Cause Of Bacterial Diarrhea Research Articles

Marginal Zinc Deficiency Aggravated Intestinal Barrier Dysfunction and Inflammation through ETEC Virulence Factors in a Mouse Model of Diarrhea.

Simple SummaryEnterotoxigenic Escherichia coli (ETEC) is one of the most common bacterial causes of diarrhea in children and farm animals. Zinc has received widespread attention for its roles in the prevention and treatment of diarrhea. However, zinc is also essential for the pathogenesis of ETEC. This study aimed to explore the accurate effect and mechanisms of marginal zinc deficiency on ETEC k88 infection and host intestinal health. Using the newly developed marginal zinc deficiency and ETEC k88 infection mouse model, we found that marginal zinc deficiency aggravated growth impairment, diarrhea, intestinal morphology, intestinal permeability, and inflammation induced by ETEC k88 infection. Consistently, intestinal ETEC k88 shedding was also higher in mice with marginal zinc deficiency. However, marginal zinc deficiency failed to affect host zinc levels and correspondingly the zinc-receptor GPR39 expression in the jejunum. In addition, marginal zinc deficiency upregulated the relative expression of virulence genes involved in heat-labile and heat-stable enterotoxins, motility, cellular adhesion, and biofilm formation in the cecum content of mice with ETEC infection. These findings provide a new explanation for zinc treatment of ETEC infection.Zinc is both essential and inhibitory for the pathogenesis of enterotoxigenic Escherichia coli (ETEC). However, the accurate effects and underlying mechanism of marginal zinc deficiency on ETEC infection are not fully understood. Here, a marginal zinc-deficient mouse model was established by feeding mice with a marginal zinc-deficient diet, and ETEC k88 was further administrated to mice after antibiotic disruption of the normal microbiota. Marginal zinc deficiency aggravated growth impairment, diarrhea, intestinal morphology, intestinal permeability, and inflammation induced by ETEC k88 infection. In line with the above observations, marginal zinc deficiency also increased the intestinal ETEC shedding, though the concentration of ETEC in the intestinal content was not different or even decreased in the stool. Moreover, marginal zinc deficiency failed to change the host’s zinc levels, as evidenced by the fact that the serum zinc levels and zinc-receptor GPR39 expression in jejunum were not significantly different in mice with ETEC challenge. Finally, marginal zinc deficiency upregulated the relative expression of virulence genes involved in heat-labile and heat-stable enterotoxins, motility, cellular adhesion, and biofilm formation in the cecum content of mice with ETEC infection. These findings demonstrated that marginal zinc deficiency likely regulates ETEC infection through the virulence factors, whereas it is not correlated with host zinc levels.

RNA-seq reveals a novel porcine lncRNA MPHOSPH9-OT1 induces CXCL8/IL-8 expression in ETEC infected IPEC-J2 cells.

Enterotoxigenic Escherichia coli (ETEC) is a major cause of bacterial diarrhea in piglets, leading to economic losses in the pig industry. In past decades, long non-coding RNAs (lncRNAs) have shown to be widely involved in the regulation of host immunity in porcine infection diseases. In this study, we explored the lncRNAs associated with ETEC F41 infection in IPEC-J2 cells by high-throughput sequencing and bioinformatic analysis. A total of 10150 novel porcine lncRNAs were identified. There were 161 differentially expressed (DE) lncRNAs associated with ETEC F41 infection, of which 65 DE lncRNAs were up-regulated and 96 DE lncRNAs were down-regulated. Functional and KEGG enrichment analysis of predicted target genes of DE lncRNAs indicated they are enriched in cell growth and inflammation-related pathways, such as endocytosis, focal adhesion, TGF-β signaling pathway, and adherens junctions. We revealed a novel candidate lncRNA MPHOSPH9-OT1 that was up-regulated after ETEC infection. The qRT-PCR validation and ELISA assessment showed the knockdown and overexpression of MPHOSPH9-OT1 resulted in significantly down- and up-regulation of cellular mRNA levels and secreted cytokine levels of CXCL8/IL-8, respectively. Meanwhile, MPHOSPH9-OT1 equilibrium is important to maintain the transepithelial electric resistance value and tight junction protein expression of IPEC-J2 cells. This study provides insights into the functionality of novel porcine lncRNAs in host immune responses to ETEC infection.

Immunization of Rabbits with a Quadrivalent Shigella Bioconjugate Vaccine Induces Functional Antibodies Reactive with Shigella Isolates from Kenya.

