Potential Enteric Pathogens Research Articles

Diverse sources of fecal contamination in macroalgae wrack-affected environment adjacent to river outflow along the Baltic Sea coast

We investigated the dynamics of feces-associated microorganisms in areas with wrack accumulation in the southeastern part of the Baltic Sea. Our study covered single-day (2021 ) and multi-day (2022) observations during the recreational season. We collected water, sand, and wrack samples and assessed the abundance of fecal indicator bacteria (FIB), as well metagenomic analysis was conducted to monitor changes in microbial composition. Based on metagenomic data we identified taxa associated with feces, sewage, and ruminant sources. Human-related fecal pollution based on genetic markers correlated with the presence of Lachnospiraceae, Prevotellaceae and Rickenellacea abundance. Higher abundance and diversity of feces-associated and ruminant-associated taxa and the presence of enteric pathogens were observed when wrack accumulated near the river outflow in 2021, suggesting a potential link with fecal pollution from the river. As a preventive measure, it is recommended to remove the wrack to reduce the risk of exposure to potential enteric pathogens if it is accumulated next to the river outflow.

Composition and function of the Galapagos penguin gut microbiome vary with age, location, and a putative bacterial pathogen

Microbial colonization plays a direct role in host health. Understanding the ecology of the resident microbial community for a given host species is thus an important step for detecting population vulnerabilities like disease. However, the idea of integrating microbiome research into conservation is still relatively new, and wild birds have received less attention in this field than mammals or domesticated animals. Here we examine the composition and function of the gut microbiome of the endangered Galapagos penguin (Spheniscus mendiculus) with the goals of characterizing the normal microbial community and resistome, identifying likely pathogens, and testing hypotheses of structuring forces for this community based on demographics, location, and infection status. We collected fecal samples from wild penguins in 2018 and performed 16S rRNA gene sequencing and whole genome sequencing (WGS) on extracted DNA. 16S sequencing revealed that the bacterial phyla Fusobacteria, Epsilonbacteraeota, Firmicutes, and Proteobacteria dominate the community. Functional pathways were computed from WGS data, showing genetic functional potential primarily focused on metabolism—amino acid metabolism, carbohydrate metabolism, and energy metabolism are the most well-represented functional groups. WGS samples were each screened for antimicrobial resistance, characterizing a resistome made up of nine antibiotic resistance genes. Samples were screened for potential enteric pathogens using virulence factors as indicators; Clostridium perfringens was revealed as a likely pathogen. Overall, three factors appear to be shaping the alpha and beta diversity of the microbial community: penguin developmental stage, sampling location, and C. perfringens. We found that juvenile penguins have significantly lower alpha diversity than adults based on three metrics, as well as significantly different beta diversity. Location effects are minimal, but one site has significantly lower Shannon diversity than the other primary sites. Finally, when samples were grouped by C. perfringens virulence factors, we found dramatic changes in beta diversity based on operational taxonomic units, protein families, and functional pathways. This study provides a baseline microbiome for an endangered species, implicates both penguin age and the presence of a potential bacterial pathogen as primary factors associated with microbial community variance, and reveals widespread antibiotic resistance genes across the population.

Occurrence of New Delhi Metallo-Beta-Lactamase 1 Producing Enterococcus Species in Oghara Water Nexus: An Emerging Environmental Implications of Resistance Dynamics.

