Gastrointestinal Panel Performance for the Diagnosis of Acute Gastroenteritis in Pediatric Patients.

BACKGROUND: Various methods are used to identify the causative organisms of acute gastroenteritis (AGE) in children. The gastrointestinal (GI) panel has the potential to detect up to 22 pathogens rapidly through the multiplex real-time PCR test. We studied the impact of the GI panel on clinical management in the pediatric population. METHODS: A retrospective study was conducted to collect data on GI panel results and clinical details of inpatient children presenting with AGE at King Hamad University Hospital, Kingdom of Bahrain, over the course of one year. RESULTS: One hundred nine samples were collected. The GI panel was positive in 96 samples (88.1%), with the majority detected in the toddler age group. Forty-one (42.7%) samples were positive for at least one organism. Salmonella was the most frequently encountered bacteria as a single isolate, 10/55 (18.2%), while enteropathogenic Escherichia coli was the most common co-infected organism, 16/41 (39%). Norovirus was the most common virus among the viruses. Bacterial detection peaked from July to October, while viral detection plateaued throughout the year. The GI panel and stool culture were positive for the same organism in 17 samples, versus one sample with a different organism. Sixty-two (56.9%) samples had a positive GI panel but negative stool cultures and stool analysis, and half of those detected viruses. The GI panel was positive in 86.2% of severely ill patients; the majority were bacteria. Bacterial detection was associated with a higher CRP compared to viruses. CONCLUSION: The GI panel is an informative tool for detecting the causative pathogen of AGE in children. However, it can detect multiple organisms, indicating a possible carrier status, which points toward future studies.

Carriage of ß-lactamase and carbapenemase-producing Enterobacteriaceae in hospitalized patients at debre tabor comprehensive specialized hospital.

Background: Antimicrobial resistance has remained global public health threat. Carriage with drug-resistant bacterial pathogens, particularly beta-lactamase and carbapenemase-producing Enterobacteriaceae is among the most concerning. The purpose of this study was to look into the magnitude, antimicrobial resistance patterns, and associated risk factors among hospitalized patients. Methods: A facility-based cross-sectional study was conducted on 383 hospitalized patients at Debre Tabor Comprehensive Specialized Hospital between September 2022 and May 2023. A pre-tested structured questionnaire was used to collect sociodemographic and clinical data. The data on the etiologic agent was collected using standard bacteriological techniques. Briefly, stool specimens were collected aseptically into sterile, leak-proof stool cups. The stool sample was inoculated onto MacConkey agar and incubated aerobically at 37 °C for 24 h. The species isolation and antimicrobial resistance patterns were then performed adhering to bacteriological procedures. In the analysis, a p-value of <0.05 was considered statistically significant. Results: There were 383 study participants, and men made up the majority (55.6%). The study participants' mean age was 33 ± 18 years. Three hundred and seventy-seven (88%) of the study's participants had no previous history of antibiotic use. There were 102 (26.6%) and 21 (5.5%) cases of gastrointestinal carriage caused by Enterobacteriaceae that produce beta-lactamase and carbapenemase, respectively. In total, 175 isolates of Enterobacteriaceae were detected. E. coli (n = 89) and K. pneumoniae (n = 51) were the most frequently recovered. In this study, 46 (79.3%) and 8 (13.8%) isolates of E. coli that produce beta-lactamase were resistant to ampicillin and amoxicillin/clavulanic acid, respectively. Furthermore, participants who had previously used antibiotics experienced a two-fold increase in exposure to gastrointestinal tract carriage by carbapenemase-producing Enterobacteriaceae [AOR, 95% CI (2.01, 1.06-2.98), p = 0.001]. Conclusions: The emergence of drug-resistant pathogens is a growing concern. An increase in the prevalence of drug-resistant infections in hospitalized patients is warranting further investigation.

Shigella as a Cause of Diarrhea Hospitalization in Children Under Five: Evaluation by Conventional and Molecular Methods.

