Fusarium Keratitis From a Comprehensive Eye Health Care Facility in South India: Molecular Characterization by MALDI-TOF Versus Polymerase Chain Reaction Sequencing, Species Complex Distribution, and Clinical Correlation.

PURPOSE: Fusarium keratitis possesses significant diagnostic and therapeutic challenges. Medically relevant Fusaria belong to various species complexes and show prominent differences in their antifungal susceptibility profile which may influence the clinical outcome. Rapid diagnostic methods are warranted for precise identification of species complexes for prompt initiation of correct antifungals. The aim of the study was to compare between matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) and polymerase chain reaction sequencing for correct species-level identification and to analyze the clinical outcome among different Fusarium species complexes. METHODS: Twenty-nine culture-proven Fusarium keratitis cases were included in this study. A phylogenetic tree was constructed after TEF1α gene sequencing and isolates were subjected to MALDI-TOF MS, followed by database expansion and identification. Clinical outcome and risk association among species complexes were analyzed retrospectively. RESULTS: Maximum likelihood phylogeny categorized 68.9% isolates as Fusarium solani species complex (FSSC), 17.2% as Fusarium dimerum species complex (FDSC), followed by 13.7% as Fusarium fujikuroi species complex (FFSC). With extended database, MALDI-TOF MS could correctly speciate 96.5% (28/29) isolates. Previous antibiotic usage ( P = 0.034) and preoperative antifungal treatment with natamycin, voriconazole, or ketoconazole ( P = 0.025) were significantly higher in the FSSC group. The patients in the FFSC group had a significantly longer duration of symptoms at the time of clinical presentation to the clinic (15 days vs. 5 days, P = 0.030). Among 11 patients with a clinically poor outcome, 9 (31%) had FSSC infection. CONCLUSIONS: Patients infected with the FSSC had more aggressive infection with poor prognosis. MALDI-TOF MS can serve as the best alternative method to conventional molecular identification with reduced turnaround time, which may help the ophthalmologists to consider the appropriate antifungals or early surgical intervention for improved outcome.

Hyponatremia in Melioidosis: Analysis of 10-year Data from a Hospital-Based Registry.

Introduction: Hyponatremia is a frequent finding in hospitalized patients and is associated with poor clinical outcomes. While hyponatremia is known to commonly occur in certain infections, its association with melioidosis has not been studied previously. We studied incidence and impact of hyponatremia on clinical outcomes in melioidosis. Methods: This was a retrospective analysis of a single-center hospital registry of culture-positive patients with melioidosis hospitalized during a 10-year period (January 01, 2010, through January 31, 2021). Hyponatremia was defined as serum sodium of <135 mmol/L, and severe hyponatremia as serum sodium <120 mmol/L. The association of hyponatremia with in-hospital mortality, need for intensive care unit (ICU) stay and mechanical ventilation was studied. Results: Of 201 patients with melioidosis, 169 (84.1%) had hyponatremia, with severe hyponatremia in 35 (17.4%) patients. Older age (adjusted odds ratios [OR] 1.03, 95% confidence intervals [CI]: 1.00-1.06; P = 0.049) and acute kidney injury (AKI) (adjusted OR 3.30, 95% CI: 1.19-9.19; P = 0.02) were independently associated with hyponatremia. Twenty-two patients had been evaluated for cause of hyponatremia and of these, 11 (50%) had syndrome of inappropriate antidiuresis. Severe hyponatremia was associated with in-hospital mortality (adjusted OR 3.75, 95% CI: 1.37-10.27; P = 0.01), need for ICU stay (adjusted OR 7.04, 95% CI: 2.88-17.19; P < 0.001) and mechanical ventilation (adjusted OR 3.99, 95% CI: 1.54-10.32; P = 0.004). Conclusion: Hyponatremia occurs in 84.1% of hospitalized patients with melioidosis. Older age and AKI are associated with a higher incidence of hyponatremia. The presence of severe hyponatremia is an independent predictor of in-hospital mortality, need for mechanical ventilation and ICU stay.

Environmental Factors Associated With Soil Prevalence of the Melioidosis Pathogen Burkholderia pseudomallei: A Longitudinal Seasonal Study From South West India.

