Jürgen May

Publications (108) View all

• Chapter: Infectious Disease Control in Ghana: Government's Interventions and Challenges to Malaria Eradication

  Julius N. Fobil, Juergen May, Alexander Kraemer
  10/2011: pages 211 - 216; , ISBN: 9781118148594
• Article: Fluorescence in situ hybridization (FISH) for rapid identification of Salmonella spp. from agar and blood culture broth-An option for the tropics?

  Hagen Frickmann, Andrea Hänle, Andreas Essig, Denise Dekker, Kennedy Boahen, Samuel Acquah, Nimako Sarpong, Yaw Adu-Sarkodie, Norbert G Schwarz, Jürgen May, Florian Marks, Ralf M Hagen, Sven Poppert
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  ABSTRACT: BACKGROUND: Salmonella enterica is an important cause of diarrhea with the potential to cause systemic infection including sepsis, particularly in the tropics. Sepsis in particular requires quick and reliable identification to allow a rapid optimization of antibiotic therapy. We describe the establishment and evaluation of fluorescence in situ hybridization (FISH) as a rapid and easy-to-perform molecular identification procedure from agar and blood culture broths. METHODS: Two newly developed FISH probes with specificity for Salmonella spp. were evaluated with 10 reference strains, 448 clinical isolates of Gram-negative bacteria from Germany and Ghana including 316 Salmonella spp. strains, and 39 environmental Salmonella spp. isolates from rivers and streams in Ghana. One FISH probe was further tested with 207 pre-incubated blood culture broths from Germany with Gram-negative rod-shaped bacteria in Gram stain. RESULTS: Evaluation of the newly designed FISH probes demonstrated sensitivity of 99.2% and specificity of 98.4% for clinical isolates, sensitivity of 97.4% for environmental Salmonella spp. isolates, and sensitivity of 100% and specificity of 99.5% for blood culture materials. CONCLUSIONS: FISH proved to be highly reliable for a rapid identification of Salmonella spp. directly from pre-incubated blood culture broths as well as after growth on agar. The inexpensive and easy-to-perform procedure is particularly suitable for resource-limited areas where more sophisticated procedures are not available.
  International journal of medical microbiology: IJMM 04/2013; · 2.80 Impact Factor
• Article: Increased detection of invasive enteropathogenic bacteria in pre-incubated blood culture materials by real-time PCR in comparison with automated incubation in Sub-Saharan Africa.

  Hagen Frickmann, Denise Dekker, Kennedy Boahen, Samuel Acquah, Nimako Sarpong, Yaw Adu-Sarkodie, Norbert G Schwarz, Jürgen May, Florian Marks, Sven Poppert, Dorothea F Wiemer, Ralf M Hagen
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  ABSTRACT: Background: Invasive enteropathogenic bacteria can cause systemic infections. Data from studies with PCR detection suggest, at least for Salmonella enterica, that blood culture may lead to underestimation in the tropics. Corresponding data are lacking for other invasive enteropathogenic bacteria. We compared classical blood culture and molecular methods for the diagnosis of blood infections. Methods: A real-time multiplex PCR for Salmonella spp., Shigella spp./entero- invasive Escherichia coli (EIEC), Yersinia spp., and Campylobacter jejuni was applied to 2321 retained blood culture samples from Ghanaian patients, after enrichment by automated culture. Results: PCR detected Salmonella DNA in 56 out of 58 pre-incubated Ghanaian blood cultures with growth of S. enterica. In 2 samples molecular diagnosis was only possible after 1:10 dilution. Twenty-two samples negative by blood culture and 1 positive with Micrococcus spp. were PCR-positive for Salmonella spp. In addition, 3 Shigella spp./EIEC, 2 Yersinia spp., and 1 C. jejuni were detected by PCR but not by culture growth. Conclusions: Real-time PCR was more sensitive in identifying invasive enteropathogenic bacteria than automated blood culture, which is hampered by a lack of evidence-based standardization of pre-analytic conditions in the tropics. Primary agar culture and Gram-staining prior to automated blood culture is advisable in cases where transportation times are long.
  Scandinavian Journal of Infectious Diseases 04/2013; · 1.72 Impact Factor
• Article: Genome-wide association study indicates two novel resistance loci for severe malaria.

