The aim of the study was to isolate and identify bacteria from used lipsticks of female students. Samples were collected from different students, well labeled and transferred to the Microbiology laboratory for analysis. Serial dilution of the samples was carried out, and a dilution factor of 104 was plated on a sterilized nutrient agar using the spread plate method. The colonies developed were counted, recorded, and their morphological appearances were noted accordingly. The colonies developed were cultured repeatedly to obtain pure isolates, which were exposed to various biochemical identification tests. Data indicated that bacterial count was in the range of 1.8x105 CFU/g to 6.5x105 CFU/g. The identified bacterial species are Pseudomonas, Rothia, Streptococcus, Escherichia, Corynebacterium, Klebsiella and Staphylococcus species. Staphylococcus spp., were the most prevalent with a relative occurrence of 27.8%. Streptococcus, Escherichia, Klebsiella. and Micrococcus species. were least prevalent with a relative occurrence of 5.55% each. The identified bacterial species may be due to direct contact with skin, environmental exposure, co-sharing and absence of preservatives. Therefore, users should avoid sharing lipsticks and maintain good personal hygiene, and manufacturers should ensure that lipsticks contain an effective system and conduct regular preservative efficacy testing to inhabit microbial growth throughout the product shelf life.
Henry et al. (Fri,) studied this question.