The interruption of bacteriological surveillance due to the COVID-19 pandemic brought serious consequences, such as the collapse of health systems and the possible increase in antimicrobial resistance. Therefore, it is necessary to know the rate of resistance and its associated mechanisms in bacteria causing hospital infections during the pandemic. The aim of this work was to show the phenotypic and molecular characteristics of antimicrobial resistance in ESKAPE bacteria in a Mexican tertiary care hospital in the second and third years of the pandemic. For this purpose, during 2021 and 2022, two hundred unduplicated strains of the ESKAPE group (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii) were collected from various clinical sources and categorized by resistance according to the CLSI. An analysis of variance (ANOVA) complemented by the Tukey test was performed to search for changes in antimicrobial susceptibility profiles during the study period. Finally, the mechanisms of resistance involved in carbapenem resistance were analyzed, and the search for efflux pumps and high-risk sequence types in A. baumannii was performed by multilocus analysis (MLST). The results showed no changes in K. pneumoniae resistance during the period analyzed. Decreases in quinolone resistance were identified in E. coli (p = 0.039) and P. aeruginosa (p = 0.03). Interestingly, A. baumannii showed increases in resistance to penicillins (p = 0.004), aminoglycosides (p < 0.001, p = 0.027), carbapenems (p = 0.027), and folate inhibitors (p = 0.001). Several genes involved in carbapenem resistance were identified (bla_NDM, bla_VIM, bla_OXA, bla_KPC, bla_OXA-40, and bla_OXA-48) with a predominance of bla_OXA-40 and the adeABCRS efflux pump in A. baumannii. Finally, MLST analysis revealed the presence of globally distributed sequence types (ST369 and ST758) related to hospital outbreaks in other parts of the world. The results presented demonstrate that the ESKAPE group has played an important role during the COVID-19 pandemic as nosocomial antibiotic-resistant pathogens and in particular A. baumannii MDR as a potential reservoir of resistance genes. The implications of the increases in antimicrobial resistance in pathogens of the ESKAPE group and mainly in A. baumannii during the COVID-19 pandemic are analyzed and discussed.

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.

In Mexico, hospital wastewater (HWW) is a source of chemical and microbiological contamination, and it is released into the municipal sewage system without prior treatment. This water may contain pathogenic bacteria and antimicrobial resistance genes, which represent a risk to Public Health and the environment. So far, there are no studies that analyse this problem comprehensively, relating bacterial population structures, chemical contaminants, and seasonality. The aim of this work was to seasonally characterise the bacterial communities of HWW, including clinically relevant bacteria and resistance genes in Hospital Juárez de México (HJM), and to evaluate the impact of physicochemical factors on their composition. A one-year observational, cross-sectional study was conducted at five HWW discharge points of HJM. Fourteen physicochemical parameters were determined by using standard methodologies, and statistical differences between discharges and seasons were evaluated. Bacterial communities were analysed by targeted amplicon sequencing of the V3-V4 region of the 16S rRNA gene. In addition, the presence of eight antimicrobial resistance genes of local epidemiological importance was assessed. Data were analysed using alpha and beta diversity indices, principal component analysis, and multivariate statistical tests. HWW showed high taxonomic diversity, with Proteobacteria, Firmicutes, and Bacteroidetes standing out. Clinically relevant bacteria were identified in 73.3% of the analyses, with Enterobacter and Escherichia-Shigella predominating. Total and dissolved solids, temperature, nitrate, and pH significantly influenced the bacterial composition of HWW. Seven out of the eight genes evaluated were identified, with bla_KPC, bla_OXA-40, and mcr-1 being the most frequent, showing significant seasonal differences. This study underlines the microbiological and chemical complexity of HWW, highlighting the impact of clinically relevant bacteria and antimicrobial resistance genes on Public Health. The findings emphasise the need to implement hospital waste management programmes and ideally specific treatment plants to minimise the associated risks and protect the environment and human health.

Infections pose a risk for patients undergoing hematopoietic stem cell (HSC) transplants due to their immunosuppression, making them susceptible to opportunistic infections. Therefore, understanding the composition of the aerobiome in this area is vital. The aim of this study was to characterize the aerobiome in an HSC transplant area, evaluating the impact of infrastructure and health personnel operations on air contamination. The environmental parameters and aerobiome of the HSC transplant area at Hospital Juárez de México were quantified over one year. Finally, a double-entry Vester matrix was constructed to classify problems according to their degree of causality. The abundance and taxonomic diversity of the aerobiome were dependent on seasonality, environmental factors, and high-efficiency filtration. Gram-positive bacteria predominated, followed by fungi and Gram-negative bacteria. ANOVA revealed significant differences in the bacterial aerobiome but not in the fungal aerobiome among the transplant rooms. Clinically, fungi such as Aspergillus fumigatus, Alternaria spp., Cladosporium spp., and Penicillium spp. were identified. ESKAPE bacteria typing revealed clonal dispersion. Finally, the Vester matrix highlighted critical problems associated with contamination due to the absence of HEPA filtration and non-adherence in patient management practices. HEPA filtration and positive pressure are essential to improve the air quality and reduce the microbiological load. However, the control areas will depend on patient management and routine activities, such as entry protocols in controlled areas.

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.

The presence of skin bacteria capable of forming biofilm, exhibiting antibiotic resistance, and displaying virulence represents a significant challenge in the field of transfusion medicine. This underscores the necessity of enhancing the microbiological safety of blood and blood components against pathogens with virulent characteristics. The aim of this work was to demonstrate bacterial inactivation in plasma by using a photoinactivation method against virulent bacteria and to evaluate coagulation factors before and after treatment. Logarithmic loads of biofilm-producing, antibiotic-resistant, and virulent bacteria isolated from skin (Enterobacter cloacae, Klebsiella ozaenae, and Staphylococcus epidermidis) were used in artificial contamination assays of fresh frozen plasma bags and subjected to photoreduction. FVIII and FI activity were evaluated before and after photoinactivation. The photoinactivation of plasma was demonstrated to be an effective method for the elimination of these bacteria. However, the efficiency of this method was found to be dependent on the bacterial load and the type of test microorganism. Conversely, decay of coagulation factors was observed with net residual activities of 61 and 69% for FVIII and FI, respectively. The photoinactivation system could have a bias in its effectiveness that is dependent on the test pathogen. These findings highlight the importance of employing technologies that increase the safety of the recipient of blood and/or blood components, especially against virulent bacteria, and show the relevance of the role of photoinactivation systems as an option in transfusion practice.