Chaitanya Tellapragada

Antifungal Susceptibility Patterns, In Vitro Production of Virulence Factors, and Evaluation of Diagnostic Modalities for the Speciation of Pathogenic Candida from Blood Stream Infections and Vulvovaginal Candidiasis

Candida spp. have emerged as successful pathogens in both invasive and mucosal infections. Varied virulence factors and growing resistance to antifungal agents have contributed to their pathogenicity. We studied diagnostic accuracy of HiCrome Candida Differential Agar and Vitek 2 Compact system for identification of Candida spp. in comparison with species-specific PCR on 110 clinical isolates of Candida from blood stream infections (54, 49%) and vulvovaginal candidiasis (56, 51%). C. albicans (61%) was the leading pathogen in VVC, while C. tropicalis (46%) was prominent among BSIs. HiCrome Agar and Vitek 2 Compact had good measures of agreement (κ) 0.826 and 0.895, respectively, in comparison with PCR. We also tested these isolates for in vitro production of proteinase, esterase, phospholipases, and biofilms. Proteinase production was more among invasive isolates (P = 0.017), while phospholipase production was more among noninvasive isolates (P = 0.001). There was an overall increase in the production of virulence factors among non-albicans Candida. Identification of clinical isolates of Candida up to species level either by chromogenic agar or by Vitek 2 Compact system should be routinely done to choose appropriate therapy.

Risk factors for preterm birth and low birth weight among pregnant Indian women: A hospital-based prospective study

Objectives: The present study was undertaken to study the maternal risk factors for preterm birth (PTB) and low birth weight (LBW) with a special emphasis on assessing the proportions of maternal genitourinary and periodontal infections among Indian women and their association with adverse pregnancy outcomes. Methods: A hospital-based prospective study comprising 790 pregnant women visiting the obstetrics clinic for a routine antenatal check-up was undertaken. Once recruited, all study participants underwent clinical and microbiological investigations for genitourinary infections followed by a dental check-up for the presence of periodontitis. The study participants were followed up until their delivery to record the pregnancy outcomes. Infectious and non-infectious risk factors for PTB and LBW were assessed using univariate and multivariate Cox regression analysis. Independent risk factors for PTB and LBW were reported in terms of adjusted relative risk (ARR) with the 95% confidence interval (CI). Results: Rates of PTB and LBW in the study population were 7.6% and 11.4%, respectively. Previous preterm delivery (ARR, 5.37; 95% CI, 1.5 to 19.1), periodontitis (ARR, 2.39; 95% CI, 1.1 to 4.9), Oligohydramnios (ARR, 5.23; 95% CI, 2.4 to 11.5), presence of Nugent’s intermediate vaginal flora (ARR, 2.75; 95% CI, 1.4 to 5.1), gestational diabetes mellitus (ARR, 2.91; 95% CI, 1.0 to 8.3), and maternal height <1.50 m (ARR, 2.21; 95% CI, 1.1 to 4.1) were risk factors for PTB, while periodontitis (ARR, 3.38; 95% CI, 1.6 to 6.9), gestational hypertension (ARR, 3.70; 95% CI, 1.3 to 10.8), maternal height <1.50 m (ARR, 2.66; 95% CI, 1.3 to 5.1) and genital infection during later stages of pregnancy (ARR, 2.79; 95% CI, 1.2 to 6.1) were independent risk factors for LBW. Conclusions: Our study findings underscore the need to consider screening for potential genitourinary and periodontal infections during routine antenatal care in developing countries.

Prevalence of Clinical Periodontitis and Putative Periodontal Pathogens among South Indian Pregnant Women

In view of recent understanding of the association of periodontal infections and adverse pregnancy outcomes, the present investigation was undertaken to study the periodontal infections among 390 asymptomatic pregnant women and to find an association of bacterial etiologies with the disease. Prevalence of gingivitis was 38% and clinical periodontitis was 10% among the study population. Subgingival plaque specimens were subjected to multiplex PCR targeting ten putative periodontopathogenic bacteria. Among the periodontitis group, high detection rates of Porphyromonas gingivalis (56%), Prevotella nigrescens (44%), Treponema denticola (32%), and Prevotella intermedius (24%) were noted along with significant association with the disease (P < 0.05).

