Molecular diagnostics of Salmonella and Campylobacter in human/animal fecal samples remain feasible after long-term sample storage without specific requirements
Rapid advances in the development of sequencing technologies, numbers of commercial providers and diminishing costs have made DNA-based identification and diagnostics increasingly accessible to doctors and laboratories, eliminating the need for local investments in expensive technology and training...
| Main Authors: | , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
AIMS Press
2021-10-01
|
| Series: | AIMS Microbiology |
| Subjects: | |
| Online Access: | https://www.aimspress.com/article/doi/10.3934/microbiol.2021024?viewType=HTML |
| _version_ | 1819002876882583552 |
|---|---|
| author | CB Harder S Persson J Christensen A Ljubic EM Nielsen J Hoorfar |
| author_facet | CB Harder S Persson J Christensen A Ljubic EM Nielsen J Hoorfar |
| author_sort | CB Harder |
| collection | DOAJ |
| description | Rapid advances in the development of sequencing technologies, numbers of commercial providers and diminishing costs have made DNA-based identification and diagnostics increasingly accessible to doctors and laboratories, eliminating the need for local investments in expensive technology and training or hiring of skilled technicians. However, reliable and comparable molecular analyses of bacteria in stool samples are dependent on storage and workflow conditions that do not introduce post-sampling bias, the most important factor being the need to keep the DNA at a stable detectable level. For that reason, there may remain other prohibitively costly requirements for cooling or freezing equipment or special chemical additives.
This study investigates the diagnostic detectability of <i>Salmonella</i> and <i>Campylobacter</i> DNA in human, pig and chicken stool samples, stored at different temperatures and with different preservation methods. Stool samples were spiked with 10<sup>6</sup> CFU/mL of both <i>Salmonella</i> and <i>Campylobacter</i> strains stored at −20 °C, 5 °C and 20 °C (Room temperature, RT) and treated with either RNAlater, EDTA or Silica/ethanol. DNA was extracted at 9 different time points within 30 days and quantified by Qubit (total DNA) and qPCR (<i>Salmonella</i> and <i>Campylobacter</i> DNA). We found no statistically significant differences among the different preservation methods, and DNA from both species was easily detected at all time points and at all temperatures, both with and without preservation. This suggests that infections by these bacteria can be diagnosed and possibly also analysed in further detail simply by taking a stool sample in any suitable sealed container that can be transported to laboratory analysis without special storage or preservation requirements. We briefly discuss how this finding can benefit infection control in both developed and developing countries. |
| first_indexed | 2024-12-20T23:12:05Z |
| format | Article |
| id | doaj.art-35a2c51eaaad4dceb26c3488b48a83c6 |
| institution | Directory Open Access Journal |
| issn | 2471-1888 |
| language | English |
| last_indexed | 2024-12-20T23:12:05Z |
| publishDate | 2021-10-01 |
| publisher | AIMS Press |
| record_format | Article |
| series | AIMS Microbiology |
| spelling | doaj.art-35a2c51eaaad4dceb26c3488b48a83c62022-12-21T19:23:42ZengAIMS PressAIMS Microbiology2471-18882021-10-017439941410.3934/microbiol.2021024Molecular diagnostics of Salmonella and Campylobacter in human/animal fecal samples remain feasible after long-term sample storage without specific requirementsCB Harder0S Persson1J Christensen 2A Ljubic3EM Nielsen4J Hoorfar51. Statens Serum institut, Dept. Bacteriology, Parasitology and Fungi, Artillerivej 5, 2300 Copenhagen, Denmark 2. Molecular Ecology, Microbial Ecology and Evolutionary Genetics, Lund University, Sölvegatan 37, 223 62 Lund1. Statens Serum institut, Dept. Bacteriology, Parasitology and Fungi, Artillerivej 5, 2300 Copenhagen, Denmark3. Danish Veterinary and Food Administration, Microbiological department, Søndervang 4, 4100 Ringsted4. AGC Biologics, Process Transfer, Vandtårnsvej 83, 2860 Søborg, Denmark1. Statens Serum institut, Dept. Bacteriology, Parasitology and Fungi, Artillerivej 5, 2300 Copenhagen, Denmark5. Technical University of Denmark, National Food Institute, 2800 Kgs. Lyngby, DenmarkRapid advances in the development of sequencing technologies, numbers of commercial providers and diminishing costs have made DNA-based identification and diagnostics increasingly