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1.
Artigo em Inglês | MEDLINE | ID: mdl-31332071

RESUMO

Bacterial keratitis causes significant blindness, yet antimicrobial resistance has rendered current treatments ineffective. Polymyxin B-trimethoprim (PT) plus rifampin has potent in vitro activity against Staphylococcus aureus and Pseudomonas aeruginosa, two important causes of keratitis. Here we further characterize this combination against P. aeruginosa in a murine keratitis model. PT plus rifampin performed comparably to or better than moxifloxacin, the gold standard, suggesting that the combination may be a promising therapy for bacterial keratitis.


Assuntos
Antibacterianos/farmacologia , Infecções Oculares Bacterianas/tratamento farmacológico , Infecções por Pseudomonas/tratamento farmacológico , Pseudomonas aeruginosa/efeitos dos fármacos , Animais , Córnea/efeitos dos fármacos , Córnea/microbiologia , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Quimioterapia Combinada/métodos , Infecções Oculares Bacterianas/microbiologia , Feminino , Ceratite/tratamento farmacológico , Ceratite/microbiologia , Camundongos , Camundongos Endogâmicos C57BL , Testes de Sensibilidade Microbiana/métodos , Polimixina B/farmacologia , Rifampina/farmacologia , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/efeitos dos fármacos , Trimetoprima/farmacologia
2.
Artigo em Inglês | MEDLINE | ID: mdl-30420484

RESUMO

Staphylococcus aureus and Pseudomonas aeruginosa are two of the most common causes of bacterial keratitis and corresponding corneal blindness. Accordingly, such infections are predominantly treated with broad-spectrum fluoroquinolones, such as moxifloxacin. Yet, the rising fluoroquinolone resistance has necessitated the development of alternative therapeutic options. Herein, we describe the development of a polymyxin B-trimethoprim (PT) ophthalmic formulation containing the antibiotic rifampin, which exhibits synergistic antimicrobial activity toward a panel of contemporary ocular clinical S. aureus and P. aeruginosa isolates, low spontaneous resistance frequency, and in vitro bactericidal kinetics and antibiofilm activities equaling or exceeding the antimicrobial properties of moxifloxacin. The PT plus rifampin combination also demonstrated increased efficacy in comparison to those of either commercial PT or moxifloxacin in a murine keratitis model of infection, resulting in bacterial clearance of 70% in the animals treated. These results suggest that the combination of PT and rifampin may represent a novel antimicrobial agent in the treatment of bacterial keratitis.


Assuntos
Antibacterianos/farmacologia , Infecções Oculares Bacterianas/tratamento farmacológico , Ceratite/tratamento farmacológico , Polimixina B/farmacologia , Infecções por Pseudomonas/tratamento farmacológico , Rifampina/farmacologia , Infecções Estafilocócicas/tratamento farmacológico , Trimetoprima/farmacologia , Animais , Córnea/efeitos dos fármacos , Córnea/microbiologia , Córnea/patologia , Modelos Animais de Doenças , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Sinergismo Farmacológico , Quimioterapia Combinada , Infecções Oculares Bacterianas/microbiologia , Infecções Oculares Bacterianas/patologia , Feminino , Humanos , Ceratite/microbiologia , Ceratite/patologia , Camundongos , Camundongos Endogâmicos BALB C , Moxifloxacina/farmacologia , Soluções Oftálmicas/farmacologia , Infecções por Pseudomonas/microbiologia , Infecções por Pseudomonas/patologia , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/crescimento & desenvolvimento , Pseudomonas aeruginosa/patogenicidade , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/patologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento , Staphylococcus aureus/patogenicidade , Resultado do Tratamento
3.
Cornea ; 43(8): 1044-1048, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-38537125

