Western Australian Methicillin-Resistant Staphylococcus aureus (MRSA) and Vancomycin Resistant Enterococcus (VRE) Epidemiology and Typing Report

Transcription

1 Australian Collaborating Centre for Enterococcus and Staphylococcus Species (ACCESS) Typing and Research Microbiology and Infectious Diseases Department PathWest Laboratory Medicine-WA, Royal Perth Hospital & Molecular Genetics Research Unit, Curtin University PHONE (8) FAX (8) Western Australian Methicillin-Resistant Staphylococcus aureus (MRSA) and Vancomycin Resistant Enterococcus (VRE) Epidemiology and Typing Report 1 July 211 to 3 June 212 Prepared By: Dr Geoffrey Coombs Senior Clinical Scientist, Department of Microbiology and Infectious Diseases, PathWest Laboratory Medicine WA, Royal Perth Hospital. Associate Professor, Molecular Genetics Research Unit, Curtin University Julie Pearson Medical Scientist-in-Charge, Department of Microbiology and Infectious Diseases, PathWest Laboratory Medicine-WA, Royal Perth Hospital. Dr Owen Robinson Consultant, Department of Microbiology and Infectious Diseases PathWest Laboratory Medicine-WA, Royal Perth Hospital. Clinical Professor Keryn Christiansen Emeritus Consultant, Department of Microbiology and Infectious Diseases PathWest Laboratory Medicine-WA, Royal Perth Hospital. February 213

2 Table of Contents 1 Overview MRSA: Key Results 1 st July 211 to 3 th June VRE: Key Results 1 st July 211 to 3 th June MRSA Nomenclature MLST Clonal Complex (CC) SCCmec Tests performed by ACCESS Typing and Research MRSA isolated in Western Australia, July 211 to June Relationship of age to MRSA Healthcare-Associated MRSA (HA-MRSA) EMRSA-15 (ST22-IV[2B]) Aus-2/3 EMRSA (ST239-III[3A]) New York/Japan MRSA (ST5-II [2A]) EMRSA-16 (ST36-II [2A]) Irish-2 EMRSA (ST8-VI [4B]) Community-Associated MRSA Queensland (Qld) (ST93-IV[2B]) Western Samoan CA-MRSA (WSPP) (ST3-IV[2B]) USA3 (ST8-IV[2B]) Taiwan CA-MRSA (ST59-V T [5C2&5]) and Taiwan A CA-MRSA (ST952-V T [5C2&5]) Bengal Bay Clone (ST772-V [5C2]) European CA-MRSA (ST8-IV[2B]) WA CA-MRSA WA MRSA-1 (ST1-IV[2B]) WA MRSA-2 (ST78-IV[2B]) WA MRSA-3 (ST5-IV[2B]) WA MRSA-121 (ST5-IV[2B]) WA MRSA-62 (ST923-IV[2B]) Number and Rate of MRSA in Western Australia by Health Region Regional data, 1 st July 211 to 3 th June Trend data, July 23 to June Vancomycin-resistant enterococcus species (VRE), July 211 to June VRE Trend Data, September 1998 to June Appendix: Typing Characteristics of HA-MRSA and major CA-MRSA clones, July 211 to June Acknowledgements References

3 1 Overview From 1 July 211 to 3 June 212, 7,32 methicillin resistant Staphylococcus aureus (MRSA) isolates from 5,589 patients and 281 vancomycin-resistant enterococci (VRE) from 273 patients were referred to ACCESS Typing and Research for epidemiological typing. Only unique isolates (duplicates excluded) are presented in this report. 1.1 MRSA: Key Results 1 st July 211 to 3 th June 212 MRSA isolated between July 211 and June 212 (5,834 unique isolates) consisted of: Community-Associated MRSA (CA-MRSA) 4,97 (85.2%) Healthcare-Associated MRSA (HA-MRSA) 864 (14.8%) The CA-MRSA can be divided according to their possession of Panton-Valentine leucocidin (PVL) and hence the potential to cause significant clinical disease. 1,582 (31.8%) of CA-MRSA were PVL positive. Mean age of infected/colonised patients: HA-MRSA 71 years (median 78 years) CA-MRSA 45 years (median 42 years) PVL positive CA-MRSA 29 years (median 26 years) PVL negative CA-MRSA 53 years (median 56 years) HA-MRSA The proportion of MRSA identified as HA-MRSA (14.8%) has remained stable since 26/ (95.8%) HA-MRSA were EMRSA-15 (ST22-IV [2B]): 7.% clinical specimens and 3.% colonisation. Thirty (3.6%) were from health care workers. Thirty two patients were identified with a PVL-positive strain. 21 (2.4%) HA-MRSA were ST239-III [3A]. Two (9.5%) were from health care workers. The remaining HA-MRSA included: 1 New York/Japan EMRSA (ST5-II [2A]), 2 variants of ST5-II (ST764-II [2A]). 1 Irish-2 EMRSA (ST8-VI [4B]), 1 EMRSA-16 (ST36-II [2A]), 1 variant of ST239-III (ST257-III [3A]). CA-MRSA The proportion of PVL positive CA-MRSA has increased since 23/24 (2% of CA- MRSA in 23/24, 4% in 24/25, 6% in 25/26, 11% in 26/27, 17% in 27/28, 2% in 28/29, 22% in 29/21, 28% in 21/211 and 32% in 211/12). 3

4 PVL positive CA-MRSA were most likely from clinical specimens (94.2%) in contrast to PVL negative CA-MRSA isolates (77.%). Health regions with the highest rate of infected/colonised patients with PVL positive CA-MRSA: Kimberley 1,176/1, Midwest 196/1, Pilbara 182/1, The PVL positive clones notified were predominantly: The Queensland clone (ST93-IV [2B]) which comprised 22.2% of all CA-MRSA isolated (19.6% in 21/211) The Western Samoan Phage pattern CA-MRSA (WSPP) (ST3-IV [2B]) which comprised 4.7% of all CA-MRSA isolated (3.9% in 21/211) Four international PVL positive CA-MRSA were identified including: 76 USA3 (ST8-MRSA-IV [2B]) 3 Bengal Bay CA-MRSA (ST772-MRSA-V [5C2]) 18 Taiwan CA-MRSA (ST59-MRSA-V T [5C2&5]) 15 Taiwan A CA-MRSA (ST952-MRSA-V T [5C2&5]) 3 European CA-MRSA (ST8-MRSA-IV [2B]) Spread of a new PVL positive clone was recorded: 68 WA MRSA-121 (ST5-IV [2B]) were characterised in 211/212 compared with one in 29/21 and none in 21/211. The majority of isolates (81%) were referred from the Kimberley. 3,388 (68.2%) of CA-MRSA were PVL negative. Although 56 WA CA-MRSA pulsotypes were identified, there were three predominant PVL negative clones: WA MRSA-1 (ST1-IV [2B]) 34.1% of CA-MRSA WA MRSA-2 (ST78-IV [2B]) 18.5% of CA-MRSA WA MRSA-3 (ST5-IV [2B]) 9.6% of CA-MRSA 1.2 VRE: Key Results 1 st July 211 to 3 th June unique isolates of VRE were referred for van gene characterisation and molecular typing: the majority (97.2%) from screening specimens. 259 (92%) were vanb E. faecium. Of these 88 (34%) were PFGE type 42 (identified in seven institutions), 65 (25%) were PFGE type 34/36 (identified in six institutions) and 35 (14%) were type 46 (identified in three institutions). Sixteen (6%) were vana E. faecium (up from 2% in 21/211). Six were PFGE type 14 and seven had unique PFGE patterns. 4

