Helmut Hotzel

Dr. Helmut Hotzel


Research Focus & Metrics

Academic Career Length

25Years (2002-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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16 December 2016 in PLOS ONE
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Journal Article
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SMStefan Monecke
Stefan Monecke
DGDolores Gavier-Widén
Dolores Gavier-Widén
HHHelmut Hotzel
Helmut Hotzel
MPMartin Peters
Martin Peters
SGSebastian Guenther
Sebastian Guenther
RERalf Ehricht
Ralf Ehricht
Staphylococcus aureus is a well-known colonizer and cause of infection among animals and it has been described from numerous domestic and wild animal species. The aim of the present study was to investigate the molecular epidemiology of S. aureus in a convenience sample of European wildlife and to review what previously has been observed in the subject field. 124 S. aureus isolates were collected from wildlife in Germany, Austria and Sweden; they were characterized by DNA microarray hybridization and, for isolates with novel hybridization patterns, by multilocus sequence typing (MLST). The isolates were assigned to 29 clonal complexes and singleton sequence types (CC1, CC5, CC6, CC7, CC8, CC9, CC12, CC15, CC22, CC25, CC30, CC49, CC59, CC88, CC97, CC130, CC133, CC398, ST425, CC599, CC692, CC707, ST890, CC1956, ST2425, CC2671, ST2691, CC2767 and ST2963), some of which (ST2425, ST2691, ST2963) were not described previously. Resistance rates in wildlife strains were rather low and mecA-MRSA isolates were rare (n = 6). mecC-MRSA (n = 8) were identified from a fox, a fallow deer, hares and hedgehogs. The common cattle-associated lineages CC479 and CC705 were not detected in wildlife in the present study while, in contrast, a third common cattle lineage, CC97, was found to be common among cervids. No Staphylococcus argenteus or Staphylococcus schweitzeri-like isolates were found. Systematic studies are required to monitor the possible transmission of human- and livestock-associated S. aureus/MRSA to wildlife and vice versa as well as the possible transmission, by unprotected contact to animals. The prevalence of S. aureus/MRSA in wildlife as well as its population structures in different wildlife host species warrants further investigation.

18 October 2017 in Gut Pathogens
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Amira Awad MoawadAmira Awad Moawad
Amira Awad Moawad
HHHelmut Hotzel
Helmut Hotzel
OAOmnia Awad
Omnia Awad
HTHerbert Tomaso
Herbert Tomaso
HNHeinrich Neubauer
Heinrich Neubauer
Hosny El-AdawyHosny El-Adawy
Hosny El-Adawy
The global incidence of foodborne infections and antibiotic resistance is recently increased and considered of public health concern. Currently, scarcely information is available on foodborne infections and ESBL associated with poultry and beef meat in Egypt. In total, 180 chicken and beef meat samples as well as internal organs were collected from different districts in northern Egypt. The samples were investigated for the prevalence and antibiotic resistance of Salmonella enterica serovars and Escherichia coli. All isolates were investigated for harbouring class 1 and class 2 integrons. Out of 180 investigated samples 15 S. enterica (8.3%) and 21 E. coli (11.7%) were isolated and identified. S. enterica isolates were typed as 9 S. Typhimurium (60.0%), 3 S. Paratyphi A (20.0%), 2 S. Enteritidis (13.3%) and 1 S. Kentucky (6.7%). Twenty-one E. coli isolates were serotyped into O1, O18, O20, O78, O103, O119, O126, O145, O146 and O158. The phenotypic antibiotic resistance profiles of S. enterica serovars to ampicillin, cefotaxime, cefpodoxime, trimethoprim/sulphamethoxazole and tetracycline were 86.7, 80.0, 60.0, 53.3 and 40.0%, respectively. Isolated E. coli were resistant to tetracycline (80.9%), ampicillin (71.4%), streptomycin, trimethoprim/sulphamethoxazole (61.9% for each) and cefotaxime (33.3%). The dissemination of genes coding for ESBL and AmpC β-lactamase in S. enterica isolates included bla CTX-M (73.3%), bla TEM (73.3%) and bla CMY (13.3%). In E. coli isolates bla TEM, bla CTX-M and bla OXA were identified in 52.4, 42.9 and 14.3%, respectively. The plasmid-mediated quinolone resistance genes identified in S. enterica were qnrA (33.3%), qnrB (20.0%) and qnrS (6.7%) while qnrA and qnrB were detected in 33.3% of E. coli isolates. Class 1 integron was detected in 13.3% of S. enterica and in 14.3% of E. coli isolates. Class 2 integron as well as the colistin resistance gene mcr-1 was not found in any of E. coli or S. enterica isolates. This study showed high prevalence of S. enterica and E. coli as foodborne pathogens in raw chicken and beef meat in Nile Delta, Egypt. The emergence of antimicrobial resistance in S. enterica and E. coli isolates is of public health concern in Egypt. Molecular biological investigation elucidated the presence of genes associated with antibiotic resistance as well as class 1 integron in S. enterica and E. coli.

