Adult bacterial conjunctivitis: resistance patterns over 12 years in patients attending a large primary eye care centre in the UK

Spectrum and resistance in bacterial infections of the ocular surface in a German tertiary referral center 2009-2019

Purpose

Aim of this study was to evaluate the frequencies, trends, and antibiotic resistance of bacteria collected from ocular surface or contact lens material in a German tertiary referral center from 2009 to 2019.

Methods

Microbiological data from 2009 to 2019 was analyzed. Culture-dependent microbial identification and analysis of antibiotic sensitivity was completed by the Institute of Microbiology. Statistical analysis of age- and sex-specific differences as well as changes in the microbial spectrum and resistance over the study period was performed with GraphPad Prism 9.0 applying nonparametric tests (level of significance: p ≦ 0.05).

Results

A total of 6361 specimens were analyzed. Positivity rate was 18.6%. Sixty-three percent (n = 680) of the bacterial isolates were derived from ocular surface and 37% (n = 399) from contact lens material. The ratio of gram-negative bacteria was significantly higher in contact lens material. Multiresistant bacteria showed a significant increase with patient age (p < 0.0001). An overall increase in resistance to levofloxacin (p = 0.0239) was detected. Only 2.4% and 3.1% isolates were resistant to a combination of moxifloxacin and gentamicin, respectively, levofloxacin and gentamicin.

Conclusions

The reported bacterial spectrum is similar to comparable centers. Our data show that it should not be assumed that the newest classes of antibiotics have the best efficacy or lowest resistance levels. In suspected bacterial conjunctivitis, we propose using gentamicin as first-line therapy. In therapy refractive cases and in involvement of the cornea, we recommend a combination of gentamicin and ofloxacin or moxifloxacin. Overall, the evaluated organisms showed good sensitivity to the regularly used antibiotics.

Characterization of Polybacterial versus Monobacterial Conjunctivitis Infections in Pediatric Subjects Across Multiple Studies and Microbiological Outcomes with Besifloxacin Ophthalmic Suspension 0.6

Introduction

The choice of empiric therapy for bacterial conjunctivitis should be guided by an awareness of typical causative pathogen distributions. Bacterial conjunctivitis can be polybacterial, although pediatric-specific data are lacking.

Methods

This was a post-hoc analysis of data in pediatric subjects (1–17 years) from five bacterial conjunctivitis trials evaluating besifloxacin ophthalmic solution 0.6%.

Results

Of the 730 pediatric subjects with culture-confirmed conjunctivitis, nearly one-fourth (23.6%) had polybacterial infections and three-fourths (76.4%) had monobacterial infections at baseline. In both polybacterial and monobacterial infections, the most prevalent organisms were Haemophilus influenzae, Streptococcus pneumoniae, Staphylococcus aureus, and Streptococcus mitis/S. mitis group. In polybacterial versus monobacterial infections, S. mitis/S. mitis group (8.7% vs 4.3%; P=0.032) and Moraxella catarrhalis (4.7% vs 0.5%; P<0.001) were identified more frequently, whereas S. pneumoniae (14.0% vs 28.1%; P<0.001) was identified less frequently, as the dominant infecting species. MICs for individual species were similar for tested antibiotics regardless of polybacterial or monobacterial infection, except Staphylococcus epidermidis for which fluoroquinolone MICs were ≥3 dilutions higher for isolates of this species sourced from polybacterial compared to monobacterial infections. Treatment with besifloxacin resulted in microbial eradication in 79.1% of polybacterial and 92.3% of monobacterial infections (P≤0.005 vs vehicle).

Discussion

One in four pediatric bacterial conjunctivitis infections is polybacterial, highlighting the need for a broad-spectrum antibiotic when choosing empiric therapy.

Common bacterial causes of external ocular infections, associated risk factors and antibiotic resistance among patients at ophthalmology unit of Felege Hiwot Referral Hospital, Northwest Ethiopia: a cross-sectional study

BACKGROUND

Ocular infections are a serious public health problem in Ethiopia with increased incidence of morbidity and blindness. Empirical therapy with topical ophthalmic broad spectrum antibiotic formulations is also a prevailing practice. The aim of this study was to determine the bacterial causes of external ocular infections (EOIs), antimicrobial resistance and its associated risk factors among patients at Felege Hiwot Referral Hospital, Northwest Ethiopia.

METHODS

A hospital based cross - sectional study was conducted from 1 February to 30 April 2019. Patients with EOIs were consecutively included from 1 February to 30 April, 2019. Data were collected using structured questionnaire by face-to-face interview and complemented with patient card review. Conjunctival, eyelid margin and lacrimal sac swabs were collected aseptically. Bacterial species were identified using standard bacteriological techniques. Antimicrobial susceptibility testing was done using Kirby-Bauer disk diffusion method. Binary logistic regression analysis was calculated to identify the factors associated with EOIs. P.value (p) < < 0.05 was considered as statistically significant.

