Programmpunkt

13:45

Titel: Rapid Sepsityper®: from identification to susceptibility testing 
ID: 13/DKMV
Art: Abstractautor
Session: Workshop 03
Diagnostic Microbiology (StAG DV)

Referent: Miriam Cordovana (Bologna/IT)


Abstract - Text

Question

Sepsis is a syndrome burdened worldwide by high morbidityand mortality. Survival rate in case of not appropriate antibiotic treatment significantly decreases hour by hour, hence the rapid identification of the causative agent is crucial for the patients" outcome.

The Rapid Sepsityper® (Bruker Daltonik) allows bacterial identification by MALDI-TOF MS directly from positive blood culture bottles in 10-15 minutes. It represents a shortened version of the conventional protocol, i.e.  MALDI identification directly from the bacterial pellet by direct spotting (without ethanol/formic acid extraction).

In this study, we evaluated the implementation of the Rapid Sepsityper into the routine practice , and the possibility to use the samebacterial pellet to carry out susceptibility testing (RUO method), in order to shorten the time to report.

 

Methods

From 12/05/2018 to 31/08/2018, the routine identification of positive blood cultures was performed by Rapid Sepsityper for n=1546 samples (corresponding to n=1165 bacteriaemic patients).

Result of MALDI identification was compared in primis with result of Gram staining, and then with the result of the plate subculture.

For n=769 samples, antibiotic susceptibility testing (Microscan Walkaway, Beckman, Colistrip, Merlin, disc-diffusion for ceftazidime/avibactam, Liofilchem) was performed using the same bacterial pellet as for species identification.

 

Results

Reliable identification at species level was obtained in 1293/1480 (87.4%) of monomicrobial samples, and in 26/66 (39.4%) of polymicrobial samples. Failed identifications were restricted in most of cases to coagulase-negative staphylococci, corynebacteria, viridans streptococci and yeasts.

For polymicrobial samples, in 21% of cases both bacteria were identified, in 18.4% one was identified.

For 722/769 (93.8%) samples, susceptibility testing using the pellet was successful,  for n=47 (6.1%) it was repeated, as bacterial growth was insufficient (mainly coagulase-negative staphylococci).

 

Conclusions

Implementation of the Rapid Sepsityper into routine showed a very good efficiency, greater than 95% for the bacterial families of major clinical relevance, such as Gram-negative bacilli, S. aureus, enterococci and haemolytic streptococci.

The bacterial pellet obtained by the Rapid Sepsityper could be suitable to perform antibiotic susceptibility testing, enabling simplification of  the routine workflow, andshorten the reporting time.