Human vitreous distribution of linezolid after a single oral dose

PURPOSE: To evaluate the relationship between vitreous linezolid concentrations versus both time and serum concentrations after a single 600 mg oral dose. METHODS: Two groups of six subjects undergoing a pars plana vitrectomy indicated by macular pucker or full thickness macular hole were given a single tablet of linezolid before surgery. The early group underwent vitrectomy at random times before the time of maximum serum linezolid concentration (i.e., 77 minutes) and the late group underwent vitrectomy at random times afterward. Each patient had a serum sample drawn shortly before and after vitrectomy and the vitreous specimen was sampled at the initiation of surgery. RESULTS: The early group and late group had mean vitreous linezolid concentrations of 0.06 mcg/mL and 1.25 mcg/mL, respectively. The vitreous linezolid concentration showed a strong correlation to the interpolated serum concentration (R2 = 0.74, P < 0.01) at the time of vitrectomy. CONCLUSION: The study demonstrates that linezolid penetrates the blood-retina barrier in noninflamed eyes. Because the vitreous concentrations appeared to exponentially trend upward with time and 33% of the late group achieved sufficient MIC90 levels for the common pathogens found in postoperative endophthalmitis, adequate concentrations might be achieved with an altered dosing regimen to achieve higher serum steady state levels. Further study is warranted.     

Sterile endophthalmitis in vitrectomised eyes due to suspected heat resistant endotoxins in the infusion fluid

PURPOSE: To report on to the possibility of development of severe postoperative sterile endophthalmitis due to heat-resistant bacterial endotoxins in commercially available infusion fluids METHODS: A case study of 4 eyes that had previously undergone vitreoretinal surgery, which developed clinical endophthalmitis within 18 hours of surgery and two eyes that had vitreous surgery with intraocular gas and did not develop clinical endophthalmitis following intraocular surgery on three consecutive operative days RESULTS: The vitreous samples were sterile, both for bacteria and fungi. The only common supply in all cases was a new batch of Ringer's lactate infusion fluid. Though the Ringer's lactate solutions in the same batch were also sterile, the infusion fluids contained abnormally high levels of bacterial endotoxins detected by gel clot method. CONCLUSION: Commercially available infusion fluid may be sterile, yet contain endotoxins from killed bacteria. This could cause postoperative sterile endophthalmitis.     

白内障术前应用不同浓度聚维酮碘的疗效观察

目的：比较白内障术前应用不同浓度聚维酮碘(PI)在结膜囊作用不同时间,观察PI的消毒效果,以及对结膜囊菌群、眼表的影响,筛选PI的最佳浓度和作用时间。

方法：本研究为前瞻性研究,选择2015-06/2017-06于我院行白内障手术患者270例270眼,根据用药浓度(5、1、0.5g/L)随机分为三组,每组90眼。根据不同作用时间(30s,1、2min)进一步随机分配各个亚组,每亚组各30眼。患者按分组情况进行术前PI结膜囊冲洗,并于冲洗前后进行结膜囊细菌样本采集,比较PI冲洗前后结膜囊细菌菌群变化和细菌培养阳性情况。同时比较术前3d与术后1、3d,1wk,1、3mo的泪膜破裂时间(BUT)、角膜荧光素染色(CFS)变化,观察PI冲洗结膜囊对眼表的影响。

结果：(1)结膜囊菌群变化：PI冲洗前结膜囊细菌培养共12种,其中革兰氏阳性菌9种,革兰氏阴性菌3种; PI冲洗后结膜囊细菌培养共4种,其中革兰氏阳性菌2种,革兰氏阴性菌2种。(2)结膜囊细菌培养阳性情况的比较：PI冲洗前结膜囊细菌培养阳性15眼,冲洗后细菌培养阳性5眼,PI冲洗前后细菌培养阳性眼数减少(P<0.05)。(3)安全性：所有患者术后末次随访,术眼均未发生眼内炎,除0.5g/L、30s组及5g/L、2min组外的所有组别,BUT均在术后3mo恢复术前水平。0.5g/L、30s组BUT术后1mo就恢复到术前水平,5g/L、2min组BUT至术后3mo仍未恢复至术前; 所有组别CFS均在术后1mo恢复至术前水平。

