Survival of enterobacteria in liquid cultures during microwave radiation and conventional heating.

Abstract

Bacteria in food have been reported to survive in larger numbers after processing by microwave radiation than after conventional processing. The bactericidal effect of a domestic microwave oven (SHARP R-7280) on certain pathogenic enterobacteria species was investigated in vitro, in comparison with conventional heating (boiling). The death rates of different nosocomial strains of Escherichia coli, Salmonella sofia, Salmonella enteritidis, Proteus mirabilis and Pseudomonas aeruginosa were tested. The microwave oven and the conventional heating system used were both calibrated in order to calculate temperatures from exposure times. For each strain duplicate samples of 25 ml of pure culture with concentrations at least 10(6) cfu/ml were exposed to microwave radiation. An equal number of samples of the same volume and concentration were exposed to conventional heating. Subsequently all samples were examined qualitatively and quantitatively following standard microbiological procedures. The results indicate that microwaves have an efficient bactericidal effect on the enterobacteria in liquid cultures.

AI evidence extraction

Main findings

In vitro testing of several nosocomial strains (E. coli, Salmonella sofia, S. enteritidis, Proteus mirabilis, Pseudomonas aeruginosa) found that microwave exposure in a domestic microwave oven produced an efficient bactericidal effect in liquid cultures, compared with conventional heating (boiling).

Outcomes measured

• Bacterial survival/death rates (qualitative and quantitative culture results)

Limitations

• Microwave frequency and exposure parameters (e.g., power, exact duration) not reported in the abstract
• Sample size details (number of strains/replicates beyond duplicates) not fully reported in the abstract
• In vitro liquid culture study; may not generalize to real food matrices or clinical settings

{
    "study_type": "in_vitro",
    "exposure": {
        "band": "microwave",
        "source": "domestic microwave oven",
        "frequency_mhz": null,
        "sar_wkg": null,
        "duration": null
    },
    "population": null,
    "sample_size": null,
    "outcomes": [
        "Bacterial survival/death rates (qualitative and quantitative culture results)"
    ],
    "main_findings": "In vitro testing of several nosocomial strains (E. coli, Salmonella sofia, S. enteritidis, Proteus mirabilis, Pseudomonas aeruginosa) found that microwave exposure in a domestic microwave oven produced an efficient bactericidal effect in liquid cultures, compared with conventional heating (boiling).",
    "effect_direction": "harm",
    "limitations": [
        "Microwave frequency and exposure parameters (e.g., power, exact duration) not reported in the abstract",
        "Sample size details (number of strains/replicates beyond duplicates) not fully reported in the abstract",
        "In vitro liquid culture study; may not generalize to real food matrices or clinical settings"
    ],
    "evidence_strength": "low",
    "confidence": 0.7399999999999999911182158029987476766109466552734375,
    "peer_reviewed_likely": "yes",
    "keywords": [
        "microwave radiation",
        "domestic microwave oven",
        "conventional heating",
        "boiling",
        "bactericidal effect",
        "enterobacteria",
        "Escherichia coli",
        "Salmonella sofia",
        "Salmonella enteritidis",
        "Proteus mirabilis",
        "Pseudomonas aeruginosa",
        "in vitro"
    ],
    "suggested_hubs": []
}

Comments

Log in to comment.

No comments yet.