Emerging antimicrobial resistance and need for antimicrobial stewardship for ocular infections in India: A narrative review

Preparation and Characterization of Essential oil from Lavandula spica Plant and its Antimicrobial Activity against Pseudomonas aeruginosa and Staphylococcus aureus

The biological properties of herbs and essential oils (EOs), such as their antibacterial, analgesic, anti-inflammatory, antioxidant, and anticancer characteristics, make them widely used in a variety of fields. This research aims to assess the antibacterial efficacy of lavender oil against Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa). The essential oil from Lavandula spica was extracted via water distillation and characterized by using Gas Chromatography-Mass Spectrometry (GC-MS) and Fourier Transform Infrared Spectroscopy (FTIR). Bacterial strains were isolated from burn wounds, confirmed by polymerase chain reaction technique, and were tested using disc diffusion method and Minimum Inhibitory Concentration (MIC) calculations. The study identified 28 components in the EO, with monoterpenes being the predominant. Out of 150 samples, 56 (45.52 %) were positive for P. aeruginosa and 67 (54.47 %) for S. aureus by using standard microbiological techniques including Gram staining, biochemical tests and Polymerase chain reaction technique. P. aeruginosa showed high resistance to cefazolin (100 %) and levofloxacin (83.3 %), while S. aureus was highly resistant to cefoxitin, piperacillin, amoxicillin/clavulanic acid, and ampicillin/sulbactam. The zone of inhibition and MIC for EO against P. aeruginosa were 9.910 ± 0.866 and 2.376 ± 0.352 while for S. aureus were 10.597 ± 0.818 and 0.894 ± 0.073 respectively with significance levels of p > 0.05 and p < 0.01. The study concluded that L. spica EO shows promising antimicrobial activity, particularly against Gram-positive bacteria suggesting its potential for further research and antimicrobial use.

Severe Microbial Keratitis in Virgin and Transplanted Cornea-Probability of Visual Acuity Improvement

Purpose: To evaluate visual acuity improvement and identify contributing factors in patients with severe keratitis affecting both virgin and transplanted corneas, treated at a hospital. Methods: A retrospective analysis was conducted on 497 patients with unilateral corneal ulcers treated at a tertiary referral center between 2008 and 2023. Data included distance (BCVA) and near best-corrected visual acuity at initial presentation and at discharge, treatments before hospital admission, demographic details, risk factors, clinical signs and symptoms, ancillary test results, and management strategies. Patients were categorized into two groups: Group A (naïve corneal ulcers, 379 patients) and Group B (post-keratoplasty infectious keratitis, 118 patients). Additional analysis focused on patients with presenting visual acuity of at least 1.0 logMAR (≤5/50 Snellen charts = legal blindness) to predict final visual outcomes. Results: The median BCVA at presentation for the entire cohort was 1.9 logMAR, advancing to 1.5 logMAR at discharge (p < 0.001). At least one line improvement in BCVA was observed in 47% of patients (52% of naïve cornea and 33% of transplanted cornea patients). Significantly worse results were observed in Group B were observed for BCVA at presentation, BCVA improvement, and distance and near vision improvement. Among patients with legal blindness at presentation, vision status improved for 52/379 (14%) in Group A and 6/118 (5%) in Group B during hospital admission (p < 0.001), while 67% of the cohort was discharged with VA equal or worse than 5/50. The average hospital stay was 9 days. Near visual acuity got better in 23% of patients (27% in Group A vs. 9% in Group B). A multivariate regression model showed that older age and worse distance BCVA on admission were independent negative predictors of improvement (p < 0.001, p < 0.001, respectively) while midperiphery ulcers were associated with better visual outcomes. Conclusions: Hospital admission leads to BCVA improvement in 47% of the patients with severe corneal ulcer, though the prognosis is significantly worse for those with post-keratoplasty microbial keratitis. At discharge, 67% of patients remained at the legal blindness level. Older age and lower BCVA at first presentation are associated with worse prognosis, while ulcers located in the corneal midperiphery are linked to better visual outcomes.

Improving Antimicrobial Utilization and Infection Control in Ophthalmology: An Information-Assisted Transparent Supervision and Multidisciplinary Team Model

Background

Using antimicrobials wisely is crucial for effective treatment and reducing antimicrobial resistance (AMR). As ocular infections can lead to serious consequences and ophthalmic surgery has a great impact on patients, the application of antimicrobials in ophthalmology needs to be managed in a standardized manner.

