In the past, I worked a lot on the seafood safety side of fisheries. When a fish is on deck, it is no longer just a fish; it has turned into food, and as such, there is a whole universe of rules, compliance, and operations that go along with it. And as usual, not many people with practical experience in fisheries are involved.
I took that whole side of fisheries quite seriously particularly when I migrated to NZ, at some stage I was responsible for most of the HACCP plans in the country and went all the way to do a Masters in Food Science in 2000 (on top of my one in Fisheries Science from 1991)… and while I enjoy that part of the work particularly in the area of EU market access conditions for vessels and landing sites (areas I still work with a bit), I moved back to fisheries that is where my hearth really is.
I keep an eye on papers on cold chain issues, histamine, and hygiene. And one of our tenants on boats, where seawater is free, is to hose down everything to death; seawater is an excellent cleaner… and we assume that with some sanitation and a good hose-down with seawater, everything should be alright.
So when I read this paper “Biofilms in water hoses from the food processing environment harbour diverse microbial communities”, which deals with the presence and composition of biofilms inside the hoses, my heart sank a bit… as if seafood safety is not complicated in itself already… sure it is in fresh water… but chances are that there would be similar biofilms with more halophilic bacteria that hopefully have low link to known pathogens like Pseudomonsa. In any case, an interesting paper and a future headache for my colleagues still working in the seafood processing arena
The study examines the presence and composition of biofilms in water hoses used in a meat processing environment. Biofilms, which are communities of microorganisms embedded in a matrix, can harbour bacteria and fungi, including opportunistic pathogens, thereby posing health risks and contamination threats in food processing facilities. The research focused on eight-month-old water hoses, sampled three times at six different locations within the facility.
Using optical coherence tomography (OCT), researchers visually examined the inner surfaces of the hoses and detected visible biofilms in 2 of them. However, biochemical analyses revealed biofilms in 14 of 15 tested hoses, indicating that OCT is less sensitive for biofilm detection than biochemical methods. The study defined biofilms as the presence of bacteria and/or fungi, confirmed by qPCR, along with at least two extracellular matrix components (carbohydrates, proteins, and extracellular DNA).
Bacteria were detected in all samples, with bacterial loads ranging from 0.93 to 5.93 log10 BCE/cm². Fungi were detected in all but one sample, with fungal loads ranging from 0.05 to 4.32 log10 FCE/cm².
The concentration of biofilm matrix components varied significantly across the hoses, suggesting heterogeneity in biofilm composition despite similar environmental conditions. The bacterial community analysis revealed that Mycobacterium was the most abundant genus across all samples, followed by unclassified Comamonadaceae, Rhodobacteraceae, Rhodococcus, and Ketobacter.
Opportunistic pathogens, such as Legionella and Pseudomonas, were detected at low levels, with Legionella present in all hoses except one. Meat spoilage bacteria, including Pseudomonas and Stenotrophomonas, were also identified in low abundances.
The fungal community showed low diversity, with Trichoderma being the most prevalent genus, followed by Sistotrema, Polyschema, and Asterostroma. Trichoderma, known for its potential health risks to immunocompromised individuals, was detected in all hoses except one.
The study found significant differences in the beta diversity of bacterial communities between hoses from different sampling locations, suggesting that factors such as water pressure and frequency of use may influence biofilm composition.
For instance, hoses used weekly showed no significant differences in bacterial load or biofilm matrix components compared to those used daily. The study also noted that fibres within the hoses' inner surfaces might contribute to biofilm growth.
The findings highlight the potential risks posed by biofilms in water hoses, including contamination of food processing environments through water flow and aerosols. Despite using the same hose material, the same water source, and similar environmental conditions, biofilms were highly heterogeneous.
The study emphasises the need for further research to understand the factors influencing biofilm formation and microbial community diversity in water hoses. This knowledge is crucial for improving hygiene standards and ensuring food safety in processing facilities.
In conclusion, water hoses in food processing environments are prone to biofilm formation, which can harbour diverse microbial communities, including opportunistic pathogens and spoilage bacteria. The study underscores the importance of addressing biofilm formation to mitigate contamination risks and enhance food safety.