反复使用抗生素患者结膜菌群的变化及耐药模式研究

目的：观察和分析反复使用抗生素患者结膜菌群的变化。此外,确定这种反复暴露对结膜菌群抵抗模式的影响。

方法：研究纳入40例眼科研究所视网膜科患者。所有受试者至少进行了连续4次、每月一次的玻璃体腔注射(IVI),其中一些患者根据需要延长至6mo或1y。将患者随机分为3组,每组给予氧氟沙星、莫西沙星或头孢他啶任意一种抗生素。使用Kirby-Bauer扩散法对所有细菌进行药敏试验。

结果：研究中,以表皮葡萄球菌(51.2%)为主,其次是金黄色葡萄球菌(14%),微球菌(12.8%)和其他凝固酶阴性葡萄球菌(CONS)占13%。结果显示,在4次随访中,与随机接受头孢他啶治疗的患者的基线培养相比,接受头孢他啶治疗的患者眼部表皮葡萄球菌的百分比有所增加。相比之下,与基线相比,金黄色葡萄球菌的百分比没有明显增加。在氟喹诺酮治疗眼中观察到表皮葡萄球菌的百分比从基线增加。与头孢他啶治疗组相比,氟喹诺酮治疗组的金黄色葡萄球菌百分比较基线升高。然而,随着新一代和老一代氟喹诺酮类药物的暴露,眼部菌群组成模式发生了变化。我们注意到,从基线开始,莫西沙星治疗组比氧氟沙星治疗组的表皮葡萄球菌增多。暴露于老一代和新一代氟喹诺酮类药物的金黄色葡萄球菌的模式没有差异。

结论：反复使用眼用抗生素不仅会改变正常眼部菌群的组成,还会选择耐药菌株。     

1至4个月龄正常婴幼儿结膜囊菌群分布特征分析

目的 探讨1至4个月龄正常婴幼儿结膜囊的菌群分布及其相关影响因素.方法 横断面研究方法.2009年1至3月天津医科大学眼科中心与天津市妇女儿童保健中心合作,采取简单随机抽样研究方法选择109例接受眼病筛查的1至4个月龄的健康小儿,进行双眼结膜囊分泌物取材并做细菌培养和鉴定.应用卡方检验、t检验和回归分析方法对数据进行统计学处理,分析结膜囊细菌种类和分布以及相关影响因素.结果 结膜囊分泌物培养阳性的小儿26例(36只眼),占23.9%.共检出7种44株细菌,包括革兰阳性球菌25株,革兰阳性杆菌18株,革兰阴性杆菌1株.其中类白喉棒状杆菌17株(17/44,38.6%),表皮葡萄球菌16株(16/44,36.4%),金黄色葡萄球菌6株(6/44,13.6%).单眼分离出2种细菌者8只眼(8/36,22.2%),均为葡萄球菌和类白喉棒状杆菌.不同月龄、性别及喂养方式的细菌培养结果差异无统计学意义(X2=0.351,X2=0.001,X2=1.182,P值均大于0.05).结膜囊培养阳性者26例(36只眼),培养阴性者83例(166只眼),两组小儿的出生体重、胎龄及受检周龄比较差异无统计学意义(t=0.078,t=0.940,t=0.686,P值均大于0.05).本研究中性别、年龄、出生体重、胎龄及喂养方式不影响结膜囊带菌状态(Wald X2=0.001,Wald X2=0.003,Wald X2=0.117,Wald X2=1.307,Wald X2=1.490,P值均大于0.05).结论 婴儿期结膜囊正常菌群已经建立,以表皮葡萄球菌和类白喉棒状杆菌为主要菌种.葡萄球菌与类白喉棒状杆菌有共生现象.小儿结膜囊带菌状态相关影响因素仍需进一步研究.     

Comparison of aerobic conjunctival bacterial flora in pregnant, reproductive-aged and postmenopausal women

AIM: To evaluate the effect of hormonal status on aerobic conjunctival flora in women.METHODS: One hundred fifty-eight women [reproductive-aged (n=55), pregnant (n=51), and postmenopausal (n=52)] who admitted to outpatient clinic of Obstetrics and Gynecology Department of Denizli State Hospital were enrolled. Age, body-mass index (BMI), obstetric history, cigarette smoking, drug usage, presence of systemic disease, and intraocular pressure (IOP) were recorded for each patient. The samples were taken from the lower fornix with two culture swabs and directly incubated in culture containing 5% sheep blood, eosin-methylene blue and chocolate agar. The other swab specimen was Gram stained. All growths and microscopic results were analyzed.RESULTS: The coagulase-negative Staphylococcus was the predominant organism isolated in the conjunctival samples in both three groups. The aerobic microorganism growth rate for all isolated aerobic organisms revealed no significant change in the three groups (P >0.05). The conjunctival culture positivity rates were similar in the three groups (49% in reproductive-aged, 57% in pregnant and 58% in postmenopausal women) (P >0.05). Age, IOP, BMI, gravidity, parity, cigarette smoking, drug usage, and presence of systemic diseases did not have an effect on culture positivity in three groups.CONCLUSION: Results of this study showed that conjunctival aerobic flora and bacterial colonization did not differ between reproductive-aged, pregnant and postmenopausal women.     

