Mechanism of Polysaccharides from Two Spleen-invigorating Chinese Medicine Prescriptions in Regulating Growth of Bacteroides fragilis in vitro： Based on Differential Expression of Polysaccharide Utilization Loci / 中国实验方剂学杂志

ObjectiveTo investigate the effects of using the polysaccharides from two Chinese medicine compound prescriptions as the carbon source on the growth of Bacteroides fragilis and to decipher the mechanism from the perspective of differential expression of polysaccharide utilization loci （PULs） based on transcriptomics. MethodThe media with different carbon sources ［20% polysaccharides of Lizhongtang， polysaccharides of Shenling Baizhusan， glucose， and brain heart infusion （BHI） Broth］ were used for the anaerobic culture of B. fragile ATCC25285. The effects of different carbon sources on the growth of B. fragilis ATCC25285 were determined by continuous sampling and spectrophotometry. Then， transcriptome sequencing was performed for the cultures obtained with different carbon sources to study the mechanism of different carbon sources in regulating bacterial growth. ResultThe concentration of bacteria with the polysaccharide of Lizhongtang， polysaccharide of Shenling Baizhusan， BHI Broth， and glucose as the carbon sources peaked at 26， 32， 26， 38 h， respectively， and the bacteria in all the four groups achieved robust growth. Gene ontology （GO） enrichment indicated that the differentially expressed genes in the Lizhongtang polysaccharide group and Shenling Baizhusan polysaccharide group were concentrated in the transport and transmembrane transport of dicarboxylic acid. The Shenling Baizhusan polysaccharide and BHI Broth groups showed high expression of PUL 4 and 27， glycoside hydrolase 13 （GH13）， and glycosyl transferases 5 （GT5）. PUL9 was highly expressed in Shenling Baizhusan polysaccharide group， and PUL 17， 19， and 20， GH3， and GH144 in the BHI Broth group. PUL27 and GT5 were highly expressed in Shenling Baizhusan polysaccharide and glucose groups. PUL 4 and 9 and GH13 were only highly expressed in Shenling Baizhusan polysaccharide group， and PUL 2， 17， and 19 and GH2 in the glucose group. Both Lizhongtang polysaccharide group and BHI group highly expressed PUL 4， 17， 19， 20， and 27， GH3， and GH144. PUL 2， 8， 23， and 27， GH2， and GH57 were highly expressed in Lizhongtang polysaccharide group， while GH13 showed high expression in the BHI group. Both the glucose and Lizhongtang polysacharride groups showed high expression of PUL 4 and 27 and GH2. PUL 4， 8， 20， and 23， GH3， and GH144 were highly expressed in Lizhongtang polysaccharide group， while PUL30 was highly expressed in the glucose group. ConclusionThe in vitro experiments and transcriptome sequencing results confirmed that the expression of PULs and GH may provide benefits or costs to the adaptive growth of Bacteroides fragilis ATCC25285 cultured with different carbon sources， which may be one of the mechanisms by which polysaccharides from Chinese medicine compound prescriptions regulate the growth of B. fragilis ATCC25285. The findings can provide a reference for further research on the relationship between B. fragilis metabolic pathway and polysaccharides of Chinese medicine compound prescriptions.

Superior mesenteric veinous thrombosis with Bacteroides fragilis infection: a case report / 中国热带医学

@#Abstract: Superior mesenteric veinous thrombosis (SMVT) is a rare complication that often occurs in conjunction with intra-abdominal diseases such as diverticulitis, appendicitis, inflammatory bowel disease, etc. Its clinical symptoms are non-specific and include fevers, abdominal pain; it has no specific symptoms, and the diagnosis depends on clinical laboratory tests and imaging studies. The occurrence of superior mesenteric veinous thrombophlebitis is related to septic phlebitis caused by the sloughing of the embolus containing bacteria into the portal vein with blood flow. Due to the nonspecific clinical features of this disease, diagnosing it based on clinical characteristics and microbiological aspects is a challenge. A case of superior mesenteric veinous septic thrombophlebitis caused by Bacteroides fragilis infection is reported and to provide a reference for the diagnosis and treatment of such diseases. The patient was a 34-year-old man who was admitted the hospital with intermittent abdominal pain and fever. Computed tomography (CT) showed partial thrombosis of the superior mesenteric vein, colonoscopy revealed diverticulitis in the ileoceca, and the blood culture grew Bacteroides fragilis. The patient was treated with anti-infection (ceftazidime 2.0 g q12h intravenous infusion for 11 days; metronidazole 0.5 g, q8h intravenous infusion for 3 days) and anticoagulation (rivaroxaban 20 mg qd orally for 8 days. On the 11th day of hospitalization, the patient's condition improved, and he was discharged. In this case, for patients with fever and abdominal pain, superior mesenteric venous thrombophlebitis should be included in the differential diagnosis. Through auxiliary examination, blood sample culture and other technologies, clear diagnosis should be made in time to improve patient outcomes.