19 September 2018 in Gut Pathogens
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Journal Article
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Amira Awad MoawadAmira Awad Moawad
Amira Awad Moawad
HHHelmut Hotzel
Helmut Hotzel
HNHeinrich Neubauer
Heinrich Neubauer
RERalf Ehricht
Ralf Ehricht
SMStefan Monecke
Stefan Monecke
Hosny El-AdawyHosny El-Adawy
Hosny El-Adawy
Poultry remains one of the most important reservoir for zoonotic multidrug resistant pathogens. The global rise of antimicrobial resistance in Gram-negative bacteria is of reasonable concern and demands intensified surveillance. In 2016, 576 cloacal swabs were collected from 48 broiler farms located in five governorates in northern Egypt. Isolates of Enterobacteriaceae could be cultivated on different media and were identified by MALDI-TOF MS and PCR. Escherichia coli isolates were genotyped by DNA-microarray-based assays. The antimicrobial susceptibility to 14 antibiotics was determined and resistance-associated genes were detected. The VITEK-2 system was applied for phenotypical confirmation of extended-spectrum β-lactamase-producing isolates. The determination of colistin resistance was carried out phenotypically using E-test and genotypically using PCR for detection of the mcr-1 gene. Out of 576 samples, 72 representatives of Enterobacteriaceae were isolated and identified as 63 E. coli (87.5%), 5 Enterobacter cloacae (6.9%), 2 Klebsiella pneumoniae (2.8%) and 2 Citrobacter spp. (2.8%). Seven out of 56 cultivated E. coli (12.5%) were confirmed as ESBL-producing E. coli and one isolate (1.8%) as ESBL/carbapenemase-producing E. coli. Five out of 63 E. coli isolates (7.9%) recovered from different poultry flocks were phenotypically resistant to colistin and harboured mcr-1 gene. This is the first study reporting colistin resistance and emergence of multidrug resistance in Enterobacteriaceae isolated from healthy broilers in the Nile Delta region, Egypt. Colistin-resistant E. coli in poultry is of public health significance. The global rise of ESBL- and carbapenemase-producing Gram-negative bacteria demands intensified surveillance. ESBL-producing E. coli in poultry farms in Egypt are of major concern that emphasizes the possibility of spread of such strains to humans. The results also reinforce the need to develop strategies and to implement specific control procedures to reduce the use of antibiotics.

