Culture Of Stool Specimens Research Articles

P1218 Non-invasive point-of-care stool sample for detection of Cytomegalovirus infection in patients with Active or Refractory Ulcerative Colitis using multiplex polymerase chain reaction (mPCR): a pilot feasibility study

Abstract Background Cytomegalovirus (CMV) infection is associated with more flare-ups and deteriorates the prognosis of active inflammatory bowel disease (IBD). Patients with refractory IBD should be tested for CMV colitis, especially if they are not responding to immunosuppressive therapy. The prevalence of CMV co-infection ranges from 10% to 30% in steroid-refractory acute colitis. Concurrent CMV-colitis is associated with an increased risk of worse therapeutic outcomes, resistance to corticosteroids, and need for salvage therapy. One of the two gold standards of diagnosis of CMV colitis in IBD patients with active disease requires the analysis of tissue biopsies using PCR. The aim of our pilot study was to evaluate the diagnostic accuracy of non-invasive point-of-care faecal samples using mPCR for detecting CMV in patients with ulcerative colitis compared to standard practice biopsies PCR. Methods We performed a prospective, observational, feasibility study including 62 consecutive patients with active ulcerative colitis (UC) requiring intravenous steroids or steroid-refractory UC in the Department of Gastroenterology of University Hospital „Tsaritsa Yoanna – ISUL", from April 2022 to October 2023. In all UC patients, colonic tissue biopsies were performed and analyzed by qualitative CMV PCR. Faecal sample mPCR CMV was performed on the positive patient cohort to compare the feasibility of (ME) Panel IVD using FilmArray mPCR (Biofire, bioMerieux, France). All the tested patients had undergone immunosuppressive therapy and initial stool specimen cultures were obtained to exclude infection with C. difficile and other pathogen flora. Results Out of 62 active UC patients with colonic tissue samples qualitative CMV PCR, n=5 (8%) were positive. Of these n=5 UC patients, n=4 (80%) were positive from the Fecal sample mPCR CMV, resulting in a compatibility of 80% for diagnosing CMV in these patients by the two DNA extraction methods. Calculated Sensitivity and diagnostic accuracy was 80% (95% CI) for the mPCR CMV. The patient cohort predominantly comprised males (75%) with a median age of 45 years (range: 30–72 years). Three patients (75%) out of this cohort group were treated with peroral antiviral agent Valganciclovir, one (25%) of them went into clinical and endoscopic remission after the treatment and two patients (50%) received colectomy. The median time performing the Faecal sample mPCR CMV was approx. 1 hour. Conclusion This novel faecal mPCR point-of-care test is a promising, fast and easy non-invasive tool for detection CMV in active or refractory UC patients, comparable with the colonic tissue CMV-DNA PCR.

P329 Stool multiplex molecular PCR assay in comparison to conventional stool tests for detecting gastrointestinal infections as cause of flares in Inflammatory Bowel Disease

Abstract Background Inflammatory bowel disease (IBD) is characterized by unpredictable flares. Other than natural history, flares can be caused by superadded gastrointestinal (GI) tract infections. Diagnosis of infection is conventionally made by microscopy and culture of stool specimens. These are limited by lengthy turnaround time, low sensitivity, inability to detect agents other than bacteria, and effect of pre-test antibiotic usage.Stool multiplex molecular PCR assay allows simultaneous detection of nucleic acids from 23 bacteria, viruses and parasites. Methods We aimed to: 1. Compare infectious organisms detected by stool multiplex PCR assay and conventional stool tests during flare in patients with IBD. 2. Determine impact of detection of infective agents in the management of flares, as measured by use of anti-infective agents. In this single centre, prospective, cohort study, every patient underwent conventional stool tests (microscopy, culture and Clostridioides Difficile toxin assay) and multiplex PCR assay by Biofire® FilmArray test. Consenting patients above 18 years with IBD flare were included. Patients with colorectal cancer, toxic megacolon, intestinal perforation, previous IBD surgery were excluded. Results Of 60 patients, 53 patients were of Ulcerative colitis (UC) and 7 were of Crohn’s disease (CD). The mean age of patients with UC was 42.32 years and that of CD was 37.5 years. Of the patients with UC, 26 were male and 27 were female. In CD, 4 were male and 3 were female. Stool Biofire® resulted in better organism detection rate (Table 1) and more frequent need for change in management (Table 2) as compared to conventional tests. The cost per stool Biofire® was INR 12000 (€142) and that of conventional stool tests INR 4300 (€51). However, the cost to achieve one positive result on stool Biofire® that led to change in management was INR 65,454 (€773) as compared to INR 86,000 (€1015) for conventional stool tests. Conclusion Stool Biofire® resulted in significantly more organism detection (33 vs 6 pts). It also led to more frequent need for change in management as compared to conventional stools tests (11 vs 3 pts). It also proved more cost-effective than conventional stool tests in terms of change in management of flare in patients with IBD.

