ABSTRACT

THE EFFECT OF STORAGE DURATION OF BLOOD AGAR PLATE MEDIA AT 2–8°C ON THE GROWTH OF BACTERIA ISOLATED FROM RECTAL SWAB SPECIMENS

Kadek Ryan Octaviani1, Anak Agung Ayu Eka Cahyani2, Sri Idayani3

Applied Bachelor’s Degree Program in Medical Laboratory Technologi Wira Medika Bali Collage of Health Science

The quality of culture media plays an important role in microbiological examinations because it affects bacterial growth and identification. Blood Agar Plate (BAP) is a commonly used medium for cultivating fastidious bacteria and observing hemolytic patterns. Storage of media at 2–8°C may affect media quality as storage duration increases. The aim is to determine the effect of Blood Agar Plate (BAP) storage duration at 2–8°C on bacterial growth from rectal swab specimens. This is pre-experimental study employed a post-test only design using 30 samples divided into three storage groups: 0 days, 7 days, and 14 days. The media were inoculated with rectal swab specimens and incubated at 37°C for 24 hours. Bacterial growth was assessed based on colony count and colony morphology characteristics. Data were analyzed using One-Way ANOVA followed by Tukey’s HSD post hoc test. The mean colony counts for media stored for 0, 7, and 14 days were 617.90, 774.80, and 166.60 colonies, respectively. Media stored for 7 days produced the highest bacterial growth, whereas media stored for 14 days showed the lowest growth. Changes in colony morphology were observed in colony size, growth pattern, and hemolysis. One-Way ANOVA showed a significant difference among the groups (p = 0.000). Storage duration of BAP media affects the quality of bacterial growth. Media stored for 7 days still provided good growth results, whereas storage for 14 days reduced media quality. Laboratories are recommended to limit media storage duration to maintain optimal bacterial culture quality.

Keywords: Blood Agar Plate, Media Storage, Bacterial Growth, Rectal Swab