,/
      ,'/
    ,' /        █████╗  ██████╗██████╗  ██████╗  (a)utomated
  ,'  /_____,  ██╔══██╗██╔════╝██╔══██╗██╔════╝  (c)ontamination
.'____    ,'   ███████║██║     ██║  ██║██║       (d)etection and
     /  ,'     ██╔══██║██║     ██║  ██║██║       (c)onfidence estimation for single-cell genome data
    / ,'       ██║  ██║╚██████╗██████╔╝╚██████╗
   /,'         ╚═╝  ╚═╝ ╚═════╝╚═════╝  ╚═════╝
  /'

Acdc is a tool to test single-cell genome data contamination. By using sophisticated dimensionality reduction and clustering methods, it uses tetramer profiles to differentiate between different species in a given sample. It automatically detects the number of clusters/species and provides confidence information.

Please read the publication at BMC Bioinformatics for details.

• C++11 compatible compiler
• CMake >= 3.0
• Boost C++ Libraries >= 1.55.0 (program_options, system, filesystem)

Other needed libraries are included.

Kraken >= 0.10.5-beta can be used to improve results by using a database. RNAmmer = 1.2 is used to highlight and extract 16S regions.

Clone the repository, run CMake and build the library

# git clone https://github.com/mlux86/acdc.git
# cd acdc
# mkdir build && cd build
# cmake ..
# make -j4

To install acdc:

make install

The installation path (prefix path) can be changed by adding the option -DCMAKE_INSTALL_PREFIX=<prefix-path> to the cmake command above.

To show the help, including various parameters of acdc, run

# acdc -h

To run acdc to check a single fasta file for contamination:

# acdc -i <path-to-fasta>

To run acdc in batch mode, supply a list of fasta files:

# acdc -I <path-to-file-with-list-of-fastas>

By default, Kraken is not included in the computation. It is necessary, to specify a database for Kraken to access, i.e.:

# acdc -K <path-to-kraken-db> -i <path-to-fasta>

Make sure that the kraken and kraken-translate executables can be found in the $PATH environment variable.

Make sure that the rnammer executable can be found in the $PATH environment variable and RNAmmer is working properly.

In the visualization, 16S genes are highlighted by a large star shape. A click on it will download the corresponding 16S sequence.

While acdc is running, it generates results in an output directory defaulting to ./results/ (can be overridden using the -o parameter). It contains the file index.html that can be viewed in any modern browser, supporting HTML5 and CSS3.

Acdc supports taxonomy annotations from external sources. The -x parameter accepts as value a text file that contains taxonomy information for contigs. Each line in the file should start with the exact contig name, followed by a TAB character, followed by the annotated taxonomy, i.e. from Blast, Kraken, or any other tool. As long as only a fraction of one cluster is annotated with a given taxonomy, the full cluster is then assumed to be represented by it. In combination with the -X parameter, which accepts a regular expression to match a given target taxonomy, acdc automatically infers what constitutes contaminant and clean contigs.

Acdc is provided on docker hub: mlux86/acdc. Pull the container using docker pull mlux86/acdc:stable.

Run acdc as follows:

# docker run --name acdc \
             -v /path/to/assemblies:/assemblies \
             -v /path/to/kraken_db:/krakendb \
             acdc -i /assemblies/test.fasta

where /path/to/assemblies contains the file test.fasta and /path/to/kraken_db contains the Kraken database.

Copy the result files to the current working directory using

# docker cp acdc:/acdc ./results

In the docker folder, acdc provides a Dockerfile script to build a docker container. Building depends on the rnammer sources which can be obtained via the RNAmmer homepage. Just put the obtained rnammer-1.2.src.tar.Z file into the docker folder and from inside the directory, run

# docker build -t acdc .

• Eigen, a C++ template library for linear algebra: matrices, vectors, numerical solvers, and related algorithms.
• SeqAn, an open source C++ library of efficient algorithms and data structures for the analysis of sequences with the focus on biological data.
• t-SNE, t-Distributed Stochastic Neighbor Embedding (t-SNE) is a technique for dimensionality reduction that is particularly well suited for the visualization of high-dimensional datasets.
• diptest: Hartigan's Dip Test Statistic for Unimodality, by Martin Maechler (originally from Fortran and S-plus by Dario Ringach, NYU.edu), modified for use in a C++ application.
• fastcluster fastcluster: Fast hierarchical clustering routines for R and Python, extracted relevant code and added pure C++ interface
• yaml-cpp
• nanoflann, a C++ header-only library for Nearest Neighbor (NN) search wih KD-trees.
• Catch, a modern, C++-native, header-only, framework for unit-tests, TDD and BDD.
• jQuery, a fast, small, and feature-rich JavaScript library.
• D3.js - Data-Driven Documents, a JavaScript library for visualizing data with HTML, SVG, and CSS.

The MIT License (MIT)

Copyright (c) [2018] [Markus Lux]

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.