RESULTS

A total of 360 patients took part in the study and majority of them were males (64.7%). The median age of study participants was 59.5 years. Overall, 208(57.8%) (95%CI = 52.6- - 62.8%) of patients had culture confirmed bacterial EOIs. The proportion of culture confirmed EOIs was 60.4% among conjunctivitis cases and 55.8% among blepharitis. Ocular trauma (P < < 0.001), ocular disease (P < < 0.001) and having eye allergy (P = 0.027) were significantly associated with EOIs. The most frequent isolates were S. aureus (37%), K. pneumoniae (13.5%), Proteus(7.2%) spp., S. pneumoniae (4.3%), Citrobacter spp. (3.4%) and P. aeruginosa (2.9%). Gram positive isolates were resistant to penicillin in 87% and ampicillin in 86.2%. Gram negative isolates were resistant to ampicillin (87.5%). P.aeruginosa isolates (85.3%) were resistant to piperacillin and 50% were resistant to tobramycin. Overall, 45.2% of the isolates were multi-drug resistant. The percentage of multi-drug resistance was 80% among Enterobacter isolates and 64.3% among K. pneumoniae.

CONCLUSIONS

Bacterial external ocular infections linked with multi-drug resistance and resistance to penicillin, ampicillin, tetracycline and piperacillin are high. Therefore, empirical treatment of eye infections in the study area needs to be monitored by regular antimicrobial-susceptibility testing of isolates.

Characterization of baseline polybacterial versus monobacterial infections in three randomized controlled bacterial conjunctivitis trials and microbial outcomes with besifloxacin ophthalmic suspension 0.6

Background/Purpose

To date, studies examining polymicrobial infections in ocular disease have mostly been limited to keratitis or endophthalmitis. We characterized polybacterial infections compared to monobacterial infections in prior clinical studies evaluating besifloxacin ophthalmic suspension 0.6% for the treatment of bacterial conjunctivitis and report on associated microbiological outcomes.

Methods

In this post-hoc analysis, microbiological data for subjects with conjunctivitis due to one or more than one bacterial species in three previous studies (two vehicle-, one active-controlled) of besifloxacin were extracted. Bacterial species identified at baseline were deemed causative if their colony count equaled or exceeded species-specific prespecified threshold criteria. In subjects with polybacterial infections, the fold-increase over threshold was used to rank order the contribution of individual species. Baseline pathogens and their minimum inhibitory concentrations (MICs) for common ophthalmic antibiotics were compared by infection type, as were microbial eradication rates following treatment with besifloxacin.

Results

Of 1041 subjects with culture-confirmed conjunctivitis, 17% had polybacterial and 83% had monobacterial conjunctivitis at baseline. In polybacterial compared to monobacterial infections, Haemophilus influenzae and Streptococcus pneumoniae were identified less frequently as the dominant infecting species (P = 0.042 and P<0.001, respectively), whereas Streptococcus mitis/S. mitis group was identified more frequently as dominant (P<0.001). Viral coinfection was also identified more frequently in polybacterial infections (P<0.001). Staphylococcus aureus was the most common coinfecting species in polybacterial infections and the second most common dominant species in such infections. With few exceptions, MICs for individual species were comparable regardless of infection type. Clinical microbial eradication rates with besifloxacin were high regardless of infection type (P≤0.016 vs vehicle at follow-up visits).

Conclusions

Approximately one in five subjects with bacterial conjunctivitis are infected with more than one bacterial species underscoring the need for a broad-spectrum antibiotic for such infections. Besifloxacin treatment resulted in robust eradication rates of these infections comparable to monobacterial infections.

Trial registration

NCT000622908, NCT00347932, NCT00348348

Treating with besifloxacin for acute bacterial conjunctivitis: a Meta-analysis

AIM

To evaluate the relative efficacy and safety of besifloxacin for treatment of acute bacterial conjunctivitis.

METHODS

A comprehensive search in PubMed, EMBASE Web of Science, Cochrane Central Database and CNKI was undertaken for randomized controlled trials (RCTs) comparing besifloxacin with other treatments or placebo. The primary outcome measures were clinical resolution, rates of bacterial eradication, individual clinical outcomes, cure rates, and bacterial eradication rates of different kinds of pathogens. Safety outcomes were the number of adverse effects (AEs). The final search was performed on August 2018.

RESULTS

Six RCTs were included. Four studies compared the efficacy and safety of besifloxacin with placebo, 1 study compared besifloxacin with moxifloxacin, and 1 study compared besifloxacin with gatifloxacin. A total of 2780 patients met the inclusion criteria. Besifloxacin presented higher efficacy and safety than did placebo in clinical resolution, rates of bacterial eradication, individual clinical outcomes, cure rates, bacterial eradication rates of different kinds of pathogens and the number of AEs. There was no significant difference between besifloxacin and moxifloxacin or gatifloxacin in the comparison items mentioned above.

