Microbial profile and antibiotic susceptibility of culture-positive bacterial endophthalmitis.

PURPOSE: To assess the distribution of microorganisms isolated from patients with bacterial endophthalmitis and their antimicrobial susceptibility. METHODS: Retrospective analysis of medical and microbiological records of patients with suspected diagnosis of endophthalmitis. The following information was assessed: number of presumed and culture-positive endophthalmitis cases, source of infection, microbiological result (aqueous and/or vitreous culture and Gram staining), microbial characterization and distribution, and antimicrobial susceptibility. RESULTS: A total of 107 (46%) of 231 patients with bacterial endophthalmitis showed positive results by gram stain or culture. Of these, 97 (42%) patients were positive for culture only. Most of them (62%) were secondary to a surgical procedure (postoperative), 12% were posttraumatic and 26% were secondary to an unknown source or the data were unavailable. A total of 100 microorganisms were isolated (38 aqueous and 67 vitreous samples) from the 97 culture-positive cases (91% were gram-positive and 9% were gram-negative). Coagulase-negative Staphylococcus(CoNS) (48%) were the most frequently isolated, followed by Stretococcus viridans(18%), and Staphylococcus aureus(13%). The antimicrobial susceptibility for CoNS was as follows: amikacin-91.6%, cephalothin-97.9%, ceftriaxone-50%, ciprofloxacin-62.5%, chloramphenicol-91.8%, gatifloxacin-79.5%, gentamicin-72.9%, moxifloxacin-89.5%, ofloxacin-70.8%, oxacillin-58.3%, penicillin-33.3%, tobramycin-85.4%, and vancomycin-100%. CONCLUSION: Gram-positive bacteria were the major causes of infectious endophthalmitis in this large series, usually following surgery. CoNS was the most common isolate. Of interest, susceptibility to oxacillin and fourth-generation quinolones was lower than previously published.

Quantitative evaluation of experimental choroidal neovascularization by confocal scanning laser ophthalmoscopy: fluorescein angiogram parallels heparan sulfate proteoglycan expression

The objective of the present study was to develop a quantitative method to evaluate laser-induced choroidal neovascularization (CNV) in a rat model using Heidelberg Retina Angiograph 2 (HRA2) imaging. The expression of two heparan sulfate proteoglycans (HSPG) related to inflammation and angiogenesis was also investigated. CNV lesions were induced with argon laser in 21 heterozygous Zucker rats and after three weeks a fluorescein angiogram and autofluorescence exams were performed using HRA2. The area and greatest linear dimension were measured by two observers not aware of the protocol. Bland-Altman plots showed agreement between the observers, suggesting that the technique was reproducible. After fluorescein angiogram, HSPG (perlecan and syndecan-4) were analyzed by real-time RT-PCR and immunohistochemistry. There was a significant increase in the expression of perlecan and syndecan-4 (P < 0.0001) in retinas bearing CNV lesions compared to control retinas. The expression of these two HSPG increased with increasing CNV area. Immunohistochemistry demonstrated that the rat retina damaged with laser shots presented increased expression of perlecan and syndecan-4. Moreover, we observed that the overexpression occurred in the outer layer of the retina, which is related to choroidal damage. It was possible to develop a standardized quantitative method to evaluate CNV in a rat model using HRA2. In addition, we presented data indicating that the expression of HSPG parallels the area of CNV lesion. The understanding of these events offers opportunities for studies of new therapeutic interventions targeting these HSPG.

Quantitative evaluation of experimental choroidal neovascularization by confocal scanning laser ophthalmoscopy: fluorescein angiogram parallels heparan sulfate proteoglycan expression.

The objective of the present study was to develop a quantitative method to evaluate laser-induced choroidal neovascularization (CNV) in a rat model using Heidelberg Retina Angiograph 2 (HRA2) imaging. The expression of two heparan sulfate proteoglycans (HSPG) related to inflammation and angiogenesis was also investigated. CNV lesions were induced with argon laser in 21 heterozygous Zucker rats and after three weeks a fluorescein angiogram and autofluorescence exams were performed using HRA2. The area and greatest linear dimension were measured by two observers not aware of the protocol. Bland-Altman plots showed agreement between the observers, suggesting that the technique was reproducible. After fluorescein angiogram, HSPG (perlecan and syndecan-4) were analyzed by real-time RT-PCR and immunohistochemistry. There was a significant increase in the expression of perlecan and syndecan-4 (P < 0.0001) in retinas bearing CNV lesions compared to control retinas. The expression of these two HSPG increased with increasing CNV area. Immunohistochemistry demonstrated that the rat retina damaged with laser shots presented increased expression of perlecan and syndecan-4. Moreover, we observed that the overexpression occurred in the outer layer of the retina, which is related to choroidal damage. It was possible to develop a standardized quantitative method to evaluate CNV in a rat model using HRA2. In addition, we presented data indicating that the expression of HSPG parallels the area of CNV lesion. The understanding of these events offers opportunities for studies of new therapeutic interventions targeting these HSPG.

