Unusual pathogenic bacterium isolated from microbial communities of bioaerosols at Chilean Patagonian lakes

Abstract

Bioaerosols are transported from warm regions and lower latitudes of the planet to colder regions and higher latitudes, such as the Chilean Patagonia. The role of bioaerosols deposition in remote lake ecosystems is a potentially important process, but it has not yet been fully studied. The aim of this study was to detect and characterize potentially pathogenic viable microorganisms in bioaerosols in a pristine area. Samples were collected from the air, at three remote lakes in the Chilean Patagonia, using a sterile filtration system equipped with 0.2-lm-pore-size nitrocellulose filters. The bacterial community present in bioaerosols was studied using scanning electron microscopy (SEM) and denaturing gradient gel electrophoresis. Isolates were identified and characterized for phenotypic and 16S rDNA analysis and antibiotic resistance. SEM observations of samples from each lake showed the presence of bacteria with different morphologies, and after culturing, the identification results revealed that they were strains of Acinetobacter, Alcaligenes, Edwarsiella, Pseudomonas, Burklolderia, Moraxella, Sphingomonas and CDC NO-1. CDC NO-1, uncommonly isolated worldwide, stands out from the rest of the isolates because it is a rarely found bacterium so far associated with dog and cat bites and was found at two out of three pristine lakes studied (Alto and Verde). This work demonstrates, for the first time, the presence of CDC NO-1, a clinically important Gram-negative microorganism, in bioaerosols and first report of CDC-NO1 isolation in Chile. Besides its presence in remote lakes, its antibiotic resistance is worth mentioning.

Bioaerosol Sources, Sampling Methods, and Major Categories: A Comprehensive Overview

“…Denaturing gradient gel electrophoresis (DGGE) is a culture-independent technique used to analyze the genetic diversity of complex microbial populations; it is based on separating PCR-amplified fragments of different sequences while maintaining the same fragment length (Muyzer et al, 1993). DGGE has been used to analyze airborne communities in many studies (Nehme et al, 2008;Kim et al, 2011;Xu and Yao, 2013;Escalante et al, 2014;Tanaka et al, 2015). PCR is used to amplify the DNA region of interest prior to the traditional Sanger sequencing.…”