Coagulase-negative staphylococci causing blood stream infection at an Indian tertiary care hospital: Prevalence, antimicrobial resistance and molecular characterisation

INTRODUCTION

Recent years have seen a rise of coagulase-negative staphylococci (CoNS) from common contaminants to agents of nosocomial blood stream infections (BSI's). Molecular typing and establishing a correlation with antibiotic resistance is essential particularly in countries like India where genotyping studies for drug-resistant CoNS are sparse.

METHODS

A prospective study was done over 18 months, wherein 42,693 blood samples were received, and 59 patients with BSI due to CoNS were evaluated. The isolates recovered were identified by a biochemical test panel and matrix-assisted laser desorption ionization - time of flight mass spectrometry followed by antimicrobial susceptibility testing by Kirby-Baur disc diffusion method and E-test strips. Staphylococcal chromosomal cassette mec (SCCmec) element was characterised by multiplex polymerase chain reaction for all methicillin-resistant (MR) isolates.

RESULTS

The majority of CoNS isolated were constituted by Staphylococcus haemolyticus (47.5%) followed by Staphylococcus epidermidis (33.9%), Staphylococcus hominis (11.86%), Staphylococcus cohnii (5.08%) and Staphylococcus warneri (1.69%). Among all isolates 57.6% were MR with statistically significant higher resistance versus methicillin sensitive-CoNS. This difference was significant for erythromycin (76% vs. 44%, P = 0.011), rifampicin (50% vs. 12%,P= 0.002) and amikacin (26.5% vs. 4%, P = 0.023), ciprofloxacin (64.7% vs. 20%, P = 0.001) and cotrimoxazole (55.9% vs. 20%, P = 0.006). SCCmec type I was predominant (61.8%, P = 0.028) and exhibited multidrug resistance (76.2%). Coexistence of SCCmec type I and III was seen in 8.82% MR isolates.

CONCLUSION

CoNS exhibit high antimicrobial resistance thereby limiting treatment options. The presence of new variants of SCCmec type in hospital-acquired CoNS may predict the antibiotic resistance pattern. This is the first evaluation of the molecular epidemiology of CoNS causing BSI from India and can serve as a guide in the formulation of hospital infection control and treatment guidelines.

The effects of perturbed cerebral blood flow and cerebrovascular reactivity on structural MRI and behavioral readouts in mild traumatic brain injury

This study investigated the effects of perturbed cerebral blood flow (CBF) and cerebrovascular reactivity (CR) on relaxation time constant (T2), apparent diffusion coefficient (ADC), fractional anisotropy (FA), and behavioral scores at 1 and 3 hours, 2, 7, and 14 days after traumatic brain injury (TBI) in rats. Open-skull TBI was induced over the left primary forelimb somatosensory cortex (N=8 and 3 sham). We found the abnormal areas of CBF and CR on days 0 and 2 were larger than those of the T2, ADC, and FA abnormalities. In the impact core, CBF was reduced on day 0, increased to 2.5 times of normal on day 2, and returned toward normal by day 14, whereas in the tissue surrounding the impact, hypoperfusion was observed on days 0 and 2. CR in the impact core was negative, most severe on day 2 but gradually returned toward normal. T2, ADC, and FA abnormalities in the impact core were detected on day 0, peaked on day 2, and pseudonormalized by day 14. Lesion volumes peaked on day 2 and were temporally correlated with forelimb asymmetry and foot-fault scores. This study quantified the effects of perturbed CBF and CR on structural magnetic resonance imaging and behavioral readouts.

Physiologically based and population PK modeling in optimizing drug development: A predict-learn-confirm analysis

Physiologically based pharmacokinetic (PBPK) modeling and classical population pharmacokinetic (PK) model‐based simulations are increasingly used to answer various drug development questions. In this study, we propose a methodology to optimize the development of drugs, primarily cleared by the kidney, using model‐based approaches to determine the need for a dedicated renal impairment (RI) study. First, the impact of RI on drug exposure is simulated via PBPK modeling and then confirmed using classical population PK modeling of phase 2/3 data. This methodology was successfully evaluated and applied to an investigational agent, orteronel (nonsteroidal, reversible, selective 17,20‐lyase inhibitor). A phase 1 RI study confirmed the accuracy of model‐based predictions. Hence, for drugs eliminated primarily via renal clearance, this modeling approach can enable inclusion of patients with RI in phase 3 trials at appropriate doses, which may be an alternative to a dedicated RI study, or suggest that only a reduced‐size study in severe RI may be sufficient.

Conversion of Lapachol to Rhinacanthin-A and other Cyclized Products

A facile synthesis of rhinacanthin-A is achieved by the side chain cyclization of lapachol with meta-chloroperbenzoic acid along with stenocarpoquinone-A, stenocarpoquinone-B and its isomer.

