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Aug 14, 2018·6 min read
Comparison of Database Search Methods for the Detection of Legionella Pneumophila in Water Samples Using Metagenomic Analysis

Comparison of Database Search Methods for the Detection of Legionella Pneumophila in Water Samples Using Metagenomic Analysis

Comparison of Database Search Methods for the Detection of Legionella Pneumophila in Water Samples Using Metagenomic Analysis

Quick Answer: Legionella pneumophila causes Legionnaires’ disease, a severe pneumonia form responsible for 75% of waterborne disease deaths in the United States. Traditional culture-based detection methods require 7–10 days and can miss viable but non-culturable (VBNC) Legionella. Metagenomic next-generation sequ. Advanced water treatment technologies including reverse osmosis provide effective solutions for water quality challenges in this area. AMPAC USA’s commercial and industrial systems are engineered to address these specific water treatment needs with certified, documented performance.

Borthong, Jednipit; Omori, Ryosuke; Sugimoto, Chihiro; Suthienkul, Orasa; Nakao, Ryo; Ito, Kimihito

FRONTIERS IN MICROBIOLOGY, 9 10.3389/fmicb.2018.01272 JUN 19 2018

Abstract: Metagenomic analysis has become a powerful tool to analyze bacterial communities in environmental samples. However, the detection of a specific bacterial species using metagenomic analysis remains difficult due to false positive detections of sequences shared between different bacterial species. In this study, 16S rRNA amplicon and shotgun metagenomic analyses were conducted on samples collected along a stream and ponds in the campus of Hokkaido University. We compared different database search methods for bacterial detection by focusing on Legionella pneumophila. In this study, we used L. pneumophila-specific nested PCR as a gold standard to evaluate the results of the metagenomic analysis. Comparison with the results from L. pneumophila-specific nested PCR indicated that a blastn search of shotgun reads against the NCBI-NT database led to false positive results and had problems with specificity. We also found that a blastn search of shotgun reads against a database of the catalase-peroxidase (katB) gene detected L. pneumophila with the highest area under the receiver operating characteristic curve among the tested search methods; indicating that a blastn search against the katB gene database had better diagnostic ability than searches against other databases. Our results suggest that sequence searches targeting long genes specifically associated with the bacterial species of interest is a prerequisite to detecting the bacterial species in environmental samples using metagenomic analyses.

https://www.frontiersin.org/articles/10.3389/fmicb.2018.01272/full

The post Title: Comparison of Database Search Methods for the Detection of Legionella Pneumophila in Water Samples Using Metagenomic Analysis appeared first on Facts About Water.

Source: Water Feed

What flow rates are available for emergency water treatment?

AMPAC USA's emergency systems range from 1,500 GPD portable units to 50,000+ GPD trailer-mounted systems. Military-specification units are available for forward operating base deployment, producing potable water meeting EPA and WHO drinking water standards from virtually any source.

Are emergency RO systems suitable for disaster relief operations?

Yes. AMPAC USA's emergency systems are used by FEMA, the U.S. military, and international NGOs for disaster relief. They treat flood water, contaminated groundwater, and brackish sources, removing bacteria, viruses, and chemical contaminants to produce safe drinking water on-site.

What power sources can emergency water purification systems use?

AMPAC USA's emergency systems can run on generator power (120/240V or 480V 3-phase), solar panels with battery backup, or vehicle power take-off (PTO). Low-power models consume as little as 0.5 kW, making them viable for off-grid deployment.

How durable are military-grade water purification systems?

AMPAC USA's military systems are built to MIL-SPEC standards with stainless steel frames, powder-coated components, and UV-resistant materials. They are designed to operate in temperatures from -20°F to 120°F and are vibration-tested for transport in military vehicles.

Conclusion

This post highlighted how emergency and military-grade water purification systems provide safe drinking water rapidly in the most challenging field conditions. For organizations requiring deployable water treatment capability, AMPAC USA engineers portable and trailer-mounted systems built to perform wherever they are needed. Contact our team at info@ampac1.com or (909) 548-4900 to discuss your emergency water treatment requirements.

Legionella Pneumophila Water Detection Metagenomic Analysis: Technical Analysis and Solutions

Legionella pneumophila causes Legionnaires’ disease, a severe pneumonia form responsible for 75% of waterborne disease deaths in the United States. Traditional culture-based detection methods require 7–10 days and can miss viable but non-culturable (VBNC) Legionella. Metagenomic next-generation sequencing (NGS) approaches allow comprehensive detection of all Legionella species and strains in a single water sample within 24–48 hours, enabling faster outbreak investigation and preventive building water system management.

Understanding the science behind water quality challenges in this area enables selection of appropriately engineered treatment solutions. Water treatment technology selection should be based on comprehensive source water analysis, contaminant characterization, and performance-verified system design.

Reverse osmosis systems from AMPAC USA provide multi-contaminant treatment capability through TFC polyamide membranes achieving 90–99% rejection of dissolved contaminants, combined with sediment pre-filtration, activated carbon treatment, and UV disinfection options. Our commercial and industrial systems are NSF/ANSI certified, providing documented performance evidence for regulatory compliance and quality assurance programs.

For specific water quality challenges in this application area, AMPAC USA’s engineering team provides source water analysis review, system sizing recommendations, and complete treatment train design to ensure water quality objectives are reliably achieved. Contact AMPAC USA to discuss your specific water treatment requirements.

Frequently Asked Questions

What is reverse osmosis water purification?

Reverse osmosis forces water under pressure through a semi-permeable membrane (0.0001 µm pores) that rejects 90–99% of dissolved contaminants while allowing pure water molecules to pass through. It is widely considered the most effective point-of-use water treatment technology.

What contaminants does reverse osmosis remove?

RO removes dissolved salts (TDS), heavy metals (lead, arsenic, chromium), nitrates, fluoride, PFAS, pharmaceuticals, bacteria, viruses, and most organic contaminants through a combination of size exclusion, charge repulsion, and hydrophobic rejection mechanisms.

How does water quality affect public health?

Access to safe, clean drinking water is fundamental to human health. Contaminated water causes an estimated 500,000 diarrheal deaths annually worldwide and contributes to chronic health conditions through long-term exposure to heavy metals, nitrates, PFAS, and other regulated and unregulated contaminants.

When should I consider a water purification system?

Consider water purification if your water has detectable lead, nitrates, arsenic, PFAS, or other contaminants; if you have a private well; if your water tastes or smells off; if you have immunocompromised family members; or if you want to reduce your dependence on bottled water.

What is the difference between water filtering and water purification?

Filtration physically removes particles and some dissolved compounds from water. Purification (including RO) achieves more comprehensive removal of dissolved contaminants through pressure-driven membrane separation. RO is considered purification because it removes dissolved ionic species that filtration alone cannot address.

How often does a water purification system need maintenance?

Reverse osmosis systems require pre-filter replacements every 6–12 months, membrane replacement every 2–5 years, and annual system sanitization. Well-maintained systems provide consistent, high-quality water for 10–15+ years with these routine service intervals.

Does AMPAC USA offer water treatment systems for this application?

Yes. AMPAC USA provides residential, commercial, and industrial water treatment systems including reverse osmosis, UV disinfection, and multi-stage treatment solutions designed for specific water quality challenges. Our systems are NSF/ANSI certified for performance verification and customer confidence.

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