Indigenous people doing citizen science to assess water quality using the BMWP in rivers of an arid semi-arid biosphere reserve in Mexico.

Arid and semi-arid areas are among the most threatened ecosystems on the planet. The Tehuacán-Cuicatlán Biosphere Reserve (TCBR), in southeastern Mexico, is an arid and semi-arid area with high biological diversity and human settlements of eight ethnic groups. Two rivers drain the reserve, Río Grande (RG) and Río Salado (RS), which are not subject to water quality monitoring by government agencies; however, measures of water quality of these rivers are needed to focus conservation actions on this resource. This work aimed to test the effectiveness of participatory water quality monitoring with the participation of three actors: Reserve management leaders, local communities, and academics, to monitoring water quality in the rivers of the TCBR. Ninety-two residents were trained to carry out water quality biomonitoring using the Biological Monitoring Working Party (BMWP) index calibrated for the reserve. The BMWP uses macroinvertebrate families to display numerical and categorical water quality scores. Additionally, the Water Quality Index (WQI) was assessed and the Normalized Difference Vegetation Index (NDVI) of the riparian zones was estimated in each study site. The mean WQI scores were 69.24 for RS (no treatment necessary for most crops and necessary treatment for public water supply) and 75.16 for RG (minor purification for crops requiring high-quality water and necessary treatment for public water supply). The BMWP showed five water quality categories (Excellent, Very Good, Good, Fair, and Poor), showing higher water quality scores in the upper portion of the basins and capable of discriminating study sites with lower scores close to human settlements. At one study site, data from participatory monitoring impelled actions taken to address a pollution source and influenced policy focus, reaching the maximum level of participatory-based monitoring. This led to avoid the discharge of wastewater into the river to conserve and protect the water resource. WQI is closely related to BMWP; however, the latter was far more sensitive to detecting areas affected by domestic water discharges. The NDVI presented low values for the TCBR, being lower in RS (the driest area). Although the NDVI showed a weak relationship with BMWP values, areas with higher NDVI values generally achieved higher BMWP values. The results of this study highlight the high sensitivity of the BMWP to detect several water quality conditions in the rivers running through the TCBR when compared to WQI. In addition, the usefulness of biomonitoring using the BMWP index was evident, as well as the importance of the participation of local inhabitants contributing to the knowledge of water quality in biosphere reserves and carrying out timely measures that allow the rivers in these reserves to be maintained in good condition.

Immune-Epithelial Cell Interactions during Epidermal Regeneration, Repair, and Inflammatory Diseases.

The multiple layers of the skin cover and protect our entire body. Among the skin layers, the epidermis is in direct contact with the outer environment and serves as the first line of defense. The epidermis functions as a physical and immunological barrier. To maintain barrier function, the epidermis continually regenerates and repairs itself when injured. Interactions between tissue-resident immune cells and epithelial cells are essential to sustain epidermal regeneration and repair. In this review, we will dissect the crosstalk between epithelial cells and specific immune cell populations located in the epidermis during homeostasis and wound repair. In addition, we will analyze the contribution of dysregulated immune-epithelial interactions in chronic inflammatory diseases.

Confiabilidad de cuestionarios electrónicos para evaluar calidad de vida y actitudes hacia la vejez en mujeres de 40 a 69 años / Reliability of electronic questionnaires to evaluate quality of life and attitudes towards old age in women aged 40 to 69 years

Introducción: el uso de cuestionarios electrónicos se ha convertido en algo común, sin embargo, depende de diversos factores (como la edad y las habilidades digitales), por lo que es necesario determinar la confiabilidad de estos instrumentos para su aplicación. Objetivo: determinar la concordancia y reproducibilidad de los cuestionarios Calidad de vida breve de la OMS (WHOQoL-B) y Actitudes autoevaluadas hacia la vejez (AAV) en formato electrónico para su aplicación vía remota a mujeres de edad madura y adulta mayor. Metodología: se realizó un estudio instrumental con el método test-retest con 35 mujeres (40-69 años). Se transfirieron ambos cuestionarios a un formulario de Google y se enviaron vía WhatsAppen dos ocasiones, con una diferencia mayor a 15 días entre la aplicación. Se calcularon los parámetros de confiabilidad por estabilidad temporal y concordancia estadística. Resultados: el WHOQoL-B obtuvo a y CCI = 0.880 y r = 0.785 en la calificación total; para sus dimensiones a > 0.740 y r > 0.590. La calificación total del AAV mostró a y CCI = 0.708 y r = 0.552 y sus dimensiones a > 0.710 y r de 0.295 a 0.508. Conclusiones: los cuestionarios WHOQoL-B y AAV en formato electrónico pueden ser utilizados para aplicación vía remota, aunque el AAV es menos consistente...(AU)