Phenotypic Pattern of Vibrio choleraeIsolates from a Tertiary Care Hospital in Vadodara, Gujarat, India

Introduction: Cholera is an acute diarrhoeal disease caused by Vibrio cholerae (V.cholerae). Based on antigenic differences of O antigen, O1 serogroup can be divided into three serotypes. In addition, by performing various biochemical reactions, O1 Serogroup can be differentiated into two biotypes. Outbreaks of Cholera occur seasonally. It is associated with monsoon season, warm temperature, heavy rainfall and increased plankton population. Aim: The aim was to determine the trends in resistance pattern and phenotypic Pattern of Vibrio cholerae. Materials and Methods: A retrospective study was conducted during the period from June 2019-December 2019. Culture of Stool specimens were done on different agar media. Biotyping was done by conventional methods. Serotyping and phage typing was also done along with the Antibiotic susceptibility testing. Descriptive analysis was used and presented in terms of percentage. Results:V.cholerae was isolated in 72 patients and they belonged to serogroup O1 and biotype El Tor. The most common serotype was Ogawa. The predominant phage type were T2 by old scheme and T27 by new scheme of phage typing. The maximum number of V. cholerae isolates was seen in the month of November, 2019 followed by October, 2019. Conclusion: The phenotypic pattern and fluctuating seasonal trend of V. cholerae and antimicrobial resistance encourage the continued epidemiological and microbiological surveillance of the disease.

Syndromic Surveillance of Communicable Diseases in Mobile Clinics During the Arbaeenia Mass Gathering in Wassit Governorate, Iraq, in 2014: Cross-Sectional Study.

BackgroundArbaeenia is the largest religious mass gathering organized annually in Karbala city, Iraq, and is attended by 8-14 million people. Outbreaks of communicable diseases are a significant risk due to overcrowding and potential food and water contamination. Syndromic surveillance is often used for rapid detection and response to disease outbreaks.ObjectiveThis study was conducted to identify the main communicable diseases syndromes among pilgrims during the Arbaeenia mass gathering in Wassit governorate, Iraq, in 2014.MethodsThis cross-sectional study was conducted in the 40 mobile clinics established within Wassit governorates along the road to Karbala during the Arbaeenia mass gathering. Six communicable disease syndromes were selected: acute watery diarrhea, bloody diarrhea, fever and cough, vomiting with or without diarrhea, fever and bleeding tendency, and fever and rash. A simple questionnaire was used to directly gather basic demographics and the syndromic diagnosis from the attendees.ResultsA total of 87,865 patients attended the clinics during the 10-day period, with an average of 219 patients/clinic/day. Approximately 5% (3999) of the attendees had communicable diseases syndromes: of these, 1693 (42%) had fever and cough, 1144 (29%) had acute diarrhea, 1062 (27%) presented with vomiting with/without diarrhea, and 100 (2%) had bloody diarrhea. The distribution of the syndromes did not vary by age or gender. Stool specimen cultures for Vibrio cholerae performed for 120 patients with acute diarrhea were all negative.ConclusionsSyndromic surveillance was useful in determining the main communicable diseases encountered during the mass gathering. Expansion of this surveillance to other governorates and the use of mobile technology can help in timely detection and response to communicable disease outbreaks.

Canadian Public Health Laboratory Network position statement: Non-culture based diagnostics for gastroenteritis and implications for public health investigations.

As clinical laboratories transition to using culture-independent detection test (CIDT) panels for cases of acute gastroenteritis, culture of clinical specimens is becoming less common. The reduction in bacterial cultures available for public health activities is expected to hinder surveillance and outbreak response by public health laboratories at the local, provincial, national and international levels. These recommendations are intended to serve as guidelines for the implementation of CIDT panels in frontline laboratories in Canada. The United States of America has already seen a significant reduction in culture of stool specimens despite the Association of Public Health Laboratories recommendation to perform reflex culture on positive CIDT specimens. Priority public health organisms addressed in these Canadian guidelines include Shiga toxin-producing Escherichia coli, Shigella and Salmonella and, under regional circumstances, other organisms such as Campylobacter jejuni/coli and Yersinia enterocolitica. These recommendations suggest active engagement between primary diagnostic laboratories and provincial public health laboratories to determine the workflow and protocols for reflex or parallel culture. Consequently, notifiable disease definitions will also need modification, with consultation of all stakeholders. Stakeholders need to work together to enhance recovery of bacterial isolates with best practices used for stool transport and storage.

