Ultrastructural lesions of enterotoxigenic Bacteroides fragilis in rabbits.
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A porcine isolate of enterotoxigenic Bacteroides fragilis colonized the intestinal tract and caused watery, nonhemorrhagic diarrhea when given orally to 12, 1- to 2-day-old gnotobiotic pigs. Diarrhea occurred 2 to 3 days post-inoculation and continued throughout the 4 to 6 day post-inoculation period. Diarrheic pigs became mildly anorexic and dehydrated. They developed intestinal lesions characterized by swelling, vacuolation, and exfoliation of enterocytes, and crypt hyperplasia throughout the large intestine and, to a lesser extent, in the distal small intestine. Bacterial adherence to, or invasion of, the intestinal mucosa was not detected. A porcine isolate of nonenterotoxigenic B. fragilis was administered orally to six control pigs. The isolate colonized the intestinal tract, but the pigs did not develop clinical disease or intestinal lesions. The pathogenetic mechanism of the disease may involve mediation by a soluble enterotoxin (or toxins) elaborated by B. fragilis.
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A 54-year-old man had had an acute anterior myocardial infarction nine years prior to this hospital admission. Since that time he had been asymptomatic with the exception of occasional episodes of precordial chest pain. The patient died from septic shock on the tenth day after the present admission. On autopsy there was an old myocardial infarct with aneurysmal dilatation of the left ventricle which contained a large thrombus with multiple abscesses. Septic infarcts were also found in the left kidney and the left temporal lobe of the brain.
During the period between 1987 and 1997, various surveillances of the antibiotic resistance of B. fragilis group isolates revealed that practically all the isolates tested were susceptible to imipenem, metronidazole and chloramphenicol; very few isolates (2.5%) exhibited resistance to amoxicillin/clavulanic acid. However, similarly as in some southern European countries, the percentages of the isolates that were resistant to ampicillin, tetracycline and clindamycin were high throughout this period, and the resistance to cefoxitin increased from 6% to 16%. In 2000, isolates with intermediate or high resistance to imipenem and isolates with increased MICs to metronidazole were emerging among the clinical isolates of B. fragilis. The presence of the cfiA gene was demonstrated by PCR in 7 of 242 isolates (2.9%); 2 of them with high MICs to carbapenems harboured the IS942 element immediately upstream of the resistance genes. In the 2 B. fragilis isolates with increased MICs to metronidazole, the nim gene could be detected by PCR. The IS1186 element was found in these isolates upregulating the metronidazole resistance gene.
Non-enterotoxigenic bacteria of the Bacteroides fragilis group and enterotoxigenic B. fragilis were identified from children with and without aqueous acute diarrhea. In this study, 170 stool samples from 96 children with and 74 without diarrhea were analyzed. Enterotoxin production and the toxin gene detection were detected by cytotoxicity assay on HT-29/C1 cells and by PCR, respectively. B. fragilis species was prevalent in both groups and enterotoxigenic B. fragilis strains were isolated from two children with diarrhea. More studies are important to evaluate the role of each bacteria of the B. fragilis group, including enterotoxigenic strains play in the diarrheal processes in children.
BACKGROUND: This study aimed to determine the relationships among interleukin (IL)-8 and granulocyte elastase levels in gingival crevicular fluid (GCF) and the concomitant presence of periodontopathogens in untreated adult periodontitis. METHODS: GCF and subgingival plaque samples were collected from 16 patients with untreated adult periodontitis and 10 healthy control subjects. IL-8 levels were determined by enzyme-linked immunosorbent assay (ELISA). Granulocyte elastase was analyzed with a neutrophilic granulocyte-specific, low molecular weight and chromogenic substrate, L-pyroglutamyl-L-prolyl-L-valine-p-nitroanilide, and the maximal rate of elastase activity (MR-EA) was calculated. Five DNA probes were used to detect the presence of A. actinomycetemcomitans (A.a.), B. forsythus (B.f.), P. gingivalis (P.g.), P. intermedia (P.i.), and T. denticola (T.d.). RESULTS: Lower IL-8 concentrations and higher granulocyte elastase activities were found in patients than in healthy controls as well as in diseased conditions co-infected with B.f., P.g., P.i., and T.d. as compared to healthy conditions without the target species (P <0.05). IL-8 concentrations were positively correlated with MR-EA levels in the periodontitis conditions co-infected with B.f., P.g., P.i., and T.d. (P <0.05). A wide range of IL-8 concentrations was found among 15 patients when the periodontitis condition was characterized by co-infection with B.f., P.g., P.i., and T.d. MR-EA levels in the high IL-8 group of subjects were significantly higher than those in the low IL-8 group of subjects (P <0.01). CONCLUSIONS: The present study shows that the local host-bacteria interactions in untreated periodontitis are diverse in terms of the intensity of inflammatory responses measured by IL-8-related granulocyte elastase activity in GCF. This might reflect different phases of the inflammatory response due to shifts in host-bacteria interactions and therefore be indicative of a range of periodontal disease activity levels.