BACKGROUND AND OBJECTIVES: Shigella is an important cause of diarrhea in children under five, often missed by conventional laboratory methods. Blood in stools has always been a syndromic indicator for Shigella diarrhea, but most cases present with watery diarrhea without blood. This study aimed to determine the frequency of Shigella detected by molecular and conventional methods in children under five. Additionally, we aimed to study the clinical profile and outcome of children with Shigella diarrhea managed as per current diarrhea treatment guidelines. METHODS: In this hospital-based prospective observational study, stool samples from 150 children (age range: one month to five years) with acute diarrhea (duration < seven days) were subjected to routine microscopic examination, stool culture, and DNA extraction. The extracted DNA from stored stool samples was subjected to polymerase chain reaction (PCR) amplification using a specific primer for the invasion plasmid antigen H gene sequence (ipaH) gene at 424 bp. Results were interpreted in the context of the percentage of isolation of Shigella by molecular (PCR) and conventional methods (stool microscopy and culture) and the follow-up outcome in terms of recurrence of diarrhea or dysentery and growth faltering over three months after discharge. RESULTS: Shigella infection was diagnosed in stool samples by PCR from 13 (8.7%) children, whereas it was isolated by conventional stool culture in only one (0.7%) child. The sensitivity of culture was only 7.7% against PCR for the diagnosis of Shigella infection, whereas blood in stools had a sensitivity of 15.4%. The majority of Shigella PCR-positive cases (11 out of 13) presented with non-bloody diarrhea. None of the evaluated clinical predictors had a significant association with the Shigella infection. No statistically significant difference was found between PCR-positive and PCR-negative children at the end of follow-up (P>0.05). CONCLUSION: The majority of children with Shigella infection present with watery diarrhea rather than bloody diarrhea, and a history of blood in stools is a poor marker for the diagnosis of shigellosis. The diagnostic performance of stool culture is also very low compared to stool PCR for the diagnosis of Shigella diarrhea.

Comparison of drug susceptibility between Escherichia coli detected in stool cultures of patients undergoing transrectal prostate needle biopsy and Escherichia coli in hospital-wide urine antibiograms.

A prostate biopsy is essential for prostate cancer diagnosis. However, infections are one of the biopsy-associated complications, and post-biopsy fever is estimated to occur in approximately 1% of all cases. It may thus be beneficial to perform a rectal swab culture before a transrectal prostate biopsy to confirm the presence of resistant bacteria and select preventive antibacterial agents according to the drug susceptibility results. This study aimed to determine whether there is a difference between the drug susceptibility of bacteria detected in the stool of patients who were scheduled to undergo prostate biopsy and the hospital-wide urine antibiogram. Patients suspected of having prostate cancer who underwent transrectal prostate biopsy via transrectal ultrasonography between August 1, 2016, and June 30, 2020, were included in this study. Stool samples were collected and cultured before biopsy. Overall, 99 patients underwent prostate biopsy, and of these, culture results were available for 81 patients (81.8%). Escherichia coli was detected in 74.0% (60 samples) of the stool culture samples, of which 4 samples were extended-spectrum ß-lactamase-producing types. We found greater susceptibility of Escherichia coli to ampicillin, fluoroquinolones, sulfamethoxazole/trimethoprim, and cefixime in the stool culture antibiogram than in the hospital-wide urine antibiogram. We also found a significantly low incidence of ESBL-positive Escherichia coli in the stool culture antibiogram with p-values of 0.009, 0.007, and 0.03 compared to the hospital-wide urine antibiograms for 2017, 2018, and 2019, respectively. Stool culture of prostate cancer patients undergoing biopsy may provide useful information for selecting prophylactic antimicrobial agents.

Prevalence and awareness of mode of transmission of typhoid fever in patients diagnosed with Salmonella typhi and paratyphi infections at the Saint Elisabeth General Hospital Shisong, Bui Division, Cameroon.

INTRODUCTION: typhoid fever is a systemic infectious disease caused by the bacteria Salmonella enterica subspecies (typhi). It is a major cause of morbidity and mortality worldwide. This cross-sectional descriptive study aimed at determining the prevalence and awareness of the mode of transmission of Salmonella typhi among patients at the Saint Elisabeth General Hospital Shisong of Cameroon. METHODS: the study carried out from March 1st, 2017 to May 31st, 2017 recruited patients who presented at the hospital with clinical signs and symptoms of typhoid fever and who had lab requests for stool culture requested by the resident physician. The prevalence of Salmonella typhi infections among the patients and the proportion of patients with adequate knowledge on the mode of transmission of Salmonella typhi were estimated at a 95% CI. Data were analyzed using Epi info7.1.3.3. RESULTS: out of the 172 patients recruited for the studies, 52 (30.1%) were diagnosed with Salmonella typhi, 59.6% of which were male. Also, 3 (5.8%) were diagnosed with Salmonella paratyphoid A. A positive correlation between knowledge on the mode of transmission of Salmonella typhi and the level of education was established, showing that 92% of participants with a higher level of education indicating that typhoid fever can be contracted through consumption of contaminated water. CONCLUSION: high prevalence of typhoid fever was observed in our study. The unawareness of the patients on typhoid fever and its contraction through contaminated water and food was positively correlated to the level of educations of the patients. These findings, therefore, suggest a public health challenge faced by inhabitants in this region where typhoid fever remains endemic. Scarcity of potable water, improper drainage systems, and problems of unsanitary toilets in Cameroon require urgent intervention.

