Comparison of MRI with x-ray in the evaluation of tuberculosis of spine

Introduction: MRI is the most valuable method for detecting early disease and is preferred technique to define the activity and extent of infection followed by x–ray. Aim: To evaluate MRI as a valuable noninvasive diagnostic tool in spinal tuberculosis and to correlate with plain radiograph for the early detection of spinal tuberculosis. Material and method: This cross-sectional study was carried out on 40 patients who were suspected as cases of spinal tuberculosis. Plain X-ray were done before the MRI examination. Results: The comparison of X-ray and MRI for evaluating spinal TB on the basis of end plate irregularity, thecal sac compression, cord compression and cord changes was statistically highly significant. It was statistically significant on the basis of Disk Space Narrowing/Disk Involvement, paravertebral Widening/Psoas abscess and Posterior Element Involvement. X-ray when compared to MRI was found to have a sensitivity of 48.72% and a specificity of 100% in detection of end plate irregularities, sensitivity of 89.47% and specificity of 100% in detection of vertebral height reduction, sensitivity of 78.79% and specificity of 100% in detection of disk Space narrowing / disk Involvement and sensitivity of 28.57% and specificity of 92.31% in detection of paravertebral widening/psoas abscess. Conclusion: MRI is a better and more Informative imaging modality in evaluation of patients of Pott’s spine providing the diagnosis earlier than conventional methods.

Role of grey scale ultrasound and Colour Doppler findings to differentiate ectopic pregnancy from corpus luteum cyst of pregnancy

Introduction: Ectopic pregnancy and corpus luteum cyst are two most common differential diagnosis in a patient with UPT positive and no sonographic evidence of intrauterine pregnancy. Aim: To diagnose ectopic pregnancy and to differentiate ectopic pregnancy from corpus luteum cyst of pregnancy on the basis of grey scale ultrasound and colour Doppler findings. Material and Methods: This was a hospital based prospective study carried out on a study group of 40 patients with UPT positive and clinical features suggestive of ectopic pregnancy over a period of two years.Grey scale ultrasound and colour Doppler parameters were studied. Results: Out of 40 patients,30 were diagnosed with ectopic pregnancy and 10 with corpus luteum cyst. Ectopic pregnancies had thicker walls as compared to corpus luteum cysts. Most of the ectopic pregnancies had hyperechoic walls as compared to ovaries (80%) and endometrium (60%). Free fluid with echoes was seen in the pelvis in 70% ectopic pregnancies whereas most of the corpus luteum cysts (80%) had no free fluid. Most of the corpus luteum cysts (70%) had clear internal echotexture whereas ectopic pregnancies were mostly lacy or solid.Yolk sac was seen exclusively in ectopic pregnancy (30%). RI <0.4 and RI >0.7 was found to be highly specific for diagnosing ectopic pregnancy. Conclusion: Wall thickness of the mass, echogenicity of the wall as compared to ovaryand endometrium, internal echotexture of the cystic mass, presence of yolk sac and presence of free fluid with echoes are significant ultrasound parameters which help to differentiate between the two. RI <0.4 and RI >0.7 was found to be highly specific for diagnosing ectopic pregnancy.

Detection of the classical G2576U mutation in linezolid resistant Staphylococcus aureus along with isolation of linezolid resistant Enterococcus faecium from a patient on short-term linezolid therapy: First report from India.

Purpose: Linezolid is an effective drug against methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE). We describe the emergence of linezolid resistance in MRSA and VRE from India. Material and Methods: One MRSA and two VRE strains were isolated from a patient on linezolid therapy of one week duration. All three isolates were resistant to linezolid with minimal inhibitory concentrations (MIC) ≥4 mg/L. The 746-bp region fl anking the possible G2576U mutation on the corresponding DNA from the 23S rRNA was amplifi ed by polymerase chain reaction (PCR) and amplicons were sequenced for all the three isolates. Conjugation experiments using the linezolid resistant MRSA (LRMRSA) and linezolid resistant VRE (LRVRE) isolates as donors and wild strains of corresponding genera as recipients were performed. Results: The MRSA isolate had the classical G2576U mutation. High quality value scores in the sequencing software validated the mutation. Conjugation studies did not indicate presence of transferable resistance for linezolid. Sequencing did not indicate presence of any mutation in the two LRVRE isolates. Conclusions: This is the fi rst report from India citing resistance in Staphylococcus and Enterococcus against Linezolid.

