Study of the role of efflux pump in ciprofloxacin resistance in Salmonella enterica serotype Typhi

PURPOSE

There are increasing reports on failure of clinical response to ciprofloxacin in typhoid fever despite the strain being sensitive to drug in in-vitro using standard guidelines and showing mutations in DNA gyrase. But this increased MIC and clinical failures with ciprofloxacin are not always co-related with mutations presently identified in gyrA and parC genes. This shows that there may be other mechanisms such as an active drug efflux pump responsible as has been shown in other Enterobacteriaceae. This study was carried out to determine the role of efflux pump in Salmonella Typhi isolates.

MATERIALS AND METHODS

Total 25 already characterized nalidixic acid sensitive and nalidixic acid resistant S. Typhi strains with different range of ciprofloxacin MIC were included to study the role of efflux pump in the presence of CCCP (efflux pump inhibitor). For genotypic characterization, the entire acrR gene was sequenced to confirm the presence of any mutation in the gene.

RESULTS

The MIC of ciprofloxacin remained same in the presence and absence of CCCP in the studied strains and no significant mutations were found in the acrR gene in any of the isolates studied.

CONCLUSIONS

No role of efflux pump in ciprofloxacin resistance was found in strains studied. There is a need to explore further mechanism of ciprofloxacin resistance in Salmonella Typhi.

In vitro antimicrobial activity of crude ethanol extracts and fractions of Terminalia catappa and Vitex doniana

BACKGROUND

The spread of microorganisms resistant to some antimicrobial agents necessitates the need to search for novel and effective antimicrobial agents. In this study, the antimicrobial activity of Terminalid catappa Linn. (Combretaceae) and Vitex doniana Sweet. (Verbenaceae), two Nigerian medicinal plants used in folk medicines for the management of various ailments related to microbial infections were evaluated.

OBJECTIVES

To evaluate the antimicrobial activity of the crude ethanol extracts and fractions of the leaves and stem bark of T. catappa and V. doniana.

METHODOLOGY

Four crude ethanol extracts and 16 (n-hexane, ethylacetate, n-butanol and aqueous) fractions of leaves and stem bark of T. catappa and V doniana were evaluated for in vitro antimicrobial activity against fifteen (15) strains of bacteria and fungi. The antimicrobial activity was determined in a 96-well plate using a resazurin based broth microdilution method. Two standard antimicrobial drugs ampicillin and nystatin were included as positive control.

RESULTS

The butanoL fraction of stem bark of T. catappa and ethanol crude extract of leaf of V don iana displayed the highest antibacterial activity with similar minimum inhibitory concentration (MIC) value of 93.75 microg/mL against S. aureus and B. subtilis. Furthermore, the ethyl acetate fraction of stem bark of T. catappa showed the highest antifungal activity with MIC of 187.5 microg/mL against A. sydowi. Amp icillin had MIC of 15.6 and 31.3 microg/mL against S. aureus and B. subtili, respectively while nystatin produced MIC of 3.9 microg/mL against A. sydowi.

CONCLUSION

Termninalia catappa and Vitex doniana may serve as useful sources of plant derived antimicrobial agents.

Using facebook for medical education: will students respond?

There is little information about the willingness of medical students to participate in Facebook for education. I analyzed my interactions with students for the past 14 months to estimate the quantity of student interaction. A Facebook Group was created. Students friend requests were accepted, but "friending" was never solicited. Questions were created around a clinical situation and posted. Forty questions were posted. 5/40 questions were about physics/chemistry. 24 questions focused on basic medical sciences. 11 questions were primarily about clinical medicine. In fourteen months, 533/810 (66%) college students joined the Group. In all, 163/533 students (30%) responded at least once. Half of all responses were comments; the rest were clicks on the "like" button. The average number of responses was 9.5 unique students/question. If participation is voluntary, and targeted students are large in number, one can expect about 66% of students to become members of a site, and about 30% of these to interact. For any given question posted on the site, about 2% of members will respond, regardless of the nature of question: clinically oriented or basic.

Cerebral phaeohyphomycosis by Exophiala dermatitidis

Cerebral phaeohyphomycosis is a rare and frequently fatal disease. We report a case of cerebral phaeohyphomycosis caused by Exophiala dermatitidis in a young immuno competent male presenting to a tertiary care hospital in Jaipur.

Antigen sequence typing of outer membrane protein (fetA) gene of Neisseria meningitidis serogroup A from Delhi & adjoining areas

BACKGROUND & OBJECTIVES

Meningitis caused by Neisseria meningitidis is a fatal disease. Meningococcal meningitis is an endemic disease in Delhi and irregular pattern of outbreaks has been reported in India. All these outbreaks were associated with serogroup A. Detailed molecular characterization of N. meningitidis is required for the management of this fatal disease. In this study, we characterized antigenic diversity of surface exposed outer membrane protein (OMP) FetA antigen of N. meningitidis serogroup A isolates obtained from cases of invasive meningococcal meningitis in Delhi, India.

