The Effect of Thermal Exposure on Antibiotic Sensitivity and Growth of Staphylococcus Epidermidis

Staphylococcus epidermidis is a common inhabitant of the human body, also frequently found in the environment and capable of causing a wide range of infections, from mild to severe, both in healthcare settings and in the community, making it a significant opportunistic pathogen. The aim of this research was to evaluate the effect of thermal exposure on the antibiotic susceptibility and growth of Staphylococcus epidermidis. The bacterial growth was monitored using optical density (O.D.) measurement at 600nm and Total viable count (CFU/ml). Also, this research investigated the potential relationship, if any, between the acquisition/possession of antibiotic resistance genes in strains of Staphylococcus epidermidis and its resistance to heat stress. These samples were heat-challenged at 1210C at different time intervals. Samples were then plated on Mueller Hinton Agar. Antibiotic susceptibility test was conducted on the isolate using the antibiotics; Erythromycin (E; 15 µg), Ofloxacin (OF; 10 µg) and Ampiclox (AMP; 30 µg). The susceptibility test conducted on the isolates showed lesser resistance compared to the control group. This indicated an increase in the susceptibility of the test group especially to Eythromycin and Ofloxacin after 24 hours of exposure. Having subjected the isolates (Staphylococcus epidermidis) to high temperature at different time intervals, there was significant decrease in the O.D. reading of the test isolate (Staphylococcus epidermidis). At 120 minutes, the Non-exposed plate had an O.D reading of 1.520 while the Exposed plate at the same time had an O.D. reading of 0.486 indicating that heat shocking these isolates inevitably had a decreasing effect on the O.D. readings of Staphylococcus epidermidis. This study also showed that thermal exposure of Staphylococcus epidermidis increased the action of the antibiotics against the test isolate.