Abstract Introduction: The electronic tests have been used on a regular basis, although their use depends on several factors such as age and digital ability, therefore it is necessary to determine the confidence of these instruments for their application. Objective: To determine the agreement and reproducibility of the WHO Quality of Life-Bref (WHOQoL-B) and the Self-Assessed Attitudes Towards Old Age (SATO) questionnaires in electronic format for application in middle-aged and older women. Methods: An instrumental study with a test-retest method was carried out with 35 women (40-69 years). Both questionnaires were transferred to a Google form and sent to the women by WhatsApp twice with a difference of more than 15 days between applications. We calculate the confidence by temporal stability and the statistical agreement. Results: For the WHOQoL-B, an a and ICC= 0.880, and r = 0.785 were obtained in the total rating; for their dimensions the result for a was > 0.740, and r > 0.590. The total rating of SATO shows an a and ICC= 0.708, and r = 0.552; for their dimensions, the a was > 0.710, and r from 0.295 to 0.508. Conclusions: The electronic tests WHOQoL and SATO can be used for remote application, although SATO is less consistent.

Tick extracellular vesicles impair epidermal homeostasis through immune-epithelial networks during hematophagy.

Hematophagous ectoparasites, such as ticks, rely on impaired wound healing for skin attachment and blood feeding. Wound healing has been extensively studied through the lens of inflammatory disorders and cancer, but limited attention has been given to arthropod-borne diseases. Here, we used orthogonal approaches combining single-cell RNA sequencing (scRNAseq), flow cytometry, murine genetics, and intravital microscopy to demonstrate how tick extracellular vesicles (EVs) disrupt networks involved in tissue repair. Impairment of EVs through silencing of the SNARE protein vamp33 negatively impacted ectoparasite feeding and survival in three medically relevant tick species, including Ixodes scapularis. Furthermore, I. scapularis EVs affected epidermal γδ T cell frequencies and co-receptor expression, which are essential for keratinocyte function. ScRNAseq analysis of the skin epidermis in wildtype animals exposed to vamp33-deficient ticks revealed a unique cluster of keratinocytes with an overrepresentation of pathways connected to wound healing. This biological circuit was further implicated in arthropod fitness when tick EVs inhibited epithelial proliferation through the disruption of phosphoinositide 3-kinase activity and keratinocyte growth factor levels. Collectively, we uncovered a tick-targeted impairment of tissue repair via the resident γδ T cell-keratinocyte axis, which contributes to ectoparasite feeding.

Predictors of Mortality in Patients with Infections Due to Carbapenem-Resistant Gram-Negative Bacteria.

INTRODUCTION: Infections caused by carbapenem-resistant Gram-negative bacteria (CR-GNB) are a significant cause of mortality and represent a serious challenge to health systems. The early identification of mortality predictors could guide appropriate treatment and follow-up. We aimed to identify the factors associated with 90-day all-cause mortality in patients with CR-GNB infections. METHODS: We conducted a cohort study from 1 January 2019 to 30 April 2022. The primary outcome was death from any cause during the first 90 days after the date of the first CR-GNB-positive culture. Secondary outcomes included infection relapse, invasive mechanical ventilation during follow-up, need for additional source control, acute kidney injury, Clostridioides difficile infection, and all-cause hospital admission after initial discharge. Bivariate and multivariate Cox-proportional hazards models were constructed to identify the factors independently associated with 90-day all-cause mortality. RESULTS: A total of 225 patients with CR-GNB infections were included. Death occurred in 76 (34%) cases. The most-reported comorbidities were immunosuppression (43%), arterial hypertension (35%), and COVID-19 (25%). The median length of stay in survivors was 18 days (IQR 10-34). Mechanical ventilation and ICU admission after diagnosis occurred in 8% and 11% of cases, respectively. Both infection relapse and rehospitalisation occurred in 18% of cases. C. difficile infection was diagnosed in 4% of cases. Acute kidney injury was documented in 22% of patients. Mechanical ventilation after diagnosis, ICU admission after diagnosis, and acute kidney injury in the first ten days of appropriate treatment were more frequently reported among non-survivors. In the multivariate analysis, age (HR 1.19 (95%CI 1.00-1.83)), immunosuppression (HR 1.84 (95%CI 1.06-3.18)), and septic shock at diagnosis (HR 2.40 (95% 1.41-4.08)) had an independent association with death during the first 90 days after the CR-GNB infection diagnosis. Receiving antibiogram-guided appropriate treatment was independently associated with a lower risk of death (HR 0.25 (95%CI 0.14-0.46)). CONCLUSIONS: The presence of advanced age, immunosuppression, septic shock at diagnosis, and inappropriate treatment are associated with higher 90-day all-cause mortality in hospitalised patients with infections due to CR-GNB. Recognition of the risk factors for adverse outcomes could further assist in patient care and the design of interventional studies that address the severe and widespread problem that is carbapenem resistance.