Surveillance Stool Culture and its Association with Microbiologically Documented Infection During Febrile Neutropenia in Patients with Acute Leukemia (AL) Undergoing Induction Chemotherapy.

The study aimed at identifying the profile of gut colonization of patients with acute leukemia who underwent induction chemotherapy and its association with induction events and outcome. Baseline bacterial stool culture with resistance pattern of isolates were recorded. Multi-drug resistance was defined as resistance to at least two antibiotic classes including beta lactam and fluoroquinolones. During induction chemotherapy, blood and clinically indicated cultures were taken during febrile neutropenic episodes. Association studies were done between gut colonization and induction events/outcome. Among 109 patients enrolled, 71 (65.13%) patients undergoing induction chemotherapy were colonized with bacteria, with nearly 50% of colonizers harboring multi-drug resistant bacteria. Organisms isolated from stool pre-induction were mostly gram negative (98%), with Escherichia coli and Klebsiella pneumoniae being the commonest. 65.13% patients developed febrile neutropenia. Overall multi-drug resistant positivity during febrile neutropenia was 70.14%. Concordance of 8.45% was observed between isolates from stool and organisms isolated from cultures during febrile neutropenia. There were significant proportion of gut colonized gram-negative multi-drug resistance bacteria among patients with acute leukemia. There was a low concordance rate between baseline stool isolates and subsequent cultures during the induction. There was no significant association between gut colonization and induction events/outcomes studied.

Clinical Significance of Toxigenic Clostridioides difficile Growth in Stool Cultures during the Era of Nonculture Methods for the Diagnosis of C. difficile Infection.

The importance of the detection of relevant toxins or toxin genes to diagnose Clostridioides difficile infection (CDI) or the prediction of clinical outcomes of CDI has been emphasized in recent years. Although stool culture of C. difficile is not routinely recommended in the era of nonculture methods as the preferred tools for CDI diagnosis, the clinical significance of toxigenic C. difficile growth (tCdG) in stool cultures was analyzed. A clinical study was conducted in medical wards of Tainan Hospital, Ministry of Health and Welfare, in southern Taiwan. Diarrheal adults with fecal glutamate dehydrogenase and C. difficile toxin between January 2013 and April 2020 were included. Of the 209 patients with CDI, 158 (75.6%) had tCdG found in stool cultures, and the rest (51, 24.4%) had no tCdG in stool. Only prior ceftazidime or ceftriaxone therapy was independently associated with no tCdG in stool (odds ratio [OR] 2.17, P = 0.02). Compared to the patients with tCDG in stool, those without tCdG in stool experienced treatment success more often (97.1% versus 67.0%, P < 0.001) if treated with metronidazole or vancomycin but had a similar in-hospital mortality or recurrence rate. In the multivariate analysis among 114 patients with CDI treated with metronidazole or vancomycin, treatment success was independently associated with no tCdG in stool (OR 12.7, P = 0.02). Despite the limited utility of stool cultures in CDI diagnoses, no tCdG in stool culture heralds a favorable therapeutic outcome among adults with CDI treated with metronidazole or vancomycin. IMPORTANCE The importance of detecting toxins or toxin genes when diagnosing Clostridioides difficile infections (CDIs) or predicting the severity and outcomes of CDI has been emphasized in recent years. Although the yielding of C. difficile from stool cultures might implicate higher bacterial loads in fecal samples, in an era of nonculture methods for the standard diagnosis of CDIs, clinical significance of positive stool cultures of toxigenic C. difficile was analyzed in this study. Despite the limited ability of stool cultures in CDI diagnoses, no yielding of C. difficile growth might predict the successful CDI therapy.