ABSTRACTDiarrheal diseases are a leading cause of global morbidity and mortality, disproportionately affecting children in resource-limited settings. Although improvements in hygiene and access to clean water are helpful, vaccines are considered essential due to the low infectious dose of Shigella species and increasing antibiotic resistance. Building on achievements with conjugate vaccines, a safe and immunogenic novel bioconjugate vaccine linking Shigella O-antigen to Pseudomonas aeruginosa exoprotein A has been developed to induce immunity against Shigella flexneri 2a, 3a, and 6 and S. sonnei. This study evaluated the breadth of reactivity and functionality of pooled serum from rabbits immunized with monovalent and quadrivalent Shigella bioconjugates formulated with or without an adjuvant against Shigella serotypes isolated in Kenya. Rabbit sera were assayed by colony blot for reactivity with 67 isolates of Shigella serotypes targeted by the vaccine, S. flexneri (2a, 3a, and 6) and S. sonnei, and 42 isolates of Shigella serotypes not targeted by the vaccine, S. flexneri (1b, 2b, 4a, and 4b), S. boydii, and S. dysenteriae. Shigella isolates testing positive in the colony blot assay were then used to assess functional activity using a bactericidal assay. Of the 41 Shigella isolates targeted by the vaccine, 22 were reactive with the adjuvanted quadrivalent and the respective monovalent rabbit sera. The S. flexneri 2a and 3a monovalent rabbit serum cross-reacted with S. flexneri 3a, 2b, and 2a, respectively. Immunization with the adjuvanted quadrivalent vaccine also induced cross-reactivity with isolates of S. flexneri 2b, 4a, and 4b. Collectively, these results suggest that the Shigella quadrivalent vaccine may be more broadly protective than designed, offering a promising solution to Shigella infections.IMPORTANCE Diarrheal diseases are the third leading cause of death globally, disproportionally affecting low- to middle-income countries like Kenya, with Shigella species being the leading cause of bacterial diarrhea, especially in children. The low infectious dose and high antibiotic resistance levels complicate treatment, leading to long-term sequelae that necessitate control measures such as vaccines to reduce morbidity and mortality rates, especially among children under 5 years of age. A quadrivalent bioconjugate Shigella vaccine was recently developed to safely and effectively induce immunity against four important Shigella spp. This study demonstrates the breadth of reactivity and functionality of the parenterally administered bioconjugate vaccine by evaluating the ability of rabbit sera to bind and kill Shigella isolates recently collected in Kenya. These results suggest that the Shigella quadrivalent vaccine may be more broadly protective than designed and may offer a promising solution to the morbidity and mortality associated with Shigella infections.

SHIGELLOSIS OUTBREAKS – AN UPDATE

"Despite the global economic development, diarrhoea remains an important health concern worldwide. The epidemiological importance of Shigella spp. infections is very high, being the leading cause of bacterial diarrhoea. Clinically, shigellosis can manifest as watery diarrhoea or dysentery, with bloody stool, accompanied by fever and abdominal pain. Children and the elderly are most susceptible to developing severe forms. In this review, we highlight the rise of antibiotic-resistant Shigella spp. strains and provide an overview of recent shigellosis outbreaks. Shigellosis is an infectious disease that should not be neglected, as evidenced by the many outbreaks reported throughout the world. Keywords: diarrhoea, outbreak, Shigella, antibiotic resistance"

Особенности этиологии и клинических проявлений бактериальных кишечных инфекций у взрослых пациентов в Республике Адыгея

