hosted by
publicationslist.org
    
Ralf M Hagen
Bernhard-Nocht-Institute for Tropical Medicine
Bernhard-Nocht-Str 74
D-20359 Hamburg
Germany
hagen@bni-hamburg.de

Journal articles

2007
 
DOI   
PMID 
Andreas Krueger, Ralf M Hagen (2007)  Short communication: first record of Aedes albopictus in Gabon, Central Africa.   Trop Med Int Health 12: 9. 1105-1107 Sep  
Abstract: The Asian tiger mosquito Aedes albopictus is an important arbovirus vector. Originating in East Asia, the species has been introduced to the Americas, the Indo-Pacific and Australasian regions as well as Europe and Africa, mostly during the past 30 years and probably by transportation in used tires. We report Ae. albopictus for the first time from Gabon (Libreville). In addition, the yellow fever mosquito Ae. aegypti ssp. formosus and 16 other culicid species were detected throughout the city, four of which are also new records for Gabon.
Notes:
2006
 
DOI   
PMID 
Herbert Tomaso, Carsten Bartling, Sascha Al Dahouk, Ralf M Hagen, Holger C Scholz, Wolfgang Beyer, Heinrich Neubauer (2006)  Growth characteristics of Bacillus anthracis compared to other Bacillus spp. on the selective nutrient media Anthrax Blood Agar and Cereus Ident Agar.   Syst Appl Microbiol 29: 1. 24-28 Jan  
Abstract: Anthrax Blood Agar (ABA) and Cereus Ident Agar (CEI) were evaluated as selective growth media for the isolation of Bacillus anthracis using 92 B. anthracis and 132 other Bacillus strains from 30 species. The positive predictive values for the identification of B. anthracis on ABA, CEI, and the combination of both were 72%, 71%, and 90%, respectively. Thus, less than 10% of all species were misidentified using both nutrient media. Species which might be misidentified as B. anthracis were B. cereus, B. mycoides, and B. thuringiensis. Particularly, 30% of B. weihenstephanensis strains were misidentified as B. anthracis.
Notes:
 
DOI   
PMID 
Holger C Scholz, Marina Joseph, Herbert Tomaso, Sascha Al Dahouk, Angela Witte, Joerg Kinne, Ralph M Hagen, Renate Wernery, Ulrich Wernery, Heinrich Neubauer (2006)  Detection of the reemerging agent Burkholderia mallei in a recent outbreak of glanders in the United Arab Emirates by a newly developed fliP-based polymerase chain reaction assay.   Diagn Microbiol Infect Dis 54: 4. 241-247 Apr  
Abstract: A polymerase chain reaction (PCR) assay targeting the flagellin P (fliP)-I S407A genomic region of Burkholderia mallei was developed for the specific detection of this organism in pure cultures and clinical samples from a recent outbreak of equine glanders. Primers deduced from the known fliP-IS407A sequence of B. mallei American Type Culture Collection (ATCC) 23344(T) allowed the specific amplification of a 989-bp fragment from each of the 20 B. mallei strains investigated, whereas other closely related organisms tested negative. The detection limit of the assay was 10 fg for purified DNA of B. mallei ATCC 23344(T). B. mallei DNA was also amplified from various tissues of horses with a generalized B. mallei infection. The developed PCR assay can be used as a simple and rapid tool for the specific and sensitive detection of B. mallei in clinical samples.
Notes:
 
