Liliana Nicolás-Sayago

Mr. Liliana Nicolás-Sayago


Research Focus & Metrics

Academic Career Length

4Years (2023-Present)

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

Representative Publications

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5 November 2025 in Pathogens
Verified
Journal Article
Open access
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LNLiliana Nicolás-Sayago
Liliana Nicolás-Sayago
Clemente Cruz-CruzClemente Cruz-Cruz
Clemente Cruz-Cruz
EDEMILIO MARIANO MANUEL DURAN
EMILIO MARIANO MANUEL DURAN
GRACIELA CASTRO-ESCARPULLIGRACIELA CASTRO-ESCARPULLI
GRACIELA CASTRO-ESCARPULLI
MOMA GUADALUPE ORTIZ
MA GUADALUPE ORTIZ
Juan Manuel Bello-LópezJuan Manuel Bello-López
Juan Manuel Bello-López
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.

25 July 2023 in Healthcare
Verified
Journal Article
Open access
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Miguel LoyolaMiguel Loyola
Miguel Loyola
FVFernández-Sánchez Verónica
Fernández-Sánchez Verónica
EDEMILIO MARIANO MANUEL DURAN
EMILIO MARIANO MANUEL DURAN
CCClaudia Calzada
Claudia Calzada
GRACIELA CASTRO-ESCARPULLIGRACIELA CASTRO-ESCARPULLI
GRACIELA CASTRO-ESCARPULLI
Juan Manuel Bello-LópezJuan Manuel Bello-López
Juan Manuel Bello-López
In Mexico, urogenital gonorrhea (UG) is one of the main sexually transmitted diseases notifiable by health systems around the world. Epidemiological data on sexually transmitted infections (STIs) in Mexico indicated that UG was “under control” until 2017. However, international epidemiological reports indicate the increase in incidence due to several factors, including an increase during the first year of the COVID-19 pandemic. These factors suggest that this phenomenon may occur in developing countries, including Mexico. Therefore, the aim of this study was to analyze national surveillance data on UG from 2003–2019 and the first year of the COVID-19 pandemic. An epidemiological study of cases and incidence of UG (2003–2020) was performed in the annual reports issued by the General Directorate Epidemiology in Mexico. Cases and incidence were classified and analyzed by year, sex, age group, and seasons (by temperature). Distribution of UG was carried out using heat maps for the whole country. Ultimately, a seasonal and correlation analysis was performed for UG cases versus temperature. The results showed that the distribution of cases and incidence by sex showed that there was no variation over 14 years. From 2016 onward, a significant increase in UG was observed before the pandemic. During the first year of the pandemic, a significant increase was observed in females aged 24–44 years. A heterogeneous distribution of UG was identified; however, border states were ranked among the top states with elevated incidences and cases. Lastly, the occurrence of UG was associated with temperature, related to summer. The information presented is intended to be useful to promote prevention and to contribute to visualize the distribution of UG over the last 18 years for decision making, and to show one of the consequences of the collapse of epidemiological surveillance of UG during the first year of the COVID-19 pandemic.

17 January 2026 in Pathogens
Verified
Journal Article
Open access
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LNLiliana Nicolás-Sayago
Liliana Nicolás-Sayago
Miguel LoyolaMiguel Loyola
Miguel Loyola
YVYesseny Vásquez-Martínez
Yesseny Vásquez-Martínez
MMMarcelo Cortez-San Martín
Marcelo Cortez-San Martín
LMLaura Margarita Márquez-Valdelamar
Laura Margarita Márquez-Valdelamar
Juan Manuel Bello-LópezJuan Manuel Bello-López
Juan Manuel Bello-López
Background: Pseudomonas aeruginosa is one of the leading agents causing healthcare-associated infections (HAIs) due to its intrinsic resistance, its capacity to acquire resistance mechanisms, and its persistence in hospital environments. In Mexico, it ranks among the most frequently reported pathogens in national surveillance systems. The aim of this study was to characterize antimicrobial resistance profiles and the genetic determinants associated with MDR/XDR phenotypes in P. aeruginosa strains from HAIs at Hospital Juárez de México (HJM). Methods: Sixty-three strains from patients with HAIs were analyzed. Identification was confirmed by 16S rRNA gene sequencing. Antimicrobial susceptibility testing followed CLSI guidelines. MDR/XDR phenotypes were classified according to the Latin American consensus for categorizing MDR, XDR, and PDR pathogens. Screening for resistance mechanisms was carried out by PCR for the main β-lactamases circulating at HJM. Finally, mutations in the oprD gene were detected in imipenem-resistant isolates through amino acid sequence alignment. Results: Resistant phenotypes allowed the identification of MDR and XDR profiles. Only the metallo-β-lactamase blaVIM was detected. Analysis of oprD porin sequences revealed recurrent mutations (S103T, T115K, L170F, G186P, and T189V) associated with imipenem resistance. Conclusions: In P. aeruginosa, the presence of blaVIM and structural alterations in OprD confirms the multifactorial nature of carbapenem resistance. These findings underscore the need to strengthen microbiological surveillance programs and antimicrobial stewardship strategies to mitigate the impact and spread of MDR/XDR isolates.

10 January 2025 in Microorganisms
Verified
Journal Article
Open access
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FVFernández-Sánchez Verónica
Fernández-Sánchez Verónica
EPEstibeyesbo Said Sigmund Reivaj Plascencia-Nieto
Estibeyesbo Said Sigmund Reivaj Plascencia-Nieto
MCMónica Alethia Cureño-Diaz
Mónica Alethia Cureño-Diaz
EDEMILIO MARIANO MANUEL DURAN
EMILIO MARIANO MANUEL DURAN
ARAIDA VERONICA RODRIGUEZ-TOVAR
AIDA VERONICA RODRIGUEZ-TOVAR
Juan Manuel Bello-LópezJuan Manuel Bello-López
Juan Manuel Bello-López
Pyogenic liver abscesses (PLAs) are serious infections in which doctors often fail in identifying the causative agent due to microbiological limitations. These limitations in detecting uncommon pathogens complicate the treatment and recovery. Molecular techniques, like massive sequencing, enable the detection of uncommon pathogens and highlight the shortcomings of traditional cultures. The aim of this work was to characterise the bacterial composition of PLAs through massive sequencing of the V3-V4 hypervariable region of the 16S rRNA gene in cases where conventional culture methods were negative. Purulent material was collected from three patients with PLAs at Hospital Juárez de México. Classical and molecular microbiological cultures were performed in parallel. Metagenomic DNA was extracted and massively sequenced (16S rRNA gene) using the Illumina MiSeq platform. A bioinformatic analysis was performed to determine the diversity at six different taxa levels and the relative abundances. The culture methods were not sufficient to detect the causative agent of the PLAs. However, the massive sequencing revealed the causative agents of the monomicrobial and polymicrobial infectious foci, with Gardnerella vaginalis, Lactobacillus iners, and Prevotella timonensis as the dominant bacteria. The massive sequencing revealed the presence of unusual pathogens that traditional culture failed to detect. There is an immediate need for molecular or comprehensive microbiological culture techniques to search for unusual bacteria in the diagnosis of PLAs.