Molecular typing of methicillin-resistant Staphylococcus aureus by PCR-RFLP and its usefulness in an epidemiological study of an outbreak.

Central Clinical Laboratory, Nara Medical University, Nara 634-8522, Japan.
Japanese journal of infectious diseases (Impact Factor: 1.2). 09/2005; 58(4):250-2.
Source: PubMed

ABSTRACT A new convenient molecular typing method, simultaneous polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) analysis, for three different genes of methicillin-resistant Staphylococcus aureus (MRSA) was evaluated using 35 isolates of MRSA and comparing results with those previously reported for sequencing-based spa typing. Twenty-nine isolates of the most frequent protein A (spa) type were discriminated into 6 different types by PCR-RFLP. In contrast, spa typing could discriminate only 1 of the 19 most frequent PCR-RFLP-type isolates. The discriminatory powers of the two methods were equal for the other isolates. These results suggest that PCR-RFLP has the advantages of both relative easiness and greater discriminatory power than spa typing. We also report the case of a suspected outbreak in which PCR-RFLP was sufficient for ruling out the possibility of an outbreak. Thus, PCR-RFLP is preferable as a preliminary screening method for epidemiological studies of nosocomial infection caused by MRSA.

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    ABSTRACT: Methicillin sensitive Staphylococcus aureus is an important bacterial pathogen associated with hospital- and community-acquired infections leading to endocarditis, skin tissue infection and pneumonia. The objective of this study was to determine both the genetic characteristics of methicillin-sensitive S. aureus (MSSA) strains, and the occurrence of virulence factors produced by S. aureus strains isolated from UMMC and healthy students in the University from year 2009. Out of 429 nasal swab samples, 67 were MSSA. The prevalence of 21 different virulence genes among 67 Malaysian clinical and community MSSA strains was determined by PCR, and their genetic features were assessed by PCR-RFLP of coa gene, agr types, spa typing and PFGE. The five predominant virulence genes were ica (79 %), efb and fnbA (61 % each), sdrE (57 %) and hlg (45 %). Toxin genes (enterotoxin, etd and pvl) were significantly more common (P < 0.05) in clinical strains compared to community strains. Three agr genotypes were observed: agr type I (45 %), agr type III (25 %) and agr type II (19 %). All 67 MSSA strains were distinguished into 26 profiles by PCR-RFLP of coa, 55 pulsotypes and 21 spa types. Four novel spa types (t7312, t7581, t7582 and t7583) were observed. In conclusion, different virulence profiles were observed in MSSA strains in Malaysia where toxin genes were more prevalent among clinical strains. No correlation between DNA profiles (coa-RFLP, PFGE and spa) and virulotypes was observed. The Malaysian MSSA strains from clinical and community sources were genetically diverse and heterogeneous.
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    ABSTRACT: Protein A is the virulence factors of Staphylococcus aureus rolling in its pathogenesis, and its gene is used for typing. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) with different enzymes has been used for this action.
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    ABSTRACT: Increased frequency of methicillin-resistant Staphylococcus aureus (MRSA) in hospitalized patients requires rapid and reliable characterization of isolates for control of MRSA spread in hospitals. This study evaluated polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) as a molecular typing technique for MRSA strains on the basis of protein A (spa) and coagulase (coa) gene polymorphisms to verify their ability in assessing the relatedness of isolates. Seventy-five MRSA isolates, from different ICUs of Alexandria University Main Hospital, were characterized using antibiotyping and PCR-RFLP analysis of coa and spa genes. Thirty-two antibiotypes were identified. coa gene PCR generated 3 types and 10 subtypes of band patterns. HaeIII restriction digestion of amplified coa gene products produced 5 major banding patterns and 12 subtypes. spa gene PCR products generated 4 major and 11 minor types, and their HaeII restriction digestion showed 5 major and 12 minor banding patterns. The combined coa and spa RFLP patterns generated 22 combined R types. Typing using coa PCR and PCR-RFLP had the same discriminatory index (DI) value (0.64), which was comparable to that of both spa PCR and PCR-RFLP techniques (0.68). The combined grouping increased the DI value to 0.836. The current study revealed that testing for multiple gene polymorphisms is more useful for local epidemiologic purposes.
    International Journal of Microbiology 01/2014; 2014:650328.


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