Seroprevalence of Anti-HIV-1, Anti-HIV-2, Hepatitis B Surface Antigen, and Anti-HCV in Eye Donors in a Tertiary Eye Hospital, Chennai, India, in the Past 13 years (2005-2017).

PURPOSE: To understand the seroprevalence of HIV, hepatitis B surface antigen (HBsAg), and hepatitis C virus (HCV) in serum samples collected from eye donors between 2005 and 2017 at Sankara Nethralaya, Chennai, India. METHOD: The reports of 7136 eye donors serologically screened for antibodies to HIV-1 and HIV-2, HBsAg, and antibodies to HCV were retrospectively analyzed. RESULT: Among the 7136 serum samples screened during this study period, the serum samples of 14 donors (0.20%) were reactive to HIV-1 antibodies, 78 donors (1.09%) were positive for detection of HBsAg, and 37 donors (0.52%) were positive for HCV antibodies. Of interest, coinfections of HIV-1 and HBV, and HIV-1 and HCV were detected in 2 and 1 serum sample of the eye donors, respectively. CONCLUSIONS: This retrospective study indicates that there is a trend of reduction in the seropositivity for HIV, HBV, and HCV among eye donors in Chennai over the last decade.

Application of six multiplex PCR's among 200 clinical isolates of Pseudomonas aeruginosa for the detection of 20 drug resistance encoding genes.

Pseudomonas aeruginosa (P. aeruginosa) is a menacing opportunistic, nosocomial pathogen; become a growing concern as conventional antimicrobial therapy is now futile against it. Multi-drug resistant P. aeruginosa (MDRPA) has distinctive resistance mechanisms such as production of ß-lactamases, repression of porin genes and over-expression of efflux pumps. The focus of this study is to standardize and application of multiplex PCR (mPCR) to detect the presence of betalactamase genes encoding blaTem, blaOXA, blaCTX-M-15, blaVim, blaGes, blaVeb, blaDIM, AmpC and Efflux pump genes encoding Mex A,B-oprM, Mex C,D-oprJ, Mex X,Y-oprN, oprD, nfxB, MexR. A total of 200 clinical isolates of P. aeruginosa were tested for the presence of the above mentioned genes genotypically through mPCR and characterized by phenotypic methods for ESBL and MBL production. Out of 200 isolates, 163 (81.5%) nfxB regulator gene, 102 (51%) MexA, 96 (48%) MexC, 93 (46.5%) MexB, 86 (43%) MexD, 81 (40.5%) OprM, 74 (37%) OprJ, 72 (36%) OprD and MexR, 53 (26.5%) Mex X and OprN, 49 (24.5%) MexY gene. Betalactamase genes 145 (72.5%) blaTem, 67 (33.5%) blaOXA, 35 (17.5%) blaVim, 25(12.50%), 23 (11.50%) blaVeb, 21 (11.5%) blaGes, 14 (7%) Ctx-m and 10 (5%) AmpC and 5 (2.5%) blaDim-1 gene were tested positive by mPCR. Phenotypically 38 (19%) and 29 (14.5%) out of 200 tested positive for ESBL and MBL production. Application of this mPCR on clinical specimens is fast, accurate, specific and low-cost reliable tool for the screening, where culture negative Eubacterial PCR positive cases for an early molecular detection of drug resistance mechanism assisting the clinician to treat the disease with appropriate antibiotic selection.

Resistome and pathogenomics of multidrug resistant (MDR) Pseudomonas aeruginosa VRFPA03, VRFPA05 recovered from alkaline chemical keratitis and post-operative endophthalmitis patient.

Eye infections due to Pseudomonas aeruginosa is an important cause of ocular morbidity. We presents the whole genomic comparative analysis of two P. aeruginosa VRFPA03 and VRFPA05 isolated from alkaline chemical injury mediated keratitis and post-cataract surgery endophthalmitis patients, respectively. The blaDIM-1 gene in VRFPA03 and the blaGes-9 gene in VRFPA05 were identified and reported for the first time from an ocular isolate. The current study revealed novel integrons In1107 and In1108, comprised of multidrug-resistant genes. Ocular virulence factors mainly mediated by exoenzymes T, Y, and U and exotoxin A, elastase B, and phenazine-specific methyltransferase. Genomic analysis uncovered multiple known and unknown factors involved in P. aeruginosa mediated ocular infection, which may lead to drug discovery and diagnostic markers to improve human vision care.

