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Molecular epidemiology of MRSA Epidemic and pandemic clones circulation in Romania Professor Lia Monica Junie Professor Lia Monica Junie, University of Medicine and Pharmacy, Cluj Napoca, Romania
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Why Staphylococcus aureus?
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Antibiotic resistance in S. aureus Gasch O & all, “Methicillin-susceptible Staphylococcus aureus clone related to the early pandemic phage type 80/81 causing an outbreak among residents of three occupational centers in Barcelona, Spain. Clin Microbiol Infect. 2012;18(7): 662-7.
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The Antibiotic resistance in S. aureus the blaZ gene, encoding for β-lactamase → resistant clones to the penicillin
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Methicillin-resistant Staphylococcus aureus mecA Gene (the methicillin-resistance determinant) encodes PBP2a
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site-specific recombinase SCCmec The staphylococcal cassette - SCCmec SCCme - types I, II, III, IV Antimicrob Agents Chemother 2004; 48: 2637–2651
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SCCmec types I, II, III,IV SCCmec types I, II, III,IV
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Methicillin-Resistant S. aureus (MRSA)
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MRSA - Hospital acquired infections
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Global spread of MRSA
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Worldwide prevalence of MRSA
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MRSA epidemic clones five pandemic MRSA clones
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EMRSA16 SCCmec type II, enterotoxin A,TSST-1, resistant to Erythromycin, Ciprofloxacin Pandemic MRSA clones
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New epidemic clones Evolution of the antibiotic resistance in ST5
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CA & HA-MRSA toxin & the AB resistance the presence of PVL toxin & the AB resistance Panton-Valentine leukocidin (PVL) - a major virulence factors of S. aureus
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The emergence of the HA & CA-MRSA
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The genom of CA-MRSA Vandenesch F. and all "Community-acquired methicillin-resistant Staphylococcus aureus carrying Panton-Valentine leukocidin genes: worldwide emergence” Emerg Infect Dis 9 (8): 978–84, 2003.
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Panton–Valentine leukocidin - PVL Wolk D M et al. J. Clin. Microbiol. 2009;47:3129-3137
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New PVL Positive EMRSA Clones Vandenesch F & all, "Community-acquired methicillin-resistant Staphylococcus aureus carrying Panton-Valentine leukocidin genes: worldwide emergence”. Emerg Infect Dis 9 (8): 978–84. 2007
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CA-MRSA strains from other continents Anne Tristan et all “Global Distribution of Panton-Valentine Leukocidin–positive Methicillin-resistant Staphylococcus aureus”, Emerg Infect Dis. 2007; 13(4): 594–600. some PVL-positive CA-MRSA have spread to several countries on various continents.
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The agr system of Staphylococcus aureus the agr locus - accessory gene regulator Deresinski S "Methicillin-resistant Staphylococcus aureus: an evolutionary, epidemiologic, and therapeutic odyssey". Clin. Infect. Dis. 40 (4): 562–573, 2005.
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S. aureus agr groups S. aureus strains can be divided into 4 major agr groups (I – IV)
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Staphylococcus enterotoxins (SEs) 19 different enterotoxins (Ses): SEA, SEB, SEC, SED, SEE. new types of SEs (SEG, SEH, SEI, SEJ, SEK, SEL, SEM, SEN, and SEO)
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Staphylococcus aureus pathogenicity islands carrying enterotoxin genes
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Research objectives Detection of the genes content of S. aureus strains isolated from hospitals by PCR : – mecA gene >> MRSA – pathogenity genes : TSST, PVL, agr, enterotoxin (sem & seg) S. aureus genes prevalence in Romanian hospitals Correlation: genes and AB resistance phenotypes
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Materials and Methods S. aureus strains – patients (medical, surgical, intensive care units) from 2 University hospitals
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S. aureus strains identification & Antibiotic Susceptibility Testing API ID 32 Staph the AB resistance to -lactamins, Kanamycin, tobramycin, gentamicin, Erythromycin, Clindamycin, Ciprofloxacin, Fusidic Acid, Glycopeptides. Vitek2 system
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PRIMER nucleotidic sequence MecA:Forward primer (5 AAA TCA GAT GGT AAA GGT TGG C3) Reverse primer (5 AGT TCT GCA GTA CCG GAT TTG C3) * Multiplex PCR (mecA and PVL gene); University Hospital of Patras (Prof. Iris Spiliopoulou, Prof Evangelos D Anastassiou) PCR in the Detection of S. aureus genes content * mecA & PVL gene agr specific group
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GenePrimerSequence (5′→3′)Amplicon size (bp) segSeg-FCCACCTGTTGAAGGAAGAGG432 semSem-FCTATTAATCTTTGGGTTAATGGAGAAC300 tsstTSST-FTGCAAAAGCATCTACAAACGA499 PCR for pathogenity genes : TSST, enterotoxin (sem & seg) Gene determination was performed in General University Hospital of Patras
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RESULTS The prevalence of MRSA among Staphylococcus aureus isolates in Romania by PCR (mec A gene+) There has been an increase in the prevalence of the MRSA isolated from hospitals over the years
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The rate of the PVL-positive isolates among S. aureus strains Many researchers have highlighted the PVL gene as a reliable marker for CA-MRSA infections.
