In vitro susceptibilities to topical antibiotics of bacteria isolated from the surface of clinically symptomatic eyes

BACKGROUND: The permanent change of resistance patterns of bacteria causing ocular infections makes repeat susceptibility testings against the most recent clinical isolates mandatory. The aim of the present study was to assess the in vitro susceptibility of ocular bacterial isolates of clinically symptomatic eyes admitted to the outpatient clinic of the eye department of a large central hospital to commonly used topical antibiotics. METHODS: Ocular isolates (n = 454) were tested for their susceptibility to ofloxacin, ciprofloxacin, norfloxacin, gentamicin, tobramycin, meomycin, bacitracin, erythromycin, tetracycline and chloramphenicol. RESULTS: All three tested fluoroquinolones were found to be very effective against gram-negative organisms but demonstrated some weakness against certain strains of gram-positive germs, in particular coagulase-negative staphylococci and Streptococcus viridans. These germs, however, were very susceptible to bacitracin and chloramphenicol. The relative overall in vitro efficacy was (in decreasing order): chloramphenicol, ciprofloxacin, ofloxacin, norfloxacin, bacitracin, tetracycline, neomycin, erythromycin, tobramycin and gentamicin. CONCLUSION: Chloramphenicol had the highest overall in vitro efficacy, but has potential lethal side effects. The fluoroquinolones were highly effective, especially being superior to the aminoglycosides tested, but no single antibiotic provided 100% coverage against all of the bacterial isolates that were tested.     

Antibiotic resistance patterns of ocular bacterial flora: a prospective study of patients undergoing anterior segment surgery

PURPOSE: To determine the antibiotic susceptibility patterns of conjunctival bacterial flora isolated preoperatively from patients undergoing anterior segment surgery. DESIGN: Prospective observational study. PARTICIPANTS: One hundred fifty-six eyes from 139 patients scheduled for anterior segment surgery were enrolled over a 6-month period from August 2001 to February 2002. METHODS: Conjunctival cultures were obtained on the day of surgery before povidone-iodine or antibiotic application. MAIN OUTCOME MEASURES: Bacterial isolates were identified and tested for antibiotic susceptibility using the Kirby-Bauer disc-diffusion technique. RESULTS: Among the 156 eyes studied, 36 were from patients who had undergone either bilateral surgery or more than one surgery in the same eye. Only the first eyes of the 120 patients that underwent initial ocular surgery were included in our analysis. Of these 120 eyes, 21 (18%) showed no bacterial growth. Of the 143 bacterial strains isolated from the remaining 99 eyes, 112 (78%) were coagulase-negative staphylococci (CNS). Among the CNS, greater than 90% were susceptible to cefotaxime, levofloxacin, imipenem, meropenem, vancomycin, and each of the aminoglycosides except neomycin. Between 70% and 90% of the CNS were susceptible to cefazolin, neomycin, ciprofloxacin, ofloxacin, norfloxacin, and chloramphenicol. Less than 70% of the isolated CNS were sensitive to the penicillin analogues, ceftazidime, erythromycin, and tetracycline. CONCLUSIONS: Preoperative conjunctival isolates of CNS seem to be most sensitive to vancomycin, the aminoglycosides (except neomycin), and levofloxacin.     

Wirksamkeit neuer Fluorchinolone gegenüber der bakteriellen Normalflora der Bindehaut

BACKGROUND: Our aim was to determine the antibiotic susceptibility of the preoperative conjunctival bacterial flora against 25 commonly used antibiotics, especially the new fluoroquinolones levofloxacin, gatifloxacin, and moxifloxacin. PATIENTS AND METHODS: The Kirby-Bauer disk-diffusion technique was used to test for the in vitro antibiotic susceptibility of conjunctival bacterial strains isolated from 160 patients (median=74 years, mean=71 years) undergoing cataract surgery at the Department of Ophthalmology, Stanford University, CA, USA. RESULTS: Among the 256 bacteria isolated, 201 (79%) were coagulase-negative staphylococci (CNS), 26 Staphylococcus aureus, 15 Streptococcus group D and 14 gram-negative rods. A total of 100 of these 256 strains (39%) were classified as multiresitant (resistant to>or=five antibiotics). The resistance rate (RR) of commonly used antibiotics for all CNS was: gatifloxacin=moxifloxacin相似文献   