Anti-obesity and Gut Microbiota Modulation Effect of Astragalus Polysaccharides Combined with Berberine on High-Fat Diet-Fed Obese Mice / 中国结合医学杂志

OBJECTIVE@#To investigate whether astragalus polysaccharides (APS) combined with berberine (BBR) can reduce high-fat diet (HFD)-induced obesity in mice.@*METHODS@#Except for normal mice, 32 HFD-induced obese mice were randomized into HFD, APS (1,000 mg/kg APS), BBR (200 mg/kg BBR), and APS plus BBR (1,000 mg/kg APS plus 200 mg/kg BBR) groups, respectively. After 6-week treatment (once daily by gavage), the obesity phenotype and pharmacodynamic effects were evaluated by histopathological examination of epididymal fat, liver, and colon using hematoxylin-eosin staining and serum biochemical analyses by an automated chemistry analyzer. The feces were collected at the 12 th week, and taxonomic and functional profiles of gut microbiota were analyzed by 16S ribosomal ribonucleic acid (16S rRNA) sequencing.@*RESULTS@#Compared with HFD group, the average body weight of APS plus BBR group was decreased (P<0.01), accompanied with the reduced fat accumulation, enhanced colonic integrity, insulin sensitivity and glucose homeostasis (P<0.05 or P<0.01). Importantly, APS combined with BBR treatment was more effective than APS or BBR alone in improving HFD-induced insulin resistance (P<0.05 or P<0.01). 16S rRNA sequence-based analysis of fecal samples demonstrated that APS combined with BBR treatment exhibited a better impact on HFD-induced gut microbiota dysbiosis, exclusively via the enriched abundances of Bacteroides, which corresponded to the large increase of predicted bacterial genes involved in carbohydrate metabolism.@*CONCLUSION@#APS combined with BBR may synergistically reduce obesity and modulate the gut microbiota in HFD-fed mice.

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.

Treatment of psoriasis vulgaris using Bacteroides fragilis BF839: a single-arm, open preliminary clinical study / 生物工程学报

Psoriasis is considered as an inflammatory disease driven by T cells, and its pathogenesis is closely related to the imbalance of intestinal bacteria flora. It has been reported that Bacteroides fragilis could play an anti-inflammatory role by regulating the expression of cytokines in T cells. To date, there is no report using B. fragilis to treat psoriasis. In this study, we explored the therapeutic effect of B. fragilis BF839 on psoriasis. We selected 27 psoriasis patients who were treated in the Second Affiliated Hospital of Guangzhou Medical University from April to October 2019. The patients were given B. fragilis BF839 orally for 12 weeks while maintaining the original treatment. The psoriasis area and severity index (PASI) score was evaluated before and after the treatment. The rate of drug withdrawal and reduction after 12 weeks of treatment were calculated. Our results showed that the rate of 12-week trial completion was 96.3% (26/27). We used PASIN to define the proportion of people whose PASI score decreased more than or equal to N% after treatment. At 12 weeks, PASI30, PASI50, and PASI75 were 65.4%, 42.3%, and 19.2%, respectively. The PASI score was 9.1±5.9 and 5.8±4.9 before and after 12 weeks of treatment respectively, and the difference was statistically significant (P0.05). The adverse reaction rate of patients was 3.8% (1/26) within 12 weeks of treatment, including 1 case of constipation, and the rate of drug withdrawal and reduction was 60.0%. The above results suggest that B. fragilis BF839 may be functional on the treatment of psoriasis by reducing the PASI score and the drug usage rate with few side effect, which deserves further study.

