Conjunctival Microbiota Research Articles

Ocular microbiota and lens contamination following Mel4 peptide-coated antimicrobial contact lens (MACL) extended wear

PurposeThe purpose of this study was to investigate the effect of Mel4 antimicrobial peptide-coated contact lenses (MACL) on the microbiota of the conjunctiva and lenses during three months of extended wear. MethodsOne hundred and seventy-six participants were recruited into a randomised, contralateral, double masked, biweekly extended wear MACL and uncoated control lens trial. At the one month and 3-month visit, the conjunctival microbiota was sampled using sterile cotton swabs and contact lenses were collected aseptically. Standard microbiological procedures were employed for culture of the swabs and contact lenses and identification of the isolated microorganisms. ResultsGram-positive bacteria (predominantly coagulase-negative staphylococci) were the most frequently isolated microbes from both contact lenses and conjunctiva. There was no difference in the frequency of isolation of most bacteria or fungi from the conjunctival swabs of eyes wearing either MACL or control lenses. The only exception was a higher frequency of eyes harbouring Staphylococcus arlettae when wearing control lenses (5%) versus MACL (<1%) (p = 0.002). There was no significant difference in the frequency of microbes isolated from MACL or control contact lenses. There were also no differences between lens types in the frequency of isolation of >1 microbial type per sampling occasion for either conjunctiva swabs or contact lenses. ConclusionMACL wear did not change the conjunctival microbiota during extended wear, and the types of microbes isolated from MACL were similar to those isolated from control lenses.

Hidrojel ve Silikon Hidrojel Kontakt Lens Kullanımı ile Konjonktivadaki Koagülaz Negatif Stafilokok Popülasyonu ve Biyofilm Oluşturan Staphylococcus epidermidis Arasındaki İlişki

Objective: The most important bacteria of the conjunctival microbiota are Staphylococcus epidermidis, diphteroid rods, Corynebacterium spp. and Cutibacterium acnes. Especially biofilm formation of S. epidermidis is very important for contact lens related infections. For this purpose, we aimed to examine the changes in the presence of biofilm-forming S. epidermidis and other coagulase-negative staphylococci in conjunctival swabs taken before and after lens usage in 140 patients (90 hydrogel, 50 silicone hydrogel) who were prepared to wear lenses. Methods: Coagulase-negative staphylococci isolated from the conjunctival microbiota identified standard clinical microbiological methods, after identification of S.epidermidis strains with API Staph; Slime production was determined by Congo red agar, standard tube and molecular methods. Results: S.epidermidis was the most frequently isolated species in conjunctival microbiota before and after lens usage. Before lens usage, slime positive S. epidermidis strains were found as 45-50% but after lens usage it was 59% in hydrogel contact lens users and 70.2% in silicone hydrogel contact lens users. For the investigation of slime production, 82 (50.9%) of 161 S. epidermidis strains were found positive by using Congo red agar, 61 (37.8%) by standard tube method and 91 (56.5%) by molecular methods. Conclusion: The result of our study suggests that there are no significant changes in bacterial ratios before and after lens use, but bacteria such as S. epidermidis can predispose to infections by using slime production and contact lens factor. Also; molecular methods and Congo Red Agar method were found to be more reliable than the Standard Tube method.

Evaluation of Healthy Canine Conjunctival, Periocular Haired Skin, and Nasal Microbiota Compared to Conjunctival Culture.