Various members of the enteric bacteria in recent times are evolving diverse survival mechanisms for antibiotic therapy resulting in failure of treatment in infection and disease cases. The Enterococcus species are potential strains implicated in gastrointestinal tract infection and are recently evolving in the resistance mechanism. The study evaluates the occurrence of New Delhi Metallo-beta-lactamase 1 (NDM-1) amongst Enterococcus species using the phenotypic and genomic characterization of environmental strains in the Oghara water nexus. Presumptive isolates of Enterococcus species were retrieved from various sampled water sources and confirmed using polymerase chain reaction (PCR). Antibiotic susceptibility testing was conducted on confirmed isolates using Kirby-Bauer disk diffusion methods. The result reveals 63 genus isolates confirmed Enterococcus species, of which 42 (67%) were Enterococcus faecium, 15 (23%) were Enterococcus faecalis, and 6 (10%) were other Enterococcus species. Fourteen among the E. faecalis isolates show resistance to Ertapenem-EDTA, while 17 (44.8%) of the E. faecium show resistance to Ertapenem-EDTA to presumptively reveal their NDM-1 phenotype. The PCR detection of the NDM-1 gene further confirmed 23 (36.5%) isolates as positive genotypes amongst the isolates that previously showed presumptive NDM-1 phenotype. It was also observed that 10 (15.9%) of Enterococcus faecium members harbored the NDM-1 genotype, whereas 8 (12.7%) members of the Enterococcus faecalis harbored the NDM-1 genotype. The observation of such resistance determinants necessitates a call for the adroit application of relevant therapeutics in the management of related infections and an environmental health caution to prevent the spread of such resistance potential enteric bacteria pathogens.

Detection of potential enteric pathogens in children with severe acute gastroenteritis using the filmarray: Results from a three - years hospital-based survey in Northern Italy

Acute gastroenteritis (AGE) are leading causes of morbidity and mortality in children. Therefore, rapid pathogens identification is needed.The AGE aetiology was investigated from 2018 to 2020 in 2,066 children in Parma (Italy) by FilmArray Gastrointestinal Panel and Enterovirus-targeting RT-PCR. Pathogens were detected in 1,162 (56.2%) stool samples from as many children; 798 (68.7%) were single and 364 (31.3%) mixed infections (68.7% vs 31.3%, P < 0.0001). Children aged 0–5 years showed the highest infection incidence (66.1%).The most frequent pathogens were Enteropathogenic Escherichia coli (EPEC; 19.14%), Clostridioides difficile (10.42%), Norovirus (10.36%), Enterovirus (9.44%), and Campylobacter (9.21%). EPEC, Campylobacter, enteroaggregative E. coli, Norovirus, and Rotavirus showed seasonality. The incidence of pathogens detected decreased between 2018 and 2020 (42.7% vs 20.8%, P < 0.0001), seemingly for the preventive measures imposed by the severe acute respiratory syndrome coronavirus-2 pandemic. A putative aetiology in half the children examined and an estimate of enteric pathogens epidemiology were assessed.

Effect of season and geographic location in the United States on detection of potential enteric pathogens or toxin genes in horses ≥6-mo-old.

We investigated the effects of season and geographic location on detection of nucleic acids of potential enteric pathogens (PEPs) or their toxins (PEP-Ts) in feces of horses ≥6-mo-old in the United States. Results of 3,343 equine diarrhea PCR panels submitted to Idexx Laboratories for horses >6-mo-old were reviewed. Submission months were grouped into 4 seasons, and states were grouped into 4 geographic regions. Logistic regression was performed to assess effects of season and region on detection rates of PEPs and PEP-Ts. Agresti-Coull CIs were determined. Detection rate of Salmonella enterica was higher in the South in summer compared to all other regions, and was also higher in the South in fall compared to the Midwest and Northeast. The Neorickettsia risticii detection rate was lower during summer in the West and higher in fall in the Midwest. Detection of Cryptosporidium spp. was lower during spring, summer, and winter in the West. Differences were not identified for detection rates of Clostridioides difficile, Clostridium perfringens, Lawsonia intracellularis, Rhodococcus equi, equine rotavirus, and equine coronavirus. Overall, our data support seasonal and regional differences in detection rates of S. enterica, N. risticii, and Cryptosporidium spp. in horses ≥6-mo-old in the United States.

Comparison of gut viral communities in diarrhoea and healthy dairy calves.