Human immature dental pulp stem cells share key characteristic features with limbal stem cells.

OBJECTIVES: Limbal stem cells (LSC) are self-renewing, highly proliferative cells in vitro, which express a set of specific markers and in vivo have the capacity to reconstruct the entire corneal epithelium in cases of ocular surface injury. Currently, LSC transplantation is a commonly used procedure in patients with either uni- or bilateral total limbal stem cells deficiency (TLSCD). Although LSC transplantation holds great promise for patients, several problems need to be overcome. In order to find an alternative source of cells that can partially substitute LSC in cornea epithelium reconstruction, we aimed at investigating whether human immature dental pulp stem cells (hIDPSC) would present similar key characteristics as LSC and whether they could be used for corneal surface reconstruction in a rabbit TLSCD model. MATERIALS: We used hIDPSC, which co-express mesenchymal and embryonic stem cell markers and present the capacity to differentiate into derivative cells of the three germinal layers. TLSCD was induced by chemical burn in one eye of rabbits. After 30 days, the opaque tissue formed was removed by superficial keratectomy. Experimental group received undifferentiated hIDPSC, while control group only received amniotic membrane (AM). Both groups were sacrificed after 3 months. RESULTS AND CONCLUSIONS: We have demonstrated, using immunohistochemistry and reverse transcription-polymerase chain reaction, that hIDPSCs express markers in common with LSC, such as ABCG2, integrin beta1, vimentin, p63, connexin 43 and cytokeratins 3/12. They were also capable of reconstructing the eye surface after induction of unilateral TLSCD in rabbits, as shown by morphological and immunohistochemical analysis using human-specific antibodies against limbal and corneal epithelium. Our data suggest that hIDPSCs share similar characteristics with LSC and might be used as a potential alternative source of cells for corneal reconstruction.

Staphylococcus aureus e estafilococos coagulase negativosresistentes à vancomicina em um Hospital Universitário Brasileiro / Vancomycin-resistant Staphylococcus aureus and coagulase-negative staphylococci in a Brazilian University Hospital

Infecções hospitalares por Methicillin-Resistant S. aureus (MRSA) e Methicillin-Resistant Coagulase-Negative Staphylococci (MRCoNS) estão entre as mais frequentes mundialmente, justificando um aumento significativo no uso de vancomicina. Com o objetivo de avaliar a presença de estafilococos resistentes aos glicopeptídeos em pacientes em uso terapêutico desse antimicrobiano, internados no Hospital de Clínicas da Universidade Federal de Uberlândia, Uberlândia MG, foi realizado um estudo longitudinal prospectivo incluindo 41 pacientes, 21 adultos e 20 crianças, entre dezembro de 2000 e março de 2002. O monitoramento microbiológico foi realizado por meio de swabs coletados a partir da cavidade bucal e reto e cultivo primário em Ágar Manitol Salgado acrescido de 6 mg/mL de oxacilina. Amostras selecionadas foram testadas quanto à sensibilidade aos glicopeptídeos pelas técnicas de gel difusão e diluição em ágar e a análise de heterorresistência, pela semeadura utilizando inóculo correspondente à escala 0,5 de McFarland (108 UFC/mL) e análise do perfil populacional. Um único paciente, nefropata em programa de hemodiálise apresentou-se colonizado com uma amostra do fenótipo Vancomycin-Intermediate S. aureus (VISA) (CIM = 8 miug/mL) e em doze, foram isoladas amostras de estafilococos heterorresistentes, correspondendo oito hVISA e quatro hVICoNS. O estudo do perfil populacional, confirmou a presença de subpopulações de células resistentes, sendo seis hVISA e duas hVICoNS. A presença de amostras heterorresistentes à vancomicina pode representar um risco potencial no futuro.

Methicillin-resistant Staphylococcus aureus (MRSA) and Methicillin-resistant Coagulase-negative Staphylococci (MRCoNS) are among the most frequent hospital infections around the world, and are associated with a significant rise in the use of vancomycin. In order to assess the presence of staphylococci resistant to glycopeptides in patients taking this antibiotic in Uberlândia Federal University Hospital, Uberlândia (MG, Brazil), a prospective longitudinal study of 41 patients (21 adults and 20 children) was performed between December 2000 and March 2002. Microbiological monitoring was carried out by means of swabs collected from the oral cavity and rectum, screened by culturing in Salt Mannitol Agar plus 6 ?g/mL oxacillin. Selected samples were tested for susceptibility to glycopeptides, by the techniques of gel diffusion and dilution in agar, and for heteroresistance, by seeding with an inoculum at a density of 0.5 on the McFarland scale (108 CFU/mL) and performing a population analysis profile (PAP). A single nephropathy patient was colonized with a strain of vancomycin intermediate S. aureus (VISA) phenotype (MIC = 8 miug/mL). In twelve patients, heteroresistant staphylococci were isolated, corresponding to eight hVISA and four hVICoNS. The PAP study confirmed the presence of six hVISA and two hVICoNS. The presence of heteroresistant vancomycin samples may pose a potential risk in the future.