BACKGROUND: Guillain-Barré syndrome (GBS), an autoimmune disorder of the peripheral nervous system, is characterized by rapidly ascending neural paralysis, hyporeflexia, and areflexia. The polyneuropathy of the GBS affects one to four humans per 100,000 of the population annually throughout the world (adults and children). The pathogenesis of GBS remains unclear. However, there are increasing indications that the disease is triggered by a preceding well-established febrile infection by cytomegalovirus (CMV). The present report describes active CMV within the periodontium of a 37-year-old patient affected by GBS. METHODS: Real-time reverse transcriptase-polymerase chain reaction (real-time RT-PCR) was performed to detect CMV, Epstein-Barr virus-1 (EBV-1), herpes simplex 1 (HSV-1) and 2 (HSV-2) virus, and enteroviruses (polio-, coxsackie-, echo-, and enteroviruses 68 and 71) from periodontal sites demonstrating advanced attachment loss. Healthy sites and sites with inflamed gingival tissue were not included in the study. Anaerobic bacterial culture determined the occurrence of potential major periodontal pathogens. RESULTS: Real-time RT-PCR and microbiologic analysis revealed the presence of a dual infection of CMV and specific bacterial plaque. CMV, Porphyromonas gingivalis, Tannerella forsythensis, and Campylobacter species were associated with periodontitis active sites, loss of attachment, and gingival bleeding. Furthermore, periodontal sites infected by active CMV had no visible radiographic crestal lamina dura. CONCLUSIONS: The periodontium may serve as a reservoir for CMV and a source of viral replication. However, further research is needed to test whether viral replication in the periodontium precedes the GBS symptoms.
Bactobilia is a frequent accompaniment of obstruction in the biliary tract, organisms present being normal intestinal aerobes and anaerobes. Bacterial colonisation of the bile may occur asymptomatically, may predispose to infection postoperatively, or may be associated with an attack of acute cholecystitis, occurring secondary to obstruction. The choice of an antimicrobial regimen for biliary infection should take into account the expected antibiotic sensitivities of organisms colonising bile, whether biliary obstruction or bacteraemia is present, and the activity of the antibiotic in bile. Often, high biliary concentrations of an antibiotic cannot be achieved due to obstruction, and in many cases high blood and tissue concentrations are of greater importance. Surgical prophylaxis should be reserved for patients at high risk of bactobilia (e.g. the elderly), when obstruction is present, for immunosuppressed patients, and those with artificial heart valves. A single perioperative dose of a 'first' or 'second generation' cephalosporin, gentamicin, or co-trimoxazole is effective. Antibiotic therapy for acute cholecystitis should be instituted if there is evidence of systemic toxicity, when surgery is to be delayed, or in patients with identified risk factors for bactobilia. Ampicillin or a cephalosporin may be appropriate in less severe disease, while in seriously ill patients, an aminoglycoside or cephalosporin with metronidazole or clindamycin is appropriate. Oral regimens include amoxycillin, an oral cephalosporin, or co-trimoxazole, in combination with metronidazole. In acute cholangitis, systemic therapy similar to that recommended for acute cholecystitis is indicated. Patients with recurrent cholangitis may have relatively antibiotic-resistant bacteria and efforts should be made to obtain a bacteriological diagnosis. Long term suppressant therapy with oral agents such as amoxycillin, cephalexin, or co-trimoxazole may be tried.
To evaluate the microbiological water quality of bathing sites along the Achaia coastline (south western Greece), a survey was conducted to determine the concentration of faecal bacterial and phage indicators as well as the presence of human viruses. Seawater samples (234) were collected from nine bathing sites on the Achaia coastline and were analysed for the presence of: total coliforms, faecal coliforms, faecal streptococci, Escherichia coli, somatic coliphages, F-RNA bacteriophages, bacteriophages infecting Bacteroides fragilis, enteroviruses, adenoviruses and hepatitis A viruses. Most of the bacteriological analysis results were in accordance with the European Union standards. In all sites, bacteriophages were detected occasionally. Enteroviruses and adenoviruses were detected in 24 samples (10.26%) and 37 samples (15.81%) respectively. No samples were positive for the presence of hepatitis A virus. The overall data indicates that bathing sites are impacted by human faecal material. Both bacterial indicators and phages have low predictive capability for the presence of human viruses in coastal waters. None of the environmental parameters analysed was strongly related to the presence of the indicator organisms and viruses. Appropriate and effective administrative measures that should be taken into account may be considered in order to improve water quality and reduce public health risk.
