APHL RFP: Validation of the MALDI-TOF for the Identification of Neisseria gonorrhoeae
Indiana State Department of Health Proposal
1. Please describe the laboratory’s current MALDI-TOF testing practices including pathogens
detected.
The Indiana State Department of Health Laboratory (ISDHL) obtained a Bruker Biotyper MALDI-
TOF MS in 2013 and converted to the CA system in July 2016. Validation of the MALDI-TOF MS
began in 2014, with validation of the Enterobacteriaceae. Since 2014, many other organisms have
been validated for use on the MALDI including Salmonella spp., Streptococcus, Staphylococcus,
Listeria spp., Mycobacteria, Haemophilus, Neisseria, and Legionella; with validations currently
underway to include Vibrio spp., Trueperella bernardiae, Corynebacterium spp., Clostridium
perfringens, Bacillus spp., and Achromobacter spp. The MALDI is utilized by the Bacteriology,
Mycology, Enterics, TB/Mycobacterial, and Food Microbiology laboratories and testing is performed
daily. Two analysts have been using the MALDI since initial validations began in 2014. Nine
additional analysts are trained in the methodology and range in experience from 6 months to two
years. Analysts have undergone training both in house and by Bruker representatives.
2. Please describe the laboratory’s experience in testing N. gonorrhoeae including methodologies.
The ISDHL has been testing Neisseria gonorhoeae for 20+ years receiving between one and six
isolates annually. Currently, the ISDHL utilizes MALDI-TOF MS and traditional biochemical tests for
Neisseria identification. MALDI-TOF MS identification of Neisseria gonorhoeae was validated in mid-
2016. MALDI-TOF MS testing is performed daily on bacterial isolates received at ISDHL, with
Neisseria isolates tested as they are received. For isolates which are unable to be identified by
standard methods, 16S sequencing is available, and has been used for the identification of bacteria APHL RFP: Validation of the MALDI-TOF for the Identification of Neisseria gonorrhoeae
Indiana State Department of Health Proposal
since early 2014. Biochemical identification has been performed for 20+ years and three analysts are
trained in the methodology with experience ranging from 4 to 10 years. Three analysts are currently
competent in 16S sequencing with experience ranging from 1 to 5 years. On average, 16S
sequencing is performed twice a week. All training for the testing of Neisseria gonorhoeae, including
MALDI-TOF MS, biochemical identification, and 16S sequencing, is performed in house.
3. Please describe the current methodologies for testing non-gonococcal Neisseria species.
The ISDHL has been testing for non-gonococcal Neisseria species for 20+ years receiving
between five and ten isolates annually. Similar to Neisseria gonorrhoeae, the ISDHL utilizes MALDI-
TOF MS, 16s sequencing, and traditional biochemical tests for the identification of non-gonococcal
Neisseria species. Algorithms, workflows, and personal are the same for gonococcal and non-
gonoccal Neisseria isolate identification. Isolates submitted as a suspected Neisseria meningitidis are
processed in a biosafety cabinet to mitigate the biosafety risk. Additionally, analysts are given the
option to become vaccinated against Neisseria meningitidis. This includes both the meningococcal
conjugate vaccine (Menactra) and the Serogroup B meningococcal vaccine (Trumenba).
4. Please describe the current collection of non-gonococcal Neisseria species.
The ISDHL non-gonococcal Neisseria collection consists of approximately 600 isolates; the majority of which are Neisseria meningitidis (n=508). Other Neisseria species present in the collection include, N. lactima, N. elongata, N. mucosa, N. sicca, N. subflava, N. weaveri, N. cinerea, N. perflava, and N. flavascens. The ISDHL collection also contains three Moraxella catarrhalis isolates and six Kingella denitrificans isolates. All isolates are stored at -70oC, see attachment for list of organisms. Organism name number of isolates in freezer Moraxella catarrhalis 3 N. meningitidis 508 N. gonhorrhoeae 71 N. lactima 6 N. elongata 7 N. mucosa 6 N. sicca 15 N. subflava 11 N. weaveri 10 Neisseria species most-like N.cinerea 9 NEISSERIA SP (MOST LIKELY N. SUBFLAVA) 7 NEISSERIA SPECIES MOST LIKE N. ZOODEGMATIS 1 Neisseria species. Most-like N. meningitidis 2 K. denitrificans 6 Neisseria sp most like N. elongata 1 Neisseria flava 1 N. flavascens 2 N. sp most like flavascens 1 N. perflava 1 N. elongata-flava 2 Neisseria species total 670