Sistema de biosíntese de acinetobactina en Acinetobacter baumannii: implicación en virulencia e caracterización de novas dianas terapéuticas

[Resumen]: A. baumannii es el microorganismo oportunista más conocido dentro del género Acinetobacter y está considerado como uno de los microorganismos más peligrosos dentro del ambiente hospitalario. Las infecciones y brotes nosocomiales causadas por este patógeno nosocomial se han incrementado notablemente en los últimos años debido a su capacidad para sobrevivir y propagarse rápidamente por el ambiente hospitalario. Su elevada plasticidad genética le permite desarrollar de forma rápida mecanismos de resistencia, lo cual favorece la aparición de cepas multirresistentes a diversas clases de antibióticos. En el presente trabajo se evalúa el papel que desempeñan los genes implicados en la ruta de síntesis del sideróforo acinetobactina en la patogénesis de A. baumannii. La acinetobactina es el principal sistema de captación de hierro presente en esta especie y, además, factor clave en el establecimiento de la infección bacteriana y generación de daño celular. Para estudiar la relevancia de estos genes se construyeron cepas mutantes derivadas de la cepa ATCC 17978 que fueron posteriormente analizadas en diferentes ensayos in vitro e in vivo.[Resumo]: A. baumannii é o microorganismo oportunista máis coñecido dentro do xénero Acinetobacter e considerado como un dos microorganismos máis perigosos dentro do ambiente hospitalario. As infeccións e brotes nosocomiais causadas por este patóxeno nosocomial incrementáronse notablemente nos últimos anos debido á sua capacidade para sobrevivir e propagarse rápidamente polo ambiente hospitalario. A súa elevada plasticidade xenética permítelle desenvolver de forma rápida mecanismos de resistencia, o que favorece a aparición de cepas multirresistentes a diversas clases de antibióticos. No presente traballo evalúase o papel que desempeñan os xenes implicados na ruta de síntesis do sideróforo acinetobactina na patoxénesis de A. baumannii. A acinetobactina é o principal sistema de captación de ferro presente nesta especie e, ademais, factor clave no establecemento da infección bacteriana e xeración de dano celular. Para estudar a relevancia destes xenes construíronse cepas mutantes derivadas da cepa ATCC 17978 que foron posteriormente analizadas en diferentes ensaios in vitro e in vivo.[Abstract]: A. baumannii is the most well-known opportunistic microorganism within the genus Acinetobacter and considered one of the most dangerous microorganisms within the hospital environment. Infections and nosocomial outbreaks caused by this nosocomial pathogen have increased markedly in recent years due to their ability to survive and spread rapidly through the hospital environment. Its high genetic plasticity allows it to develop rapid mechanisms of resistance, which favors the appearance of multiresistant strains to a variety of classes of antibiotics. In the present work the role played by the genes involved in the pathway of synthesis of the siderophore acinetobactin in the pathogenesis of A. baumannii is evaluated. Acinetobactin is the main iron uptake system present in this species and, furthermore, a key factor in the establishment of bacterial infection and generation of cell damage. To study the relevance of these genes, mutant strains derived from the strain ATCC 17978 were constructed and subsequently analyzed in different in vitro and in vivo assays.Traballo fin de mestrado (UDC.CIE). Bioloxía molecular, celular e xenética. Curso 2017/201

In-Depth Analysis of the Role of the Acinetobactin Cluster in the Virulence of Acinetobacter baumannii

