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Savitri Sharma

Publications and source records attributed to Savitri Sharma.

At least 19 recordsLinked to original sources
PubMed2006

Confocal microscopy for Nocardia keratitis.

PURPOSE: To assess the role of confocal microscopy for in vivo detection of Nocardia in patients with microbial keratitis. DESIGN: Retrospective interventional case series. PARTICIPANTS: Three patients with microbiologically proven Nocardia keratitis. INTERVENTION: Confocal microscopy. METHODS: We performed confocal microscopy in microbiologically proven cases of Nocardia asteroides keratitis. A masked observer examined the images. For better understanding of the images, we also performed confocal microscopy on a blood agar culture plate with Nocardia growth. RESULTS: Confocal microscopy of infiltrated cornea revealed highly reflective, short, thin branching filaments with bright inflammatory cells in the background. The filaments were seen clearly at the edge of the infiltrate. In scans with faint images, these filaments became more visible on inversion of bright and dark components. Confocal microscopy of cultured organisms also revealed filamentous beaded structures with a morphology identical to that of those seen in vivo. CONCLUSION: Nocardia, a filamentous bacterium, produces a distinct image on confocal microscopy. This in vivo examination technique may be useful in cases of deep-seated infiltrates where routine microbiology workup does not yield positive results.

Adult↗
PubMed2006

Histopathological evaluation of ocular microsporidiosis by different stains.

BACKGROUND: There is limited data on comparing stains in the detection of microsporidia in corneal biopsies. Hence we wanted to evaluate various stains for their ability to detect microsporidia in corneal tissue sections. METHODS: Four cases diagnosed with microsporidiosis on Hematoxylin and Eosin and Periodic Acid Schiff's stained sections of the corneal button between January 2002 and December 2004, were included. Further sections were prospectively stained with calcofluor white, Gram, Giemsa, Masson's trichrome, acridine orange, Gomori's methenamine silver, Gram's chromotrope and modified acid fast stain. The stained sections were analyzed for the spore characteristics in terms of size, shape, color contrast, cell wall morphology, waist band in cytoplasm and ease of detection. RESULTS: All sections showed microsporidial spores as 3-5 microm, oval bodies. 1% acid fast, Gram's chromotrope and GMS stains provided a reliable diagnosis of microsporidia as diagnostic waist band could be identified and good contrast helped distinguish the spores from inflammatory debris. CONCLUSION: Considering the ease of performance, cost effectiveness and rapidity of the technique, 1% acid fast stain and Gram's chromotrope stain are ideal for the detection of microsporidia.

Journal Article↗
PubMed2006

Clinical and microbiological profile of microsporidial keratoconjunctivitis in southern India.

PURPOSE: To report the clinical and microbiological profile of microsporidial keratoconjunctivitis in immunocompetent individuals in southern India. DESIGN: Retrospective noncomparative case series. PARTICIPANTS: Nineteen cases of microsporidial keratoconjunctivitis diagnosed between January 2002 and December 2004 were studied. METHODS: All medical and laboratory records of patients with infectious keratitis during the study period were reviewed. In all cases, after relevant history recording and slit-lamp examination, corneal/conjunctival scrapings were collected. Multiple scrapings were taken from the lesions and examined by fluorescence or light microscopy after staining with potassium hydroxide and calcofluor white (KOH + CFW), Gram's stain, Kinyoun's, and Giemsa stain. In some cases, the serum was tested for human immunodeficiency virus antibody by enzyme-linked immunosorbent assay. MAIN OUTCOME MEASURES: Clinical course, demographic features, predisposing factors, microbiological profile, treatment, and final outcome. RESULTS: Of 4822 cases of suspected microbial keratitis seen during the period, 19 (0.4%) were identified as microbiologically proven microsporidial keratitis. All patients were apparently healthy; 8 had a history of ocular trauma, and 3 mentioned bathing in unclean river water. All but 2 had unilateral involvement. The mean age of the patients was 38.4+/-13.7 years (range, 23-73). The duration of symptoms ranged from 1 day to 2 years, with 11 of 19 (58%) presenting within a week of onset of symptoms. Slit-lamp examination revealed multifocal, coarse, punctate, raised epithelial lesions in all patients. A mild to moderate nonpurulent conjunctivitis was present in all cases, with papillary and/or follicular reaction in 14. Corneal/conjunctival scrapings demonstrated microsporidial spores by KOH + CFW in 16 of 17 cases tested, whereas the diagnosis was made by Giemsa stain in 2 cases and by Gram's stain in one. Kinyoun's (1% acid fast) stain was confirmatory in all cases. In all patients, treatment was started after debridement and included oral and/or topical antimicrobial agents. At last follow-up, 15 of 19 achieved a visual acuity of 20/20. CONCLUSIONS: Microsporidial keratoconjunctivitis should be considered in the differential diagnosis of atypical punctate epithelial keratitis associated with conjunctivitis and can be diagnosed by routine microbiological methods. The disease can occur in healthy individuals, and the outcome of treatment is often satisfactory.