Melioidosis is a seasonal infectious disease in tropical and subtropical areas caused by the soil bacterium Burkholderia pseudomallei. In many parts of the world, including South West India, most cases of human infections are reported during times of heavy rainfall, but the underlying causes of this phenomenon are not fully understood. India is among the countries with the highest predicted melioidosis burden globally, but there is very little information on the environmental distribution of B. pseudomallei and its determining factors. The present study aimed (i) to investigate the prevalence of B. pseudomallei in soil in South West India, (ii) determine geochemical factors associated with B. pseudomallei presence and (iii) look for potential seasonal patterns of B. pseudomallei soil abundance. Environmental samplings were performed in two regions during the monsoon and post-monsoon season and summer from July 2016 to November 2018. We applied direct quantitative real time PCR (qPCR) together with culture protocols to overcome the insufficient sensitivity of solely culture-based B. pseudomallei detection from soil. A total of 1,704 soil samples from 20 different agricultural sites were screened for the presence of B. pseudomallei. Direct qPCR detected B. pseudomallei in all 20 sites and in 30.2% (517/1,704) of all soil samples, whereas only two samples from two sites were culture-positive. B. pseudomallei DNA-positive samples were negatively associated with the concentration of iron, manganese and nitrogen in a binomial logistic regression model. The highest number of B. pseudomallei-positive samples (42.6%, p < 0.0001) and the highest B. pseudomallei loads in positive samples [median 4.45 × 103 genome equivalents (GE)/g, p < 0.0001] were observed during the monsoon season and eventually declined to 18.9% and a median of 1.47 × 103 GE/g in summer. In conclusion, our study from South West India shows a wide environmental distribution of B. pseudomallei, but also considerable differences in the abundance between sites and within single sites. Our results support the hypothesis that nutrient-depleted habitats promote the presence of B. pseudomallei. Most importantly, the highest B. pseudomallei abundance in soil is seen during the rainy season, when melioidosis cases occur.

Burkholderia pseudomallei in Environment of Adolescent Siblings with Melioidosis, Kerala, India, 2019.

In 2019, Burkholderia pseudomallei was isolated from the backyard of 2 siblings with melioidosis in Kerala, India. This finding highlights the value of healthcare providers being aware of risk for melioidosis in febrile patients, of residents taking precautions when outside, and of increasing environmental surveillance for B. pseudomallei in this region.

Epidemiology of sepsis and risk factors for mortality in intensive care unit: a hospital based prospective study in South India.

OBJECTIVE: The present study was aimed at elucidating the epidemiology of sepsis, with a special emphasis on identifying the common bacterial aetiology, proportion of infections caused by multi-drug resistant (MDR) bacteria, and risk factors associated with 28-day mortality at a university hospital in South India. METHODS: A prospective study was undertaken from January 2017 to March 2018. Adult patients with the diagnosis of sepsis requiring intensive care unit (ICU) care were recruited. Baseline clinical, epidemiological, and laboratory data were recorded, and their association with 28-day mortality was assessed using logistic regression models. RESULTS: 400 subjects with a qSOFA score ≥2 at the time of ICU admission were included in the study. The mean age was 55.7 ± 16.6 years, and 69% were males. The mean SOFA score at the time of admission was 9.9 ± 2.7. Bacterial aetiology of sepsis was established in 53.5% of cases and 24% were caused by MDR pathogens. Carbapenem resistance was observed in 37% of the Gram-negative isolates. Escherichia coli (34.1%) was the leading pathogen. Overall, the 28-day mortality in ICU was 40%. 38% died within 48 h of ICU admission. Hypertension and SOFA > 9, male gender, and baseline-creatinine values >2.4 mg/dl were risk factors for mortality. CONCLUSIONS: Male gender, hypertension, SOFA > 9, and increased creatinine were identified as the predictors for mortality. Infectious aetiology remained undetected in nearly half of the cases using routine microbiology culture methods. Mortality within the first 48 h of admission to ICU is high and prompts the need for increasing awareness about early sepsis diagnosis in community health care settings.

Acute kidney injury and its outcomes in melioidosis.

