Distribution of the arginine catabolic mobile element associated arcA and opp3 genes among methicillin resistant Staphylococcus aureus isolated from intensive care units, Sina Hospital, 2020

Abstract

Staphylococcus aureus is one of the most important pathogens involved in hospital infections, especially in the ICU, which includes up to 30% of cases. The purpose of this study is to determine the frequency of arcA, opp3, pvl, tst, eta, etb, fnbB, fnbA, clfB, clfA genes and to determine SCCmec and agr types of methicillin-resistant Staphylococcus aureus isolates collected from patients hospitalized in ICU departments of Sina Hospital Tabriz. methods: A total of 95 isolates of S. aureus collected from patients hospitalized in ICU departments of Sina Tabriz Hospital were prepared. The identity of the isolates was determined by phenotypic tests in the microbiology laboratory of the Faculty of Medicine in Tabriz. The antibiotic sensitivity pattern of the isolates was determined by the kirby Bauer method and according to CLSI guidelines. to investigate the risk factors associated with MRSA infections, the clinical history of the patients was examined. Finally, PCR was used to detect mecA, arcA, opp3, fnbB, fnbA, clfB, clfA pvl, tst, eta, etb genes and to determine agr and SCCmec types, PCR-multiplex method was used. Results: In this study, 34.7% of isolates were MRSA and 65.3% were MSSA. Diabetes Mellitus with 18.6% was the highest risk factor associated with S. aureus infections in patients hospitalized in ICU. All the isolates were sensitive to the antibiotic linezolid, and the highest bacterial resistance was observed against penicillin (96.8%), erythromycin (64.2%) and clindamycin (63.2%). From a total of 95 isolates, the ACME-arcA gene was detected in 24 isolates and the opp3 gene was detected in 15 isolates. Among the genes encoding adhesin proteins and toxin-producing genes, clfB with 81.1% and tst with 24.2% were most distributed. In this study, agrI and SCCmecIII were identified as the dominant types in the region.