Category Archives: Microbiology

Research – Microbial ecology: Salmonella and the dairy calf

AllAboutFeed

 

Besides faeces and other cattle, pathogenic vectors in the dairy farm can include feed, water, rodents, wild animals, flies, birds, etc. What are the producer’s management priorities to sustain dairy calf health?

A dairy farm in the simplest form is a population of dairy cattle living in barns, corrals, or pastures that surround a centralised milking parlour where animals are milked for commerce. However, co-existing on these facilities is another population, one that is often overlooked as it is invisible to the naked eye. It is the microbial population. The dairy farm’s microbial populace consists of a vast and diverse array of commensal and pathogenic micro-organisms that are easily transmitted. Among the pathogens, there are viruses, fungi, algae, protozoa, and bacteria. Among the bacteria, Salmonella can have an especially serious impact on calf health.

Research – Microbiological and real-time mechanical analysis of Bacillus licheniformis and Pseudomonas fluorescens dual-species biofilm

Microbiology Research

n natural habitats, bacterial species often coexist in biofilms. They interact in synergetic or antagonistic ways and their interactions can influence the biofilm development and properties. Still, very little is known about how the coexistence of multiple organisms impact the multispecies biofilm properties. In this study, we examined the behaviour of a dual-species biofilm at the air–liquid interface composed by two environmental bacteria: Bacillus licheniformis and a phenazine mutant of Pseudomonas fluorescens . Study of the planktonic and biofilm growths for each species revealed that P. fluorescens grew faster than B. licheniformis and no bactericidal effect from P. fluorescens was detected, suggesting that the growth kinetics could be the main factor in the dual-species biofilm composition. To validate this hypothesis, the single- and dual-species biofilm were characterized by biomass quantification, microscopy and rheology. Bacterial counts and microscale architecture analysis showed that both bacterial populations coexist in the mature pellicle, with a dominance of P. fluorescens . Real-time measurement of the dual-species biofilms’ viscoelastic (i.e. mechanical) properties using interfacial rheology confirmed that P. fluorescens was the main contributor of the biofilm properties. Evaluation of the dual-species pellicle viscoelasticity at longer time revealed that the biofilm, after reaching a first equilibrium, created a stronger and more cohesive network. Interfacial rheology proves to be a unique quantitative technique, which combined with microscale imaging, contributes to the understanding of the time-dependent properties within a polymicrobial community at various stages of biofilm development. This work demonstrates the importance of growth kinetics in the bacteria competition for the interface in a model dual-species biofilm.

Research – The effect of silver nanocomposite packaging based on melt mixing and sol–gel methods on shelf life extension of fresh chicken stored at 4 °C

Wiley Online

Abstract

In the present study, seven types of films were produced using different proportions of polyethylene containing silver, clay, and titanium dioxide nanoparticles. Following the determination of the minimum inhibitory concentration of the films in the eradication of Staphylococcus aureus and Escherichia coli, the film containing 5% silver nanoparticles and 5% titanium dioxide nanoparticles was found to have the highest antimicrobial property and was determined to be an ideal cover for food products. The antibacterial effect of the films on the shelf life extension and quality of the chicken stored at 4 °C in the Days 1, 3, and 5 of the experiment was checked. The structure and morphology of the nanoparticles and the selected films were evaluated using a field emission scanning electron microscope, scanning electron microscope, transmission electron microscope, Fourier‐transform infrared spectroscopy, and dynamic light scattering. The analysis of the results indicated that the most appropriate inhibition growth was observed with S. aureus and E. coli in nutrient agar and the largest diameter of the radial inhibition zone occurred with S. aureus. Moreover, the analysis of variance showed that the effect of different concentrations of silver and titanium dioxide nanoparticles was significant (p < .05). The results of this study showed that the produced nanocomposite was used to preserve chicken meat for 5 days at 4 °C inhibited the growth of both types of bacteria.

Practical applications

Nowadays production of active packaging is increasing worldwide as they were proved to have numerous effects on inhibiting of microbial growth and even bactericidal effects. Therefore, a wide variety of food producers in different sections namely agriculture, dairy, and meat industries have applied nanopackaging using different nanoparticles. Thus, more research on different physicochemical and antimicrobial effects are needed.

RASFF Alerts – Animal Feed – Salmonella – Fish Meal – Organic Sunflower Cake – Pet Food – Rape Seed Expeller

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RASFF – Salmonella enterica ser. Montevideo (presence /25g) and Salmonella enterica ser. Münster (presence /25g) in fish meal from the United States in Greece

RASFF – Salmonella enterica ser. Senftenberg (presence /250g) in fish meal from the United States in Greece

RASFF – Salmonella enterica ser. Senftenberg (presence /25g) in organic sunflower cake from Croatia in Austria

RASFF – Salmonella enterica ser. Typhimurium (presence /25g) in petfood from the United Kingdom in Norway

RASFF – Salmonella enterica ser. Agona (presence /25g) in rape seed expeller from Lithuania in Finland

Research – Is Climate Change Increasing Cases of Legionnaires’ Disease?

Legionella Control Legionella_Plate_01

Is climate change increasing cases of Legionnaires’ disease?