5 Section 2 MRSA Nomenclature 5

6 2 MRSA Nomenclature Since July 23, the Australian Collaborating Centre for Enterococcus and Staphylococcus Species (ACCESS) Typing and Research has employed the international MRSA nomenclature system described by Dr Mark Enright et al [1]. This system provides a universally standardised MRSA nomenclature allowing MRSA clones to be readily compared between laboratories. It is based upon the combination of seven housekeeping genes sequence types (STs) using multilocus sequence typing (MLST) and the SCCmec type using multiplex PCR. The MRSA genotype is therefore the sum of the SCCmec type and the type of its recipient chromosome. For example, an MRSA clone of ST22 and SCCmec type IV is referred to as ST22-IV [2B]. 2.1 MLST MLST is a highly discriminatory method of characterising MRSA. For each of the seven housekeeping gene fragments, different sequences are assigned as distinct alleles, and an isolate is defined by the alleles of each of the seven housekeeping loci (the allelic profile or ST). The ST can be compared with other strains using the program BURST located on the MLST website ( As there are many alleles for each loci, isolates are highly unlikely to have identical ST by chance, and therefore isolates with the same ST are considered members of the same clone. 2.2 Clonal Complex (CC) Clonal complexes are determined using the eburst V3 algorithm at the MLST website. Clones that diverge at no more than one of the seven MLST loci are considered to belong to the same CC. Double locus variants (dlvs) are included in the CC if the linking single locus variant (slv) is present in the MLST database. 2.3 SCCmec ACCESS Typing and Research uses the guidelines published by the International Working Group on the Classification of Staphylococcal Cassette Chromosome Elements (IWG- SCCmec). Eleven SCCmec types have been identified globally. The structural type is indicated by a roman numeral with a lowercase letter indicating the subtype. The ccr gene complex and the mec gene complex follow in parentheses. Types I [1B], II [2A], III [3A] and VI [4B] (previously known as IV paediatric ) are frequently associated with healthcare-associated MRSA while types IV [2B], V [5C2], VII [5C1] and VIII [4A] are frequently associated with Community-Associated MRSA. Since 211 three additional SCCmec types have been described including IX [1C2], X [7C1] and XI [8E]. Where the combination of the ccr gene allotype and the class of the mec gene complex has not been described, the SCCmec element is described as novel. Using MLST/SCCmec typing ACCESS Typing and Research has identified several MRSA clones which previously were collectively known as WA MRSA. These clones have been fully characterised using a variety of molecular and non-molecular methods. MRSA have been identified as either HA-MRSA or CA-MRSA and assigned a MLST/SCCmec type. The previous nomenclature applied to HA-MRSA has also been reported. 6

7 Section 3 Tests performed by ACCESS Typing and Research July 211 to June 212 7

8 3 Tests performed by ACCESS Typing and Research. Table 1: Tests performed by ACCESS Typing and Research, July 211 to June 212 Number tested Routine Antibiogram (9 antibiotics) 7,32 meca/nuc PCR 1,222 Panton-Valentine leucocidin (PVL) PCR 2,577 Coagulase Gene PCR Restriction Fragment Length Polymorphism (RFLP) 5,973 Resistogram (2 chemicals) 45 Pulsed-Field Gel Electrophoresis (PFGE) - MRSA 1,622 Pulsed-Field Gel Electrophoresis (PFGE) - VRE 35 Urease Reaction 7,382 Multilocus Sequencing Typing (MLST) 27 SCCmec PCR 27 Mupirocin 2μg disc 85 Ciprofloxacin Etest 126 spa typing 25 dru typing 3 Total Number of Tests Performed 26,739 Susceptibilities were determined by disk diffusion for gentamicin, erythromycin, tetracycline, trimethoprim, ciprofloxacin, gentamicin, rifampicin, fusidic acid and mupirocin. CLSI criteria were used to interpret results for all agents except fusidic acid and mupirocin (EUCAST). A resistogram was determined by the disk diffusion method for mercuric chloride (.4 mmol/l), and phenylmercuric acetate (5 mmol/l). MRSA clones were initially identified by phenotype (antibiogram and urease production) and coagulase PCR-RFLP [2], PFGE [3], PVL PCR [4], MLST[5], SCCmec [6], spa [7] and dru [8] typing were performed as required. Molecular testing (apart from PVL PCR on select isolates) was not performed on duplicate isolates. 8

9 Section 4 MRSA isolated in Western Australia July 211 to June 212 9

10 4 MRSA isolated in Western Australia, July 211 to June 212 From 1 July 211 to 3 June 212, 7,32 methicillin resistant Staphylococcus aureus (MRSA) from 5,589 patients were referred to ACCESS Typing and Research for epidemiological typing (a 12% increase from the 6,552 MRSA referred in 21/211). Unique isolate data, (n=5,834 - duplicate isolates excluded) are presented in this report. A duplicate isolate is defined as an isolate with an identical phenotype to an isolate received from the same patient within the previous 12 month period. Table 2: Unique isolates of MRSA in Western Australia, July 211 to June 212 Patient Isolates n=5,726 (98.1%) Staff Isolates n=18 (1.9%) MRSA Clinical Screen Clinical Screen n (%) HA-MRSA (14.8) CA-MRSA, PVL-negative 2, ,388 (58.1) CA-MRSA, PVL-positive 1, ,582 (27.1) Total MRSA 4,643 1, , Relationship of age to MRSA Increasing age is a risk factor for infection or colonisation with HA-MRSA and CA-MRSA. The mean age of patients infected/colonised with HA-MRSA is significantly higher (P<.1) (mean 71 years, median 78 years) compared to patients with CA-MRSA (mean 45 years, median 42 years): a reflection of the increasing health care contact amongst the middleaged and elderly. While the rate of PVL-negative CA-MRSA increases with age, the rate of PVL-positive CA-MRSA is highest among children and the young adult age groups (teens to 3s). The mean age of patients infected/colonised with PVL positive CA-MRSA was 29 years (median 26 years) significantly younger (P<.1) than patients with PVL negative CA- MRSA (mean 53 years, median 56 years). Figure 1: Median age and range of patients infected or colonised with HA-MRSA and CA- MRSA Age (y) HA-MRSA CA-MRSA PVL positive CA-MRSA PVL negative CA-MRSA 1

11 Figure 2: Proportion of HA-MRSA and CA-MRSA by age, July 211 to June 212 1% 9% 8% 3% 1% 7% 7% 6% 8% 17% 3% 33% 7% 6% 5% 4% 3% 97% 99% 93% 93% 94% 92% 83% 7% 67% 2% 1% % Age Range (y) CA-MRSA HA-MRSA Figure 3: Rate of HA-MRSA (per 1, population) by age, July 211 to June Rate (per 1,) Age Range (y) 11