Aim: To assess the structure of acute intestinal infections (AIIs) over the period of 2017–2021 and characterize the etiology and clinical course of bacterial AIIs in adult patients in the Republic of Adygeya. Patients and Methods: this retrospective cohort study used the following resources: 1) official statistical reports on viral and bacterial AIIs over the period of 2017–2021 in the Republic of Adygeya to assess trends in the morbidity rates and 2) medical records of 50 patients with bacterial AIIs who received treatment in 2020–2021 in the Adygeya Republican Infectious Diseases Hospital to identify clinical and laboratory findings associated with the bacterial causes of diarrhea. A complete blood cell count, biochemistry blood test, stool analysis and stool culture test were performed in the studied patients. First, the stool samples were inoculated onto an enrichment medium, and then elective nutrient media were used for the detection of pathogens. Results: over the last five years, 4,474 AII cases were reported in the Republic, and in 3,317 (74.14%) of them the etiology was not determined. In 2017–2019, bowel infections of viral etiology prevailed in the structure of AIIs. In 2020 and 2021, amid a significant decline in AII morbidity rates, the percentage of viral and bacterial AIIs was similar: 7.14% and 7.71% in 2020 and 1.11% and 3.05% in 2021, respectively. The median age of patients with verified AIIs of bacterial etiology was 34.5 years, most of the patients were females. Salmonellosis caused by Salmonella entеritidis constituted the highest percentage of bacterial AIIs. Most of the patients had moderate illnesses with enterocolitis symptoms and prevailing secretory diarrhea. Conclusion: over the last five years, 4,474 AII cases were reported in the Republic of Adygeya, and in most patients the etiology was not determined. In 2020 and 2021, amid a significant decline in AII morbidity rates, the percentage of viral and bacterial AIIs was similar. Salmonellosis was dominating in the structure of AIIs (moderate illnesses with enterocolitis symptoms and prevailing secretory diarrhea). Biochemistry tests are necessary for patients with bacterial AIIs to identify pathogenetic mechanisms implicated in the development of post- infectious disease syndrome and gastrointestinal diseases. KEYWORDS: acute intestinal infections, bacterial intestinal infections, etiology, post-infectious disease syndrome, irritable bowel syndrome, gastrointestinal diseases. FOR CITATION: Tlyustangelova R.K., Pshenichnaya N.Yu., Khaidarov S.S. The etiology and clinical characteristics of bacterial intestinal infections in adult patients in the Republic of Adygeya. Russian Medical Inquiry. 2022;6(11):608–611 (in Russ.). DOI: 10.32364/2587-6821- 2022-6-11-608-611.

Intradermally Administered Enterotoxigenic Escherichia coli Vaccine Candidate MecVax Induces Functional Serum Immunoglobulin G Antibodies against Seven Adhesins (CFA/I and CS1 through CS6) and Both Toxins (STa and LT)

There are no vaccines licensed for enterotoxigenic Escherichia coli (ETEC), a leading bacterial cause of children's diarrhea and travelers' diarrhea. MecVax, a multivalent E. coli vaccine candidate composed of two epitope- and structure-based polyvalent proteins (toxoid fusion 3xSTaN12S-mnLTR192G/L211A and colonization factor antigen [CFA]/I/II/IV multiepitope fusion antigen [MEFA]), is designed to induce broad antiadhesin and antitoxin antibodies against heterogeneous ETEC pathovars. When administered intraperitoneally or intramuscularly, MecVax was shown to induce antibodies against seven ETEC adhesins (CFA/I and CS1 to CS6) produced by ETEC pathovars that cause over 60% of ETEC-associated diarrheal cases and moderate-to-severe cases and both toxins (heat-labile toxin [LT] and heat-stable toxin [STa]) expressed by all ETEC strains. To further characterize the immunogenicity of this protein-based injectable subunit vaccine candidate and to explore other parenteral administration routes for the product, in this study we immunized mice intradermally (i.d.) with MecVax and measured antigen-specific antibody responses and further antibody functional activities against the adhesins and toxins targeted by the vaccine. Data showed that mice immunized i.d. with MecVax developed robust anti-CFA/I, CS1, CS2, CS3, CS4, CS5, CS6, LT and anti-STa IgG responses. Furthermore, antibodies derived from MecVax administered via the i.d. route inhibited the adherence of ETEC or E. coli strains expressing any of the seven target adhesins (CFA/I and CS1 to CS6) and neutralized the enterotoxicity of LT and STa. These results confirmed broad immunogenicity of MecVax and suggested that this multivalent ETEC subunit vaccine candidate can be effectively delivered via the i.d. route. IMPORTANCE ETEC is a leading bacterial cause of diarrhea in children living in developing countries and international travelers. Developing an effective vaccine for ETEC diarrhea has been hampered because of the challenges of virulence heterogeneity and the difficulties of inducing neutralizing antibodies against the key toxin STa. MecVax, a subunit vaccine candidate carrying two polyvalent protein antigens, for the first time induces functional antibodies against the most important ETEC adhesins, which are associated with a majority of diarrheal cases and moderate-to-severe cases, and also against the enterotoxicity of LT and more importantly STa, which plays a key role in children's diarrhea and travelers' diarrhea, potentially leading to the development of a truly effective ETEC vaccine. Data from this study may also indicate that this ETEC subunit vaccine can be administered effectively via the i.d. route, expanding clinical administration options for this vaccine product.

