Evolving risk factors and antibiotic sensitivity patterns for microbial keratitis at a large county hospital.
Purpose:To identify the risk factors, causative organisms, antimicrobial susceptibility and outcomes of microbial keratitis in a large county hospital in Houston, Texas.Design:Case series.



Setting: A large county hospital in Houston, Texas.



Patients with known diagnosis of microbial keratitis from January 2011 to May 2015.



Retrospective chart review.



Epidemiology, risk factors, outcomes and antibiotic susceptibility of microbial keratitis.



The most commonly identified risk factors were contact lens use (34.4%), ocular trauma (26.3%), diabetes mellitus (16.7%), ocular surgery (13.5%), ocular surface diseases (11.5%), previous keratitis (10.4%), glaucoma (6.3%), cocaine use (5.2%) and HIV-positive status (4.2%). Eyes with positive cultures (61.5%) were associated with worse visual outcomes (p=0.019) and a higher number of follow-up visits (p=0.007) than eyes with negative cultures (38.5%). Corneal perforation was the most common complication (11.5%). Gram-negative organisms (21.9%) were all susceptible to ceftazidime, tobramycin and fluoroquinolones. Gram-positive organisms (33.3%) had worse outcomes than Gram-negative organisms (21.9%) and exhibited a wide spectrum of antibiotic resistance, but all were susceptible to vancomycin. Twenty-seven per cent of the coagulase-negativeStaphylococciwere resistant to fluoroquinolones.



This study identified a recent shift in risk factors and antibiotic resistance patterns in microbial keratitis at a County Hospital in Houston, Texas. In our patient population, fluoroquinolone monotherapy is not recommended for severe corneal ulcers. On the basis of these results, vancomycin and tobramycin should be used for empirical therapy until microbial identity and sensitivity results are available.
Department of Ophthalmology, School of Medicine, Baylor College of Medicine, Houston, Texas, USA.
Haoxing
H
Jin
Ophthalmology, Cullen Eye Institute, Baylor College of Medicine, Houston, Texas, USA.
Walter T
WT
Parker
Department of Ophthalmology, School of Medicine, Baylor College of Medicine, Houston, Texas, USA.
Nathan W
NW
Law
Department of Ophthalmology, School of Medicine, Baylor College of Medicine, Houston, Texas, USA.
Cameron L
CL
Clarke
Department of Ophthalmology, School of Medicine, Baylor College of Medicine, Houston, Texas, USA.
Jordan D
JD
Gisseman
Ophthalmology, Cullen Eye Institute, Baylor College of Medicine, Houston, Texas, USA.
Stephen C
SC
Pflugfelder
Ophthalmology, Cullen Eye Institute, Baylor College of Medicine, Houston, Texas, USA.
Li
L
Wang
Ophthalmology, Cullen Eye Institute, Baylor College of Medicine, Houston, Texas, USA.
Zaina N
ZN
Al-Mohtaseb
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D002648:Child; D024881:Drug Resistance, Bacterial; D015818:Eye Infections, Bacterial / Q000188:drug therapy* / Q000453:epidemiology / Q000382:microbiology; D005260:Female; D005500:Follow-Up Studies; D006766:Hospitals, County / Q000706:statistics & numerical data*; D061847:Hospitals, High-Volume; D006801:Humans; D015994:Incidence; D007634:Keratitis / Q000188:drug therapy* / Q000453:epidemiology / Q000382:microbiology; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D013781:Texas / Q000453:epidemiology; D055815:Young Adult
D000900:Anti-Bacterial Agents
Cornea; Epidemiology; Infection; Microbiology