BACKGROUND: Melioidosis is a potentially fatal tropical infection caused by Burkholderia pseudomallei. Kidney involvement is possible, but has not been well described. AIM: This study aimed to assess the risk of acute kidney injury (AKI) and its outcomes in melioidosis. METHODS: A retrospective observational cohort study was performed. Case records of consecutive patients with culture-confirmed melioidosis, observed from January 1st, 2012 through December 31st, 2019 were analysed for demographics, presence of comorbidities, including chronic kidney disease (CKD), diabetes mellitus (DM), and presence of bacteraemia, sepsis, shock, AKI, and urinary abnormalities. The outcomes we studied were: mortality, need for hospitalisation in an intensive care unit (ICU), duration of hospitalization. We then compared the outcomes between patients with and without AKI. RESULTS: Of 164 patients, AKI was observed in 59 (35.98%), and haemodialysis was required in eight (13.56%). In the univariate analysis, AKI was associated with CKD (OR 5.83; CI 1.140-29.90, P = 0.03), bacteraemia (OR 8.82; CI 3.67-21.22, P < 0.001) and shock (OR 3.75; CI 1.63-8.65, P = 0.04). In the multivariate analysis, CKD (adjusted OR 10.68; 95% CI 1.66-68.77; P = 0.013) and bacteraemia (adjusted OR 8.22; 95% CI 3.15-21.47, P < 0.001) predicted AKI. AKI was associated with a greater need for ICU care (37.3% vs. 13.3%, P = 0.001), and mortality (32.2% vs. 5.7%, P < 0.001). Mortality increased with increasing AKI stage, i.e. stage 1 (OR 3.52, CI 0.9-13.7, P = 0.07), stage 2 (OR 6.79, CI 1.92-24, P = 0.002) and stage 3 (OR 17.8, CI 5.05-62.8, P < 0.001), however kidney function recovered in survivors. Hyponatremia was observed in 138 patients (84.15%) and isolated urinary abnormalities were seen in 31(18.9%). CONCLUSIONS: AKI is frequent in melioidosis and occurred in 35.9% of our cases. Hyponatremia is likewise common. AKI was predicted by bacteraemia and CKD, and was associated with higher mortality and need for ICU care; however kidney function recovery was observed in survivors.

Epidemiology, resistance characteristics, virulence determinants, and treatment outcomes of Staphylococcus aureus bone and joint infections: a one-year prospective study at a tertiary care hospital in India.

PURPOSE: The study was aimed to explore the differences between the Staphylococcus aureus osteosynthesis-associated infection (OAI) and non-implant related infections (NIRI) in terms of epidemiology, resistance characteristics, virulence determinants, treatment, risk factors, and outcome. METHODS: A prospective study was conducted from 2018 through 2019. The phenotypic and genotypic characterization of S. aureus, risk factors, treatment, and outcome were compared. RESULTS: A total of 60 patients were included. 50% had OAIs (70%) (p = .045). Overall, MRSA (OR 0.69; p = .020) and old age (OR 0.95; p = 0.035) were the important risk factors. Implanted patients presented with the features of chronic osteomyelitis (93.3%, p = 0.01). NIRI cases composed of only 66.7% of OM, and 55% of them were acute. OAI isolates were more frequently luk gene positives (50%) than isolates from the NIRI group (33.3%). Patients with OAI by luk positive isolates significantly had prolonged hospital stay (p = 0.043; OR-0.96, CI-0.91-1.0). Most of the NIRIs (60%) managed with antibiotics, but frequent surgical intervention (OR 10.68; p = .024) with prolonged systemic antibiotics (OR 1.07; p = .029) helped all OAIs to recover. Patients without implants were recovered in a higher number (83.3%). CONCLUSION: Our study highlighted that the differences exist between the OAI and NIRI, specifically in terms of clinical features, distribution of luk genes, treatment approach, and outcome. Risk factors for both types of infection remained the same.

Melioidosis in Gujarat: a neglected tropical disease.

We report what we believe is the first case in Gujarat of melioidosis in a 67-year-old man. Awareness of this disease is limited, especially in areas supposed not to be endemic.

Melioidosis In Suspected Recurrent Tuberculosis: A disease in disguise.

