Ocular Bacterial Infections Research Articles

English

Bacterial external ocular infection is a common health problem along with increase and spread of drug resistance in Ethiopia. The objective of this study was to identify potential bacterial isolate of external ocular infections and their antimicrobial susceptibility patterns in patients attending eye clinic of the Hawassa University Teaching and Referral Hospital, from December 2012 to April 2013. A total of 281 consecutive, non-repetitive ocular specimens were collected among conjunctivitis cases (n=140), blepharitis cases (n=55), keratitis cases (n=31), dacryocystitis cases (n=19), and other cases (n=36). All samples were processed for culture and identification by standard methods. Susceptibility testing was done by Kirby-Bauer method as per Clinical and Laboratory Standards Institute (CLSI) guideline. Out of 281 ocular specimens submitted to culture, 137 (48.8%) specimen were positive. The most common bacterial isolates were Gram positive cocci (n=88; 61.5%). The predominant bacterial species isolated was Staphylococcus aureus (n=30; 21.0%) followed by coagulase negative Staphylococci (CoNS) (n=26; 18.2%) and Streptococcus pneumoniae (n=20; 14.0%). In vitro ciprofloxacin was effective against 86% of isolated pathogen. Multi-drug resistance was observed in 69.9% of the bacterial isolates. Our study confirmed that S. aureus was the overall predominant isolated pathogen followed by CoNS, S. pneumoniae and Klebsiella spp. Gram positive isolates were more susceptible to amoxicillin-clavulanic acid and vancomycin, whereas Gram negative isolates were more susceptible to ciprofloxacin and gentamicin. Relatively, ciprofloxacin is effective against most isolated pathogen. Key words: External ocular infections, conjunctivitis, blepharitis, keratitis, dacryocystitis, susceptibility.

Therapeutic Potential of the Antimicrobial Peptide OH-CATH30 for Antibiotic-Resistant Pseudomonas aeruginosa Keratitis

The therapeutic potential of antimicrobial peptides (AMPs) has been evaluated in many infectious diseases. However, the topical application of AMPs for ocular bacterial infection has not been well investigated. The AMP OH-CATH30, which was identified in the king cobra, exhibits potent antimicrobial activity. In this study, we investigated the therapeutic potential of OH-CATH30 for Pseudomonas aeruginosa keratitis. Ten isolates of P. aeruginosa from individuals with keratitis were susceptible to OH-CATH30 but not to cefoperazone, ciprofloxacin, gentamicin, and levofloxacin. The microdilution checkerboard assay showed that OH-CATH30 exhibited synergistic activity with ciprofloxacin and levofloxacin against antibiotic-resistant P. aeruginosa. Meanwhile, P. aeruginosa did not develop resistance to OH-CATH30, even after exposure at 0.5× the MIC for up to 25 subcultures. Furthermore, treatment with OH-CATH30, alone or in combination with levofloxacin, significantly improved the clinical outcomes of rabbit keratitis induced by antibiotic-resistant P. aeruginosa. Taken together, our data indicate that the topical application of OH-CATH30 is efficacious against drug-resistant P. aeruginosa keratitis. In addition, our study highlights the potential application of AMPs in treating ocular bacterial infections.

Infectious Keratitis: Secreted Bacterial Proteins That Mediate Corneal Damage

Ocular bacterial infections are universally treated with antibiotics, which can eliminate the organism but cannot reverse the damage caused by bacterial products already present. The three very common causes of bacterial keratitis—Pseudomonas aeruginosa, Staphylococcus aureus, and Streptococcus pneumoniae—all produce proteins that directly or indirectly cause damage to the cornea that can result in reduced vision despite antibiotic treatment. Most, but not all, of these proteins are secreted toxins and enzymes that mediate host cell death, degradation of stromal collagen, cleavage of host cell surface molecules, or induction of a damaging inflammatory response. Studies of these bacterial pathogens have determined the proteins of interest that could be targets for future therapeutic options for decreasing corneal damage.