12 Figure 4: Rate of CA-MRSA (per 1, population) by age, July 211 to June Rate (per 1,) Age Range (y) Figure 5: Proportion of known PVL-positive and PVL-negative CA-MRSA by age, July 211 to June 212 1% 9% 8% 7% 49% 58% 49% 41% 38% 29% 16% 6% 3% 6% 5% 4% 3% 2% 51% 42% 51% 59% 62% 71% 84% 94% 97% 1% % Age Range (y) Known PVL-negative CA-MRSA Known PVL-positive CA-MRSA 12

13 Figure 6: Rate (per 1, population) of known PVL-negative CA-MRSA by age, July 211 to June Rate (per 1,) Age Range (y) Figure 7: Rate (per 1, population) of known PVL-positive CA-MRSA by age, July 211 to June Rate (per 1,) Age Range (y) 13

14 4.2 Healthcare-Associated MRSA (HA-MRSA) The early MRSA clones were HA-MRSA. HA-MRSA probably originated through the transfer of SCCmec into a limited number of S. aureus lineages. The antimicrobial resistance genes associated with SCCmec types I [1B], II [2B] and III [3A] conferred an advantage to the bacteria in a healthcare setting. In contrast to CA-MRSA, HA-MRSA clones are frequently ciprofloxacin resistant (98% compared to 8% resistance in CA-MRSA) and, apart from EMRSA-15, carry SCCmec types I, II or III. Table 3: HA-MRSA isolated in Western Australia, July 211 to June 212 Patient Isolates n=83 (93.8%) Staff Isolates n= 34 (6.2%) MLST-SCCmec Clone CC* Clinical Screen Clinical Screen n (%) ST22-IV [2B] ST239-III [3A) ST5-II [2A] ST764-II [2A] EMRSA-15, Barnim EMRSA Aus-2 EMRSA, Aus-3 EMRSA New York/Japan MRSA / USA1 New York/Japan variant (95.8) 21 (2.4) 1 (1.2) (.2) ST8-VI [4B] Irish-2 EMRSA (.1) ST36-II [2A] EMRSA-16 / USA (.1) ST257-III [3A] Aus-3 variant B (.1) Total *Clonal Complex EMRSA-15 (ST22-IV[2B]) Introduced into WA in 1997 by overseas healthcare workers, EMRSA-15 is the State s most prevalent HA-MRSA [9]. This strain is characterised by ciprofloxacin (+/- erythromycin) resistance although variants and multiresistant (resistant to three or more non-β-lactam antimicrobials) strains occur (7% of total). From 1 st July 211 to 3 th June 212, 828 EMRSA-15 were referred from 36 laboratories. EMRSA-15 was detected in all health regions; however the majority (93%) of patients resided in the Metropolitan Perth Health Region which also had the highest rate (42/1, population respectively). Thirty EMRSA-15 were isolated from staff screening swabs. The mean age of patients with EMRSA-15 was 71 years (median 79y); a reflection of the frequent isolation of EMRSA-15 from patients residing in nursing homes. 14

15 Figure 8: Median age and range of patients infected or colonised with EMRSA-15 compared to other HA-MRSA Age (y) EMRSA-15 Other HA-MRSA EMRSA-15 is usually PVL negative however in 211/212, 32 patients were identified with a PVL-positive strain. An increased MIC to gentamicin ( 4mg/L) and/or ciprofloxacin susceptibility are markers for PVL-positive ST22-IV [2B]. In the 211/212 year, all isolates with a gentamicin MIC 4mg/L and 36% of ciprofloxacin susceptible EMRSA-15 were PVL positive. Figure 9: Annual number of referred isolates of EMRSA-15 in Western Australia, July 1997 to June / / / 2/1 21/2 22/3 23/4 24/5 25/6 26/7 27/8 28/9 29/1 21/11 211/12 15

16 Figure 1: EMRSA-15 as a percentage of the annual number of referred MRSA in Western Australia, July 2 to June % 2% 15% 1% 5% % 1997/ / Aus-2/3 EMRSA (ST239-III[3A]) 1999/ 2/1 21/2 22/3 23/4 24/5 25/6 26/7 27/8 28/9 29/1 21/11 211/12 Aus-2/3 EMRSA is a multiresistant clone, thought to have originated on the eastern seaboard of Australia, where it is still a predominant clone in hospitals ( A MRSA search and destroy policy implemented by the WA Department of Health in 1982 has prevented this clone from becoming established in WA hospitals. From 1 st July 211 to 3 th June 212, 21 Aus-2/3 EMRSA were referred from 14 laboratories in six health regions (Metropolitan Perth [13 isolates], Kimberley [two isolates], Pilbara [one isolate], Midwest [one isolate], Wheatbelt [one isolate] and Great Southern [one isolate]). Two isolates were from patients with interstate addresses. 16

17 Figure 11: Annual number of referred isolates of Aus-2/3 EMRSA in Western Australia, July 2 to June /1 21/2 22/3 23/4 24/5 25/6 26/7 27/8 28/9 29/1 21/11 211/12 Figure 12: Aus-2/3 EMRSA as a percentage of the annual number of referred MRSA in Western Australia, July 2 to June 212 7% 6% 5% 4% 3% 2% 1% % 2/1 21/2 22/3 23/4 24/5 25/6 26/7 27/8 28/9 29/1 21/11 211/12 17

18 4.2.3 New York/Japan MRSA (ST5-II [2A]) In the early 199s this strain was reported as the dominant clone in Japanese hospitals and by the mid-199s was the dominant clone in New York metropolitan hospitals with spread to several neighbouring states [1]. Reports indicated that the New York/Japan clone was replacing the pre-existing HA-MRSA clones [11]. An outbreak in the south west of WA in 25 was brought under control by the WA Health Department by the application of the WA MRSA search and destroy management strategies [12]. The index case was a colonised health care worker who had previously been hospitalised overseas. From 1 st July 211 to 3 th June 212, 1 New York/Japan MRSA were referred from seven laboratories in two health regions (nine Metropolitan Perth and one South West). The South West isolate was indistinguishable from the outbreak strain. The New York/Japan strain is characterised by resistance to erythromycin and ciprofloxacin, however it can be multiresistant (13% of isolates). Figure 13: Annual number of referred isolates of New York/Japan MRSA in Western Australia, July 23 to June /4 24/5 25/6 26/7 27/8 28/9 29/1 21/11 211/12 18

19 Figure 14: New York/Japan MRSA as a percentage of the annual number of referred MRSA in Western Australia, July 23 to June %.9%.8%.7%.6%.5%.4%.3%.2%.1%.% 23/4 24/5 25/6 26/7 27/8 28/9 29/1 21/11 211/ EMRSA-16 (ST36-II [2A]) EMRSA-16 was one of the predominant MRSA clones in the United Kingdom (UK) healthcare setting [13]. In recent years this strain has become increasingly rare [14]. EMRSA-16, characterised by resistance to erythromycin and ciprofloxacin, caused an outbreak in in a Perth metropolitan hospital - the index case was a colonised health care worker. Since this time only small numbers of isolates have been detected. From 1 st July 211 to 3 th June 212, one EMRSA-16 was referred from the Metropolitan Perth Health Region. 19

20 Figure 15: Annual number of referred isolates of EMRSA-16 in Western Australia, July 1999 to June / 2/1 21/2 22/3 23/4 24/5 25/6 26/7 27/8 28/9 29/1 21/11 211/12 Figure 16: EMRSA-16 as a percentage of the annual number of referred MRSA in Western Australia, July 1999 to June % 1.8% 1.6% 1.4% 1.2% 1.%.8%.6%.4%.2%.% 1999/ 2/1 21/2 22/3 23/4 24/5 25/6 26/7 27/8 28/9 29/1 21/11 211/12 2

