Aetiology, risk factors and microbiota composition in children with prolonged diarrhoea: A prospective case-controlled cohort study.

AIM: Prolonged diarrhoea (ProD) refers to acute-onset diarrhoea that persists for longer than 1 week. As the aetiology, risk factors and management are poorly defined, we prospectively enrolled children hospitalised in a high-income setting to assess these outcomes and investigate the potential role of gut microbiota. METHODS: All children aged 30 days to 14 years admitted for acute-onset diarrhoea lasting 7-14 days were included. Children consecutively admitted in the same period for acute diarrhoea (AD) served as controls. High-throughput sequencing of 16S rRNA gene amplicons was used to analyse stool samples from a subset of patients and healthy controls. RESULTS: Sixty-eight with ProD and 104 with AD were enrolled. Intestinal infections were the main aetiology of diarrhoea in both groups (ProD 92.9% vs. AD 97.8%). ProD children showed a higher prevalence of bacterial infections compared to AD (30.8% vs. 8.9%, p = 0.024). Neither age, host-related factors, nor microbiome alterations were specifically linked to ProD. However, ProD children had a more severe initial clinical presentation than AD. CONCLUSION: ProD is often the result of an unusually severe intestinal infection that runs a course longer than expected but generally resolves without further problems. No specific management or therapies should be undertaken in most cases.

The role of mucin O-glycans in microbiota dysbiosis, intestinal homeostasis, and host-pathogen interactions.

Mucin O-linked glycans are important mediators of host-microbiota-pathogen interactions in the gastrointestinal tract. The major component of intestinal mucus, the MUC2 mucin, is densely glycosylated, with up to 80% of its weight-to-volume ratio represented by O-linked glycans. Glycosylation of secretory gel-forming mucins has an enormous impact on intestinal barrier function, microbial metabolism, and mucus colonization by both pathogenic and commensal microbes. Mucin O-glycans and glycan-derived sugars may be degraded and used as a nutrient source and may regulate microbial gene expression and virulence. Short-chain fatty acids, produced as a by-product of glycan fermentation, can regulate host immunity and goblet cell activity and are important for host-microbe homeostasis. Mucin glycans may also act as microbial binding sites, influencing intestinal colonization and translocation through the mucus gel barrier. Recent findings indicate that alterations to mucin glycosylation impact the susceptibility of mucins to degradation, resulting in altered barrier function and intestinal permeability. Alterations to mucin glycosylation patterns are frequently observed during intestinal infection and inflammation and have been implicated in microbiota dysbiosis and expansion of pathobionts. Recent work has demonstrated that these alterations can play key roles in disease pathogenesis. The precise mechanisms remain obscure. This review highlights the important roles of O-linked glycans in host-microbe interactions and disease pathogenesis in the context of intestinal infections.

Genomic and phenotypic profiling of Staphylococcus aureus isolates from bovine mastitis for antibiotic resistance and intestinal infectivity.

BACKGROUND: Staphylococcus aureus is one of the prevalent etiological agents of contagious bovine mastitis, causing a significant economic burden on the global dairy industry. Given the emergence of antibiotic resistance (ABR) and possible zoonotic spillovers, S aureus from mastitic cattle pose threat to both veterinary and public health. Therefore, assessment of their ABR status and pathogenic translation in human infection models is crucial. RESULTS: In this study, 43 S. aureus isolates associated with bovine mastitis obtained from four different Canadian provinces (Alberta, Ontario, Quebec, and Atlantic provinces) were tested for ABR and virulence through phenotypic and genotypic profiling. All 43 isolates exhibited crucial virulence characteristics such as hemolysis, and biofilm formation, and six isolates from ST151, ST352, and ST8 categories showed ABR. Genes associated with ABR (tetK, tetM, aac6', norA, norB, lmrS, blaR, blaZ, etc.), toxin production (hla, hlab, lukD, etc.), adherence (fmbA, fnbB, clfA, clfB, icaABCD, etc.), and host immune invasion (spa, sbi, cap, adsA, etc.) were identified by analyzing whole-genome sequences. Although none of the isolates possessed human adaptation genes, both groups of ABR and antibiotic-susceptible isolates demonstrated intracellular invasion, colonization, infection, and death of human intestinal epithelial cells (Caco-2), and Caenorhabditis elegans. Notably, the susceptibilities of S. aureus towards antibiotics such as streptomycin, kanamycin, and ampicillin were altered when the bacteria were internalized in Caco-2 cells and C. elegans. Meanwhile, tetracycline, chloramphenicol, and ceftiofur were comparatively more effective with ≤ 2.5 log10 reductions of intracellular S. aureus. CONCLUSIONS: This study demonstrated the potential of S. aureus isolated from mastitis cows to possess virulence characteristics enabling invasion of intestinal cells thus calling for developing therapeutics capable of targeting drug-resistant intracellular pathogens for effective disease management.