Effect of influenza A virus infection on pulmonary flora and chemokines CCL5 and CXCL10 in mice and intervention of Maxing Shigan Decoction / 中草药

Objective: To investigate the potential mechanism of Maxing Shigan Decoction (MSD) in the prevention and treatment of influenza virus infection by influencing pulmonary flora and expression of chemokines CCL5 and CXCL10 of mice. Method The infected mice model of influenza A virus was tested by intranasal inoculation. After 3 and 7 d of gavage or saline, the lung index and lung index inhibition rate were calculated. Pathological changes of lung tissue were detected by HE staining. The expression of CCL5 and CXCL10 in the lung tissue of mice was detected by immunohistochemistry and ELISA. The expression of CCL5 mRNA and CXCL10 mRNA in lung tissue of mice was detected by real-time fluorescence quantitative PCR (RT-PCR). The bacteria in lung tissue was sequenced by using the V3-V4 variable region of 16S rRNA, annotated and clustered. The alpha diversity, beta diversity and the species difference among groups were analyzed. The correlation of the expression of CCL5 and CXCL10 with the change of intestinal flora was also analyzed. Results: After 3 d of administration, the lung index of model group was significantly higher than normal group (P < 0.01) and drug group (P < 0.05, 0.01). Pulmonary inflammatory cell infiltration was obvious. The infiltration of pulmonary inflammatory cells in MSD group was significantly reduced, and the inhibition rate of lung index was similar to that in oseltamivir group. The value of IQA in lung injury was decreased significantly (P < 0.01). The expressions of CCL5 and CXCL10 in the lung tissue of the model control group were significantly higher than those of the normal control group (P < 0.01), and the expressions of CCL5 and CXCL10 in the oseltamivir group and the MSD were significantly lower than those in the model control group (P < 0.05, 0.01). The results of 16S rRNA gene sequencing showed the relative abundances of Bacteroides, Escherichia, and Proteus were increased, while that of Coprococcus was decreased in the model control group. In oseltamivir group and MSD group, the relative abundances of Bacteroides, Escherichia, and Proteus were significantly decreased, while the relative abundance of Coprococcus was increased. The results of alpha diversity showed that the ace index, Chao1 index, and Shannon index of each group were all higher than 0.05, and there was no difference in richness and diversity among groups. The results of beta diversity showed that there was no intersection of sample points among groups and difference in the composition of pulmonary flora among groups. Species among groups were significant differences. Spearman correlation analysis showed that the expression of CCL5 and CXCL10 was positively correlated with the abundance of Escherichia, Proteus, and Bacteroides, and negatively correlated with the abundance of Coprococcus. After 7 d of administration, there was no significant difference in the composition of pulmonary flora and the expression of CCL5 and CXCL10. Conclusion: MSD may improve the micro-ecological environment and immune microenvironment of the lung by promoting the growth of beneficial bacteria, and has a certain protective effect on the lung injury caused by influenza virus.

Recuperación de bacterias aerobias y anaerobias de pacientes con apendicitis aguda mediante botellas de hemocultivo / Recovery of aerobic and anaerobic bacteria from patients with acute appendicitis using blood culture bottles

Introducción. La apendicitis aguda es la primera causa de abdomen agudo; sin embargo, poco se conoce sobre las bacterias asociadas y su perfil de sensibilidad. Objetivo. Identificar y determinar el patrón de resistencia de las bacterias aerobias y anaerobias aisladas en cultivo de líquido periapendicular tomado de los pacientes con apendicitis aguda, y establecer la proporción de bacterias según la fase clínica. Materiales y métodos. Se llevó a cabo un estudio descriptivo y prospectivo en el Hospital Universitario de San José de Bogotá (Colombia), en pacientes mayores de 16 años sometidos a apendicectomía abierta. Se tomaron muestras de líquido periapendicular, las cuales se sembraron directamente en botellas de hemocultivos para aerobios y anaerobios. Resultados. Se incluyeron 154 pacientes. Del total de cultivos, el 87 % (n=134) fueron positivos: 77 % (n=118) para aerobios y 51 % (n=79) para anaerobios. La proporción de cultivos positivos fue inferior en los casos de apendicitis no complicada, en comparación con aquellos de apendicitis complicada (80 % (66/83) Vs. 95 % (67/71); p=0,003). Los microorganismos aislados con mayor frecuencia fueron: Escherichia coli (53 %) (n=84), Bacteroides sp. (25 %) (n=25), Propionibacterium acnes (21 %) (n=21), Staphylococci coagulasa negativo (17 %) (n=27), Enterococcus sp. (10 %) (n=15) y Fusobacterium sp. (11 %) (n=11). La sensibilidad de E. coli a la amplicilina sulbactam fue de 30 %. La sensibilidad de Bacteroides spp. a la clindamicina y la ampicilina sulbactam fue de 91 %. El 100 % de los anaerobios fueron sensibles a piperacilina tazobactam, ertapenem, meropenem y metronidazol. Conclusiones. Los cultivos intraoperatorios son pertinentes en la apendicitis para determinar el patrón epidemiológico local, y establecer los antibióticos profilácticos y terapéuticos para esta enfermedad. Su siembra directa en botellas de hemocultivo permite una gran recuperación de microorganismos.

