Yes, antibiotics have been used to treat these infections, but antibiotic success is not assured. Injectable antibiotics are slow to act systemically if they work at all. A report on bacterial samples from 45 swine farms in 5 US swine-producing states documented the commonality of methicillin resistant S. aureus (MRSA), highlighting a key threat to animals and humans.⁸ The bacteria referred to as “superbugs” were found in swab samples from pigs, from workers on the same farms, and from others in the workers’ households. One of the MRSA used in the present study was selected from among those represented in the swab survey’s findings. This research details the extent to which Oinkment, a spray-on flexi-film bandage containing GRAS OTC microbiocidal components, sterilized two MRSA pathogens, one known to infect both pigs and pig farm workers, and a pig epidermal S. hyicus, the infectious agent responsible for exudative dermatitis or greasy pig disease.

MATERIALS AND METHODS

Researchers tested the antimicrobial effect of Oinkment spray bandage against three pathogenic Staphylococcus bacteria isolates.9

1. S. aureus ATCC 6538 MRSA
2. S. aureus ATCC BAA-41, MRSA with t002 gene reported in swine and farm workers
3. S. hyicus ATCC 11249 isolated from pig epidermis

Procedure: Triplicates of plate count agar were inoculated with 10µl of a 24-hour culture of each of the test bacteria grown in MacFarland suspension. Oinkment was applied to a 47mm diameter area of the bacteria-inoculated plate and the bandage remained in contact for varying durations of 4 hours, 8 hours, and 24 hours. After the contact time elapsed the bandage film was removed, the plate was incubated for 24 hours, then inverted and incubated at 30-35°C for 18-24 hours. The diameter of the original bandaged area was assessed for bacterial growth, along with the area of no bacterial growth extending beyond the edges of the bandaged area. Bandaged plates were compared to non-bandaged control plates inoculated with the same organism and non-inoculated media control plates.¹⁰

RESULTS

Inoculated control plates contained copious bacterial overgrowth, too numerous to count, confirming the organism viability and the adequacy of the test conditions. Control plates containing media alone contained no growth, indicating there was no unintended bacteria present in the test system.

No bacteria remained viable under the area contacted by the 47mm diameter bandage for any of the organisms at any contact duration, exhibiting Oinkment’s antibacterial effect when in direct contact with the underlying pathogenic bacteria (Table).

Beyond the bandage edge for most of the organism and contact time combinations, additional areas of bactericidal effect expanded the bacteria kill zones. These expanded zones demonstrated that the bandage’s antimicrobial impact indirectly reached beyond the area contacted by the bandage material. Specifically, the total area of bacterial elimination of S. aureus ATCC 6538 increased, ranging 137-152% of the area directly under the bandage. The total sterilization area of S. aureus ATCC BAA-41 ranged 142-174% of the treated area. The S. hyicus ATCC 11249 bacteria exhibited less susceptibility to this expansion, ranging 100-118%. The extent of these additional kill zones on the culture plates is a function of each organism’s susceptibility to the antimicrobials migrating through the culture plate media. Such migration and kill zone expansion may not be as extensive in vivo, highlighting the importance of complete wound coverage when spraying the bandage.

The antibacterial effect was swift as well as pronounced, evidenced by each of the organisms being completely killed at the shortest 4 hour contact time (Figure). This evidence reinforces the importance of quickly spraying the bandage on piglet processing incisions and responding to open cuts and abrasions as soon as they are identified to initiate effective wound care.

CONCLUSIONS AND APPLICATIONS

Accelerating healing through good wound care requires a moist, clean environment, free from contaminants and dead tissue, encouraging fresh cells to infiltrate to the exposed wound. Oinkment’s flexi-film spray supports this need, adhering to skin, conforming to the body shape, supplementing the natural function of a scab (which is frequently abraded off in live production environments), sealing out filth and holding in moisture.

