Childhood malnutrition affects physiology and development. It increases infection rates, which may not present clinical signs in severe cases. The World Health Organization recommends prophylactic treatment with cotrimoxazole (SXT) and nutritional recovery to overcome this issue. This treatment is controversial, since evidence of a reduction in morbidity and mortality is not a consensus and could induce the development of antibiotic-resistant bacteria. Moreover, the impact of using this wide-spectrum antibiotic on gut microbiota in a critical period of development, and weakness is unknown. To understand how SXT prophylaxis could affect gut microbiota in undernutrition, we induced protein–energy undernutrition (PEU) in weaning C57BL/6 mice for three weeks and treated animals with SXT for two weeks. Using 16S rRNA gene sequencing, we compared the taxonomic composition and metabolic pathways of control mice, animals submitted to undernutrition (UND), treated with SXT, or undernourished and SXT treated (UND + SXT). We identified that UND mice had a significant increase in predicted pathways related to metabolic syndromes later in life. The prophylactic SXT treatment alone resulted in a significant loss in community richness and beta diversity. Furthermore, we identified the reduction of three genera in SXT treated mice, including the butyrate producers Faecalibacterium and Anaerotruncus. Both UND and double challenge (UND + SXT) resulted in a reduction of the amino acid’s biosynthesis pathway related to cell growth. Our results show that the SXT prophylaxis of young mice during an undernourishment period did not re-establish the undernourished microbiota community composition similar to healthy controls but induced a distinct dysbiotic profile with functional metabolic consequences.

Background: Babesia spp. are widespread tick-borne intraerythrocytic protozoa, infecting a broad range of vertebrate hosts. Red foxes are reservoirs of Babesia vulpes, belonging to the Babesia microti -like group (clade I), and play an important role in the epidemiology of canine and wildlife babesiosis. Besides B. vulpes , another species of this genus was molecularly reported in red foxes from Israel and Iraq and provisionally named “ Babesia sp. MML-2014”; however, no morphological description of this small Babesia species was provided, preventing a proper species naming. Methods: Infection with piroplasmid species was detected and described by microscopy of stained blood smears in one red fox from Southern Italy. Molecular characterization of the Babesia sp. and differentiation from B. vulpes was performed through PCR amplification of nuclear ( 18S rRNA , ITS1-5.8S-ITS2) and mitochondrial (cytochrome c oxidase subunit 1, cox1 ) gene markers, followed by DNA sequencing and phylogenetic analysis. In addition, Ixodes kaiseri ticks collected from the infected fox were screened for piroplasmids by PCR. Results: Sequence comparison of piroplasmids showed 98–99% identity with the undescribed Babesia sp. MML-2014 and phylogenetic analyses confirmed that this taxon belongs to the Western group (clade III) and is differentiated by B. vulpes . Morphological and morphometric analyses further demonstrated that Babesia sp. nov. is a distinct small piroplasm and is characterized by unique Maltese cross forms. Based on the above, we named Babesia banethi sp. nov. as a new taxon. In addition, Babesia sp. nov. DNA was detected in the intestine of one engorged I. kaiseri specimen. Conclusions: This study provides genetic and morphological findings of B. banethi sp. nov. A morphological description with measurements of the parasite forms in red fox erythrocytes, differential diagnosis supplemented by genetic characterization, and the deposition of the holotype in suitable collections have been made in compliance with the ICZN guidelines. Graphical