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1.
Indian J Otolaryngol Head Neck Surg ; 76(1): 611-619, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38440599

ABSTRACT

We aimed to compare the demography, clinical profile, histopathology, fungal culture, radiology, surgery performed, medical therapy and outcomes of patients with acute invasive fungal sinusitis seen during the first and second waves of the COVID-19 pandemic by retrospectively reviewing their case records. Of 238 patients, 43(18.1%) presented during the first wave and 195(81.9%) during the second wave. Patients seen during the first wave were older (p = 0.04) and more likely to have visual impairment (p = 0.004), frozen eye (p = 0.012), altered sensorium (p = 0.007) and stage 3 disease (p = 0.03). Those seen during the second wave were more often COVID-19 positive and had newly diagnosed diabetes mellitus (p = 0.04)and stage 1 disease (p = 0.03). Most patients had a positive culture for Rhizopus species during both waves. Histopathology showed broad aseptate hyphae in all patients but angioinvasion was seen more often during the first wave (p = 0.04). The majority of patients were treated with endoscopic+/- open debridement followed by intravenous amphotericin B and oral posaconazole. While the overall survival rate was similar (first wave 65.1%; second wave 79%; p = 0.106), mortality after discharge was greater during the first wave (11.6% vs 1.5%; p = 0.001). Mortality was higher in patients with stage 3 disease (p = 0.003). Significant differences in clinical presentation, histopathology, radiological stage of disease and post-discharge survival were noted between the two waves of the COVID-19 pandemic, the causes for which were multi-factorial.

2.
Lancet Infect Dis ; 24(2): 140-149, 2024 Feb.
Article in English | MEDLINE | ID: mdl-37918414

ABSTRACT

BACKGROUND: Childhood tuberculosis remains a major cause of morbidity and mortality in part due to missed diagnosis. Diagnostic methods with enhanced sensitivity using easy-to-obtain specimens are needed. We aimed to assess the diagnostic accuracy of the Cepheid Mycobacterium tuberculosis Host Response prototype cartridge (MTB-HR), a candidate test measuring a three-gene transcriptomic signature from fingerstick blood, in children with presumptive tuberculosis disease. METHODS: RaPaed-TB was a prospective diagnostic accuracy study conducted at four sites in African countries (Malawi, Mozambique, South Africa, and Tanzania) and one site in India. Children younger than 15 years with presumptive pulmonary or extrapulmonary tuberculosis were enrolled between Jan 21, 2019, and June 30, 2021. MTB-HR was performed at baseline and at 1 month in all children and was repeated at 3 months and 6 months in children on tuberculosis treatment. Accuracy was compared with tuberculosis status based on standardised microbiological, radiological, and clinical data. FINDINGS: 5313 potentially eligible children were screened, of whom 975 were eligible. 784 children had MTB-HR test results, of whom 639 had a diagnostic classification and were included in the analysis. MTB-HR differentiated children with culture-confirmed tuberculosis from those with unlikely tuberculosis with a sensitivity of 59·8% (95% CI 50·8-68·4). Using any microbiological confirmation (culture, Xpert MTB/RIF Ultra, or both), sensitivity was 41·6% (34·7-48·7), and using a composite clinical reference standard, sensitivity was 29·6% (25·4-34·2). Specificity for all three reference standards was 90·3% (95% CI 85·5-94·0). Performance was similar in different age groups and by malnutrition status. Among children living with HIV, accuracy against the strict reference standard tended to be lower (sensitivity 50·0%, 15·7-84·3) compared with those without HIV (61·0%, 51·6-69·9), although the difference did not reach statistical significance. Combining baseline MTB-HR result with one Ultra result identified 71·2% of children with microbiologically confirmed tuberculosis. INTERPRETATION: MTB-HR showed promising diagnostic accuracy for culture-confirmed tuberculosis in this large, geographically diverse, paediatric cohort and hard-to-diagnose subgroups. FUNDING: European and Developing Countries Clinical Trials Partnership, UK Medical Research Council, Swedish International Development Cooperation Agency, Bundesministerium für Bildung und Forschung; German Center for Infection Research (DZIF).