Bacterial spectrum and resistance patterns in corneal infections at a Tertiary Eye Care Center in South China

AIM: To investigate the spectrum and antibiotic susceptibility of bacteria isolated from patients with suspected corneal infections in Zhongshan Ophthalmic Center in South China over the past four years retrospectively. METHODS: Totally 1943 corneal scrapes from patients with corneal infections from 2010 to 2013 were cultured and processed using standard microbiological procedures to identify bacterial isolates. Simultaneously, the bacterial isolates were tested for antibiotic susceptibility to 8 antibiotics (ceftazidime, cefuroxim, cefazolin, levofloxacin, ofloxacin, neomycin, tobramycin, chloramphenicol) using the Kirby-Bauer disc diffusion technique. RESULTS: Of the total 1943 scrapes, 397 (20.43%) were culture-positive, of which 294 (74.06%) were gram-positive (GP) and 103 (25.94%) were gram-negative (GN) bacteria. Of the GP organisms, the most prevalent genera were Staphylococcus spp. (56.17%, n=223), Kocuria spp. (5.29%, n=21) and Micrococcus spp. (1.26%, n=5). On the other hand, the most prevalent genera were Pseudomonas spp. (12.85%, n=51), Burkholderia spp. (2.02%, n=8) and Acinetobacter spp. (1.51%, n=6) for the GN organisms. Among five antibiotics that have eye drop products, the resistant to neomycin of GP (7.82%, 95% CI: 4.72%-10.92%) and GN isolates (9.71%, 95% CI: 4.01%-15.41%) was lowest, while the resistant to chloramphenicol was highest (GP: 34.35%, 95% CI: 28.92%-39.78%; GN: 60.19%, 95% CI: 50.74%-69.64%). CONCLUSION: Staphylococcus spp. was the most common bacterial pathogens isolated from patients with corneal infections in this setting. High percentages of GP and GN bacteria were mostly susceptible to neomycin and highly resistant to chloramphenicol.     

Topical fluoroquinolones: antimicrobial activity and in vitro corneal epithelial toxicity

To assess the potential of fluoroquinolones as topical antimicrobial agents, we evaluated in vitro the antimicrobial activity of five fluoroquinolones (ciprofloxacin, norfloxacin, ofloxacin, pefloxacin, and temafloxacin), as well as gentamicin, tobramycin, and cefazolin against 96 isolates of common bacterial corneal pathogens. Ciprofloxacin and temafloxacin were the most active quinolones [minimal inhibitory concentration inhibiting 90% of stains (MIC90) of 1 microgram/ml], followed by ofloxacin (MIC90 2 micrograms/ml), and norfloxacin and pefloxacin (MIC90s 4 micrograms/ml). In contrast, gentamicin and tobramycin MIC90s were 32 and 64 micrograms/ml, respectively; cefazolin MIC90 was greater than 2048 micrograms/ml. The corneal epithelial cytotoxicity of the fluoroquinolones also was evaluated utilizing an in vitro assay of 3H-thymidine uptake of rabbit corneal epithelial cell cultures. The least to greatest toxicity of the fluoroquinolones were as follows: ciprofloxacin and temafloxacin less than norfloxacin less than ofloxacin less than pefloxacin. Our study suggests that the fluoroquinolones, especially ciprofloxacin and temafloxacin, possess excellent in vitro activity against common bacterial corneal pathogens and are less toxic to the corneal epithelium than the aminoglycosides.     

