title: Diversity of a chlorine-resistant Bacillus population isolated from a wastewater treatment station.
abstract: This paper describes the phenotypic and genotypic diversity of a Gram-positive, aerobic bacterial population isolated from the chlorine tank of a wastewater treatment plant. A total of 12 sporeforming, rod-shaped isolates were identified using 16S rRNA gene sequencing and biochemical tests. Pairwise genetic comparisons revealed the identity among sequences obtained from isolates varied from 92.6 to 100%. Similarity searches on GenBank showed that five strains were closely related (99 to 100% identity) to Bacillus subtilis and two were almost identical (99%) to B. megaterium and B. licheniformis. Because the five remaining strains were either closely related (97 to 99% identity) or identical to B. cereus, B. thuringiensis, and B. anthracis, they were classified as belonging to the B. cereus group. Apart from one strain, all clades in the phylogenetic tree were identical to clusters formed in the dendrogram based on biochemical tests results. According to the biochemical profiles, all isolates were characterized as different strains. In addition to chlorine resistance, all isolates were found to be resistant to at least one of five antibiotics tested. These results identify the potential risk of spreading antibiotic resistance genes in the environment by chlorine-resistant strains of Bacillus.
authors: Laboratório de Ecología Microbiana e Biotecnologia (LEMBiotech), Departamento de Biología, Universidade Federal do Ceará, Fortaleza, Ceará, Brazil.
authors: Fernanda A
authors: FA
authors: Paes
authors: Denise C
authors: DC
authors: Hissa
authors: Alysson L
authors: AL
authors: Angelim
authors: Natasha W
authors: NW
authors: Pinto
authors: Thalles B
authors: TB
authors: Grangeiro
authors: Vânia M M
authors: VM
authors: Melo
mesh_terms: D001407:Bacillus / Q000145:classification / Q000187:drug effects / Q000302:isolation & purification*; D002713:Chlorine / Q000494:pharmacology*; D004203:Disinfection; D024881:Drug Resistance, Bacterial; D010802:Phylogeny; D014865:Waste Disposal, Fluid; D014871:Water Microbiology; D018508:Water Purification
chemical_list: D002713:Chlorine