21 4.2.5 Irish-2 EMRSA (ST8-VI [4B]) Irish-2 EMRSA, characterised by erythromycin, ciprofloxacin and trimethoprim resistance, was initially isolated in Ireland and the UK. From 1 st July 211 to 3 th June 212, one Irish-2 EMRSA was referred from the Metropolitan Perth Health Region. Figure 17: Annual number of referred isolates of Irish-2 EMRSA in Western Australia, July 1997 to June / / / 2/1 21/2 22/3 23/4 24/5 25/6 26/7 27/8 28/9 29/1 21/11 211/12 21

22 Figure 18: Irish-2 EMRSA as a percentage of the annual number of referred MRSA in Western Australia, July 1997 to June % 3.5% 3.% 2.5% 2.% 1.5% 1.%.5%.% 4.3 Community-Associated MRSA 1997/ / / 2/1 21/2 22/3 23/4 24/5 25/6 26/7 27/8 28/9 29/1 21/11 211/12 The earliest reports of CA-MRSA infections involved indigenous people living in remote communities in the sparsely populated Kimberley Health Region of WA [15]. Prior to the global evolution and expansion of CA-MRSA, five CA-MRSA lineages were identified in this region [16]. However since 1989 the CA-MRSA population in WA has become genetically diverse consisting of 112 unique PFGE strains from which 72 MLST/SCCmec types have been characterised [17]. Up to 59 MLST/SCCmec CA-MRSA clones are thought to have evolved within this region. While SCCmec IV [2A] and V [5C2] are the predominant SCCmec elements, SCCmec VIII and several novel and composite SCCmec elements are present in 3% of these strains. The emergence of MRSA in diverse S. aureus clonal complexes suggests horizontal transmission of the SCCmec element has occurred on multiple occasions [17]. PVL is a necrotizing toxin that causes leukocyte destruction and tissue necrosis and is associated with abscesses and severe pneumonia [18]. It is present in the majority of CA- MRSA studied in Europe and USA [19, 2]. Initial studies have shown WA CA-MRSA infrequently carry the genes encoding PVL. However, due to importation of overseas and interstate CA-MRSA, the overall prevalence of PVL positive clones is increasing in WA. To date six interstate or overseas origin PVL-positive clones and their variants have been identified: ST93-IV [2B] Qld Clone ST3-IV [2B] Western Samoan clone (WSPP) also known as the South Western Pacific clone or the Oceania MRSA ST8-IV [2B] USA3 22

23 ST772-V [5C2] ST59/952-V T [5C2&5] ST8/583/728-IV [2B] Bengal Bay Clone Taiwan and Taiwan A CA-MRSA European, European A and European B CA-MRSA Further investigations are required to determine if the PVL-positive ST1-IV (approximately 3% of isolates) are USA4 MRSA or WA MRSA-1 that have acquired the PVL genes. Based on clone identification, 1,582/4,97 (31.8%) CA-MRSA (27.1% of total MRSA) characterised in WA between 1 st July 211 and 3 th June 212 were PVL positive. Since 23/24, the following PVL positive clones have increased significantly (P<.1) in WA: Qld clone, WSPP, USA3, Taiwan clone, Bengal Bay Clone, WA MRSA-62 and WA MRSA-121. The Qld clone showed the greatest increase from.7% of all MRSA in 23/24 to 18.9% in 211/212 (Figure 23). The greatest rate of PVL positive infection and/or colonisation is in the Kimberley, Midwest and Pilbara (1,176, 196 and 182/1, population respectively) where the Qld clone is frequently isolated. The Kimberley also has high numbers of a recently introduced or evolved PVL-positive clone WA MRSA-121 (see section ). The average age of patients infected/colonised with PVL positive CA-MRSA was 29 years (median 26 years) significantly younger (P<.1) than patients with PVL negative CA- MRSA (mean 53 years, median 56 years). 94% of PVL positive CA-MRSA strains were isolated from clinical specimens (as opposed to screening swabs), predominantly skin and soft tissue infections, compared to 76% of PVL negative CA-MRSA. Figure 19: Median age and range of patients infected or colonised with PVL positive and PVL negative CA-MRSA Age (y) PVL positive CA-MRSA PVL negative CA-MRSA 23

24 From 1 st July 211 to the 3 th June 212, 44 CA-MRSA clones (4,97 isolates, 64 pulsotypes, 15 CCs, 2 singletons and two with undetermined CCs) were characterised. Table 4: CA-MRSA isolated in Western Australia, July 211 to June 212 Patient Isolates n= 4,896 Staff Isolates n= 74 MLST/SCCmec Clone CC PVL # Clinical Screen Clinical Screen n (%) ST1-IV [2B] WA MRSA-1 1 Neg* 1, ,697 (34.1) ST93-IV[2B] Qld Clone S Pos 1, ,15 (22.2) ST78-IV[2B] WA MRSA-2 88 Neg (18.5) ST5-IV[2B] WA MRSA-3 5 Neg # (9.6) ST3-IV[2B] WSPP MRSA 3 Pos (4.7) ST8-IV[2B] USA3 8 Pos (1.5) ST5-IV [2B] WA MRSA Pos (1.4) ST772-V[5C2] Bengal Bay Clone 1 Pos (.6) ST59/952- V T [5C2&5] Taiwan and Taiwan A CA- MRSA 59 Pos (.7) ST923-IV [2B] WA MRSA-62 8 Pos (.5) Other known PVL-positive CA-MRSA clones Pos (.2) Other known PVL-negative CA-MRSA clones Neg (6.) Total 4, ,97 Percentage figures relate to CA-MRSA isolates. PVL testing not routinely performed on all MRSA *Approximately 3% of WA MRSA-1 are PVL positive. # Approximately 4% of WA MRSA-3 are PVL positive. 24

25 Figure 2: PVL positive clones, July 23 to June /4 24/5 25/6 26/7 27/8 28/9 29/1 21/11 211/212 ST93-IV (Qld) ST3-IV (WSPP) ST8-IV (USA3) ST59/952-V (Taiwan/A) ST772-V (Bengal Bay) ST8-IV (European) ST5-IV (WA 121) Other PVL positive MRSA Figure 21: PVL positive clones as a proportion of CA-MRSA, July 23 to June % 3% 25% 2% 15% 1% 5% % 23/4 24/5 25/6 26/7 27/8 28/9 29/1 21/11 211/212 25

26 4.3.1 Queensland (Qld) (ST93-IV[2B]) The Qld clone is a known PVL-positive clone. First detected on the east coast of Australia in the Caucasian population in 2, this clone has become one of the most prevalent CA-MRSA isolated in Australia ( shrink.pdf). Although the Queensland clone was first detected into WA in 21, PVL positive ST93-MSSA was identified as the most prevalent S. aureus lineage in WA s remote indigenous communities in surveys performed in the mid 199s and early 2s [16]. From 1 st July 211 to 3 th June 212, 1,15 Qld clone MRSA were referred from 39 laboratories. The Qld Clone was found in all health regions in 211/212 however the rate was highest in the Kimberley (934/1, population). Isolates were also referred from patients with interstate addresses (27) and overseas addresses (seven) including the UK, Ireland, Canada, New Zealand and India. The average age of patients was 27 years (median 24 years). Figure 22: Annual number of isolates of Qld Clone in Western Australia, July 23 to June /4 24/5 25/6 26/7 27/8 28/9 29/1 21/11 211/12 26

