Evaluation of Microbiological Quality of Indoor Air and Water in Laboratory Environments at the State University of Maringá
DOI:
https://doi.org/10.17921/1415-6938.2026v30n2p166-183Abstract
The microbiological quality of air and water in laboratory environments is essential for biosafety, occupational health, and the reliability of analytical results. The increasing use of air-conditioned environments favors the dispersion of microbiological contaminants, especially fungi and bacteria, in addition to enhancing risks associated with water used in laboratories. This study aimed to evaluate, in an integrated manner, the microbiological quality of conditioned air and water in laboratories located in blocks: I90, J90, K10, and T20, belonging to the Departments of Clinical Analysis and Biomedicine and Basic Health Sciences at the State University of Maringá. Air sampling was performed using the impaction method, with population quantification of bacteria and fungi, followed by morphological analysis and Gram staining for bacterial classification. Water samples were analyzed using the chromogenic substrate method for the detection of total coliforms (TC) and Escherichia coli, with subsequent biochemical identification of isolates positive for TC. The results indicated that airborne bacterial counts remained within regulatory limits, while most environments showed fungal growth above the maximum recommended value (≤ 750 CFU/m³), with confluent growth. A predominance of Gram-positive cocci was observed in the air, followed by Gram-negative and Gram-positive bacilli. In the microbiological analysis of water, two samples showed contamination by total coliforms, with the identification of Klebsiella pneumoniae and Serratia liquefaciens. The results highlight the need for preventive maintenance of air-conditioning systems and periodic water monitoring, thereby establishing the continuous adoption of biosafety measures in laboratory environments.
Keywords: Microorganisms. Microbiological Analysis. Quality Control. Air-conditioned Environment.
Resumo
A qualidade microbiológica do ar e da água em ambientes laboratoriais é essencial para a biossegurança, saúde ocupacional e confiabilidade dos resultados analíticos. O uso crescente de ambientes climatizados favorece a dispersão de contaminantes microbiológicos, especialmente fungos e bactérias, além de potencializar riscos associados à água utilizada em laboratórios. Este estudo teve como objetivo avaliar, de forma integrada, a qualidade microbiológica do ar climatizado e da água em laboratórios dos blocos I90, J90, K10 e T20, pertencentes aos Departamentos de Análises Clínicas e Biomedicina e de Ciências Básicas da Saúde da Universidade Estadual de Maringá. A amostragem do ar foi realizada pelo método de impactação, com quantificação populacional de bactérias e fungos, seguida da análise morfológica e coloração de Gram para classificação bacteriana. As amostras de água foram analisadas pelo método do substrato cromogênico para detecção de coliformes totais (CT) e Escherichia coli, com posterior identificação bioquímica dos isolados positivos para CT. Os resultados indicaram que as contagens bacterianas do ar permaneceram dentro dos limites normativos, enquanto a maioria dos ambientes apresentou crescimento fúngico acima do valor máximo recomendado (≤ 750 UFC/m³), com crescimento confluente. Observou-se predominância de cocos Gram-positivos no ar, seguidos por bacilos Gram-negativos e Gram-positivos. Nas análises microbiológicas da água, verificou-se que duas das amostras apresentaram contaminação por CT, sendo identificadas as bactérias Klebsiella pneumoniae e Serratia liquefaciens. Os resultados evidenciam a necessidade de manutenção preventiva dos sistemas de climatização e do monitoramento periódico da água, estabelecendo, portanto, a adoção contínua de medidas de biossegurança em ambientes laboratoriais.
Palavras-chave: Microrganismos. Análise Microbiológica. Controle de Qualidade. Ambiente Climatizado.
Downloads
References
ABBAS, R. et al. General overview of Klebsiella pneumonia: Epidemiology and the role of siderophores in its pathogenicity. Biology, v.13, n.2, p.78, 2024. doi: https://doi.org/10.3390/biology13020078.
ABNT - Associação Brasileira De Normas Técnicas. ABNT NBR 17037: Qualidade do ar interior em ambientes climatizados artificialmente – Parâmetros físicos, químicos e biológicos. Rio de Janeiro: ABNT, 2023.
APHA - American Public Health Association; American Water Works Association; Water Environment Federation. Standard Methods for the Examination of Water and Wastewater. Washington: APHA, 2022.
BAKKER, A. et al. Bacterial and fungal ecology on air conditioning cooling coils is influenced by climate and building factors. Indoor Air, v.30, n.2, p.326-334, 2020. doi: https://doi.org/10.1111/ina.12632.
BAO, J.R. et al. 2021. Recovery and its dynamics of filamentous fungi from clinical specimen cultures: An extensive study. Microbiol. Spectr., v.9, n.1, 2021. doi: https://doi.org/10.1128/spectrum.00080-21.
BRASIL. Ministério da Saúde. Resolução nº 09, de 16 de janeiro de 2003. Dispõe sobre o regulamento técnico contendo diretrizes para a qualidade do ar interior em ambientes climatizados de uso público e coletivo. Diário Oficial da União, Brasília, DF, 20 jan. 2003.