结论：0.5g/L PI结膜囊冲洗30s能有效减少结膜囊细菌,较其他作用时间和浓度组对眼表的损伤更小,用于白内障术前结膜囊消毒是安全有效的。     

Vitreal penetration of oral moxifloxacin in humans

PURPOSE: To investigate the vitreal penetration of moxifloxacin after oral administration. DESIGN: Prospective, nonrandomized clinical series. METHODS: Twenty-four patients (mean age = 62.8 years) undergoing elective pars plana vitrectomy were assigned to a dosing group: control (n = 3), which received no medication; single-dose (n = 11), which received one 400 mg oral dose of moxifloxacin 3 hours before surgery; and five-dose (n = 10), which received one 400 mg dose on each of the 4 days preceding surgery and a fifth dose 3 hours before surgery. Vitreous samples were obtained and analyzed. RESULTS: Control, below quantifiable levels; single-dose, 0.572 +/- 0.239 microg/mL; and five-dose, 1.200 +/- 0.645 microg/mL. CONCLUSIONS: Five doses of oral moxifloxacin lead to higher intravitreal drug concentrations than single-dose administration. Both regimens, however, achieve levels that exceed the MIC90 of many bacteria implicated in postoperative endophthalmitis.     

Preoperatively administered flomoxef sodium concentration in aqueous humor

PURPOSE: We intravenously administered flomoxef sodium (FMOX) 0.5-3.5 hours before cataract surgery and measured the concentration of the agent in the aqueous humor to investigate its penetration into the aqueous humor and its efficacy in the prevention of postoperative endophthalmitis. METHODS: 56 patients who underwent cataract surgery were enrolled in this study. They received 1 g FMOX via a 20-minute intravenous drip beginning 0.5-3.5 hours before the operation. Aqueous humor was aspirated from the anterior chamber and assayed for FMOX concentration using high-performance liquid chromatography. RESULTS: The mean intraoperative FMOX concentrations in the patients' aqueous humor were 0.79 +/- 0.24 microg/ml (administered 3.5 hours before surgery)--1.47 0.79 microg/ml (administered 1.5 hours before surgery). These concentrations administered 0.5-3.0 hours before surgery sufficiently exceeded the minimum inhibitory concentration (MIC) 90 values against Staphylococcus epidermidis, Staphylococcus aureus and Propionibacterium acnes, but did not achieve the MIC90 values against Enterococcus faecalis and Pseudomonas aeruginosa. CONCLUSIONS: The FMOX concentrations in the aqueous humor sampling were adequate to kill bacteria in vitro. This drug may be efficacious in the prevention of postoperative endophthalmitis in patients undergoing cataract surgery.     

16S rDNA测序技术对细菌性眼内炎房水和玻璃体标本中细菌的鉴别作用

背景 眼内炎是多种内眼手术的严重并发症,以往感染菌的确定多采用细菌培养和涂片染色法,但存在花费时间长和阳性率低的问题.16S rDNA是细菌染色体上编码rRNA的序列,利用16S rDNA分子测序技术检测细菌具有高度的特异性. 目的 利用16S rDNA测序技术对细菌性眼内炎房水和/或玻璃体标本中的感染菌进行鉴定,探讨该技术在眼部感染性炎症诊断中的作用.方法 收集2015年6-12月在青岛眼科医院临床诊断为细菌性眼内炎的患者5例5眼,抽取每例患者的房水0.1～0.2 ml或玻璃标体标本0.5 ～1.0ml,各取50 μl用于高通量测序,剩余标本行涂片检查和细菌培养.采用D3096-01微量DNA试剂盒提取标本中细菌DNA,对收集的标本DNA样品进行16S rRNA基因V3-V4区PCR扩增,应用MiSeq 300测序仪对扩增的16S rDNA高变区序列进行测序,分析标本中病原菌的分类组成、分布特点以及各病原菌在标本中的相对含量,取50 μl无RNA酶水于一次性无菌离心管内作为空白对照. 结果 共收集到5份房水或玻璃体标本,涂片染色结果阳性者2例,外伤性细菌性眼内炎为革兰阳性杆菌,滤过泡感染性细菌性眼内炎为革兰阴性杆菌,而细菌培养法结果均为阴性.16S rDNA测序技术发现,5例标本检测阳性率为100％.外伤性细菌性眼内炎标本中高丰度菌属为葡萄球菌属、链球菌属和假单胞菌属,分别占65.28％、18.90％和12.76％;白内障术后2d急性细菌性眼内炎患眼标本中高丰度菌属有假单胞菌属、不动杆菌属和Limnobacter菌属,分别占53.68％、8.62％和5.96％;滤过泡感染性细菌性眼内炎标本中高丰度菌属有莫拉菌属和假单胞菌属,分别占88.89％和9.52％;白内障术后22 d迟发性细菌性眼内炎标本中相对含量较高的菌属有假单胞菌属,占84.63％;白内障术后1d急性细菌性眼内炎患眼标本中相对含量较高的有假单胞菌属,占97.89％.结论 16S rDNA测序可准确鉴别眼内炎患者房水和玻璃体标本中的致病菌,该方法检测的阳性率明显高于传统的涂片染色法和细菌培养法.     

