Bacterial culture isolates from hospitalized pediatric patients with conjunctivitis

Bacterial Etiology and Antibiotic Susceptibility of Conjunctivitis Patients' Isolates in Kashan, Iran

Background

Conjunctivitis is a very common ocular disease, which can be caused by a wide variety of microorganisms. This study was aimed to assess the bacterial etiology and antibiotic susceptibility of conjunctivitis patients' isolates from Central Iran.

Materials and Methods

This study was performed in 180 patients referred to the Department of Ophthalmology in Kashan University with symptoms of conjunctivitis from July 2017 to December 2017. To detect of different bacteria, Gram staining, morphological characterization, pigment production, biochemical characteristics, coagulase test, optochin and PYR tests, oxidase test, and culture on specific media were used. Antibiotic susceptibility of the bacteria isolated was done using the Kirby-Bauer method. Methicillin resistance in staphylococci isolated from the patients was identified using polymerase chain reaction technique.

Results

Of the 195 bacteria isolated, about 81.5% were Staphylococcus epidermidis and Staphylococcus aureus and the remaining 19.5% included other species. In the present study, Pseudomonas aeruginosa was most resistant to ampicillin. In the case of S. epidermidis and S. aureus, the highest resistance was observed against erythromycin and the least resistance was against rifampicin and linezolid.

Conclusion

In this study, S. aureus and S. epidermidis are the most common causes of conjunctivitis in all age groups, however, this condition decreases with age and is also influenced by other factors such as season and weather conditions. The results of this study can be helpful in planning more prudent treatment strategies for patients with conjunctivitis in Kashan.

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

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

Pasteurella canis and Granulicatella adiacens conjunctivitis outbreak resistant to empirical treatment in a child welfare agency

PURPOSE

To investigate pathogens associated with bacterial conjunctivitis resistant to the empirical treatment and their antibiotic resistance in a child welfare agency.

METHODS

Twenty-eight eyes in 14 children with a median age of 3 months with conjunctivitis resistant to the empirical treatment were included in this study. Samples were taken three times from the inferior fornix in both eyes using cotton swabs, cultured onto chocolate and blood agar, and prepared for Gram staining. Antibiograms were evaluated according to the Clinical and Laboratory Standards Institute criteria by disc diffusion method.

RESULTS

The conjunctival culture positivity rate was 35.7% in eyes with conjunctivitis resistant to the empirical treatment. The most common isolated bacteria were Pasteurella canis (25%), penicillin-nonsusceptible Streptococcus pneumoniae (7.1%), and Granulicatella adiacens (3.6%). According to culture results, ophthalmic solutions of vancomycin (50 mg/mL) or gentamicin (30 mg/mL) were applied in eyes with positive conjunctival culture. Previously applied multiple treatments were stopped in eyes with negative conjunctival culture. All eyes improved clinically during follow-up.

CONCLUSION

Because unusual pathogens may cause a conjunctivitis outbreak, physicians should not insist on empirical treatment. Taking conjunctival culture and antibiotic switching according to antibiogram may be helpful.

A novel cell-associated protection assay demonstrates the ability of certain antibiotics to protect ocular surface cell lines from subsequent clinical Staphylococcus aureus challenge

In vivo effectiveness of topical antibiotics may depend on their ability to associate with epithelial cells to provide continued protection, but this contribution is not measured by standard antibiotic susceptibility tests. We report a new in vitro method that measures the ability of test antibiotics azithromycin (AZM), erythromycin (ERY), tetracycline (TET), and bacitracin (BAC) to associate with mammalian cells and to protect these cells from destruction by bacteria. Mammalian cell lines were grown to confluence using antibiotic-free medium and then incubated in medium containing a single antibiotic (0 to 512 μg/ml). After incubation, the cells were challenged with Staphylococcus aureus ocular isolates, without antibiotics added to the culture medium. Epithelial cell layer integrity was assessed by gentian violet staining, and the minimum cell layer protective concentration (MCPC) of an antibiotic sufficient to protect the mammalian cells from S. aureus was determined. Staining was also quantified and analyzed. Bacterial viability was determined by culture turbidity and growth on agar plates. Preincubation of Chang and human corneal limbal epithelial cells with AZM, ERY, and TET at ≥64 μg/ml provided protection against AZM-susceptible S. aureus strains, with increasing protection at higher concentrations. TET toxicity was demonstrated at >64 μg/ml, whereas AZM displayed toxicity to one cell line at 512 μg/ml. BAC failed to show consistent protection at any dose, despite bacterial susceptibility to BAC as determined by traditional antibiotic susceptibility testing. A range of antibiotic effectiveness was displayed in this cell association assay, providing data that may be considered in addition to traditional testing when determining therapeutic dosing regimens.

