Coagulase Gene Polymorphism Research Articles

Koyunlarda Gangrenöz Mastitise Neden Olan Bakterilerin İdentifikayonu ve Gangrenli Sütlerdeki Staphylococcus aureus’un PCR ile Tespit Edilmesi

Summary The objective of this study was to identify bacteria causing gangrenous ovine mastitis as well as to detect and genotype Staphylococcus aureus in milk samples by using polymerase chain reaction (PCR) amplification and restriction fragment length polymorphism (RFLP) of coagulase gene. A total of 264 milk samples were collected from Awassi sheep with gangrenous mastitis raised in Sanliurfa province of Turkey. By using bacteriological examination Staphylococcus aureus (75%), Mannheimia haemolytica (7.2%), coagulase negative staphylococci (6.43%), Escherichia coli (4.55%), Corynebacterium spp. (0.76%) and Actinomyces pyogenes (0.76%) were identified. Bacterial DNA was isolated from 155 randomly selected milk sample. By PCR amplification of coagulase gene S. aureus was detected in 91.6% of the milk samples. Three different amplicons of 420 (0.7%), 580 (65.3%) and 780 (34%) bp band sizes, each showing a specific RFLP profile were observed. In conclusion, S. aureus was found to be mostly responsible for gangrenous mastitis in sheep raised in this region. S. aureus in milk samples could be more rapidly detected by PCR method. Two coa genotype of S. aureus were found to be common suggesting that limited number of strains were responsible for most cases of gangrenous mastitis in the region under the study.

Characterization of Staphylococcus aureus strains isolated from raw milk of bovine subclinical mastitis in Tehran and Mashhad

Staphylococcus aureus is considered one of the most important food borne pathogens. A total of 111 isolates of S. aureus were cultured from raw milk samples during January 2009 to June 2009 from Tehran and Mashhad. The coagulase gene polymorphism and the prevalence of classical enterotoxin genes of S. aureus strains were determined by PCR-RFLP (restriction fragment length polymorphism) and Multiplex-PCR. Disk diffusion method was used to determine the susceptibility of isolates to antimicrobial agents as instructed by Clinical and Laboratory Standards Institute. Sixty-seven % of the isolates harboured one or more enterotoxin genes. The most prevalent gene was sec, found in 59 % of the isolates. Approximately 8% of the isolates were positive for sea, seb and sed genes. Only one isolate had see gene. The rate of coexistence of enterotoxin genes was 14%. All S. aureus isolates were susceptible to ciprofloxacin, gentamicin, imipenem, minocycline, oxacillin and vancomycin. They were resistant to ampicillin (64%), penicillin (56%), clindamycin (22%), tetracycline (22%), doxycycline (19%), teicoplanin (13%), rifampin (2%) and trimethoprim-sulfamethoxazole (2%). On the basis of coagulase gene analysis of 111 S. aureus isolates, the PCR products of 56 isolates were digested with Alu I that produced three distinct patterns. These data indicate the high prevalence of enterotoxigenic S. aureus in raw bovine milk in Tehran and Mashhad, and highlight the importance of proper quality control of dairy products for public health.

Coa types and antimicrobial resistance profile of Staphylococcus aureus isolates from cases of bovine mastitis

The objective of the study was to determine the interrelationship between coa types of Staphylococcus aureus isolates from bovine mastitis cases and their susceptibility patterns to commonly used antimicrobial agents. In this study, a total of 63 S. aureus isolates obtained from 387 clinical and subclinical bovine mastitis milk specimens were examined for antimicrobial susceptibility against various classes of antibiotics and coa typing according to the size of the PCR product. Overall, five resistance profiles, nomenclatured PA, PAAc, PAE, PAAcE, and PAAcT according to their resistance and five different coa types, numbered I to V, were noted among the isolates studied. The most coa types were type I (38.1% of the 63 isolates) and type III (36.51%) and indicates that a few coagulase gene types of S. aureus are responsible for the majority of bovine mastitis cases. Resistance to penicillin, ampicillin, and amoxicillin/clavulanic acid were most common, respectively, with 63 (100%), 63 (100%), and 41 (65.1%) isolates and appeared to be higher than those usually reported. No resistance was detected for trimethoprim and gentamicin. Furthermore, a good relationship between phenotypic antibiogram and the polymorphism of coagulase gene was found in this study. Predominant coa types I and III were significantly associated with resistance profiles PAAcT and PAAcE, respectively. These two predominant types also showed high antibiotic resistance characteristic in comparison with rare types. As a result, this study illustrated a tendency for isolates from different coa types to have specific antimicrobic susceptibility profiles, presumably because of genetic diversity between isolates and/or selection force through the use of drugs.

