Chagas disease (CD) is a parasitic disease caused by Trypanosoma cruzi protozoa, presenting with cardiomyopathy, megaesophagus, and/or megacolon. To determine the mechanisms of gastrointestinal (GI) CD tissue tropism, we systematically characterized the spatial localization of infection-induced metabolic and microbiome alterations, in a mouse model of CD. Notably, the impact of the transition between acute and persistent infection differed between tissue sites, with sustained large-scale effects of infection in the esophagus and large intestine, providing a potential mechanism for the tropism of CD within the GI tract. Infection affected acylcarnitine metabolism; carnitine supplementation prevented acute-stage CD mortality without affecting parasite burden by mitigating infection-induced metabolic disturbances and reducing cardiac strain. Overall, results identified a previously-unknown mechanism of disease tolerance in CD, with potential for new therapeutic regimen development. More broadly, results highlight the potential of spatially resolved metabolomics to provide insight into disease pathogenesis and infectious disease drug development.

Leptospira spp. are delicate bacteria that cannot be studied by usual microbiological methods. They cause leptospirosis, a zoonotic disease transmitted to humans through infected urine of wild or domestic animals. We studied the incidence of this disease in the Uruguayan population, its epidemiologic and clinical features, and compared diagnostic techniques. After examining 6,778 suspect cases, we estimated that about 15 infections/100,000 inhabitants occurred yearly, affecting mainly young male rural workers. Awareness about leptospirosis has grown among health professionals, and its lethality has consequently decreased. Bovine infections were probably the principal source of human disease. Rainfall volumes and floods were major factors of varying incidence. Most patients had fever, asthenia, myalgias or cephalalgia, with at least one additional abnormal clinical feature. 30-40% of confirmed cases presented abdominal signs and symptoms, conjunctival suffusion and altered renal or urinary function. Jaundice was more frequent in patients aged > 40 years. Clinical infections followed an acute pattern and their usual outcome was complete recovery. Laboratory diagnosis was based on indirect micro-agglutination standard technique (MAT). Second serum samples were difficult to obtain, often impairing completion of diagnosis. Immunofluorescence was useful as a screening test and for early detection of probable infections.

Introduction/Aim: Recent studies have shown that seroprevalence is quite variable depending on the country, the population and the time of the pandemic in which the serological tests are performed. Here, we investigated the prevalence of IgG antibodies against SARS-CoV-2 in a population living in Veracruz City, Mexico. Methods: From of June 1 to July 31, 2020, the consecutive adult patients that attended 2 ambulatory diagnostic private practice centers for testing were included. Samples were run on the Abbott Architect instrument using the commercial Abbott SARS-CoV-2 IgG assay. The main outcome was seroprevalence. Demographics, previous infection to SARS-CoV-2 (according to a previous positive polymerase-chain reaction nasopharyngeal swab), self-suspicious of virus of infection (according to have in the previous 4 weeks either fever, headache, respiratory symptoms but not a confirmatory PCR) or no having symptoms were also evaluated. Results: A total of 2174 subjects were tested, included 53.6% women (mean age 41.8, range 18-98 years). One thousand and forty-one (52.5%) subjects were asymptomatic, 722 (33.2%) had suspicious of infection and 311 (14.3%) had previous infection. Overall, 642 of 2174 (29.5% [95% CI 27.59%-31.47%]) of our population were seropositive. Seropositivity among groups was 21.3% in asymptomatic, 23.4% in self-suspicious patients and 73.9% in previous infection patients. Conclusions: We found one of the highest seroprevalences reported for SARS-CoV-2 worldwide in asymptomatic subjects (21.3%) as well in subjects with self-suspicious of COVID-19 (23.4%). The number of infected subjects in our population is not encouraging and it should be interpreted with caution.

Background Group B Streptococcus (GBS) remains a leading cause of infant morbidity and mortality. A candidate vaccine targets 6 GBS serotypes, offering a potential alternative to intrapartum antibiotic prophylaxis to reduce disease burden. However, our understanding of the contributions of specific capsule types to GBS colonization and disease remains limited. Methods Using allelic exchange, we generated isogenic GBS strains differing only in the serotype-determining region in 2 genetic backgrounds, including the hypervirulent clonal complex (CC) 17. Using a murine model of vaginal cocolonization, we evaluated the roles of the presence of capsule and of expression of specific capsular types in GBS vaginal colonization fitness independent of other genetic factors. Results Encapsulated wild-type strains COH1 (CC17, serotype III) and A909 (non-CC17, serotype Ia) outcompeted isogenic acapsular mutants in murine vaginal cocolonization. COH1 wild type outcompeted A909. Notably, expression of type Ia capsule conferred an advantage over type III capsule in both genetic backgrounds. Conclusions Specific capsule types may provide an advantage in GBS vaginal colonization in vivo. However, success of certain GBS lineages, including CC17, likely involves both capsule and noncapsule genetic elements. Capsule switching in GBS, a potential outcome of conjugate vaccine programs, may alter colonization fitness or pathogenesis.

As the world becomes increasingly industrialized, understanding the biological consequences of these lifestyle shifts and what it means for past, present, and future human health is critical. Indeed, industrialization is associated with rises in allergic and autoimmune health conditions and reduced microbial diversity.