Evidence map›Paper›PMID 40801958›Full record

ArticleAntonie van Leeuwenhoek2025

Hidden risks of biofilm-forming and multidrug-resistant Gram-negative bacteria in water vending machines.

Kah Le Soon, Siti Aishah Rashid, Raheel Nazakat, Lujin Al Quwatli, Calvin Yin-Ming Shee, Adzzie Shazleen Azman, Muhamad Afiq Aziz

Abstract read
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In one paragraph

Article in Antonie van Leeuwenhoek, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

1 citing paper in PubMed.

  1. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

7 authors.

Kah Le SoonInstitute of Biological Sciences, Faculty of Science, Universiti Malaya, 50603, Kuala Lumpur, Malaysia.
Siti Aishah RashidEnvironmental Health Research Centre, Institute for Medical Research, National Institutes of Health (NIH), Ministry of Health, 40170, Shah Alam , Selangor, Malaysia.
Raheel NazakatEnvironmental Health Research Centre, Institute for Medical Research, National Institutes of Health (NIH), Ministry of Health, 40170, Shah Alam , Selangor, Malaysia.
Lujin Al QuwatliInstitute of Biological Sciences, Faculty of Science, Universiti Malaya, 50603, Kuala Lumpur, Malaysia.
Calvin Yin-Ming SheeInstitute of Biological Sciences, Faculty of Science, Universiti Malaya, 50603, Kuala Lumpur, Malaysia.
Adzzie Shazleen AzmanSchool of Science, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway, 47500, Subang Jaya, Selangor, Malaysia.
Muhamad Afiq AzizInstitute of Biological Sciences, Faculty of Science, Universiti Malaya, 50603, Kuala Lumpur, Malaysia. afiqaziz@um.edu.my.

Funding

Universiti Malaya Sustainable Development Centre (UMSDC) LL2023FYP010
6 · The paper itself

Abstract

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.

Indexed as

BiofilmsDrinking WaterDrug Resistance, Multiple, BacterialGram-Negative BacteriaWater MicrobiologyAnti-Bacterial AgentsHumansMalaysiaMicrobial Sensitivity TestsAnti-Bacterial AgentsDrinking WaterAntibiotic resistanceBiofilm formationDrinking water qualityGram-negative bacteriaVending machines

Identifiers

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Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.