Iqbal R Kaur

Changing trends in bacteriology of burns in the burns unit, Delhi, India

A retrospective study of bacterial isolates from the wounds of patients admitted to burns unit, was undertaken at Guru Tegh Bahadur Hospital, University College of Medical Sciences, Delhi, India, over a period of 5 years between July 1997 and April 2002. The study compared the results obtained with the previous 5 years data (June 1993-June 1997) from the same unit to determine the changing patterns and emerging trends of bacterial isolates and their antimicrobial susceptibilities. Pseudomonas species (31%) and Staphylococcus aureus (22%) were the most common pathogens followed by Klebsiella species (19%). Multi-drug resistant (MDR) Acinetobacter species (9%) have emerged as an important nosocomial pathogen in our burn unit. Most of the gram-negative isolates obtained were found to be multi-drug resistant and 61% of the tested isolates were extended spectrum beta-lactamase (ESBL) producers. Concomitant resistance to penicillin and aminoglycosides was observed in 61% of Enterococcus fecalis isolates. When compared with the results of previous 5 years (June 1993-June 1997) Pseudomonas spp. was still the commonest pathogen in the burns unit. However, isolation of this organism and other gram-negative organisms has decreased in comparison to previous years. The incidence of antimicrobial resistance has markedly increased over the past years resulting in limitation of therapeutic options.

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.

T helper 1 to T helper 2 shift in cytokine expression: an autoregulatory process in superantigen- associated psoriasis progression?

Psoriasis is an inflammatory skin disorder characterized by increased activation of CD4(+) T lymphocytes, and systemic and local overexpression of pro-inflammatory cytokines such as interleukin 2 (IL-2), gamma interferon (IFN-gamma), IL-6 and tumour necrosis factor alpha, indicating that immunopathogenesis of the disease is T helper 1 (Th1) mediated. Several studies suggest a pivotal role of bacterial superantigens in the initiation and/or exacerbation of this illness. This study was conducted to assess the systemic Th1/Th2 imbalance in Indian psoriasis patients presenting with variable duration of disease by studying systemic superantigen-stimulated peripheral blood mononuclear cell (PBMC) cytokine expression. PBMCs were isolated and stimulated in vitro with superantigens (streptococcal pyrogenic exotoxin A and staphylococcal enterotoxin B), and the cytokines released (IFN-gamma for a Th1 response, and IL-4 and IL-10 for a Th2 response) were assayed. In contrast to controls, psoriasis patients in the early course of disease were characterized by significantly increased expression of the pro-inflammatory cytokine IFN-gamma, whilst a shift towards IL-10 secretion (Th2 response) was observed in those presenting with increased duration of disease. These observations suggest a possible shift from a Th1 to a Th2 cytokine response with superantigen-associated progression for the duration of psoriasis, perhaps as an adaptive process by the immune system in an attempt to downregulate abnormal inflammatory Th1 immune responses.

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.

Pattern of Candida isolates in Hospitalized Children

Nosocomial candidemia is the 4th most common pathogen in blood stream infection. Emergence of non-albicans Candida species with often intrinsically resistance fluconazole pattern may lead to difficulty in management of septicemia. Although the present study isolated 80% of non albicans candida species with C.tropicalis as the most common (35%) species, 96% of our Candida species isolated were sensitive to fluconazole. The probable causes of low resistance pattern to fluconazole in our institute are discussed. It is however necessary to identify the complete clinical response to the given treatment. Therefore, appropriate identification of species with susceptibility testing would be advisable before start of anti-fungals. This would prevent emergence of fluconazole resistance.

Efficacy and safety of vi-tetanus toxoid conjugated typhoid vaccine (PedaTyph™) in Indian children: School based cluster randomized study

ABSTRACT Vi polysaccharide typhoid vaccines cannot be used in children <2 years owing to poor immunogenic and T cell independent properties. Conjugate vaccine prepared by binding Vi to tetanus toxoids (Vi-TT) induces protective levels even in children <2 years. We evaluated efficacy and safety following vaccination with a Vi-TT vaccine in children 6 months to 12 years of age. Overall, 1765 subjects were recruited from two registered municipal urban slums of southern Kolkata. Most of the children of the slum dwellers attended the schools in the locality which was selected with permission from the school authority. Schools were randomly divided into vaccinated (Test group) and unvaccinated group (Control group). Children and their siblings of test group received 2-doses of PedaTyph™ vaccine at 6 weeks interval. Control group received vaccines as per national guidelines. Adverse events (AEs) were examined after 30 minutes, 1 month and clinical events were observed till 12 months post-vaccination. Incidence of culture positive typhoid fever in the control group was 1.27% vis-a-vis none in vaccine group during 12 months. In subgroup evaluated for immunogenicity, an antibody titer value of 1.8 EU/ml (95% CI: 1.5 EU/ml, 2.2 EU/ml), 32 EU/ml (95% CI: 27.0 EU/ml, 39.0 EU/ml) and 14 EU/ml (95% CI: 12.0 EU/ml, 17.0 EU/ml) at baseline, 6 weeks and 12 months, respectively was observed. Sero-conversion among the sub-group was 100% after 6 weeks of post-vaccination and 83% after 12 months considering 4-fold rise from baseline. The efficacy of vaccine was 100 % (95% CI: 97.6%, 100%) in the first year of follow-up with minimal AEs post vaccination. Vi conjugate typhoid vaccine conferred 100% protection against typhoid fever in 1765 children 6 months to 12 years of age with high immunogenicity in a subgroup from the vaccine arm.