Coagulase gene polymorphism of Staphylococcus aureus isolated from clinical and sub-clinical bovine mastitis in Isfahan and Chaharmahal va Bakhtiari provinces of Iran

Mastitis is a common disease in dairy cattle and is an inflammatory response of the breast tissue to bacterial attack to this tissue. Mastitis causes considerable loss to the dairy industry, among the several bacterial pathogens that can cause mastitis; Staphylococcus aureus is probably the most lethal agent because it causes chronic and deep infection in the mammary glands that is extremely difficult to cure. Several virulence factors including coagulase gene are produced by S. aureus and may contribute to its pathogenicity. This study was conducted to investigate the coagulase gene polymorphism of S. aureus isolated from clinical and sub-clinical bovine mastitis milk samples in Isfahan and Chaharmahal va Bakhtiari provinces of Iran. Amplification of the coagulase gene from 86 S. aureus strains isolates by specific primers showed 31 specimens contained 970 bp fragment, and 11 strains contained 730 bp fragment relevant to coa gene (coagulase) in PCR. After enzymatic digestion with AluI, 31 specimens contained three bands: 320, 490, and 160 bp (genotype I) and 11 specimens contained two bands: 490 and 240 bp (genotype VIII) in the RFLP.

Molecular Analysis of Coagulase Gene Polymorphism in Clinical Isolates of Methicilin Resistant Staphylococcus aureus by Restriction Fragment Length of Polymorphism Based Genotyping

Molecular Analysis of Coagulase Gene Polymorphism in Clinical Isolates of Methicilin Resistant Staphylococcus aureus by Restriction Fragment Length of Polymorphism Based Genotyping

Biochemical profiles, restriction fragment length polymorphism (RFLP), random amplified polymorphic DNA (RAPD) and multilocus variable number tandem repeat analysis (MLVA) for typing Staphylococcus aureus isolated from dairy products

The study concerns 130 Staphylococcus aureus strains isolated from different raw-milk dairy products (122 isolates) and human samples (eight isolates). Four different typing techniques were applied: biochemical profiles (Biolog GP), restriction fragment length polymorphism of coagulase gene (coaRFLP), random amplified polymorphic DNA (RAPD) and multilocus variable number tandem repeat analysis (MLVA). Moreover multiplex-PCR was used to study the distribution of genes encoding staphylococcal enterotoxins. The results of this study reveal marked genomic and phenotypic variability among the tested S. aureus. The considered techniques were all found useful for strain typing, but, based on discriminatory power as the key parameter of the typing system, MLVA and Biolog GP were found to be the most powerful techniques. The methods showed little concordance in terms of discerning the clusters of related strains.

Differentiation of Staphylococcus aureus strains by CE, zeta potential and coagulase gene polymorphism

Staphylococcus aureus is a common cause of infection in both hospitals and the community, and it is becoming increasingly virulent and resistant to antibiotics. Possibilities of fast, sensitive and cheap determination of these pathogenic bacteria are extremely important in antimicrobial therapy. In the present study, CE with chemically modified capillary and zeta potential measurements were used for differentiation of three different clinical strains of S. aureus. The data presented in this contribution suggested that electrophoretic behavior and the values of zeta potential should be very useful in distinguishing between closely related strains, which exhibited coagulase gene/protein polymorphism. Understanding the differences between S. aureus strains could help to improve our knowledge about S. aureus pathogenecity and to monitor for and respond to emergence of more virulent strains.

