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The New Zealand National Antimicrobial Susceptibility Testing Committee (NZ NAC) was formed in late 2017 to provide expert advice to New Zealand diagnostic laboratories and to further the collaboration and sharing of skill development in the area of antimicrobial susceptibility testing within New Zealand.


    (as of October 2018)

Josh Freeman

Clinical Microbiologist

NZ NAC Chair, Canterbury Health Laboratories

Michael Addidle

Clinical Microbiologist

Pathlab, ESR

Michelle Balm

Clinical Microbiologist, ID Physician

Wellington SCL

Julie Creighton

Senior Scientist

NZ NAC Deputy Chair, Canterbury Health   Laboratories

Jan Deroles-Main

Charge Scientist

MedLab Central (Palmerston North)

Dragana Drinkovic

Clincal Microbiologist

North Shore Hospital

Kristin Dyet

Scientist, AMR Reference Lab


Juliet Elvy

Clinical Microbiologist

MedLab Nelson-Marlborough, Wellington   SCL

Sean Munroe

Technical specialist – microbiology

Waikato Hospital

Murray Robinson

HD Microbiology and Molecular Biology

Pathlab (Tauranga)

Susan Taylor

Clinical Microbiologist

Middlemore Hospital

Koen van der Werff

HD Microbiology and Molecular Biology

Wellington SCL

Sarah Underwood

NZMN Administrator




  NZ NAC documents

Minimum laboratory requirements for the detection of carbapenemase-producing Enterobacteriaceae from clinical samples and screening specimens  [PDF, 1.1 MB]

This document provides a minimum requirement for the laboratory detection of CPE in New Zealand with the aim of ensuring that laboratories take a consistent approach to screening high-risk patients for CPE.  Details are given so that laboratories can identify when confirmatory testing, referral of CPE isolates, and notification to clinical and infection prevention teams is required.  


  NZ NAC study reports

Colistin antimicrobial susceptibility testing study [PDF, 428 KB]

EUCAST have issued a warning regarding the poor performance of disc diffusion, MIC gradient strips and automated systems for reliably detecting colistin resistance in Gram-negative bacilli. The issues include the poor diffusion of colistin molecules into the agar, drug powder composition and heteroresistance. The discovery of a readily transferable, plasmid-mediated gene, mcr-1, has further complicated detection of resistance. As such, EUCAST currently recommends broth microdilution (BMD) as the only valid method to determine colistin susceptibility. The NZ NAC group conducted a small study to evaluate a variety of commercial methods for the detection of colistin resistance, including Liofilchem colistin MIC Test Strips, BD Phoenix NMIC-404, Rapid Polymyxin NP, Liofilchem SensiTest Colistin BMD, and Trek Sensititre EURGNCOL BMD.


Haemophilus influenzae antimicrobial susceptibility testing study [PDF, 530 KB]

Several laboratories have indicated an increase of β-lactamase-negative ampicillin-resistant (BLNAR) H. influenzae, after switching from CLSI to EUCAST. A recent study looking at 100 H. influenzae clinical isolates; measuring penicillin, ampicillin and cefuroxime disc zone sizes, as well as ampicillin MICs, using EUCAST guidelines has been carried out. Analysis of ftsI gene mutations (PBP3 substitutions) was also performed. The study found an excellent correlation between the EUCAST recommended screening method of penicillin 1 unit disc and ftsI gene mutations, predominantly affecting cephalosporins rather than ampicillin.  


NZ NAC newsletters

Newsletter 1 - October 2018 [PDF, 418 KB]


National Carbapenemase Producing Enterobacterales (CPE) Antibiogram

2016-2017 CPE isolates


Antibiograms from diagnostic laboratories in NZ


Combined CCDHB,HVDHB,WDHB hospitals antibiogram 2016 [PDF, 286 KB]

Nelson Marlborough hospital and community antibiogram 2016 [PDF, 401 KB]

Pathlab (BOP all, and Waikato community) antibiogram 2016 (external link)

LabPLUS antibiotic susceptibility reports (external link)



Antimicrobial Reference Laboratory reference and confirmatory testing services: Specialist Testing | ESR (external link)

ESR antimicrobial resistance surveillance reports: Antimicrobial Resistance Surveillance Reports (external link)   

Australian National AST Committee (external link)

EUCAST (external link)


  Contact Us

All communications and enquiries to the NZ NAC should be through the NZ NAC administrator, Sarah Underwood