Therapeutic management of Mycobacterium avium subspecies paratuberculosis infection with complete resolution of symptoms and disease in a patient with advanced inflammatory bowel syndrome.

BACKGROUND: A 26-year-old male had a history of frequent bowel movements, mushy stool with mucus and loss of 25 kg body weight in 6 months was diagnosed as a case of inflammatory bowel disease (IBD). The patient did not respond to routine and standard treatment for IBD. His condition was steadily deteriorating, and he was in a very precarious state when he reported to us. METHODS: Upon laboratory investigation by using IS900 specific PCR [which is specific for Mycobacterium avium subspecies paratuberculosis (MAP)], the blood and stool samples were found negative. However, the presence of low titer MAP-antibodies by indigenous ELISA were found followed by detection of the typical acid-fast MAP bacilli (with 3 + or 4 + grade) microscopically. The MAP stool culture was positive after 6 months incubation. The biotyping by IS1311 specific polymerase chain reaction restriction enzyme (PCR-RE) confirmed infection with 'Indian Bison Type Genotype', a dominant biotype infecting the domestic livestock population of India. Standard anti-MAP therapy was initiated under supervision of the treating physician. The drug of choice in prescribed treatment regimen included Isoniazid (5 mg/kg), Rifampicin (10 mg/kg), Ethambutol (15-25 mg/kg) once a day for 24 weeks and Clarithromycin (250 mg)/Levofloxacin (250 mg) twice a day for 6 weeks. RESULTS: Following treatment, the patient started improving progressively with reduction in bowel movement frequency and gained body weight with an enhanced appetite propensity. Upon follow-up of the patient after 1 year of treatment, stool-microscopy and stool-culture were found negative for MAP. Till the recent past, the patient was further monitored for disease relapse, if any. CONCLUSIONS: This patient has experienced a complete resolution of IBD using a combination of anti-MAP antibiotics. The initial detection of heavy shedding of acid-fast MAP bacilli and typical colony morphology with its characterization obtained from culturing of stool sample indicated the infection of MAP. Interestingly, the present case is one more example of the linkage of demonstrable MAP infection treated with anti-MAP therapy in the presence and then absence of disease in the human host.

A Case Series of Diarrheal Diseases Associated with Yersinia frederiksenii.

To date, Yersinia pestis, Yersinia enterocolitica, and Yersinia pseudotuberculosis are the three Yersinia species generally agreed to be pathogenic in humans. However, there are a limited number of studies that suggest some of the "non-pathogenic" Yersinia species may also cause infections. For instance, Yersinia frederiksenii used to be known as an atypical Y. enterocolitica strain until rhamnose biochemical testing was found to distinguish between these two species in the 1980s. From our regional microbiology laboratory records of 18 hospitals in Eastern Ontario, Canada from 1 May 2018 to 1 May 2021, we identified two patients with Y. frederiksenii isolates in their stool cultures, along with their clinical presentation and antimicrobial management. Both patients presented with diarrhea, abdominal pain, and vomiting for 5 days before presentation to hospital. One patient received a 10-day course of sulfamethoxazole-trimethoprim; his Y. frederiksenii isolate was shown to be susceptible to amoxicillin-clavulanate, ceftriaxone, ciprofloxacin, and sulfamethoxazole-trimethoprim, but resistant to ampicillin. The other patient was sent home from the emergency department and did not require antimicrobials and additional medical attention. This case series illustrated that diarrheal disease could be associated with Y. frederiksenii; the need for antimicrobial treatment should be determined on a case-by-case basis.

Prevalence of enteric bacteria and enteroparasites in human immunodeficiency virus-infected individuals with diarrhoea attending antiretroviral treatment clinic, Arba Minch General Hospital, southern Ethiopia.