Next-generation sequencing (NGS) methods have been used to identify a diverse ocular surface (OS) microbiota in humans. These results have highlighted limitations in microbial detection via traditional culture-based techniques. The OS has mechanisms such as tear film and mechanical blinking, which may aid in preventing adherence and colonization of microbes, suggesting that only low populations of microbes may reside on the OS. Additionally, closely related tissues to the OS are exposed to a similar array of microbes, but demonstrate different defense mechanisms. Information regarding concordance of microbial communities of the OS and nearby tissues is lacking. Our study purposes were to (1) characterize the conjunctival microbiota of healthy dogs, (2) compare the conjunctival microbiota to the periocular haired skin and distal nose, and (3) compare the bacteria identified by culture to NGS of the healthy canine conjunctiva. Here, NGS was used to evaluate samples from 25 healthy adult dogs of the conjunctiva, periocular haired skin, and distal nose. Additional samples were collected from each dog for traditional conjunctival culture. The 16S rRNA gene amplicon libraries were evaluated for coverage, relative abundance, richness, and diversity. Site-dependent similarities evaluated using principal coordinate analysis (PCoA) and PERMANOVA demonstrated relatedness in community compositions between sites. The conjunctiva of healthy dogs yielded a rich and diverse microbiota based on NGS. While some regional continuity was noted, microbial communities of the conjunctiva, periocular haired skin, and nose were significantly different from each other. Comparatively, traditional culture markedly underestimated the number of bacterial taxa present on the healthy canine OS. Findings suggest similarities in nasal and conjunctival microbial communities, which may be a result of similarities in mucosal immunity and anatomic connection via the nasolacrimal system. Further investigation using NGS into changes of the composition of bacterial communities in disease is warranted.

Feline conjunctival microbiota in a shelter: effects of time, upper respiratory disease and famciclovir administration.

The aim of this study was to evaluate changes in the conjunctival microbiota of shelter-housed cats with time, upper respiratory disease (URD) and famciclovir administration. Cats were assigned to treatment groups on shelter entry. Healthy cats or cats with URD received ~30 mg/kg or ~90 mg/kg of famciclovir or placebo PO q12h for 7 days, or were untreated. Swabs were collected from ventral conjunctival fornices prior to (day 1) and immediately after (day 8) the treatment period. Microbiota analysis was conducted on 124 randomly selected swabs from healthy (56 swabs) or URD-affected (68 swabs) cats. Following DNA extraction and amplification of the V4 region of the 16S rRNA gene, sequences were assembled into operational taxonomic units (OTUs). Over-represented OTUs (as determined by linear discriminate analysis effect size), alpha and beta diversity, and median relative abundance of known feline ocular surface pathogens were assessed for the entire population and in 10 clinically relevant subpopulations of cats. Bacteria from 33 phyla and 70 genera were identified. Considering all cats, median relative abundance of Mycoplasma increased from day 1 to day 8, while Proteobacteria decreased. Community membership and structure (beta diversity) differed between days 1 and 8 for all famciclovir-treated cats (regardless of health status or dose) and healthy or URD-affected cats (regardless of famciclovir dose). Differences in taxonomic diversity within a sample (alpha diversity) between day 1 and day 8 were not detected in any subpopulations. Within 1 week of shelter entry, there were significant changes in community structure and membership of the feline conjunctival microbiota, with a shift towards over-representation of feline ocular surface pathogens. Although famciclovir may impact beta diversity of the feline conjunctival microbiota, absence of change in alpha diversity suggests minimal shift in individual cats.

Characterization of the normal equine conjunctival bacterial community using culture-independent methods.

The equine conjunctival microbiota has often been reported to be dominated by Gram-positive species such as Staphylococcus sp., Bacillus sp., and Corynebacterium sp. However, traditional culture-based methods can only recover a fraction of the bacterial species present in the sample. This pilot study aimed at exploring the diversity of the equine conjunctival microbiota using culture-independent methods. Eight horses were included in this study, and only eyes with normal ophthalmic examination (n=15 eyes) were sampled. Conjunctival biopsies (culture-independent) were collected, and DNA was extracted from the tissues. Bacterial communities in conjunctival biopsies were characterized by next-generation sequencing of the 16S rRNA genes. Individual reads were ascribed to operational taxonomic units (OTUs) using BLASTn and Greengenes databases. Species richness, evenness, and Good's coverage were determined for each conjunctiva-associated microbial community. Culture-independent samples produced a total of 329 bacterial OTUs. The main OTUs identified in the study belonged to the Gram-negative species Ralstonia mannitolilytica (88.0%), Nicoletella semolina (3.3%), and Pseudomonas tolaasii (1.5%). Contrary to previously published data based on culture-dependent methods, the horse eye microbial community was dominated by Gram-negative bacteria of the phylum Proteobacteria.

