Carmen Elena Castillo

Dr. Carmen Elena Castillo

orcid

Research Focus & Metrics

Academic Career Length

17Years (2010-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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14 December 2010 in Clinical Chemistry and Laboratory Medicine (CCLM)
Verified
Journal Article
Open access
ÁCÁngela Casado
Ángela Casado
MCManuel Angeles Castellanos
Manuel Angeles Castellanos
MLMa Encarnación López-Fernández
Ma Encarnación López-Fernández
RRRocío Ruiz
Rocío Ruiz
EIEulalia López Imedio
Eulalia López Imedio
AFAna María Fernández-Nieto
Ana María Fernández-Nieto
Background: In previous work, we demonstrated that some occupational workers in stressful conditions can have increases in several markers of oxidative stress when compared to other workers. We investigated two antioxidant enzymes, superoxide dismutase (SOD) and catalase (CAT) activities, and malondialdehyde (MDA) concentrations, according to demographics, lifestyle and occupational parameters in palliative care unit workers, and analyzed the relationship with occupational burnout. Methods: Fifty-two palliative care unit workers and 50 gender- and aged matched healthy individuals as controls were surveyed. Spectrophotometric and high-pressure liquid chromatography methods were used for biochemical determinations. Results: No significant variation with respect to gender were detected with respect to SOD and CAT activities, MDA concentrations or occupational burnout. MDA concentrations increased with age in controls and palliative care unit workers, and we observed significant differences in MDA between controls and palliative care unit workers for all age groups. Significant variation in MDA concentrations were detected between unmarried (287.22±8.31 nmol/mg hemoglobin) and married individuals (317.18±6.24 nmol/mg hemoglobin), but not with respect to divorced individuals (288.41±5.64 nmol/mg hemoglobin). Significant differences were detected between smokers and non-smokers for SOD, CAT and MDA, but not for alcohol, coffee, tea or cola consumption. Significant differences were seen in MDA concentrations between those who frequently practice some kind of sport (280.59±7.62 nmol/mg hemoglobin) and those who never practice any kind of sport (299.12±8.09 nmol/mg hemoglobin), and between those who frequently ate fruit and greens (291.05±8.11 nmol/mg hemoglobin) and those who never eat fruit and greens (316.31±7.42 nmol/mg hemoglobin). SOD activity and MDA concentrations are higher in palliative care workers who work the evening and night shifts (p<0.01), and these workers also show significantly higher levels of stress. Conclusions: Our findings suggest that oxidative stress, occupational stress and occupational burnout levels are similar in men and women. Occupational stress increases oxidative stress levels probably as a response to increased generation of reactive oxygen species. Working during the evening and night shifts increases oxidative levels and burnout levels.

30 March 2024 in IJID Regions
Verified
Journal Article
Open access
MCMark A. Caudell
Mark A. Caudell
Carmen Elena CastilloCarmen Elena Castillo
Carmen Elena Castillo
LSLucas F. Santos
Lucas F. Santos
Laura GrajedaLaura Grajeda
Laura Grajeda
JRJuan Carlos Romero
Juan Carlos Romero
BRBrooke M. Ramay
Brooke M. Ramay
Objectives: The spread of extended-spectrum cephalosporin-resistant Enterobacterales (ESCrE) and carbapenemresistant Enterobacterales (CRE) has resulted in increased morbidity, mortality, and health care costs worldwide. To identify the factors associated with ESCrE and CRE colonization within hospitals, we enrolled hospitalized patients at a regional hospital located in Guatemala. Methods: Stool samples were collected from randomly selected patients using a cross-sectional study design (March-September, 2021), and samples were tested for the presence of ESCrE and CRE. Hospital-based and household variables were examined for associations with ESCrE and CRE colonization using lasso regression models, clustered by ward (n = 21). Results: A total of 641 patients were enrolled, of whom complete data sets were available for 593. Colonization with ESCrE (72.3%, n = 429/593) was negatively associated with carbapenem administration (odds ratio [OR] 0.21, 95% confidence interval [CI] 0.11-0.42) and positively associated with ceftriaxone administration (OR 1.61, 95% CI 1.02-2.53), as was reported hospital admission within 30 days of the current hospitalization (OR 2.84, 95% CI 1.19-6.80). Colonization with CRE (34.6%, n = 205 of 593) was associated with carbapenem administration (OR 2.62, 95% CI 1.39-4.97), reported previous hospital admission within 30 days of current hospitalization (OR 2.58, 95% CI 1.17-5.72), hospitalization in wards with more patients (OR 1.05, 95% CI 1.02-1.08), hospitalization for >= 4 days (OR 3.07, 95% CI 1.72-5.46), and intubation (OR 2.51, 95% CI 1.13-5.59). No household-based variables were associated with ESCrE or CRE colonization in hospitalized patients. Conclusion: The hospital-based risk factors identified in this study are similar to what has been reported for risk of health care-associated infections, consistent with colonization being driven by hospital settings rather than community factors. This also suggests that colonization with ESCrE and CRE could be a useful metric to evaluate the efficacy of infection and prevention control programs in clinics and hospitals.