眼部体外培养细菌对常用氟喹诺酮类药物敏感性的研究

目的　研究眼部体外培养细菌对常用氟喹诺酮类药物的敏感性。方法　对 1999年 1月至 2 0 0 0年 12月间北京市眼科研究所微生物室收集的 132 8份眼部标本行体外细菌培养 ,采用纸片扩散法观察体外培养阳性细菌对氧氟沙星、环丙沙星和诺氟沙星等药物的敏感性。结果　体外培养阳性细菌共 347株 ,其中革兰阳性球菌 192株 ( 5 5 3 %) ,革兰阴性球菌 16株 ( 4 6 %) ;革兰阳性杆菌 44株( 12 7%) ,革兰阴性杆菌 89株 ( 2 5 7%) ;放线菌 6株 ( 1 7%)。氧氟沙星、环丙沙星和诺氟沙星的总耐药性分别为 2 8 5 %、2 5 9%和 34 9%。链球菌属对环丙沙星和氧氟沙星的耐药性明显低于庆大霉素和妥布霉素 ,诺氟沙星明显低于妥布霉素 ,两者比较差异有非常显著意义 (P <0 0 1) ;假单胞菌属对环丙沙星耐药性明显低于庆大霉素 ,两者比较差异有非常显著意义 (P <0 0 1) ,而对氧氟沙星和诺氟沙星的耐药性低于庆大霉素 ,差异有显著意义 (P <0 0 5 )。常见葡萄球菌对庆大霉素和妥布霉素的耐药性明显低于诺氟沙星 ,差异有显著意义 (P <0 0 1) ;革兰阳性杆菌对 3种氟喹诺酮类药物的耐药性比较 ,差异无显著意义 (P >0 0 5 )。结论　多数眼部常见细菌对环丙沙星和氧氟沙星的敏感性较高 ,而常见葡萄球菌对环丙沙星和氧氟沙星的敏     

Perioperative microbiologic profile of the conjunctiva in photorefractive keratectomy

PURPOSE: Therapeutic soft contact lenses are used commonly as an adjunctive treatment after photorefractive keratectomy (PRK) to decrease postoperative pain caused by the movement of lids over the corneal epithelial defect and to facilitate epithelial healing. We assessed the microbiological profile of the conjunctiva of patients undergoing PRK for myopia, before and after the concurrent use of a therapeutic soft contact lens, and compared the effect on ocular bacterial colonization of prophylactic administration of topical tobramycin 0.3% versus ofloxacin 0.3%. METHODS: Forty-three consecutive eyes from 37 patients underwent PRK for myopia or myopic astigmatism. Eyes were assigned randomly to prophylactic antibacterial treatment with either topical ofloxacin 0.3% or tobramycin 0.3%, applied prior to surgery and three times daily after surgery until therapeutic soft contact lens removal. Material from the conjunctival sac was obtained for bacteriologic cultures prior to surgery. Clinical evaluation of all eyes was conducted prospectively. Three days after PRK, the therapeutic soft contact lenses were removed and cultured. Cultures from the conjunctival sac were then repeated. RESULTS: No statistically significant differences were observed in culture positivity between the two groups of eyes, in spite of some positive preoperative and postoperative cultures. Only one out of 43 eyes (assigned to the ofloxacin group) developed a peripheral corneal infiltrate. The corneal infiltrate healed completely without sequelae using antibiotic and corticosteroid therapy. CONCLUSIONS: The use of therapeutic soft contact lenses after PRK with either topical tobramycin 0.3% or ofloxacin 0.3% were well tolerated. However, perioperative positive conjunctival cultures were relatively frequent and prophylactic antibiotics should be used in the setting of an epithelial defect and therapeutic soft contact lens following PRK.     

The comparative in vitro activity of ofloxacin and selected ophthalmic antimicrobial agents against ocular bacterial isolates