RESUMO

PURPOSE: Antimicrobial resistance is a global health threat, compounded by the reduction in the discovery of new antibiotics. A repurposed drugs-based approach could provide a viable alternative for the treatment of multidrug-resistant (MDR) bacterial infections. In this study, we sought to evaluate the in vitro efficacy of a novel drug combination, polymyxin B/trimethoprim (PT) + rifampin on MDR isolates from patients with bacterial keratitis in India. METHODS: Forty-three isolates, which included 20 Staphylococcus aureus , 19 Pseudomonas aeruginosa , 3 Pseudomonas stutzeri , and 1 Acinetobacter baumannii , were evaluated for their antibiotic resistance by minimum inhibitory concentration (MIC). Fractional Inhibitory Concentration Index (FICI) testing was performed to measure the antimicrobial impact of PT + rifampin in combination. RESULTS: Among S. aureus isolates, 100% were resistant to at least 1 antibiotic class, 12 (60%) were MDR, and 14 (70%) were classified as methicillin-resistant. Among the gram-negative isolates, >90% were classified as MDR. Fractional Inhibitory Concentration (FIC) testing revealed that PT + rifampin was effective in completely inhibiting growth of all isolates while also displaying additive or synergistic activity in approximately 70% of the strains. Mean FICI values were 0.753 ± 0.311 and 0.791 ± 0.369 for S. aureus and gram-negative isolates, respectively, and a >2-fold reduction in MIC was measured for both PT and rifampin when tested in combination versus alone. CONCLUSIONS: Our data demonstrate the ability of PT + rifampin to eliminate all isolates tested, even those conferring MDR, highlighting the promise of this drug combination for the treatment of bacterial keratitis.


Assuntos
Antibacterianos , Combinação de Medicamentos , Farmacorresistência Bacteriana Múltipla , Infecções Oculares Bacterianas , Testes de Sensibilidade Microbiana , Polimixina B , Rifampina , Humanos , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Infecções Oculares Bacterianas/microbiologia , Infecções Oculares Bacterianas/tratamento farmacológico , Rifampina/farmacologia , Rifampina/uso terapêutico , Polimixina B/farmacologia , Trimetoprima/farmacologia , Trimetoprima/uso terapêutico , Quimioterapia Combinada
4.
Front Cell Infect Microbiol ; 13: 1250257, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37671149

RESUMO

Bacterial keratitis (bacterial infection of the cornea) is a major cause of vision loss worldwide. Given the rapid and aggressive nature of the disease, immediate broad-spectrum antibiotics are essential to adequately treat this disease. However, rising antibiotic resistance continues to accelerate, rendering many commonly used therapeutics increasingly ineffective. As such, there is a significant effort to understand the basic pathogenesis of common causative organisms implicated in keratitis in part, to fuel the development of novel therapies to treat this blinding disease. This review explores two common causes of bacterial keratitis, Staphylococcus aureus and Pseudomonas aeruginosa, with regards to the bacterial mediators of virulence as well as novel therapies on the horizon.


Assuntos
Infecções Oculares Bacterianas , Ceratite , Infecções por Pseudomonas , Infecções Estafilocócicas , Humanos , Staphylococcus aureus , Pseudomonas aeruginosa
5.
Cornea ; 42(12): 1555-1561, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-37106486

RESUMO

PURPOSE: Infectious keratitis is a serious disease requiring immediate, intensive, and broad-spectrum empiric treatment to prevent vision loss. Given the diversity of organisms that can cause serious corneal disease, current guidelines recommend treatment with several antimicrobial agents simultaneously to provide adequate coverage while awaiting results of microbiology cultures. However, it is currently unknown how the use of multiple ophthalmic antimicrobial agents in combination may affect the efficacy of individual drugs. METHODS: Using a panel of 9 ophthalmic antibiotics, 3 antifungal agents, and 2 antiacanthamoeba therapeutics, fractional inhibitory concentration testing in the standard checkerboard format was used to study 36 antibiotic-antibiotic combinations, 27 antibiotic-antifungal combinations, and 18 antibiotic-antiacanthamoeba combinations against both Staphylococcus aureus and Pseudomonas aeruginosa for synergistic, additive, neutral, or antagonistic drug-drug interactions. RESULTS: We demonstrate that while most combinations resulted in no change in antimicrobial efficacy of individual components, the combination of erythromycin + polyhexamethylene biguanide was found to be antagonistic toward P. aeruginosa . Conversely, 18 combinations toward S. aureus and 15 combinations toward P. aeruginosa resulted in additive or synergistic activity, including 4 with improved activity toward both species. CONCLUSIONS: Understanding how drug-drug interactions may affect drug efficacy is critical to selecting the appropriate combination therapy and improving clinical outcomes of this blinding disease.