Clinico-epidemiological profile and high-level aminoglycoside resistance in enterococcal septicemia from a tertiary care hospital in east Delhi.

Background: Emergence of high-level aminoglycoside and glycopeptide resistance has significantly contributed to the mortality, particularly in serious enterococcal infections. Objectives: This study was aimed to determine the prevalence of high-level gentamicin resistance (HLGR), high-level streptomycin resistance (HLSR) and vancomycin resistance in enterococcal isolates recovered from patients with bacteremia. Materials and Methods: A total of 110 blood culture isolates of enterococci were recovered from septicemic patients. Routine antibiotic susceptibility testing was performed and screening for ampilcillin, high-level aminoglycoside resistance (HLAR) and high-level vancomycin resistance was done by agar screen method. Results: Out of 110 isolates, Enterococcus faecium accounted for 53% of these isolates, followed by Enterococcus fecalis (33%), Enterococcus casseliflavus (8%), Enterococcus raffinosus (4%) and Enterococcus dispar (2%). Resistance to ampicillin, HLGR, HLSR and HLAR was detected in 58%, 62%, 58% and 54% of the isolates, respectively. No isolate was resistant to vancomycin. Conclusion: This study illustrates the high prevalence of HLAR in enterococci from patients with septicemia in our region, which emphasizes the need to predict synergy between beta-lactams and aminoglycosides for management of enterococcal infections.

Gender Differences in Outcomes of Low Birth Weight and Preterm Neonates: the Male Disadvantage

Various studies conducted worldwide have shown that male neonates have higher rates of mortality and morbidity in the perinatal period compared with females. However, there has been only one study from India on this subject. Therefore, this study was conducted to establish the difference in mortality between males and females among neonates born with two established risk factors of septicaemia--low birth weight (<2.5 kg) and preterm birth (<37 weeks). One hundred and fifty consecutive neonates which were either preterm or had low birth weight were recruited after obtaining informed consent from the parents. Blood culture was done, and the bacterial isolates were identified by standard protocol. Statistically significant association was found between male gender and mortality among culture-positive neonates. Therefore, results of the present study indicate that preterm or low birth weight male neonates have higher likelihood of mortality compared with their female counterparts in the Indian scenario.

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.

Vitamin D supplementation for treatment and prevention of pneumonia in under-five children: A randomized double-blind placebo controlled trial

ObjectiveTo evaluate the efficacy of single oral mega-dose of Vitamin D3 for treatment and prevention of pneumonia in underfive children.DesignRandomized, double blind, placebo-controlled trial.SettingTertiary-care hospital.Participants324 children (of 980 assessed) between 6 mo-5 y age (median (IQR): 12 (7,19.8) mo) with WHO-defined severe pneumonia. Of these, 126 (39%) were vitamin D deficient (serum 25(OH)D <12 ng/mL).Intervention100,000 IU of oral cholecalciferol (n= 162) or placebo (n= 162) in single dose, administered at enrolment.Outcome variablesPrimary: Time to resolution of severe pneumonia and proportion of children having recurrence of pneumonia in next 6 months; Secondary: Change in serum levels of 25(OH)D; immunoglobulins IgA, IgG, IgM, and cathelicidin 2 weeks following supplementation; and time taken for overall resolution of illness.ResultsMedian (95% CI) time for resolution of severe pneumonia was 30 (29, 31) h in the vitamin D group as compared to 31 (29,33) h in the placebo group [adjusted hazard ratio (95% CI): 1·39 (1·11, 1·76); P=0·005]. The risk of recurrence of pneumonia in next 6 months was comparable in the two groups [placebo: 36/158 (22·8%); vitamin D: 39/156 (25%); RR (95% CI): 1·13 (0·67,1·90); P=0·69]. Proportion of vitamin D deficient children declined from 38% to 4% in the supplementation group, and from 41% to 33% in the placebo group, two weeks after supplementation. There was no significant effect of vitamin D supplementation on serum levels of cathelicidin, IgA and IgG. The time taken for complete recovery from pneumonia, duration of hospitalization, and fever clearance time were comparable for the two groups. No adverse event was noted related to the intervention.ConclusionThere is no robust evidence of a definite biological benefit, either for therapy or prevention, to suggest a routine megadose supplement of vitamin D3 for under-five children with severe pneumonia.