The in vitro activity of ofloxacin, a new fluoroquinolone anti-infective agent, was evaluated against 419 ocular bacterial isolates of 55 species to determine its potential as a topical agent for the treatment of ocular infections. Other agents tested in this study, in which a modified tube-dilution procedure was used, include norfloxacin, gentamicin, tobramycin, chloramphenicol, and polymyxin B. Ofloxacin demonstrated good to excellent activity against a variety of gram-positive and gram-negative pathogens. The minimum inhibitory concentration against 90% of all bacterial strains tested (MIC90) of ofloxacin was 0.5 microgram/ml for Staphylococcus aureus and S. epidermidis, 2 micrograms/ml for Streptococcus pneumoniae, and 4 micrograms/ml for Pseudomonas aeruginosa. These species were more susceptible to ofloxacin than to any of the nonquinolones tested. The MIC90 of ofloxacin was lower than that of norfloxacin, another quinolone, against S. aureus, S. epidermidis, and St. pneumoniae and equal to that of norfloxacin against P. aeruginosa. Because of its broad spectrum of activity and excellent in vitro activity, we concluded that ofloxacin has the potential for development into a superior topical treatment for ocular infection.     

青少年配戴角膜塑形镜后结膜囊菌群状况及药敏分析

目的：研究青少年配戴角膜塑形镜后结膜囊细菌菌群状况及药物敏感性分析。方法：观察性横断面研究。招募2021-09/2022-08在西安市第一医院门诊就诊的8～14岁青少年患者101例,其中配戴角膜塑形镜组51例及配戴框架眼镜组50例,均取右眼入组。比较两组患者结膜囊细菌培养情况,采用基质辅助激光解吸/电离飞行时间质谱仪鉴定种类,对配戴角膜塑形镜组培养阳性菌株进行药物敏感性实验。结果：配戴角膜塑形镜组患者结膜囊细菌培养阳性率为68.6%(35/51),配戴框架眼镜组培养阳性率为60.0%(30/50)(P&#x003E;0.05),两组检出率最高的菌种均为表皮葡萄球菌和金黄色葡萄球菌。配戴角膜塑形镜组检出菌株对药物的敏感率为：左氧氟沙星(98%)、莫西沙星(98%)、加替沙星(98%)、头孢呋辛(98%)、头孢硫脒(98%)、利福平(98%)、氯霉素(96%)、头孢西丁(95%)、克林霉素(80%)、庆大霉素(74%)、夫西地酸(72%)、妥布霉素(64%)、复方新诺明(26%)、美洛西林(10%)、阿奇霉素(6%),其中革兰氏阳性球菌对万古霉素敏感率为100%。结论：青少年配戴角膜塑形镜后结膜囊主要分离菌属为革兰氏阳性球菌,戴镜不会明显提高其结膜囊细菌阳性率。药敏结果对戴镜者发生眼部感染后的经验性用药可能有指导意义。     

Comparison of in vitro susceptibilities of ocular bacterial isolates to gatifloxacin and other topical antibiotics

PURPOSE: To compare the in vitro activity of gatifloxacin with that of other topical antibiotics against fresh bacterial isolates from various types of human ocular infections. METHODS: A total of 498 strains of ocular bacterial isolates were tested for their susceptibility to gatifloxacin, ofloxacin, ciprofloxacin, norfloxacin, gentamicin, tobramycin, neomycin, chloramphenicol, erythromycin, tetracycline and amikacin. RESULTS: Ninety-nine percent of gram-positive and 92% of gram-negative bacterial strains were found to be susceptible in vitro to gatifloxacin, whereas lower percentages of gram-positive and gram-negative bacteria were found to be susceptible to other antibiotics. CONCLUSIONS: In vitro, gatifloxacin exhibits good activity against various bacterial species isolated from different ocular sites. This requires corroboration in the clinical setting.     

Antibiotic susceptibility of preoperative normal conjunctival bacteria

PURPOSE: To determine the antibiotic susceptibility of preoperative conjunctival bacterial flora. DESIGN: In vitro study. METHODS: Antibiotic susceptibility of conjunctival bacterial strains isolated from 164 patients undergoing intraocular surgery was determined using the Kirby-Bauer disk-diffusion technique. RESULTS: Among the 162 bacteria isolated, 124 (76%) were coagulase-negative staphylococci (CNS), with 2% resistant to gatifloxacin and moxifloxacin, and none were resistant to vancomycin or minocycline. Other bacteria isolated were 19 Staphylococcus aureus (S. aureus), 8 Streptococcus Group D, and 11 gram-negative rods. Most S. aureus (>85%) were susceptible to all antibiotics except for the penicillin and macrolide groups. No streptococci were resistant to gatifloxacin, levofloxacin, moxifloxacin, mezlocillin, imipenem, or vancomycin. None of the gram-negative rods were resistant to the fluoroquinolones. Approximately one half of all bacteria were resistant to erythromycin. One in three patients harbored multi-resistant bacteria (resistant to > or = five antibiotics). CONCLUSIONS: Newer-generation fluoroquinolones provide excellent broad-spectrum coverage against conjunctival bacterial flora.     