Calf diarrhoea has been a major cause of economic losses in the global dairy industry. Many factors, including multiple pathogen infections, can directly or indirectly cause calf diarrhoea. This study compared the faecal virome between 15 healthy calves and 15 calves with diarrhoea. Significantly lower diversity of viruses was found in samples from animals with diarrhoea than those in the healthy ones, and this feature may also be related to the age of the calves. Viruses belonging to the families Astroviridae and Caliciviridae that may cause diarrhoea in dairy calves have been characterized, which revealed that reads of caliciviruses and astroviruses in diarrhoea calves were much higher than those in healthy calves. Five complete genomic sequences closely related to Smacoviridae have been identified, which may participate in the regulation of the gut virus community ecology of healthy hosts together with bacteriophages. This research provides a theoretical basis for further understanding of known or potential enteric pathogens related to calf diarrhoea.

Detection of pathogens in blood or feces of adult horses with enteric disease and association with outcome of colitis.

BackgroundRates of detecting ≥1 potential enteric pathogens (PEP) or toxins (PEP‐T) in feces, blood, or both of horses ≥6 months of age with enteric disease and impact of multiple detections on outcome of horses with colitis has not been reported.ObjectiveTo determine detection rates of PEP/PEP‐T in feces, blood, or both of horses with enteric disease and effect of detecting multiple agents on outcome of horses with colitis.AnimalsThirty‐seven hundred fifty‐three fecal samples submitted to IDEXX Laboratories and 239 fecal and blood samples submitted to Michigan State University's Veterinary Diagnostic Laboratory (MSUVDL).MethodsRetrospective evaluation of PEP/PEP‐T testing results was performed to determine rates of detection of 1 or more PEP/PEP‐T. Impact of detecting multiple agents on outcome was assessed in 239 horses hospitalized for colitis.ResultsOne or more PEP/PEP‐T was detected in 1175/3753 (31.3%) and 145/239 (60.7%) of samples submitted to IDEXX Laboratories and MSUVDL, respectively. In a hospitalized cohort, survival to discharge was lower (76%) in horses with 1 agent, compared to horses with either no (88%) or multiple (89%) agents. There was no difference (P = .78) in days of hospitalization between horses with 0 (1–17), 1 (1–33), and > 1 positive (1–20) result. There was no difference in cost of hospitalization (P = .25) between horses with 0 ($2357, $1110‐15 553), 1 ($2742, $788‐11 005), and >1 positive ($2560, $1091‐10 895) result.Conclusions and Clinical ImportanceDetection rates of PEP/PEP‐T in horses with colitis vary with cohorts and tests performed. Detection of more than 1 PEP or PEP‐T did not affect outcome.

Depicting the composition of gut microbiota in children with tic disorders: an exploratory study.

Symptom improvement in children with tic disorder (TD) following fecal microbiota transplantation led us to investigate the gut microbiota in TD. This exploratory study aims to depict the gut microbial profile in patients with TD and explore the impact of dopamine receptor antagonist (DRA) drugs on the composition and metabolic function of the gut microbiota. The gut microbiota were profiled in fecal samples of 49 children with TD and 50 matched healthy controls (HC) using shotgun metagenomic sequencing. A random forest (RF) model was constructed using the gut bacterial species to distinguish TD from HC. Associations between clinical metadata and microbial abundance or function were analyzed using MaAsLin2 and Spearman correlation. The gut microbiota in children with TD was featured by higher abundances of Bacteroides plebeius and Ruminococcus lactaris (a potential pro-inflammatory taxon) and lower abundances of Prevotella stercorea and Streptococcus lutetiensis compared to HC. The constructed RF model accurately distinguished TD from HC based on the gut microbiota profile, resulting in an AUC of 0.884. Significant correlations were observed between tic symptom severity and the abundances of multiple bacterial species and gut microbiota metabolic functions. Multivariate analysis identified an upregulation of 4-aminobutanoate (GABA) degradation in the gut microbiota associated with TD status. The gut microbiota of DRA-treated TD children showed a distinct gut microbiota compared to the treatment-naïve group, represented by an increase in some potential enteric pathogens such as Escherichia coli, a decline in several species including Akkermansia muciniphila, and alterations in various metabolic functions. Bacterial species promoting inflammatory responses and those modulating neurotransmitters such as GABA may be involved in the pathogenesis of TD. The use of DRA drugs is likely to induce overgrowth of some enteric pathogens and alter the gut microbiota metabolism.