Fungal Infections in the ICU during the COVID-19 Pandemic in Mexico.

Background: Invasive Fungal Infections (IFI) are emergent complications of COVID-19. In this study, we aim to describe the prevalence, related factors, and outcomes of IFI in critical COVID-19 patients. Methods: We conducted a nested case-control study of all COVID-19 patients in the intensive care unit (ICU) who developed any IFI and matched age and sex controls for comparison (1:1) to evaluate IFI-related factors. Descriptive and comparative analyses were made, and the risk factors for IFI were compared versus controls. Results: We found an overall IFI prevalence of 9.3% in COVID-19 patients in the ICU, 5.6% in COVID-19-associated pulmonary aspergillosis (CAPA), and 2.5% in invasive candidiasis (IC). IFI patients had higher SOFA scores, increased frequency of vasopressor use, myocardial injury, and more empirical antibiotic use. CAPA was classified as possible in 68% and 32% as probable by ECMM/ISHAM consensus criteria, and 57.5% of mortality was found. Candidemia was more frequent for C. parapsilosis Fluconazole resistant outbreak early in the pandemic, with a mortality of 28%. Factors related to IFI in multivariable analysis were SOFA score > 2 (aOR 5.1, 95% CI 1.5-16.8, p = 0.007) and empiric antibiotics for COVID-19 (aOR 30, 95% CI 10.2-87.6, p = <0.01). Conclusions: We found a 9.3% prevalence of IFIs in critically ill patients with COVID-19 in a single center in Mexico; factors related to IFI were associated with higher SOFA scores and empiric antibiotic use for COVID-19. CAPA is the most frequent type of IFI. We did not find a mortality difference.

Aquatic macroinvertebrate assemblages in rivers influenced by mining activities.

Mining is one of the major pollution sources worldwide, causing huge disturbances to the environment. Industrial and artisanal mining activities are widespread in Mexico, a major global producer of various metals. This study aimed to assess the ecological impairments resulting from mining activities using aquatic macroinvertebrates assemblages (MA). A multiple co-inertia analysis was applied to determine the relationships between environmental factors, habitat quality, heavy metals, and aquatic macroinvertebrates in 15 study sites in two different seasons (dry and wet) along two rivers running across the Central Plateau of Mexico. The results revealed three contrasting environmental conditions associated with different MAs. High concentrations of heavy metals, nutrients, and salinity limit the presence of several families of seemingly sensitive macroinvertebrates. These factors were found to influence structural changes in MAs, showing that not only mining activities, but also agriculture and presence of villages in the basin, exert adverse effects on macroinvertebrate assemblages. Diversity indices showed that the lowest diversity matched both the most polluted and the most saline rivers. The rivers studied displayed high alkalinity and hardness levels, which can reduce the availability of metals and cause adverse effects on periphyton by inhibiting photosynthesis and damaging MAs. Aquatic biomonitoring in rivers, impacted by mining and other human activities, is critical for detecting the effect of metals and other pollutants to improve management and conservation strategies. This study supports the design of cost-effective and accurate water quality biomonitoring protocols in developing countries.

Outbreak of NDM-1-Producing Escherichia coli in a Coronavirus Disease 2019 Intensive Care Unit in a Mexican Tertiary Care Center.

Emergency department areas were repurposed as intensive care units (ICUs) for patients with acute respiratory distress syndrome during the initial months of the coronavirus disease 2019 (COVID-19) pandemic. We describe an outbreak of New Delhi metallo-ß-lactamase 1 (NDM-1)-producing Escherichia coli infections in critically ill COVID-19 patients admitted to one of the repurposed units. Seven patients developed infections (6 ventilator-associated pneumonia [VAP] and 1 urinary tract infection [UTI]) due to carbapenem-resistant E. coli, and only two survived. Five of the affected patients and four additional patients had rectal carriage of carbapenem-resistant E. coli. The E. coli strain from the affected patients corresponded to a single sequence type. Rectal screening identified isolates of two other sequence types bearing blaNDM-1. Isolates of all three sequence types harbored an IncFII plasmid. The plasmid was confirmed to carry blaNDM-1 through conjugation. An outbreak of clonal NDM-1-producing E. coli isolates and subsequent dissemination of NDM-1 through mobile elements to other E. coli strains occurred after hospital conversion during the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. This emphasizes the need for infection control practices in surge scenarios. IMPORTANCE The SARS-CoV-2 pandemic has resulted in a surge of critically ill patients. Hospitals have had to adapt to the demand by repurposing areas as intensive care units. This has resulted in high workload and disruption of usual hospital workflows. Surge capacity guidelines and pandemic response plans do not contemplate how to limit collateral damage from issues like hospital-acquired infections. It is vital to ensure quality of care in surge scenarios.

