Investigation of aminoglycoside modifying enzyme genes in methicillin-resistant staphylococci.
Methicillin-resistant staphylococci may also be resistant to some other antibiotics as well as beta-lactams. In this study, co-existence of resistance to methicillin and aminoglycosides was genetically investigated in staphylococci. A total of 50 staphylococci from in-patients, 17 Staphylococcus aureus and 33 coagulase negative staphylococci (CNS) that contained mecA (gene encoding PBP 2a, an altered penicillin-binding protein) determined by polymerase chain reaction (PCR) were included in the study. Aminoglycoside modifying enzyme (AME) genes were investigated using multiplex-PCR. Aminocyclitol-6'-acetyltransferase-aminocyclitol-2''-phosphotransferase [aac(6')/aph(2'')] gene (encoding bifunctional acetyltransferases/phosphotransferases) was determined in 66% of the isolates, aminocyclitol-4'-adenylytransferase (ant(4')-Ia) gene (encoding phosphotransferases) in 24%, and aminocyclitol-3'-phosphotransferase (aph(3')-IIIa) gene (encoding nucleotidyltransferases) in 8%. Two isolates contained all these three genes. Thirty-six (72%) isolates had at least one of these genes. Three CNS and one S. aureus isolates sensitive to oxacillin had the mecA gene. In conclusion, a high rate of aminoglycoside resistance was determined in methicillin-resistant staphylococci. The aac(6')/aph(2'') was the most frequently detected.
Ardic
Nurittin
N
Department of Microbiology and Clinical Microbiology, Gulhane Military Medical Academy, GATA Haydarpasa Training Hospital, 81327 Uskudar/Istanbul, Turkey. nurittinardic@yahoo.com
Sareyyupoglu
Baris
B
Ozyurt
Mustafa
M
Haznedaroglu
Tuncer
T
Ilga
Uğur
U
D000123:Acetyltransferases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D000617:Aminoglycosides / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D005838:Genotype; D006801:Humans; D016106:Methicillin Resistance / Q000235:genetics*; D046915:Penicillin-Binding Proteins; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016133:Polymerase Chain Reaction; D013203:Staphylococcal Infections / Q000382:microbiology; D013210:Staphylococcus / Q000187:drug effects* / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development
D000617:Aminoglycosides; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D046915:Penicillin-Binding Proteins; C487789:mecA protein, Staphylococcus aureus; C108453:6'-aminoglycoside acetyltransferase-2''-aminoglycoside phosphotransferase; D000123:Acetyltransferases; D017853:Phosphotransferases (Alcohol Group Acceptor)