Multiple carbapenem hydrolyzing genes in clinical isolates of Acinetobacter baumannii.

Purpose: Carbapenem resistance in Acinetobacter baumannii has become highly rampant, which has been ascribed to the presence of multiple carbapenemases. The objective of the present study was to prospectively investigate the presence of multiple carbapenemase encoding genes in clinical isolates of A. baumannii. Materials and Methods: A total of 30 imipenem resistant, consecutive non-repeat clinical isolates A. baumannii from a Tertiary Care Centre of Delhi were subjected to antimicrobial susceptibility testing (AST), screening for carbapenemase production by modified Hodge test (MHT) and determination of minimum inhibitory concentration for imipenem by E-Test® . These were subjected to Real time PCR for blaIMP-1 and 2 , blaVIM-1 and 2 , blaOXA23, 24, 51 and 58 using SYBR green-I. These were grouped together on the basis of their genotype as each isolate harboured multiple carbapenemases and correlated with their AST profile. Detection of the novel carbapenemase blaNDM-1 was performed by real time PCR using TaqMan probes on 14 isolates. Results: Colistin appeared to be the most effective drug in vitro, followed by tetracycline and beta lactam/beta lactamase inhibitor combinations. All, but one isolate were positive for the MHT. All 30 isolates were positive for blaOXA-51 like gene as well as blaIMP-1 and blaVIM-1 genes. blaOXA 24 and 58 were not detected in any of the isolates. blaIMP-2 , blaVIM-2 , blaOXA-23 were present in 15, 6 and 14 isolates respectively. Grouping based on the genotypic profile did not correlate with susceptibility pattern. Nine among the 14 isolates also harboured the novel blaNDM-1 gene. Conclusions: This is the first study from North India, which comprehensively detected the presence of multiple carbapenemases as well the blaNDM-1 gene. The presence of the novel gene blaNDM-1 indicated ability of A. baumannii to acquire new carbapenemase genes despite the existence of multiple carbapenemase genes. The present study confirmed the presence of multiple genetic mechanisms for carbapenemases production among the clinical isolates of A. baumannii in north India.

Zinc-dependent carbapenemases in clinical isolates of family Enterobacteriaceae.

Purpose: The emergence and spread of zinc-dependent carbapenem resistance has become a diagnostic challenge for clinical microbiologists. The objective of the present study was to screen zinc-dependent carbapenemase activity in clinical isolates of family Enterobacteriaceae. Materials and Methods: A total of 102 multidrug-resistant organisms (MDROs), non-repeat clinical isolates of family Enterobacteriaceae from two tertiary care centres in Delhi, were screened for carbapenemase production by a modified Hodge test (MHT) and additionally by a re-modified Hodge test, EDTA double disc synergy test, and combined disc test (or disc enhancement test) to determine zinc dependence of carbapenemases harbouring bacteria. Results: Of the total 102 clinical isolates (June through November 2010), 91 were from urine and 11 were from blood specimens. The isolates were obtained from patients visiting the outpatient department (18 isolates), admitted in non-ICU inpatient care units (74 isolates) and patients admitted in ICUs (4 isolates). MHT identified 92 (90.2%) isolates as carbapenemases producers. Among those found negative for MHT (n=10), metallo-beta-lactamases (MBLs) activity was demonstrated through the EDTA disc diffusion synergy test and the combined disc test in 8 and 9 isolates respectively. A total of 63 (61.7%) isolates demonstrated MBL activity despite in vitro sensitivity to Imipenem. Conclusions: The study demonstrated that supplementing the MHT with at least one of the screening methods increases the likelihood of picking up such isolates that may be missed by the MHT. The study also demonstrates the wide-spread presence of MBLs in Enterobacteriaceae members from patients visiting hospitals in east Delhi.

Zinc-dependent carbapenemases in clinical isolates of family Enterobacteriaceae.