PMID 
M B Wittig, P Wohlsein, R M Hagen, S Al Dahouk, H Tomaso, H C Scholz, K Nikolaou, R Wernery, U Wernery, J Kinne, M Elschner, H Neubauer (2006)  Glanders--a comprehensive review   Dtsch Tierarztl Wochenschr 113: 9. 323-330 Sep  
Abstract: Since 1990 the number of glanders outbreaks in race, military and pleasure horses in Asia and South America is steadily increasing. Glanders, which is eradicated in Western Europe, Australia and Northern America, is currently considered a re-emerging disease. Consequently, the disease may be introduced into glanders-free regions by subclinical carriers at any time. The causative agent of glanders, Burkholderia (B.) mallei, is highly contagious and leads to chronic disease in horses whereas in donkeys and mules the disease is acute and often fatal. Occurrence of the disease leads to international trading restrictions and infected animals immediately have to be culled and safely disposed off. In humans B. mallei infection results in a severe clinical course, and is fatal without appropriate therapy. Its pathogenicity makes B. mallei a potential biological agent that may be used in bioterroristic attacks. Due to the eradication of glanders in the second half of the last century, veterinarians in western European countries are no longer familiar with its clinical presentation in solipeds. Having these facts in mind, this review describes the epidemiology, clinical signs, pathology and the current eradication strategy of this interesting zoonosis. Pictures of imported endurance horses infected with glanders taken during an eradication campaign in Dubai, United Arab Emirates, in 2004 illustrate most typical clinical findings.
Notes:
 
PMID 
Sascha Al Dahouk, Thomas Schneider, Andreas Jansen, Karsten Nöckler, Herbert Tomaso, Ralf M Hagen, Holger C Scholz, Martin Rudwaleit, Heinrich Neubauer, Andreas J Morguet (2006)  Brucella endocarditis in prosthetic valves.   Can J Cardiol 22: 11. 971-974 Sep  
Abstract: Human brucellosis is a multiple organ disease that presents with fever and is most often transmitted via contaminated, unpasteurized goat milk and cheese. In chronic cases, focal complications (eg, spondylitis, neurobrucellosis and endocarditis) are frequently seen. Although the disease may be severely debilitating, the mortality rate is low. Fatal cases are often due to endocarditis. Because Brucella endocarditis is a rare complication (2% to 5%), therapeutic considerations are based on single-case experiences only. Therapy includes long-term antibiotic treatment using combinations of various antimicrobial drugs and surgical valve replacement when required. A case of Brucella endocarditis complicated by the infection of two valvular prostheses implanted after involvement of the mitral and aortic valve due to rheumatic fever is described. The patient was successfully treated by a medical and surgical approach. Therapeutic strategies in Brucella endocarditis are discussed in light of the current literature.
Notes:
2005
 
DOI   
PMID 
Andreas Jansen, Ralf M Hagen, Wolfgang Schmidt, Ralf Ignatius, Alejandra Perez-Canto, Martin Zeitz, Thomas Schneider (2005)  Pulmonary melioidosis associated with bronchiolitis obliterans organizing pneumonia.   J Infect 50: 1. 68-71 Jan  
Abstract: We report a case of pulmonary melioidosis associated bronchiolitis obliterans with organizing pneumonia (BOOP). While antibiotic treatment alone did not show any major effect, addition of corticosteroids resulted in rapid clinical improvement. To our knowledge this is the first documented case of melioidosis associated with organising pneumonia. The possible therapeutic implications for the treatment of severe pulmonary melioidosis are discussed.
Notes:
 