BRASIL. Lei nº 13.589, de 4 de janeiro de 2018. Dispõe sobre a manutenção de instalações e equipamentos de sistemas de climatização de ambientes. Diário Oficial da União: seção 1, Brasília, DF, 5 Jan. 2018.
BRASIL. Ministério da Saúde. Portaria GM/MS nº 888, de 4 de maio de 2021. Estabelece os procedimentos e responsabilidades relativos ao controle e à vigilância da qualidade da água para consumo humano e seu padrão de potabilidade, e dá outras providências. Diário Oficial da União, Brasília, DF, 7 May 2021.
CHAMSEDDINE, A.; ELZEIN, I.M.; HASSAN, N. Indoor air quality in critical indoor environments: a review paper. Water Air Soil Pollut., v.236, n.885, 2025. doi: https://doi.org/10.1007/s11270-025-08512-y.
CHAWLA, H. et al. A comprehensive review of microbial contamination in the indoor environment: sources, sampling, health risks, and mitigation strategies. Front Public Health, v.11, 2023. doi: https://doi.org/10.3389/fpubh.2023.1285393.
CHINAKWE, E.C. et al. Physico-chemical and microbiological qualities of abattoir wastewater in Egbu, Imo State, Nigeria. Microbiol. Res. J. Int., v.32, n.4, p.31-36, 2022. doi: https://doi.org/10.9734/mrji/2022/v32i430383.
COX, J. et al. Field sampling of indoor bioaerosols. Aerosol Sci. Technol., v.54, n.5, p.572-587, 2019. doi: https://doi.org/10.1080/02786826.2019.1688759.
CRISPIM, N.R. et al. Heteroresistance to amikacin in Klebsiella aerogenes isolates from patients in an intensive care unit in Brazil. Microbiol. Spectr., v.14, n.4, 2026. doi: https://doi.org/10.1128/spectrum.02833-25.
DOKUTA, S. et al. ESBL-producing Enterobacterales in food and clinical samples: antimicrobial resistance organisms and genes in Chiang Mai, Thailand. Sci. Rep., v.15, n.23886, 2025. doi: https://doi.org/10.1038/s41598-025-06410-1.
DOURADINHA, B. Should multidrug resistant Klebsiella pneumoniae strains displaying hypervirulent traits be reclassified as either ultravirulent or supervirulent? Microbiol. Res., v.275, e127446, 2023. doi: https://doi.org/10.1016/j.micres.2023.127446.
GÓMEZ-SÁNCHEZ, N. et al. Risk of exposure to bioaerosols in clinical environments: Bronchoscopy. Am. J. Infect. Control, v.54, n.5, p.559-564, 2025. doi: https://doi.org/10.1016/j.ajic.2025.11.026.
HAFIZ T. A. et al. Klebsiella pneumoniae bacteremia epidemiology: Resistance profiles and clinical outcome of King Fahad Medical City isolates, Riyadh, Saudi Arabia. BMC Infect. Dis., v.23, n.579, 2023. doi: https://doi.org/10.1186/s12879-023-08563-8.
JIN, R. et al. Exometabolomic exploration of culturable airborne microorganisms from an urban atmosphere. Atmos. Chem. Phys., v.25, n.3, p.1805-1829, 2025. doi: https://doi.org/10.5194/acp-25-1805-2025.
KANAMORI, H. et al. Role of the contaminated environment in transmission of multidrug-resistant organisms in nursing homes and infection prevention. Am. J. Infect. Control., v.51: 151-157. doi: https://doi.org/10.1016/j.ajic.2023.01.003.
KAMRUZZAMAN, M. et al. Water quality and pollution dynamics in the Padma River, Bangladesh: Characterization of microbiological and chemical contaminants. Reg. Stud. Mar. Sci., v., e104695, 2026. doi: https://doi.org/10.1016/j.rsma.2025.104695.
KAUCH, K.; BRĄGOSZEWSKA, E.; MAINKA, A. Microbiological air quality in healthcare environments: A review of selected facilities. Appl. Sci., v.15, n.16, e8976, 2025. doi: https://doi.org/10.3390/app15168976.
LABORCLIN PRODUTOS PARA LABORATÓRIOS. Sistema Bactray: Identificação bioquímica de bacilos Gram negativos. LB 172013, Rev. 18 – 06/2024. Pinhais: Laborclin, 2024.
LEE, H. et al. Assessment of airborne bacteria in the indoor of public-use facilities concentrated on influencing factors and opportunistic pathogenic bacteria. Air Qual Atmos Health, v.17, p.1725-1738, 2024. doi: https://doi.org/10.1007/s11869-024-01540-3.
LI, F. et al. Comparison of bacteremic pneumonia caused by Escherichia coli and Klebsiella pneumoniae: a retrospective study. Saudi Med. J., v.45, n.3, p.241–251, 2024. doi: https://doi.org/10.15537/smj.2024.45.3.20230428.
MASOTTI, F. et al. Airborne contamination in the food industry: An update on monitoring and disinfection techniques of air. Trends Food Sci. Technol., v.90, p.147–156, 2019. doi: https://doi.org/10.1016/j.tifs.2019.06.006.
