New Variants of Pseudomonas aeruginosa High-Risk Clone ST233 Associated with an Outbreak in a Mexican Paediatric Hospital.

Recent multidrug resistance in Pseudomonas aeruginosa has favoured the adaptation and dissemination of worldwide high-risk strains. In June 2018, 15 P. aeruginosa strains isolated from patients and a contaminated multi-dose meropenem vial were characterized to assess their association to an outbreak in a Mexican paediatric hospital. The strains were characterized by antibiotic susceptibility profiling, virulence factors' production, and biofilm formation. The clonal relationship among isolates was determined with pulse-field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST) sequencing. Repressor genes for the MexAB-OprM efflux pump were sequenced for haplotype identification. Of the strains, 60% were profiled as extensively drug-resistant (XDR), 33% as multidrug-resistant (MDR), and 6.6% were classified as sensitive (S). All strains presented intermediate resistance to colistin, and 80% were sensitive to aztreonam. Pyoverdine was the most produced virulence factor. The PFGE technique was performed for the identification of the outbreak, revealing eight strains with the same electrophoretic pattern. ST235 and ten new sequence types (STs) were identified, all closely related to ST233. ST3241 predominated in 26.66% of the strains. Twenty-five synonymous and seventeen nonsynonymous substitutions were identified in the regulatory genes of the MexAB-OprM efflux pump, and nalC was the most variable gene. Six different haplotypes were identified. Strains from the outbreak were metallo-ß-lactamases and phylogenetically related to the high-risk clone ST233.

Infectious Agents in Childhood Leukemia.

Acute leukemia is the most common pediatric cancer, representing one-third of all cancers that occurs in under 15 year olds, with a varied incidence worldwide. Although a number of advances have increased the knowledge of leukemia pathophysiology, its etiology remains less well understood. The role of infectious agents, such as viruses, bacteria, or parasites, in the pathogenesis of leukemia has been discussed. To date, several cellular mechanisms involving infectious agents have been proposed to cause leukemia following infections. However, although leukemia can be triggered by contact with such agents, they can also be beneficial in developing immune stimulation and protection despite the risk of leukemic clones. In this review, we analyze the proposed hypotheses concerning how infectious agents may play a role in the origin and development of leukemia, as well as in a possible mechanism of protection following infections. We review reported clinical observations associated with vaccination or breastfeeding, that support hypotheses such as early life exposure and the resulting early immune stimulation that lead to protection.

[Maternal-fetal transmission of Trypanosoma cruzi, a health problem slightly studied in Mexico: case Chiapas]. / Transmisión materno-fetal de Trypanosoma cruzi, un problema de salud poco estudiado en México: caso Chiapas.

OBJECTIVE: To determine the Trypanosoma cruzi infection prevalence in 1125 pregnant women and the transmission frequency to their children from Tapachula and Palenque, Chiapas. MATERIALS AND METHODS: We determined the prevalence by serology tests and the transmission frequency by polymerase chain reaction (PCR) and T. cruzi reactivity capacity after 12 months. RESULTS: Total maternal infection prevalence were 23/1 125 (2.04%), 9/600 (1.5%) were from Tapachula and 14/525 (2.6%) from Palenque. The seropositive women were between 20 and 35 years old, 31.8% have Premature Rapture of Membrane and 9.1% have history of perinatal death. The total percentage of positive newborns by PCR was 9/23 (39.13%), out of those 2/9 (22.2%) are from Tapachula and 7/14 (50%) from Palenque. The Maternal Fetal transmission frequency was. 2/9 (22.2%) in Tapachula and 1/14 (7.14%) in Palenque, all positive infants were asynthomatic. CONCLUSION: The maternal-fetal transmission rate in Chiapas State is variable; the reason could be the maternal immunological status and T. cruzi strain.