8 November 2017 in Nature Communications
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GIGregorio Iraola
Gregorio Iraola
SFSamuel Forster
Samuel Forster
NKNitin Kumar
Nitin Kumar
PLPhilippe Lehours
Philippe Lehours
SBSadjia Bekal
Sadjia Bekal
TLTrevor D. Lawley
Trevor D. Lawley
Campylobacter fetus is a venereal pathogen of cattle and sheep, and an opportunistic human pathogen. It is often assumed that C. fetus infection occurs in humans as a zoonosis through food chain transmission. Here we show that mammalian C. fetus consists of distinct evolutionary lineages, primarily associated with either human or bovine hosts. We use whole-genome phylogenetics on 182 strains from 17 countries to provide evidence that C. fetus may have originated in humans around 10,500 years ago and may have “jumped” into cattle during the livestock domestication period. We detect C. fetus genomes in 8% of healthy human fecal metagenomes, where the human-associated lineages are the dominant type (78%). Thus, our work suggests that C. fetus is an unappreciated human intestinal pathobiont likely spread by human to human transmission. This genome-based evolutionary framework will facilitate C. fetus epidemiology research and the development of improved molecular diagnostics and prevention schemes for this neglected pathogen.

27 August 2016 in Gut Pathogens
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Journal Article
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TNTuan Ngoc Minh Nguyen
Tuan Ngoc Minh Nguyen
HHHelmut Hotzel
Helmut Hotzel
JNJohn Njeru
John Njeru
JMJoyce Mwituria
Joyce Mwituria
Hosny El-AdawyHosny El-Adawy
Hosny El-Adawy
HHHafez Mohamed Hafez
Hafez Mohamed Hafez
Thermophilic Campylobacter species are a major cause of bacterial foodborne diarrhoea in humans worldwide. Poultry and their products are the predominant source for human campylobacteriosis. Resistance of Campylobacter to antibiotics is increasing worldwide, but little is known about the antibiotic resistance in Campylobacter isolated from chicken in Kenya. In this study, 35 suspected Campylobacter strains isolated from faeces and cloacal swabs of chicken were tested for their susceptibility to seven antibiotics using a broth microdilution assay and molecular biological investigations. Overall, DNA of thermophilic Campylobacter was identified in 53 samples by PCR (34 C. jejuni, 18 C. coli and one mix of both species) but only 35 Campylobacter isolates (31 C. jejuni and 4 C. coli) could be re-cultivated after transportation to Germany. Isolates were tested for their susceptibility to antibiotics using a broth microdilution assay. Additionally, molecular biological detection of antibiotic resistance genes was carried out. C. jejuni isolates showed a high rate of resistance to nalidixic acid, tetracycline and ciprofloxacin of 77.4, 71.0 and 71.0 %, respectively. Low resistance (25.8 %) was detected for gentamicin and chloramphenicol. Multidrug resistance in C. jejuni could be detected in 19 (61.3 %) isolates. Resistance pattern of C. coli isolates was comparable. Resistance to ciprofloxacin was confirmed by MAMA–PCR and PCR–RFLP in all phenotypically resistant isolates. The tet(O) gene was detected only in 54.5 % of tetracycline resistant C. jejuni isolates. The tet(A) gene, which is also responsible for tetracycline resistance, was found in 90.3 % of C. jejuni and in all C. coli isolates. Thirteen phenotypically erythromycin-resistant isolates could not be characterised by using PCR–RFLP and MAMA–PCR. To the best of our knowledge, this study is the first report about resistance to antibiotics in thermophilic Campylobacter originating from chicken in Kenya. Campylobacter spp. show a high level of resistance to ciprofloxacin, nalidixic acid and tetracycline but also a remarkable one to chloramphenicol and gentamicin and they are multidrug resistant. Resistance to antibiotics is a global public health concern. In Kenya, resistance surveillance needs further attention in the future. Efforts to establish at least a National Laboratory with facilities for performing phenotypic and genotypic characterization of thermophilic Campylobacter is highly recommended.

1 April 2018 in Veterinary Microbiology
Verified
Journal Article
Closed access
SMStefan Monecke
Stefan Monecke
PSPeter Slickers
Peter Slickers
DGDarius Gawlik
Darius Gawlik
EMElke Müller
Elke Müller
ARAnnett Reissig
Annett Reissig
RERalf Ehricht
Ralf Ehricht