Adult↗
PubMed2006

Fluorescent amplified fragment length polymorphism (FAFLP) genotyping demonstrates the role of biofilm-producing methicillin-resistant periocular Staphylococcus epidermidis strains in postoperative endophthalmitis.

BACKGROUND: An observational case series was used to study the virulence characteristics and genotypes of paired Staphylococcus epidermidis isolates cultured from intraocular samples and from periocular environment of patients with postcataract surgery endophthalmitis. METHODS: Eight S. epidermidis isolates were obtained from three patients (2 from patients #1 and 2 and 4 from patient #3) whose vitreous and/or anterior chamber (AC) specimens and preoperative lid/conjunctiva samples were culture positive. Cultures were identified by API-Staph phenotypic identification system and genotypically characterized by Fluorescent Amplified Fragment Length Polymorphism (FAFLP) and checked for their antimicrobial susceptibility. The isolates were tested for biofilm-production and methicillin-resistance (MR) by PCR amplification of icaAB and mecA gene respectively. RESULTS: Four out of eight S. epidermidis strains showed multiple drug resistance (MDR). All the eight strains were PCR positive for mecA gene whereas seven out of eight strains were positive for icaAB genes. In all three patients FAFLP typing established vitreous isolates of S. epidermidis strains to be indistinguishable from the strains isolated from the patient's conjunctival swabs. However, from patient number three there was one isolate (1030b from lid swab), which appeared to be nonpathogenic and ancestral having minor but significant differences from other three strains from the same patient. This strain also lacked icaAB gene. In silico analysis indicated possible evolution of other strains from this strain in the patient. CONCLUSION: Methicillin-resistant biofilm positive S. epidermidis strains colonizing the conjunctiva and eyelid were responsible for postoperative endophthalmitis (POE).

Adult↗
PubMed2006

Intravitreal triamcinolone acetonide in the management of exogenous bacterial endophthalmitis.

PURPOSE: To determine the effectiveness of intravitreal triamcinolone acetonide in the management of bacterial endophthalmitis. DESIGN: Interventional case series. METHODS: This pilot case series included five patients (three patients after trauma and two patients after cataract surgery) with culture proven bacterial endophthalmitis. After 48 to 72 hours of the initial surgical procedure, 4 mg/0.1 ml of intravitreal triamcinolone acetonide was injected, after confirmation that the vitreous isolate was sensitive to the initially administered intravitreal antibiotics. All patients received oral ciprofloxacin 750 mg twice each day for seven days. The course of inflammation and the clinical outcome were noted. RESULTS: In all the five cases, there was complete resolution of inflammation with favorable clinical outcome at the end of one month that was maintained at the end of three months. CONCLUSION: Intravitreal triamcinolone acetonide could be a treatment option in the selected cases of bacterial endophthalmitis.

Administration, Oral↗
PubMed2006

Use of different stains for microscopic evaluation of corneal scrapings for diagnosis of microsporidial keratitis.

Retrospective evaluation of potassium hydroxide plus calcofluor white (KOH+CFW), Gram, Giemsa, and modified Ziehl-Neelsen (1% H(2)SO(4), cold) stains for the detection of microsporidia in corneal scrapings from 30 patients showed KOH+CFW and acid-fast stains to be most efficient (29/30 [96.7%] and 28/30 [93.3%], respectively) in the diagnosis of microsporidial keratitis.

Benzenesulfonates↗
PubMed2006

Microsporidial keratitis in India: 16S rRNA gene-based PCR assay for diagnosis and species identification of microsporidia in clinical samples.

