All Issue

2025 Vol.55, Issue 2 Preview Page

Original Article

Abundance, Diversity, and Antibiotic Resistance of Aeromonas spp. in Well Water from Selected Barangays in Iloilo City, Philippines
Lois Recalcar1
,
Therese Angela Leñar1
,
Kylene Marie Luzano1
,
William Matandac Jr.1
,
Miles Roland Pentojo1
,
Simon John Robles1
,
Stephen Sabinay23
,
Peter Palma4
,
Rolando Pakingking Jr.1*
1College of Medical Laboratory Science, Central Philippine University, Jaro, Iloilo City 5000, Iloilo, Philippines
2Biotechnology and Biomedical Research Laboratory, West Visayas State University, College of Medicine, Luna St., La Paz, Iloilo City, 5000, Iloilo, Philippines
3Physical Sciences Department, College of Arts and Sciences, West Visayas State University, Luna St., La Paz, Iloilo City, 5000, Iloilo, Philippines
4Institute of Aquaculture, University of Stirling, Stirling FK9 4LA, Scotland, United Kingdom
*rolando102969@gmail.com
30 June 2025. pp. 160-175
PDF XML Citation
Abstract

This study investigated the abundance, diversity, and antibiotic resistance patterns of Aeromonas spp. in well water from five selected barangays (villages) in Iloilo City, alongside heterotrophic bacterial counts and physicochemical parameters during the dry (March to May) and wet (June to August) seasons. Presumptive Aeromonas counts reached 10³ CFU/mL during the dry season and 10² CFU/mL during the wet season, while heterotrophic plate counts peaked at 10⁴ CFU/mL and 10³ CFU/mL, respectively. Seasonal variations significantly influenced water quality, with higher temperatures, biochemical oxygen demand, and total dissolved solids recorded during the dry season, while dissolved oxygen levels were elevated during the wet season (p < 0.05). Aeromonas hydrophila was the most prevalent (59%), followed by A. veronii (21%). Other predominant bacterial species included Escherichia coli (12%), Enterococcus faecium (5%), and Staphylococcus aureus (7%), the latter found only in the wet season. Antimicrobial susceptibility testing of 10 antibiotics commonly used in human-veterinary medicine, and aquaculture, revealed high resistance to amoxicillin (A. hydrophila: 98.6%; A. veronii: 96%; E. faecium: 100%; E. coli: 100%; S. aureus: 100%), erythromycin (100%; 60%; 100%; 100%; 100%), and neomycin (97.1%; 92%; 50%; 57.1%; 100%). Multidrug resistance was widespread, with MAR indices exceeding 0.2, indicating substantial antibiotic exposure and contamination from high-risk sources. This is the first report on the load, composition, and antibiotic resistance of Aeromonas spp. in well water in the Philippines, underscoring the need for continuous microbial monitoring, improved well-water disinfection, and strengthened antibiotic stewardship to mitigate public health risks associated with contaminated groundwater sources.

Keywords
Well water
Aeromonas hydrophila
Antibiotic
Resistance
MAR index
References
1

WHO. World Health Organization. 2023. Available at https://www.who.int/initiatives/sdg3-global-action-plan/pro gress-and-impact/progress-reports/2023 [accessed on 20 February 2025].

2

He C, Liu Z, Wu J, Pan X, Fang Z, Li J, et al. Future global urban water scarcity and potential solutions. Nat Commun. 2021;12(1):4667.

10.1038/s41467-021-25026-334344898PMC8333427
3

Fernández-Bravo A, Figueras MJ. An Update on the genus Aeromonas: Taxonomy, epidemiology, and pathogenicity. Microorganisms. 2020;8(1):129.

10.3390/microorganisms801012931963469PMC7022790
4

Gonçalves Pessoa RB, de Oliveira WF, Marques DSC, dos Santos Correia MT, de Carvalho EVMM, Breitenbach Barroso Coelho LC. The genus Aeromonas: A general approach. Microb Pathog. 2019;130:81-94.

10.1016/j.micpath.2019.02.03630849490
5

Janda JM, Abbott SL. The Genus Aeromonas: Taxonomy, Pathogenicity, and Infection. Clin Microbiol Rev. 2010;23(1):35-73.

10.1128/CMR.00039-0920065325PMC2806660
6

Didugu H, Thirtham M, Nelapati K, Reddy KK, Kumbhar BS, Poluru A, et al. A study on the prevalence of Aeromonas spp. and its enterotoxin genes in samples of well water, tap water, and bottled water. Vet World. 2015;8(10):1237-1242.

