Biofilm formation and its effect on the management of culture-positive bacterial endophthalmitis

Purpose: To compare the clinicomicrobiological features and outcomes in patients with infectious endophthalmitis caused by biofilm?positive (BP) and biofilm?negative (BN) bacteria. Methods: This was a prospective, interventional, comparative, nonrandomized, consecutive case series. Culture?positive bacterial endophthalmitis cases from August 1, 2018 to July 31st 31, 2019 were included. All vitreous samples were tested for biofilm using crystal violet plate and XTT (2,3?bis?(2?methoxy?4?nitro?5?sulfophenyl)?2H?tetrazolium?5?carboxanilide) methods and classified as BN and BP. The antibiotic susceptibility of all organisms was determined. Anatomic and functional success was defined as intraocular pressure >5 mm Hg and final best?corrected vision ?20/400, respectively, at last visit. Results: There were 50 eyes in the BN group and 33 eyes in the BP group. BN group eyes required 2.86 ± 1.45 surgical interventions, and BP group eyes needed surgical 6.36 ± 2.89 interventions, P < 0.0001, 95% Confidence Interval, CI: 2–4. Median follow?up was 6 and 5 months, respectively (P = 0.33). Final logMAR vision was a median of 1.2 and 1.9 respectively; P = 0.0005, 95% C.I.: 0.4–1.7. Functional success was achieved in 44% and 21.2% (P = 0.03, 95% C.I.: 1.86%–40.08%) and anatomic success was achieved in 68% and 42.42%, respectively (P = 0.02, 95% C.I.: 3.85%–45.47%). The antimicrobial resistance patterns between the two groups were comparable. Conclusion: Endophthalmitis caused by the biofilm?forming bacteria needs a greater number of surgical interventions. The anatomic and functional outcomes are poorer than non?biofilm?forming bacterial endophthalmitis. The increased virulence and poorer outcomes can be hypothesized to be due to the physical barrier effect of the biofilm on the antibiotics

Diagnóstico de endoftalmitis por método microbiológico convencional y molecular en pacientes de centros oftalmológicos de Paraguay / Diagnosis of endophthalmitis by molecular and conventional microbiological methods in patients from ophthalmologic centers of Paraguay

La endoftalmitis infecciosa es una condición intraocular grave, aunque poco frecuente, que puede llevar a la pérdida de la visión. El diagnóstico etiológico precoz y el tratamiento adecuado llevan a una mejor evolución. Las técnicas microbiológicas convencionales tienen baja sensibilidad en el diagnóstico de la endoftalmitis infecciosa, en cambio la reacción en cadena de la polimerasa (PCR) es un método de mayor sensibilidad que está siendo utilizado ampliamente. El objetivo fue determinar por cultivo y PCR la etiología de la endoftalmitis infecciosa en pacientes que consultaron en centros oftalmológicos de Paraguay. Se estudiaron muestras de humor vítreo obtenidas por punción de 51 pacientes con endoftalmitis. La muestra se dividió en dos alícuotas; una para el estudio microbiológico convencional y la otra para la PCR anidada. Esta última utiliza un par de cebadores basado en secuencias conservadas del gen 16S ribosomal y cebadores específicos para bacterias gram positivas. Se estandarizó la PCR logrando una sensibilidad de detección de 3.10-5 ng/µl para S. aureus, 2,5.10-3 ng/µl para S. pneumoniae y 6.10-7 ng/µl para E. coli. De las 51 muestras, 12 (23,5%) fueron positivas por métodos microbiológicos convencionales y 26 (51,0%) por la PCR anidada. Por cultivo se identificaron predominantemente bacterias grampositivas 8/11 (73%) y un aislado de hongo filamentoso. La PCR anidada presentó muy buena sensibilidad y de gran utilidad en la identificación del origen bacteriano de la endoftalmitis, mejorando la sensibilidad del cultivo en 27,5%. La discriminación bacteriana en grampositivos y gramnegativos por la PCR se correlacionó con el cultivo en el 100% de los casos(AU)

Clinical Results of Bacterial Endophthalmitis: Bacterial Culture and Visual Acuity Outcomes