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CA-MRSA IN Romania & in other European countries, PVL-positive
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The CA-MRSA strains 3 clones of PVL-positive CA-MRSA, were isolated from patients. in Romania
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The resistance phenotypes of CA-MRSA strains PVL+ clones Clone 1 is the multiresistant ST8-USA300 clone?; Clone 2 VISA is ST5 clone ? [4Clone 3 carrying the arg III gene: resistant to β-lactamins, K, FA, GISA - is the clone ST80, that was identified in Greece and it has also widespread to the rest of the European countries? [4].
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Emerge of new MRSA clone ST8=USA300 a CA-MRSA clone, that carries characteristically the SCCmec type IVa, the Panton-Valentine leukocidin (PVL) & the enterotoxins Q, K, Yasuhiro Shibuya & all ”Emergence of the community-acquired methicillin-resistant Staphylococcus aureus USA300 clone in Japan” Journal of Infection and Chemotherapy, 2008, 14, 6, Tenover FC & all, Goering RV “Methicillin- resistant Staphylococcus aureus strain USA300: origin and epidemiology”, Antimicrob. Chemother. 2009, 64 (3): 441
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is Resistance to oxacillin, erythromycin, ciprofloxacin, ± mefloxacine, ± tetracicline The typical antibiotic profile of ST8 - USA300
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The prevalence of agr groups in S. aureus isolates agr+ = 46,8%
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S.aureus arg positive strains
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The agr group of MRSA clones
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The role of agr during infection The association between agr specific groups and S. aureus infection type Jarraud et al. >> agr group IV strains ~ SSSS* Agr group III ~ TSS toxin1 producing isolates agr groups I and II ~ endocarditis agr group I ~ invasive infections, especially bacteremia *Staphylococcal scalded skin syndrome (SSSS)
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The resistance phenotypes of the agr + MRSA strains Clone1 = ST8 - USA300 clone; Clone 2 VISA is ST5 clone ? Clone 3 = clone ST80 ? Clone 4 ~ Brazilian MRSA clone ?
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The enterotoxin & agr genes in S. Aureus Our data suggests that 44,7% of S. aureus strains contain SEs (seg and sem in 29,8%), lower as reported by other authors for other European countries (e.g. in France, 85.4% expressed multiple SEs (19).
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The enterotoxin genes in MRSA & MSSA isolates the enterotoxin genes (sem+ seg+) were detected in 21,3% MRSA & 23,4% MSSA isolates:
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The enterotoxin genes in MRSA isolates the enterotoxins genes (sem & seg) were present both or alone in 21,3% MRSA from which in 8,5% CA-MRSA (PVL+ MRSA)
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They are not significant differences in the enterotoxin genes content of these clones The enterotoxin genes in MSSA isolates
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The Resistance phenotype of MSSA strains clone 1 = susceptible to all AB; clone 2 = GISA/GRSA; clone 3 = resistant to β lactam and E; clone 4 = resistant to Cip and E Clone 5 = resistant to β lactam and E; IS Clin; GISA
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Conclusions Our results showed the circulation in our area of different MRSA clones with different resistance phenotypes, carrying the agr gene alone/associated with the enterotoxin genes and with the PVL genes. it doesn’t exist a correlation of the presence of the genes with a certain resistance phenotype, that could suggest their existence. → the necessity to trace S. aureus strains using the PCR method and involving them in clinical diseases
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Local area Clinical microbiology Lab Higher forums International programs: ICAR, SENTRY, National surveillance programs Conclusions 57,5% MRSA, in Ro/ Cluj Napoca circulating phenotypes: First report in Romania PCR methods Surveillance of antibiotic resistance
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…Thank you!
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