Subject(s)
HIV Infections , Mycobacterium tuberculosis , Tuberculosis, Pulmonary , Tuberculosis , Child , Humans , Mycobacterium tuberculosis/genetics , Prospective Studies , Developing Countries , Tuberculosis, Pulmonary/drug therapy , Sensitivity and Specificity , Tuberculosis/diagnosis , South Africa , Sputum/microbiology
3.
Front Cell Infect Microbiol ; 13: 1251456, 2023.
Article in English | MEDLINE | ID: mdl-38029246

ABSTRACT

Introduction: Mucormycosis is an acute invasive fungal disease (IFD) seen mainly in immunocompromised hosts and in patients with uncontrolled diabetes. The incidence of mucormycosis increased exponentially in India during the SARS-CoV-2 (henceforth COVID-19) pandemic. Since there was a lack of data on molecular epidemiology of Mucorales causing IFD during and after the COVID-19 pandemic, whole genome analysis of the Rhizopus spp. isolated during this period was studied along with the detection of mutations that are associated with antifungal drug resistance. Materials and methods: A total of 50 isolates of Rhizopus spp. were included in this prospective study, which included 28 from patients with active COVID-19 disease, 9 from patients during the recovery phase, and 13 isolates from COVID-19-negative patients. Whole genome sequencing (WGS) was performed for the isolates, and the de novo assembly was done with the Spades assembler. Species identification was done by extracting the ITS gene sequence from each isolate followed by searching Nucleotide BLAST. The phylogenetic trees were made with extracted ITS gene sequences and 12 eukaryotic core marker gene sequences, respectively, to assess the genetic distance between our isolates. Mutations associated with intrinsic drug resistance to fluconazole and voriconazole were analyzed. Results: All 50 patients presented to the hospital with acute fungal rhinosinusitis. These patients had a mean HbA1c of 11.2%, and a serum ferritin of 546.8 ng/mL. Twenty-five patients had received steroids. By WGS analysis, 62% of the Rhizopus species were identified as R. delemar. Bayesian analysis of population structure (BAPS) clustering categorized these isolates into five different groups, of which 28 belong to group 3, 9 to group 5, and 8 to group 1. Mutational analysis revealed that in the CYP51A gene, 50% of our isolates had frameshift mutations along with 7 synonymous mutations and 46% had only synonymous mutations, whereas in the CYP51B gene, 68% had only synonymous mutations and 26% did not have any mutations. Conclusion: WGS analysis of Mucorales identified during and after the COVID-19 pandemic gives insight into the molecular epidemiology of these isolates in our community and establishes newer mechanisms for intrinsic azole resistance.


Subject(s)
COVID-19 , Mucorales , Mucormycosis , Humans , Mucormycosis/epidemiology , Mucormycosis/diagnosis , Mucormycosis/microbiology , Rhizopus/genetics , Pandemics , Phylogeny , Prospective Studies , Bayes Theorem , COVID-19/epidemiology , SARS-CoV-2/genetics , Mucorales/genetics , Antifungal Agents/pharmacology , Antifungal Agents/therapeutic use
4.
J Clin Tuberc Other Mycobact Dis ; 32: 100372, 2023 Aug.
Article in English | MEDLINE | ID: mdl-37168873

ABSTRACT

Mycobacterium orygis is a member of the Mycobacterium tuberculosis complex (MTBC) and causes tuberculosis in a variety of animals, including humans in South Asia. Here, we describe the clinical features associated with 8 human cases of whole genome sequence (WGS) confirmed M. orygis from a tertiary care hospital in South India during 2018-2019. The patient ages ranged from 9 to 51 years, with 5 females and 3 males included. All the patients had extrapulmonary disease with 2 having concomitant pulmonary involvement. Clinical improvement was documented after a full course of anti-tuberculosis therapy in 6 cases for whom follow-up was available. Taken together, the results show that M. orygis causes human tuberculosis in India, with a predominant extrapulmonary disease. Standardized molecular assays of this emerging member of the MTBC are needed to provide further information on the frequency of M. orygis infection in India and other countries where it is found in livestock and domestic wildlife.

5.
Sci Rep ; 13(1): 3746, 2023 03 06.
Article in English | MEDLINE | ID: mdl-36879040

ABSTRACT

Paradoxical reactions (PRs) are poorly studied complex immunological phenomena, among patients with tuberculosis (TB). When PRs involves critical structures like the central nervous system (CNS), immunomodulatory therapy is often required. Predictors for PRs in TB to pre-empt appropriate treatment strategies in high-risk groups are lacking. TT genotype of Leukotriene A4 hydrolase (LTA4H) promoter region rs17525495 polymorphisms are associated with exaggerated immune responses in Tuberculous meningitis (TBM), the most severe form of extrapulmonary tuberculosis (EPTB). The association of these polymorphisms with PRs is not known. We evaluated this plausibility among 113 patients with EPTB, at high risk of PRs. Majority [81 (71.7%)] had disseminated tuberculosis with prominent CNS [54 (47.8%)] and lymph node involvement [47 (41.6%)]. Human immunodeficiency Virus (HIV) co-infection was seen among 23 (20.3%) patients. PRs were noted in 38.9% patients, at a median duration of 3 months (IQR 2-4). LTA4H rs17525495 single nucleotide polymorphism (SNP) analysis showed 52 (46%) patients had CC, 43 (38.1%) had CT and 18 (15.9%) had TT genotypes. There was no statistically significant difference in occurrence [CC 38.5% vs CT 39.5% vs TT 38.7%] and time of onset [median (IQR)] of PRs across the genotypes [CC 3 (1-4.7), CT 3 (2-5), TT 2 (2-3)]. PRs was shown to be significantly linked with HIV co-infection (RR 0.6, 95% CI 0.29-1.28), culture positivity (RR 0.5, 95% CI 0.28-1.14), TB Lymphadenitis (RR 0.7, 95% CI 0.44-1.19) and CNS involvement RR 2.1, 95% CI 1.27-3.49) in the univariate analysis (p < 0.2). On multivariate analysis, CNS involvement alone was associated with PRs (aRR 3.8 (1.38-10.92); p < 0.01). PRs were associated with CNS involvement but not with LTA4H rs17525495 polymorphisms.