PURPOSE: To evaluate the clinical characteristics of bacterial culture, and visual outcome in patients with acute endophthalmitis. METHODS: Clinical records of patients treated for acute endophthalmitis in GNUH from 2000 to 2009 were reviewed. The specimens for culture were obtained from the anterior chamber or vitreous. Clinical outcome measures were bacterial culture, culture rate, and final visual acuity. RESULTS: Cultures (total 59 cases) showed bacterial growth in 37 cases (63%). Among 35 cases vitreous specimens, bacteria growth was found in 22 cases (63%), and from the 27 anterior chamber specimens, 12 cases (44%) were culture positive. From these 37 bacterial-positive cultures, 11 (30%) were coagulase negative Staphylococcus species, 16 (43.0%) were other Gram-positive species, 9 (24%) were Gram-negative species, and 1 (3%) produced a polymicrobial culture. Final visual acuity above 0.5 was achieved in 16 of 59 (27%) cases and coagulase negative Staphylococcus species had the greatest proportion being 5 of 11 (45%). CONCLUSIONS: The bacterial culture positivity rate in bacterial endophthalmitis was 63%, and the culture yield rate from the vitreous was higher than the anterior chamber aqueous samples. Coagulase negative Staphylococcus species were the most common causative organisms and showed the best final visual outcome in endophthalmitis.

A Case of Bacterial Endophthalmitis Following Penetrating Keratoplasty

Endophthalmitis is an intraocular inflammation caused by bacteria or fungus. Although endophthalmitis may result from an endogenous source elsewhere in the body, it most commonly occurs following intraocular surgery or penetrating ocular injury. But endophthalmitis following penetrating keratoplasty reveals the significantly lower incidence than by other causes. We have experienced one case of bacterial endophthalmitis following penetrating keratoplasty which was proved to be Pseudomonas aeruginosa by bacterial culture. In spite of two intravitreal injection of proper antibiotics, his clinical symptoms and signs did not improve and his visual acuity decreased to hand movement. So, we performed pars plana vitrectomy and third intravitreal injection of antibiotic and achieved a successful results with final visual acuity of 6/20. We report a case of endophthalmitis following penetrating keratoplasty and with the review of literature.

A Case of Pseudomonas Aeruginosa Endophthalmitis Treated with Intravitreal Ceftazidime Injection

Bacterial endophthalmitis is an ocular emergency that requires rapid diagnosis and therapeutic decision making. Before the use of intravitreal antibiotics, endophthalmitis almost always resulted in the loss of vision in the affected eye. The introduction of intravitreal injection of antibiotics had been a major advancement because it has resulted in a marked improvement in visual outcome. Current therapy is to administer broad-spectrum antibiotic agents covering both gram-positive and gram-negative organisms. Typically, vancomycin hydrochloride and aminoglycoside, such as amikacin sulfate, are administered as separate intrvitreal injections on an empiric basis. We experienced a case of culture-proven Pseudomonas aeruginosa endophthalmitis treated with intravitreal ceftazidime injection. We present it with a review of literature.

A case of endogenous bacterial endophthalmitis developed in alcoholics patient

Endpgenous bacterial endophthalmitis develops mainly in a extremely ill patient or a immunologically compromised patient. As reported earlier, early suspicion and careful diagnostic evaluation and early aggressive treatment are important to treat endophthalmitis and prevent poor visual acuity. The authors experienced a case of endogenous endophthalmitis developed from pneumonia in chronic alcoholics patient. The pathogen was proved to be a Staphylococcus aureus by the culture of specimen obtained from the aqueous. Systemic, topical, subconjunctival and intravitreal antibiotic therapy were done, but the patient's eye progressed to phthisis state.

Retinal Toxicity of Vancomycin in Vitreous Replacement Fluid

Vancomycin is an anti biotic produced by Streptomyces orientalis and is primarily active against gram-positive bacteria, especially against methicillin-resistant Staphylococcus aureus and Staphylococcus epidermidis. It has been increasingly recommended for intravitreal injection on behalf of conventional therapy in bacterial endophthalmitis caused by gram-positive organisms due to increasing resistance to the cefazolin. Authors evaluated the retinal toxic reaction after vitrectomy with infravitreal infusion containing various doses of vancomycin between 1 microgram/ml to 500 microgram/ml into 20 rabbit eyes to determine the safe dose of vancomycin. The histologic features of the rabbit eyes treated with 20 microgram/ml or more showed toxic reactions including hypertrophy of retinal pigment epithelium, disorganization and loss of the photoreceptor cells and accummulation of inflammatory cells in subretinal space. These results suggest that intravitreal infuion of vancomycin in a dose of 10 microgram/ml or less appears to have no retinal toxicity in the rabbit model.