PURPOSE: To evaluate 16S rRNA-based polymerase chain reactions for the detection and species identification of the microsporidia that cause keratitis. METHODS: Of the 5892 cases of microbial keratitis seen between September 2002 and December 2005, 31 (0.5%) microscopically diagnosed cases of microsporidial keratitis were included in the test group; 103 patients with nonmicrosporidial keratitis constituted the control group. A 16S rRNA-based pan-microsporidian PCR was chosen for the detection of microsporidian DNA. Species level identification was made using species-specific primer sets of Encephalitozoon spp (E. cuniculi, E. hellem, and E. intestinalis). Sequencing and BLAST analysis of amplicons obtained with pan-microsporidian primers were performed for validation. RESULTS: The corneal scrapings from 26 of 31 cases in the test group and 2 of 103 cases in the control group showed a 250- to 280-bp amplicon in PCR by pan-microsporidian primers (sensitivity of 83% and specificity of 98%). The amplicons of 13 of 26 test group samples were identified by species-specific PCR: E. cuniculi, n = 7 (549 bp); E. hellem; n = 3 (549 bp); E. intestinalis; n = 1 (520 bp). The two cases in the control group were identified to be E. cuniculi. The remaining 15 cases (test group) were confirmed to be Vittaforma corneae by sequencing and BLAST analysis. All species were confirmed by sequencing and database homology comparison. CONCLUSIONS: This study is the first to validate PCR-based assays for detection of microsporidial DNA in corneal scrapings. Pan microsporidian PCR can be a useful adjunct with smear examination in the diagnosis of microsporidial keratitis.

Adolescent↗
PubMed2006

Acanthamoeba keratitis after LASIK.

PURPOSE: To report a case of Acanthamoeba infection following LASIK. METHODS: A 20-year-old woman developed pain, redness, decreased vision, and corneal infiltrate in the right eye 15 days after bilateral LASIK. She did not use contact lenses postoperatively. Patient examination 3 months after surgery revealed a large, central, full-thickness corneal infiltrate with multiple satellite lesions in the right eye. Corneal scrapings were taken and the flap excised, and submitted for histopathologic examination. RESULTS: Microscopic examination of smears revealed Acanthamoeba cysts and non-nutrient agar showed a significant growth of Acanthamoeba. Histopathology examination of the excised flap demonstrated numerous Acanthamoeba cysts in tissue sections. The infiltrate was treated with a combination of topical polyhexamethylene biguanide, chlorhexidine, atropine sulfate, and oral itraconazole and resolved within 2 months. CONCLUSIONS: Laser in situ keratomileusis can be complicated by Acanthamoeba infection. Microbiologic evaluation is essential for accurate early diagnosis and treatment.

Acanthamoeba↗
PubMed2005

High-resolution genotyping of Pseudomonas aeruginosa strains linked to acute post cataract surgery endophthalmitis outbreaks in India.

BACKGROUND: Investigation of two independent outbreaks of post cataract surgery endophthalmitis identified the reservoir of epidemic strains of P. aeruginosa. METHODS: Patient isolates cultured from vitreous fluid of all the nine cases and from the peripheral devices of phacoemulsification machine were subjected to high-resolution Fluorescent Amplified Fragment Length Polymorphism (FAFLP) analysis. RESULTS: FAFLP based genotyping of the isolates confirmed nosocomial transmission. Although biochemical characterization and antibiotic susceptibility profiles grouped all the isolates together, FAFLP based genotyping revealed that, all the outbreak isolates were derived from 2 different strains, with independent origins. One group of isolates was traced to phacoprobe and the second one to the internal tubing system of the phacoemulsification machine used in cataract surgery. In silico analysis indicated possible evolution in both the clusters of P. aeruginosa isolates due to genetic polymorphisms. The polymorphisms were mapped to gene products (cell envelope, outer membrane proteins) possibly having significant role in pathogenesis. CONCLUSION: The present study is probably the first one to apply FAFLP typing successfully to investigate outbreaks of postoperative endophthalmitis (POE) in an ophthalmic setting, which was able to identify the source, and helped to make rational decisions on sterilization procedures that halted more cases of infection in these hospitals.