Introduction: Acute appendicitis is the first cause of acute abdomen, however, there is a little information about the associated bacteria and its sensibility profile. Objetive: To identify and to determine the resistance pattern of aerobic and anaerobic bacteria isolated in periapendicular fluid cultures taken in patients with acute appendicitis and to establish the proportions of isolates according to the clinical phase. Materials and methods: A descriptive and prospective study was undertaken at the Hospital Universitario de San José (Bogotá, Colombia) of patients older than sixteen years of age, undergoing an open appendectomy. A sample of periappendiceal fluid was taken, which was deposited directly into aerobic and anaerobic blood culture bottles. Results: One hundred and fifty-four patients were included. The overall positivity of cultures was 87% (n=1344); 77% (n=118) for aerobes and 51% (n=79) for anaerobes. The proportion of positive cultures was lower in the uncomplicated appendicitis cases as compared to the complicated ones (80% (66/83) vs. 95%(67/71), p = 0.003). The microorganisms isolated most frequently were: Escherichia coli (53%) (n=84); Bacteroides spp. (25%) (n=25); Propionibacterium acnes (21%) (n=21); coagulase negative Staphylococci (17%) (n=27); Enterococcus spp. (11%) (n=15), and Fusobacterium spp. (11%) (n=11). The sensitivity of E.coli to ampicillin/sulbactam was 30%. The sensitivity of Bacteroides spp. to clindamycin and ampicillin/sulbactam was 91%. All anaerobe isolates were sensitive to piperacillin/tazobactam, ertapenem, meropenem and metronidazole. Conclusions: Intraoperative cultures in acute appendicits are relevant in order to determine the local epidemiological pattern and to establish prophylactic and therapeutic antibiotics for this pathology; direct inoculation in blood culture bottles allows a high recovery of microorganisms.

Leche materna: características funcionales de los oligosacáridos de la leche materna (Parte 2) / Breast milk: functional characteristics of breast milk oligosaccharides (Part 2)

Durante los primeros meses de vida, los oligosacáridos de la leche materna (HMOs) aportados por la leche materna participan en procesos asociados con la maduración de tejidos y sistemas del tubo digestivo, modulan algunos de sus procesos metabólicos y ejercen efectos prebióticos y antimicrobianos. Otros efectos estudiados son su contribución a la instalación, desarrollo y estimulación de la microbiota residente con predomino de Bifidobacterium y Bacteroides, con efectos protectores frente a posibles colonizaciones o patologías por enteropatógenos (bacterianas, virus o parásitarias) que pueden actuar nivel local en el tubo digestivo, pero también pueden influir a nivel sistémico. Los HMOs modularían el desarrollo de la inmunidad innata y adaptativa, y probablemente previenen el desarrollo de fenómenos de atopia/alergia. Una patología propia de la etapa neonatal de los prematuros es la enterocolitis necrosante y algunos HMOs podrían disminuir el riesgo de su manifestación. Las actividades de los oligosacáridos de la leche materna contribuyen a la adaptación del lactante a los desafíos que plantea su entorno incluyendo la prevención de algunas patologías en edades posteriores, como es el caso de la diabetes tipo 1 y la obesidad.

During the first months of life, breast milk oligosaccharides (HMOs) stimulate development of the gastrointestinal tract in newborns and young infants; they modulate its metabolism and transport capabilities. Additionally, they exert prebiotic and antimicrobial activities and contribute to the development of the resident intestinal microbiota with a predominance of Bifidobacterium and Bacteroides and protect from colonization and infections by enteropathogens (bacteria, virus or parasites). It is highly probable that their activities extend beyond infancy and persist into adult life. HMOs stimulate the development of the innate and adaptive immune systems and decrease the risk of atopy/allergy. Their intake has been associated with a degree of protection against as necrotizing enterocolitis among premature infants. HMOs contribute to the long term adaptation and protection of newborn infants to unfavorable conditions of their environment and in this way may contribute to protect breastfed infants from type 1 diabetes and obesity.

