Isolation of Asian endemic and livestock associated clones of methicillin resistant Staphylococcus aureus from ocular samples in Northeastern Iran.
OBJECTIVE
Methicillin Resistant Staphylococcus aureus (MRSA) strains are divided into Community Associated (CA-) and Hospital Associated (HA-) MRSA. These strains vary in antimicrobial resistance and pathogenicity. S. aureus is one of the most common microorganisms in ocular infections. This study was aimed to determine antimicrobial resistance patterns and genetic characteristics of MRSA strains isolated from ocular infections in Iran.


METHODS
Out of 171 S. aureus strains isolated from various clinical samples during September-December 2011 at Mashhad Emam Reza Hospital, 3 were cultured from eye discharge samples. Antimicrobial resistance tests were performed with MIC and disk diffusion methods and also genetic evaluation was done with Staphylococcal Cassette Chromosome mec (SCCmec), Accessory Gene Regulator (agr) and Staphylococcal Protein A (spa) typing, Multi Locus Sequence Typing (MLST) and determination of toxin gene profile.


RESULTS
All strains were MRSA and showed resistance to tetracycline, gentamicin and clindamycin too. Vancomycin, minocyclin and trimethoprim/sulfamethoxazole were effective on all ocular isolates. All isolates belonged to SCCmec IV type. MRSA1 belonged to ST239, CC8, Spa type t7688 and agrIII and had tst1 and hla toxin genes. MRSA2 belonged to ST239, CC8, Spa type t037 and agrI and had the hla toxin gene. Finally, MRSA3 belonged to ST291, CC398, Spa type t304, and agrI and had pvl and hla toxin genes.


CONCLUSIONS
Phenotypic and genotypic evaluation of the isolated MRSA strains revealed that these strains belong to endemic Asian and livestock related clones that could reach from other body sites or environment to the eye of patients and developed ocular infection.
Department of Pathobiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.
Seyed Asghar
SA
Havaei
Department of Pathobiology and Anatomy, School of Medicine, North Khorasan University of Medical Sciences, Bojnurd, Iran.
Amir
A
Azimian
Department of Pathobiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.
Hosein
H
Fazeli
Molecular Biology and Genetic Engineering Department, Stem Cell Technology Research Center, Tehran, Iran.
Mahmood
M
Naderi
Department of Microbiology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
Kiarash
K
Ghazvini
Food and Drug Laboratory Research Center, Ministry of Health and Medical Education, No. 408, Emam Khomeini Ave., Tehran, Iran.
Siamak Mirab
SM
Samiee
Department of Hematology, School of Medical Science, Tarbiat Modares University, Tehran, Iran.
Masoud
M
Soleimani
MLST; MRSA; SCCmec type; Spa typing; Staphylococcus aureus; agr; ocular infection