PubMed Health⌕ Search

Biomedical subjects

F Carta

Publications and source records attributed to F Carta.

At least 19 recordsLinked to original sources

Discoid lupus erythematosus of the eyelids associated with staphylococcal blepharitis and Meibomian gland dysfunction.

Lower eyelid involvement occurs in 6% of patients with discoid lupus erythematosus (DLE). Eyelid lesions are rarely the initial manifestation of DLE. We describe a 25-year-old woman presenting with discoid lesions of the lower eyelids, staphylococcal blepharitis and Meibomian gland dysfunction, who later developed a discoid lesion on the chin. Histopathological and immunofluorescence studies of a biopsy specimen from this lesion established the diagnosis of DLE. We are unaware of any previously reported cases of DLE presenting with discoid eyelid lesions associated with staphylococcal blepharitis and Meibomian gland dysfunction. DLE should be considered as a differential diagnosis in chronic blepharitis that persists despite usual medical management and eyelid hygiene. Misdiagnosis may lead to eyelid margin deformities, necessitate a complicated full-thickness biopsy, and delay diagnosis of systemic lupus.

Adult↗

Visual prognosis after indirect traumatic optic neuropathy.

OBJECTIVE: To investigate a possible correlation between final visual acuity and the presence at baseline of various systemic and local (orbital/ocular) signs in patients affected by indirect traumatic optic neuropathy. METHODS: 35 cases of traumatic optic neuropathy were examined retrospectively and 13 variables were tested. Univariate analysis with "no recovery of visual acuity" as the primary outcome was performed. Relative risk (RR) and 95% confidence intervals (CI) were calculated. Fisher's exact test was used for two variables to test differences between proportions. RESULTS: Four variables showed a significantly increased risk for no recovery of visual acuity: presence of blood within the posterior ethmoidal cells (RR = 2.25, 95% CI 1.25 to 4.04); age over 40 years (RR = 1.79, 1.07 to 2.99); loss of consciousness associated with traumatic optic neuropathy (RR = 2.21, 1.17 to 4.16); and absence of recovery after 48 hours of steroid treatment (p < 0.01, Fisher's exact test). Recovery documented at the first follow up visit after treatment was significantly associated with recovery at the last follow up visit (p < 0.01, Fisher's exact test). CONCLUSIONS: These four negative prognostic signs in patients affected by traumatic optic neuropathy may be useful in predicting the visual outcome in patients developing visual loss after head trauma and in deciding on the need for surgical treatment.

Adult↗

Mycoplasma hominis and Trichomonas vaginalis symbiosis: multiplicity of infection and transmissibility of M. hominis to human cells.

We recently reported that most Trichomonas vaginalis isolates cultured in vitro are infected by Mycoplasma hominis. In this work, we have characterized some aspects of the relationships between the two microorganisms. PCR, cultivation, and immunological methods revealed that the number of M. hominis organisms carried by T. vaginalis in culture varied from isolate to isolate, suggesting a specific multiplicity of infection. Moreover, infected T. vaginalis isolates were able to pass bacteria not only to M. hominis-free protozoa, but also to human-derived epithelial cells. The in vitro transmission of the bacterium from T. vaginalis to both uninfected parasite isolates and human epithelial cells suggests a role for T. vaginalis as a carrier of the M. hominis infection in vivo.

Animals↗

Simultaneous storage and degradation of PHB and glycogen in activated sludge cultures.

Bacteria in activated sludge are subjected to periods of substrate availability and absence of external substrates. The response of bacteria to such dynamic conditions was studied in a 2 L sequencing batch reactor (SBR) by subjecting a mixed microbial population to successive periods of external substrate availability (feast period) and no external substrate availability (famine period). In previous studies, acetate or glucose was used as single substrate leading to the storage of polyhydroxybutyrate or glycogen, respectively. In this study, a mixture of acetate and glucose was used. It appeared that both substrates were consumed simultaneously. The relative contribution of growth and storage processes was in these experiments similar as in the systems fed with a single substrate only. The ratio of substrate uptake over substrate storage was 0.6 Cmol/Cmol for both substrates. The uptake rate of acetate was not influenced by the simultaneous uptake of glucose. The degradation kinetics and rates of the storage compounds were the same as for the systems in which only one compound was stored in the activated sludge. The global performance of the culture grown on mixed substrates could therefore be described as the sum of the conversions observed in cultures fed with the individual substrates.