MONARDO, R. et al. Clinical and genomic characterization of Serratia bloodstream infections: From military experiments to current practice. CMI Commun., v.2, n.4, e105128, 2025. doi: https://doi.org/10.1016/j.cmicom.2025.105128.
MONTEIRO, A. et al. High proportions of multidrug-resistant Klebsiella pneumoniae isolates in community-acquired infections, Brazil. Sci Rep., v.15, e9698, 2025. doi: https://doi.org/10.1038/s41598-025-92549-w.
NIE, T. et al. Effects of indoor air quality on human physiological impact: A review. Buildings, v. 15, n. 8, e1296, 2025. doi: https://doi.org/10.3390/buildings15081296.
NIKAEEN, M.; SHAMSIZADEH, Z.; MIRHOSEINI, S.H. Direct monitoring of Gram-negative agents of nosocomial infections in hospital air by a PCR-based approach. Aerosol Air Qual., v.18, p.2612–2617, 2018. doi: https://doi.org/10.4209/aaqr.2017.11.0441.
OLIVEIRA, M.; TIWARI, B. K.; DUFFY, G. Emerging technologies for aerial decontamination of food storage environments to eliminate microbial cross-contamination. Foods, v.9, n.12, e1779, 2020. doi: https://doi.org/10.3390/foods9121779.
OLIVER, J.C.; PAULA, R.A.O.; VEIGA, S.M.O.M. Chemical and bacteriological analysis of the water from drinking fountains located in a Higher Education Institution. Res., Soc. Dev., v.10, n.2, e8010212145, 2021. doi: https://doi.org/10.33448/rsd-v10i2.12145.
PAIVA, D.S. et al. Exploring differences in culturable fungal diversity using standard freezing incubation; a case study in the limestones of Lemos Pantheon (Portugal). J. Fungi, v.9, n.4, e501, 2023. doi: https://doi.org/10.3390/jof9040501.
PERERA, P.D.V.M. et al. Phenotypic and genotypic distribution of ESBL, AmpC β-lactamase and carbapenemase-producing Enterobacteriaceae in community-acquired and hospital-acquired urinary tract infections in Sri Lanka. J. Glob. Antimicrob. Resist., v.30, p.115-122, 2022. doi: https://doi.org/10.1016/j.jgar.2022.05.024.
PÉREZ-VISO, B. et al. A long-term survey of Serratia spp. bloodstream infections revealed an increase of antimicrobial resistance involving adult population. Microbiol. Spectr., v.12, n.2, e0242524, 2024. doi: https://doi.org/10.1128/spectrum.02425-24.
PRATAP, B. et al. Wastewater generation and treatment by various eco-friendly technologies: Possible health hazards and further reuse for environmental safety. Chemosphere, v.313, 2023. doi: https://doi.org/10.1016/j.chemosphere.2022.137547.
RAMÍREZ, O. et al. Identification of culturable fungi in particulate matter (PM10) on a university campus in a peri-urban area of Northern South America. Aerobiologia, v.41, p.591-608, 2025. doi: https://doi.org/10.1007/s10453-025-09866-w.
SBIBIH, Y. et al. Interest of water quality in clinical laboratory experience of the central laboratory of Mohammed VI University Hospital of Oujda. Mater. Today: Proc., v.72, p.3712-3717, 2023. doi: https://doi.org/10.1016/j.matpr.2022.09.128.
SÉNÉCHAL, H. et al. A review of the effects of major atmospheric pollutants on pollen grains, pollen content, and allergenicity. Sci. World J., v.2015, n.1, e940243, 2015. doi: http://dx.doi.org/10.1155/2015/940243.
STOCKWELL, R. et al. Indoor hospital air and the impact of ventilation on bioaerosols: A systematic review. J. Hosp. Infect., v. 103, p. 175-184, 2019. doi: https://doi.org/10.1016/j.jhin.2019.06.016.
VERAS, C.E. et al. Seasonal total coliform dynamics in a drinking water reservoir. Water Res., v. 284, e123850, 2025. doi: https://doi.org/10.1016/j.watres.2025.123850.
WHO - World Health Organization. Guidelines for drinking-water quality: incorporating first and second addenda – Volume 1: Recommendations. Geneva: WHO, 2008.
WHO - World Health Organization. Drinking-water. Geneva: WHO, 2023.
WHO - World Health Organization. Household air pollution. Geneva: WHO, 2024.
YIEK, W.K. et al. Outbreaks of healthcare-associated infections linked to water-containing hospital equipment: a literature review. Antimicrob Resist Infect Control., v.10, p.77, 2021. doi: https://doi: 10.1186/s13756-021-00935-6.
YOO, K. et al. Molecular approaches for the detection and monitoring of microbial communities in bioaerosols: a review. J. Environ. Sci., v.51, p.234-247, 2017. doi: https://doi.org/10.1016/j.jes.2016.07.002.
Downloads
Published
How to Cite
Issue
Section
License
Copyright (c) 2026 Etyene Maria Moreira Custódio, Emilly Brito Ferreira, Jean Lopes da Silva, Benício Alves de Abreu Filho, Fabrícia Gimenes
This work is licensed under a Creative Commons Attribution 4.0 International License.