27 Figure 23: Qld Clone as a percentage of the annual number of referred MRSA in Western Australia, July 23 to June 212 2% 18% 16% 14% 12% 1% 8% 6% 4% 2% % 23/4 24/5 25/6 26/7 27/8 28/9 29/1 21/11 211/ Western Samoan CA-MRSA (WSPP) (ST3-IV[2B]) WSPP, also known as the South West Pacific (SWP) Clone or Oceania MRSA, is a known PVL positive clone. WSPP was first reported in 1997 in the Eastern States of Australia amongst Polynesians presenting with furunculosis [21]. From 1 st July 211 to 3 th June 212, 234 WSPP were referred from 29 laboratories. WSPP was the second most isolated PVL positive clone in WA. The highest number of isolates (128) was detected in the Metropolitan Perth Health Region, however the highest rate was in the Kimberley and Pilbara (96 and 37/1, population respectively). Nine WSPP were isolated from patients with interstate addresses and three from patients with overseas addresses (UK, Ireland and France). The average age of patients was 34 years (median 32 years). 27

28 Figure 24: Annual number of isolates of WSPP MRSA in Western Australia, July 2 to June /1 21/2 22/3 23/4 24/5 25/6 26/7 27/8 28/9 29/1 21/11 211/12 Figure 25: WSPP MRSA as a percentage of the annual number of referred MRSA in Western Australia, July 2 to June % 4.5% 4.% 3.5% 3.% 2.5% 2.% 1.5% 1.%.5%.% 2/1 21/2 22/3 23/4 24/5 25/6 26/7 27/8 28/9 29/1 21/11 211/12 28

29 4.3.3 USA3 (ST8-IV[2B]) USA3 is a known PVL-positive clone [22]. USA3 has been the dominant MRSA strain in the North American community for several years and is now frequently isolated in the hospital setting. It has also been reported from other countries including Canada, Denmark, Germany, Japan, Switzerland and the UK [22]. USA3 was first reported in WA in 23 and is now the third most frequently isolated PVL positive clone in WA (sixth most isolated CA-MRSA). From 1 st July 211 to 3 th June 212, 76 USA3 were referred from 21 laboratories. The majority (76%) of USA3 were isolated from patients in the Metropolitan Perth Health Region. Isolates were referred from the South West (eight isolates), Pilbara (four isolates), Goldfields (two isolates) and Great Southern (one isolate). One patient had an interstate address and two patients had overseas addresses (Ireland). The average age of patients with USA3 was 36 years (median 33 years). The numbers of USA3 referred to ACCESS Typing and Research have stabilized in WA since 27/28. This may be due to the WA Department of Health s initiatives to reduce USA3 transmission in the WA community. Figure 26: Annual number of isolates of USA3 MRSA in Western Australia, July 23 to June /4 24/5 25/6 26/7 27/8 28/9 29/1 21/11 211/12 29

30 Figure 27: USA3 as a percentage of the annual number of referred MRSA in Western Australia, July 23 to June % 1.4% 1.2% 1.%.8%.6%.4%.2%.% 23/4 24/5 25/6 26/7 27/8 28/9 29/1 21/11 211/ Taiwan CA-MRSA (ST59-V T [5C2&5]) and Taiwan A CA-MRSA (ST952-V T [5C2&5]) The Taiwan and Taiwan A CA-MRSA are known PVL-positive clones [6]. WA MRSA-52 (ST952-V T [5C2&5]) is homogeneous to the Taiwan clone by microarray studies and differs by only one base pair by MLST and has therefore been renamed the Taiwan A clone [6]. The Taiwan clone is the predominant CA-MRSA in the Asia Pacific region and is an important cause of morbidity in Taiwan [23, 24]. This clone has acquired a novel type V SCCmec element (V [5C2&5], also known as V T ) [25]. The Taiwan clone and other CC59 strains have now been reported in other countries, including the United States of America (USA1), Sweden, Germany, the UK and Vietnam [6]. From 1 st July 211 to 3 th June 212, 18 Taiwan CA-MRSA and 15 Taiwan A CA-MRSA were referred from 13 laboratories. The majority (85%) of Taiwan/A CA-MRSA were isolated from patients in the Metropolitan Perth Health Region. Two isolates were referred from patients in the South West, two from the Pilbara and one from the Goldfields. The average age of patients was 3 years (median 27 years). 3

31 Figure 28: Annual number of isolates of Taiwan and Taiwan A CA-MRSA in Western Australia, July 23 to June /4 24/5 25/6 26/7 27/8 28/9 29/1 21/11 211/12 Figure 29: Taiwan and Taiwan A CA-MRSA as a percentage of the annual number of referred MRSA in Western Australia, July 23 to June 212.8%.7%.6%.5%.4%.3%.2%.1%.% 23/4 24/5 25/6 26/7 27/8 28/9 29/1 21/11 211/12 31

32 4.3.5 Bengal Bay Clone (ST772-V [5C2]) The Bengal Bay clone is a multiresistant PVL-positive clone first reported in Bangladesh. The Bengal Bay clone has been identified in India [26], Malaysia and the UK [27]. This clone is typically resistant to gentamicin, erythromycin, ciprofloxacin and trimethoprim and therefore may be mistaken for Aus 2/3 EMRSA. From 1 st July 211 to 3 th June 212, 3 Bengal Bay Clone MRSA were referred from 13 laboratories. The average age of patients was 37 years (median 32 years). The majority of patients (87%) resided in the Metropolitan Perth Health Region. Isolates were also from the Great Southern (two isolates) and South West (one isolate). One patient had an overseas address (India). The 211/212 year saw the first decrease in numbers of this clone since it was introduced to WA in 26/27. This may be due to the WA Department of Health s initiatives to reduce Bengal Bay MRSA transmission in the WA community. Figure 3: Annual number of isolates of Bengal Bay Clone in Western Australia, July 23 to June /4 24/5 26/7 27/8 28/9 29/1 21/11 211/12 32

33 Figure 31: Bengal Bay Clone as a percentage of the annual number of referred MRSA isolated in Western Australia, July 23 to June 212.9%.8%.7%.6%.5%.4%.3%.2%.1%.% 23/4 24/5 26/7 27/8 28/9 29/1 21/11 211/ European CA-MRSA (ST8-IV[2B]) The European CA-MRSA is a known PVL-positive clone [28]. The European CA-MRSA is widespread in Europe and the Middle East [28]. In Europe, it has been isolated in Austria, Denmark (where this strain was detected as early as 1993), France, Germany, Greece, Ireland, Malta, the Netherlands, Norway, Portugal, Sweden, Switzerland and the UK. In Greece, a considerable percentage of MRSA infections can be attributed to this strain. In the Middle East the European clone has been isolated in Abu Dhabi, Kuwait, Lebanon, Israel, Egypt, Algeria, and Tunisia. Travel associated cases have been reported in the European literature (patients returning from Saudi Arabia, Libya and Turkey). This strain is not commonly isolated in WA. From 1 st July 211 to 3 th June 212, three European CA-MRSA were referred from three laboratories. All patients resided in the Metropolitan Perth Health Region. 33

