The incidence of antibiotics and transcriptional regulation of ARGs in isolated bacteria from wastewater needs to be explored. By HPLC, in samples of untreated wastewater, ampicillin (49.74 ± 5.70 µg/mL), chloramphenicol (0.60 ± 0.03 µg/mL), tylosin (72.95 ± 2.03 µg/mL), and oxytetracycline (0.22 ± 0.01 µg/mL) was determined. Through metagenomic analysis identified 58 bacterial species belonging to 9 phyla and at least 14 species have shown resistance to a variety of antibiotics. Twenty-two bacterial isolates were proved to be resistant to fifteen antibiotics of new generation and used in medical research to combat infectious diseases. Fourteen strains were shown to harbor plasmids in size ranges of 2–5 Kb, 6–10 Kb and plasmids with size greater than 10 Kb. By quantitative PCR it was possible to identify genes sul, qnr, cat1, aadA1, and sat-1 gene were shown to be present in gDNA samples from treated and untreated samples of wastewater and by relative expression analysis, differential expression of cat1, ermB, act, and tetA genes was demonstrated in strains that showed identity with Escherichia coli, Bacteroides fragilis, and Salmonella thyphi, and that were stressed with different concentrations of antibiotics. The presence of ARGs in untreated water samples, as well as in bacterial isolates, was indicative that in these habitats there are microorganisms that can resist β-lactams, aminoglycosides, tetracyclines, sulfonamides, and quinolones.

Hospital wastewater (HWW) is a major source of microbiological contamination, often released into the municipal sewage system without prior treatment. This HWW may contain pathogens with antimicrobial resistance, posing risks to public health. The aim of this work was to assess the risks associated with the seasonal release of ESKAPE bacteria resistant to β-lactam antibiotics and the release of carbapenems and cephalosporins through HWW of Hospital Juárez de México. The 12-month seasonal variation in β-lactam-resistant bacterial populations was assessed in the HWW of five discharge points. Resistant isolates were identified by mass spectrometry (MALDI-TOF) coupled with PCR assays to search for antimicrobial resistance genes, while β-lactamic antibiotics were detected using high-performance liquid chromatography (HPLC). Finally, a double-entry Vester matrix was constructed to classify the problems of HWW according to their degree of causality. Seasonal differences in bacterial loads were observed, with higher levels in warmer months. A wide variety of resistant pathogens were identified, including ESKAPE bacteria, as well as emerging bacteria carrying β-lactamase-encoding genes. The release of meropenem was detected most commonly, followed by cefepime and ceftazidime. The Vester matrix allowed the identification of critical clinical and environmental scenarios where two discharge points contribute significantly to the spread of microbiological contamination. This study highlights the importance of proper management of HWW and the need for stricter regulations to reduce the risks associated with the release of resistant pathogens with health impacts.

Stenotrophomonas maltophilia is considered one of the emerging bacterial agents causing healthcare-associated infections (HAIs) in hospital environments. This microorganism has been identified as multidrug-resistant, capable of forming mature biofilms—an ability that promotes adherence to surfaces and invasive medical devices, favoring persistence in hospital environments and the potential to generate outbreaks. The aim of this study was to characterize S. maltophilia strains isolated from HAI cases at the Hospital Juárez de México and to determine the presence of hidden outbreaks. Antibiotic resistance profiles were determined, along with the typing of 20 genes associated with virulence factors and the assessment of the ability to form mature biofilms on inert surfaces. Finally, sequence type (ST) was obtained through multilocus sequence typing (MLST) analysis, and a phylogenetic tree was constructed to determine the clonal diversity of the isolates. All strains showed uniform resistance to β-lactam antibiotics tested while remaining sensitive to fluoroquinolones, phenicols, tetracyclines, and trimethoprim/sulfamethoxazole. Some isolates exhibited adherent activity, with the “strong biofilm-former” phenotype predominating. Sixteen virulence-related genes were heterogeneously detected, revealing broad genetic diversity. MLST analysis grouped the isolates into nine ST related to infection cases reported in others countries. Phylogenetic analyses demonstrated the presence of three potential clones distributed across Internal Medicine and the Pediatric Intensive Care Unit. These results highlight the importance of investigating S. maltophilia as an HAI-associated pathogen that remains understudied.