The antibiotics of choice for the treatment of melioidosis in Indian set up

Therapeutic options for the treatment of melioidosis caused by Burkholderia pseudomallei are limited due to the inherent resistance conferred by this pathogen to various groups of antibiotics. Witnessing an increase in the number of microbiological culture-confirmed cases of melioidosis at our settings in the past few years, we undertook this study to estimate the minimum inhibitory concentrations of clinical isolates of B. pseudomallei against the four commonly employed antimicrobial agents in the patient management at our settings, namely, ceftazidime, meropenem, trimethoprim-sulfamethoxazole and doxycycline. All isolates were susceptible to the antibiotics tested, except for one isolate which showed resistance to doxycycline (minimum inhibitory concentration [MIC]: 32 μg/ml). MIC50 and 90 for all the four antibiotics were estimated. From this study, we conclude that the clinical isolates of B. pseudomallei from the southern part of India are well susceptible to the commonly employed antimicrobial agents for therapy.

Performance evaluation of Active Melioidosis Detect-Lateral Flow Assay (AMD-LFA) for diagnosis of melioidosis in endemic settings with limited resources

Melioidosis is a fatal infection caused by the soil saprophyte Burkholderia pseudomallei. Early diagnosis and befitting medical management can significantly influence the clinical outcomes among patients with melioidosis. Witnessing an annual increment in the number of melioidosis cases, over the past few years, mainly from the developing tropical nations, the present study was undertaken to evaluate the diagnostic utility of Active Melioidosis DetectTMLateralFlow Assay (AMD-LFA), in comparison with enrichment culture and PCR. A total of 206clinical specimens obtained from 175 patients with clinical suspicion of melioidosis were considered for the evaluation. Positivity for B.pseudomallei using enrichment culture, PCR and AMD-LFA were observed among 63 (30.5%), 55 (26.6%) and 63 (30.5%) specimens respectively. The AMD-LFA failed to detect melioidosis from 9 culture-confirmed cases (6 whole blood specimens, 2 pus samples, and one synovial fluid). Further the test gave faint bands from 9 urine samples which were negative by culture and PCR. AMD-LFA demonstrated a sensitivity, specificity, of 85.71%(CI:74.61% to 93.25%) and 93.62% (CI:88.23% to 97.04%), with positive predictive value of 85.71% (CI: 75.98% to 91.92%) and negative predictive value of 93.62% (CI:88.89% to 96.42%). The test needs further evaluation in view of the faint bands from negative urine samples, for incorporating the test as a point of care assay.In view of its rapidity and ease of testing AMD-LFA might be useful in early diagnosis of melioidosis at resource constraint settings.

Does the size matter? Evaluation of effect of incorporation of silver nanoparticles of varying particle size on the antimicrobial activity and properties of irreversible hydrocolloid impression material

OBJECTIVES The main objective of the present in vitro study is to evaluate the antimicrobial activity and properties of irreversible hydrocolloid impression material incorporated with silver nanoparticles of varying size at different concentrations. METHODS Silver nanoparticles of 80-100, 50-80, 30-50 and 10-20nm size were added to irreversible hydrocolloid impression material at 0.5, 1.0, 2.0 and 5.0wt%. Antimicrobial activity of the silver nanoparticle incorporated irreversible hydrocolloid was measured using disk diffusion method. The gel strength, flow, gelation time and permanent deformation were measured according to American Dental Association specification #18. Data were analyzed using analysis of variation at a confidence interval of 95% (α=0.05). RESULTS Silver nanoparticles of 80-100nm size have imparted superior antimicrobial activity to the irreversible hydrocolloid in a dose-dependent manner whereas finer nanoparticle size did not exhibit any antimicrobial activity. The addition of silver nanoparticles did not alter the properties of irreversible hydrocolloid at 0.5 and 1.0wt% whereas at higher concentrations significant differences in flow, gelation time and strength were observed. SIGNIFICANCE The results of the present study indicate that silver nanoparticles of size range 80-100nm are superior in imparting antimicrobial activity to irreversible hydrocolloid compared to finer particle size range.

