Chloramine is a secondary disinfectant used to maintain microbial control throughout public water distribution systems. This study investigated the relationship between chloramine concentration, heterotrophic bacteria, and specific Mycobacterium species. Sixty-four water samples were collected at four locations within the utility's distribution network on four occasions. Water samples were analyzed for total chlorine and monochloramine. Traditional culture methods were applied for heterotrophic bacteria and nontuberculous mycobacteria (NTM), and specific quantitative polymerase chain reaction (qPCR) assays were used to detect and quantify Mycobacterium avium, M. intracellulare, and M. abscessus. Total chlorine and monochloramine concentrations decreased between the distribution entry point (4.7 mg/L and 3.4 mg/L as Cl₂, respectively) to the maximum residence time location (1.7 mg/L and 1.1 mg/L as Cl₂, respectively). Results showed that heterotrophic bacteria and NTM counts increased by two logs as the water reached the average residence time (ART) location. Microbiological detection frequencies among all samples were: 86% NTMs, 66% heterotrophic bacteria, 64% M. abscessus, 48% M. intracellulare, and 2% M. avium. This study shows that heterotrophic bacteria and NTM are weakly correlated with disinfectant residual concentration, R²=0.18 and R²=0.04, respectively. Considering that specific NTMs have significant human health effects, these data fill a critical knowledge gap regarding chloramine's impact on heterotrophic bacteria and Mycobacterial species survival within public drinking water distribution systems.

氯胺是一种二次消毒剂，用于维持整个公共供水系统的微生物控制。本研究调查了氯胺浓度、异养细菌和特定分枝杆菌种类之间的关系。共四次在公用事业配送网络内的四个地点采集了 64 份水样。分析水样的总氯和一氯胺。异养菌和非结核分枝杆菌（NTM）采用传统培养方法，特异性定量聚合酶链反应（qPCR）检测用于鸟分枝杆菌、 胞内分枝杆菌和 脓肿分枝杆菌的检测和定量. 总氯和一氯胺浓度在分布入口点（分别为 4.7 mg/L 和 3.4 mg/L 作为 Cl ₂）到最大停留时间位置（分别为 1.7 mg/L 和 1.1 mg/L 作为 Cl ₂）之间下降。结果表明，随着水达到平均停留时间 (ART) 位置，异养细菌和 NTM 计数增加了两个对数。所有样品的微生物检测频率为：86% NTM、66% 异养细菌、64%脓肿分枝杆菌、48%胞内分枝杆菌和 2%鸟分枝杆菌。本研究表明异养菌和NTM与消毒剂残留浓度呈弱相关，R ² =0.18，R² = 0.04，分别。考虑到特定的 NTM 对人类健康有重大影响，这些数据填补了关于氯胺对公共饮用水分配系统中异养细菌和分枝杆菌物种生存影响的关键知识空白。