Can the genetic variability of Blastocystis sp. be associated with the climatic region of its human carriers?

Blastocystis sp. is a widespread microorganism that colonizes the intestinal tract of several animals, including human beings, while its pathogenic role in humans is still under debate. The objective of the present study was to describe the frequency of Blastocystis sp. subtypes (STs) and their genetic variation within and among samples recovered from scholars inhabiting two rural villages with tropical climates and compare this information with previously documented data from arid and temperate zones in Mexico. Blastocystis sp. positive samples and ST identification were achieved by coprological analysis screening and Polymerase Chain Reaction-sequencing, respectively. Classical population genetics indexes (nucleotide diversity (π), haplotype polymorphism (θ), gene flow (Nm), genetic differentiation (ST), and Tajima's D) were calculated by comparing the sequences here obtained (n = 42) and those from previous studies from the arid (n = 80) and temperate (n = 61) climates from Mexico. Although Blastocystis sp. was the parasite most frequently found between 33% and 26% in both communities, only STs 1-3 were found. Haplotype network inference of Blastocystis sp. STs showed different haplotype profiles among STs vs. climate zones, although no specific haplotypes were identified for any particular climatic zone. Population genetics indexes showed different values within STs and climate zones (π and θ values ranged from 0.004 to 0.147; Nm > 4 and ST from 0.006 to 0.12). Our results show that Blastocystis sp. subtypes exhibit a different genetic variability profile according to the climate zone, suggesting a balancing process between the genetic variability within the Blastocystis sp. subtype and the number of haplotypes identified in each climate.

A New Record of the Introduced Species Triatoma infestans (Hemiptera: Reduviidae) in Mexico.

Here, we report a new record of Triatoma infestans (Klug) in Mexico after 50 years and provide a brief description of the discovery area. Fifty-nine specimens (71.2% adults) of the introduced species were collected from the peridomestic areas of a single house in the port of Manzanillo in the state of Colima, Mexico. Thirty-one specimens (52.5%) were collected from the exterior walls of the house and were apparently attracted to light. The other specimens (47.5%) were associated with chickens. No specimen was infected with Trypanosoma cruzi Chagas, the causative agent of Chagas disease, possibly because they were feeding on chickens. We speculate that the introduced species travelled from South America to Mexico via seed shipment in a twenty-foot equivalent unit (TEU) maritime container. Because Mexican phytosanitary regulations demand only the cargo to be inspected, the triatomines could have escaped notice during inspection. Subsequently, as the cargo was unloaded and the TEU was stored, the triatomines likely flew to and invaded the nearby residential areas. The rediscovery of this domestic vector of T. cruzi in Mexico warrants further investigation owing to the potential risk of transmission to the inhabitants of the study area.

Genetic diversity of Chlamydia pecorum detected in sheep flocks from Mexico.

Chlamydia pecorum, an obligate intracellular bacterium, is associated with reproductive and systemic diseases in sheep, goats, pigs, cattle, and koalas. The main conditions include polyarthritis, conjunctivitis, enteritis, pneumonia, encephalomyelitis, orchitis, placentitis, and abortion. Even though there are several studies showing that C. pecorum infections are widely spread in the world, in Mexico there are no reports. During 2016, as part of a sheep restocking program in Mexico, sheep were imported from New Zealand. Briefly after their arrival in the herds in the State of Mexico, these sheep presented abortions during the last third of gestation. A total of 62 sheep vaginal swabs that had presented abortion from different municipalities of the State of Mexico were collected. Bacterial isolation was performed using L929 mouse fibroblasts, and molecular identification was achieved by 23S rRNA (Chlamydiaceae family) and ompA gene (species-specific) real-time polymerase chain reaction (PCR). In addition, the 16S rRNA subunit and ompA gene were amplified and sequenced. Seven of 62 samples were positive for C. pecorum by bacterial isolation, 23S rRNA, and ompA gene real-time PCR. The 16S rRNA subunit and ompA gene amplicons were purified and the nucleotide sequence was determined in both directions. The consensus sequences homology search was performed using BLASTn analysis and showed a 100% of homology with the C. pecorum 16S rRNA subunit and 99% with the C. pecorum ompA gene. The population structure analyses using ompA gene demonstrated 15 genetic populations or clusters of 198 sequences from GenBank and our sequences were in a particular genetic structure corresponding to genotype "O." Herein, we describe the presence of C. pecorum in sheep imported from New Zealand into Mexico. Genetic analysis of the ompA gene showed that the isolates belong to genotype O and are related to strains isolated from sheep, cattle, and koalas.

Characterization of aortic and brachiocephalic filariasis by Filarioidea sp (Nematoda:Spirurida:Filarioidea) in Mexican ramphastids.