Potential intestinal infection and faecal-oral transmission of human coronaviruses.

Human coronaviruses (HCoVs) were first described in 1960s for patients experiencing common cold. Since then, increasing number of HCoVs have been discovered, including those causing severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS), and the circulating coronavirus disease 2019 (COVID-19), which can cause fatal respiratory disease in humans on infection. HCoVs are believed to spread mainly through respiratory droplets and close contact. However, studies have shown that a large proportion of patients with HCoV infection develop gastrointestinal (GI) symptoms, and many patients with confirmed HCoV infection have shown detectable viral RNA in their faecal samples. Furthermore, multiple in vitro and in vivo animal studies have provided direct evidence of intestinal HCoV infection. These data highlight the nature of HCoV GI infection and its potential faecal-oral transmission. Here, we summarise the current findings on GI manifestations of HCoVs. We also discuss how HCoV GI infection might occur and the current evidence to establish the occurrence of faecal-oral transmission.

Hypermucoviscous Carbapenem-Resistant Klebsiella pneumoniae ST25 Infect Human Intestinal Epithelial Cells and Induce Moderate Inflammation.

Klebsiella pneumoniae is an opportunistic pathogen that can produce moderate and severe infections in immunosuppressed hosts. In recent years, an increase in the isolation of hypermucoviscous carbapenem-resistant K. pneumoniae with sequence type 25 (ST25) in hospitals in Norwest Argentina was observed. This work aimed to study the virulence and inflammatory potential of two K. pneumoniae ST25 strains (LABACER01 and LABACER27) in the intestinal mucosa. The human intestinal Caco-2 cells were infected with the K. pneumoniae ST25 strains, and their adhesion and invasion rates and changes in the expression of tight junction and inflammatory factors genes were evaluated. ST25 strains were able to adhere and invade Caco-2 cells, reducing their viability. Furthermore, both strains reduced the expression of tight junction proteins (occludin, ZO-1, and claudin-5), altered permeability, and increased the expression of TGF-ß and TLL1 and the inflammatory factors (COX-2, iNOS, MCP-1, IL-6, IL-8, and TNF-α) in Caco-2 cells. The inflammatory response induced by LABACER01 and LABACER27 was significantly lower than the one produced by LPS or other intestinal pathogens, including K. pneumoniae NTUH-K2044. No differences in virulence and inflammatory potential were found between LABACER01 and LABACER27. In line with these findings, no major differences between the strains were found when the comparative genomic analysis of virulence factors associated with intestinal infection/colonization was performed. This work is the first to demonstrate that hypermucoviscous carbapenem-resistant K. pneumoniae ST25 infects human intestinal epithelial cells and induces moderate inflammation.

Research progress on the regulation mechanism of probiotics on the microecological flora of infected intestines in livestock and poultry.

The animal intestine is a complex ecosystem composed of host cells, gut microbiota and available nutrients. Gut microbiota can prevent the occurrence of intestinal diseases in animals by regulating the homeostasis of the intestinal environment. The intestinal microbiota is a complex and stable microbial community, and the homeostasis of the intestinal environment is closely related to the invasion of intestinal pathogens, which plays an important role in protecting the host from pathogen infections. Probiotics are strains of microorganisms that are beneficial to health, and their potential has recently led to a significant increase in studies on the regulation of intestinal flora. Various potential mechanisms of action have been proposed on probiotics, especially mediating the regulation mechanism of the intestinal flora on the host, mainly including competitive inhibition of pathogens, stimulation of the host's adaptive immune system and regulation of the intestinal flora. The advent of high-throughput sequencing technology has given us a clearer understanding and has facilitated the development of research methods to investigate the intestinal microecological flora. This review will focus on the regulation of probiotics on the microbial flora of intestinal infections in livestock and poultry and will depict future research directions.

