, P < 0.05, P < 0.05). CONCLUSION Oral administration with lower-dose biologically active recombinant BFT-2 inhibited colorectal tumorigenesis in mice.

Bacteroides utilization for dietary polysaccharides and their beneficial effects on gut health

Polysaccharide was a class of macromolecular substance with various bioactive functions.Gut symbiotic microorganisms could utilize the polysaccharides from various sources,thus have important impact on human health.Bacteroides represented one of the dominant colonizers in the human gut.The utilization of polysaccharide by Bacteroides was important for supporting the function and stability of gut microbiota.After the degradation of polysaccharides by Bacteroides,gut microbes could ferment the monosaccharides and oligosaccharides degraded from polysaccharides into some metabolites,such as short-chain fatty acids(SCFAs),amino acids,etc.Among the metabolites,the SCFAs could have beneficial effects on gut health.This review summarized the niches of Bacteroides among gut microbiota,and also described the gene clusters and membrane proteins involved in the utilization processes of polysaccharide by gut Bacteroides.SCFAs could act as energy substrates for intestinal epithelial cells,inhibit histone deacetylases and activate G protein-coupled receptors.In addition,the future perspectives in investigating new degradation pathways for polysaccharide,and using polysaccharides or their metabolites as therapeutic approaches for diseases mediated by the gut dysbiosis were also provided.

Capsular polysaccarides of probiotics and their immunomodulatory roles

Studies have determined the immunomodulatory activities of cell-surface polysaccharides of lactic acid bacteria(LAB)and Bacteroides;however,the mechanisms,synthesis,regulation,structure,and functional links have not been systematically discussed.We first introduce the structure of the capsular poly saccharides(CPS s)of commonly studied probiotics and Bacteroides.Wzx-Wzy dependent and ATP-binding cassette(ABC)transporter-dependent pathways are the two main biosynthesis and secretion of CPS pathways.The genes known to be associated with these two pathways are mainly those associated with priming glycosyltransferase(pGT);a variable number of genes encoding for different glycosyl transferases(GTs);Wzx/Wzy-encoding enzymes related to flippases and polymerases;and ABC-transporter genes.In addition,the effects of CPSs on host immunity as well as their related underlying mechanisms are described.Surface polysaccharides on probiotics can serve as a mask to aid in their escape from attacks from the host’s immune system.In turn,they also exhibit immunomodulatory activities,such as strengthening the functions of macrophages,promoting the maturation of antigen-presenting cells,and inducing regulatory T cells.All of these effects of cell-surface polysaccharides exhibit their significant protective properties in immunocompromised diseases,such as colitis,arthritis,and dermatitis.Finally,we focused on their structure and functional links.

Bacteroides fragilis enterotoxin upregulates heme oxygenase-1 in dendritic cells via reactive oxygen species-,mitogen-activated protein kinase-,and Nrf2-dependent pathway

BACKGROUND Enterotoxigenic Bacteroides fragilis(ETBF)causes colitis and diarrhea,and is considered a candidate pathogen in inflammatory bowel diseases as well as colorectal cancers.These diseases are dependent on ETBF-secreted toxin(BFT).Dendritic cells(DCs)play an important role in directing the nature of adaptive immune responses to bacterial infection and heme oxygenase-1(HO-1)is involved in the regulation of DC function.AIM To investigate the role of BFT in HO-1 expression in DCs.METHODS Murine DCs were generated from specific pathogen-free C57BL/6 and Nrf2−/−knockout mice.DCs were exposed to BFT,after which HO-1 expression and the related signaling factor activation were measured by quantitative RT-PCR,EMSA,fluorescent microscopy,immunoblot,and ELISA.RESULTS HO-1 expression was upregulated in DCs stimulated with BFT.Although BFT activated transcription factors such as NF-κB,AP-1,and Nrf2,activation of NF-κB and AP-1 was not involved in the induction of HO-1 expression in BFT-exposed DCs.Instead,upregulation of HO-1 expression was dependent on Nrf2 activation in DCs.Moreover,HO-1 expression via Nrf2 in DCs was regulated by mitogenactivated protein kinases such as ERK and p38.Furthermore,BFT enhanced the production of reactive oxygen species(ROS)and inhibition of ROS production resulted in a significant decrease of phospho-ERK,phospho-p38,Nrf2,and HO-1 CONCLUSION These results suggest that signaling pathways involving ROS-mediated ERK and p38 mitogen-activated protein kinases-Nrf2 activation in DCs are required for HO-1 induction during exposure to ETBF-produced BFT.