Tracheal Aspirate Galactomannan Testing in COVID-19-Associated Pulmonary Aspergillosis.

Among critically ill patients, COVID-19-associated pulmonary aspergillosis (CAPA) is a challenging complication. The recommended diagnostic methods for this disease are bronchoalveolar lavage (BAL) culture and galactomannan (GM) testing, which were not widely available during the pandemic. There is scarce information regarding GM testing in other respiratory specimens. Our objective was to compare the agreement of GM between BAL and tracheal aspirate (TA) samples. We selected patients with COVID-19 and those with suspected CAPA who were admitted in the intensive care unit (ICU). GM was routinely done in BAL. We performed GM in TA samples and compared the results. The agreement was evaluated with Cohen's Kappa coefficient. GM was considered positive when an OD index ≥ 1 in BAL and ≥ 2 in TA were found. Probable CAPA was considered when the ECMM/ISHAM criteria were met. A descriptive analysis of clinical characteristics and mortality was made. We included 20 patients with suspected CAPA from 54 patients with critical COVID-19, of which 5 (9%) met the probable category. Aspergillus fumigatus was the most frequent isolate. We found moderate agreement between BAL and TA GM (Kappa = 0.47, p = 0.01, 95% CI.04-0.9), whereas TA GM had 75% sensitivity (95% CI 19.4-99.4%), 81.2% specificity (95% CI 54.4-95.9%), 50% positive predictive value (95% CI 23.8-76.3%),] and 92.8% negative predictive value (95% CI 70.1-98.6%), and 80% accuracy (95% CI 56.3-94.3%). Lastly, three (60%) patients with CAPA died during hospitalization compared to 40% (6/15) without CAPA (p = 0.4). In conclusion, a moderate agreement between TA GM and BAL was found. Therefore, TA testing may aid in ruling out CAPA due to high negative predictive value when bronchoscopies are unavailable.

daf-16/FOXO blocks adult cell fate in Caenorhabditis elegans dauer larvae via lin-41/TRIM71.

Many tissue-specific stem cells maintain the ability to produce multiple cell types during long periods of non-division, or quiescence. FOXO transcription factors promote quiescence and stem cell maintenance, but the mechanisms by which FOXO proteins promote multipotency during quiescence are still emerging. The single FOXO ortholog in C. elegans, daf-16, promotes entry into a quiescent and stress-resistant larval stage called dauer in response to adverse environmental cues. During dauer, stem and progenitor cells maintain or re-establish multipotency to allow normal development to resume after dauer. We find that during dauer, daf-16/FOXO prevents epidermal stem cells (seam cells) from prematurely adopting differentiated, adult characteristics. In particular, dauer larvae that lack daf-16 misexpress collagens that are normally adult-enriched. Using col-19p::gfp as an adult cell fate marker, we find that all major daf-16 isoforms contribute to opposing col-19p::gfp expression during dauer. By contrast, daf-16(0) larvae that undergo non-dauer development do not misexpress col-19p::gfp. Adult cell fate and the timing of col-19p::gfp expression are regulated by the heterochronic gene network, including lin-41 and lin-29. lin-41 encodes an RNA-binding protein orthologous to LIN41/TRIM71 in mammals, and lin-29 encodes a conserved zinc finger transcription factor. In non-dauer development, lin-41 opposes adult cell fate by inhibiting the translation of lin-29, which directly activates col-19 transcription and promotes adult cell fate. We find that during dauer, lin-41 blocks col-19p::gfp expression, but surprisingly, lin-29 is not required in this context. Additionally, daf-16 promotes the expression of lin-41 in dauer larvae. The col-19p::gfp misexpression phenotype observed in dauer larvae with reduced daf-16 requires the downregulation of lin-41, but does not require lin-29. Taken together, this work demonstrates a novel role for daf-16/FOXO as a heterochronic gene that promotes expression of lin-41/TRIM71 to contribute to multipotent cell fate in a quiescent stem cell model.

Skin-resident immune cells actively coordinate their distribution with epidermal cells during homeostasis.

Organs consist of multiple cell types that ensure proper architecture and function. How different cell types coexist and interact to maintain their homeostasis in vivo remains elusive. The skin epidermis comprises mostly epithelial cells, but also harbours Langerhans cells (LCs) and dendritic epidermal T cells (DETCs). Whether and how distributions of LCs and DETCs are regulated during homeostasis is unclear. Here, by tracking individual cells in the skin of live adult mice over time, we show that LCs and DETCs actively maintain a non-random spatial distribution despite continuous turnover of neighbouring basal epithelial cells. Moreover, the density of epithelial cells regulates the composition of LCs and DETCs in the epidermis. Finally, LCs require the GTPase Rac1 to maintain their positional stability, density and tiling pattern reminiscent of neuronal self-avoidance. We propose that these cellular mechanisms provide the epidermis with an optimal response to environmental insults.