Assuntos
Anti-Infecciosos , Ceratite , Humanos , Staphylococcus aureus , Sinergismo Farmacológico , Antibacterianos/uso terapêutico , Anti-Infecciosos/uso terapêutico , Ceratite/microbiologia , Interações Medicamentosas , Testes de Sensibilidade Microbiana , Pseudomonas aeruginosa
6.
Front Ophthalmol (Lausanne) ; 3: 1192019, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38983018

RESUMO

Hydroxychloroquine (HCQ) is a commonly used medication for its immunosuppressive and dermatologic effects. It has known ocular side effects, which include retinopathy, corneal deposits, and choroidal thinning. Herein, we report the first known case of HCQ-induced hyperpigmentation of the sclera. A 75-year-old female presented after 10 months of gradual progression of painless blue-gray discoloration of the bilateral sclera, fingernails, and lower extremities secondary to oral HCQ therapy. Cessation of the drug led to a partial reversal of the hyperpigmentation at 5 months, further supporting HCQ as the causative agent. Hyperpigmentation reactions can be distressing to patients and lead to decreased medication adherence; given the widespread use of HCQ, it is important to increase awareness of this potential drug reaction.

7.
Invest Ophthalmol Vis Sci ; 64(5): 5, 2023 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-37133835

RESUMO

Purpose: Staphylococcus aureus is an important cause of corneal infections (keratitis). To better understand the virulence mechanisms mediating keratitis, a recent comparative genomics study revealed that a set of secreted enterotoxins were found with higher prevalence among ocular versus non-ocular S. aureus clinical infection isolates, suggesting a key role for these toxins in keratitis. Although well known to cause toxic shock syndrome and S. aureus food poisoning, enterotoxins have not yet been shown to mediate virulence in keratitis. Methods: A set of clinical isolate test strains, including a keratitis isolate that encodes five enterotoxins (sed, sej, sek, seq, ser), its corresponding enterotoxin deletion mutant and complementation strain, a keratitis isolate devoid of enterotoxins, and the non-ocular S. aureus strain USA300 along with its corresponding enterotoxin deletion and complementation strains, were evaluated for cellular adhesion, invasion and cytotoxicity in a primary corneal epithelial model as well as with microscopy. Additionally, strains were evaluated in an in vivo model of keratitis to quantify enterotoxin gene expression and measure disease severity. Results: We demonstrate that, although enterotoxins do not impact bacterial adhesion or invasion, they do elicit direct cytotoxicity in vitro toward corneal epithelial cells. In an in vivo model, sed, sej, sek, seq, ser were found to have variable gene expression across 72 hours of infection and test strains encoding enterotoxins resulted in increased bacterial burden as well as a reduced host cytokine response. Conclusions: Our results support a novel role for staphylococcal enterotoxins in promoting virulence in S. aureus keratitis.


Assuntos
Enterotoxinas , Ceratite , Infecções Estafilocócicas , Staphylococcus aureus , Humanos , Enterotoxinas/genética , Enterotoxinas/metabolismo , Ceratite/virologia , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/genética , Staphylococcus aureus/patogenicidade , Virulência
8.
PLoS Genet ; 5(3): e1000439, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19325886

RESUMO

SXT is an integrative and conjugative element (ICE) that confers resistance to multiple antibiotics upon many clinical isolates of Vibrio cholerae. In most cells, this approximately 100 Kb element is integrated into the host genome in a site-specific fashion; however, SXT can excise to form an extrachromosomal circle that is thought to be the substrate for conjugative transfer. Daughter cells lacking SXT can theoretically arise if cell division occurs prior to the element's reintegration. Even though approximately 2% of SXT-bearing cells contain the excised form of the ICE, cells that have lost the element have not been detected. Here, using a positive selection-based system, SXT loss was detected rarely at a frequency of approximately 1 x 10(-7). As expected, excision appears necessary for loss, and factors influencing the frequency of excision altered the frequency of SXT loss. We screened the entire 100 kb SXT genome and identified two genes within SXT, now designated mosA and mosT (for maintenance of SXT Antitoxin and Toxin), that promote SXT stability. These two genes, which lack similarity to any previously characterized genes, encode a novel toxin-antitoxin pair; expression of mosT greatly impaired cell growth and mosA expression ameliorated MosT toxicity. Factors that promote SXT excision upregulate mosAT expression. Thus, when the element is extrachromosomal and vulnerable to loss, SXT activates a TA module to minimize the formation of SXT-free cells.


