在现代水基金属加工液(MWF)中定殖的微生物已与机械师的各种职业呼吸健康危害有关。了解特定微生物组/属/种(致病性或致敏性)及其内毒素的暴露风险,以及对有效,及时的流体管理保证了对微生物多样性的建立和普遍存在的流体相关因素的实时扩展跟踪。在目前的研究中,微生物群落组成,继承,并且在50周内实时跟踪了新充电的工业半合成MWF操作的动态,使用微生物和分子方法的组合。即使在新充电的MWF中,大量的初始细菌计数(可行和不可行)也表明了倾倒的效率低下,清洁,和充电(DCR)过程。随后使用优化的靶向属/组特异性qPCR进行的时间分析证实了假单胞菌的存在,Enterics,军团,分枝杆菌(M.免疫原性),放线菌,和真菌。相比之下,使用商业培养基进行选择性培养产生非特异性分离株,并共同显示革兰氏阴性(代表19个分离株的13个属)和革兰氏阳性(代表6个分离株的2个属)细菌和真菌,而不是分枝杆菌。柠檬酸杆菌sp.蜡样芽孢杆菌代表了最常见的革兰氏阴性和革兰氏阳性分离株,分别,在不同的培养基上和Nectria血球菌的分离是这种真菌病原体定植半合成MWF的第一个证据。无偏PCR-DGGE分析显示,整个群落组成更加多样化,揭示了22种细菌基因型及其演替。内毒素水平的激增与革兰氏阴性细菌种群和杀生物剂添加的峰值一致。一起来看,结果表明,半合成MWF有利于高度多样化的微生物群落的生长,包括潜在的细菌和真菌病原体,当前的DCR实践在对抗微生物重建方面效率低下,并且定期添加杀生物剂的实践促进了内毒素和非存活细菌群体的积累。
Microorganisms colonizing modern water-based metalworking fluids (MWFs) have been implicated in various occupational respiratory health hazards to machinists. An understanding of the exposure risks from specific microbial groups/genera/species (pathogenic or allergenic) and their endotoxins and the need for strategies for effective, timely fluid management warrant real-time extended tracking of the establishment of microbial diversity and the prevailing fluid-related factors. In the current study, the microbial community composition, succession, and dynamics of a freshly recharged industrial semi-synthetic MWF operation was tracked in real-time over a period of 50 weeks, using a combination of microbiological and molecular approaches. Substantial initial bacterial count (both viable and non-viable) even in the freshly recharged MWF pointed to the inefficiency of the dumping, cleaning, and recharge (DCR) process. Subsequent temporal analysis using optimized targeted genus/group-specific qPCR confirmed the presence of Pseudomonads, Enterics, Legionellae, Mycobacteria (M. immunogenum), Actinomycetes, and Fungi. In contrast, selective culturing using commercial culture media yielded non-specific isolates and collectively revealed Gram-negative (13 genera representing 19 isolates) and Gram-positive (2 genera representing 6 isolates) bacteria and fungi but not mycobacteria. Citrobacter sp. and Bacillus cereus represented the most frequent Gram-negative and Gram-positive isolates, respectively, across different media and Nectria haematococca isolation as the first evidence of this fungal pathogen colonizing semi-synthetic MWF. Unbiased PCR-DGGE analysis revealed a more diverse whole community composition revealing 22 bacterial phylotypes and their succession. Surges in the endotoxin level coincided with the spikes in Gram-negative bacterial population and biocide additions. Taken together, the results showed that semi-synthetic MWF is conducive for the growth of a highly diverse microbial community including potential bacterial and fungal pathogens, the current DCR practices are inefficient in combating microbial reestablishment, and the practice of periodic biocide additions facilitates the build-up of endotoxins and non-viable bacterial population.