DOI   
PMID 
S Al Dahouk, K Nöckler, A Hensel, H Tomaso, H C Scholz, R M Hagen, H Neubauer (2005)  Human brucellosis in a nonendemic country: a report from Germany, 2002 and 2003.   Eur J Clin Microbiol Infect Dis 24: 7. 450-456 Jul  
Abstract: Human brucellosis has become a rare disease in Germany since the eradication of bovine and ovine/caprine brucellosis in this country. Therefore, most physicians are unfamiliar with the illnesses clinical presentation, diagnostic tools, and therapeutic strategies. This retrospective study was carried out to evaluate the epidemiological, clinical, and laboratory features of human brucellosis in Germany in the years 2002 and 2003. Thirty-one bacterial isolates from 30 patients sent to the German national reference laboratory were characterized using the genus-specific bcsp31 real-time PCR, the species-specific AMOS-PCR, and standard microbiological methods for the detection and identification of Brucella spp. The medical records of all patients with bacteriologically confirmed brucellosis were evaluated. All 31 isolates proved to be Brucella (30 Brucella melitensis and 1 Brucella suis). Most of the brucellosis patients were infected in endemic countries while visiting friends and relatives during their summer holidays. One case of laboratory-acquired infection was identified. Brucellosis was transmitted mainly by the consumption of contaminated unpasteurized milk or cheese from goats and sheep. The patients presented primarily with flu-like symptoms, i.e. fever, chills, sweating, headaches, arthralgia, and myalgia. In most cases, however, symptoms and signs of focal complications, e.g. spondylitis, endocarditis, and meningoencephalitis, predominated. The rate of complications was much higher than that in endemic countries, presumably as a result of diagnostic delay due to a low index of suspicion. In summary, physicians in nonendemic countries such as Germany must be aware of brucellosis being a possible cause of fever of unknown origin in immigrants and tourists travelling from endemic countries.
Notes:
 
DOI   
PMID 
Sascha Al Dahouk, Ralf M Hagen, Karsten Nockler, Herbert Tomaso, Martina Wittig, Holger C Scholz, Gilles Vergnaud, Heinrich Neubauer (2005)  Failure of a short-term antibiotic therapy for human brucellosis using ciprofloxacin. A study on in vitro susceptibility of Brucella strains.   Chemotherapy 51: 6. 352-356 Oct  
Abstract: BACKGROUND: Human brucellosis is characterized byfocal complications, chronic courses, and therapeutic failures. METHODS: In a relapsed case of brucellosis after short-term antibiotic therapy using doxycycline and ciprofloxacin two Brucella strains were isolated, before and after treatment.In vitro susceptibilities of both isolates were determined by E tests including a great variety of antibiotics. In a killing rate experiment the bactericidal activities of doxycycline, streptomycin, rifampin and ciprofloxacin as single agents and in combinations were determined. RESULTS: Lowest MIC values were measured for doxycycline and ciprofloxacin. MICs did not change under therapy. Streptomycin alone exhibited the most effective killing within 6 h, whereas the other single agents did not show bactericidal activity. Doxycycline plus ciprofloxacin was the most active combination in vitro. CONCLUSION: Routine susceptibility testing of Brucellae is not obligatory as most of the 'traditional' anti-Brucella antibiotics are active in vitro and bactericidal efficacy may differ in vivo.
Notes:
 
PMID 
Chantal Bottex, Yves P Gauthier, Ralf M Hagen, Ernst J Finke, Wolf D Splettstösser, François M Thibault, Heinrich Neubauer, Dominique R Vidal (2005)  Attempted passive prophylaxis with a monoclonal anti-Burkholderia pseudomallei exopolysaccharide antibody in a murine model of melioidosis.   Immunopharmacol Immunotoxicol 27: 4. 565-583  
Abstract: Melioidosis is a severe gram-negative infection caused by the facultative intracellular bacterium Burkholderia pseudomallei, which is responsible for a broad spectrum of symptoms in both humans and animals. No licensed vaccine currently exists. This study evaluated the protective effect of a monoclonal antibody (Mab Ps6F6) specific to B. pseudomallei exopolysaccharide in an outbred murine model of sub-acute melioidosis. When administered before the infectious challenge, Ps6F6 significantly increased resistance to infection and restrained bacterial burden in the spleen over a 30-days period. Patterns of IFN-gamma production were similar in the treated and non treated groups of mice. However, Ps6F6 lowered IFN-gamma levels over the duration of the assay period, except on day 1, suggesting a transient and rapid production of IFN-gamma under Ps6F6 control. Minor but persisting increases occurred in IL-12 levels while TNF-alpha was detected only in the controls at the later stages of infection. No IL-10 secretion was detected in both groups of mice. These data suggest that passive prophylaxis with Mab Ps6F6 provide a moderate and transient induction of inflammatory responses in infected mice but failed to trigger a sterilizing protective immunity.
Notes:
 
