A conserved active site PenA β-lactamase Ambler motif specific for Burkholderia pseudomallei/B. mallei is likely responsible for intrinsic amoxicillin-clavulanic acid sensitivity and facilitates a simple diagnostic PCR assay for melioidosis

Nawarat Somprasong; Johannah P Hagen; Jason W Sahl; Jessica R Webb; Carina M Hall; Bart J Currie; David M Wagner; Paul Keim; Herbert P Schweizer

doi:10.1016/j.ijantimicag.2023.106714

A conserved active site PenA β-lactamase Ambler motif specific for Burkholderia pseudomallei/B. mallei is likely responsible for intrinsic amoxicillin-clavulanic acid sensitivity and facilitates a simple diagnostic PCR assay for melioidosis

Int J Antimicrob Agents. 2023 Mar;61(3):106714. doi: 10.1016/j.ijantimicag.2023.106714. Epub 2023 Jan 12.

Authors

Nawarat Somprasong¹, Johannah P Hagen¹, Jason W Sahl², Jessica R Webb³, Carina M Hall¹, Bart J Currie⁴, David M Wagner², Paul Keim², Herbert P Schweizer⁵

Affiliations

¹ The Pathogen and Microbiome Institute, Northern Arizona University, 1395 S Knoles Dr. Flagstaff, AZ 86001-4073, USA.
² The Pathogen and Microbiome Institute, Northern Arizona University, 1395 S Knoles Dr. Flagstaff, AZ 86001-4073, USA; Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona, USA.
³ Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Northern Territory, Australia; Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, Australia.
⁴ Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Northern Territory, Australia; Department of Infectious Diseases and Northern Territory Medical Programme, Royal Darwin Hospital, Darwin, Northern Territory, Australia.
⁵ The Pathogen and Microbiome Institute, Northern Arizona University, 1395 S Knoles Dr. Flagstaff, AZ 86001-4073, USA; Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona, USA. Electronic address: herbert.schweizer@nau.edu.

PMID: 36640845
DOI: 10.1016/j.ijantimicag.2023.106714

Abstract

Burkholderia pseudomallei is a soil- and water-dwelling Gram-negative bacterium that causes melioidosis in humans and animals. Amoxicillin-clavulanic acid (AMC) susceptibility has been hailed as an integral part of the screening algorithm for identification of B. pseudomallei, but the molecular basis for the inherent AMC susceptibility of this bacterium remains undefined. This study showed that B. pseudomallei (and the closely-related B. mallei) wild-type strains are the only Burkholderia spp. that contain a ⁷⁰STSK⁷³ PenA Ambler motif. This motif was present in >99.5% of 1820 analysed B. pseudomallei strains and 100% of 83 analysed B. mallei strains, and is proposed as the likely cause for their inherent AMC sensitivity. The authors developed a polymerase chain reaction (PCR) assay that specifically amplifies the penA⁷⁰ST(S/F)K⁷³-containing region from B. pseudomallei and B. mallei, but not from the remaining B. pseudomallei complex species or the ⁷⁰STFK⁷³ region from the closely-related penB of B. cepacia complex species. The abundance and purity of the 193-bp PCR fragment from putative B. pseudomallei isolates from clinical and environmental samples is likely sufficient for reliable confirmation of the presence of B. pseudomallei. The PCR assay is designed to be especially suited for use in resource-constrained areas. While not further explored in this study, the assay may allow diagnosis of putative B. mallei in culture isolates from animal and human samples.

Keywords: Amoxicillin-clavulanic acid; Burkholderia pseudomallei; Class A β-lactamase; Diagnostic PCR; Susceptibility.

MeSH terms

Amoxicillin-Potassium Clavulanate Combination / pharmacology
Animals
Burkholderia mallei* / genetics
Burkholderia pseudomallei* / genetics
Catalytic Domain
Humans
Melioidosis* / diagnosis
Melioidosis* / microbiology
Polymerase Chain Reaction
beta-Lactamases

Substances

Amoxicillin-Potassium Clavulanate Combination
beta-Lactamases