In VitroandIn VivoBiofilm Characterization of Methicillin-ResistantStaphylococcus aureusfrom Patients Associated with Pharyngitis Infection

Abstract

The present investigation was deliberately aimed at evaluating the biofilm-forming ability of 63 clinical MRSA isolates recovered from pharyngitis patients through different phenotypic assays. The molecular detection of adhesion (icaA/icaD/icaB/icaC), adhesins (fnbA/fnbB,clfA, andcna), staphylococcal accessory regulator (sarA), andα-toxin (hla) genes was done by employing polymerase chain reaction (PCR). Out of 63 isolates, 49 (77.8%) were found slime positive by the Congo red agar (CRA) method and 44 (69.8%) as biofilm positive by the quantitative microtitre plate assays. The results of MATH assay showed that most of the test pathogens are hydrophilic in nature. The molecular investigation of biofilm-associated genes revealed that 84.13% (n=53) of isolates were found positive foricaADBCgenes. ThefnbAandfnbBgenes were present in 49 (77.8%) and 51 (81%) MRSA isolates, respectively. In addition, 58.7% (n=37), 73% (n=46), and 69.8% (n=44) of the isolates harboured theclfA,cna, andhlagenes, respectively. Further, nearly 81% (n=51) of the isolates were found positive for the genesarAand all theicanegative isolates were also negative for the gene. Furthermore, the results ofin vivoadherence assay unveiled the factual commonness in thein vitroadherence method.