Purpose: The emergence and spread of zinc-dependent carbapenem resistance has become a diagnostic challenge for clinical microbiologists. The objective of the present study was to screen zinc-dependent carbapenemase activity in clinical isolates of family Enterobacteriaceae. Materials and Methods: A total of 102 multidrug-resistant organisms (MDROs), non-repeat clinical isolates of family Enterobacteriaceae from two tertiary care centres in Delhi, were screened for carbapenemase production by a modified Hodge test (MHT) and additionally by a re-modified Hodge test, EDTA double disc synergy test, and combined disc test (or disc enhancement test) to determine zinc dependence of carbapenemases harbouring bacteria. Results: Of the total 102 clinical isolates (June through November 2010), 91 were from urine and 11 were from blood specimens. The isolates were obtained from patients visiting the outpatient department (18 isolates), admitted in non-ICU inpatient care units (74 isolates) and patients admitted in ICUs (4 isolates). MHT identified 92 (90.2%) isolates as carbapenemases producers. Among those found negative for MHT (n=10), metallo-beta-lactamases (MBLs) activity was demonstrated through the EDTA disc diffusion synergy test and the combined disc test in 8 and 9 isolates respectively. A total of 63 (61.7%) isolates demonstrated MBL activity despite in vitro sensitivity to Imipenem. Conclusions: The study demonstrated that supplementing the MHT with at least one of the screening methods increases the likelihood of picking up such isolates that may be missed by the MHT. The study also demonstrates the wide-spread presence of MBLs in Enterobacteriaceae members from patients visiting hospitals in east Delhi.

Development of TaqMan real-time polymerase chain reaction for the detection of the newly emerging form of carbapenem resistance gene in clinical isolates of Escherichia coli, Klebsiella pneumoniae, and Acinetobacter baumannii.

Purpose: The newly emerging form of the so-called New Delhi Metallo-beta-lactamases (NDM-1) has been reported recently from patients worldwide and broadly thought as a potential source for the major global health problem. Thus, it is important to study the epidemiology of the so-called NDM-1 harbouring bacteria to prevent its further spread and to place effective control measures. The present study describes the use of the real-time polymerase chain reaction (PCR) assay for the detection of the bla NDM-1 gene using TaqMan probes among clinical isolates. Materials and Methods: Clinical isolates of Escherichia coli (11 strains), Klebsiella pneumoniae (17 strains) and Acinetobacter baumannii (six strains) that were resistant to either of the carbapenems (meropenem or imipenem) were included in the study. The presence of carbapenemases in such strains was confirmed using the modified Hodge test. A real-time PCR assay was optimized for the detection of NDM-1 using a cloned synthetic gene fragment followed by testing of the clinical isolates. The findings were further confirmed using PCR and gene sequencing. Results: TaqMan probe assay displayed a good detection limit with analytical sensitivity of the assay up to 10 copies of bla NDM-1 gene per reaction. The isolates of E. coli and K. pneumoniae revealed narrow range crossing point values (Cp values) between (12-17) cycles (mean Cp value 14), indicating number of bla NDM-1 gene copies of 106-108. The wider range of Cp values (15-34) cycles with a higher mean Cp value (23.6) was observed in A. baumannii with number of bla NDM-1 gene copies of 103-108. Conclusions: The study demonstrates that real-time PCR assay based on TaqMan chemistry is a useful technique for the detection of bla NDM-1 harbouring clinical isolates of E. coli, K. pneumoniae and A. baumannii. The assay has great precision in measuring the number of bla NDM-1 gene copies per specimen of DNA.

Evaluation of nitrate reductase assay for direct detection of drug resistance in Mycobacterium tuberculosis: Rapid and inexpensive method for low-resource settings.

The aim of this study was to evaluate a nitrate reductase assay (NRA) for the direct detection of multidrug resistance (MDR) in Mycobacterium tuberculosis from 100 smear-positive sputum samples. The NRA results were compared with the reference proportion method for 100 sputum specimens for which comparable results were available. NRA results were obtained at day 7 for 61 specimens, results for 26 specimens were obtained at day 10, and the results for 13 specimens were obtained at day 14. Thus, 87% of NRA results were obtained in 10 days. NRA is a rapid, accurate, and cost-effective method for the detection of MDR in M. tuberculosis isolates as compared to the proportion method, which is time consuming. Therefore, NRA constitutes a useful tool for detection of tuberculosis drug resistance in low-resource countries with limited laboratory facilities due to its low-cost, ease of performance and lack of requirement of sophisticated equipment.

