Who are the participants?

Transcription

1 Elucidating the pathogenesis of staphylococcal diseases by studying virulence factors of Indian Community Associated Methicillin Resistant Staphylococcus aureus Jerome Etienne University of Lyon, France Dean of the Faculty of Medicine Gayathri Arakere, Indian Institute of Science Bangalore Who are the participants? Europe: Sweden The Netherlands France India: Bangalore

2 The research setting: the bacteria A bacteria called Staphylococcus aureus Commensal of the human beings Responsible for infections 2 Can become resistant to antibiotics 3 and spread in hospitals or the community MRSA MRSA 4 Epidemiology of MRSA Clone recognition? The concept of clones ST for Sequence Type ST22 ST23 ST ST2 ST5 ST4 ST3 ST4 ST5 ST6 ST7 ST8 Clonal complex Strains with highly related "sequence types" (STs) are grouped in Clonal Complexes (CCs) Epidemiology at a worldwide level Staphylococcus aureus How to determine sequence types?

3 Characterization of methicillin resistant Staphylococcus aureus (MRSA) clones Multilocus Sequence Typing different alleles of the same genes Hospital Specific hospital-associated clones - i.e.: New York Japan clone - i.e.: EMRSA5 clone Community Specific community-associated clones - i.e.: USA3 clone (ST8) Other tools? Other tools for clone chacterization Microarrays Detection of 322 alleles or genes : virulence determinant (ie: the Panton Valentine leukocidin genes) antibiotic resistance genes clone assignment but also, - PFGE - SCCmec typing - spa typing The respective expertise

4 Mixing individual expertise altogether France Gene amplification virulence factor detection Gene sequencing clone characterization Microarrays 322 genes detected India Gene amplification virulence factor detection Gene sequencing clone characterization The Netherlands Immune response antibodies detection Previously published works Example of epidemiological study This article has been cited 843 times in Web of Knowledge.

5 Mixing information Clinical information Bacteriological data This article has been cited 925 times in Web of Knowledge. Example of clinical study This article has been cited 787 times in Web of Knowledge.

6 Example of epidemiological study How to be successful? What do we need to be successful in our project? Healthy volunteers Infected patients Clinical information (often lacking) French MD is now in Bangalore for 4 months Bacteria Exportation!!!! Connection with Sera from Industryo patients Laboratories with complemental experiences Travels to Europe Exchanges Travels to India N

7 Community associated Staphylococcus aureus from India: Toxins and Virulence factors in carriers and patients Gayathri Arakere Senior Scientist Society for Innovation and Development, Indian Institute of Science, Bangalore 562 India Staphylococcus aureus S. aureus inhabits the skin and nasopharynx of humans. S. aureus affects different organs causing a wide variety of diseases from simple skin infections to septicemia and necrotizing pneumonia. S. aureus avoids innate and induced immunity both in the commensal state and when it causes infection.

8 Types of MRSA Hospital associated MRSA: SCCmec types I, II, III Multidrug resistant Community associated MRSA: present only in the community in healthy adults, SCCmec types IV, V β lactam antibiotics resistant The distinction between the two is blurring with CA-MRSA replacing HA-MRSA in hospitals with changing antibiotic sensitivities Objectives of the Study Survey various S. aureus pools present among healthy carriers and diseased individuals Determine sequence types which have acquired the meca gene for methicillin resistance Characterize clonal complexes prevalent in India Detect toxins, virulence factors and immune evasion factors present among Indian isolates The broad objectives of the study are to identify biomarkers of S. aureus diseases.

9 Molecular techniques for genotyping S. aureus SCCmec element typing- I, II, III, IV, V Multi Locus Sequence Typing (MLST) Staphylococcal Protein A typing (Spa) Phylogenetic analysis by Pulsed Field Gel Electrophoresis (PFGE) Microarray to determine the presence of 85 genes Sample collection from carriers and patients 38 Nasal swabs from Carriers- samples include some rural and some urban from OPD of Victoria Hospital 3 Disease isolates from skin wounds, abscesses, blood and pleural fluids from different hospitals 33 isolates from severe and non severe eye infections

10 Clonal complexes and percentages among Indian S. aureus CC/ST 22/22 /772 2/2 3/ /72 45/45 5/5 6 5/99 398/29 7 Isolate Carrier MSSA MRSA 4 4 Dis MSSA MRSA Total % of Total Differences in sequence types from Microarray data ST# Isolates hlb sak chip scin ccrc ZH47 egc spla splb sple ssl3 ssl6 ssl8 ssl 22/ / / /

11 Diseases caused by S.aureus Type of infection Percent Skin and soft tissue infections 7 Cerebal abscesses Meningitis pyomyositis Necrotizing pneumonia 3 Plural empyema Summary EMRSA-5 is predominant in disease isolates followed by ST 772 (SCCmec type V) We are reporting two new clones ST672 and ST28 (SCCmec type V) in disease isolates for the first time and two isolates of bovine origin in ST29 7% of Indian S. aureus are PVL positive The diversity of sequence types of MSSA isolates in the small sample number is large. Microarray data on virulence factors point to genetic back ground of isolates rather than carrier or disease status.

12 Severe and non severe eye infections Severe ST % Non-severe ST % Microbial Keratitis , 5 3 Endophthalmitis Suture induced infiltrate Lacrimal sac abscess Preseptal cellulitis O. Cellulitis 3 Upper lid abscess , Buckle infection 72 3 External Hordeolum Orbital abscess 88 3 Conjuctivitis 672, Evolution and origin of ST

13 Acknowledgements Collaborators: Jerome Etienne Michele Bes Anna Norrby-Teglund Mattias Svensson Willem van Wamel Funding: NPP-Indigo SIDA Dorabji Tata Trust We thank all the clinicians for isolates