Despite managers tending to these vital physical wound care techniques, a wound that remains contaminated with invisible, often antibiotic-resistant organisms, cannot repair itself optimally. This study definitively established that the non-antibiotic antimicrobial action embedded in Oinkment’s spray film can completely sterilize harmful Staphylococcus organisms common in swine farms within 4 hours of being applied. Safe and non-toxic, the microbiocidal skin protectant, analgesic, and antifungal elements in Oinkment support AMDUCA compliance, being approved as OTC in 21 CFR 310.545. They, along with all other components, are also affirmed as GRAS in the 21 CFR list of direct food substances. The bandage contains no antibiotics and requires no preslaughter withdrawal.

While the wound is healing, the film covering remains in place to protect the bed of fragile fresh cells, helping new tissue stay soft and pliable. The wound remains sealed as the film adheres to the healthy skin surrounding the wound. It is not necessary to remove the patch, but if it is removed gently with moisture or by environmental abrasion, the adhering film will debride the wound, removing dead tissue and dirt to facilitate clean growth. Re-applying the spray patch daily or as needed keeps the area sealed and on-the-mend, contributing positively to animal health, welfare, and farm productivity.

Figure. Photos comparing bacterial growth on control culture plates with no Oinkment® versus plates treated with Oinkment spray bandage applied for 4 hours

^aControl plates demarking the central untreated 47mm diameter target areas and illustrating copious bacterial growth to the plate edge, too numerous to count (TNTC).

^bBacteria-free area of plates treated with Oinkment spray bandage. Clear kill zones include the 47mm diameter Oinkment application area plus indirect elimination extending beyond the margins of the Oinkment application. Mean of 3 replicates of each culture plate.

REFERENCES AND NOTES

1. Anonymous. Abscesses. 5m Publishing, Sheffield, England. Accessed online May 2020.
https://thepigsite.com/disease-guide/abscess

2. Meyer, D., M. Hewinker-Trautwein, M. Hartmann, L. Kreienbrock and E. Grosse. 2019. Scoring shoulder ulcers in breeding sows – is a distinction between substantial and insubstantial animal welfare-related lesions possible on clinical examination? Porc Health Manag 5, 3. Accessed online May 2020.
https://porcinehealthmanagement.biomedcentral.com/articles/10.1186/s40813-018-0108-3

3. Anonymous. Preputial ulceration. 5m Publishing, Sheffield, England. Accessed online May 2020.
https://thepigsite.com/disease-guide/preputial-ulcers

4. Anonymous. Vice (tail-biting, flank chewing, ear biting). 5m Publishing, Sheffield, England. Accessed online May 2020.
https://thepigsite.com/disease-guide/vice-abnormal-behaviour-tail-biting-flankchewing-ear-biting

5. Greiner, L. 2012. Understanding umbilical hernias. National Hog Farmer. Accessed online May 2020.
https://www.nationalhogfarmer.com/health/understanding-umbilical-hernias

6. M. Giles. 2019. Small-scale pig keeping: prohibiting zoonotic pathogens. 5m Publishing, Sheffield, England. Accessed online May 2020.
https://thepigsite.com/articles/small-scale-pig-keeping-prohibitingzoonotic-pathogens

7. Edwards, L. 2019. What can pig carcasses tell us about farm welfare? 5m Publishing, Sheffield, England. Accessed online May 2020.
https://thepigsite.com/articles/what-can-pig-carcases-tell-usabout-farm-welfare

8. Smith, T.C., W.A. Gebreyes, M.J. Abley, A.L. Harper, B.M. Forshey, M.J. Male, H.W. Martin, B.Z. Molla, S. Sreevatsan, S. Thakur, M. Thiruvengadam and P.R. Davies. 2013. Methicillin-resistant Staphylococcus aureus in pigs and farm workers on conventional and antibiotic-free swine farms in the USA. PLoS One. Accessed online May 2020.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3646818/

9. Pearce, P.J. 2020. Personal communication. Report of antimicrobial susceptibility assessment performed by Nova Biologicals, Inc. Conroe, Texas, USA.

10. Hudzicki, J. 2009. Kirby-Bauer disk diffusion susceptibility test protocol, American Society for Microbiology. Manual of Microbiology, 9th ed. 2007 FAO JECFA Monograph, vol 4.