Alteration in the Efficacy of in Vitro Vancomycin and Ceftazidime Prepared in Normal Saline Versus Balanced Salt Solution in the Management of Ocular Infections

Objective: The purpose of this review article is to highlight the efficacy of Vancomycin and Ceftazidime formulated in different solutions for ocular use in the management of microbiological Ocular infections varies. Methodology: To locate and assess all relevant literature, we employed systematic review as a search approach, utilizing punctilious and unambiguous methodologies. We initiated by stipulating key terms and selecting appropriate databases for your literature search. To find replicable and reportable publications from high-quality peer-reviewed journals, we used Google Scholar, PubMed, and Research Gate. Results: Ceftazidime precipitated at 37 degree Celsius, but not at room temperature, however it did not show any effect on the pH of the medium. In both the media of Normal Saline and Balanced Salt Solution, it precipitated on its own or when coupled with vancomycin. Ceftazidime was initially prepared in Balanced Salt Solution rather than Normal Saline, which resulted in further precipitation. Ceftazidime prepared in Normal Saline precipitated to 54% after 168 hours in the dialysis chambers, compared to 88% in Balanced Salt Solution. Ceftazidime synthesized in Normal Saline declined from an initial concentration of 137.5 to 73.4 µg/ml after 48 hours, while ceftazidime prepared in Balanced Salt Solution decreased to 6.3µg/ml. Vancomycin precipitation was inappreciable. Conclusion: Vancomycin did not precipitate in Normal Saline or Balanced Salt Solution, according to this systemic study. Regardless of the presence of vancomycin, ceftazidime precipitated, and it precipitated more expeditiously if it was produced in Balanced Salt Solution rather than Normal Saline.

Clinical Features and Molecular Characteristics of Methicillin-Susceptible Staphylococcus aureus Ocular Infection in Taiwan

This study analyzed the clinical features and molecular characteristics of methicillin-susceptible Staphylococcus aureus (MSSA) ocular infections in Taiwan and compared them between community-associated (CA) and health-care-associated (HA) infections. We collected S. aureus ocular isolates from patients at Chang Gung Memorial Hospital between 2010 and 2017. The infections were classified as CA or HA using epidemiological criteria, and the isolates were molecularly characterized using pulsed-field gel electrophoresis, multilocus sequence typing, and Panton-Valentine leukocidin (PVL) gene detection. Antibiotic susceptibility was evaluated using disk diffusion and an E test. A total of 104 MSSA ocular isolates were identified; 46 (44.2%) were CA-MSSA and 58 (55.8%) were HA-MSSA. Compared with HA-MSSA strains, CA-MSSA strains caused a significantly higher rate of keratitis, but a lower rate of conjunctivitis. We identified 14 pulsotypes. ST 7/pulsotype BA was frequently identified in both CA-MSSA (28.3%) and HA-MSSA (37.9%) cases. PVL genes were identified in seven isolates (6.7%). Both CA-MSSA and HA-MSSA isolates were highly susceptible to vancomycin, teicoplanin, tigecycline, sulfamethoxazole–trimethoprim, and fluoroquinolones. The most common ocular manifestations were keratitis and conjunctivitis for CA-MSSA and HA-MSSA, respectively. The MSSA ocular isolates had diverse molecular characteristics; no specific genotype differentiated CA-MSSA from HA-MSSA. Both strains exhibited similar antibiotic susceptibility.

Incidence of fungal keratitis in Libya: An epidemiological study

Objectives: The aim of this study was to assess the occurrence of eye fungal infection among patients attending the eye hospital in Tripoli city, Libya. Materials and Methods: Seventy-one patients with ocular fungal infections were subjected to clinical and microbiological investigations. They were selected from patients attending the Tripoli Eye Hospital. The specimens of the external ocular infections were collected using sterile swab and inoculated to different culture media. Data were presented as count and percentages. Results: The current findings showed that Aspergillus was the most common causative agent, being responsible for 91.54% of the all cases, followed by Candida albicans (8.46%). Conclusion: Occurrence of fungal keratitis gradually increased in the years after 2009, especially after 2013. Knowledge of the pathological course and clinical features of fungal keratitis will undoubtedly bead in early diagnosis and treatment, with reduction in ocular morbidity.