An anti-CD154 domain antibody prolongs graft survival and induces Foxp3(+) iTreg in the absence and presence of CTLA-4 Ig

The use of monoclonal antibodies targeting the CD154 molecule remains one of the most effective means of promoting graft tolerance in animal models, but thromboembolic complications during early clinical trials have precluded their use in humans. Furthermore, the role of Fc-mediated deletion of CD154-expressing cells in the observed efficacy of these reagents remains controversial. Therefore, determining the requirements for anti-CD154-induced tolerance will instruct the development of safer but equally efficacious treatments. To investigate the mechanisms of action of anti-CD154 therapy, two alternative means of targeting the CD40-CD154 pathway were used: a nonagonistic anti-CD40 antibody and an Fc-silent anti-CD154 domain antibody. We compared these therapies to an Fc-intact anti-CD154 antibody in both a fully allogeneic model and a surrogate minor antigen model in which the fate of alloreactive cells could be tracked. Results indicated that anti-CD40 mAbs as well as Fc-silent anti-CD154 domain antibodies were equivalent to Fc-intact anti-CD154 mAbs in their ability to inhibit alloreactive T cell expansion, attenuate cytokine production of antigen-specific T cells and promote the conversion of Foxp3(+) iTreg. Importantly, iTreg conversion observed with Fc-silent anti-CD154 domain antibodies was preserved in the presence of CTLA4-Ig, suggesting that this therapy is a promising candidate for translation to clinical use.

Role of simvastatin in prevention of vasospasm and improving functional outcome after aneurysmal sub-arachnoid hemorrhage: a prospective, randomized, double-blind, placebo-controlled pilot trial

BACKGROUND

Vasospasm plays a major role in the morbidity and mortality after aneurysmal subarachnoid hemorrhage (aSAH). The preliminary studies suggest that statins protect against cerebral vasospasm.

OBJECTIVE

The aim of the study was to determine the role of simvastatin in preventing clinical vasospasm and improving functional outcome in patients with aSAH.

METHODS

All patients with aSAH admitted within 96 h of ictus were randomized to receive either Simvastatin or placebo - 80 mg/day for 14 days. Thirty eight patients were recruited in the study- 19 received Simvastatin and 19 placebo. All the patients underwent surgical clipping of the aneurysm. The primary outcome of the study was the development of clinical cerebral vasospasm. The secondary outcomes included Glasgow Outcome Score (GOS), Modified Rankin Scale (MRS) and Barthel Index Score (MBI) at follow-up at 1, 3 and 6 months.

RESULTS

16% of the patients in the simvastatin group had high Middle Cerebral Artery velocities (> 160 cm/sec) on transcranial Doppler on one or more than one day during the study duration as compared to 26% of the patients in the placebo group (p = 0.70). Neurological deterioration occurred in 26% and 42% of the patients in simvastatin group versus placebo group, respectively (p = 0.31). There was an improvement in the functional outcome in the simvastatin group at 1, 3 or 6 months in the follow-up; however, this difference was not statistically significant.

CONCLUSIONS

There was benefit of simvastatin in terms of reduction in clinical vasospasm, mortality or improved functional outcome, however, this was not statistically significant.

Use of intravenous immune globulin in the ICU: a retrospective review of prescribing practices and patient outcomes

RATIONALE

Intravenous immune globulin (IVIG) is a pooled human blood product. Much of IVIG use in Canada is prescribed for 'unlabelled' or 'off-label' indications. Due to costs, risk of use and limited supply, knowledge about the use of IVIG is important. We collected data regarding the usage of IVIG and outcomes of patients receiving IVIG in the intensive care units (ICUs) of two community and three academic hospitals.

METHODS

We reviewed the charts of adult patients who received IVIG in the five ICUs over a 5-year period. Data collection included demographics, severity of illness, indication for and dose of IVIG, mortality and adverse effects. On the basis of a classification developed by Canadian Blood Services, the indications for IVIG were then classified as 'appropriate' or 'inappropriate'.

RESULTS

One hundred and forty-five patients received IVIG in the ICU. In all, 19% of IVIG prescriptions were for 'appropriate' indications and 7% were 'inappropriate'. The remaining 74% were prescribed for indications with some evidence to support their use. Three indications accounted for 50% of all IVIG prescribed: Guillain-Barre syndrome (GBS), necrotising fasciitis (NF) and toxic epidermal necrolysis (TEN). Both the community and academic centres prescribed IVIG for similar indications. Adverse effects associated with IVIG administration included deep vein thrombosis/pulmonary embolism, fever and renal failure, although direct causation related to IVIG could not be established. The overall mortality rate was 55%.

CONCLUSIONS

IVIG is used relatively infrequently in the critical care setting. The most common indications were GBS, TEN and NF. Mortality was high. There was no difference between community and academic ICUs.