Diagnostic accuracy of antigen detection in urine and molecular assays testing in different clinical samples for the diagnosis of progressive disseminated histoplasmosis in patients living with HIV/AIDS: A prospective multicenter study in Mexico.

BACKGROUND: The progressive disseminated histoplasmosis (PDH) has been associated with severe disease and high risk of death among people living with HIV (PLWHIV). Therefore, the purpose of this multicenter, prospective, double-blinded study done in ten Mexican hospitals was to determine the diagnostic accuracy of detecting Histoplasma capsulatum antigen in urine using the IMMY ALPHA Histoplasma EIA kit (IAHE), clarus Histoplasma GM Enzyme Immunoassay (cHGEI IMMY) and MiraVista Histoplasma Urine Antigen LFA (MVHUALFA); as well as the Hcp100 and 1281-1283220SCAR nested PCRs in blood, bone-marrow, tissue biopsies and urine. METHODOLOGY/PRINCIPAL FINDINGS: We included 415 PLWHIV older than 18 years of age with suspicion of PDH. Using as diagnostic standard recovery of H. capsulatum in blood, bone marrow or tissue cultures, or histopathological exam compatible, detected 108 patients (26%, [95%CI, 21.78-30.22]) with proven-PDH. We analyzed 391 urine samples by the IAHE, cHGEI IMMY and MVHUALFA; the sensitivity/specificity values obtained were 67.3% (95% CI, 57.4-76.2) / 96.2% (95% CI, 93.2-98.0) for IAHE, 91.3% (95% CI, 84.2-96.0) / 90.9% (95% CI, 87.0-94.0) for cHGEI IMMY and 90.4% (95% CI, 83.0-95.3) / 92.3% (95% CI, 88.6-95.1) for MVHUALFA. The Hcp100 nested PCR was performed on 393, 343, 75 and 297, blood, bone marrow, tissue and urine samples respectively; the sensitivity/specificity values obtained were 62.9% (95%CI, 53.3-72.5)/ 89.5% (95%CI, 86.0-93.0), 65.9% (95%CI, 56.0-75.8)/ 89.0% (95%CI, 85.2-92.9), 62.1% (95%CI, 44.4-79.7)/ 82.6% (95%CI, 71.7-93.6) and 34.9% (95%CI, 24.8-46.2)/ 67.3% (95%CI, 60.6-73.5) respectively; and 1281-1283220SCAR nested PCR was performed on 392, 344, 75 and 291, respectively; the sensitivity/specificity values obtained were 65.3% (95% CI, 55.9-74.7)/ 58.8% (95%CI, 53.2-64.5), 70.8% (95%CI, 61.3-80.2)/ 52.9% (95%CI, 46.8-59.1), 71.4% (95%CI, 54.7-88.2)/ 40.4% (95%CI, 26.4-54.5) and 18.1% (95%CI, 10.5-28.1)/ 90.4% (95%CI, 85.5-94.0), respectively. CONCLUSIONS/SIGNIFICANCE: The cHGEI IMMY and MVHUALFA tests showed excellent performance for the diagnosis of PDH in PLWHIV. The integration of these tests in clinical laboratories will certainly impact on early diagnosis and treatment.

Accuracy of galactomannan testing on tracheal aspirates in COVID-19-associated pulmonary aspergillosis.

OBJECTIVE: Our aim was to evaluate the performance of two galactomannan (GM) assays (Platelia Aspergillus EIA, Bio-Rad® , and Aspergillus GM LFA, IMMY® ) in tracheal aspirate (TA) samples of consecutive critically ill patients with COVID-19. METHODS: We included critically ill patients, performed GM-EIA and GM-Lateral Flow Assay (GM-LFA) in TA and followed them until development of COVID-19-associated pulmonary aspergillosis (CAPA) or alternate diagnosis. CAPA was defined according to the modified AspICU criteria in patients with SARS-CoV-2 infection. We estimated sensitivity, specificity, positive and negative predictive values for GM-EIA, GM-LFA, the combination of both or either positive results for GM-EIA and GM-LFA. We explored accuracy using different breakpoints, through ROC analysis and Youden index to identify the optimal cut-offs. We described antifungal treatment and 30-day mortality. RESULTS: We identified 14/144 (9.7%) patients with CAPA, mean age was 50.35 (SD 11.9), the median time from admission to CAPA was 8 days; 28.5% received tocilizumab and 30-day mortality was 57%. ROC analysis and Youden index identified 2.0 OD as the best cut-off, resulting in sensitivity and specificity of 57.1% and 81.5% for GM-EIA and 60% and 72.6% for GM-LFA, respectively. CONCLUSIONS: The diagnostic performance of GM in tracheal aspirates improved after using a cut-off of 2 OD. Although bronchoalveolar lavage testing is the ideal test, centres with limited access to bronchoscopy may consider this approach to identify or rule out CAPA.