Intraocular Viral Communities Associated With Post-fever Retinitis

The virome of ocular fluids is naive. The results of this study highlight the virome in the vitreous fluid of the eye of individuals without any ocular infection and compare it with the virome of the vitreous fluid of individuals with retinitis. A total of 1,016,037 viral reads were generated from 25 vitreous fluid samples comprising control and post-fever retinitis (PFR) samples. The top 10 viral families in the vitreous fluids comprised of Myoviridae, Siphoviridae, Phycodnaviridae, Herpesviridae, Poxviridae, Iridoviridae, Podoviridae, Retroviridae, Baculoviridae, and Flaviviridae. Principal coordinate analysis and heat map analysis clearly discriminated the virome of the vitreous fluid of the controls from that of the PFR virome. The abundance of 10 viral genera increased significantly in the vitreous fluid virome of the post-fever retinitis group compared with the control group. Genus Lymphocryptovirus, comprising the human pathogen Epstein-Barr virus (EBV) that is also implicated in ocular infections was significantly abundant in eight out of the nine vitreous fluid viromes of post-fever retinitis group samples compared with the control viromes. Human viruses, such as Hepacivirus, Circovirus, and Kobuvirus, were also significantly increased in abundance in the vitreous fluid viromes of post-fever retinitis group samples compared with the control viromes. The Kyoto Encyclopedia of Genes and Genomes (KEGG) functional analysis and the network analysis depicted an increase in the immune response by the host in the post-fever retinitis group compared with the control group. All together, the results of the study indicate changes in the virome in the vitreous fluid of patients with the post-fever retinitis group compared to the control group.

Antibiotic Resistance Pattern of Staphylococcus Aureus Isolated From Pediatrics With Ocular Infections: A 6-Year Hospital-Based Study in China

Staphylococcus aureus (S. aureus) is an important pathogen of ocular infections in pediatrics. The study aimed to identify the prevalence and resistance pattern of S. aureus, especially methicillin-resistant S. aureus (MRSA), in Chinese children with ocular infections. All patients with S. aureus infections were reviewed at a tertiary children's hospital during 2015–2020, and those with ocular infections were investigated for susceptibility results. Of 1,668 S. aureus strains, there were 177 unique isolates from ocular infection. Among them, 45 (25.4%) were MRSA and 132 (74.6%) were methicillin-sensitive S. aureus (MSSA). The proportion of MRSA did not change over time. Most of the strains were obtained from the neonate ward and ophthalmology department (n = 88, 49.7%, and n = 85, 48.0%, respectively), while eye secretion and pus were the main specimen types (n = 128, 72.3%, and n = 37, 20.9%, respectively). MRSA was significantly resistant against penicillin class (97.8%), erythromycin (71.1%), clindamycin (71.1%), and tetracycline (32.1%), with a high multidrug resistance (MDR) rate of 71.1%. However, MRSA was highly sensitive to levofloxacin. Resistance rates against erythromycin and ciprofloxacin as well as MDR percentage all increased among MSSA in children above 1 year of age, ophthalmology department, and outpatient population and decreased in eye secretion specimen. The mean resistance percentage remained stable for MRSA and MSSA during the study period. The survey of ocular S. aureus pathogens in pediatrics and their antibiotic resistance patterns helps in clinical treatment. MRSA with many strains demonstrating MDR is highly prevalent in children with ocular infections in Southeast China. Levofloxacin is an effective topical antibiotic for ocular MRSA infection, while erythromycin has a high resistance rate. The antibiotic resistance patterns of MRSA and MSSA differs and varies by different stratifications. A cautious use of antibiotics should be considered.

Ocular Sporotrichosis

Sporotrichosis is a subacute or chronic mycosis predominant in tropical and subtropical regions. It is an infection of subcutaneous tissue caused by Sporothrix fungus species, but occasionally resulting in an extracutaneous condition, including osteoarticular, pulmonary, nervous central system, and ocular disease. Cases of ocular sporotrichosis are rare, but reports have been increasing in recent decades. Ocular infections usually occur in hyperendemic areas of sporotrichosis. For its classification, anatomic criteria are used. The clinical presentation is the infection in the ocular adnexal and intraocular infection. Ocular adnexa infections include palpebral, conjunctivitis, and infections of the lacrimal sac. Intraocular infection includes exogenous or endogenous endophthalmitis. Most infections in the ocular adnexal have been reported in Brazil, China and Peru, and intraocular infections are limited to the USA and Brazil. Diagnosis is performed from Sporothrix isolation in the mycological examination from ocular or skin samples. Both sporotrichosis in the ocular adnexa and intraocular infection can mimic several infectious and non-infectious medical conditions. Ocular adnexa infections are treated with potassium iodide and itraconazole. The intraocular infection is treated with amphotericin B. This review describes the clinical findings and epidemiological, diagnosis, and treatment of ocular sporotrichosis.

