title: Isolation and molecular characterization of catalase-negative Staphylococcus aureus from sputum of a patient with aspiration pneumonia.
abstract: Staphylococcus aureus produces various virulence factors. The catalase enzyme, in particular,  is considered to be involved in oxidative stress resistance, and catalase activity is an important criterion  for differentiating staphylococci from streptococci. In this report, we describe the catalase-negative S.  aureus strain SH3064, which was isolated from the sputum of a patient with aspiration pneumonia. To evaluate  the causes of the lack of catalase activity in S. aureus SH3064, we analyzed the sequence of katA gene  encoding the catalase enzyme in this strain. We amplified the complete sequence of katA gene of S. aureus  SH3064 by polymerase chain reaction using 2 sets of primers. The katA sequence showed 99.6% sequence  identity (1512/1518 bp) with that of S. aureus ATCC 12600. We detected 2 mutations in the katA gene from S.  aureus SH3064, an A217T substitution leading to a threonine 73-to-serine substitution and a single-base  pair deletion (c.637delG) resulting in a frameshift mutation. The lack of catalase activity in this strain  was attributed to the shift of the nucleotide reading frame.
authors.affiliation: Department of Laboratory Medicine, Shinshu University Hospital, Matsumoto 390-8621, Japan.
authors.forename: Kazuki
authors.initials: K
authors.lastname: Horiuchi
authors.forename: Takehisa
authors.initials: T
authors.lastname: Matsumoto
authors.forename: Eiko
authors.initials: E
authors.lastname: Hidaka
authors.forename: Eriko
authors.initials: E
authors.lastname: Kasuga
authors.forename: Mitsutoshi
authors.initials: M
authors.lastname: Sugano
authors.forename: Kozue
authors.initials: K
authors.lastname: Oana
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Kawakami
authors.forename: Takayuki
authors.initials: T
authors.lastname: Honda
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D002374:Catalase / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D009154:Mutation; D011015:Pneumonia, Aspiration / Q000382:microbiology*; D013183:Sputum / Q000382:microbiology*; D013203:Staphylococcal Infections / Q000382:microbiology*; D013211:Staphylococcus aureus / Q000201:enzymology / Q000235:genetics* / Q000302:isolation & purification*
chemical_list: D001426:Bacterial Proteins; D002374:Catalase