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Examination of intramammary devices from infected and uninfected mammary quarters by scanning electron microscopy
Abstract:
Polyethylene intramammary devices were removed from six infected and four uninfected mammary quarters of seven lactating cows and examined by scanning electron microscopy. Infecting organisms included Corynebacterium bovis, coagulase-negative staphylococci, and an unidentified fungus. Intramammary devices from infected quarters had amorphous material adhering to large areas of the polyethylene. Large numbers of inflammatory cells and microorganisms were found concentrated within the material. Devices from uninfected quarters had less amorphous material with few adhering inflammatory cells. The amorphous material appeared to be restricted to abraded surfaces of the polyethylene. Milk somatic cell counts in stripping milk of quarters infected with Corynebacterium bovis and coagulase-negative staphylococci before and 3 wk after removal of intramammary device averaged 1.2 X 10(6) and .2 X 10(6)/ml, respectively. Results suggest that increased cell counts of infected quarters containing intramammary devices were associated with microbial colonization of the amorphous material.
Insights
Polyethylene intramammary devices in infected cow udders accumulate inflammatory cells and microbes on their surface. Removing these devices reduced milk somatic cell counts, suggesting a link between device contamination and infection.
Area of Science:
- Veterinary Medicine
- Microbiology
- Materials Science
Background:
- Intramammary devices are used in cattle, but their role in infection is not fully understood.
- Polyethylene devices can become colonized by microorganisms and host inflammatory cells.
Purpose of the Study:
- To investigate the surface characteristics of polyethylene intramammary devices from infected and uninfected bovine mammary quarters.
- To correlate device findings with milk somatic cell counts and microbial presence.
Main Methods:
- Scanning electron microscopy was used to examine intramammary devices from seven lactating cows.
- Devices were collected from both infected and uninfected mammary quarters.
- Milk somatic cell counts were analyzed before and after device removal.
Main Results:
- Infected devices showed significant adherence of amorphous material, inflammatory cells, and microorganisms (Corynebacterium bovis, coagulase-negative staphylococci, fungus).
- Uninfected devices had minimal material and fewer inflammatory cells, primarily on abraded surfaces.
- Removal of devices from infected quarters led to a decrease in milk somatic cell counts.
Conclusions:
- The amorphous material on polyethylene intramammary devices facilitates microbial colonization and contributes to inflammation.
- Device-associated microbial contamination is linked to elevated milk somatic cell counts in infected quarters.