[Abstract] Acinetobacter baumannii is a multidrug-resistant pathogen that represents a serious threat to global health. A. baumannii possesses a wide range of virulence factors that contribute to the bacterial pathogenicity. Among them, the siderophore acinetobactin is one of the most important, being essential for the development of the infection. In this study we performed an in-depth analysis of the acinetobactin cluster in the strain A. baumannii ATCC 17978. For this purpose, nineteen individual isogenic mutant strains were generated, and further phenotypical analysis were performed. Individual mutants lacking the biosynthetic genes entA, basG, basC, basD, and basB showed a significant loss in virulence, due to the disruption in the acinetobactin production. Similarly, the gene bauA, coding for the acinetobactin receptor, was also found to be crucial for the bacterial pathogenesis. In addition, the analysis of the ΔbasJ/ΔfbsB double mutant strain demonstrated the high level of genetic redundancy between siderophores where the role of specific genes of the acinetobactin cluster can be fulfilled by their fimsbactin redundant genes. Overall, this study highlights the essential role of entA, basG, basC, basD, basB and bauA in the pathogenicity of A. baumannii and provides potential therapeutic targets for the design of new antivirulence agents against this microorganism.This work was funded by Projects PI15/00860 awarded to GB and PI17/01482 to AB and MP, all within in the National Plan for Scientific Research, Development and Technological Innovation 2013–2016 and funded by the ISCIII – General Subdirection of Assessment and Promotion of the Research-European Regional Development Fund (FEDER) “A way of making Europe.” The study was also funded by project IN607A 2016/22 (GAIN- Agencia Gallega de Innovación – Consellería de Economía, Emprego e Industria) awarded to GB. This work was also supported by Planes Nacionales de I + D + i 2008–2011/2013–2016 and Instituto de Salud Carlos III, Subdirección General de Redes y Centros de Investigación Cooperativa, Ministerio de Economía y Competitividad, Spanish Network for Research in Infectious Diseases (REIPI RD16/0016/006) co-financed by European Development Regional Fund “A way to achieve Europe” and operative program Intelligent Growth 2014–2020. This work was also supported by Grant RTI2018-093634-B-C22 (AEI/FEDER, EU) from the State Agency for Research (AEI) of Spain, co-funded by the FEDER Programme from the European Union and Xunta de Galicia for the support of Grant ED431E 2018/03 for CICA-INIBIC strategic and the initiative “Seed Projects 2019–2020.” JV-U was financially supported by the ISCIII project FI18/00315, LÁ-F by the ISCIII project PI14/00059 and the IN606B-2018/011, MM-G was financially supported by the Grant Clara Roy (SEIMC, Spanish Society of Clinical Microbiology and Infectious Diseases), KC-P by IN607A 2016/22 and AECC (Asociación Española Contra el Cáncer) predoctoral fellowship and LA by Xunta de Galicia co-funded with the European Social Fund (FSE) of the European Union (ED481A-2019/081)Xunta de Galicia; IN607A 2016/22Xunta de Galicia; ED431E 2018/03Xunta de Galicia; IN606B-2018/011Xunta de Galicia; IN607A 2016/22Xunta de Galicia; ED481A-2019/08

Modeling the Number of People Infected With SARS-COV-2 From Wastewater Viral Load in Northwest Spain

Financiado para publicación en acceso aberto: Universidade da Coruña/CISUG[Abstract] The quantification of the SARS-CoV-2 RNA load in wastewater has emerged as a useful tool to monitor COVID–19 outbreaks in the community. This approach was implemented in the metropolitan area of A Coruña (NW Spain), where wastewater from a treatment plant was analyzed to track the epidemic dynamics in a population of 369,098 inhabitants. Viral load detected in the wastewater and the epidemiological data from A Coruña health system served as main sources for statistical models developing. Regression models described here allowed us to estimate the number of infected people (R2 = 0.9), including symptomatic and asymptomatic individuals. These models have helped to understand the real magnitude of the epidemic in a population at any given time and have been used as an effective early warning tool for predicting outbreaks in A Coruña municipality. The methodology of the present work could be used to develop a similar wastewater-based epidemiological model to track the evolution of the COVID–19 epidemic anywhere in the world where centralized water-based sanitation systems exist.This work was supported by EDAR Bens S.A., A Coruña, Spain [grant references INV04020, INV12120 and INV05921 to MP], the National Plan for Scientific Research, Development and Technological Innovation 2013-2016 funded by the ISCIII, Spain - General Subdirection of Assessment and Promotion of the Research-European Regional Development Fund (FEDER) “A way of making Europe” [grant numbers PI15/00860 to GB, PI17/01482 and PI20/00413 to MP], the GAIN, Xunta de Galicia, Spain [grant number IN607A 2016/22 to GB, ED431C-2016/015 and ED431C-2020/14 to RC, ED431C 2017/58 to SL, ED431G 2019/01 to RC and SL, and ED431C 2017/66 to MCV], MINECO, Spain [grant number MTM2017-82724-R to RC], Ministerio de Ciencia e Innovación, Spain [grant number PID2020-113578RB-100 to RC], and the Spanish Network for Research in Infectious Diseases [REIPI RD16/0016/006 to GB]. The work was also supported by the European Virus Archive Global (EVA-GLOBAL) project that has received funding from the European Union's Horizon 2020 - Research and Innovation Framework Programme under grant agreement no 871029. SR-F was financially supported by REIPI RD16/0016/006, KC-P by IN607A 2016/22 and the Spanish Association against Cancer (AECC) and JAV by IN607A 2016/22. Funding for open access charge: Universidade da Coruña/CISUGEDAR Bens S.A.; INV04020EDAR Bens S.A.; INV12120EDAR Bens S.A.; INV05921Xunta de Galicia; IN607A 2016/22Xunta de Galicia; ED431C-2016/015Xunta de Galicia; ED431C-2020/14Xunta de Galicia; ED431C 2017/58Xunta de Galicia; ED431G 2019/01Xunta de Galicia; ED431C 2017/6

