Dissertation defence (Medical Microbiology): MSc Erastus Haindongo
Time
27.9.2024 at 12.00 - 16.00
MSc Erastus Haindongo defends the dissertation in Medical Microbiology titled “Surveillance of Antimicrobial Resistant bacteria in Africa and Namibia” at the University of Turku on 27 September 2024 at 12.00 (University of Turku, ARCANUM, Aava auditorium, Arcanuminkuja 1, 20500, Turku).
Opponent: Professor Gunnar Skov Simonsen (The Arctic University of Norway, Norway)
Custos: Docent Antti Hakanen (University of Turku)
Doctoral Dissertation at UTUPub: https://urn.fi/URN:ISBN:978-951-29-9866-1
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Summary of the Doctoral Dissertation:
This thesis, conducted under the Cotutelle agreement jointly by the University of Turku and the University of Namibia, highlights the concerning antimicrobial resistance (AMR) situation for clinically important bacterial pathogens both in the World Health Organization (WHO) African region as well as in Namibia.
Sub-Saharan Africa faces a growing AMR threat. Antimicrobial resistant bacterial organisms pose a serious problem to human infection treatment, particularly urinary tract infections and bloodstream infections. Due to inadequate surveillance systems, information gaps on AMR prevalence in Africa including Namibia exist.
First, in order to gain an understanding of the AMR prevalence and trends of common bacteremic pathogens, namely Escherichia coli and Staphylococcus aureus in the WHO Africa region a systematic review on previous publications on this topic was conducted. Only a quarter of countries had reported AMR data. The analysis also indicated a concerning degree of resistance rates of extended spectrum-ß-lactamase-producing (ESBL) E.coli and methicillin-resistant S.aureus (MRSA) pathogens, thus hindering the efficacy of clinically important antibiotics.
In addition, two large nationwide retrospective laboratory-based AMR analysis in Namibia were conducted. Here we focused in addition to bacteremic isolates also on isolates from female urinary infections. Antibiotic susceptibility testing (AST) was performed using disk diffusion and Vitek 2 according to the CLSI guidelines.
Amongst Namibian female urinary infection isolates, estimated ESBL-bacterial isolate prevalence was 22% based on cefotaxime resistance. Nitrofurantoin resistance was low in non-ESBL isolates but increased in ESBL isolates (12.9% to 19%), with one region reaching 59% resistance. Thus, nitrofurantoin remains a useful empirical antimicrobial for female urinary tract E.coli infections, although regional variations necessitate enhanced surveillance.
Analysis of the blood culture AST results showed that the E. coli resistance was: piperacillin-tazobactam (8%), cefotaxime (32%), ciprofloxacin (29%), gentamicin (18%) and co-trimoxazole (79%). S. aureus showed 18.8% oxacillin-resistance with low resistance (10%) to clindamycin, gentamicin and rifampin and none to teicoplanin. The resistance findings on Namibian clinical bacterial isolates underscore the importance of AST-guided therapy.
Opponent: Professor Gunnar Skov Simonsen (The Arctic University of Norway, Norway)
Custos: Docent Antti Hakanen (University of Turku)
Doctoral Dissertation at UTUPub: https://urn.fi/URN:ISBN:978-951-29-9866-1
***
Summary of the Doctoral Dissertation:
This thesis, conducted under the Cotutelle agreement jointly by the University of Turku and the University of Namibia, highlights the concerning antimicrobial resistance (AMR) situation for clinically important bacterial pathogens both in the World Health Organization (WHO) African region as well as in Namibia.
Sub-Saharan Africa faces a growing AMR threat. Antimicrobial resistant bacterial organisms pose a serious problem to human infection treatment, particularly urinary tract infections and bloodstream infections. Due to inadequate surveillance systems, information gaps on AMR prevalence in Africa including Namibia exist.
First, in order to gain an understanding of the AMR prevalence and trends of common bacteremic pathogens, namely Escherichia coli and Staphylococcus aureus in the WHO Africa region a systematic review on previous publications on this topic was conducted. Only a quarter of countries had reported AMR data. The analysis also indicated a concerning degree of resistance rates of extended spectrum-ß-lactamase-producing (ESBL) E.coli and methicillin-resistant S.aureus (MRSA) pathogens, thus hindering the efficacy of clinically important antibiotics.
In addition, two large nationwide retrospective laboratory-based AMR analysis in Namibia were conducted. Here we focused in addition to bacteremic isolates also on isolates from female urinary infections. Antibiotic susceptibility testing (AST) was performed using disk diffusion and Vitek 2 according to the CLSI guidelines.
Amongst Namibian female urinary infection isolates, estimated ESBL-bacterial isolate prevalence was 22% based on cefotaxime resistance. Nitrofurantoin resistance was low in non-ESBL isolates but increased in ESBL isolates (12.9% to 19%), with one region reaching 59% resistance. Thus, nitrofurantoin remains a useful empirical antimicrobial for female urinary tract E.coli infections, although regional variations necessitate enhanced surveillance.
Analysis of the blood culture AST results showed that the E. coli resistance was: piperacillin-tazobactam (8%), cefotaxime (32%), ciprofloxacin (29%), gentamicin (18%) and co-trimoxazole (79%). S. aureus showed 18.8% oxacillin-resistance with low resistance (10%) to clindamycin, gentamicin and rifampin and none to teicoplanin. The resistance findings on Namibian clinical bacterial isolates underscore the importance of AST-guided therapy.
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