Pearson Jc

Formal infectious diseases consultation is associated with decreased mortality in Staphylococcus aureus bacteraemia

To determine the impact of infectious diseases consultation (IDC) in Staphylococcus aureus bacteraemia. All MRSA bacteraemia and a random subset of MSSA bacteraemia were retrospectively analysed. Out of 599 SAB episodes, 162 (27%) were followed by an IDC. Patients with IDC were younger and more frequently intravenous drug users, but fewer resided in a long-term care facility or were indigenous. Hospital length of stay was longer (29.5 vs 17xa0days, pu2009<u20090.001), and endocarditis (19.1% vs 7.3%, pu2009<u20090.001) and metastatic seeding (22.2% vs 10.1%, pu2009<u20090.001) were more frequent in the IDC group; however, SAPS II scores were lower in the IDC group (27 vs 37, pu2009<u20090.001). ICU admission rates in the two groups were similar. The isolate tested susceptible to empirical therapy more frequently in the IDC group (88.9% vs 78.0%, pu2009=u20090.003). Seven-day (3.1 vs 16.5%), 30-day (8.0% vs 27.0%) and 1-year mortality (22.2% vs 44.9%) were all lower in the IDC group (all pu2009<u20090.001). Multivariate analysis showed that effective initial therapy was the only variable associated with the protective effect of IDC. In patients with SAB, all-cause mortality was significantly lower in patients who had an IDC, because of the higher proportion of patients receiving effective initial antibiotics.

Type V Staphylococcal Cassette Chromosome mec in Community Staphylococci from Australia

ABSTRACT Twenty Australian community staphylococci harboring the type V staphylococcal cassette chromosome mec (SCCmec) were found to belong to eight multilocus sequence types. Five were previously unreported novel type V SCCmec elements. The mec complexes were of two types, based on the polymorphisms in the IS431 transposase genes. Five isolates were multiresistant.

Controlling a Multicenter Outbreak Involving the New York/Japan Methicillin-Resistant Staphylococcus aureus Clone

OBJECTIVEnTo describe the control of an outbreak of infection and colonization with the New York/Japan methicillin-resistant Staphylococcus aureus (MRSA) clone in multiple healthcare facilities, and to demonstrate the importance of making an MRSA management policy involving molecular typing of MRSA into a statewide public health responsibility.nnnSETTINGnA range of healthcare facilities, including 2 metropolitan teaching hospitals and a regional hospital, as well as several community hospitals and long-term care facilities in a nonmetropolitan healthcare region.nnnINTERVENTIONSnA comprehensive, statewide MRSA epidemiological investigation and management policy.nnnRESULTSnIn May 2005, there were 3 isolates referred to the Western Australian Gram-Positive Bacteria Typing and Research Unit that were identified as the New York/Japan MRSA clone, a pandemic MRSA clone with the ability to spread and replace existing clones in a region. Subsequent investigation identified 28 additional cases of infection and/or colonization dating from 2002 onward, including 1 involving a colonized healthcare worker (HCW) who had previously been hospitalized overseas. Of the 31 isolates detected, 25 were linked epidemiologically and via molecular typing to the isolate recovered from the colonized HCW. Four isolates appeared to have been introduced separately from overseas. Although the isolate from the single remaining case patient was genetically indistinct from the isolates that spread within Western Australia, no specific epidemiological link could be established. The application of standard outbreak management strategies reduced further spread.nnnCONCLUSIONSnThe elimination of the New/York Japan MRSA clone in a healthcare region demonstrates the importance of incorporating MRSA management policy into statewide public health programs. The mainstays of such programs should include a comprehensive and effective outbreak identification and management policy (including pre-employment screening of HCWs, where applicable) and MRSA clone identification by multilocus sequence typing.

