Arborator

• Introduction
  • Citation
  • Contact
• Install
  • Compatibility
• Getting Started
  • Usage
  • Configuration and Settings
  • Data Input
  • Data Output
• Troubleshooting and FAQs
• Other information
• Legal and Compliance Information
• Updates and Release Notes

Table of contents generated with markdown-toc

Introduction

Operationalized pathogen genomic surveillance and outbreak detection frequently makes use dendrograms in conjunction with organism specific genetic distance thresholds to "rule out" cases which are sufficiently genetically distinct that they are not part of the same "event". The genomic data is then combined with contextual sample data to assess the situation and inform further action. There are many different types of outbreaks within food/waterborne pathogens which may involve a general failure of a process where contamination is generalized and is multi-organism, which is identified through other means.

Arborator is designed to make the process of taking genomic profiles of alleles/snps/mutations and contextual metadata and perform:

1. Splitting a large target collection of samples into individual profile and metadata files
2. Calculating within group genetic diversity statistics, generating dendrograms along with flat clusters based on thresholds, outlier detection, and loci summary reports
3. Summarized report across all analyzed groups

Citation

Robertson, James, Wells, Matthew, Schonfeld, Justin, Reimer, Aleisha. Arborator: Streamlining public health pathogen outbreak and surveillance operations. 2024. https://github.com/phac-nml/arborator

Contact

James Robertson: james.robertson@phac-aspc.gc.ca

Install

Install the latest released version from conda:

    conda create -c bioconda -c conda-forge -n arborator arborator

Install using pip:

    pip install arborator

Install the latest master branch version directly from Github:

    pip install git+https://github.com/phac-nml/arborator.git*

Compatibility

The following tools and dependencies should be installed by the conda environment:

• pyarrow==12.0.0
• fastparquet==2023.4.0'
• numba==0.57.1
• numpy==1.24.4
• tables==3.8.0
• six>=1.16.0
• pandas==2.0.2
• psutil
• scipy'
• profile_dists
• genomic_address_service

Getting Started

Usage

If you run arborator, you should see the following usage statement:

usage: arborator [-h] --profile PROFILE --metadata METADATA
                 [--config CONFIG] --outdir OUTDIR --partition_col
                 PARTITION_COL --id_col ID_COL
                 [--outlier_thresh OUTLIER_THRESH]
                 [--min_cluster_members MIN_CLUSTER_MEMBERS] [-n] [-s]
                 [--missing_thresh MISSING_THRESH] -t THRESHOLDS
                 [-d DELIMETER] [-e METHOD] [--force] [--cpus CPUS] [-V]*

Quick Start

Run the test dataset using the data included in the repository under test_data

arborator --profile ./test_data/profile.tsv --metadata ./test_data/metadata.tsv --config ./test_data/config.json --outdir ./test_data/results --id_col id --partition_col outbreak --thresholds 10,9,8,7,6,5,4,3,2,1

Configuration and Settings

There are a large number of parameters to configure within Arborator.

The parameters are explained as follows:

• --profile location of profile.tsv
• --metadata location of metadata.tsv
• --config (optional) location of config.json
• --outdir designated output folder
• --partition_col name of column to partition data
• --id_col name of column with sample IDs
• --outlier_thresh integer value to designate outliers
• --min_cluster_members minimum number of samples to designate a cluster
• -n (--count_missing) Count missing alleles (0s) as differences
• -s (--skip_qc) Skip QA/QC steps
• --missing_thresh Maximum percentage of missing data allowed per locus (0 - 1)
• -t vector of threshold levels for clustering
• -d delimiter separating clustering threshold vector
• -e clustering method
• --force overwrite existing output results
• --cpus indicates numbers of cpus to use with multithreading
• -V prints version string

To enable consistency, we accept a configuration json object that allows the user to specify operations for summarizing columns, and configured report templates. Users can setup specific configurations for each of their target organisms of interest and use the config file as input to arborator for routine operations.