Subject(s)
Coinfection , Tuberculosis, Extrapulmonary , Humans , Epoxide Hydrolases/genetics , Polymorphism, Genetic
6.
Pediatr Infect Dis J ; 42(5): 353-360, 2023 05 01.
Article in English | MEDLINE | ID: mdl-36854097

ABSTRACT

INTRODUCTION: An estimated 1.2 million children develop tuberculosis (TB) every year with 240,000 dying because of missed diagnosis. Existing tools suffer from lack of accuracy and are often unavailable. Here, we describe the scientific and clinical methodology applied in RaPaed-TB, a diagnostic accuracy study. METHODS: This prospective diagnostic accuracy study evaluating several candidate tests for TB was set out to recruit 1000 children <15 years with presumptive TB in 5 countries (Malawi, Mozambique, South Africa, Tanzania, India). Assessments at baseline included documentation of TB signs and symptoms, TB history, radiography, tuberculin skin test, HIV testing and spirometry. Respiratory samples for reference standard testing (culture, Xpert Ultra) included sputum (induced/spontaneous) or gastric aspirate, and nasopharyngeal aspirate (if <5 years). For novel tests, blood, urine and stool were collected. All participants were followed up at months 1 and 3, and month 6 if on TB treatment or unwell. The primary endpoint followed NIH-consensus statements on categorization of TB disease status for each participant. The study was approved by the sponsor's and all relevant local ethics committees. DISCUSSION: As a diagnostic accuracy study for a disease with an imperfect reference standard, Rapid and Accurate Diagnosis of Pediatric Tuberculosis Disease (RaPaed-TB) was designed following a rigorous and complex methodology. This allows for the determination of diagnostic accuracy of novel assays and combination of testing strategies for optimal care for children, including high-risk groups (ie, very young, malnourished, children living with HIV). Being one of the largest of its kind, RaPaed-TB will inform the development of improved diagnostic approaches to increase case detection in pediatric TB.


Subject(s)
Mycobacterium tuberculosis , Tuberculosis , Humans , Child , Prospective Studies , Sensitivity and Specificity , Tuberculosis/diagnosis , Tuberculin Test , Feces , Sputum
7.
Otolaryngol Head Neck Surg ; 168(4): 669-680, 2023 04.
Article in English | MEDLINE | ID: mdl-35503655

ABSTRACT

OBJECTIVE: We aimed to study the literature on chronic granulomatous invasive fungal sinusitis to elucidate the changing trends in the management of the disease. DATA SOURCES: Using specific keywords, we searched the PubMed, PubMed Central, and Scopus databases over the past 50 years, which yielded 938 articles in the English language. REVIEW METHODS: Scrutiny of 147 relevant articles revealed 15 homogenous case series (255 cases of histologically proven chronic granulomatous fungal sinusitis alone) and 8 heterogeneous case series (patients with other types of fungal sinusitis included), which were analyzed in detail (all with >5 cases each). CONCLUSIONS: The disease typically affected middle-aged adults with immunocompetence. Most reports were from Sudan, India, and Saudi Arabia. A slowly progressive orbital, cheek, or palatal mass with proptosis (88.2%) or sinonasal symptoms (39.2%) was typical. Ethmoid (57.2%) and maxillary (51.4%) sinuses were chiefly affected with intracranial extension in 35.1%. Aspergillus flavus (64%) was the most frequent isolate reported. Endoscopic excision (78.8%) followed by azole therapy was the preferred treatment in recent reports. Orbital exenteration and craniotomy were infrequently performed. Complete resolution or improvement was reported in 91.3% of patients. Mortality ranged from 5.9% to 22.2%. There is a trend in the literature toward less radical and disfiguring surgery and preferential use of azoles, with good outcomes even in advanced cases. IMPLICATIONS FOR PRACTICE: Chronic granulomatous fungal sinusitis should be diagnosed on the basis of well-defined histopathologic features. A combination of endoscopic sinus surgery and azole therapy usually yields good outcomes.


