Mastan Singh

Onychomycosis in central India: a clinicoetiologic correlation

Background  Onychomycosis is mainly caused by dermatophytes, but yeasts and nondermatophyte molds have also been implicated, giving rise to diverse clinical presentations. The etiological agents of the disease may show geographic variation. The aim of the present study was to isolate the causative pathogens and to determine the various clinical patterns of onychomycosis in central India.

Pathogenomics of uropathogenic Escherichia coli

Subset of faecal E. coli that can enter, colonize urinary tract and cause infection are known as uropathogenic E. coli (UPEC). UPEC strains act as opportunistic intracellular pathogens taking advantage of host susceptibility using a diverse array of virulence factors. Presence of specific virulence associated genes on genomic/pathogenicity islands and involvement of horizontal gene transfer appears to account for evolution and diversity of UPEC. Recent success in large-scale genome sequencing and comparative genomics has helped in unravelling UPEC pathogenomics. Here we review recent findings regarding virulence characteristics of UPEC and mechanisms involved in pathogenesis of urinary tract infection.

Molecular characterization of dengue viruses circulating during 2009–2012 in Uttar Pradesh, India

Dengue is the most rapidly spreading mosquito‐borne viral disease in the world; in India it has taken endemic proportion implicating all the four known dengue virus serotypes. Dengue infection is caused by a small, single stranded RNA virus comprising of four antigenically distinct virus serotypes designated as dengue virus type 1–4 (DENV‐1–4). On the basis of genomic variations, each serotype is classified further into its genotypes. Epidemiological studies have shown that the emergence of a newer dengue serotype/genotype after an interval always leads to a major outbreak; therefore a continuous epidemiological surveillance is needed to monitor the epidemiology of dengue viruses. The present study was planned to identify the serotype/genotype of dengue viruses circulating in Uttar Pradesh, India. Of 433 dengue suspected patients, tested by reverse transcriptase PCR (RT‐PCR), 136 were positive for dengue virus RNA. Of these, DENV‐1, 2, and 3 were detected in 26 (19.1%), 77 (56.6%), and 33 (24.3%) patients, respectively. Of 136 RT‐PCR positive samples, 24 samples were sequenced to identify their genotypes. For sequencing C–prM gene junction of dengue virus genome was chosen. Phylogenetic analysis of sequenced dengue strains revealed that all the 12 DENV‐1 strains were genotype III, all the eight DENV‐2 strains were genotype IV (Cosmopolitan genotype) and among four DENV‐3 strains, three were genotype III and one was genotype I. In conclusion, the co‐circulation of multiple dengue virus serotypes and genotypes is alarming in U.P., India. J. Med. Virol. 87: 68–75, 2015.

Prevalence of gyrA and B gene mutations in fluoroquinolone-resistant and -sensitive clinical isolates of Mycobacterium tuberculosis and their relationship with MIC of ofloxacin.

The study was done to know the prevalent mutations of gyrA and gyrB genes, and their significance with drug resistance in clinical isolates of Mycobacterium tuberculosis. A total of 100 ofloxacin- (OFX) resistant and 100 OFX-sensitive isolates of M. tuberculosis were consecutively selected from routine Tuberculosis laboratory. Drug resistance pattern of these isolates was recorded. MIC of OFX was tested in all these isolates by absolute concentration method. Quinolone resistance determining region (QRDR) of gyrA and gyrB genes of 320 and 428 bp, respectively, were amplified and sequenced. Sequencing data were analyzed by BLAST on NCBI with reference strain H37Rv. Of 100 OFX-sensitive isolates, 30 were pansusceptible, 28 were monoresistant, 10 were polyresistant and 32 were multidrug resistant (MDR). Among 100 OFX-resistant isolates, 19 were OFX monoresistant, 16 were polyresistant and 65 were MDR. Mutations in gyrA and gyrB genes were observed in 79% and 5% of OFX-resistant isolates, respectively. Most prevalent mutation was found at codon 94 in QRDR of gyrA gene. Double mutations found in gyrA gene and in both gyrA and gyrB genes signifies higher levels of OFX resistance. In one isolate, a substitution at codon 592 (Pro592Ser) was found as a novel mutation outside the QRDR of gyrB gene. Our findings support previous studies that the OFX resistance to M. tuberculosis is associated with mutations in the QRDR of gyrA gene; however, the level of OFX resistance may not be predicted based on the mutation patterns in the gyrA gene.