34 Figure 32: Annual number of isolates of European Clone in Western Australia, July 23 to June /4 24/5 25/6 26/7 27/8 28/9 29/1 21/11 211/12 Figure 33: European Clone as a percentage of the annual number of referred MRSA in Western Australia, July 23 to June 212.4%.3%.3%.2%.2%.1%.1%.% 23/4 24/5 25/6 26/7 27/8 28/9 29/1 21/11 211/12 34

35 4.3.7 WA CA-MRSA From 1 st July 211 to the 3 th June 212, 3,478 WA CA-MRSA were referred to ACCESS Typing and Research. Using MLST-SCCmec typing 37 clones (56 pulsotypes) of WA MRSA were identified. Table 5: WA CA-MRSA clones isolated in Western Australia, July 211 to June 212 Patient Isolates n= 3,415 (98%) Staff Isolates n= 63 (2%) MLST-SCCmec Clone PVL Clinical Screen Clinical Screen n (%) Clonal Complex 1 ST1-IV [2B] WA MRSA-1 Neg* 1, ,697 (48.8) ST188-IV [2B] WA MRSA-38 Neg (.2) ST15-IV [2B] WA MRSA-57 Neg (.1) ST188-IV [2B] WA MRSA-78 Neg 1 1 (.3) Clonal Complex 5 ST5-IV [2B] WA MRSA-3 Neg # (13.7) ST5-IV [2B] WA MRSA-121 Pos (2.) ST835-novel WA MRSA-48 Neg (1.2) ST73-IV [2B] WA MRSA-65 Neg (1.2) ST5-IV [2B] WA MRSA-71 Neg (1.) ST835-V [5C2&5] WA MRSA-4 Neg (.3) ST5-V [5C2] WA MRSA-19 Neg± (.2) ST5-V [5C2] WA MRSA-14 Neg (.6) ST6-IV [2B] WA MRSA-51 Neg (.6) ST6-IV [2B] WA MRSA-66 Neg 2 2 (.6) ST5-V [5C2] WA MRSA-9 Neg (.6) ST73-IV [2B] WA MRSA-95 Neg (.6) ST835-novel WA MRSA-13 Neg (.6) ST5-IV [2B] WA MRSA-15 Neg 2 2 (.6) ST5-V [5C2] WA MRSA-18 Neg (.6) ST5-novel WA MRSA-18 Neg 1 1 (.3) ST5-V [5C2&5] WA MRSA-34 Neg 1 1 (.3) ST5-V [5C2] WA MRSA-35 Neg 1 1 (.3) ST5-IV [2B] WA MRSA-74 Neg 1 1 (.3) ST835-V [5C2&5] WA MRSA-87 Neg 1 1 (.3) 35

36 Patient Isolates n= 3,415 (98%) Staff Isolates n= 63 (2%) MLST-SCCmec Clone PVL Clinical Screen Clinical Screen n (%) ST5-IV [2B] WA MRSA-94 Neg 1 1 (.3) ST5dlv-IV [2B] WA MRSA-122 Neg 1 1 (.3) ST5-V [5C2] WA MRSA-123 Neg 1 1 (.3) Clonal Complex 7 ST7-V (5C2&5)&1 WA MRSA-116 Neg 1 1 (.3) Clonal Complex 8 ST923-IV [2B] WA MRSA-62 Pos (.7) ST8-IV [2B] WA MRSA-5 Neg (.5) ST612-IV [2B] WA MRSA-2 Neg 2 2 (.6) ST576-IV [2B] WA MRSA-31 Neg 1 1 (.3) ST8-V [5C2] WA MRSA-115 Neg 1 1 (.3) ST2471-V [5C2] WA MRSA-12 Neg 1 1 (.3) Clonal Complex 9 ST834-IV [2B] WA MRSA-13 Neg (.1) Clonal Complex 3 ST3-novel WA MRSA-12 Neg 1 1 (.3) Clonal Complex 45 ST45-IV [2B] WA MRSA-75 Neg (1.3) ST45-IV [2B] WA MRSA-23 Neg (.2) ST45-V [5C2] WA MRSA-4 Neg 2 2 (.6) ST45-V [5C2&5] WA MRSA-84 Neg (.6) ST197-V [5C2] WA MRSA-16 Neg (.6) Clonal Complex 59 ST59-IV [2B] WA MRSA-15 Neg (.1) ST59-IV [2B] WA MRSA-55 Pos 4 4 (.1) ST59-IV [2B] WA MRSA-118 Neg 1 1 (.3) Clonal Complex 72 ST72-novel WA MRSA-97 Neg 4 4 (.1) ST72-V [5C2] WA MRSA-91 Neg 1 1 (.3) Clonal Complex 75 ST134-IV [2B] WA MRSA-72 Neg 1 1 (.3) 36

37 Patient Isolates n= 3,415 (98%) Staff Isolates n= 63 (2%) MLST-SCCmec Clone PVL Clinical Screen Clinical Screen n (%) Clonal Complex 88 ST78-IV [2B] WA MRSA-2 Neg (26.4) ST88-V [5C2] WA MRSA-117 Pos 1 1 (.3) Clonal Complex 97 ST953-IV(2B) WA MRSA-54 Neg (.3) Clonal Complex 121 ST577-V [5C2] WA MRSA-22 Neg 2 2 (.6) Clonal Complex 152 ST1633-V [5C2] WA MRSA-89 Pos 1 1 (.3) Singleton ST883-IV [2B] WA MRSA-47 Neg (.1) Undetermined Clonal Complex ST133-IV [2B] WA MRSA-76 Neg 1 1 (.3) ST779-IV [2B] WA MRSA-1 Neg 1 1 (.3) ST193-IV [2B] WA MRSA-119 Pos 1 1 (.3) Total 2, ,478 *Approximately 3% WA MRSA-1 are PVL positive. # Approximately 4% WA MRSA-3 are PVL positive. ±Approximately 3% of WA MRSA-19 are PVL positive. Approximately 15% of WA MRSA-51 are PVL positive. Percentage figures relate to the WA CA-MRSA isolates. Not all isolates are tested for PVL. 37

38 Figure 34: Annual number of isolates of WA MRSA in Western Australia, July 23 to June /4 24/5 25/6 26/7 27/8 28/9 29/1 21/11 211/12 Figure 35: WA MRSA as a percentage of the annual number of referred MRSA in Western Australia, July 23 to June 212 9% 8% 7% 6% 5% 4% 3% 2% 1% % 23/4 24/5 25/6 26/7 27/8 28/9 29/1 21/11 211/12 38

39 4.3.8 WA MRSA-1 (ST1-IV[2B]) WA MRSA-1 was first isolated from a clinical specimen in 1995 and is now the most isolated MRSA clone isolated in WA [16, 29]. The vast majority (98%) of WA MRSA-1 are non-multiresistant, with erythromycin resistance (26% of isolates) and fusidic acid resistance (19%) being the most common antimicrobial phenotype. From 1 st July 211 to the 3 th June 212, 1,697 WA MRSA-1 were referred from 45 laboratories. The highest number of isolates (1,47) was detected in the Metropolitan Perth Health Region, however the highest rate was in the Kimberley (454/1, population respectively). Although WA MRSA-1 is the same MLST/SCCmec clone type as USA4 (a PVLpositive clone in the United States), WA MRSA-1 pre-dates USA4 and is PVL-negative. A small proportion (~3%) of PVL-positive ST1-IV has been detected in WA but these are thought to be USA4. Figure 36: Annual number of isolates of WA MRSA-1 in Western Australia, July 23 to June /4 24/5 25/6 26/7 27/8 28/9 29/1 21/11 211/12 39