Phenotypic and antibiogram pattern of V. cholerae isolates from a tertiary care hospital in Mumbai during 2004–2013: a retrospective cross-sectional study

ObjectivesCholera is a major gastroenteric disease with reports on fluctuation and resistance. Hence, the objective is to determine the trend in seasonality, resistance pattern, prevalent biotypes, serotypes and phage types...

<i>Clostridium difficile </i>トキシン迅速検査キットの評価と 微生物学的検討

We evaluated two rapid toxin tests for C. difficile combined with stool specimen cultures used from January 2006 to March 2009. Stool specimens numbered 877, 102 among which were from the cases of diagnosed clinical C. difficile-associated diarrhea (CDAD). Rapid toxin A 'Uniquick' detection kits were used until October 2007 and toxin A&B 'TOX A/B' detection kits thereafter. Clinical CDAD was considered the detection gold standard. Uniquick sensitivity, specificity, and positive and negative predictive values were 54.3%, 99.1%, 90.5%, and 93.2% while those for TOX A/B were 46.2%, 97.6%, 65.2%, and 95.0% and for culture 42.2%, 95.5%, 55.1%, and 92.6%. Rapid toxin tests tended to have better sensitivity than culture results although not significantly so, and Uniquick showed significantly better positive predictive value than TOX A/B or culture results. Among clinical CDAD cases, concordance with culture was 24.3% for Uniquick and 53.1% for TOX A/B. For stored strains, 27 were typed toxin A+B+ (48.1%), toxin A-B+ (37.0%) and toxin A-B- (14.8%) with toxin gene detection by PCR. Eight of the 10 toxin A-B+ strains were classified into two cluster by ribotyping, and 7 of those were detected in two hospital wards, indicated the possibility of nosocomial toxin A-B+ strain spread. The rapid toxin test for both toxins A and B should be used if toxin A-B+ predominate. Simultaneous culture testing may be useful for detecting clinical CDAD more accurately, however.

Detection of Clostridium difficile in Stool Samples From Patients in the Early Period After Liver Transplantation

Objective We examined the frequency of detection of Clostridium difficile (CD) toxins compared with the recovery of C. difficile in stool specimen cultures among orthotopic liver transplant (OLT) patients with nosocomial diarrhea in the early period. Materials and Methods The study included stool samples obtained during the first 30 days after OLT in adults who were suspected of CD-associated diseases. The identification of cultured CD strains was performed by standard microbiological methods. The presence of CD toxins was assayed using a commercial immunoassay. Results All patients were followed prospectively for CD infections from the date of OLT for the first 4 weeks after surgery. Among 54 samples, 16.7% were culture-positive for CD. CD toxins were tested on 54 samples, yielding 63% toxin-positive samples and 30% toxin- and culture-negative results. In the first week after OLT, samples from 19 patients were subjected to CD investigation. Among 19 samples positive for toxin, 52.6% of all samples were culture-negative. We analyzed 35 samples from the second to the fourth week after OLT in 31 recipients. Among 35 samples, 68.6% and 25.7% were positive for CD toxin and for culture, while 20% of samples were negative for toxin and culture. Conclusion In our study, 63% of samples were toxin-positive with 16.7% yielding growth of CD and 30% being negative for toxins and cultures.

Risk factors for Clostridium difficile colonisation and toxin production.

to examine risk factors for patients becoming Clostridium difficile culture and toxin positive. prospective cohort study. two medicine for the elderly wards. patients admitted to the wards over a 17-month period. presence of Clostridium difficile on culture of stool specimens and toxins A and/or B. Patient's age, sex, source of admission, antibiotic, laxative, antacid and steroid use, presence/absence of colonic disease, neoplasia, leukaemia and nasogastric or percutaneous endoscopic gastrostomy tube feeding. 390 of 865 patients admitted provided a total of 1003 faecal specimens. Age (OR 1.04, 95% CI 1.001-1.07 per year), admission from another hospital (OR 2.13, 95% CI 1.29-3.50), non-cephalosporin antibiotics (OR 2.08, 95% CI 1.25-3.46) and cephalosporin use (OR 8.45, 95% CI 2.99-23.9) increased risk of becoming Clostridium difficile culture positive. Becoming toxin-positive was associated with antibiotic use only (OR 3.02, 95% CI 1.15-7.92), specifically amoxycillin (OR 8.72, 95% CI 1.66-45.9) and cephalosporins other than ceftriaxone (OR 7.28, 95% CI 1.34-39.6). different risk factors are important for the two stages leading to Clostridium difficile diarrhoea. Age, source of admission and third generation cephalosporins increase risk of becoming culture positive, whilst only antibiotic use is associated with the step of becoming toxin-positive. Understanding these differential risks may aid infection control strategies.