PMID 
Ralf M Hagen, Irene Seegmüller, Jila Navai, Ines Kappstein, Norbert Lehn, Thomas Miethke (2005)  Development of a real-time PCR assay for rapid identification of methicillin-resistant Staphylococcus aureus from clinical samples.   Int J Med Microbiol 295: 2. 77-86 Jun  
Abstract: A major drawback of mecA PCR to detect methicillin-resistant Staphylococcus aureus (MRSA) directly from patient materials is the high frequency of methicillin-resistant coagulase-negative staphylococci. Therefore, a reliable detection method for MRSA from clinical samples using real-time PCR was developed. The PCR assay targeting the integration site (orfX) of the staphylococcal cassette chromosome mec (SCCmec) was evaluated in MRSA SCCmec reference strains (n = 9), MRSA ST strains (n = 16) and clinical isolates of MRSA (n = 124), MSSA (n = 53), methicillin-resistant coagulase-negative staphylococci (n = 47), and methicillin-susceptible, coagulase-negative staphylococci (n = 32). The diagnostic values of the assay were 98% sensitivity and 100% specificity. Furthermore, the PCR detection method was evaluated with 60 swabs from different body sites which were incubated overnight in brain-heart infusion. The PCR gave positive results for 27 of 29 swabs which were found to contain MRSA by conventional methods. The diagnostic values of the PCR assay for these samples were 93% sensitivity and 100% specificity. To determine the in vitro sensitivity of the assay, swabs were inoculated with serially diluted bacterial suspensions. After overnight enrichment the detection limit of the PCR was less than 10 CFU/swab. This new real-time PCR assay proved to be a fast, sensitive and specific tool for MRSA detection in a routine microbiological laboratory.
Notes:
2002
 
PMID 
R M Hagen, Y P Gauthier, L D Sprague, D R Vidal, G Zysk, E - J Finke, H Neubauer (2002)  Strategies for PCR based detection of Burkholderia pseudomallei DNA in paraffin wax embedded tissues.   Mol Pathol 55: 6. 398-400 Dec  
Abstract: Recently, several cases of melioidosis imported to Europe have been reported. The diagnosis of the acute or chronic infection remains challenging. This report describes an optimised protocol for fast and reliable DNA preparation for use in two different polymerase chain reaction (PCR) assays, namely: (1) a seminested PCR assay targeting a genus specific sequence of the ribosomal protein subunit 21 (rpsU) gene and (2) a nested PCR assay targeting the gene encoding the filament forming flagellin (fliC). Various strains of Burkholderia spp, strains of closely related genera, and spleen tissue samples of experimentally infected mice were investigated. The combination of PCR and sequencing of the amplicons resulted in high sensitivity and specificity. These procedures may allow rapid, sensitive, and reliable detection of B pseudomallei DNA in routinely formalin fixed and paraffin wax embedded samples, thus providing a safe diagnostic tool and avoiding the cultivation of a risk group 3 agent. In addition, this method could be useful for retrospective histopathological investigations.
Notes:
 
PMID 
Lisa D Sprague, Gregor Zysk, Ralf M Hagen, Hermann Meyer, Jill Ellis, Narisara Anuntagool, Yves Gauthier, Heinrich Neubauer (2002)  A possible pitfall in the identification of Burkholderia mallei using molecular identification systems based on the sequence of the flagellin fliC gene.   FEMS Immunol Med Microbiol 34: 3. 231-236 Nov  
Abstract: Amotile Burkholderia mallei and motile Burkholderia pseudomallei display a high similarity with regard to phenotype and clinical syndromes, glanders and melioidosis. The aim of this study was to establish a fast and reliable molecular method for identification and differentiation. Despite amotility, the gene of the filament forming flagellin (fliC) could be completely sequenced in two B. mallei strains. Only one mutation was identified discriminating between B. mallei and B. pseudomallei. A polymerase chain reaction-restriction fragment length polymorphism assay was designed making use of the absence of an AvaII recognition site in B. mallei. All seven B. mallei, 12 out of 15 B. pseudomallei and 36 closely related apathogenic Burkholderia thailandensis strains were identified correctly. However, in three B. pseudomallei strains a point mutation at gene position 798 (G to C) disrupted the AvaII site. Therefore, molecular systems based on the fliC sequence can be used for a reliable proof of strains of the three species but not for the differentiation of B. mallei and B. pseudomallei isolates.
Notes:
2001
 
