Epidemic Spread of Symbiotic and Non-Symbiotic Bradyrhizobium Genotypes Across California

The patterns and drivers of bacterial strain dominance remain poorly understood in natural populations. Here, we cultured 1292 Bradyrhizobium isolates from symbiotic root nodules and the soil root interface of the host plant Acmispon strigosus across a >840-km transect in California. To investigate epidemiology and the potential role of accessory loci as epidemic drivers, isolates were genotyped at two chromosomal loci and were assayed for presence or absence of accessory "symbiosis island" loci that encode capacity to form nodules on hosts. We found that Bradyrhizobium populations were very diverse but dominated by few haplotypes-with a single "epidemic" haplotype constituting nearly 30 % of collected isolates and spreading nearly statewide. In many Bradyrhizobium lineages, we inferred presence and absence of the symbiosis island suggesting recurrent evolutionary gain and or loss of symbiotic capacity. We did not find statistical phylogenetic evidence that the symbiosis island acquisition promotes strain dominance and both symbiotic and non-symbiotic strains exhibited population dominance and spatial spread. Our dataset reveals that a strikingly few Bradyrhizobium genotypes can rapidly spread to dominate a landscape and suggests that these epidemics are not driven by the acquisition of accessory loci as occurs in key human pathogens.

Shewanella algae in acute gastroenteritis

Shewanella algae is an emerging bacteria rarely implicated as a human pathogen. Previously reported cases of S. algae have mainly been associated with direct contact with seawater. Here we report the isolation of S. algae as the sole etiological agent from a patient suffering from acute gastroenteritis with bloody diarrhoea. The bacterium was identified by automated identification system and 16S rRNA gene sequence analysis. Our report highlights the importance of looking for the relatively rare aetiological agents in clinical samples that does not yield common pathogens. It also underscores the usefulness of automated systems in identification of rare pathogens.

Neoadjuvant chemotherapy followed by surgery in very locally advanced technically unresectable oral cavity cancers

BACKGROUND

The median survival of technically unresectable oral-cavity cancers (T4a and T4b) with non surgical therapy is 2-12 months. We hypothesized that neoadjuvant chemotherapy (NACT) could reduce the tumour size and result in successful resection and ultimately improved outcomes. We present a retrospective analysis of consecutive patients who received NACT at our centre between January 2008 and August 2012.

PATIENTS AND METHODS

All patients with technically unresectable oral cancers were assessed in a multidisciplinary clinic and received 2 cycles of NACT. After 2 cycles, patients were reassessed and planned for either surgery with subsequent CTRT or nonsurgical therapy including CT-RT, RT or palliation. SPSS version 16 was used for analysis of locoregional control and overall survival (OS). Univariate and multivariate analysis was done for factors affecting the OS.

RESULTS

721 patients with stage IV oral-cavity cancer received NACT. 310 patients (43%) had sufficient reduction in tumour size and underwent surgical resection. Of the remaining patients, 167 received chemoradiation, 3 radical radiation and 241 palliative treatment alone The locoregional control rate at 24 months was 20.6% for the overall cohort, 32% in patients undergoing surgery and 15% in patients undergoing non surgical treatment (p=0.0001). The median estimated OS in patients undergoing surgery was 19.6 months (95% CI, 9.59-25.21 months) and 8.16 months (95%, CI 7.57-8.76) in patients treated with non surgical treatment (p=0.0001).

CONCLUSION

In our analysis, NACT led to successful resection and improved overall survival in a significant proportion of technically unresectable oral-cancer patients.

Dysplasia detection rate of confirmatory EGD in nondysplastic Barrett's esophagus

Current guidelines for endoscopic surveillance of Barrett's esophagus (BE) recommend that patients with newly diagnosed BE undergo confirmatory esophagogastroduodenoscopy (EGD) to exclude the presence of dysplasia. The extent to which confirmatory endoscopy alters management and detects missed dysplasia in newly diagnosed BE has not been reported. The frequency with which confirmatory endoscopy changed surveillance management in patients with newly diagnosed BE was assessed. A two center cohort analysis was conducted on patients newly diagnosed with BE. The rate of dysplasia on confirmatory endoscopy for patients who had nondysplastic BE was obtained. Demographic and endoscopic variables were assessed for association with dysplasia detection using Firth logistic regression model. Out of the 146 patients newly diagnosed with BE and initially determined to be without dysplasia, 12 had dysplasia on the confirmatory second EGD (8.2%). Eleven of 12 cases with dysplasia on confirmatory endoscopy had long-segment BE (LSBE). Among all the LSBE cases in our cohort, 11 had newly diagnosed dysplasia on confirmatory EGD, 29.7% (11/37). The average number of biopsies obtained from the 11 LSBE cases with dysplasia was comparable with the rest of the LSBE cases without dysplasia (6.73 and 5.42, respectively, P-value 0.205). The rate of dysplasia detection in short-segment BE (SSBE) was much lower, 0.95% (1 out of 105). There were no cases of high-grade dysplasia (HGD) or cancer detected in any SSBE case. HGD was detected on confirmatory EGD in two cases, both were LSBE. Segment length was the only statistically significant factor to predict the presence of dysplasia on confirmatory endoscopy (odds ratio 9.158, P. 0.008). Confirmatory EGD in newly diagnosed LSBE had significant rate of dysplasia detection (29.7%) in this cohort. Among patients with SSBE, there was a low rate of dysplasia detection with confirmatory EGD, less than 1% of cases. No additional cases of HGD or esophageal carcinoma in SSBE cases were detected. This suggests that the yield of confirmatory EGD is greater in patients with LSBE.

