Emerging Pathogens Attention Alert: A Case Report on Isolation and Preliminary Characterization of Escherichia albertii and Kosakonia cowanii from Citrus

Fresh fruits may act as vehicles for microorganisms introduced during cultivation, harvest, and handling, especially in settings where crop production occurs close to animal farming. In this study, three Gram-negative strains incidentally recovered during the screening of lactic acid bacteria from Rangpur limes (Citrus × limonia) were identified and characterized. Phenotypic and biochemical analyses, rep-PCR, and 16S rRNA gene sequencing identified one strain as Escherichia albertii and two strains as Kosakonia cowanii. The Escherichia albertii and two Kosakonia cowanii strains were further evaluated for β-galactosidase production, antimicrobial susceptibility, hemolytic activity, biogenic amine production, and virulence-associated genes. The three studied strains were hemolytic, positive for β-galactosidase, showed presumptive amino acid decarboxylase activity, and demonstrated resistance to ampicillin, with intermediate susceptibility to nalidixic acid. Classical virulence genes such as eae, cva, iss, iroN, iut, and omp were not detected, whereas fim and hly were observed. These findings indicate that Rangpur limes cultivated at the animal–crop interface may harbor opportunistic and emerging bacteria of relevance to food safety and One Health surveillance.