长期应用前列腺素类似物滴眼液对青光眼患者结膜菌群的影响

目的：探讨长期应用前列腺素类似物滴眼液对青光眼患者结膜菌群的影响。

方法：选择2016-06/2017-06在我院就诊的应用拉坦前列素滴眼液治疗的69例113眼青光眼患者,所有患者分别于入组后、用药3mo,1a时检查结膜菌群及表皮葡萄球菌对抗生素敏感性。

结果：入组时、用药3mo,1a时检出细菌例数分别为63、66、67例(χ²=2.496,P=0.287)。患者入组时、用药3mo,1a时表皮葡萄球菌、链球菌属、金黄色葡萄球菌、人葡萄球菌、溶血葡萄球菌、莫拉菌属等检出率均无差异(P>0.05); 用药3mo时耐甲氧西林表皮葡萄球菌(MRSE)比率高于入组时(χ²=3.063,P=0.062),用药1a时MRSE比率高于入组时和用药3mo时(χ²=38.945、24.984,均P<0.001)。用药3mo时表皮葡萄球菌对左氧氟沙星、加替沙星、莫西沙星、头孢他啶、妥布霉素、头孢甲肟、红霉素的敏感性均低于入组时,但无差异(P>0.0167),对氯霉素敏感性低于入组时(P<0.0167); 用药1a时表皮葡萄球菌对左氧氟沙星、加替沙星、莫西沙星、头孢他啶、头孢甲肟、妥布霉素、氯霉素、红霉素敏感性低于入组时和用药3mo时(P<0.0167)。

结论：长期应用拉坦前列素滴眼液不会影响结膜菌群的检出率,但可增加MRSE的发生率,临床对需要长期应用拉坦前列素滴眼液的患者应综合考虑,防止耐药菌株产生,以防发生不可控制的感染。     

Effects of moxifloxacin exposure on the conjunctival flora and antibiotic resistance profile following repeated intravitreal injections

AIM:To evaluate the effects of moxifloxacin exposure on the conjunctival flora and antibiotic resistance profile following repeated intravitreal injections.METHODS:Seventy-two eyes of 36 patients [36 eyes in control group, 36 eyes in intravitreal injection (IVI) group] were enrolled in the study. All the eyes had at least one IVI and had diabetic macular edema (DME) or age-related macular degeneration (ARMD). Moxifloxacin was prescribed to all the patients four times a day for five days following injection. Conjunctival cultures were obtained from the lower fornix via standardized technique with every possible effort made to minimize contamination from the lids, lashes, or skin. Before the application of any ophthalmic medication, conjunctival cultures were obtained from both eyes using sterile cotton culture. An automated microbiology system was used to identify the growing bacteria and determine antibiotic sensitivity. RESULTS:The bacterial cultures were isolated from 72 eyes of 36 patients, sixteen of whom patients (44.4%) were male and twenty (55.6%) were female. Average age was 68.4±9.0 (range 50-86). The average number of injections before taking cultures was 3.1+1.0. Forty-eight (66.7%) of 72 eyes had at least one significant organism. There was no bacterial growth in 8 (20.5%) of IVI eyes and in 16 (44.4%) of control eyes (P=0.03). Of the bacteria isolated from culture, 53.8% of coagulase negative staphylococci (CoNS) in IVI eyes and 47.2% CoNS in control eyes. This difference between IVI eyes and control eyes about bacteria isolated from culture was not statistically significant (P=0.2). Eleven of 25 bacteria (44.0%) isolated from IVI eyes and 11 (57.9%) of 19 bacteria isolated from control eyes were resistant to oxacillin. The difference in frequency of moxifloxacine resistance between two groups was not statistically significant (12.0% in IVI eyes and 21.1% in control eyes) (P=0.44). There were no cases of resistance to vancomycin, teicoplanin and linezolid.CONCLUSION:There was no difference in species of bacteria isolated from cultures, or in the frequency of resistance to antibiotics between eyes that had recurrent IVI followed by moxifloxacin exposure compared with control eyes. However, the number of eyes that had bacterial growth was higher in IVI group than in the control group.     

