Water as a Source of Indoor Air Contamination with Potentially Pathogenic Aeromonas hydrophila in Aquaculture.

Iwona Gołaś,Mariusz Szmyt,Katarzyna Glińska-Lewczuk

doi:10.3390/ijerph19042379

Abstract

Human activities influence the presence of potentially pathogenic bacteria in indoor air. The aim of this study was to determine the effect of the experimental rearing of European grayling and European perch in a recirculating aquaculture system on the contamination of indoor air with potentially pathogenic Aeromonas hydrophila (PPAH) and the resulting health risks to humans. The PPAH counts, their resistance to seven antibiotics, and the multiple antibiotic resistance (MAR) index were determined in samples of indoor air and water from rearing tanks. The PPAH counts were highest in the laboratory bioaerosol where two fish species were reared. The calculated indoor/outdoor ratio (I/O > 1) demonstrated that tank water was the internal source of PPAH emissions. The unconstrained PCA revealed strong positive relationships (p ≤ 0.05) between the PPAH counts in the indoor air and water samples. Most of the PPAH strains isolated from laboratory air were resistant to tetracycline, cefotaxime, and erythromycin, and 26–82% of the isolates exhibited multiple drug resistance. The values of the MAR index were similar in samples of laboratory air and water (0.23–0.34 and 0.24–0.36, respectively). Agglomerative clustering revealed two clusters of strains isolated from laboratory air and tank water. The results of this study indicate that aquaculture can be a source of indoor air contamination with PPAH.

Highlights

Indoor air is a highly dynamic system where particles of biological and non-biological origin are distributed and displaced
In the air samples collected from the laboratory (LAEG, LAEP), where rearing experiments were conducted on European grayling and European perch, the counts of potentially pathogenic A. hydrophila (PPAH) were several-fold higher than those in the outdoor air samples (CAEG and CAEP)
The bacterial strains isolated from laboratory air (LAEG and LAEP) were examined for resistance to seven popular antibiotics, and the analysis revealed that the laboratory employees were at a higher risk of infection

Summary

Introduction

Indoor air is a highly dynamic system where particles of biological and non-biological origin are distributed and displaced. The microbiological quality and safety of indoor air (IAQ) affect human health. During a single working day, employees breathe in around 10 m3 of air, and 106 microbial cells reach their lungs [1,2]. Bioaerosol particles are one of the main causes of poor air quality, and their content in indoor air can be as high as 34% [4]. Bioaerosols pose a serious health threat for humans because airborne bacteria and fungi can cause respiratory and digestive tract infections, as well as infections of the skin, eyes, and ears. Human activities and animal rearing can be a source of indoor contamination with microbial species that are predominant in bioaerosols [2,5,6]

Objectives

Methods

Results

Discussion

Conclusion