Genetic Homogeneity Among Methicillin-ResistantStaphylococcus AureusStrains From Saudi Arabia

Abstract

Ninety-four strains of methicillin-resistant Staphylococcus aureus (MRSA) were collected from patients nursed in several hospitals in Saudi Arabia, before they were referred to King Faisal Specialist Hospital and Research Centre for tertiary care. The hospitals were from geographically diverse regions and as such the entirety of Saudi Arabia was covered. All strains were genetically typed by random amplification of polymorphic DNA (RAPD) analysis using three different primers and a representative subset of the strains was analyzed with pulsed-field gel electrophoresis (PFGE) as well. It was concluded that 87 out of 94 (93%) belong to a single clonally related lineage of MRSA. In the other 7 cases, the DNA banding patterns were shown to differ only slightly from those determined for the clonal type. PFGE analysis confirmed the homogeneity of the collection of strains. When the RAPD and PFGE fingerprints obtained for the Saudi clone were compared to those generated for a collection of MRSA with a more diverse geographical background, it was shown that the clonal type from Saudi Arabia was not identical to any of these MRSA strains. Our data provide another example of the capacity of certain MRSA clones to expand through entire nations and establish themselves permanently among large number of hospitals and, consequently, even larger numbers of patients.

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“…These values are quite similar to those reported by van Belkum et al[26], 1997 from King Faisal Specialist hospital – which was one of the hospitals included in the present study – isolated from patients referred to it from several other hospitals in Saudi Arabia. They report procurement of 66% of their isolates from male patients and 34% from females.…”

Molecular epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) isolates from major hospitals in Riyadh, Saudi Arabia

“…M1 followed by M2 have been isolated from all included hospitals, indicating their widespread existence. This finding does not fully support the results of a previous study that reported the dominance of a single PFGE type in the Kingdom of Saudi Arabia (van Belkum et al 1997). That study, however, involved testing a small number of isolates by PFGE (7 only) and inferred that conclusion mainly from random amplified polymorphic DNA (RAPD) analysis, although they do state that results for RAPD did not correlate with PFGE for the same strains.…”

Molecular Epidemiology of Methicillin-ResistantStaphylococcus aureusStrains: State of Affairs and Tomorrow's Possibilities

“…Nationwide MRSA surveillance studies include those performed in countries as diverse as Saudi Arabia, 168,199 Turkey, 175 Republic were in 92% of cases shown to belong to the Brasilian or Iberian clones.103 A paper that appears in the present issue of Microbial Drug Resistance192 identifies spread of just a couple of major MRSA clones in Europe. This is defined by automated ribotyping and its shows that 65% of a large sample of pan-European MRSA isolates belong to a single clonal lineage with a distinct antibiogram.…”