Six Feet under Microbiota: Microbiologic Contamination and Toxicity Profile in Three Urban Cemeteries from Lisbon, Portugal

Carla Viegas; Renata Cervantes; Marta Dias; Bianca Gomes; Pedro Pena; Elisabete Carolino; Magdalena Twarużek; Robert Kosicki; Ewelina Soszczyńska; Susana Viegas; Liliana Aranha Caetano

doi:10.3390/toxins14050348

Six Feet under Microbiota: Microbiologic Contamination and Toxicity Profile in Three Urban Cemeteries from Lisbon, Portugal

Toxins (Basel). 2022 May 16;14(5):348. doi: 10.3390/toxins14050348.

Authors

Carla Viegas^{1

2

3}, Renata Cervantes¹, Marta Dias^{1

2

3}, Bianca Gomes¹, Pedro Pena¹, Elisabete Carolino¹, Magdalena Twarużek⁴, Robert Kosicki⁴, Ewelina Soszczyńska⁴, Susana Viegas^{1

2

3}, Liliana Aranha Caetano^{1

5}

Affiliations

¹ H&TRC-Health & Technology Research Center, ESTeSL-Escola Superior de Tecnologia e Saúde, Instituto Politécnico de Lisboa, 1990-096 Lisbon, Portugal.
² NOVA National School of Public Health, Public Health Research Centre, Universidade Nova de Lisboa, 1099-085 Lisbon, Portugal.
³ Comprehensive Health Research Center (CHRC), NOVA Medical School, Universidade NOVA de Lisboa, 1169-056 Lisbon, Portugal.
⁴ Department of Physiology and Toxicology, Institute of Experimental Biology, Faculty of Natural Sciences, Kazimierz Wielki University, Chodkiewicza 30, 85-064 Bydgoszcz, Poland.
⁵ Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, University of Lisbon, 1649-003 Lisbon, Portugal.

Abstract

Cemeteries are potential environmental reservoirs of pathogenic microorganisms from organic matter decomposition. This study aimed to characterize the microbial contamination in three cemeteries, and more specifically in grave diggers' facilities. One active sampling method (impingement method) and several passive sampling methods (swabs, settled dust, settled dust filters and electrostatic dust cloths-EDC) were employed. The molecular detection of Aspergillus sections and SARS-CoV-2, as well as mycotoxin analysis, screening of azole resistance, and cytotoxicity measurement were also conducted. Total bacteria contamination was 80 CFU·m^-2 in settled dust samples, reached 849 CFU·m^-2 in EDC and 20,000 CFU·m^-2 in swabs, and ranged from 5000 to 10,000 CFU·m^-2 in filters. Gram-negative bacteria (VRBA) were only observed in in settled dust samples (2.00 × 10⁵ CFU·m^-2). Regarding Aspergillus sp., the highest counts were obtained in DG18 (18.38%) and it was not observed in azole-supplemented SDA media. SARS-CoV-2 and the targeted Aspergillus sections were not detected. Mycophenolic acid was detected in one settled dust sample. Cytotoxic effects were observed for 94.4% filters and 5.6% EDC in A549 lung epithelial cells, and for 50.0% filters and 5.6% EDC in HepG2 cells. Future studies are needed in this occupational setting to implement more focused risk management measures.

Keywords: Aspergillus; SARS-CoV-2; azole resistance; cemeteries; cytotoxicity; mycotoxins; occupational health.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Aspergillus
Azoles
COVID-19*
Cemeteries
Dust / analysis
Microbiota*
Portugal
SARS-CoV-2

Substances

Azoles
Dust

Grants and funding

This research was funded by FCT—Fundação para a Ciência e a Tecnologia, I.P. (Portugal) for funding the EEA Grants Project “EXPOGreen FBR38” and by Instituto Politécnico de Lisboa, for funding the Project “Occupational exposure of ambulance drivers to bioburden” (IPL/2020/BIO-AmbuDrivers_ESTeSL) and by Polish Minister of Science and Higher Education, under the program "Regional Initiative of Excellence" in 2019—2022 (Grant No. 008/RID/2018/19). H&TRC authors gratefully acknowledge the FCT/MCTES national support through the UIDB/05608/2020 and UIDP/05608/2020 and the PhD Grant UI/BD/151431/2021.