Chlamydial eye infections: Current perspectives

Chlamydia trachomatis, an obligate intraocular bacteria causing trachoma, adult and neonatal inclusion conjunctivitis, was the leading cause of blindness in the last century worldwide. Improvement in socioeconomic and living conditions, availability of antibiotics, and introduction of National Trachoma Control Programmes reduced the prevalence in developed countries, but it persisted in resource-poor settings of Africa and Asia, including India. In 2016, as per the WHO report, trachoma is restricted to 42 countries, causing blindness/visual impairment in ~1.9 million people. India is one of the five countries with nearly half of total active trachoma patients. Introduction of Global Elimination of Trachoma 2020 program by the WHO, using SAFE strategy (surgery for trachomatous trichiasis; Antibiotics for C. trachomatis; Facial cleanliness; and environmental improvement) greatly reduced the prevalence, but trachoma still persists in India. Global increase in the reproductive tract infection by C. trachomatis urogenital serotypes (D-K) has led to concurrent increase in C. trachomatis eye infections. Therefore, kerato eye infections due to chlamydial infections continue to be seen in hospitals. Over the years, there have been advances in laboratory diagnostics, in understanding the pathogenesis, tissue tropism, C. trachomatis genomics, and treatment modalities. Due attention and research is still needed for the study of C. trachomatis eye infections

Molecular characterization of drug-resistant and drug-sensitive Aspergillus isolates causing infectious keratitis

Purpose: To study the susceptibilities of Aspergillus species against amphotericin B in infectious keratitis and to find out if drug resistance had any association with the molecular characteristics of the fungi. Materials and Methods: One hundred and sixty Aspergillus isolates from the corneal scrapings of patients with keratitis were tested for susceptibilities to amphotericin B by broth microdilution method. These included Aspergillus flavus (64 isolates), A. fumigatus (43) and A. niger (53). Fungal DNA was extracted by glass bead vertexing technique. Polymerase chain reaction (PCR) assay was standardized and used to amplify the 28S rRNA gene. Single-stranded conformational polymorphism (SSCP) of the PCR product was performed by the standard protocol. Results: Of the 160 isolates, 84 (52.5%) showed low minimum inhibitory concentration (MIC) values (≤ 1.56 μg/ml) and were designated as amphotercin B-sensitive. Similarly, 76 (47.5%) had high MICs (≥ 3.12 μg/ml) and were categorized as amphotericin B-resistant. MIC 50 and MIC 90 values ranged between 3.12-6.25 μg/ml and 3.12-12.5 μg/ml respectively. A. flavus and A. niger showed higher MIC 50 and MIC 90 values than A. fumigatus. The SSCP pattern exhibited three extra bands (150 bp, 200 bp and 250 bp each) in addition to the 260 bp amplicon. Strains (lanes 1 and 7) lacking the 150 bp band showed low MIC values (≤ 1.56 μg/ml). Conclusion: A. niger and A. flavus isolates had higher MICs compared to A. fumigatus, suggesting a high index of suspicion for amphotericin B resistance. PCR-SSCP was a good molecular tool to characterize Aspergillus phenotypes in fungal keratitis

C. trachomatis in Female Reproductive Tract Infections and RFLP-Based Genotyping: A 16-Year Study from a Tertiary Care Hospital

Presence of Chlamydia trachomatis in endocervix was determined in 2466 women attending a tertiary care hospital in New Delhi, India over a period of 16 years, using a monoclonal-based direct immunofluorescence assay, tissue culture isolation, and a conventional PCR assay. Chlamydia antigen could be detected in 391 out of 2466 (15.85%) of patients studied; in 27.27% women with PID, 16.74% women with cervicitis, 16.03% women with infertility, and 12.06% women with adverse pregnancy outcomes, respectively. There was a statistically significant decreasing trend in Chlamydia antigen positivity between the years 1994–1999 and 2000–2004; the apparent decline in antigen positivity between the years 2000–2004 and 2005–2010 was not statistically significant. Antigen detection assay detected equal number of positives as the PCR assay; tissue culture isolation demonstrated lower positivity. In a few representative specimens from cervicitis patients, genotyping was done using RFLP pattern analysis of C. trachomatis MOMP gene amplified by PCR assay, all of these belonged to Chlamydia trachomatis serovar E

Clinicomicrobiological profile of endophthalmitis: A 10 year experience in a Tertiary Care Center in North India