Role of Bacteroides fragilis in Colorectal Diseases and Prospect of Microflora Therapy / 胃肠病学

Bacteroides fragilis (BF) is a symbiotic bacterium in human intestine, and has a variety of effect on intestinal environment. BF can be divided into enterotoxigenic Bacteroides fragilis (ETBF) and nontoxigenic Bacteroides fragilis (NTBF). ETBF can lead to diarrhea, colitis, inflammatory bowel disease and colorectal cancer, while NTBF has a protective effect on intestinal homeostasis. NTBF not only can provide nutritional support for other microorganisms, but also enhance the anti-inflammatory effect of immune cells. This article reviewed the effect of BF on colorectal diseases and prospect of microflora therapy.

Research Progress of Polysaccharide Utilization Loci and Its Application in Pharmacological Research of Chinese Medicinal Herb / 中国实验方剂学杂志

Polysaccharide utilization loci (PULs) are a group of gene clusters related to polysaccharides catabolism and located in specific areas, including starch utilization system(SusC), SusD, encoding outer membrane glycoprotein binding proteins, and carbohydrate active enzymes. The wide existence of PULs in Bacteroides, and the extraordinary ability of utilizing polysaccharide is its survival strategy to adapt to the intestinal tract. On one hand, Bacteroides feature a high abundance and variety, making it the most important bacterial target group regulated by traditional Chinese medicine(TCM). On the other hand, polysaccharide is an important effective constituent among TCM chemicals, with a high content, and can also be used as a competitive carbon source for intestinal bacteria. Therefore, what is the mechanism of regulating the intestinal flora based on the carbon source of polysaccharide is an important part of the pharmacological research of TCM. According to the latest literatures, this paper introduces the gene and protein composition of PULs, reviews the latest developments in PULs research, and analyzes the structure of PULs in the genomes of Bacteroides fragilis and Bacteroides thetaiotaomicron. Furthermore, we also put forward a prospect for the pharmacological micro-ecological mechanism of TCM based on PULs based on our carbon source experiments, which focuses the effects of Bacteroides by TCM polysaccharides in vitro. This research is not only the new content of bacterial PULs researches, but also the important part of researches of "human-drug-bacteria" holistic view and TCM spleen-tonifying concept.

Evaluation of MALDI-TOF mass spectrometry (VITEK-MS) compared to the ANC card (VITEK 2) for the identification of clinically significant anaerobes / Avaliação da espectrometria de massas MALDI-TOF (VITEK-MS) diante do cartão ANC (VITEK 2) na identificação de anaeróbios clinicamente significantes

ABSTRACT Introduction: The identification of anaerobic bacteria by conventional methods employed in clinical laboratories requires a lot of work and a long response time [turnaround time (TAT)]. Matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) is an accurate, rapid and inexpensive technique with promising results for bacterial identification. Objective: To evaluate the MALDI-TOF mass spectrometry (VITEK-MS, bioMérieux, France) compared to the ANC card (VITEK 2, bioMérieux, France) for the identification of anaerobes, and also veriying the cost variation between both methodologies. Methods: 421 anaerobes were concomitantly identified by ANC (VITEK 2) and MALDI-TOF (VITEK MS). The conflicting results or those presenting low differentiation of the species were subjected to the 16S ribosomal ribonucleic acid (rRNA) sequencing. Results: Thirty-five strains were not identified by ANC (VITEK 2), and only one isolate was not identified by MALDI-TOF (VITEK MS). From the 386 anaerobes identified by the two methodologies, 97% agreement was observed on the identification of genus and species between the methodologies. Thirteen (3%) isolates were submitted to 16S sequencing. The agreement observed was 70% using ANC (VITEK 2) using 92% by MALDI-TOF (VITEK MS). Conclusion: Both methodologies showed an excellent performance for the identification of the strains tested with great differences in relation to cost-benefit. MALDI-TOF MS allowed 35 additional identifications and a saving of BRL$ 7,786 with the release of culture positive result five days ahead of the ANC (VITEK 2). TAT reduction may contribute to a successful clinical resolution.