10.14202/vetworld.2015.1237-124227047024PMC4774662
7

Khor WC, Puah SM, Tan JA, Puthucheary SD, Chua KH. Phenotypic and genetic diversity of Aeromonas species isolated from fresh water lakes in Malaysia. PLOS ONE. 2015;10(12):e0145933.

10.1371/journal.pone.014593326710336PMC4692508
8

Baron S, Granier SA, Larvor E, Jouy E, Cineux M, Wilhelm A, et al. Aeromonas Diversity and antimicrobial susceptibility in freshwater-an attempt to set generic epidemiological cut-off values. Front Microbiol. 2017;8:503.

10.3389/fmicb.2017.0050328400760PMC5368242
9

Figueira V, Vaz-Moreira I, Silva M, Manaia CM. Diversity and antibiotic resistance of Aeromonas spp. in drinking and waste water treatment plants. Water Res. 2011;45(17):5599-5611.

10.1016/j.watres.2011.08.02121907383
10

Igbinosa IH, Igumbor EU, Aghdasi F, Tom M, Okoh AI. Emerging Aeromonas species infections and their significance in public health. Scientific World Journal. 2012;2012:625023.

10.1100/2012/62502322701365PMC3373137
11

Pakingking R Jr, Española JG, Palma P, Usero R. Motile aeromonads recovered from tilapia (Oreochromis niloticus) cultured in earthen ponds in the Philippines: assessment of antibiotic susceptibility and multidrug resistance to selected antibiotics. Israeli J Aquaculture - Bamidgeh. 2022;74.

10.46989/001c.37010
12

Khajanchi BK, Fadl AA, Borchardt MA, Berg RL, Horneman AJ, Stemper ME, et al. Distribution of virulence factors and molecular fingerprinting of Aeromonas species isolates from water and clinical samples: suggestive evidence of water-to-human transmission. Appl Environ Microbiol. 2010;76(7):2313-2325.

10.1128/AEM.02535-0920154106PMC2849238
13

Baird RB, Eaton AD, Rice EW, Bridgewater L. Standard methods for the examination of water and wastewater. American Public Health Association. Published online 2017.

14

Pakingking R Jr, Palma P, Usero R. Quantitative and qualitative analyses of the bacterial microbiota of tilapia (Oreochromis niloticus) cultured in earthen ponds in the Philippines. World J Microbiol Biotechnol. 2015;31(2):265-275.

10.1007/s11274-014-1758-125555375
15

Pakingking R Jr, Palma P, Usero R. Aeromonas load and species composition in tilapia (Oreochromis niloticus) cultured in earthen ponds in the Philippines. Aquaculture Research. 2020;51(11):4736-4747.

10.1111/are.14820
16

Holt JG. Bergey's Manual of Determinative Bacteriology. Baltimore: Lippincott Williams & Wilkins; 1994.

17

Bauer AW, Kirby WM, Sherris JC, Turck M. Antibiotic susceptibility testing by a standardized single disk method. Am J Clin Pathol. 1966;45(4):493-496.

10.1093/ajcp/45.4_ts.4935325707
18

Gołaś I. The influence of aquaculture effluents on the prevalence and biocides resistance of opportunistic Pseudomonas fluorescens Bacteria in the Drwęca River Protected under the Natura 2000 Network. Water. 2020;12(7):1947.

10.3390/w12071947
19

Clinical and Laboratory Standards Institute. Performance Standards for Susceptibility Tests, Approved Standard, 11th ed. Published online 2012.

20

Krumperman PH. Multiple antibiotic resistance indexing of Escherichia coli to identify high-risk sources of fecal contamination of foods. Appl Environ Microbiol. 1983;46(1):165-170.

10.1128/aem.46.1.165-170.19836351743PMC239283
21

Stratev D, Odeyemi OA. Antimicrobial resistance of Aeromonas hydrophila isolated from different food sources: A mini-review. J Infect Public Health. 2016;9(5):535-544.

10.1016/j.jiph.2015.10.00626588876
22

Ghenghesh KS, El-Ghodban A, Dkakni R, Abeid S, Altomi A, Abdussalam T, et al. Prevalence, species differentiation, haemolytic activity, and antibiotic susceptibility of aeromonads in untreated well water. Mem Inst Oswaldo Cruz. 2001;96(2):169-173.

10.1590/S0074-0276200100020000611285492
23

Rahim Z, Khan SI, Chopra AK. Biological characterization of Aeromonas spp. isolated from the environment. Epidemiol Infect. 2004;132(4):627-636.