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Here, we report the management of a type I endoperiodontal lesion with furcation bone loss. A 59-year-old female attended our hospital with the chief complaint of mobility of tooth 46 and recurrent gingival swelling around the tooth. She previously received dental treatment from two dentists, but her condition did not improve. The tooth manifested the symptoms of typical periodontitis, such as gingival swelling, tooth mobility, pus discharge from the periodontal pocket and furcation bone loss. The tooth had no caries and the pulp reacted to an electric pulp test. Careful examination of the gingiva revealed traces of dental fistula. X-ray examination via a gutta percha inserted into the fistula revealed that furcation bone loss was associated with the periapical lesion. We diagnosed a type I endoperiodontal lesion, and applied Periocheck, a detection kit for peptidase-producing bacteria, to check for decreases in bacteria in the furcation and root canals. Soon after non-surgical root canal treatment, the condition of tooth 46 improved without periodontal treatment. After confirming a negative score with Periocheck, the root canal was filled. After 3 months, the furcation bone loss was on the way to recovery. These results indicate that proper diagnosis and confirmation of a decrease in root canal bacteria are important for treating endoperiodontal lesions.
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The efficacy of metronidazole in otitis media due to Bacteroides fragilis was evaluated in a guinea pig model. Fifty-nine animals received an injection of 10(8) live B. fragilis bacteria through the tympanic membrane into the right middle ear cavity and metronidazole therapy was started 7 days later. On day 14 after challenge the animals were sacrificed and their middle ears analysed. Intraperitoneal injection of 6 mg metronidazole (about 20 mg per kg) once daily, 6 mg twice daily and 15 mg (50 mg per kg) once daily reduced the incidence of culture positive ears from 13/17 among untreated controls to 7/17 (p = 0.08), 3/10 (p = 0.05) and 2/15 (p = 0.001), respectively. The therapeutic efficacy of metronidazole in experimental otitis media was less than that expected from the concentrations of drug recorded in serum and the drug levels presumed to be achieved in the middle ear effusion.
Anaerobic arthritis due to Bacteroides fragilis was diagnosed in a 33-year-old patient with prolonged fever suffering from sickle cell/thalassaemia. The causative agent was isolated from blood and purulent synovial fluid from both knee joints. A combination of chloramphenicol plus metronidazole treatment proved effective. Anaerobic arthritis has not previously been described in patients with sickle cell disease, and may reflect the well-known susceptibility of these patients to pathogens.
Enterotoxigenic strains of Bacteriodes fragilis (ETBF) have recently been found to be associated with diarrheal illness in Apache and Bangladeshi children. This study was conducted to define the role of ETBF in diarrhea of children in an urban setting. Fecal specimens from 991 children with diarrhea and 581 asymptomatic age-matched controls were cultured for B. fragilis (BF). The isolates were tested for enterotoxin production using a human colonic epithelial cell line. BF was isolated from 318 (32.1%) of the patients and 123 (21.2%) of the controls (p < 0.001). In children < 1 year old which comprised about 50% of both patients and controls, the BF isolation rates were comparable (26.5% vs 25.7%; p = 0.812), contrasting with the significant difference in isolation rates for children > or = 1 year (37.6% vs 16.5%; p = < 0.001). Overall, ETBF were identified in 4.4% of patients and 3.1% of controls (p = 0.2). However, ETBF were significantly associated with diarrheal disease in children 1-5 years (5.4% vs 1.8%; p = 0.033) and 1-10 years (4.8% vs 1.5%; p = 0.021) in age. ETBF were isolated the year round and comprised 14.4% and 15% of the BF isolated from the patients and controls, respectively, suggesting that part of the indigenous BF are inherently enterotoxin producers. In this study, BF and ETBF were associated with diarrheal illness in children 1-10 years old.
During a 7-year period Bacteroides bacteraemia was found in 51 patients, corresponding to 1.9% of all patients with positive blood cultures. Many patients had serious underlying diseases, most frequently in the gastrointestinal tract, and 80% were subjected to surgery. Frequent clinical findings were shock (27%), phlebitis (24%) and jaundice (22%). The overall mortality was 55%. Increased mortality was associated with shock, advanced age and phlebitis. Bacteroides fragilis, showing a very homogeneous biochemical pattern, was the species most frequently isolated. The strains were sensitive to chloramphenicol and tetracycline, and as a rule also to erythromycin. It was confirmed that Bacteroides isolated from the blood usually indicates true bacteraemia.
We identified enterotoxigenic Bacteroides fragilis in stool specimens of patients with inflammatory bowel disease and other gastrointestinal disorders. The organism was detected in 11 (13.2%) of 83 patients with inflammatory bowel disease. Of 57 patients with active disease, 19.3% were toxin positive; none of those with inactive disease had specimens positive for enterotoxigenic Bacteroides fragilis gene sequences.