Clinical Characteristics of Stenotrophomonas maltophilia Keratitis.

PURPOSE: Stenotrophomonas maltophilia is an important opportunistic pathogen but an uncommon cause of corneal infections. This study aimed to report the clinical features, antibiotic susceptibility, treatments, and visual outcomes of S. maltophilia keratitis. METHODS: The medical records of 21 patients with culture-proven S. maltophilia-associated infectious keratitis in our hospital between January 1, 2003, and December 31, 2014, were retrospectively reviewed. The clinical features of patients with S. maltophilia keratitis were compared with those of patients from 17 previously reported cases. RESULTS: The most common risk factors for S. maltophilia keratitis were preexisting corneal disease or previous corneal surgery (16), followed by soft contact lens wear (9). Nine patients (42.9%) were multifactorial. Polymicrobial infections was detected in 12 eyes (57.1%). All S. maltophilia isolates were susceptible to levofloxacin and moxifloxacin. A total of 17 of 21 patients (81.0%) had favorable responses to topical antimicrobial treatment, and 10 (47.6%) required surgical intervention for promotion of reepithelialization (6) and corneal perforation (4). Final vision ranged from light perception to 20/20. The clinical features of S. maltophilia keratitis in our cases and in previously reported cases were similar. CONCLUSIONS: S. maltophilia keratitis primarily affects patients with compromised ocular surfaces. S. maltophilia demonstrates in vitro susceptibility and a strong clinical response to fluoroquinolones.

Shifting Trends in Bacterial Keratitis in Taiwan: A 10-Year Review in a Tertiary-Care Hospital.

PURPOSE: To investigate the distribution, current trends, and antibiotic susceptibility profiles of bacterial keratitis isolates over 10 years. METHODS: We retrospectively reviewed the microbiology records of all corneal scrapings undertaken for cultures at Chang Gung Memorial Hospital from 2003 through 2012. We identified bacterial isolates and verified antibiotic susceptibilities by using the disk diffusion method. The Mantel-Haenszel linear-by-linear association χ test was used to detect the trends. RESULTS: We collected 2012 corneal scrapings, and the culture was positive in 992 samples (49.3%), yielding 1282 isolates. Bacterial isolates were identified for 1039 isolates (81.1%), including 533 gram-positive and 506 gram-negative isolates. An increase in the percentage of gram-positive isolates was significant (P = 0.008), as was a decrease in that of gram-negative isolates (P = 0.002). The most common bacterial isolates were Pseudomonas aeruginosa (24.4%) and coagulase-negative Staphylococcus (16.6%). For gram-positive organisms, the susceptibilities were as follows: vancomycin 100%, ciprofloxacin 88.9%, sulfamethoxazole-trimethoprim 86.8%, clindamycin 73.2%, and oxacillin 56.5%. The susceptibility of gram-positive bacteria to clindamycin and oxacillin increased significantly (P = 0.009 and P = 0.001). For gram-negative organisms, the susceptibilities were as follows: ciprofloxacin 93.7%, piperacillin 91.9%, ceftazidime 90.9%, amikacin 88.3%, and gentamicin 84.7%. No change in trend occurred. CONCLUSIONS: In Taiwan, we documented an increasing trend in the percentage of gram-positive bacteria. Methicillin-resistant microorganisms accounted for 43.5% of all gram-positive bacteria, but the trend of resistance to oxacillin and clindamycin significantly decreased. Ciprofloxacin continued to be a good empiric antibiotic for treating bacterial keratitis.

Methicillin-Resistant Staphylococcus aureus Ocular Infection in Taiwan: Clinical Features, Genotying, and Antibiotic Susceptibility.

