Kamaleldin B Said
Carleton University, Canada
Title: clfA- R domain based objective molecular typing of methicillin resistant Staphylococcus aureus isoates from patients and screening procedures reveal domiant host-specific clonal lineages in a tertiary care hospital in Buraidah, Qassim, KSA
Biography
Biography: Kamaleldin B Said
Abstract
Despite enormous efforts, the molecular mechanisms of specialization and emergence of invasive methicillin-resistant Staphylococcus aureus (MRSA) in a clonal background has been quite elusive. In an effort to contain the devastating outbreaks, significant reseach has been conducted that included many contraverses and inconsistent reports. We have previously shown that a reason for this to occur when genotypes used for vertical analysis were determined based only on the DNA pattern of the marker irrespective of its function, the host, and the strain factors. Furthermore, major genome based subtyping processes often fail to recognize minor differences in clonal genomes. We have established in recent years through multicenter collaborations that the use of adaptation-sensitive repeats in subtyping followed by subsequent genome wide expressions yielded relavant data on host and clonal differentiations. In this study, applicatoin of clfA- R-domain genotyping of clinical Staphylococcus aureus isolates revealed 14 different repeat types (RTs) designated, A to L, and Q and X while eight sequenced strains belonged to 3 types A, C, and Q. The most dominant types were D (24 isolates, 57 copies), X (19 isolates, 52 copies), B (13 isolates, 60 copies), E (11 isolates, 55 copies), and F and Q (8 isolates 49, 47 copies each). Interestingly, the genotypes showed long-variable and short-clonal copy numbers reflective of the length and functional properties of clfA in human-specific and animal-associated lineages, respectively. Furthermore, presence of resistant phenotypes of the global genotype X among human isolates suggested potential transmission of bovine lineage to human hospital. Thus, we have shown the dominant types as well as the potential transmission lines of MRSA in a tertiary care hospitals. Future vertical analysis and genome-wide sequence expression profiling of host-specific lineages would reveal potential candidates for vaccine and therapeutic developments.