1 September 2025 in Journal of Water and Health
Verified
Journal Article
Open access
BRBrooke M. Ramay
Brooke M. Ramay
Carmen Elena CastilloCarmen Elena Castillo
Carmen Elena Castillo
PGPaulina Garzaro
Paulina Garzaro
Natalie FahsenNatalie Fahsen
Natalie Fahsen
LSLucas Santos
Lucas Santos
MCMark A. Caudell
Mark A. Caudell
Access to safe drinking water remains a major public health challenge in low- and middle-income countries (LMICs), with 4.4 billion people lacking safely managed sources. Contaminated water contributes to infectious diseases and antimicrobial resistance, increasing morbidity and mortality. While interventions guided by the WHO/UNICEF Joint Monitoring Programme (JMP) aim to improve water access, sociocultural factors influencing water use are likely to play a critical role in developing effective interventions. To assess how sociocultural factors can inform water safety interventions, this study combines cultural consensus analysis of drinking water quality with microbiological assessments of water quality in 30 urban and 30 rural households in Quetzaltenango. Water samples were tested for coliforms, Escherichia coli, and antimicrobial-resistant Enterobacterales. Participants ranked bottled water as the safest source, yet laboratory analysis revealed bottled water had the highest coliform contamination (83.3%). Piped household water, another highly ranked source, exhibited high E. coli contamination (27.8%), presence of extended-spectrum beta-lactamase (ESBL) Enterobacterales (11.1%), and presence of carbapenem-resistant Enterobacterales (11.1%). While JMP guidelines are essential for water safety assessments, sociocultural perceptions play a crucial role in shaping water consumption behaviors. Integrating ethnographic methods with water quality assessments can lead to the design of more nuanced water safety interventions.

29 May 2025 in Scientific Reports
Verified
Journal Article
Open access
PDF file
BRBrooke M. Ramay
Brooke M. Ramay
MCMark A. Caudell
Mark A. Caudell
Carmen Elena CastilloCarmen Elena Castillo
Carmen Elena Castillo
LGLaura Grajeda
Laura Grajeda
LSLucas F. Santos
Lucas F. Santos
DCDouglas R. Call
Douglas R. Call
Colonization with extended-spectrum cephalosporin-resistant Enterobacterales (ESCrE) in communities may contribute to proliferation of resistance genes and drug-resistant community and hospital infections. Previous work in the Western Highlands of Guatemala found that approximately 46% of the population is colonized with these bacteria, setting the stage to identify factors that are associated with increased odds of ESCrE colonization. Stool samples and questionnaire data were collected from randomly selected participants in the catchment area of the third largest tertiary hospital in Guatemala. Logistic regression path analysis was used for this cross-sectional study to identify potential direct and indirect risk factors for colonization with ESCrE. Participants (N = 951) had a higher odds of ESCrE colonization if they had exposure to a healthcare facility within 30 days of enrollment (OR: 2.12, 95% CI = 1.19–3.77), if they resided in urban areas (OR: 1.93, 95% CI 1.09–3.42), if they did not have a service to remove household trash (OR: 1.99, 95% CI 1.11–3.58), and if the household reported drinking water from non-bottled sources (OR:1.53, 95% CI 1.0–2.33). Antibiotic self-medication was not significantly associated with the risk of colonization (OR: 1.16, 95% CI 0.65–2.06). Multiple transmission-related factors were associated with increased likelihood of ESCrE colonization, but the cross-sectional nature of this study does not distinguish factors that are correlated with an individual’s risk for colonization whence exposed. Assessing risk factors associated with colonization with antibiotic resistant bacteria may be useful for identifying mitigation strategies and evaluating the effectiveness of interventions against antibiotic resistance in community settings.