Methods

A multidisciplinary team (MDT) on antimicrobial stewardship was set up by adopting comprehensive management measures and a continuous improvement model with all-staff training and empowerment, information-assisted medical prescription control, and transparent supervision.

Results

After intervention, the antibiotics use density, antibiotics utilization rate and antibiotics prophylactic utilization rate for type I incision operation among inpatients decreased from 30.02%, 49.64% and 58.04% in 2018 to 8.78% (decrease by 70.77%), 18.31% (p < 0.001) and 8.93% (p < 0.001) in 2022, respectively; the microbiological submission rate related to antibiotics utilization, etiological submission rate before antibiotic therapy and before combined use of key antibiotics rose from 13.44%, 17.39% and 50.00% to 27.33% (p < 0.001), 51.3% (p < 0.001) and 100.00% (increase by 100%), respectively; the incidence of nosocomial infection and surgical site infection for type I incision operation both reduced to zero, while the use of hand hygiene products markedly increased. For pathogen detection, a total of 489 pathogens were isolated from 2018 to 2022, of which 69.30% were Gram-positive bacteria, 26.02% were Gram-negative bacteria, and 4.68% were fungi. Ocular secretion was the main detection site (89.31%). Antibiotic resistance analysis results indicated that Staphylococci maintained complete sensitivity to linezolid, vancomycin, and teicoplanin. Streptococcus pneumoniae maintained complete sensitivity to vancomycin, benzathine, levofloxacin, and moxifloxacin, with resistance to penicillin G and ceftriaxone down to zero.

Conclusion

Multidisciplinary team and information-assisted transparent supervision have displayed obvious effects in promoting the standardized application of antimicrobials in ophthalmology, via distinctly improving indicators relevant to antimicrobial application and nosocomial infection. Our work may provide guidance for improving the medical quality and curbing the AMR.

Audit of antibiotic utilization patterns and practice for common eye infections at the ambulatory clinic of a teaching hospital in Ghana: Findings and implications

BACKGROUND

Antimicrobial resistance (AMR) is a serious public health issue which is exacerbated by increased inappropriate use of antibiotics for common eye infections. This cross sectional survey was to assess the appropriate use of antibiotics for eye infections in an ambulatory clinic in Ghana and possible determinants.

METHOD

The medical records of all patients who sought eye care between January 2022 to December 2022 and were prescribed antibiotics were extracted from the hospital's electronic database. Descriptive, bivariate and multivariate analyses were then conducted.

RESULTS

A total of 1925 patient medical records were extracted, whose median age was 40 years (IQR 26-69), and were mostly females (58.91%, n = 1134/1925). The eye condition commonly treated with antibiotics was bacteria conjunctivitis (33.51%, n = 645/1925). The most prescribed antibiotic was gentamycin (22.96%, n = 442/1925) followed by ciprofloxacin (16.78%, n = 321/1925). These were mostly topical dosage forms (82.13%, n = 1581/1925). Systemic antibiotics prescribed were mostly from the WHO 'Access' class (83.33%, n = 280/338). The appropriate choice of antibiotic prescribed was 42.44% (n = 817/1925) and this was positivity associated with age (p<0.001), number of antibiotics prescribed (p <0.001), the prescription of topical dosage forms (p <0.001), and WHO 'Access' antibiotic class (p <0.034).

CONCLUSION

The level of appropriateness of antibiotic prescriptions for eye infections was sub-optimal. Antimicrobial stewardship programs, including prescriber education on guidelines and prescription audit to address associated factors, must now be instigated in this hospital to improve future antibiotic use and prevent the rise of AMR.

Topical Antiseptics in Minimizing Ocular Surface Bacterial Load Before Ophthalmic Surgery: A Randomized Controlled Trial

PURPOSE

To investigate the reduction of the ocular surface bacterial load induced by 2 commercially available ophthalmic antiseptic formulations, povidone-iodine (PVI) 0.6% and chlorhexidine (CLX) 0.02%, before ocular surgery.

DESIGN

Randomized controlled trial.