Wastewater early warning system for SARS-CoV-2 outbreaks and variants in a Coruña, Spain

Financiado para publicación en acceso aberto: Universidade da Coruña/CISUG[Abstract]: Wastewater-based epidemiology has been widely used as a cost-effective method for tracking the COVID-19 pandemic at the community level. Here we describe COVIDBENS, a wastewater surveillance program running from June 2020 to March 2022 in the wastewater treatment plant of Bens in A Coruña (Spain). The main goal of this work was to provide an effective early warning tool based in wastewater epidemiology to help in decision-making at both the social and public health levels. RT-qPCR procedures and Illumina sequencing were used to weekly monitor the viral load and to detect SARS-CoV-2 mutations in wastewater, respectively. In addition, own statistical models were applied to estimate the real number of infected people and the frequency of each emerging variant circulating in the community, which considerable improved the surveillance strategy. Our analysis detected 6 viral load waves in A Coruña with concentrations between 103 and 106 SARS-CoV-2 RNA copies/L. Our system was able to anticipate community outbreaks during the pandemic with 8-36 days in advance with respect to clinical reports and, to detect the emergence of new SARS-CoV-2 variants in A Coruña such as Alpha (B.1.1.7), Delta (B.1.617.2), and Omicron (B.1.1.529 and BA.2) in wastewater with 42, 30, and 27 days, respectively, before the health system did. Data generated here helped local authorities and health managers to give a faster and more efficient response to the pandemic situation, and also allowed important industrial companies to adapt their production to each situation. The wastewater-based epidemiology program developed in our metropolitan area of A Coruña (Spain) during the SARS-CoV-2 pandemic served as a powerful early warning system combining statistical models with mutations and viral load monitoring in wastewater over time.Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. Funding for open access charge: Universidade da Coruña/CISUG. This work was supported by EDAR Bens S.A., A Coruña, Spain [grant references INV04020, INV12120, INV05921, and INV148721 to MP], by the National Plan for Scientific Research, Development and Technological Innovation funded by the Institute of Health Carlos III (ISCIII), Spain—General Subdirection of Assessment and Promotion of the Research-European Regional Development Fund (FEDER) “A way of making Europe” [grant references PI15/00860 to GB, PI17/01482, and PI20/00413 to MP], by the Galician Innovation Agency (GAIN) (Xunta de Galicia, Spain) [grant references IN607A 2016/22 to GB, ED431C-2016/015 and ED431C-2020/14 to RC, ED431C 2021/53 to SL and ED431G 2019/01 and COV20/00604 to RC and SL, by Ministry of Economic Affairs and Digital Transformation (MINECO), Spain [grant references MTM2017-82724-R to RC], by the Spanish Network for Research in Infectious Diseases [REIPI RD16/0016/0006 to GB], by the “Innova Saúde” Program, (INNOVAMICROLAB project) co-founded by the Galician Healthcare Service (SERGAS) and the Spanish Ministry of Science and Innovation, and by the Spanish Network of Research in Infectious Diseases (CIBERINFEC, ISCIII), and by the European Virus Archive Global (EVA-GLOBAL) project that has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No 871029. SR-F was financially supported by REIPI RD16/0016/006, KC-P by IN607A 2016/22 and the Spanish Association against Cancer (AECC) and JAV by IN607A 2016/22. DP was funded by grant EPICOVIGAL FONDO SUPERA-COVID19 from Banco Santander-CSIC-CRUE, Spain, and grant CT850A-2 from (Health Knowledge Agency) ACIS SERGAS from the Consellería de Sanidade of Xunta de Galicia, Spain.EDAR Bens S.A.; INV04020EDAR Bens S.A.; INV12120EDAR Bens S.A.; INV05921EDAR Bens S.A.; INV148721Xunta de Galicia; IN607A 2016/22Xunta de Galicia; ED431C-2016/015Xunta de Galicia; ED431C-2020/14Xunta de Galicia; ED431C 2021/53Xunta de Galicia; ED431G 2019/01Xunta de Galicia; COV20/0060

