Comparison of culture-negative and culture-positive microbial keratitis: cause of culture negativity, clinical features and final outcome

Bhadange, Yogesh; Das, Sujata; Kasav, Mahesh K; Sahu, Srikant K; Sharma, Savitri

doi:10.1136/bjophthalmol-2014-306414

Cited by 47 publications

(48 citation statements)

References 11 publications

(12 reference statements)

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“…Although our ultimate goal in treatment of corneal ulcers is ulcer healing, our immediate objective of therapy is to eliminate the infection. Baseline culture positivity despite antibiotic therapy has been associated with poor outcomes in bacterial and fungal keratitis 8,9,12,14 Similarly, positive fungal donor rim cultures have also been shown to predict increased risk of fungal endophthalmitis after corneal transplant. 15 By contrast in our fungal smear positive population, baseline culture status did not predict clinical outcomes.…”

Section: Discussionmentioning

confidence: 99%

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The Utility of Repeat Culture in Fungal Corneal Ulcer Management: A Secondary Analysis of the MUTT-I Randomized Clinical Trial

Ray

Lalitha

Prajna

et al. 2017

American Journal of Ophthalmology

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PURPOSE To determine whether patients who had a positive repeated culture was predictive of worse clinical outcome than those who achieved microbiological cure at 6 days in the Mycotic Ulcer Treatment Trial I (MUTT-I). DESIGN Secondary analysis from a multicenter, double-masked, randomized clinical trial. METHODS Setting Multiple hospital sites of the Aravind Eye Care System, India. Study Population Patients with culture-positive filamentous fungal ulcers and visual acuity of 20/40 to 20/400 re-examined 6 days after initiation of treatment Intervention Corneal scraping and cultures were obtained from study participants at day-6 after enrollment. Main outcome Measures We assess 3-month best spectacle corrected visual acuity (BSCVA), 3-month infiltrate/scar size, corneal perforation and re-epithelialization rates stratified by culture positivity at day 6. RESULTS Of the 323 patients with smear positive ulcers enrolled in MUTT-I, 299 (92.6%) were scraped and cultured six days after enrollment. Repeat culture positivity was 31% (92/299). Among patients who tested positive at enrollment, those with positive 6-day cultures had significantly worse 3-month BSCVA (0.39 LogMAR; 95% CI: 0.24 to 0.44; P<0.001), larger 3-month scar-size (0.39 mm; 95% CI: 0.06 to 0. 73; P=0.02), were more likely to perforate or require therapeutic penetrating keratoplasty (OR: 6.27; 95% CI: 2.73 to 14.40; P<0.001), and were slower to re-epithelialize (HR: 0.33; 95% CI: 0.21 to 0.50; P<0.001) than those with a negative 6-day culture result. CONCLUSIONS Early microbiological cure on culture is a predictor of clinical response to treatment. TRIAL REGISTRATION clinicaltrials.gov Identifier NCT00996736

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Section: Discussionmentioning

confidence: 99%

“…In the Steroids for Corneal Ulcer Trial (SCUT), baseline culture positivity in bacterial ulcers despite prior appropriate antibiotic treatment was associated with worse visual acuity outcomes. 8–12 Here, we investigate the utility of repeat culture for determining prognosis and management of fungal ulcers.…”

Section: Introductionmentioning

confidence: 99%

The Utility of Repeat Culture in Fungal Corneal Ulcer Management: A Secondary Analysis of the MUTT-I Randomized Clinical Trial

Ray

Lalitha

Prajna

et al. 2017

American Journal of Ophthalmology

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“…[6][7][8] Risk of culture negativity has been associated with longer use of topical antimicrobial medication prior to specimen acquisition. 9 Lack of a sample of traumatic lens material and the absence of positive cultures does not provide for a histopathologic diagnosis. However, even with a culture's limitations, culture negativity, results of our institution's Retina Service consultation, and the patient's clinical course were consistent with a diagnosis of phacoanaphylactic uveitis.…”

Section: Discussionmentioning

confidence: 99%

Iris melanin pigment as a masquerade of Gram-positive cocci after penetrating ocular trauma

et al. 2018

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We describe a case of penetrating eye injury that resulted in a post-injury day 1 hypopyon, leading to concern for endophthalmitis and phacoanaphylaxis. A Gram stain prepared by the clinical microbiology laboratory was interpreted as Gram-positive cocci (GPC). However, when cultures returned negative, further investigation with microbiology and pathology found that what was thought to be GPC was actually iris melanin pigment. Although endophthalmitis following ocular trauma remains an important diagnosis to consider, this microbiologic masquerade of iris melanin pigment as GPC should be considered in cases where Gram stain is positive yet cultures return negative. On the first postoperative day, visual acuity with a +9.00 lens was 20/50, the hypopyon had resolved, and the