Subject(s)
Aspergillosis , Mycoses , Sinusitis , Adult , Middle Aged , Humans , Aspergillosis/diagnosis , Aspergillosis/therapy , Aspergillosis/microbiology , Sinusitis/surgery , Mycoses/diagnosis , Mycoses/therapy , Mycoses/microbiology , Immunocompetence , Azoles
8.
Int J Mycobacteriol ; 11(4): 400-406, 2022.
Article in English | MEDLINE | ID: mdl-36510925

ABSTRACT

Background: India is endemic for Tuberculosis (TB), contributing to the world's highest number of active cases. Diabetes (DM), with its increasing burden in India, could contribute to adverse outcomes among patients with TB. Methods: Consecutive patients with sputum smear positive pulmonary tuberculosis were included in the study. We defined cases as those patients with diabetes at recruitment. Controls were non diabetics (NDM). Sputum samples for AFB smears, AFB culture and Xpert PCR along with blood samples for glycosylated Haemoglobin and glucose levels were collected at recruitment and at 6 months from patients with sputum positive pulmonary TB. Blood glucose levels and sputum smears were repeated at 2 months and monthly till they tested negative. The primary outcome studied was mortality at 6 month follow-up. The secondary outcomes included the time to conversion of sputum smears and cure rates between cases and controls. Results: We recruited 124 patients of which 68 were cases. Mortality after therapy was 15% in cases and 7% in controls, however, the difference was not statistically significant. Equal proportions in each group (Diabetics: 9% vs. NDM 9%) had persistent smear positivity at 2 months. There was no association between delayed sputum conversion and uncontrolled diabetes. Only about 57% of cases and 50% of controls were documented to have completed treatment or been cured. A significant reduction in HbA1c after 6 months of Antituberculous therapy was noted among the cases. [Mean difference - 1.76, P-value - 0.001, 95% CI of difference - (1.01 - 2.52)]. Conclusions: Diabetes did not have adverse outcomes in the form of increased mortality or delayed sputum conversion rates. The high proportion of loss to follow-up seems to be a trend of concern, which should be addressed emergently.


Subject(s)
Diabetes Mellitus , Mycobacterium tuberculosis , Tuberculosis, Pulmonary , Humans , Antitubercular Agents/therapeutic use , Tuberculosis, Pulmonary/epidemiology , Sputum
9.
J Trop Pediatr ; 68(6)2022 10 06.
Article in English | MEDLINE | ID: mdl-36370459

ABSTRACT

BACKGROUND: Bacille Calmette-Guérin (BCG) adenitis is an uncommon complication following BCG vaccination. In rare cases, infants can develop other complications. Controversy exists regarding the diagnosis and management of these cases. Not much information is available in literature regarding their microbiological and immunological characteristics. METHODS: Electronic medical records of children presenting to the Pediatric Infectious Diseases clinic in a tertiary care hospital from January 2011-December 2020 with a diagnosis of BCG adenitis were retrospectively reviewed. Their clinical, microbiological, treatment and follow-up data were noted and analyzed. FINDINGS: During the study period, 40 infants presented with a probable diagnosis of BCG adenitis with or without disseminated BCG. Median age at symptom onset was 4(2.5-5.9) months. Nine infants had disseminated disease at presentation. Fifteen infants were suspected to have underlying immune deficiency of whom 12 had proven defects in immune function. On multivariable logistic regression analysis, presence of disseminated disease was the only factor predictive of underlying immunodeficiency. Isoniazid monoresistance was seen in seven cases (32%) of the 22 samples sent for TB cultures. CONCLUSIONS: Though BCG adenitis runs a benign course, it could rarely be the first manifestation of an underlying immune defect. There is sizable isoniazid monoresistance, hence sending tissue samples for microbiologic evaluation is necessary to guide anti-tubercular therapy.


Subject(s)
Lymphadenitis , Mycobacterium bovis , Tuberculosis , Infant , Child , Humans , Retrospective Studies , Tuberculosis/diagnosis , BCG Vaccine/adverse effects , Isoniazid , Lymphadenitis/diagnosis , Lymphadenitis/drug therapy , Lymphadenitis/etiology , Treatment Outcome
10.
Proc Natl Acad Sci U S A ; 119(8)2022 02 22.
Article in English | MEDLINE | ID: mdl-35193957

