A273 INCREASING THE REPRESENTATION OF INDIANS IN MICROBIOME RESEARCH: HOW DOES THEIR GUT MICROBIOME DIFFER?

Background

During the 1900s when industrialization was on the rise in western countries, inflammatory bowel disease (IBD) began to present itself and continually increase over the decades. Now, newly industrialized countries such as India are following this same pattern, and with a population reaching over one billion, India is projected to have one of the highest IBD prevalence worldwide. Furthermore, pediatric diagnoses of IBD are more frequently reported in India and in Indian children living in Canada, suggesting this disease may present differently in those of Indian descent. While the etiology of IBD remains unclear, a gut microbiome that is no longer symbiotic with its host is a key player. However, Indians are one of the least represented in microbiome research, therefore we cannot accurately assess the role of their gut microbiome in IBD. To effectively understand the nature of IBD in Indians, we must first define their gut microbiome.

Purpose

Our study characterizes the microbiome of Indians living in India to explore how it differs from Canadians of European descent.

Method

Stool samples from healthy volunteers (ages 18-55) were collected from Indians in India and Euro-Canadians in Kelowna, BC. Microbial DNA was extracted for 16S sequencing on the Illumina MiSeq platform and QIIME2 was used for microbiome analysis.

Result(s)

We will discuss the similarities and differences comparing the gut microbiome of Indians to Euro-Canadians, further highlighting the need for more microbiome research of this demographic.

Conclusion(s)

Our research aims to increase representation of Indians in microbiome research in the hopes of improving our knowledge of the predispositions to IBD, which will aid in the information required to develop effective preventive measures. With elevated risk for IBD in Indians residing in Canada, future studies should also aim to analyze if the gut microbiome in Indians change as they migrate and adopt the westernized lifestyle.

Disclosure of Interest

None Declared

Metagenomics of pigmented and cholesterol gallstones: the putative role of bacteria

There is growing evidence for bacteria playing a role in the pathogenesis and formation of pigmented gallstones from humans. These studies mainly involved cultivation of gallstone-associated bacteria and 16S rRNA profiling, providing an indirect link between processes involved in gallstone formation by the bacteria in-situ. Here, we provide functional metagenomic evidence of a range of genes involved in bile stress response, biofilm formation, and anaerobic energy metabolism by Gram-negative Klebsiella in pigmented gallstones from a 76-year-old male patient. Klebsiella was also present in one cholesterol-type stone in a 30-year-old female patient who had additional cholesterol gallstones characterised by Gram-positive bacteria. Pigmented stones further revealed a predominance of genes involved in carbohydrate metabolism, whilst cholesterol stones indicated a profile dominanted by protein metabolism possibly reflecting known chemical differences between Gram-negative and Gram-positive biofilm matrices. Archaeal genes were not detected. Complementary carbon and hydrogen isotopic analyses of cholesterol within the patients’ stones revealed homogeneity, suggesting a common diet or cholesterol biosynthesis pathway that has little influence on microbial composition. This pilot study provides a framework to study microbial processes that play a potential role in gallstone formation across markedly different types of stones and patient backgrounds.

Lateral ankle and hindfoot instability: a new clinical based classification

Ankle sprains are one of the most common soft tissue injuries accounting for nearly 40% of sports injuries. There are large number of procedures for its treatment reported in the literature with largely good results. The ankle forms a functional unit with the subtalar joint. We present a new classification for peritalar lateral instability. There are two intents of this classification. Firstly, the classification demonstrates an assessment and treatment guideline for the many causes of peritalar lateral instability. The second use of the classification is for research purposes so that cohorts of patients can be accurately described and the efficacy of different operations in different groups can be properly assessed.

Detection of diarrheagenic Escherichia coli by multiplex PCR

BACKGROUND

Diarrheagenic E.coli (DEC) are an important cause of childhood diarrhea.Identification of DEC strains needs to detect factors that determine the virulence of these organisms. There is not much data regarding the importance of DEC as a cause of diarrhea in children in India.The prevalence of DEC in children below five years with and without diarrhea was studied using two multiplex PCR assays.

MATERIALS AND METHODS

Two multiplex polymerase chain reaction assays were used to detect genes of five types of DEC.The targets selected for each category were eae and bfpA (bundle-forming pilus) for Enteropathogenic E.coli (EPEC), hlyA for Enterohemorrhagic E.coli (EHEC), elt and stla for Enterotoxigenic E.coli (ETEC), CVD432 for Enteroaggregative E.coli (EAEC) and ial for Enteroinvasive E.coli (EIEC).

