Field trials of blood culture identification FilmArray in regional Australian hospitals.

Purpose. In this field trial of rapid blood culture identification (BCID), we aimed to determine whether the improved speed and accuracy of specific BCID predicted in our earlier pilot study could be obtained in regional hospitals by deploying a multiplex PCR FilmArray (Biomerieux, France) capability in their laboratories.Methods. We trained local hospital laboratory staff to operate the FilmArray equipment and act on the results. To do this, we integrated the multiplex PCR into the standard laboratory blood culture workflow and reporting procedure.Results. Of 100 positive blood culture episodes, BCID FilmArray results were correct in all 42 significant monobacterial cultures, with a fully predictive identity in 38 (90.5 %) and a partial identity in another four (9.5 %). There was one major error; a false positive Pseudomonas aeruginosa. The minor errors were the detection of one methicillin-resistant Staphylococcus aureus, which proved to be a methicillin-sensitive S. aureus mixed with a methicillin-resistant coagulase-negative staphylococcus, five false negative coagulase-negative staphylococci and one false negative streptococcus species. We found that 41/49 (84 %) clinically significant mono- and polymicrobial culture results were fully predictive of culture-based identification to bacterial species level at a mean of 1.15 days after specimen collection.Conclusions. There was a reduction of 1.21 days in the time taken to produce a definitive BCID compared to the previous year, translating into earlier communication of more specific blood culture results to the treating physician. Reduced time to definitive blood culture results has a direct benefit for isolated Australian communities at great distances from specialist hospital services.

M protein gene (emm type) analysis of group A Streptococcus isolates recovered during an acute glomerulonephritis outbreak in northern Western Australia.

Certain M protein types of group A streptococcus (GAS) are known to cause acute post-streptococcal glomerulonephritis (APSGN). Outbreaks of APSGN can occur regularly in tropical regions but the emm types responsible are geographically and temporally diverse. GAS isolates from Western Australia (WA) were analysed for emm type and emm cluster during the period of increased APSGN activity in the tropical northern Kimberley region of WA. Although emm types 49, 75 and 108 and corresponding emm clusters E3, E6 and D4 were more common in WA during the outbreak there was no predominant circulating emm type or cluster found to correspond to the APSGN activity. This is consistent with the high diversity of GAS strains found during APSGN outbreaks in other countries. Potential vaccine coverage of the new 30-valent M-protein GAS vaccine was 70%.

The implications of endemic IMP-4 carbapenemase for clinical laboratory susceptibility testing.

A local predominance of carbapenemase producing Enterobacteriaceae with low minimum inhibitory concentrations (MIC) to meropenem prompted a review of methods available for carbapenemase detection. We report on results using two selective media, temocillin discs, CarbaNP test, GeneXpert Carba-R assay and an in-house PCR assay.

Improved blood culture identification by FilmArray in cultures from regional hospitals compared with teaching hospital cultures.

Rapid identification of bacteria isolated from blood cultures by direct matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is now in wide spread use in major centres but is not yet feasible in smaller hospital laboratories. A FilmArray multiplex PCR panel for blood culture isolate identification (BCID) provides an alternative approach to near point-of-care microbial identification in regional hospitals. We assessed the accuracy and time to identification of the BCID FilmArray in a consecutive series of 149 blood cultures from 143 patients in a teaching hospital and smaller regional hospitals, currently identified by direct MALDI-TOF and proprietary molecular methods. The BCID FilmArray contained 18 of 34 species and 20 of 23 species isolated from teaching and regional hospital, respectively. Overall, 85 % of the teaching hospital and 100 % of the regional hospital monomicrobial blood cultures were identified, compared with 60 and 68 %, respectively, for direct MALDI-TOF on the same cultures. There were no incorrect results from blood cultures containing Staphylococcus aureus, streptococci, Pseudomonas aeruginosa or Enterobacteriaceae. The three discrepant results were all in mixed cultures. The mean reduction in time to identification of blood culture isolates was 53 h, which did not include the time required to transport cultures from regional centres to a central laboratory. The overall performance of the BCID FilmArray is stronger in blood cultures from smaller regional hospitals that encounter a narrower range of bacterial species dominated by the commonest species. This approach is more suited to smaller clinical laboratories than the MALDI-TOF direct method.

Pandemic influenza testing at the coalface: time for reassessment?

Australian federal and state governments were advised several years ago that an influenza pandemic would overwhelm Australian public reference laboratories. It was proposed at the time that currently underused capacity in the private sector be used to enhance pandemic responses. The current outbreak of pandemic influenza has confirmed the predictions of advisors from the private sector. Future official pandemic plans should be adjusted to take into account these observations.