Organic chemistry

Agar

Vancomycin

Antibiotics

Bacteria

Agar plate

Biology

Microbiology

Adsorption

Chemistry

Antibiotic sensitivity

Congo red

Staphylococcus aureus

Linezolid

Genetics

Biofilm

Medicine

Open Access Macedonian Journal of Medical Sciences

AIMS: To evaluate three in vitro phenotypic methods; tissue culture plate, tube method, and Congo red agar for detection of biofilm formation in staphylococci and assess the relation of biofilm formation with methicillin resistance and anti-microbial resistance.&#x0D; METHODS: The study included 150 staphylococcal isolates. Biofilm detection in staphylococci was performed using tissue culture plate, tube method, and Congo red agar.&#x0D; RESULTS: Tissue culture plate, tube method, and Congo red agar detected 74%, 42.7%, and 1.3% biofilm producing staphylococci respectively. S. aureus isolates were more common biofilm producers (53.2%) than CONS (46.8%). Biofilm production in CONS species was highest in S. hemolyticus (57.7%). Tube method was 51.4% sensitive, 82.1% specific. As for Congo red agar, sensitivity was very low (0.9%), but specificity was 97.4%. Biofilm producers were mostly; isolated from blood specimens (82.6%) and detected in methicillin-resistant strains 96/111 (86.5%). They were resistant to most antibiotics except vancomycin and linezolid.&#x0D; CONCLUSIONS: Tissue culture plate is a more quantitative and reliable method for detection of biofilm producing staphylococci compared to tube method and Congo red agar. Hence, it can still be used as a screening method for biofilm detection. Vancomycin and Linezolid are the most sensitive antibiotics among biofilm producing staphylococci.

Detection of Biofilm Producing Staphylococci among Different Clinical Isolates and Its Relation to Methicillin Susceptibility