Acute Disease↗
PubMed2005

Is microsporidial keratitis an emerging cause of stromal keratitis? A case series study.

BACKGROUND: Microsporidial keratitis is a rare cause of stromal keratitis. We present a series of five cases of microsporidial keratitis from a single centre in southern India with microbiologic and histopathologic features. CASE PRESENTATION: Patient charts of five cases of microsporidial stromal keratitis diagnosed between January 2002 and June 2004 were reviewed retrospectively for clinical data, microbiologic and histopathologic data. The presence of microsporidia was confirmed by special stains on corneal scrapings and/or corneal tissues, and electron microscopy. All patients were immunocompetent with a preceding history of trauma in three. Four patients presented with unilateral, small, persisting deep stromal infiltrates, of uncertain etiology, in the cornea, which were not responding to conventional antimicrobial treatment and required penetrating keratoplasty in three. Fifth case was unsuspected and underwent keratoplasty for post-traumatic scar. Three of five cases were diagnosed on corneal scrapings, prior to keratoplasty, while two were diagnosed only on histology. The microsporidia appeared as oval well defined bodies with dense staining at one pole. None of the patients showed recurrence following keratoplasty. CONCLUSION: Microsporidia, though rare, should be suspected in chronic culture-negative stromal keratitis. Organisms could lie dormant without associated inflammation.

Adult↗
PubMed2005

Relationship between clinical presentation and visual outcome in postoperative and posttraumatic endophthalmitis in south central India.

PURPOSE: To determine risk factors for poor visual outcome in postoperative and posttraumatic endophthalmitis in a large referral center in south central India. METHODS: In this prospective observational series the authors examined 388 patients of postoperative (n= 206) and posttraumatic (n= 182) endophthalmitis at the L V Prasad Eye Institute in Hyderabad, India between 1991 and 1997. The analysis was confined to 236 patients-128 (62.1%) postoperative and 108 (59.3%) posttraumatic patients who were followed for a minimum period of 3 months. A detailed protocol was followed. Chi-square and logistic regression analysis were used to determine risk factors for visual outcome worse than 6/18 and worse than 6/120. RESULTS: Postoperative endophthalmitis: In univariate analysis the features associated with poor visual acuity (grouped as < 6/18 and < 6/120) included intracapsular cataract surgery, poor presenting visual acuity, presence of vitreous cells, inability to visualise the optic disc on indirect ophthalmoscopy, presence of vitreous membranes on ultrasonography, and a culture-positive vitreous biopsy. In the multivariate analysis, visual acuity of less or equal light perception (LP) at presentation was associated with a 3-month postoperative visual acuity of < 6/18, with an odds ratio of 5.85 [1.25 - 27.42, 95% CI], and vitreous membranes seen on ultrasonography was associated with a final visual acuity of < 6/120, with an odds ratio of 2.47 [1.05 - 5.83, 95% CI]. Posttraumatic endophthalmitis: In univariate analysis the features associated with poor visual acuity (grouped as < 6/18 and < 6/120) included a retained intraocular foreign body (IOFB), trauma by needle (hypodermic or sewing), poor presenting visual acuity, inability to visualise the optic disc on indirect ophthalmoscopy, presence of vitreous membranes on ultrasonography, and a culture-positive vitreous biopsy. In multivariate analysis, IOFB was associated with a 3-month follow-up visual acuity of < 6/18, with an odds ratio of 5.90 [1.85 - 18.78, 95% CI], and trauma by a needle (hypodermic or sewing) and retained IOFB was associated with a final visual acuity of < 6/120, with an odds ratio of 4.47 [1.22 - 16.38, 95%CI] and 3.76 [1.36 - 10.37, 95% CI] respectively. CONCLUSION: This is the largest, single-centre, prospective study on risk factors for poor visual outcome in postoperative and posttraumatic endophthalmitis. The independent risk factor for 3-month follow-up visual acuity of < 6/18 was the presenting visual acuity of < or =LP in postoperative endophthalmitis and a retained IOFB in posttraumatic endophthalmitis. The independent risk factor for 3-month visual acuity of < 6/120 was the presence of vitreous membranes on ultrasonography in postoperative endophthalmitis, and trauma by a needle (hypodermic/ sewing) and retained IOFB in posttraumatic endophthalmitis.