Molecular Epidemiology of Enterococcal Bacteremia in Australia

ABSTRACT Enterococci are a major cause of health care-associated infections and account for approximately 10% of all bacteremias globally. The aim of this study was to determine the proportion of enterococcal bacteremia isolates in Australia that are antimicrobial resistant, with particular emphasis on susceptibility to ampicillin and the glycopeptides, and to characterize the molecular epidemiology of the Enterococcus faecalis and Enterococcus faecium isolates. From 1 January to 31 December 2011, 1,079 unique episodes of bacteremia were investigated, of which 95.8% were caused by either E. faecalis (61.0%) or E. faecium (34.8%). The majority of bacteremias were health care associated, and approximately one-third were polymicrobial. Ampicillin resistance was detected in 90.4% of E. faecium isolates but was not detected in E. faecalis isolates. Vancomycin nonsusceptibility was reported in 0.6% and 36.5% of E. faecalis and E. faecium isolates, respectively. Unlike Europe and the United States, where vancomycin resistance in E. faecium is predominately due to the acquisition of the vanA operon, 98.4% of E. faecium isolates harboring van genes carried the vanB operon, and 16.1% of the vanB E. faecium isolates had vancomycin MICs at or below the susceptible breakpoint of the CLSI. Although molecular typing identified 126 E. faecalis pulsed-field gel electrophoresis pulsotypes, >50% belonged to two pulsotypes that were isolated across Australia. E. faecium consisted of 73 pulsotypes from which 43 multilocus sequence types were identified. Almost 90% of the E. faecium isolates were identified as CC17 clones, of which approximately half were characterized as ST203, which was isolated Australia-wide. In conclusion, the Australian Enterococcal Sepsis Outcome Programme (AESOP) study has shown that although they are polyclonal, enterococcal bacteremias in Australia are frequently caused by ampicillin-resistant vanB E. faecium.

Clinical and laboratory features of invasive community-onset methicillin-resistant Staphylococcus aureus infection: a prospective case–control study

Differences between the features of invasive community-onset methicillin-resistant Staphylococcus aureus (cMRSA) and methicillin-susceptible S. aureus (cMSSA) infections are incompletely understood. Fifty-seven patients with invasive cMRSA infection were prospectively identified at two teaching hospitals; for each cMRSA case, two cases of invasive cMSSA infection acted as controls. The primary outcome was 30-day all-cause mortality. Patients with invasive cMRSA infection were more likely to be Aboriginal (25% vs. 14%, age-adjusted odds ratio [OR] 2.5, pu2009=u20090.037), reside in a long-term care facility and/or have been hospitalised in the previous year (51% vs. 34%, pu2009=u20090.04) and less likely to have endocarditis (2% vs. 12%, pu2009=u20090.02) or require admission to an intensive care unit or high-dependency area (7% vs. 21%, pu2009=u20090.02). All-cause mortality at 30xa0days was similar in the cMRSA and cMSSA groups (9% vs. 7%, pu2009=u20090.68). Panton–Valentine leukocidin (PVL) genes were detected in a similar proportion of cMRSA and cMSSA isolates (32% vs. 27%, pu2009=u20090.49) and the presence of PVL genes was associated with younger age (35xa0years vs. 55xa0years, pu2009<u20090.001), Aboriginal ethnicity (38% vs. 10%, pu2009<u20090.001), skin and soft-tissue infection (54% vs. 19%, pu2009<u20090.001), lower illness severity at presentation (SAPS II score 9 vs. 21, pu2009=u20090.001) and shorter hospitalisation (9xa0days vs. 24xa0days, pu2009<u20090.001). Patients with “PVL-positive” and “PVL-negative” S. aureus infection had similar 30-day all-cause mortality (4% vs. 9%, pu2009=u20090.28). Few clinical features differentiated patients with invasive cMRSA infection from those with infection caused by cMSSA. Invasive “PVL-positive” S. aureus infection was associated with less morbidity but similar mortality to “PVL-negative” infection.

Epidemiological, clinical, outcome and antibiotic susceptibility differences between PVL positive and PVL negative Staphylococcus aureus infections in Western Australia: a case control study