S3497 Fecal Microbiota Transplant (FMT) in a Patient With Multi-Drug Resistant Clostridium difficile (MDR C. diff)

Introduction: Studies have shown MDR C. diff is the most common bacterial cause of diarrhea in resource rich settings. One of the most feared outcome of MDR C. diff infection is pseudomembranous colitis. Multiple studies indicate FMT is the most effective yet underutilized in treating recurrent C. diff. Case Description/Methods: Case report: A 73 year old man presented with complaints of diarrhea and fever of 3 days duration. The diarrhea was watery, voluminous, and up to 10 times per day with associated abdominal discomfort. Patient was hospitalized twice in the last 2 months for similar complaints which were treated with oral antibiotics. On physical examination: Temperature 99.5 B/P 161/86 HR 114 and RR 20. Abdominal distention, mild tenderness and hyperactive bowel sounds. Cardiac and chest exams were unremarkable. Laboratory were significant for hypokalemia, elevated BUN and creatinine, lactic acidosis and leukocytosis. C. diff enzyme immune assay was positive for C. diff antigen and C. diff toxins A+B. Upon admission to the floor, IV fluid and electrolyte replacement began. A 10 day antibiotics regimen showed no clinical improvement. The patient’s son donated stool, and two rounds of FMT were administered via colonoscopy; improving patient’s clinical condition. Resolving leukocytosis and electrolyte abnormalities. Discussion: Conclusion: FMT is strongly suggested in patients with MDR C. diff as it decreases fatal complications and hospital readmission.

In Silico designing and immunogenic production of the multimeric CfaB*ST, CfaE, LTB antigen as a peptide vaccine against Enterotoxigenic Escherichia coli

Enterotoxigenic Escherichia coli (ETEC) is the most frequent bacterial cause of diarrhea particularly reported in children of developing countries and also travelers. Enterotoxins and colonization factor antigens (CFAs) are two major virulence factors in ETEC pathogenesis. Colonization factor antigen I (CFA/I) includes major pilin subunit CfaB, and a minor adhesive subunit (CfaE), and enterotoxins consisting of heat-labile toxin subunit B (LTB) and heat-stable toxin (ST). Chimeric proteins (CCL) carrying epitopes and adjuvant sequences increase the possibility of eliciting a broad cellular or effective immune response. In the present study, a chimeric candidate vaccine containing CfaB*ST, CfaE, and LTB (CCL) was designed via in silico techniques. This chimeric gene was synthesized by using codon usage of E. coli for increasing the expression of the recombinant protein. After designing the chimeric construct, it showed a high antigenicity index estimated by the vaxiJen server. Linear and conformational B-cell epitopes were identified and indicated suitable immunogenicity of this multimeric recombinant protein. Thermodynamic analyses for mRNA structures revealed the appropriate folding of the RNA representative good stability of this molecule. In silico scanning was done to predict the 3D structure of the protein, and modeling was validated using the Ramachandran plot analysis. The chimeric protein (rCCL) was expressed in a prokaryotic expression system (E. coli), purified, and analyzed for their immunogenic properties. It was revealed that the production of a high titer of antibody produced in immunized mice could neutralize the ETEC using the rabbit ileal loop tests. The results indicated that the protein inferred from the recombinant protein (rCCL) construct could act as a proper vaccine candidate against three critical causative agents of diarrheal bacteria at the same time.

Association of Broiler Litter Microbiome Composition and Campylobacter Isolation.

Infection with Campylobacter species is one of the leading causes of bacterial diarrhea in humans in the US. Chickens, which become colonized on the farm, are important reservoirs of this bacterium. Campylobacter can establish itself in the broiler house via a variety of sources, can survive in the litter of the house, and possibly persist over successive flock cycles. However, the role of the broiler litter microbiome on Campylobacter persistence is not clear. A matched case-control study was conducted to determine whether the broiler litter microbiome composition was associated with Campylobacter isolation within the broiler house. Flocks were classified as cases when either Campylobacter jejuni or Campylobacter coli was isolated in boot sock samples, or as controls otherwise. Case and control flocks were matched at the broiler house level. Composite broiler litter samples were collected and used for DNA extraction and 16S rRNA gene V4 region sequencing. Reads were processed using the DADA2 pipeline to obtain a table of amplicon sequence variants. Alpha diversity and differential bacterial relative abundance were used as predictors of Campylobacter isolation status in conditional logistic regression models adjusting for flock age and sampling season. Beta diversity distances were used as regressors in stratified PERMANOVA with Campylobacter isolation status as predictor, and broiler house as stratum. When Campylobacter was isolated in boot socks, broiler litter microbiome richness and evenness were lower and higher, respectively, without reaching statistical significance. Campylobacter isolation status significantly explained a small proportion of the beta diversity (genus-level Aitchison dissimilarity distance). Clostridium and Anaerostipes were positively associated with Campylobacter isolation status, whereas Bifidobacterium, Anaerosporobacter, and Stenotrophomonas were negatively associated. Our results suggest the presence of bacterial interactions between Campylobacter and the broiler litter microbiome. The negative association of Campylobacter with Bifidobacterium, Anaerosporobacter, and Stenotrophomonas in litter could be potentially exploited as a pre-harvest control strategy.