Draft genome sequence of blaVeb-1, blaoxa-10 producing multi-drug resistant (MDR) Pseudomonas aeruginosa strain VRFPA09 recovered from bloodstream infection.

Pseudomonas aeruginosa (P. aeruginosa) bacteremia causes significant mortality rate due to emergence of multidrug resistant (MDR) nosocomial infections. We report the draft genome sequence of P. aeruginosa strain VRFPA09, a human bloodstream isolate, phenotypically proven as MDR strain. Whole genome sequencing on VRFPA09, deciphered betalactamase encoding blav(eb-1) and bla(OXA-10) genes and multiple drug resistance, virulence factor encoding genes.

Draft genome sequence of blaVeb-1, blaoxa-10producing multi-drug resistant (MDR) Pseudomonas aeruginosastrain VRFPA09 recovered from bloodstream infection

Pseudomonas aeruginosa (P. aeruginosa) bacteremia causes significant mortality rate due to emergence of multidrug resistant (MDR) nosocomial infections. We report the draft genome sequence of P. aeruginosa strain VRFPA09, a human bloodstream isolate, phenotypically proven as MDR strain. Whole genome sequencing on VRFPA09, deciphered betalactamase encoding bla_veb-1 and bla_OXA-10genes and multiple drug resistance, virulence factor encoding genes.

Hepatitis C Virus NS3 Mediated Microglial Inflammation via TLR2/TLR6 MyD88/NF-κB Pathway and Toll Like Receptor Ligand Treatment Furnished Immune Tolerance.

BACKGROUND: Recent evidence suggests the neurotrophic potential of hepatitis C virus (HCV). HCV NS3 protein is one of the potent antigens of this virus mediating inflammatory response in different cell types. Microglia being the immune surveillance cells in the central nervous system (CNS), the inflammatory potential of NS3 on microglia was studied. Role of toll like receptor (TLR) ligands Pam2CSK3 and Pam3CSK4 in controlling the NS3 mediated microglial inflammation was studied using microglial cell line CHME3. METHODS: IL (Interleukin)-8, IL-6, TNF-α (Tumor nicrosis factor alpha) and IL-1ß gene expressions were measured by semi quantitative RT-PCR (reverse transcription-PCR). ELISA was performed to detect IL-8, IL-6, TNF-α, IL-1ß and IL-10 secretion. FACS (Flourescent activated cell sorting) was performed to quantify TLR1, TLR2, TLR6, MyD88 (Myeloid differntiation factor 88), IkB-α (I kappaB alpha) and pNF-κB (phosphorylated nuclear factor kappaB) expression. Immunofluorescence staining was performed for MyD88, TLR6 and NF-κB (Nuclear factor kappaB). Student's t-test or One way analysis of variance with Bonferoni post hoc test was performed and p < 0.05 was considered significant. RESULTS: Microglia responded to NS3 by secreting IL-8, IL-6, TNF-α and IL-1ß via TLR2 or TLR6 mediated MyD88/NF-κB pathway. Transcription factor NF-κB was involved in activating the cytokine gene expression and the resultant inflammatory response was controlled by NF-κB inhibitor, Ro106-9920, which is known to down regulate pro-inflammatory cytokine secretion. Activation of the microglia by TLR agonists Pam3CSK4 and Pam2CSK4 induced immune tolerance against NS3. TLR ligand treatment significantly down regulated pro-inflammatory cytokine secretion in the microglia. IL-10 secretion was suggested as the possible mechanism by which TLR agonists induced immune tolerance. NS3 as such was not capable of self-inducing immune tolerance in microglia. CONCLUSION: In conclusion, NS3 protein was capable of activating microglia and the inflammatory response could be controlled via blocking the transcription factor NF-κB, or by treating the microglia with TLR ligands which likely function via secreting anti-inflammatory cytokines such as IL-10. This can have therapeutic potential in controlling HCV mediated neuroinflammation.

Genotypic Detection of Epstein Barr Virus from Clinically Suspected Viral Retinitis Patients in a Tertiary Eye Care Centre, India.