BackgroundPanton Valentine Leukocidin (PVL) has been associated with invasive Staphylococcus aureus soft tissue and pneumonic infections.MethodsFrom September 2007 to January 2009 at Royal Perth Hospital we tested for the PVL gene in S. aureus isolates from an invasive site, a suspected PVL-related soft tissue infection and all MRSA isolates. We could access medical records for 141 PVL positive (PVLu2009+u2009ve) infections and compared these to a control group comprised of 148 PVL negative (PVL-ve) infections.ResultsIn the PVLu2009+u2009ve group 62 isolates were MRSA (48 were ST93-MRSA-IV) and 79 isolates were methicillin-sensitive S. aureus, and in the PVL-ve group 56 were MRSA (50 were WA-MRSA strains) and 92 were methicillin-sensitive S. aureus. We found the presence of PVL to be significantly associated with younger age, aboriginality, intravenous drug use, community acquisition, shorter length of hospital stay and lower mortality at 1xa0year. Overall PVLu2009+u2009ve infections more often required surgical intervention (73.0% versus 44.6%, pu2009<u20090.001) and were less often polymicrobial (8.5% versus 41.2%, pu2009<u20090.001). PVLu2009+u2009ve isolates were more often susceptible to clindamycin (87.9% versus 73.0%, pu2009=u20090.002).ConclusionsThis study demonstrates that PVLu2009+u2009ve infections are associated with a distinct clinical picture, predominantly pyogenic skin and soft tissue infections often requiring surgery, disproportionately affecting patients who are younger, indigenous or with fewer health-care risk factors.

Knowing prior methicillin-resistant Staphylococcus aureus (MRSA) infection or colonization status increases the empirical use of glycopeptides in MRSA bacteraemia and may decrease mortality

To compare the management and outcome of methicillin-resistant Staphylococcus aureus (MRSA) bacteraemia in patients known to be MRSA-colonized/infected (C-patients) with the management and outcome in those not known to be colonized/infected (NC-patients), we conducted a 10-year retrospective review of MRSA bacteraemia in an adult tertiary hospital. Clinical data were obtained by chart review, and mortality data from linked databases. Prior MRSA colonization/infection status was available to treating clinicians at the time of the bacteraemia as a Micro-Alert tag on the patients labels, in medical charts, and in electronic information systems. C-patients accounted for 35.4% of all MRSA bacteraemia episodes. C-patients were more likely to be indigenous, to be diabetic, or to have a history of previous S. aureus infection. Markers of illness severity (Simplified Acute Physiology Score (SAPS)-II, need for admission to the intensive-care unit, length of stay, and metastatic seeding) were similar in both groups. Empirical therapy included a glycopeptide in 49.3% of C-patients vs. 18.9% of NC-patients (p <0.01), and contained an antibiotic to which the MRSA isolate tested susceptible in vitro in 56.7% of C-patients vs. 45.1% of NC-patients (p 0.13). All-cause 7-day and 30-day mortality were 7.5% vs. 18.9% (p 0.04), and 22.4% vs. 31.1% (p 0.20), in the C-patient and NC-patient groups, respectively. Knowing MRSA colonization status was significantly associated with lower 30-day mortality in Cox regression analysis (p <0.01). These data suggest that mortality from MRSA bacteraemia is lower in C-patients, which may reflect the earlier use of glycopeptides. The low use of empirical glycopeptides in septic patients known to be previously MRSA-colonized/infected may represent a missed opportunity for infection control to positively impact on clinical management.

Intrafamilial transmission of methicillin-resistant Staphylococcus aureus.