Effect of scleral lens use on conjunctival microbiota

AimThis study aimed to investigate the effect of scleral lens (SL) use on conjunctival microbiota. MethodA total of 26 eyes of 26 patients using an SL and 25 eyes of 25 healthy controls were included in the study. The samples were obtained from the lower fornices of the eyes using sterile swabs. For the bacteriological examination, a bacterial culture was obtained by inoculating the samples on chocolate agar, blood agar, MacConkey agar, and fluid thioglycollate medium. After 24–48 h of incubation at 37 0C, the growth of different colonies of bacteria was identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (Bruker MALDI Biotyper). ResultsThe mean age of the study group was 41.6 ± 19.1 years (18–65); the mean age of the control group was 40 ± 6 (21–62) (p = 0.69). There were 10 male patients and 16 female patients in the study group and 9 male patients and 16 female patients in the control group (p = 0.86). The mean duration of SL use was 13.7 ± 13.4 months (1–42 months). No bacterial growth was observed in 17 (65.4 %) of the 26 eyes in the SL group and 5 (20 %) of the 25 eyes in the control group (p = 0.001). The most commonly observed microorganisms were Staphylococcus epidermidis (S.epidermidis) and Staphylococcus aureus (S.aureus) in both groups. ConclusionSL users were found to have a higher rate of culture negativity in comparison to the healthy controls, suggesting that SLs have a significant effect on conjunctival microbiota.

An Omics Approach to Diagnosing or Investigating Fungal Keratitis.

Fungal keratitis (FK) is one of the most severe corneal infectious diseases. FK often leads to poor visual prognosis and thus requires accurate diagnosis. Conventional approaches, including clinical diagnoses, smears, and cultures, often fail to provide reliable diagnostic value. Omics approaches, such as those using genomic, metagenomic, and tear proteomic data sources, provide promising features for improving the diagnosis and monitoring the progression of FK. Genomic approaches are based mainly on detecting amplicons of ribosomal RNA genes, and internal transcribed spacers are gradually gaining popularity in clinical practices. A metagenomic approach based on 16S rRNA genes may help monitor the dynamic change of conjunctival microbiota associated with an FK event, whereas that based on shot-gun and 18S rRNA target enrichment sequencing could have the potential to diagnose FK using clinical samples. A tear proteomic approach may provide comprehensive information about ocular surface defense and injury during FK. Representative up- and down-regulated proteins during FK could also be used as biomarkers to determine the clinical course and develop a treatment strategy in different stages of FK. Consequently, a personalized tear proteomic approach will soon play a key role in FK management.

Conjunctival dysbiosis in mucosa-associated lymphoid tissue lymphoma

To investigate the conjunctival microbiota and the association between the development of conjunctival mucosa-associated lymphoid tissue (MALT) lymphoma and dysbiosis, DNA samples were collected from 25 conjunctival MALT lymphoma patients and 25 healthy controls. To compare the microbiota, samples were collected from the following four body locations: conjunctiva, meibomian gland, periocular skin and hand. Extracted DNA was analyzed by 16S rRNA sequences, and libraries were sequenced on an Illumina MiSeq sequencer. The differences in bacteria were characterized by using principal coordinate analysis of metagenomics data, and the differences in bacterial compositions were evaluated by linear discriminant analysis effect size. The conjunctival microbiota of MALT lymphoma patients was compositionally different from that of healthy controls. For the conjunctival MALT lymphoma patients, alterations in the microbial composition were detected, and a remarkable change was detected at the conjunctiva. Detailed analysis showed that a specific population of the microbiota, the genus Delftia, was significantly more abundant in conjunctival MALT lymphoma patients, and the genera Bacteroides and Clostridium were less abundant in the MALT lymphoma patients. A specific microbiota on the ocular surface in conjunctival MALT lymphoma patients was detected, and dysbiosis may play an important role in the pathophysiology of conjunctival MALT lymphoma.

