1
|
Ghita AM, Iliescu DA, Ghita AC, Ilie LA. Susceptibility of Ocular Surface Bacteria to Various Antibiotic Agents in a Romanian Ophthalmology Clinic. Diagnostics (Basel) 2023; 13:3409. [PMID: 37998545 PMCID: PMC10670825 DOI: 10.3390/diagnostics13223409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 10/31/2023] [Accepted: 11/07/2023] [Indexed: 11/25/2023] Open
Abstract
Periodic assessment of bacterial contamination is necessary as it allows proper guidance in cases of eye infections through the use of appropriate antibiotics. Due to the extensive use of antibiotic treatment, many strains of the microbiota that cause infections are resistant to the usual ophthalmic antibiotics. The present study provides an updated assessment of the susceptibility of Gram-positive and Gram-negative bacteria found on the ocular surface to the most commonly used antibiotic agents in patients undergoing cataract surgery. A total of 993 patients were included in the study with ages between 44 and 98 years old. Conjunctival cultures were collected 7 days before cataract surgery. The response of Gram-positive and Gram-negative bacteria to various antibiotic classes, such as glycopeptides, cephalosporins, carbapenems, fluoroquinolones, aminoglycosides, phenicols, tetracyclines, rifamycins, macrolides and penicillins, was assessed. From the tested antibiotics, vancomycin had 97.8% efficacy on Gram-positive bacteria. In the cephalosporin category, we observed a high level of resistance of the cefuroxime for both Gram-positive and negative bacteria. Antibiotics that have more than 90% efficacy on Gram-positive bacteria are meropenem, imipenem, netilmicin, amikacin and rifampicin. On Gram-negative bacteria, we found 100% efficacy of all tested fluoroquinolones, i.e., aminoglycosides (except for tobramycin), doxycycline, azithromycin, clarithromycin and chloramphenicol. The current study illustrates patterns of increased resistance in certain bacteria present on the ocular surface to some of the commonly used antibiotics in ophthalmological clinical practice. One such revealing example is cefuroxime, which has been highly used as an intracameral antibiotic for the prevention of bacterial endophthalmitis after cataract surgery.
Collapse
Affiliation(s)
- Aurelian Mihai Ghita
- Department of Physiology, “Carol Davila” University of Medicine and Pharmacy, 8 Eroii Sanitari Bld., 050474 Bucharest, Romania;
- Ophthalmology Department, Bucharest University Emergency Hospital, 169 Splaiul Independenței Street, 050098 Bucharest, Romania
- Ocularcare Ophthalmology Clinic, 128 Ion Mihalache Bld., 012244 Bucharest, Romania; (A.C.G.); (L.A.I.)
| | - Daniela Adriana Iliescu
- Department of Physiology, “Carol Davila” University of Medicine and Pharmacy, 8 Eroii Sanitari Bld., 050474 Bucharest, Romania;
- Ocularcare Ophthalmology Clinic, 128 Ion Mihalache Bld., 012244 Bucharest, Romania; (A.C.G.); (L.A.I.)
| | - Ana Cristina Ghita
- Ocularcare Ophthalmology Clinic, 128 Ion Mihalache Bld., 012244 Bucharest, Romania; (A.C.G.); (L.A.I.)
| | - Larisa Adriana Ilie
- Ocularcare Ophthalmology Clinic, 128 Ion Mihalache Bld., 012244 Bucharest, Romania; (A.C.G.); (L.A.I.)