Discovery of Enteric Pathogens in the Alaskan Subsistence Diet

Abstract Objectives Transmission of enteric pathogens from food ingestion is an ongoing public health concern, with commensal bacteria in ruminant animal species causing human disease. Enteric pathogens Salmonella, Shigella, and Shiga toxin producing Escherichia coli (STEC) have been isolated from domesticated animals. However, the Alaskan subsistence diet relies on wild game, such as reindeer, caribou, and moose for their food supply. Research concerning enteric pathogens in wildlife has not established. Therefore, we conducted a pilot survey on moose and reindeer to determine potential enteric pathogen transfer risk. Methods Between July 2018 and January 2019, we collected 72 fecal samples from reindeer and moose migrating in Fairbanks, Anchorage, and the Matanuska Valley. Samples were cultured for enteric pathogens, including E coli 0157, using standard clinical microbial process. Phenotypic Shiga toxin production was verified by enzyme immunoassay. Results Reindeer were statistically significant for enteric pathogens when compared to moose (P &lt; .05) Eighty percent of the reindeer population were colonized for either Shigella, Yersinia, or Shiga toxin-producing E coli, with 20% positive for multiple pathogens. Non-0157 Shiga toxin production was observed in 30% of reindeer samples, generated by a sorbitol fermenting E coli. In contrast, moose population showed a near absence of enteric pathogens with only 5% positive for Shigella. Salmonella was not identified in either animal. Conclusion Reindeer, moose, and caribou meat are prominent in the Alaskan subsistence diet. Although moose had limited enteric pathogen colonization, reindeer were significant for transmission risk, including non-0157 Shiga toxin producing E coli, which has been linked to hemolytic uremic syndrome. Isolation of a non-0157 STEC in wildlife indicates environmental colonization. Because reindeer and caribou are closely linked in diet and migration, Alaska clinical laboratories should screen for enteric pathogens, including non-0157 Shiga toxins.

Rapid and in-situ detection of fecal indicator bacteria in water using simple DNA extraction and portable loop-mediated isothermal amplification (LAMP) PCR methods

Contamination of water by fecal matter and potential human enteric pathogens is a serious health concern. Microbiological water quality has been assessed by conventional culture-based methods of fecal indicator bacteria (FIB). Recently, molecular techniques for FIB have been introduced as alternative tools for rapid detection. However, such molecular techniques require a modern laboratory setting, expensive equipment, and skilled personnel. In this study, we developed a simple and rapid DNA extraction method based on a syringe filter without any specialized equipment. Furthermore, loop-mediated isothermal amplification (LAMP) PCR for fecal indicator bacteria (FIB) (i.e. E. coli and E. faecalis) was carried out using the DNA extracts from the syringe-filter based DNA extraction method. The efficiency of the extracted DNA from the syringe-filter based method was comparable to the results of the commercial kit method. We also tested fresh and marine-water collected directly from different locations in Singapore that were spiked with E. coli or E. faecalis. The LAMP assays combined with our DNA extraction method showed higher sensitivity and more tolerance to PCR inhibitors than that of conventional PCR methods. We further developed a portable LAMP device to conduct isothermal PCR reactions for rapid on-site measurement of FIB. As the color changes in the end point of the LAMP reaction can be observed with the naked eye, the portable LAMP device was easily operated and quick, obtaining results in 30 min. The simple, portable and user-friendly platform can be used as an initial screening for the rapid detection of the presence FIB in lower-resource settings. In conclusion, the portable LAMP device coupled with a syringe-filter based DNA extraction method enables us to detect the presence of FIB for assessing microbial water quality within 1 h without any sophisticated laboratory equipment or highly trained personnel.