RESULTS

In 200 children with diarrhea 52 (26%) DEC infections were found. Among 100 controls 8 (8%) DEC infections were found. EAEC was the most common DEC by multiplex PCR both in cases (26, 13%)and controls (5,5%), followed by EPEC seen in 16% cases and 3% controls. ETEC and EIEC were found in 7 (3.5%) and 3 (1.5%) of the diarrheal cases. EIEC and ETEC were not detected in the control cases. EHEC was not isolated from either the diarrheal or control cases.

CONCLUSION

DEC strains are a significant cause of diarrhea in children. The two Multiplex PCR assays can be used for the detection of DEC in routine diagnostic laboratories. These assays are specific and sensitive for the rapid detection of DEC. EAEC was the most frequent pathotype in the population under study.

The Oncosurge strategy for the management of colorectal liver metastases – An external validation study

INTRODUCTION

Because most patients with colorectal liver metastases (CRLM) present to general surgeons and oncologists without a specialist interest in their management, a computer program (OncoSurge) has been created that identifies individual patient resectability and recommends optimal treatment strategies. The aim of this study was to validate the Oncosurge strategy by comparing its recommendations with the decisions made by a multidisciplinary (MDT) meeting, in a supra-regional hepatobiliary referral centre, using real cases with known outcomes.

METHODS

We reviewed the records and imaging of 98 consecutive patients with CRLM, who had been referred for decision making to our MDT meeting between January 1, 2004 and December 31, 2004. All patient and tumour characteristics were entered onto the Oncosurge decision model, which was accessed at www.evidis.com/oncosurge/

RESULTS

There was concordance between Oncosurge and MDT decisions in 93/98 cases. The observed kappa (kappa) was 0.850 (95% CI: 0.728-0.972). In descriptive terms, a kappa score greater than 0.8 equates to "almost perfect agreement".

CONCLUSIONS

Our results demonstrate the validity of the Oncosurge system when compared to one year of decision making in an established hepatobiliary MDT meeting. This confirms the utility of the Oncosurge system for decision making, audit and educational purposes.

Assessment of a patient consultation questionnaire-based scoring system for stratification of outpatient risk of colorectal cancer

BACKGROUND

The UK government's fast-track 2-week wait (2WW) rule and colorectal cancer guidelines aimed to detect patients at high risk of having colorectal cancer, but the yield has been poor. A patient consultation questionnaire (PCQ)-based scoring system may be an effective tool for prioritizing colorectal referrals. The aim of this study was to validate the system in a large and ethnically diverse population and to compare it with 2WW referrals.

METHODS

Over a 1-year period, all colorectal referrals (2WW and traditional letters) at nine hospitals in Leicestershire were sent a PCQ to complete and return. A weighted numerical score (WNS), which reflects the patient's risk of having colorectal cancer, was calculated and compared with the hospital diagnosis.

RESULTS

Of a total of 1422 PCQs returned, 83 patients were diagnosed with colorectal cancer. The 2WW referrals constituted 35.7 per cent of all referrals. The mean WNS of patients with colorectal cancer was significantly higher than that of the other patients (mean 76.3 versus 48.9 respectively; P < 0.001). For similar cancer detection rates (or sensitivity), the specificity of a WNS cut-off of 70 was significantly better than that of the 2WW system (82.7 versus 66.1 per cent; P < 0.001).

CONCLUSION

The PCQ-based WNS system improves specificity for detecting colorectal cancer, particularly when the WNS exceeds 70.

Antimicrobial action of calcium hydroxide, chlorhexidine and their combination on endodontic pathogens

BACKGROUND

The common recovery of Candida albicans and Enterococcus faecalis from failed root canals of teeth in which previous treatment has failed is notable. These organisms have been shown to be resistant to antimicrobial action of calcium hydroxide but are sensitive to chlorhexidine gluconate. The aim of the present in vitro study was to investigate the antimicrobial efficacy of calcium hydroxide paste, 2% chlorhexidine gel and their combination against Candida albicans and Enterococcus faecalis.

METHODS

Inoculae of these organisms were used to make lawn cultures on Sabouraud's dextrose agar and blood agar plates. Wells were prepared with these lawn cultures and filled with calcium hydroxide paste, 2% chlorhexidine gel and their combination. The agar plates were kept overnight for incubation at 37 degrees C and the zone of inhibition was examined after 24 and 72 hours.

RESULTS

The results suggest that 2% chlorhexidine gel alone is more effective at 72 hours than calcium hydroxide paste alone or in combination with 2% chlorhexidine gel against both the organisms, even though calcium hydroxide showed better antifungal efficacy against Candida albicans at 24 hours.