INTRODUCTION: Melioidosis, caused by the soil saprophyte B. pseudomallei, is a 'neglected' infectious disease in many Asian countries. It remained undiagnosed or misdiagnosed in India for long due to a lack of awareness and facilities to diagnose the disease; however, it is slowly gaining the status of an emerging disease recently. The disease is well known as a great mimicker, as the presentations are very similar to many other tropical diseases, and more importantly, to tuberculosis . METHODOLOGY: A prospective observational study was conducted from January 2016 - December 2018 to find the occurance of melioidosis  in patients with 'recurrent' tuberculosis infection in a tertiary health care hospital from southern India. All suspected cases of recurrent tuberculosis were simultaneously tested for the presence of B. pseudomallei, and basic demographics and clinical details were documented. RESULT: Among 11,138 patients admitted with suspected tuberculosis infection, 586 (5.2%) patients were confirmed. There was recurrent Mycobacterium tuberculosis infection in 11/586 (1.8%) cases, and 7/586 (1.2%) had growth of B. pseudomallei in culture. Patients with melioidosis had either pulmonary involvement, or bone and joint infections and deep abscesses.  Uncontrolled diabetes mellitus was the major risk factor. CONCLUSION: The study foreshadows the need for prompt and accurate microbiological diagnosis along with a high index of suspicion from the clinicians in countries which are endemic for both melioidosis and tuberculosis, thus ameliorating the irrational anti-tuberculosis treatment.

Implications of environmental and pathogen-specific determinants on clinical presentations and disease outcome in melioidosis patients.

BACKGROUND: Melioidosis is gaining recognition as an emerging infectious disease with diverse clinical manifestations and high-case fatality rates worldwide. However, the molecular epidemiology of the disease outside the endemic regions such as northeast part of Thailand and northern Australia remains unclear. METHODOLOGY/PRINCIPAL FINDINGS: Clinical data and B. pseudomallei isolates obtained from 199 culture-confirmed cases of melioidosis diagnosed during 2006-2016 in South India were used to elucidate the host and pathogen specific variable virulence determinants associated with clinical presentations and disease outcome. Further, we determined the temporal variations and the influence of ecological factors on B.pseudomallei Lipopolysaccharide (LPS) genotypes causing infections. Severe forms of the disease were observed amongst 169 (85%) patients. Renal dysfunction and infection due to B.pseudomallei harboring BimABm variant had significant associations with severe forms of the disease. Diabetes mellitus, septicemic melioidosis and infection due to LPSB genotype were independent risk factors for mortality. LPSB (74%) and LPSA (20.6%) were the prevalent genotypes causing infections. Both genotypes demonstrated temporal variations and had significant correlations with rainfall and humidity. CONCLUSION/SIGNIFICANCE: Our study findings suggest that the pathogen specific virulence traits under the influence of ecological factors are the key drivers for geographical variations in the molecular epidemiology of melioidosis.

Disseminated Nocardia asiatica infection in an immunocompromised individual: A rare entity needs careful vigilance.

Nocardia asteroides complex and Nocardia brasiliensis are common etiological agents of disseminated nocardiosis among immunocompromised individuals. Here we reported an uncommon case of disseminated nocardiosis with the involvement of lung, brain, soft tissue & pancreas by a rarely isolated species Nocardia asiatica in a HIV infected individual. Diagnosis was initially misinterpreted as tuberculosis based on the clinical and radiological findings. The isolate was identified to the species level with a 16S rRNA gene analysis & in vitro susceptibility was done as resistance is not uncommon among them. Clinical cure & radiological regression of lesions was observed except for brain after treatment with meropenem, amikacin & cotrimoxazole.

Molecular analysis of clinical Burkholderia pseudomallei isolates from southwestern coastal region of India, using multi-locus sequence typing.

