Waldo Franz Salvatierra Espinola

Prof. Dr. Waldo Franz Salvatierra Espinola

orcid

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

View All Publications
3 October 2023 in Medicina
Verified
Journal Article
Open access
PDF file
David García-CedrónDavid García-Cedrón
David García-Cedrón
MNMagaly De La Cruz Noriega
Magaly De La Cruz Noriega
LCLuis Cabanillas
Luis Cabanillas
NGNelida Milly Esther Otiniano García
Nelida Milly Esther Otiniano García
Walter Andres Rojas VilacortaWalter Andres Rojas Vilacorta
Walter Andres Rojas Vilacorta
MVManuela Luján Velásquez
Manuela Luján Velásquez
Background and Objectives: In Peru, the presence of antimicrobial-resistant bacteria is a constant concern in hospitals and has likely increased in frequency during the pandemic. The objective of the study was to analyze the frequency of carbapenemase-producing bacteria resistant to two carbapenems (Imipenem and Meropenem), which were isolated from Peruvian patients in the intensive care unit of the Victor Lazarte Echegaray Hospital in Trujillo (Peru) during the COVID-19 pandemic. Materials and Methods: The biological samples of the patients hospitalized in the ICU were processed in the Microbiology Diagnostic Laboratory of the Víctor Lazarte Echegaray Hospital between May 2021 and March 2022. Antimicrobial sensitivity was determined with the automated system AutoScan-4, and for the identification of the type of carbapenemase, the RESISIT-3 O.K.N K-SET cassettes were used. Results: The results show that 76 cultures (76/129) had resistance to the two carbapenems (imipenem or meropenem), where the most frequent were Klebsiella pneuomoniae (31.6%), Pseudomonas aeruginosa (26.3%), and Acinetobacter baumannii (14.5%). Pseudomonas aeruginosa cultures showed at least three carbapenemase types (KPC, NDM, and OXA-48), while A. baumannii, Escherichia coli, and Burkholderia cepacia complex presented at least two carbapenemases (NDM and OXA-48). The carbapenemase NDM was detected in Enterobacter cloacae, Morganella morganii, and Proteus mirabilis, while KPC was present in all Klebsiella pneumoniae and Klebsiella oxytoca cultures. Conclusions: The samples from patients hospitalized in the Victor Lazarte Echegaray Hospital ICU showed a high prevalence of imipenem- and meropenem-resistant bacteria. These findings are relevant and concerning from the perspective of antibiotic-resistant bacteria monitoring, control, and disinfection. Thus, an appropriate antibiotic policy must be implemented.

22 September 2023 in Sustainability
Verified
Journal Article
Open access
PDF file
DLDafne Lecca-Caballero
Dafne Lecca-Caballero
EVEyber Vega-Moreno
Eyber Vega-Moreno
LCLuis Cabanillas
Luis Cabanillas
KAKaren Diaz Del Aguila
Karen Diaz Del Aguila
Walter Andres Rojas VilacortaWalter Andres Rojas Vilacorta
Walter Andres Rojas Vilacorta
MNMagaly De La Cruz Noriega
Magaly De La Cruz Noriega
Heavy metal contamination of water is a widespread problem in Peru and represents a potential threat to the ecosystem. Bacteria are an ecological alternative to treating these effluents. This research aims to determine the influence of temperature and pH on the lead (Pb) bioremoval in surface water using Serratia marcescens under laboratory conditions. The sample was collected from a stream located in Santiago de Chuco City (Peru). Treatments (T) were carried out by combining pH (5 and 7) and temperature (25, 30, and 35 °C). The bacterial inoculum (S. marcescens) was 3 × 108 CFU/mL, which was constant in all treatments. The lead bioremoval evaluation was performed in an airlift bioreactor and the incubation time was 24 h. The total lead concentration was determined using atomic absorption spectrophotometry. The results show that treatment 6 (temperature: 35 °C, pH: 5, and inoculum: 3 × 108 UFC/mL) showed a better result than the other treatments, with a removal value of 63.94%. Furthermore, the total lead concentration decreased from an initial concentration of 0.268 mg Pb/L to a final value of 0.0964 mg Pb/L. These results are still above the allowed water value (15 µg/L) according to Peruvian standards. On the other hand, temperature and pH influenced lead removal from surface water when S. marcescens was used after a short incubation period (24 h). Although an attempt was made to improve lead bioremoval by varying two parameters, temperature and pH, future research is still needed to investigate the effect of different inoculum concentrations, the use of microbial consortia, and a broader range of physicochemical parameters.

15 July 2026 in Microorganisms
Verified
Journal Article
Open access
PDF file
MNMagaly De La Cruz Noriega
Magaly De La Cruz Noriega
AVAna María de los Angeles Sabogal Vargas
Ana María de los Angeles Sabogal Vargas
Walter Andres Rojas VilacortaWalter Andres Rojas Vilacorta
Walter Andres Rojas Vilacorta
WEWaldo Franz Salvatierra Espinola
Waldo Franz Salvatierra Espinola
CCClaudio Eduardo Quiñones Cerna
Claudio Eduardo Quiñones Cerna
This scientometric and bibliometric study analyzes global research trends on polyhydroxyalkanoate (PHA)-producing microorganisms and their applications in bio-based packaging between 2014 and 2025. Using the Scopus database and advanced tools such as Bibliometrix in RStudio and VOSviewer, scientific output and international collaboration networks were evaluated. The results demonstrate exponential growth in publications, driven by the urgent need to mitigate the petrochemical plastics crisis and develop biodegradable alternatives within the circular economy. Multidisciplinary analysis reveals a thematic shift from basic physiological and taxonomic studies towards complex applications in metabolic engineering, synthetic biology, the optimization of low-cost substrates such as industrial effluents, multi-omics tools, gene editing with CRISPR-Cas9, and, as an emerging exploratory approach, quantum modeling to optimize cell performance. Despite significant progress, critical technological gaps were identified related to challenges in downstream processing, the management of mixed microbial communities, and insufficient funding for the characterization of physicochemical and biocompatibility properties. It is concluded that, to ensure the commercial scalability and sustainability of PHAs, future research must prioritize overcoming these economic and technological bottlenecks, fostering strategic collaboration between academia and the biotechnology industry.