Virulence factors in multidrug (MDR) and Pan-drug resistant (XDR) Pseudomonas aeruginosa: a cross-sectional study of isolates recovered from ocular infections in a high-incidence setting in southern India

Background Global concerns have been raised due to upward trend of Multi-drug Resistant (MDR) Pseudomonas aeruginosa reports in ocular infections. Our aim was to characterize the virulence determinants of MDR P. aeruginosa causing ocular infections. Methods P. aeruginosa strains were isolated from 46 patients with conjunctivitis (2), endophthalmitis (11) and active keratitis (25) seen at our Institute, between 2016 and 2020. The isolates were identified by Vitek-2 and characterized based on growth kinetics, biofilm formation, motility, pyoverdine and pyocyanin production, phospholipase and catalase activity, urease production along with expression of exotoxins (exo-A, exo-U and exo-S) and correlated to its antibiotic profiles. Results Of the 46 P. aeruginosa isolates, 23 were MDR and were significantly (p = 0.03) associated with older (> 65) patients, along with higher production of pyoverdine (58.3%), pyocyanin (30.4%), phospholipase (91.6%) and protease (62.5%) activity, formed strong biofilms and exo-A (30.4%). No significant relation between motility, urease and catalase production with antibiotic susceptibility was observed. Heatmap and PCoA analysis confirmed this unique virulence profile associated with MDR-PA strains. Conclusion Phenotypic characteristics of P.aeruginosa might be responsible for increased colonization and antibiotic resistance observed in vivo and understanding these differences may lead to development of clinical guidelines for the management of MDR infections.

Microbiological spectrum of ocular infections in patients of tertiary care eye hospital of Punjab

Eye is a complex and sensitive organ and is therefore more vulnerable to trauma and various infections ocular infections are one of the most commonly encountered infections. Any part of the eye can be infected by bacteria, fungi, parasites or viruses. In order to minimize the ocular morbidity and mortality, timely antimicrobial treatment must be initiated on the basis of clinical and microbial evaluation. For specific antibacterial treatment, isolation and identification of bacterial pathogens along with antibiotic susceptibility spectrum is essential. Hence, this study was undertaken to isolate and identify the bacterial and fungal pathogens responsible for the development of ocular infections and to determine their in vitro susceptibilities to commonly used antibiotics. A total of 203 samples of suspected ocular infections comprising 117 conjunctival swabs, 34 corneal specimens, 24 lacrimal pus samples and 28 vitreous specimens were analysed. Out of them 102(50.1%) showed growth. 82(40%) were bacterial and 21(10.3%) were fungal isolates. Due to the emergence of drug resistance it is imperative that all ophthalmological samples must be tested for antibiotic resistance as far as possible. Indiscriminate use of over the counter antibiotic eye formulations should be avoided and also it is important to know the changing pattern of pathogens.

Antimicrobial Susceptibility, Minimum Inhibitory Concentrations, and Clinical Profiles of Stenotrophomonas maltophilia Endophthalmitis

Stenotrophomonas maltophilia has been reported in various ocular infections, including keratitis, conjunctivitis, preseptal cellulitis, and endophthalmitis, all of which may lead to vision loss. However, the S. maltophilia strain is resistant to a wide variety of antibiotics, including penicillins, third-generation cephalosporins, aminoglycosides, and imipenem. In this study, we retrospectively reviewed the clinical characteristics, antibiotic susceptibility, antimicrobial minimum inhibitory concentrations (MICs), and visual outcomes for S. maltophilia endophthalmitis. The data of 9 patients with positive S. maltophilia cultures in a tertiary referral center from 2010 to 2019 were reviewed. Cataract surgery (n = 8, 89%) was the most common etiology, followed by intravitreal injection (n = 1, 11%). S. maltophilia’s susceptibility to levofloxacin and moxifloxacin was observed in 6 cases (67%). Seven isolates were resistant to sulfamethoxazole-trimethoprim (78%). The MIC90 for S. maltophilia was 256, 256, 256, 8, 12, 12, 12, and 8 μg/mL for amikacin, cefuroxime, ceftazidime, tigecycline, sulfamethoxazole-trimethoprim, levofloxacin, galtifloxacin, and moxifloxacin, respectively. Final visual acuity was 20/200 or better in 5 patients (56%). Fluoroquinolones and tigecycline exhibited low antibiotic MIC90. Therefore, the results suggest that fluoroquinolones can be used as first-line antibiotics for S. maltophilia endophthalmitis.