Methicillin-resistant Staphylococcus aureus (MRSA) infection is an important public health issue. This observational study aimed to characterize clinical features, antibiotic susceptibility, and genotypes of ocular infections caused by MRSA based on the clinical and molecular definitions of community-associated (CA) and healthcare-associated (HA) strains.Fifty-nine patients with culture-proven S aureus ocular infection were enrolled from January 1, 2010 to December 31, 2011 at Chang Gung Memorial Hospital, Taiwan. Antibiotic susceptibility was verified using disk diffusion/E test. For characterization, staphylococcal cassette chromosome mec (SCCmec), pulsed-field gel electrophoresis (PFGE), multilocus sequence type (MLST), and Panton-Valentine leukocidin (PVL) gene, were performed. MRSA isolates from the patients with HA factors were classified as clinically defined HA-MRSA, and those carrying SCCmec type I to III as molecularly defined HA-MRSA.Thirty-four patients with MRSA ocular infection were identified. The most common clone of CA-MRSA and HA-MRSA isolates was ST59/PFGE type D/SCCmec IV,VT/PVL (+) (n = 12) and CC 239/PFGE type A/SCCmec III, IIIA/PVL(-) (n = 10), respectively. All the 11 patients with molecularly defined HA-MRSA infections and 50% of the 22 patients with molecularly defined CA-MRSA infections were found to have HA factors (P = .005). CA-MRSA tended to cause lid infections, whereas HA-MRSA tended to cause corneal infections. Contrary to HA-MRSA isolates, nearly all the CA-MRSA isolates were susceptible to trimethoprim/sulfamethoxazole and fluoroquinolones under either clinical or molecular classifications.In Taiwan, CA-MRSA isolates exhibited considerably higher susceptibility to fluoroquinolones when compared with HA-MRSA isolates. A strong correlation was observed between the HA factors and molecularly defined HA-MRSA isolates.

Clinical characteristics of alternaria keratitis.

Purpose. Alternaria spp. are an uncommon cause of mycotic keratitis. Previous studies on Alternaria keratitis have generally been limited to case reports. We examined the clinical characteristics of Alternaria keratitis in this study. Methods. The characteristics and outcomes of 7 patients with culture-proven Alternaria keratitis treated in our hospital were compared with 25 previously reported cases. Results. The risk factors for Alternaria keratitis were trauma in 5 patients and soft contact lenses in 1 patient. Six patients with early diagnosis (<2 weeks) were cured with medical antimicrobial treatment; a patch graft was required in 1 patient with perforation. When incorporated with previous reports on Alternaria keratitis (n = 32), 14 (44%) infections followed trauma, 10 (31%) were associated with preexisting corneal disease or previous ocular surgery, and 5 (16%) occurred in soft contact lens wearers. Successful medical treatment was achieved in 23 (72%) patients, including 10 out of 21 eyes (48%) treated with natamycin and/or amphotericin B. Therapeutic penetrating keratoplasty was performed in 9 (28%) cases. Conclusions. Alternaria keratitis is generally associated with specific risk factors and responds to medical treatment when early diagnosis is performed and prompt antifungal treatment is initiated.

Pediatric microbial keratitis in Taiwan: clinical and microbiological profiles, 1998-2002 versus 2008-2012.

PURPOSE: To identify the change in clinical and microbiological profiles of pediatric microbial keratitis in Taiwan between 1998-2002 and 2008-2012. DESIGN: Retrospective, observational study. METHOD: setting: Chang Gung Memorial Hospital, a referral center in Taiwan. patient population: We retrospectively reviewed the medical records of 68 eyes of 67 children aged 16 years or younger who were diagnosed with microbial keratitis and treated at our hospital between July 2008 and December 2012. main outcomes and measures: Predisposing factors, isolated organisms, antibiotic susceptibility, and clinical outcomes. The findings were compared with the results of our previous study conducted between July 1998 and December 2002. RESULTS: As in 1998-2002, the leading risk factor for microbial keratitis during 2008-2012 was contact lens use, and the infection rate significantly increased from 40.7% to 52.9% (P = .024), which was mainly attributable to the recent increase in the rate of orthokeratology-related keratitis from 9.9% to 19.1% (P = .011). Pseudomonas aeruginosa remained the most commonly isolated organism (30.6%), but the number of isolated coagulase-negative Staphylococcus cases increased significantly in the 2008-2012 cases (P = .04). Antibiotic susceptibility of organisms did not change significantly between the 2 study periods. By using multiple linear stepwise regression analysis, we found that gram-negative bacterial infection played a crucial role in poor visual outcome. CONCLUSIONS: Contact lens-related microbial keratitis increased in Taiwanese children over time, especially because of the use of overnight orthokeratology. Clinicians must understand the infection background and pay further attention to contact lens use in pediatric patients.