Bacterial contamination of the anterior chamber during phacoemulsification cataract surgery

PURPOSE: To determine the incidence of bacterial contamination of the anterior chamber after phacoemulsification cataract surgery with intraocular lens (IOL) implantation. SETTING: Department of Ophthalmology, Royal Prince Alfred Hospital, Sydney, Australia. METHODS: Ninety-eight consecutive eyes of 96 patients having phacoemulsification cataract surgery with IOL implantation were included in this prospective study. Two intraoperative anterior chamber aspirates were obtained from each patient, 1 taken at the start and the other at the conclusion of surgery. In addition, preoperative and postoperative conjunctival swabs were acquired. The 4 specimens were cultured using direct culturing techniques under aerobic and anaerobic conditions for 14 days. No preoperative antibiotics were used. RESULTS: The incidence of intraoperative anterior chamber contamination was 0% (95% confidence interval, 0%-3.7%) as all intraoperative anterior chamber samples proved culture negative. Sixty-five percent of the preoperative conjunctival swabs were positive for growth, with corynebacteria, coagulase-negative staphylococci, and Propionibacterium acnes being the most frequently cultured organisms. Sixteen percent of the postoperative conjunctival swabs were positive for growth, with corynebacteria and coagulase-negative staphylococci being the most common bacteria. One patient developed culture-positive postoperative endophthalmitis; using pulsed-field gel electrophoresis for further typing, the implicated Staphylococcus epidermidis was indistinguishable from that isolated from the patient's preoperative conjunctival swab. CONCLUSIONS: The bacterial contamination rate of the anterior chamber after phacoemulsification and IOL implantation was extremely low. Additional findings support the conjunctiva as being a primary source of bacteria causing postoperative endophthalmitis as well as the ability of povidone-iodine to reduce the conjunctival bacterial load.     

Determination of aqueous and vitreous concentration of moxifloxacin 0.5% after delivery via a dissolvable corneal collagen shield device

PURPOSE: To determine the penetration of moxifloxacin 0.5% in the human aqueous and vitreous when delivered by a presoaked collagen shield. SETTING: University-based clinical practice. METHODS: Moxifloxacin 0.5% was administered before vitrectomy surgery in 10 patients using a 24-hour dissolvable cross-linked corneal collagen shield delivery device. Aqueous and vitreous samples were obtained after the shield was placed for 4 hours in the first 5 patients and for 24 hours in the second 5 patients. Assays were performed using high-performance liquid chromatography. RESULTS: Delivery of moxifloxacin via a collagen shield revealed a mean aqueous concentration of 0.30 microg/mL +/- 0.17 (SD) 4 hours after placement (n = 5). Vitreous levels at 4 hours and aqueous and vitreous levels at 24 hours were negligible using this route of administration. Peak aqueous moxifloxacin levels occurred soon after shield placement. This is when high concentrations of moxifloxacin are most needed to clear the aqueous of bacteria. The minimum inhibitory concentration at which 90% of the isolates were inhibited for organisms commonly responsible for endophthalmitis was exceeded in the 4-hour aqueous group. Negligible concentrations were detected at 24 hours. CONCLUSIONS: Although aqueous moxifloxacin levels achieved through the use of a collagen shield delivery device are lower than via topical drops, there are several advantages to this route of delivery that make it appealing in the immediate postoperative period. Future studies will be needed to define precisely the role of fourth-generation fluoroquinolones and presoaked collagen shields in the prophylaxis or management of intraocular infections.     