CONCLUSION

Besifloxacin is highly effective and safe for treatment of acute bacterial conjunctivitis. Further comparative trials regarding the effect of besifloxacin for treatment of acute bacterial conjunctivitis will aid in treatment decisions.

Antibacterial resistance in ophthalmic infections: a multi-centre analysis across UK care settings

BACKGROUND

Bacterial ophthalmic infections are common. Empirical treatment with topical broad-spectrum antibiotics is recommended for severe cases. Antimicrobial resistance (AMR) to agents used for bacterial ophthalmic infections make it increasingly important to consider changing resistance patterns when prescribing, however UK data in this area are lacking. We evaluate the epidemiology and antimicrobial susceptibilities of ophthalmic pathogens across care settings and compare these with local and national antimicrobial prescribing guidelines.

METHODS

A retrospective, multi-centre observational analysis was undertaken of ophthalmic microbiology isolates between 2009 and 2015 at a centralised North-West London laboratory (incorporating data from primary care and five London teaching hospitals). Data were analysed using descriptive statistics with respect to patient demographics, pathogen distribution (across age-groups and care setting), seasonality, and susceptibility to topical chloramphenicol, moxifloxacin, and fusidic acid.

RESULTS

Two thousand six hundred eighty-one isolates (n = 2168 patients) were identified. The commonest pathogen in adults was Staphylococcus spp. across primary, secondary, and tertiary care (51.7%; 43.4%; 33.6% respectively) and in children was Haemophilus spp. (34.6%;28.2%;36.6%). AMR was high and increased across care settings for chloramphenicol (11.8%;15.1%;33.8%); moxifloxacin (5.5%;7.6%;25.5%); and fusidic acid (49.6%;53.4%; 58.7%). Pseudomonas spp. was the commonest chloramphenicol-resistant pathogen across all care settings, whilst Haemophilus spp. was the commonest fusidic acid-resistant pathogen across primary and secondary care. More isolates were recorded in spring (31.6%) than any other season, mostly due to a significant rise in Haemophilus spp.

CONCLUSIONS

We find UK national and local antimicrobial prescribing policies for ophthalmic infections may not be concordant with the organisms and antimicrobial susceptibilities found in clinical samples. We also find variations in microbial incidence related to patient age, clinical setting, and season. Such variations may have further important implications for prescribing practices and modification of antimicrobial guidelines.

The trend of resistance to antibiotics for ocular infection of Staphylococcus aureus, coagulase-negative staphylococci, and Corynebacterium compared with 10-years previous: A retrospective observational study

OBJECTIVE

To retrospectively identify epidemiological trends of infection on the ocular surface and investigate trends of resistance to bacterial antibiotics compared with 10-years previous for Staphylococcus aureus, coagulase-negative staphylococci (CNS), and Corynebacterium in Japan.

MATERIALS AND METHODS

Bacterial isolate samples were collected from the conjunctival sacs of eyes afflicted with conjunctivitis, keratitis, dacryocystitis, and hordeolum from September 2004 through November 2005 (n = 145 isolates) and September 2014 through November 2015 (n = 195 isolates) at the Baptist Eye Institute, Kyoto, Japan. The prevalence of methicillin-resistant S. aureus (MRSA), methicillin-resistant CNS (MR-CNS), and fluoroquinolone-resistant Corynebacterium were examined, and susceptibility of isolated bacteria to levofloxacin (LVFX), cefmenoxime (CMX), chloramphenicol (CP), erythromycin (EM), vancomycin (VCM), and arbekacin (ABK) were compared between both time periods using the disc susceptibility method.

RESULTS

Over the 10-year period from initial to final examination, the prevalence of MRSA and MR-CNS significantly decreased from 52% to 22% (P < 0.05) and from 47% to 25% (P < 0.05), respectively, yet there was no change in the prevalence of fluoroquinolone-resistant Corynebacterium (60% and 54%; P = 0.38). Antibiotic-resistance trend analysis revealed that susceptibility to antibiotics in 2014-2015 was similar to that in 2004-2005. MRSA and MR-CNS were susceptible to CP (88%), VCM (100%), and ABK (100%), while fluoroquinolone-resistant Corynebacterium was susceptible to CMX (100%), VCM (100%), and ABK (96%).

CONCLUSION

The prevalence of MRSA and MR-CNS significantly decreased between the two time periods, yet more than 50% of the Corynebacterium isolates were still resistant to LVFX. Although no increase in bacterial resistance to antibiotics was found, a cautionary use of fluoroquinolone eye drops should be considered.