In Ethiopia, only limited data are available regarding the prevalence of enteric bacterial pathogens and enteroparasites in human immunodeficiency virus (HIV) -infected individuals with diarrhoea. Hence, this study aims to assess the prevalence of enteric bacteria and enteroparasites, and also the antibiotic susceptibility patterns of bacteria in them. An institution-based cross-sectional study was performed in HIV patients with diarrhoea, who visited the Anti-Retroviral Therapy Clinic of the Arba Minch General Hospital between 1 March and 31 August 2019. Data pertaining to sociodemographic characteristics and other factors were collected using a structured questionnaire. Stool culture is of utmost importance in the case of HIV-infected individuals with diarrhoea. Stool samples were collected and examined for bacterial and parasitic pathogens following standard procedures. The antibiotic susceptibility test was performed as per the Kirby-Bauer disc diffusion technique. Data were analysed using SPSS software. A total of 180 individuals were included in the stool collection process. The prevalence rates of enteric bacteria and enteroparasites were 8.3% and 36.1%, respectively. Parasitic infections were more frequent than bacterial infections in these HIV-infected individuals; commonly identified enteroparasites were Giardia lamblia (8.9%) and Cryptosporidium parvum (8.3%). Campylobacter sp. was the most predominant enteric bacterial isolate (4.4%), followed by Salmonella (2.1%) and Shigella (1.1%) species. CD4 counts <200 cells/µL was significantly associated with both bacterial infections (adjusted OR 9.55, 95% CI 1.54-59.3, p 0.015) and parasitic infections (adjusted OR 3.53, 95% CI 1.3-17.9, p 0.03). Multidrug resistance was also detected in 100%, 75% and 60% of Shigella, Campylobacter and Salmonella sp., respectively. We found that enteroparasitic infections were more frequent than bacterial infections. Statistical analysis revealed that CD4 T-cell counts <200 cells/µL, quality of drinking water sources, hand washing habits after toilet and the presence of domestic animals were significantly associated with the prevalence of enteric pathogens.

Assessment of Talaromyces Marneffei Infection of the Intestine in Three Patients and a Systematic Review of Case Reports.

BACKGROUND: Hematogenous dissemination of Talaromyces marneffei can result in multiorgan involvement (skin, lung, and reticuloendothelial system involvement); however, few studies have reported intestinal T marneffei infections. We investigated clinical features, management, and patient outcomes concerning Talaromyces-related intestinal infections. METHODS: Patients with Talaromycosis between August 2012 and April 2019 at The First Affiliated Hospital of Guangxi Medical University, China, were retrospectively analyzed. Patients presenting with intestinal Talaromycosis and endoscopy-confirmed diagnoses were investigated. We also undertook a systematic review of the relevant English and Chinese literature. RESULTS: Of 175 patients diagnosed with Talaromycosis, 33 presented with gastrointestinal symptoms, and 31 underwent stool cultures, 1 of which tested positive. Three patients had gastrointestinal symptoms and negative stool cultures, and endoscopic tissue biopsy confirmed a pathological diagnosis. A systematic review of 14 reports on human Talaromycosis identified an additional 16 patients. Fever, weight loss, and anemia were the most common symptoms, along with abdominal pain, diarrhea, and bloody stools. Abdominal computed tomography showed intestinal wall edema and thickening and/or abdominal lymphadenopathy. Endoscopy showed erosion, hyperemia, edema, and multiple intestinal mucosal ulcers. Of the 19 patients, 16 received antifungal therapy, 14 of whom recovered and 2 died. Three patients received no therapy and died. CONCLUSIONS: Gastrointestinal disseminated Talaromycosis is not rare and can affect the stomach, duodenum, and colon, and may involve the entire digestive tract. Colon is the most common site. Endoscopy is needed for patients presenting with gastrointestinal symptoms in T marneffei-infected endemic areas. Systemic application of effective antifungal therapy can improve the prognosis.

Caracterización de agentes bacterianos aislados en brotes de enfermedades transmitidas por alimentos / Characterization of bacterial agents isolated in diseases outbreaks transmitted by foods

Introducción: Las enfermedades transmitidas por alimentos se producen por ingestión de un alimento, incluido el agua, que puede estar contaminado por diversos agentes. Objetivo: Caracterizar los agentes bacterianos aislados en brotes de enfermedades transmitidas por alimentos. Métodos: Se realizó un estudio observacional, descriptivo y transversal de 100,0 % de los brotes de enfermedades transmitidas por alimentos en la provincia de Santiago de Cuba, desde enero de 2018 hasta diciembre de 2019, para lo cual se seleccionaron muestras de alimentos y heces fecales. La caracterización de las bacterias aisladas se basó en los resultados del crecimiento y otras pruebas bioquímicas-metabólicas. Se utilizaron resultados del aislamiento y confirmación de los agentes identificados en cada uno de los brotes a partir de las muestras antes citadas. Entre las variables analizadas figuraron: número de brotes, muestras de alimentos, de heces fecales y resultados de pruebas bioquímicas y metabólicas. Resultados: Se obtuvo un aislamiento de agentes bacterianos en 100,0 % de las muestras de alimentos. Hubo una mayor frecuencia de bacterias Gram negativas (82,0 %) y la menor correspondió a microorganismos Gram positivos (18,0 %). La Salmonella D fue el microorganismo más frecuente. Conclusiones: Este resultado representa un instrumento para el diagnóstico etiológico de los brotes de enfermedades transmitidas por alimentos en Santiago de Cuba.