Differential Outcome between BALB/c and C57BL/6 Mice after Escherichia coli O157:H7 Infection Is Associated with a Dissimilar Tolerance Mechanism.

Enterohemorrhagic Escherichia coli (EHEC) infections can result in a wide range of clinical presentations despite that EHEC strains belong to the O157:H7 serotype, one of the most pathogenic forms. Although pathogen virulence influences disease outcome, we emphasize the concept of host-pathogen interactions, which involve resistance or tolerance mechanisms in the host that determine total host fitness and bacterial virulence. Taking advantage of the genetic differences between mouse strains, we analyzed the clinical progression in C57BL/6 and BALB/c weaned mice infected with an E. coli O157:H7 strain. We carefully analyzed colonization with several bacterial doses, clinical parameters, intestinal histology, and the integrity of the intestinal barrier, as well as local and systemic levels of antibodies to pathogenic factors. We demonstrated that although both strains had comparable susceptibility to Shiga toxin (Stx) and the intestinal bacterial burden was similar, C57BL/6 showed increased intestinal damage, alteration of the integrity of the intestinal barrier, and impaired renal function that resulted in increased mortality. The increased survival rate in the BALB/c strain was associated with an early specific antibody response as part of a tolerance mechanism.

Direct Evidence of Active SARS-CoV-2 Replication in the Intestine.

BACKGROUND: Currently, there is no direct evidence to prove the active replication of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the intestinal tract and relevant pathological changes in the colon and rectum. We investigated the presence of virions and pathological changes in surgical rectal tissues of a patient with clinically confirmed coronavirus disease 2019 (COVID-19) with rectal adenocarcinoma. METHODS: The clinical data were collected during hospitalization and follow-up of this patient. Quantitative reverse transcriptase-polymerasechain reaction (RT-PCR) was performed on the rectal tissue specimens obtained from surgical resection, succus entericus and intestinal mucosa of ileostomy, and rectal mucosa during follow-up after recovery. Ultrathin sections of surgical samples were observed for SARS-CoV-2 virions using electron microscopy. Histopathological examination was performed using hematoxylin-eosin stain. Immunohistochemical analysis and immunofluorescence were carried out on rectal tissues to evaluate the distribution of SARS-CoV-2 antigen and immune cell infiltrations. RESULTS: The patient had fever and cough on day 3 postoperatively, was diagnosed with COVID-19 on day 7, and was discharged from the hospital on day 41. RNA of SARS-CoV-2 was detected in surgically resected rectal specimens but not in samples collected 37 days after discharge. Notably, coincident with rectal tissues of surgical specimens testing nucleic acid positive for SARS-CoV-2, typical coronavirus virions in rectal tissue were observed under electron microscopy. Moreover, abundant lymphocytes and macrophages (some were SARS-CoV-2 positive) infiltrating the lamina propria were found with no significant mucosal damage. CONCLUSIONS: We first report the direct evidence of active SARS-CoV-2 replication in a patient's rectum during the incubation period, which might explain SARS-CoV-2 fecal-oral transmission.

Assessment of probiotic adhesion and inhibitory effect on Escherichia coli and Salmonella adhesion.