Post-Marketing Surveillance of Levofloxacin 0.5% Ophthalmic Solution for External Ocular Infections

Levofloxacin 0.5% ophthalmic solution is an antibacterial formulation, which was approved and marketed for the treatment of ocular infections in Japan in 2000. This study was designed to investigate the safety and efficacy of levofloxacin 0.5% ophthalmic solution in patients who received treatment for external ocular bacterial infections in regular clinical practice. Patients were recruited from more than 800 medical facilities in Japan, in accordance with Japanese Ministry of Health, Labour and Welfare ordinance guidelines. They were followed during three distinct time periods: April 2000 to December 2001, January 2002 to June 2003, and July 2003 to December 2004. Information from 6760 patients receiving levofloxacin for the treatment of a variety of ocular infections was collected. Levofloxacin was well tolerated: adverse drug reactions (ADRs) were reported in 42 of 6686 patients (0.63%), with no serious ADRs reported. The most commonly reported ADRs were ocular disorders such as blepharitis, eye irritation, and punctate keratitis. The incidence of ADRs did not differ significantly with age, but it was significantly higher in females (0.82%) than in males (0.36%; p = 0.028). A clinical response was observed in 95.5% of patients receiving levofloxacin, with no difference in response between the three time periods. The rate of response to levofloxacin by bacterial disease ranged from 97.4% in keratitis to 88.3% in dacryocystitis. The rate was lower in patients with dacryocystitis, elderly patients, patients with a long duration of illness, and relapsing cases (all p < 0.001). This post-marketing surveillance of levofloxacin, conducted over 4 years, confirms the safety and efficacy of levofloxacin in regular clinical use and highlights that levofloxacin is a promising treatment for a variety of external ocular bacterial infections.

Post-marketing surveillance of levofloxacin 0.5% ophthalmic solution for external ocular infections.

BackgroundLevofloxacin 0.5% ophthalmic solution is an antibacterial formulation, which was approved and marketed for the treatment of ocular infections in Japan in 2000.ObjectiveThis study was designed to investigate the safety and efficacy of levofloxacin 0.5% ophthalmic solution in patients who received treatment for external ocular bacterial infections in regular clinical practice.MethodsPatients were recruited from more than 800 medical facilities in Japan, in accordance with Japanese Ministry of Health, Labour and Welfare ordinance guidelines. They were followed during three distinct time periods: April 2000 to December 2001, January 2002 to June 2003, and July 2003 to December 2004.ResultsInformation from 6760 patients receiving levofloxacin for the treatment of a variety of ocular infections was collected. Levofloxacin was well tolerated: adverse drug reactions (ADRs) were reported in 42 of 6686 patients (0.63%), with no serious ADRs reported. The most commonly reported ADRs were ocular disorders such as blepharitis, eye irritation, and punctate keratitis. The incidence of ADRs did not differ significantly with age, but it was significantly higher in females (0.82%) than in males (0.36%; p = 0.028). A clinical response was observed in 95.5% of patients receiving levofloxacin, with no difference in response between the three time periods. The rate of response to levofloxacin by bacterial disease ranged from 97.4% in keratitis to 88.3% in dacryocystitis. The rate was lower in patients with dacryocystitis, elderly patients, patients with a long duration of illness, and relapsing cases (all p < 0.001).ConclusionThis post-marketing surveillance of levofloxacin, conducted over 4 years, confirms the safety and efficacy of levofloxacin in regular clinical use and highlights that levofloxacin is a promising treatment for a variety of external ocular bacterial infections.

