Background: The waste generated at the end of a mining process contains potentially toxic elements (PTEs) and, depending on the extraction method, may also contain cyanide. These threaten ecosystems because PTEs are non-biodegradable and can accumulate in organisms through bioaccumulation. Cyanide is particularly dangerous as it is highly toxic and can inhibit the growth of plant species that could be used in phytoremediation. Objective: To evaluate the cyanide survival capacity of four desert native plant species from the state of Baja California, and their ability to phytostabilize EPTs. Methodology: Completely randomized experiments were conducted under greenhouse conditions, using experimental units with mine tailings amended with four different proportions of plant compost as a mine tailings improver (0 %, 5 %, 10 %, and 15 %). Four native plant species were used for the study: Prosopis sp., Psorothamnus spinosus, Pluchea sericea, and Encelia farinosa. Results: Prosopis sp. demonstrated a high survival capacity in mine tailings containing cyanide (155 mg kg-1) and potentially toxic elements accumulated mainly in the root. Implications: Many plant species show adverse effects on their growth and development due to the toxicity of these elements. Furthermore, phytostabilizing species must be able to survive the climatic conditions of the area where this technique is implemented and tolerate cyanide. Conclusion: It was demonstrated that Prosopis sp. has phytostabilizing capacity by accumulating higher PTE concentrations in its roots without exceeding concentrations in the aerial part. The optimal treatments for this technique were those with 10 % and 15 % compost, which helped the species tolerate cyanide. Therefore, Prosopis sp. is confirmed as an effective native species for phytostabilization.

Background: Heavy metals and cyanide compounds are common pollutants derived from mining activities. Cyanide can transform into hydrogen cyanide, a highly toxic substance for humans, and inhibits the growth of plants and microorganisms. If mining areas used as waste repositories remain without vegetation, pollutants remain exposed and can spread to other areas through wind or water. There is limited information on solutions that use plants and microorganisms to remediate cyanide-contaminated sites. Objective: To propose a strategy to adapt Prosopis sp. (mesquite) in a mining waste contaminated with 155 mg kg-1 of cyanide, using pine sawdust and an inoculant of arbuscular mycorrhizal fungi (AMF). Methodology: An experiment was conducted using 50 mL polypropylene tubes with the following treatments: mining waste (MT) and mining waste with 20% sawdust (MTS) as controls, along with the same treatments inoculated with mycorrhizae (MT-AMF and MTS-AMF). The experiment lasted for 60 days. pH, electrical conductivity (EC), and the number of bacteria in the substrate were measured, as well as the dry weight of the plants and the presence of mycorrhizal colonization. Results: Treatments that included pine sawdust and AMF showed healthy plants, decreased pH (from 7.82 to 7.15), reduced EC (from 6.25 to 4.71 mS cm-1), and significantly increased the number of bacteria. Implications: The combination of pine sawdust and arbuscular mycorrhizal fungi may facilitate the adaptation of Prosopis sp. in cyanide-contaminated mining soils, suggesting its potential as a bioremediation strategy. Conclusion: Pine sawdust and AMF can aid in adapting Prosopis sp. and represent a promising alternative for the recovery of cyanide-contaminated areas.

Antibiotic resistance remains a major public health concern, particularly in regions with high rates of hospital- and community-acquired infections. This study aimed to quantify multidrug-resistant (MDR) bacterial strains in northern Mexico and to identify the most prevalent resistance phenotypes, the antibiotic classes with the highest resistance and susceptibility rates, the predominant MDR species, and the specimen types yielding the greatest number of isolates. Clinically relevant strains were collected from patients with confirmed infections. Microorganism identification and antimicrobial susceptibility test-ing were performed using the Vitek 2 Compact system (bioMérieux), and the results were analyzed descriptively. Of the 1544 strains analyzed, 761 (49.29%) exhibited multidrug resistance. Escherichia coli was the most frequently isolated MDR species, followed by Pseudomonas aeruginosa. Acinetobacter baumannii showed the highest resistance rate, with 95.55% of its strains classified as MDR, whereas P. aeruginosa had the lowest MDR proportion at 30.73%. These findings underscore the urgent need for rational antibiotic use and the development of new therapeutic agents, particularly those targeting Gram-negative bacilli, to mitigate the growing threat of antimicrobial resistance in this region.

The brown dog tick, Rhipicephalus sanguineus sensu lato (s.l.), is of medical and veterinary relevance and is primarily controlled with acaricides. Because acaricide resistance in this tick is a growing concern, evaluating effective acaricides is particularly important in Baja California, where tick-borne pathogens associated with R. sanguineus s.l. are endemic. This study aimed to estimate a candidate discriminating concentration (DC) for fipronil in R. sanguineus s.l. from the city of Mexicali and to assess fipronil susceptibility in three tick populations. Engorged female ticks were collected from naturally infested dogs in Valle de Puebla, Solidaridad Social, and El Encanto. After hatching, larvae were exposed to seven concentrations of a commercial fipronil formulation (0.0016%, 0.0032%, 0.0047%, 0.0062%, 0.0093%, 0.0125%, and 0.025%) using the larval packet test. Mortality at 24 h was analyzed by probit regression to estimate the median lethal concentration (LC50) and the lethal concentration for 99% mortality (LC99). The estimated LC50 and LC99 were 0.0031% (95% CI: 0.0022–0.0042%) and 0.025% (95% CI: 0.0178–0.0331%). A candidate DC of 0.05% was estimated for the Valle de Puebla population. Application of this concentration to the other populations showed 100% mortality when exposed to both 0.025% and 0.05% fipronil, indicating similar susceptibility across all evaluated populations. These findings provide preliminary susceptibility data for future monitoring of fipronil susceptibility in R. sanguineus s.l. populations from Mexicali and suggest that this acaricide may remain a useful option for urban tick control where local populations are susceptible.