PURPOSE: To evaluate the diagnostic value of PCR on aqueous humour for detection and genotyping of Epstein Bar Virus in patients with viral retinitis. METHODS: 70 AH samples were collected from 20 HIV positive patients with clinically suspected viral retinitis and 25 patients with serpignous choroiditis and 25 AH from patients undergoing cataract surgery. PCR was performed to screen HHV-1 to HHV-5, Mtb and Toxoplasma gondii. Genotype prevalence was confirmed by phylogenetic analysis targetig EBV. RESULTS: EBV was detected in 17 (37.7%) samples. Genotyping to subtype EBV, revealed the circulation of only one subtype (Type 1). PCR results for other infective agents were negative except for the presence of CMV in 5 (11.1%) AH. CONCLUSION: The application of PCR to detect genotypes can be used as an epidemiological tool for clinical management. To our knowledge this is the first report on genotyping of EBV performed on intra ocular samples.

Patients with dry eye without hepatitis C virus infection possess the viral RNA in their tears.

PURPOSE: Dry eye is one of the suggested extrahepatic complications associated with hepatitis C virus (HCV) infection. HCV RNA has been detected from the tear fluid of patients with chronic HCV. There has been no literature evidence on the presence of HCV RNA in the tear fluid of patients with dry eye without HCV infection. In this study, tear fluid of patients with dry eye with no HCV infection was screened for the presence of HCV RNA. METHODS: Tear fluid was collected from patients with dry eye (n = 36) and healthy controls (n = 20). Real-time polymerase chain reaction was performed to detect HCV RNA in the tear fluid. Anti-HCV enzyme-linked immunosorbent assay, alkaline phosphatase, and alanine aminotransferase tests were performed in the serum samples collected from 15 patients with dry eye. RESULTS: Viral RNA was detected in 58.3% of the patients. Serum samples collected from 15 patients with dry eye were negative for anti-HCV. Alkaline phosphatase levels were elevated in 12 of 15 patients. Alanine aminotransferase levels were normal in all 15 patients. The odds ratio for the presence of HCV RNA in patients with dry eye was 22.4. CONCLUSIONS: These results indicate a direct correlation between dry eye and HCV in non-HCV patients.

Hepatitis C virus core and NS3 antigens induced conjunctival inflammation via toll-like receptor-mediated signaling.

PURPOSE: Dry eye condition is an extrahepatic manifestation associated with chronic hepatitis C virus (HCV) infection. Since conjunctival inflammation can contribute to the dry eye condition, in the present study we analyzed the conjunctival inflammatory response to HCV core and NS3 proteins. METHODS: We used primary human conjunctival fibroblasts for our study. Cytokines were measured with enzyme-linked immunosorbent assay (ELISA). Toll-like receptor (TLR) and cell adhesion molecule gene expression patterns were analyzed with semiquantitative reverse transcription (RT)-PCR. Immunofluorescence staining was performed for the MyD88, nuclear factor-kappa B (NF-kB), and inducible nitric oxide synthase (iNOS) proteins. Nitric oxide (NO) was measured with the Griess assay; terminal deoxynucleotidyl transferase-mediated uridine 5'-triphosphate-biotin nick end labeling (TUNEL) and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays were performed for apoptosis and cell viability, respectively. RESULTS: When exposed to the HCV core and NS3 proteins, the conjunctival fibroblasts secreted interleukin-8 (IL-8), IL-6, tumor necrosis factor-alpha (TNF-α), and IL-10 in a dose-dependent manner. Various TLRs were involved in the innate immune response via MyD88 signaling without NF-kB involvement. The gene expression of cell adhesion molecules such as CD44 and ICAM-1 was upregulated, and the cells secreted NO via iNOS. As the sum of these stress responses, the cells underwent apoptosis, which eventually lead to cell death. CONCLUSIONS: HCV core and NS3 proteins induced conjunctival inflammation that may form the pathogenesis of dry eye condition.

HCV core and NS3 proteins mediate toll like receptor induced innate immune response in corneal epithelium.

Direct association of dry eye syndrome and hepatitis C virus (HCV) infection is a well established fact. In this context, the current study examines the in vitro corneal inflammatory response with respect to HCV core and NS3 antigens. Toll like receptors (TLRs) are pattern recognition receptors which can mediate innate immune response. In the present study, corneal epithelial cells responded to HCV core and NS3 proteins by secreting pro-inflammatory cytokines IL-8, IL-6 and TNF-α via TLR1, TLR2 and TLR6 mediated innate immune response. MyD88/NF-kB signalling was involved in pro-inflammatory cytokine production. Corneal epithelium synthesised nitric oxide (NO) via iNOS during HCV core and NS3 exposure. On later stages of inflammation, cells underwent apoptosis which lead to cell death. SiRNA mediated silencing of TLR1, TLR2 and TLR6 resulted in a significant down regulation of IL-8 and NO. In conclusion, this study indicates that HCV core and NS3 proteins are capable of inducing immune response in corneal epithelium which can potentiate the pathology of HCV associated dry eye condition. Blocking specific TLR response can have therapeutic application in controlling the inflammatory response associated with this dry eye condition.