In this study, we screened bacterial strains to identify specific probiotics to treat pig diarrhea caused by Escherichia coli or Salmonella. The potential probiotics were assayed for their survival in gastrointestinal solution, their antimicrobial activity, cell-surface properties, adhesion to Caco-2 cells, and inhibition of pathogen adhesion. Nine out of the 20 strains tested showed high tolerance of a simulated gastrointestinal environment and six strains exerted antagonistic effects against enterohemorrhagic E. coli (EHEC) O157:H7 and Salmonella Typhimurium MQ. Lactobacillus johnsonii pDX1e exhibited a higher potent antibacterial activity. Four strains (pDX1a, pDX1e, pDX3a, and pDX5a) displayed auto-aggregation, hydrophobicity, and adhesion to Caco-2 cells similar to those of the reference strain Lacticaseibacillus rhamnosus GG (LGG). Enterococcus durans pDX5a showed the highest adhesion capacity (13.86%), followed by the reference strain LGG (11.20%). All the tested strains competitively suppressed the attachment of pathogens to Caco-2 cells (by 30.73-55.18%); L. johnsonii pDX1e and Ent. durans pDX5a significantly inhibited the adhesion of pathogens by substitution and exclusion, respectively. Therefore, pDX1e and pDX5a were selected as probiotic strains for further investigation and application.

Commonality of adherent-invasive Escherichia coli isolated from patients with extraintestinal infections, healthy individuals and the environment.

Adherent-invasive Escherichia coli (AIEC) has been implicated as a microbiological factor in inflammatory bowel disease (IBD) pathogenesis. These strains are defined by their ability to adhere to and invade intestinal epithelial cells, and to survive and replicate in macrophages. We postulated that AIEC strains may commonly inhabit the gut of healthy individuals (HI), cause extraintestinal infections, and be found in sewage treatment plants (STP) and surface waters (SW). A total of 808 E. coli strains isolated from HI; patients with community-acquired urinary tract infection (CA-UTI), septicaemia and urosepsis; STP; and SW, showing a diffuse adhesion pattern to Caco-2 cells were included in this study. Typing of the strains using a combination of RAPD-PCR and PhPlate fingerprinting grouped them into 48 common clones (CCs). Representatives of each CC were tested for the ability to invade Caco-2 cells, survive and replicate in macrophages, and for the presence of six virulence genes commonly found among AIEC strains. Twenty CCs were deemed AIEC based on their ability to survive and replicate in macrophages, while encoding htrA, dsbA and clbA genes. These CCs primarily originated from HI and CA-UTI patients but were also detected in secondary locations including STP and SW. Strains lacking intramacrophagic survival and replication abilities were regarded as diffusely adhering E. coli (DAEC). Certain clones of AIEC are common in the gut of HI whilst promoting CA-UTI. The survival and persistence of AIEC in STP and SW may have serious public health ramifications for individuals predisposed to IBD.

Elective Caesarean Delivery Associated with Infant Hospitalisation for Intestinal But Not Respiratory Infection.

OBJECTIVES: We assessed the impact of caesarean delivery on offspring respiratory and intestinal infection. METHODS: Data were extracted from all live births (n = 429,058) occurring in the Australian state of Queensland between January 2009 and December 2015, and followed for 12 months. Births were categorised as either non-medically indicated caesarean or vaginal delivery and each offspring had a record (present/absent) of respiratory and intestinal infection hospitalisation for each month from birth to 12 months. RESULTS: Infants delivered by non-medically indicated caesarean were more likely to experience respiratory infection [OR = 1.51 (1.15, 1.99)] and intestinal infection [OR = 1.74 (1.19, 2.55)] than those born by vaginal delivery. In the propensity score weighted analyses the estimate for respiratory infection was similar but non-significant [OR = 1.52 (0.99, 2.31)], while the association with intestinal infection strengthened [OR = 2.21 (1.25, 3.89)]. CONCLUSIONS FOR PRATICE: Our findings provide strong evidence for a specific and clinically meaningful link between non-medically indicated caesarean delivery and infant intestinal infection.

Daily consumption of a homeopathic product decreases intestinal damage and stool bacterial counts in mice challenged with Escherichia coli.

