-
Gut Microbes 2021The functional diversity of the mammalian intestinal microbiome far exceeds that of the host organism, and microbial genes contribute substantially to the well-being of... (Review)
Review
The functional diversity of the mammalian intestinal microbiome far exceeds that of the host organism, and microbial genes contribute substantially to the well-being of the host. However, beneficial gut organisms can also be pathogenic when present in the gut or other locations in the body. Among dominant beneficial bacteria are several species of , which metabolize polysaccharides and oligosaccharides, providing nutrition and vitamins to the host and other intestinal microbial residents. These topics and the specific organismal and molecular interactions that are known to be responsible for the beneficial and detrimental effects of species in humans comprise the focus of this review. The complexity of these interactions will be revealed.
Topics: Animals; Bacteroides; Extracellular Vesicles; Gastrointestinal Microbiome; Gastrointestinal Tract; Humans; Microbial Interactions; Polysaccharides; Virulence Factors
PubMed: 33535896
DOI: 10.1080/19490976.2020.1848158 -
Clinical Microbiology Reviews Oct 2007Bacteroides species are significant clinical pathogens and are found in most anaerobic infections, with an associated mortality of more than 19%. The bacteria maintain a... (Review)
Review
Bacteroides species are significant clinical pathogens and are found in most anaerobic infections, with an associated mortality of more than 19%. The bacteria maintain a complex and generally beneficial relationship with the host when retained in the gut, but when they escape this environment they can cause significant pathology, including bacteremia and abscess formation in multiple body sites. Genomic and proteomic analyses have vastly added to our understanding of the manner in which Bacteroides species adapt to, and thrive in, the human gut. A few examples are (i) complex systems to sense and adapt to nutrient availability, (ii) multiple pump systems to expel toxic substances, and (iii) the ability to influence the host immune system so that it controls other (competing) pathogens. B. fragilis, which accounts for only 0.5% of the human colonic flora, is the most commonly isolated anaerobic pathogen due, in part, to its potent virulence factors. Species of the genus Bacteroides have the most antibiotic resistance mechanisms and the highest resistance rates of all anaerobic pathogens. Clinically, Bacteroides species have exhibited increasing resistance to many antibiotics, including cefoxitin, clindamycin, metronidazole, carbapenems, and fluoroquinolones (e.g., gatifloxacin, levofloxacin, and moxifloxacin).
Topics: Adult; Anti-Bacterial Agents; Bacteroides; Bacteroides Infections; Bacteroides fragilis; Child; Child, Preschool; Drug Resistance, Bacterial; Gastrointestinal Tract; Humans; Infant; Infant, Newborn; Microbial Sensitivity Tests; Virulence
PubMed: 17934076
DOI: 10.1128/CMR.00008-07 -
Acta Odontologica Scandinavica Dec 1994The loose definition of Bacteroides, some species of which are important etiologic agents of oral diseases, has enabled isolates with only marginal similarities to be... (Review)
Review
The loose definition of Bacteroides, some species of which are important etiologic agents of oral diseases, has enabled isolates with only marginal similarities to be reposited in this genus. Many attempts have been made over the years to improve the taxonomy of this heterogeneous group of bacteria. The present article reviews major chemotaxonomic characters and techniques that have been used for this purpose: pigmentation, metabolites, whole-cell fatty acids, phospholipids, isoprenoid quinones, carbohydrates of lipopolysaccharide, whole-cell proteins, peptidoglycans, enzymes, pyrolysis mass spectrometry, DNA composition, restriction fragment length polymorphisms of DNA and ribosomal (r) RNA, homology of DNA and RNA, DNA-rRNA hybridization, and 16S and 5S rRNA oligonucleotide cataloging and sequencing. Despite improvements in their taxonomy, some bacteroides are still misclassified. Suggestions for further improvements in the taxonomy of bacteroides are made.
