title: Phenotypic features and phylogenetic background of extraintestinal hemolytic Escherichia coli responsible of mortality in puppies.
abstract: A 10-day-old litter of five puppies of Bracco Italiano dog breed showed weakness and diarrhea and, 2 days later, four of them died. At the same time, the bitch showed high hyperthermia (40 °C) and endometritis. The necropsy of a puppy revealed a severe lobar pneumonia accompanied with a bilateral nephrosis. No gross lesions were detected in other organs. Histopathology of the lung revealed severe multifocal fibrino-suppurative necrotizing bronchiolar-alveolitis associated with rod-shaped bacterial aggregates and diffuse interstitial lymphocytic infiltration. The kidney showed severe multifocal necrosis of the tubular epithelium and diffuse severe congestion of the parenchyma. A pure culture of hemolytic Escherichia coli carrying the Cnf-1 gene was identified, from both the puppy organs and bitch's milk. Moreover, phylo-typing assigned them to the phylogroup B2. Two weeks later, fecal samples from the bitch and the survived puppy were collected for a second microbiological analysis, identifying two hemolytic E. coli strains, Cnf positive and Cdt negative and Cnf and Cdt negative, respectively. Some E. coli pathogenic strains may cause enteric or extraintestinal disease. In dogs and cats, strains of extraintestinal pathogenic E. coli (ExPEC) produce specific virulent factors such as hemolysis and cytotoxin necrotizing factors (Cnf). In this episode, we hypothesize that the bitch's milk could be the main source of ExPEC infection causing high puppies mortality. The role of the bitch as a carrier could not be excluded: stressful conditions, such as pregnancy and delivery, would change the host-pathogen dynamics possibly increasing the release of the infectious burden.
authors.affiliation: Istituto Zooprofilattico Sperimentale delle Venezie, Viale dell'Università 10, 35020 Legnaro, Italy. Electronic address: turchettos@izsvenezie.it.
authors.forename: Sara
authors.initials: S
authors.lastname: Turchetto
authors.affiliation: Istituto Zooprofilattico Sperimentale delle Venezie, Viale dell'Università 10, 35020 Legnaro, Italy. Electronic address: mustulin@izsvenezie.it.
authors.forename: Martina
authors.initials: M
authors.lastname: Ustulin
authors.affiliation: Istituto Zooprofilattico Sperimentale delle Venezie, Viale dell'Università 10, 35020 Legnaro, Italy. Electronic address: ccitterio@izsvenezie.it.
authors.forename: Carlo Vittorio
authors.initials: CV
authors.lastname: Citterio
authors.affiliation: Istituto Zooprofilattico Sperimentale delle Venezie, Viale dell'Università 10, 35020 Legnaro, Italy. Electronic address: czanardello@izsvenezie.it.
authors.forename: Claudia
authors.initials: C
authors.lastname: Zanardello
authors.affiliation: Istituto Zooprofilattico Sperimentale delle Venezie, Viale dell'Università 10, 35020 Legnaro, Italy. Electronic address: mvascellari@izsvenezie.it.
authors.forename: Marta
authors.initials: M
authors.lastname: Vascellari
authors.affiliation: Istituto Zooprofilattico Sperimentale delle Venezie, Viale dell'Università 10, 35020 Legnaro, Italy. Electronic address: dvio@izsvenezie.it.
authors.forename: Denis
authors.initials: D
authors.lastname: Vio
authors.affiliation: Istituto Zooprofilattico Sperimentale delle Venezie, Viale dell'Università 10, 35020 Legnaro, Italy. Electronic address: gconedera@izsvenezie.it.
authors.forename: Gabriella
authors.initials: G
authors.lastname: Conedera
authors.affiliation: Istituto Zooprofilattico Sperimentale delle Venezie, Viale dell'Università 10, 35020 Legnaro, Italy. Electronic address: nferromilone@izsvenezie.it.
authors.forename: Nicola Maria Ferro
authors.initials: NM
authors.lastname: Milone
authors.affiliation: Istituto Zooprofilattico Sperimentale delle Venezie, Viale dell'Università 10, 35020 Legnaro, Italy. Electronic address: mcocchi@izsvenezie.it.
authors.forename: Monia
authors.initials: M
authors.lastname: Cocchi
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001427:Bacterial Toxins / Q000235:genetics; D004283:Dog Diseases / Q000382:microbiology* / Q000401:mortality; D004285:Dogs; D004926:Escherichia coli / Q000235:genetics / Q000302:isolation & purification*; D004927:Escherichia coli Infections / Q000382:microbiology / Q000401:mortality / Q000473:pathology / Q000662:veterinary*; D029968:Escherichia coli Proteins / Q000235:genetics; D005243:Feces / Q000382:microbiology; D005260:Female; D054884:Host-Pathogen Interactions; D010641:Phenotype; D010802:Phylogeny
chemical_list: D001427:Bacterial Toxins; D029968:Escherichia coli Proteins; C060296:cytotoxic necrotizing factor type 1
keywords: Biofilm; Dog puppy; Escherichia coli; ExPEC; Phylogroup