Assessment of seasonal and spatial variations of biochemical markers in Corydalus sp. (Megaloptera: Corydalidae), a non-conventional biomonitor, in a mountain cloud forest in Mexico.

Rivers are critical ecosystems for protecting and harboring high biodiversity. Tropical rivers particularly are unique for facing extreme climatic events under the current accelerated disruption from human activities. The Bobos-Nautla river basin is exposed to climatic events and disturbances from anthropogenic impacts that stress aquatic organisms. We assessed the health condition of this river system using a non-conventional biomonitor, Corydalus sp., with a set of early-warning biomarkers including lipid peroxidation levels (LPO) and antioxidant activity, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and the neurotransmitter acetylcholinesterase (AChE) considering their spatial and temporal variations. Biomarkers and water quality parameters were analyzed, and the integrated biomarker response (IBR) was assessed as a stress index. Biomarkers showed no significant spatial differences; however, a high-stress period during the rainy season was detected, evidenced by the highest LPO levels; this period is related to the leaching of allochthonous materials from agricultural and urban zones. The peak IBR value during the rainy season confirmed the seasonality of biomarkers. A slight increase in IBR was recorded in lowlands, seemingly associated with agricultural land and human settlements. A principal component analysis showed nutrient enrichment during the rainy season and depletion during the cold-dry season, together with a peak activity of antioxidant enzymes. These results highlight the importance of climatic events such as the rainy season on the health condition of Corydalus sp., which is highly sensitive to the complex mixtures of pollutants that enter the waterbody during extreme climatic events, promoting oxidative stress. Our results also showed the ability of Corydalus sp. to recover and return to a basal level.

Mitochondrial activity in fern spores of Cyathea costaricensis as an indicator of the impact of land use and water quality in rivers running through cloud forests.

Early-warning biomarkers, such as mitochondrial activity, have become a key tool in ecosystem assessment. This study aims to evaluate the response of mitochondrial activity in spores of the autochthonous fern Cyathea costaricensis as a bioassessment tool concurrently with land use and physicochemical evaluation in 11 sites along Bobos River, Veracruz, Mexico, to assess river water quality. Bobos River is located in the Nautla basin, northeastern Veracruz (Mexico); the upper river runs through a protected natural area (Filobobos River and adjacent areas). The study involved three monitoring periods: February, June and September 2014. In each study site, physicochemical water quality parameters were recorded to calculate the Water Quality Index (WQI); also, study sites were characterized in terms of land use. Water samples were collected to perform bioassays where spores of C. costaricensis were exposed to samples to assess mitochondrial activity; a positive control exposure test was run under controlled conditions to maximize mitochondrial activity. A Principal Component Analysis was performed to correlate land-use attributes with environmental variables and mitochondrial activity. Three river sections were identified: the upper portion was characterized by the dominance of native vegetation, the highest WQI (in September), and the lowest mitochondrial activity (63.87%-77.47%), related to the geological nature of the basin and high hardness levels. Mitochondrial activity peaked in September (98.32% ± 9.01), likely resulting from nutrient enrichment in the rainy season, and was lowest in February (74.54% ± 1.60) (p < 0.05). Mitochondrial activity was found to be a good benchmark for the assessment of water quality, reflecting the effects of physicochemical characteristics. Mitochondrial activity showed changes along the river and between seasons, associated with environmental characteristics such as land use and the geological nature of the basin, as well as with those related to human impacts.

Trends of Mycobacterium bovis Isolation and First-Line Anti-tuberculosis Drug Susceptibility Profile: A Fifteen-Year Laboratory-Based Surveillance.

BACKGROUND: Mycobacterium tuberculosis causes the majority of tuberculosis (TB) cases in humans; however, in developing countries, human TB caused by M. bovis may be frequent but undetected. Human TB caused by M. bovis is considered a zoonosis; transmission is mainly through consumption of unpasteurized dairy products, and it is less frequently attributed to animal-to-human or human-to-human contact. We describe the trends of M. bovis isolation from human samples and first-line drug susceptibility during a 15-year period in a referral laboratory located in a tertiary care hospital in Mexico City. METHODOLOGY/PRINCIPAL FINDINGS: Data on mycobacterial isolates from human clinical samples were retrieved from the laboratory's database for the 2000-2014 period. Susceptibility to first-line drugs: rifampin, isoniazid, streptomycin (STR) and ethambutol was determined. We identified 1,165 isolates, 73.7% were M. tuberculosis and 26.2%, M. bovis. Among pulmonary samples, 16.6% were M. bovis. The proportion of M. bovis isolates significantly increased from 7.8% in 2000 to 28.4% in 2014 (X(2)trend, p<0.001). Primary STR resistance was higher among M. bovis compared with M. tuberculosis isolates (10.9% vs.3.4%, p<0.001). Secondary multidrug resistance (MDR) rates were 38.5% and 34.4% for M. bovis and M. tuberculosis, respectively (p = 0.637). A rising trend of primary STR monoresistance was observed for both species (3.4% in 2000-2004 vs. 7.6% in 2010-2014; p = 0.02). CONCLUSIONS/SIGNIFICANCE: There is a high prevalence and a rising trend of M. bovis isolates in our region. The proportion of pulmonary M. bovis isolates is higher than in previous reports. Additionally, we report high rates of primary anti-tuberculosis resistance and secondary MDR in both M. tuberculosis and M. bovis. This is one of the largest reports on drug susceptibility of M. bovis from human samples and shows a significant proportion of first-line anti-tuberculosis drug resistance.

