title: Antimicrobial resistance of Campylobacter isolates from small scale and backyard chicken in Kenya.
abstract: BACKGROUND
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.
authors: Hung Vuong University, Phu Tho, Vietnam ; Friedrich-Loeffler-Institut, Institute of Bacterial Infections and Zoonoses, Jena, Germany ; Institute of Poultry Diseases, Free University Berlin, Berlin, Germany.
authors: Tuan Ngoc Minh
authors: TN
authors: Nguyen
authors: Friedrich-Loeffler-Institut, Institute of Bacterial Infections and Zoonoses, Jena, Germany.
authors: Helmut
authors: H
authors: Hotzel
authors: Friedrich-Loeffler-Institut, Institute of Bacterial Infections and Zoonoses, Jena, Germany ; Centre for Microbiology Research (CMR), Kenya Medical Research Institute, Nairobi, Kenya.
authors: John
authors: J
authors: Njeru
authors: Centre for Microbiology Research (CMR), Kenya Medical Research Institute, Nairobi, Kenya.
authors: Joyce
authors: J
authors: Mwituria
authors: Friedrich-Loeffler-Institut, Institute of Bacterial Infections and Zoonoses, Jena, Germany ; Department of Poultry Diseases, Faculty of Veterinary Medicine, Kafrelsheikh University, Kafrelsheikh, Egypt.
authors: Hosny
authors: H
authors: El-Adawy
authors: Friedrich-Loeffler-Institut, Institute of Bacterial Infections and Zoonoses, Jena, Germany.
authors: Herbert
authors: H
authors: Tomaso
authors: Friedrich-Loeffler-Institut, Institute of Bacterial Infections and Zoonoses, Jena, Germany.
authors: Heinrich
authors: H
authors: Neubauer
authors: Institute of Poultry Diseases, Free University Berlin, Berlin, Germany.
authors: Hafez M
authors: HM
authors: Hafez
keywords: Antibiotic resistance; Campylobacter; Chicken; Kenya; Microdilution