Introduction: Diseases transmitted by foods are produced due to ingestion of a food, including water that can be contaminated by diverse agents. Objective: To characterize the bacterial agents isolated in diseases outbreaks transmitted by foods. Methods: An observational, descriptive and cross-sectional study of 100.0 % of the diseases outbreaks transmitted by foods in Santiago de Cuba, from January, 2018 to December, 2019 was carried out, for which samples of foods and stools were selected. The characterization of the isolated bacterias was based on the results of growth and other biochemical-metabolic tests. Results of the isolation and confirmation of agents identified in each one of the outbreaks from the samples mentioned above were used. Among the analyzed variables we can mention: number of outbreaks, samples of foods, samples of stools and results of biochemical and metabolic tests. Results: An isolation of bacterial agents was obtained in 100.0 % of foods samples. There was a higher frequency of Gram negative bacterias (82.0 %) and the lower corresponded to Gram positive microorganisms (18.0 %). Salmonella D was the most frequent microorganism. Conclusions: This result represents an instrument for the etiological diagnosis of diseases outbreaks transmitted by foods in Santiago de Cuba.

Rapid culture-based identification of Shiga toxin-producing Escherichia coli and Shigella spp./Enteroinvasive E. coli using the eazyplex® EHEC complete assay.

Shiga toxin-producing Escherichia coli (STEC) and Shigella spp./enteroinvasive E. coli (EIEC) are common diarrheagenic bacteria that cause sporadic diseases and outbreaks. Clinical manifestations vary from mild symptoms to severe complications. For microbiological diagnosis, culture confirmation of a positive stool screening PCR test is challenging because of time-consuming methods for isolation of strains, wide variety of STEC pathotypes, and increased emergence of non-classical strains with unusual serotypes. Therefore, molecular assays for the rapid identification of suspect colonies growing on selective media are very useful. In this study, the performance of the newly introduced eazyplex® EHEC assay based on loop-mediated isothermal amplification (LAMP) was evaluated using 18 representative STEC and Shigella strains and 31 isolates or positive-enrichment broths that were collected from clinical stool samples following screening by BD MAX™ EBP PCR. Results were compared to real-time PCR as a reference standard. Overall, sensitivities and specificities of the eazyplex® EHEC were as follows: 94.7% and 100% for Shiga toxin 1 (stx1), 100% and 100% for stx2, 93.3% and 97.1% for intimin (eae), 100% and 100% for enterohemolysin A (ehlyA), and 100% and 100% for invasion-associated plasmid antigen H (ipaH) as Shigella spp./EIEC target, respectively. Sample preparation for LAMP took only some minutes, and the time to result of the assay ranged from 8.5 to 13 min. This study shows that eazyplex® EHEC is a very fast and easy to perform molecular assay that provides reliable results as a culture confirmation assay for the diagnosis of STEC and Shigella spp./EIEC infections.

Performance of molecular methods for the detection of Salmonella in human stool specimens.

Background: The relationship between asymptomatic Salmonella exposure within the gastrointestinal tract and Salmonella bacteraemia is poorly understood, in part due to the low sensitivity of stool culture, and the lack of validated molecular diagnostic tests for the detection of Salmonella in stool. The study aimed to determine a reliable molecular diagnostic test for Salmonella in stool specimens. Methods: We optimized an in-house monoplex real time polymerase chain reaction (PCR) for the detection of Salmonella TTR and InvA genes in stool by including a selenite broth pre-culture step for Salmonella before DNA extraction, and validated their specificity against other local common pathogens. Then we assessed their performance  against a well-validated multiplex PCR targeting the same TTR and InvA genes, and against stool culture using clinical stool specimens collected from a cohort of 50 asymptomatic healthy Malawian children that were sampled at 1-month intervals over a period of 12 months. We employed a latent Markov model to estimate the specificities and sensitivities of PCR methods. Results: TTR and InvA primers were both able to detect all the different Salmonella serovars tested, and had superior limits of detection if DNA was extracted after selenite pre-culture. TTR sensitivity and specificity for monoplex-PCR were (99.53%, 95.46%) and for multiplex-PCR (90.30%, 99.30%) respectively. InvA specificity and specificity for using monoplex-PCR was (95.06%, 90.31%) and multiplex-PCRs (89.41%, 98.00%) respectively. Sensitivity and specificity for standard stool culture were 62.88% and 99.99% respectively. Culture showed the highest PPV (99.73%) and mono-TTR had the highest NPV (99.67%). Conclusion: Test methods demonstrated high concordance although stool culture and monoplexed TTR primers had superior specificity and sensitivity respectively. The use of selenite pre-enrichment step increased Salmonella detection rate. Taken together, molecular detection methods used here could be used to reveal the true extent of both asymptomatic and symptomatic Salmonella exposure events.