[Spatial and temporal variation patterns in aquatic macroinvertebrates of Tecocomulco Lake, Hidalgo (México)]. / Patrones de variación espacial y temporal de los macroinvertebrados acuáticos en la Laguna de Tecocomulco, Hidalgo (México).

Lake Tecocomulco, Hidalgo, is a relic of the ancient lakes ofAnahuac, important for the conservation of resident and migratory birds. However, the composition of aquatic macroinvertebrates is unknown; this is an important gap in conservation as they play an important role in the food web. This study analyzed the spatial and temporal variations in macroinvertebrate assemblages and their relationship with habitat characteristics. We carried out four monitoring campaigns covering the rainy and dry seasons. The monitoring was conducted at six study sites (four in the littoral zone and two in the middle part of the lake), environmental factors were recorded at each study site, water samples were collected for their physical and chemical analysis and aquatic macroinvertebrates were collected. A principal component analysis (PCA) was used to group study sites based on physical and chemical characteristics. Richness of taxa was analysed with rarefaction. We assessed the importance value index of each taxon (considering their frequency of occurrence and abundance). Similarity analyzes were performed between study sites and similarity of taxa with indices of Jaccard and Bray-Curtis, respectively. We performed a canonical correspondence analysis (CCA) between environmental factors and macroinvertebrate taxa. The PCA showed a marked seasonal variation represented by warm periods, with high values of conductivity, alkalinity, hardness, sulfates, and macronutrients (N and P) and the cold period with low values. We found a total of 26 taxa of aquatic macroinvertebrates and the highest richness was found in August. The Jaccard similarity analysis found differences between the littoral area and the limnetic zone, which differ also in the composition of macrophytes. The littoral zone had the highest taxa richness of macroinvertebrates and macrophytes, while the lowest diversity was found in the offshore zone. The CCA related physicochemical characteristics of the water body with macroinvertebrate taxa showing the influence of both physicochemical characteristics and the composition of macrophytes in the spatio-temporal patterns of aquatic macroinvertebrates in the lake. The dominance of Corixidae highlights a strong grazing activity in the lake and in turn suggests an important amount of food available for higher trophic levels. Our study shows that the macroinvertebrates of Tecocomulco Lake have spatial and seasonal variations that are related to both environmental and biotic factors with groups being dominant.

Patrones de variación espacial y temporal de los macroinvertebrados acuáticos en la Laguna de Tecocomulco, Hidalgo (México)

Spatial and temporal variation patterns in aquatic macroinvertebrates of Tecocomulco Lake, Hidalgo (México). Lake Tecocomulco, Hidalgo, is a relic of the ancient lakes of Anahuac, important for the conservation of resident and migratory birds. However, the composition of aquatic macroinvertebrates is unknown; this is an important gap in conservation as they play an important role in the food web. This study analyzed the spatial and temporal variations in macroinvertebrate assemblages and their relationship with habitat characteristics. We carried out four monitoring campaigns covering the rainy and dry seasons. The monitoring was conducted at six study sites (four in the littoral zone and two in the middle part of the lake), environmental factors were recorded at each study site, water samples were collected for their physical and chemical analysis and aquatic macroinvertebrates were collected. A principal component analysis (PCA) was used to group study sites based on physical and chemical characteristics. Richness of taxa was analysed with rarefaction. We assessed the importance value index of each taxon (considering their frequency of occurrence and abundance). Similarity analyzes were performed between study sites and similarity of taxa with indices of Jaccard and Bray-Curtis, respectively. We performed a canonical correspondence analysis (CCA) between environmental factors and macroinvertebrate taxa. The PCA showed a marked seasonal variation represented by warm periods, with high values of conductivity, alkalinity, hardness, sulfates, and macronutrients (N and P) and the cold period with low values. We found a total of 26 taxa of aquatic macroinvertebrates and the highest richness was found in August. The Jaccard similarity analysis found differences between the littoral area and the limnetic zone, which differ also in the composition of macrophytes. The littoral zone had the highest taxa richness of macroinvertebrates and macrophytes, while the lowest diversity was found in the offshore zone. The CCA related physicochemical characteristics of the water body with macroinvertebrate taxa showing the influence of both physicochemical characteristics and the composition of macrophytes in the spatio-temporal patterns of aquatic macroinvertebrates in the lake. The dominance of Corixidae highlights a strong grazing activity in the lake and in turn suggests an important amount of food available for higher trophic levels. Our study shows that the macroinvertebrates of Tecocomulco Lake have spatial and seasonal variations that are related to both environmental and biotic factors with groups being dominant. Rev. Biol. Trop. 62 (Suppl. 2): 81-96. Epub 2014 April 01.