40 Figure 37: WA MRSA-1 as a percentage of the annual number of referred MRSA in Western Australia, July 23 to June 212 5% 45% 4% 35% 3% 25% 2% 15% 1% 5% % 23/4 24/5 25/6 26/7 27/8 28/9 29/1 21/11 211/ WA MRSA-2 (ST78-IV[2B]) WA MRSA-2 was first isolated in 1995 [16] from a nasal screening swab. WA MRSA-2 is the third most isolated MRSA clone isolated in WA (after WA MRSA-1 and the Queensland clone). The majority (95%) of isolates were resistant to erythromycin. From 1 st July 211 to the 3 th June 212, 919 WA MRSA-2 were referred from 4 laboratories. The highest number of isolates (68) was detected in the Metropolitan Perth Health Region, however the highest rate was in the Midwest (72/1, population respectively). 4

41 Figure 38: Annual number of isolates of WA MRSA-2 in Western Australia, July 23 to June /4 24/5 25/6 26/7 27/8 28/9 29/1 21/11 211/12 Figure 39: WA MRSA-2 as a percentage of the annual number of referred MRSA in Western Australia, July 23 to June 212 3% 25% 2% 15% 1% 5% % 23/4 24/5 25/6 26/7 27/8 28/9 29/1 21/11 211/12 41

42 4.3.1 WA MRSA-3 (ST5-IV[2B]) WA MRSA-3 belongs to clonal complex 5 one of the most diverse S. aureus clonal complexes [3]. WA MRSA-3 was first isolated in 1995 from a nasal screening swab [16]. WA MRSA-3 is the fourth most frequently isolated MRSA clone in WA. Erythromycin resistance was the most common antimicrobial resistance phenotype (3% of isolates). Ciprofloxacin resistance was also frequently reported (12%). From 1 st July 211 to the 3 th June 212, 476 WA MRSA-3 were referred from 38 laboratories. The highest number of isolates (298) was detected in the Metropolitan Perth Health Region, however the highest rate was in the Kimberley (165/1, population respectively). Figure 4: Annual number of isolates of WA MRSA-3 in Western Australia, July 23 to June /4 24/5 25/6 26/7 27/8 28/9 29/1 21/11 211/12 42

43 Figure 41: WA MRSA-3 as a percentage of the annual number of referred MRSA in Western Australia, July 23 to June 212 1% 9% 8% 7% 6% 5% 4% 3% 2% 1% % 23/4 24/5 25/6 26/7 27/8 28/9 29/1 21/11 211/ WA MRSA-121 (ST5-IV[2B]) WA MRSA-121 is a PVL positive clone. WA MRSA-121 was initially isolated in 21 from an abdominal abscess in a 62 year old non aboriginal male patient living in the Kimberley. However the majority of patients with WA MRSA-121 are aboriginal, of which two thirds are under the age of 3, including almost 4% under the age of ten. WA MRSA-121 is primarily cultured from boils and abscesses. Similar to other CC5 clones, WA MRSA-121 carries the enterotoxin gene cluster egc (seg, sei, sem, sen, seo and seu/y) and the β-hemolysin-converting phages harboring sak, scn, and chp. However unlike PVL negative WA MRSA-3, WA MRSA-121 carries the edina epidermal cell differentiation inhibitor gene, a type IVc SCCmec element (rarely identified in WA- MRSA) and is phenotypically trimethoprim resistant. WA MRSA-121 seems to be a highly transmissible PVL-positive CA-MRSA which has successfully adapted to the local community environment. Whether WA MRSA-121 was introduced into the Kimberley region or has evolved by the horizontal transfer of a PVL harbouring phage and a SCCmec IVc element, is currently not known. From 1 st July 211 to the 3 th June 212, 68 WA MRSA-121 were referred from 12 laboratories. The highest number of isolates (55) and rate (146/1, population) was detected in the Kimberley Health Region. WA MRSA-121 was also isolated in Metropolitan Perth (6), Pilbara (4), Midwest (1) and Wheatbelt (1). One patient had a Northern Territory address. 43

44 The average age of patients was 24 years (median 21 years): the youngest mean age of all the PVL positive CA-MRSA. Figure 42: Annual number of isolates of WA MRSA-121 in Western Australia, July 23 to June /4 24/5 25/6 26/7 27/8 28/9 29/1 21/11 211/12 Figure 43: WA MRSA-121 as a percentage of the annual number of referred MRSA in Western Australia, July 23 to June % 1.8% 1.6% 1.4% 1.2% 1.%.8%.6%.4%.2%.% 23/4 24/5 25/6 26/7 27/8 28/9 29/1 21/11 211/12 44

45 WA MRSA-62 (ST923-IV[2B]) WA MRSA-62 is a CC8 PVL positive clone. From 1 st July 211 to the 3 th June 212, 26 WA MRSA-62 were referred from 11 laboratories. WA MRSA-62 was detected in the Metropolitan Perth Health Region (18 isolates) and the South West (7 isolates) which also had the highest rate (4/1, population). One isolate was from a patient with an interstate address. The average age of patients was 3 years (median 27 years). Figure 44: Annual number of isolates of WA MRSA-62 in Western Australia, July 23 to June /4 24/5 25/6 26/7 27/8 28/9 29/1 21/11 211/12 45

46 Figure 45: WA MRSA-62 as a percentage of the annual number of referred MRSA in Western Australia, July 23 to June 212.6%.5%.4%.3%.2%.1%.% 23/4 24/5 25/6 26/7 27/8 28/9 29/1 21/11 211/12 46

47 Section 5 Number and Rate of MRSA in Western Australia by Health Region 47

48 5 Number and Rate of MRSA in Western Australia by Health Region 5.1 Regional data, 1 st July 211 to 3 th June 212 The majority (63%) of MRSA were referred from the Metropolitan Perth Health Region. The Kimberley accounted for 12% of referred MRSA (up from 9% in 21/211, P<.1), with all other health regions contributing 2 6% of isolates. MRSA infection and/or colonisation rates were highest for the Kimberley (1,916/1, population). The Metropolitan Perth Health Region had the highest rate of HA-MRSA (43/1, population) while the Kimberley, Midwest and Pilbara had the highest rates of CA-MRSA (19, 59 and 45/1, population respectively). These health regions also had the highest rates of PVLpositive CA-MRSA (1,176, 196 and 182/1, population respectively). 48