Assuntos
Antitoxinas/genética , Toxinas Bacterianas/genética , Resistência Microbiana a Medicamentos/genética , Escherichia coli , Genes Bacterianos , Genoma Bacteriano , Vibrio cholerae
9.
PLoS Genet ; 5(12): e1000786, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20041216

RESUMO

Integrating and conjugative elements (ICEs) are one of the three principal types of self-transmissible mobile genetic elements in bacteria. ICEs, like plasmids, transfer via conjugation; but unlike plasmids and similar to many phages, these elements integrate into and replicate along with the host chromosome. Members of the SXT/R391 family of ICEs have been isolated from several species of gram-negative bacteria, including Vibrio cholerae, the cause of cholera, where they have been important vectors for disseminating genes conferring resistance to antibiotics. Here we developed a plasmid-based system to capture and isolate SXT/R391 ICEs for sequencing. Comparative analyses of the genomes of 13 SXT/R391 ICEs derived from diverse hosts and locations revealed that they contain 52 perfectly syntenic and nearly identical core genes that serve as a scaffold capable of mobilizing an array of variable DNA. Furthermore, selection pressure to maintain ICE mobility appears to have restricted insertions of variable DNA into intergenic sites that do not interrupt core functions. The variable genes confer diverse element-specific phenotypes, such as resistance to antibiotics. Functional analysis of a set of deletion mutants revealed that less than half of the conserved core genes are required for ICE mobility; the functions of most of the dispensable core genes are unknown. Several lines of evidence suggest that there has been extensive recombination between SXT/R391 ICEs, resulting in re-assortment of their respective variable gene content. Furthermore, our analyses suggest that there may be a network of phylogenetic relationships among sequences found in all types of mobile genetic elements.


Assuntos
Conjugação Genética , Evolução Molecular , Genômica , Sequências Repetitivas Dispersas/genética , Sequência de Bases , Sequência Conservada , DNA Bacteriano/genética , Genes Bacterianos/genética , Variação Genética , Dados de Sequência Molecular , Filogenia , Plasmídeos/genética , Vibrio/genética
10.
Am J Ophthalmol Case Rep ; 26: 101561, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35535133

RESUMO

Purpose: PVC is a synthetic plastic polymer used worldwide for a wide range of applications. While it is often associated with ocular trauma, little is known regarding how PVC may interact with ocular tissues. Herein we report the clinical course of a patient with polyvinyl chloride (PVC) embedded in the cornea after a projectile injury, utilizing anterior segment optical tomography to study the relative antigenicity and reactivity of this industrial material in the cornea. Observations: A 29-year-old male presented with acute, unilateral vision loss in the left eye following ocular trauma while working with PVC. On exam, he had a near full-thickness corneal laceration with multiple small fragments of PVC in the corneal stroma. Given the small size and depth of the fragments, the patient was medically managed with close follow-up. After 6 days, his visual acuity returned to baseline and the corneal laceration was found to be well healed. Anterior OCT imaging identified discrete, individual fragments and there was no associated inflammatory response. At 3 months, the patient continued to do well with no signs of ocular inflammation. Conclusions and Importance: PVC is a commonly used plastic in workplace settings that pose a risk for projectile injuries to the eye. This case highlights that at least in the short-term, PVC appears to be inert in the corneal stroma, allowing for medical management and close follow-up, rather than surgical removal.