Acute endophthalmitis following intravitreal bevacizumab (Avastin) injection.

PURPOSE: To report two cases of acute endophthalmitis following intravitreal bevacizumab injection. METHODS: Two patients with exudative age-related macular degeneration were treated sequentially with an intravitreal injection of bevacizumab and developed signs of severe but painless infectious endophthalmitis 2 days later. Vitreous samples were obtained, followed by the injection of vancomycin 1 mg/0.1 ml and ceftazidime 2.25 mg/0.1 ml. Pulsed-field gel electrophoresis (PFGE) was used to determine whether the isolated microorganisms were the same. RESULTS: Coagulase-negative staphylococci were identified and isolated from the vitreous specimen of both patients. PFGE revealed different patterns of banding, excluding that interpatient contamination occured. CONCLUSIONS: Infectious endophthalmitis is a potential complication of intravitreal bevacizumab injection.

Hospital surface contamination in wards occupied by patients infected with MRSA or MSSA in a Brazilian university hospital

The hospital environment, especially surfaces, represents a secondary reservoir for pathogens such as Staphylococcus aureus. The present study was carried out at the Hospital de Clínicas da Universidade Federal de Uberlândia (HC-UFU) in Brazil, from January to August 2004, with the aim of qualitatively and quantitatively assessing the presence of S. aureus on surfaces touched by hands (bed rail, bedside table and door handle), on the floor and in the air, in wards where the patients were infected or not infected with this organism. Twenty-six wards with at least one infected patient and 26 wards with uninfected patients were investigated. Surfaces and air were sampled during bedmaking, by means of sterile 10cm2 adhesive tapes and 90mm-diameter exposed culture plates, respectively. Cultures were carried out on Egg Yolk Salt Agar, containing 7.5% NaCl and 1% egg yolk, and colonies identified by lecithinase and coagulase tests and Gramstain. About 50% of the wards were S. aureus contaminated, without significant differences between the groups (46.1% in the infected patient wards versus 53.8% in controls); the correlation between counts of the pathogen on the surfaces and in the air was 66.7%. Inspite of the fact that these bacteria were frequently present in the assessed wards, the microbial density waslow (less than 1 CFU/cm2). The association between environmental contamination and the epidemiology of S. aureus nosocomial infections is complex and thus further investigations are needed to reach a better understanding of this relationship.

Effect of the aqueous extract of Hyptis pectinata on liver mitochondrial respiration.

Some studies have indicated that mitochondria may be the target organelle of plants. We therefore decided to assess the effects of the aqueous extract of Hyptis pectinata leaves on liver mitochondrial respiratory function in vitro. Eight rat livers were subjected to isolation of mitochondria by differential centrifugation. In an adequate medium, the plant extract was added at different concentrations. The analyzed data were: state 3, state 4 and respiratory control ratio (RCR). H. pectinata extract caused a statistically significant decrease in state 3 (at 0.05, 0.1 and 0.2 mg/mg protein) and RCR (at 0.05, 0.1 and 0.2 mg/mg protein). Respiratory state 4 was not altered by the increasing concentrations. In conclusion, the aqueous extract of H. pectinata leaves may not injure the mitochondrial inner membrane but decreases significantly the oxidative phosphorylation.

Efeitos do extrato aquoso da hyptis pectinata sobre a regeneraçäo hepática após hepatectomia parcial de 70 por cento: resultados preliminares / Effects of the aqueous extract of hyptis pectinata on liver regeneration after 70 percent partial hepatectomy: preliminary results

O uso de plantas medicinais tem aumentado bastante na populaçäo mundial. O objetivo desta pesquisa é avaliar os efeitos do extrato aquoso das folhas da Hyptis pectinata, popularmente conhecida como "sambacaitá" ou "canudinho", sobre a regeneraçäo hepática após hepatectomia parcial de 70 por cento. Foram utilizados 24 ratos, divididos em 4 grupos: grupo OS, em que se realizou operaçäo simulada e aplicaçäo oral de água destilada por 4 dias; grupo OSD200, também submetido à laparotomia com manipulaçäo do fígado e aplicaçäo de 200 mg de extrato/Kg de animal durante o mesmo período; grupo HP, hepatectomizado a 70 por cento após 4 dias de aplicaçäo por via oral de água destilada; e grupo HPD200, hepatectomizado a 70 por cento após 4 dias de administraçäo de 200 mg extrato/Kg de animal. Foram dosadas fosfatase alcalina, bilirrubina total e as aminotransferases e estudou-se o estado III da funçäo mitocondrial. O grupo OSD200, quando comparado ao OS, apresentou reduçäo significativa da fosfatase alcalina. O grupo HPD200, em comparaçäo ao HP, teve reduçäo estatisticamente significativa no nível da AST e do estado III da funçäo mitocondrial.