Cover Picture: Electrophoresis 17'09

AbstractIssue no. 17 is an Emphasis Issue with 10 articles on various aspects of “Proteins and Proteomics” while the remaining 10 articles are arranged into 3 different parts including “Chip Technology”, “Nucleic Acids”, and “Methodologies, Assays and Applications.”Selected articles are:Proteomic analysis of Oenococcus oeni freeze‐dried culture to assess the importance of cell acclimation to conduct malolactic fermentation in wine ((10.1002/elps.200900228))Complete sequencing and oxidative modification of Mn‐SOD (SOD2) in medulloblastoma cells ((10.1002/elps.200900168))Differentiation of Staphylococcus aureus strains by capillary electrophoresis, zeta potential and coagulase gene polymorphism ((10.1002/elps.200900186))

Molecular Analysis of Coagulase Gene Polymorphism in Clinical Isolates of Methicilin Resistant Staphylococcus aureus by Restriction Fragment Length Polymorphism Based Genotyping

Problem statement: To investigate coagulase gene variants through Restriction Fragment Length Polymorphism (RFLP) amongst clinical isolates of Methicillin-Resistant Staphylococcus Aureus (MRSA) collected from Chennai based hospitals. Approach: A total of 85 MRSA clinical isolates collected from various clinical sources were studied for the molecular typing purpose. To perform coagulase gene typing, the repeated units encoding hypervariable regions of the Staphylococcus aureus coagulase gene were amplified by the PCR followed by AluI and HaeIII restriction enzyme digestion of the PCR product and analyzed for RFLP. Results: Cluster analysis performed with Un-weighted Pair Grouping Using Arithmetic Mean Analysis (UPGMA) at >80% similarity level classified all strains into 31 and 21 genotypes based upon AluI and HaeIII RFLP patterns respectively. AluI RFLP patterns gave a high discriminatory index and proved to be better than that of HaeIII in typing of MRSA strains. Conclusion: Method investigated in this study, proved to be quick, reliable and useful for typing large number of MRSA strains from various clinical isolates with high fidelity. Grouping of strains based on RFLP patterns of both enzymes, improved the discriminatory index. Finally, using this methodology group of epidemiological strains can be typed reliably and effectively using both enzymes. Significance and impact of the study: This efficient and reliable typing procedure is beneficial to develop efficient infection control measures in hospitals for staphylococcal infection. This typing procedure could be used to analyze large number of strains with in a short period of time and thus useful for epidemiological investigations.

Molecular Analysis of Coagulase Gene Polymorphism in Clinical Isolates of Methicilin Resistant Staphylococcus aureus by Restriction Fragment Length Polymorphism Based Genotyping

Molecular Analysis of Coagulase Gene Polymorphism in Clinical Isolates of Methicilin Resistant Staphylococcus aureus by Restriction Fragment Length Polymorphism Based Genotyping

Molecular typing ofStaphylococcus aureusisolated from Italian dairy products on the basis of coagulase gene polymorphism, multiple-locus variable-number tandem-repeat and toxin genes

Coagulase gene restriction fragment length polymorphism (RFLP), six-locus variable-number tandem-repeat analysis patterns (MLVA) and detection of enterotoxin genes (se) (sea, sec, sed, seg, seh, sei, sej and sel) were used to determine the phylogenetic relationship among isolates of Staphylococcus aureus isolated from dairy products from different regions of Italy. A total of 25 Staph. aureus were subtyped into 16 coagulase genotypes by RFLP, and MLVA revealed marked genomic variability. Furthermore, 17 of the isolates harboured at least one toxin gene, with the predominance of sea, sed and sej among cow isolates and sec-sel among the goat and sheep strains. Combined RFLP, MLVA polymorphism and se genes were found to be useful techniques for discriminating several genetic variants in Staph. aureus isolates.

Molecular Typing ofStaphylococcus aureusIsolated from Blood on the Basis of Coagulase Gene Polymorphism and Toxin Genes

Coagulase is produced by all strains of Staphylococcus aureus. The 3' coding region of the coagulase (coa) gene contains varying numbers of 81 bp tandem repeats. S. aureus produces a variety of extracellular protein toxins. Here, we typed S. aureus strains isolated from blood by coa gene restriction fragment length polymorphism (RFLP) patterns and toxin gene profiles. A total of 120 strains of S. aureus were isolated from blood cultures during 2003-2006 at Kangdong Sacred Heart Hospital. The isolates were typed by PCR RFLP analysis of the coa gene and by multiplex PCR for detection of genes encoding enterotoxins (sea, seb, sec, sed, and see), toxic shock syndrome toxin-1 (tst), exfoliative toxins (eta and etb), mecA and femA. All the S. aureus strains were classified into 16 types on the basis of coa gene RFLP and could be further differentiated into 34 types according to the combined patterns of coa gene RFLP and toxin gene profiles. Of 85 methicillin-resistant S. aureus (MRSA) strains, 43 (50.6%) and 36 (42.4%) belonged to the RFLP pattern L5 and pattern L1, respectively. MRSA strains belonging to pattern L5 frequently carried tst (93.0%) or sec gene (81.4%), and strains belonging to pattern L1 frequently carried sea (88.9%) or see gene (44.4%). The rate of the pattern L5 in MRSA strains increased over the past few years and was higher in intensive care unit than in other wards. We typed S. aureus strains isolated from blood on the basis of coa gene RFLP and toxin genes. The strains belonging to coa gene RFLP pattern L5 and L1 appeared to be the major types of MRSA isolasted from bacteremia and revealed specific toxin gene profiles according to the coa gene RFLP patterns.