RESUMO Introdução: A identificação das bactérias anaeróbias por métodos convencionais empregados nos laboratórios clínicos demanda muito trabalho e um longo tempo de resposta (TAT). A espectrometria de massa por ionização e dessorção a laser assistida por matriz (MALDI-TOF MS) é uma técnica precisa, rápida e barata, com resultados promissores para a identificação bacteriana. Objetivo: Avaliar a espectrometria de massas MALDI-TOF (VITEK MS, bioMérieux, France) diante do cartão ANC (VITEK 2, bioMérieux, France) para a identificação de anaeróbios, bem como verificar a variação de custos entre as metodologias. Métodos: Foram identificados 421 anaeróbios concomitantemente pelo ANC (VITEK 2) e pelo MALDI-TOF (VITEK MS). Os resultados discordantes ou que apresentaram baixa discriminação das espécies foram submetidos ao sequenciamento do 16S do ácido ribonucleico ribossonal (rRNA). Resultados: Trinta e cinco cepas não foram identificadas pelo ANC (VITEK 2), e somente um isolado ficou sem identificação pelo MALDI-TOF (VITEK MS). Dos 386 anaeróbios identificados pelas duas metodologias, a concordância na identificação de gênero e espécie foi observada em 97%. Treze (3%) isolados foram submetidos ao sequenciamento do 16S; a concordância observada foi de 70% com o ANC (VITEK 2) e 92% com MALDI-TOF (VITEK MS). Conclusão: Ambas as metodologias demonstraram ótimo desempenho para identificação das cepas testadas com grandes diferenças em relação ao custo-benefício. O MALDI-TOF MS permitiu 35 identificações adicionais e uma economia de R$ 7.786,00 com a liberação do resultado positivo da cultura cinco dias à frente do ANC (VITEK 2). A redução do TAT pode contribuir para uma resolução clínica bem-sucedida.

Inactivation of MarR gene homologs increases susceptibility to antimicrobials in Bacteroides fragilis

ABSTRACT Bacteroides fragilis is the strict anaerobic bacteria most commonly found in human infections, and has a high mortality rate. Among other virulence factors, the remarkable ability to acquire resistance to a variety of antimicrobial agents and to tolerate nanomolar concentrations of oxygen explains in part their success in causing infection and colonizing the mucosa. Much attention has been given to genes related to multiple drug resistance derived from plasmids, integrons or transposon, but such genes are also detected in chromosomal systems, like the mar (multiple antibiotic resistance) locus, that confer resistance to a range of drugs. Regulators like MarR, that control expression of the locus mar, also regulate resistance to organic solvents, disinfectants and oxygen reactive species are important players in these events. Strains derived from the parental strain 638R, with mutations in the genes hereby known as marRI (BF638R_3159) and marRII (BF638R_3706) were constructed by gene disruption using a suicide plasmid. Phenotypic response of the mutant strains to hydrogen peroxide, cell survival assay against exposure to oxygen, biofilm formation, resistance to bile salts and resistance to antibiotics was evaluated. The results showed that the mutant strains exhibit statistically significant differences in their response to oxygen stress, but no changes were observed in survival when exposed to bile salts. Biofilm formation was not affected by either gene disruption. Both mutant strains however, became more sensitive to multiple antimicrobial drugs tested. This indicates that as observed in other bacterial species, MarR are an important resistance mechanism in B. fragilis.

Identification of the alpha-enolase P46 in the extracellular membrane vesicles of Bacteroides fragilis

BACKGROUND Members of the Bacteroides fragilis group are the most important components of the normal human gut microbiome, but are also major opportunistic pathogens that are responsible for significant mortality, especially in the case of bacteraemia and other severe infections, such as intra-abdominal abscesses. Up to now, several virulence factors have been described that might explain the involvement of B. fragilis in these infections. The secretion of extracellular membrane vesicles (EMVs) has been proposed to play a role in pathogenesis and symbiosis in gram-negative bacteria, by releasing soluble proteins and other molecules. In B. fragilis, these vesicles are known to have haemagglutination and sialidosis activities, and also contain a capsular polysaccharide (PSA), although their involvement in virulence is still not clear. OBJECTIVE The aim of this study was to identify proteins in the EMV of the 638R B. fragilis strain by mass spectrometry, and also to assess for the presence of Bfp60, a surface plasminogen (Plg) activator, previously shown in B. fragilis to be responsible for the conversion of inactive Plg to active plasmin, which can also bind to laminin-1. METHODS B. fragilis was cultured in a minimum defined media and EMVs were obtained by differential centrifugation, ultracentrifugation, and filtration. The purified EMVs were observed by both transmission electron microscopy (TEM) and immunoelectron microscopy (IM). To identify EMV constituent proteins, EMVs were separated by 1D SDS-PAGE and proteomic analysis of proteins sized 35 kDa to approximately 65 kDa was performed using mass spectrometry (MALDI-TOF MS). FINDINGS TEM micrographs proved the presence of spherical vesicles and IM confirmed the presence of Bfp60 protein on their surface. Mass spectrometry identified 23 proteins with high confidence. One of the proteins from the B. fragilis EMVs was identified as an enolase P46 with a possible lyase activity. MAIN CONCLUSIONS Although the Bfp60 protein was not detected by proteomics, α-enolase P46 was found to be present in the EMVs of B. fragilis. The P46 protein has been previously described to be present in the outer membrane of B. fragilis as an iron-regulated protein.