Toward an Integrated Genome-Based Surveillance of Salmonella enterica in Germany.

Despite extensive monitoring programs and preventative measures, Salmonella spp. continue to cause tens of thousands human infections per year, as well as many regional and international food-borne outbreaks, that are of great importance for public health and cause significant socio-economic costs. In Germany, salmonellosis is the second most common cause of bacterial diarrhea in humans and is associated with high hospitalization rates. Whole-genome sequencing (WGS) combined with data analysis is a high throughput technology with an unprecedented discriminatory power, which is particularly well suited for targeted pathogen monitoring, rapid cluster detection and assignment of possible infection sources. However, an effective implementation of WGS methods for large-scale microbial pathogen detection and surveillance has been hampered by the lack of standardized methods, uniform quality criteria and strategies for data sharing, all of which are essential for a successful interpretation of sequencing data from different sources. To overcome these challenges, the national GenoSalmSurv project aims to establish a working model for an integrated genome-based surveillance system of Salmonella spp. in Germany, based on a decentralized data analysis. Backbone of the model is the harmonization of laboratory procedures and sequencing protocols, the implementation of open-source bioinformatics tools for data analysis at each institution and the establishment of routine practices for cross-sectoral data sharing for a uniform result interpretation. With this model, we present a working solution for cross-sector interpretation of sequencing data from different sources (such as human, veterinarian, food, feed and environmental) and outline how a decentralized data analysis can contribute to a uniform cluster detection and facilitate outbreak investigations.

Protective effect of Bifidobacterium bifidum FSDJN7O5 and Bifidobacterium breve FHNFQ23M3 on diarrhea caused by enterotoxigenic Escherichia coli.

Enterotoxigenic Escherichia coli (ETEC) is the main bacterial cause of diarrhea among children in developing countries and of traveler's diarrhea. In this study, a mouse model was used to evaluate the effect of Bifidobacterium on alleviating diarrhea caused by ETEC. The results showed that B. breve FHNFQ23M3 and B. bifidum FSDJN7O5 could relieve the symptoms of diarrhea. Both strains significantly reduced the stool water content, restored the villi structure in the jejunum and ameliorated the fecal short-chain fatty acid (SCFA) content. In addition, B. breve FHNFQ23M3 restored body weight to the level before ETEC challenge and significantly reduced interferon-γ (IFN-γ), while B. bifidum FSDJN7O5 significantly improved interleukin (IL)-10. Furthermore, all the Bifidobacterium strains used in this study could significantly downregulate tumor necrosis factor-α (TNF-α) and restore the unbalanced gut microbiota, which had a high content of pathogenic Escherichia-Shigella and low content of Blautia and Clostridium innocuum groups due to ETEC. All the results proved that Bifidobacterium could be a potential probiotic for alleviating diarrhea from ETEC infection.

A Multiplex Quantitative Polymerase Chain Reaction Using Applied Biosystems 7500 Fast System for Simultaneous Identification of Three Campylobacter Species with Potential Applications to Food Analysis.

Consumption of Campylobacter-contaminated food is one of the most common causes of bacterial diarrhea. A previously developed quantitative polymerase chain reaction (qPCR) utilizing the SmartCycler instrument platform for identification of Campylobacter jejuni, Campylobacter coli, and Campylobacter lari had to be modified to address the recent discontinuation of the SmartCycler system. In this study, a multiplex qPCR assay was optimized on the Applied Biosystems 7500 Fast (AB7500F) platform to continue using qPCR for the identification of three target Campylobacter spp. AB7500F qPCR efficiencies obtained by testing reference genomic DNA (gDNA) were 90.9%, 86.4%, and 94.6% for C. jejuni, C. coli, and C. lari, respectively, with all correlation coefficient values >0.99. The qPCR results exhibited 100% specificity by testing gDNA samples from 37 non-target reference strains and 86 target strains (50 C. jejuni, 27 C. coli, and 9 C. lari strains) in this study. The lowest detection level using gDNA was 4, 7, and 2 genome copies per reaction for C. jejuni, C. coli, and C. lari, respectively. With a 2-day enrichment procedure, the qPCR method correctly detected target species in a spiked food matrix (frog leg, an aquaculture product). The sensitivity in 25 g food matrix was 4 colony-forming units (CFUs) for C. jejuni, 3 CFUs for C. coli, and 2 CFUs for C. lari. The results suggest that this AB7500F-based qPCR has potential applications for the identification of C. jejuni, C. coli, and C. lari in contaminated food.