Cytokine response to dietary rehabilitation with curd (Indian dahi) & leaf protein concentrate in malnourished children.

Background & objectives: Protein energy malnutrition (PEM), an important cause of secondary immune deficiency, is associated with several abnormalities in the immune system including cytokine production. In the present study cytokine levels (both pro- and anti-inflammatory) were evaluated in protein energy malnourished children following nutritional rehabilitation with curd (Indian dahi) and leaf protein concentrate (LPC). Methods: Eighty moderately and severely malnourished children, 1-5 yr of age, received the WHO recommended diet for severe malnutrition, modified according to local dietary habits, containing in addition either curd or micronutrient-rich leaf protein concentrate, for a period of 15 days. Cytokine levels [tumour necrosis factor α (TNFα), interferon γ (IFNγ), interleukin-10 (IL-10), interleukin-4 (IL-4)] were measured before and after dietary rehabilitation. Results: The baseline cytokine levels (TNFα, IFNγ, IL-10 and IL-4) were high in malnourished children. Both the diets caused an increase in serum pro-inflammatory (TNFα, IFNγ), and anti-inflammatory (IL-10) cytokine levels after nutritional rehabilitation. The increase in IL-10 was significant in children receiving curd. There was an insignificant fall in IL-4 levels with both the diets. The cytokine response was comparable in children with moderate and severe malnutrition, as also in children < 2 yr to those between 2-5 yr. Interpretation & conclusions: The study suggests that cytokines (TNFα, IFNγ, IL-10 and IL-4) may serve as biological markers to assess the effect of functional foods like curd or LPC on immunity in malnutrition. Curd may help to maintain the balance in cytokine production by increasing the production of IL-10, and may be considered in place of milk in the nutritional rehabilitation of malnourished children.

Simple and economical method for speciation and resistotyping of clinically significant coagulase negative staphylococci.

An attempt was made to speciate 102 clinically significant isolates of coagulase negative staphylococci (CoNS) by a practical scheme adapted from various references. This scheme utilizes slide and tube coagulase test, urease test ornithine decarboxylase, novobiocin susceptibility and aerobic acid from mannose for assigning species group. Inclusion of one or two additional tests in a species group could identify the isolates to species level. Ninety eight (97%) isolates were conveniently identified as S. epidermidis (41%), S. saprophyticus (16.6%), S. haemolyticus (14.7%), S. hominis (14.7%), S. lugdunensis (4.9%), S. schleiferi (1.9%) and S. capitis (1.9%). Only four isolates were not identified to the species level, two of which were probably S. capitis subspecies ureolyticus / S. warneri / S. simulans . Antibiotic susceptibility testing showed maximum resistance to ampicillin (89%) followed by cefotaxime (59%) with no resistance to vancomycin. The increasing recognition of pathogenic potential of CoNS and emergence of drug resistance amongst them denotes the need to adopt simple laboratory procedures to identify and understand the diversity of staphylococci isolated from clinical material.

Leprosy and herpes zoster; an association or dissociation?

Nerve involvement is common to the pathogenesis of both leprosy and herpes zoster. We report two cases of borderline leprosy in which the skin lesions characteristically spared the healed zoster scar. Possible mechanisms and relationship are discussed.

Preliminary survey of leptospirosis amongst febrile patients from urban slums of East Delhi.

AIM: To determine the possibility of leptospirosis among patients from urban slums presenting with febrile illness during monsoon and post-monsoon season. METHODS: Evidence of leptospirosis in 180 patients with febrile illness was determined by looking for presence of immunoglobulin M (IgM) antibodies by leptospiral IgM enzyme linked immunosorbent assay (ELISA). The test was carried out on 160 Widal test negative and 20 Widal test positive sera received from febrile patients during June to September 2001. RESULTS: Twenty-seven out of 180 (15%) sera were positive for leptospiral IgM antibodies. CONCLUSIONS: This preliminary survey indicates that leptospirosis could be an important cause of febrile illness in patients from urban slums during monsoon and post-monsoon season.

Inhibition of mutagenicity of food-derived heterocyclic amines by sulforaphane--a constituent of broccoli.

