Pink-pigmented Non-fermentative Gram-negative Rods Associated with Human Infections: a Clinical and Diagnostic Challenge

Abstract

Over the past several decades, the appearance of pink-pigmented bacteria in clinical specimens has gone from being a microbiologic curiosity in the clinical laboratory to the recognition of these aerobic microorganisms as etiologic agents of human disease, most notably bloodstream infections. Advances in the fields of molecular taxonomy and phylogenetics indicate that at least four distinct genera and eight different species are associated with clinical infections in susceptible patient populations. However, these bacteria are slow growing and present multiple diagnostic challenges to the microbiology laboratory including culture, isolation, and identification to species rank. This article provides a current review of these unusual non-fermentative chromogenic bacteria including their disease spectrum, taxonomy, and laboratory identification. The review also highlights the pitfalls or shortcomings we currently have in our knowledge of these microbes and their disease-producing capabilities.

Bacteremia Due to Imipenem-resistant Roseomonas mucosa in a Child With Acute Lymphoblastic Leukemia

“…1 Roseomonas are opportunistic pathogens that have rarely been reported in human infections, although an increasing number of cases has been documented in the last decade. Infections mainly consisted of primary or health care-associated bacteremia in immunocompromised adult patients with or without indwelling devices, whereas pediatric cases have been rarely reported.…”

Cultivation-Independent Characterization of Methylobacterium Populations in the Plant Phyllosphere by Automated Ribosomal Intergenic Spacer Analysis

“…They have been detected in soil, dust, freshwater, lake sediments, and the air and on plants (16). They have also been found in association with humans (2), and some members of this genus have increasingly been reported to be a cause of opportunistic infections in immunocompromised patients (22). The genus Methylobacterium currently comprises 28 described species (28,60).…”

Genome Sequence of Roseomonas sp. Strain B5, a Quorum-Quenching N -Acylhomoserine Lactone-Degrading Bacterium Isolated from Malaysian Tropical Soil

“…Roseomonas spp. have also been isolated from clinical samples, including blood, wounds, peritoneal dialysis fluid, and bone (2,3,6,8,10,17). Roseomonas spp.…”

“…Roseomonas spp. appear to have low pathogenic potential for humans, but some species may cause clinically serious or even fatal diseases, especially in immunocompromised patients (10).…”