Diagnostic value of pediatric blood culture bottles for acute postoperative endophthalmitis

Endogenous Endophthalmitis - A Major Review

Endogenous endophthalmitis (EE) is an uncommon but potentially devastating ocular infection involving the inner layers of the eye. The global incidence of EE is on the rise. Common ocular signs and symptoms associated with EE include conjunctival injection, ocular pain, and reduced visual acuity. On clinical examination, a history of prior or coexisting systemic infections, symptoms (e.g., fever, malaise), and localizing features may be noted. Clinical diagnosis is often challenging, resulting in critical delays that contribute to a poor prognosis. Blood cultures and ocular fluid samples can aid in conforming causative pathogen(s), after which empirical antibiotic therapy, both systemic and intravitreal, should be instated. The use of steroids to suppress inflammation remains controversial. Surgical options include pars plana vitrectomy. Overall prognosis varies depending on host and pathogen factors, and early diagnosis and initiation of appropriate treatment are crucial.

Acute postoperative endophthalmitis: Microbiology from the laboratory to the bedside

Postoperative endophthalmitis is a dreaded complication of intraocular surgery. Acute presentations need prompt management and good knowledge of differential diagnoses. In the last 10 years, progress in direct microbial detection and identification from intraocular samples included the use of blood culture systems and, more recently, matrix-assisted laser desorption ionization time-of-flight mass spectrometry, improving the rate of bacterial identification. Whatever the method used, diagnostic sensitivity is better for vitreous samples than for aqueous humor samples. Besides, molecular biology techniques have further improved the identification rate of infectious agents in intraocular samples. They also provide faster results compared to culture-based techniques. Quantitative real-time PCR (qPCR) can also determine the bacterial load in intraocular samples. Several studies have shown that intraocular bacterial loads in endophthalmitis patients are usually high, which helps differentiating infection from contamination. The prognostic value of qPCR remains to be validated. Whole genome DNA sequencing technologies facilitate direct and sequencing of single DNA molecules. They have the potential to increase the rate of microbiological identification. Some antibiotic resistance markers (e.g., methicillin resistance in staphylococci and vancomycin resistance in enterococci) may be detected earlier using molecular techniques (usually real-time PCR tests). Early determination of the involved microorganism and their antibiotic resistances can help establishing an earlier therapeutic strategy.

Surveillance of post-cataract endophthalmitis at a tertiary referral center: a 10-year critical evaluation

BACKGROUND

Acute post-cataract endophthalmitis (APE) is a rare complication potentially causing irreversible visual loss. A 10-year study of APE was conducted to determine its incidence, microbiological spectra and antibiotic resistance profile of APE-related pathogens at a major tertiary referral center in Brazil.

METHODS

APE cases reported between January 2010 and December 2019 were included. Phacoemulsification and extracapsular cataract techniques were eligible; combined procedures, traumatic and congenital cataract were excluded. Vitreous samples were cultured and antimicrobial resistance was compared for the periods of 2010-2014 and 2015-2019. The results were analyzed with Fisher's exact test.

RESULTS

Our sample consisted of 40,491 cataract surgeries and 51 (0.126%) APE cases. Culture was positive in 35 cases (71.4%), of which 31 (88.6%) Gram-positive, 3 (8.6%) Gram-negative, and 1 (2.9%) fungal. The most frequently isolated organism was Staphylococcus epidermidis (n = 17/35, 48.6%), followed by Staphylococcus aureus (n = 4/35, 11.4%). From 2010-2014 to 2015-2019, antimicrobial resistance increased against moxifloxacin (11.1-54.5%, p = 0.07), ciprofloxacin (54.5-72.7%, p = 0.659) and oxacillin (66.7-93.3%, p = 0.13).

CONCLUSIONS

The observed incidence and microbial spectra were compatible with previous studies. A trend towards growing moxifloxacin and ciprofloxacin resistance was observed. Surveillance remains crucial to prevent treatment failure from antimicrobial resistance.