Aerosolized Microbes from Organic Rich Materials: Case Study of Bat Guano from Caves in Romania

Abstract

Cave air, bat guano, and swabs of bat fur from caves with bat guano in Romania were analyzed by using RIDAHCOUNT cultivation plates and standard selective media for Staphylococcus and Streptococcus. 7 CFU/g). The gravity-settling principle was applied to sample airborne microorganisms, and a new method was developed for evaluation of aerosolization potential. In cave air, the concentration of total bacteria was higher than yeast and molds. In addition to coliforms, enterobacteria, E. coli, and unidentified cultivable bacteria in the air samples, we also identified Chryseomonas luteola, Klebsiella pneumoniae, Micrococcus, Salmonella, Staphylococcus, and Streptococcus. In the experiment that provoked microbial aerosolization from guano, 3.35% of total cultivable fungi were aerosolized, up to 0.10% of bacteria, and 0.00% of E. coli. The concentration of Staphylococcus in the air exceeded counts of Streptococcus. The highest concentrations of airborne microorganisms were on the ground level. Using cultivation plates as a robust method we demonstrated that the relative proportion of microbial subgroups in the air remained constant in different seasons, with lower concentrations of airborne microbiota in the autumn. Caves as simplified natural systems demonstrated complex relationships between atmospheric parameters and microorganisms. Bats introduce into caves varying, but not negligible, concentrations of microbes on their fur. Caves with guano had relative high concentration of airborne microbes that may represent a biohazard for animals and humans.

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“…Overall, our results show that the external microbial communities on bats follow similar local and regional-scale bacteria patterns as noted in the eastern China soils study (Ma, et al, 2016), bat fecal and internal microbiome studies (Daniel et al, 2013;Borda et al, 2014;Leigue dos Santos et al, 2014), and share predictors with bat species richness in Arizona and New Mexico (S8). We might expect some of the microbial patterns to be driven by differences in rates of bacterial dispersion.…”

“…In a culture-dependent study by Borda et al (2014), common bacteria found in the air above guano piles included: Chryseomonas, Klebsiella, Micrococcus, Salmonella, Staphylococcus, and Streptococcus. Bacillus, Enterobacter, Enterococcus, Escherichia, Klebsiella, Pantoea, Pseudomonas and Serratia were found in the gut of the short-nosed fruit bat (Daniel et al, 2013).…”

“…Because P. destructans is a novel species for cave ecosystems in North America, it is likely affecting the natural external microbiome of bats and caves. Current microbiome studies on bats focus on the gut or fecal microbiome (Carrillo-Araujo et al, 2015;Borda et al, 2014), and knowledge on a regional-scale of the external bat microbiome in a WNS-free area is lacking. The influence of local factors including abiotic and biotic variables in geographic patterns of the bat external microbiome at the local and regional-scale is needed in order to understand the potential natural defenses of the natural external bat microbiota.…”

ATP luminescence assay as a bioburden estimator of biomass accumulation in caves

“…The gravity-settling method (Borda et al, 2014) was used to sample airborne biomass in Postojna Cave. Sterilized limestone tablets with a diameter of 41 mm were exposed to the atmosphere for 34 days, starting on 30 September 2015.…”

Identification and Characterization of Chitinase Enzyme Producing Bacteria from Bat Guano and its Potential to Inhibit The Growth of Fungus Colletotrichum Sp. Cause Anthracnose on the Chili by In Vitro

“…The results of bacterial isolation can be seen in Table 2. The number of bacteria on bat guano based on Table 2 were calculated using the formula is 3,347x10 7 cfu/ g. Microorganism diversity in guano fueled by the condition of the guano that has a high temperature and high humidity (96.5% to 99.8%) where that condition can interact with components of guano and provide nutrients for microorganisms reproduction and create a habitat for microorganisms [9].…”