IM has discussed about alternative methods for the detection of hazardous or harmful bacteria with Dr. Elias Hakalehto.
It is most important to know the pathogens which will appear in patient samples. Clinical microbiologists shall know who are the enemies of the ill people: their metabolic capabilities, antibiotic resistence patterns etc. Their overall features are easy to find from literature or internet whenever the name of the species is known. This identification can be performed by selective cultivations on agar plates or in PMEU incubator, and further tests like microscopic examinations, API ID systems, immunological tests and/or PCR can be done to confirm the basic identification.
Paper mill is definitely another challenge for microbiologist. In some (relatively rare cases) the names of microorganisms are important to know: if the product shall have high hygiene quality (like LPB and other food-grade cartonboards) or questions about bioterrorism have been arisen (spore-forming Bacillus anthracis as an example). The occurrence of Legionella pneumophila is also a risk in the waste water treatment of paper industry today. Selective cultivations, either on plates or in PMEU, are the solid solutions for continuous microbiological control in those cases. PMEU is preferred because its speed (hours, compared to days with colony count analyses).
Papermakers shall focus more on the metabolic activities than the names of bacteria which they are living with in paper mills, however. Continuous inoculation of the paper production processes by contaminants, delivered with incoming lots of starches, mineral fillers, raw water, dry pulp etc. shall be controlled to avoid spoilage (amylolytic activity as an example), biofilm and slime growth, tastes and odours, spots and colours in the product etc. Because the wide range of bacterial species and their origin from the nature itself, clinical methods do not suit very well for this monitoring. There is no time to start labourous cultivations, pure cultures and identifications when the bacterial input continues day and night, "7/24". PMEU seems to be an excellent tool to check the basic features of process populations, their biocide resistence patterns included.
One important fact must also be taken into account. There are a lot of harmful microbes which actually cannot be cultivated on agar at all. One example are certain filamentous bacteria which may cause biofilm layers into the processes. They can be cultivated in some broths, however, but the usage of the original samples as the growth medium is the best way to detect them all. This can be done with ordinary mb laboratory equipment or with PMEU incubator.
Identification of bacterial species is still needed when the mapping of contamination routes into the processes is the subject of the study. IM will discuss about the microbiological mapping in his next posts (please see http://industrymicrobiologist.blogspot.com/).
“The way we're really going to grow the economy is to invest in people, to invest in innovation, to have the government put money in the kind of research that will create the new high-technology, BIOTECHNOLGY industries that will create millions of new jobs.” - Joseph Lieberman-
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The growth characteristics and metabolic behaviour of micro-organisms are significantly differing on solid medium from that in the liquid media. As the bacterial or other cells are surrounded by the medium in the broth, on the Petri dish they are forming colonies consisting of cells on the top of other cells. Many bacteria are able to move though, but the movement is different on the surfaces from the flagellae propelled movement in the liguid environment. According to the experience it is usually easier to get the bacterial cells to recover in the liquid nutrient broth. The most favourable site and surroundings for their recovery being the Portable Microbe Enrichment Unit (PMEU). When new microbiological standards or protocols are developed, this alternative should be taken into account. Elias Hakalehto
I agree,Elias! You have right opinions. Bacteria give their typical metabolic responses in a nutrient broth, agars are often too artificial environments for the studies of microbial metabolism.
Research of biofilm formation is another topic, but PMEU can act as a tool for those studies, too, whenever test coupons only are installed in the sampling syringaes with the original samples, containing both the representative biofilm organisms and their growth factors.
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