Conjuntivite bacteriana secundária à doença dentária em chinchilas (Chinchilla lanigera)

São relatados três casos de conjuntivite bacteriana associada à doença dentária grave em chinchilas. Todas as chinchilas afetadas tinham histórico de emagrecimento, hipersalivação e epífora, que progrediu para exsudação ocular purulenta. Durante a necropsia, foi constatado marcado alongamento da coroa clínica dos incisivos e molares, e crescimento do ápice dentário, causando deformação óssea e compressão do canal lacrimal. Histologicamente, observou-se infiltrado de neutrófilos na conjuntiva e pálpebras. Cultivo microbiológico do exsudato ocular revelou crescimento de Staphylococcus coagulase-positiva . Uma compressão do canal lacrimal pelo crescimento dentário excessivo impediu a drenagem das lágrimas, resultando em epífora. Esse é um importante fator predisponente para infecção bacteriana ocular em chinchilas.

Screening of OcularEnterobacteriaceaeIsolates for Presence of ChromosomalblaNDM-1and ESBL Genes: A 2-Year Study at a Tertiary Eye Care Center

Since, to our knowledge, there are no reports on the prevalence of the blaNDM-1 gene among ocular isolates of Enterobacteriaceae, and only limited information on the prevalence of extended spectrum beta-lactamases (ESBLs) among ocular bacterial isolates are available, our study was undertaken. A prospective study was done on 74 Enterobacteriaceae isolates from patients presenting with clinical suspicion of bacterial ocular infections during a period from January 2010-December 2011. All isolates were subjected to detection of ESBLs by double disc synergy and screened for the presence of CTX-M -I, II, III, and IV groups, and OXA, TEM, SHV, blaNDM-1 genes by PCR. Of 74 ocular Enterobacteriaceae isolates 57 (77%) were ESBL producers tested by the double disc diffusion test. PCR-based DNA sequencing of these 57 ocular isolates showed the presence of CTX-M-15 (14.0%), blaOXA-1 (5.2%), blaSHV-1 (8.7%), and blaTEM-1 (7.0%) types. The blaNDM-1 was absent among these ocular isolates. The most widely disseminated ESBL gene among ocular isolates was CTX-M-15. Phenotypic and genotypic results showed 100% correlation. To our knowledge, this is the first extensive study performed to genotype ESBL-producing ocular Enterobacteriaceae isolates. The isolation of ESBL-producing Enterobacteriaceae organisms predominantly from conjunctival specimens indicates community-acquired infections/colonization by these bacteria in the conjunctiva of the patients, and cases are not related to hospital-acquired infections because of the short stay of ophthalmic patients in the hospitals. A shift in the resistance rates of ceftazidime from 37.5% to 79.7% over the years proves the increase in drug resistance among ocular clinical isolates.

Is antibiotic resistance a major problem in ophthalmology?

AbstractPurpose Ocular antibiotic bacterial resistance becomes problematic when: 1) intrinsically susceptible bacteria become resistance, 2) antibiotic resistance spreads from patient –to‐patient, and 3) effective antibiotic treatment is unavailable. The “Standard of Care” of ocular bacterial infections will be accordingly evaluated.Methods Based on the findings of our dedicated ophthalmic microbiology laboratory, the trends in ocular susceptibility in regards to bacterial pathogen and disease (endophthalmitis, keratitis, conjunctivitis, and blepharitis) were analyzed for evidence of acquired resistance, possible infection spread, and the armament of treatment.Results Our studies indicate that based on the bacterial pathogen, bacterial resistance is most prevalent with endophthalmitis isolates of Staphylococcus aureus and coagulase‐negative Staphylococcus. There is evidence that endophthalmitis isolates of Staphylococcus aureus may be hospital acquired. Although Haemophilus influenza and Streptococcus pneumonia isolated from conjunctivitis are probably spread patient‐to patient, an increase in antibiotic resistance has not occurred. There does not appear to be a treatment problem for Pseudomonas aeruginosa keratitis based on in vitro antibiotic resistance.Conclusion Our study concludes that antibiotic resistance does occur for ocular bacterial pathogens, but ocular infection does not spread from patient to patient. There is a plethora of effective topical antibiotic agents to treat all types of bacterial ocular infections. It is important to culture all severe ocular infections to optimize therapy and to guard against the creation of antibiotic resistant bacteria. The future of antibacterial therapy may rely on preventing infections instead of the production of new drugs.