Staphylococcus aureus keratitis: a review of hospital cases.

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) infection is an important public health issue. The study aimed to characterize the patient demographics, clinical features, antibiotic susceptibility, and clinical outcomes of keratitis caused by S. aureus, and to make a comparison between MRSA and methicillin-sensitive S. aureus (MSSA) isolates. METHODOLOGY/PRINCIPAL FINDINGS: Patients (n = 59) with culture-proven S. aureus keratitis treated in Chang Gung Memorial Hospital between January 1, 2006, and December 31, 2010, were included in our study. Patients' demographic and clinical data were retrospectively reviewed. Twenty-six MRSA (44%) and 33 MSSA (56%) isolates were collected. The MRSA keratitis was significantly more common among the patients with healthcare exposure (P = 0.038), but 46.2% (12/26) of patients with MRSA keratitis were considered to have community-associated infections. All isolates were susceptible to vancomycin. MRSA isolates were significantly more resistant to clindamycin, erythromycin, and sulfamethoxazole/trimethoprim. Ocular surface disease was a significant risk factor for MRSA keratitis (P = 0.011). Visual outcome did not differ significantly between the MRSA and MSSA groups. However, age (B = 0.01, P = 0.035, 95% confidence interval [CI]: 0.001-0.019) and visual acuity at presentation (B = 0.749, P<0.001, 95% CI: 0.573-0.926) were significantly correlated with visual outcome. CONCLUSIONS/SIGNIFICANCE: Ocular surface disease is an important predisposing factor for S. aureus keratitis, especially for MRSA infections. Advanced age and poor visual acuity at presentation are important prognostic indicators for poor visual outcome in S. aureus keratitis. Oxacillin resistance may not be a significant prognostic indicator.

Therapeutic penetrating keratoplasty in severe infective keratitis using glycerol-preserved donor corneas.

PURPOSE: To report the surgical outcome of therapeutic penetrating keratoplasty (TPKP) using glycerol-preserved donor corneas in severe infective keratitis. METHODS: Glycerol-preserved corneas were obtained from the recipient corneas of the patients who underwent optical penetrating keratoplasty and preserved in glycerol. Eight eyes of 8 patients (3 men/5 women; average age, 69.7 years) with severe corneal ulcer with perforation were treated with TPKP using glycerol-preserved corneas. RESULTS: With a mean follow-up time of 31.1 months (range, 9-58 months), satisfactory anatomical integrity was obtained in 7 patients (87.5%) at the end of the follow-up. Eradication of infection without recurrence was obtained in 7 eyes (87.5%). The mean reepithelialization time was 10.2 days. One patient (12.5%) received secondary optical penetrating keratoplasty. The pre-TPKP visual acuity ranged from no light perception to 0.06. After surgery, 4 eyes (50%) improved or maintained preoperative visual acuity and four eyes (50%) had no light perception but maintained anatomical integrity. One had a recurrent infection and needed antibiotics and amniotic membrane graft. One suffered from secondary glaucoma and received evisceration 19 months later. CONCLUSIONS: Glycerol-preserved donor corneas may be effective substitutes in TPKP to control severe infective keratitis and preserve anatomical integrity.

Retained Descemet's membrane after penetrating keratoplasty.

Retained Descemet's membrane is a rare complication of penetrating keratoplasty (PKP). The membrane can become progressively opaque and threaten the health of the corneal graft. We report such a case involving a 53-year-old man. Simultaneous surgical removal of the membrane and phacoemulsification with intraocular lens implantation were performed 3 months after PKP. The graft remained clear and best corrected visual acuity was 20/20 2 years after secondary surgery.