A Review of Next-Generation Sequencing (NGS): Applications to the Diagnosis of Ocular Infectious Diseases

ABSTRACT

Purpose: To review the value of next-generation sequencing (NGS) in identifying the pathogens which cause ocular infections, thereby facilitating prompt initiation of treatment with an optimal anti-microbial regimen. Both contemporary and futuristic approaches to identifying pathogens in ocular infections are covered in this brief overview.

Methods: Review of the peer reviewed literature on conventional and advanced methods as applied to the diagnosis of infectious diseases of the eye.

Conclusion: NGS is a novel technology for identifying the pathogens responsible for ocular infections with the potential to improve the accuracy and speed of diagnosis and hastening the selection of the best therapy.     

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。     

年龄相关性白内障术后发生感染性眼内炎的病原学特点及相关因素

目的：探究年龄相关性白内障手术后发生感染性眼内炎的病原学特点及相关因素与预防。

方法：回顾性分析本院2016-01/2018-01收治的1 365例年龄相关性白内障患者,统计患者感染性眼内炎发生情况,并分析感染性眼内炎病原学特点及相关危险因素。

结果：患者28例发生感染性眼内炎,共检出病原菌36株,其中表皮葡萄球菌9株(25.00%),铜绿假单胞菌9株(25.00%),芽孢杆菌8株(22.22%)。铜绿假单胞菌、芽孢杆菌对头孢唑林、头孢噻肟、阿莫西林具有较强的耐药性; 对头孢哌酮-舒巴坦、美罗培南的敏感性较高; 表皮葡萄球菌对青霉素、红霉素、阿奇霉素有较强的耐药性,对万古霉素、呋喃妥因、米诺环素的敏感性较高。Logistic多因素回归分析,年龄(≥70岁)、糖尿病、手术时间(≥15min)、术中玻璃体溢出是年龄相关性白内障术后发生感染性眼内炎的独立危险因素(P<0.05)。

结论：年龄相关性白内障手术后感染性眼内炎病原菌以表皮葡萄球菌、铜绿假单胞菌、芽孢杆菌多见。年龄(≥70岁)、糖尿病、手术时间(≥15min)、术中玻璃体溢出为年龄相关性白内障手术后发生感染性眼内炎的独立危险因素。     

Fe3+及血红蛋白铁对眼源性蜡样芽胞杆菌生长能力的影响

目的 探讨Fe³⁺及血红蛋白铁对眼源性蜡样芽胞杆菌生长能力的影响。方法 实验研究。收集2011年6月至2017年2月温州医科大学附属眼视光医院外伤性蜡样芽胞杆菌性眼内炎患者26例并分离出蜡样芽胞杆菌26株。根据患者治疗后有无光感将菌株分为有光感（LP）组和无光感（NLP）组,以蜡样芽胞杆菌模式菌株ATCC14579作为对照组,检测不同菌株在缺铁环境、不同Fe³⁺浓度环境、富含Hb环境中生长的光密度（OD）值。采用独立样本t检验对数据进行统计分析。结果 26株眼部来源的蜡样芽胞杆菌在缺铁环境中生长的OD值小于模式菌株ATCC14579（t=54.098,P<0.001）。在一定范围内（0~500 μmol/L）增加Fe³⁺浓度,菌株生长的OD值随之逐渐增加,当Fe³⁺浓度高于1 000 μmol/L时,细菌生长的OD值开始下降。在Fe³⁺或血红蛋白铁为主要铁资源的环境中,NLP组菌株生长的OD值均高于LP组（t=2.618,P=0.015;t=2.202,P=0.037）。结论 眼源性蜡样芽胞杆菌的生长对Fe³⁺具有较强的依赖性;在Fe³⁺或血红蛋白铁为主的铁资源环境中生长较快的菌株感染患者,其临床预后较差。     

An in Vitro Experimental Study on the Antimicrobial Activity of Silicone Oil against Anaerobic Bacteria

Purpose: To investigate the in vitro antimicrobial activity of silicone oil against anaerobic agents, specifically Propionibacterium acnes, Peptostreptococcus spp., Peptostreptococcus anaerobius, Bacteroides fragilis, Fuobacterium spp., and Clostridium tertium.

Method: A 0.5 McFarland turbidity of Propionibacterium acnes, Peptostreptococcus spp., Peptostreptococcus anaerobius, Bacteroides fragilis, Fuobacterium spp., and Clostridium tertium was prepared, and 0.1?mL was inoculated into 0.9?mL of silicone oil. Control inoculations were performed in anaerobic blood agar and fluid thioglycollate medium without silicone oil.

Results: Propionibacterium acnes retained their viability on the 3rd day in the presence of silicone oil. In total, 9.7?×?10⁶ colonies were enumerated from 1?mL of silicone oil. After a prolonged incubation of 7 days, the number of colonies observed was 9.2?×?10⁶. The other bacteria disappeared after the 3rd day of incubation in silicone oil.