Progress toward the Development of Glycan-Based Vaccines against Campylobacteriosis.

As one of the main causes of bacterial diarrhea and a major risk factor for triggering Guillain-Barré autoimmune syndrome, campylobacteriosis, that is, Campylobacter spp. infections, represents a major health issue worldwide. There is thus a pressing need for developing an effective and broad-coverage campylobacteriosis vaccine. Campylobacter jejuni, an encapsulated, multidrug resistant Gram-negative bacterium, expresses virulence-associated capsular polysaccharides (CPSs), which constitute exquisite targets for the design of glycoconjugate vaccines. In that context, synthetic carbohydrate chemistry acts as a crucial enabling technology for the preparation of homogeneous constructs while allowing antigenic epitopes to be deciphered and probed at the molecular level. This review aims at covering recent developments in CPS-based campylobacteriosis vaccines as well as in the total syntheses of C. jejuni-related mono- and oligosaccharide mimics.

Enfeksiyöz ishallerde Campylobacter jejuni prevalansının çeşitli yöntemlerle araştırılması

In our study, stool samples that were sent to the department of Microbiology for routine bacteriologic culture and parasitological examination were used in to estimate the prevalence of Campylobacter jejuni. Samples collected for 6 months. We depend on traditional methods such as culture for identifying the C. jejuni strains and molecular methods. Fresh diarrheal stool samples were streaked on Skirrow blood agar and incubated in a microaerophilic conditions at two different temperatures (35°C, 42°C) for 48 hours. Conventional methods were used for identification of C. jejuni. Antibiotic susceptibilities of the isolates were tested by disc diffusion method and the results were evaluated according to the EUCAST guidelines. All stool specimens were re-evaluated using (BD MAX™) Enteric Bacterial Panel system by real-time PCR method targeting tuf gen regions of C. jejuni/coli. From a total of 300 stool samples tested by both culture and molecular methods, only 3 C. jejuni strains were isolated by culture; however, using molecular method a total of 5 C. jejuni/coli positive were given.In conclusion, the culture for Campylobacter jejuni should be routinely included in our laboratories because of its importance as a bacterial cause of diarrhea in children. Also molecular methods are thought to be useful in the detection.

Evaluation of molecular rapid diagnosis of enteric bacterial infection in patients with diarrhoeal disease and its clinical and infection control impact at a large district hospital, UK

Introduction: Acute diarrhoeal syndromes are usually self-limiting, but diagnostic testing and treatment may be required in some instances. Stool cultures require a significant level of technologist expertise and are labour intensive. The BD MAX™ Enteric Bacterial Panel detects over 90% of bacteria causing infectious gastroenteritis and provide rapid diagnosis. The aim of this study is to assess the diagnostic and clinical value of this rapid diagnostic tool. Methods: Fresh stool samples received from 68 patients were cultured according to SMI methods, and by BD MAX™ Enteric. Further 25 frozen samples were processed by both methods. Any discrepancies between the two methods where sent to reference laboratory for confirmation. Results: Five samples (4 fresh and one frozen) were excluded from the study due to PCR inhibition. The turnaround time was 48 hours and 4-5 days for negative and positive culture respectively. BD MAX™ Enteric provided same day result. The sensitivity of BD MAX™ Enteric was 100% for fresh samples but this was reduced to 66% if performed on frozen samples. The rapid availability of negative results guided further clinical investigation and management. While the positive results allowed timely implementation of infection control management and guided antibiotic decision process. Conclusion: BD MAX™ is sensitive and provides same-day results. This allowed implementation of infection control measures in timely manner and guided further patient management. However, as this panel is restricted to bacterial causes of diarrhoea, if PCR there will be a need for further testing to exclude other possible infectious causes

Campylobacter Abundance in Breastfed Infants and Identification of a New Species in the Global Enterics Multicenter Study.

