Extended-Spectrum β-lactamase (ESBL) producing Enterobacter aerogenes phenotypically misidentified as Klebsiella pneumoniae or K. terrigena

Abstract

Background: Enterobacter aerogenes and Klebsiella pneumoniae are common isolates in clinical microbiology and important as producers of extended spectrum β-lactamases (ESBL). The discrimination between both species, which is routinely based on biochemical characteristics, is generally accepted to be straightforward. Here we report that genotypically unrelated strains of E. aerogenes can be misidentified as K. pneumoniae by routine laboratories using standard biochemical identification and using identification automates.

Co-occurrence of Extended-Spectrum Beta-Lactamases in Isolated Enterobacter spp. From Patients Specimens

“…such as Salmonella spp., Yersinia spp., Escherichia coli (E. coli), Enterobacter agglomerans (E. agglomerans), Enterobacter cloacae (E. cloacae), and Klebsiella spp. are members of the large family of Enterobacteriaceae (1). These organisms may cause a wide spectrum of healthcareassociated infections (HAIs), including urinary tract infections (UTIs), as well as wounds, lungs, abdominal cavity, surgical sites and soft tissues infections (2).…”

Case report: A successfully treated case of community-acquired urinary tract infection due to Klebsiella aerogenes in Bangladesh

“…K. aerogenes , previously known as Enterobacter aerogenes , is phylogenetically closer to Klebsiella species than Enterobacter species ( 10 ). K. aerogenes is often misidentified as K. pneumoniae due to delayed expression of certain phenotypic characteristics ( 46 ). This report identified a K. aerogenes strain RD99, with delayed motility and ornithine decarboxylase-positivity.…”

“…This report identified a K. aerogenes strain RD99, with delayed motility and ornithine decarboxylase-positivity. Misidentification is also a concern while utilizing automated technologies like Vitek2 and Phoenix ( 46 ). Therefore, we carried out bacterial WGS for accurate taxonomic identification.…”

LightCycler SeptiFast technology in patients with solid malignancies: clinical utility for rapid etiologic diagnosis of sepsis

“…To assess the true positivity of both microbiological methods, discrepant cases were evaluated in the context of clinical and laboratory findings by two independent physicians experienced in critical care (Figure 1 ). The clinically relevant presence of a pathogen detected by blood culture but not by SeptiFast was recorded for Klebsiella pneumoniae/oxytoca , and in both cases the presence of another member of Enterobacteriaceae was reported by SeptiFast, Escherichia coli and Enterobacter cloacae/aerogenes - thus misidentification of strains with atypical phenotype cannot be excluded [ 3 ]. Our results also show that SeptiFast is more efficient in detection of clinically relevant infection by E. coli and Pseudomonas aeruginosa .…”