Polymerase chain reaction for diagnosis of enterohemorrhagic Escherichia coli infection and hemolytic-uremic syndrome.

Two pairs of oligonucleotide primers were designed to amplify fragments of the genes for Shiga-like toxin I (SLT-I) and SLT-II in a single reaction. A 370-bp segment and a 283-bp segment were amplified for SLT-I and SLT-II, respectively. The specificities of the polymerase chain reaction (PCR) amplification products were confirmed by using radioactively labeled oligonucleotide probes. SLT sequences were amplified from DNA isolated from 13 previously characterized enterohemorrhagic Escherichia coli (EHEC) strains. No amplification product was produced by using DNA from 20 non-EHEC strains. As little as one bacterial genome was detectable. PCR was then applied to DNA isolated directly from stool samples. We had to remove inhibitors of PCR that were present in lysates prepared from stool samples before amplification was achieved. First, we evaluated the sensitivity of PCR for the detection of known numbers of EHEC added to normal stools. Second, three children with SLT in their stools were shown to have SLT sequences in their stools by PCR. Two of these children had hemolytic-uremic syndrome, and a third child was asymptomatic. Stool specimens collected from another 26 asymptomatic children were negative by PCR for SLT sequences. PCR can be used to diagnose EHEC infections without prior culture of stool specimens.

Faecal mycobacteria and their relationship to HIV-related enteritis in Lusaka, Zambia

The prevalence of infection with mycobacteria, both typical and atypical, is increasing along with prevalence of infection with HIV. Patients with pulmonary tuberculosis (PTB) and patients with chronic diarrhoea are forming a growing proportion of the patient population in hospitals in central Africa. To investigate the possibility that mycobacteria may be responsible for some of the HIV-related enteropathy seen in Lusaka, we studied 89 patients in four different diagnostic groups, clinically, by Mantoux test and by microscopy and culture of stool specimens for mycobacteria. In the HIV-positive group with chronic diarrhoea (n = 31), two patients were found to have mycobacteria on faecal smear and three were culture positive while of the 15 HIV-negative controls, three were smear positive and three were culture positive. Of the 15 patients with proven PTB, three had positive faecal smears but none were culture positive. In the fourth group of 24 patients with suspected PTB, seven were smear positive and five, culture positive. Only in this last group was there some correlation between smear results and culture results. Although this last finding is difficult to explain, it appears that there is no correlation between the symptom of chronic diarrhoea and the presence of mycobacteria in the stool. We conclude that mycobacteria do not play a significant role in the pathogenesis of HIV-related enteropathy in Lusaka.

Routine culture of stool specimens for Yersinia enterocolitica is not a cost-effective procedure.

Cefsulodin-Irgasin-novobiocin (CIN) agar was used to isolate Yersinia enterocolitica from 3,622 stool specimens received in our laboratory during a 1-year period. Seven specimens (0.2%) yielded Y. enterocolitica strains from a total of five patients. The low frequency of Y. enterocolitica isolation observed, coupled with the isolation of this pathogen from three of the five patients by our standard stool examination protocol, leads us to conclude that routine culture of stool specimens on CIN agar is not a cost-effective procedure.

Intestinal parasitic infection and other sexually transmitted diseases in asymptomatic homosexual men.

76/133 (57%) asymptomatic homosexual men harboured intestinal parasites. Of these, 40 had Entamoeba histolytica or Giardia lamblia, or both. In a control group of heterosexual men, no pathogenic protozoa were found. Stool specimen cultures for Salmonella, Shigella, and Campylobacter were negative. 7% of the homosexual men were infected with Neisseria gonorrhoeae in the pharynx or rectum, or both, and 5% with Chlamydia trachomatis in the urethra or rectum. Serological evidence of syphilis was detected in 18 men (13.5%) of whom 2 were untreated. Serological markers of hepatitis A were found in 20% and of hepatitis B in 48%. The prevalence of antibodies to cytomegalovirus was higher in homosexual than in heterosexual men (88% versus 59%).