Laboratory based antimicrobial resistance surveillance for Pseudomonas aeruginosa blood isolates from South Africa

  • Ashika Singh-Moodley National Institute for Communicable Diseases, Johannesburg, South Africa
  • Adriano Duse University of the Witwatersrand and National Health Laboratory Service, Johannesburg, South Africa
  • Preneshni Naicker University of Cape Town and National Health Laboratory Service, Groote Schuur Hospital, Cape Town, South Africa
  • Ranmini Kularatne University of the Witwatersrand and National Health Laboratory Service, Johannesburg, South Africa
  • Trusha Nana University of the Witwatersrand and National Health Laboratory Service, Johannesburg, South Africa
  • Ruth Lekalakala University of Limpopo and National Health Laboratory Service, Polokwane, South Africa
  • Nontombi Mbelle University of Pretoria and National Health Laboratory Services, Pretoria, South Africa
  • Halima Dawood University of KwaZulu-Natal, South Africa
  • Khine Swe Swe Han University of KwaZulu-Natal, Durban, South Africa
  • Praksha Ramjathan University of KwaZulu-Natal and National Health Laboratory Service, KwaZulu-Natal, South Africa
  • Prathna Bhola University of KwaZulu-Natal Durban, South Africa
  • Andrew Whitelaw Stellenbosch University and National Health Laboratory Service, Tygerberg Hospital, Cape Town, South Africa
  • Olga Perovic National Institute for Communicable Diseases, Johannesburg, South Africa
Keywords: Antimicrobial susceptibility testing, resistance genes, carbapenemases, efflux pumps, porins

Abstract

Introduction: Antimicrobial resistant bacterial infections are widespread globally and increases in antimicrobial resistance presents a major threat to public health. Pseudomonas aeruginosa is an opportunistic healthcare-associated pathogen with high rates of morbidity and mortality and an extensive range of resistance mechanisms. This study describes the antibiotic susceptibility profiles of P. aeruginosa isolates from patients with bacteraemia submitted by sentinel laboratories in South Africa from 2014 to 2015.

Methodology: Organism identification and antimicrobial susceptibility testing were done using automated systems. Molecular methods were used to detect common resistance genes and mechanisms.

Results: Overall the susceptibility was high for all antibiotics tested with a decrease over the two-year period. There was no change in the MIC50 and MIC90 breakpoints for all antibiotics from 2014 to 2015. The MIC50 was within the susceptible breakpoint range for most antibiotics and the MIC90 was within the susceptible breakpoint range for colistin only. Phenotypically carbapenem non-susceptible isolates harboured the following plasmid-mediated genes: blaVIM (n = 81, 12%) and blaGES (n = 6, 0.9%); blaNDM (n = 4, 0.6%) and blaOXA-48 and variants (n = 3, 0.45%). Porin deletions were observed in one meropenem non-susceptible isolate only, and multi-drug resistance efflux pumps were expressed in the majority of the non-susceptible isolates investigated. BlaVEB-1, blaIMP and blaKPC were not detected.

Conclusion: The prevalence of resistance to commonly used antibacterial agents was low for P. aeruginosa isolates and similarly, tested resistance mechanisms were detected in a relatively small proportion of isolates. Findings in this study represent baseline information for understanding antimicrobial susceptibility patterns in P. aeruginosa isolates from blood. Our surveillance report may assist in contributing to hospital treatment guidelines.

Author Biographies

Ashika Singh-Moodley, National Institute for Communicable Diseases, Johannesburg, South Africa

Centre for Healthcare-associated infections, Antimicrobial Resistance and Mycoses

Adriano Duse, University of the Witwatersrand and National Health Laboratory Service, Johannesburg, South Africa

Department of Clinical Microbiology and Infectious Diseases, School of Pathology

Preneshni Naicker, University of Cape Town and National Health Laboratory Service, Groote Schuur Hospital, Cape Town, South Africa

Division of Medical Microbiology, Department of Pathology, Faculty of Health

Olga Perovic, National Institute for Communicable Diseases, Johannesburg, South Africa

Centre for Healthcare-associated infections, Antimicrobial Resistance and Mycoses

Published
2018-08-31
How to Cite
1.
Singh-Moodley A, Duse A, Naicker P, Kularatne R, Nana T, Lekalakala R, Mbelle N, Dawood H, Swe Swe Han K, Ramjathan P, Bhola P, Whitelaw A, Perovic O (2018) Laboratory based antimicrobial resistance surveillance for Pseudomonas aeruginosa blood isolates from South Africa. J Infect Dev Ctries 12:616-624. doi: https://doi.org/10.3855/jidc.9539
Section
Original Articles