Porcine Torovirus (PToV)-A Brief Review of Etiology, Diagnostic Assays and Current Epidemiology.

Porcine torovirus (PToV) is a potential enteric swine pathogen, found at especially high rates in piglets with diarrhea. It was first reported in the Netherlands in 1998 and has emerged in many countries around the world. Infections are generally asymptomatic and have not directly caused large economic losses, though co-infections with other swine pathogens and intertype recombination may lead to unpredictable outcomes. This review introduces progress in PToV research regarding its discovery, relationship with other Toroviruses, virion morphological characteristics, genetic structure and variation, recent epidemiology, diagnostic methods, and possibilities for future research.

High-Throughput Sequence Analyses of Bacterial Communities and Multi-Mycotoxin Profiling During Processing of Different Formulations of Kunu, a Traditional Fermented Beverage.

Kunu is a traditional fermented single or mixed cereals-based beverage popularly consumed in many parts of West Africa. Presently, the bacterial community and mycotoxin contamination profiles during processing of various kunu formulations have never been comprehensively studied. This study, therefore, investigated the bacterial community and multi-mycotoxin dynamics during the processing of three kunu formulations using high-throughput sequence analysis of partial 16S rRNA gene (hypervariable V3-V4 region) and liquid chromatography tandem mass spectrometry (LC-MS/MS), respectively. A total of 2,303 operational taxonomic units (OTUs) were obtained across six processing stages in all three kunu formulations. Principal coordinate analysis biplots of the Bray-Curtis dissimilarity between bacterial communities revealed the combined influences of formulations and processing steps. Taxonomically, OTUs spanned 13 phyla and 486 genera. Firmicutes (phylum) dominated (relative abundance) most of the processing stages, while Proteobacteria dominated the rest of the stages. Lactobacillus (genus taxa level) dominated most processing stages and the final product (kunu) of two formulations, whereas Clostridium sensu stricto (cluster 1) dominated kunu of one formulation, constituting a novel observation. We further identified Acetobacter, Propionibacterium, Gluconacetobacter, and Gluconobacter previously not associated with kunu processing. Shared phylotypes between all communities were dominated by lactic acid bacteria including species of Lactobacillus, Lactococcus, Leuconostoc, Pediococcus, and Weissella. Other shared phylotypes included notable acetic acid bacteria and potential human enteric pathogens. Ten mycotoxins [3-Nitropropionic acid, aflatoxicol, aflatoxin B1 (AFB1), AFB2, AFM1, alternariol (AOH), alternariolmethylether (AME), beauvericin (BEAU), citrinin, and moniliformin] were quantified at varying concentrations in ingredients for kunu processing. Except for AOH, AME, and BEAU that were retained at minimal levels of < 2 μg/kg in the final product, most mycotoxins in the ingredients were not detectable after processing. In particular, mycotoxin levels were substantially reduced by fermentation, although simple dilution and sieving also contributed to mycotoxin reduction. This study reinforces the perception of kunu as a rich source of bacteria with beneficial attributes to consumer health, and provides in-depth understanding of the microbiology of kunu processing, as well as information on mycotoxin contamination and reduction during this process. These findings may aid the development of starter culture technology for safe and quality kunu production.

A case control study on the prevalence of enterovirus in children samples and its association with diarrhea.