Transmisión materno-fetal de Trypanosoma cruzi, un problema de salud poco estudiado en México: caso Chiapas / Maternal-fetal transmission of Trypanosoma cruzi, a health problem slightly studied in Mexico: case Chiapas

Resumen: Objetivo: Determinar la prevalencia de infección de Trypanosoma cruzi en 1 125 mujeres embarazadas y la frecuencia con que éstas la transmiten a sus hijos en Tapachula y Palenque, Chiapas. Material y métodos: Se determinó la prevalencia materna por serología, la frecuencia de transmisión por reacción en cadena de la polimerasa (PCR) y la capacidad reactiva a T. cruzi a los 12 meses de edad del niño. Resultados: La prevalencia materna total fue 23/1 125 (2.04%); 9/600 (1.5%) en Tapachula y 14/525 (2.6%) en Palenque. Las mujeres seropositivas tenían entre 20 y 35 años; 31.8% tuvo ruptura prematura de membrana (RPM) y 9.1% tuvo antecedentes de muerte perinatal. La frecuencia de transmisión materno-fetal en Tapachula fue de 2/9(22.2%) y en Palenque de 1/14(7.14%); todos los niños positivos eran asintomáticos. Conclusión: La tasa de transmisión materno-fetal en el estado de Chiapas es variable; la razón podría ser el estado inmunológico de la madre o la cepa de T. cruzi.

Abstract: Objective: To determine the Trypanosoma cruzi infection prevalence in 1125 pregnant women and the transmission frequency to their children from Tapachula and Palenque, Chiapas. Materials and methods: We determined the prevalence by serology tests and the transmission frequency by polymerase chain reaction (PCR) and T. cruzi reactivity capacity after 12 months. Results: Total maternal infection prevalence were 23/1 125 (2.04%), 9/600 (1.5%) were from Tapachula and 14/525 (2.6%) from Palenque. The seropositive women were between 20 and 35 years old, 31.8% have Premature Rapture of Membrane and 9.1% have history of perinatal death. The total percentage of positive newborns by PCR was 9/23 (39.13%), out of those 2/9 (22.2%) are from Tapachula and 7/14 (50%) from Palenque. The Maternal Fetal transmission frequency was. 2/9 (22.2%) in Tapachula and 1/14 (7.14%) in Palenque, all positive infants were asynthomatic. Conclusion: The maternal-fetal transmission rate in Chiapas State is variable; the reason could be the maternal immunological status and T. cruzi strain.

Determinación de la frecuencia de anticuerpos contra Trypanosoma cruzi por la técnica de Eliza y wetern blot en pacientes de un hospital de pediátrico de Villahermosa, Tabasco / Determination of the frequency of antibodies against Trypanosoma cruzi by ELISA and western blot in pediatric patients from a hospital in Villahermosa, Tabasco

La infección por Trypanosoma cruzi en niños del estado de Tabasco ha sido poco estudiada a pesar de ser una zona endémica que presenta un número importante de adultos con enfermedad de Chagas. La ausencia de una sintomatología sugestiva y las condiciones inmunológicas del huésped juegan un papel muy importante para que la enfermedad pase desapercibida o se enmascare al presentarse junto con otra patología. El propósito de este trabajo fue investigar la existencia de riesgos de infección con T. cruzi en una población de niños que acuden a un hospital pediátrico por diferentes padecimientos, y determinar algunas de las limitantes para identificar el comportamiento de la infección. Se determinó la presencia de anticuerpos IgG específicos para T. cruzi en suero mediante las técnicas de ELISA y western blot en 182 niños que acudieron al Hospital "Rodolfo Nieto Padrón" en Villahermosa, Tabasco, sin tener datos clínicos relacionados con la enfermedad de Chagas y con edades de menos de un año a 16 años. De acuerdo con el diagnóstico se les clasificó por entidades nosológicas, zona de localización habitacional y su relación con la presencia de anticuerpos específicos. La frecuencia de anticuerpos fue 9/182 (4.94 por ciento) con un IC a 95 por ciento = 2.4 a 9.4 por ciento. La distribución por sexo y edad esta relacionada con el número de muestras positivas no mostró diferencias; 47.25 por ciento pertenecieron al sexo femenino; de éstos, 5.81 por ciento presentó anticuerpos específicos para T. cruzi positivos fue en las enfermedades oncológicas e infecciosas. La frecuencia de anticuerpos fue mayor al reportado en la población abierta, por lo que deberá ponerse mayor antención a niños que reciben tratamiento inmunosupresor, como en las enfermedades oncológicas infecciosas, en donde se observó la mayor frecuencia de infección