[Influence of magnetic field on the growth of pathogen microorganisms isolated from the indoor environment at the Archivo Nacional de la República de Cuba].

Abstract

INTRODUCTION: Electromagnetic pollution has been detected at the Archivo Nacional de la República de Cuba and the influence of extremely low frequency magnetic fields could be quantified with pathogenic microorganisms isolated from the indoor environment. OBJECTIVE: To quantify the influence of an extremely low frequency magnetic field on the growth of pathogenic microorganisms isolated from the environment at the Archivo Nacional. MATERIALS AND METHODS: We used five microorganisms isolated at the Archivo Nacional: Streptococcus sp. (1), Listeria sp. (2) and Candida guillermondii (3), and Escherichia coli ATCC 25922 (4) and Saccharomyces cerevisiae (5) as references. We applied this magnetic field of extremely low frequency, 60 Hz/220 V (3 mT), for two hours to these microorganisms on three culture tubes with distilled water and nutrient broth. Then we inoculated 0.1 mL in the following solid culture mediums on Petri dishes: CromoCen SC Agar (1 and 2), Potato Dextrose Agar (3), CromoCen DC 4227 (4) and Malt Extract Agar (5). The colonies were counted (log CFU/mL) by digital processing of the images of Petri dishes using the MatLab ® tool. RESULTS: We observed a statistically significant stimulation (p=0.05) in the quantity of treated colonies as compared to controls, which was higher in nutrient broth than in distilled water, and in bacteria (nutrient broth and treated colonies: 9.43 to 10.62 CFU/mL) as compared with yeasts (nutrient broth-treated colonies: 8.31 to 8.79 CFU/mL). In decreasing order, stimulation was as follows: Listeria sp., E. coli ATCC 25922, Streptococcus sp., C. guillermondii and S. cerevisiae . CONCLUSION: We concluded that the magnetic field applied had a stimulating effect on the microorganisms under study, which increases the risk to the health of staff and visitors at the Archivo Nacional .

AI evidence extraction

Main findings

An extremely low frequency magnetic field exposure (60 Hz, 3 mT) for 2 hours produced a statistically significant stimulation (p=0.05) in colony quantity in treated samples compared with controls. The stimulation was greater in nutrient broth than in distilled water and greater for bacteria than for yeasts; the reported decreasing order of stimulation was Listeria sp., E. coli ATCC 25922, Streptococcus sp., Candida guillermondii, and Saccharomyces cerevisiae.

Outcomes measured

• Microbial growth/colony counts (log CFU/mL)
• Differences in growth between treated vs control conditions
• Comparison of growth effects by medium (nutrient broth vs distilled water)
• Comparison of growth effects by organism type (bacteria vs yeasts)

Limitations

• Sample size/number of replicates not reported in the abstract
• Only five microorganisms tested (three isolates plus two reference organisms)
• Single exposure condition reported (60 Hz, 3 mT, 2 hours)

{
    "study_type": "in_vitro",
    "exposure": {
        "band": "ELF",
        "source": "other",
        "frequency_mhz": 6.00000000000000015200514458246772164784488268196582794189453125e-5,
        "sar_wkg": null,
        "duration": "2 hours"
    },
    "population": null,
    "sample_size": null,
    "outcomes": [
        "Microbial growth/colony counts (log CFU/mL)",
        "Differences in growth between treated vs control conditions",
        "Comparison of growth effects by medium (nutrient broth vs distilled water)",
        "Comparison of growth effects by organism type (bacteria vs yeasts)"
    ],
    "main_findings": "An extremely low frequency magnetic field exposure (60 Hz, 3 mT) for 2 hours produced a statistically significant stimulation (p=0.05) in colony quantity in treated samples compared with controls. The stimulation was greater in nutrient broth than in distilled water and greater for bacteria than for yeasts; the reported decreasing order of stimulation was Listeria sp., E. coli ATCC 25922, Streptococcus sp., Candida guillermondii, and Saccharomyces cerevisiae.",
    "effect_direction": "benefit",
    "limitations": [
        "Sample size/number of replicates not reported in the abstract",
        "Only five microorganisms tested (three isolates plus two reference organisms)",
        "Single exposure condition reported (60 Hz, 3 mT, 2 hours)"
    ],
    "evidence_strength": "low",
    "confidence": 0.7399999999999999911182158029987476766109466552734375,
    "peer_reviewed_likely": "yes",
    "keywords": [
        "extremely low frequency",
        "magnetic field",
        "60 Hz",
        "3 mT",
        "in vitro",
        "microorganisms",
        "colony count",
        "indoor environment",
        "Archivo Nacional de la República de Cuba",
        "Listeria",
        "Streptococcus",
        "Escherichia coli",
        "Candida guillermondii",
        "Saccharomyces cerevisiae"
    ],
    "suggested_hubs": []
}

Comments

Log in to comment.

No comments yet.