Knowledge of the sequencing of the 16S rRNA gene constitutes a true revolution in understanding the composition of the intestinal microbiota and its implication in health states. This study details microbial composition through next-generation sequencing (NGS) technology in children with anemia. Anemia is the most frequent hematological disorder that affects human beings. In Peru, it is one of the conditions that presents the most significant concern due to the adverse effects that cause it, such as delayed growth and psychomotor development, in addition to a deficiency in cognitive development.

The water and soils pollution due to mercury emissions from mining industries represents a serious environmental problem and continuous risk to human health. Although many strategies have been designed for the recovery or elimination of this metal from environmental sources, microbial bioremediation has proven to be the most effective and environmentally friendly strategy and thus control heavy metal contamination. The main objective of this work, using native bacterial strains obtained from contaminated soils of the Peruvian region of Secocha, was to identify which of these strains would have growth capacity on mercury substrates to evaluate their adsorption behavior and mercury removal capacity. Through a DNA analysis (99.78% similarity) and atomic absorption spectrometry, the Gram-positive bacterium Zhihengliuella alba sp. T2.2 was identified as the strain with the highest mercury removal capacity from culture solutions with an initial mercury concentration of 162 mg·L${}^{-1}$. The removal capacity reached values close to 39.5% in a period of incubation time of 45 days, with maximum elimination efficiency in the first 48 h. These results are encouraging and show that this native strain may be the key to the bioremediation of water and soils contaminated with mercury.

Anemia is the most common hematological disorder affecting humans. In Peru, anemia is a pressing issue that present the most significant concern due to its adverse effects, such as delayed growth and psychomotor development, in addition to a deficiency in cognitive development. Anemia is a significant public health issue in Peru, which has one of the highest prevalence rates in infants in the Latin American and Caribbean (LAC) region, affecting approximately 43.6 % of children under three years nationally as of 2017, with rural areas experiencing a higher prevalence of approximately 53.3 %. In 2019, the prevalence was highest in the Sierra (48.8 %) and Selva regions (44.6 %), whereas the coast had a lower rate of 33.9 % in children under 36 months.

Bioremediation of soils and waters due to mercury (Hg) contamination represents one of the most critical environmental challenges. In addition, this challenge is even greater in arid soils due to the low economic interest in these regions. Such is the case of the Secocha Annex, located in the Arequipa province of Camaná in Southern Peru. In this region, the excessive use of Hg in artisanal and small-scale gold mining (ASGM) activities has seriously endangered the health of its inhabitants. Unfortunately, there are few projects aimed at improving the environmental and sanitary conditions of this locality. An alternative to conventional cleaning technology is the use of native microorganisms that allow the recovery of ecological environments with low-cost and low-tech techniques. This work aims to present two new Hg-resistant bacterial strains obtained from Hg-polluted soils of the Secocha Annex as potential bioremediation agents. Both strains showed growth capacity on Hg substrates and their adsorption behaviors and Hg removal capacities were evaluated. By deoxyribonucleic acid (DNA) analysis, both Gram-positive strains were identified as Kocuria sp. (99.35% similarity) and Zhihengliuella sp. (99.78% similarity). Spectrometry results showed elimination capacities with values close to 28.4 and 33.3 % in an incubation time period of 45 days, with the maximum elimination efficiency in the first 24 h. These results are encouraging and offer new possibilities for the use of native strains in the bioremediation of arid soils contaminated with Hg in the Secocha Annex. Furthermore, due to the low cost and minimization of negative impacts, this technique and our bacterial strains could be used in other regions of Peru.

Textile effluents derived from azo-reactive dyeing processes represent a severe problem for aquatic ecosystems and human health. The large amounts of water used in this process and the poor quality of the discharges urge the need to develop treatment systems that involve reusing treated water. In this research, we present the optimization of a feasible, simple, and efficient treatment system that improves the quality of the effluents from the cotton fabric dyeing process. Through the characterization of the influents and effluents, we have identified seven parameters that have allowed the optimization of the treatment. Analytical techniques, such as nephelometry, EDTA, gravimetry, and BOD5, among others, and specialized equipment, such as the spectrophotometer, have been used for these purposes. The results showed that using combustion gases in the neutralization stage and new flocculant-coagulant reagents improved parameters, such as pH, total solids, hardness, and conductivity. The quality of the effluents thus obtained allowed their reuse only in the stages before the dyeing bath without affecting the final quality of the cotton fabrics in dark colors. This effort implies savings in water and supplies, and opens the door to future research on the treatment of textile effluents that help improve the environmental conditions of our region.

Objective To identify the characteristics of anemia in children living at different geographical altitude in the Arequipa Region of Peru. Methods We did a descriptive and retrospective study. The population consisted of 106 499 children under five years of age living in the Arequipa Region at different geographical altitude and receiving care by the Ministry of Health of Arequipa. Of these, 32 454 had anemia (30.5%). Socio-demographic data related to age, province, and beneficiary of the Comprehensive Health System program, home visits, and growth and development were obtained, in addition to data regarding anemia such as frequency, hemoglobin, and severity. Results The results were categorized by the geographical altitude of origin of children under 0 to 59 months of age and hemoglobin levels according to geographical altitude. Of the sample studied, the frequency of anemia at different geographical altitudes of Arequipa in children under five for the 2017 to 2019 period was: 18.7% at 0 to 999 meters above sea level; 29.6% at 1000 to 1999 meters; 31.6% at 2000 to 2999 meters; 42.9% at 3000 to 3999 meters; and 54.4% at 4000 to 4999 meters. There was a higher prevalence of anemia when the geographic altitude correction factor was used. Conclusions A significant statistical relationship (p < 0.05) was observed between the corrected hemoglobin according to the World Health Organization parameters and the altitude at which children with anemia live: the higher the geographical altitude, the greater the anemia in children. Supplementation programs should be included during home visits and at the time of evaluation of children's growth and development.