BACKGROUND: The Gram-negative soil dwelling bacterium Burkholderia pseudomallei is the etiological agent of melioidosis. The disease is endemic in most parts of Southeast Asia and northern Australia. Over last few years, there has been an increase in number of melioidosis cases from India; however the disease epidemiology is less clearly understood. Multi-locus sequence typing (MLST) is a powerful genotypic method used to characterize the genetic diversity of B. Pseudomallei both within and across the geographic regions. METHODS: In this study, MLST analysis was performed on 64 B. pseudomallei clinical isolates. These isolates were obtained between 2008-2014 from southwestern coastal region of India. Broad population patterns of Indian B. pseudomallei isolates in context with isolates of Southeast Asia or global collection was determined using in silico phylogenetic tools. RESULTS: A total of 32 Sequence types (STs) were reported among these isolates of which 17 STs (53%) were found to be novel. ST1368 was found as group founder and the most predominant genotype (n = 11, 17%). Most of the B. pseudomallei isolates reported in this study (or other Indian isolates available in MLST database) clustered in one major group suggesting clonality in Indian isolates; however, there were a few outliers. When analyzed by measure of genetic differentiation (FST) and other phylogenetic tools (e.g. PHYLOViZ), Indian STs were found closer to Southeast Asian isolates than Australian isolates. The phylogenetic analysis further revealed that within Asian clade, Indian isolates grouped more closely with isolates from Sri Lanka, Vietnam, Bangladesh and Thailand. CONCLUSIONS: Overall, the results of this study suggest that the Indian B. pseudomallei isolates are closely related with lesser heterogeneity among them and cluster in one major group suggesting clonality of the isolates. However, it appears that there are a few outliers which are distantly related to the majority of Indian STs. Phylogenetic analysis suggest that Indian isolates are closely related to isolates from Southeast Asia, particularly from South Asia.

Fatal Cryptococcus gattii meningitis with negative cryptococcal antigen test in a HIV-non-infected patient.

Cryptococcus gattii predominantly causes central nervous system and pulmonary infection in both immunocompromised and immunocompetent patients with substantial morbidity. We report a case of rapidly fatal meningitis by C. gattii in an HIV-non-infected man with CD4 lymphopenia who tested negative for cryptococcal antigen. This case may serve as an alert to its wider occurrence and less explored risk factors.

Melioidosis in South Asia (India, Nepal, Pakistan, Bhutan and Afghanistan).

Despite the fact that South Asia is predicted to have the highest number of cases worldwide, melioidosis is a little-known entity in South Asian countries. It has never been heard of by the majority of doctors and has as yet failed to gain the attention of national Ministries of Health and country offices of the World Health Organization (WHO). Although a few centers are diagnosing increasing numbers of cases, and the mortality documented from these institutions is relatively high (nearly 20%), the true burden of the disease remains unknown. In India, most cases have been reported from southwestern coastal Karnataka and northeastern Tamil Nadu, although this probably simply reflects the presence of centers of excellence and researchers with an interest in the disease. As elsewhere, the majority of cases have type 2 diabetes mellitus and occupational exposure to the environment. Most present with community-acquired pneumonia and/or bacteremia, especially during heavy rainfall. The high seropositivity rate (29%) in Karnataka and isolation of B. pseudomallei from the environment in Tamil Nadu and Kerala confirm India as melioidosis-endemic, although the full extent of the distribution of the organism across the country is unknown. There are limited molecular epidemiological data, but, thus far, the majority of Indian isolates have appeared distinct from those from South East Asia and Australia. Among other South Asian countries, Sri Lanka and Bangladesh are known to be melioidosis-endemic, but there are no cases that have conclusively proved to have been acquired in Nepal, Bhutan, Afghanistan or Pakistan. There are no surveillance systems in place for melioidosis in South Asian countries. However, over the past two years, researchers at the Center for Emerging and Tropical Diseases of Kasturba Medical College, University of Manipal, have established the Indian Melioidosis Research Forum (IMRF), held the first South Asian Melioidosis Congress, and have been working to connect researchers, microbiologists and physicians in India and elsewhere in South Asia to raise awareness through training initiatives, the media, workshops, and conferences, with the hope that more patients with melioidosis will be diagnosed and treated appropriately. However, much more work needs to be done before we will know the true burden and distribution of melioidosis across South Asia.

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.

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.

Melioidosis: the great mimicker presenting as spondylodiscitis.

Melioidosis, a syndrome with protean clinical manifestations, is caused by Gram-negative soil saprophyte Burkholderiapseudomallei Among its diverse clinical presentations, the involvement of spine is a rare phenomenon and can mimic tuberculosis on presentation. A 65-year-old female with a known case of diabetes presented with fever with lower back pain. Blood culture grew Staphylococcus aureus, and as per sensitivity report, clindamycin and cefazolin were started. X-ray and MRI lumbosacral spine showed spondylodiscitis (likely Koch's). Decompression and biopsy were done, and a sample was sent for microbiological investigations that showed no growth of any significant pathogen; furthermore, all tests for tuberculosis diagnosis also remained negative. Active Melioidosis Detect Lateral Flow Assay was used on the tissue sample, which was positive for B. pseudomallei Capsular Polysaccharide (CPS) antigen; the case was confirmed by typethree secretion system 1 PCR for melioidosis. Antibiotics were changed to parenteral ceftazidime for 2 weeks followed by oral cotrimoxazole. A dedicated team of microbiologists and physicians is required to identify and treat the disease.