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“…The diagnosis of bacterial keratitis in eyes with a corneal ulcer was made based on the clinical characteristics [3,4], responsiveness to appropriate antibiotics, and identification of the bacteria in the corneal scrapings by one or more of the following findings: (1) detection of bacteria in smear by Gram staining, (2) positive bacterial culture, and (3) detection of the specific pathogens, e.g., Staphylococcus aureus, Pseudomonas aeruginosa, and mycobacterium species, by conventional PCR.…”

Section: Patients Eligibility and Diagnosis Criteria Of Bacterial Infmentioning

confidence: 99%

“…The exclusion of bacterial keratitis and corneal ulcers as the diagnosis was based on the clinical characteristics of "nonbacterial" keratitis, lack of the clinical characteristic of bacterial infection, responsiveness to appropriate anti-fungal or anti-viral drugs, and differential diagnosis by the exclusion diagnostic criteria [3][4][5][6][7][8][9][10], e.g., identification of fungi or acanthamoeba cysts in the corneal scrapings stained with Fungiflora Y Ⓡ , positive cultures of fungi or acanthamoeba, and the identification of a genome of fungi, acanthamoeba, human herpes virus, or adenovirus in the corneal scrapings by conventional PCR [11]. Cases with a final diagnosis of autoimmune keratitis or corneal ulcer were also classified as "non-bacterial" keratitis when these tests were negative.…”

Section: Patients Eligibility and Diagnosis Criteria Of Bacterial Infmentioning

confidence: 99%

Effectiveness of 16S ribosomal DNA real-time PCR and sequencing for diagnosing bacterial keratitis

Shimizu

Miyazaki

Ehara

et al. 2019

Graefes Arch Clin Exp Ophthalmol

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Purpose To evaluate the efficacy of real-time PCR for 16S ribosomal DNA (16S r-DNA) and sequencing for diagnosing microbial keratitis. Methods We studied 272 eyes of 272 patients with keratitis. Eyes with keratitis were classified as "definite" (N = 118), "likely" (N = 71), or "non-bacterial" (N = 83) to have bacterial keratitis. The diagnostic efficacy of real-time PCR and conventional testing was determined by receiver operating characteristic analysis. The copy numbers of bacterial DNA and clinical characteristics were retrospectively analyzed for association with concordant culture results in the "definite" cases. Results The level of bacterial DNA was significantly associated with the diagnostic probability of the three diagnostic categories. The level of bacterial DNA had comparable diagnostic efficacy with the area under the curve (AUC) at 0.67, by culture at 0.65, and by smear testing at 0.73. The efficacy was significantly improved by combining the DNA level with the conventional culture testing with an AUC of 0.81. Analysis of the "definite" cases showed culture positivity in 51.8% (58 eyes), and of these, 41 eyes (70.7%) were higher than the cutoff PCR values and 40 eyes were identified by 16S r-DNA sequencing. In the culture-negative eyes, the level of bacterial DNA was significantly lower (P = 0.0008). Eyes with higher bacterial DNA levels had significantly concordant outcomes with sequencing and culture results (P = 0.006). Previous antibiotic treatments decreased the bacterial DNA amount by 0.09-fold, and it was a significant factor for discordance (P = 0.006). Conclusion Quantification of the bacterial DNA level and conventional testing improves the diagnostic efficacy of infectious bacterial keratitis.

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Comparison of culture-negative and culture-positive microbial keratitis: cause of culture negativity, clinical features and final outcome

Abstract: CN keratitis is associated with long duration of topical medication. The number of major surgical interventions in CN keratitis is significantly less compared with CP keratitis. However, the final outcome of treatment is similar in both CP and CN keratitis.

Cited by 47 publications

References 11 publications

The Utility of Repeat Culture in Fungal Corneal Ulcer Management: A Secondary Analysis of the MUTT-I Randomized Clinical Trial

The Utility of Repeat Culture in Fungal Corneal Ulcer Management: A Secondary Analysis of the MUTT-I Randomized Clinical Trial

Iris melanin pigment as a masquerade of Gram-positive cocci after penetrating ocular trauma

Effectiveness of 16S ribosomal DNA real-time PCR and sequencing for diagnosing bacterial keratitis

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