11.
Case Rep Ophthalmol ; 13(2): 550-555, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36160482

RESUMO

Bacterial keratitis (corneal infection) caused by more than one organism is rare and exceedingly difficult to treat due to variable antibiotic susceptibilities. Intrastromal injections of antibiotics may be necessary to achieve higher drug concentrations at the site of infection, particularly in the case of deep stromal disease refractory to topical therapy. However, while this approach is increasingly used for fungal keratitis, there is a paucity of the literature regarding the use of intrastromal antibiotics bacterial keratitis. In the current case, an 86-year-old patient presented with a left corneal ulcer with corresponding microbiologic cultures positive for Staphylococcus epidermidis, Staphylococcus aureus, and Achromobacter species. The ulcer continued to progress despite maximal topical antibiotic treatment yet demonstrated marked improvement after two intrastromal injections of moxifloxacin administered 2 weeks apart. Polymicrobial keratitis can be particularly challenging to eradicate despite maximal topical antibiotic therapeutics. Intrastromal corneal injections provide a mechanism for drug delivery directly to the site of infection and thus may represent an important alternative in refractory cases.

12.
Transl Vis Sci Technol ; 11(5): 26, 2022 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-35612831

RESUMO

Purpose: Pseudomonas aeruginosa is a leading cause of corneal infections. Recently, we discovered an antimicrobial drug combination, polymyxin B/trimethoprim (PT) + rifampin, that displayed impressive efficacy toward P. aeruginosa in both in vitro and in vivo studies. As such, this combination was further evaluated as a potential keratitis therapeutic through testing the combination's efficacy against a diverse set of P. aeruginosa clinical isolates. Methods: Minimum inhibitory concentrations (MICs) of moxifloxacin, levofloxacin, erythromycin, tobramycin, PT, polymyxin B (alone), trimethoprim (alone), and rifampin were determined for 154 ocular clinical P. aeruginosa isolates, 90% of which were derived from corneal scrapings. Additionally, the efficacy of PT + rifampin was evaluated utilizing fractional inhibitory concentration (FIC) testing. Results: While 100% of isolates were resistant to erythromycin (average MIC 224 ± 110 µg·mL-1) and trimethoprim (alone) (206 ± 67.3 µg·mL-1), antibiotic resistance was generally found to be low: moxifloxacin (2% of isolates resistant; average MIC 1.08 ± 1.61 µg·mL-1), levofloxacin (3.9%; 1.02 ± 2.96 µg·mL-1), tobramycin (1%; 0.319 ± 1.31 µg·mL-1), polymyxin B (0%; 0.539 ± 0.206 µg·mL-1), PT (0%; 0.416 ± 0.135 µg·mL-1), and rifampin (0%; 23.4 ± 6.86 µg·mL-1). Additionally, FIC testing revealed that PT + rifampin eradicated 100% of isolates demonstrating additive or synergistic activity in 95% of isolates (average FIC index 0.701 ± 0.132). Conclusions: The drug combination of PT + rifampin was effective against a large panel of clinically relevant P. aeruginosa strains and, as such, may represent a promising therapeutic for P. aeruginosa keratitis. Translational Relevance: This work furthers the preclinical development of a novel antibiotic combination for the treatment of corneal infections (bacterial keratitis).


Assuntos
Ceratite , Infecções por Pseudomonas , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Bacitracina/farmacologia , Bacitracina/uso terapêutico , Combinação de Medicamentos , Eritromicina/farmacologia , Eritromicina/uso terapêutico , Framicetina/farmacologia , Framicetina/uso terapêutico , Humanos , Ceratite/tratamento farmacológico , Ceratite/microbiologia , Levofloxacino/farmacologia , Levofloxacino/uso terapêutico , Moxifloxacina/farmacologia , Moxifloxacina/uso terapêutico , Polimixina B/farmacologia , Polimixina B/uso terapêutico , Infecções por Pseudomonas/tratamento farmacológico , Infecções por Pseudomonas/microbiologia , Pseudomonas aeruginosa , Rifampina/farmacologia , Rifampina/uso terapêutico , Tobramicina/farmacologia , Tobramicina/uso terapêutico , Trimetoprima/farmacologia , Trimetoprima/uso terapêutico
13.
Transl Vis Sci Technol ; 11(11): 12, 2022 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-36383392