To the Editor: Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) infection was first described in our region over 15 years ago (1). More recently, CA-MRSA has become a global concern and is now a common cause of skin and soft tissue infections in the United States (2). An association between severe CA-MRSA infection (e.g., necrotizing fasciitis and pneumonia) and the synergohymenotrophic exotoxin Panton-Valentine leukocidin (PVL) has been made (3,4). Reports have documented CA-MRSA transmission among household members; however, most cases have been mild or moderate infections or asymptomatic colonization (5–7). We describe intrafamilial transmission of a PVL-containing CA-MRSA clone common in Australia (ST30-MRSA-IV) between a nurse who suffered recurrent abscesses and her husband, who died of severe pneumonia. n nIn July 2006, a 61-year-old previously healthy nurse (Mrs A) sought treatment for an infected seborrheic cyst of the scalp. Culture of pus yielded MRSA that was susceptible to clindamycin. She was treated with oral clindamycin. After resolution of the infection, topical MRSA decolonization therapy with 3% hexachlorophane body wash (daily), 20% cetrimide shampoo (3×/wk), and 2% mupirocin nasal ointment (3×/d) was administered for 10 days, as per our institutional protocol for MRSA-colonized healthcare workers. Subsequently, MRSA surveillance swabs from the nose, throat, and scalp obtained weekly for 10 weeks and cultured on selective MRSA chromogenic agar and in selective broth enrichment media were negative. Household members were not screened for MRSA colonization. n nSix months later, in January 2007, the patient’s husband (Mr A), a 60-year-old smoker who was her only household contact, was admitted with a 1-day history of dyspnea, pleuritic chest pain, cough with sputum, fever, vomiting, and diarrhea. On admission, he was unwell, with tachycardia (pulse rate 132 bpm), hypotension (95/60 mm Hg), tachypnea (40 breaths/min), and hypoxia (oxygen saturation 93% on 15 L O2/min). A chest radiograph showed bilateral infiltrates and a right pleural effusion. He was diagnosed with community-acquired pneumonia and treated with intravenous ceftriaxone and azithromycin as per local protocol. However, within 12 hours, his condition deteriorated, necessitating admission to the intensive care unit for ventilation and inotropic support. Broncho-alveolar lavage (BAL) fluid demonstrated gram-positive cocci in tetrads, and intravenous vancomycin and dicloxacillin were added to therapy. Despite aggressive supportive measures, Mr A’s condition continued to deteriorate, and he died 28 hours after admission. MRSA was subsequently cultured from blood, sputum, and BAL fluid; an autopsy was not performed. n nIn June 2007, Mrs A sought treatment for an abscess with cellulitis on the left thigh. The abscess was surgically drained, and cultures again yielded MRSA. She was treated with intravenous and oral clindamycin for 10 days and subsequently underwent repeat MRSA decolonization therapy; again, swabs taken 1×/wk for 10 weeks postdecolonization were negative. n nMolecular typing of the MRSA isolates obtained from Mrs A at the time of her initial skin infection, Mr A’s blood culture, and Mrs A’s second skin infection was performed by using contour-clamped homogenous electric field electrophoresis (CHEF) according to a previously described method (8) (Figure). The CHEF patterns were indistinguishable and were identical to the known CHEF pattern for ST30-MRSA-IV (9). All 3 isolates contained the lukF-PV/lukS-PV genes that encode PVL and had the same antibiogram (i.e., isolates were resistant only to β-lactam antimicrobial agents). n n n nFigure n nContour-clamped homogenous electric field electrophoresis of Staphylococcus aureus isolates. Lanes 2, 3, and 4 (Sma1 restriction): methicillin-resistant S. aureus (MRSA) isolated from Mrs A’s first infection, Mr A’s blood culture, and ... n n n nWe describe intrafamilial MRSA transmission (defined as >2 family members who live at the same postal address and who are colonized or infected with a MRSA strain having the same CHEF pattern) that resulted in a fatal outcome. The MRSA strain responsible (ST30-MRSA-IV, or Western Samoan phage pattern/Oceania strain MRSA) is a common cause of CA-MRSA infection in Australia. n nRecurrent MRSA infection developed in Mrs A several months after completion of apparently successful MRSA decolonization therapy. We could not determine whether this recurrence was because of persistent MRSA colonization not detected by surveillance (e.g., perineal or gastrointestinal colonization) or whether Mrs A was successfully decolonized but Mr A’s colonization/infection resulted in recolonization and subsequent infection. Whatever the explanation, this case highlights a potential weakness in MRSA surveillance programs that rely on short-term, limited-site surveillance. n nA comprehensive MRSA search-and-destroy policy in place for over 25 years has prevented MRSA from becoming endemic in our institution (10). However, the rapidly changing epidemiology of MRSA in becoming a predominantly community pathogen represents a significant challenge to the ongoing success of this policy. In response to this challenge, the Western Australian Department of Health has implemented a community-based MRSA search-and-destroy program for patients with MRSA infection caused by exotic PVL-positive clones (e.g., ST30-MRSA-IV, ST93-MRSA-IV, ST80-MRSA-IV, and ST8-MRSA-IV/USA300). This program includes treatment/decolonization therapy for the index case, screening of household members for MRSA infection/colonization, and simultaneous treatment/decolonization if MRSA is identified. Although a similar approach has proved successful in Denmark (6), whether this success can be sustainable on a larger scale remains to be seen.

