Occurrence, Antibiotic Susceptibility Pattern and Physiological Studies of Pseudomonas Species Isolated from Ready to Eat Foods in Ibadan, Oyo State, Nigeria

Abstract

Aim: This study was conducted to determine the occurrence, antibiotic susceptibility pattern and physiological properties of Pseudomonas species isolated from ready to eat foods in some selected areas in Ibadan, Oyo state, Nigeria. Study Design: Identification of Pseudomonas species in ready to eat foods, determination of its antibiotics sensitivity pattern and physiological properties. Place and Duration of Study: All works were carried out in the Department of Microbiology, Faculty of Science, University of Ibadan, from January, 2015 – February, 2016. Methodology: The Pseudomonas species were isolated using culture depended method and identified based on morphological and biochemical characteristics. Susceptibility of the microorganisms to antibiotic compounds was tested by employing the disc diffusion method and the physiological study was carried out using standard methods and the growth of microorganisms was measured using the spectrophotometer. Results: A total of 196 Pseudomonas species were isolated from wara, smoked shawa fish, (Llisha africana) Meat pie and Kununzaki and they were identified as P. aeruginosa (43), P. putida (61), P. mendocina (41), P. alcaligenes (2), P. xiamenensis (9), P. fluorescens (1), P. fragi (39). It was revealed that the highest total aerobic count (TAC) of 2.73±0.25x108 cfug-1 was observed in wara obtained from Bodija market while the corresponding Pseudomonas count (PC) of 4.85±2.74x107 cfug-1 was recorded in wara sample collected from Sawmill market. The lowest TAC of 1.27±2.12x105 cfug-1 was noted in smoked fish purchased from Bodija market while the corresponding PC of 2.80±2.04x103 cfug-1 was recorded in smoked fish purchased from Moniya market. The screening for antibiotic susceptibility showed that 93.5% of the Pseudomonas species was resistant to Aztreonam from wara purchased from Oritamerin market. Highest Multiple Antibiotic Resistance (MAR) index recorded was 0.7 by P. xiamenensis and the least was 0.1 shown by P. aeruginosa, P. putida. P. mendocina. The physiological studies showed that all the Pseudomonas species grew at temperature range of 30 -42°C. NaCl concentration range of 2-5% and pH   range of 3-9 which infers that the eradication of this bacteria from the environment will be very difficult. In conclusion, the presence of high load of Pseudomonas species in ready to eat foods is an indication of high level of contamination and could pose a serious problem to public health especially in the area of antibiotic therapy.