Acetates↗

Bacillus cereus keratitis associated with contact lens wear.

OBJECTIVE: We report the first case of contact lens-related Bacillus cereus keratitis and ulcer associated with B. cereus contamination of the contact lens case. This is also the first study to investigate and establish the genetic identity of an organism isolated from the cornea and contact lens case in a patient with contact lens-associated keratitis. DESIGN: Case report. INTERVENTION AND TESTING: Conjunctival swabs and corneal scrapings from the left eye were inoculated for culture. The contact lens case was also cultured. Antibiotic susceptibility testing was determined by agar disk diffusion method. Initial treatment with topical ciprofloxacin and fortified tobramycin was given. Genetic analysis of the bacterial isolates was performed using polymerase chain reaction (PCR) with enterobacterial repetitive intergenic consensus primers (ERIC; ERIC-PCR). Susceptibility of B. cereus to heat and contact lens disinfecting solutions containing hydrogen peroxide, hydrogen peroxide-catalase, polyquaternium-1, and polyaminopropyl biguanide (PAPB) was tested. MAIN OUTCOME MEASURES: Clinical features, culture results, and antibiotic susceptibility testing were analyzed. The ERIC-PCR amplification products were visualized in ethidium bromide-stained agarose gel. Bacterial growth after exposure to heat and contact lens disinfecting solutions was assessed on blood agar plates. RESULTS: B. cereus was grown from the conjunctiva, corneal ulcer, and contact lens case. All isolates were sensitive to gentamicin, tobramycin, ciprofloxacin, clindamycin, and vancomycin. The corneal ulcer gradually healed over the next 6 days. Results of ERIC-PCR showed that the isolates from the cornea and contact lens case were indistinguishable, thus demonstrating the source of infecting organism to be the contaminated contact lens case. Exposure to a temperature of 80 degrees C for 20 minutes and incubation with hydrogen peroxide-catalase, polyquaternium-1, and PAPB for the minimum recommended time failed to kill B. cereus. Only exposure to hydrogen peroxide for 4 hours eradicated the organism. CONCLUSIONS: B. cereus should be considered a possible etiologic agent of contact lens-associated keratitis. Heat and many types of contact lens disinfecting solutions may be ineffective in eradicating B. cereus from contaminated contact lens cases. Only prolonged exposure to hydrogen peroxide appeared to be sporicidal to B. cereus in this study.

Bacillaceae Infections↗

In vitro adherence of Staphylococcus epidermidis to polymethyl methacrylate and acrysof intraocular lenses.