Topics: Bacteroides; Classification; DNA, Bacterial; Humans; Mouth Diseases; Pigmentation; Porphyromonas; Prevotella
PubMed: 7887145
DOI: 10.3109/00016359409029033 -
Clinical Infectious Diseases : An... Jun 1993Antimicrobial resistance in Bacteroides species has a direct impact on the selection of chemotherapy for anaerobic infections. Multiple studies have documented... (Comparative Study)
Comparative Study Review
Antimicrobial resistance in Bacteroides species has a direct impact on the selection of chemotherapy for anaerobic infections. Multiple studies have documented differences in susceptibility patterns related to individual hospitals, geographic areas, and antibiotic-prescribing practices. Resistance to beta-lactam antibiotics, tetracycline, clindamycin, and metronidazole has been documented in Bacteroides species. The prime mechanism for beta-lactam resistance is the production of beta-lactamases, including penicillinases, cephalosporinases, and the metallo-beta-lactamases that can hydrolyze imipenem. Resistance to tetracycline is mediated by ribosomal protection by the tetQ class. Resistance to clindamycin is mediated by ribosomal modification. Metronidazole resistance may be caused by a combination of decreased antibiotic uptake, decreased nitroreductase activity, and decreased pyruvate:ferredoxin oxidoreductase activity accompanied by increased lactate dehydrogenase activity. Most disturbing is the appearance of resistance to multiple agents in the same organism. Understanding the mechanisms of resistance and the mechanisms of action of these drugs not only will lead to the design of new antimicrobial agents but will permit informed selection of therapy for bacteroides infections.
Topics: Anti-Bacterial Agents; Bacteroides; Bacteroides Infections; Base Sequence; DNA, Bacterial; Drug Resistance, Microbial; Humans; In Vitro Techniques; Molecular Sequence Data; beta-Lactamases; beta-Lactams
PubMed: 8324154
DOI: 10.1093/clinids/16.supplement_4.s390 -
Future Microbiology May 2009Bacteroides spp. organisms, though important human commensals, are also opportunistic pathogens when they escape the colonic milieu. Resistance to multiple antibiotics... (Review)
Review
Bacteroides spp. organisms, though important human commensals, are also opportunistic pathogens when they escape the colonic milieu. Resistance to multiple antibiotics has been increasing in Bacteroides spp. for decades, and is primarily due to horizontal gene transfer of a plethora of mobile elements. The mechanistic aspects of conjugation in Bacteroides spp. are only now being elucidated at a functional level. There appear to be key differences between Bacteroides spp. and non-Bacteroides spp. conjugation systems that may contribute to promiscuous gene transfer within and from this genus. This review summarizes the mechanisms of action and resistance of antibiotics used to treat Bacteroides spp. infections, and highlights current information on conjugation-based DNA exchange.
Topics: Anti-Bacterial Agents; Bacteroides; Conjugation, Genetic; Drug Resistance, Bacterial; Gene Transfer, Horizontal; Humans; Interspersed Repetitive Sequences
PubMed: 19416011
DOI: 10.2217/fmb.09.12 -
Carbohydrate Polymers Sep 2023Although many polysaccharides utilization loci (PULs) have been investigated by genomics and transcriptomics, the detailed functional characterization lags severely...
Although many polysaccharides utilization loci (PULs) have been investigated by genomics and transcriptomics, the detailed functional characterization lags severely behind. We hypothesize that PULs on the genome of Bacteroides xylanisolvens XB1A (BX) dictate the degradation of complex xylan. To address, xylan S32 isolated from Dendrobium officinale was employed as a sample polysaccharide. We firstly showed that xylan S32 promoted the growth of BX which might degrade xylan S32 into monosaccharides and oligosaccharides. We further showed that this degradation was performed mainly via two discrete PULs in the genome of BX. Briefly, a new surface glycan binding protein (SGBP) BX_29290 was identified, and shown to be essential for the growth of BX on xylan S32. Two cell surface endo-xylanases Xyn10A and Xyn10B cooperated to deconstruct the xylan S32. Intriguingly, genes encoding Xyn10A and Xyn10B were mainly distributed in the genome of Bacteroides spp. In addition, BX metabolized xylan S32 to produce short chain fatty acids (SCFAs) and folate. Taken together, these findings provide new evidence to understand the food source of BX and the BX-directed intervention strategy by xylan.
