Ultrastructural characterization of Anaerobiospirillum succiniciproducens and its differentiation from Campylobacter species

Anaerobiospirillum succiniciproducens-induced bacteremia in a healthy man

Anaerobiospirillum succiniciproducens is rarely associated with bacteremia but results in significant mortality. Almost all reported bacteremia cases have occurred in immunocompromised hosts, such as those with alcoholic liver disease, atherosclerosis, recent surgery, malignancies, or acquired immunodeficiency syndrome. We describe here, to our knowledge, the first clinical evidence for A succiniciproducens bacteremia in a healthy man. A 61-year-old man had fallen from a roof and was admitted to our emergency department with severe left flank pain without an external wound. He was given transcatheter arterial embolization for the left kidney injury on the same day, and his condition stabilized. Four days after admission, he had fever without gastrointestinal signs and symptoms. Spiral-shaped, gram-negative anaerobic bacteria were isolated from 2 sets of blood cultures, and the oxidase and catalase test results were negative. The isolated bacteria were different from the Campylobacter spp. On the next day, the bacteria were confirmed as A succiniciproducens by 16S rRNA sequencing. The patient responded to sulbactam/ampicillin. On day 13, the patient was discharged with a 7-day prescription for oral amoxicillin/clavulanate. Six months after admission, the patient was free of recurrent infection. A succiniciproducens bacteremia can occur in healthy adults. When large gram-negative spiral-shaped bacteria are detected, this bacterial species should be considered and differentiated from the Campylobacter spp because A succiniciproducens is often resistant to macrolide antibiotics.

Bloodstream infection with Anaerobiospirillum succiniciproducens: a potentially lethal infection

Anaerobiospirillum succiniciproducens (A succiniciproducens), a spiral, Gram-negative anaerobic rod which is part of the normal intestinal flora of cats and dogs, has rarely been reported as a cause of bacteremia and diarrhea in humans, particularly in immunocompromised hosts. Although it can be associated with significant mortality, the full extent of its pathogenicity, clinical spectrum, and optimal therapy remain to be determined. We review the available literature on microbiology, clinical manifestations, and treatment options for Anaerobiospirillum infection.

First report of treatment of Anaerobiospirillum succiniciproducens bloodstream infection with levofloxacin

The full extent of the clinical spectrum and optimal therapy of Anaerobiospirillum succiniciproducens infections remains to be determined. We describe the first case of bloodstream infection (BSI) due to A. succiniciproducens in an asymptomatic elderly male with poor dentition that was treated with levofloxacin.

Ileocolitis associated with Anaerobiospirillum in cats

Ileocolitis associated with spiral bacteria identified as an Anaerobiospirillum sp. was found in six cats. Two cats had acute onset of gastrointestinal signs characterized by vomiting and diarrhea in one cat and vomiting in another cat, one cat had chronic diarrhea that was refractory to medical therapy; one cat had acute onset of anorexia and lethargy, and two cats had clinical signs that were not related to the gastrointestinal tract. The presence of an Anaerobiospirillum sp. was demonstrated on the basis of ultrastructural morphology of spiral bacteria associated with intestinal lesions and PCR amplification of a genus-specific 16S rRNA gene from affected tissues from each cat. The colons of three clinically healthy cats without lesions and one cat with mild colitis not associated with spiral bacteria were negative for Anaerobiospirillum spp. in the same assay. Comparative nucleotide sequence analysis of cloned PCR products from three affected cats further suggested that the spiral bacteria were closely related to Anaerobiospirillum succiniciproducens.

Anaerobiospirillum succiniciproducens bacteraemia

This report describes a case of bacteraemia caused by Anaerobiospirillum succiniciproducens. Anaerobiospirillum succiniciproducens is a rare cause of bacteraemia in humans, and when encountered usually occurs in immunocompromised patients. The organism is an anaerobic, spiral shaped, Gram negative bacillus with bipolar tufts of flagella. In this report, the morphology, with special reference to electron microscopic features, culture characteristics, and antimicrobial susceptibility are described.

Isolation and characterization of Campylobacter, Helicobacter, and Anaerobiospirillum strains from a puppy with bloody diarrhea

We carried out a microscopic examination of stools from a 2-month-old female puppy with bloody diarrhea, and this revealed large numbers of different spiral-shaped bacteria. To isolate these organisms, a rectal swab specimen was inoculated onto plates of Skirrow's agar and incubated at 37 degrees C for 6 days in a microaerobic atmosphere. Finally, a total of six different spiral-shaped bacteria (strains G1104, 94105, FR106, B0101, 3J102, and J2103) were isolated. Based on their morphology, biochemical traits, whole-cell protein profiles, and analysis of their 16S rDNA sequences, they were identified as Campylobacter upsaliensis, Helicobacter cinaedi, 'Flexispira rappini', two Anaerobiospirillum spp. with different morphologies, and Helicobacter sp., respectively. Analysis of 16S rRNA gene sequence data for strains 94150 (H. cinaedi) and FR106 (F. rappini) revealed that this approach has limitations when identifying isolates to the species level because of a high degree of sequence homology between these species (>99%) and considerable sequence variation among different isolates within these species. The dog was treated orally with amoxicillin for 3 days, which resolved the diarrhea. However, 1 day after the last dose the bloody diarrhea recurred but regarded to six more days amoxicillin treatment. This suggests a bacterial cause for the diarrhea. The approach to identification to microaerobic spiral-shaped bacteria in diarrheic dogs can be applied further to characterize their role in diarrhea illness.