Effect of microwaves on survival of some bacterial strains.

Abstract

While the inhibitory effect of microwave radiation on microorganisms is being researched intensively, how microwave radiation brings about this effect has been a matter of discussion. Some researchers support that this effect is of a thermal character, whereas some others maintain a non-thermal effect. In this work, 1 ml suspensions of Pseudomonas aeruginosa, Pseudomonas acidovorans staphylococcus aureus and Staphylococcus epidermidis bacteria were subjected to microwave radiation at 2450 MHz and 550 Watts for periods of 5, 6, 7, 8, 10, 12, 14, 16, 18, 20, 25 and 30 seconds. When each result was compared with the CFU/ml results obtained from unradiated control group bacterial suspensions derived from stock cultures, significant conclusions were attained (P < 0.001). The same experiments were repeated with the application of conventional heating. The difference between the CFU/ml values of similar bacterial suspensions subjected to microwave radiation and conventional heating was significant (P < 0.001). Concurrently, the fact that the effect was exacerbated upon increasing of liquid volume during the application of microwave radiation was established via the results obtained through the application of microwave radiation to 1 ml and 5 ml bacterial suspensions (P < 0.001).

AI evidence extraction

Main findings

Bacterial suspensions exposed to 2450 MHz microwaves at 550 W for 5–30 seconds showed CFU/ml differences versus unradiated controls (P < 0.001). CFU/ml values also differed significantly between microwave-exposed suspensions and those subjected to conventional heating (P < 0.001). The effect was reported to be exacerbated when liquid volume increased from 1 ml to 5 ml during microwave exposure (P < 0.001).

Outcomes measured

• Bacterial survival (CFU/ml)

Limitations

• No quantitative CFU/ml results reported in the abstract.
• Sample size/number of replicates not stated.
• Exposure characterization beyond frequency and power (e.g., temperature achieved, field distribution, dosimetry/SAR) not provided in the abstract.
• Bacterial strain list includes a capitalization/formatting inconsistency in the abstract ("staphylococcus aureus").

{
    "study_type": "in_vitro",
    "exposure": {
        "band": "microwave",
        "source": null,
        "frequency_mhz": 2450,
        "sar_wkg": null,
        "duration": "5–30 seconds (multiple time points)"
    },
    "population": null,
    "sample_size": null,
    "outcomes": [
        "Bacterial survival (CFU/ml)"
    ],
    "main_findings": "Bacterial suspensions exposed to 2450 MHz microwaves at 550 W for 5–30 seconds showed CFU/ml differences versus unradiated controls (P < 0.001). CFU/ml values also differed significantly between microwave-exposed suspensions and those subjected to conventional heating (P < 0.001). The effect was reported to be exacerbated when liquid volume increased from 1 ml to 5 ml during microwave exposure (P < 0.001).",
    "effect_direction": "harm",
    "limitations": [
        "No quantitative CFU/ml results reported in the abstract.",
        "Sample size/number of replicates not stated.",
        "Exposure characterization beyond frequency and power (e.g., temperature achieved, field distribution, dosimetry/SAR) not provided in the abstract.",
        "Bacterial strain list includes a capitalization/formatting inconsistency in the abstract (\"staphylococcus aureus\")."
    ],
    "evidence_strength": "low",
    "confidence": 0.7399999999999999911182158029987476766109466552734375,
    "peer_reviewed_likely": "yes",
    "keywords": [
        "microwave radiation",
        "2450 MHz",
        "bacteria",
        "Pseudomonas aeruginosa",
        "Pseudomonas acidovorans",
        "Staphylococcus aureus",
        "Staphylococcus epidermidis",
        "CFU/ml",
        "conventional heating",
        "thermal vs non-thermal"
    ],
    "suggested_hubs": []
}

Comments

Log in to comment.

No comments yet.