accessible to doctors and laboratories, eliminating the need for local investments in expensive technology and training or hiring of skilled technicians. However, reliable and comparable molecular analyses of bacteria in stool samples are dependent on storage and workflow conditions that do not introduce post-sampling bias, the most important factor being the need to keep the DNA at a stable detectable level. For that reason, there may remain other prohibitively costly requirements for cooling or freezing equipment or special chemical additives. This study investigates the diagnostic detectability of <i>Salmonella</i> and <i>Campylobacter</i> DNA in human, pig and chicken stool samples, stored at different temperatures and with different preservation methods. Stool samples were spiked with 10<sup>6</sup> CFU/mL of both <i>Salmonella</i> and <i>Campylobacter</i> strains stored at −20 °C, 5 °C and 20 °C (Room temperature, RT) and treated with either RNAlater, EDTA or Silica/ethanol. DNA was extracted at 9 different time points within 30 days and quantified by Qubit (total DNA) and qPCR (<i>Salmonella</i> and <i>Campylobacter</i> DNA). We found no statistically significant differences among the different preservation methods, and DNA from both species was easily detected at all time points and at all temperatures, both with and without preservation. This suggests that infections by these bacteria can be diagnosed and possibly also analysed in further detail simply by taking a stool sample in any suitable sealed container that can be transported to laboratory analysis without special storage or preservation requirements. We briefly discuss how this finding can benefit infection control in both developed and developing countries.https://www.aimspress.com/article/doi/10.3934/microbiol.2021024?viewType=HTMLdetection thresholdcampylobactersalmonellagastritisdna stabilitydiagnosticspreservation methodspathogens |
| spellingShingle | CB Harder S Persson J Christensen A Ljubic EM Nielsen J Hoorfar Molecular diagnostics of Salmonella and Campylobacter in human/animal fecal samples remain feasible after long-term sample storage without specific requirements AIMS Microbiology detection threshold campylobacter salmonella gastritis dna stability diagnostics preservation methods pathogens |
| title | Molecular diagnostics of Salmonella and Campylobacter in human/animal fecal samples remain feasible after long-term sample storage without specific requirements |
| title_full | Molecular diagnostics of Salmonella and Campylobacter in human/animal fecal samples remain feasible after long-term sample storage without specific requirements |
| title_fullStr | Molecular diagnostics of Salmonella and Campylobacter in human/animal fecal samples remain feasible after long-term sample storage without specific requirements |
| title_full_unstemmed | Molecular diagnostics of Salmonella and Campylobacter in human/animal fecal samples remain feasible after long-term sample storage without specific requirements |
| title_short | Molecular diagnostics of Salmonella and Campylobacter in human/animal fecal samples remain feasible after long-term sample storage without specific requirements |
| title_sort | molecular diagnostics of salmonella and campylobacter in human animal fecal samples remain feasible after long term sample storage without specific requirements |
| topic | detection threshold campylobacter salmonella gastritis dna stability diagnostics preservation methods pathogens |
| url | https://www.aimspress.com/article/doi/10.3934/microbiol.2021024?viewType=HTML |
| work_keys_str_mv | AT cbharder moleculardiagnosticsofsalmonellaandcampylobacterinhumananimalfecalsamplesremainfeasibleafterlongtermsamplestoragewithoutspecificrequirements AT spersson moleculardiagnosticsofsalmonellaandcampylobacterinhumananimalfecalsamplesremainfeasibleafterlongtermsamplestoragewithoutspecificrequirements AT jchristensen moleculardiagnosticsofsalmonellaandcampylobacterinhumananimalfecalsamplesremainfeasibleafterlongtermsamplestoragewithoutspecificrequirements AT aljubic moleculardiagnosticsofsalmonellaandcampylobacterinhumananimalfecalsamplesremainfeasibleafterlongtermsamplestoragewithoutspecificrequirements AT emnielsen moleculardiagnosticsofsalmonellaandcampylobacterinhumananimalfecalsamplesremainfeasibleafterlongtermsamplestoragewithoutspecificrequirements AT jhoorfar moleculardiagnosticsofsalmonellaandcampylobacterinhumananimalfecalsamplesremainfeasibleafterlongtermsamplestoragewithoutspecificrequirements |