Determination of baseline values for routine ophthalmic tests in bearded capuchin (Sapajus libidinosus).

Establish baseline values for ophthalmic diagnostic tests in Sapajus libidinosus. Ophthalmic diagnostic tests, namely Schirmer tear test 1 (STT-1), intraocular pressure (IOP), B-mode ultrasound, culture of the bacterial conjunctival microbiota, and conjunctival exfoliative cytology, were performed in 15 S.libidinosus. Mean values found were as follows: 2.50±2.94mm/min for the STT-1; 13.3±3.32mmHg for the IOP; 2.47±0.41mm for the depth of the anterior chamber; 2.86±0.96mm for the axial length of the lens; 10.97±0.48mm for the depth of the vitreous chamber; and 16.32±1.24mm for the axial length of the eyeball. The bacterial genus most frequently found was Staphylococcus spp. Conjunctival cytology showed intermediate epithelial, squamous superficial epithelial, and keratinized cells. Determination of baseline values for eye measurements and ophthalmic tests will assist in the diagnosis of eye diseases in S.libidinosus monkeys.

Molecular characterization and potential sources of aqueous humor bacterial contamination during phacoemulsification with intraocular lens implantation in dogs

Bacterial contamination of the anterior chamber during cataract surgery is one of the main responsible for endophthalmitis postoperative. Phacoemulsification is a less invasive technique for cataract treatment, although it does not exclude the possibility of contamination. In this study, bacterial contaminants of aqueous humor collected pre- and post-phacoemulsification with intraocular lens implantation (IOL) of twenty dogs were identified. As the conjunctival microbiota constitute a significant source of anterior chamber contamination, bacterial isolates from aqueous humor were genetically compared with those present in the conjunctival surface of the patients. Three dogs presented bacterial growth in both aqueous humor and conjunctival surface samples. Bacterial isolates from these samples were grouped according to their genetic profiles by repetitive-element PCR (rep-PCR) and their representatives were identified by 16S rRNA sequencing. Isolates from conjunctival surface were identified as Enterobacter spp., Staphylococcus spp. and S. aureus; and from aqueous humor samples as Enterobacter spp., Pantoea spp., Streptococcus spp. and Staphylococcus spp., respectively in decreasing order of prevalence. According to the rep-PCR analysis, 16.6% of Enterobacter spp. isolates from conjunctival surface were genetically similar to those from aqueous humor. The rest of isolates encountered in aqueous humor were genetically distinct from those of conjunctival surface. The significant genetic diversity of bacterial isolates found in the aqueous humor samples after surgery denoted the possibility of anterior chamber contamination during phacoemulsification by bacteria not only from conjunctival surface but also from different sources related to surgical environment.

Caracterización de la microbiota conjuntival transitoria y residente de adultos jóvenes