La Laguna de Tecocomulco (Hidalgo) es un relicto de los antiguos Lagos del Anáhuac con suma importancia para la conservación de aves acuáticas. No obstante, se desconoce su composición de macroinvertebrados. En el presente estudio se analizaron las variaciones espaciales y temporales de los macroinvertebrados acuáticos de la laguna. Se realizaron cuatro campañas de monitoreo (lluvias y estiaje). Se estudiaron seis sitios (litorales y en interior de la laguna), se registraron factores ambientales, se determinaron parámetros de calidad del agua y se recolectaron macroinvertebrados acuáticos. Se obtuvo la riqueza de familias y se calculó su Índice de Valor de Importancia. Se realizaron análisis multivariados de ordenación por componentes principales (ACP) con base en sus características físicas y químicas y de similitud entre sitios y familias con los índices de Jaccard y Bray-Curtis. Tambien se hizo un análisis de correspondencias canónicas (ACC) de factores ambientales y macroinvertebrados acuáticos y macrófitas. El ACP mostró la variación estacional, con el período cálido (mayo y agosto) y el periodo frío (noviembre y enero) mostrando altos valores de conductividad, alcalinidad, dureza, sulfatos y macronutrientes (N y P). Se encontraron 26 familias de macroinvertebrados, con la máxima riqueza en agosto. El análisis de similitud de Jaccard diferenció los sitios litorales por su mayor riqueza de familias de la zona limnética, mismos que presentan diferencias en la composición de macrófitas. El estudio revela que la Laguna de Tecocomulco tiene variaciones espaciales y temporales relacionadas tanto con factores ambientales como bióticos con la presencia de grupos dominantes. En ese sentido, y considerando su diversidad de macroinvertebrados, la Laguna de Tecocomulco debe ser sujeta a un plan de conservación y manejo.

WhiB5, a transcriptional regulator that contributes to Mycobacterium tuberculosis virulence and reactivation.

The proteins belonging to the WhiB superfamily are small global transcriptional regulators typical of actinomycetes. In this paper, we characterize the role of WhiB5, a Mycobacterium tuberculosis protein belonging to this superfamily. A null mutant was constructed in M. tuberculosis H37Rv and was shown to be attenuated during both progressive and chronic mouse infections. Mice infected with the mutant had smaller bacillary burdens in the lungs but a larger inflammatory response, suggesting a role of WhiB5 in immunomodulation. Most interestingly, the whiB5 mutant was not able to resume growth after reactivation from chronic infection, suggesting that WhiB5 controls the expression of genes involved in this process. The mutant was also more sensitive than the wild-type parental strain to S-nitrosoglutathione (GSNO) and was less metabolically active following prolonged starvation, underscoring the importance of GSNO and starvation in development and maintenance of chronic infection. DNA microarray analysis identified 58 genes whose expression is influenced by WhiB5, including sigM, encoding an alternative sigma factor, and genes encoding the constituents of two type VII secretion systems, namely, ESX-2 and ESX-4.

DNA fingerprinting of Vibrio cholerae and Aeromonas species by pulsed-field minigel electrophoresis.

DNA molecules of Vibrio cholerae and Aeromonas species were prepared by incubating immobilized cells for 4 and 2 h, respectively, with a nonenzymatic solution that contains chemical reagents only (NDSUPlus). This method gave results as reproducible as the enzymatic one that uses proteinase K, and rendered DNA molecules suitable for fingerprinting by mini-CHEF electrophoresis. As rapid DNA separations at high electric field are achieved in mini-CHEF chamber with low heat evolution, DNA restriction fragments were separated in 5 h at 10 V/cm in a single resolution window. Then, fragment separations in three resolution windows were done in 15 h. This time is shorter than the one needed by the large CHEF chamber for resolving fragments in a single resolution window. Three windows permitted to include larger numbers of restriction fragments in the calculation of isolate similarities. Both sample preparation and mini-CHEF electrophoresis may represent an alternative for performing massive epidemiological studies of V. cholerae and Aeromonas species.