Example config file

    {
        "outlier_thresh": "25",
        "clustering_method": "average",
        "clustering_threshold": "500,100,75,50,25,15,10,5,2,1,0",
        "min_cluster_members": 2,
        "partition_column_name": "outbreak",
        "id_column_name": "sample_id",
        "only_report_labeled_columns": "False",
        "skip_qa": "False",
        
        #Used to configure the order and opperations of columns in the grouped summary (optional)
        "grouped_metadata_columns":{ 
            "outbreak":{ "data_type": "None","label":"National Outbreak Code","default":"","display":"True"},  #Changing the label configures the output file to use this as the header name
            "geo_loc":{ "data_type": "categorical","label":"Country of collection","default":"","display":"True"},
            "age":{ "data_type": "desc_stats","label":"Patient Age (years)","default":"","display":"True"}, #Changing data_type to desc_stats causes the column to be reported in terms of min, median, mean, max values in the column
            "collection date":{ "data_type": "min_max","label":"serovar","default":"","display":"True"}, #Changing data_type to min_mac causes the column to be reported in terms of min, max values in the column
        },
        #Used to configure the display of columns in the line list for individual samples (optional)
        "linelist_columns":{
            "outbreak":{ "data_type": "None","label":"National Outbreak Code","default":"","display":"True"},
            "geo_loc":{ "data_type": "categorical","label":"organism","default":"","display":"True"},
            "age":{ "data_type": "desc_stats","label":"Patient Age (years)","default":"","display":"True"}, #Changing data_type to desc_stats causes the column to be reported in terms of min, median, mean, max values in the column
            "collection date":{ "data_type": "min_max","label":"serovar","default":"","display":"False"}, #Toggling false removes this column from output
        }
    
    }

Data Input

Profile input format

Arborator supports several different formats for input of sample profiles, Native, chewBBACA and Hashed. See below for examples:

Native

id	locus_1	locus_2	locus_3	locus_4	locus_5	locus_6	locus_7
S1	1	1	1	1	1	1	1
S2	1	1	2	2	?	4	1
S3	1	2	2	2	1	5	1
S4	1	2	3	2	1	6	1
S5	1	2	?	2	1	8	1
S6	2	3	3	-	?	9	0

• Direct support for missing data in the form of ?, 0, -, None or space

chewBBACA

id	locus_1	locus_2	locus_3	locus_4	locus_5	locus_6	locus_7
S1	1	INF-2	1	1	1	1	1
S2	1	1	2	2	NIPH	4	1
S3	1	2	2	2	1	5	1
S4	1	LNF	3	2	1	6	1
S5	1	2	ASM	2	1	8	1
S6	2	INF-8	3	PLOT3	PLOT5	9	NIPH

• All non integer fields will be converted into missing data '0'

Hashes

id	locus_1	locus_2	locus_3	locus_4	locus_5	locus_6	locus_7
S1	dc0a04880d1ad381ffd54ce9f6ad1e7a	-	b9f94bf167f34b9fcf45d79cab0e750a	8a07b9cb0ab7560ad07b817ca34036bb	80c8156d77d724ac0bb16ec60993bc84	7a1d0a48f16fa25910cddfea38dab229	e1ee776b32c2f6131a7238ce50b75469
S2	dc0a04880d1ad381ffd54ce9f6ad1e7a	0af06522a32865cd2db2cf5a854d195b	9fc502308c616ae34146d7f7b0081bd8	4577dec2c840472800a3b104c88bb0ef	-	bba24c25c28c08058d6f32ecfbf509e9	e1ee776b32c2f6131a7238ce50b75469
S3	dc0a04880d1ad381ffd54ce9f6ad1e7a	04d45219ee5f6065caf426ba740215e5	9fc502308c616ae34146d7f7b0081bd8	4577dec2c840472800a3b104c88bb0ef	80c8156d77d724ac0bb16ec60993bc84	874225c0dec5219dd64584ba32938dbd	e1ee776b32c2f6131a7238ce50b75469
S4	dc0a04880d1ad381ffd54ce9f6ad1e7a	-	e79562c280691c321612ecdf0dadad9e	4577dec2c840472800a3b104c88bb0ef	80c8156d77d724ac0bb16ec60993bc84	c8087ad8b01d9f88e8eb2c3775ef2e64	e1ee776b32c2f6131a7238ce50b75469
S5	dc0a04880d1ad381ffd54ce9f6ad1e7a	04d45219ee5f6065caf426ba740215e5	-	4577dec2c840472800a3b104c88bb0ef	80c8156d77d724ac0bb16ec60993bc84	4d547ea59e90173e8385005e706aae96	e1ee776b32c2f6131a7238ce50b75469
S6	8214e9d02d1b11e6239d6a55d4acd993	-	e79562c280691c321612ecdf0dadad9e	-	-	e3088425be5e7de8d9a95da8e59a9ea8	-