Performance of Widal test and stool culture in the diagnosis of typhoid fever among suspected patients in Dar es Salaam, Tanzania.

OBJECTIVE: We set an experiment to determine the diagnostic performance of the Widal test and stool culture in typhoid-suspected cases attending tertiary hospitals in Dar es Salaam, Tanzania using blood culture as a golden standard. We also evaluated the agreement between Widal, stool and blood culture. RESULTS: This was a cross-sectional study conducted between June and September 2018, in three Regional Referral Hospitals in Dar es Salaam, Tanzania. A total of 158 typhoid-suspected cases were enrolled, after obtaining an informed consent. Of the 158 patients participated in the study, 128 (81%) tested positive for the Widal test and 17 (11%) patients were stool culture positive. Widal test recorded 81.5% sensitivity, 18.3% specificity, 10.1% positive predictive value and 89.7% negative predictive value. Stool culture showed 31.3% sensitivity, 91.5% specificity, 29% positive predictive value and 91.5% negative predictive value. In conclusion, Widal test is not reliable for diagnosis of typhoid fever since false positive and negative results are common. In addition, Widal test recorded poor agreement with the blood culture (kappa = 0.014, p < 0.05) while stool culture had strong agreement with the blood culture (kappa = 0.22, p < 0.05).

Culture of Rectal Swab Specimens for Enteric Bacterial Pathogens Decreases Time to Test Result While Preserving Assay Sensitivity Compared to Bulk Fecal Specimens.

Diarrheal illness is a major cause of morbidity and mortality throughout the world, yet the etiologic agent of many cases of gastrointestinal illness remains unspecified, often due to the lack of convenient, timely, and sensitive diagnostic testing. Although bulk fecal specimens remain the recommended specimen type for enteric culture, rectal swabs may be an option preferred by clinicians and patients due to the convenience and timing of collection. However, the lack of data evaluating the sensitivity of rectal swabs compared to fecal specimens for detection of enteric pathogens precludes this specimen type from being recommended by national guidelines. In this study, we retrospectively reviewed 480 paired rectal swab and fecal specimens submitted for enteric culture to the Barnes-Jewish Hospital and St. Louis Children's Hospital microbiology laboratories in St. Louis, MO, from 2002 to 2017. We report 32% positivity of paired specimens with an overall agreement of 93% and Cohen's κ of 0.84 (95% confidence interval, 0.78 to 0.89). Additionally, we evaluated the time to result from the time of patient presentation to the health care setting and demonstrate that rectal swabs have a significantly shorter time to an actionable result than bulk fecal specimens (median, 67.4 h versus 78.4 h, respectively; P < 0.001). These findings indicate that rectal swabs facilitate on-demand culture-based testing with a sensitivity comparable to that of fecal specimens and thus should be recommended for enteric bacterial culture when bulk fecal specimens are unavailable.

Positive stool culture could predict the clinical outcomes of haploidentical hematopoietic stem cell transplantation.

We aimed to identify the effect of positive stool cultures (PSCs) on the clinical outcomes of patients undergoing haploidentical hematopoietic stem cell transplantation (haplo-HSCT) (n = 332). PSCs were observed in 61 patients (PSC group, 18.4%). Enterobacteriaceae in stool specimens was associated with a higher risk of bloodstream infection, and Candida in stool specimens was related to a higher risk of platelet engraftment failure. The cumulative incidence of infection-related mortality 1 year after haplo-HSCT in the PSC group was higher than that of the patients who showed persistently negative stool cultures (NSC group; 19.2% vs. 8.9%, P = 0.017). The probabilities of overall survival (71.4% vs. 83.8%, P = 0.031) and disease-free survival (69.6% vs. 81.0%, P = 0.048) 1 year after haplo-HSCT for the PSC group were significantly lower than those for the NSC group, particularly for patients who had Candida in their stool specimens. In multivariate analysis, Candida in stool specimens significantly increased the risk of mortality and was associated with poorer survival. Our results showed that PSC influenced the clinical outcomes after haplo-HSCT, particularly those who had Candida in their stool specimens.

