Occurrence of methicillin resistant Staphylococcus aureus (MRSA) among clinical samples in tehran-iran and its correlation with polymorphism of specific accessory gene regulator (AGR) groups

Abstract

Methicillin-Resistant Staphylococcus aureus (MRSA) is responsible for an increasing number of serious hospital and community acquired infections. Virulence gene expression in Staphylococcus aureus is orchestrated by regulators such as the accessory gene regulator (agr). Staphylococcal strains are divided into four major agr groups (agrI-IV) on the basis of agrD and agrC polymorphisms. The purpose of this study was to define the prevalence of MRSA strains in appointed Tehran's hospitals and then to define and compare the proportion of agr I, II, III, IV polymorphisms between MRSA and Methicillin Sensitive Staphylococcus aureus (MSSA) strains. A total of 235 isolates were evaluated by conventional antibiotic susceptibility tests and PCR for agr and mecA genes. 112 strains were MRSA (47.5%) and the most prevalent agr specific group was agr I followed by agr III, agr II and agr IV, respectively. The prevalence of agr groups amongst MRSA and MSSA strains was not statistically significant (P≥0.05). This study suggests that agr I is not only the most prevalent agr type in MRSAs but also the most common one in Methicillin Sensitive Staphylococcus aureus (MSSA) strains in Iran.

Typing of Methicillin-Resistant Staphylococcus aureus Isolate from Healthcare Workers in Larestan, Iran

“…In the past two decades, the prevalence of MRSA strains has increased in many parts of the world. For example, in a study in Iran among 235 isolates of S. aureus, 112 strains (47.5%) were MRSA [10].…”

Characterization ofStaphylococcus aureusIsolates That Colonize Medical Students in a Hospital of the City of Cali, Colombia

“…According to this gene's variability pattern, to date, four variants have been defined, denominated as groups I to IV [ 17 ]. Isolates belonging to group III are related to infections associated with the community, while group II is detected predominantly in strains isolated at intrahospital level [ 18 , 19 ].…”

Prevalencia de Staphylococcus aureus que coloniza el personal de salud de un hospital de la ciudad de Cali

“…Este clon solo se encuentra entre los aislamientos hospitalarios (sarm-ah). En este sentido, el análisis molecular del locus agr, en los cuatro aislamientos de sarm detectados en este estudio, evidencia que pertenecen al grupo agr ii, este grupo es compatible con aislamientos de origen nosocomial, lo que confirma los hallazgos microbiológicos (18).…”

“…Las reacciones de pcr se realizaron de acuerdo con el protocolo establecido por Azimian et al, en un volumen de 50 μl de una mezcla de reacción compuesta por MgCl 2 25 mM, 200 μM de los cuatro dNTP's, 0,5 U de Taq dna polimerasa (Invitro-gen®), 10 pmol de cada cebador y 5 μl de solución de adn en un termociclador GeneAmp pcr System 2400® (18). Como control positivo, se empleó la cepa atcc 25923 de S. aureus y el control negativo, la cepa atcc 25922 de Eschericchia coli.…”