Early mammal embryogenesis starts with oocyte fertilization, giving rise to the zygote. The events that the newly formed zygote surpasses are crucial to the embryo developmental success. Shortly after activation of its genome, cells of the embryo segregate into the inner cell mass (ICM) or the trophectoderm (TE). The first will give rise to the embryo while the latter will become the placenta. This first segregation involves cellular and molecular processes that include cell polarity linked to intracellular pathway activation, which will regulate the transcription of trophectoderm-related genes. Then, cells of the ICM undergo the second event of mammalian cell differentiation, which consists of the separation between epiblast (EPI) and hypoblast or primitive endoderm (PrE). This second segregation involves paracrine signaling, leading to differential expression of key genes that will dictate the fate of the cell. Although these processes are described in detail in the mouse, recent studies suggest that the bovine embryo could also be an interesting model for early development, since there are differences to the mouse and similarities with early human embryogenesis. In this review, we gathered the main data available in the literature upon bovine and mouse early development events, suggesting that both models should be analyzed and studied in a complementary way, to better model early events occurring in human development.

Enteropathogenic Escherichia coli (EPEC) are pathogens associated with gastrointestinal illnesses. Dogs and cats can harbor EPEC, and antimicrobial resistance may impair necessary treatments. This study characterized E. coli strains from dogs and cats, focusing on phylogroup classification, virulence factors, and antimicrobial resistance profiles. Ninety-seven E. coli isolates from fecal samples of 31 dogs and 3 cats were obtained from a private diagnostic laboratory in Botucatu, Brazil, from March to October 2021. The antimicrobial susceptibility was assessed using the disk diffusion method. Polymerase chain reaction (PCR) was employed to screen for bla_CTX-M and genes encoding virulence factors, as well as to classify the isolates into phylogroups. Twenty isolates were positive for intimin encoding gene eae and, consequently, these isolates were classified as EPEC (20.62%). Notably, 5.1% (5/97) of the isolates exhibited extended-spectrum β-lactamase (ESBL) production and 13.4% (13/97) were identified as multidrug-resistant bacteria. Phylogroups A and B2 were the most prevalent, comprising 29.9% (29/97) and 26.8% (26/97) of the bacterial isolates, respectively. This characterization highlights the prevalence of EPEC in domestic animals, emphasizing the potential risk they pose to public health and highlighting the urgency of responsible antimicrobial use in veterinary practices and the important role of laboratories in the surveillance of pathogenic multidrug-resistant bacteria.

•Invasive species can act as silent carriers of multidrug-resistant bacterial species.•Invasive species in natural environments without predators can amplify the spread of antimicrobial resistance.•Global data on WHO priority bacteria and antimicrobial resistance in invasive species are provided.•Epidemiological surveillance of antimicrobial resistance in invasive species is discussed.

A one-year-old female miniature goat was presented to an emergency service after calving a dead goatling. Physical and ultrasonographic examination revealed the presence of a viable fetus; therefore, the goat was submitted to an emergency cesarean section. In the postoperative period, the animal had septic peritonitis caused by Enterococcus faecium and Enterococcus casseliflavus. Both bacterial strains showed contrasting antimicrobial resistance profiles. Laparohysterectomy and abdominal cavity lavage were performed, but, once the animal had adhesions and necrotic lesions in abdominal organs, euthanasia was executed. A post-mortem examination revealed fibrino-necrotic septic peritonitis secondary to uterine rupture. To the authors’ knowledge, this is the first detailed report of polymicrobial septic peritonitis in a miniature goat and the first report of septic peritonitis caused by E. faecium and E. casseliflavus.