A Clonal Complex 12 Methicillin-Resistant Staphylococcus aureus Strain, West Australian MRSA-59, Harbors a Novel Pseudo-SCCmec Element

ABSTRACT A West Australian methicillin-resistant Staphylococcus aureus strain (WA MRSA-59) was characterized by microarray and sequencing. Its pseudo-staphylococcal cassette chromosome mec (SCCmec) element comprised dcs, Q9XB68-dcs, mvaS-SCC, Q5HJW6, dru, ugpQ, ydeM, mecA-mecR-mecI, txbi mecI, tnp IS431, copA2-mco (copper resistance), ydhK, arsC-arsB-arsR (arsenic resistance), open reading frame PT43, and per-2. Recombinase genes, xylR (mecR2), and PSM-mec (phenol-soluble modulin) were absent. We suggest that mec complex A should be split into two subtypes. One harbors PSM-mec and xylR (mecR2). It is found in SCCmec types II, III, and VIII. The second subtype, described herein, is present in WA MRSA-59 and some coagulase-negative staphylococci.

Genomic epidemiology and population structure of Neisseria gonorrhoeae from remote highly endemic Western Australian populations

BackgroundNeisseria gonorrhoeae causes gonorrhoea, the second most commonly notified sexually transmitted infection in Australia. One of the highest notification rates of gonorrhoea is found in the remote regions of Western Australia (WA). Unlike isolates from the major Australian population centres, the remote community isolates have low rates of antimicrobial resistance (AMR).Population structure and whole-genome comparison of 59 isolates from the Western Australian N. gonorrhoeae collection were used to investigate relatedness of isolates cultured in the metropolitan and remote areas. Core genome phylogeny, multilocus sequencing typing (MLST), N. gonorrhoeae multi-antigen sequence typing (NG-MAST) and N. gonorrhoeae sequence typing for antimicrobial resistance (NG-STAR) in addition to hierarchical clustering of sequences were used to characterize the isolates.ResultsPopulation structure analysis of the 59 isolates together with 72 isolates from an international collection, revealed six population groups suggesting that N. gonorrhoeae is a weakly clonal species. Two distinct population groups, Aus1 and Aus2, represented 63% of WA isolates and were mostly composed of the remote community isolates that carried no chromosomal AMR genotypes. In contrast, the Western Australian metropolitan isolates were frequently multi-drug resistant and belonged to population groups found in the international database, suggesting international transmission of the isolates.ConclusionsOur study suggests that the population structure of N. gonorrhoeae is distinct between the communities in remote and metropolitan WA. Given the high rate of AMR in metropolitan regions, ongoing surveillance is essential to ensure the enduring efficacy of the empiric gonorrhoea treatment in remote WA.Neisseria gonorrhoeae causes gonorrhoea, the second most commonly notified sexually transmitted infection in Australia. One of the highest notification rates of gonorrhoea is found in the remote regions of Western Australia (WA). Unlike isolates from the major Australian population centres, the remote community isolates have low rates of antimicrobial resistance (AMR). Population structure and whole-genome comparison of 59 isolates from the Western Australian N. gonorrhoeae collection were used to investigate relatedness of isolates cultured in the metropolitan and remote areas. Core genome phylogeny, multilocus sequencing typing (MLST), N. gonorrhoeae multi-antigen sequence typing (NG-MAST) and N. gonorrhoeae sequence typing for antimicrobial resistance (NG-STAR) in addition to hierarchical clustering of sequences were used to characterize the isolates. Population structure analysis of the 59 isolates together with 72 isolates from an international collection, revealed six population groups suggesting that N. gonorrhoeae is a weakly clonal species. Two distinct population groups, Aus1 and Aus2, represented 63% of WA isolates and were mostly composed of the remote community isolates that carried no chromosomal AMR genotypes. In contrast, the Western Australian metropolitan isolates were frequently multi-drug resistant and belonged to population groups found in the international database, suggesting international transmission of the isolates. Our study suggests that the population structure of N. gonorrhoeae is distinct between the communities in remote and metropolitan WA. Given the high rate of AMR in metropolitan regions, ongoing surveillance is essential to ensure the enduring efficacy of the empiric gonorrhoea treatment in remote WA.