ABSTRACT

Mycobacterium tuberculosis (Mtb) endures a combination of metal scarcity and toxicity throughout the human infection cycle, contributing to complex clinical manifestations. Pathogens counteract this paradoxical dysmetallostasis by producing specialized metal trafficking systems. Capture of extracellular metal by siderophores is a widely accepted mode of iron acquisition, and Mtb iron-chelating siderophores, mycobactin, have been known since 1965. Currently, it is not known whether Mtb produces zinc scavenging molecules. Here, we characterize low-molecular-weight zinc-binding compounds secreted and imported by Mtb for zinc acquisition. These molecules, termed kupyaphores, are produced by a 10.8 kbp biosynthetic cluster and consists of a dipeptide core of ornithine and phenylalaninol, where amino groups are acylated with isonitrile-containing fatty acyl chains. Kupyaphores are stringently regulated and support Mtb survival under both nutritional deprivation and intoxication conditions. A kupyaphore-deficient Mtb strain is unable to mobilize sufficient zinc and shows reduced fitness upon infection. We observed early induction of kupyaphores in Mtb-infected mice lungs after infection, and these metabolites disappeared after 2 wk. Furthermore, we identify an Mtb-encoded isonitrile hydratase, which can possibly mediate intracellular zinc release through covalent modification of the isonitrile group of kupyaphores. Mtb clinical strains also produce kupyaphores during early passages. Our study thus uncovers a previously unknown zinc acquisition strategy of Mtb that could modulate host-pathogen interactions and disease outcome.


Subject(s)
Lipopeptides/metabolism , Mycobacterium tuberculosis/metabolism , Zinc/metabolism , Animals , Bacterial Proteins/metabolism , Biological Transport , Chelating Agents/metabolism , Disease Models, Animal , Homeostasis , Host-Pathogen Interactions , Metals/metabolism , Mice , Mice, Inbred BALB C , Mycobacterium tuberculosis/growth & development , Siderophores/metabolism , Tuberculosis/microbiology
11.
Indian J Thorac Cardiovasc Surg ; 38(2): 177-182, 2022 Mar.
Article in English | MEDLINE | ID: mdl-34744334

ABSTRACT

Pulmonary mucormycosis (PM) is a rare disease. Literature about the surgical management of PM in India is sparse. Recently, there has been a surge in the number of cases of mucormycosis in association with the coronavirus disease 2019 (COVID-19) pandemic, igniting the interest in PM. Hence, we endeavoured to analyse our surgical experience in treating PM prior to the pandemic, in a tertiary care centre, to provide insight into this disease. Data of 10 adult patients with isolated PM, who underwent surgery between the years 2009 and 2020, and maintained in our departmental database, were retrieved and analysed.

12.
Indian J Med Microbiol ; 40(1): 109-112, 2022.
Article in English | MEDLINE | ID: mdl-34176665

ABSTRACT

PURPOSE: Accurate diagnosis of TB in children is hampered by poor specificity of symptoms in endemic countries and the paucibacillary nature of childhood TB. This study was done to compare the accuracy and agreement of the tuberculin skin test (TST) and the QuantiFERON-TB Gold In-tube test (QFT) in diagnosing tuberculosis (TB) in a predominantly BCG-vaccinated population of children. METHODS: This retrospective cohort study enrolled all children aged 1-15 years who underwent TST and QFT testing as part of screening for TB. Children were classified according to the 2014 WHO case definition of TB, and statistical analysis was done to generate data on concordance between the TST and the QFT as well as sensitivity and specificity within WHO-defined groups. RESULTS: TST and QFT concordance was 83.9% overall (kappa 0.51), 79% in those with WHO-defined TB and 89% in those without TB. TST+/QFT-discordance was commoner than QFT+/TST- discordance across groups. The sensitivity of the TST vs. the QFT was 70.8% vs. 50% for WHO-defined TB, with comparable specificity at 89% vs. 90% respectively. CONCLUSIONS: The higher sensitivity of the cheaper and simpler TST supports its use for TB diagnosis in a normally nourished population of BCG-vaccinated children.


Subject(s)
Latent Tuberculosis , Tuberculosis , BCG Vaccine , Child , Humans , Latent Tuberculosis/diagnosis , Retrospective Studies , Sensitivity and Specificity , Tuberculin Test , Tuberculosis/diagnosis
13.
Transplant Cell Ther ; 28(1): 45.e1-45.e8, 2022 01.
Article in English | MEDLINE | ID: mdl-34607073

