Isolation of Brevibacillus brevis from tracheal aspirates of a hospitalized patient

Isolation of phages against Streptococcus species in the oral cavity for potential control of dental diseases and associated systemic complications

Dental infections and systemic complications caused by Streptococcus species in the oral cavity are increasingly exhibiting resistance to commonly used antibiotics, posing a potential threat to global public health. Phage therapy may offer a superior alternative, given that bacteriophages can be easily isolated and rapidly replicate in large numbers. In this study, six Streptococcus species from the oral cavity were characterized. Bacteriophages isolated from wastewater using five of these species as hosts produced plaques ranging from 0.2 to 2.4 mm in size. The phages demonstrated stability within a temperature range of 4 ℃ to 37 ℃. However, at temperatures exceeding 45 ℃, a noticeable reduction in bacteriophage titer was observed. Similarly, the phages showed greater stability within a pH range of 5 to 10. The isolated phages exhibited latency periods ranging from 15 to 20 min and had burst sizes varying from 10 to 200 viral particles. This study supports the potential use of bacteriophages in controlling infections caused by Streptococcus species.

A Case of Brevibacillus brevis Meningitis and Bacteremia

Brevibacillus species are environmental organisms that are rarely implicated as human pathogens. We present the case of postsurgical Brevibacillus brevis bacterial meningitis and an associated bacteremia after debulking surgery for a newly diagnosed pilocytic astrocytoma in a 19-year-old woman. The patient experienced clinical cure with a 4-week course of vancomycin, but her postinfectious course was complicated by the development of a pseudomeningocele that required surgical repair. To our knowledge, this is the first described case of a central nervous system infection caused by Brevibacillus brevis in the literature.

Screening of a beta-cypermethrin-degrading bacterial strain Brevibacillus parabrevis BCP-09 and its biochemical degradation pathway

A novel beta-cypermethrin (Beta-CP)-degrading strain isolated from activated sludge was identified as Brevibacillus parabrevis BCP-09 based on its morphological and physio-biochemical characteristics, and 16S rRNA gene analysis. Strain BCP-09 could effectively degrade Beta-CP at pH 5.0-9.0, 20-40 °C, and 10-500 mg L^-1 Beta-CP. Under optimal conditions (pH 7.41, 38.9 °C, 30.9 mg L^-1 Beta-CP), 75.87% Beta-CP was degraded within 3 days. Beta-CP degradation (half-life, 33.45 h) and strain BCP-09 growth were respectively described using first-order-kinetic and logistic-kinetic models. Seven metabolites were detected by high-performance liquid chromatography and gas chromatography-mass spectrometry- methyl salicylate, catechol, phthalic acid, salicylic acid, 3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylic acid, 3-phenoxybenzaldehyde, and 3-phenoxybenzoic acid (3-PBA). The major Beta-CP metabolite, 3-PBA was further degraded into phenol, benzoic acid, and 4-methylhexanoic acid. BCP-09 also degraded aromatic compounds such as phenol, catechol, and protocatechuic acid. Beta-CP appears to be mainly degraded into 3-PBA, which is continuously degraded into smaller benzene or chain compounds. Thus, strain BCP-09 could form a complete degradation system for Beta-CP and might be considered a promising strain for application in the bioremediation of environments and agricultural products polluted by Beta-CP.