Topics: Humans; Xylans; Polysaccharides; Bacteroides; Gene Expression Profiling
PubMed: 37230606
DOI: 10.1016/j.carbpol.2023.121005 -
Gut Microbes 2021Dysbiosis of gut microbiota has been retrospectively linked to autism spectrum disorders but the temporal association between gut microbiota and early neurodevelopment...
Dysbiosis of gut microbiota has been retrospectively linked to autism spectrum disorders but the temporal association between gut microbiota and early neurodevelopment in healthy infants is largely unknown. We undertook this study to determine associations between gut microbiota at two critical periods during infancy and neurodevelopment in a general population birth cohort.Here, we analyzed data from 405 infants (199 females) from the CHILD (Canadian Healthy Infant Longitudinal Development) Cohort Study. Neurodevelopmental outcomes were objectively assessed using the Bayley Scale of Infant Development (BSID-III) at 1 and 2 years of age. Microbiota profiling with 16S rRNA gene sequencing was conducted on fecal samples obtained at a mean age of 4 and 12 months.Using clustering methods, we identified three groups of infants based on relative abundance of gut microbiota at 12 months: -dominant cluster (22.4% higher abundance at 12 months), -dominant cluster (46.0% higher abundance at 12 months) and Bacteroidetes-dominant cluster (31.6% higher abundance at 12 months). Relative to the -dominant cluster, the -dominant cluster was associated with higher scores for cognitive (4.8 points; FDRp = .02), language (4.2 points; FDRp≤0.001), and motor (3.1 points; FDRp = .03) development at age 2 in models adjusted for covariates. When stratified by sex, only male infants with a -dominant microbiota had more favorable cognitive (5.9 points, FDRp = .06) and language (7.9 points; FDRp≤0.001) development. Genus abundance in gut microbiota was positively correlated with cognitive and language scores at age 2. Fully adjusted linear mixed model analysis revealed a positive association between -dominant cluster and change in cognitive and language performance from 1 to 2 years, predominantly among males. No associations were evident between 4-month microbiota clusters and BSID-II scores. Noteworthy is that enhanced sphingolipid synthesis and metabolism, and antagonism or competition between and were characteristic of a -dominant gut microbiota.This study found strong evidence of positive associations between Bacteroidetes gut microbiota in late infancy and subsequent neurodevelopment, most prominently among males but not females.
Topics: Bacteria; Bacteroides; Canada; Child Development; Female; Follow-Up Studies; Gastrointestinal Microbiome; Humans; Infant; Male; Nervous System; RNA, Ribosomal, 16S; Retrospective Studies
PubMed: 34132157
DOI: 10.1080/19490976.2021.1930875 -
The Journal of Applied Bacteriology Dec 1983
Review
Topics: Acids; Bacteroides; Base Composition; Cell Wall; DNA, Bacterial; Fatty Acids; Lipid Metabolism; Pigments, Biological; Species Specificity; Vitamin K
PubMed: 6363375
DOI: 10.1111/j.1365-2672.1983.tb01680.x -
The Journal of Antimicrobial... Feb 1987
Review
Topics: Anti-Bacterial Agents; Bacteroides; Bacteroides fragilis; Drug Resistance, Microbial
PubMed: 3553132
DOI: 10.1093/jac/19.2.143 -
Microbiological Reviews Mar 1988
Review
Topics: Antigens, Bacterial; Bacterial Toxins; Bacteroides; Microbial Sensitivity Tests; Virulence
PubMed: 3280965
DOI: 10.1128/mr.52.1.134-152.1988