Guillermo Salvatierra

Dr. Guillermo Salvatierra

orcid

Research Focus & Metrics

Academic Career Length

12Years (2015-Present)

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

Representative Publications

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31 October 2021 in Microbiology Spectrum
Verified
Journal Article
Open access
PRPedro E. Romero
Pedro E. Romero
Alejandra Dávila-BarclayAlejandra Dávila-Barclay
Alejandra Dávila-Barclay
GSGuillermo Salvatierra
Guillermo Salvatierra
LGLuis González
Luis González
DCDiego Cuicapuza
Diego Cuicapuza
PTPablo Tsukayama
Pablo Tsukayama
The evolution of SARS-CoV-2 variants with potentially increased transmissibility, virulence, and resistance to antibody neutralization poses new challenges for the control of COVID-19 (1), particularly in low- and middle-income countries (LMICs) where transmission remains high and vaccination progress is still incipient.

22 April 2021 in Antibiotics
Verified
Journal Article
Open access
PDF file
SLSteev Loyola
Steev Loyola
FCFátima Concha-Velasco
Fátima Concha-Velasco
JPJimena Pino-Dueñas
Jimena Pino-Dueñas
NVNancy Vasquez-Luna
Nancy Vasquez-Luna
PCPaola Estela Juarez Cardenas
Paola Estela Juarez Cardenas
ALAndres Lescano
Andres Lescano
Urinary tract infections (UTIs) are a common human infection. Antibiotic resistance in extended-spectrum β-lactamase (ESBL)-producing uropathogenic E. coli (UPEC) is a major therapeutic challenge due to limited treatment alternatives. The aim was to characterize the antimicrobial resistance (AMR) and dynamics of ESBL-producing UPEC isolates from UTI cases seen at a local hospital in Cusco, Peru. Ninety-nine isolates from respective patients were characterized against 18 different antibiotics. Latent class analysis (LCA) was used to evaluate the dynamics across the study time according to resistance patterns. The median age of patients was 51 years old, and nearly half were women. ESBL-producing UPEC isolates were slightly more frequent in outpatient services than emergency rooms, and there were higher resistance rates in males compared to females. Half of the ESBL producers were resistant to aminoglycosides and nitrofurantoin. Cefoxitin and fosfomycin resistance was 29.3% and 14.1%, respectively. Resistance to carbapenems was not observed. All isolates were multidrug-resistant bacteria, and 16.2% (16/99) were also classified as extensively drug-resistant bacteria. The resistance patterns varied across the study time and differed regarding sex and healthcare service. The study revealed high levels of AMR to commonly used antimicrobials and a dynamic circulation of ESBL-producing UPEC isolates with varying resistance patterns.

1 February 2022 in Antibiotics
Verified
Journal Article
Open access
PDF file
María Emilia Dávalos-AlmeydaMaría Emilia Dávalos-Almeyda
María Emilia Dávalos-Almeyda
AGAgustín Guerrero
Agustín Guerrero
GMGermán Medina
Germán Medina
Alejandra Dávila-BarclayAlejandra Dávila-Barclay
Alejandra Dávila-Barclay
GSGuillermo Salvatierra
Guillermo Salvatierra
PTPablo Tsukayama
Pablo Tsukayama
Poultry farming represents Peru’s primary food animal production industry, where antimicrobial growth promoters are still commonly used, exerting selective pressure on intestinal microbial populations. Consumption and direct animal-to-human transmission have been reported, and farmworkers are at high risk of colonization with resistant bacteria. We conducted a cross-sectional survey among 54 farmworkers to understand their current antimicrobial resistance (AMR) awareness in Ica, Peru. To gain insight into the potential work-related risk of exposure to bacteria, we also measured the AMR rates in Escherichia coli isolated among 50 broiler chickens. Farmworkers were unaware of antimicrobial resistance (31.5%) or antibiotic resistance (16.7%) terms. Almost two-thirds (61%) consumed antibiotics during the previous month, and only 42.6% received a prescription from a healthcare professional. A total of 107 E. coli chicken isolates were obtained, showing a high frequency of multidrug-resistant (89.7%) and extended-spectrum beta-lactamase (ESBL) production (71.9%). Among ESBL-producer isolates, 84.4% carried the blaCTX-M gene. Results identified gaps in knowledge that reflect the need for interventions to increase antimicrobial awareness among poultry farmworkers. The high AMR rates among E. coli isolates highlight the need to reduce antimicrobial use in poultry farms. Our findings reveal a critical need for effective policy development and antimicrobial stewardship interventions in poultry production in Ica, Peru.