| |
Collapse
|
2
|
Durán-Manuel EM, Bello-López JM, Salinas-Bobadilla AD, Vargas-De-León C, Nieto-Velázquez NG, Moreno-Eutimio MA, Pastelin-Palacios R, Calzada-Mendoza CC, Blanco-Hernández DMR. Molecular Characterization of Bacterial Agents Causing External Ocular Infections Isolates of Patients in a Third Level Hospital. Pathogens 2023; 12:1294. [PMID: 38003759 PMCID: PMC10675722 DOI: 10.3390/pathogens12111294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 10/23/2023] [Accepted: 10/26/2023] [Indexed: 11/26/2023] Open
Abstract
Empirical use of antibiotics in the treatment of eye infections leads to bacterial pathogens becoming resistant to antibiotics; consequently, treatment failure and eye health complications occur. The aim of this study was to describe the phenotype and genotype of the resistance and adherence of bacterial agents causing eye infections in patients at Hospital Juárez de México. An observational, prospective, cross-sectional, and descriptive study was carried out in patients with signs and symptoms of ocular infection. Bacterial agents were isolated and identified by classical microbiology and mass spectrometry. Antibiotic resistance and adherence profiles were determined. Finally, resistance (mecA/SCCmec) and virulence (icaA and icaD) genes were detected in the Gram-positive population. The results showed that blepharitis was the most prevalent condition in the study population. A MALDI-TOF analysis revealed that Staphylococcus and Pseudomonas genus were the most prevalent as causal agents of infection. Resistances to β-lactams were detected of 44 to 100%, followed by clindamycins, aminoglycosides, folate inhibitors, and nitrofurans. A multiple correspondence analysis showed a relationship between mecA genotype and β-lactams resistance. The identification of SCCmecIII and SCCmecIV elements suggested community and hospital sources of infection. Finally, the coexistence of icaA+/icaD+/mecA(SCCmecIII) and icaA+/icaD+/mecA(SCCmecIV) genotypes was detected in S. aureus. The identification of resistant and virulent isolates highlights the importance of developing protocols that address the timely diagnosis of ocular infections. Herein, implications for the failure of antimicrobial therapy in the treatment of ocular infections in susceptible patients are analysed and discussed.
Collapse
Affiliation(s)
- Emilio Mariano Durán-Manuel
- Hospital Juárez de México, Mexico City 07760, Mexico
- Sección de Estudios de Posgrado e Investigación, Escuela Superior de Medicina, Instituto Politécnico Nacional, Mexico City 11340, Mexico
| | | | | | - Cruz Vargas-De-León
- Hospital Juárez de México, Mexico City 07760, Mexico
- Sección de Estudios de Posgrado e Investigación, Escuela Superior de Medicina, Instituto Politécnico Nacional, Mexico City 11340, Mexico
| | | | - Mario Adán Moreno-Eutimio
- Facultad de Química, Universidad Nacional Autónoma de México, Ciudad Universitaria, Mexico City 04510, Mexico
| | - Rodolfo Pastelin-Palacios
- Facultad de Estudios Superiores Zaragoza, Universidad Nacional Autónoma de México, Mexico City 09230, Mexico
| | - Claudia Camelia Calzada-Mendoza
- Sección de Estudios de Posgrado e Investigación, Escuela Superior de Medicina, Instituto Politécnico Nacional, Mexico City 11340, Mexico
| | | |
Collapse
|
3
|
Haile Z, Mengist HM, Dilnessa T. Bacterial isolates, their antimicrobial susceptibility pattern, and associated factors of external ocular infections among patients attending eye clinic at Debre Markos Comprehensive Specialized Hospital, Northwest Ethiopia. PLoS One 2022; 17:e0277230. [PMID: 36327266 PMCID: PMC9632921 DOI: 10.1371/journal.pone.0277230] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Accepted: 10/22/2022] [Indexed: 11/06/2022] Open
Abstract
Background External eye infection caused by bacteria can lead to reduced vision and blindness. Therefore, pathogen isolation and antimicrobial susceptibility testing are vital for the prevention and control of ocular diseases. Objective The main aim of this study was to assess bacterial isolates, their antimicrobial susceptibility pattern, and associated factors of external ocular infection (EOI) among patients attended eye clinic at Debre Markos Comprehensive Specialized Hospital (DMCSH), Northwest Ethiopia. Methods We conducted a cross-sectional study in patients with external ocular infections from January 1, 2021, to June 30, 2021, at DMCSH. Socio-demographic and clinical data were collected using semi-structured questionnaires. Following standard protocols, external ocular swabs were collected and inoculated onto blood agar, chocolate agar, MacConkey agar and mannitol salt agar (MSA). Finally, bacterial