Isolation and Identification of Bacterial Contaminants in Some Cosmetic Products Shared in Beauty Salons in Gharyan City, Libya

Abstract

Cosmetic products provide a favorable environment for microbial growth due to their composition and conditions of use, which necessitates studying the extent of their contamination and the associated health risks, especially with their increasing daily and shared use among individuals. This study aimed to evaluate the degree of microbial contamination in certain commonly used cosmetic products and to identify the bacterial genera most frequently responsible for such contamination. A total of 50 samples of various cosmetic products were collected from different beauty salons, including those used for the skin (sponges, foundation, lipstick, blush, assorted brushes, concealer) and those used for the eyes (mascara, eyeliner, eyeshadow, eyebrow gel, glitter). Sampling was conducted between July 9, 2024, and May 17, 2025. The samples were cultured on two types of media: MacConkey agar and Blood agar. Plates were examined, and preliminary identification of bacterial isolates was performed based on the morphological characteristics of the colonies. The isolates were further identified under sterile laboratory conditions using Gram staining and light microscopy to determine bacterial cell morphology. The results revealed bacterial growth in 43 samples (86%) of the total. Brushes and sponges were the most contaminated items. The most frequently isolated bacterial genera were Klebsiella (43.4%), followed by Pseudomonas (39.4%), and Staphylococcus (17.2%), which included Staphylococcus epidermidis and Staphylococcus aureus. The findings indicate that cosmetic products used in beauty salons are contaminated with bacteria, contributing to the spread of pathogens that may cause serious skin infections. Therefore, it is recommended to avoid the use of shared cosmetic products, limit their long-term use in salons, and store them in dry and cool conditions to reduce microbial growth.