青少年角膜塑形镜配戴者结膜囊及镜盒菌群研究

目的研究配戴角膜塑形镜对青少年结膜囊菌群的影响,以及角膜塑形镜存储盒带菌情况。方法实验研究。分别对101名配戴角膜塑形镜（配戴组）和110名未配戴角膜塑形镜青少年（对照组）进行结膜囊细菌培养,并对158个角膜塑形镜存储盒进行细菌培养。所有标本置于37 ℃恒温箱中培养48 h后统计培养阳性率。数据比较采用卡方检验。结果对照组结膜囊培养菌株68株,阳性率为30.9%;配戴组结膜囊培养菌株59株,阳性率为29.4%;2组结膜囊细菌培养阳性率差异无统计学意义（χ²=0.12,P>0.05）。角膜塑形镜存储盒细菌培养菌株72株,阳性率为45.6%。2组研究对象结膜囊和镜盒菌群培养阳性率首位均为表皮葡萄球菌。结论配戴角膜塑形镜不会提高青少年结膜囊带菌率,镜片及镜盒的清洁可降低镜片污染率。     

Conjunctival flora in anophthalmic patients: microbiological spectrum and antibiotic sensitivity

AIM: To identify the spectrum and susceptibility pattern of isolated microorganisms from conjunctival flora of anophthalmic patients. METHODS: A cross-sectional clinical study including 60 patients with unilateral anophthalmia. Patients with use of antibiotic drops in their socket during the last month were also included. From each patient, three microbiological samples were taken from the lower conjunctival sac (healthy eye, pre-prosthesis, and retro-prosthesis space of socket). The 180 samples obtained were cultured. Isolates were identified and their antibiotic sensitivities were determined. RESULTS: A total of 251 isolates were recovered (62 isolates from healthy eye, 93 from pre-prosthesis, and 96 from retro-prosthesis space). The most common organism was Staphylococcus epidermidis, in both healthy eyes (64.5%) and sockets (45.5%). Altogether, coagulase-positive Staphylococci, Streptococci, and Gram-negative bacteria accounted for less than 15% of isolates in healthy eyes and more than 35% in sockets. Regarding the antibiotic sensitivities, there were no significant differences between isolates from sockets and healthy eyes. Nine patients recognized the use of self-prescribed antibiotic drops in their socket. In the healthy eyes of these subjects, Gram-positive microorganisms showed significantly greater resistance to aminoglycosides and tetracycline. CONCLUSION: Sockets of anophthalmic patients show a greater number of pathogens compared to healthy eyes. The use of antibiotic drops in the socket promotes a resistant flora not only in the socket but also in the healthy eye. Quinolones and macrolides may be better therapeutic options than aminoglycosides for treating conjunctivitis of anophthalmic sockets, since these antibiotics are less active against Staphylococcus epidermidis.     

氟喹诺酮药物的眼部表皮葡萄球菌防耐药突变浓度的测定

目的探讨氟喹诺酮药物对眼部分离的表皮葡萄球菌的防耐药突变浓度(MPC),并比较MPC与最低抑菌浓度(MIC)的关系。方法采用标准琼脂二倍稀释法测定表皮葡萄球菌对环丙沙星(CIP)、氧氟沙星(OFL)、左氧氟沙星(LVF)及加替沙星(GTF)的MIC值。挑选血液琼脂培养基上表皮葡萄球菌菌落,置于MullerHinton肉汤(MH)中增菌,菌液浓度至1×108cfu/ml,1∶10稀释,每种药每个浓度MullerHinton琼脂培养基(MHA)上接种1μl菌液,菌接种量104cfu。采用混菌法测定MPC值。以上述各种药物对该菌群的MIC50为参考,选择测定MPC时的药物浓度。每平皿中加入1ml药液和19ml细菌与MHA的混悬液,最终菌接种量约1010cfu。结果GTF的MIC90最低,为0.25mg/L;LVF次之,为0.50mg/L;CIP和OFLMIC90相等,为1.00mg/L。GTF对表皮葡萄球菌的MPC50和MPC90最低,分别是1.00mg/L和2.00mg/L;其次是LVF和CIP,均分别为2.00mg/L和4.00mg/L;OFL的MPC50和MPC90分别是2.00mg/L和8.00mg/L。结论LVF和GTF不仅抗菌作用强,而且在预防表皮葡萄球菌耐药突变方面有着明显的优势。(中华眼科杂志,2006,42989-991)     

Increasing ofloxacin resistance of bacterial flora from conjunctival sac of preoperative ophthalmic patients in Japan

PURPOSE: To examine the in vitro resistance to ofloxacin of preoperative bacterial isolates from the conjunctival sac of Japanese patients.METHODS: The database of bacterial flora cultured preoperatively from the conjunctival sac of 1455 Japanese patients (1455 eyes) between 1995 and 1999 was reviewed retrospectively.RESULTS: The incidence of resistance of isolates to ofloxacin in vitro increased from 13.5% in 1995 to 32.8% in 1999. The percentage of Staphylococcus epidermidis and Staphylococcus aureus isolates resistant to ofloxacin was 19.6% and 15.0%, respectively, in 1995 and 33.7% and 28.1%, respectively, in 1999. Logistic regression analysis showed that diabetes mellitus and aging were significantly associated with ofloxacin-resistant strains of bacteria.CONCLUSION: Clinicians should be aware of the increased likelihood that conjunctival sac flora is resistant to ofloxacin, especially in elderly and diabetic patients.     