Sulforaphane, a constituent of broccoli was investigated for its antimutagenic potential against different classes of cooked food mutagens (heterocyclic amines). These include imidazoazaarenes such as 2-amino-3-methylimidazo[4,5-f]quinoline (IQ), 2-amino-3,4-dimethylimidazo[4,5-f]quinoline (MeIQ), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP); pyridoindole derivatives such as 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1) and 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2); and, dipyridoimidazole derivative such as 2-amino-6-methyldipyrido[1,2-a:3',2'-d]imidazole (Glu-P-1). Tests were carried out by Ames Salmonella/reversion assay using Salmonella typhimurium TA98 (frame shift mutation sensitive) and TA100 (base pair mutation sensitive) bacterial strains in the presence of Aroclor 1254-induced rat liver S9. Results of these in vitro antimutagenicity studies strongly suggest that sulforaphane is a potent inhibitor of the mutagenicity induced by imidazoazaarenes such as IQ, MeIQ and MeIQx (approximately 60% inhibition) and moderately active against pyridoindole derivatives such as Trp-P-1 and Trp-P-2 (32-48% inhibition), but ineffective against dipyridoimidazole derivative (Glu-P-1) in TA 100.

Inhibitory effect of curcumin and its natural analogues on genotoxicity of heterocyclic amines from cooked food.

Curcumin (C) and its natural analogues demethoxycurcumin (dmC) and bisdemethoxycurcumin (bdmC), known for their potent anti-inflammatory, antioxidant, antimutagenic and anticarcinogenic effects, were tested for their possible inhibitory effects against seven cooked food mutagens (heterocyclic amines): 2-amino-3-methylimidazo[4,5-f]quinoline (IQ), 2-amino-3,4-dimethylimidazo[4,5-f]quinoline (MeIQ), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1), 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2), 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) and 2-amino-6-methyldipyrido[1,2-a:3',2'-d]imidazole (Glu-P-1), in both TA98 and TA100 strains of Salmonella typhimurium using Ames Salmonella/reversion assay in the presence of Aroclor induced rat liver S9 homogenate. In the present investigations, curcumin as well as its two natural analogues i.e., dmC and bdmC were found to be highly effective in suppressing genotoxicity of all the tested cooked food mutagens in a dose-dependent manner, in both the frame shift (TA98) as well as base pair mutation sensitive (TA100) strains of S. typhimurium. However, bdmC appeared to be a relatively less active antimutagen compared to C and dmC. More than 80% inhibition of mutagenicity was observed at 200 microg/plate in case of C and dmC in both TA98 and TA100 against all tested cooked food mutagens. Where as, bdmC showed 39-79% inhibition in TA100 and 60-80% inhibition in TA98, at a dose of 200 microg/plate. These findings warrant further biochemical, enzymatic and in vivo investigations in animal models as well as in humans to establish the chemoprotective effect of these agents against mutagenic heterocyclic amines found in cooked food.

Electrophoretic analysis of Salmonella typhi and other bacteria.

A comparative study involving SDS-PAGE of Salmonella typhi and other Bacteria was conducted. Protoplasmic antigens of Salmonella typhi. Salmonella paratyphi A, Salmonella typhimurium, Proteus sp, Klebsiellas sp. Pseudomonas aeruginosa, Shigella flexneri, Staphylococcus aureus were separated and compared on SDS-PAGE followed by checking of their cross reactivity by gel diffusion using antisera raised against whole cell and lysates of Salmonella typhi. Lines of identity between Salmonella typhi, Salmonella paratyphi A and Salmonella typhimurium were observed. No lines of identity were seen among Salmonella typhi, Pseudomonas aeruginosa and Sfaphylococcus aureus.

Palmoplantar lesions in leprosy.

Palms and soles are considered immune to leprosy. A study was carried out to assess the frequency of lesions over palms and soles and to correlate their occurrence with various parameters. Two hundred eighty leprosy patients were screened for lesions over palms and soles. Palmo-plantar lesions were observed in 10% of the patients screened. Slit-skin smears and biopsies were done from routine sites and palmo-plantar lesions. Histopathology and slit-skin smear confirmed the presence of disease. Eight were in type I reaction, and 50% of patients with type I reaction screened showed lesions over palms and/or soles. The reason for this is not known; probably inapparent lesions become apparent during reactions. Lesions of various morphology were observed. Silky hand was observed in one case.