Identification of Non-fermenters by Matrix Assisted Laser Desorption/Ionisation-Time of Flight Mass Spectrometry- Case Series of Achromobacter Infections

摘要

Achromobacter is a non-fermenting Gram Negative Bacillus (GNB) belonging to the family Alcaligenaceae. It is emerging asa pathogen, causing myriad of infections in different patient groups. Often wrongly identified by conventional microbiologicaltechniques, Achromobacter when recovered from clinical specimens have often been discarded as contaminants. Accuratespecies identification of the currently known 21 species of Achromobacter, is difficult, labour-intensive and time-consuming.Automation has made it possible to reliably and correctly identify Achromobacter species and other non-fermenters. MatrixAssisted Laser Desorption Ionisation-Time Of Flight-Mass Spectrometry (MALDI-TOF-MS) is a boon as it rapidly and accuratelyidentifies Achromobacter species in clinical specimens. Three cases of Achromobacter infection, highlighting the pathogenicpotential of the bacteria and the role of automation in its identification are presented with due consent from relatives or patientthemselves. This case series highlights that Achromobacter when recovered from clinical specimens should not be discarded ascontaminants especially if isolated repeatedly. Case 1 was a patient who had developed pyelonephritis and sepsis, associatedwith bacteraemia and ended fatally, Achromobacter was recovered on two occasions from the blood culture. Case 2 was apatient who was diagnosed of acute pancreatitis with an infected peripancreatic collection who recovered with prolonged therapy,Achromobacter was repeatedly isolated from the pus draining from the peripancreatic collection. Case 3 was a patient with aninfected malignant ulcer with purulent discharge from the swelling. In all three cases Achromobacter was isolated and identifiedby MALDI-TOF-MS.