Effects of microwave (2.45 GHz) irradiation on some biological characters of Salmonella typhimurium.

Comptes rendus biologies · 2013 · Mixed · Low evidence

← Research stream

MixedLow evidencePaper 6534

Study snapshot

PublicationComptes rendus biologies · 2013

Study typein_vitro

Reported directionMixed

Evidence ratingLow

Abstract

The present study was carried out to evaluate the effects of sub-lethal doses of microwave radiation on some biological characteristics in Salmonella typhimurium. The aim was to show the relationship between this treatment and the development of radiotolerance in this pathogen because there is a need for more information on physiological responses of pathogens to sub-lethal doses of microwave radiation. So, the bacterial strain was treated with a dose of 3600J (40-s exposure with power P=90 W) to cause cellular damage. The results have shown that the exposure of bacteria to microwaves resulted in a significant inhibition of cellular growth. This treatment has notably increased the effectiveness of the most tested antibiotics by the amelioration or the appearance of sensitivity in exposed bacteria. Gas chromatography (GC) analysis was performed to demonstrate the modification of the fatty acids (FA) composition. Results obtained have shown that this treatment had a significant effect on the FA content with an increase of unsaturated FA percentage. The acquisition of sensitivity to the sodium deoxycholate and the significant increase in the amount of extracellular proteins in exposed bacteria has confirmed the weakening of the bacterial membrane by microwaves. This study represents one of the few demonstrating the modifications on the bacterial membrane as a cellular response to survive the non-ionising radiation stress.

Machine Enhanced Logic

AI evidence extraction

Structured fields below were generated from the paper’s abstract and metadata to make the evidence easier to inspect. Automated extraction may be incomplete or incorrect; verify important details against the original paper.

Study typein_vitro

Effect directionmixed

PopulationSalmonella typhimurium (bacterial strain)

Sample sizeNot supplied

Exposuremicrowave · 2450 MHz · 40 s (P=90 W; dose 3600 J)

Evidence strengthLowConfidence: 78% · Peer reviewed: yes

Main findings

Exposure to 2.45 GHz microwaves (40 s, 90 W; 3600 J) significantly inhibited bacterial growth. The treatment increased effectiveness of most tested antibiotics via improved or newly appearing sensitivity, altered fatty-acid composition (increased unsaturated FA percentage), increased sensitivity to sodium deoxycholate, and increased extracellular proteins, consistent with membrane weakening/modification.

Outcomes measured

cellular growth inhibition
antibiotic sensitivity/effectiveness
fatty acid composition (unsaturated FA percentage)
sensitivity to sodium deoxycholate
extracellular protein amount
bacterial membrane weakening/modification

Limitations

Sample size not reported in abstract
Only sub-lethal exposure condition described; limited exposure characterization beyond power, time, and energy
In vitro bacterial model; generalizability to other organisms/conditions not addressed in abstract

View raw extracted JSON

{
  "study_type": "in_vitro",
  "exposure": {
    "band": "microwave",
    "source": null,
    "frequency_mhz": 2450,
    "sar_wkg": null,
    "duration": "40 s (P=90 W; dose 3600 J)"
  },
  "population": "Salmonella typhimurium (bacterial strain)",
  "sample_size": null,
  "outcomes": [
    "cellular growth inhibition",
    "antibiotic sensitivity/effectiveness",
    "fatty acid composition (unsaturated FA percentage)",
    "sensitivity to sodium deoxycholate",
    "extracellular protein amount",
    "bacterial membrane weakening/modification"
  ],
  "main_findings": "Exposure to 2.45 GHz microwaves (40 s, 90 W; 3600 J) significantly inhibited bacterial growth. The treatment increased effectiveness of most tested antibiotics via improved or newly appearing sensitivity, altered fatty-acid composition (increased unsaturated FA percentage), increased sensitivity to sodium deoxycholate, and increased extracellular proteins, consistent with membrane weakening/modification.",
  "effect_direction": "mixed",
  "limitations": [
    "Sample size not reported in abstract",
    "Only sub-lethal exposure condition described; limited exposure characterization beyond power, time, and energy",
    "In vitro bacterial model; generalizability to other organisms/conditions not addressed in abstract"
  ],
  "evidence_strength": "low",
  "confidence": 0.78,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "microwave",
    "2.45 GHz",
    "non-ionising radiation",
    "Salmonella typhimurium",
    "bacterial membrane",
    "fatty acids",
    "antibiotic sensitivity",
    "radiotolerance"
  ],
  "suggested_hubs": []
}

AI can be wrong. Always verify against the paper.

AI-extracted fields are generated from the abstract and metadata and may be incomplete or incorrect. This material is for informational purposes and is not medical advice.

Identifiers and source

DOI: 10.1016/j.crvi.2013.04.003
PubMed: 23849722

Read the original paper →

Related papers

← Back to the Research Library