ABSTRACT

Haploidentical stem cell transplantation (SCT) using post-transplantation cyclophosphamide for graft-versus-host disease (GVHD) prophylaxis is a reasonable therapeutic option for patients who do not have a matched sibling donor. Between 2010 and June 2020, 257 patients underwent 269 Haploidentical transplantations, including 122 children. Indications included both malignant (56.8%) and non-malignant (43.2%) diseases. Conditioning regimens included both myeloablative (57.6%) and nonmyeloablative regimens (42.4%). Peripheral blood stem cells were the predominant graft source (96.2%). Based on the disease risk index, patients were classified into early-, intermediate-, and late-stage disease. Engraftment was seen in 205 patients (76.2%) whereas 39 (14.4%) died before engraftment and 23 (8.6%) had primary graft failure. The cumulative incidence of grade II-IV acute GVHD was 47.8% with a 23.9% incidence of grade III-IV acute GVHD. Chronic GVHD was seen in 41.9% with a 15.4% incidence of extensive chronic GVHD. More than 90% had at least 1 documented infection with a 44% incidence of bacterial, 71% viral, and 38% fungal infection. The 2-year overall survival is 40.5% ± 3.2% with a higher survival among children (48.2% ± 3.4%) compared to adults (34.2% ± 4.1%). Survival was poor with late-stage disease (23.6% ± 4.3%) compared to early- (62.5% ± 7.5%) and intermediate-stage (50.3% ± 4.3%). Factors adversely affecting survival included older age of patient (P = .007), late disease status (P = .000), nonmyeloablative conditioning regimen (P = .003), bone marrow as graft source (P = .006), presence of acute GVHD (P = .069), primary graft failure (P = .000), and presence of a documented bacterial (P = .000) and fungal infection (P = .000). On multivariate analysis, older age (P = .027), presence of acute GVHD (P = .033), documented bacterial infection (P = .000), documented fungal infection (P = .000) and primary graft failure (P = .012) continued to remain significant. Haploidentical SCT offers a reasonable chance of cure for patients with both malignant and nonmalignant hematological diseases. Strategies to reduce aGVHD and infection related mortality needs to be explored further. © 20XX American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.


Subject(s)
Graft vs Host Disease , Hematopoietic Stem Cell Transplantation , Aged , Cyclophosphamide , Graft vs Host Disease/epidemiology , Humans , Transplantation Conditioning , Transplantation, Haploidentical
14.
Microbiol Spectr ; 9(2): e0109821, 2021 10 31.
Article in English | MEDLINE | ID: mdl-34494864

ABSTRACT

Mycobacterium bovis bacillus Calmette-Guérin (BCG) is a live attenuated vaccine which can result in local or disseminated infection, most commonly in immunocompromised individuals. Differentiation of BCG from other members of the Mycobacterium tuberculosis complex (MTBC) is required to diagnose BCG disease, which requires specific management. Current methods for BCG diagnosis are based on mycobacterial culture and conventional PCR; the former is time-consuming and the latter often unavailable. Further, there are reports that certain BCG strains may be associated with a higher rate of adverse events. This study describes the development of a two-step multiplex real-time PCR assay which uses single nucleotide polymorphisms to detect BCG and identify early or late BCG strains. The assay has a limit of detection of 1 pg BCG boiled lysate DNA and was shown to detect BCG in both pure cultures and experimentally infected tissue. Its performance was assessed on 19 suspected BCG clinical isolates at Christian Medical College in Vellore, India, taken from January 2018 to August 2020. Of these 19 isolates, 10 were identified as BCG (6 early and 4 late strains), and 9 were identified as other MTBC members. Taken together, the results demonstrate the ability of this assay to identify and characterize BCG disease from cultures and infected tissue. The capacity to identify BCG may improve patient management, and the ability to discriminate between BCG strains may enable BCG vaccine pharmacovigilance. IMPORTANCE Vaccination against tuberculosis with bacillus Calmette-Guérin (BCG) can lead to adverse events, including a rare but life-threatening complication of disseminated BCG. This complication often occurs in young children with immunodeficiencies and is associated with an ∼60% mortality rate. A rapid method of reliably identifying BCG infection is important because BCG requires treatment unique to tuberculosis. BCG is resistant to the first-line antituberculosis drug pyrazinamide. Additionally, diagnosis of BCG disease would lead to further investigation of a possible underlying immune condition. We have developed a diagnostic assay to identify BCG which improves upon previously published methods and can reliably identify BCG from bacterial culture or directly from infected tissue. This assay can also differentiate between strains of BCG, which have been suggested to be associated with different rates of adverse events. This assay was validated on 19 clinical isolates collected at Christian Medical College in Vellore, India.