Ocular flora in patients undergoing intravitreal injections: antibiotic resistance patterns and susceptibility to antiseptic picloxydine

AIM: To study antibiotic resistance patterns and susceptibility to eye antiseptic picloxydine of conjunctival flora in patients undergoing intravitreal injections(IVIs).METHODS: Conjunctival swabs were taken in 4 groups of patients, 20 patients in each group(n=80): without IVIs and ophthalmic operations in history(group N1;control group);with the first IVI and antibiotic eye drops Tobrex applied 3 d before IVI and 5 d after it(group N2);with 20 or more IVIs and repeated courses of antibiotic eye drops(group N3);with the first IVI and antiseptic eye drops Vitabact(picloxydine) applied 3 d before IVI and 5 d after it(group N4). In groups N2 and N4 swabs were taken at baseline and after the treatment. Efficacy of picloxydine in inhibition of growth of conjunctival isolates susceptible and resistant to antibiotic was studied in vitro. Minimal inhibition concentrations(MIC) were determined with microdilution test.RESULTS: Two of the three patients who had to undergo the IVI procedure showed conjunctiva bacterial contamination. Along with few Staphylococcus aureus and Gram-negative isolates susceptible to most antibiotics, the majority(71%-77%) of causative agents were coagulase-negative Staphylococci(Co NS), 40%-50% of which were multidrug resistant(MDR). Eye disinfection in the operating room and peri-injection courses of Tobrex or Vitabact resulted in total elimination of isolates found at baseline. However, in 10% and 20% of patients, respectively, recolonization of the conjunctiva with differing strains occurred. In patients with repeated IVI and Tobrex/Maxitrol treatment, the conjunctival flora showed high resistance rates: 90% of Co NS were MDR. In the in vitro study, picloxydine showed bactericidal effect against Staphylococci isolates both antibiotic resistant and susceptible with MIC≥13.56 μg/m L. Incubation of bacteria for 15 min in Vitabact eye drops, commercially available form of picloxydine, 434 μg/m L, showed total loss of colony forming units of all tested isolates including Pseudomonas aeruginosa. CONCLUSION: The confirmed efficacy of eye antiseptic picloxydine against conjunctival bacterial isolates and the presence of its commercial form, 0.05% eye drops, convenient for use by patients before and after injection, make this eye antiseptic promising for prophylaxis of IVIassociated infectious complications.     

Effect of prophylactic antibiotics on antimicrobial resistance of viridans streptococci in the normal flora of cataract surgery patients

PURPOSE: To evaluate the effect of prophylactic treatment including vancomycin in the irrigating solution and topical chloramphenicol on antimicrobial resistance in viridans-group streptococci in the normal flora of patients having cataract surgery. SETTING: Department of Ophthalmology, Turku University Central Hospital and Antimicrobial Research Laboratory, National Public Health Institute, Turku, Finland. METHODS: Minimal inhibitory concentrations (MICs) of 15 antimicrobials were determined for 529 viridans streptococci isolated from throat, nasopharyngeal, and conjunctival swabs of 23 patients on 4 sampling occasions: before cataract surgery and 1 day, 1 month, and 3 months after surgery. Resistance mechanisms of erythromycin-resistant isolates were studied by the double-disk test and polymerase chain reaction of resistance genes. RESULTS: No statistically significant changes occurred in the proportions of isolates with elevated MICs between different sampling occasions. Resistance to vancomycin or chloramphenicol was not found. Resistance to tetracycline, erythromycin, penicillin, quinupristin-dalfopristin, clindamycin, levofloxacin, and moxifloxacin was found on different sampling occasions in 27.9% to 38.7%, 13.1% to 21.8%, 11.5% to 19.4%, 8.9% to 16.9%, 2.3% to 5.6%, 0% to 2.4%, and 0% to 2.2% of the isolates, respectively. Of the erythromycin-resistant isolates, 80.8% had the M phenotype and mefA gene and 19.2% has the macrolide-lincosamide-streptogramin B phenotype and ermB gene. CONCLUSIONS: Development of resistance of viridans streptococci in the normal flora to vancomycin and chloramphenicol during prophylactic use with uneventful cataract surgery is unlikely; the effect on resistance patterns of other antimicrobials is minor. Routine use of prophylactic vancomycin is discouraged, however, because of the lack of scientific proof of its efficacy in preventing postoperative endophthalmitis.     

[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.