白内障术后感染性眼内炎的治疗方法以及易感因素

目的：探讨白内障术后感染性眼内炎的治疗方法以及易感因素。 方法：回顾性分析2003-06/2013-06在我院确诊为白内障术后感染性眼内炎的患者8例8眼。所有患者均行手术治疗。术前均常规抽取房水及玻璃体液送细菌、真菌培养加药物敏感试验,观察分析患者病原菌及药敏情况,手术前后视力、术后感染控制情况及有无并发症等情况。 结果：术后随访6～12mo,8例患者手术后1,6mo视力与手术前视力比较显著提高,差异有统计学意义（P〈0.05）;所有患者术后眼内炎症均得以控制,无1例出现术后并发症。8例患者中有7例检测到致病菌,其中4例为表皮葡萄球菌感染,3例为粪肠球菌D群感染;两种致病菌均对万古霉素敏感。易感因素有：高龄、糖尿病、慢性阻塞性肺病、肾功能衰竭、结核。 结论：尽早行前房冲洗联合玻璃体腔注药术或者玻璃体切割术联合玻璃体腔注药术均能够有效治疗感染性眼内炎。万古霉素是有效的抗菌药物。     

Human aqueous humor levels of oral ciprofloxacin, levofloxacin, and moxifloxacin

PURPOSE: To evaluate the penetration of ciprofloxacin, levofloxacin, and moxifloxacin into the aqueous humor after oral administration. SETTING: Alcorcon Hospital, Madrid, Spain. METHODS: Forty-two patients having cataract surgery were randomly divided into 3 groups the day before surgery. The first group received 2 oral 500 mg doses of ciprofloxacin at 12-hour intervals. The second group received a single oral 500 mg dose of levofloxacin. The third group received a single oral 400 mg dose of moxifloxacin. At the time of surgery, 0.1 mL aqueous fluid was aspirated from the anterior chamber just before the operation and immediately stored at -80 degrees C. Drug concentrations were measured using a biological assay. RESULTS: The mean aqueous level of ciprofloxacin was 0.50 microg/mL +/- 0.25 (SD); of levofloxacin, 1.50 +/- 0.50 microg/mL; and of moxifloxacin, 2.33 +/- 0.85 microg/mL. The mean aqueous levels of levofloxacin and moxifloxacin were above the 90% minimum inhibitory concentration for most of the common microorganisms that cause endophthalmitis. CONCLUSIONS: Therapeutic concentrations of fluoroquinolones, mainly levofloxacin and moxifloxacin, were reached with oral administration. These antibiotics may be effective for prophylaxis and adjuvant therapy of bacterial endophthalmitis.     

Identification of bacterial pathogens in patients with endophthalmitis by 16S ribosomal DNA typing

PURPOSE: To determine whether sequence analysis of 16S ribosomal DNA (rDNA) can be used to detect bacterial pathogens in patients with postoperative endophthalmitis. METHODS: In 10 eyes of 10 patients, vitreous specimens were collected for culture and rDNA typing. Variable segments of each ribosomal DNA specimen were amplified by polymerase chain reaction (PCR), sequenced, and aligned by BLAST, a computer alignment program, against sequences in GenBank at the National Institutes of Health. RESULTS: Specimens were available from five eyes with bacterial endophthalmitis diagnosed by Gram stain or culture. Amplified 16s rDNA sequences from the eyes of three patients were identical to microbiologic results. Polymerase chain reaction results were negative in two cases in which unusual organisms were detected. All five control specimens from patients with nonbacterial endophthalmitis or uveitis were PCR negative. Approximately 48 to 72 hours are required under ideal conditions for final species identification with this ribosomal typing technique. CONCLUSIONS: 16S rDNA typing shows potential as a relatively rapid technique for identifying bacteria in vitreous samples.     