Molecular Typing of Methicillin-Resistant Staphylococcus aureusIsolated in a Bahrain Hospital

Objective: To investigate antibacterial resistance patterns and genetic relatedness of methicillin-resistant Staphylococcus aureus (MRSA) obtained at the Salmaniya Medical Complex in Bahrain. Methods: A total of 53 consecutive MRSA isolates obtained from 53 patients were studied using antibacterial resistance patterns, coagulase gene polymorphism, staphylococcal cassette chromosome mec (SCCmec) typing and pulsed-field gel electrophoresis (PFGE). Results: There was a high prevalence of resistance to fusidic acid (92.5%), ciprofloxacin (92.5%), erythromycin (90.6%), tetracycline (88.7%), trimethoprim (88.7%), streptomycin (88.7%), kanamycin (83.0%) and gentamicin (73.6%). Coagulase gene typing divided the isolates into five coagulase types comprising coagulase type 36 (86.7%), type 20 (3.8%), type 16 (3.8%), type 38 (1.9%) and type 384 (3.8%). They belonged to SCCmec type III (86.7%) and SCCmec type IV (13.3%). PFGE identified five pulsotypes (types A–E) with PFGE type A and its subtypes comprising 83% of the isolates. PFGE type A isolates were multiresistant and had the SCCmec type III and coagulase type 36 genotype. The SCCmec type IV isolates were nonmultiresistant with different genetic backgrounds. Conclusions: The study identified two types of MRSA in the hospital during the study period. One type consisted of a persistent multiresistant PFGE clone with the SCCmec type III and coagulase type 36 genotypes. The second type consisted of nonmultiresistant isolates that belonged to different genetic backgrounds and were isolated less frequently.

Antibiogram and Coagulase Diversity in Staphylococcal Enterotoxin-Producing Staphylococcus aureus from Bovine Mastitis

We investigated antibiogram and coagulase gene diversity in staphylococcal enterotoxin (StE)-producing Staphylococcus aureus isolated from raw milk samples of cows infected with mastitis from 140 dairy farms in Korea between 1997 and 2004. Of the 696 Staph. aureus isolates collected in this study, 164 isolates (23.6%) produced one or more staphylococcal enterotoxins (A to D), and 19 isolates (2.7%) were methicillin-resistant. The percentage of StE-producing Staph. aureus (SES) isolates resistant to methicillin, kanamycin, neomycin, amikacin, and tetracycline was greater than that of non-SES. Ten coagulase genotype patterns were observed, including 4 main types comprising I (25.4%), II (13.9%), VII (13.2%), and VIII (17.8%). More than 4 Staph. aureus types were isolated from each of 82 dairy farms in different geographic locations, and only 1 coagulase genotype pattern was observed in 39 of the herds (47.6%). There was no significant correlation between coagulase genotypes harbored by Staph. aureus and their specific StE type. The percentage of isolates producing major StE types (A, B, AC, and ABCD) and being resistant to cephalothin and methicillin was greater among the Staph. aureus isolates with the 4 predominant coagulase genotypes (I, II, VII, and VIII) than among the isolates harboring the 6 rare coagulase types (III, IV, V, VI, IX, and X). Based on coagulase gene polymorphisms, our data indicate that a broad distribution of identical or closely related enterotoxin-producing Staph. aureus strains seem to contribute to bovine mastitis in the Republic of Korea.