CONCLUSION

In failed root canal treatments, 2% chlorhexidine gel may be a more effective intracanal medicament than calcium hydroxide paste or their combination against Candida albicans and Enterococcus faecalis.

The risk of cross-infection when marking surgical patients prior to surgery - review of two types of marking pens

INTRODUCTION

Two types of marker pens were compared to find whether they produced different risks of infection transmission over different time intervals.

PATIENTS AND METHODS

Twenty-four patients were marked according to the type of surgery: each had a set of new dry white-board marker (DWM) and a permanent marker (PM) pen. Once used, their tips were used to inoculate blood agar plates at different time intervals.

RESULTS

At 0 min, 96% of the DWM pens and 29% of the PM pens were positive of growth. At 3 and 10 min, all of the DWM pens remained positive. The rate dropped to 16.67% in 3 min down to none at 10 min for the PM pens.

CONCLUSIONS

DWM pens carry a significant risk of transmitting infection between patients. It is recommended that they are not used in marking. PM pens should not be used between patients in less than a 10-min interval.

The adenoma carcinoma sequence: an indoctrinated model for tumorigenesis, but is it always a clinical reality?

OBJECTIVE

Evidence exists to support alternative pathways to the adenoma carcinoma sequence. Some mutations in key onco-suppressor genes relate to the anatomical site of the tumour. This link is typified by microsatellite instability and proximal neoplasia. However, rectal tumours are rarely considered separately. We hypothesized that tumour behaviour in the rectum may differ in terms of pathogenesis and malignant propensity. Therefore, we aimed to look for an association between the histopathological features of adenomas and their anatomical location as compared with the distribution of cancers.

METHODS

A single centre prospective study was undertaken over a four-year period. Patients referred to a colorectal assessment clinic with bowel symptoms underwent a minimum investigation of flexible sigmiodoscopy. Neoplastic lesions were either biopsied or removed after noting distance from the anal margin. Adenomas, differentiated by size, villous architecture and degree of dysplasia were compared to both early and advanced carcinomas.

RESULTS

Of 4089 patients, polyps were identified in 8.0% and cancer in 4.2%. There was a clear difference between the distribution of cancer and adenomas > 1 cm, P < 0.001. All degrees of dysplasia in large adenomas were more prevalent in the sigmoid colon as compared to cancer, P < 0.001. Seventy-five percent of high risk diminutive adenomas were rectal in origin.

CONCLUSION

Our data provides indirect evidence to support the concept that a significant proportion of rectal cancers may arise via an alternative pathway to the Vogelstein model. Polyp behaviour along with malignant propensity may actually be site dependent, with rectal polyps harbouring a more aggressive phenotype.

Symptomatic presentation of early colorectal cancer

INTRODUCTION

It is believed that increased detection of earlier stage colorectal cancer can only be achieved by screening asymptomatic individuals. We describe a referral pathway for a symptomatic population which achieves a 30% Dukes' A detection rate.

PATIENTS AND METHODS

From October 1999, 4253 patients with distal colonic symptoms, referred by general practitioners, completed a patient consultation questionnaire (PCQ) linked to a computerised record. A weighted numerical score (WNS) was derived for each patient. Patients underwent flexible sigmoidoscopy, a diagnostic outcome was recorded and later Dukes' stage appended. Early and advanced colorectal cancers were separated and PCQ derived symptom profiles compared. Chi-square, Fisher exact, Student's t-test and logistic regression were used for statistical analysis.

RESULTS

A total of 183 patients had cancer, 55 (30%) were Dukes' A early colorectal cancers, 112 were advanced colorectal cancers (Dukes' B-D) and 16 could not be staged. Early colorectal cancers had significant symptoms and comparable profile to advanced colorectal cancers. The tendency in advanced colorectal cancers was towards greater symptom prevalence for only a few primary and systemic symptoms, as reflected by a higher WNS of 75 (P = 0.001).

CONCLUSIONS

Early colorectal cancers do have significant symptoms which can easily be captured by a PCQ and objective scoring tool in the secondary care setting. Detection of these cancers has the potential to improve survival.

Pitfalls in the construction of cancer guidelines demonstrated by the analyses of colorectal referrals

INTRODUCTION

The aim of this study was to develop a system to compare and validate cancer referral guidelines, identifying the pitfalls in their development and provide a mechanism to evaluate their efficacy.