Etiology and Antibacterial Susceptibility Pattern of Bacterial Ocular Infections in a Children Hospital in North Jordan (2005-2009)

Etiology and Antibacterial Susceptibility Pattern of Bacterial Ocular Infections in a Children Hospital in North Jordan (2005-2009)

Safety and Efficacy of Moxifloxacin-Dexamethasone Eyedrops as Treatment for Bacterial Ocular Infection Associated with Bacterial Blepharitis

Treatments that offer two medications in a fixed combination have the potential to offer efficacious and safe treatment with advantages such as a regimen that is simpler than administering two separate solutions. This study evaluated the safety and efficacy of fixed-combination versus concomitant moxifloxacin 0.5% and dexamethasone 0.1% ocular solutions for the treatment of bacterial ocular inflammation and infection. The clinical study design was a randomized, double-masked, active-controlled, parallel-group trial of 102 subjects with bacterial blepharitis in which two patients also had bacterial conjunctivitis. All subjects received two bottles of study medication: either a fixed combination of moxifloxacin 0.5%/dexamethasone 0.1% ophthalmic solution and placebo eye drops (fixed-dose group), or moxifloxacin 0.5% ophthalmic solution and dexamethasone 0.1% (concomitant group). One drop of each study medication was instilled bilaterally four times per day for 7 days. Clinical resolution, signs, symptoms, and safety were assessed. Microbiological specimens were collected from the eyelid margin and conjunctivae of each eye from each patient at the time of enrollment and at the exit visit. Clinical resolution occurred similarly in both groups (81.6% of eyes, fixed-dose group; 82.3% of eyes, concomitant group). Moreover, the microbiological efficacy of the treatment was also similar for both the fixed-dose group (84%) and the concomitant group (83%). Ocular symptoms and signs improved over time, with no significant differences between groups after 7 days of treatment, except the fixed-dose group had significantly more eyes with clinical resolution in eyelid erythema (100%, n = 98/98, fixed-dose group; 92.7%, n = 89/96, concomitant group; P = 0.0194) and eyelid scaling/crusting (98%, n = 96/98, fixed-dose group; 89.6%; n = 86/96 eyes, concomitant group; P = 0.0337). Both regimens were safe and well tolerated. The fixed-dose combination of moxifloxacin, 0.5% and dexamethasone, 0.1% was therapeutically equivalent and as well tolerated as the concomitant dosage.

Safety and Tolerability of Loteprednol Etabonate 0.5% and Tobramycin 0.3% Ophthalmic Suspension in Pediatric Subjects

Loteprednol etabonate 0.5% and tobramycin 0.3% ophthalmic suspension (LE/T) is indicated for steroid-responsive inflammatory ocular conditions where superficial bacterial ocular infection or a risk of bacterial ocular infection exists. LE/T was shown to be safe in healthy volunteers and patients aged 18 years and older with minimal effect on intraocular pressure (IOP). The aim of the study was to evaluate the safety of LE/T in pediatric subjects by examining data from two clinical studies. Two randomized, multicenter, double-masked, parallel-group (one two-arm, the other four-arm) studies were conducted in subjects aged 0-6 years (N = 245). One study assessed LE/T compared with vehicle in the management of lid inflammation (n = 108) and the other compared LE/T with loteprednol etabonate ophthalmic suspension 0.5% (LE), tobramycin ophthalmic solution 0.3% (tobramycin), and vehicle in the treatment of blepharoconjunctivitis (n = 137). In the first study, subjects were randomized to LE/T or vehicle administered four times daily (qid) for the first 7 days followed by twice daily (bid) for 7 days along with warm compresses bid for the entire 2 weeks. In the second study, subjects were randomized to LE/T, LE, tobramycin, or vehicle administered qid for 14 days. Treatment-emergent ocular and non-ocular adverse events (AEs) and bilateral vision were assessed at all study visits in both studies. In addition, in the lid inflammation study, IOP was assessed at all visits. The primary safety endpoint in both studies was the incidence of treatment-emergent AEs. The incidence of LE/T treatment-emergent AEs was low. A total of four ocular AEs were reported for three LE/T-treated subjects in the first study (conjunctivitis [two events], meibomian gland dysfunction, and corneal staining), and one ocular AE was reported for an LE/T-treated subject in the second study (eye pain). A total of 13 non-ocular AEs were reported for eight LE/T-treated subjects in the two trials. The most prevalent non-ocular AEs were pyrexia (three events) and rash (two events). There were no differences in the incidence of specific ocular and non-ocular AEs between the LE/T group and the comparator treatment group. In both studies, there were no clinically meaningful reductions in vision at follow-up visits. Mean IOP and IOP changes from baseline, assessed in the lid inflammation study, were not different between LE/T and vehicle treatment groups at any study visits. The results of these two clinical trials demonstrate the short-term safety of treatment with topical LE/T in pediatric subjects (0-6 years of age) with lid inflammation or blepharoconjunctivitis.