RESUMO

Purpose: Bacterial keratitis (BK) severity in murine models has traditionally been measured by subjective clinical grading or quantification of ocular bacterial burden. This investigation explores an objective and repeatable quantification of slit lamp photography (SLP) images to measure BK severity. Methods: BALB/c strain mice underwent three parallel scratches of the right cornea with subsequent inoculation of 107Staphylococcus aureus cells. SLP imaging and clinical severity grading were performed at 48 hours post-infection. Stromal infiltrate (SI) area on SLP images were quantified. Bacterial burden was determined after enucleation and homogenization. Spearman rank correlations (rs) were used to estimate associations between SI area, clinical severity grades, and bacterial burden. Results: BALB/c strain mice (n = 14) were evaluated with an average SI area of 0.92 mm2 (standard deviation, SD = 0.65) and average bacterial burden of 3.16 × 105 colony forming units per milliliter (CFU/mL) (SD = 8.3 × 105). Clinical severity grade positively correlated with SI area (rs = 0.59, p = 0.0276) and bacterial burden (rs = 0.66, p = 0.0106). There was a trend towards positive association between SI area and bacterial burden (rs = 0.51, p = 0.0543). Conclusions: SLP annotation of SI area is correlated with clinical severity and may provide an objective, quantitative, and repeatable assessment of BK disease severity. Translational Relevance: SLP annotation of SI area is a novel quantitative method to evaluate bacterial keratitis severity longitudinally in mouse models which may be a powerful tool to better understand BK pathogenesis and response to treatments.


Assuntos
Infecções Oculares Bacterianas , Ceratite , Infecções Estafilocócicas , Camundongos , Animais , Staphylococcus aureus , Modelos Animais de Doenças , Infecções Estafilocócicas/diagnóstico por imagem , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/patologia , Contagem de Colônia Microbiana , Ceratite/diagnóstico , Ceratite/microbiologia , Ceratite/patologia , Infecções Oculares Bacterianas/diagnóstico , Infecções Oculares Bacterianas/microbiologia , Infecções Oculares Bacterianas/patologia , Camundongos Endogâmicos BALB C
14.
PLoS One ; 16(5): e0250975, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33939761

RESUMO

Staphylococcus aureus is a major cause of ocular infections, often resulting in devastating vision loss. Despite the significant morbidity associated with these infections, little is yet known regarding the specific strain types that may have a predilection for ocular tissues nor the set of virulence factors that drive its pathogenicity in this specific biological niche. Whole genome sequencing (WGS) can provide valuable insight in this regard by providing a prospective, comprehensive assessment of the strain types and virulence factors driving disease among specific subsets of clinical isolates. As such, a set of 163-member S. aureus ocular clinical strains were sequenced and assessed for both common strain types (multilocus sequence type (MLST), spa, agr) associated with ocular infections as well as the presence/absence of 235 known virulence factors in a high throughput manner. This ocular strain set was then directly compared to a fully sequenced 116-member non-ocular S. aureus strain set curated from NCBI in order to identify key differences between ocular and non-ocular S. aureus isolates. The most common sequence types found among ocular S. aureus isolates were ST5, ST8 and ST30, generally reflecting circulating non-ocular pathogenic S. aureus strains. However, importantly, ocular isolates were found to be significantly enriched for a set of enterotoxins, suggesting a potential role for this class of virulence factors in promoting ocular disease. Further genomic analysis revealed that these enterotoxins are located on mobile pathogenicity islands, thus horizontal gene transfer may promote the acquisition of enterotoxins, potentially amplifying S. aureus virulence in ocular tissues.


Assuntos
Olho/microbiologia , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/genética , Staphylococcus aureus/isolamento & purificação , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Genes Bacterianos/genética , Genômica/métodos , Genótipo , Humanos , Lactente , Recém-Nascido , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Virulência/genética , Fatores de Virulência/genética , Sequenciamento Completo do Genoma/métodos , Adulto Jovem
15.
Am J Ophthalmol Case Rep ; 18: 100713, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32346653