Improved detection of Burkholderia pseudomallei from non-blood clinical specimens using enrichment culture and PCR: narrowing diagnostic gap in resource-constrained settings.

OBJECTIVES: 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. METHODS: Clinical specimens (n = 525) obtained from patients presenting at a tertiary care hospital of South India with clinical symptoms suggestive of community-acquired pneumonia, lower respiratory tract infections, superficial or internal abscesses, chronic skin ulcers and bone or joint infections were tested for the presence of Burkholderia pseudomallei using conventional culture (CC), enrichment culture (EC) and PCR. Sensitivity, specificity, positive and negative predictive values of CC and PCR were initially deduced using EC as the gold standard method. Further, diagnostic accuracies of all the three methods were analysed using Bayesian latent class modelling (BLCM). RESULTS: Detection rates of B. pseudomallei using CC, EC and PCR were 3.8%, 5.3% and 6%, respectively. Diagnostic sensitivities and specificities of CC and PCR were 71.4, 98.4% and 100 and 99.4%, respectively in comparison with EC as the gold standard test. With Bayesian latent class modelling, EC and PCR demonstrated sensitivities of 98.7 and 99.3%, respectively, while CC showed a sensitivity of 70.3% for detection of B. pseudomallei. An increase of 1.6% (95% CI: 1.08-4.32%) in the case detection rate of melioidosis was observed in the study population when EC and/or PCR were used in adjunct to the conventional culture technique. CONCLUSIONS: Our study findings underscore the diagnostic superiority of enrichment culture and/or PCR over conventional microbiological culture for improved case detection of melioidosis from non-blood clinical specimens.

Melioidosis: Reinfection going incognito as relapse.

Melioidosis has recently gained importance as an emerging disease in India. Recurrent melioidosis has been reported from different parts of the world and can be due to relapse or reinfection. Distinction between relapse and reinfection is important for epidemiology, investigation and management. Here, we present the data regarding rate of recurrence and utility of multilocus sequence typing (MLST) in differentiating relapse form reinfection amongst melioidosis patients from a tertiary care hospital in South India. Amongst the 31 patients who survived and underwent follow-up, 4 (13%) presented with recurrence. Three cases (75%) were identified as reinfection and one (25%) as relapse based on MLST. Re-exposure to environmental Burkholderia pseudomallei amongst patients with melioidosis in endemic areas is likely. In such a scenario, more often than not, recurrence of melioidosis can be attributed to reinfection.

Unravelling the Molecular Epidemiology and Genetic Diversity among Burkholderia pseudomallei Isolates from South India Using Multi-Locus Sequence Typing.

There is a slow but steady rise in the case detection rates of melioidosis from various parts of the Indian sub-continent in the past two decades. However, the epidemiology of the disease in India and the surrounding South Asian countries remains far from well elucidated. Multi-locus sequence typing (MLST) is a useful epidemiological tool to study the genetic relatedness of bacterial isolates both with-in and across the countries. With this background, we studied the molecular epidemiology of 32 Burkholderia pseudomallei isolates (31 clinical and 1 soil isolate) obtained during 2006-2015 from various parts of south India using multi-locus sequencing typing and analysis. Of the 32 isolates included in the analysis, 30 (93.7%) had novel allelic profiles that were not reported previously. Sequence type (ST) 1368 (n = 15, 46.8%) with allelic profile (1, 4, 6, 4, 1, 1, 3) was the most common genotype observed. We did not observe a genotypic association of STs with geographical location, type of infection and year of isolation in the present study. Measure of genetic differentiation (FST) between Indian and the rest of world isolates was 0.14413. Occurrence of the same ST across three adjacent states of south India suggest the dispersion of B.pseudomallei across the south western coastal part of India with limited geographical clustering. However, majority of the STs reported from the present study remained as "outliers" on the eBURST "Population snapshot", suggesting the genetic diversity of Indian isolates from the Australasian and Southeast Asian isolates.