Automated detection of choroid boundary and vessels in optical coherence tomography images

Structural changes in the choroid, a layer located between the retina and sclera, could indicate various vision impairments. Consequently, ophthalmologists inspect optical coherence tomography (OCT) scans of the posterior section of the eye towards making diagnosis. With a view to assist diagnosis, we propose an automated technique for segmentation of the choroid layer. Specifically, we detect the upper and lower boundaries of the choroid using structural similarity and adaptive Hessian analysis. Subsequently, we detect choroid vessels within those boundaries using a level set method. Experimental results are presented using spectral domain (SD) OCT images.

Endophthalmitis caused by Acinetobacter baumanni: a case series

PURPOSE

To profile the etiology, clinical outcomes and drug sensitivity patterns in endophthalmitis caused by Acinetobacter baumanni.

METHODS

Retrospective analysis of all the cases of Acinetobacter baumanni endophthalmitis presenting to tertiary referral care ophthalmic hospital in Eastern India from January 2009 to December 2011 were done.

RESULTS

A total of four cases were included in the study. Out of the four cases one was post traumatic and the rest were post cataract surgery. All the cases underwent vitreoretinal surgical intervention followed by intravitreal antibiotics. A. Baumanni was isolated from vitreous in all the cases. Among all the drugs tested bacteria were found sensitive to ciprofloxacin (100 %) whereas all tested resistant to ceftazidime. Out of the four cases one had to be eviscerated, another developed retinal detachment post vitrectomy, one was phthisical at final followup, and only one patient achieved a vision of 20/200 with clear media and attached retina at final visit.

CONCLUSION

A. Baumanni is a very rare cause of endophthalmitis with poor visual and anatomical outcomes. Ciprofloxacin should be considered as first the line intravitreal antibiotic.

Short-term complications after vaginal prolapse surgery: do suture characteristics influence morbidity?

Pelvic organ prolapse (POP) surgery can be associated with early postoperative morbidity resulting in significant service utilisation. This study aimed to investigate whether different suture materials cause different rates of early postoperative morbidity by comparing two cohorts using case-control methodology. A total of 100 women undergoing POP surgery with vaginal closure with 1 Vicryl (polyglycolic acid) multifilament sutures were matched by operation with a cohort in which 2/0 Monocryl (poliglecaprone 25) monofilament sutures were used. The multifilament suture group had significantly higher rates of offensive discharge (p<0.001), vaginal bleeding (p<0.001) and vaginal pain (p=0.004). They were more likely to receive medical advice (0.007). Patients in the multifilament group were no more likely to suffer from a UTI (p=1.000) or to be readmitted postoperatively (p=1.000). Size 1 multifilament sutures result in higher levels of postoperative morbidity when compared with 2/0 monofilament sutures.

Estrogen, progesterone and HER2 receptor expression in breast tumors of patients, and their usage of HER2-targeted therapy, in a tertiary care centre in India

BACKGROUND

This study was undertaken to document the pattern of expression of estrogen (ER), progesterone (PR) and human epidermal growth factor receptor-2 (HER2) and the usage of HER2-targeted therapy in a large tertiary care hospital in India in the year 2008.

MATERIALS AND METHODS

The histopathology reports of all breast cancer patients registered in the hospital in 2008 were extracted from the electronic medical record system. All the cases were immunohistochemically evaluated for estrogen and progesterone receptor status (ER and PR), and c-erbB-2 protein (HER2) expression using standard immunoperoxidase method. The use of HER2-targeted therapies was evaluated by extracting relevant information from the database of the hospital pharmacy and case charts of patients enrolled in ongoing approved trials.

RESULTS

A total of 2001 new patients of invasive breast cancers with available pathology reports were registered in the hospital in the year 2008. ER and/or PR expression was positive in tumors of 1025 (51.2%) patients. HER2 3+ expression by immunohistochemistry (IHC) was found in 335 (16.7%) and HER2 2+ in 163 (8.1%). The triple negative phenotype was found in 596 (29.8%) patients. An estimated 441 patients were eligible to receive HER2-targeted therapy based on their HER2 status. Of these 38 (8.6%) patients received some form of HER2-targeted therapy; 20 patients (4.5%) as part of ongoing clinical trials and 18 (4.1%) as part of routine care.

CONCLUSIONS

The overwhelming majority of patients eligible for HER2-targeted therapy in our institution are unable to receive it because of financial constraints and limited access to health insurance. There is a higher fraction of patients with the triple negative phenotype compared to the Western population.