Challenges in Assessing Microbial Susceptibility and Predicting Clinical Response to Newer-Generation Fluoroquinolones

To determine the most appropriate methods for assessing the potential effectiveness of the newer topical fluoroquinolones gatifloxacin, moxifloxacin, and besifloxacin. This article is based on a literature search for published articles about the pharmacokinetic (PK) and pharmacodynamic (PD) characteristics of and measure of bacterial susceptibility to topical ophthalmic fluoroquinolones. Search terms included fluoroquinolones, susceptibility, resistance, minimal/minimum inhibitory concentration (MIC), PDs, PKs, and ocular, ophthalmic, or topical antibiotics. Topical fluoroquinolones, particularly besifloxacin, gatifloxacin, and moxifloxacin, have become important treatment options for common ocular bacterial infections due to their broad-spectrum bactericidal activity and low toxicity. An important challenge in ophthalmology is identifying the most accurate in vivo and in vitro methods for evaluating the efficacy of these topical fluoroquinolones. The MIC is the most commonly used measure of in vitro susceptibility. In systemic therapy, this measure is combined with PK data of antibiotics to generate PD indices PK/PD whose breakpoints differentiate clinically susceptible from nonsusceptible bacterial pathogen populations. PD breakpoints are further tested in prospective studies for their ability to predict clinical efficacy. However, it is not known whether systemically derived breakpoints apply to the assessment of clinical susceptibility to ocular agents. Topical ocular antibiotics likely achieve higher concentrations at the target site than do systemically administered antibiotics, but these higher concentrations can be quickly reduced by reflex tearing and blinking induced by instillation. Hence, studies have been conducted in animals and humans to determine the PK concentrations of topically administered antibiotics in ocular compartments. When combined with MIC values for topical pathogens, the results have the potential to predict clinical efficacy after identification of the appropriate PK/PD target. Ocular studies incorporating PK/PD assessments have recently begun to be reported with newer fluoroquinolones, including besifloxacin, gatifloxacin, and moxifloxacin, whose prolonged contact time and potent bactericidal activity have translated into some of the most favorable PK/PD target values. However, the clinical relevance of these studies has yet to be determined. There is still a clear need for predictive models to extend our understanding of the clinical susceptibility of ocular pathogens.

A European Perspective on Topical Ophthalmic Antibiotics: Current and Evolving Options

