Anaerobic Infections in the Surgical Patient: Microbial Etiology and Therapy

Edmiston, Charles E.; Krepel, Candace J.; Seabrook, Gary R.; Jochimsen, William G.

doi:10.1086/341931

Cited by 35 publications

(32 citation statements)

References 32 publications

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“…; Edmiston et al. ). Following initial bacterial peritoneal contamination, the host defenses – lymphatic clearance, phagocytosis, and sequestration by fibrin – rapidly clear the bacteria within minutes via lymphatic system and exposed them to systemic defenses (McClean et al.…”

Section: Introductionmentioning

confidence: 98%

Expression of Bacteroides fragilis hemolysins in vivo and role of HlyBA in an intra‐abdominal infection model

et al. 2013

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Bacteroides fragilis is the most frequent opportunistic pathogen isolated from anaerobic infections. However, there is a paucity of information regarding the genetic and molecular aspects of gene expression of its virulence factors during extra-intestinal infections. A potential virulence factor that has received little attention is the ability of B. fragilis to produce hemolysins. In this study, an implanted perforated table tennis “ping-pong” ball was used as an intra-abdominal artificial abscess model in the rat. This procedure provided sufficient infected exudate for gene expression studies in vivo. Real-time reverse transcription polymerase chain reaction (RT-PCR) was used to quantify the relative expression of hlyA, hlyB, hlyC, hlyD, hlyE, hlyF, hlyG, and hlyIII mRNAs. The hlyA mRNA was induced approximately sixfold after 4 days postinfection compared with the mRNA levels in the inoculum culture prior to infection. The hlyB mRNA increased approximately sixfold after 4 days and 12-fold after 8 days postinfection. Expression of hlyC mRNA increased sixfold after 1 day, 45-fold after 4 days, and 16-fold after 8 days postinfection, respectively. The hlyD and hlyE mRNAs were induced approximately 40-fold and 30-fold, respectively, after 4-days postinfection. The hlyF expression increased approximately threefold after 4-days postinfection. hlyG was induced approximately fivefold after 4 and 8 days postinfection. The hlyIII mRNA levels had a steady increase of approximately four-, eight-, and 12-fold following 1, 4, and 8 days postinfection, respectively. These findings suggest that B. fragilis hemolysins are induced and differentially regulated in vivo. Both parent and hlyBA mutant strains reached levels of approximately 3–8 × 109 cfu/mL after 1 day postinfection. However, the hlyBA mutant strain lost 2 logs in viable cell counts compared with the parent strain after 8 days postinfection. This is the first study showing HlyBA is a virulence factor which plays a role in B. fragilis survival in an intra-abdominal abscess model.

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Section: Introductionmentioning

confidence: 98%

Expression of Bacteroides fragilis hemolysins in vivo and role of HlyBA in an intra‐abdominal infection model

et al. 2013

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“…This gram-negative bacterium, which is part of the normal intestinal flora, causes infections arising from exposure of normally sterile body sites to even minute amounts of fecal material. B. fragilis has a marked tendency to provoke abscess formation and is frequently isolated from the blood during life-threatening sepsis in association with intra-abdominal or pelvic abscesses (2,6,9). Lipopolysaccharide (LPS), a major constituent of the cell wall of gram-negative bacteria, plays an important role in the pathophysiology of sepsis (7).…”

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confidence: 99%

Bacteroides fragilis-Derived Lipopolysaccharide Produces Cell Activation and Lethal Toxicity via Toll-Like Receptor 4

et al. 2005

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Bacteroides fragilis, which is part of the normal intestinal flora, is a frequent cause of serious disease, especially in diabetic and surgical patients. In these conditions, B. fragilis lipopolysaccharide (LPS) is likely to play a major pathophysiologic role. B. fragilis LPS is structurally different from classical enterobacterial LPS, whose biological activities are mediated by Toll-like receptor 4 (TLR4) activation. The ability of B. fragilis LPS to activate TLR4 and TLR2 was investigated here, since evidence on this issue is scarce and controversial. Each of four different protein-free B. fragilis LPS preparations could induce interleukin-8 responses in cells cotransfected with TLR4/CD14/MD2 but not TLR4/CD14 alone. Two of the preparations also induced cytokine production in cells cotransfected with TLR2/CD14 or in peritoneal macrophages from TLR4 mutant C3H/HeJ mice. Both of these activities, however, were lost after repurification with a modified phenol reextraction procedure. Importantly, all preparations could induce endotoxic shock in TLR2-deficient mice, but not in TLR4 mutant C3H/HeJ mice. Consistent with these findings, anti-TLR4 and anti-CD14, but not anti-TLR2, antibodies could inhibit B. fragilis LPS-induced cytokine production in human monocytes. Collectively, these results indicate that B. fragilis LPS signals via a TLR4/CD14/MD2-dependent pathway, and it is unable to activate TLR2. Moreover, our data document the occurrence of TLR2-activating contaminants even in highly purified B. fragilis LPS preparations. This may explain earlier contradictory findings on the ability of B. fragilis LPS to activate cells in the absence of functional TLR4. These data may be useful to devise strategies to prevent the pathophysiologic changes observed during B. fragilis sepsis and to better understand structure-activity relationships of LPS.

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“…The most common source of anaerobic infections in surgical patients is endogenous normal flora or environmental contamination of wound injuries [10]. Although this anaerobic bacillus has not yet been isolated from normal human flora, the presentation of a case of a post-surgical site infection following a sigmoid colectomy suggests that the source of infection was the disruption of the mucosal barrier [4].…”

Section: Discussionmentioning

confidence: 99%

Robinsoniella peoriensis infection following surgery for scoliosis: a case report

et al. 2012

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IntroductionRobinsoniella peoriensis was recently identified as a Gram-positive, spore-forming, anaerobic bacillus originally isolated from swine manure storage pits. Seven isolates have been subsequently reported from human sources.Case presentationWe report the case of an infection caused by R. peoriensis in a 45-year-old Caucasian woman after posterior instrumentation correction of idiopathic thoracolumbar scoliosis. The identification was made by culture of samples inoculated onto blood agar and chocolate agar and was confirmed by 16 S ribosomal ribonucleic acid gene sequencing.ConclusionsWe discuss similar cases suggesting that R. peoriensis is responsible for health care-associated infections with the colonic flora as a potential source of infection.

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Anaerobic Infections in the Surgical Patient: Microbial Etiology and Therapy

Cited by 35 publications

References 32 publications

Expression of Bacteroides fragilis hemolysins in vivo and role of HlyBA in an intra‐abdominal infection model

Expression of Bacteroides fragilis hemolysins in vivo and role of HlyBA in an intra‐abdominal infection model

Bacteroides fragilis-Derived Lipopolysaccharide Produces Cell Activation and Lethal Toxicity via Toll-Like Receptor 4

Robinsoniella peoriensis infection following surgery for scoliosis: a case report

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