Phenotypic and Genetic Antibiogram of Methicillin-Resistant Staphylococci Isolated from Bovine Mastitis in Korea

Staphylococcus aureus belongs to the group of major contagious mastitis pathogens, whereas the coagulase-negative staphylococci (CNS) are also capable of causing opportunistic bovine mastitis. Many of these strains are resistant to penicillin or ampicillin because of the long-term use of β-lactam antibiotics in agricultural and healthcare settings. Based on the simple and highly specific coagulase genotyping by PCR-RFLP used for discriminating among Staph. aureus strains, the relationship between phenotypic antibiogram and the polymorphism of coagulase gene was determined in this study. The staphylococci strains (835 Staph. aureus and 763 CNS) were isolated from 3,047 bovine mastitic milk samples from 153 dairy farms in 8 provinces from 1997 to 2004 in the Republic of Korea. Twenty-one (2.5%) Staph. aureus and 19 (2.4%) CNS strains were resistant to methicillin [oxacillin minimum inhibitory concentration (MIC) ≥4μg/mL]. The mecA gene was also found in 13 methicillin-resistant Staph. aureus (MRSA) and 12 methicillin-resistant CNS (MRCNS) isolates with a significantly higher detection rate of the mecA gene in MRSA with high MIC (≥16μg/mL) compared with those with MIC≤8μg/mL. Methicillin-resistant Staph. aureus and MRCNS were also more resistant to other antibiotics (ampicillin, cephalothin, kanamycin, and gentamicin) than methicillin-susceptible staphylococci. Among 10 different coa PCR-RFLP patterns (A to J) in 706 Staph. aureus strains, the main types were A (26.9%), B (17.0%), G (10.5%), and H (15.4%), with the frequent observation of the A and H types (6 and 10 isolates) in MRSA. This study indicates that major epidemic Staph. aureus clones may be spread between different dairy farms, and the profile of coa genotype can be applied for epidemiological investigations and control of bovine mastitis, particularly one caused by MRSA with specific prevalent coa types.

Coagulase gene polymorphisms detected by PCR in Staphylococcus aureus isolated from subclinical bovine mastitis in Turkey

The genetic relatedness of coagulase ( coa) positive Staphylococcus aureus isolated from cows with subclinical mastitis in Turkey was investigated by polymerase chain reaction (PCR)-based restriction fragment length polymorphism (RFLP) analysis. Among 700 milk samples positive in the California Mastitis Test (CMT), species specific PCR identified 200 (28.6%) isolates as S. aureus and 161 (80.5%) of these isolates were positive for the 3′ end of the coa gene by PCR. Most isolates ( n = 135, 83.9%) produced a single band on coa PCR, with molecular sizes ranging from 500 to 1400 bp, whereas a small number of isolates ( n = 26, 16.1%) yielded two amplification products. Coa RFLP analysis using AluI and Hin6I revealed 23 and 22 band patterns, respectively. The detection of double bands by coa PCR, previously reported in human isolates, suggests that milking personnel can play a role in the transmission of S. aureus.

Antibacterial Resistance and Molecular Typing of Methicillin-Resistant Staphylococcus aureus in a Kuwaiti General Hospital

Objective: To investigate antibiotic resistance and genetic relatedness of methicillin-resistant Staphylococcus aureus (MRSA) isolated in a general hospital in Kuwait over a period from 1996 to 1998 and 2001. Material and Methods: The isolates were characterized by antibacterial susceptibility testing, coagulase serotyping, coagulase gene polymorphism (coag-RFLP) and pulsed-field gel electrophoresis (PFGE). Results: The MRSA isolates were highly resistant to gentamicin, kanamycin, ciprofloxacin, tetracycline, fusidic acid and mupirocin. The prevalence of gentamicin, kanamycin, streptomycin, tetracycline and erythromycin resistance remained high (80–96%) throughout the study period, but the prevalence of resistance to ciprofloxacin, fusidic acid and mupirocin steadily increased. The already high mupirocin resistance level increased from 12.5 in 1996, to 85.7% in 2001, and the fusidic acid resistance varied between 70.8 and 85.7%. In contrast, chloramphenicol and trimethoprim resistance declined from 25 and 29% in 1996 to 4.7 and 14.2% in 2001, respectively. The majority (91.5%) of the isolates were coagulase serotype 4. AluI restriction endonuclease analysis of amplified coagulase gene generated four coag-RFLP patterns: 92% of them were coag-RFLP type 1, while types 2, 3 and 4 were 3.5, 4.6 and 1.1% respectively. PFGE differentiated them into seven pulsotypes (PFGE types 1–7). The PFGE type 1 pulsotype constituted 90.2% of the isolates. Isolates with the type A coag-RFLP also had the type1 PFGE pulsotypes. Conclusion: The concordant results of PFGE and coag-RFLP demonstrated the presence of a persistent MRSA clone in the hospital during the study period.