Postoperative endophthalmitis: establishment and results of a national registry

PURPOSE: To determine the incidence, clinical presentation, etiology, and outcomes of postoperative endophthalmitis in Norway and to explore the potential of and establish a platform for improving diagnostics, prophylaxis, and treatment of postoperative endophthalmitis. SETTING: All ophthalmic surgical units and relevant microbiology laboratories in Norway. METHODS: A national registry of cases of postoperative endophthalmitis was established in 1996. All ophthalmic surgery units in Norway were asked to return forms including preoperative, perioperative, and postoperative data for each case of endophthalmitis occurring between January 1996 and December 1998 after any intraocular surgery irrespective of the time between the surgery and the onset of endophthalmitis symptoms. All microbiology laboratories in Norway were asked to return questionnaires regarding their routine handling procedures of eye specimens in cases of endophthalmitis. RESULTS: From 1996 to 1998, 111 suspected endophthalmitis cases were reported, all after cataract surgery. Eighty cases were culture positive, 75 with gram-positive bacteria, 4 with gram-negative bacteria, and 1 with Candida albicans. Depending on the definition, the incidence of postoperative endophthalmitis was between 0.11% and 0.16%. Thirteen percent of cases had "delayed" endophthalmitis. Twenty-nine percent of eyes had an outcome of permanent amaurosis or light perception visual acuity; 56% (47/84) retained or improved their categorized visual acuity in the affected eye compared to preoperatively. Positive bacterial growth was associated with a worse visual outcome (P =.008). The degree of inflammation when endophthalmitis was diagnosed and the visual outcomes were worse in cases with growth of streptococci than in cases with growth of staphylococci (P =.009 and P<.001, respectively). The questionnaire to the microbiology laboratories revealed a lack of consensus on how to handle the specimens. CONCLUSIONS: Postoperative endophthalmitis remains a serious complication of intraocular surgery, although the prognosis depends greatly on the microbe isolated. Common guidelines should be established regarding clinical and microbiological diagnosis and treatment. Further improvement of the registry would make it a suitable platform for evaluating prophylactic treatments.     

Effect of topical netilmicin on the reduction of bacterial flora on the human conjunctiva

PURPOSE: To investigate the effects of topical netilmicin on human conjunctival bacterial flora. METHODS: Fifty-six patients' eyes with cataract were treated three times a day with netilmicin 1 day before the surgery. The fellow eyes of the patients were not treated. After 1 day of netilmicin application cultures of the inferior palpebral conjunctiva were performed in both eyes. Bacterial evaluation is qualitative. McNemar test was used for statistical analyses. RESULTS: The number of eyes with positive culture for coagulase negative staphylococcus (CNS) in untreated eyes was 43 (76.8%) and in treated eyes it was 5 (8.93%) and the difference was statistically significant (p=0.000). In untreated eyes number of negative cultures with no bacterial growth was 8 (14.3%) and it was 47 (83.9%) in the treated eyes. The difference among groups was statistically significant (p=0.000). Netilmicin is found very effective for CNS as the percentage of positive cultures (n=43) in untreated eyes to positive cultures (n=4) in the treated fellow eye was 90.7%. Likewise, all patients with Staphylococcus aureus positive cultures in untreated eyes (n=5) had negative culture for this microorganism in their treated fellow eyes (100%). CONCLUSIONS: The Endophthalmitis Vitrectomy Study demonstrated that the most common causes of postoperative endophthalmitis are coagulase negative microorganisms, S aureus and Streptococcus species. As netilmicin was found effective to reduce the number of positive cultures for these bacteria, it can be used to lower the incidence of postoperative endophthalmitis before surgery.     

Penetration of moxifloxacin into the human aqueous humour after oral administration

AIMS: To determine the pharmacokinetics of moxifloxacin, a new generation fluoroquinolone, in the anterior chamber of the human uninflamed eye. METHODS: 35 patients undergoing cataract surgery received two doses of 400 mg of oral moxifloxacin with a 12 hour interval and were divided into six groups. Moxifloxacin levels in aqueous humour and serum were determined by a microbiological agar well diffusion technique at 2, 4, 6, 8, 10, and 12 hours after the second dose in each group respectively. RESULTS: Mean moxifloxacin levels in the anterior chamber were 1.20 (SD 0.35) microg/ml at the 2 hours group, 1.22 (0.48) microg/ml at the 4 hours group, 1.20 (0.45) microg/ml at the 6 hours group, 1.58 (0.38) microg/ml at the 8 hours group, 1.37 (0.44) microg/ml at the 10 hours group, and 1.23 (0.55) microg/ml at the 12 hours group. The mean ratio of aqueous to serum moxifloxacin level was 38%. CONCLUSION: Moxifloxacin penetrates well into the anterior chamber of the human uninflamed eye after oral administration, reaching early significant levels, which are maintained for at least 12 hours and are much higher than the MIC(90) values of Gram positive and Gram negative pathogens commonly implicated in intraocular infections with the exceptions of fluoroquinolone resistant staphylococci, MRSA, and Pseudomonas aeruginosa.     