Subject(s)
Mycobacterium Infections, Nontuberculous/diagnosis , Mycobacterium bovis/genetics , Mycobacterium bovis/isolation & purification , Real-Time Polymerase Chain Reaction/methods , Vaccines, Attenuated/adverse effects , Adolescent , Animals , Child , Child, Preschool , Female , Humans , Limit of Detection , Male , Mice , Mice, Inbred C57BL , Mycobacterium Infections, Nontuberculous/microbiology , Mycobacterium Infections, Nontuberculous/therapy , Mycobacterium bovis/immunology , Polymorphism, Single Nucleotide/genetics , Tuberculosis/prevention & control , Vaccines, Attenuated/immunology , Young Adult
15.
Access Microbiol ; 3(2): 000189, 2021 Feb.
Article in English | MEDLINE | ID: mdl-34151144

ABSTRACT

Azithromycin is increasingly being used for the treatment of shigellosis despite a lack of interpretative guidelines and with limited clinical evidence. The present study determined azithromycin susceptibility and correlated this with macrolide-resistance genes in Shigella spp. isolated from stool specimens in Vellore, India. The susceptibility of 332 Shigella isolates to azithromycin was determined using the disc diffusion method. Of these, 31 isolates were found to be azithromycin resistant. The azithromycin minimum inhibitory concentration (MIC) was determined using the broth microdilution method. In addition, isolates were screened for mphA and ermB genes using conventional PCR. Furthermore, an isolate that was positive for resistance genes was subjected to complete genome analysis, and was analysed for mobile genetic elements. The azithromycin MIC for the 31 resistant Shigella isolates ranged between 2 and 16 mg l-1. PCR results showed that a single isolate of Shigella sonnei carried a mphA gene. Complete genome analysis revealed integration of an IncFII plasmid into the chromosome of S. sonnei , which was also found to carry the following resistance genes: sul1, bla DHA1, qnrB4, mphA, tetR. Mutations in the quinolone-resistance-determining region (QRDR) were also observed. Additionally, prophages, insertion sequences and integrons were identified. The novel finding of IncFII plasmid integration into the chromosome of S. sonnei highlights the potential risk of Shigella spp. becoming resistance to azithromycin in the future. These suggests that it is imperative to monitor Shigella susceptibility and to study the resistance mechanism of Shigella to azithromycin considering the limited treatment choices for shigellosis.

16.
Indian J Med Microbiol ; 39(2): 192-195, 2021 Apr.
Article in English | MEDLINE | ID: mdl-33966861

ABSTRACT

BACKGROUND: Recently, a novel species contaminans belonging to the family Burkholderia cepacia complex (Bcc) is rising as a hospital pathogen. Detection of Burkholderia contaminans, a member of Bcc can be done only by MALDI TOF and sequencing techniques. We report the diagnostic challenges faced in an outbreak of bacteremia due to B. contaminans grown in diltiazem vials. METHOD: The department of microbiology notified the infection control team about a cluster of eleven patients with B. contaminans isolated from blood culture. An outbreak investigation was initiated by performing environmental surveillance and sterility testing of solutions given for the patients. Routine phenotypical methods for identification of species followed by MALDI-TOF and sequencing was performed to identify the pathogen. RESULTS: All the patients detected with B. contaminans were having cardiac disease and received diltiazem. Sterility testing of diltiazem vials given for the patient and an unopened vial of same batch has grown B. contaminans. Clonal typing has confirmed the sequence similarities between patient and solution isolates. CONCLUSION: Due to diagnostic challenge in identifying the species of Bcc, MALDI TOF and clonal typing remains the key diagnostic tools available to detect Bcc species at an earliest especially in an outbreak.


Subject(s)
Burkholderia Infections , Burkholderia , Drug Contamination , Blood Culture , Burkholderia Infections/diagnosis , Burkholderia Infections/epidemiology , Burkholderia cepacia complex , Diltiazem , Disease Outbreaks , Humans , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , Tertiary Care Centers
17.
Microbiol Resour Announc ; 10(1)2021 Jan 07.
Article in English | MEDLINE | ID: mdl-33414309

ABSTRACT

We report the complete 4,352,172-bp genome sequence of Mycobacterium orygis strain 51145 assembled into a single circular chromosome. Comparative genomic analyses with other lineages of the Mycobacterium tuberculosis complex can provide insights into the biology, evolution, and epidemiology of this important group of pathogenic mycobacteria.

18.
Future Sci OA ; 6(9): FSO612, 2020 Jul 30.
Article in English | MEDLINE | ID: mdl-33235807

ABSTRACT

AIM: To evaluate the performance of VITEK®MS with DNA sequencing for laboratory diagnosis of non-tuberculous mycobacteria (NTM) species in a resource-limited setting. METHODS: 16SrRNA sequencing and MALDI-TOF mass spectrometry (VITEK®MS) was performed at a tertiary-care hospital in India. MALDI-TOF results were confirmed by 16S rRNA sequencing. In addition, sequencing of the internal transcribed spacer region was performed on slowly growing NTM. RESULTS: Commonest species isolated were M. abscessus, M. intracellulare, M. avium, M. fortuitum and M. simiae. 16S rRNA sequencing and MALDI-TOF results had agreement of 94.5% for rapidly growing and 77.5% for slowly growing NTM. CONCLUSION: There is good correlation between VITEK®MS and sequencing for rapidly growing NTM. For slowly growing species, sequencing would be required in a third isolates.