La microbiota ocular se encuentra principalmente en la conjuntiva y está constituida por bacterias de los géneros Staphylococcus corynebacterium spp., Bacillus spp., Neisseria spp., Moraxella spp. y Streptococcus spp. Esta diversidad puede variar según las condiciones estacionales, la temperatura, la edad y la exposición ambiental. Objetivo: caracterizar la diversidad de la microbiota residente y transitoria de la conjuntiva en adultos jóvenes. Metodología: estudio observacional descriptivo de corte transversal en 67 adultos jóvenes, hombres y mujeres entre 18 y 25 años de edad, que cumplieron con los criterios de inclusión y aceptaron firmar el consentimiento informado. A cada sujeto se le tomaron dos muestras del saco conjuntival, con un intervalo de una semana. Estas se cultivaron en agar sangre y agar chocolate a 37 °C por 24 horas. Las colonias aisladas se identificaron mediante el sistema automatizado VITEK. Resultados: se determinaron 16 géneros y 29 especies diferentes. El género más frecuente fue Staphylococcus (55,6 %), seguido de Acinetobacter (12,0 %), Bacillus (7,0 %), Pasterella (4,6 %) y Escherichia (3,7 %). La microbiota residente estuvo constituida principalmente por el género Staphylococcus y sus especies más representativas fueron S. epidermidis (50,0 %) y S. lentus (13,3 %). Conclusión: existe gran diversidad de bacterias en la microbiota conjuntival, mayor en la microbiota transitoria que en la residente; probablemente, esto depende del ambiente en el que se encuentra el individuo.

Conjunctival Microbiome Changes Associated With Soft Contact Lens and Orthokeratology Lens Wearing.

Usage of different types of contact lenses is associated with increased risk of sight-threatening complications. Changes in the ocular microbiome caused by contact lens wear are suggested to affect infection development in those individuals. To address this question, this study compares conjunctival microbial communities in contact lens wearers with those in noncontact lens wearers. Paired-end sequencing of the V3 region of the 16S rRNA gene was used to characterize the bacterial communities on the conjunctival surfaces of contact lens wearers and nonwearers. No differences in microbial diversity were detected between contact lens wearers and nonwearers. Nevertheless, some slight microbe variability was evident between these two different groups. Bacillus, Tatumella and Lactobacillus abundance was less in orthokeratology lens (OKL) wearers than in nonwearers. In soft contact lenses (SCL) wearers, Delftia abundance decreased whereas Elizabethkingia levels increased. The difference in the SCL and nonwearer group was smaller than that in the OKL group. Variations in the conjunctival taxonomic composition between SCL wearers were larger than those in other groups. Sex differences in the conjunctival microbiota makeup were only evident among nonwearers. Even though there were slight percentage changes between contact lens wearers and nonwearers in some microbes, there were no differences in their diversity. On the other hand, contact lens usage might cause relative abundance of some taxa to change. Our results will help assess whether or not conjunctival microbiome changes caused by contact lens wear affect infection risk.

Defining the normal core microbiome of conjunctival microbial communities

Bacterial ocular infections are common. Traditional culture and molecular biological methods have obvious limitations to identify the conjunctival microbiota, while metagenomic studies can avoid the defects of these methods. We used the Illumina high-throughput sequencing technology (MiSeq Illumina Sequencing Platform) to sequence the 16S rDNA V3–V4 hypervariable region of all bacteria in conjunctival swab samples. The operational taxonomic units were obtained from the sequences. The bioinformatic analyses of taxonomy, abundance and alpha diversity were performed. A total of 840 373 high-quality sequencing reads were generated from 31 conjunctival samples. The number of the species operational taxonomic units ranged from 159 to 2042, indicating high microbial diversity. The combined bacterial community was classified into 25 phyla and 526 distinct genera. At the genus level, Corynebacterium (28.22%), Pseudomonas (26.75%), Staphylococcus (5.28%), Acinetobacter (4.74%), Streptococcus (2.85%), Millisia (2.16%), Anaerococcus (1.86%), Finegoldia (1.68%), Simonsiella (1.48%) and Veillonella (1.00%) accounted for over 76% of the microbial community, possibly representing the core genera in normal conjunctival microbiota. The composition and diversity of microbiota in the normal adult human conjunctiva were characterized using high-throughput sequencing. A framework for investigating potential roles played by the diverse microbiota in disease related with the ocular surface was provided.