PURPOSE: To investigate the adherence of one clinically relevant ocular isolate of Staphylococcus epidermidis to polymethyl methacrylate (PMMA) and Acrysof (Alcon Surgical, Fort Worth, TX) intraocular lenses (IOLs). DESIGN: Experimental study. PARTICIPANTS: The authors examined the in vitro adherence of one clinically relevant ocular isolate of S. epidermidis. Adherence was tested on 12 PMMA IOLs and 12 Acrysof IOLs. METHODS: Six IOLs (three of each type) were placed in different test tubes containing bacterial suspension (10(8) cfu/ml) and incubated at 37 degrees C. At different times (3 minutes, 30 minutes, and 90 minutes), each IOL type was removed from the test tube, rinsed in sterile phosphate-buffered saline, and transferred into sterile brain-heart infusion broth. The broth with the IOL was sonicated on low power for 3 minutes to remove adhered bacteria. Two serial 10-fold dilutions of the broth containing the dislodged bacteria were plated on mannitol agar plates. The plates were incubated overnight at 37 degrees C and then bacterial colonies were counted. All assays were performed in triplicate. Additional lenses (three of each type) were incubated with S. epidermidis for different times (3 minutes, 30 minutes, and 90 minutes) and then examined with scanning electron microscopy. MAIN OUTCOME MEASURES: The number of adhered bacteria per area (mm ) of IOL optic was calculated. Statistical analysis included calculation of arithmetic means and 95% confidence intervals (t test). RESULTS: Direct counting of viable adherent bacteria released by sonication showed that the amount of adhered bacteria per area of IOL optic after 3, 30, and 90 minutes' incubation in S. epidermidis suspension was 0.1 x 10(2)/mm2, 3.6 x 10(2)/mm2, and 11 x 10(2)/mm2 (PMMA IOLs), and 4.4 x 10(2)/mm2, 3.1 x 10(2)/mm2, and 2.3 x 10(2)/mm2 (Acrysof IOLs). Direct counting of adherent bacteria in scanning electron microscopy photographs revealed that the total amount of adhered bacteria per area of IOL optic after 3, 30, and 90 minutes' incubation in S. epidermidis suspension was 1.1 x 10(2)/mm2, 4.4 x 10(2)/mm2, and 5.5 x 10(2)/mm2 (PMMA IOLs) and 13 x 10(2)/mm2, 33.9 x 10(2)/mm2, and 72 x 10(2)/mm2 (Acrysof IOLs). CONCLUSIONS: Results suggest that in vitro adherence of S. epidermidis to IOLs is influenced by IOL materials. After 3 minutes' incubation, Acrysof IOLs appeared to be more permissive to S. epidermidis adherence than PMMA IOLs. The difference was statistically significant (P < 0.05). However, at 90 minutes, Acrysof IOLs had a lower viable bacterial count than did the PMMA IOLs. Bacterial adherence appeared to be greater in areas with surface irregularities. Adherence of S. epidermidis to IOLs may play a role in the pathogenesis of some forms of endophthalmitis after cataract surgery.

Acrylic Resins↗

Adherence of ocular isolates of staphylococcus epidermidis to ACRYSOF intraocular lenses. A scanning electron microscopy and molecular biology study.

PURPOSE: To investigate the adherence of two clinically relevant ocular isolates of Staphylococcus epidermidis to ACRYSOF intraocular lenses (IOLs) (Alcon Surgical, Fort Worth, Texas) and to determine whether the strains under study carried the intercellular adhesion (ica) locus, which encodes production of S. epidermidis antigens mediating adherence to biomaterials. DESIGN: Experimental study. PARTICIPANTS: The authors examined the in vitro adherence of two clinically relevant ocular isolates of S. epidermidis (S. epidermidis 1 and S. epidermidis 2). Adherence was tested on six ACRYSOF IOLs. METHODS: Three IOLs were placed in three separate test tubes containing 5 ml of S. epidermidis 1 suspension, and three other IOLs were placed in three test tubes containing 5 ml of S. epidermidis 2 suspension. At different times (3, 30, and 90 minutes), the IOLs were removed from the test tubes and rinsed in sterile phosphate buffered solution. The lenses were then fixed in glutaraldehyde, postfixed in osmium tetroxide, and serially dehydrated in ethyl alcohol. After critical point drying, they were sputter-coated with gold and then examined with a scanning electron microscope. In addition, polymerase chain reaction amplification was used to investigate whether the isolates under study carried the ica locus. MAIN OUTCOME MEASURES: The number of adhered bacteria per area (square millimeters) of IOL optic was calculated. Statistical analysis included calculation of arithmetic means and 95% confidence intervals (t test). Polymerase chain reaction amplification products were visualized in ethidium bromide-stained agarose gel. RESULTS: Direct counting of adherent bacteria in scanning electron microscopy photographs revealed that the total amount of adhered bacteria per area of IOL optic after 3, 30, and 90 minutes of incubation in bacterial suspension was 1306/mm(2), 3389/mm(2), and 7195/mm(2) (S. epidermidis 1) and 778/mm(2), 1056/mm(2), and 3861/mm(2) (S. epidermidis 2). Differences at 30 and 90 minutes were statistically significant (P: = 0.01 and 0.02, respectively). Polymerase chain reaction amplification revealed that S. epidermidis 1 contained the ica locus, whereas S. epidermidis 2 was ica negative. CONCLUSIONS: Different ocular isolates of S. epidermidis may differ significantly with regard to adherence to ACRYSOF IOLs. Adherence appeared to be greater when the bacterial DNA contained the ica locus. Strains of S. epidermidis carrying the ica locus may play an important role in the pathogenesis of some forms of endophthalmitis occurring after cataract surgery.