  Christian Timmann, Thorsten Thye, Maren Vens, Jennifer Evans, Jürgen May, Christa Ehmen, Jürgen Sievertsen, Birgit Muntau, Gerd Ruge, Wibke Loag, [......], Alex Osei Yaw Akoto, Justice Sylverken, Michael Brendel, Kathrin Schuldt, Christina Loley, Andre Franke, Christian G Meyer, Tsiri Agbenyega, Andreas Ziegler, Rolf D Horstmann
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  ABSTRACT: Malaria causes approximately one million fatalities per year, mostly among African children. Although highlighted by the strong protective effect of the sickle-cell trait, the full impact of human genetics on resistance to the disease remains largely unexplored. Genome-wide association (GWA) studies are designed to unravel relevant genetic variants comprehensively; however, in malaria, as in other infectious diseases, these studies have been only partly successful. Here we identify two previously unknown loci associated with severe falciparum malaria in patients and controls from Ghana, West Africa. We applied the GWA approach to the diverse clinical syndromes of severe falciparum malaria, thereby targeting human genetic variants influencing any step in the complex pathogenesis of the disease. One of the loci was identified on chromosome 1q32 within the ATP2B4 gene, which encodes the main calcium pump of erythrocytes, the host cells of the pathogenic stage of malaria parasites. The second was indicated by an intergenic single nucleotide polymorphism on chromosome 16q22.2, possibly linked to a neighbouring gene encoding the tight-junction protein MARVELD3. The protein is expressed on endothelial cells and might therefore have a role in microvascular damage caused by endothelial adherence of parasitized erythrocytes. We also confirmed previous reports on protective effects of the sickle-cell trait and blood group O. Our findings underline the potential of the GWA approach to provide candidates for the development of control measures against infectious diseases in humans.
  Nature 08/2012; 489(7416):443-6. · 36.28 Impact Factor
• Article: Incidence and Characteristics of Bacteremia among Children in Rural Ghana.

  Maja Verena Nielsen, Nimako Sarpong, Ralf Krumkamp, Denise Dekker, Wibke Loag, Solomon Amemasor, Alex Agyekum, Florian Marks, Frank Huenger, Anne Caroline Krefis, Ralf Matthias Hagen, Yaw Adu-Sarkodie, Jürgen May, Norbert Georg Schwarz
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  ABSTRACT: The objective of the study was to describe systemic bacterial infections occurring in acutely ill and hospitalized children in a rural region in Ghana, regarding frequency, incidence, antimicrobial susceptibility patterns and associations with anthropometrical data.Blood cultures were performed in all children below the age of five years, who were admitted to Agogo Presbyterian Hospital (APH), Asante Region, Ghana, between September 2007 and July 2009. Medical history and anthropometrical data were assessed using a standardized questionnaire at admission. Incidences were calculated after considering the coverage population adjusted for village-dependent health-seeking behavior.Among 1,196 hospitalized children, 19.9% (n = 238) were blood culture positive. The four most frequent isolated pathogens were nontyphoidal salmonellae (NTS) (53.3%; n = 129), Staphylococcus aureus (13.2%; n = 32), Streptococcus pneumoniae (9.1%; n = 22) and Salmonella ser. Typhi (7.0%; n = 17). Yearly cumulative incidence of bacteremia was 46.6 cases/1,000 (CI 40.9-52.2). Yearly cumulative incidences per 1,000 of the four most frequent isolates were 25.2 (CI 21.1-29.4) for NTS, 6.3 (CI 4.1-8.4) for S. aureus, 4.3 (CI 2.5-6.1) for S. pneumoniae and 3.3 (CI 1.8-4.9) for Salmonella ser. Typhi. Wasting was positively associated with bacteremia and systemic NTS bloodstream infection. Children older than three months had more often NTS bacteremia than younger children. Ninety-eight percent of NTS and 100% of Salmonella ser. Typhi isolates were susceptible to ciprofloxacin, whereas both tested 100% susceptible to ceftriaxone. Seventy-seven percent of NTS and 65% of Salmonella ser. Typhi isolates were multi-drug resistant (MDR). Systemic bacterial infections in nearly 20% of hospitalized children underline the need for microbiological diagnostics, to guide targeted antimicrobial treatment and prevention of bacteremia. If microbiological diagnostics are lacking, calculated antimicrobial treatment of severely ill children in malaria-endemic areas should be considered.
  PLoS ONE 01/2012; 7(9):e44063. · 4.09 Impact Factor