Conjunctival Microbiota and Antibiotic Resistance Pattern in Patients Submitted to Cataract Surgery and Antibacterial Activity of Some Plant Essential Oils

Objective: The objective of this study was to identify the conjunctival microbiota of patients undergoing cataract surgery and evaluate its antibiotic resistance pattern. Also to in-vitro evaluate the antimicrobial effects of some essential oils against multidrug resistant isolates. Methodology: Ocular samples were collected using swabs and polymethyl-metaacrylate (PMMA) intraocular lenses from seventy patients submitted to cataract surgery. Isolation and identification of bacteria was performed using conventional microbiological methods. Antibiotic sensitivity was done by disc diffusion method. The sensitivity of 16 essential oils against isolated bacteria was tested using well diffusion method. Results: Thirty six strains were isolated from patients submitted to cataract surgery. Gram positive microorganisms represent 75% of the isolates with coagulase-negative Staphylococci (CoNS) the most common isolate (47.2%) followed by S.aureus (19.4%), whereas gram negative occurred in 25% of cases, with Moraxella spp. the most frequent Gram negative isolate. Antibiotic sensitivity test revealed that the highest antibiotic resistance was exhibited against ceftazidime (100%) followed by clindamycin (86%), ampicillin (80.5%), erythromycin (72.2%) and tetracycline (69.4%). Gentamycin displayed the best activity (55.5%) followed by chloramphenicol (44.4%) and vancomycin (38.88%). Fifteen essential oils showed antibacterial effect against one or more bacterial strains. The most potent oils were peppermint oil, dill oil, cinnamon oil which showed promising inhibitory activity against most tested bacterial species, whereas cotton, ginger, chamomile, blue green, cod liver and parsley oil were the least active against tested strains. Olive oil failed to inhibit any of the tested strains. In general, St. pneumoniae was the most susceptible organism as it inhibited by ten oils. Conclusion: Our results indicate a promising antibacterial effect of peppermint oil, dill oil and cinnamon oil against conjunctival microorganisms.

Selected ophthalmic diagnostic tests, bony orbit anatomy, and ocular histology in sambar deer (Rusa unicolor).

The purpose of this study was to establish reference values for diagnostic ophthalmic tests in sambar deer (Rusa unicolor) as well as to describe the most relevant features of the bony orbital anatomy and ocular histology. Twenty healthy animals, free living in a forest reserve, that were captured for clinical evaluation as part of a health survey were evaluated. Schirmer tear test-1 (STT1), conjunctival microbiota, intraocular pressure (IOP), conjunctival cytology, anatomy of the bony orbit, and ocular histology were studied. Mean±SD STT1 and IOP values were 18.8±4.7mm and 11.4±2.8mmHg, respectively. IOP was significantly higher in adult (4-8years) animals (P=0.04). Bacterial growth was present in 100% of the samples, with a prevalence for Staphylococcus sp. and Bacillus sp. The conjunctival cytology revealed predominance of columnar epithelial cells with mild pigmentation. The sambar deer orbit is completely encompassed by bone. The ocular histology was very similar to most mammalians. The findings in this study will be useful in the diagnosis of ocular diseases in Rusa unicolor.

O olho da coruja-orelhuda: observações morfológicas, biométricas e valores de referência para testes de diagnóstico oftálmico

Objetivou-se relatar características morfológicas do bulbo ocular e determinar valores de referência para testes oftálmicos selecionados em corujas-orelhudas (Asio clamator). Foram estudados 32 olhos de 16 corujas (Asio clamator), adultas e jovens, machos e fêmeas, de vida livre. Sendo compilados dados referentes a observações morfológicas do crânio, bulbo ocular e anexos, além de mensuração de testes oftálmicos, incluindo, Teste Lacrimal de Schirmer (TLS), cultura da microbiota normal da conjuntiva, estesiometria, pressão intraocular (PIO), espessura de córnea central (ECC), diâmetro horizontal da rima palpebral, diâmetro horizontal da córnea e oftalmoscopia indireta. Vinte e dois tipos de bactérias foram identificados em 12 corujas havendo predominância de microrganismos Gram-positivos. A média encontrada para o TLS foi de 5,03±3,28mm/min, para o diâmetro horizontal da rima palpebral em 16 corujas foi 21,24±1,17mm, e 15,7±2,74mm para o diâmetro horizontal da córnea. O valor médio para o teste de estesiometria foi de 0,80±0,59cm, a PIO média de 13,81±5,62mmHg e ECC média de 0,28±0,03cm. O estudo contribuiu para a caracterização da morfologia ocular e para o estabelecimento de valores de referências de testes diagnósticos oftálmicos em corujas-orelhudas, sendo necessário ainda o desenvolvimento de estudos complementares sobre histologia ocular desta espécie.

