Therapeutic Uses and Side Effects
Fazal-I-Akbar Danish, Ahmed Ehsan Rabbani in Pharmacology in 7 Days for Medical Students, 2018
2nd Generation: H. Influenzae infection.Morexella catarrhalis infection.Sinusitis.Otitis media.Meningitis.Anaerobic (Bacteroides fragilis) infection.Peritonitis.Diverticulitis.Surgical prophylaxis (colorectal surgery, hysterectomy, appendicectomy, etc.).
Peritonitis (General Considerations)
Peter Sagar, Andrew G. Hill, Charles H. Knowles, Stefan Post, Willem A. Bemelman, Patricia L. Roberts, Susan Galandiuk, John R.T. Monson, Michael R.B. Keighley, Norman S. Williams in Keighley & Williams’ Surgery of the Anus, Rectum and Colon, 2019
Despite the large number of bacterial species that can be cultured or genetically identified in the colon, only a limited number are recognised as having clinical participation in peritonitis. E. coli is the most common gram-negative rod with Klebsiella sp., Enterobacter sp. and Proteus mirabilis being occasionally cultured.7 The Enterococcus sp. are the most common of the gram-positive cocci to be identified. Many anaerobic species including Bacteroides sp., Lactobacillus sp., Clostridium sp., Bifidobacterium sp. and many others may be seen. Amongst all obligate anaerobes, Bacteroides fragilis is of greatest pathophysiologic significance8 because of its virulence factors and antimicrobial resistance.
Impact of Probiotics on Human Gut Microbiota and the Relationship with Obesity
Marcela Albuquerque Cavalcanti de Albuquerque, Alejandra de Moreno de LeBlanc, Jean Guy LeBlanc, Raquel Bedani in Lactic Acid Bacteria, 2020
Several studies have demonstrated the potential of probiotics in reducing inflammation and improving depressive and anxiety symptoms in both human and animal studies (Vaghef-Mehrabany et al. 2014, Pinto-Sanchez et al. 2017, Schachter et al. 2018). Strains of Bifidobacterium and Lactobacillus are the microorganisms most used to study beneficial effects on neurological and metabolic diseases (Kim et al. 2018). Probiotic Bacteroides fragilis has also been associated with improvement of gut permeability and microbiota composition as well as with sensorimotor and anxiety-like behaviours (Hsiao et al. 2013). Besides bacteria, some yeasts, such as Saccharomyces boulardii have also been shown to have beneficial effects on obesity, reducing fat mass, body weight, and serum concentrations of different pro-inflammatory cytokines in mice (Everard et al. 2014). According to Sonnenburg et al. (2016), the different beneficial bacteria interact with each other and with different dietary components leading to the release of bioactive metabolites, which signal to the host via the gut-brain axis.
“Driver-passenger” bacteria and their metabolites in the pathogenesis of colorectal cancer
Published in Gut Microbes, 2021
Marion Avril, R. William DePaolo
Bacteroides fragilis is a common gram-negative anaerobic bacterium belonging to the Bacteroidetes phylum. B. fragilis has two subgroups, the enterotoxigenic strains (ETBF) that possess the bft gene encoding the B. fragilis toxin (BFT or fragilysin), while the nontoxigenic strains (NTBF) do not. ETBF has been implicated in diarrhea41 and is considered oncogenic under certain circumstances due the actions of BFT which can induce DNA damage and inflammation in vivo.18,42 BFT is a metalloproteinase and has been shown to rapidly alter the structure and function of colonic epithelial cells, including the cleavage of the tumor suppressor protein, E-cadherin. Once cleaved this triggers β-catenin/Wnt signaling leading to permeability of the intestinal barrier. One of the molecular mechanisms in which ETBF triggers colitis and induces colon tumorigenesis in multiple intestinal neoplasia (Min) mice, is via the activation of signal transducer and activator of transcription 3 (STAT3) and induction of T-helper type-17 (TH17) T cell responses.
Enterotoxigenic Bacteroides fragilis induces the stemness in colorectal cancer via upregulating histone demethylase JMJD2B
Published in Gut Microbes, 2020
Qian-Qian Liu, Chun-Min Li, Lin-Na Fu, Hao-Lian Wang, Juan Tan, Yun-Qian Wang, Dan-Feng Sun, Qin-Yan Gao, Ying-Xuan Chen, Jing-Yuan Fang
The TLR signaling pathway is activated in response to Bacteroides fragilis (B. fragilis) intervention.37,38 Consistent with these findings, we found that TLR4 was highly expressed after ETBF infection (Figure 4A), whereas the mRNA levels of other TLRs that are located on the cell membrane were not notably affected (data not shown). To examine whether TLR4 participates in ETBF-induced stemness, we transfected CRC cells with TLR4 siRNA and co-cultured the cells with ETBF. We found that knockdown of TLR4 significantly reduced the formation of ETBF-induced tumorspheres and abolished the effect of ETBF on NFAT5, JMJD2B, and NANOG expression (Figure 4B, C). Moreover, ectopic expression of NFAT5 or JMJD2B in HCT116 and DLD1 cells significantly reversed the TLR4 siRNA-impaired stemness and dramatically attenuated the reduction of JMJD2B and NANOG expression caused by the TLR4 siRNA (Figure 4D-G). Furthermore, ETBF-induced tumorigenesis was suppressed by knocking down TLR4 in the CRC xenograft mouse model, as shown by reduced tumor weight and tumor volume (Figure 4H-J). In addition, knockdown of TLR4 downregulated NFAT5, JMJD2B, and NANOG expression in the xenograft tumor tissues (Figure 4K).
Interspecies interactions in mixed-species biofilms formed by Enterococcus faecalis and gram-negative bacteria isolated from polymicrobial diabetic foot ulcers
Published in Biofouling, 2023
Florencia Mariani, Guillermo E. Juarez, Claudia Barberis, Florencia Veiga, Carlos Vay, Estela M. Galvan
It has been described that the microorganisms found in DFU infections vary by geographical location (Saeed et al. 2020). S. aureus, coagulase-negative staphylococci, Streptococcus spp., Enterococcus spp., Enterobacteriaceae, Corynebacterium spp. and Pseudomonas aeruginosa are among the most commonly isolated facultative aerobic bacteria, especially in developed western countries, while in Africa, Asia and Latin America Gram-negative bacteria are more often found (Saeed et al. 2020; Carro et al. 2022). Anaerobic bacteria include Gram-positive cocci, Prevotella spp., Porphyromonas spp. and several species of the Bacteroides fragilis group (Saeed et al. 2020).
Related Knowledge Centers
- Bacteria
- Commensalism
- Microbiome
- Mucosal Immunology
- Obligate Anaerobe
- Pilus
- Bacillus
- Large Intestine
- Gram-Negative Bacteria
- Pleomorphism