TY - JOUR
T1 - Characterisation of key genotypic and phenotypic traits of clinical cystic fibrosis Staphylococcus aureus isolates
AU - Mossop, Micaela
AU - Robinson, Luca
AU - Jiang, Jhih-Hang
AU - Peleg, Anton Y.
AU - Blakeway, Luke V.
AU - Macesic, Nenad
AU - Perry, Audrey
AU - Bourke, Stephen
AU - Ulhuq, Fatima R.
AU - Palmer, Tracy
N1 - Funding information: This study was supported by the Wellcome Trust (through Investigator Awards 10183/Z/15/Z and 224151/Z/21/Z to TP) and by Monash-Newcastle Partnership 2019 Small Project (Seed) Funding. AYP and NM was funded by the Australian National Health and Medical Research Council (NHMRC) Practitioner Fellowship and Investigator Grant. JHJ was supported by the NHMRC Ideas Grant (APP2002921).
PY - 2023/6/8
Y1 - 2023/6/8
N2 - Introduction. One third of people with CF in the UK are co-infected by both Staphylococcus aureus and Pseudomonas aeruginosa . Chronic bacterial infection in CF contributes to the gradual destruction of lung tissue, and eventually respiratory failure in this group. Gap Statement. The contribution of S. aureus to cystic fibrosis (CF) lung decline in the presence or absence of P. aeruginosa is unclear. Defining the molecular and phenotypic characteristics of a range of S. aureus clinical isolates will help further understand its pathogenic capabilities. Aim. Our objective was to use molecular and phenotypic tools to characterise twenty-five clinical S. aureus isolates collected from mono- and coinfection with P. aeruginosa from people with CF at the Royal Victoria Infirmary, Newcastle upon Tyne. Methodology. Genomic DNA was extracted and sequenced. Multilocus sequence typing was used to construct phylogeny from the seven housekeeping genes. A pangenome was calculated using Roary, and cluster of Orthologous groups were assigned using eggNOG-mapper which were used to determine differences within core, accessory, and unique genomes. Characterisation of sequence type, clonal complex, agr and spa types was carried out using PubMLST, eBURST, AgrVATE and spaTyper, respectively. Antibiotic resistance was determined using Kirby-Bauer disc diffusion tests. Phenotypic testing of haemolysis was carried out using ovine red blood cell agar plates and mucoid phenotypes visualised using Congo red agar. Results. Clinical strains clustered closely based on agr type, sequence type and clonal complex. COG analysis revealed statistically significant enrichment of COG families between core, accessory and unique pangenome groups. The unique genome was significantly enriched for replication, recombination and repair, and defence mechanisms. The presence of known virulence genes and toxins were high within this group, and unique genes were identified in 11 strains. Strains which were isolated from the same patient all surpassed average nucleotide identity thresholds, however, differed in phenotypic traits. Antimicrobial resistance to macrolides was significantly higher in the coinfection group. Conclusion. There is huge variation in genetic and phenotypic capabilities of S. aureus strains. Further studies on how these may differ in relation to other species in the CF lung may give insight into inter-species interactions.
AB - Introduction. One third of people with CF in the UK are co-infected by both Staphylococcus aureus and Pseudomonas aeruginosa . Chronic bacterial infection in CF contributes to the gradual destruction of lung tissue, and eventually respiratory failure in this group. Gap Statement. The contribution of S. aureus to cystic fibrosis (CF) lung decline in the presence or absence of P. aeruginosa is unclear. Defining the molecular and phenotypic characteristics of a range of S. aureus clinical isolates will help further understand its pathogenic capabilities. Aim. Our objective was to use molecular and phenotypic tools to characterise twenty-five clinical S. aureus isolates collected from mono- and coinfection with P. aeruginosa from people with CF at the Royal Victoria Infirmary, Newcastle upon Tyne. Methodology. Genomic DNA was extracted and sequenced. Multilocus sequence typing was used to construct phylogeny from the seven housekeeping genes. A pangenome was calculated using Roary, and cluster of Orthologous groups were assigned using eggNOG-mapper which were used to determine differences within core, accessory, and unique genomes. Characterisation of sequence type, clonal complex, agr and spa types was carried out using PubMLST, eBURST, AgrVATE and spaTyper, respectively. Antibiotic resistance was determined using Kirby-Bauer disc diffusion tests. Phenotypic testing of haemolysis was carried out using ovine red blood cell agar plates and mucoid phenotypes visualised using Congo red agar. Results. Clinical strains clustered closely based on agr type, sequence type and clonal complex. COG analysis revealed statistically significant enrichment of COG families between core, accessory and unique pangenome groups. The unique genome was significantly enriched for replication, recombination and repair, and defence mechanisms. The presence of known virulence genes and toxins were high within this group, and unique genes were identified in 11 strains. Strains which were isolated from the same patient all surpassed average nucleotide identity thresholds, however, differed in phenotypic traits. Antimicrobial resistance to macrolides was significantly higher in the coinfection group. Conclusion. There is huge variation in genetic and phenotypic capabilities of S. aureus strains. Further studies on how these may differ in relation to other species in the CF lung may give insight into inter-species interactions.
KW - Microbiology (medical)
KW - General Medicine
KW - Microbiology
U2 - 10.1099/jmm.0.001703
DO - 10.1099/jmm.0.001703
M3 - Article
SN - 0022-2615
VL - 72
JO - Journal of Medical Microbiology
JF - Journal of Medical Microbiology
IS - 6
M1 - 001703
ER -