Prevalence of Adhesion and Regulation of Biofilm-Related Genes in Different Clones ofStaphylococcus aureus

Abstract

Clinical information about genotypically different clones of biofilm-producing Staphylococcus aureus is largely unknown. We examined whether different clones of methicillin-sensitive and methicillin-resistant S. aureus (MSSA and MRSA) differ with respect to staphylococcal microbial surface components recognizing adhesive matrix molecules (MSCRAMMs) in biofilm formation. The study used 60 different types of spa and determined the phenotypes, the prevalence of the 13 MSCRAMM, and biofilm genes for each clone. The current investigation was carried out using a modified Congo red agar (MCRA), a microtiter plate assay (MPA), polymerase chain reaction (PCR), and reverse transcriptase polymerase chain reaction (RT-PCR). Clones belonging to the same spa type were found to have similar properties in adheringto the polystyrene microtiter plate surface. However, their ability to produce slime on MCRA medium was different. PCR experiments showed that 60 clones of MSSA and MRSA were positive for 5 genes (out of 9 MSCRAMM genes). icaADBC genes were found to be present in all the 60 clones tested indicating a high prevalence, and these genes were equally distributed among the clones associated with MSSA and those with MRSA. The prevalence of other MSCRAMM genes among MSSA and MRSA clones was found to be variable. MRSA and MSSA gene expression (MSCRAMM and icaADBC) was confirmed by RT-PCR.

High Prevalence of Icaadbc Genes Responsible for Biofilm Formation in Clinical Isolates of Staphylococcus aureus From Hospitalized Children

“…Catheter and blood stream Staphylococcal infections play an important role in biofilms (25,26). We confirmed no significant difference between MSSA and MRSA isolates of S. aureus regarding the presence of icaADBC genes, similar to survey Atshan et al (27), in which icaADBC genes were compared between MRSA and MSSA. Furthermore, we previously observed that most isolates belonged to accessory gene regulator (agr) group I (28), but the relationship of agr groups and icaADBC expression needs more studies.…”

Biofilm formation and antimicrobial resistance in methicillin-resistant Staphylococcus aureus isolated from burn patients, Iran

“…There are several methods for the quantification of biofilm formation [29], but there is still no standard protocol for the detection of biofilm production. Although various methods are currently used for this purpose, the most widely used assay for evaluation of biofilm formation is the microtiter plate method [13].…”

“…The microtiter plate method was conducted as previously described [13]. Briefly, 200 µlof bacterial suspension grown in trypticase soy broth (TSB), supplemented with 1% glucose and diluted.…”

“…Biofilms are organized communities of bacterial cells that are accumulated in a polymeric matrix produced by bacteria and can be attached to living or inanimate surfaces [12,13]. Researchers have demonstrated that the first stage of staphylococcal infections is attachment to surfaces such as host tissues [14].Recently, studies about genes involved in biofilm formation and their role in staphylococcal infections have received a great deal of attention [15].…”

The Comparison ofStaphylococcus aureusIsolated From Blood and Wound Specimens for Genes Encoding Polysaccharide Intercellular Adhesion (PIA)

“…Moreover, thermal profile for icaA gene concluded at 94ᵒC (five minutes), followed by 30 cycles at 94ᵒC (one minute), 52ᵒC (30 seconds) and 72ᵒC (1.5 minute) with final extension at 72ᵒC (10 minutes). The annealing temperature for icaB, icaC and icaD was set at 55ᵒC for one minute (16). The DNA of the positive control isolate for the genes was kindly provided by Dr. Ghaznavi Rad.…”