Contaminations contaminate common databases

Area of Science:

• Molecular biology
• Parasitology
• Ornithology

Background:

• Polymerase chain reaction (PCR) is a sensitive molecular technique for pathogen detection.
• The high sensitivity of PCR can lead to the amplification of artificial DNA copies, posing a contamination risk.
• Unidentified PCR contamination can result in inaccurate conclusions regarding pathogen occurrence, host range, and geographic distribution.

Purpose of the Study:

• To evaluate whether published records of avian haemosporidian parasites in unusual hosts or regions may be attributed to PCR contamination.
• To identify potential sources of PCR contamination within the experimental workflow.
• To raise awareness and aid in developing procedures to minimize PCR contamination.

Main Methods:

• Review of published records of avian haemosporidian parasites with unusual host or geographical occurrences.
• Analysis of case studies to identify steps in the PCR workflow that may lead to contamination.
• Comparative evaluation of potential contamination sources versus novel biological findings.

Main Results:

• Several published records of avian haemosporidian parasites in unusual host species or geographical regions are suspected to be artifacts of PCR contamination.
• Specific steps in the PCR process, such as template carryover, are highlighted as potential contamination sources.
• The findings suggest that contamination can inflate estimates of parasite host range and geographic distribution.

Conclusions:

• PCR contamination is a significant issue that can lead to erroneous conclusions in pathogen identification.
• Awareness of potential contamination sources is crucial for accurate molecular identification of parasites and pathogens.
• Implementing stringent laboratory procedures is essential to minimize PCR contamination and ensure the validity of research findings.