» Articles » PMID: 33037786

Contaminations Contaminate Common Databases

Abstract

The polymerase chain reaction (PCR) is a very powerful method to detect and identify pathogens. The high sensitivity of the method, however, comes with a cost; any of the millions of artificial DNA copies generated by PCR can serve as a template in a following experiment. If not identified as contaminations, these may result in erroneous conclusions on the occurrence of the pathogen, thereby inflating estimates of host range and geographic distribution. In the present paper, we evaluate whether several published records of avian haemosporidian parasites, in either unusual host species or geographical regions, might stem from PCR contaminations rather than novel biological findings. The detailed descriptions of these cases are shedding light upon the steps in the work process that might lead to PCR contaminations. By increasing the awareness of this problem, it will aid in developing procedures that keep these to a minimum. The examples in the present paper are from haemosporidians of birds, however the problem of contaminations and suggested actions should apply generally to all kinds of PCR-based identifications, not just of parasites and pathogens.

Citing Articles

Location and timing of infection drives a sex-bias in prevalence in a hole-nesting bird.

Jones W, Menon P, Qvarnstrom A Parasitology. 2024; 151(8):875-883.

PMID: 39428850 PMC: 11578888. DOI: 10.1017/S0031182024001021.


Considerations for first field trials of low-threshold gene drive for malaria vector control.

Connolly J, Burt A, Christophides G, Diabate A, Habtewold T, Hancock P Malar J. 2024; 23(1):156.

PMID: 38773487 PMC: 11110314. DOI: 10.1186/s12936-024-04952-9.


Exo-erythrocytic development of two Haemoproteus species (Haemosporida, Haemoproteidae), with description of Haemoproteus dumbbellus, a new blood parasite of bunting birds (Emberizidae).

Duc M, Himmel T, Ilgunas M, Eigirdas V, Weissenbock H, Valkiunas G Int J Parasitol. 2023; 53(10):531-543.

PMID: 37263375 PMC: 7615398. DOI: 10.1016/j.ijpara.2023.02.009.


Host shift and natural long-distance dispersal to an oceanic island of a host-specific parasite.

Ellis V, Ciloglu A, Yildirim A, Bensch S Biol Lett. 2023; 19(3):20220459.

PMID: 36918035 PMC: 10014241. DOI: 10.1098/rsbl.2022.0459.


Parasite detection and quantification in avian blood is dependent on storage medium and duration.

Lynton-Jenkins J, Chaine A, Russell A, Bonneaud C Ecol Evol. 2023; 13(2):e9819.

PMID: 36789332 PMC: 9911630. DOI: 10.1002/ece3.9819.


References
1.
Musa S, Mackenstedt U, Woog F, Dinkel A . Avian malaria on Madagascar: prevalence, biodiversity and specialization of haemosporidian parasites. Int J Parasitol. 2018; 49(3-4):199-210. DOI: 10.1016/j.ijpara.2018.11.001. View

2.
Aurrecoechea C, Barreto A, Basenko E, Brestelli J, Brunk B, Cade S . EuPathDB: the eukaryotic pathogen genomics database resource. Nucleic Acids Res. 2016; 45(D1):D581-D591. PMC: 5210576. DOI: 10.1093/nar/gkw1105. View

3.
Valkiunas G, Zehtindjiev P, Hellgren O, Ilieva M, Iezhova T, Bensch S . Linkage between mitochondrial cytochrome b lineages and morphospecies of two avian malaria parasites, with a description of Plasmodium (Novyella) ashfordi sp. nov. Parasitol Res. 2007; 100(6):1311-22. DOI: 10.1007/s00436-006-0409-3. View

4.
Imura T, Suzuki Y, Ejiri H, Sato Y, Ishida K, Sumiyama D . Prevalence of avian haematozoa in wild birds in a high-altitude forest in Japan. Vet Parasitol. 2011; 183(3-4):244-8. DOI: 10.1016/j.vetpar.2011.07.027. View

5.
Fallon S, Ricklefs R, Swanson B, Bermingham E . Detecting avian malaria: an improved polymerase chain reaction diagnostic. J Parasitol. 2003; 89(5):1044-7. DOI: 10.1645/GE-3157. View