It’s a matter of record that our planet’s climate has changed almost continually throughout its history.

It would therefore be foolhardy to assume it would remain identical to the position it was in millions of years ago.

However, most of the climate changes seen in the past have been caused by natural events; that is, changes that have occurred due to factors outside of our control.

A good example would be the earth’s orbit making marginal changes, changes that have influenced the climate on our planet.

However, we have seen these gradual trends change in the last century or so.

Research – Hot Tubs Caused Legionnaires Outbreak of 1999 Killing At Least 32

Legionella Control

One of the largest recorded outbreaks of Legionnaires’ disease

An outbreak of Legionnaires’ disease can affect many people, depending on the circumstances and how long it takes for the outbreak to be discovered. One of the largest ever known outbreaks of the disease to date took place in the Netherlands in 1999. It was named after the town in which it occurred, Bovenkarspel in Northern Holland.

The outbreak began on 25th February that year, in the middle of the Westfriese Flora, which was later renamed as the Holland Flowers Festival. The exhibition took place indoors and attracted many hundreds of visitors. The festival ended on 28th of that month, although it would not be known for some days that anything was amiss.

Research – New compound which kills antibiotic-resistant superbugs discovered

Science Daily

A new compound which visualises and kills antibiotic resistant superbugs has been discovered by scientists at the University of Sheffield and Rutherford Appleton Laboratory (RAL).

The team, led by Professor Jim Thomas, from the University of Sheffield’s Department of Chemistry, is testing new compounds developed by his PhD student Kirsty Smitten on antibiotic resistant gram-negative bacteria, including pathogenic E. coli.

Gram-negative bacteria strains can cause infections including pneumonia, urinary tract infections and bloodstream infections. They are difficult to treat as the cell wall of the bacteria prevents drugs from getting into the microbe.

Antimicrobial resistance is already responsible for 25,000 deaths in the EU each year, and unless this rapidly emerging threat is addressed, it’s estimated by 2050 more than 10 million people could die every year due to antibiotic resistant infections.

Doctors have not had a new treatment for gram-negative bacteria in the last 50 years, and no potential drugs have entered clinical trials since 2010.

The new drug compound has a range of exciting opportunities. As Professor Jim Thomas explains: “As the compound is luminescent it glows when exposed to light. This means the uptake and effect on bacteria can be followed by the advanced microscope techniques available at RAL.

RASFF Alerts – Animal Feed – Salmonella – Poultry Protein – Fish Meal – Soy Flakes – Organic Soya Cake

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RASFF – Salmonella (presence /25g) in processed poultry protein from Spain in Belgium

RASFF – Salmonella enterica ser. Derby (presence /25g), Salmonella enterica ser. Kalina (presence /25g) and Salmonella enterica ser. Lexington (presence /25g) in fish meal from Mauritania in Greece

RASFF – Salmonella enterica ser. Mbandaka (in 2 out of 8 samples /25g) in organic soya cake from Denmark in Sweden

RASFF – Salmonella enterica ser. Mbandaka (presence /25g) in soy flakes from the Netherlands in Belgium

Research – Microbe Profile: Listeria monocytogenes: a paradigm among intracellular bacterial pathogens

Microbiology Research

Listeria monocytogenes is a food-borne bacterial pathogen that is responsible for listeriosis, a disease characterized by occasional febrile gastroenteritis in immunocompetent individuals, abortions in pregnant women, meningitis in the newborn and fatal bacteraemia in immunocompromised individuals or the elderly. The ability of L. monocytogenes to produce disease is intimately associated with its potential to traverse several human barriers (including the intestinal, placental and blood/brain barriers), to promote its internalization within diverse populations of epithelial cells and to proliferate in the intra-ic environment while escaping host immune responses. L. monocytogenes is often regarded as a paradigm for intracellular parasitism.

USA – The Village Company Issues Voluntary Nationwide Recall of La Bella Extreme Sport Styling Gel Due to Bacterial Contamination

FDA

On May 24, 2019, The Village Company initiated a voluntary nationwide recall of the 22-ounce La Bella Extreme Sport Styling Gel. Four lots failed micro testing due to bacterial contamination, resulting in potential contamination of 2,377 cases (or 9,508 units). The bacteria found is Burkholderia cepacia and a group of related strains.

Burkholderia cepacia and group of related strains rarely cause infections in healthy people, but pose serious risk to individuals with cystic fibrosis, weakened immune systems, and chronic lung disease. If you are feeling ill after having used the product, consult with your doctor. Washing your hands, hair brush, combs and other hair items, counter tops and other surfaces with warm soapy water are good practices to help prevent the spread of bacteria.

The Village Company has not received any reports from consumers related to this recall. Consumers who have a product from any of the affected lots should stop using it immediately.

The recalled La Bella Extreme Sport Styling Gel was manufactured by Kapra Cosmetics, Inc. (Kapra) and distributed to retail starting March 5, 2019.

The following lot numbers have been recalled:
La Bella Extreme Sport Styling Gel
Lot Numbers: 19057B, 19072C, 19072E, 19072G
22-ounce bottle