BackgroundEye infections can be vision-threatening and must be treated effectively by appropriate and safe use of topical ophthalmic anti-infectives. This review will essentially consider the current and evolving treatment options for the various types of bacterial eye infections. Ocular surface bacterial infections affect subjects of all ages with a high frequency in newborns and children.MethodsThis article presents a review of the peer-reviewed published scientific literature in order to define the well-established uses of anti-infective eye drops in the field of ocular infections. A comprehensive search of the recent published literature including topical ophthalmic anti-infectives effective in bacterial ocular infections was performed. Clinical studies provide relevant data concerning the characteristics and clinical efficacy of antibacterial eye drops in ocular anterior segment infections or for perioperative prophylaxis. Publications were included to cover the current options of antibacterial eye drops available in Europe.ResultsSeveral recent publications identified effective topical ocular antibacterials requiring a reduced dose regimen and a short treatment course. Additional literature reviewed included data on novel perioperative prophylaxis, indications for topical fortified antibiotics and innovative research including the risk of resistance.ConclusionsSafe and effective topical antibiotic eye drops for the treatment and prevention of ocular infections must be adapted to the type of bacteria suspected. Usual topical antimicrobials should be replaced by more recent and more effective treatments. The use of highly effective fluoroquinolones should be reserved for the most severe cases to avoid resistance. Short treatment courses, such as azithromycin, can be easily used in children, thereby improving quality of life.

Preparation and physicochemical characterization of Eudragit® RL100 Nanosuspension with potential for Ocular Delivery of Sulfacetamide

Purpose: Polymeric nanosuspension was prepared from an inert polymer resin (Eudragit® RL100) with the aim of improving the availability of sulfacetamide at the intraocular level to combat bacterial infections. Methods: Nanosuspensions were prepared by the solvent displacement method using acetone and Pluronic® F108 solution. Drug to polymer ratio was selected as formulation variable. Characterization of the nanosupension was performed by measuring particle size, zeta potential, Fourier Transform infrared spectra (FTIR), Differential Scanning Calorimetry (DSC), Powder X-Ray Diffraction (PXRD), drug entrapment efficiency and in vitro release. In addition, freeze drying, redispersibility and short term stability study at room temperature and at 40C were performed. Results: Spherical, uniform particles (size below 500 nm) with positive zeta potential were obtained. No significant chemical interactions between drug and polymer were observed in the solid state characterization of the freeze dried nanosuspension (FDN). Drug entrapment efficiency of the selected batch was increased by changing the pH of the external phase and addition of polymethyl methacrylate in the formulation. The prepared nanosuspension exhibited good stability after storage at room temperature and at 40C. Sucrose and Mannitol were used as cryoprotectants and exhibited good water redispersibility of the FDN. Conclusion: The results indicate that the formulation of sulfacetamide in Eudragit® RL100 nanosuspension could be utilized as potential delivery system for treating ocular bacterial infections.

Reviews for Immune Privilege in the Year 2010: Immune Privilege and Infection

Advances in understanding host innate/adaptive immunity and abrogation of immune privilege in ocular viral and bacterial infections have been accomplished using animal models. In Pseudomonas aeruginosa keratitis, mouse models have shown that IL-12-driven IFN-γ production in Th1 responder strains such as C57BL/6 contributes to corneal perforation, while IL-18-driven IFN-γ production is associated with bacterial killing and less disease in Th2 responders (BALB/c). The role of neuropeptides, macrophages, and regulation of neutrophil apoptosis is discussed. The potentially blinding Th1 CD4 T-cell-mediated immunopathology referred to as herpes stromal keratitis (HSK) is characterized by breakdown of the normal barrier to blood and lymph angiogenesis in the cornea, a dramatic increase in mature professional antigen-presenting cells, and a heavy leukocytic infiltrate composed primarily of neutrophils. HSK is more frequent and severe in BALB/c than C57BL/6 mice, and varies in severity with the strain and dose of HSV-1 used to infect the cornea.

