The Dichloromethane Fraction of Croton sonorae, A Plant Used in Sonoran Traditional Medicine, Affect Entamoeba histolytica Erythrophagocytosis and Gene Expression.

Intestinal parasites are a global problem, mainly in developing countries. Obtaining information about plants and compounds that can combat gastrointestinal disorders and gastrointestinal symptoms is a fundamental first step in designing new treatment strategies. In this study, we analyzed the antiamoebic activity of the aerial part of Croton sonorae. The dichloromethane fraction of C. sonorae (CsDCMfx) contained flavonoids, terpenes, alkaloids, and glycosides. The ultrastructural morphology of the amoebae treated for 72 h with CsDCMfx was completely abnormal. CsDCMfx reduced erythrophagocytosis of trophozoites and the expression of genes involved in erythrocyte adhesion (gal/galnac lectin) and actin cytoskeleton rearrangement in the phagocytosis pathway (rho1 gtpase and formin1). Interestingly, CsDCMfx decreased the expression of genes involved in Entamoeba histolytica trophozoite pathogenesis, such as cysteine proteases (cp1, cp4, and cp5), sod, pfor, and enolase. These results showed that C. sonorae is a potential source of antiamoebic compounds.

Clinical Manifestations of Cryptosporidiosis and Identification of a New Cryptosporidium Subtype in Patients From Sonora, Mexico.

The aim of this study was to identify the clinical manifestations of cryptosporidiosis and the distribution of Cryptosporidium spp. and subtypes in children in Sonora, Mexico. Two subtypes of C. parvum, including IIaA15G2R1 and IIcA5G3a, and 6 subtypes of Cryptosporidium hominis, including IaA14R3, IaA15R3, IbA12G3, IdA23, IeA11G3T3, and a new subtype IaA14R11, were identified. Cryptosporidium as an etiologic agent for acute gastroenteritis is discussed.

Comparison of the genetic variability of Blastocystis subtypes between human carriers from two contrasting climatic regions of México.

Blastocystis sp. is an anaerobic intestinal microorganism commonly identified in the feces of several animals, including humans. Blastocystis exhibits high genetic polymorphism and at least 17 subtypes (ST) have been identified; ST1-ST3 are frequently found in the Americas. Furthermore, in vitro assays have shown that temperature and humidity can affect the viability of Blastocystis cysts. In this study, we describe the genetic variability and genetic differentiation among and within Blastocystis STs in adults and children from the cities of Hermosillo and Morelia cities, which represent arid and humid subtropical climatic regions of México, respectively. Phylogenetic and genetic diversity was assessed by analyzing a region of the small subunit ribosomal DNA (SSU rDNA) gene as a marker. Blastocystis ST3 and ST1 were associated with children from Hermosillo and Morelia, respectively. An analysis of the nucleotide diversity (π) and haplotype polymorphism (θ) indexes showed that they were similar within each ST, but different between ST1 and ST3. Interestingly, the group of symptomatic carriers from Hermosillo showed scarce mean nucleotide diversity compared to the asymptomatic carriers (0.0039±0.0030 and 0.0329±0.0286, respectively). Furthermore, the gene flow and genetic differentiation indexes between the children and adults suggested that the Blastocystis haplotypes in the adult carriers were "highly mobile" among humans, while the haplotypes found in the children were more isolated and genetically differentiated between them.

Cryptosporidium canis in Two Mexican Toddlers.

Cryptosporidium canis is reported for the first time in 2 toddlers in Northwestern Mexico. The 2 toddlers (33 and 34 months old) were symptomatic at diagnosis, presenting diarrhea and fever, and 1 case presented chronic malnutrition. Both toddlers were HIV-negative. C. canis was identified by SspI and VspI restriction enzyme digestion of the 18S rRNA polymerase chain reaction products and confirmed by sequence analysis.