Adolescent↗
PubMed2004

Keratocyte loss in corneal infection through apoptosis: a histologic study of 59 cases.

BACKGROUND: Keratocyte loss by apoptosis following epithelial debridement is a well-recognized entity. In a study of corneal buttons obtained from patients of corneal ulcer undergoing therapeutic keratoplasty, we observed loss of keratocytes in the normal appearing corneal stroma, surrounding the zone of inflammation. Based on these observations, we hypothesized that the cell loss in the inflammatory free zone of corneal stroma is by apoptosis that could possibly be a non-specific host response, independent of the nature of infectious agent. METHODS: To test our hypothesis, in this study, we performed Terminal deoxyribonucleotidyl transferase-mediated d-Uridine 5" triphosphate Nick End Labelling (TUNEL) staining on 59 corneal buttons from patients diagnosed as bacterial, fungal, viral and Acanthamoeba keratitis. The corneal sections were reviewed for morphologic changes in the epithelium, stroma, type, degree and depth of inflammation, loss of keratocytes in the surrounding stroma (posterior or peripheral). TUNEL positivity was evaluated in the corneal sections, both in the zone of inflammation as well as the surrounding stroma. A correlation was attempted between the keratocyte loss, histologic, microbiologic and clinical features. RESULTS: The corneal tissues were from 59 patients aged between 16 years and 85 years (mean 46 years) and included fungal (22), viral (15), bacterial (14) and Acanthamoeba (8) keratitis. The morphological changes in corneal tissues noted were: epithelial ulceration (52, 88.1%), destruction of Bowman's layer (58, 99%), mild to moderate (28; 47.5%) to severe inflammation (31; 52.5%). Morphologic evidence of disappearance or reduced number of keratocytic nuclei in the corneal stroma was noted in 49 (83%) cases; while the TUNEL positive brown cells were identified in all cases 53/54 (98%), including cases of fungal (19), bacterial (14), viral (13), and Acanthamoeba keratitis. TUNEL staining was located mostly in the deeper stroma and in few cases the peripheral stroma. TUNEL positivity was also noted with the polymorphonuclear infiltrates and in few epithelial cells (10 of 59, 17%) cases, more with viral infections (6/10; 60%). CONCLUSIONS: We report apoptotic cell death of keratocytes in the corneal stroma in infectious keratitis, a phenomenon independent of type of infectious agent. The inflammatory cells in the zone of inflammation also show evidence of apoptotic cell death. It could be speculated that the infective process possibly triggers keratocyte loss of the surrounding stroma by apoptosis, which could possibly be a protective phenomenon. It also suggests that necrotic cell death and apoptotic cell deaths could occur simultaneously in infective conditions of the cornea.

Adolescent↗
PubMed2004

Acanthamoeba keratitis in non-contact lens wearers in India: DNA typing-based validation and a simple detection assay.

OBJECTIVES: To establish that the protozoan Acanthamoeba is one of the causative organisms associated with non-contact lens-related keratitis in the Indian population and to develop a simple and sensitive diagnostic assay for clinical testing. DESIGN: DNA sequencing of nuclear 18S and 26S ribosomal DNA motifs was performed and compared with the reference Acanthamoeba strains, to establish the genetic identity of the putative amoeba isolates obtained from the corneal scrapings of non-contact lens-wearing patients with keratitis. Ribosomal DNA typing of clinical corneal scrapings from the patients with keratitis was performed by means of a simple agarose gel-based multiplex polymerase chain reaction assay, to detect the cases of Acanthamoeba keratitis. RESULTS: The ribosomal DNA analysis of 15 putative amoeba isolates obtained from the corneal scrapings of 14 patients with keratitis and 1 from the patients' environment established the isolates to be pathogenic formsof Acanthamoeba belonging to type T4 ribosomal DNA genotype. Multiplex polymerase chain reaction assay was specific and sensitive enough to detect as low as 5 pg of Acanthamoeba DNA. Its utility as a reliable diagnostic assay was demonstrated directly with the use of 34 additional corneal scrapings. CONCLUSIONS: Acanthamoeba is one of the causative organisms of keratitis in Indian patients with no history of contact lens usage. Moreover, the Acanthamoeba infection can be easily detected in the clinical samples by means of the simple multiplex polymerase chain reaction assay based on ribosomal DNA typing. Clinical Relevance This study suggests the need and means to determine the incidence and prevalance of Acanthamoeba keratitis in India and elsewhere. Moreover, the polymerase chain reaction assay would help in early and definitive diagnosis, leading to better prognosis of Acanthamoeba keratitis condition.