Loteprednol and tobramycin in combination: a review of their impact on current treatment regimens

Importance of the field: The treatment of ocular inflammation continues to be a challenge. Topical corticosteroids are effective in reducing ocular inflammation but are limited by adverse events including elevation of intraocular pressure, development of cataracts, glaucoma and inhibition of wound healing with associated risk of infection. Loteprednol etabonate (LE) is a unique C-20 ester corticosteroid designed to produce a predictable therapeutic effect with a low incidence of side effects. Zylet® (LE/T) a combination of LE and tobramycin (T) is indicated for the treatment of steroid-responsive ocular inflammatory conditions in which there exists either superficial bacterial ocular infection or a potential risk of bacterial infection.Areas covered in this review: The current review of the literature (Medline and the Cochrane Library, 1996 – 2009) examines the safety and efficacy of LE/T in the treatment of ocular inflammation.What the reader will gain: Studies with either LE or LE/T indicate that LE has a lower risk of IOP elevation compared with C-20 ketone corticosteroids owing to its rapid de-esterification to inactive metabolites. LE also lacks the ability to form Schiff base intermediates with lens proteins, a common first step in cataractogenesis. LE/T was noninferior to dexamethasone 0.1%/tobramycin 0.3% in the treatment of blepharokeratoconjunctivitis.Take home message: LE/T may be a safer treatment option for ocular inflammation in which there is risk of superficial bacterial infections.

Besifloxacin: a novel anti-infective for the treatment of bacterial conjunctivitis

Bacterial conjunctivitis, commonly known as pink eye, is demographically unbiased in its prevalence and can be caused by a variety of aerobic and anaerobic bacteria. Timely empiric treatment with a broad-spectrum anti-infective, such as a topical fluoroquinolone, is critical in preventing potentially irreversible ocular damage. However, the rise in ocular methicillin- resistant Staphylococcus aureus isolates and the patterns of fluoroquinolone resistance for patients with other ocular bacterial infections mandate the need for new agents targeted for ocular use. Besifloxacin, a novel broad-spectrum fluoroquinolone, is approved for the treatment of bacterial conjunctivitis. It has a uniquely balanced dual-targeting activity that inhibits both DNA gyrase and topoisomerase IV and is associated with a lower incidence of resistance development. Besifloxacin is not marketed in other formulations, ensuring that its exposure is limited to bacterial populations in and around the eye. This specifically precludes any bacterial exposure to besifloxacin resulting from systemic use, which further reduces the likelihood of emergence of bacterial resistance. In vitro, besifloxacin has demonstrated equivalent or superior activity compared with other commonly used topical antibiotics. In clinical trials, besifloxacin has consistently demonstrated efficacy and safety in the treatment of patients with bacterial conjunctivitis. Besifloxacin is considered safe and is well tolerated with no observed contraindications.

Prevalence of bacterial pathogens causing ocular infections in South India

The eye may be infected from external sources or through intra-ocular invasion of micro-organisms carried by the blood stream. This study was undertaken to isolate and identify the specific bacterial pathogens causing ocular infections and to determine their in-vitro antibacterial susceptibilities to commonly used antibacterial agents. A retrospective analysis of all patients with clinically diagnosed bacterial ocular infections such as blepharitis, conjunctivitis, internal and external hordeolum, suppurative scleritis, canaliculitis, keratitis, dacryocystitis, preseptal cellulitis, endophthalmitis and panophthalmitis presenting between January 2005 and December 2005 was performed. Extra-ocular and intra-ocular specimens were collected and were subjected to direct microscopy and culture. A total of 756 patients with bacterial ocular infections were analyzed, of which 462(61%) eyes had adnexal bacterial infection, 217(28.7%) had corneal infection, 6 (0.8%) had scleral involvement and the remaining 71(9.39%) eyes had infection of the intra-ocular tissues. The predominant bacterial species isolated was S. aureus (195 of 776; 25%) followed by S. pneumoniae (169 of 776; 21.78%) and coagulase negative staphylococci (142 of 776; 18.3%). The largest number of gram-positive isolates were susceptible to cefazolin (545 of 624; 87.34%), chloramphenicol (522 of 624; 83.65%) and gatifloxacin (511 of 624; 81.89%) and gram-negative isolates were to amikacin (127 of 136; 93.38%), gatifloxacin (125 of 136; 91.91%) and ofloxacin (119 of 136; 87.5%), while aerobic actinomycetes were to amikacin (100%), gatifloxacin (14 of 16; 87.5%), chloramphenicol (14 of 16; 87.5%) and ofloxacin (13 of 16; 81.25%). S. aureus frequently causes infections of eyelids and conjunctiva, S. pneumoniae of lacrimal apparatus and cornea and coagulase negative staphylococci causes intra-ocular infections. Of all routinely used antibacterials tested, flouroquinolones, especially gatifloxacin and ofloxacin represented a good choice for treating bacterial ocular infections.