Diversity of Bacteria at Healthy Human Conjunctiva

Ocular surface (OS) microbiota contributes to infectious and autoimmune diseases of the eye. Comprehensive analysis of microbial diversity at the OS has been impossible because of the limitations of conventional cultivation techniques. This pilot study aimed to explore true diversity of human OS microbiota using DNA sequencing-based detection and identification of bacteria. Composition of the bacterial community was characterized using deep sequencing of the 16S rRNA gene amplicon libraries generated from total conjunctival swab DNA. The DNA sequences were classified and the diversity parameters measured using bioinformatics software ESPRIT and MOTHUR and tools available through the Ribosomal Database Project-II (RDP-II). Deep sequencing of conjunctival rDNA from four subjects yielded a total of 115,003 quality DNA reads, corresponding to 221 species-level phylotypes per subject. The combined bacterial community classified into 5 phyla and 59 distinct genera. However, 31% of all DNA reads belonged to unclassified or novel bacteria. The intersubject variability of individual OS microbiomes was very significant. Regardless, 12 genera-Pseudomonas, Propionibacterium, Bradyrhizobium, Corynebacterium, Acinetobacter, Brevundimonas, Staphylococci, Aquabacterium, Sphingomonas, Streptococcus, Streptophyta, and Methylobacterium-were ubiquitous among the analyzed cohort and represented the putative "core" of conjunctival microbiota. The other 47 genera accounted for <4% of the classified portion of this microbiome. Unexpectedly, healthy conjunctiva contained many genera that are commonly identified as ocular surface pathogens. The first DNA sequencing-based survey of bacterial population at the conjunctiva have revealed an unexpectedly diverse microbial community. All analyzed samples contained ubiquitous (core) genera that included commensal, environmental, and opportunistic pathogenic bacteria.

Fungal microbiota from ocular conjuctiva of clinically healthy horses belonging to the military police cavalry of alagoas.

Normal fungal conjunctiva microbiota of horses remains stable in healthy animals, free from ocular and/or systemic diseases which may, eventually, cause ocular alterations. The knowledge of the fungal microbiota is of great importance due to the reduced number of studies reported in the literature and also to the large occurrence of ocular alterations, mainly keratomycosis, in these animals. The aim of this study was to isolate and to identify the fungi present in the ocular conjunctiva of healthy horses belonging to the Military Police Cavalry of Alagoas. Samples from both conjunctival sacks from 50 horses were taken using a sterile swab and submitted to fungal cultures. These samples were seeded by radial spreading of the swabs on the Sabouraud agar surface with chloramphenicol, at a concentration of 50mg/L, in Petri dishes. Next, dishes were incubated at room temperature (± 28°C) for 15 days. Horses conjunctival fungal microbiota was found to be composed by Aspergillus spp. (62%), Microsporum gypseum (6%), Penicillium spp. (6%), Curvularia spp. (5%), Candida spp. (3%), Fusarium spp. (3%), Acremonium spp. (2%), Bipolaris sp. (1%), Cladosporium sp. (1%), Chrysosporium sp. (1%), Rhodotorula sp. (1%), Aureobasidium sp. (1%) and Scopulariopsis sp. (1%). There is a wide variety of yeast-like and filamentous fungi colonizing the clinically healthy horses’ ocular conjunctiva, out of which Aspergillus sp. is predominant. Although this was a straightforward study and have not recorded any ocular lesions that suggest fungi infections, these fungi might eventually be involved in this type of ocular pathology for the studied species.