PATIENTS AND METHODS

3302 patients referred from primary care with colorectal symptoms over a 3-year period were assessed. All participants had a comprehensive history obtained via a questionnaire that incorporated all colorectal symptoms. The questionnaires were completed prior to assessment at the hospital. All patients were then assessed at the Colorectal One Stop Clinic (CROSC), underwent investigation and diagnosis achieved. All data were entered into a databank. Current prioritisation guidelines and tools that are used to assess colorectal referrals were applied to this colorectal databank to test their efficacy for cancer detection and referral prioritisation. Sensitivity and specificity for cancer detection and referral rates were assessed.

RESULTS

Cancer was detected in 156 patients (4.7%). All prioritisation models (NHS guidelines, Weighted Numerical Score [WNS], Netherlands, Harvard, Mersey, and Somerset) differentiated cancer from non-cancer patients. The use of a few symptoms as risk predictors (e.g. NHS guidelines) causes a decrease in specificity in contrast to a comprehensive risk tool, for example, the WNS at a score of 50 (NHS 54.1%, WNS 62.9%). This results in a significantly higher referral rate (NHS 47.6%, WNS 39.4%) and identifies fewer cancers (NHS 80.1%, WNS 85.9%). Non-evidence based modifications of the NHS guidelines (Somerset and Mersey) caused a further deterioration in specificity, which was reflected in an increased referral rate. Using the WNS, which is objective and a continuous scale, allows adaptation of the referral threshold, balancing sensitivity and specificity to the resources available within a hospital. For example, the WNS of > or = 40 has a sensitivity of 96.8% for cancer detection.

CONCLUSIONS

Accurate prospective data collection into a data bank allows testing of referral guidelines as well as providing an adjunct to guideline construction.

Variations in the evaluation of colorectal cancer risk

OBJECTIVES

To test the variability in estimating cancer risk and demonstrate the consequences that subjectivity has on patient care.

SUBJECTS AND METHODS

Forty-three clinicians were each asked to assess 40 symptomatic colorectal referrals. Each clinician was provided with a comprehensive history on the 40 patients. The clinicians graded the referral according to a malignancy risk score, decided on the required first line investigation and the priority of that investigation. The main outcome measures used was accuracy in cancer detection and appropriateness of investigations selected.

RESULTS

There was a wide degree of variation among all clinicians grading both benign and malignant disease with the overall correct classification of 54% (P-value of <0.001). On average, the clinicians correctly diagnosed 71.3% of the cancer patients as compared to 44% of the benign patients. Of the cancer patients, 47% were correctly classified as an urgent referral whilst 52% of the benign patients were over classified and graded as an urgent referral. The mean number chosen by clinicians to have a flexible sigmoidoscopy as the appropriate first investigation was 13 (of 40 patients); this was despite the diagnosis being possible in all cases with a flexible sigmoidoscopy. The choice to use full colonic investigation was seen throughout all disciplines. Junior doctors demonstrated the highest tendency choosing full colonic investigation in 92.3%. Consultants and senior grades showed the least tendency to choose full colonic imaging although even here colonoscopy or barium enema represented 48.5%.

CONCLUSION

Subjective assessment of cancer referrals is a significant problem that needs to be confronted. Improvements are needed to resolve the inherent problems of subjectivity and operator bias if uniform quality of patient care and best use of resources is to be achieved.

Correlation of the suicide phenomenon in Aeromonas species with virulence and enteropathogenicity

Certain strains of mesophilic Aeromonads like A. hydrophila, A. veronii biotype sobria and A. caviae when grown in broth containing 0.5% glucose, undergo growth inhibition concomitant with acetate accumulation. As these strains become nonviable after 24 h, this phenomenon is termed suicide. We investigated suicidal strains of Aeromonas species as means of understanding animal virulence and enteropathogenicity. Non suicidal strains of A. Hydrophila showed and overall 88.8% lethality rate and non suicidal strains of A. veronii biotype sobria showed 83.3% lethality rate and was nil for its suicidal part. Of the two suicidal A. caviae strains tested, none were lethal. The present data suggest that the suicide phenomenon may explain strain specific [A. veronii biotype sobria, A. hydrophila] and species specific [A. caviae] virulence and enteropathogenicity.

Bacteriological spectrum of cholecystitis and its antibiogram

Bile Cultures for aerobic and anaerobic bacteria were carried out on 125 samples from patients with chronic cholecystitis with cholelithiasis. Cultures grew 71(56.8%) aerobes and 17(13.6%) anaerobic microorganisms. Polymicrobial infection was seen in 7(16.2%) cases. E. coli (45.07%) and Klebsiella (25.35%) were predominant among the aerobes and Bacteroides fragilis (58.82%) was predominant among the anaerobes. Highest incidence of the disease was observed in the fourth decade of life and females predominated in this study.