Purpose: To determine the clinicomicrobiological profile of infectious agents and their antibiotic susceptibility in different type of endophthalmitis. Methods: A retrospective review of clinical and microbiological records from January 2001 to December 2010, was performed in 1110 patients diagnosed with different type of endophthalmitis (postoperative, posttraumatic, endogenous and post keratitis) to record the demographic details, clinical presentations; microbiological agents isolated with their antimicrobial sensitivity pattern. Antimicrobial susceptibility testing for various culture positive isolates (bacterial/fungal) was performed by the disc diffusion technique. Results: Out of the 1110 intra-ocular specimens processed, 384 (34.6%) were positive for bacteria. S epidermidis was the most predominant isolate accounting for 42.7% of all bacteria obtained, followed by Pseudomonas aeruginosa (24.5%). Besides Pseudomonas, Acinetobacter spp. were the next common gram negative bacilli detected (8.3%) followed by Klebsiella, E. coli, Enterobacter and Alkaligenes in 2.6%, 0.8%, 0.8% and 0.5% cases respectively. The predominant fungal species were Aspergillus spp., in 36.1%, followed by Fusarium spp. in 26.4% cases. Overall susceptibility pattern in our study showed that gram positive bacteria were most susceptible to glycopeptides like vancomycin (80-100%) and fluoroquinolones (87-91%). The sensitivity pattern of gram negative organisms like Pseudomonas and Klebsiella towards fluoroquinolones ranged between 61% - 82%. Conclusion: S epidermidis was the most common bacteria isolated in postoperative and posttraumatic endophthalmitis, Pseudomonas aeruginosa was the most common bacterial isolated in posttraumatic endophthalmitisAmongst fungi Aspergillus was the most common organism

Prevalence of Trachoma in Car-Nicobar Island, India after Three Annual Rounds of Mass Drug Administration with Azithromycin.

A high proportion of active trachoma infection in children of Car-Nicobar Island was reported through the Trachoma Rapid Assessment survey conducted in year 2010 by the same researchers. Annual mass drug treatment with azithromycin was administered from years 2010-12 to all individuals residing in this island for reducing the burden of active trachoma infection. A cross-sectional prevalence survey was conducted in the year 2013 to assess the post-treatment burden of trachoma in this population.In the 15 randomly selected compact segments from each village of the island, children aged 1-9 years were examined for evidence of active trachoma infection and participants aged ten years and above were examined for trachomatous trichiasis and corneal opacity.A total of 809 children (1-9 years) and 2735 adults were examined. Coverage with azithromycin for all the three rounds was more than 80%. The prevalence of active trachoma infection in children aged 1-9 years old was 6.8% (95% CI 5.1, 8.5) and Trachomatous Trichiasis (TT) was 3.9% (95% CI 3.2, 4.6). The risk factors associated with active trachoma infection were older age and unclean faces. The risk factors associated with TT were older age and lower literacy level.Trachoma has not been eliminated from Car-Nicobar Island in accordance to 'Global Elimination of Trachoma, 2020' guidelines. Sustained efforts and continuous surveillance admixed with adequate programmatic response is imperative for elimination of trachoma in the island

Chlamydia trachomatis Antigen Positivity in Patients with Different Ocular Manifestations over 8 Years

Laboratory confirmation of chlamydial antigen in clinically suspected cases of chlamydial eye infections is important, as similar clinical picture can be presented by different infective or noninfective causes. We retrospectively analyzed the presence of Chlamydia trachomatis antigen in 690 clinically suspected patients over the last 8 years (2009–2016). The chlamydial antigen was detected using direct immunofluorescence assay. Overall, Chlamydia-specific antigen positivity was 45.5%. The highest positivity was seen in 2014 (68.6%) and the least in 2016 (9.4%). The antigen positivity in years 2015 (13.4%) and 2016 (9.4%) was significantly less than in all the previous study years (P < 0.0001). Antigen positivity in patients having clinical diagnosis of trachoma was significantly higher than those having other eye manifestations suggestive of chlamydial infections (P = 0.0274). Stringent surveillance both at community level and in hospital attendees is required to know the actual load of this pathogen

Spectrum of mycotic keratitis in north India: Sixteen years study from a tertiary care ophthalmic centre

Introduction: To analyse the fungal culture results of patients with fungal keratitis over sixteen years and look for variations in the trends over years and distribution across ages, gender and seasons. Materials and methods: Clinical and demographic records and microbiology reports of 18,898 patients of fungal keratitis from 2001 to 2016 were analysed. Results: Overall fungal culture positivity was 21.5%. 67.3% were males and 32.7% were females. Maximum numbers of samples (17.9%) were received from age group 41–50 years, and maximum fungal culture positivity was seen in age group 31–40 years (30.8%). Most common fungus was Aspergillus species (31.1%), followed by Fusarium species (24.5%), Alternaria (10.5%), Curvularia (10.2%), Helminthosporium (5.7%), Bipolaris (5.4%), Penicillium (4.5%), Candida (4.4%), Acremonium (1.2%), Rhizopus (1.0%), Paecilomyces (0.8%), Rhodotorula (0.5%) and Mucor (0.2%). Fungal culture positivity and relative frequency of fungi remained almost stable over the study duration, except Rhodotorula spp, which showed a rise 2014 onwards. Highest numbers of culture proven fungal keratitis cases were seen in monsoon season. Conclusions: To the best of our knowledge, our study is the largest compilation of epidemiological and microbiological features of fungal keratitis, throwing light on important attributes relevant to management of mycotic keratitis patients. Keywords: Keratomycosis, Fungal culture, Corneal scraping, Pathogenic fung