METHODS

Eight isolates of N. meningitidis were collected from cerebrospinal fluid during October 2008 to May 2011 from occasional cases of meningococcal meningitis. Seven isolates were from outbreaks of meningococcal meningitis in 2005-2006 in Delhi and its adjoining areas. These were subjected to molecular typing of fetA gene, an outer membrane protein gene.

RESULTS

All 15 N. meningitides isolates studied were serogroup A. This surface exposed porin is putatively under immune pressure. Hence as a part of molecular characterization, genotyping was carried out to find out the diversity in outer membrane protein (FetA) gene among the circulating isolates of N. meningitidis. All 15 isolates proved to be of the same existing allele type of FetA variable region (VR) when matched with global database. The allele found was F3-1 for all the isolates.

INTERPRETATION & CONCLUSIONS

There was no diversity reported in the outer membrane protein FetA in the present study and hence this protein appeared to be a stable molecule. More studies on molecular characterization of FetA antigen are required from different serogroups circulating in different parts of the world.

Comparative genomics and association mapping approaches for blast resistant genes in finger millet using SSRs

The major limiting factor for production and productivity of finger millet crop is blast disease caused by Magnaporthe grisea. Since, the genome sequence information available in finger millet crop is scarce, comparative genomics plays a very important role in identification of genes/QTLs linked to the blast resistance genes using SSR markers. In the present study, a total of 58 genic SSRs were developed for use in genetic analysis of a global collection of 190 finger millet genotypes. The 58 SSRs yielded ninety five scorable alleles and the polymorphism information content varied from 0.186 to 0.677 at an average of 0.385. The gene diversity was in the range of 0.208 to 0.726 with an average of 0.487. Association mapping for blast resistance was done using 104 SSR markers which identified four QTLs for finger blast and one QTL for neck blast resistance. The genomic marker RM262 and genic marker FMBLEST32 were linked to finger blast disease at a P value of 0.007 and explained phenotypic variance (R²) of 10% and 8% respectively. The genomic marker UGEP81 was associated to finger blast at a P value of 0.009 and explained 7.5% of R². The QTLs for neck blast was associated with the genomic SSR marker UGEP18 at a P value of 0.01, which explained 11% of R². Three QTLs for blast resistance were found common by using both GLM and MLM approaches. The resistant alleles were found to be present mostly in the exotic genotypes. Among the genotypes of NW Himalayan region of India, VHC3997, VHC3996 and VHC3930 were found highly resistant, which may be effectively used as parents for developing blast resistant cultivars in the NW Himalayan region of India. The markers linked to the QTLs for blast resistance in the present study can be further used for cloning of the full length gene, fine mapping and their further use in the marker assisted breeding programmes for introgression of blast resistant alleles into locally adapted cultivars.

Imaging features of primary and metastatic alveolar soft part sarcoma: single institute experience in 25 patients

OBJECTIVE

To describe imaging features of primary and metastatic alveolar soft part sarcoma (ASPS).

METHODS

In this institutional review board-approved and Health Insurance Portability and Accountability Act-compliant retrospective study, 25 patients (14 males; mean age, 25 years; range, 18-40 years) with pathologically proven ASPS seen at our institute between 1995 and 2013 were included. Imaging of primary tumours in 5 patients and follow-up imaging in 25 patients were reviewed by 2 radiologists in consensus. Clinical information was obtained from electronic medical records.

RESULTS

The most common sites for the primary tumour were extremities (17/25, 68%) and torso (6/25, 24%). Primary tumours (n = 5) were well circumscribed, compared with skeletal muscle, were isodense on CT, hyperintense on T1 and T2 weighted images with intense post-contrast enhancement, prominent feeders on CT and flow voids on MRI. Metastases developed in 23/25 (92%) patients, 18 at presentation. The most common sites of metastases were the lungs (100%), lymph nodes (74%), bones (57%) and brain (43%). Visceral and nodal metastases were hypervascular. At the time of reporting the results, 15 patients have died, 6 are alive and 4 were lost to follow-up. Median survival was 74 months for those without brain metastases (n = 8) and 60 months for those with brain metastases (n = 7). Median survival was shorter for patients with metastases at presentation.

CONCLUSION

ASPS most commonly involves the lower extremities of young adults, is hypervascular on imaging, often metastasizes at presentation, frequently to lung, nodes, bones and brain, and has an indolent course despite metastases. Brain metastases and high tumour burden (number of metastatic sites) at presentation decreased survival in our study.

ADVANCES IN KNOWLEDGE

ASPS has an unusual pattern of metastases to the brain and nodes in addition to lung and bones. It has an indolent course despite metastases.