METHODS

Seventy adult patients undergoing intraocular surgery (phacoemulsification) were randomized to receive in the index eye PVI (group A) 4 times a day for 3 days or CLX (group B) 4 times a day for 3 days before surgery. The untreated eye was used as control. A conjunctival swab was taken in both eyes before (T0) and after (T1) therapy. Microbial DNA was quantified with real-time polymerase chain reaction (PCR) analysis. The Mick algorithm was used to compare the abundance of each genus/genera against the distribution of abundances from the reference. At T1, patients filled a questionnaire to evaluate therapy-induced symptoms. Primary outcome was the reduction of bacterial DNA at T1 (microbial load), vs control arm, expressed as mean number of real-time PCR cycle times (CTs). Secondary outcomes were taxonomic composition, differential abundance, and therapy-induced ocular symptoms.

RESULTS

The T0-T1 difference in CT was significant in group B, but not in group A (mean [95% CI], 0.99 [0.33] vs 0.26 [0.15], P < .001, and 0.65 [0.3] vs 0.45 [0.41], P = .09, respectively). The taxonomic composition, alpha, and beta diversity remained consistent at all time points in both groups. The rate of patients reporting therapy-induced ocular symptoms and the mean discomfort grade were greater in group A than in group B (97% vs 26% and 4.97±2.48 vs 0.66±1.53, respectively).

CONCLUSIONS

Compared with PVI 0.6%, CLX 0.02% induced a greater reduction of ocular surface bacterial load, with no significant alterations of the taxonomic composition. Moreover, CLX was better tolerated than PVI.

Antimicrobial resistance in ocular infection: A review

Antimicrobial resistance (AMR) is a global public health threat with significant impact on treatment outcomes. The World Health Organization's Global Action Plan on AMR recommended strengthening the evidence base through surveillance programs and research. Comprehensive, timely data on AMR for organisms isolated from ocular infections are needed to guide treatment decisions and inform researchers and microbiologists of emerging trends. This article aims to provide an update on the development of AMR in ocular organisms, AMR in bacterial ocular infections and on AMR stewardship programs globally. The most common ocular pathogens are Pseudomonas aeruginosa, Staphylococcus spp., Streptococcus pneumoniae, and Haemophilus influenzae in ocular infections. A variety of studies and a few surveillance programs worldwide have reported on AMR in these infections over time. Fluoroquinolone resistance has increased particularly in Asia and North America. For conjunctivitis, the ARMOR cumulative study in the USA reported a slight decrease in resistance to ciprofloxacin. For keratitis, resistance to methicillin has remained stable for S. aureus and CoNS, while resistance to ciprofloxacin has decreased for MRSA globally. Methicillin-resistance and multidrug resistance are also emerging, requiring ongoing monitoring. Antimicrobial stewardship (AMS) programmes have a critical role in reducing the threat of AMR and improving treatment outcomes. To be successful AMS must be informed by up-to-date AMR surveillance data. As a profession it is timely for ophthalmology to act to prevent AMR leading to greater visual loss through supporting surveillance programmes and establishing AMS.

New Approaches to Overcoming Antimicrobial Resistance in Endophthalmitis

Endophthalmitis is a rare but vision-threatening infection characterized by marked inflammation of intraocular fluids and tissues, uncommonly seen following surgery and intravitreal injection. Antimicrobials are used worldwide in the prophylaxis and treatment of bacterial and fungal infections of the eye and are standard treatment in the preoperative and postoperative care of surgical patients. However, antimicrobials are reported to be overprescribed in many parts of the world, which contributes to antimicrobial resistance (AMR). AMR complicates the prophylaxis and treatment of endophthalmitis. This article examines the prevalence and mechanisms of AMR in ocular microorganisms, emphasizing the importance of understanding AMR patterns for tailored treatments. It also explores prophylaxis and management strategies for endophthalmitis, with a discussion on the use of intracameral antibiotic administration. The use of prophylactic intracameral antibiotics during cataract surgery is common in many parts of the world but is still controversial in some locations, especially in the US. Finally, it highlights the role of stewardship in ophthalmology and its benefits in the treatment of endophthalmitis.