Ciprofloxacin and levofloxacin resistance among methicillin-sensitive Staphylococcus aureus isolates from keratitis and conjunctivitis

PURPOSE: The majority of Staphylococcus aureus isolated from ocular infections are methicillin sensitive (MSSA). Fluoroquinolone resistance among methicillin- resistant Staphylococcus aureus is well known but not among MSSA. In this study we investigate the emergence of fluoroquinolone (ciprofloxacin, levofloxacin) resistance among methicillin-sensitive Staphylococcus aureus isolates from keratitis and conjunctivitis. DESIGN: Cross-sectional study. METHODS: Minimal inhibitory concentration susceptibility profiles for 1230 S. aureus isolates from keratitis and conjunctivitis were analyzed. Historical and current rates of emerging fluoroquinolone resistance for methicillin-resistant (MRSA) and methicillin-sensitive isolates (MSSA) were evaluated. Sensitivity patterns for vancomycin and gentamicin were also documented. RESULTS: Ciprofloxacin resistance among corneal and conjunctival S. aureus isolates during the first 6 years after its introduction (baseline) (1990-1995) was 8% and ranged from 3% to 11%. The rate for the most recent 6 years (current) (1996-2001) was 20.7%. Baseline ciprofloxacin resistance for MSSA isolates was 2% vs 55.8% for MRSA. The current resistance rate for MSSA is 5% vs 83.7% for MRSA. The general resistance rate from January 2000 to December 2001 for levofloxacin was 25.5% vs 33.2% for ciprofloxacin (P =.13). The levofloxacin-resistance rate for MSSA was 4.7% vs 11.9% for ciprofloxacin (P =.05). In MRSA isolates, a higher resistance rate was found for ciprofloxacin (95.7%) vs levofloxacin (82.1%) (P =.04). No resistance for vancomycin was documented for any of the S. aureus isolates. Gentamicin susceptibility for MSSA was 99% and MRSA was 86%. CONCLUSIONS: Ciprofloxacin and levofloxacin resistance among methicillin-sensitive S. aureus corneal and conjunctival isolates is increasing. This is of concern because it narrows treatment choices for the management of these common ocular infections.     

四种氟喹诺酮类药物对眼部分离细菌的体外敏感试验

目的研究眼部分离细菌对4种氟喹诺酮类药物的敏感性。方法对525份眼部标本行体外细菌培养,K-B法观察培养阳性细菌对环丙沙星、氧氟沙星、左氧氟沙星和加替沙星的敏感性。结果体外培养阳性细菌321株,革兰阳性球菌最多,为245株(76.3%),其次,革兰阴性杆菌48株(15.0%),革兰阳性杆菌20株(6.2%),革兰阴性球菌8株(2.5%),环丙沙星、氧氟沙星、左氧氟沙星和加替沙星的总敏感性分别为59.2%、66.4%、80.7%和96.6%。环丙沙星、氧氟沙星对表皮葡萄球菌的敏感性(47.6%,55.3%)明显低于左氧氟沙星和加替沙星(76.0%和97.1%)(P<0.05)。结论眼部分离细菌以表皮葡萄球菌最多,其次为金黄色葡萄球菌。加替沙星的敏感性最好,其次是左氧氟沙星。     

Topical 0.3% ciprofloxacin, norfloxacin, and ofloxacin in treatment of bacterial keratitis: a new method for comparative evaluation of ocular drug penetration.

