Browsing by Author "Panzner Ursula"

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    Detection of Salmonella Typhi nucleic acid by RT-PCR and anti-HlyE, -CdtB, -PilL, and -Vi IgM by ELISA at sites in Ghana, Madagascar and Ethiopia
    (BioMed Central, 2022) Panzner Ursula; Mogeni Daniel Ondari; Owusu-Dabo Ellis; Adu‑Sarkodie Yaw; Toy Trevor...et al
    Background: We aimed to assess the prevalence of Salmonella Typhi through DNA and IgM-antibody detection methods as a prelude to extended surveillance activities at sites in Ghana, Madagascar, and Ethiopia. Methods: We performed species-specifc real-time polymerase reaction (RT-PCR) to identify bacterial nucleic acid, and enzyme-linked immunosorbent assay (ELISA) for detecting HlyE/STY1498-, CdtB/STY1886-, pilL/STY4539- and Vi-antigens in blood and biopsy specimens of febrile and non-febrile subjects. We generated antigen-specifc ELISA proxy cut-ofs by change-point analyses, and utilized cumulative sum as detection method coupled with 1000 repeti‑ tive bootstrap analyses. We computed prevalence rates in addition to odds ratios to assess correlations between ELISA outcomes and participant characteristics. Results: Defnitive positive RT-PCR results were obtained from samples of febrile subjects originating from Adama Zuria/Ethiopia (1.9%, 2/104), Wolayita Sodo/Ethiopia (1.0%, 1/100), Diego/Madagascar (1.0%, 1/100), and Kintampo/ Ghana (1.0%, 1/100), and from samples of non-febrile subjects from Wolayita Sodo/Ethiopia (1%, 2/201). While IgM antibodies against all antigens were identifed across all sites, prevalence rates were highest at all Ethiopian sites, albeit in non-febrile populations. Signifcant correlations in febrile subjects aged<15 years versus≥15 years were detected for Vi (Odds Ratio (OR): 8.00, p=0.034) in Adama Zuria/Ethiopia, STY1498 (OR: 3.21, p=0.008), STY1886 (OR: 2.31, p=0.054) and STY4539 (OR: 2.82, p=0.022) in Diego/Madagascar, and STY1498 (OR: 2.45, p=0.034) in Kintampo/Ghana. We found statistical signifcance in non-febrile male versus female subjects for STY1498 (OR: 1.96, p=0.020) in Adama Zuria/Ethiopia, Vi (OR: 2.84, p=0.048) in Diego/Madagascar, and STY4539 (OR: 0.46, p=0.009) in Kintampo/Ghana. Conclusions: Findings indicate non-discriminatory stages of acute infections, though with site-specifc diferences. Immune responses among non-febrile, presumably healthy participants may mask recall and/or reporting bias leading to misclassifcation, or asymptomatic, subclinical infection signs induced by suppression of infammatory
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    he genomic epidemiology of multi drug resistant invasive non-typhoidal Salmonella in selected sub-Saharan African countries
    (BMJ GLOBAL HEALTH, 2021) Park Eun Se; Panzner Ursula; Adu-Sarkodie Yaw; Owusu-Dabo Ellis; Soura Bassiahi Abdramane....et al
    Background Invasive non-typhoidal Salmonella (iNTS) is one of the leading causes of bacteraemia in sub-Saharan Africa. We aimed to provide a better understanding of the genetic characteristics and transmission patterns associated with multi-drug resistant (MDR) iNTS serovars across the continent. Methods A total of 166 iNTS isolates collected from a multi-centre surveillance in 10 African countries (2010–2014) and a fever study in Ghana (2007–2009) were genome sequenced to investigate the geographical distribution, antimicrobial genetic determinants and population structure of iNTS serotypes–genotypes. Phylogenetic analyses were conducted in the context of the existing genomic frameworks for various iNTS serovars. Population-based incidence of MDR-iNTS disease was estimated in each study site. Results Salmonella Typhimurium sequence-type (ST) 313 and Salmonella Enteritidis ST11 were predominant, and both exhibited high frequencies of MDR; Salmonella Dublin ST10 was identified in West Africa only. Mutations in the gyrA gene (fluoroquinolone resistance) were identified in S. Enteritidis and S. Typhimurium in Ghana; an ST313 isolate carrying blaCTX-M-15 was found in Kenya. International transmission of MDR ST313 (lineage II) and MDR ST11 (West African clade) was observed between Ghana and neighbouring West African countries. The incidence of MDR-iNTS disease exceeded 100/100 000 person-years-of-observation in children aged <5 years in several West African countries