The manuscript presented herein documents the findings of filaria nematodes in 5 keel-billed toucans, and one emerald toucanet, originated from 2 private aviaries in Mexico City during two years. The birds displayed ruffled feathers, depression, inability to perch, convulsions, and sudden death. Furthermore, thickened wall of the aortic and brachiocephalic arteries, with connective tissue proliferation and chondroid metaplasia were observed. Molecular characterization matched Filarioidea sp (Nematoda: Spirurida: Filarioidea). To the authors' knowledge, this is the first documented report of filariae Filarioidea sp. causing mortality in ramphastids in Mexico. This manuscript may contribute to expand current knowledge of filariasis and the health risks and livability of wild birds.

Mutations in the FGFR2 gene in Mexican patients with Apert syndrome.

Apert syndrome (AS) is a frequent acrocephalosyndactyly, with autosomal dominant inheritance. AS has been associated with mutations in fibroblast growth factor receptor 2 (FGFR2), and approximately 99% of cases show 2 of the frequent mutations located in exon IIIa (Ser252Trp or Pro253Arg). The purpose of the present study was to describe the mutations in exon IIIa of FGFR2 in Mexican AS patients and the relationships with clinical features. Exon IIIa of FGFR2 from 6 AS patients was amplified by polymerase chain reaction. Mutations in exon IIIa of the FGFR2 gene were identified by digestion with the restriction endonuclease Bstx1 and polyacrylamide gel electrophoresis. PCR fragments were cloned into the PCR 2.1 vector, and both DNA strands were sequenced using the T7 promoter and M13 universal cloning region oligonucleotides. Sequence alignment was performed using the MEGA software version 5. The patients' major clinical features included craniosynostosis, hypertelorism, proptosis, otitis media, midfacial hypoplasia, rhizomelic shortening, and hyperhidrosis. Mutation S252W was present in 4 patients, while the other 2 patients had P253R. In conclusion, either S252W or P253R mutations were present independently in AS patients; however, the 2 mutations were not found together. None of the clinical features were associated with any of the mutations, suggesting that other mutations may be involved in the development of this syndrome.

[Irritable bowel syndrome: frequency and phylogenetic relationship of Blastocystis sp. from Mexican patients]. / Síndrome de intestino irritable: frecuencia y relación filogenética de Blastocystis sp. de pacientes mexicanos.

INTRODUCTION: Recent studies reported increased presence of Blastocystis in patients with Irritable Bowel Syndrome (IBS) and an etiologic role has been proposed. The pathogenic role of Blastocystis is controversial, because it is frequently found not only in individuals with enteric symptoms but also in healthy and asymptomatic subjects. Furthermore, there are few studies of blastocistosis in Mexico. OBJECTIVE: To assess the frequency of Blastocystis sp. in IBS patients using molecular techniques and to describe its phylogenetic relationship with sequences of other countries. METHODS: IBS patients according to Rome III criteria were enrolled. In all patients evaluations included: colonoscopies, coproparasitoscopic studies, coproculture, fecal virus screening. PCR and sequencing for Blastocystis sp. were also performed. RESULTS: We recruited 11 men and 51 women with a mean age of 45.6 (SD ± 15.7) years. Eighty-six percent of the IBS patients presented a normal colonoscopy, 8% showed polyps and 6% diverticular disease. Blastocystis sp. was identified in 25% patients (all of them with normal colonoscopy), while two patients had Endolimax nana and Entamoeba histolytica/E. dispar, respectively. Phylogenetic analysis showed that major sequences of Mexican carriers clustered together with sequences of parasites from Japan and Denmark; furthermore, two sequences from IBS patients were grouped in a single cluster. CONCLUSIONS: Blastocystis sp. was identified in 25% of the IBS patients. Our data support the hypothesis of clonal lineages in distinct geographical areas in the world.

[Ultrasonic measurement of the normal portal vein in children]. / Medición de la vena porta normal en niños por ultrasonido.

The portal vein was measured in 244 children from under a year old to 18 years of age in order to have normal measurement values for the vein according to age groups. No tables seem to be available containing this information. From the group, 164 patients were selected and were placed in six different groups according to their ages. The tables show the values obtained, a percentile curve, averages with standard deviations and ranges.

[Frequency of neonatal necrotizing enterocolitis at a pediatric hospital]. / Frecuencia de enterocolitis necrosante neonatal en un hospital pediátrico.

A revision study of 322 cases of neonatal necrotizing enterocolitis (NEC) in a six year period at a pediatric hospital is presented. The frequency of NEC was 7.2% of the newborn (NB) admitted to the hospital. Fifty two percent corresponded to grade I on Bell's classification, 37% to grade II and 11% to grade III. Most of the cases were seen in at term newborn (51.3%) even though the proportional frequency in relation to the admissions was 38% in at term newborn and 62% in premature. The main clinical manifestations were abdominal distention, vomiting, and blood in feces. The frequency and intensity of other clinical signs as well as other signs as acidosis, anemia, hyponatremia and hypoprothrombinemia were directly proportional to the severity of the NEC. The radiological data of portal pneumatosis were more frequent in grade III NEC, and several cases of gastric pneumatosis were seen in the grade II NEC. Thirty four patients (10.6%) underwent surgery. The global mortality was 29.5% and in those who underwent surgery 79.4%.