isolates were identified by Gram stain, colony morphology, and biochemical tests. Antimicrobial susceptibility testing was done by using the modified Kirby-Bauer disk diffusion technique according to Clinical and Laboratory Standards Institute (CLSI) guideline. Cleaned and coded data were entered into EpiData version 4.2 software and exported to Statistical Packages for Social Sciences (SPSS) version 22 for analysis. Bivariate logistic regression was applied to investigate the association between predictors and outcome variables. P-values ≤ 0.05 with 95% confidence interval were considered statistically significant. Results Two hundred seven study participants were enrolled in this study. More than half of them (57.5%, 119/207) were males, and 37.7% (78/207) of them were ≥ 65 years old. A total of 130 (62.8%) bacterial isolates were identified, with Gram-positive bacteria accounting for 78.5% (102/130) of the isolates. Staphylococcus aureus was the most common isolate with a 46.2% (60/130) prevalence. Ciprofloxacin was comparatively effective against Gram-positive and Gram-negative bacteria. The prevalence of culture-confirmed bacteria was significantly associated with age groups 15–24 (AOR: 9.18, 95%CI: 1.01–82.80; P = 0.049) and 25–64 (AOR: 7.47, 95%CI: 1.06–52.31; P = 0.043). Being farmer (AOR: 5.33, 95% CI: 1.04–37.33; P = 0.045), previous history of eye surgery (AOR: 5.39, 95% CI: 1.66–17.48; P = 0.005), less frequency of face washing (AOR: 5.32, 95% CI: 1.31–7.23; P = 0.010) and face washing once a day (AOR: 3.07, 95% CI: 1.13–25.13; P = 0.035) were also significantly associated with the prevalence of culture-confirmed bacteria. Conclusion The prevalence of culture-confirmed bacteria among patients with EOI was high in the study area. A considerable proportion of bacterial isolates exhibited mono and/or multi-drug resistance. Age (15–64 years), being farmer, previous history of eye surgery and less frequency of face washing were significantly associated with the prevalence of culture-confirmed bacteria. Bacterial isolation and antibiotic susceptibility testing should be routinely performed in the study area to combat the emergence of antibiotic resistance.
Collapse
Affiliation(s)
- Zewodie Haile
- Department of Medical Microbiology Laboratory, Debre Markos Comprehensive Specialized Hospital, Debre Markos, Ethiopia
- Department of Medical Laboratory Sciences, College of Health Sciences, Debre Markos University, Debre Markos, Ethiopia
| | - Hylemariam Mihiretie Mengist
- Department of Medical Laboratory Sciences, College of Health Sciences, Debre Markos University, Debre Markos, Ethiopia
- * E-mail: (HMM); (TD)
| | - Tebelay Dilnessa
- Department of Medical Laboratory Sciences, College of Health Sciences, Debre Markos University, Debre Markos, Ethiopia
- * E-mail: (HMM); (TD)
| |
Collapse
|
4
|
Kowalski RP, Nayyar SV, Romanowski EG, Jhanji V. Anti-Infective Treatment and Resistance Is Rarely Problematic with Eye Infections. Antibiotics (Basel) 2022; 11:antibiotics11020204. [PMID: 35203807 PMCID: PMC8868068 DOI: 10.3390/antibiotics11020204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 02/01/2022] [Accepted: 02/03/2022] [Indexed: 11/16/2022] Open
Abstract
The treatment of eye infections is very different than treating other body infections that require systemic anti-infectives. Endophthalmitis, keratitis, conjunctivitis, and other ocular infections are treated with direct injection and with topical drops directly to the infection site. There are no anti-infective susceptibility standards to interpret treatment success, but the systemic standards can be used to guide ocular therapy if the concentration of anti-infective in the ocular tissue is assumed to be higher than the concentration in the blood serum. This Perspective describes: (1) eye infections, (2) diagnostics of eye infections, (3) anti-infective treatment of eye infections, (4) anti-infective resistance of ocular pathogens, and (5) alternative anti-infective delivery and therapy. The data, based on years of clinical and laboratory research, support the premise that ocular infections are less problematic if etiologic agents are laboratory-diagnosed and if prompt, potent, anti-infective therapy is applied. Anti-infective susceptibility should be monitored to assure continued therapeutic success and the possibility of new-found resistance. New delivery systems and therapies may be helpful to better treat future ocular infections.
Collapse
Affiliation(s)
- Regis P. Kowalski
- Department of Ophthalmology, The Eye and Ear Institute, School of Medicine, University of Pittsburgh, 203 Lothrop Street, Pittsburgh, PA 15213, USA; (E.G.R.); (V.J.)