Escherichia coli is a bacterium normally found in the gastrointestinal tract of domestic animals that can usually control the infection. Nevertheless, some factors (high exposure, stress conditions, animal category, among others) can favor the exacerbation of E. coli infection and cause of disease. Because it is a zoonotic bacterium, it is important to control the infection, avoiding contamination of home interiors in the case of pets. There are various forms of treatment for E. coli; nevertheless, there are few options for prevention. In the present study, we evaluated homeopathy. Thus, the objective of this study was to determine whether administration of a prophylactic homeopathic in water would minimize the negative effects of E. coli infection, as well as reducing bacterial counts in the feces of a experimental model. Forty mice were divided into four experimental groups (n = 10/group). Groups NC (negative control) and PC (positive control) were not treated; in group T1, the animals received 0.002 mL/day/animal of the homeopathic in water, and animals in group T2 0.004 mL/day/animal. The experiment lasted 54 days, and on the 31st day, mice of T1, T2 and PC groups were infected orally a 0.2 mL inoculum of 1.5 × 108 CFU of E. coli. Euthanasia and sample collection were performed on the 40th and 54th days of the experiment (n = 5/group/time point). Blood, liver, spleen, intestine, and feces samples were collected from the final portion of the intestine. There was no significant difference in animal weight between groups at the end of the experiment. Neutrophil count was lower in PC group animals on day 40, while on day 54, the counts were lower in T2 and PC. Lymphocyte counts were lower only in the PC group than in the NC group on day 54. Globulins were lower in the NC and PC groups than in T1 and T2 on day 40, remaining lower the PC group and higher in T1 on day 54; levels of immunoglobulin IgG and IgM were higher in groups T1 and T2, which differed from PC and NC. TNF-α levels were higher in the T1 and T2 groups at 40 and 54 days. INF-γ levels were higher in T1, T2, and PC compared to NC on day 40, remaining higher than NC in groups T1 and T2 on day 54. Total bacterial count, total coliforms and E. coli counts were lower in group T1 and higher in NC and PC on days 40 and 54, when they were lower for T1 and T2. Histologically, no lesions were observed in extra-intestinal tissues; however the height of intestinal crypts in the PC group was smaller than the others on day 40. On day 54, villi and crypts of all infected groups were larger in T1 and T2 than in NC; sizes in the PC group were higher than those of all other groups. These data suggest that the homeopathic agent in the drinking water improved health of the mice.

Dysregulated haemolysin promotes bacterial outer membrane vesicles-induced pyroptotic-like cell death in zebrafish.

Inflammasomes are important innate immune components in mammals. However, the bacterial factors modulating inflammasome activation in fish, and the mechanisms by which they alter fish immune defences, remain to be investigated. In this work, a mutant of the fish pathogen Edwardsiella piscicida (E. piscicida), called 0909I, was shown to overexpress haemolysin, which could induce a robust pyroptotic-like cell death dependent on caspase-5-like activity during infection in fish nonphagocyte cells. E. piscicida haemolysin was found to mainly associate with bacterial outer membrane vesicles (OMVs), which were internalised into the fish cells via a dynamin-dependent endocytosis and induced pyroptotic-like cell death. Importantly, bacterial immersion infection of both larvae and adult zebrafish suggested that dysregulated expression of haemolysin alerts the innate immune system and induces intestinal inflammation to restrict bacterial colonisation in vivo. Taken together, these results suggest a critical role of zebrafish innate immunity in monitoring invaded pathogens via detecting the bacterial haemolysin-associated OMVs and initiating pyroptotic-like cell death. These new additions to the understanding of haemolysin-mediated pathogenesis in vivo provide evidence for the existence of noncanonical inflammasome signalling in lower vertebrates.

Quorum-sensing regulator RhlR but not its autoinducer RhlI enables Pseudomonas to evade opsonization.

When Drosophila melanogaster feeds on Pseudomonas aeruginosa, some bacteria cross the intestinal barrier and eventually proliferate in the hemocoel. This process is limited by hemocytes through phagocytosis. P. aeruginosa requires the quorum-sensing regulator RhlR to elude the cellular immune response of the fly. RhlI synthesizes the autoinducer signal that activates RhlR. Here, we show that rhlI mutants are unexpectedly more virulent than rhlR mutants, both in fly and in nematode intestinal infection models, suggesting that RhlR has RhlI-independent functions. We also report that RhlR protects P. aeruginosa from opsonization mediated by the Drosophila thioester-containing protein 4 (Tep4). RhlR mutant bacteria show higher levels of Tep4-mediated opsonization, as compared to rhlI mutants, which prevents lethal bacteremia in the Drosophila hemocoel. In contrast, in a septic model of infection, in which bacteria are introduced directly into the hemocoel, Tep4 mutant flies are more resistant to wild-type P. aeruginosa, but not to the rhlR mutant. Thus, depending on the infection route, the Tep4 opsonin can either be protective or detrimental to host defense.