19.
mSphere ; 5(5)2020 10 07.
Article in English | MEDLINE | ID: mdl-33028681

ABSTRACT

Shigella is the second leading cause of bacterial diarrhea worldwide. Recently, Shigella sonnei seems to be replacing Shigella flexneri in low- and middle-income countries undergoing economic development. Despite this, studies focusing on these species at the genomic level remain largely unexplored. Here, we compared the genome sequences of S. flexneri and S. sonnei isolates from India with the publicly available genomes of global strains. Our analysis provides evidence for the long-term persistence of all phylogenetic groups (PGs) of S. flexneri and the recent dominance of the ciprofloxacin-resistant S. sonnei lineage in India. Within S. flexneri PGs, the majority of the study isolates belonged to PG3 within the predominance of serotype 2. For S. sonnei, the current pandemic involves globally distributed multidrug-resistant (MDR) clones that belong to Central Asia lineage III. The presence of such epidemiologically dominant lineages in association with stable antimicrobial resistance (AMR) determinants results in successful survival in the community.IMPORTANCEShigella is the second leading cause of bacterial diarrhea worldwide. This has been categorized as a priority pathogen among enteric bacteria by the Global Antimicrobial Resistance Surveillance System (GLASS) of the World Health Organization (WHO). Recently, S. sonnei seems to be replacing S. flexneri in low- and middle-income countries undergoing economic development. Antimicrobial resistance in S. flexneri and S. sonnei is a growing international concern, specifically with the international dominance of the multidrug-resistant (MDR) lineage. Genomic studies focusing on S. flexneri and S. sonnei in India remain largely unexplored. This study provides information on the introduction and expansion of drug-resistant Shigella strains in India for the first time by comparing the genome sequences of S. flexneri and S. sonnei isolates from India with the publicly available genomes of global strains. The study discusses the key differences between the two dominant species of Shigella at the genomic level to understand the evolutionary trends and genome dynamics of emerging and existing resistance clones. The present work demonstrates evidence for the long-term persistence of all PGs of S. flexneri and the recent dominance of a ciprofloxacin-resistant S. sonnei lineage in India.


Subject(s)
Anti-Bacterial Agents/pharmacology , Ciprofloxacin/pharmacology , Drug Resistance, Multiple, Bacterial/genetics , Evolution, Molecular , Phylogeny , Shigella sonnei/drug effects , Dysentery, Bacillary/epidemiology , Dysentery, Bacillary/microbiology , Feces/microbiology , Genome, Bacterial , Humans , India/epidemiology , Serogroup , Shigella flexneri/genetics , Shigella sonnei/classification , Whole Genome Sequencing
20.
J Obstet Gynaecol India ; 70(4): 304-309, 2020 Aug.
Article in English | MEDLINE | ID: mdl-32764852

ABSTRACT

AIMS: The objective of this study was to describe the clinicopathological details in patients referred to the Gynaecologic Oncology Department with possible ovarian or primary peritoneal cancer where the final diagnosis turned out to be abdominal tuberculosis. METHODOLOGY: Retrospective chart analysis of 23 cases diagnosed with abdominal tuberculosis who were admitted under the Division of Gynaecologic Oncology suspected to have disseminated peritoneal malignancy, during 2014-2017. RESULTS: There were 23 patients who were referred to the Gynaecologic Oncology outpatient for evaluation of ascites, to rule out malignancy. The mean age of this patient group was 35 years (SD 14.5, range 14-65). The mean CA 125 was 333.5 [400.7 (9.09-1568)]. Ascitic fluid analysis confirmed TB in 26%; omental biopsy revealed TB in 69%, and operative diagnostic procedures (laparoscopy and laparotomy) were done in 15 of the 23 patients which had a positive pick up rate of 100% to confirm the diagnosis of TB. Culture of ascitic fluid/omental tissue and PCR yields were poor with a pick up rate of 33% and 6%. CONCLUSIONS: Abdominal TB is common in India and can mimic ovarian malignancy, and hence, high degree of suspicion needed. The isolation of AFB is the gold standard for diagnosis of pulmonary tuberculosis but has a low yield in abdominal TB. Ultrasound-guided procedure is reasonable as an initial procedure. As much time can be lost in working up these patients through multiple diagnostic algorithms using ascitic tap, USG biopsy and then an operative procedure, diagnostic laparoscopy could be considered early in the work up. It is a simple, time-saving and cost-effective way of establishing a diagnosis sooner with least complications.

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