RESUMO

PURPOSE: To describe the corneal findings and management of a 61-year-old female with vortex keratopathy following short term, high dose hydroxychloroquine used in the setting of a clinical trial for recurrent breast cancer. OBSERVATIONS: The patient was found to have significant corneal vortex keratopathy without retinal pathology within 3 months of 1200 mg daily hydroxychloroquine treatment as an adjuvant medication for cancer therapy. Cessation of the medication led to the resolution of the corneal verticillata within 1 month yet the vision did not return to baseline. Ultimately, remaining irregular astigmatism and ocular surface disease required a scleral contact lens to achieve a BSCVA of 20/25 OU. CONCLUSIONS AND IMPORTANCE: Hydroxychloroquine-induced vortex keratopathy is largely considered dose and duration dependent and is uncommon with most standard treatment algorithms. However, with increasing use of high-dose hydroxychloroquine in adjunct cancer therapy, corneal findings are likely to become more frequent. Persistent visual impairment may occur, thus increased understanding of this pathology can aid in counseling patients and guiding treatment recommendations.

16.
Cornea ; 39(11): 1433-1435, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32243416

RESUMO

PURPOSE: To highlight the novel application of anterior segment optical coherence tomography (AS-OCT) to detect corneal silver deposition in a case of ocular argyrosis. METHODS: This is a case report and review of the literature. RESULTS: A 67-year-old man with a 30-year history of chronic occupational exposure to silver-halides secondary to photographic film manufacturing presented with significant ocular argyrosis. His ophthalmic examination was notable for bilateral, widespread pinpoint gray deposits throughout his conjunctiva and cornea at the level of Descemet membrane. Further evaluation with AS-OCT showed deposition in 2 distinct, diffusely hyperreflective bands, corresponding to Bowman layer and Descemet membrane. CONCLUSIONS: AS-OCT provides a useful imaging modality in evaluating corneal deposition diseases. In this case of ocular argyrosis, AS-OCT led to the detection of a hyperreflective Bowman layer and Descemet membrane, representing silver deposition in both these anatomic locations.


Assuntos
Argiria/diagnóstico , Córnea/diagnóstico por imagem , Oftalmopatias/diagnóstico , Tomografia de Coerência Óptica/métodos , Idoso , Humanos , Masculino , Microscopia Confocal
17.
Cornea ; 39(10): 1278-1284, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32639313

RESUMO

PURPOSE: Staphylococcus aureus is a leading cause of keratitis requiring urgent antimicrobial treatment. However, rising antibiotic resistance has rendered current ophthalmic antibiotics increasingly ineffective. First, a diverse, ocular S. aureus strain set was evaluated for resistance to 6 commonly used ophthalmic antibiotics. Next, a recently discovered antimicrobial drug combination containing polymyxin B/trimethoprim (PT) + rifampin that displayed impressive efficacy toward S. aureus in both in vitro and in vivo studies was evaluated as a potential novel keratitis therapeutic through testing this combination's efficacy against the clinical strain set. METHODS: A total of 163 S. aureus isolates were collected either commercially or from the Flaum Eye Institute, University of Rochester. The minimum inhibitory concentrations of moxifloxacin, levofloxacin, vancomycin, erythromycin, tobramycin, rifampin, and PT were determined for the entire strain set to establish the incidence of resistance to current treatment options among a contemporary clinical isolate set and compared with the performance of PT + rifampin. RESULTS: Among all 163 isolates tested, high rates of antibiotic resistance were found toward erythromycin (69% resistance), moxifloxacin (33%), levofloxacin (40%), and tobramycin (17%). Conversely, the entire strain set, including multidrug resistant isolates, was sensitive to PT + rifampin, demonstrating the potency of this combination. CONCLUSIONS: We established that antibiotic resistance is pervasive among clinical S. aureus isolates, underscoring the concern for the effectiveness of current ophthalmic antibiotics. The drug combination of PT + rifampin, however, eradicated 100% of isolates tested, demonstrating the ability to overcome existing circulating resistance factors, and as such, might represent a promising therapeutic for S. aureus keratitis.


