Electron microscopic study of the effects of antimicrobial agents on the cellular architecture of Leptospira

Area of Science:

• Microbiology
• Bacteriology
• Cell Biology

Background:

• Leptospira are pathogenic spirochetes responsible for leptospirosis.
• Understanding the cellular targets of antibiotics is crucial for effective treatment.
• Previous studies have not detailed the ultrastructural effects of specific antibiotics on Leptospira.

Purpose of the Study:

• To investigate the morphological alterations in Leptospira induced by ampicillin, streptomycin, and ciprofloxacin.
• To characterize the time-dependent effects of these antimicrobial agents on Leptospira cell structure.
• To provide the first report on the ultrastructural impact of aminoglycoside and new quinolone antibiotics on Leptospira.

Main Methods:

• Transmission electron microscopy (TEM) was employed to visualize Leptospira.
• Cells were treated with ampicillin, streptomycin, or ciprofloxacin.
• Uranyl acetate was used for staining to enhance contrast and detail.

Main Results:

• Observed changes included irregularities in cell coiling, loss of hooks, and spherical swellings.
• Disruption of the outer membrane, exposure and detachment of flagella were noted.
• Dye penetration and cell lysis indicated compromised cell integrity, occurring in a time-dependent fashion.

Conclusions:

• Aminoglycoside (streptomycin) and new quinolone (ciprofloxacin) antibiotics, along with ampicillin, induce significant and characteristic morphological changes in Leptospira.
• These ultrastructural alterations are associated with the known sites of action of these antimicrobial agents.
• This study provides novel insights into the mechanisms of antibiotic action against Leptospira at the morphological level.