• Direct support for missing data in the form of ?, 0, - or space*

Metadata input format

Arborator allows for a lot of flexibility with metadata format. The only constraint is that the first column must be the sample identifier column and the file must be tab-delimited.

Example 1

id	Country	Source	Date
S1	Canada	Chicken	2024-01-01
S2	Canada	Chicken	2024-01-02
S3	United States	Chicken	2024-01-03
S4	United Kingdom	Chicken	2024-01-04
S5	Brazil	Chicken	2023-12-01
S6	Canada	Chicken	2023-11-02

Example 2

sample_id	geo_loc	age	collection date	outbreak
S1	Canada	50	2024-01-01	1
S2	Canada	25	2024-01-02	1
S3	United States	10	2024-01-03	1
S4	United Kingdom	1	2024-01-04	2
S5	Brazil	56	2023-12-01	2
S6	Canada	17	2023-11-02	2

Input configuration format

Supported column summarization choices

These values can be named after data_type to inform Arborator the type of summarization the user wants for each column.

1. none - All values within the column are concatenated by a comma

2. categorical - Counts for all unique values are determined and then the count is provided in the format count_{column name}_{lable} : {count} (default)

3. min_max - The minimum and maximum values for the column are determined (dates and numerical data only) and reported as {column name}_min_value, {column name}_max_value,

4. desc_stats - Descriptive stats are determined for the column values (numerical data only) and reported as {column name}_min_value, {column name}_median_value, {column name}_mean_value, {column name}_max_value

Data Output

{Output folder name}
├── {group label 1}
    └── clusters.tsv
    ├── loci.summary.tsv
    ├── matrix.tsv
    ├── metadata.tsv
    ├── outliers.tsv
    ├── profile.tsv
    └── tree.nwk
├── {group label n}
    └── clusters.tsv
    ├── loci.summary.tsv
    ├── matrix.tsv
    ├── metadata.tsv
    ├── outliers.tsv
    ├── profile.tsv
    └── tree.nwk   
├── cluster_summary.tsv
├── metadata.excluded.tsv
├── metadata.included.tsv
├── threshold_map.json
└── run.json - Contains logging information for the run including parameters and quality information

Arborator will output a set of folders that are separated based on the designated grouping metadata column. Within each folder are a consistent set of files:

• cluster report (clusters.tsv)
• summary of the loci (loci.summary.tsv)
• distance matrix (matrix.tsv)
• summarized metadata (metadata.tsv)
• detected outliers (outliers.tsv)
• arborator formatted profiles for each sample, see below for format (profile.tsv)
• newick formatted phylogenetic tree for within group samples (tree.nwk) It also will output the following run summary files:
• cluster summary report of all clusters detected (cluster_summary.tsv)
• all samples excluded from designated metadata group column (metadata.excluded.tsv)
• all samples included from designated metadata group column (metadata.included.tsv)
• Actual threshold levels used when clustering (threshold_map.json)
• Log of run parameters and quality information (run.json)

profile.tsv format

Native

id	locus_1	locus_2	locus_3	locus_4	locus_5	locus_6	locus_7
S1	1	1	1	1	1	1	1
S2	1	1	2	2	0	4	1
S3	1	2	2	2	1	5	1
S4	1	2	3	2	1	6	1
S5	1	2	0	2	1	8	1
S6	2	3	3	0	0	9	0

• All columns are converted to contain only integers with missing data represented as a 0

Troubleshooting and FAQs

Coming soon

Benchmarking

Coming soon

Legal and Compliance Information

Copyright Government of Canada 2023

Written by: National Microbiology Laboratory, Public Health Agency of Canada

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this work except in compliance with the License. You may obtain a copy of the License at:

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

Updates and Release Notes

Please see the CHANGELOG.md.