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MARCoNS Nasal Swab Testing

Louise Carder
Louise Carder
Written on
April 20, 2022

Nasal Swab Testing

More than 7000 litres of air is breathed in every day by the average healthy human adult.  With that air comes 104 - 106 bacterial cells per cubic metre of air (Kumpitsch etc al 2019). The upper respiratory area has therefore a variety of micro-environments that are home to microorganism colonies. Whilst this microbiome has been extensively studied with regards to bacteria, less well-studied are frequency of virus or fungal organisms.


Certain species of bacteria are known to highly associate with chronic sinusitis and these include H.influenzae, S. pneumoniae, B.catarrhalis and S.pyogenes (Jousimies-Somer et al. 1989). These bacteria predominate with a loss of overall variety and other key commensal species.  As with the gut where most of the work has been undertaken on ‘dysbiosis’ we should consider that sino-nasal dysbiosis may be just as relevant for optimal health.


Going beyond the bacteria themselves is also becoming increasingly important with laboratories now able to measure the level of biofilm for key species.  When it comes to Chronic Inflammatory Response Syndrome (CIRS) the presence of biofilm relating to Multiply Antibiotic Resistant Coagulase Negative Staphylococcus (MARCoNS) is of critical importance.


Coag. Neg. Staph. is not an unusual bacteria to find in the sinuses.  However, antibiotic resistance  to 2 or more antibiotics is unusual. Studies indicate that in patients with low alpha melanocyte stimulating hormone (aMSH) 80% of nasal cultures were positive for MARCoNS. In those with normal aMSH levels the MARCoNS positive results were less than 1% (Shoemaker, 2004).  Why might this be?


The most significant aspect of MARCoNS biofilm is the ability of the bacteria to produce exotoxins which break down alpha Melanocyte Stimulating Hormone (aMSH) locally in the sinuses. It is not uncommon to see low aMSH on CIRS biomarker testing, due to wider CIRS-related inflammatory effects on the pituitary.


aMSH and MARCoNS have a bidirectional relationship. Under normal conditions, aMSH protects the mucus membranes in the nose from colonisation. aMSH deficiency eliminates the protective barrier.  As aMSH is produced in the pituitary we have to consider that pituitary function may have been compromised when levels are low, or that biofilm formation/MARCoNS/MARCoNS by-products have been excessively advantageous.


In addition, studies indicate MARCoNS/by-products can:

•  Suppress mitochondrial RNA (Shoemaker 2018)

•  Induce grey matter atrophy (Shoemaker, 2018)

•  Support transference of drug resistance between other organisms (Zhen Xu et al 2018)

•  Express membrane damaging factors e.g. hemolysins and PSMs (Vandenesch et al 2012)

Reasons to Consider Nasal Swab Testing

Nasal swab testing can be an important first-step in assessing the nasal biome, but there are several other reasons to consider nasal swab testing, especially in relation to the CIRS picture:

1. Symptoms and/or history of sinusitis or post-nasal drip- find out what is present!

2. Confirmation of MARCoNS presence + biofilm for CIRS consideration

3. Confirmation of fungi/mould exposure

4. Concern over downstream effects of ongoing stealth infections in the sinuses e.g. Bredesen’s Type 3 Cognitive Decline (Inhalational Alzheimer’s) or other microbiome related changes that are associated with other conditions e.g. M.S., Parkinson’s

5. Greater understanding of antibiotic resistance in a patient (perhaps in addition to stool testing)

6. Connecting the dots for long term sub-clinical anaemia patients (evidence of hemolysin-producers)

7. Consideration of reservoir source of opportunistic bacteria in the gut (contextualising stool testing)

8. Re-testing to track progress


In the case of CIRS though what are we testing for?

MARCoNS is found primarily colonising the human nasopharynx but can also be found in:

•   Dogs noses(they can also become infected from our infections!)

•   Dental Cavitation's

•   Foreign body replacements such as joints and valves


The work of Dr Shoemaker showed that if MARCoNS is not eradicated then the therapeutic process can stall. This work was underscored when genomic testing began in 2011-12 and it was identified that suppression of mitoribosomal function was associated with the presence of MARCoNS (Shoemaker2018).  Eradication of MARCoNS is therefore front and centre in the Shoemaker Protocol.  It sits at step 3 of 12, coming after removal from exposure and initiation of binder therapy.


Eradication can take between 30 days and 6 months with the idea being to eradicate MARCoNS in conjunction with monitoring aMSH levels.  If aMSH levels are not sufficiently robust then re-colonisation may be more likely to occur. Currently EDTA nasal spray is the Shoemaker recommended treatment, alongside natural therapeutics such as Formula 1 NSB, Grapefruit seed extract or WHisoBAX (witch hazel) nasal sprays.  N-acetyl cysteine and EDTA in particular are recognised biofilm-busters!  The historic BEG spray is no longer recommended.


To conclude, MARCoNS is of paramount importance as it shows that our own natural defences are compromised. The focus of that compromise is aMSH, but we must also remember that there are many immune factors in the sino-nasal environment that offer protection and that a healthy nasal microbiome is something we should all be striving for.


Colab Services Limited offer the full suite of nasal swab testing. Bacteria (including assessment for MARCoNS, Fungi and Biofilm can all be tested and individual testing can be undertaken if required, especially when repeat testing.  Please contact for further details or visit



Kumpitsch, C, Koskinen K, Schöpf V, Moissl-Eichunger C The microbiome of the upper respiratory tract in health and disease BMC Biology 2019 17:87


Jousimies-Somer, HR, Savolainen S, Ylikoski JS Comparison of the nasal bacterial floras in two groups of health subjects and in patients with acute maxillary sinusitis. J. Clin. Microbiol. 1989 Dec; 27 (12): 2736-2743


Shoemaker R. Surviving Mold: Life in the Era of Dangerous Buildings. Baltimore, MD: Otter Bay Books; 2010


Shoemaker RC. MARCoNS, biofilms and extracellular products.  What are those bacteria making?(presentation, 4th Annual CIRS Conference, Salisbury, Maryland, 2018 May 4-6)


Zhen Xu et al. The prevalence, antibiotic resistance and mecA. Characterisation of coagulase negative staphylococci recovered from non-healthcare settings in London, UK. Anti biotic Resistance and Infection Control (2018) 7:73


Vandenesch, F, Lina G, Henry, Thomas “Staphylococcus aureus hemolysins, bi-component leukocidins and cytolytic peptides: a redundant arsenal of membrane-damaging virulence factors? Frontiers in Cellular and Infection Microbiology (2012) 16 February