Cheese consumption provides humans with minerals, proteins, carbohydrates, and vitamins. In Mexico, several cheese varieties are produced, each with its texture, scent, and flavor. The artisanal cheeses made in the states of Tabasco and Chiapas—including, among others, the varieties named crema (cream), doble crema (double cream), oaxaca, panela, fresco, bola, poro, cotija, and asadero—have a high demand in the domestic and foreign markets. The intensification of anthropic activity in these states causes an increased emission to the environment of contaminants like heavy metals, which could reach human foodstuffs through the food chains. In particular, heavy metal contents in cheeses consumed daily by these states’ local populations might represent a public health risk. Because of that, our objectives in this work were to determine the concentrations of lead, cadmium, nickel, copper, zinc, and iron in artisanal cheeses produced in the states of Tabasco and Chiapas and to determine the values of the hazard quotient (HQ), total hazard quotient (THQ), and cancer risk total (CRT) for adult and young men and women. The results of our analyses of cheese samples from the states of Tabasco and Chiapas showed that the average concentrations (mg kg⁻¹) of cadmium (0.0023 ± 0.002, 0.0023 ± 0.002 mg kg⁻¹, respectively, for each state), lead (0.0047 ± 0.00, 0.0051 ± 0.002), nickel (0.0039 ± 0.0046, 0.0031 ± 0.0039), copper (0.0199 ± 0.021, 0.0202 ± 0.022), zinc (0.1611 ± 0.18, 0.194 ± 0.21), and iron (61.84 ± 4.23, 65.76 ± 6.61 mg kg⁻¹), the first three values lower than the limits established by the FAO/WHO and Codex Alimentarius. The value of THQ that we obtained was less than one, and that of CRT was within the limits established by the US-EPA, which means that the consumption of artisanal cheeses from Tabasco and Chiapas by humans does not imply a risk of disease or cancer.

SARS-CoV-2 was the cause of the global pandemic that caused a total of 14.9 million deaths during the years 2020 and 2021, according to the WHO. The virus presents a mutation rate between 10−5 and 10−3 substitutions per nucleotide site per cell infection (s/n/c). Due to this, studies aimed at knowing the evolution of this virus could help us to foresee (through the future development of new detection strategies and vaccines that prevent the infection of this virus in human hosts) that a pandemic caused by this virus will be generated again. In this research, we performed a functional annotation and identification of changes in Nsp (non-structural proteins) domains in the coronavirus genome. The comparison of the 13 selected coronavirus pangenomes demonstrated a total of 69 protein families and 57 functions associated with the structural domain’s differentials between genomes. A marked evolutionary conservation of non-structural proteins was observed. This allowed us to identify and classify highly pathogenic human coronaviruses into alpha, beta, gamma, and delta groups. The designed Nsp cluster provides insight into the trajectory of SARS-CoV-2, demonstrating that it continues to evolve rapidly. An evolutionary marker allows us to discriminate between phylogenetically divergent groups, viral genotypes, and variants between the alpha and betacoronavirus genera. These types of evolutionary studies provide a window of opportunity to use these Nsp as targets of viral therapies.

The increasing burden of dengue represents a growing global public health concern. Among the factors associated with rising dengue incidence, climate change, particularly increasing temperatures, has been frequently highlighted, alongside other environmental, biological, and social determinants. The emergence of dengue in previously non-endemic areas and its sustained increase in incidence have become increasingly common in recent decades. Objective: The aim of this study was to describe national dengue case trends in Mexico from 1990 to 2023 and to assess their association with temperature over the same period using a descriptive, retrospective analysis of epidemiological surveillance and temperature data. Methods: Epidemiological data on confirmed dengue cases and incidence were obtained from the Morbidity Yearbook of the General Directorate of Epidemiology (DGE) of the Mexican Ministry of Health. These data were used to construct epidemic curves and to analyze the geographic distribution of incidence using quartiles. Temperature data were derived from the national annual mean calculated from monthly reports issued by the National Water Commission (CONAGUA). Associations between temperature and dengue cases and incidence were explored over the study period. Results: Temporal analysis revealed a significant increase in both dengue cases and incidence in Mexico, with a positive association with temperature during the same period. Quartile-based geographic analysis showed that state-level classifications remained relatively stable across periods, with several states clustering within or tending toward the group considered endemic. Conclusions: The results of this study show an increase in cases and incidence of dengue over time, as well as a positive association between cases/incidence of dengue in Mexico and the increase in the national average temperature during the study period; however, due to its descriptive and retrospective design, causal inference is not possible. Dengue transmission is inherently multifactorial, and the observed trends likely reflect the combined influence of climatic conditions, historical expansion of transmission cycles, vector establishment, and unmeasured socio-epidemiological factors. The absence of entomological indicators, additional climatic variables, and spatially or seasonally disaggregated analyses limits the ability to capture localized dynamics. Overall, temperature should be interpreted as a contributing factor within a complex system rather than as the sole driver of dengue trends, underscoring the need for integrated surveillance and control strategies in both endemic and non-endemic regions.