Bacillus oleronius and Demodex mite infestation in patients with chronic blepharitis

Abstract

To better recognize the pathogenicity of ocular Demodex mites, we analysed Bacillus oleronius infection in patients with Demodex-related chronic blepharitis. The studies were conducted on 68 adult patients, in whom ophthalmological and parasitological tests permitted the distinction of a group of 38 patients with a diagnosis of Demodex-related chronic blepharitis (group 1, including a subgroup 1a with moderate blepharitis and a subgroup 1b with severe blepharitis) and a group of 30 healthy individuals (group 2). In every person studied six eyelashes were epilated from each eye and the number of Demodex per eyelash was scored. In parallel, bacterial culture and isolation allowed their phenotypic and molecular identification. The drug sensitivity of the isolates was tested using E-tests. Intensity of Demodex infestation showed no significant differences between subgroups 1a and 1b. From the epilated eyelashes 23 bacterial isolates were obtained, identified as being B. oleronius. All the studied strains were sensitive to ciprofloxacin, doxycycline and gentamicin. The Demodex mite represents an independent aetiopathogenetic factor in blepharitis. In parallel, the parasite may act as a carrier of B. oleronius bacteria, which most probably function as a co-pathogen in the development of severe forms of blepharitis.

Blepharitis and Demodex spp. infection

“…Lacey et al [48] isolated Bacillus oleronius from within the D. folliculorum of a patient of acne rosacea and specific antigens from the serum of examined patients. Similar results were reported by Szkaradkiewicz et al [49]. They described both Demodex spp.…”

Prospective evaluation of intense pulsed light and meibomian gland expression efficacy on relieving signs and symptoms of dry eye disease due to meibomian gland dysfunction

“…By treating rosacea, this obstruction can be considerably reduced. Other explanations include facilitating expression by softening the meibum as a result of heat transfer to the eyelids and meibomian glands;13 upregulating anti-inflammatory molecules, such as interleukins;34 augmenting the production of collagen by stimulating fibroblasts;35 and eradicating Demodex mites,36 which thrive on rosacea skin and are infested with Bacillus olerinus 37. This would have the indirect effect on decreasing the bacterial load on the eyelids.…”

Rosacea: a clinical review

“…Bacillus oleronius is a Gram-negative bacteria isolated in Demodex. 17 The bacteria are sensitive to tetracyclines. There is a very complex microbiota in Demodex mites from rosacea patients.…”