Gram-negative anaerobic rods and cocci: Difference between revisions
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''Bacteroides'' are '''gram-negative pleomorphic rods''' with rounded ends, usually '''encapsulated''' . They are characterized by '''resistance''' to bile acids . They massively colonize the large and small intestine, where they play a role in the digestion of complex molecules, the upper respiratory tract. In the vagina, it belongs to the commensal species B. fragilis, B. capillosus or B. ureolyticus . Their endotoxin has little biological activity. | ''Bacteroides'' are '''gram-negative pleomorphic rods''' with rounded ends, usually '''encapsulated''' . They are characterized by '''resistance''' to bile acids . They massively colonize the large and small intestine, where they play a role in the digestion of complex molecules, the upper respiratory tract. In the vagina, it belongs to the commensal species B. fragilis, B. capillosus or B. ureolyticus . Their endotoxin has little biological activity. | ||
Pathogenicity | |||
The most important pathogens include '''B. fragilis''' with a polysaccharide capsule as a virulence factor. It can cause peritonitis , surgical infections in the digestive tract, and appendicitis . It inhibits phagocytosis and, like other species of this genus, is resistant to beta-lactams , aminoglycosides , and recently species resistant to erythromycin and tetracycline have appeared . The genus ''Bacteroides'' also includes, for example, ''B. ovatus'' , ''B. vulgatus'' and ''B. gracilis'' . | The most important pathogens include '''B. fragilis''' with a polysaccharide capsule as a virulence factor. It can cause peritonitis , surgical infections in the digestive tract, and appendicitis . It inhibits phagocytosis and, like other species of this genus, is resistant to beta-lactams , aminoglycosides , and recently species resistant to erythromycin and tetracycline have appeared . The genus ''Bacteroides'' also includes, for example, ''B. ovatus'' , ''B. vulgatus'' and ''B. gracilis'' . | ||
Revision as of 00:30, 27 January 2023
Bacteria from group G− anaerobes belong to species that are difficult to cultivate, therefore it is difficult to identify them as the causative agent of the disease. We include the clinically important genera Bacteroides, Prevotella, Fusobacterium, Mobiluncus a Veillonella. [1]
Gram-negative anaerobic rods
Anaerobic G− bacilli form the normal flora of mucous membranes, often acting as 'secondary pathogens. These are pleomorphic bacteria that are difficult to cultivate. The main pathogenic mechanism is non-specific tissue damage by the acids produced.Bakteroidy a fusobakteria they produce enzymes that facilitate their penetration into tissues and spread.
These bacteria can cause infections anywhere in the human body: oral, pleuropulmonary, intra-abdominal, periodontal, also in the small pelvis and female genital infections. They are an infectious agent even in tissues damaged by injury or surgery. abscesses filled with foul-smelling pus form in the affected area. They are used for therapy lincomycin, chloramphenicol, clindamycin and metronidazole, it is often necessary to choose a ``surgical intervention (incision, drainage). [2] [3]
Bacteroides spp.
Bacteroides spp. Bacteria of the genus Bacteroides are an important part of the natural intestinal flora, some species are potentially pathogenic. Their membrane contains sphingolipids , they have diaminopimelic acid in the wall. Bacteroides are gram-negative pleomorphic rods with rounded ends, usually encapsulated . They are characterized by resistance to bile acids . They massively colonize the large and small intestine, where they play a role in the digestion of complex molecules, the upper respiratory tract. In the vagina, it belongs to the commensal species B. fragilis, B. capillosus or B. ureolyticus . Their endotoxin has little biological activity.
Pathogenicity
The most important pathogens include B. fragilis with a polysaccharide capsule as a virulence factor. It can cause peritonitis , surgical infections in the digestive tract, and appendicitis . It inhibits phagocytosis and, like other species of this genus, is resistant to beta-lactams , aminoglycosides , and recently species resistant to erythromycin and tetracycline have appeared . The genus Bacteroides also includes, for example, B. ovatus , B. vulgatus and B. gracilis .
Prevotella spp.
Fusobacterium spp.
Mobiluncus spp.
Gram-negative anaerobic cocci
The G− group of anaerobic cocci includes Acidaminococcus spp., Megasphaera spp., which are part of the natural bacterial flora of humans. Bacteria of the genus Veillonella are clinically important. [3]
Veillonella spp.
Links
Reference
- ↑ GLOBALRPh. Anaerobes (gram positive and negative): [online]. [cit. 2014-10-19]. <http://www.globalrph.com/bacterial-strains-anaerobic.htm>.
- ↑ BARON, S. Anaerobic Gram-Negative Bacilli [online]. [cit. 2014-10-18]. <https://www.ncbi.nlm.nih.gov/books/NBK8438/>.
- ↑ Jump up to: a b VOTAVA, Miroslav. Lékařská mikrobiologie speciální. 1. edition. Brno : Neptun, 2003. ISBN 80-902896-6-5.
