Interspecies transfer of blaimp-4 in a patient with prolonged colonization by IMP-4-producing enterobacteriaceae

A patient was colonized by IMP-4-producing Enterobacter cloacae and Escherichia coli strains for 7 months. IMP-4-producing E. cloacae strains were first and last isolated at day 33 and at 8 months after admission, respectively. IMP-4-producing E. coli strains were first and last isolated at days 88 and 181 after admission, respectively. The E. cloacae and E. coli isolates shared identical genetic features in terms of bla(IMP-4), bla(TEM-1), qnrB2, aacA4, HI2 plasmids, and ISCR1. This study shows the first prolonged colonization with in vivo interspecies transfer of bla(IMP-4)

Staphylococcus aureus Bacteremia, Australia

S. aureus bacteremia in Australia is increasingly caused by MRSA, which is likely to affect empiric prescribing of antimicrobial drugs in suspected cases

Staphylococcus aureus bacteremia, Australia

Staphylococcus aureus bacteremia (SAB) is common and increasing worldwide. A retrospective review wyas undertaken to quantify the number of cases, their place of acquisition, and the proportions caused by methicillin-resistant S. aureus (MRSA) in 17 hospitals in Australia. Of 3,192 episodes, 1,571 (49%) were community onset. MRSA caused 40% of hospital-onset episodes and 12% of community-onset episodes. The median rate of SAB was 1.48/1,000 admissions (range 0.61-3.24; median rate for hospital-onset SAB was 0.7/1,000 and for community onset 0.8/1,000 admissions). Using these rates, we estimate that ≈6,900 episodes of SAB occur annually in Australia (35/100,000 population). SAB is common, and a substantial proportion of cases may be preventable. The epidemiology is evolving, with >10% of community-onset SAB now caused by MRSA. This is an emerging infectious disease concern and is likely to impact on empiric antimicrobial drug prescribing in suspected cases of SAB

Molecular characterization of endocarditis-associated Staphylococcus aureus

Infective endocarditis (IE) is a life-threatening infection of the heart endothelium and valves. Staphylococcus aureus is a predominant cause of severe IE and is frequently associated with infections in health care settings and device-related infections. Multilocus sequence typing (MLST), spa typing, and virulence gene microarrays are frequently used to classify S. aureus clinical isolates. This study examined the utility of these typing tools to investigate S. aureus epidemiology associated with IE. Ninety-seven S. aureus isolates were collected from patients diagnosed with (i) IE, (ii) bloodstream infection related to medical devices, (iii) bloodstream infection not related to medical devices, and (iv) skin or soft-tissue infections. The MLST clonal complex (CC) for each isolate was determined and compared to the CCs of members of the S. aureus population by eBURST analysis. The spa type of all isolates was also determined. A null model was used to determine correlations of IE with CC and spa type. DNA microarray analysis was performed, and a permutational analysis of multivariate variance (PERMANOVA) and principal coordinates analysis were conducted to identify genotypic differences between IE and non-IE strains. CC12, CC20, and spa type t160 were significantly associated with IE S. aureus. A subset of virulence-associated genes and alleles, including genes encoding staphylococcal superantigen-like proteins, fibrinogen-binding protein, and a leukocidin subunit, also significantly correlated with IE isolates. MLST, spa typing, and microarray analysis are promising tools for monitoring S. aureus epidemiology associated with IE. Further research to determine a role for the S. aureus IE-associated virulence genes identified in this study is warranted

Nematode Symbiont for Photorhabdus asymbiotica

Photorhabdus asymbiotica is an emerging bacterial pathogen that causes locally invasive soft tissue and disseminated bacteremic infections in the United States and Australia. Although the source of infection was previously unknown, we report that the bacterium is found in a symbiotic association with an insect-pathogenic soil nematode of the genus Heterorhabditis

Community-Acquired Methicillin-Resistant Staphylococcus aureus Carrying Panton-Valentine Leukocidin Genes: Worldwide Emergence

Infections caused by community-acquired (CA)-methicillin resistant Staphylococcus aureus (MRSA) have been reported worldwide. We assessed whether any common genetic markers existed among 117 CA-MRSA isolates from the United States, France, Switzerland, Australia, New Zealand, and Western Samoa by performing polymerase chain reaction for 24 virulence factors and the methicillin-resistance determinant. The genetic background of the strain was analyzed by pulsed-field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST). The CA-MRSA strains shared a type IV SCCmec cassette and the Panton-Valentine leukocidin locus, whereas the distribution of the other toxin genes was quite specific to the strains from each continent. PFGE and MLST analysis indicated distinct genetic backgrounds associated with each geographic origin, although predominantly restricted to the agr3 background. Within each continent, the genetic background of CA-MRSA strains did not correspond to that of the hospital-acquired MRSA

Control of an outbreak of carbapenem-resistant Acinetobacter baumannii in Australia after introduction of environmental cleaning with a commercial oxidizing disinfectant

In the midst of an outbreak, carbapenem-resistant Acinetobacter baumannii was grown from samples of multiple environmental sites in an intensive care unit. A commercial oxidizing disinfectant (potassium peroxomonosulphate 50%, sodium alkyl benzene sulphonate 15%, and sulphamic acid 5%) was introduced throughout the intensive care unit, and its use coincided with cessation of the outbreak

CO‐MRSA Infections in Australia Cost $3.5B Per Annum

Introduction The health and economic burdens of community-onset methicillin resistant Staphylococcus aureus (CO-MRSA) infections are needed to inform policy, planning and evidence-based practice. We aimed to synthesise data from a range of public sources to generate the first estimate of the national incidence and cost of CO-MRSA infections. Methods Incidences of CO-MRSA skin and soft tissue (SSTI), lower respiratory tract (LRTI) and bloodstream (BSI) infections were calculated for regions of Australia using data from existing literature and correspondence with specialists. Simulations estimated costs using treatment models developed for children and adults in primary or tertiary care settings and including bed-stay, diagnostics, procedures, mortalities and loss of productivity. Results Annually, in Australia there were found to be 3702 CO-MRSA SSTIs, 559 CO-MRSA BSIs and 425 CO-MRSA LRTIs, occupying 147,000 bed-days, including 1600 bed-days in intensive care. Incidence ranged from 4 /100,000 person-years in Tasmania to 243 /100,000 person-years in central Australia. CO-MRSA cost $3.5b annually in Australia. The higher incidence of SSTIs resulted in costs greater than summing the costs of BSIs and LRTIs. The greatest cost was mortality. The cost to the health system was found to be$1.9b, with bed occupancies accounting for ≥94%. Conclusion This was the first evaluation of the health and economic burden of CO-MRSA in Australia. We found a need for increased and more consistent data collection for a significant and expensive disease. Disclosure of Interest Statement: This research was funded by NHMRC grant GNT1027589

Rapid detection of Staphylococcus aureus Panton-Valentine leukocidin in clinical specimens by enzyme-linked immunosorbent assay and immunochromatographic tests

10.1128/JCM.02274-09Journal of Clinical Microbiology4841384-139