Some serotypes of enterovirus (EV) may lead to transient and symptomatic gastrointestinal infections while others are commensal residents of the human gut. To determine whether certain EV types are more often associated with diarrhea, we conducted a preliminary study on the prevalence of EV serotypes and common diarrhea viruses in fecal samples of diarrhea children and healthy controls. EV was tested with one step nest polymerase chain reaction and typed by direct sequencing while common causative diarrhea viruses rotavirus (RV), norovirus (NoV), adenovirus (AdV), bocavirus (HBoV), and astrovirus (AstV) were screened with multiplex PCR assays. Human Rhinovirus (HRV) and human EVs that were present in both groups were further quantified and their odds ratios (OR) were calculated. Enteric pathogens were detected in 89 (32.6%) of 273 children with diarrhea and included human EVs (51, 18.68%), HRV (32, 11.72%), RV (38, 13.92%), AdV (24, 8.79%), NoVGII (16, 8.79%), HBoV (8, 2.93%) and AstV (3, 1.09%). Potential enteric pathogens were found in 25 (6.93%) of 361 healthy controls and included human EV (59, 16.34%), HRV (8, 2.22%), RV (1, 0.28%), NoVGII (5, 1.39%), AstV (2, 0.55%), AdV (16, 4.43%) and HBoV (1, 0.28%). In addition, EV71, echovirus 3,9,14,25 and coxsackievirus A14 existed in healthy controls only, while HRV, echovirus11,18, coxsackievirus A2,4,6 and B2,4 were found in both patients and healthy controls. OR assessment confirmed a strong association of HRV (P < 0.001) and a weak one for echovirus 11 and coxsackievirus A6 with diarrhea (P > 0.05). Our results indicate the diversity of EV serotypes in diarrhea and healthy control groups varies, and the potential etiological role of HRV in diarrhea.

A case-control study on diarrheagenic E. coli infection in children

Objective To understand the regional epidemiology and antibiotic resistance pattern of diarrheagenic E. coli infection in children, and to clarify the pathogenic association between diarrheagenic E. coli infection and childhood diarrhea. Methods Totally 680 diarrheal children in the outpatient setting and 680 non-diarrheal control children were enrolled prospectively. The stool samples were collected and the potential enteric pathogens were detected. Minimal inhibitory concentration (MIC) method was used to determine the antimicrobial susceptibility for diarrheagenic E. coli isolates. Results The isolation rates of diarrheagenic E. coli in diarrhea group and control group were 15.6% and 13.1%, respecitvely, and diarrheagenic E. coli was the most commonly detected enteric bacteria. Multivariate logistic regression analysis adjusted for age suggested no clinical association between diarrhea and infection with enteropathogenic E. coli (EPEC) (aOR=1.2, 95%CI: 0.8-1.8), enteroadhesive E. coli (EAEC) (aOR=1.1, 95%CI: 0.7-1.6) and enterotoxigenic E. coli (ETEC) (aOR=1.8, 95%CI: 0.5-6.2). Among 199 diarrheagenic E. coli strains, the rates of resistance to ampicillin, tetracycline, trimethoprim-sulfamethoxazole, azithromycin, and ceftriaxone were 63.8%, 55.8%, 48.2%, 34.2% and 26.6%, respectively, while the rates of resistance to ciprofloxacin, amoxicillin-clavulanate and cefoxitin were 4.5%, 1.5% and 0.5%, respectively. Conclusions Diarrheagenic E. coli is the most common enteric bacteria detected in the stool samples from children with and without diarrhea in this study. The pathogenic role of infections with EPEC, EAEC and ETEC in childhood diarrhea is not determined. EHEC and EIEC are rarely detected and further studies are needed to clarify the pathogenic association between infection with EHEC, EIEC and childhood diarrhea. Key words: Child; Diarrhea; Drug resistance, microbial; Diarrheagenic E. coli

Assessment of Water Quality in Roof-Harvested Rainwater Barrels in Greater Philadelphia