49 Table 6: New MRSA cases notified to Department of Health by Health Region according to postcode of residence, July 211 to June 212 Health Region MLST/SCCmec PFGE Kimb Pilb Midw Gold Wheat Metro SthW GSth Not WA Total HA-MRSA ST239-III [3A] Aus-2/3 EMRSA ST257-III [3A] Aus -2/3 EMRSA variant B 1 1 ST22-IV [2B] EMRSA-15* ST36-II [2A] EMRSA ST8-VI [4B] Irish -2 EMRSA 1 1 ST5-II [2A] New York/Japan MRSA ST764-II [2A] New York/Japan MRSA variant 2 2 Total HA-MRSA PVL-negative CA-MRSA ST72-IV[2B] Korean Clone ST1-IV [2B] WA MRSA ST78-IV [2B] WA MRSA ST5-IV [2B] WA MRSA ST45-V [5C2] WA MRSA ST8-IV[2B] WA MRSA ST834-IV [2B] WA MRSA ST5-V [5C2] WA MRSA ST59-IV [2B] WA MRSA ST5-novel WA MRSA ST612-IV [2B] WA MRSA ST577-V[5C2] WA MRSA ST45-IV [2B] WA MRSA ST576-IV [2B] WA MRSA ST5-V [5C2&5] WA MRSA ST5-V [5C2] WA MRSA ST188-IV [2B] WA MRSA ST835-V [5C2&5] WA MRSA ST883-IV[2B) WA MRSA ST835-novel WA MRSA ST6-IV [2B] WA MRSA ST953-IV [2B] WA MRSA ST15-IV [2B] WA MRSA ST73-IV [2B] WA MRSA ST6-IV[2B] WA MRSA ST5-IV [2B] WA MRSA ST134-IV [2B] WA MRSA ST5-IV [2B] WA MRSA ST45-IV(2B) WA MRSA ST133-IV [2B] WA MRSA

50 Health Region MLST/SCCmec PFGE Kimb Pilb Midw Gold Wheat Metro SthW GSth Not WA Total ST188-IV [2B] WA MRSA ST45-V [5C2&5] WA MRSA ST835-V[5C2&5) WA MRSA ST5-V [5C2] WA MRSA ST72-V[5C2] WA MRSA ST5-IV [2B] WA MRSA ST73-IV [2B] WA MRSA ST72-novel WA MRSA ST779-IV [2B] WA MRSA ST3-novel WA MRSA ST835-novel WA MRSA ST5-IV [2B] WA MRSA ST197-V [5C2] WA MRSA ST5-V [5C2] WA MRSA ST5-V [5C2] WA MRSA ST8-V [5C2] WA MRSA ST7-V [5C2&5]&1 WA MRSA ST59-IV [2B] WA MRSA ST2471-V [5C2] WA MRSA ST5dlv-IV [2B] WA MRSA ST5-V [5C2] WA MRSA Total PVL-negative CA-MRSA PVL-positive CA-MRSA ST772-V[5C2] Bengal Bay Clone ST8-IV [2B] European Clone 3 3 ST93-IV [2B] Qld Clone ST59-V [5C2&5] Taiwan CA-MRSA ST952-V [5C2&5] Taiwan A CA-MRSA ST8-IV [2B] USA3 MRSA ST59-IV [2B] WA MRSA ST923-IV[2B] WA MRSA ST1633-V [5C2] WA MRSA ST88-V [5C2] WA MRSA ST193-IV [2B] WA MRSA ST5-IV [2B] WA MRSA ST3-IV [2B] WSPP MRSA Total PVL-positive CA-MRSA Total CA-MRSA Total MRSA Kimb = Kimberley, Pilb = Pilbara, Midw = Midwest, Gold = Goldfields, Wheat = Wheatbelt, Metro = Metropolitan Perth, SthW = South West, GSth Great Southern, Not WA = Outside WA. MLST/SCCmec types may have multiple PFGE pulsotypes. *Address details could not be sourced for one isolate. 5

51 Table 7: MRSA notification rates per 1, population by Health Region according to postcode of residence, July 211 to June 212 Health Region MLST/SCCmec PFGE Kimb Pilb Midw Gold Wheat Metro SthW GSth WA HA-MRSA ST239-III [3A] Aus-2/3 EMRSA ST257-III [3A] Aus -2/3 EMRSA variant B.5.4 ST22-IV [2B] EMRSA ST36-II [2]) EMRSA ST8-VI [4B] Irish -2 EMRSA.5.4 ST5-II [2A] New York/Japan MRSA ST764-II [2A] New York/Japan MRSA variant.11.9 Total HA-MRSA PVL-negative CA-MRSA ST72-IV[2B] Korean Clone ST1-IV [2B] WA MRSA ST78-IV [2B] WA MRSA ST5-IV [2B] WA MRSA ST45-V [5C2] WA MRSA ST8-IV[2B] WA MRSA ST834-IV [2B] WA MRSA ST5-V [5C2] WA MRSA ST59-IV [2B] WA MRSA ST5-novel WA MRSA ST612-IV [2B] WA MRSA ST577-V[5C2] WA MRSA ST45-IV [2B] WA MRSA ST576-IV [2B] WA MRSA ST5-V [5C2&5] WA MRSA ST5-V [5C2] WA MRSA ST188-IV [2B] WA MRSA ST835-V [5C2&5] WA MRSA ST883-IV[2B) WA MRSA ST835-novel WA MRSA ST6-IV [2B] WA MRSA ST953-IV [2B] WA MRSA ST15-IV [2B] WA MRSA ST73-IV [2B] WA MRSA ST6-IV[2B] WA MRSA ST5-IV [2B] WA MRSA ST134-IV [2B] WA MRSA ST5-IV [2B] WA MRSA ST45-IV(2B) WA MRSA ST133-IV [2B] WA MRSA

52 Health Region MLST/SCCmec PFGE Kimb Pilb Midw Gold Wheat Metro SthW GSth WA ST188-IV [2B] WA MRSA ST45-V [5C2&5] WA MRSA ST835-V[5C2&5) WA MRSA ST5-V[5C2] WA MRSA ST72-V[5C2] WA MRSA ST5-IV [2B] WA MRSA ST73-IV [2B] WA MRSA ST72-novel WA MRSA ST779-IV [2B] WA MRSA ST3-novel WA MRSA ST835-novel WA MRSA ST5-IV [2B] WA MRSA ST197-V [5C2] WA MRSA ST5-V [5C2] WA MRSA ST5-IV [2B] WA MRSA ST8-V [5C2] WA MRSA ST7-V [5C2&5]&1 WA MRSA ST59-IV [2B] WA MRSA ST2471-V [5C2] WA MRSA ST5dlv-IV [2B] WA MRSA ST5-V [5C2] WA MRSA Total PVL-negative CA-MRSA PVL-positive CA-MRSA ST772-V[5C2] Bengal Bay Clone ST8-IV [2B] European Clone ST93-IV [2B] Qld Clone ST59-V [5C2&5] Taiwan CA-MRSA ST952-V [5C2&5] Taiwan A CA-MRSA ST8-IV [2B] USA3 MRSA ST59-IV [2B] WA MRSA ST923-IV[2B] WA MRSA ST1633-V [5C2] WA MRSA ST88-V [5C2] WA MRSA ST5-IV [2B] WA MRSA ST3-IV [2B] WSPP MRSA Total PVL-positive CA-MRSA 1, Total CA-MRSA 1, Total MRSA 1, Kimb = Kimberley, Pilb = Pilbara, Midw = Midwest, Gold = Goldfields, Wheat = Wheatbelt, Metro = Metropolitan Perth, SthW = South West, GSth = Great Southern, UD = Undetermined Population figures (211) obtained from Epidemiology Branch, Department of Health WA. 52