Isolation of Asaia sp. in two bacteraemia cases in patients with idiopathic dilated cardiomyopathy awaiting heart transplants
Abstract number: P1142
Juretschko S., Beavers-May T., Helsel L., Steigerwalt A., Stovall S.
Objectives: The genus Asaia consists of 3 species, A. bogorensis, A. krungthepensis, and A. siamensis, all described as acetic acid bacteria and originally isolated from tropical flowers in SE Asia. A. bogorensis is the only species that has been associated with human disease, in a case of bacteraemia and another of peritonitis. A fourth species designation, "A. lannaensis", is unpublished; however, a corresponding sequence has been deposited in GenBank. Here we describe the first two cases of nosocomial infections with Asaia sp., closely affiliated to "A. lannaensis".
Case study: Two patients, 15 months and 5 years old, with idiopathic dilated cardiomyopothy awaiting cardiac transplantations in one unit at Arkansas Children's Hospital developed bacteraemia. Both patients within one week developed similar symptoms, such as high grade fever, hypotension, leukopenia, and thrombocytopenia. Multiple blood cultures drawn from PICC lines, central venous lines and a peripheral culture (from one patient) were positive for Gram-negative rods. Isolates from both patients were non-motile, non-hemolytic, strictly aerobic, catalase positive and showed negative reactions for oxidase, indole, urea and esculin hydrolysis. The pink pigmented colonies grew on blood and chocolate agar, but not on MacConkey and Mueller-Hinton. Growth was seen at 25 and 35°C, but not at 42°C. The BD Phoenix identified the organisms as Pseudomonas luteola and Acinetobacter baumannii with confidence values of 99 and 90%, respectively. The Remel rapID NH kit resulted the pathogen as Gardnerella vaginalis with a probability of >99.9% in each case. Non-matching biochemical results excluded these organisms for true identification. The organisms were submitted to the CDC for 16S rDNA sequence analysis and extensive biochemical tests revealing that both strains are 100% identical to each other. Further phylogenetic analyses showed the two unknown organisms to be 100% identical with A. lannaensis and a 99.6% similarity with A. bogorensis. Both patients received 14 days of meropenem and had their lines removed. Subsequent both patients recovered and received heart transplants.
Conclusion: This is the first report of human infection with the bacterium "A. lannaensis". The physical location of both patients, the temporal association of infections as well as the isolation of two identical pathogens suggests a nosocomial infection. An epidemiological investigation did not identify a source of this organism.
|Session name:||18th European Congress of Clinical Microbiology and Infectious Diseases|
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