Activity of Ocimum sanctum (the traditional Indian medicinal plant) against the enteric pathogens

Aqueous & alcoholic extracts of O. sanctum were prepared. Two concentrations of these extracts (30 mg & 60 mg) were tried against the enteric pathogens & candida albicans by Agar diffusion method. Wide zones of inhibition were observed at 60 mg concentration of extract. Aqeous extract showed wider zone of inhibition when compared to alcoholic extract. Aqueous extract showed wider zones of inhibition for Klebisella, E. Coil, Proteus & Staphylococcus aureus. Alcoholic extract showed wider zone for vibrio cholerae.

Chromobacterium violaceum diarrhea

This is the first case of Chromobacterium violaceum diarrhoea from coastal Karnataka reported in a 2 year 10 months old girl. Stool culture yielded Chromobacterium violaceum and was sensitive to ampicillin, gentamicin, chloramphenicol, erythromycin and septran. Patient completely recovered with ampicillin and gentamicin.

Cryptosporidium and isospora belli diarrhoea in immunocompromised hosts

Cryptosporidium and isospora, two of the intestinal coccidian parasites known to be the causative agents of acute diarrhoea in animals, have now emerged as one of the main causes of prolonged life threatening diarrhoea in immunocompromised patients particularly so in patients with AIDS. Between June 1996 and December 1997, a total of 75 immunocompromised patients presenting with diarrhoea were investigated both for Cryptosporidium and Isospora. The study group consisted of cancer and AIDS patients with history of diarrhoea. Cryptosporidium oocysts were detected in 35 patients (46.7%). One of the faecal samples from an AIDS patient with diarrhoea showed the presence of both Cryptosporidium and Isospora oocysts. To the best of our knowledge, this is the second documented report of Isospora associated diarrhoea in an AIDS patient from India. The various techniques used for demonstration of these parasites were modified acid fast staining, Safranine Methylene-blue staining and direct immunofluorescence test.

Shigella and the fluorinated quinolones

Between July 1996 to June 1997 a total of 531 Stool samples from cases of acute diarrhoea, dysentry, colitis admitted to Kasturba Medical College Hospital, Manipal were investigated. Shigella were isolated from 29 samples (5.46%). Out of them, Shigella flexneri were 16 (55.17%), Shigella boydii 8 (27.58%), Shigella dysentriae 3 (10.34%) and Shigella sonnei 2 (6.89%). Five strains of Shigella flexneri and one strain of Shigella dysentriae were found to show resistance to Nalidixic acid and the newer fluoroquinolones viz., Ciprofloxacin, Norfloxacin and Ofloxacin. The in vitro 'R' factor transfer study showed that the resistance was not transferable.

Prevalence of rubella virus in suspected cases of congenital infections

This study includes a total of 342 infants suspected of having congenital infections from January 1991-December 1993. Serum samples of these infants were tested for rubella specific IgM antibodies by mu ELISA. Of the total 342 infants, 52 (15.2%) were found to be positive for IgM antibodies to rubella virus. The commonest clinical presentation in infants with IgM antibodies to rubella virus was bilateral congenital cataract and hepatosplenomegaly.

Rotavirus and bacterial enteropathogens causing acute diarrhea

The etiology of rotavirus in acute diarrhoeal illness in children 0-5 years of age, admitted to the Pediatric wards of Kasturba Medical College Hospital, Manipal was studied, over a period of one year. Rotavirus in the faecal samples detected by the slide latex agglutination test accounted for 14.9% of the diarrheas with maximum incidence in the 7-12 months of age group (57.5%). Bacterial enteropathogens continued to play a significant role in diarrheal diseases. Salmonella enteritis was found more in the age group 0-6 months and shigellosis in 37-60 months. In a control study of 100 children who had no diarrhea, 2 were found positive for rotaviruses.

Mycotic keratitis: a study in coastal Karnataka

Fungi were isolated from 67 cases out of the 295 cases of corneal ulcers investigated. Aspergillus species and species of Candida were the major fungal members isolated. Allescheria boydii was isolated from 3 cases, having no previous history of injury to the eye or infection with bacterial or viral agents. A boydii corneal infection is a rare occurrence. Higher incidence of mystic keratitis was seen among females than males. No relationship to seasonal changes could be established. Bacterial infection was associated in 46. 27% of the cases of mycotic keratitis and Staphylococcus was the predominant bacterial pathogen observed.