Assuntos
Antibacterianos/uso terapêutico , Polimixina B/uso terapêutico , Rifampina/uso terapêutico , Staphylococcus aureus/efeitos dos fármacos , Trimetoprima/uso terapêutico , Administração Oftálmica , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Quimioterapia Combinada , Infecções Oculares Bacterianas/microbiologia , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Soluções Oftálmicas , Staphylococcus aureus/isolamento & purificação , Resultado do Tratamento
18.
J Bacteriol ; 190(9): 3353-61, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18326579

RESUMO

Integrating conjugative elements (ICEs) are self-transmissible mobile elements that transfer between bacteria via conjugation and integrate into the host chromosome. SXT and related ICEs became prevalent in Asian Vibrio cholerae populations in the 1990s and play an important role in the dissemination of antibiotic resistance genes in V. cholerae. Here, we carried out genomic and functional analyses of ICEPdaSpa1, an SXT-related ICE derived from a Spanish isolate of Photobacterium damselae subsp. piscicida, the causative agent of fish pasteurellosis. The approximately 102-kb DNA sequence of ICEPdaSpa1 shows nearly 97% DNA sequence identity to SXT in genes that encode essential ICE functions, including integration and excision, conjugal transfer, and regulation. However, approximately 25 kb of ICEPdaSpa1 DNA, including a tetracycline resistance locus, is not present in SXT. Most ICEPdaSpa1-specific DNA is inserted at loci where other SXT-related ICEs harbor element-specific DNA. ICEPdaSpa1 excises itself from the chromosome and is transmissible to other Photobacterium strains, as well as to Escherichia coli, in which it integrates into prfC. Interestingly, the P. damselae virulence plasmid pPHDP10 could be mobilized from E. coli in an ICEPdaSpa1-dependent fashion via the formation of a cointegrate between pPHDP10 and ICEPdaSpa1. pPHDP10-Cm integrated into ICEPdaSpa1 in a non-site-specific fashion independently of RecA. The ICEPdaSpa1::pPHDP10 cointegrates were stable, and markers from both elements became transmissible at frequencies similar to those observed for the transfer of ICEPdaSpa1 alone. Our findings reveal the plasticity of ICE genomes and demonstrate that ICEs can enable virulence gene transfer.


Assuntos
Conjugação Genética , Doenças dos Peixes/microbiologia , Sequências Repetitivas Dispersas/fisiologia , Infecções por Pasteurella/veterinária , Photobacterium/genética , Plasmídeos/genética , Fatores de Virulência/genética , Animais , Sequência de Bases , Farmacorresistência Bacteriana/genética , Escherichia coli/genética , Ordem dos Genes , Genoma Bacteriano , Genômica , Sequências Repetitivas Dispersas/genética , Dados de Sequência Molecular , Infecções por Pasteurella/microbiologia , Photobacterium/patogenicidade , Análise de Sequência de DNA
20.
Cornea ; 35(7): 1026-8, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27149534

RESUMO

PURPOSE: To describe the complex surgical management and novel medical approach for a keratoprosthesis (KPro Boston type I) in a monocular, 73-year-old patient with ectodermal dysplasia and chronic, noninfectious corneal necrosis. METHODS: Best-corrected visual acuity (BCVA) was measured with Snellen letters. Surgical intervention included an amniotic membrane graft, complete replacement of the KPro, conjunctival flap graft, corneal donor tissue grafts combined with inferior rectus muscle advancement, periosteal tissue graft, tarso-conjunctival flap construction, and symblepharolysis. Infliximab was used as a medical adjunctive therapy. RESULTS: Initial KPro placement provided a BCVA of 20/25 and long-term stability. Subsequent chronic melting at the optic border necessitated numerous surgeries to prevent extrusion and failure. Ultimate fistulization was addressed with the formation of a surgical pocket. The addition of infliximab promoted ocular surface stability, and the patient has maintained a BCVA of 20/80. CONCLUSIONS: Ectodermal dysplasia can result in eyelid and corneal abnormalities, requiring a KPro for visual restoration. In the setting of chronic, sterile corneal melt, novel surgical approaches and the off-label use of infliximab allowed for visual rehabilitation.


Assuntos
Órgãos Artificiais , Bioprótese , Córnea , Opacidade da Córnea/cirurgia , Displasia Ectodérmica/cirurgia , Idoso , Opacidade da Córnea/etiologia , Displasia Ectodérmica/complicações , Feminino , Humanos , Implantação de Prótese , Estudos Retrospectivos , Transtornos da Visão/fisiopatologia , Transtornos da Visão/reabilitação , Acuidade Visual
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