Abstract P1-01-19: Comparison of Ultrasound-Guided Fine Needles Aspiration Cytology and Ultrasound Guided Core Biopsy in Pre-Operative Axillary Staging for Early Breast Cancer

Introduction: Pre-operative axillary staging is now widely accepted as a prerequisite in surgical management of the axilla for patients newly diagnosed with early breast cancer. For those patients having breast tumour excision who are found to have nodal involvement, axillary clearance can be performed at the same time without prior sentinel node biopsy. Ultrasound (US) alone has low sensitivity, but can be used to direct needle biopsy. We assessed and compared the sensitivity and specificity of US-guided core biopsies (USCB) and US-guided fine needle cytology (USFNAC) used in our unit.

Patients and methods: A retrospective and prospective data collection was performed between November 2007 and May 2010 on all newly diagnosed breast cancer patients in our unit since the introduction of routine pre-operative axillary US. Patients whose nodes looked benign or normal on US were offered sentinel node biopsy (SNB). Patients found to have suspicious nodes were offered USFNAC or USCB, according to the individual preference of the radiologists. Patients with positive cytology or histology underwent axillary node clearances (ANC), those with benign cytology or histology were offered SNB. The final histology results were reviewed and correlated to their pre-operative histology or cytology.

Results: Of 559 Axillary ultrasound scans performed in our department between November 2007 and May 2010, 229 patients had pre-operative US scans of the axilla for newly diagnosed, clinically node-negative breast cancer. Of these 46 had USFNAC, 44 had USCB and 139 had normal/benign US. The USFNAC and USCB groups had similar proportions of positive results on postoperative histology, namely 70% and 79% respectively, allowing direct comparisons to be made. Of the 46 USFNAC patients, 17 (37%) had positive cytology (all confirmed by axillary clearance final histology). The 29 USFNAC patients with negative cytology had 15 (52%) with positive histology on sentinel node biopsy. The sensitivity of USFNAC was 53% and the specificity 100%. Of the 44 USCB patients, 26 (59%) were positive (all confirmed by axillary clearance final histology). Of the 18 USCB-negative patients, 7 (39%) were found to be positive on axillary clearance. The sensitivity of USCB was 79% and the specificity 100%. Of the 139 patients with normal US, 42 (30%) were found to be positive on sentinel node biopsies. For US alone, sensitivity was 61% and specificity was 80%.

Conclusion: US staging of the axilla is superior to clinical staging. However, there is still a high incidence of false negative results, making US a crude way of assessing the axilla and confirming the necessity for sentinel node biopsy in US-negative axillae. For patients with axillae that are indeterminate on US, our data supports routine use of ultrasound core biopsy (USCB) over Ultrasound fine needle aspiration cytology (USFNAC) for preoperative staging of the axilla, where technically feasible.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P1-01-19.

Targeted therapy for high-grade glioma with the TGF-β2 inhibitor trabedersen: results of a randomized and controlled phase IIb study

This randomized, open-label, active-controlled, dose-finding phase IIb study evaluated the efficacy and safety of trabedersen (AP 12009) administered intratumorally by convection-enhanced delivery compared with standard chemotherapy in patients with recurrent/refractory high-grade glioma. One hundred and forty-five patients with central reference histopathology of recurrent/refractory glioblastoma multiforme (GBM) or anaplastic astrocytoma (AA) were randomly assigned to receive trabedersen at doses of 10 or 80 µM or standard chemotherapy (temozolomide or procarbazine/lomustine/vincristine). Primary endpoint was 6-month tumor control rate, and secondary endpoints included response at further timepoints, survival, and safety. Six-month tumor control rates were not significantly different in the entire study population (AA and GBM). Prespecified AA subgroup analysis showed a significant benefit regarding the 14-month tumor control rate for 10 µM trabedersen vs chemotherapy (p= .0032). The 2-year survival rate had a trend for superiority for 10 µM trabedersen vs chemotherapy (p = .10). Median survival for 10 µM trabedersen was 39.1 months compared with 35.2 months for 80 µM trabedersen and 21.7 months for chemotherapy (not significant). In GBM patients, response and survival results were comparable among the 3 arms. Exploratory analysis on GBM patients aged ≤55 years with Karnofsky performance status >80% at baseline indicated a 3-fold survival at 2 and 3 years for 10 µM trabedersen vs chemotherapy. The frequency of patients with related or possibly drug-related adverse events was higher with standard chemotherapy (64%) than with 80 µM trabedersen (43%) and 10 µM trabedersen (27%). Superior efficacy and safety for 10 µM trabedersen over 80 µM trabedersen and chemotherapy and positive risk–benefit assessment suggest it as the optimal dose for further clinical development in high-grade glioma.