Eales' disease - current concepts in diagnosis and management.

Eales' disease, first described by the British ophthalmologist Henry Eales in 1880, is characterized by three overlapping stages of venous inflammation (vasculitis), occlusion, and retinal neovascularization. Diagnosis is mostly clinical and requires exclusion of other systemic or ocular conditions that could present with similar retinal features. In recent years, immunological, molecular biological, and biochemical studies have indicated the role of human leukocyte antigen, retinal autoimmunity, Mycobacterium tuberculosis genome, and free radical-mediated damage in the etiopathogenesis of this disease. However, its etiology appears to be multifactorial. The management depends on the stage of the disease and consists of medical treatment with oral corticosteroids in the active inflammatory stage and laser photocoagulation in the advanced retinal ischemia and neovascularization stages.

Screening of ocular enterobacteriaceae isolates for presence of chromosomal blaNDM-1 and ESBL genes: a 2-year study at a tertiary eye care center.

PURPOSE: Since, to our knowledge, there are no reports on the prevalence of the blaNDM-1 gene among ocular isolates of Enterobacteriaceae, and only limited information on the prevalence of extended spectrum beta-lactamases (ESBLs) among ocular bacterial isolates are available, our study was undertaken. METHODS: A prospective study was done on 74 Enterobacteriaceae isolates from patients presenting with clinical suspicion of bacterial ocular infections during a period from January 2010-December 2011. All isolates were subjected to detection of ESBLs by double disc synergy and screened for the presence of CTX-M -I, II, III, and IV groups, and OXA, TEM, SHV, blaNDM-1 genes by PCR. RESULTS: Of 74 ocular Enterobacteriaceae isolates 57 (77%) were ESBL producers tested by the double disc diffusion test. PCR-based DNA sequencing of these 57 ocular isolates showed the presence of CTX-M-15 (14.0%), blaOXA-1 (5.2%), blaSHV-1 (8.7%), and blaTEM-1 (7.0%) types. The blaNDM-1 was absent among these ocular isolates. The most widely disseminated ESBL gene among ocular isolates was CTX-M-15. Phenotypic and genotypic results showed 100% correlation. CONCLUSIONS: To our knowledge, this is the first extensive study performed to genotype ESBL-producing ocular Enterobacteriaceae isolates. The isolation of ESBL-producing Enterobacteriaceae organisms predominantly from conjunctival specimens indicates community-acquired infections/colonization by these bacteria in the conjunctiva of the patients, and cases are not related to hospital-acquired infections because of the short stay of ophthalmic patients in the hospitals. A shift in the resistance rates of ceftazidime from 37.5% to 79.7% over the years proves the increase in drug resistance among ocular clinical isolates.

Studies on New Delhi Metallo-Beta-Lactamse-1 producing Acinetobacter baumannii isolated from donor swab in a tertiary eye care centre, India and structural analysis of its antibiotic binding interactions.

Gram-negative bacilli, Enterobacteriaceae and Non-fermentors with resistance to carbapenems and metallo beta-lactams are the major cause of concern in clinical problems in current human healthcare. The most highly emerging dreadful Metallo Beta-lactamses is New Delhi metallo-beta-lactamase (blaNDM-1) which confers resistance to carbapenems; susceptible only to colistin and, less consistently to tigecycline, leading to no therapeutic options. In the present study, we demonstrate the effects of cephalosporins and carbepenems on biofilm producing A. baumanii clinical isolate and also to infer the probable inhibitory binding mode through molecular docking studies. The result of MIC on Biofilm producing A. baumanii and the docking analysis results were found to be concordant. Moreover, we also found cephalosporins and carbepenem groups to interact with 162-166 region of blaNDM-1, which is unique for NDM-1 and also documented to be a potential drug targeting region.

A study on isolation rate and prevalence of drug resistance among microorganisms isolated from multiorgan donor and donor corneal rim along with a report on existence of bla NDM-1 among Indian population.

