Microbial Analysis and Antibiogram of Reusable Plastic Bottles Used for Packaging Food Products in the Ikot Ekpene Metropolis

Abstract

The reuse of plastic bottles for packaging food products has become increasingly common in many developing countries due to economic and environmental considerations. However, inadequate cleaning and poor handling practices may promote microbial contamination and pose significant public health risks. This study investigated the microbial contamination and antibiotic susceptibility patterns of microorganisms isolated from reusable plastic bottles used for packaging food products within Ikot Ekpene metropolis, Akwa Ibom State, Nigeria. Thirty (30) reusable plastic bottles were randomly collected and subjected to microbiological analysis using standard culture, biochemical, and microscopic techniques. Antibiotic susceptibility testing of bacterial isolates was performed using the Kirby–Bauer disc diffusion method. The results showed that 25 (83.3%) of the samples exhibited bacterial contamination, with total bacterial counts ranging from 3.0 × 10⁵ to 5.9 × 10⁵ CFU/mL, while 22 (73.3%) samples showed fungal contamination with counts ranging from 0.1 × 10⁵ to 2.0 × 10⁵ CFU/mL. Six bacterial species were identified, namely Escherichia coli, Staphylococcus aureus, Bacillus spp., Klebsiella spp., Pseudomonas aeruginosa, and Streptococcus spp. Four fungal genera were also isolated, including Aspergillus spp., Penicillium spp., Cladosporium spp., and Candida spp. Antibiotic susceptibility testing revealed that Escherichia coli and Streptococcus spp. were susceptible to all antibiotics tested, whereas Klebsiella spp., Pseudomonas aeruginosa, and Staphylococcus aureus exhibited resistance to one or more antibiotics. Ciprofloxacin, Augmentin, and Streptomycin demonstrated the broadest spectrum of activity against the bacterial isolates.The study revealed that reusable plastic bottles used for packaging food products in Ikot Ekpene metropolis harbour diverse bacterial and fungal contaminants, including potential pathogens and antibiotic-resistant organisms. The presence of these microorganisms underscores the need for improved sanitation practices, proper bottle disinfection, use of potable water during washing, and stricter regulatory monitoring to ensure food safety and protect public health.