A study of water quality parameters was conducted in 38 small-scale roof-harvested rainwater barrels (RHRB) located in urban and peri-urban Philadelphia, USA in winter (November–December) 2014 and summer (June–August 2016). Parameters included two fecal indicator bacteria (FIB) (Escherichia coli and Enterococcus spp.) measured using culture-based methods, eight potential enteric and opportunistic pathogens (Campylobacter jejuni, Acanthamoeba spp., Legionella spp., L. pneumophila, Naegleria fowleri, Pseudomonas aeruginosa, Mycobacterium avium and Mycobacterium intracellulare) measured using quantitative polymerase chain reaction (qPCR), and two metals (lead and zinc) using inductively coupled plasma mass spectrometry (ICP-MS). Fecal indicator bacteria were detected in greater than 60% RHRB samples and concentrations (up to &gt;103 per 100 mL) exceeded US Food and Drug Administration (USFDA) irrigation water quality standards. Among the enteric and opportunistic pathogens tested, 57.9, 44.7, 21.1, 18.4, 5 and 3% were PCR positive for Legionella spp., M. intracellulare, M. avium, Acanthamoeba spp., P. aeruginosa, and C. jejuni, respectively. N. fowleri and L. pneumophila were not detected in any sample. The concentrations of enteric and opportunistic pathogens ranged from 102 to 107 gene copies/L of barrel water. Lead and zinc were each observed in 88.5% of RHRB but the concentrations did not exceed US Environmental Protection Agency (USEPA) standards for irrigating produce, with the exception of one zinc observation (2660 µg/L). Based on these data, it appears that the risk associated with metals in RHRB is likely to be low, as these barrels are only used for gardening and non-potable purposes. However, risks due to fecal and opportunistic pathogens may be higher due to exposure to aerosols during gardening activities and produce consumed raw, and should be investigated further.

The Spirochete Brachyspira pilosicoli, Enteric Pathogen of Animals and Humans.

Brachyspira pilosicoli is a slow-growing anaerobic spirochete that colonizes the large intestine. Colonization occurs commonly in pigs and adult chickens, causing colitis/typhlitis, diarrhea, poor growth rates, and reduced production. Colonization of humans also is common in some populations (individuals living in village and peri-urban settings in developing countries, recent immigrants from developing countries, homosexual males, and HIV-positive patients), but the spirochete rarely is investigated as a potential human enteric pathogen. In part this is due to its slow growth and specialized growth requirements, meaning that it is not detectable in human fecal samples using routine diagnostic methods. Nevertheless, it has been identified histologically attached to the colon and rectum in patients with conditions such as chronic diarrhea, rectal bleeding, and/or nonspecific abdominal discomfort, and one survey of Australian Aboriginal children showed that colonization was significantly associated with failure to thrive. B. pilosicoli has been detected in the bloodstream of elderly patients or individuals with chronic conditions such as alcoholism and malignancies. This review describes the spirochete and associated diseases. It aims to encourage clinicians and clinical microbiologists to consider B. pilosicoli in their differential diagnoses and to develop and use appropriate diagnostic protocols to identify the spirochete in clinical specimens.

Isolation and Selection of Potential Probiotic Bacteria from the Pig Gastrointestinal Tract

The present study aimed to isolate bacterial strains from the pig gastrointestinal tract that have antagonistic activity against potential pathogens and are able to produce antimicrobial compounds. That ability would be a first requirement for the strains' possible use as probiotics. Samples obtained from pig intestinal mucosa and contents were screened for the presence of antagonistic activity against pathogenic indicator strains of Escherichia coli, Salmonella, and Listeria by means of the double-layer technique. Samples displaying the largest inhibitory halos were further studied for the production of inhibitory substances using the agar diffusion and microtitration methods. The three most promising isolates were identified by sequencing of the 16S rRNA gene and showed highest affiliation to Lactobacillus salivarius. Optimal growth conditions and bacteriocin production were recorded in de Man, Rogosa, and Sharpe broth under anaerobic conditions at 37°C. The antimicrobial substances were found to be sensitive to proteolytic enzymes but showed good stability at pH values below 6. Our findings suggest that these three intestinal strains are able to produce antimicrobial substances capable of inhibiting the growth of potential enteric pathogens and might have potential as probiotic feed additives for the prevention of gastrointestinal diseases.

Prevalence and diversity of waterborne Arcobacter butzleri in southwestern Alberta, Canada.