Campylobacter jejuni is a leading cause of bacterial diarrhea worldwide and is associated with high rates of mortality and growth stunting in children inhabiting low- to middle-resource countries. To better understand the impact of breastfeeding on Campylobacter infection in infants in sub-Saharan Africa and South Asia, we examined fecal microbial compositions, bacterial isolates, and their carbohydrate metabolic pathways in Campylobacter-positive infants <1 year of age from the Global Enterics Multicenter Study. Exclusively breastfed infants with diarrhea exhibited high Campylobacter abundances, and this negatively correlated with bacterial carbohydrate metabolism. Although C. jejuni and Campylobacter coli are prevalent among these infants, the second most abundant Campylobacter species was a new species, which we named "Candidatus Campylobacter infans." Asymptomatic Campylobacter carriers also possess significantly different proportions of specific gut microbes compared to diarrheal cases. These findings provide insight into Campylobacter infections in infants in sub-Saharan Africa and South Asia and help inform strategies aimed at eliminating campylobacteriosis in these areas.IMPORTANCECampylobacter is the primary cause of bacterial diarrhea in the United States and can lead to the development of the postinfectious autoimmune neuropathy known as Guillain-Barré syndrome. Also, drug-resistant campylobacters are becoming a serious concern both locally and abroad. In low- and middle-income countries (LMICs), infection with Campylobacter is linked to high rates of morbidity, growth stunting, and mortality in children, and breastfeeding is important for infant nutrition, development, and protection against infectious diseases. In this study, we examined the relationship between breastfeeding and Campylobacter infection and demonstrate the increased selection for C. jejuni and C. coli strains unable to metabolize fucose. We also identify a new Campylobacter species coinfecting these infants with a high prevalence in five of the seven countries in sub-Saharan Africa and South Asia examined. These findings indicate that more detailed studies are needed in LMICs to understand the Campylobacter infection process in order to devise a strategy for eliminating this pathogenic microbe.

Bovine Colostrum in the Treatment of Acute Diarrhea in Children: A Double-Blinded Randomized Controlled Trial.

To evaluate the effect of bovine colostrum (BC) on the treatment of children with acute diarrhea attending the outpatient clinic. This double-blind randomized controlled trial was conducted on 160 children with diarrhea; 80 cases were randomly treated with BC group and 80 cases randomly received placebo (placebo group). All cases were investigated for bacterial causes of diarrhea (Salmonella spp, Shigella spp, diarrheagenic E. coli (DEC), Campylobacter spp., and Vibrio cholerae) as well as for Rotavirus antigen in stool. After 48 h, the BC group had a significantly lower frequency of vomiting, diarrhea and Vesikari scoring compared with the placebo group (p = 0.000, p = 0.000, p = 0.000, respectively), whether it was due to Rotavirus or E. coli infection. BC is effective in the treatment of acute diarrhea and can be considered as adjuvant therapy in both viral and bacterial diarrhea to prevent diarrhea-related complications.

Burden of laboratory-confirmed shigellosis infections in Guatemala 2007-2012: results from a population-based surveillance system

BackgroundWe describe the epidemiology and antimicrobial susceptibility patterns of culture-confirmed Shigella infections in facility-based surveillance sites in Guatemala. Current studies using quantitative molecular diagnostics suggest Shigella may contribute most to the global diarrheal disease burden. Since identification of Shigella requires culturing techniques using stool specimens and few laboratories in Guatemala routinely culture for this pathogen, little is known about the true burden of Shigella in Guatemala or, importantly, the antimicrobial resistance patterns.MethodsClinical, epidemiological, and laboratory data were collected on 5399 patients with acute diarrhea (≥3 loose stools in 24 h) from June 2007–August 2012. Multidrug resistance (MDR) was defined as resistance to ampicillin and trimethoprim/sulfamethoxazole.ResultsFive percent (261) of stool specimens yielded Shigella spp. The annual incidence of laboratory-confirmed infections ranged from 5.0 to 24.1 per 100,000 persons in Santa Rosa and 0.3 to 6.2 per 100,000 in Quetzaltenango; 58% of cases occurred in children < 5 years of age. Thirty patients were hospitalized; one patient died. Oral rehydration or intravenous solution was used to treat 72% of hospitalized and 15% of ambulatory cases. Fifty-nine percent of cases were S. flexneri and 51% of cases were MDR.ConclusionsShigella is an important cause of bacterial diarrhea in children and prevalence of MDR highlights the importance of appropriate treatment regimens. This study demonstrates that strengthening laboratory capacity in Guatemala can help determine causes which can lead to prevention of diarrheal diseases, particularly in children. Such capacity building is also critical for rapid detection and control of public health threats at their source and therefore for global health security.