AIMS--This study was designed to assess the relative corneal penetration of topical drops of three antibiotics and to relate those levels to minimum inhibitory concentrations for organisms associated with bacterial keratitis. METHODS--Four drops of each of ciprofloxacin, norfloxacin, and ofloxacin (0.3% topical ophthalmic preparations) were given to 12 patients undergoing corneal transplantation. After the recipient tissue was removed, corneal drug penetration was measured using high performance liquid chromatography. RESULTS--Intracorneal concentrations of ofloxacin (geometric mean 0.81 mg kg-1) were significantly higher than both ciprofloxacin (0.60 mg kg-1; p = 0.048) and norfloxacin (0.54 mg kg-1; p = 0.012). Ciprofloxacin and norfloxacin concentrations did not differ significantly (p = 0.33). CONCLUSIONS--Review of the minimum inhibitory concentrations of the fluoroquinolones against ocular pathogens reveals that ciprofloxacin is more potent than ofloxacin against many bacteria; ofloxacin is in turn more potent than norfloxacin. These data favour the selection of ciprofloxacin and ofloxacin rather than norfloxacin for the empirical treatment of corneal infection. The greater potency of ciprofloxacin offsets the superior penetration of ofloxacin. There is a need for improved clinical trial data concerning the use of fluoroquinolone eyedrops in ulcerative keratitis; some encouraging data are available for ciprofloxacin but not (in humans) for norfloxacin or ofloxacin.     

Treatment of acute bacterial conjunctivitis with topical lomefloxacin 0.3% compared to topical ofloxacin 0.3%

PURPOSE: The main purpose of this prospective study was to compare the efficacy, local tolerance, and safety of topical lomefloxacin 0.3% and topical ofloxacin 0.3% in the treatment of acute bacterial conjunctivitis. PATIENTS AND METHODS: Forty patients with acute bacterial conjunctivitis were included in a randomized, prospective, parallel-group study. Twenty patients were assigned to the lomefloxacin group (Okacin, CIBA Vision Ophthalmics) and 20 patients to ofloxacin (Oflox, Allergan). Lomefloxacin 0.3% was given 1 drop every 2 hours during waking hours on the first day then twice daily for one week. Ofloxacin 0.3% eyedrops were given four times daily. All patients underwent eye examination and clinical findings were graded and recorded according to severity of lid hyperemia, lid edema, lid crusting, conjunctival edema and discharge, bulbar conjunctival hyperemia, palpebral conjunctival hyperemia, corneal edema, and ocular discomfort. The score for each clinical sign was recorded before and after treatment. The mean cumulative sum score (CSS) was obtained by adding the scores for signs and symptoms. All conjunctival swabs were cultured and tested for sensitivity. Patients with confirmed bacterial conjunctivitis were included. RESULTS: There were 10 male and 10 female patients in each group. The age range was from 1 to 78 years, and the mean age was 35 years in the lomefloxacin group. In the ofloxacin group the age range was from 1 to 70 years, and the mean age was 26 years. There was no significant difference between the two groups in relation to age or sex. The causative organisms were Staphylococcus epidermidis in 16 cases (36%), alpha-hemolytic Streptococci in 9 (20%), Haemophilus spp. 6 (13%), Staphylococcus aureus 5 (11%), Streptococcus pneumoniae 4 (9%), Pseudomonas aeruginosa 3 (7%), and other 2 (4%). The mean CSS for conjunctivitis was 12.1 before therapy in the lomefloxacin group and 12.7 in the ofloxacin group. On the 7th day of therapy, the mean CSS was 0.7 in the lomefloxacin group, and 1.6 for ofloxacin. All patients showed improvement, but a total of 18 out of 20 (88%) in the lomefloxacin group showed complete resolution compared to 15 (75%) in the ofloxacin group. The difference was not statistically significant (p = 0.08). Tolerance was excellent in both groups, and no side effects were reported. A burning sensation was noted by two patients, one in each group. CONCLUSIONS: Lomefloxacin and ofloxacin were equally effective and safe in the treatment of acute bacterial conjunctivitis.     