Potential clinical use of azithromycin against gastroenteritis-causing pathogens other than Campylobacter.

The activity of azithromycin against enteritis-producing agents other than Campylobacter spp. was studied. The susceptibility to azithromycin, through gradient test, of 88 clinical isolates (51 Salmonella spp., 23 Aeromonas spp., 10 Shigella sonnei and 4 Yersinia enterocolitica) for one year was studied prospectively. The results were compared with the activity of ampicillin, trimethoprim-sulfamethoxazole and ciprofloxacin by microdilution. For azithromycin, the minimum inhibitory concentration (MIC) 50 and MIC90 were 4 and 12 mg/l, respectively. Six (6.8%) isolates were simultaneously resistant to ampicillin, trimethoprim- sulfamethoxazole and ciprofloxacin, and 3 (50%) of them presented a MIC >256 mg/l. Azithromycin may be a good empirical therapeutic option for the treatment of bacterial enteritis.

The role of midgut nonspecific esterase in the susceptibility of Galleria mellonella larvae to Bacillus thuringiensis.

Some mechanisms of resistance to Bacillus thuringiensis, including esterase activity in the midgut, can appear in laboratory and field insect populations. We found that B. thuringiensis infection significantly reduced the esterase activity in the midgut of greater wax moth Galleria mellonella 48 h post infection. Esterase activity was inhibited 1.5-fold by triphenyl phosphate to test the impact of the enzyme in resistance to the bacteria. Bioassays demonstrated that pre-exposure of the insects to triphenyl phosphate followed by bacterial infection resulted in two-fold elevated susceptibility of the greater wax moth larvae to B. thuringiensis.

[The Role of Ecological Factors in Acute Enteric Infection Morbidity of Population of the People's Republic of Bangladesh].

The studying of influence of natural factors on distribution of acute intestinal infections in the territory of the People's Republic of Bangladesh was organized and carried out for the first time. Bangladesh is one of the most densely populated countries in the world. The country occupies the 8th place of population density making up to 1237,51 people per km2. It is one of the poorest states in Asia with annual income per capita $520 (as of 2008) whereas the average world income per capita makes up to $10 200. One more feature of Bangladesh is the country annually is exposed to large number of natural disasters and the most frequent is flood. The dense population, poverty, unsatisfactory sanitary and hygienic conditions, illiteracy promote wide circulation in Bangladesh of acute intestinal infections which take first place in the structure of general incidence of the population of the country. It is shown that the nature of spread of acute intestinal infections in the country is defined by ecological, demographic, social and economic and sanitary and hygienic factors. As a result of a complex ecological hygienic research of the causes of wide circulation of acute intestinal diseases among population of the country the correlation relationship between natural features, social and ecological conditions and incidence for each of 64 administrative regions of the People's Re-public of Bangladesh were revealed. On the basis of the obtained regularities the recommendations were submitted to decrease epidemiological tension in the country related to diarrheal diseases.

Experimental bovine rotavirus-A (RV-A)infection causes intestinal and extra-intestinal pathology in suckling mice.