Relationships between the enrichment of ETBF, Fn, Hp in intestinal and colorectal cancer / 中华肿瘤杂志

Objective@#To explore relationships between the enrichment of ETBF, Fn, Hp in feces, tissues and colorectal cancer.@*Methods@#Feces, lesion tissue and adjacent tissue from 24 patients with colorectal cancer and 31 patients with adenomas were collected, and we collected Feces and tissue of 20 healthy control persons. Then the copy numbers of enterotoxigenic B. fragilis (ETBF), Fusobacterium nucleatum (Fn) and Helicobacter pylori (Hp) were determined by quantitative real-time PCR. Immunohistochemical method was used to examine the expression intensity of EGFR and p53, and the relationships between different expression intensity of EGFR, p53 and the numbers of three bacterias.@*Results@#In the feces, copy numbers of ETBF and Fn were as follous: colorectal cancer group>adenomas group>healthy control group (P<0.05). Copy numbers of Hp were as follous: colorectal cancer group>healthy control group (P<0.01); adenomas group>healthy control group (P<0.01). In the tissue, copy numbers of ETBF, Fn were as follows: colorectal cancer group>adenomas group>healthy control group (P<0.05). Copy numbers of Hp were as follows: colorectal cancer group>healthy control group (P<0.01); adenomas group>healthy control group (P<0.01). Copy numbers of those three bacteria in the lesion tissue and the adjacent tissue had no significant difference. This happened both in colorectal cancer group and adenomas group. The different expression intensity of EGFR, p53 and the number of three bacteria showed no obviously statistical correlation(P>0.05).@*Conclusion@#Adenomatous polyp and colorectal cancer patients show high enrichment of ETBF, Fn and Hp in both feces and tissues. ETBF, Fn and Hp probably contribute to the development of adenomatous polyp and colorectal cancer. Trial registration Chinese Clinical Trial Registry, ChiCTR-BOC-17012509.

Characterization of the fecal microbiota differs between age groups in Koreans

BACKGROUND/AIMS: Tens of trillions of microorganisms constitute the gut microbiota of the human body. The microbiota plays a critical role in maintaining host immunity and metabolism. Analyses of the gut microbial composition in Korea are limited to a few studies consisting of small sample sizes. To investigate the gut microbial community in a large sample of healthy Koreans, we analyzed the 16S ribosomal RNA of 4 representative bacterial genera Lactobacillus, Bifidobacterium, Bacteroides, and Clostridium. METHODS: A total of 378 DNA samples extracted from 164 infants and 214 adults were analyzed using quantitative real-time polymerase chain reaction. RESULTS: Analysis of 16S ribosomal RNA of 4 representative bacterial genera Lactobacillus, Bifidobacterium, Bacteroides, and Clostridium showed that the gut microbiota in infants had higher relative abundances of Bifidobacterium and Lactobacillus than that in adults, which was dominated by Bacteroides and Clostridium. CONCLUSIONS: To the best of our knowledge, this was the first study evaluating the distinct characteristics of the microbial community of Korean infants and adults. The differences between the 2 populations suggest that external factors such as age, diet, and the environment are important contributing factors to the change in gut microbial composition during development.

Metronidazole-Induced Encephalopathy in Treatment for a Thoracic Aortic Aneurysm Infected by Bacteroides fragilis / 日本心臓血管外科学会雑誌

A 77-year-old man presented with fever and back pain. Computed tomography revealed a distal arch aneurysm. Bacteroides fragilis was found in a blood culture, and we diagnosed a thoracic infected aneurysm. Because of the rapid enlargement of the aneurysm and his frailty, a TEVAR procedure was urgently performed. He left the hospital after antibiotic treatment with meropenem. However, he was re-hospitalized due to recurrence of the infection. The infection was well-controlled by treatment with intravenous meropenem, and the subsequent oral administration of metronidazole (MNZ). He was re-hospitalized again 7 weeks after discharge due to unsteady gait and articulatory disorder. MNZ-induced encephalopathy (MIE) was diagnosed because FLAIR brain magnetic resonance imaging revealed an area of high signal intensity in the bilateral basal dentate nuclei. These symptoms improved after MNZ was changed to AMPC/CVA. Fifteen months later, the patient was doing well and had no recurrence of the infection. We performed TEVAR for a patient with a thoracic aneurysm infected by B. fragilis. The recurrence of the infection was controlled by adequate antibiotic therapy, which included the administration of MNZ. However, patients who are treated with MNZ should be carefully observed to detect the development of neurological signs, as MNZ may induce encephalopathy. The early detection and withdrawal of metronidazole is important for the improvement of MIE.

