This study aimed to assess the microbiological quality of natural mineral waters commercialized in 20 L returnable packs in Brazil by investigating the presence of bacteria and viruses in packs with different manufacturing times (T_m). With this purpose, 99 water samples from 33 lots (n = 3/batch) of 15 brands, obtained from packs with three intervals of T_m, were analyzed. Total coliforms (16.2%), Pseudomonas aeruginosa (9.9%), sulphite-reducing Clostridium (5.0%) and Escherichia coli (2.0%) were detected but enterococci and norovirus GII not. Regarding brands, 11 (73.3%) presented unsatisfactory results for at least one of the lots analyzed. Pseudomonas aeruginosa analysis revealed six sequence types and strains were susceptible to all antibiotics tested and were able to produce biofilms. Human adenovirus (4) and norovirus GI (9) were also identified in nine samples randomly selected. Natural mineral waters commercialized in 20 L packs with T_m ≥ 2 years presented more microbiological contamination (P ≤ 0.012) than ones with a T_m of 0–1 year or a T_m of 1–2 years. These results suggest that the validity period of reusable 20 L packs should be reduced or that they can no longer be reused.

中文翻译：

---

根据巴西20升可回收包装的生产时间，评估天然矿泉水的微生物质量。

这项研究旨在通过调查不同制造时间（T _m）的包装中细菌和病毒的存在，评估巴西20升可回收包装中商业化的天然矿泉水的微生物质量。为此，分析了 从三个间隔为T _m的包装中获得的15个品牌的33个批次（n = 3 /批次）中的99个水样。检出总大肠菌群（16.2％），铜绿假单胞菌（9.9％），还原亚硫酸盐梭菌（5.0％）和大肠杆菌（2.0％），但未检测到肠球菌和诺如病毒GII。对于品牌，至少有11个批次（73.3％）的分析结果不令人满意。铜绿假单胞菌分析显示六种序列类型和菌株对所有测试的抗生素敏感，并能够产生生物膜。在随机选择的九个样本中还鉴定了人腺病毒（4）和诺如病毒GI（9）。天然矿泉水中有T 20个包商品化_米 ≥2年呈现更多的微生物污染（P 比那些具有T≤0.012）_米0-1岁的或T_米的1 - 2年。这些结果表明，应减少可重复使用的20升包装的有效期，或者它们无法再使用。