Effect of short-term practice of pranayamic breathing exercises on cognition, anxiety, general well being and heart rate variability

There has been an increasing interest in pranayamic breathing exercises which have been known to improve the quality of life. Present study was conducted to find out the effect of Bhastrika and Anulom Vilom Pranayam and yogasana on heart rate variability, general well being, cognition and anxiety levels of the medical students. Ninety-six medical students were randomly divided into two groups. One group performed Bhastrika and Anulom Vilom Pranayam and the second Suryanamaskar for six weeks. The subjects were made to fill in PGI memory scale, Hamilton- anxiety scale and psychological general well being schedule and recording of heart rate variability parameters was done, before and after six weeks of pranayam practice. The results showed highly significant increase in high frequency (HF) components of heart rate variability and decrease in low frequency (LF) components and LF/HF inthe group practising pranayam. There was also highly significant improvement of cognition, general well being and anxiety as shown by the PGI memory scale, Hamilton- anxiety scale and psychological general well being schedule scores in this group. In the yogasana group no significant changes were observed in the heart rate variability, cognition and anxiety although psychological general well being schedule scores significantly improved after six weeks practice of yogasana. The study shows that practice of slow breathing type of pranayam for six weeks improves cognition, anxiety and general well being and Increases the parasympathetic activity. Whereas there was no effect of the yogasana on the above parameters except improvements in the general well being.

Correlation of progression of diabetic retinopathy with the alterations in retrobulbar circulation

Introduction: Color Doppler Imaging (CDI) is used widely to study retrobulbar circulation. Objectives: To determine the association between progression of diabetic retinopathy (DR) and alterations in retrobulbar arterial circulation using CDI studies. Materials and methods: Prospective observational case series. It is single institutional study of 50eyes of nonproliferative diabetic retinopathy in 50 patients with type II diabetes mellitus. DR was graded according to ETDRS system. Retrobulbar circulation was studied in patients for Peak systolic velocity (PSV), End diastolic velocity (EDV) and Resistive index (RI) in Central retinal artery (CRA), Ophthalmic artery (OA) and Posterior ciliary artery (PCA) using CDI initially and reevaluated after 6 months or later for any change in retinopathy grade and arterial circulation parameters. The patients were grouped as Group I not showing progression of DR and Group II showing progression. The two groups were compared for any significant change in CDI parameters. Results: The baseline resistive indices were higher than normal population. There was significant increase in RI in PCA and CRA in all patients after 6 months. 14 patients (28%) showed progression of DR and 36 (72%) did not show progression of DR. There was no significant association with progression of retinopathy and CDI findings. (p=>0.05). Conclusion: The retrobulbar arterial circulation seems to be affected in all diabetics with DR. The changes appear to be progressive. The CDI findings in arterial circulation however lack predictive power for progression of diabetic retinopathy in non proliferative DR. Nepal J Ophthalmol 2013; 5(10): 147-153 DOI: http://dx.doi.org/10.3126/nepjoph.v5i2.8705

Atorvastatin in clinically-significant macular edema in diabetics with a normal lipid profile

INTRODUCTION

Lipid-lowering drugs preserve vision and reduce the risk of hard exudates in clinically-significant macular edema(CSME) in diabetics with an abnormal lipid profile. But their role in reducing CSME in diabetics with a normal lipid profile is not yet known.

OBJECTIVE

To evaluate the role of atorvastatin in CSME in diabetics with a normal lipid profile.

MATERIALS AND METHODS

A prospective, randomized clinical trial was carried out. Thirty CSME patients with a normal lipid profile were randomly divided into Group A and B. Atorvastatin had been started in Group A four weeks prior to laser treatment. The main outcome measures were any improvement or deterioration in visual acuity and macular edema and hard exudates at six months follow-up.

STATISTICS

Both the groups were compared using unpaired t test for quantitative parameters and chi-square test for qualitative parameters. A p value of less than 0.05 was taken as significant.

RESULTS

Visual acuity, macular edema and hard exudates resolution was not significantly different in the two groups (P = 0.14, 0.62, 0.39 respectively).

CONCLUSION

Atorvastatin does not affect treatment outcome in CSME with a normal lipid profile over a short term follow-up.

Probable Vogt-Koyanagi-Harada's syndrome associated with tonic pupils

BACKGROUND

Pupillary abnormalities with complete or incomplete form of VKH have rarely been reported. We report a case of "probable" Vogt- Koyanagi-Haradas (VKH) disease associated with tonic pupils.

CASE

A young healthy male presented with 15 days' history of bilateral decrease in vision. The patient had bilateral panuveitis with exudative retinal detachment associated with tonic pupils. There were no other systemic associations. The ultrasonography and fluorescein angiography findings were consistent with VKH disease.

CONCLUSION

Pupillary reaction abnormalities though uncommon could be seen in association with "probable" VKH disease.