The chinchilla eye: morphologic observations, echobiometric findings and reference values for selected ophthalmic diagnostic tests

To carry out a descriptive investigation into the most relevant morphological features of the chinchilla eye and bony orbit, as well as to perform selected ophthalmic diagnostic tests with the aim of establishing normal anatomic and physiologic references for this species. A total of 57 healthy, chinchillas were used to test most of the parameters in this investigation. Besides morphologic observations of the globe and adnexa, selected ocular tests and parameters were investigated, including blink frequency, palpebral fissure length (PFL), Schirmer tear test (STT), esthesiometry, intraocular pressure (IOP), central corneal thickness (CCT), B-mode echobiometric measurements of the globe and culture of the normal conjunctival bacterial microbiota. Morphologic observations were made using six formalin-fixed globes and four macerated skulls. Normal parameters found for selected ocular diagnostic tests were: blink frequency: 2.6 ± 0.84 blinks per 10 min; STT: 1.07 ± 0.54 mm; esthesiometry: 1.24 ± 0.46 cm; IOP: 17.71 ± 4.17 mmHg; CCT: 0.34 ± 0.03 mm; PFL: 1.44 ± 0.11 cm; anterior chamber depth: 2.01 ± 0.2 mm; axial lens thickness: 5.49 ± 0.43 mm; vitreous chamber depth (internal): 3.69 ± 0.52 mm; axial globe length: 1.14 ± 0.07 cm. The most frequent bacteria isolated from the conjunctiva were Streptococcus sp. (27.45%), Staphylococcus aureus (23.52%) and coagulase-negative Staphylococcus (19.60%). No statistically significant differences between left or right eyes or genders were found for any of the results. Reference data and morphologic observations obtained in this investigation will help veterinary ophthalmologists to recognize unique morphological features and more accurately diagnose ocular diseases in the chinchilla, an animal already being used as a biological model for ophthalmic studies.

Microbiota bacteriana da conjuntiva no pré-operatório de injeção intravítrea de antiangiogênico por degeneração macular relacionada à idade comparada com a de cirurgia de catarata

To evaluate the conjunctival bacterial microbiota and antibiogram profile in the preoperative of antiangiogenic intravitreous injection for age-related macular degeneration, and compare to the preoperative microbiota of patients submitted to cataract surgery.Cross-sectional, observational, case series study. Two groups were organized: group I (macular degeneration) with 26 eyes from 26 patients (12 men/14 women) with mean age of 69.2 +/- 11.5 years; group II (cataract) with 27 eyes from 27 patients (9 men/18 women) with mean age of 67.6 +/- 7.9 years. The groups were similar regarding age (p=0.538) and gender (p=0.787). The lower conjunctival sac was swabbed and the obtained material was immediately put in a tube filled with liquid culture media BHI ("brain heart infusion"). Samples were processed according to standard laboratory techniques and antibiogram was determined for each bacterial colony.Twenty-six bacterial colonies growth in group I, with 2 eyes showing no growth and 30 colonies growth in group II. Gram positive bacteria were more prevalent in both groups: 23/26 colonies (88.4%) in group I and 29/30 colonies (96.7%) in group II, with a Staphylococcus aureus predominance in both groups, with 16 samples (61.5%) and 17 (56.7%), respectively. Coagulase negative Staphylococcus was the second most common identified bacteria, with 19.2% in group I and 20.0% in group II. No differences between the groups reached statistical significance. No statistically significant difference was noted on the antibiotic sensibility between both groups.There was no difference in the distribution of bacteria and antibiogram profile of the conjunctival microbiota in the preoperative of intravitreous injection of antiangiogenic for macular degeneration compared to the preoperative of cataract surgery.