Preliminary study of biofilm formation properties and antibiotic susceptibility pattern of MRSA and MSSA isolates obtained in Yogyakarta, Indonesia

ABSTRACT

Aims: Nowadays, Staphylococcus aureus, especially methicillin resistant Staphylococcus aureus (MRSA), emerged as a major pathogenic agent of nosocomial infection and sepsis worldwide. Infections caused by these bacteria are often difficult to treat because of the development of antibiotic resistance. Biofilm formation is an important factor in the pathogenicity of staphylococcal infections and one of the reason of antibiotic treatment failure. In this study, the relationship between biofilm formation properties, the presence of mecA, icaA/D genes and antimicrobial resistance pattern were investigated in 10 methicillin sensitive Staphylococcus aureus (MSSA) and 10 MRSA clinical isolates. Methodology and results: Staphylococcal strains were identified by conventional microbiological methods, while determination of methicillin susceptibility was distinguished by the presence of mecA gene. To investigate biofilm production, congo red agar and microtiter plate test were performed. PCR was done to detect the presence of icaA/D genes, which responsible for biofilm production. Antibiotic sensitivity was carried out by agar diffusion method. The majority of MRSA isolates (90%) were not able to form biofilm, only one isolate (10%) showed capability of weak biofilm producer. Meanwhile, fully established biofilms were formed by all of MSSA isolates (100%). In addition, all MRSA and almost MSSA isolates (90%) harboured both icaA/D genes in their chromosomes. Antibiotic resistance profile of MRSA was more dominant than MSSA isolates. Conclusion, significance, and impact of study Biofilm production of staphylococci showed difference regulation with regard to methicillin susceptibility. Antibiotic resistance profile was more dominant in MRSA, however biofilm production was found mostly in MSSA isolates.