We describe here the intestinal and extra-intestinal spread of the species A rotavirus (RV-A) and associated lesions thereof in Swiss albino suckling mice pups, inoculated with a bovine-origin RV-A strain. In total, 35 suckling pups were used, wherein 20 pups received cell culture isolated RV-A @ 160 µL (TCID50/ml, 5 × 106.5) per pup [oral 80 µL and intra peritoneal (IP) 80 µL] and served as an infected group, while 15 pups were kept in the control group and inoculated the same volume of phosphate buffered saline (PBS) of neutral pH orally and IP. Four pups from the infected group and 3 from control group were sacrificed at 3, 5, 7, 9 and 12 day post infection (DPI). Of note, infected pups exhibited signs of dullness and restlessness till 5DPI, but none showed diarrhea at any point of time. No appreciable gross lesions were evident in any of the organs, except for mild congestion of the small intestine and yellowish catarrhal smearing over the luminal surface. However, light microscopic lesions in hematoxylin and eosin (H&E) stained sections of jejunum and ileum revealed vacuolation and pyknosis of nuclei of the mature enterocytes, their lysis and detachment, constriction and detachment of villi, mild mononuclear cells (MNCs) infiltration in the lamina propria and mildcell depletion of Peyer's patches and mesenteric lymph nodes (MLN). The extra-intestinal lesions of the cellular degeneration and mild MNCs infiltration were identified in the liver and kidneys from 3 to 7 DPI, but no lesion was seen in the brain. Interstitial thickening with MNCs of lung parenchyma was visible from 3 to 7 DPI. The lesions in the intestine, lymphoid tissues and lungs resolved after 7 DPI. The presence of viral nucleic acid was seen in the intestinal contents from 3 to 5 DPI by using a RV-A specific reverse-transcription polymerase chain reaction (RT-PCR), while in the MLNs and the lungs it could be detected till 5 DPI by both the RT-PCR and direct fluorescent antigen test (dFAT). However, liver, spleen and brain were tested negative for the presence of RV-A by any of these tests. Nonetheless, the persistence of the RV-A was seen in the MLNs even after the absence of virus from the small intestines. Findings here conclusively indicates that heterologous host origin RV-A has an affinity not only to the intestine but also to extra-intestinal tissues like MLNs and lung tissues.

[Gastro-intestinal infections with Clostridium difficile in the elderly]. / Les infections digestives à Clostridium difficile chez la personne âgée.

In view of its high frequency and its consequences which can be dramatic for patients, it is necessary to know how to identify Clostridium difficile infection. The high risk of an epidemic means it is especially important to know how to treat it, in terms of the hygiene and isolation rules, as well as which medication to use.

[Identification of Shiga toxin in patients with acute intestinal infections in the presence of mono- and mixed-O-antigens of pathogens]. / Vyiavlenie Shiga-toksina u bol'nykh ostrymi kishechnymi infektsiiami v prisutstvii mono- i mikst-O-antigenov vozbuditelei.

AIM: To investigate the time course of changes in the detection rates and levels of Shiga toxin antigen (STA) in their stool and middle-molecule circulating immune complexes (CICs) containing IgG (IgG CIC) in patients with acute intestinal infections (AIIs) in the presence of the body's circulation of mono- and mixed-LPS/O-antigens of intestinal pathogens. SUBJECTS AND METHODS: A total of 147 patients aged 15 to 55 years who had been hospitalized with AIIs were examined. The diagnosis was bacteriologically verified in 19% of the patients; in the others, it was confirmed by the detection of LPS/O-antigens of Shigella, Salmonella, Yersinia, and Campylobacter in their stool by means of the reaction of coagglutination (RCA) on glass slides. Plates for RCA displayed STA in the fecal and IgG CIC samples. RESULTS: Mono- and mixed infections were detected in 32 and 68%, respectively. The RCA plates exhibited STA in 25.2% of the fecal samples and in 90.5% of the IgG CIC ones from patients with AIIs and did not in those from donors. In monoinfection, the detection rates and levels of STA in the feces became lower in the course of the disease and remained unchanged in IgG CIC and the levels of STA also decreased in the feces, but increased in IgG CIC in mixed infection. CONCLUSION: In 25.2% of the patients with early AIIs, their stools show free STA; its detection rate and levels are significantly higher in mixed infections than those in monoinfection. The level of STA in serum IgG CIC was significantly higher in mixed infection, suggesting an active immune response to the pathogen. Given that the Shiga toxin-producing strains are present in patients with AIIs, caution should be exercised in the choice of an antibacterial drug to prevent horizontal gene transfer and to enhance toxin production and the body's intoxication. One of the advantages of RCA is the possibility of rapidly changing the spectrum of test systems, depending on the region of their application and the epidemiological situation.