Laboratory diagnosis in ulcerative keratitis

AIMS: To identify the common bacterial and fungal isolates from corneal ulcers and to determine the antimicrobial susceptibility patterns of bacterial isolates to commonly used antibiotics at B.P. Koirala Institute of Health Sciences (BPKIHS), eastern Nepal. Culture and direct microscopic correlation and reliability were also compared. METHODS: All patients with suspected corneal ulceration presenting to the Ophthalmology Department of BPKIHS from 1st August 1998 to 31st July 2001 were evaluated. Corneal scraping was performed and processed for direct microscopy and culture for bacterial and fungal isolates. Bacterial isolates were subjected to antimicrobial susceptibility testing. RESULTS: Of 447 specimens examined direct microscopy was positive in 216 (48%) specimens. Culture positivity could be correlated with direct microscopy in 179 (83%) of specimens. Growth of etiologic agents was found in 303 (67.8%) samples. Of these 145 (47.8%) had pure fungal growth, 103 (34%) had pure bacterial growth and 55 (18.2%) had mixed fungal and bacterial infection. The commonest fungal pathogen was Aspergillus spp.in 78 (38.4%) followed by Fusarium spp. in 45 (22%). Aureobasidium sp. was isolated in 25 (12.3%) samples. Staphylococcus aureus (93, 56.7%) dominated the scene as the commonest bacterial agent. Streptococcus pneumoniae (33, 20%) was second in the list. Most of the bacterial isolates were sensitive to commonly used antibiotics. CONCLUSION: This study emphasizes the importance and need of the continued surveillance of the agents and their antimicrobial susceptibility for the prevention and management of corneal ulcers and their complications.     

Bacterial corneal ulcers among Arabs in Kuwait

A retrospective clinicomicrobiological study of 228 patients with bacterial corneal ulcers was performed. Positive cultures of corneal ulcer samples were obtained from 68% of all patients. A high incidence of Staphylococcus epidermidis was isolated from patients' ulcers, Staphylococcus aureus, Pseudomonas, Streptococcus pneumoniae, and Streptococcus were the next most frequent pathogens. Of some help in identifying the causative organism were the locations of the ulcer, the presence or absence of hypopyon and the frequency of perforation of the ulcer. Cephaloridine, gentamicin and polymyxin were found to be the most effective therapy. Gram strains of ulcer samples were positive for organisms in only 13% of patients and accordingly were not considered useful in determining initial therapy of ulcers. Since corneal and conjunctival cultures in the majority of the control group were negative, one can presume that most of the S. epidermidis isolated from patients' ulcers was exogenous in nature.     

中国白内障人群术前结膜囊细菌培养结果的Meta分析

目的：系统研究中国白内障人群术前结膜囊细菌构成和药物敏感情况的变化,为白内障术前无菌化准备提供科学的理论依据。

方法：计算机检索中文科技期刊数据库、万方数据库、中国知网学术文献网络出版总库及中文生物医学文献数据库。收集2004-01/2013-09发表的有关中国人群白内障结膜囊细菌培养的文献,并辅以手工检索、因特网搜索。并采用Meta分析对所纳入研究结果进行分析。

结果：共纳入7篇文献,共11499眼,白内障患者术前结膜囊培养阳性率为26.03%(2993/11499),主要由G⁺球菌(86.40%)、G⁺杆菌(8.10%)、G^-杆菌(4.13%)以及G^-球菌(1.37%)构成。G⁺球菌主要以表皮葡萄球菌(67.30%)、金黄色葡萄球菌(12.53%)和微球菌(6.98%)为主。大多菌株对妥布霉素、万古霉素、环丙沙星和庆大霉素敏感,对妥布霉素和环丙沙星耐药性有上升趋势。

结论：白内障术前的结膜囊主要由表皮葡萄球菌构成,对青霉素和红霉素耐药,大多数菌株对妥布霉素、万古霉素、环丙沙星和庆大霉素敏感,对妥布霉素和环丙沙星耐药性有上升趋势。     

[Online First]Intravitreal dexamethasone implant in naïve and previously treated patients with diabetic macular edema: a retrospective study

