ABSTRACT
Se presentan 2 casos de bacteriemias insidiosas por bacilos gram negativos anaerobios curvos, espiralados, móviles e infrecuentes en pacientes atendidos en un hospital de la ciudad de Buenos Aires. Estas bacteriemias, asociadas al aislamiento de Anaerobiospirillum y Desulfovibrio, fueron de origen poco claro y afectaron a pacientes inmunocomprometidos, con patologías simultáneas. Pruebas claves en la identificación del género Anaerobiospirillum fueron el estudio de la micromorfología, su carácter de anaerobio estricto, el resultado negativo en la prueba de catalasa, el patrón de discos de interés taxonómico, la fermentación de glucosa y la producción de β-N-acetilglucosaminidasa. El género Desulfovibrio se diferenció por el perfil presentado en las pruebas con discos, por ser asacarolítico, sin actividad de enzimas glucosídicas, y por producir desulfoviridina y H2S. Se alerta sobre la resistencia o sensibilidad intermedia de Anaerobiospirillum succiniciproducens (especie a la que correspondió el aislado de Anaerobiospirillum) a algunos de los antimicrobianos de primera línea frente a bacilos gram negativos anaerobios, como el metronidazol; fueron activas las combinaciones de aminopenicilinas con inhibidores de β-lactamasas y el imipenem. Desulfovibrio desulfuricans (especie a la que correspondió el aislado de Desulfovibrio) fue productora de β-lactamasas y resistente a las cefalosporinas; en cambio, fueron activos el metronidazol, el imipenem y la levofloxacina. La identificación confiable de estos microorganismos orienta hacia el mejor esquema terapéutico.
Two cases of insidious bacteremia by uncommon curve and spiral-shaped, motile anaerobic gram-negative rods are presented. Both of them were of an unclear origin and occurred in immunosuppressed patients with simultaneous diseases. The key tests for the identification of Anaerobiospirillum were its micromorphology, a strictly anaerobic condition, negative catalase activity, the special-potency disk profile, glucose fermentation, and β-NAG production. Desulfovibrio species was identified by all the above preliminary tests but with a different disk profile, as well as for being asaccharolytic and desulfoviridin and H2S producer. We here alert about the resistance or intermediate susceptibility of Anaerobiospirillum succiniciproducens against antimicrobial agents, such as metronidazole, one of the first-line drugs used for the treatment of anaerobic gram-negative infections. Aminopenicillins with β-lactamase-inhibitor combinations and imipenem were active for this agent. Desulfovibrio desulfuricans was β-lactamase producer and resistant to cephalosporins, while metronidazole, imipenem and levofloxacin were active. A reliable identification of these microorganisms is important for establishing the best therapeutic scheme.
Subject(s)
Humans , Gram-Negative Bacterial Infections , Bacteremia/microbiology , Anaerobiospirillum , Desulfovibrio desulfuricans , Immunocompromised Host , Gram-Negative Bacterial Infections/diagnosis , Gram-Negative Bacterial Infections/drug therapy , Anaerobiospirillum/isolation & purification , Desulfovibrio desulfuricans/isolation & purification , Anti-Bacterial AgentsABSTRACT
Anaerobiospirillum thomasii ha sido descrito como causante de diarrea en humanos, pero no se han informado bacteriemias asociadas a este organismo. En esta comunicación describimos el primer aislamiento de A. thomasii como causa de bacteriemia fatal en una paciente alcohólica
Anaerobiospirillum thomasii has been reported as a causative agent of diarrhea in humans; however no bacteremia associated with this pathogen has been described so far. We present here the first case of fatal A. thomasii bacteremia in an alcoholic patient
Subject(s)
Humans , Female , Middle Aged , Bacteremia/complications , Anaerobiospirillum/pathogenicity , RNA, Ribosomal, 16S/analysis , Bacteremia/microbiology , Fatal Outcome , Anaerobiospirillum/metabolismABSTRACT
Succinic acid is one of the key intermediates in the tricarboxylic acid cycle (TCA)and has huge potentials in biopolymer, food, medicine applications. This article reviews recent research progress in the production of succinic acid by microbial fermentation, including discovery and screening of the succinic-acid-producing microbes, the progress of genetic engineering strategy and metabolic engineering technology for construction of succinic acid-producing strains, and fermentation process control and optimization. Finally, we discussed the limitation of current progress and proposed the future research needs for microbial production of succinic acid.
Subject(s)
Actinobacillus , Genetics , Metabolism , Anaerobiospirillum , Genetics , Metabolism , Fermentation , Industrial Microbiology , Methods , Metabolic Engineering , Methods , Succinic Acid , MetabolismABSTRACT
Anaerobiospirillum succiniciproducens is a spiral-shaped, gram-negative anaerobic bacterium. A. succiniciproducens is a rare cause of bacteremia in human, especially immunocompromised patients. This organism may be mistakenly identified when using an automated bacterial identification system, and may be mistaken for Campylobacter spp. when using Gram staining. We report a case of bacteremia caused by A. succiniciproducens, which was negative for catalase, oxidase, and urease and confirmed by 16S rRNA sequencing (analysis revealed a 99% similarity), in a 69-year-old patient who was undergoing chemotherapy for treatment of a malignancy. To the best of our knowledge, this is the first report of bacteremia caused by A. succiniciproducens in Korea.
Subject(s)
Aged , Humans , Anaerobiospirillum , Bacteremia , Campylobacter , Catalase , Immunocompromised Host , Korea , Oxidoreductases , UreaseABSTRACT
The potential of succinic acid as an important chemical intermediates had been realized and fermentation is one of the best ways to make it possible in economical aspect. Fermentation organism is the key part of the fermentation method. The updated research developments of fermentation organisms and the fermentation characteristics and problems of them were reviewed and analyzed in this paper. Finally,the development future of fermenation organism was forecasted.
Subject(s)
Actinobacillus , Metabolism , Anaerobiospirillum , Metabolism , Bioreactors , Microbiology , Escherichia coli , Metabolism , Fermentation , Genetic Engineering , Methods , Industrial Microbiology , Methods , Succinic Acid , MetabolismABSTRACT
Anaerobiospirillum succiniciproducens is an anaerobic, Gram-negative, spiral shaped bacteria, which is motile by means of bipolar tuffs of flagella. This organism appears to be a rare cause of bacteremia in humans, and it usually affects patients submitted to immunosuppressive therapy. Anaerobiospirillum succiniciproducens resembles Campylobacter spp. in Gram-stained preparations, however, it is considered resistant to most antimicrobial drugs that are used to treat Campylobacter infections. We observed Gram-negative, spiral shaped bacteria in Gram-stained preparations from blood culture flasks. Growth occurred only under anaerobic incubation, and identification to the species level was achieved by PCR amplification of the 16S rRNA gene, followed by direct sequencing and a GenBank homology search. To the best of our knowledge, this is the first reported Brazilian case of Anaerobiospirillum succiniciproducens bacteremia.