- The Charles T. Campbell Eye Microbiology Laboratory, Department of Ophthalmology, University of Pittsburgh Medical Center, The Eye and Ear Institute, University of Pittsburgh School of Medicine, 203 Lothrop Street, Room 642, Pittsburgh, PA 15213, USA;
- Correspondence: ; Tel.: +1-412-647-7211
| | - Shannon V. Nayyar
- The Charles T. Campbell Eye Microbiology Laboratory, Department of Ophthalmology, University of Pittsburgh Medical Center, The Eye and Ear Institute, University of Pittsburgh School of Medicine, 203 Lothrop Street, Room 642, Pittsburgh, PA 15213, USA;
| | - Eric G. Romanowski
- Department of Ophthalmology, The Eye and Ear Institute, School of Medicine, University of Pittsburgh, 203 Lothrop Street, Pittsburgh, PA 15213, USA; (E.G.R.); (V.J.)
- The Charles T. Campbell Eye Microbiology Laboratory, Department of Ophthalmology, University of Pittsburgh Medical Center, The Eye and Ear Institute, University of Pittsburgh School of Medicine, 203 Lothrop Street, Room 642, Pittsburgh, PA 15213, USA;
| | - Vishal Jhanji
- Department of Ophthalmology, The Eye and Ear Institute, School of Medicine, University of Pittsburgh, 203 Lothrop Street, Pittsburgh, PA 15213, USA; (E.G.R.); (V.J.)
- The Charles T. Campbell Eye Microbiology Laboratory, Department of Ophthalmology, University of Pittsburgh Medical Center, The Eye and Ear Institute, University of Pittsburgh School of Medicine, 203 Lothrop Street, Room 642, Pittsburgh, PA 15213, USA;
| |
Collapse
|
5
|
Bispo PJM, Sahm DF, Asbell PA. A Systematic Review of Multi-decade Antibiotic Resistance Data for Ocular Bacterial Pathogens in the United States. Ophthalmol Ther 2022; 11:503-520. [PMID: 35113406 PMCID: PMC8927494 DOI: 10.1007/s40123-021-00449-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Accepted: 12/15/2021] [Indexed: 11/30/2022] Open
Abstract
INTRODUCTION Since 2009, the Antibiotic Resistance Monitoring in Ocular Microorganisms (ARMOR) surveillance study has been assessing in vitro antibiotic resistance for bacterial isolates sourced from ocular infections in the US. The main goal of this systematic review was to compare in vitro resistance data for ocular pathogens from published US studies with the most recently published data from the ARMOR study (2009-2018) and, where possible, to evaluate trends in bacterial resistance over time over all studies. METHODS A literature search was conducted using MEDLINE®, BIOSIS Previews®, and EMBASE® databases (1/1/1995-6/30/2021). Data were extracted from relevant studies and antibiotic susceptibility rates for common ocular pathogens (Staphylococcus aureus, coagulase-negative staphylococci [CoNS], Streptococcus pneumoniae, Pseudomonas aeruginosa, and Haemophilus influenzae), longitudinal changes in susceptibility, and multidrug resistance (MDR) were compared descriptively. RESULTS Thirty-two relevant studies were identified. High in vitro resistance was found among S. aureus and CoNS to fluoroquinolones, macrolides, and methicillin/oxacillin across studies, with high rates of MDR noted, specifically among methicillin-resistant staphylococci. Data from studies pre-dating or overlapping the early years of ARMOR reflected increasing rates of S. aureus resistance to fluoroquinolones, macrolides, methicillin/oxacillin, and aminoglycosides, while the ARMOR data suggested slight decreases in resistance to these classes between 2009 and 2018. Overall, methicillin-resistant S. aureus (MRSA) prevalence peaked from 2005 to 2015 with a possible decreasing trend in more recent years. DISCUSSION AND CONCLUSIONS Data from local and regional US datasets were generally consistent with data from the national ARMOR surveillance study. Continued surveillance of ocular bacterial pathogens is needed to track trends such as methicillin resistance and MDR prevalence and any new emerging antibiotic resistance phenotypes. Susceptibility data from ARMOR can inform initial choice of therapy, especially in practice areas where local antibiograms are unavailable.