Multi-aptamer-mediated hairpin allosteric and aptamer-assisted CRISPR system for detection of S. pneumoniae and S. aureus

A novel nucleic acid aptamer nanoprobes-mediated hairpin allosteric and aptamer-assisted CRISPR system for detection of Streptococcus pneumoniae and Staphylococcus aureus is presented. In this fluorescence assay system, utilizing the hairpin allosteric effect caused by the aptamer binding to the target bacteria, the detection of S. pneumoniae is first achieved through changes in fluorescence due to FRET. Subsequently, a Cas12a protein mixture is added to detect S. aureus. The amplified output signal is triggered by two methods to ensure the sensitivity of the method: the synergistic FRET effect is achieved by the assembly of multi-aptamer through the conjugation of streptavidin-biotin, and the trans-cleavage function of CRISPR/Cas 12a. Under the optimized conditions, the proposed hairpin allosteric aptasensor could achieve high sensitivity (a detection limit of 135 cfu/mL) and broad-concentration quantification (dynamic range of 103-107 cfu/mL) of S. pneumoniae. The aptamer-assisted CRISPR system for S. aureus detection showed good linearity (R2 = 0.996) in the concentration range 102-108 cfu/mL, with a detection limit of 39 cfu/mL. No cross-reactivity with other foodborne pathogenic bacteria was observed in both systems. Taking only 55 min, this method of multiple pathogen detection proved to be promising.

Microbiological spectrum and antibiotic susceptibility patterns of non-viral conjunctivitis over 16 years at a tertiary eye care center in Southern India

PURPOSE

To determine the trends in the microbial spectrum and antibacterial susceptibility patterns of non-viral conjunctivitis over 16 years.

METHODS

Microbiology data were reviewed from 2006-2021 for all the patients with clinically and culture-proven infectious conjunctivitis. Conjunctival swabs and/or conjunctival scrapings were collected for microbiological workup, and the demographic and antibiotic susceptibility data were extracted from the EMR (Electronic Medical Record). For statistical analysis, χ2-test was performed.

RESULTS

Of the 1711 patients, 814 (47.57%) were culture positive and 897 (52.43%) were culture negative. Of the total culture-proven conjunctivitis cases, 775/814 (95.20%) were bacteria, and 39/814 (4.80%) were fungi. Among these bacterial isolates, 75.74% were gram-positive bacteria, while 24.26% were gram negative. The predominant gram-positive pathogens isolated were S. epidermidis (16.7%), S. aureus (17.9%) (p < 0.05), and S. pneumoniae (18.2%), while Haemophilus spp. (36.2%) (p < 0.05) was the most often isolated gram-negative bacteria (36.2%), and Aspergillus spp. was the most commonly isolated fungus (50%). The susceptibility of gram-positive bacteria to cefazoline increased from 90.46 to 98% (p = 0.01), whereas the susceptibility for gatifloxacin decreased in both gram-positive (81-41%; p < 0.0001) and gram-negative bacteria (73-58%; p = 0.02).

CONCLUSIONS

Increasing resistance of ocular isolates to mainstay antibiotics is a concern, and this data can assist healthcare practitioners in making informed choices regarding the treatment of ocular infections with ophthalmic antibiotics.

Antibiotic prophylaxis for cataract surgery - Practice patterns amongst Indian Ophthalmologists

Purpose

To assess the current trends in use of perioperative antibiotic prophylaxis, especially intracameral antibiotics (ICAB), for cataract surgery in India.

Methods

This was an E-survey using a previously validated questionnaire carried out by the All India Ophthalmological Society (AIOS) in August 2022. An E-mail invitation to complete an online 40-point survey was sent to all members of the AIOS using a digital E-mail service (Survey Monkey) and social media platforms.

Results

Out of 1804 total respondents, 58% (n = 1022) reported using routine ICAB prophylaxis. Of those using ICAB, 89% (n = 909) reported using it for all cases, whereas the rest used it for specific indications such as post-PC rent (n = 43), one eyed patient (n = 19), and high-risk cases (n = 50). Commercially available moxifloxacin was by far the commonest agent used for ICAB (n = 686, 67%). Eighty respondents (8%) reported noticing occasional toxic reactions and nontoxic corneal edema (n = 64, 6%) with ICAB. Surgeons with >10 years' experience especially practicing in medical colleges used fewer ICAB (OR = 0.52, 95%CI = 0.38 - 0.72, P < 0,001) compared to younger surgeons (<5-year experience) in solo clinics. The commonest reason for nonadoption of IC antibiotics was "unconvinced of the need to use it in my setting" (n = 296, 52% of those who answered this question).

