Exiguobacterium aurantiacum virulent pigment producing a novel pathogenic bacteria associated with cases of corneal ulcers

Abstract

Blindness is a major public health problem in most developing countries. Corneal ulcer (Keratitis) is a major cause of blindness throughout the world. About 10% cases of blindness are due to corneal ulcer. "Corneal ulcer means loss of corneal substances as a result of infection and formation of raw, excavated area." Bacterial keratitis is an acute or chronic, transient or recurrent infection of the cornea with varying predilection for anatomical and topographical parts of the cornea like marginal or central. This study demonstrates the Novel pathogenic bacteria Exiguobacterium aurantiacum with bad pigment production, which are causing corneal ulcer and determine the best possible empirical therapy and specific therapy. Particular attention should be given to this condition as it can progress very rapidly with complete corneal destruction can be occur within 24-48 hours.

Pseudomonas gessardii—A novel pathogenic bacterium associated with the cases of corneal ulcers and producing virulent pyoverdine pigment

“…The present study utilized the pigment extraction technique mentioned in Jain and Kamble's [16] and Shatila et al's [17] studies.…”

“…The scavenging activity assay was carried out using methods by Jain and Kamble [16], Awah et al [18], Parul et al [19], and Iheanyichukwu et al [20]. The chemicals used were sodium nitroprusside (10 mM), methanol and Griess reagent (1% sulfanilamide in 5% phosphoric acid and 0.1% naphthyl ethylenediamine dihydrochloride).…”

First Isolation of Exiguobacterium aurantiacum in Serbia

“… Pitt et al (2007) determined susceptibility of E. aurantiacum to all tested antimicrobial drugs, as we did in our study, while Jain with associates (2018) and Chen with collaborators (2017) determined the susceptibility of the bacteria to penicillin, meropenem, gentamicin, ciprofloxacin and rifampicin, and their resistance to tetracycline, erythromycin, clindamycin. The susceptibility to vancomycin was railed in these two studies; the bacteria were sensitive according to Chen et al (2017) and resistant in the publication of Jain and Kamble (2018) . It has been shown that environmental bacteria are involved in the horizontal flow of resistance genes.…”

“…They form orange-yellow pigmented colonies on blood agar ( Takemura et al 2009 ). E. aurantiacum has been very rarely reported to cause infections in humans worldwide, such as bacteremia in the UK, corneal ulcers in India, and pneumonia in China ( Pitt et al 2007 ; Chen et al 2017 ; Jain and Kamble 2018 ), however, in most works, the origin of the infection is still unclear.…”

“…Based on literature reviews, E. aurantiacum is isolated occasionally from various human clinical specimens like blood, broncho-alveolar lavage fluid, or corneal ulcers in only a few countries worldwide, such as the UK, China, and India. In most cases, the origin of the infection remained unclear or unknown, while in pneumonia, the inhalation route was confirmed, and in corneal ulcer, the connection with contact lenses was certified ( Pitt et al 2007 ; Chen et al 2017 ; Jain and Kamble 2018 ). Our research concluded that the source of bacteria was distilled water, especially since the same pathogen was reisolated from the repeated samples of distilled water.…”