Category Archives: water microbiology

Research -Microbacteria can build up in your reusable water bottle

The Jakarta Post

Both oral and environmental bacteria and viruses could be building up on reusable water bottles that are not cleaned on a regular basis, according to a scientist from the Center for Ecology and Hydrology.

Senior scientist Andrew Singer was recently interviewed by the Huffington Post UK, where he explained that even E. coli could find its way into an unclean reusable water bottle.

“When you flush the toilet, the toilet water will get aerosolized and a fraction of the water droplets can land on and in your water bottle,” Singer explained.

Singer said that poor personal hygiene habits, such as rarely or not washing your hands after using the toilet, or taking your water bottle to the toilet with you, could increase the chances of getting serious infections.

 

Research – Behavior of foodborne pathogens, Listeria monocytogenes and Staphylococcus aureus, in mixed-species biofilm exposed to biocides

Orbit

In nature and man-made environments, microorganisms reside in mixed-species biofilm where behavior is modified compared to the single-species biofilms. Pathogenic microorganisms may be protected against adverse treatments in mixed-species biofilms leading to health risk for humans. Here, we developed two mixed-five-species biofilms that included the foodborne pathogens Listeria monocytogenes or Staphylococcus aureus, respectively. The five species, including the pathogen, were isolated from a single food-processing environmental sample thus mimicking the environmental community. In mature mixed five-species biofilms on stainless steel, the two pathogens remained at a constant level of ∼105 CFU/cm2 The mixed-five-species biofilms as well as the pathogens in mono-species biofilms were exposed to biocides to determine any pathogen-protective effect of the mixed biofilm. Both pathogens and their associate microbial communities were reduced by peracetic acid treatments. S. aureus decreased 4.6 log cycles in mono-species biofilm, but the pathogen was protected in the five-species biofilm and decreased only 1.1 log cycles. Sessile cells of L. monocytogenes were affected equally as a mono-biofilm or as a member in the mixed-species biofilm; decreasing by three log cycles when exposed to 0.0375 % peracetic acid. When the pathogen was exchanged in each associate microbial community, S. aureus was eradicated while there was no significant effect of the biocide on L. monocytogenes or the mixed community. This indicates that particular members or associations in the community offered the protective effect. Further studies are needed to clarify the mechanisms of biocide protection, and the species playing the protective role in microbial communities of biofilms. Importance: This study demonstrates that foodborne pathogens can be established in mixed species biofilms and that this can protect them from biocide action. The protection is not due to specific characteristics of the pathogen, here S. aureus and L. monocytogenes, but likely caused by specific members or associations in the mixed species biofilm. Biocide treatment and resistance is a challenge for many industries and biocide efficacy should be tested on microorganisms growing in biofilms, preferably mixed systems, mimicking the application environment.

Research – Legionella & Fire Sprinkler Systems – Is there a Risk?

Legionella Control Legionella A

Legionella is a bacterium that is commonly found in natural water sources such as lakes, reservoirs and rivers, usually in small concentrations that pose no threat to public health. However, once this water enters man-made water systems such as fire sprinkler systems, under certain environmental conditions there is a risk that any Legionella bacteria that are present in the water may proliferate, increasing the risks associated with Legionnaires’ disease.

Fire sprinkler systems do present a legionella risk and so sprinkler maintenance routines should be amended and incorporated in to the legionella monitoring and control programmes that you currently have in place.

Research – Study could explain higher rates of human E. coli infection in Scotland

The Roslin Institute ecoli

A subtype of E. coli O157 found in cattle may be responsible for higher rates of severe human infection in Scotland, report suggests.

E. coli O157 is a bacterium carried by cattle, which can cause life-threatening human infections when it enters the food chain. Scientists found that cattle in Scotland have a higher level of a subtype of E. coli O157 – PT21/28, which is known to cause more severe human infection.

It may be that local exposure to this particular subtype is a potential factor for the rates of people infected by E. coli O157 in Scotland being around three times higher than in England and Wales.

Causes of E. coli outbreaks

Researchers used Whole Genome Sequencing (WGS) to define which specific subtypes of E. coli caused an outbreak. For example, data obtained from WGS helped to understand whether a human infection is likely to have arisen from local farm animals or by a strain present in imported food or as a consequence of travel abroad.

The team have also combined WGS data with machine learning to predict which subtypes of  E. coli O157 pose the greatest threat to human health.

Research – Bursting bubbles launch bacteria from water to air

Science Daily

Wherever there’s water, there’s bound to be bubbles floating at the surface. From standing puddles, lakes, and streams, to swimming pools, hot tubs, public fountains, and toilets, bubbles are ubiquitous, indoors and out.

A new MIT study shows how bubbles contaminated with bacteria can act as tiny microbial grenades, bursting and launching microorganisms, including potential pathogens, out of the water and into the air.

In the study, published in the journal Physical Review Letters, the researchers found that bacteria can affect a bubble’s longevity: A bacteria-covered bubble floating at the water’s surface can last more than 10 times longer than an uncontaminated one can, persisting for minutes instead of seconds. During this time, the cap of the contaminated bubble thins. The thinner the bubble, the higher the number of droplets it can launch into the air when the bubble inevitably bursts. A single droplet, the researchers estimate, can carry up to thousands of microorganisms, and each bubble can emit hundreds of droplets.

USA – Illinois: Another Legionnaires’ disease cluster reported

Outbreak News Today

 

legionellacIn a follow-up to the recent Legionnaires’ disease clusters in Illinois, state and county health officials are investigating a cluster of three cases at McHenry Villa, an independent senior living community.

Public health officials confirmed the third case this week. McHenry Villa is notifying residents, the residents’ identified contact, and staff.  All three cases had outside exposures, and two of the cases had potential exposures at Centegra Hospital-McHenry.  Public health officials will continue to investigate any other potential sources.

Information – How Many Legionella Species Exist & Which Ones Cause Legionnaires’ Disease?

Legionella Control Legionella A

While there are more than 50 different recognised Legionella species, less than half of those can cause illness in humans. However, while around 20 species are known to be harmful to us, just one has been identified as the cause of most outbreaks of Legionnaires’ disease. Read further at the link above.