10.1017/S095026880400229815310164PMC2870143
24

Kozak C, Fernandes CVS, Braga SM, do Prado LL, Froehner S, Hilgert S. Water quality dynamic during rainfall episodes: integrated approach to assess diffuse pollution using automatic sampling. Environ Monit Assess. 2019;191(6):402.

10.1007/s10661-019-7537-631134382
25

Liu Y, Guo W, Wei C, Huang H, Nan F, Liu X, et al. Rainfall-induced changes in aquatic microbial communities and stability of dissolved organic matter: Insight from a Fen river analysis. Environ Res. 2024;246:118107.

10.1016/j.envres.2024.11810738181848
26

van Bel N, van der Wielen P, Wullings B, van Rijn J, van der Mark E, Ketelaars H, et al. Aeromonas species from non-chlorinated distribution systems and their competitive planktonic growth in drinking water. Appl Environ Microbiol. 2021;87(5):e02867-20.

10.1128/AEM.02867-2033310721PMC8090877
27

Odeyemi OA, Ahmad A. Antibiotic resistance profiling and phenotyping of Aeromonas species isolated from aquatic sources. Saudi J Biol Sci. 2017;24(1):65-70.

10.1016/j.sjbs.2015.09.01628053573PMC5198916
28

Harnisz M, Korzeniewska E. The prevalence of multidrug-resistant Aeromonas spp. in the municipal wastewater system and their dissemination in the environment. Sci Total Environ. 2018;626:377-383.

10.1016/j.scitotenv.2018.01.10029353783
29

Carabin A, Cassivi A, Dorea C, Rodriguez M, Huot C. Heterotrophic plate counts (HPC) in drinking water distribution systems: A comprehensive review and meta-analysis. Water Quality Research Journal. 2024;59(3):126-158.

10.2166/wqrj.2024.027
30

Molale-Tom LG, Olanrewaju OS, Kritzinger RK, Fri J, Bezuidenhout CC. Heterotrophic bacteria in drinking water: evaluating antibiotic resistance and the presence of virulence genes. Microbiol Spectr. 2024;12(2):e03359-23.

10.1128/spectrum.03359-2338205959PMC10845987
31

Bagordo F, Brigida S, Grassi T, Caputo MC, Apollonio F, De Carlo L, et al. Factors influencing microbial contamination of groundwater: a systematic review of field-scale studies. Microorganisms. 2024;12(5):913.

10.3390/microorganisms1205091338792743PMC11124417
32

Santarosa LV, Pinto GVF, Blandón L, Juan S, Gastmans D. Remote sensing to quantify potential aquifer recharge as a complementary tool for groundwater monitoring. Hydrological Sciences Journal. 2024;69(16):2455-2465.

10.1080/02626667.2024.2412741
33

Gomez EJ, Delgado JA, Gonzalez JM. Environmental factors affect the response of microbial extracellular enzyme activity in soils when determined as a function of water availability and temperature. Ecol Evol. 2020;10(18):10105-10115.

10.1002/ece3.667233005367PMC7520203
34

John DE, Rose JB. Review of factors affecting microbial survival in groundwater. Environ Sci Technol. 2005;39(19):7345-7356.

10.1021/es047995w16245801
35

Sun C, Wang Z, Li Y, Huang J. Antibiotic resistance spectrums of Escherichia coli and Enterococcus spp. strains against commonly used antimicrobials from commercial meat-rabbit farms in Chengdu City, Southwest China. Front Vet Sci. 2024;11:1369655.

10.3389/fvets.2024.136965538756516PMC11096573
36

Vestergaard M, Frees D, Ingmer H. Antibiotic resistance and the MRSA problem. Microbiol Spectr. 2019;7(2).

10.1128/microbiolspec.GPP3-0057-201830900543PMC11590431
Information
  • Publisher :The Korean Society for Microbiology and The Korean Society of Virology
  • Publisher(Ko) :대한미생물학회‧대한바이러스학회
  • Journal Title :JOURNAL OF BACTERIOLOGY AND VIROLOGY
  • Volume : 55
  • No :2
  • Pages :160-175
  • Received Date : 2025-04-03
  • Revised Date : 2025-06-11
  • Accepted Date : 2025-06-18
  • DOI :https://doi.org/10.4167/jbv.2025.55.2.160
Journal Informaiton JOURNAL OF BACTERIOLOGY AND VIROLOGY JOURNAL OF BACTERIOLOGY AND VIROLOGY
  • NRF
  • 임플란트학회 전용 배너
  • KOFST
  • crossref crossmark
  • crossref cited-by
  • crossref funder-registry
  • crosscheck
  • orcid
  • open access
  • ccl
Journal Informaiton Journal Informaiton - close