3 July 2021 in medRxiv
Verified
Preprint
Open access
PDF file
PRPedro E. Romero
Pedro E. Romero
Alejandra Dávila-BarclayAlejandra Dávila-Barclay
Alejandra Dávila-Barclay
GSGuillermo Salvatierra
Guillermo Salvatierra
LGLuis González
Luis González
DADiego Bernhard Cuicapuza Arteaga
Diego Bernhard Cuicapuza Arteaga
PTPablo Tsukayama
Pablo Tsukayama
We report the emergence of a novel lineage of SARS-CoV-2 in South America, termed C.37. It presents seven nonsynonymous mutations in the Spike gene (Δ247-253, G75V, T76I, L452Q, F490S, T859N) and a deletion in the ORF1a gene (Δ3675-3677) also found in variants of concern (VOCs) Alpha, Beta, and Gamma. Initially reported in Lima, Peru, in late December 2020, it now accounts for 97% of Peruvian public genomes in April 2021. It is expanding in Chile and Argentina, and there is evidence of onward transmission in Colombia, Ecuador, Mexico, the USA, Germany, and Israel. On June 15, 2021, the World Health Organization designated C.37 as Variant of Interest (VOI) Lambda.

16 March 2021 in Revista Peruana de Medicina Experimental Y Salud Pública
Verified
Journal Article
Open access
PDF file
PCPool Marcos Carbajal
Pool Marcos Carbajal
GSGuillermo Salvatierra
Guillermo Salvatierra
JYJosé Luis YARETA YARETA
José Luis YARETA YARETA
JPJimena Pino
Jimena Pino
NVNancy Vásquez
Nancy Vásquez
PTPablo Tsukayama
Pablo Tsukayama
Se caracterizó la resistencia antimicrobiana de 70 aislados de Escherichia coli obtenidos de pacientes con infección del tracto urinario (ITU) provenientes de ocho hospitales públicos en el Perú. Los perfiles de resistencia fueron identificados mediante el uso del sistema automatizado MicroScan®. Se utilizó una reacción en cadena de la polimerasa convencional para la detección de los genes blaTEM, blaCTX-M, blaSHV y blaPER. El 65,7% (46/70) de los aislados presentó un fenotipo multidrogorresistente y el 55,7% (39/70) fue identificado como productores de betalactamasas de espectro extendido. Se detectaron altos niveles de resistencia para ampicilina (77,1%), ciprofloxacina (74,3%), trimetoprim/sulfametoxazol (62,9%), cefepime (57,1%) y cefuroxima (57,1%). El gen blaTEM fue el más frecuente con un 31,4%, seguido por blaCTX-M (18,6%) y blaSHV (2,9%). Los resultados evidencian altos niveles de resistencia a antimicrobianos de importancia clínica en aislados de E. coli de pacientes con ITU en el Perú.

4 February 2025 in Microbiology Spectrum
Verified
Journal Article
Open access
FKFiorella Krapp
Fiorella Krapp
DCDiego Cuicapuza
Diego Cuicapuza
GSGuillermo Salvatierra
Guillermo Salvatierra
JBJean P. Buteau
Jean P. Buteau
CACatherine Amaro
Catherine Amaro
PTPablo Tsukayama
Pablo Tsukayama
The emergence of carbapenem-resistant Klebsiella pneumoniae (CRKP) poses a significant public health threat, particularly in low- and middle-income countries (LMICs) with limited surveillance and treatment options. This study examines the genetic diversity, resistance patterns, and transmission dynamics of 66 CRKP isolates recovered over 5 years (2015–2019) after the first case of CRKP was identified at a tertiary care hospital in Lima, Peru. Our findings reveal a shift from bla KPC-2 to bla NDM-1 as the dominant carbapenemase gene after 2017. Lineage ST45 was the most prevalent and persisted for multiple years, followed by high-risk clones ST11 and ST147. The bla NDM-1 gene was carried almost exclusively by a Tn125-like transposon, similar to the one reported in previous studies from two Peruvian hospitals. Long-read sequencing revealed nearly identical bla NDM -carrying plasmids across the four assessed lineages. A comparative analysis of 1,023 South American CRKP genomes confirmed a unique pattern in Peru, where bla NDM-1 (81.4%) outpaced bla KPC-2 , which remained dominant (59.4%) elsewhere. In addition, emerging clones ST45 and ST348 found in Peru were rarely found elsewhere in South America, suggesting potential regional adaptation. In conclusion, our study provides a comprehensive picture of the intra-hospital dynamics of these emerging pathogens and provides a framework for studying their genomic diversity in the understudied South American region. IMPORTANCE: This study provides novel insights into the transmission and genetic diversity of carbapenem-resistant Klebsiella pneumoniae , a bacteria responsible for severe infections, with limited treatment options. By examining isolates recovered over 5 years at a major hospital in Lima, Peru, we demonstrated a shift from one type of resistance gene, bla KPC , to another, bla NDM , which is more challenging to treat. Our findings reveal that specific bacterial lineages carrying the bla NDM gene in a specific plasmid are emerging in Peru, including well-known high-risk strains and others rarely found elsewhere in South America. This pattern highlights an urgent need for targeted surveillance and infection control as these strains pose a significant challenge to healthcare systems. Our study provides crucial data on Klebsiella pneumoniae in Peru, contributing to broader efforts to monitor and control antibiotic-resistant infections in South America and globally.