Monthly Archives: January 2018

Research – The potential spread of infection caused by aerosol contamination of surfaces after flushing a domestic toilet

Wiley Online

Aims:  To determine the level of aerosol formation and fallout within a toilet cubicle after flushing a toilet contaminated with indicator organisms at levels required to mimic pathogen shedding during infectious diarrhoea.

Conclusions:  Although a single flush reduced the level of micro-organisms in the toilet bowl water when contaminated at concentrations reflecting pathogen shedding, large numbers of micro-organisms persisted on the toilet bowl surface and in the bowl water which were disseminated into the air by further flushes.

Significance and Impact of the Study:  Many individuals may be unaware of the risk of air-borne dissemination of microbes when flushing the toilet and the consequent surface contamination that may spread infection within the household, via direct surface-to-hand-to mouth contact. Some enteric viruses could persist in the air after toilet flushing and infection may be acquired after inhalation and swallowing.

Research – Potential for aerosolization of Clostridium difficile after flushing toilets: the role of toilet lids in reducing environmental contamination risk

Science Direct

Summary

Background

Toilet facilities in healthcare settings vary widely, but patient toilets are commonly shared and do not have lids. When a toilet is flushed without the lid closed, aerosol production may lead to surface contamination within the toilet environment.

Aim

To substantiate the risks of airborne dissemination of C. difficile following flushing a toilet, in particular when lids are not fitted.

Methods

We performed in-situ testing, using faecal suspensions of C. difficile to simulate the bacterial burden found during disease, to measure C. difficile aerosolization. We also measured the extent of splashing occurring during flushing of two different toilet types commonly used in hospitals.

Findings

C. difficile was recoverable from air sampled at heights up to 25 cm above the toilet seat. The highest numbers of C. difficile were recovered from air sampled immediately following flushing, and then declined 8-fold after 60 min and a further 3-fold after 90 min. Surface contamination with C. difficile occurred within 90 min after flushing, demonstrating that relatively large droplets are released which then contaminate the immediate environment. The mean numbers of droplets emitted upon flushing by the lidless toilets in clinical areas were 15–47, depending on design. C. difficile aerosolization and surrounding environmental contamination occur when a lidless toilet is flushed.

Conclusion

Lidless conventional toilets increase the risk of C. difficile environmental contamination, and we suggest that their use is discouraged, particularly in settings where CDI is common.

Research – Intensified Sampling in Response to a Salmonella Heidelberg Outbreak Associated with Multiple Establishments Within a Single Poultry Corporation

Science Direct

On June 28, 2013, the Food Safety and Inspection Service (FSIS) was notified by the Centers for Disease Control and Prevention (CDC) of an investigation of a multistate cluster of illnesses of Salmonella enterica serovar Heidelberg. Since case-patients in the cluster reported consumption of a variety of chicken products, FSIS used a simple likelihood-based approach using traceback information to focus on intensified sampling efforts. This article describes the multiphased product sampling approach taken by FSIS when epidemiologic evidence implicated chicken products from multiple establishments operating under one corporation. The objectives of sampling were to (1) assess process control of chicken slaughter and further processing and (2) determine whether outbreak strains were present in products from these implicated establishments. As part of the sample collection process, data collected by FSIS personnel to characterize product included category (whole chicken and type of chicken parts), brand, organic or conventional product, injection with salt solutions or flavorings, and whether product was skinless or skin-on. From the period September 9, 2013, through October 31, 2014, 3164 samples were taken as part of this effort. Salmonella percent positive declined from 19.7% to 5.3% during this timeframe as a result of regulatory and company efforts. The results of intensified sampling for this outbreak investigation informed an FSIS regulatory response and corrective actions taken by the implicated establishments. The company noted that a multihurdle approach to reduce Salmonella in products was taken, including on-farm efforts such as environmental testing, depopulation of affected flocks, disinfection of affected houses, vaccination, and use of various interventions within the establishments over the course of several months.