Collapse
Affiliation(s)
- Paulo J M Bispo
- Department of Ophthalmology, Infectious Diseases Institute, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA
| | - Daniel F Sahm
- International Health Management Associates Inc, Schaumburg, IL, USA
| | - Penny A Asbell
- Department of Ophthalmology, Hamilton Eye Institute, The University of Tennessee Health Science Center, 20 Madison Ave, Memphis, TN, 38163, USA.
| |
Collapse
|
6
|
Petrillo F, Pignataro D, Di Lella FM, Reibaldi M, Fallico M, Castellino N, Parisi G, Trotta MC, D’Amico M, Santella B, Folliero V, Della Rocca MT, Rinaldi M, Franci G, Avitabile T, Galdiero M, Boccia G. Antimicrobial Susceptibility Patterns and Resistance Trends of Staphylococcus aureus and Coagulase-Negative Staphylococci Strains Isolated from Ocular Infections. Antibiotics (Basel) 2021; 10:antibiotics10050527. [PMID: 34063711 PMCID: PMC8147806 DOI: 10.3390/antibiotics10050527] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 04/28/2021] [Accepted: 05/01/2021] [Indexed: 11/16/2022] Open
Abstract
Ocular bacterial infections represent a serious problem that affecting people of all age and genders. These infections can lead to visual impairment and blindness if not properly treated. The current study evaluates the antimicrobial resistance profiles and the resistance trend of both Staphylococcus aureus (S. aureus) and coagulase-negative staphylococci (CoNS), the main pathogens involved in eye infections. A total of 322 isolates of S. aureus and CoNS, were collected from patients with bacterial conjunctivitis and keratitis at the "Luigi Vanvitelli" University Hospital of Campania in Naples, Italy, between 2017 and 2020. The isolated bacteria showed a high percentage of resistance to methicillin and other antibiotics commonly used for the treatment of ocular infections. Trends in antibiotic resistance were not encouraging, recording-especially among CoNS strains-an increase of more than 20% in resistance to methicillin and aminoglycosides during the study period. Instead, the resistance rates to tetracycline had a significant decrease in CoNS isolates while no changes in their susceptibility to fluoroquinolones and macrolides were observed. However, all isolates showed no resistance to trimethoprim/sulfamethoxazole and chloramphenicol. In this scenario, preventive identification of the infection causative agents and the evaluation of the antimicrobial susceptibility patterns are essential to set up an ocular infection effective drug treatment and also prevent antibiotic resistance.
Collapse
Affiliation(s)
- Francesco Petrillo
- Section of Ophthalmology, University Hospital “Policlinico-Vittorio Emanuele”, 95123 Catania, Italy; (F.P.); (M.F.); (N.C.); (T.A.)
| | - Danilo Pignataro
- Section of Microbiology and Virology, University Hospital “Luigi Vanvitelli”, 80138 Naples, Italy; (D.P.); (F.M.D.L.); (B.S.); (V.F.); (M.T.D.R.)
| | - Federica Maria Di Lella
- Section of Microbiology and Virology, University Hospital “Luigi Vanvitelli”, 80138 Naples, Italy; (D.P.); (F.M.D.L.); (B.S.); (V.F.); (M.T.D.R.)
| | - Michele Reibaldi
- Department of Surgical Sciences, Eye Clinic Section, University of Turin, 10122 Turin, Italy; (M.R.); (G.P.)
| | - Matteo Fallico
- Section of Ophthalmology, University Hospital “Policlinico-Vittorio Emanuele”, 95123 Catania, Italy; (F.P.); (M.F.); (N.C.); (T.A.)
| | - Niccolò Castellino
- Section of Ophthalmology, University Hospital “Policlinico-Vittorio Emanuele”, 95123 Catania, Italy; (F.P.); (M.F.); (N.C.); (T.A.)
| | - Guglielmo Parisi
- Department of Surgical Sciences, Eye Clinic Section, University of Turin, 10122 Turin, Italy; (M.R.); (G.P.)
| | - Maria Consiglia Trotta
- Department of Experimental Medicine, Division of Pharmacology, University of Campania “Luigi Vanvitelli”, 80138 Naples, Italy; (M.C.T.); (M.D.)