Effect of Periodontal Infection on Birth Weight of Infants: A Clinical and Microbiological Study

Background: Maternal periodontal infection has been proposed to influence pre-term delivery and low birth weight infants through mechanisms involving inflammatory mediators or direct bacterial assault on the amnion. Thus, the aim of the present study was to assess the presence of periodontal pathogens in maternal periodontal infection and their effect on the birth weight of infants. Materials and Methods: The case-control study included 30 mothers with a singleton gestation and gestational age of >37 weeks. Data regarding the periodontal status, pregnancy outcome variables, hemoglobin levels (Hb%) and other factors that may influence adverse pregnancy outcomes were collected. A qualitative analysis of the predominant anaerobic organisms was conducted. The data was analysed using one-way ANOVA test and Scheffe’s test. Results: The microbiological results showed that prevalent colonies of organisms isolated from the experimental groups were of Bacteroides spp. (n = 3), Fusobacterium spp. (n = 3) and Peptostreptococcus spp. (n = 9). In the control group, Peptostreptococcus spp. (n = 15) were predominant. In the experimental group, it was seen that Bacteroides spp. (p = 0.003) and Fusobacterium spp. (p = 0.050) were statistically significant with the birth weight of the infant. The one-way ANOVA test showed that the birth weight of the infant was inversely proportionate with increase in severity of the periodontal disease. Scheffe’s test showed that presence of a periodontal pocket showed most significance to the birth weight of an infant as compared to presence of local factors or bleeding on probing. Conclusion: The study revealed that the gram negative organisms, Bacteroides spp. and Fusobacterium spp. were significantly associated with the low birth weight (LBW) of the infants, although there was not a significant difference in the clinical periodontal status between the experimental groups and the controls. It could be proposed that specific groups of pathogens may have a contributory role in the risk of LBW.

Extended role for insertion sequence elements in the antibiotic resistance of Bacteroides

The Bacteroides species are important micro-organisms, both in the normal physiology of the intestines and as frequent opportunistic anaerobic pathogens, with a deeply-rooted phylogenetic origin endowing them with some interesting biological features. Their prevalence in anaerobic clinical specimens is around 60%-80%, and they display the most numerous and highest rates of antibiotic resistance among all pathogenic anaerobes. In these antibiotic resistance mechanisms there is a noteworthy role for the insertion sequence(IS) elements, which are usually regarded as representatives of ‘selfish' genes; the IS elements of Bacteroides are usually capable of up-regulating the antibiotic resistance genes. These include the cep A(penicillin and cephalosporin), cfx A(cephamycin), cfi A(carbapenem), nim(metronidazole) and erm F(clindamycin) resistance genes. This is achieved by outwardoriented promoter sequences on the ISs. Although some representatives are well characterized, e.g., the resistance gene-IS element pairs in certain resistant strains, open questions remain in this field concerning a better understanding of the molecular biology of theantibiotic resistance mechanisms of Bacteroides, which will have clinical implications.