Analysis in saliva microbiome composition in patients with NAFLD and normal subjects / 实用医学杂志

Objective To analyze the diversity of salivary bacteria in patients with nonalcoholic fatty liv-er disease(NAFLD group)and healthy control group(HC group). Methods Saliva samples were collected from 24 patients with nonalcoholic fatty liver disease and 22 healthy control.Genomic DNA of the samples was extracted and extended to 16S rRNA V4-V5 hypervariable region after PCR with Illumina high-throughput sequencing tech-nology.All the data,including operational taxonomic units,diversity indexes and species annotation,etc.was ana-lyzed. Results 39118 optimized sequences in the saliva of each group were obtained,including nonalcoholic fatty liver group clustering OTUs about 308 ± 48 and healthy control group clustering OTUs about 305 ± 53.The diversi-ty analysis of NAFLD group and HC group showed that there was little difference in diversity of the whole salivary bacteria.The data of the species analysis of the saliva bacteria in two group indicate that the composition was simi-lar and the relative abundance was different in phylum and genus.In NAFLD group,the ratio of the abundance of firmicutes(20.42%)increased and the proportion of bacteroides(36.75%)decreased in phylum. Genus of the NAFLD group,the ratio of fusobacterium,porphyromonas and veillonella increased significantly,and the ratio of prevotella and[Prevotella]decreased.Conclusion In the NAFLD group,the abundance of firmicutes increased, and the abundance of the bacteria decreased.It was speculated that the imbalance of the salivary bacteria is associ-ated with nonalcoholic fatty liver disease.

Septic Arthritis Caused by Bacteroides thetaiotaomicron Bacteremia in a Patient with Multiple Myeloma / 대한내과학회지

Septic arthritis is rarely caused by anaerobic bacteria, which is mostly secondary to hematogenous dissemination among the immunocompromised host. We report a patient of septic arthritis on the right knee joint caused by Bacteroides thetaiotaomicron. To the best of knowledge, this is the first report of septic arthritis caused by Bacteroides spp. in Korea.

Bacteroides nordii and Bacteroides salyersiae Isolated from Post-operative Peritonitis Patients

In this study, we report three cases in which two species of the Bacteroides fragilis group, 'Bacteroides nordii' and 'Bacteroides salyersiae', were isolated from peritoneal fluid cultures from post-operative peritonitis patients. The two species of the B. fragilis group were initially misidentified as B. fragilis/Bacteroides stercoris and Bacteroides ovatus by Rapid ID 32A (bioMérieux, France), and finally confirmed as B. nordii and B. salyersiae using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and 16s rRNA sequencing. For the identification of anaerobes, particularly B. fragilis group organisms, MALDI-TOF MS is a useful method not only because of its concordance with 16S rRNA sequencing results, but also because of its rapidity and simple procedure.

Multidrug-resistant Bacteroides fragilis Isolated from a Case of Pyopneumothorax.

Aim: The aim of this case report is to present an unusual case of multidrug- resistant Bacteroides fragilis from a patient with pyopneumothorax who had a blunt injury to the thorax and got admitted in a tertiary care hospital, South India. Presentation of Case: The patient developed pyopneumothorax after a blunt injury and on admission was treated empirically with piperacillin-tazobactam and metronidazole. Following antibiotic sensitivity testing the B. fragilis strain isolated showed multidrug resistance including metronidazole. Imipenem was initiated replacing empiric therapy with a successful clinical outcome. Discussion: Bacteroides species are obligate anaerobic bacteria that are usually found in the gastrointestinal tract of the human body. Bacteroides species are the most commonly isolated anaerobic organisms from intra-abdominal lesions and rarely from intrathoracic disease conditions like pyopneumothorax. Pyopneumothorax caused by Bacteroides species is associated with high treatment failure and mortality rates in antibiotic-resistant cases. Though metronidazole is the mainstay of treating anaerobic infections, attention has to be given to the possibility of multidrug resistance when treating critical diseases. Conclusion: This case report summarizes the multidrug- resistance in Bacteroides fragilis strain isolated from a case of pyopneumothorax. The situation calls attention to the possibility of multidrug-resistance being underestimated when given as empirical therapy and institution of appropriate and timely antibiotic policy measures to prevent mortality.