Microbiology and Epidemiology of Escherichia albertii—An Emerging Elusive Foodborne Pathogen

Abstract

Escherichia albertii, a close relative of E. coli, is an emerging zoonotic foodborne pathogen associated with watery diarrhea mainly in children and immunocompromised individuals. E. albertii was initially classified as eae-positive Hafnia alvei, however, as more genetic and biochemical information became available it was reassigned to its current novel taxonomy. Its infections are common under conditions of poor hygiene with confirmed transmission via contaminated water and food, mainly poultry-based products. This pathogen has been isolated from various domestic and wild animals, with most isolates being derived from birds, implying that birds among other wild animals might act as its reservoir. Due to the absence of standardized isolation and identification protocols, E. albertii can be misidentified as other Enterobacteriaceae. Exploiting phenotypes such as its inability to ferment rhamnose and xylose and PCR assays targeting E. albertii-specific genes such as the cytolethal distending toxin and the DNA-binding transcriptional activator of cysteine biosynthesis encoding genes can be used to accurately identify this pathogen. Several gaps exist in our knowledge of E. albertii and need to be bridged. A deeper understanding of E. albertii epidemiology and physiology is required to allow the development of effective measures to control its transmission and infections. Overall, current data suggest that E. albertii might play a more significant role in global infectious diarrhea cases than previously assumed and is often overlooked or misidentified. Therefore, simple, and efficient diagnostic tools that cover E. albertii biodiversity are required for effective isolation and identification of this elusive agent of diarrhea.

Identification and Genomic Characterization of Escherichia albertii in Migratory Birds from Poyang Lake, China

“…Our proposed method of bacterial isolation and identification faces several key limitations that must be acknowledged. First, the E. albertii specific primers proposed by Lindsey et al [ 19 ] targeting EAKF1_ch4033 can only correctly identify 96.5% (305/316) and missed 11 strains [ 9 ]. Second, the selection of white or colorless colonies in MacConkey agar might result in the exclusion of other lactose-fermenting E. albertii isolates [ 9 ].…”

“…First, the E. albertii specific primers proposed by Lindsey et al [ 19 ] targeting EAKF1_ch4033 can only correctly identify 96.5% (305/316) and missed 11 strains [ 9 ]. Second, the selection of white or colorless colonies in MacConkey agar might result in the exclusion of other lactose-fermenting E. albertii isolates [ 9 ]. These limitations might result in underestimation of the actual pathogen occurrence rate.…”

“…E. albertii has been isolated from various animal sources, such as poultry, pigs, cats, dogs, bats, and raccoons as well as animal-derived raw meats [ 9 , 10 ], yet its natural reservoirs and transmission route to humans remain uncertain. Previous epidemiological investigations demonstrated that birds may be considered as potential reservoirs of E. albertii [ 11 , 12 , 13 ].…”

Draft Genome Sequences of Four Escherichia albertii Isolates from Hunted Wild Boars in Switzerland

“… Escherichia albertii is a Gram-negative, nonmotile, non-spore-forming, facultative anaerobic bacterium of the family Enterobacteriaceae ( 1 ). This zoonotic pathogen has sporadically been associated with gastroenteritis in humans ( 2 , 3 ), and the wild animal reservoirs are not yet well defined ( 1 ). In this study, we screened 52 hunted wild boars from different regions in Switzerland for potential carriage of E. albertii .…”

Seasonality of detection rate of <i>Escherichia albertii</i> in wild raccoons (<i>Procyon lotor</i>) in Osaka, Japan

“…Escherichia albertii has been recognized as an emerging zoonotic enteropathogen. Several foodborne outbreaks and sporadic cases of gastroenteritis in children mediated by E. albertii have been reported from Japan [ 6 ]. Thus, it is important to understand the prevalence of this pathogen in the environment to control infections.…”