Arcobacter butzleri is a potential enteric pathogen to human beings, but its reservoirs and modes of transmission are largely unverified. Microbiological and molecular detection and subtyping techniques can facilitate surveillance of A. butzleri in hosts and environmental reservoirs. We isolated A. butzleri from 173 surface water samples (25.6%) and 81 treated wastewater samples (77.9%) collected in southwestern Alberta over a 1-year period. Arcobacter butzleri isolates (n = 500) were genotyped and compared to determine diversity of A. butzleri in southwestern Alberta. Culture methods affected the frequency of detection and genotype diversity of A. butzleri, and isolation comprehensiveness was different for surface waters and treated wastewaters. Detection of A. butzleri in the Oldman River Watershed corresponded with season, river flow rates, and fecal coliform densities. Arcobacter butzleri was detected most frequently in treated wastewater, in the Oldman River downstream from treated wastewater outfalls, and in tributaries near areas of intensive confined feeding operations. All sample sources possessed high genotype diversity, and A. butzleri isolates from treated wastewaters were genetically similar to isolates from the Oldman River downriver from treated wastewater outfall sites. In southwestern Alberta, municipal and agricultural activities contribute to the density and genotype diversity of A. butzleri in surface waters.

SIV Infection-Mediated Changes in Gastrointestinal Bacterial Microbiome and Virome Are Associated with Immunodeficiency and Prevented by Vaccination.

AIDS caused by simian immunodeficiency virus (SIV) infection is associated with gastrointestinal disease, systemic immune activation, and, in cross-sectional studies, changes in the enteric virome. Here we performed a longitudinal study of a vaccine cohort to define the natural history of changes in the fecal metagenome in SIV-infected monkeys. Matched rhesus macaques were either uninfected or intrarectally challenged with SIV, with a subset receiving the Ad26 vaccine, an adenovirus vector expressing the viral Env/Gag/Pol antigens. Progression of SIV infection to AIDS was associated with increased detection of potentially pathogenic viruses and bacterial enteropathogens. Specifically, adenoviruses were associated with an increased incidence of gastrointestinal disease and AIDS-related mortality. Viral and bacterial enteropathogens were largely absent from animals protected by the vaccine. These data suggest that the SIV-associated gastrointestinal disease is associated with the presence of both viral and bacterial enteropathogens and that protection against SIV infection by vaccination prevents enteropathogen emergence.

Aetiology of diarrhoeal disease and evaluation of viral–bacterial coinfection in children under 5 years old in China: a matched case–control study

Globally, diarrhoeal diseases are the second leading cause of death among children under 5 years old. Few case–control studies on the aetiology of diarrhoea have been conducted in China. A case–control study on 922 children under 5 years old who presented with diarrhoea and individually matched controls was conducted in China between May 2011 and January 2013. Quantitative PCR was used to analyze stool samples for 10 diarrhoeal pathogens. Potential enteric pathogens were detected in 377 (81.8%) of 461 children with diarrhoea and 215 controls (46.6%, p <0.001). Rotavirus, norovirus GII, Shigella and adenovirus were qualitatively associated with diarrhoea. Using receiver operating characteristic curves, the optimal cutoff threshold for defining a symptomatic individual was 72, 5840, and 104 copies per reaction for rotavirus (odds ratio 259), norovirus GII (odds ratio 10.6) and Shigella (odds ratio 5.1). The attributable fractions were 0.18 for rotavirus, 0.08 for norovirus GII, 0.01 for Shigella and 0.04 for adenovirus. Coinfections between pathogens were common. Two pairs, rotavirus and adenovirus, and norovirus GII and Salmonella were positively associated. The co-occurrence of rotavirus and sapovirus, astrovirus, enterotoxigenic Escherichia coli or Campylobacter jejuni only occurred in children with disease. Coinfection was not correlated with clinical symptoms. Quantitative data are critical. Our results indicate that increased pathogen loads increase the OR between diarrhoea and rotavirus, norovirus GII and Shigella. Coinfections with rotavirus and norovirus GII are common and occur in a nonrandom distribution. Despite testing for ten diarrhoeal pathogens, over two-thirds of cases do not have a recognized attributable cause.