Conclusion

IC antibiotic prophylaxis for cataract surgery has significantly increased in India from 40% in 2017 to 58% in 2022. Commercially available moxifloxacin was preferred by the majority users. Intraocular inflammation may occur occasionally and needs safer formulations to avoid this.

Recent advancements in nanotechnology-based bacteriophage delivery strategies against bacterial ocular infections

Antibiotic resistance is growing as a critical challenge in a variety of disease conditions including ocular infections leading to disastrous effects on the human eyes. Staphylococcus aureus (S. aureus) mediated ocular infections are very common affecting different parts of the eye viz. vitreous chamber, conjunctiva, cornea, anterior and posterior chambers, tear duct, and eyelids. Blepharitis, dacryocystitis, conjunctivitis, keratitis, endophthalmitis, and orbital cellulitis are some of the commonly known ocular infections caused by S. aureus. Some of these infections are so fatal that they could cause bilateral blindness like panophthalmitis and orbital cellulitis, which is caused by methicillin-resistant S. aureus (MRSA) and vancomycin-resistance S. aureus (VRSA). The treatment of S. aureus infections with known antibiotics is becoming gradually difficult because of the development of resistance against multiple antibiotics. Apart from the different combinations and formulation strategies, bacteriophage therapy is growing as an effective alternative to treat such infections. Although the superiority of bacteriophage therapy is well established, yet physical factors (high temperatures, acidic pH, UV-rays, and ionic strength) and pharmaceutical barriers (poor stability, low in-vivo retention, controlled and targeted delivery, immune system neutralization, etc.) have the greatest influence on the viability of phage virions (also phage proteins). A variety of Nanotechnology based formulations such as polymeric nanoparticles, liposomes, dendrimers, nanoemulsions, and nanofibres have been recently reported to overcome the above-mentioned obstacles. In this review, we have compiled all these recent reports and discussed bacteriophage-based nanoformulations techniques for the successful treatment of ocular infections caused by multidrug-resistant S. aureus and other bacteria.

The landscape of bacterial antibiotic susceptibility in a multi-tier ophthalmology network in India: an electronic medical record driven analytics report

Introduction. Injudicious use of antibiotics often leads to antibiotic resistance which contributes to significant morbidity and mortality. Knowledge of local antibiogram is important in informing appropriate empiric antimicrobial therapy.

Hypothesis / Gap. It is the first and largest study that examines bacterial isolates from multiple ocular infections across South India and provides a overview of susceptibility patterns for each individual bacteria in the detailed interactive dashboard.

Aim. To study the landscape of bacterial antibiotic susceptibility patterns of ocular infections in patients undergoing microbiological investigations across a multi-tier ophthalmology network in India.

Methodology. This cross-sectional hospital-based study included 15 822 patients in whom microbiology samples were analysed between September 2013 and December 2021. Ocular tissue of patients in whom a microbiology sample was processed in at least one eye were included as cases. The data were collected using an indigenously developed electronic medical record (EMR) system.

Results. Among the 15 822 patients, bacteria (51.06 %) was the most common aetiology, followed by fungus (38.27 %). The majority of the patients were male (68.10 %) and the majority were adults (90.01 %). The most common age group was during the sixth decade with 2914 (18.42 %) patients. The patients were more commonly from the lower socio-economic status (51.61 %) and rural geography (46.82 %). The majority of the specimens sent for microbiological analysis were corneal scraping (68.61 %). Gram-positive cocci and Gram-positive bacilli were most sensitive towards vancomycin (86.83 and 92.89% respectively) followed by cefazolin (80.88 %) and amikacin, while Gram-negative bacilli were most sensitive towards ofloxacin (65.24%).

Conclusion. The most common aetiology of infection in ocular disease is bacterial and the majority of the patients presented from the rural geography and from lower socio-economic status. While vancomycin continues to be the drug of choice for Gram-positive organisms, increasing resistance to fluoroquinolones and ceftazidime was observed. Adoption of this model will enable access to antimicrobial susceptibility data, leading to reliable decisions and better clinical outcomes.