PCR-RFLP-mediated detection and speciation of bacterial species causing endophthalmitis

PURPOSE: To determine the usefulness of polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in the identification and speciation of bacteria causing endophthalmitis. METHODS: PCR-RFLP was performed on 53 strains of 14 bacterial species (eight Gram positive and five Gram negative) collected from both keratitis and endophthalmitis patients. Two pairs of oligonucleotide primers based on the 16S rDNA gene were used to PCR-amplify 1.2- and 1.0-kb fragments of bacterial genomic DNA. RFLPs within the PCR product were used to speciate the organisms. RESULTS: The sensitivity of the nested PCR amplification reaction was one organism. All bacteria tested could be identified and speciated using RFLP analysis except for Escherichia coli and Serratia marcescens, which could not be interdifferentiated using RFLP. Molecular analysis of two vitreous samples from two eyes with typical signs of bacterial endophthalmitis confirmed the presence of E. coli in the vitreous from a culture-positive case with E. coli endophthalmitis and revealed the presence of Staphylococcus epidermidis in the vitreous of a culture-negative case. CONCLUSIONS: It is expected that this technique will provide a useful laboratory tool for future microbiologic diagnosis of patients presenting with endophthalmitis, especially for those eyes that prove culture negative.     

Endogenous bacterial endophthalmitis: a 17-year prospective series and review of 267 reported cases

Endogenous bacterial endophthalmitis is a rare but serious condition that occurs when bacteria cross the blood-ocular barrier and multiply within the eye. We provide an overview of endogenous bacterial endophthalmitis by reviewing 267 reported cases and integrating this with our experience of an additional 19 cases. The majority of patients with endogenous bacterial endophthalmitis are initially misdiagnosed and many have an underlying disease known to predispose to infection. This condition is often previously undiagnosed. Blood cultures are the most frequent means of establishing the diagnosis. The most common Gram positive organisms are Staphylococcus aureus, group B streptococci, Streptococcus pneumoniae,and Listeria monocytogenes.The most common Gram negative organisms are Klebsiella spp., Escherichia coli, Pseudomonas aeruginosa, and Neisseria meningitidis. Gram negative organisms are responsible for the majority of cases reported from East Asian hospitals, but Gram positive organisms are more common in North America and Europe. The visual outcome is poor with most cases leading to blindness in the affected eye. Many patients have extraocular foci of infection, with an associated mortality rate of 5%. The outcome of endogenous bacterial endophthalmitis has not improved in 55 years and clinicians need to have a high level of awareness of this commonly misdiagnosed condition.     

Vitreal penetration of oral and topical moxifloxacin in humans

PURPOSE: To investigate the vitreal penetration of moxifloxacin after oral and topical administration. DESIGN: Prospective, nonrandomized clinical trial. METHODS: Twenty-four patients were assigned to one of four dosing groups: control (n = 3), which received no medication; oral (n = 8), which received two 400 mg oral doses of moxifloxacin before surgery; topical (n = 8), which received one drop of topical moxifloxacin 0.5% every 15 minutes for the hour preceding surgery; and combined (n = 5), which received two 400 mg oral doses and one drop of topical moxifloxacin 0.5% hourly for 18 hours prior to surgery. Vitreous samples were obtained and analyzed. RESULTS: Control, below quantifiable levels; oral, 1.553 +/- 0.33 microg/ml; topical, 0.027 microg/ml; and combined, 2.219 +/- 0.71 microg/ml. One topical patient developed postoperative endophthalmitis. CONCLUSIONS: In contrast to topical moxifloxacin, oral moxifloxacin achieves significant levels in the noninflamed human vitreous.     

Methicillin resistance of bacteria isolated from vitreous fluid from patients undergoing vitrectomy.