Development of a novel multiplex electrochemiluminescent-based immunoassay to aid enterotoxigenic Escherichia coli vaccine development and evaluations

Enterotoxigenic Escherichia coli (ETEC) is a leading cause of bacterial diarrhea both among children in low and middle income countries and in travelers to these regions. Although there are several approaches to develop an effective vaccine for ETEC, no licensed vaccines are currently available. The most advanced ETEC vaccine candidates include multiple colonization factors along with the heat labile toxin B subunit. In the absence of known correlates of protection, and to understand the mechanism of protection, monitoring immune responses to a majority of the vaccine associated antigens using various types of samples is needed. Unfortunately, a traditional ELISA is time consuming, labor intensive and requires substantial amounts of antigens and sample volumes. To address these constraints, we developed and validated a novel high throughput electrochemiluminescent (ECL) - based multiplex immunoassay using Meso Scale Discovery (MSD) platform for analyzing immune responses to ETEC antigens. The ETEC multiplex ECL assay is an 8-plex assay which includes the ETEC colonization factor antigens (CFA/I, CS1, CS2, CS3, CS5 and CS6) along with the two subunits of heat labile toxin (LTA and LTB). Our data suggested that a single dilution of sample provides a quantifiable result for a wide range of sample titers. To compare ETEC multiplex ECL with ELISA, we carried out assays using the same antigens with the two immunoassay platforms using a common sample set of serum and ALS (antibodies in lymphocyte supernatant) specimens. The MSD platform achieved excellent correlations with ELISA for the antigens tested, consistently detecting comparable antibody levels in the samples. The ETEC multiplex ECL can serve as a fundamental platform in evaluating performances of candidate ETEC vaccines in future field trials.

The in vitro antibacterial activity of Morinda lucida and Acalypha wilkesiana leaf extracts against Campylobacter and Escherichia coli relevant in poultry infections

The most common cause of bacterial diarrhea in humans worldwide is infection with Campylobacter species, particularly Campylobacter jejuni and C. coli. The disease is zoonotic and domestic animals such as poultry, pigs and cattle may act as reservoirs. Colibacillosis is caused by Escherichia coli which is both a food and water borne zoonotic disease from poultry, calves and pigs. The development of resistant strains against the conventional antibiotics has reduced the efficacy of the antibiotics. Therefore, there is urgency to develop drug leads or templates with good activity against these pathogens. The antibacterial activity and safety of acetone, methanol, hot and cold aqueous leaf extracts of Morinda lucida and Acalypha wilkesiana on Campylobacter coli and selected clinical isolates of Escherichia coli was investigated in vitro using serial microdilution and cytotoxicity assays. The MIC values of selected plant extracts against the test organisms generally ranged from 0.03 to 2.50 mg/ml. MIC values of the acetone extracts ranged from 0.03 to 0.46 mg/ml, methanolic extract MICs ranged from 0.15 to 0.78 mg/ml, cold aqueous extract MICs ranged from 0.03 to 2.50 mg/ml while MICs of the hot aqueous extracts ranged from 0.03 to 1.25 mg/ml. The MIC of the positive control, gentamicin, against Campylobacter species ranged from 0.001 to 0.62 mg/ml while those of Escherichia isolates were extremely promising, ranging from 0.0002 to 0.001 mg/ml. The LC50 values of the acetone and cold aqueous extracts of Morinda lucida against the intestinal CaCo‐2 cell line were 0.46 and 0.58 mg/ml respectively while those of acetone, methanolic and hot aqueous extracts of Acalypha wilkesiana were 1.56, 0.11 and 0.19 mg/ml respectively. The selectivity index (SI) values of the acetone extract of Morinda lucida ranged from 2.55 to 9.20 while those of the cold aqueous extracts ranged from 0.23 to 19.33 with the acetone extract having better SI than the cold aqueous extract. The SI values of the acetone extract of Acalypha wilkesiana ranged from 2.22 to 52, methanolic extract ranged from 0.14 to 0.73 and hot aqueous extract ranged from 0.15 to 6.33 with the acetone extract having the best SI relative to cold aqueous, methanolic and hot aqueous extracts of both plant extracts, indicating that the observed antimicrobial activity was not due to toxicity to mammalian cells. These results highlight the potential of Morinda lucida and Acalypha wilkesiana as an alternative for treatment of campylobacteriosis and colibacillosis in poultry. However, in vivo data is necessary to determine the potential usefulness of these plant speciesThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.