Determination of live:dead bacteria as a function of antibiotic treatment

• Published in: Journal of microbiological methods 2018-11, Vol.154, p.73-78
• Main Authors: Li, Runze, Dhankhar, Dinesh, Chen, Jie, Cesario, Thomas C., Rentzepis, Peter M.
• Format: Article
• Language: English
• Subjects: Ampicillin - pharmacology; Anti-Bacterial Agents - pharmacology; Bacillus thuringiensis - drug effects; Bacteria - drug effects; Bacteria - isolation & purification; Bacteria identification; Bacteria inactivation; DNA, Bacterial - analysis; Drug Resistance, Bacterial - drug effects; Escherichia coli - drug effects; Fluorescence; Fluorescence spectra; Microbial Viability - drug effects; Polymyxin B - pharmacology; Principle component analysis; Spectrometry, Fluorescence - methods; Tryptophan; Tyrosine
• ISSN: 0167-7012; 1872-8359
• DOI: 10.1016/j.mimet.2018.10.010

Antibiotics are drugs that react against, kill, or inhibit the growth of bacteria. The method most often employed to evaluate the effectiveness of an antibiotic to kill bacteria requires at least 16 to 24 h for bacterial incubation. The requirement of long periods of time for the determination of the number of bacteria still alive after antibiotic treatment, may, in many cases, be detrimental to the patient's health. In addition, with increasing of bacterial antibiotic resistance, the need to utilize methods for distinguishing between live and dead bacteria within a short period of time after treatment with antibiotic agents, is becoming more crucial. To that effect, we have utilized a hand-held double monochromator to record in situ and within minutes the synchronous and normal fluorescence spectra of bacteria and other species. The fluorescence spectra of bacterial components such as tryptophan, tyrosine and DNA are clearly displayed. In addition, principal component analysis, PCA, makes it possible to display live and dead bacteria separately and determine the ratio of live:dead bacteria before and after treatment with antibiotics. •A hand-held spectrometer was introduced as a rapid means for bacteria identification.•Live:dead bacteria after antibiotics treatment is distinguishable in situ, within minutes.•Bacteria species are distinguished in situ, within minutes.•May be a new means for bacteria detection in operation rooms and remote clinics