Conclusions: Propionibacterium acnes, which is the most common chronic postoperative endophthalmitis agent, is thought to be resistant to silicone oil.     

Infectious endophthalmitis. Review of 36 cases

A three-year retrospective study of 36 cases of infectious endophthalmitis seen at a large referral eye center between 1977 and 1980 was conducted. The criterion for infectious endophthalmitis was the culture of microorganisms from aqueous or vitreous on at least two media. The most frequent pathogen was Staphylococcus epidermis; it was isolated from 18 (50%) of the cases. In cases of infectious endophthalmitis following recent cataract extraction, S. epidermidis was isolated from 10 to 17 eyes (58.8%). Complete loss of visual function occurred in 16 of the 36 eyes (44.4%); a visual acuity of 20/400 or better as recorded in 15 eyes (41.6%) and 20/100 or better in eight (22.2%). Fifty percent of the cases were treated with vitrectomy and intraocular antibiotics. Poor visual outcome was associated with gram-negative organisms or delay of vitrectomy more than 24 hours after the initial diagnosis. In cases of postoperative S. epidermidis endophthalmitis, the most favorable visual outcomes were associated with use of intraocular antibiotics and vitrectomy; 80% of cases so treated had a final visual acuity of 20/400 or better and 60% had a visual acuity of 20/100 or better.     

Management of Infectious Endophthalmitis

Diagnostic anterior chamber and vitreous aspiration confirmed an infectious etiology in 78 of 140 eyes (56%) with suspected endophthalmitis. In 27 eyes the vitreous aspirate was positive, while the anterior chamber aspirate was negative. Intraocular antibiotics were used in 88 eyes including 50 which underwent therapeutic vitrectomy. Vision of 20/20 to 20/400 was achieved in 57% of recently operated, culture-positive eyes treated with intraocular antibiotics, and in 59% of those treated with combined vitrectomy and intraocular antibiotics.     

玻璃体切除术后的化脓性眼内炎

目的：总结玻璃体手术后化脓性眼内炎的发生率、临床特点、治疗及预后。方法：收集１９８７～１９９８年因各种原因引起玻璃体混浊、复杂性视网膜脱离而进行玻璃体手术（不包括穿孔性眼外伤或眼内炎病例），术后经过临床或培养而证实为化脓性眼内炎病例。结果：符合标准者共４６１０例，其中３例术后发生化脓性眼内炎，发生率为０６５‰。１例培养出葡萄球菌和霍米奇肠杆菌。分别在术后第６、８和１０天控制炎症。最终视力２例保留光感，１例００２，２例视网膜脱离未能复位，眼球萎缩。结论：玻璃体切除术后眼内炎发生罕见，但视力预后差，必须高度重视。     

Congenital endophthalmitis following maternal shellfish ingestion

Purpose: To highlight an unusual organism causing a unilateral endophthalmitis by transplacental spread.
Method: We report a case of Plesiomonas shigelloides endophthalmitis, presenting in a newborn, with co-existing septicaemia and meningitis. There was a significant maternal history of diarrhoea associated with the ingestion of oysters 2 weeks prior to delivery.
Result: The endophthalmitis was treated with parenteral antibiotics and topical mydriatics with complete resolution, although subsequent assessment of the affected eye suggests a poor visual outcome.
Conclusion: Endophthalmitis in the newborn is an unusual clinical finding and usually presents with other manifestations of bacteraemia. Plesiomonas shigelloides is fortunately an infrequent cause of neonatal infection, but is associated with a high degree of morbidity and mortality. We postulate that this neonate acquired P. shigelloides via the transplacental route, and suggest that this organism be included in the list of 'other' causes of transplacental infection that has been abbreviated to 'O' in the acronym TORCH.     

Neonatal candidiasis associated with meningitis and endophthalmitis

From January 1991 to March 1993, a total of 11 infants with positive blood, urine, cerebrospinal fluid (CSF) or stool cultures of Candida albicans were found in the nursery or neonatal intensive care unit of the Chung Shan Medical and Dental College Hospital. Clinical features including respiratory deterioration, poor activity, abdominal distension and/or apnea were noted. Indwelling peripheral venous catheters had been used in all patients to provide parenteral nutrition and broad spectrum antibiotic therapy and six infants had received intravenous fat emulsions. Prolonged endotracheal intubation with mechanical ventilation had been used in eight infants. Six infants (54.5%) had meningitis, five infants (45.5%) had endophthalmitis, and two infants (18.2%) had arthritis. All 11 infants received intravenous amphotericin B therapy, and the concurrent oral administration of 5-fluorocytosine was used in the six infants with meningitis. Three infants died later. Since meningitis was recognized in 54.5% patients and endophthalmitis was recognized in 45.5% patients with systemic candidiasis, the author recommends that culture and analysis of CSF along with indirect ophthalmoscopy should be performed on all infants suspected of having systemic candidiasis.