PMID 
T Arnold, A Hensel, R Hagen, S Aleksic, H Neubauer, H C Scholz (2001)  A highly specific one-step PCR - assay for the rapid discrimination of enteropathogenic Yersinia enterocolitica from pathogenic Yersinia pseudotuberculosis and Yersinia pestis.   Syst Appl Microbiol 24: 2. 285-289 Jul  
Abstract: Based on differences within the yopT-coding region of Yersinia. enterocolitica, Y pseudotuberculosis and Y pestis, a rapid and sensitive one-step polymerase chain reaction assay with high specificity for pathogenic Y enterocolitica was developed. By this method pathogenic isolates of Y enterocolitica can be easily identified and discriminated from other members of this genus. The entire coding sequence of the yopT effector gene of Y. pseudotuberculosis Y36 was determined.
Notes:
 
PMID 
Y P Gauthier, R M Hagen, G S Brochier, H Neubauer, W D Splettstoesser, E J Finke, D R Vidal (2001)  Study on the pathophysiology of experimental Burkholderia pseudomallei infection in mice.   FEMS Immunol Med Microbiol 30: 1. 53-63 Feb  
Abstract: Burkholderia pseudomallei is the etiological agent of melioidosis, a potentially fatal disease occurring in man and animals. The aim of this study was to investigate the pathophysiological course of experimental melioidosis, and to identify the target organs, in an animal model. For this purpose SWISS mice were infected intraperitoneally with the virulent strain B. pseudomallei 6068. The bacterial load of various organs was quantified daily by bacteriological analysis and by an enzyme-linked immunosorbent assay (ELISA) based on a monoclonal antibody specific to B. pseudomallei exopolysaccharide (EPS). Electron microscopic investigation of the spleen was performed to locate the bacteria at the cellular level. In this model of acute melioidosis, B. pseudomallei had a marked organ tropism for liver and spleen, and showed evidence of in vivo growth with a bacterial burden of 1.6x10(9) colony forming units (CFU) per gram of spleen 5 days after infection with 200 CFU. The highest bacterial loads were detected in the spleen at all time points, in a range from 2x10(6) to 2x10(9) CFU g(-1). They were still 50-80 times greater than the load of the liver at the time of peak burden. Other investigated organs such as lungs, kidneys, and bone marrow were 10(2)-10(4)-fold less infected than the spleen, with loads ranging from 3x10(2) to 3x10(6) CFU g(-1). The heart and the brain were sites of a delayed infection, with counts in a range from 10(3) to 10(7) times lower than bacterial counts in the spleen. The EPS-specific ELISA proved to be highly sensitive, particularly at the level of those tissues in which colony counting on agar revealed low contamination. In the blood, EPS was detected at concentrations corresponding to bacterial loads ranging from 8x10(3) to 6x10(4) CFU ml(-1). Electron microscopic examination of the spleen revealed figures of phagocytosis, and the presence of large numbers of intact bacteria, which occurred either as single cells or densely packed into vacuoles. Sparse figures suggesting bacterial replication were also observed. In addition, some bacteria could be seen in vacuoles that seemed to have lost their membrane. These observations provide a basis for further investigations on the pathogenesis of the disease.
Notes:
Powered by publicationslist.org.