Challenging diagnosis of Plasmodium ovale malaria in a Colombian traveler: the importance of including P. ovale wallikeri in molecular screening.

This study reports a challenging diagnosis of Plasmodium ovale malaria in a Colombian citizen returning from Cameroon. Initial microscopy screenings conducted at two private hospitals yielded conflicting results, with the first showing negative smears and the second diagnosing P. vivax. Subsequent microscopy examinations at two government laboratories identified P. ovale, although the routine species-specific PCR strategy was negative. PCR confirmation was finally obtained when P. ovale wallikeri primers were used. Although P. ovale is not frequently found in Colombia, there is a clear need to include both P. ovale curtisi and P. ovale wallikeri in the molecular diagnostic strategy. Such need stems primarily from their extended latency period, which affects travelers, the increasing number of African migrants, and the importance of accurately mapping the distribution of Plasmodium species in Colombia.

Differential gut microbiome in spondyloarthritis patients associated to Blastocystis colonization.

The role of Blastocystis in intestinal health is an open controversy, and little is known about the potential effect of this microorganism in autoinflammatory diseases such as spondyloarthritis (SpA). Here, we analyzed the gut microbiome of 36 SpA patients and 13 control individuals and demonstrated that the richness, diversity, and taxonomic composition between these two groups are different. We also showed that colonization by Blastocystis in control individuals increases the richness and diversity of the intestinal microbiome, whereas in SpA patients, it does not seem to have any impact. This may reflect a potential role of Blastocystis in sculpting the gut microbiome architecture in control individuals, whereas in subjects with SpA, the modulation of the microbiome may be governed by disease-dependent factors that cannot be overcome by Blastocystis. Regarding taxonomic characterization, SpA patients colonized by Blastocystis showed significant increases in the phylum Pseudomonadota, class Gammaproteobacteria, family Succinivibrionaceae, and genus Succinivibrio. Simultaneously, there were significant increases in the class Bacilli, order Lactobacillales, families Lactobacillaceae and Clostridiaceae, and genera Lactobacillus and Clostridium in non-colonized SpA patients. On the other hand, PICRUSt analysis in Blastocystis-positive SpA patients showed elevations in pathways that may enhance antioxidant capacities and alleviate intestinal inflammation, while Blastocystis-negative SpA patients showed significant changes in pathways that promote cell division/proliferation and can lead to larger changes in the gut microbiome. Our analyses lead us to believe that these changes in the gut microbiome of SpA patients may trigger protective mechanisms as an initial response to inflammation in an attempt to restore balance in the intestinal environment.