Bacterial etiology of ocular and periocular infections, antimicrobial susceptibility profile and associated factors among patients attending eye unit of Shashemene comprehensive specialized hospital, Shashemene, Ethiopia

Bacterial pathogens and antimicrobial susceptibility in ocular infections: A study at Boru-Meda General Hospital, Dessie, Ethiopia

INTRODUCTION

The eye consists of both internal and external compartments. Several variables, including microbes, dust, and high temperatures can cause eye illnesses that can result in blindness. Bacterial eye infections continue to be a major cause of ocular morbidity and blindness, and their prevalence is periodically rising. The objective of the study was to detect bacterial pathogens and assess their susceptibility profiles to antibiotics in the ophthalmology unit of Boru-meda Hospital in Dessie, Ethiopia.

METHODS

A hospital-based cross-sectional study was conducted from February 1 to April 30, 2021, among 319 study participants with symptomatic ocular or peri-ocular infections who were enrolled using a consecutive sampling technique. After proper specimen collection, the specimen was immediately inoculated with chocolate, blood, and MacConkey agar. After pure colonies were obtained, they were identified using standard microbiological methods. The Kirby Bauer disk diffusion method was used to test antimicrobial susceptibility patterns, based on the guidelines of the Clinical and Laboratory Standards Institute.

RESULTS

The majority of participants developed conjunctivitis 126 (39.5%), followed by blepharitis 47 (14.73%), and dacryocystitis 45 (14.1%). Overall, 164 (51.4%) participants were culture positive, six (1.9%) participants had mixed bacterial isolates, giving a total of 170 bacterial isolates with an isolation rate of 53.3%. The predominant species was CoNS 47 (27.6%), followed by S. aureus 38 (22.4%) and Moraxella species 32 (18.8%). The overall Multi-Drug Resistance (MDR) rate was 62.9%, with 33 (44.6%) being gram-negative and 74 (77.1%) being gram-positive isolates.

CONCLUSION

Conjunctivitis was the dominant clinical case and CoNS, was the predominant isolate. A higher rate of MDR isolates, particularly gram-positive ones, was observed. Efficient peri-ocular or ocular bacterial infection surveillance, including microbiological laboratory data, is necessary for monitoring disease trends.

Molecular Characterization of Bacterial Agents Causing External Ocular Infections Isolates of Patients in a Third Level Hospital

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.

Gatifloxacin Loaded Nano Lipid Carriers for the Management of Bacterial Conjunctivitis

Bacterial conjunctivitis (BC) entails inflammation of the ocular mucous membrane. Early effective treatment of BC can prevent the spread of the infection to the intraocular tissues, which could lead to bacterial endophthalmitis or serious visual disability. In 2003, gatifloxacin (GTX) eyedrops were introduced as a new broad-spectrum fluoroquinolone to treat BC. Subsequently, GTX use was extended to other ocular bacterial infections. However, due to precorneal loss and poor ocular bioavailability, frequent administration of the commercial eyedrops is necessary, leading to poor patient compliance. Thus, the goal of the current investigation was to formulate GTX in a lipid-based drug delivery system to overcome the challenges with the existing marketed eyedrops and, thus, improve the management of bacterial conjunctivitis. GTX-NLCs and SLNs were formulated with a hot homogenization-probe sonication method. The lead GTX-NLC formulation was characterized and assessed for in vitro drug release, antimicrobial efficacy (against methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa), and ex vivo permeation. The lead formulation exhibited desired physicochemical characteristics, an extended release of GTX over a 12 h period, and was stable over three months at the three storage conditions (refrigerated, room temperature, and accelerated). The transcorneal flux and permeability of GTX from the GTX-NLC formulation were 5.5- and 6.0-fold higher in comparison to the commercial eyedrops and exhibited a similar in vitro antibacterial activity. Therefore, GTX-NLCs could serve as an alternative drug delivery platform to improve treatment outcomes in BC.

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.

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

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.