Improved detection of Burkholderia Pseudomallei from non-blood Clinical Specimens using Enrichment Culture and PCR: Narrowing Diagnostic gap in Resource Constrained Settings

To evaluate the diagnostic utility of enrichment culture and PCR for improved case detection rates of non‐bacteraemic form of melioidosis in limited resource settings.

Human brucellosis: an experience from a tertiary care hospital in southern India

The aim of our study was to examine and compare the clinical presentations, complications, laboratory findings, treatment and outcome of patients with acute, subacute and chronic forms of brucellosis in a tertiary care setting. This hospital-based observational study was undertaken between April 2015 and March 2017. Patients diagnosed with brucellosis, either by blood culture and/or serology, were recruited. A total of 94 cases of brucellosis of acute, subacute and chronic forms were observed in 78.7%, 15.9% and 5.3%, respectively. Blood culture grew Brucella spp. in 70.2% cases. Serological tests showed positivity in 96.8% of the patients. Using multivariate logistic regression analysis, fever and upper back pain were significant predictors for both acute and chronic forms of the disease, respectively. There is a need to increase awareness and understand the local sero-epidemiological pattern of brucellosis as it is still little known.

Screening of vulvovaginal infections during pregnancy in resource constrained settings: Implications on preterm delivery

The present study was undertaken to evaluate the efficacy of clinical and microbiological investigations available in limited resource settings for an effective diagnosis of vaginal infections/abnormal vaginal microbiota among pregnant women. As an outcome of the study we intended to find the association of various vaginal infections during pregnancy with preterm delivery. Pregnant women presenting for routine antenatal care at an antenatal clinic in south India were enrolled in the study. Each participant underwent clinical and microbiological examinations for the diagnosis of vaginal infections such as bacterial vaginosis (BV), vulvovaginal candidiasis (VVC) and trichomoniasis. In addition, Grams stained high-vaginal smears were evaluated for the presence of partial BV and vaginitis. Diagnostic accuracies of clinical diagnosis for the aforementioned infections was determined in comparison with gold standard microbiological diagnosis. Proportion of women with vulvovaginal infections were estimated using descriptive statistics and incidence risk ratio for preterm delivery with each form of the infection was estimated using univariate analysis. A total of 790 pregnant women were recruited in the study. Positive predictive values of clinical diagnosis for BV, VVC and Trichomoniasis in comparison with reference method were 72.7, 33.5 and 37.6% respectively. Partial BV (3.2%) and vaginitis due to mixed bacterial etiology (9.4%) were per exclusionem diagnosed using the microbiological smear examination. Microbiological diagnosis of BV and vaginitis were found to have a statistically significant association with preterm delivery. Effective diagnosis of vaginal infections/abnormal vaginal microbiota associated with preterm delivery can be achieved by the adjunct of microbiological smear examination of the vaginal smears to the clinical examination in limited resource settings.

Stamp's modified Ziehl–Neelsen staining for Brucella: Beware of the first impressions

one copy mutates, there will be others that can be detected. However, a report to the contrary[3] has put us on guard. To scrutinise the stability of the target, we extracted DNA from 39 clinical isolates of N. gonorrhoeae from New Delhi and 22 clinical isolates obtained from across the country in the last 2 years. The presence of 188 bp amplicon in all affirms the conservation of the same among our local isolates, thereby offering a real potential for diagnostic use for Indian setting.