Acanthamoeba↗
PubMed2004

Herpes simplex virus-1--associated congenital cataract.

PURPOSE: To report association of herpes simplex virus-type 1 (HSV-1) in four cases of congenital cataract. DESIGN: Prospective interventional case series. METHODS: Four infants younger than 12 months, presenting with unilateral or bilateral congenital cataract, were included. The cases were clinically evaluated by the pediatric ophthalmologist. The lens aspirates collected at the time of cataract surgery were processed for HSV-1 culture in rabbit corneal epithelial (SIRC) cell line and for HSV-1 DNA by polymerase chain (PCR). The sera of the children and the mother were tested for HSV-1 immunoglobulin (Ig) M and IgG by enzyme linked immunosorbent assay (ELISA). RESULTS: HSV-1 was isolated in tube cultures in three of four lens aspirates, and all four lens aspirates were positive for HSV-1 DNA by PCR. Serum HSV-1 IgM was positive in all babies and in three cases HSV-1 IgM was positive in the mother's serum. CONCLUSION: Based on a computerized literature search, we believe this may be the first report of HSV-1 associated congenital cataract.

Antibodies, Viral↗
PubMed2004

Microbiologic spectrum and susceptibility of isolates in scleral buckle infection in India.

PURPOSE: To present the microbial spectrum and susceptibility of isolates in scleral buckle infections in India. DESIGN: Retrospective case series. METHOD: Seventy-three isolates from 55 eyes with scleral buckle infection were studied. RESULTS: The isolates included 30 gram-positive cocci (41.1%), 15 acid-fast bacilli (20.5%), 11 fungi (15.1%), 10 gram-positive bacilli (13.7%), and 7 gram-negative bacilli (9.6%). Eighteen eyes (32.7%) had polymicrobial infections. Gram-positive, gram-negative, and acid-fast isolates were most commonly susceptible to vancomycin (93%), ciprofloxacin (86%), and amikacin (80%), respectively. CONCLUSION: This large single-center study indicates the high prevalence of fungal, acid-fast organisms and polymicrobial organisms in buckle infections.

Anti-Bacterial Agents↗
PubMed2004

Is the cystatin-like domain of TSL functionally active in external ocular infections and during the normal diurnal cycle?

PURPOSE: To test whether the cystatin-like functional domain in tear specific lipocalin (TSL) is functionally active in tears during the normal diurnal cycle and during external ocular infections. METHODS: Capillary tube collected reflex (RTF), open (OTF) and closed (CTF) eye tear samples were recovered from six normals and semi-quantitatively western blot assayed for cystatin C and TSL. CTF samples were immunoprecipitated with antibodies raised against TSL, cystatin C and other antiproteases and screened for the co-precipitation of proteases by casein and gelatin zymography. OTF samples recovered from individuals with viral, fungal and bacterial keratitis were similarly screened for TSL-bound proteases. Human tissue was subjected to immunohistochemical study. RESULTS: Western blot analysis reveals a progressive increase in cystatin C in going from RTF to OTF to CTF samples (approximately 3, 7 and 30 ng microl(-1), respectively). In contrast, the concentration of TSL remains constant (approximately 1500 ng microl(-1)). Immunocytochemistry data show staining of the apical surface of the human conjunctiva and some intra-cellular staining for cystatin C, but not for cystatin A. Zymography confirms earlier data that CTF contains exceptionally high levels of proteases bound to a wide range of specific inhibitors. However, only trace amounts of proteases are complexed with cystatin C and no protease can be detected bound to TSL in either the pathological or CTF samples. CONCLUSION: Although TSL contains a functional cystatin-like domain, it is not physiologically active during the normal diurnal cycle or during external ocular infections. Reactive proteases in CTF are most likely controlled by the presence of excess levels of more reactive cystatins, especially cystatin C, which accumulates during prolonged eye closure. Immunohistochemical data suggest that the apical conjunctiva may be a contributing source for the accumulating cystatin C.

Carrier Proteins↗