Coagulase gene polymorphism of Staphylococcus aureus isolated from goat mastitis in Brazilian dairy herds

To investigate the coagulase gene polymorphism of Staphylococcus aureus isolated from mastitic goat's milk. A typing procedure based on coagulase gene polymorphism was used to discriminate S. aureus isolated from goat mastitis. Thirty-six strains collected from goats belonging to herds from northern Ceara State and Serrana region of Rio de Janeiro State were analysed. Based on restriction fragment length polymorphism of 3' end coagulase gene, the goat strains were grouped into 11 types. In northern Ceara herds, the predominant type was found in 60% of the strains, while in the Serrana region herds the two most common accounting for 62.5% of the strains. The analysis of the coa gene proved to be useful for typing S. aureus from goat mastitis. Although the results showed that goats from the studied regions were infected by S. aureus strains harbouring more than one coagulase genotype, only one or two types predominated. The identification of the prevalent strains within a herd or region is a necessity. The important virulence factors could be identified in such strains and this information can then be used as a specific base to develop S. aureus mastitis control measures.

Antimicrobial Susceptibility and Coagulase Gene Typing of Staphylococcus aureus Isolated from Bovine Clinical Mastitis Cases in Turkey

The objectives of this study were to determine antimicrobial resistance patterns of Staphylococcus aureus strains isolated from bovine clinical mastitis cases and to subtype the strains by polymerase chain reaction (PCR) technique based on coagulase gene polymorphism. Two hundred sixty-five S. aureus isolates collected from individual animals in different herds (n = 235) from 1995 to 2004 were tested for susceptibility to penicillin, ampicillin, amoxicillin-clavulanate, oxacillin, oxytetracycline, enrofloxacin, kanamycin-cephalexin, and trimethoprim-sulfamethoxazole using the agar disc diffusion test. Strains were also tested for β-lactamase production. A total of 29.8% of the strains were susceptible to all antimicrobial agents tested. The highest resistance was observed in 63.3% of the strains against β-lactam antibiotics, penicillin and ampicillin. Oxytetracycline resistance was observed in 27.9% of the strains, either alone or in combination with β-lactams. No resistance was detected for amoxicillin-clavulanate, oxacillin, enrofloxacin and kanamycin-cephalexin. β-Lactamase production and resistance to β-lactam antibiotics were usually correlated. Resistance against β-lactams increased from 43.5% in 1995 to 58 to 77% from 1999 to 2004.One hundred twenty-five strains were examined for coagulase gene polymorphism. The isolates were subtyped into 4 types by coagulase gene-based PCR. A predominant 1000-bp PCR product was observed in 60.8% of the isolates typed. The results indicate that a few coagulase gene types of S. aureus are responsible for the majority of bovine clinical mastitis cases in one province of Central Anatolia region, Turkey.

Emergence of Rifampicin Resistance in Methicillin-ResistantStaphylococcus aureusIsolated at a Turkish University Hospital

Twenty-three rifampicin-resistant methicillin-resistant Staphylococcus aureus (MRSA) isolated in three wards at a university hospital in Turkey between June, 2000, and February, 2001, were studied for their genetic relatedness using a combination of antibiogram, coagulase serotyping, coagulase gene polymorphism (coa-RFLP), and pulsed-field gel electrophoresis (PFGE). They all expressed high-level rifampicin resistance (MIC, >256 mg/L) and were resistant to gentamicin, kanamycin, amikacin, ciprofloxacin, tetracycline, and cadmium acetate and were susceptible to fusidic acid, vancomycin, trimethoprim, and mupirocin. They belonged to the same coagulase serotype (serotype IV) and had identical coa-RFLP patterns. In contrast, PFGE generated nine banding patterns designated type A, types A1-A5, B, C, and D. The most common PFGE pattern (type A) and its subtypes (types A1-A5) were seen in 20 (87%) of the 23 isolates in the three wards. The results demonstrated the acquisition of rifampicin resistance by different MRSA clones and the spread of one clone among patients in the three wards.