Emergence of Carbapenemase Genes in Gram-Negative Bacteria Isolated from the Wastewater Treatment Plant in A Coruña, Spain

Wastewater treatment plants (WWTPs) are recognized as important niches of antibiotic-resistant bacteria that can be easily spread to the environment. In this study, we collected wastewater samples from the WWTP of A Coruña (NW Spain) from April 2020 to February 2022 to evaluate the presence of Gram-negative bacteria harboring carbapenemase genes. Bacteria isolated from wastewater were classified and their antimicrobial profiles were determined. In total, 252 Gram-negative bacteria carrying various carbapenemase genes were described. Whole-genome sequencing was conducted on 55 selected carbapenemase producing isolates using Oxford Nanopore technology. This study revealed the presence of a significant population of bacteria carrying carbapenemase genes in WWTP, which constitutes a public health problem due to their risk of dissemination to the environment. This emphasizes the usefulness of WWTP monitoring for combating antibiotic resistance. Data revealed the presence of different types of sequences harboring carbapenemase genes, such as blaKPC-2, blaGES-5, blaGES-6, blaIMP-11, blaIMP-28, blaOXA-24, blaOXA-48, blaOXA-58, blaOXA-217, and blaVIM-2. Importantly, the presence of the blaKPC-2 gene in wastewater, several months before any clinical case was detected in University Hospital of A Coruña, suggests that wastewater-based epidemiology can be used as an early warning system for the surveillance of antibiotic-resistant bacteria

Building-Scale Wastewater-Based Epidemiology for SARS-CoV-2 Surveillance at Nursing Homes in A Coruña, Spain

Wastewater-based epidemiology (WBE) has become an effective tool in the surveillance of infectious diseases such as COVID-19. In this work, we performed a brief study of monitoring the SARS-CoV-2 viral load in wastewater from six nursing homes located in the metropolitan area of A Coruña (Spain) between December 2020 and March 2021. The main objective was to detect SARS-CoV-2 outbreaks among residents and study the efficacy of the vaccination campaign. SARS-CoV-2 viral load (RNA copies per L of wastewater) was determined by reverse-transcription quantitative PCR (RT-qPCR) using the quantification cycle (Cq) values for the nucleocapsid (N) gene. Our results showed that the increase in viral load preceded the increase in clinical cases, favoring an early warning system that detects COVID-19 outbreaks in advance, making it possible to contain and stop the transmission of the virus among residents. In addition, the efficacy of the new COVID-19 vaccines was evidenced, since after the vaccination campaign in nursing homes in A Coruña, it was observed that many residents did not present any symptoms of the disease, although they excreted high amounts of virus in their feces. WBE is a cost-effective strategy that should be implemented in all cities to prevent new emerging diseases or future pandemic threats