Evaluating the preservation and isolation of stool pathogens using the COPAN FecalSwab™ Transport System and Walk-Away Specimen Processor.

The isolation of stool pathogens is difficult due to their fastidious nature and the rapid overgrowth of fecal flora. In this study, we evaluate the preservation and isolation of enteric pathogens from stool using the automated COPAN Walk-Away Specimen Processor (WASP®) in conjunction with FecalSwab™ and selenite media. Pathogen viability and fecal commensal abundance were stable in FecalSwab™ media under both room-temperature and refrigerated incubation conditions, resulting in a significantly increased number of well-isolated pathogen colonies observed when compared to samples incubated in modified Cary-Blair media. Isolation of individual pathogen colonies was improved via WASP® planting compared to those planted using the Isoplater system. Furthermore, preincubation using the newly formulated COPAN selenite media significantly enhanced the yield of Salmonella enterica serovar Typhimurium. Together, the automated WASP® system combined with FecalSwab™ and selenite media represents a rapid and efficient approach for the processing of stool specimens compared to standard methods.

An Unconventional Diagnostic Method for Cryptosporidial Enteritis in a Healthy Host: Never Call It Quits!

Cryptosporidial enteritis has a rising incidence in the USA, mostly affecting immunocompromised individuals and children. It has a self-limiting course in healthy hosts. Herein, we present a unique case of a healthy middle-aged female who presented with a 1-month history of voluminous watery diarrhea and acute blood loss anemia. Cryptosporidial enteritis was diagnosed based on endoscopy with biopsy-proven evidence of 2 jejunal peptic ulcers infected with Cryptosporidiumspp. that was originally missed on routine stool culture, ova and parasite tests. The patient was successfully treated with nitazoxanide, and eradication of the protozoan was also confirmed on repeat endoscopic biopsies of the ulcer that were carried out 6 months later. To our knowledge, this is the first case to be reported in the literature with infective colonization of peptic ulcers with Cryptosporidiumspp. with consequent systemic symptoms.

Performance of Stool-testing Recommendations for Acute Gastroenteritis When Used to Identify Children With 9 Potential Bacterial Enteropathogens.

BACKGROUND: The ability to identify bacterial pathogens that necessitate specific clinical management or public health action in children with acute gastroenteritis is crucial to patient care and public health. However, existing stool-testing guidelines offer inconsistent recommendations, and their performance characteristics are unknown. We evaluated 6 leading gastroenteritis guidelines (eg, those of the Centers for Disease Control and Prevention and Infectious Disease Society of America) that recommend when to test children's stool for bacterial enteropathogens. METHODS: Via 2 emergency departments in Alberta, Canada, we enrolled 2447 children <18 years old who presented with ≥3 episodes of diarrhea and/or vomiting in a 24-hour period. All participants were tested for 9 bacterial enteropathogens: Aeromonas, Campylobacter, Escherichia coli O157, other Shiga toxin-producing E. coli, enterotoxigenic E. coli, Salmonella, Shigella, Vibrio, and Yersinia. Patient data gathered at the index visit were used to determine whether guidelines would recommend testing. Sensitivity and specificity to recommend testing for children with bacterial enteropathogens were calculated for each guideline. RESULTS: Outcome data were available for 2391 (97.7%) participants, and 6% (144/2391) of participants tested positive for a bacterial enteropathogen. Guideline sensitivity ranged from 25.8% (95% confidence interval [CI] 18.7-33.0%) to 66.9% (95% CI 59.3-74.6%), and varied for individual pathogens. Guideline specificity for all bacterial enteropathogens ranged from 63.6% (95% CI 61.6-65.6%) to 96.5% (95% CI 95.7-97.2%). CONCLUSIONS: No guideline provided optimally balanced performance. The most sensitive guidelines missed one-third of cases and would drastically increase testing volumes. The most specific guidelines missed almost 75% of cases.