Pathogens

Brucellosis remains an underreported zoonotic disease in Ecuador. Its control program in cattle integrates diagnostic testing, vaccination, and eradication incentives, although participation is largely voluntary. Since 2025, vaccination has become compulsory nationwide. Human surveillance remains largely passive, and strain-level data are very limited. This study applied an integrated approach, combining serology (Rose Bengal and SAT-EDTA), microbiological culture, and molecular diagnostics, to assess the presence and diversity of Brucella spp. in cattle and pigs from six slaughterhouses in the northern Andean highlands. A total of 2054 cattle and 1050 pigs from Carchi, Imbabura, and Pichincha were sampled. Among cattle, 133 (6.5%; 95% CI: 5.5–7.6) were seropositive, and viable B. abortus strains were isolated from 17 (12.8%). Genus identification was confirmed by IS711-PCR, while species- and biovar-level differentiation was achieved with AMOS-PCR; additional assays targeting the ery gene and RB51 marker were used to distinguish field from vaccine strains. Biotyping and molecular analysis revealed a predominance of B. abortus biovar 4 (13/17 isolates) over biovar 1, all confirmed as field strains. In pigs, 10 animals (0.95%) tested seropositive, but no isolates were recovered, highlighting limitations of serology in swine. Most livestock, including the positives, originated locally, reinforcing the representativeness of our findings. The successful isolation and molecular characterization of B. abortus demonstrates the value of combining diagnostic strategies beyond serology. These results underscore the utility of active surveillance when supported by traceability systems; this approach may also contribute to guide interventions to reduce infection risk in livestock and humans.

A systematic review of toxoplasmosis cases in patients receiving targeted immunotherapy with biologics or small molecules was performed. This systematic review searched for case reports, case series and observational studies in PubMed; last search was on 19 July 2025. The review identified 46 toxoplasmosis cases among patients receiving biologics (including CAR T-Cell Therapies) or small molecules for diverse autoimmune, oncologic and transplant conditions. These cases were reported from 18 countries, including the United States and several European countries. Most patients developed severe disease. Fifty percent (23/46) presented with cerebral toxoplasmosis, 33% (15/46) with ocular toxoplasmosis, 7% (3/46) with lymphadenopathy, 4% (2/46) with disseminated disease, 2% (1/46) with both cerebral and ocular disease, 2% (1/46) with pneumonic toxoplasmosis, and 2% (1/46) with severe fetal congenital toxoplasmosis. Among those were also four cases with fatal outcomes due to toxoplasmosis and eight cases with permanent ocular or neurological deficits. In addition, there was a case of fetal congenital toxoplasmosis that occurred despite maternal discontinuation of adalimumab five months before conception, resulting in elective pregnancy termination due to severe fetal cerebral disease. Overall, 44% (20/46) of cases were due to reactivation of chronic latent Toxoplasma infections and 39% (18/46) due to acute primary infections; 17% did not report this information. One case of disseminated acute toxoplasmosis was also identified after eating wild boar sausages, and two cases of severe acute ocular toxoplasmosis after eating undercooked venison meat, and undercooked unspecified type of meat respectively, while on small molecules or biologics. Details on the clinical presentations, management and clinical outcomes of these cases were reported. Recommendations for the management of toxoplasmosis in patients with targeted immunotherapies were also provided. Health care providers should consider toxoplasmosis in patients on biologics or small molecules who present with compatible clinical syndromes. Prompt diagnosis and treatment can be lifesaving.

The recruitment of peripheral membrane proteins is tightly regulated by membrane lipid composition and local electrostatic microenvironments. Our experimental observations revealed that Vp54, a viral matrix protein, exhibited preferential binding to lipid bilayers enriched in anionic lipids such as phosphatidylglycerol (PG) and phosphatidylserine (PS), compared to neutral phosphatidylcholine/phosphatidylethanolamine liposomes, and this occurred in a curvature-dependent manner. To elucidate the molecular basis of this selective interaction, we performed a series of computational analyses including helical wheel projection, electrostatic potential calculations, electric field lines simulations, and electrostatic force analysis. Our results showed that the membrane-proximal region of Vp54 adopted an amphipathic α-helical structure with a positively charged interface. In membranes containing PG or PS, electrostatic potentials at the interface were significantly more negative, enhancing attraction with Vp54. Field line and force analyses further confirmed that both the presence and spatial clustering of anionic lipids intensify membrane–Vp54 electrostatic interactions. These computational findings align with experimental binding data, jointly demonstrating that membrane lipid composition and organization critically modulate Vp54 recruitment. Together, our findings highlight the importance of electrostatic complementarity and membrane heterogeneity in peripheral protein targeting and provide a framework applicable to broader classes of membrane-binding proteins.