Extreme temperature gradients in polar volcanoes are capable of selecting different types of extremophiles. Deception Island is a marine stratovolcano located in maritime Antarctica. The volcano has pronounced temperature gradients over very short distances, from as high as 100°C in the fumaroles to subzero next to the glaciers. These characteristics make Deception a promising source of a variety of bioproducts for use in different biotechnological areas. In this study, we isolated thermophilic bacteria from sediments in fumaroles at two geothermal sites on Deception Island with temperatures between 50 and 100°C, to evaluate the potential capacity of these bacteria to degrade petroleum hydrocarbons and produce biosurfactants under thermophilic conditions. We isolated 126 thermophilic bacterial strains and identified them molecularly as members of genera Geobacillus, Anoxybacillus, and Brevibacillus (all in phylum Firmicutes). Seventy-six strains grew in a culture medium supplemented with crude oil as the only carbon source, and 30 of them showed particularly good results for oil degradation. Of 50 strains tested for biosurfactant production, 13 showed good results, with an emulsification index of 50% or higher of a petroleum hydrocarbon source (crude oil and diesel), emulsification stability at 100°C, and positive results in drop-collapse, oil spreading, and hemolytic activity tests. Four of these isolates showed great capability of degrade crude oil: FB2_38 (Geobacillus), FB3_54 (Geobacillus), FB4_88 (Anoxybacillus), and WB1_122 (Geobacillus). Genomic analysis of the oil-degrading and biosurfactant-producer strain FB4_88 identified it as Anoxybacillus flavithermus, with a high genetic and functional diversity potential for biotechnological applications. These initial culturomic and genomic data suggest that thermophilic bacteria from this Antarctic volcano have potential applications in the petroleum industry, for bioremediation in extreme environments and for microbial enhanced oil recovery (MEOR) in reservoirs. In addition, recovery of small-subunit rRNA from metagenomes of Deception Island showed that Firmicutes is not among the dominant phyla, indicating that these low-abundance microorganisms may be important for hydrocarbon degradation and biosurfactant production in the Deception Island volcanic sediments.
Resistance in Neisseria gonorrhoeae is a global public health challenge. However, little is known about N. gonorrhoeae isolates from Brazil. In this study, we characterized 116 N. gonorrhoeae isolates obtained in Rio de Janeiro between 2006 and 2015 according to antimicrobial susceptibility profiles, resistance mechanisms, and clonal diversity. We determined antimicrobial minimal inhibitory concentrations by agar dilution, and whole genome sequencing was conducted to investigate alleles related to resistance, determine multilocus sequence typing profiles, and group isolates based on core genome single nucleotide polymorphisms. Resistance to penicillin, tetracycline, ciprofloxacin, and azithromycin was observed since 2006. Resistance to penicillin was mediated by β-lactamase plasmids and chromosomal mutations in ponA and porB genes, and tetracycline resistance was mediated by TetM plasmids, and porB and rspJ mutations. Ciprofloxacin resistant isolates presented cumulative point mutations in the quinolone resistance-determining region (QRDR) of gyrA and parC. Alterations in rrl genes encoding 23S rRNA, mtrR, and the mtrR promoter region were responsible for resistance to azithromycin. Phylogenetic analysis identified seven main clades, which included isolates with similar resistance profiles that mainly belonged to a limited number of sequence types that occurred during different years. Our results demonstrated high penicillin, tetracycline, and ciprofloxacin resistance rates associated with the persistence of successful resistant gonococcal lineages, and the polyclonal emergence of azithromycin resistance. Moreover, we reinforce the importance of surveillance to monitor the evolution of this scenario and to allow the early detection of possible changes to azithromycin and ceftriaxone as effective treatment options in the city.
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