Epidemiology of gram-negative conjunctivitis in neonatal intensive care unit patients

PURPOSE

To describe the epidemiologic features, risk factors, and antibiotic susceptibilities for gram-negative conjunctivitis among neonatal intensive care unit (NICU) patients.

DESIGN

Retrospective, observational study.

METHODS

In a University Tertiary Care Hospital with a level III-IV NICU, 65 NICU infants (< eight weeks of age) with positive culture results for conjunctivitis between January 1, 2001 and June 1, 2007, were included. Patient demographics, clinical examination results, device usage, and antibiotic susceptibility data were compared between infants with gram-negative conjunctivitis and infants without gram-negative conjunctivitis.

RESULTS

One or more episodes of gram-negative conjunctivitis occurred in 38% (n = 25/65) of NICU infants. Predominant pathogens included Klebsiella species (23%), Escherichia coli (17%), Serratia marcescens (17%), Pseudomonas aeruginosa (3%), and Enterobacter species (2%). Birth weight and gestational age were significantly less in infants with gram-negative conjunctivitis than in infants without gram-negative conjunctivitis (P = .008 and P = .008, respectively). With multivariate analysis, birth weight less than 1500 g (odds ratio [OR], 4.35; 95% confidence interval [CI], 1.42 to 13.36), and gestational age of 29 weeks or fewer (OR, 5.60; 95% CI, 1.88 to 16.66) were identified as risk factors for the development of gram-negative conjunctivitis. Antibiotic resistance of gram-negative organisms to ampicillin, cefazolin, gentamicin, and levofloxacin were 96%, 52%, 13%, and 7% respectively. Of the Klebsiella isolates, two (25%) of eight were resistant to gentamicin.

CONCLUSIONS

Low birth weight and low gestational age in NICU infants with clinical signs of conjunctivitis should raise the suspicion for a gram-negative cause. Given the observed resistance patterns of Klebsiella isolates, gentamicin resistance should be considered when designing empiric treatment.

Antibacterial phenolic components from Eriocaulon buergerianum

Five phenolic components, 1,3,6-trihydroxy-2,5,7-trimethoxyxanthone (1), 7,3'-dihydroxy-5,4',5'-trimethoxyisoflavone (2), toralactone-9-O-beta-D-glucopyranoside (3), patuletin-3-O-[2-O-E-feruloyl-beta-d-glucopyranosyl-(1-->6)-beta-d-glucopyranoside] (4), patuletin-3-O-[beta-d-glucopyranosyl-(1-->3)-2-O-E-caffeoyl-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranoside] (5), along with 19 known compounds were isolated from Eriocaulon buergerianum (Eriocaulaceae). Their structures were determined by spectroscopic and chemical methods. All 24 isolated compounds were tested against the pathogenic bacteria Staphylococcus aureus (ATCC 25923); as a result, 10 compounds were found to exhibit antibacterial activity with MICs ranging from 32 to 256 microg/ml.

Acute bacterial conjunctivitis

Acute bacterial conjunctivitis is the eye disease most commonly seen by general practitioners, and is estimated to represent approximately 1% of all consultations in primary care. This article gives a review of the epidemiology, aetiology, clinical picture, complications, differential diagnoses, in vitro examinations and therapy of acute bacterial conjunctivitis. Until now, topical antibacterial therapy has generally been preferred by both physicians and patients because this will usually shorten the course of the disease slightly and allow the early readmittance of children to their kindergarten or school. Recently, several reports from primary care have confirmed the well-known clinical experience that the disorder has an excellent prognosis with a high frequency of spontaneous remission. In accordance, an expectant attitude or delayed prescription policy are now frequently strongly recommended. However, these reports also emphasize the difficulty in making a correct clinical distinction between bacterial and viral conjunctivitis. The effect of a general non-prescription attitude on transmission rates of pathogens also remains to be clarified. This must be born in mind when deciding how these patients should be handled. The socioeconomic and medical pros and cons of different treatment policies are discussed, and a highly personal view on the optimal handling strategy for these patients is also presented.