In Ahwaz, a city in west southern Iran, the majority of households are using Point of Use (PoU) water treatment units. The heterotrophic plate count (HPC) bacteria were isolated from these units while they were mounted on water distribution system in order to determine the variations in HPC and diversity of the bacterial population using polymerase chain reaction (PCR). Results showed that bacterial population regrowth in PoU units could increase HPC exceeding the limit of the 500 CFU/mL in outlet water. In around 70% of the input water samples, the HPC was less than 500 CFU/ml with a mean of 226.7 (CI 95%: 28.1–425.3). HPC in output treated water samples had an increasing trend from the start of the unit operation with a mean of 2416.4 (CI 95%: 1074.9–3757.9). Out of 49 detected bacterial strains, 20 strains were Gram-negative and 29 Gram-positive. Bacillus was the most frequent genes detected in inlet and outlet water samples. Most of the identified bacterial strains were opportunistic pathogens potentially dangerous for immunocompromised population. HPC population in PoU units significantly can be increased during a one-month period of operation, so replacement of the filters must be done regularly.

在伊朗南部西部城市阿瓦士，大多数家庭都在使用使用点 (PoU) 水处理装置。将异养平板计数 (HPC) 细菌从这些单元中分离出来，同时将它们安装在配水系统上，以便使用聚合酶链式反应 (PCR) 确定 HPC 的变化和细菌种群的多样性。结果表明，PoU 单位中的细菌种群再生可以增加 HPC，超过出水 500 CFU/mL 的限制。在大约 70% 的输入水样中，HPC 低于 500 CFU/ml，平均值为 226.7 (CI 95%: 28.1–425.3)。输出处理过的水样中的 HPC 从装置运行开始就呈上升趋势，平均值为 2416.4（CI 95%：1074.9-3757.9）。在检测到的 49 种细菌菌株中，芽孢杆菌是在入口和出口水样中检测到的最常见的基因。大多数已鉴定的细菌菌株是机会性病原体，对免疫功能低下的人群具有潜在危险。在一个月的运行期间，PoU 单元中的 HPC 数量会显着增加，因此必须定期更换过滤器。