Etiology and antibacterial susceptibility pattern of community-acquired bacterial ocular infections in a tertiary eye care hospital in south India.

Aims:To identify the etiology, incidence and prevalence of ocular bacterial infections, and to assess the in vitro susceptibility of these ocular bacterial isolates to commonly used antibiotics.Materials and Methods:Retrospective analysis of consecutive samples submitted for microbiological evaluation from patients who were clinically diagnosed with ocular infections and were treated at a tertiary eye care referral center in South India between January 2002 and December 2007.Results:A total of 4417 ocular samples was submitted for microbiological evaluation, of which 2599 (58.8%) had bacterial growth, 456 (10.3%) had fungal growth, 15 (0.34%) had acanthamoebic growth, 14 (0.32%) had mixed microbial growth and the remaining 1333 (30.2%) had negative growth. The rate of culture-positivity was found to be 88% (P < 0.001) in eyelids’ infection, 70% in conjunctival, 69% in lacrimal apparatus, 67.4% in corneal, 51.6% in intraocular tissues, 42.9% in orbital and 39.2% in scleral infections. The most common bacterial species isolated were Staphylococcus aureus (26.69%) followed by Streptococcus pneumoniae (22.14%). Sta. aureus was more prevalent more in eyelid infections (51.22%; P = 0.001) coagulase-negative staphylococci in endophthalmitis (53.1%; P = 0.001), Str. pneumoniae in lacrimal apparatus and corneal infections (64.19%; P = 0.001), Corynebacterium species in blepharitis and conjunctivitis (71%; P = 0.001), Pseudomonas aeruginosa in keratitis and dacryocystitis (66.5%; P = 0.001), Haemophilus species in dacryocystitis and conjunctivitis (66.7%; P = 0.001), Moraxella lacunata in blepharitis (54.17%; P = 0.001) and Moraxella catarrhalis in dacryocystitis (63.83%; P = 0.001). The largest number of gram-positive isolates was susceptible to moxifloxacin (98.7%) and vancomycin (97.9%), and gram-negative isolates to amikacin (93.5%) and gatifloxacin (92.7%).Conclusions:Gram-positive cocci were the most frequent bacteria isolated from ocular infections and were sensitive to moxifloxacin and vancomycin, while gram-negative isolates were more sensitive to amikacin and gatifloxacin.

Impact of antibiotic resistance in the management of ocular infections: the role of current and future antibiotics

This article reviews the effects of the increase in bacterial resistance on the treatment of ocular infections. Interpretive assessment. Literature review and interpretation. Ocular bacterial infections include conjunctivitis, keratitis, endophthalmitis, blepharitis, orbital cellulitis, and dacryocystitis. Treatment for most ocular bacterial infections is primarily empiric with broad-spectrum antibiotics, which are effective against the most common bacteria associated with these ocular infections. However, the widespread use of broad-spectrum systemic antibiotics has resulted in a global increase in resistance among both Gram-positive and Gram-negative bacteria to a number of the older antibiotics as well as some of the newer fluoroquinolones used to treat ophthalmic infections. Strategies for the prevention of the increase in ocular pathogen resistance should be developed and implemented. In addition, new antimicrobial agents with optimized pharmacokinetic and pharmacodynamic properties that have low toxicity, high efficacy, and reduced potential for the development of resistance are needed. New antimicrobial agents that treat ocular infections effectively and have a low potential for the development of resistance could be a part of strategies to prevent the global increase in ocular pathogen resistance.