Clinical characteristics of external bacterial ocular and periocular infections and their antimicrobial treatment patterns among a Ghanaian ophthalmic population

Empirical antimicrobial therapy is linked to a surge in antimicrobial resistant infections. However, an insight on the bacteria etiology of ocular infections is essential in the appropriation of choice of antimicrobial among clinicians, yet there remains a dearth of data from Ghana. We investigated the bacteria etiology of external ocular and periocular infections and antimicrobial treatment patterns among a Ghanaian ophthalmic population. A multicenter study design with purposive sampling approach was employed. Patients demographics and clinical data were collated using a pretested structure questionnaire. Cornea specimens and conjunctival swabs were obtained for bacterial isolation following standard protocols. About 95% (98/103) of ocular samples were positive for bacteria culture. The proportion of Gram-negative bacteria was 58.2%, and the predominant bacteria species were Pseudomonas aeruginosa 38.8% and Staphylococcus aureus 27.6%. Conjunctivitis 40.0% and keratitis 75.0% were mostly caused by Pseudomonas aeruginosa. The routinely administered antimicrobial therapy were polymyxin B 41.2%, neomycin 35.1% and ciprofloxacin 31.6%. Participants demographic and clinical characteristics were unrelated with positive bacteria culture (p > 0.05). Our results showed a markedly high burden of ocular bacterial infections and variations in etiology. Bacterial infection-control and antimicrobial agent management programs should be urgently institutionalized to prevent the emergence of resistant infections.

Evaluation of the Pathogenic Potential of Escherichia coli Strains Isolated from Eye Infections

While primarily Gram-positive bacteria cause bacterial eye infections, several Gram-negative species also pose eye health risks. Currently, few studies have tried to understand the pathogenic mechanisms involved in E. coli eye infections. Therefore, this study aimed to establish the pathogenic potential of E. coli strains isolated from eye infections. Twenty-two strains isolated between 2005 and 2019 from patients with keratitis or conjunctivitis were included and submitted to traditional polymerase chain reactions (PCR) to define their virulence profile, phylogeny, clonal relationship, and sequence type (ST). Phenotypic assays were employed to determine hemolytic activity, antimicrobial susceptibility, and adhesion to human primary corneal epithelial cells (PCS-700-010). The phylogenetic results indicated that groups B2 and ST131 were the most frequent. Twenty-five virulence genes were found among our strains, with ecp, sitA, fimA, and fyuA being the most prevalent. Two strains presented a hemolytic phenotype, and resistance to ciprofloxacin and ertapenem was found in six strains and one strain, respectively. Regarding adherence, all but one strains adhered in vitro to corneal cells. Our results indicate significant genetic and virulence variation among ocular strains and point to an ocular pathogenic potential related to multiple virulence mechanisms.

Potency of commonly retailed antibiotics in pharmacies found in Adama, Oromia regional state, Ethiopia

Introduction

Antibiotics are commonly used for the treatment and prevention of bacterial infections. The potency of antibiotics can be affected by factors such as temperature, light, moisture, and storage conditions. Inappropriate storage and transportation of antibiotics may lead to loss of potency earlier than the expiry date. The aim of this study was to determine the potency and associated factors of commonly retailed antibiotics.

Method

Institution-based cross-sectional study was conducted on commonly retailed antibiotics in pharmacies that are available in Adama, Ethiopia from March 2018 to June 2018. This study focused on commonly ordered antibiotics such as amoxicillin, azithromycin, ciprofloxacin, and ceftriaxone. Antibiotics to be tested were selected by using a simple random sampling technique. Socio-demographic and related data were collected using a semi-structured questionnaire. Antibiotic susceptibility testing was performed using the disc diffusion method as described in the Clinical Laboratory Standard Institute guideline.

Results

Mean inhibition zones of amoxicillin, ciprofloxacin, azithromycin, and ceftriaxone were 14.2 ± 4 mm, 30.9 ± 4.2 mm, 17.47 ± 3.83 mm, and 32.7±1.8 respectively. Out of 164 antibiotics tested, 61% passed the potency test. The potency of antibiotics varies across different countries in which 53.7% and 54.6 of antibiotics from India and Ethiopia passed the potency test. All ceftriaxone tested in this study passed the potency test. Factors such as air condition of pharmacy (X² = 4.27; p = 0.039), source of all antibiotics (X² = 5.41; p = 0.02), and source of amoxicillin (X² = 4.73; p = 0.03) were significantly associated with potency of antibiotics.

Conclusions

About 40% of antibiotics tested in the current study did not pass the potency test; this warrants further investigation to identify the magnitude of the problem and its causes at a large scale.