| | - Michele D’Amico
- Department of Experimental Medicine, Division of Pharmacology, University of Campania “Luigi Vanvitelli”, 80138 Naples, Italy; (M.C.T.); (M.D.)
| | - Biagio Santella
- Section of Microbiology and Virology, University Hospital “Luigi Vanvitelli”, 80138 Naples, Italy; (D.P.); (F.M.D.L.); (B.S.); (V.F.); (M.T.D.R.)
| | - Veronica Folliero
- Section of Microbiology and Virology, University Hospital “Luigi Vanvitelli”, 80138 Naples, Italy; (D.P.); (F.M.D.L.); (B.S.); (V.F.); (M.T.D.R.)
| | - Maria Teresa Della Rocca
- Section of Microbiology and Virology, University Hospital “Luigi Vanvitelli”, 80138 Naples, Italy; (D.P.); (F.M.D.L.); (B.S.); (V.F.); (M.T.D.R.)
| | - Michele Rinaldi
- Department of Ophthalmology, University Hospital “Luigi Vanvitelli”, 80138 Naples, Italy;
| | - Gianluigi Franci
- Department of Medicine, Surgery and Dentistry “Scuola Medica Salernitana”, University of Salerno, 84081 Baronissi, Italy;
| | - Teresio Avitabile
- Section of Ophthalmology, University Hospital “Policlinico-Vittorio Emanuele”, 95123 Catania, Italy; (F.P.); (M.F.); (N.C.); (T.A.)
| | - Marilena Galdiero
- Section of Microbiology and Virology, University Hospital “Luigi Vanvitelli”, 80138 Naples, Italy; (D.P.); (F.M.D.L.); (B.S.); (V.F.); (M.T.D.R.)
- Correspondence: (M.G.); (G.B.)
| | - Giovanni Boccia
- Department of Medicine, Surgery and Dentistry “Scuola Medica Salernitana”, University of Salerno, 84081 Baronissi, Italy;
- Correspondence: (M.G.); (G.B.)
| |
Collapse
|
7
|
Tummanapalli SS, Willcox MD. Antimicrobial resistance of ocular microbes and the role of antimicrobial peptides. Clin Exp Optom 2021; 104:295-307. [PMID: 32924208 DOI: 10.1111/cxo.13125] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Isolation of antimicrobial-resistant microbes from ocular infections may be becoming more frequent. Infections caused by these microbes can be difficult to treat and lead to poor outcomes. However, new therapies are being developed which may help improve clinical outcomes. This review examines recent reports on the isolation of antibiotic-resistant microbes from ocular infections. In addition, an overview of the development of some new antibiotic therapies is given. The recent literature regarding antibiotic use and resistance, isolation of antibiotic-resistant microbes from ocular infections and the development of potential new antibiotics that can be used to treat these infections was reviewed. Ocular microbial infections are a global public health issue as they can result in vision loss which compromises quality of life. Approximately 70 per cent of ocular infections are caused by bacteria including Chlamydia trachomatis, Staphylococcus aureus, and Pseudomonas aeruginosa and fungi such as Candida albicans, Aspergillus spp. and Fusarium spp. Resistance to first-line antibiotics such as fluoroquinolones and azoles has increased, with resistance of S. aureus isolates from the USA to fluoroquinolones reaching 32 per cent of isolates and 35 per cent being methicillin-resistant (MRSA). Lower levels of MRSA (seven per cent) were isolated by an Australian study. Antimicrobial peptides, which are broad-spectrum alternatives to antibiotics, have been tested as possible new drugs. Several have shown promise in animal models of keratitis, especially treating P. aeruginosa, S. aureus or C. albicans infections. Reports of increasing resistance of ocular isolates to mainstay antibiotics are a concern, and there is evidence that for ocular surface disease this resistance translates into worse clinical outcomes. New antibiotics are being developed, but not by large pharmaceutical companies and mostly in university research laboratories and smaller biotech companies. Antimicrobial peptides show promise in treating keratitis.
Collapse
Affiliation(s)
| | - Mark Dp Willcox
- School of Optometry and Vision Science, The University of New South Wales, Sydney, Australia
| |
Collapse
|