AIM: To assess the effect of the intravitreal dexamethasone implant (DEX) Ozurdex on the best corrected visual acuity (BCVA) and central retinal thickness (CRT) in patients with diabetic macular edema (DME). METHODS: Totally 43 eyes (24 naïve and 19 previously treated) were included in the study. Retrospective and single-center study involved patients with a clinical diagnosed of DME, who received treatment with DEX implant and had a follow-up of at least 12mo. Primary endpoints included changes in BCVA and CRT. RESULTS: At month 12, mean improvement in BCVA from baseline was 20.4±20.8 letters and 6.8±6.9 letters in naïve and previously treated patients, respectively (P=0.0132). The naïve patients achieved the BCVA improvement significantly faster (2.4±1.5mo) than the previously treated ones (3.5±2.4mo, P=0.0298; Mann-Whitney test). The proportion of eyes gaining ≥15 letters was 54.2% and 21.1% in the non-previously treated and previously treated groups, respectively (P=0.0293). CRT was significantly reduced from 484.0±119.8 µm and 487.5±159.9 µm to 272.0±39.2 µm and 233.5±65.7 µm in the naïve and previously treated patients, respectively; P<0.0001 each, respectively. The presence of subretinal fluid was significantly associated with the proportion of patients achieving a BCVA improvement ≥5 letters [HR (95%CI), 1.23 (1.04 to 1.45), P=0.0145]; ≥10 letters [HR (95%CI), 1.75 (1.10 to 2.77), P=0.0182]; and ≥15 letters [HR (95% CI), 2.04 (1.03 to 4.02), P=0.0407]. Naïve patients received less DEX implants throughout the study than the previously treated ones (1.8±0.6 vs 2.3±0.6, P=0.0172, respectively). Totally 9 patients (20.9%) have developed ocular hypertension, which was successfully controlled with topical hypotensive drugs. Of the 23 phakic eyes at baseline, 5 eyes (21.7%) either had new onset lens opacity or progression of an existing opacity during the study follow-up. Four of them (2 in the naïve group and 2 in the previously treated one) required cataract surgery at months 4, 6, 6, and 6, respectively. CONCLUSION: The results obtained in this study might support the early use of DEX Ozurdex as first line therapy in naïve patients.     

Prospective randomized study determining whether a 3-day application of ofloxacin results in the selection of fluoroquinolone-resistant coagulase-negative Staphylococcus

PURPOSE: To determine whether a 3-day application of ofloxacin results in the selection of fluoroquinolone-resistant conjunctival coagulase-negative Staphylococcus. DESIGN: Prospective randomized trial. METHODS: Patients scheduled for ocular surgery were randomized to a control (89 eyes) or study group (70 eyes). The study group received topical ofloxacin (0.3%) four times a day for 3 days. Conjunctival cultures were obtained at baseline (T0) and after 3 days of ofloxacin (T1). Cultures were also obtained at T0 and T1 for the control group, but these eyes did not receive an antibiotic. Bacteria isolated were identified and antibiotic susceptibility was determined. RESULTS: At T0, 53 out of 89 patients (60%) in the control and 48 out of 70 patients (69%) in the study group harbored coagulase-negative Staphylococcus. Among these coagulase-negative Staphylococcus, 12 out of 53 in the control and 11 out of 48 in the study group were resistant to ofloxacin (p>0.9999). At T1, significantly fewer coagulase-negative Staphylococcus (p=0.0003) were isolated from the study group (18 coagulase-negative Staphylococcus), compared the control group (48 coagulase-negative Staphylococcus). Of these, 5 out of 17 coagulase-negative Staphylococcus in the study group and 9 out of 48 coagulase-negative Staphylococcus in the control group were resistant to ofloxacin (p=0.5649). There was no significant difference in the number of coagulase-negative Staphylococcus resistant to ciprofloxacin or norfloxacin in the study group compared to the control group at T1. CONCLUSIONS: Ofloxacin given four times a day for 3 days does not select out for conjunctival fluoroquinolone-resistant coagulase-negative Staphylococcus.