Mucosal bacterial dysbiosis in patients with nodular lymphoid hyperplasia in the terminal ileum

BACKGROUND Nodular lymphoid hyperplasia(NLH)in the small intestine is a rare benign lesion characterized by multiple small nodules on the intestinal surface.Patients with terminal ileal NLH may experience long-term abdominal pain,diarrhea,and abdominal distension,among other symptoms.Supplementation with probiotics could mitigate these symptoms.NLH is linked to the immune system,and it may result from accumulation of plasma-cell precursors due to a maturational defect during the development of B lymphocytes.The intestinal microbiome plays an essential role in the immune system.Thus,we speculate that the gut flora plays a key role in terminal ileal NLH.AIM To explore the correlation between intestinal flora and terminal ileal NLH.METHODS We collected mucosal biopsy samples that were obtained via colonoscopy from 15 patients with terminal ileal NLH(the test group)and 15 normal subjects(the control group).We subsequently performed 16 S-r RNA gene amplicon sequencing of these samples,and the results were evaluated using alpha diversity,beta diversity and microbial composition analyses.The Phylogenetic Investigation of Communities by Reconstruction of Unobserved States was used to predict the metabolic pathways and orthologous groups according to the Kyoto Encyclopedia of Genes and Genomes database.RESULTS Compared with the control group,the terminal ileal NLH group showed an increased alpha diversity(P<0.05).The overall intestinal microbiota in the NLH group was significantly different from that of the control group(P<0.05),implying that there was the dysbiosis in the terminal ileal NLH patients.The relative abundance of phylum Bacteroidetes was significantly lower in the NLH group,while that of Patescibacteria and Campilobacterota was significantly higher.The genus Bacteroides was the dominant gut microbiota in both groups,but its abundance was significantly lower in the test group than it was in the control group.Conversely,the relative abundances of Haemophilus,Streptococcus,Pseudomonas,Actinomyces,TM7 X,Fusobacterium nucleatum,Parvimonas,Granulicatella,Helicobacter,and the[Eubacterium]nodatum group were significantly higher in the test group than they were in the control group.In addition,several altered metabolic pathways,orthologous groups,and modules were found.For example,the Peptidoglycan biosynthesis and Aminoacyl t RNA biosynthesis were both increased in the test group.CONCLUSION Maintaining the microbial balance and supplementing targeted protective bacteria could improve symptoms and potentially reduce the risk of lymphoma transformation in patients with terminal ileal NLH.

Endophthalmitis caused by Bacteroides fragilis after pars plana vitrectomy and treatment approach

Rationale:Endophthalmitis is an uncommon but serious ocular infection often resulting in probable visual loss.Bacteroides fragilis is a rare cause of endophthalmitis.Patient concerns:A 46-year-old male patient complained of eye pain and low vision after pars plana vitrectomy.Diagnosis:Bacteroides fragilis endophthalmitis after pars plana vitrectomy was diagnosed.Interventions:Pars plana vitrectomy and silicone oil implantation were performed.Outcomes:Early treatment and choice of tamponade in endophthalmitis after pars plana vitrectomy may possibly prevent evisceration and progression of endophthalmitis.Lessons:Bacteroides fragilis can be seen in cases of endophthalmitis after pars plana vitrectomy.

对抗生素抗性蔓延的畏惧

给家畜饲喂抗生素可以导致人体产生抗生素抗性。伊利诺斯大学的Abigail Salyers断定抗生素抗性基因能够从猪、羊和牛消化道内的细菌中转移到人体内的远缘细菌中。由于抗生素抗性有扩散到人类病原体中的危险,Salyers认为必须花时间重新评价给动物饲喂大量抗生素这一事实。 经鉴定发现分离自家畜肠道细菌的四环素抗性基因(tetQ)的DNA序列与引起人牙周病的细菌的tetQ基因完全一致。Salyers从家畜肠道Prevotella、人肠道Bacteroides和人口腔Prevotella intermedia中获得12种tetQ基因,有3个基因具98%的DNA序列相似性,最低的相似性为94%。Prev-

厌氧菌类杆菌噬菌体的调查研究

近年由于厌氧菌培养技术的发展,已引起临床医生的广泛重视。因从60％的患者感染标本中可检出厌氧菌,使临床正确诊断,指导用抗菌素和医疗措施等方面都产生了不可忽视的效果。解放军150中心医院专家组李东阳主任技师对厌氧菌噬菌体,尤其对最常见的有致病性的类杆菌(Bacteroides)及其噬菌体(Bacteriophages)进行了系列研究。首先对类杆菌噬菌体(Bacteriophages of Bacteriodes)的分布进行了调查。