Molecular and culture-based diagnosis of Clostridium difficile isolates from Côte d'Ivoire after prolonged storage at disrupted cold chain conditions.
BACKGROUND
Although Clostridium difficile is a major cause of diarrhoea, its epidemiology in tropical settings is poorly understood. Strain characterisation requires work-up in specialised laboratories, often after prolonged storage without properly maintained cold chain.


METHODS
We screened 298 human faecal samples from Côte d'Ivoire using a rapid test for C. difficile glutamate dehydrogenase (GDH). GDH-positive samples were aerobically stored at disrupted cold chain conditions (mean duration: 11 days) before transfer to a reference laboratory for anaerobic culture, susceptibility testing, PCR assays and ribotyping.


RESULTS
Sixteen samples (5.4%) had a positive GDH screening test. C. difficile infection was confirmed in six specimens by culture and PCR, while no nucleic acids of C. difficile were detected in the culture-negative samples. Further analysis of stool samples harbouring toxigenic C. difficile strains confirmed that both GDH and toxins remained detectable for at least 28 days, regardless of storage conditions (aerobic storage at 4°C or 20°C).


CONCLUSIONS
Storage conditions only minimally affect recovery of C. difficile and its toxins in stool culture. A rapid GDH screening test and subsequent transfer of GDH-positive stool samples to reference laboratories for in-depth characterisation may improve our understanding of the epidemiology of C. difficile in the tropics.
Institute of Medical Microbiology and Hygiene, Saarland University, Kirrberger Straße, Building 43, D-66421 Homburg/Saar, Germany Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, P.O. Box, CH-4002 Basel, Switzerland University of Basel, P.O. Box, CH-4003 Basel, Switzerland soeren.becker@uks.eu.
Sören L
SL
Becker
Département de Médecine Interne, Hôpital Méthodiste de Dabou, Dabou, Côte d'Ivoire.
Justin K
JK
Chatigre
Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, P.O. Box, CH-4002 Basel, Switzerland University of Basel, P.O. Box, CH-4003 Basel, Switzerland Unité de Formation et de Recherche Biosciences, Université Félix Houphouët-Boigny, 02 BP 770, Abidjan 02, Côte d'Ivoire Centre Suisse de Recherches Scientifiques en Côte d'Ivoire, 01 BP 1303, Abidjan 01, Côte d'Ivoire.
Jean T
JT
Coulibaly
Coris BioConcept, Rue Jean Sonet 4A, B-5032 Gembloux, Belgium.
Pascal
P
Mertens
Centre Suisse de Recherches Scientifiques en Côte d'Ivoire, 01 BP 1303, Abidjan 01, Côte d'Ivoire.
Bassirou
B
Bonfoh
Institute of Medical Microbiology and Hygiene, Saarland University, Kirrberger Straße, Building 43, D-66421 Homburg/Saar, Germany.
Mathias
M
Herrmann
Department of Medical Microbiology, Leiden University Medical Center, Albinusdreef 2, NL-2333 Leiden, The Netherlands.
Ed J
EJ
Kuijper
Unité de Formation et de Recherche Biosciences, Université Félix Houphouët-Boigny, 02 BP 770, Abidjan 02, Côte d'Ivoire Centre Suisse de Recherches Scientifiques en Côte d'Ivoire, 01 BP 1303, Abidjan 01, Côte d'Ivoire.
Eliézer K
EK
N'Goran
Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, P.O. Box, CH-4002 Basel, Switzerland University of Basel, P.O. Box, CH-4003 Basel, Switzerland.
Jürg
J
Utzinger
Institute of Medical Microbiology and Hygiene, Saarland University, Kirrberger Straße, Building 43, D-66421 Homburg/Saar, Germany soeren.becker@uks.eu.
Lutz
L
von Müller
D000465:Algorithms; D016022:Case-Control Studies; D016360:Clostridioides difficile / Q000201:enzymology / Q000302:isolation & purification*; D003015:Clostridium Infections / Q000175:diagnosis* / Q000201:enzymology / Q000453:epidemiology; D007560:Cote d'Ivoire / Q000453:epidemiology; D005243:Feces / Q000382:microbiology; D005838:Genotype; D005969:Glutamate Dehydrogenase / Q000032:analysis; D006801:Humans; D007124:Immunoenzyme Techniques; D010641:Phenotype; D016133:Polymerase Chain Reaction; D012034:Refrigeration; D021521:Ribotyping
D005969:Glutamate Dehydrogenase
Côte d'Ivoire; Diagnosis; Diarrhoea; Polymerase chain reaction; Rapid diagnostic test; Storage conditions