PURPOSE: To study the rate of isolation and prevalence of drug resistance among bacteria isolated from conjunctival swabs collected from multiorgan donor and Donor corneal rim specimens obtained from a tertiary eye hospital in South India. METHODS: Donor corneal rims (DCR) and conjunctival swabs from multiorgan donors collected over a period of 6 months were screened for the prevalent species of bacteria and drug resistance associated with them against the first line of antibiotics by phenotypic methods and multidrug resistant isolates were further subjected for genotypic analysis. RESULTS: Seventy-six DCR specimens were screened out of which 46 (60.5%) specimens showed bacterial growth, the predominant isolate being Coagulase negative Staphylococci, the rest 30 (39.5%) did not show any culture growth. All 42 (100%) conjunctival swabs collected from multiorgan donors were positive for bacterial culture, the prevalent species once again, being Coagulase negative Staphylococci. Among the other gram positive bacterial genus encountered were Streptococci, Bacillus, Diphtheroids and the gram negatives were Enterobacteriaceae and nonfermentors. Antibiotic resistance was significantly high among gram positive group. Seven (29.1%) gram negative isolates were positive for Extended Spectrum Beta Lactamases (ESBL's) by conventional and molecular method. A blaNDM -1 carrying Acinetobacter baumannii was isolated from a multiorgan donor. CONCLUSION: Preexcision culture in multiorgan donor is necessary to prevent postoperative endophthalmitis. Preexcision culture and antibiotic susceptibility testing of bacterial isolates of DCR will aid in understanding antibiotic pattern as institution of correct antibiotic will prevent the emergence of postoperative endophthalmitis. Molecular methods help in reducing the turn-around time for understanding the drug resistance genotypes.

Application of PCR-based DNA sequencing technique for the detection of Leptospira in peripheral blood of septicemia patients

Aim: Isolation, dark field detection and microscopic agglutination test (MAT) are considered ―gold standard‖ tests for diagnosis of Leptospirosis. Several PCR assays are reported but very few have been evaluated for detection of Leptospirosis. Therefore, this study was undertaken. This study aims to design and standardize polymerase chain reaction (PCR) -based DNA sequencing technique for the detection of pathogenic Leptospira from peripheral blood of patients clinically diagnosed with septicemia. Methodology and Results: Two hundred and seven (207) blood samples from patients were diagnosed with septicemia which includes 100 bacterial (other than Leptospira) culture positive and 107 bacterial culture negative samples were studied. Primers for Nested PCR targeting LipL32 gene of Leptospira interrogans were designed and the specificity of primers was tested against serum samples positive/negative by either MAT or dark field microscopy. PCR amplified products were further confirmed by DNA sequencing. The standardized nPCR was sensitive and specific to Leptospira interrogans. Twenty-one (21%) out of 100 culture positive blood samples, three (2.8%) out of 107 culture negative samples showed nPCR positivity and were confirmed as Leptospira interrogans by DNA sequencing (p<0.001). A sensitive nPCR specific to Leptospira interrogans was developed. Conclusion, significance and impact of study: The p value (<0.001) signifies that Leptospira is commonly associated with other bacteria circulating in blood indicating that a decreased immune status is created primarily by a bacterium with enhanced possibility of development of Leptospiral infection probably be of an endogenous origin.

Comparison of a novel semi-nested polymerase chain reaction (PCR) with a uniplex PCR for the detection of Acanthamoeba genome in corneal scrapings.

A semi-nested polymerase chain reaction (snPCR) was developed to improve the sensitivity of detection of Acanthamoeba sp. genome from corneal scrapings of Acanthamoeba keratitis patients. The snPCR was developed using a laboratory designed inner forward primer targeting the 450-bp product of the 18s rRNA-gene-based PCR. The snPCR was optimized using 11 Acanthamoeba sp. culture isolates and further applied onto 35 corneal scrapings from keratitis patients. The sensitivity and specificity of the snPCR was compared against conventional methods (smear and/or culture-gold standard) and the uniplex PCR described by Schroeder et al. Eleven out of the 35 corneal scrapings were positive by the gold standard and snPCR, whereas only 3 of these 11 were positive by the uniplex PCR. The clinical sensitivity and specificity of the snPCR was 100% when compared with the gold standard. DNA sequencing was performed on first round amplicons of four culture isolates and one specimen, and all of them were identified as genus Acanthamoeba when compared with the GenBank database sequences. Application of snPCR on the 11 culture isolates yielded amplicons ranging 120-160 bp in size, indicating sequence variation among the different culture isolates. The clinical sensitivity of snPCR was higher than the conventional methods and the uniplex PCR reported earlier.