Soon Kah Le, Rashid Siti Aishah, Nazakat Raheel, Al Quwatli Lujin, Shee Calvin Yin-Ming, Azman Adzzie Shazleen, Aziz Muhamad Afiq
Institute of Biological Sciences, Faculty of Science, Universiti Malaya, 50603, Kuala Lumpur, Malaysia.
Environmental Health Research Centre, Institute for Medical Research, National Institutes of Health (NIH), Ministry of Health, 40170, Shah Alam , Selangor, Malaysia.
Antonie Van Leeuwenhoek. 2025 Aug 13;118(9):128. doi: 10.1007/s10482-025-02142-4.
Water vending machines are widely utilised in various locations, including workplaces, universities and urban areas due to their convenience and accessibility. However, the microbial quality of the water dispensed from these machines, particularly in residential colleges, has not been thoroughly studied. This study aims to analyse the physicochemical and microbiological quality of drinking water collected from water vending machines located in 14 residential colleges around Universiti Malaya, Kuala Lumpur. Our study revealed that all drinking water samples met WHO acceptable limits for pH, TDS and electrical conductivity. However, dissolved oxygen and free chlorine levels were slightly below the acceptable range. No faecal contamination was detected in the drinking water samples, as indicated by the absence of enterococci and coliform bacteria, including faecal coliforms. Nevertheless, Gram-negative non-coliform bacteria were identified in water samples from 11 residential colleges. The identified bacteria included Pseudomonas spp., Acinetobacter spp., Bosea sp., Stenotrophomonas sp., Achromobacter sp., Roseatels sp. and Cupriavidus sp. Using CLSI guidelines as the standard, antibiotic sensitivity tests showed that all bacterial isolates were resistant to penicillin G (100%), while most were susceptible to ofloxacin (> 80%). Notably, Pseudomonas spp., Acinetobacter spp., Stenotrophomonas sp., Achromobacter sp. and Cupriavidus sp. were identified as multidrug-resistant bacteria, showing resistance to three or more categories of antimicrobial agents tested in this study. The biofilm assay confirmed that Bosea sp., Roseateles sp. and Acinetobacter sp. possess biofilm formation capacity. Overall, this study highlights that while the water from vending machines generally meets physicochemical standards and is free of faecal contamination, multidrug-resistant Gram-negative bacteria are still prevalent. Although these bacteria may not pose immediate health risks upon consumption, their presence poses long-term risks due to biofilm accumulation, resistance gene transfer and poor maintenance. This underscores the need for proper maintenance measures of water vending machines, including regular cleaning and effective disinfection, to ensure the microbial safety of drinking water.
由于其便利性和易获取性，售水机在包括工作场所、大学和城市地区在内的各种地点被广泛使用。然而，这些机器所供应水的微生物质量，特别是在住宿学院，尚未得到充分研究。本研究旨在分析从吉隆坡马来亚大学周边14所住宿学院的售水机收集的饮用水的理化和微生物质量。我们的研究表明，所有饮用水样本的pH值、总溶解固体（TDS）和电导率均符合世界卫生组织的可接受限值。然而，溶解氧和游离氯水平略低于可接受范围。饮用水样本中未检测到粪便污染，这表现为不存在肠球菌和大肠菌群，包括粪大肠菌群。尽管如此，在11所住宿学院的水样中鉴定出了革兰氏阴性非大肠菌群细菌。鉴定出的细菌包括假单胞菌属、不动杆菌属、博斯氏菌属、嗜麦芽窄食单胞菌属、无色杆菌属、玫瑰单胞菌属和贪铜菌属。以临床和实验室标准协会（CLSI）指南为标准，抗生素敏感性试验表明，所有细菌分离株对青霉素G均耐药（100%），而大多数对氧氟沙星敏感（>80%）。值得注意的是，假单胞菌属、不动杆菌属、嗜麦芽窄食单胞菌属、无色杆菌属和贪铜菌属被鉴定为多重耐药菌，对本研究中测试的三类或更多类抗菌药物表现出耐药性。生物膜检测证实，博斯氏菌属、玫瑰单胞菌属和不动杆菌属具有生物膜形成能力。总体而言，本研究强调，虽然售水机的水一般符合理化标准且无粪便污染，但多重耐药革兰氏阴性细菌仍然普遍存在。尽管这些细菌在饮用时可能不会立即对健康构成风险，但由于生物膜积累、耐药基因转移和维护不善，它们的存在会带来长期风险。这凸显了对售水机采取适当维护措施的必要性，包括定期清洁和有效消毒，以确保饮用水的微生物安全。