Intravenous methyl prednisolone in patients with solitary cysticercus granuloma: A random evaluation

PURPOSE To evaluate the role of intravenous methyl prednisolone in patients with solitary cysticercus granuloma with new-onset seizures. METHODS In this open-label, randomized, prospective, follow-up study, 52 patients with new-onset seizures and a single enhancing CT lesion of cysticercus were randomly divided in two groups to receive either intravenous methyl prednisolone for 5 days along with antiepileptic drug (n=25) or antiepileptic drug monotherapy (n=27) alone. The patients were followed up for at least for 9 months. Repeat CT scans were performed after 2 months. RESULTS After 2 months, lesion disappeared in 60% patients of intravenous methyl prednisolone group and 18.5% patients receiving only antiepileptic drug (p=0.001). As far as seizure recurrence was concerned, a lower number (16% versus 33%) of intravenous methyl prednisolone treated patient had recurrence, the difference was insignificant. CONCLUSION Intravenous methyl prednisolone therapy helps in early resolution of solitary cysticercus granuloma.

Analysis of carbapenem-resistant Acinetobacter from a tertiary care setting in North India

Multidrug-resistant (MDR) Acinetobacter baumannii is a worldwide concern as cause of serious nosocomial infections. We analysed 140 non-duplicate Acinetobacter sp. isolates from hospitalised patients in a tertiary care centre; 87% were MDR and 20% (28/140) meropenem resistant. Metallo-β-lactamase was produced by 16 of these, detected by ethylene-diamine-tetra-acetic acid disc synergy test. AmpC β-lactamase and efflux pump were present in 17 and 4 of the meropenem-resistant Acinetobacter, respectively. 9/16 MBL-positive isolates carried genes for carbapenem resistance as shown by polymerase chain reaction.

Oropharyngeal candidiasis and Candida colonization in HIV positive patients in northern India.

INTRODUCTION Oropharyngeal candidiasis (OPC) is the most common opportunistic fungal infection reported in human immunodeficiency virus (HIV) positive patients worldwide. This prospective study was undertaken to investigate OPC and Candida colonization (CC) and their correlation with CD4+ cell counts and antiretroviral therapy (ART) in HIV-positive patients. METHODOLOGY In total, 190 HIV-positive patients were enrolled for study in three groups as follows: Group A, 90 patients without ART; Group B, 100 patients undergoing treatment with ART; and Group C, 75 HIV-negative control patients. All HIV patients underwent clinical examination and were subjected to CD4+ cell counts. Swabs were collected from the oral cavity of all individuals and plated on Sabourauds dextrose agar. Identification of Candida species was performed by conventional methods. RESULTS Candida species were isolated in 84/190 (44.2%) and 20/75 (26.6%) of the HIV-positive subjects and controls respectively (p<0.01). OPC was noted in 21/190 (11%) of the HIV-positive patients. Candida albicans was the most frequently isolated species. Patients with CD4+ cell counts ≤ 200 cells/mm3 were significantly (p<0.001) more frequently colonized (37/63; 58.7%) and infected (18/21; 85.7 %) with Candida species. Candida species was seen in patients with CC and OPC with CD4+cell counts between 201 and 500 (21/63; 33.4% vs 3/21; 14.3%) and > 500 cell/mm3 (5/63; 7.9% versus 0/21 0%) respectively. CONCLUSION OPC and Candida colonization occur more frequently in HIV-positive patients with CD4+ cell counts ≤ 200 cell/mm3. ART significantly reduces OPC. C. albicans is the most frequently isolated species in both OPC and colonization, suggesting endogenous infection.