Acrylates↗

Molecular characterization and antibiotic susceptibilities of ocular isolates of Staphylococcus epidermidis.

Nineteen isolates of Staphylococcus epidermidis from patients with ocular infections were analyzed. Patients were selected in retrospect, by choosing cases in which S. epidermidis was the sole isolate. Twelve different patterns were obtained after hybridization with a probe with high-level homology to insertion sequences found in S. epidermidis. Susceptibilities to penicillin, methicillin, gentamicin, tetracycline, erythromycin, ciprofloxacin, vancomycin, and teicoplanin were determined. Six strains were resistant to three or more antibiotics.

Anti-Bacterial Agents↗

Identification and antibiotic susceptibility of coagulase negative staphylococci isolated in corneal/external infections.

AIMS: To identify and determine antibiotic susceptibility of coagulase negative staphylococci (CoNS) isolated from patients with chronic blepharitis, purulent conjunctivitis, and suppurative keratitis. METHODS: A retrospective review of all culture positive cases of chronic blepharitis, purulent conjunctivitis, and suppurative keratitis between July 1995 and December 1996 was performed. Cases in which CoNS were the sole isolates were analysed. Species identification was performed by using a commercially available standardised biochemical test system. Antibiotic susceptibility to penicillin, gentamicin, tetracycline, erythromycin, ciprofloxacin, and teicoplanin was determined by agar disc diffusion (Kirby-Bauer method). Teicoplanin resistance was confirmed by agar dilution. RESULTS: 42 Staphylococcus epidermidis, four S warneri, three S capitis, two S hominis, one each of S xylosus, S simulans, S equorum, and S lugdunensis were identified. 37 CoNS were penicillin resistant, 12 gentamicin resistant, 28 tetracycline resistant, 18 erythromycin resistant, four ciprofloxacin resistant, and one teicoplanin resistant (MIC, 32 microg/ml). In total, 16 strains were resistant to three or more antibiotics. CONCLUSION: Species of CoNS apart from S epidermidis may be isolated from patients with corneal and external infection. Antibiotic susceptibility of CoNS is unpredictable and multiresistant strains are common. As a result, antibiotic susceptibility testing should be performed in all cases of clinically significant ocular infections caused by CoNS.

Anti-Bacterial Agents↗

Cloning and molecular characterization of a cDNA clone coding for Trichomonas vaginalis alpha-actinin and intracellular localization of the protein.

We have identified and sequenced a cDNA clone coding for Trichomonas vaginalis alpha-actinin. Analysis of the obtained sequence revealed that the 2,857-nucleotide-long cDNA contained an open reading frame encoding 849 amino acids which showed consistent homology with alpha-actinins of different species. Such homology was particularly significant in regions which have been reported to represent the actin-binding and Ca2+-binding domains in other alpha-actinins. The deduced protein was also characterized by the presence of a divergent central region thought to play a role in its high immunogenicity. A study of protein localization performed by immunofluorescence revealed that the protein is diffusely distributed throughout the T. vaginalis cytoplasm when the cell is pear shaped. When parasites adhere and transform into the amoeboid morphology, the protein is located only in areas close to the cytoplasmic membrane and colocalizes with actin. Concomitantly with transformation into the amoeboid morphology, alpha-actinin mRNA expression is upregulated.

Actinin↗