PURPOSE: The aim of this study was to compare the resistance patterns of bacteria in vitreous fluid from patients undergoing vitrectomy for diagnostic reasons, with bacteria of other nosocomial infections. METHODS: Vitreous fluid samples (n=144) were obtained from 133 patients undergoing vitrectomy for endophthalmitis, and 11 for uveitis as suspected endophthalmitis. They were Gram stained and cultured. Antibiotic susceptibility tests were run on all isolates. RESULTS: Gram stains were positive in 45/144 cases (31%), among which 38/45 (84%) were confirmed by a positive culture. Cultures were positive in 74/144 patients (51%) with mainly coagulase-negative staphylococci (n = 44) and Staphylococcus aureus (n = 13). In 133 patients endophthalmitis occurred after lens implantation (80 cases) and in 53 cases there was another origin (e.g. corneal transplantation, endogenous). In 26/80 post-lens implantation infections, culture remained negative; 32 infections occurred with coagulase-negative staphylococci, 10 with Staphylococcus aureus, 9 with streptococci and 3 with gram-negative bacteria. For endophthalmitis, ophthalmologists in our institution give an intraocular injection of vanccmycin and ceftazidim after vitrectomy. Among the 44 isolates of coagulase-negative staphylococci, 12 (27%) were resistant to methicillin. This is in contrast to other hospital-related coagulase-negative staphylococcus infections in general, and the resistance rate is 75% in our hospital. Only 2/13 Staphylococcus aureus isolates were methicillin-resistant. CONCLUSIONS: We conclude that isolates of coagulase-negative staphylococci from vitreous fluid are less resistant to methicillin than those isolated in other nosocomial infections.     

Perspectives on antibiotics for postoperative endophthalmitis prophylaxis: potential role of moxifloxacin

To aid the cataract surgeon's understanding of rational approaches to antimicrobial prophylaxis and place the European Society of Cataract & Refractive Surgeons (ESCRS) postoperative endophthalmitis study in perspective, a review was conducted of published and unpublished data on intracameral antibiotic use during cataract surgery and the antimicrobial efficacy, pharmacodynamics, ocular penetration, and safety of moxifloxacin. The ESCRS-sponsored study of postoperative endophthalmitis prophylaxis reported rates of presumed infectious postoperative endophthalmitis of 0.07% with intracameral cefuroxime treatment and 0.34% in control groups. Postoperative endophthalmitis after cefuroxime use was mostly due to cefuroxime-resistant gram-positive bacteria. Intracameral cefuroxime also requires extemporaneous compounding, has short-term stability, and carries a risk for hypersensitivity. Moxifloxacin, a fourth-generation fluoroquinolone, has potent and rapid bactericidal activity against the most common gram-positive postoperative endophthalmitis pathogens, has excellent ocular penetration after topical administration, and is available in a self-preserved ophthalmic formulation that has been shown safe and effective in preventing endophthalmitis when administered intracamerally in an animal model. Available data suggest that the optimum antibiotic regimen and route of delivery for cataract surgery antimicrobial prophylaxis require further study. Moxifloxacin offers many theoretical advantages that make it an attractive first-line choice for topical use and of interest for intracameral administration.     

准分子激光原位角膜磨镶术前结膜囊细菌分析

目的观察准分子激光原位角膜磨镶术(1aser in situ keratomileusis，LASIK)术前患者结膜囊细菌分布及药物敏感性。方法对LASIK术前100例患者(200只眼)结膜囊取材进行细菌培养，并观察培养阳性的细菌对10种常见抗生索的体外药物敏感性。结果在200只眼结膜囊标本中细菌培养阳性者58眼(71株)，阳性率29%，共分离鉴定出12个细菌种属；其中革兰氏阳性菌为85．9％，革兰氏阴性菌为14．1％；金黄色葡萄球菌、表皮葡萄球菌、棒状杆菌属及假单胞菌属为LASIK术前患者结膜囊存在的常见菌属。药敏结果发现所分离细菌对阿米卡星和左氧氟沙星最敏感。结论革兰氏阳性菌是LASIK术前患者结膜囊存在的最常见菌，术前预防性抗生素使用应注意选择对革兰氏阳性菌敏感的抗生素。