Comparative Study of Biofilm Formation in Pseudomonas aeruginosa Isolates from Patients of Lower Respiratory Tract Infection.

BACKGROUND This study assessed biofilm formations of P.aeruginosa which was isolated from patients with Lower Respiratory Tract Infections (LRTIs). OBJECTIVE This study was conducted to compare different methods of biofilm formations seen in P. aeruginosa which was obtained from LRTI patients. MATERIALS AND METHODS In this cross-sectional study, we investigated a total of 80 P. aeruginosa isolates obtained from LRTI patients by different methods. Tube method (TM), tissue culture plate (TCP) method and modified tissue culture plate (MTCP) method. They were subjected to biofilm detection methods. RESULTS The MTCP method produced a higher accuracy ratio than TCP method. In terms of sensitivity and specificity, the MTCP method was considered to be superior to TM. We observed a higher antibiotic resistance in biofilm producing bacteria than in non-biofilm producers. CONCLUSION In our study, MTCP was found to be more sensitive and specific method for biofilm detection than TCP and TM.

A study on pre-XDR & XDR tuberculosis & their prevalent genotypes in clinical isolates of Mycobacterium tuberculosis in north India

Background & objectives: Pre-extensively drug resistant (pre-XDR) and extensively drug resistant tuberculosis (XDR-TB) have been areas of growing concern, and are posing threat to global efforts of TB control. The present study was planned to study the presence of pre-XDR and XDR Mycobacterium tuberculosis and their genotypes in clinical isolates obtained from previously treated cases of pulmonary TB. Methods: A total of 219 isolates obtained from previously treated cases of pulmonary TB were subjected to first-line (streptomycin, isoniazid, rifampicin and ethambutol) and second-line (ofloxacin, kanamycin, capreomycin and amikacin) drug susceptibility testing on solid Lowenstein-Jensen medium by proportion method. Genotyping was done for pre-XDR and XDR-TB isolates using 12 loci Mycobacterial Interspersed Repetitive Units-Variable Number Tandem Repeats (MIRU-VNTR). Results: Multi-drug resistance was observed in 39.7 per cent (87/219) isolates. Pre-XDR and XDR M. tuberculosis isolates amongst 87 multi-drug resistant (MDR) TB isolates were 43 (49.4%) and 10 (11.4%), respectively. Two most dominant genotypes among pre-XDR and XDR M. tuberculosis isolates were Beijing and Delhi/CAS types. Interpretation & conclusions: Resistance to second-line anti-tubercular drugs should be routinely assessed in areas endemic for TB. Similar genotype patterns were seen in pre-XDR and XDR-TB isolates. Beijing and Delhi/CAS were predominant genotypes.

Comparative evaluation of pan-fungal real-time PCR, galactomannan and (1-3)-β-D-glucan assay for invasive fungal infection in paediatric cancer patients

Limited specific data and investigations are available for the diagnosis of Invasive Fungal Infection (IFI) in paediatrics cancer patients. Three non‐invasive tests; Platelia Aspergillus EIA for galactomannan (GM), β‐D‐glucan (BDG) assay and pan‐fungal real‐time PCR for fungal DNA in blood were evaluated. One hundred twenty‐five paediatrics cancer patients at the high risk of IFI were enrolled. Single blood and serum samples were evaluated by all the three methods. Patients were classified into 10 proven, 52 probable and 63 no IFI cases in accordance with EORTC MSG 2008 revised guidelines. The sensitivity, specificity, PPV and NPV of all the three tests in proven, probable and no IFIs cases were analysed singly and in combination. The sensitivity, specificity, PPV and NPV of GM, BDG and pan‐fungal real‐time PCR were: 87%, 61%, 81%, 69.5% for GM, 88%, 59.5%, 81%, 71.4% for BDG and 89%, 69.2%, 85%, 67.5% for PCR (95% CI). Among different combinations, best combination was found to be GM and PCR with sensitivity, specificity, PPV and NPV of 98.2%, 89.3%, 97.1% and 90% respectively. Single samples must be evaluated by combination of tests.