 

Research – Microbial Biogeography of Public Restroom Surfaces

PlosOne

We spend the majority of our lives indoors where we are constantly exposed to bacteria residing on surfaces. However, the diversity of these surface-associated communities is largely unknown. We explored the biogeographical patterns exhibited by bacteria across ten surfaces within each of twelve public restrooms. Using high-throughput barcoded pyrosequencing of the 16 S rRNA gene, we identified 19 bacterial phyla across all surfaces. Most sequences belonged to four phyla: Actinobacteria, Bacteriodetes, Firmicutes and Proteobacteria. The communities clustered into three general categories: those found on surfaces associated with toilets, those on the restroom floor, and those found on surfaces routinely touched with hands. On toilet surfaces, gut-associated taxa were more prevalent, suggesting fecal contamination of these surfaces. Floor surfaces were the most diverse of all communities and contained several taxa commonly found in soils. Skin-associated bacteria, especially the Propionibacteriaceae, dominated surfaces routinely touched with our hands. Certain taxa were more common in female than in male restrooms as vagina-associated Lactobacillaceae were widely distributed in female restrooms, likely from urine contamination. Use of the SourceTracker algorithm confirmed many of our taxonomic observations as human skin was the primary source of bacteria on restroom surfaces. Overall, these results demonstrate that restroom surfaces host relatively diverse microbial communities dominated by human-associated bacteria with clear linkages between communities on or in different body sites and those communities found on restroom surfaces. More generally, this work is relevant to the public health field as we show that human-associated microbes are commonly found on restroom surfaces suggesting that bacterial pathogens could readily be transmitted between individuals by the touching of surfaces. Furthermore, we demonstrate that we can use high-throughput analyses of bacterial communities to determine sources of bacteria on indoor surfaces, an approach which could be used to track pathogen transmission and test the efficacy of hygiene practices.

Research – Biofilm formation and genetic characterization of New Zealand Cronobacter isolates

Wiley Online Library 

The study aimed to determine genetic diversity of a collection of New Zealand Cronobacter isolates collected from different sources and their ability to form a biofilm on different materials under different conditions. Isolates were screened for the presence of biofilm associated genes. Furthermore, suppression subtractive hybridization (SSH) was used to identify unique genes, present in a C. sakazakii strain (isolate ES191) which forms a stronger biofilm than the reference strain C. sakazakii BAA894. Results indicated that New Zealand Cronobacter spp. strains were genetically diverse. Biofilm formation was both temperature and nutrient dependent and varied widely within and between clinical, dairy, and environmental isolates. Moreover, C. akazakii adhered more to polyvinyl chloride followed by silicone, polyurethane and stainless steel and all the isolates harbored biofilm related genes. Of the 72 PCR products sequenced from the SSH library, 16 unique gene sequences were identified, of which nine were expressed only in ES191 and were found to be involved in hypothetical protein, energy production, and virulence. This study suggests the choice of enteral neonatal feeding tube material could dramatically influence the attachment, growth, and biofilm formation of C. sakazakii.

 

UK – 918 cases of E.Coli blood poisoning in Devon as county sees cases rocket

Devon on Line

The number of potentially-lethal blood infections caused by E. Coli in Devon has increased more than the national average in one year.

Across Devon there were 918 cases of E. Coli infecting the blood stream – called bacteraemia – in 2016/17.

That was a 10% increase on the 836 cases recorded the year before.

Bacteraemia is a serious infection that occurs when bacteria get into the bloodstream. It may lead to sepsis and can be fatal.

E. Coli is a blanket name given to several species of bacteria – in the same way that humans all belong to the same species but are not identical to each other.

RASFF Alerts – Salmonella -Frozen Raw Chicken Breast – Organic Sesame Seeds -Pork and Calf Meat Sausage

kswfoodworld food safety poisoning

RASFF-Salmonella enterica ser. Enteritidis (present /25g) in frozen raw chicken breast fillets from Thailand in the UK

RASFF -Salmonella (in 3 out of 5 samples /25g) in organic sesame seeds from Nigeria in the Netherlands

RASFF-Salmonella (presence /10g) in pork and calf meat sausage from the Netherlands in the Netherlands

RASFF Alerts – Ochratoxin A – Raisins – Dried Figs

kswfoodworld food safety poisoning

RASFF-ochratoxin A (34.2 µg/kg – ppb) in raisins from Turkey in Bugaria

RASFF-ochratoxin A (47 µg/kg – ppb) in dried figs from Turkey in Germany

RASFF Alert -Vibrio vulnificans – Wild Raw Giant Tiger Shrimps

kswfoodworld food safety poisoning

RASFF-Vibrio vulnificus (in 4 out of 5 samples /25g) in frozen wild raw giant tiger shrimps (Penaeus monodon) from Indonesia in France

RASFF Alert – Listeria monocytogenes – Frozen Organic Pumpkin and Carrot Cream

kswfoodworld food safety poisoning

RASFF-Listeria monocytogenes (present /25g) in frozen organic pumpkin and carrot cream from Italy in Italy