Pathogenesis of cancrum oris (noma): confounding interactions of malnutrition with infection.
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This study showed that impoverished Nigerian children at risk for cancrum oris (noma) had significantly reduced plasma concentrations of zinc (< 10.8 micromol/L), retinol (< 1.05 micromol/L), ascorbate (< 11 micromol/L), and the essential amino acids, with prominently increased plasma and saliva levels of free cortisol, compared with their healthy counterparts. The nutrient deficiencies, in concert with previously reported widespread viral infections (measles, herpesviruses) in the children, would impair oral mucosal immunity. We postulate, subject to additional studies, that evolution of the oral mucosal ulcers including acute necrotizing gingivitis to noma is triggered by a consortium of microorganisms of which Fusobacterium necrophorum is a key component. Fusobacterium necrophorum elaborates several dermonecrotic toxic metabolites and is acquired by the impoverished children via fecal contamination resulting from shared residential facilities with animals and very poor environmental sanitation. (+info)
Lemierre's syndrome (necrobacillosis).
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Lemierre's syndrome or postanginal septicaemia (necrobacillosis) is caused by an acute oropharyngeal infection with secondary septic thrombophlebitis of the internal jugular vein and frequent metastatic infections. Fusobacterium necrophorum is the most common pathogen isolated from the patients. The interval between the oropharyngeal infection and the onset of the septicaemia is usually short. The most common sites of septic embolisms are the lungs and joints, and other locations can be affected. A high degree of clinical suspicion is needed to diagnose the syndrome. Computed tomography of the neck with contrast is the most useful study to detect internal jugular vein thrombosis. Treatment includes intravenous antibiotic therapy and drainage of septic foci. The role of anticoagulation is controversial. Ligation or excision of the internal jugular vein may be needed in some cases. (+info)
Phylogenetic analysis of Fusobacterium alocis and Fusobacterium sulci based on 16S rRNA gene sequences: proposal of Filifactor alocis (Cato, Moore and Moore) comb. nov. and Eubacterium sulci (Cato, Moore and Moore) comb. nov.
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Genes encoding the 16S rRNA of Fusobacterium alocis ATCC 35896T and Fusobacterium sulci ATCC 35585T were sequenced. These sequences did not have any affinity with the 16S rRNA gene sequences of members of the genus Fusobacterium. Fusobacterium alocis ATCC 35896T and Fusobacterium sulci ATCC 35585T belonged to Clostridium cluster XI; the species most closely related to these strains were Filifactor villosus NCTC 11220T and Eubacterium infirmum W1471, respectively. Two new combinations are proposed: Filifactor alocis (Cato, Moore and Moore) comb. nov. (type strain ATCC 35896T) and Eubacterium sulci (Cato, Moore and Moore) comb. nov. (type strain ATCC 35585T). (+info)
Serological study of trichloroacetic acid extracts of Bacteroides fragilis.
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Immunodiffusion techniques were used on trichloroacetic acid extracts from 10 strains of Bacteroides fragilis in detecting precipitating antibodies against this species in immune rabbit sera. Species and even strain specificities were observed in these precipitin reactions. Multiple antigens were detected in the extracts from some strains, whereas only one precipitin band per extract developed during agar-gel diffusion tests of others. The antigen extracts were found to be both heat stable and resistant to hydrolysis by alpha-chymotrypsin. Four serological patterns were demonstrated in homologous and heterologous reactions with the B. fragilis. antigen-antibody systems used. The results showed that some strains were serologically distinct from others, indicating that the strains tested are of more than one serotype. (+info)
Detection of tetQ and ermF antibiotic resistance genes in Prevotella and Porphyromonas isolates from clinical specimens and resident microbiota of humans.
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Gram-negative anaerobes belonging to the genera Fusobacterium, Prevotella and Porphyromonas were investigated for the presence of tetQ and ermF, which have been shown to be spread by conjugal elements. One hundred isolates from either sites of infection or various body sites in healthy subjects were studied. PCR was used to detect tetQ, and DNA-DNA hybridization studies on EcoRI chromosomal digests were undertaken to detect the presence of tetQ and ermF. Antibiotic sensitivity assays were performed on selected isolates to detect tetracycline, erythromycin and penicillin resistance. Twenty Fusobacterium isolates lacked tetQ, and were tetracycline sensitive. Twenty per cent of Prevotella spp. isolates both from clinical specimens and from healthy subjects were found to possess tetQ. Of 20 Porphyromonas isolates tested, one (Porphyromonas levii) from a case of bacterial vaginosis was shown to possess tetQ in the chromosome. The presence of tetQ was always associated with tetracycline resistance. Four isolates of Prevotella melaninogenica and one isolate of Prevotella were ermF-positive, although expression of erythromycin resistance was not consistently associated with detection of this gene. Antibiotic resistance phenotypes of Prevotella isolates were shown to be related to specific chromosomal restriction patterns by hybridization studies: tetracycline resistance and tetracycline/erythromycin resistance are conferred by Bacteroides tetracycline-resistant ERL elements, whereas the tetracycline/penicillin resistance phenotype could be due to spread of elements identified in Prevotella only. Tetracycline/erythromycin-resistant and tetracycline/erythromycin/penicillin-resistant P. melaninogenica isolates were found in this study. It appeared that the presence of tetQ and ermF in Bacteroides and Prevotella contributed to the persistence of antibiotic resistance isolates within the host and to potential spread to other organisms through conjugal elements. (+info)
Human necrobacillosis, with emphasis on Lemierre's syndrome.
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Lemierre's syndrome is the classical presentation of human necrobacillosis. It is characterized by a primary infection in the head in a young, previously healthy person who subsequently develops persistent high fever and disseminated metastatic abscesses, frequently including a septic thrombophlebitis of the internal jugular vein. The main pathogen is Fusobacterium necrophorum, an obligate anaerobic, pleomorphic, gram-negative rod. Clinical microbiologists have a key role in alerting clinicians and advising proper antibiotic treatment when the characteristic microscopic morphology of the pleomorphic F. necrophorum is seen in Gram stains from positive anaerobic cultures of blood and pus. Early diagnosis and prolonged appropriate antibiotic treatment with good anaerobic coverage are crucial to reduce morbidity and mortality. F. necrophorum also causes human necrobacillosis with foci caudal to the head, mainly in elderly patients with high mortality related to age and predisposing diseases, such as cancers of the primary focus. (+info)
A simple method for rapid identification of Sphaerophorus necrophorus isolates.
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A hemagglutination inhibition test for the rapid identification of Sphaerophorus necrophorus is described. Erythrocytes from six species of animals were tested and human cells were found to be the best agglutination indicators. Antiserum prepared in rabbits was found to be specific for S. necrophorus hemagglutinins when tested against 20 isolates of S. necrophorus and 117 other bacteria belonging to 22 genera. The possibility of using a hemagglutination inhibition test for the detection of bovine necrobacillosis was explored. (+info)
Fusobacteriosis in captive wild-caught pronghorns (Antilocapra americana).
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An outbreak of Fusobacterium necrophorum-induced septicemia occurred in a group of 40 captive wild-caught pronghorns (Antilocapra americana). Primary pododermatitis or necrotic stomatitis progressed to produce fatal septicemia with metastatic lesions in the forestomachs, lung, liver, and cecum in 38 of the animals. Two remaining animals were euthanatized because of chronic pododermatitis. Housing the animals in a pasture previously used by bovids and heavy rains with persistence of ground water pools in the pasture were contributing factors in the pathogenesis of this outbreak. (+info)