Enumeration of total viable microorganisms in an antibiotic raw material using ChemScan solid phase cytometer

Area of Science:

• Microbiology
• Analytical Chemistry
• Pharmaceutical Science

Background:

• Accurate enumeration of microbial contamination is crucial for pharmaceutical quality control.
• Macrolide antibiotics like Spiramycin require rigorous testing to ensure product safety and efficacy.
• Traditional microbial detection methods can be affected by the antibiotic's activity.

Purpose of the Study:

• To evaluate epifluorescence cytometry using the ChemScan solid phase cytometer for enumerating microorganism contamination in Spiramycin.
• To compare the recovery rates of epifluorescence cytometry with the conventional plate method.

Main Methods:

• Spiramycin powder was artificially spiked with pure cultures of four different microorganisms.
• Microbial enumeration was performed using epifluorescence with the ChemScan solid phase cytometer.
• Parallel enumeration was conducted using the conventional plate method.

Main Results:

• Epifluorescence cytometry achieved complete recovery of all tested microorganisms, irrespective of their sensitivity to Spiramycin.
• The conventional plate method only achieved complete recovery for Spiramycin-resistant organisms.
• Microorganisms sensitive to Spiramycin were inhibited or stressed, preventing growth on the plates.

Conclusions:

• Epifluorescence cytometry offers a superior method for detecting microorganism contamination in Spiramycin compared to conventional plate counts.
• This technique is valuable for accurate pharmaceutical quality control, especially for antibiotics with bacteriostatic activity.
• ChemScan solid phase cytometry provides reliable enumeration of microbial contaminants in antibiotic formulations.