Verified
Journal Article
Open access
PDF file
PGPaulina Garzaro
Paulina Garzaro
Carmen Elena CastilloCarmen Elena Castillo
Carmen Elena Castillo
Natalie FahsenNatalie Fahsen
Natalie Fahsen
LSLucas Santos
Lucas Santos
JLJoyce Lu
Joyce Lu
BRBrooke M. Ramay
Brooke M. Ramay
Introduction: Healthcare-associated infections are a significant public health challenge, particularly in resource-limited settings. While hand hygiene is critical for infection prevention, contaminated water from hand hygiene stations (HHSs) in healthcare facilities (HCFs) may undermine infection control efforts. Chlorination can reduce microbial contamination in HHSs, ensuring that water intended for hygiene does not become an infection source. Methods: Water quality was monitored before and after the installation of on-site chlorine dispensers (CDs) in water tanks and HHSs of HCFs in Quetzaltenango, Guatemala, to evaluate their effectiveness in improving water quality. Focus groups were conducted to develop action plan proposals to ensure the intervention’s sustainability. Results: Before the intervention, 75% of HHS water samples tested positive for total coliforms, with 50% testing positive for presumptive extended-spectrum beta-lactamase (ESBL)-producing total coliforms, while 20% were E. coli-positive, with 50% presumptive ESBL-producing E. coli. After installing CD, 1% of samples were coliform-positive over a six-month period. Focus groups identified resource limitations and political barriers and proposed solutions such as developing operational manuals, strengthening inter-institutional relationships, and forming alliances with external organizations. Conclusion: Localized chlorination was successfully implemented using a community participatory approach to improve water quality in resource-limited HCFs. These findings have important implications for infection prevention and control.

13 October 2025 in Vaccine
Verified
Journal Article
Open access
BRBrooke M. Ramay
Brooke M. Ramay
JYJonathan Yoder
Jonathan Yoder
Carmen Elena CastilloCarmen Elena Castillo
Carmen Elena Castillo
Natalie FahsenNatalie Fahsen
Natalie Fahsen
LGLaura Grajeda
Laura Grajeda
DCDouglas R. Call
Douglas R. Call
We aimed to determine if vaccination against rotavirus (RV) or pneumococcus (PCV13) is associated with reduced colonization with extended-spectrum cephalosporin-resistant Enterobacterales (ESCrE) in children (<15 years) living in Guatemala. Questionnaire information, vaccine records, and stool samples were collected from enrolled participants. Specimens were plated onto selective media with antibiotic susceptibility confirmed using a VITEK®2. We employed an instrumental variables approach with maximum likelihood for a system of three nested probit regression equations for binary outcomes of RV or PCV13 vaccination, diarrhea or clinic visits, and ESCrE colonization. Participants (n = 406) ranged from 0 to 14 years old, 123 (30.3 %) were 0-2 years old, 103 (25.4 %) were 3-5 years old, and 180 (44.3 %) were 6-14 years old. PCV13 vaccination had indirect negative effects on ESCrE colonization (-0.092, P < 0.01) mediated through clinic visits (-0.461, P < 0.01), while antibiotic use had a direct positive effect on clinic visits (0.226, P < 0.01), but no significant effects on ESCrE colonization. Effects of RV on ESCrE colonization were inconclusive likely due to the limited sample size of RV-unvaccinated children. Protective effects of yogurt consumption on ESCrE colonization (-0.064, P < 0.01; -0.062, P < 0.01) and positive direct effects of land used for agriculture (0.232, P < 0.01; 0.224, P 〈001) were detected in both RV and PCV13 models, respectively. Report of diarrhea in the past 30 days had a direct positive effect on colonization (0.731, P < 0.01) in the RV model, and indirect positive effects on ESCrE colonization (0.090, P < 0.01) in the PCV13 model. Vaccination for pneumococcal disease was associated with a reduction in colonization with ESCrE bacteria. Antibiotic use did not contribute directly or indirectly to ESCrE colonization. These findings should be confirmed through studies designed to collect clinical outcomes data. Findings from this and other studies suggest that ESCrE colonization is mediated by a complex interplay of factors.