Desulfovibrio Fairfieldensis Research Articles

Biochemical-genetic analysis and distribution of DES-1, an Ambler class A extended-spectrum beta-lactamase from Desulfovibrio desulfuricans.

Desulfovibrio spp. are gram-negative anaerobes phylogenetically related to Bacteroides spp., which are rarely isolated and which are mostly isolated from intra-abdominal abscesses. Desulfovibrio desulfuricans clinical isolate D3 had a clavulanic acid-inhibited beta-lactam resistance profile and was resistant to some expanded-spectrum cephalosporins. A beta-lactamase gene, bla(DES-1), was cloned from whole-cell DNA of isolate D3 and expressed in Escherichia coli. Purified beta-lactamase DES-1, with a pI value of 9.1, had a relative molecular mass of ca. 31 kDa and a mature protein of 288 amino acids. DES-1 was distantly related to Ambler class A beta-lactamases and most closely related to PenA from Burkholderia pseudomallei (48% amino acid identity). It was weakly related to class A beta-lactamases CblA, CepA, CfxA, and CfxA2 from other anaerobic species, Bacteroides spp. and Prevotella intermedia. Its hydrolysis spectrum included amino- and ureidopenicillins, narrow-spectrum cephalosporins, ceftriaxone, and cefoperazone. bla(DES-1)-like genes were not identified in phylogenetically related Desulfovibrio fairfieldensis isolates. However, they were found in some but not all D. desulfuricans strains, thus suggesting that these genes may be present in a given D. desulfuricans subspecies.

Isolation of the provisionally named Desulfovibrio fairfieldensis from human periodontal pockets.

Sulfate-reducing bacteria have recently been associated with periodontitis and proposed to play a role in the pathogenesis of this chronic inflammatory process. Eight isolates of sulfate-reducing bacteria belonging to the genus Desulfovibrio were obtained from the periodontal pockets of five out of seven patients presenting with active periodontitis. A multiplex PCR was devised for their identification at the species level. All isolates were identified as Desulfovibrio fairfieldensis, a recently proposed new species. This finding reinforces the suggestion that Desulfovibrio fairfieldensis is a human bacterium that may present a pathogenic potential.

Reclassification of the only species of the genus Desulfomonas, Desulfomonas pigra, as Desulfovibrio piger comb. nov.

The growth characteristics, DNA G+C content and sequences of 16S rDNA and the transcribed 16S-23S rDNA internal spacer were determined for Desulfomonas pigra ATCC 29098T, Desulfovibrio desulfuricans subsp. desulfuricans strains Essex 6T (= ATCC 29577T) and MB (= ATCC 27774) and 'Desulfovibrio fairfieldensis' ATCC 700045. Despite phenotypic differences (shape and motility) between Desulfomonas pigra and Desulfovibrio strains, the molecular analysis suggests that Desulfomonas pigra should be reclassified within the genus Desulfovibrio. Thus, the reclassification is proposed of Desulfomonas pigra, the type and only species of the genus, as Desulfovibrio piger comb. nov., which implies the emendation of the description of the genus Desulfovibrio.

Sulfate-reducing bacteria in human feces and their association with inflammatory bowel diseases

We have searched for sulfate-reducing bacteria in the feces of 41 healthy individuals and 110 patients from a Hepato-Gastro-Enterology Unit using a specific liquid medium (Test-kit Labège, Compagnie Française de Géothermie, Orléans, France). The 110 patients were separated in 22 patients presenting with inflammatory bowel diseases and 88 patients hospitalized for other lower (n=30) or upper (n=58) digestive tract diseases. Sulfate-reducing bacteria were isolated from 10 healthy individuals (24%), 15 patients presenting with inflammatory bowel diseases (68%), and 33 patients with other symptoms (37%). A multiplex PCR was devised for the identification of Desulfovibrio piger (formerly Desulfomonas pigra), Desulfovibrio fairfieldensis and Desulfovibrio desulfuricans, and applied to the above isolates. The strains of sulfate-reducing bacteria consisted of D. piger (39 isolates), D. fairfieldensis (19 isolates) and D. desulfuricans (one isolate). The prevalence of D. piger was significantly higher in inflammatory bowel disease patients (55%) as compared to healthy individuals (12%) or patients with other symptoms (25%) (P<0.05).

Sulfate-reducing bacteria in human feces and their association with inflammatory bowel diseases

We have searched for sulfate-reducing bacteria in the feces of 41 healthy individuals and 110 patients from a Hepato-Gastro-Enterology Unit using a specific liquid medium (Test-kit Labège ®, Compagnie Française de Géothermie, Orléans, France). The 110 patients were separated in 22 patients presenting with inflammatory bowel diseases and 88 patients hospitalized for other lower ( n=30) or upper ( n=58) digestive tract diseases. Sulfate-reducing bacteria were isolated from 10 healthy individuals (24%), 15 patients presenting with inflammatory bowel diseases (68%), and 33 patients with other symptoms (37%). A multiplex PCR was devised for the identification of Desulfovibrio piger (formerly Desulfomonas pigra), Desulfovibrio fairfieldensis and Desulfovibrio desulfuricans, and applied to the above isolates. The strains of sulfate-reducing bacteria consisted of D. piger (39 isolates), D. fairfieldensis (19 isolates) and D. desulfuricans (one isolate). The prevalence of D. piger was significantly higher in inflammatory bowel disease patients (55%) as compared to healthy individuals (12%) or patients with other symptoms (25%) ( P<0.05).

Isolation of Desulfomicrobium orale sp. nov. and Desulfovibrio strain NY682, oral sulfate-reducing bacteria involved in human periodontal disease.

The species of sulfate-reducing bacteria that prevail in sites affected by periodontal disease may be different from those commonly occurring in the digestive tracts of healthy individuals. Ten strains of mesophilic sulfate-reducing bacteria (SRB) were isolated from subgingival plaque in periodontal lesions of ten patients with periodontitis. Characterization on the basis of morphological, physiological and phylogenetic properties demonstrated two distinct types of oral SRB. One strain was a curved rod with high motility. For dissimilatory sulfate reduction, lactate or pyruvate was oxidized incompletely to equimolar amounts of acetate. Desulfoviridin and cytochrome c3 were present in this mesophilic vibrio and the cellular lipid profile was similar to that from members of the genus Desulfovibrio. The 16S rDNA sequence was similar to that of the proposed 'Desulfovibrio fairfieldensis'. Cells of the nine other strains were straight, rod-shaped, exhibited a low growth rate and oxidized substrates incompletely to acetate. These SRB, like members of the genus Desulfomicrobium, lacked desulfoviridin. Analysis of the 16S rDNA sequences of seven of the nine isolates showed a high degree of similarity among these oral strains, forming a distinct lineage within the genus Desulfomicrobium. The cellular lipid profile of a representative oral strain, NY678T, was in accordance with that of other Desulfomicrobium species, but also showed dissimilar features. The phenotypic and phylogenetic analyses indicate that these rod-shaped SRB from the oral cavity could be regarded as a new species, for which the designation Desulfomicrobium orale sp. nov. is proposed.

Bacteremia Caused by a Strain of Desulfovibrio Related to the Provisionally Named Desulfovibrio fairfieldensis

Bacteremia Caused by a Strain of <i>Desulfovibrio</i> Related to the Provisionally Named <i>Desulfovibrio fairfieldensis</i>