{"title":"Microbial contamination of air filters of air conditioning system of urban buses.","authors":"D Obitková, C Čereiová, M Mráz, E Pavlík","doi":"10.61568/emi/11-6492/20250428/140416","DOIUrl":null,"url":null,"abstract":"<p><p>The use of HVAC in urban buses in developed countries increases the comfort and indoor air quality in the means of ground transportation. The microbial contamination was studied on outlet and inlet surfaces of 5 air filters removed from the urban buses HVAC during regular maintenance. To acquire samples from both the outlet and the inlet sides of the filters, dry swabbing technique was used. Cultivation was performed on different selective or selective-diagnostic agars, to cultivate viable bacteria. To identify the bacterial species, Gram stain and immerse microscopy was used. Selected colonies underwent the proteomic study (MALDI-TOF) as well. After identification, bacteria were quantified. The bacteria of the genus Bacillus - Bacillus cereus, Bacillus subtilis, Bacillus licheniformis, Bacillus pumilus, Bacillus flexus prevailed on both inlet and outlet surfaces of the filters. The members of genera Staphylococcus, Brevibacillus, Peribacillus or Paenibacillus were also identified. The quantification of colony forming units showed low contamination of the outlet surfaces of filters 1 and 2. The contamination of inlet and outlet sides of filters 3, 4, and 5 was comparable, revealed nearly the same contamination of inlet and outlet surfaces. In the case of filters 3, 4 and 5 we recommend more frequent filter changing or more efficient filter choice.</p>","PeriodicalId":54374,"journal":{"name":"Epidemiologie Mikrobiologie Imunologie","volume":"74 2","pages":"107-112"},"PeriodicalIF":0.5000,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Epidemiologie Mikrobiologie Imunologie","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.61568/emi/11-6492/20250428/140416","RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"MICROBIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
The use of HVAC in urban buses in developed countries increases the comfort and indoor air quality in the means of ground transportation. The microbial contamination was studied on outlet and inlet surfaces of 5 air filters removed from the urban buses HVAC during regular maintenance. To acquire samples from both the outlet and the inlet sides of the filters, dry swabbing technique was used. Cultivation was performed on different selective or selective-diagnostic agars, to cultivate viable bacteria. To identify the bacterial species, Gram stain and immerse microscopy was used. Selected colonies underwent the proteomic study (MALDI-TOF) as well. After identification, bacteria were quantified. The bacteria of the genus Bacillus - Bacillus cereus, Bacillus subtilis, Bacillus licheniformis, Bacillus pumilus, Bacillus flexus prevailed on both inlet and outlet surfaces of the filters. The members of genera Staphylococcus, Brevibacillus, Peribacillus or Paenibacillus were also identified. The quantification of colony forming units showed low contamination of the outlet surfaces of filters 1 and 2. The contamination of inlet and outlet sides of filters 3, 4, and 5 was comparable, revealed nearly the same contamination of inlet and outlet surfaces. In the case of filters 3, 4 and 5 we recommend more frequent filter changing or more efficient filter choice.
期刊介绍:
The journal publishes original papers, information from practice, reviews on epidemiological and microbiological subjects. Sufficient space is devoted to diagnostic methods from medical microbiology, parasitology, immunology, and to general aspects and discussions pertaining to preventive medicine. It also brings translations and book reviews useful for medical doctors and research workers and professionals in public health.