Legionella Pneumophila: Infecting Amoeba, Infecting Macrophages – Poem

Published on 06/28/2019 | by Waterline Admin

Legionella pneumophila.
It’s the bringer of an atypical pneumonia
Called Legionnaires’ disease.

L. pneumophila infects a type of white blood cell,
Grows inside,
And then bursts out of the cell
To infect others.

Found naturally in freshwater,
It often travels elsewhere:
Hot water tanks,
Hot tubs,
And cooling towers.
Yes, it really likes water.

In freshwater,
L. pneumophila can grow within another organism:
The amoeba.

It’s an interesting relationship.
Where temperatures and other conditions are key.

With higher temperatures, L. pneumophila multiples,
And the chances of transmission and disease increases.

But if the amoeba gets stressed,
(yes microbes get stressed: suboptimal temperatures, limited nutrients, and the like)
The amoeba turns into a cyst.
Bacterial growth within ceases
And still any L. pneumophila inside survives.

In better times,
The bacterial cells begin to multiply,
Soon reaching a point where they escape from the amoeba.
The amoeba bursts and bacteria escape into open waters,
In vesicles or on their own.

But interesting thing about L. pneumophila cells that have gone through stress,
When they get released from the amoeba,
They are more resilient to harsh conditions
Compared to those that were not stressed.
And now better suited for infection.

Further reading:

Cellular microbiology and molecular ecology of Legionella–amoeba interaction. Virulence. 2013.


Diary Dates & Events

Grime Scene


Following on from the successful Grime Scene competition, we have decided to continue the theme for another year, but with a twist. This year, we are asking for photographs of the grimiest pictures you can find accompanied with another photograph of how the ‘scene’ has been improved by your maintenance or cleaning.

We will display the photographs in each of the Waterline editions throughout 2024. The ‘most improved’ picture will be chosen by WMSoc members via an online vote. The winner will receive a £25 Amazon Gift Voucher after the Winter 2024/25 edition has been published.

Please send your photographs to:

Product & Service Spotlight

Introducing B & V Chemicals' new film forming amines for closed circuits and steam boilers.

Product Launch: Film forming amines.

This all-in-one solution offers low-dose, cost-effective treatment. Improves heat transfer efficiency by removing corrosion deposits, leading to cleaner surfaces. Enhances energy and resource efficiency by reducing Total Dissolved Solids (TDS). The stable film provided by polyamines ensures superior corrosion control, promoting longer equipment lifespan.

Plus - environmentally friendly, offering a greener alternative to traditional treatments.

Contact us on ownlabel@bvwater.co.uk for further information.

How the NEW SolidTek® Biocide Feeder Package will BENEFIT YOU

SolidTek® has launched its NEW Biocide Feeder which is functional, compact, and environmentally-friendly.

Designed for use with SolidTek’s® enhanced bromine biocide, BromTek, it offers multiple benefits:

Reduced exposure to fumes and bromine dust (non-pressurised system).

Use with field proven mixed hydantoin biocide - better performance than standard bromine tablets.

Wall mounted reducing footprint of installation.

Charge with product in under 5 minutes without isolation from the system.

Product calculators and tech support available.

Lovibond MD640 Photometer (PTSA & Fluorescein capable)

Product Spotlight Drop Test Kits

How many times have you heard … ‘we’re not sure what the system volume is’. A common problem which can be expensive - wasting chemical over dosing, or underdosing so the treatment is ineffective (i.e. shock dosing a biocide). The MD640 photometer has PTSA & Fluorescein capability built in. Simply use our System Checkers to add to an unknown system and read a PTSA or Fluorescein levels to accurately identify the system volume.

The Hydrosense PRO range


The Hydrosense PRO range pioneers Legionella pneumophila detection, the cause of over 97% of Legionnaires’ disease outbreaks, by identifying all the serogroups 1-15 of this dangerous Legionella species. This easy-to-use, highly sensitive test uses unique filtration, offering a three-line test result that distinguishes between serogroup 1 and serogroups 2-15 within 25 minutes. The water test has a level of detection of 100 CFU/L and swab tests detect 200 CFU per swabbed area, providing crucial, rapid insights for water safety management.