Gastrointestinal Colonization Research Articles

Inflammatory Immune Responses and Gut Microbiota Changes Following Campylobacter coli Infection of IL-10-/- Mice with Chronic Colitis.

Human infections with the food-borne enteropathogens Campylobacter are progressively rising. Recent evidence revealed that pre-existing intestinal inflammation facilitates enteropathogenic infection subsequently exacerbating the underlying disease. Given that only little is known about C. coli–host interactions and particularly during intestinal inflammation, the aim of the present study was to survey gastrointestinal colonization properties, gut microbiota changes and pro-inflammatory sequelae upon peroral C. coli-infection of IL-10-/- mice with chronic colitis. C. coli colonized the gastrointestinal tract of mice with varying efficiencies until day 28 post-infection and induced macroscopic and microscopic inflammatory changes as indicated by shorter colonic lengths, more distinct histopathological changes in the colonic mucosa and higher numbers of apoptotic colonic epithelial cells when compared to mock-infected controls. Furthermore, not only colonic innate and adaptive immune cell responses, but also enhanced systemic TNF-α secretion could be observed following C. coli as opposed to mock challenge. Notably, C. coli induced intestinal inflammatory sequelae were accompanied with gut microbiota shifts towards higher commensal enterobacterial loads in the infected gut lumen. Moreover, the pathogen translocated from the intestinal tract to extra-intestinal tissue sites in some cases, but never to systemic compartments. Hence, C. coli accelerates inflammatory immune responses in IL-10-/- mice with chronic colitis.

Kpi, a chaperone-usher pili system associated with the worldwide-disseminated high-risk clone Klebsiella pneumoniae ST-15

Control of infections caused by carbapenem-resistant Klebsiella pneumoniae continues to be challenging. The success of this pathogen is favored by its ability to acquire antimicrobial resistance and to spread and persist in both the environment and in humans. The emergence of clinically important clones, such as sequence types 11, 15, 101, and 258, has been reported worldwide. However, the mechanisms promoting the dissemination of such high-risk clones are unknown. Unraveling the factors that play a role in the pathobiology and epidemicity of K. pneumoniae is therefore important for managing infections. To address this issue, we studied a carbapenem-resistant ST-15 K. pneumoniae isolate (Kp3380) that displayed a remarkable adherent phenotype with abundant pilus-like structures. Genome sequencing enabled us to identify a chaperone-usher pili system (Kpi) in Kp3380. Analysis of a large K. pneumoniae population from 32 European countries showed that the Kpi system is associated with the ST-15 clone. Phylogenetic analysis of the operon revealed that Kpi belongs to the little-characterized γ2-fimbrial clade. We demonstrate that Kpi contributes positively to the ability of K. pneumoniae to form biofilms and adhere to different host tissues. Moreover, the in vivo intestinal colonizing capacity of the Kpi-defective mutant was significantly reduced, as was its ability to infect Galleria mellonella The findings provide information about the pathobiology and epidemicity of Kpi+K. pneumoniae and indicate that the presence of Kpi may explain the success of the ST-15 clone. Disrupting bacterial adherence to the intestinal surface could potentially target gastrointestinal colonization.

Prevalence of Carbapenem-Resistance among Enterobacteriaceae Isolated from Patients Attending Uduth Sokoto, North West Nigeria

The major problem threatening the continued success of antimicrobial drugs is the development of resistant organisms. This study was designed to determine the occurrence and prevalence of carbapenem resistance among enterobacteriaceae isolated from in-patients attending Usmanu Danfodiyo University Teaching Hospital (UDUTH) Sokoto, and also to determine the antimicrobial susceptibility patterns of the organisms isolated. The Methodology involves the use of trypticase soy broth containing 10 μg of carbapenem (imipenem) for primary isolation. The secondary isolation involves the use of MacConkey agar and biochemical (Simmon citrate Agar) for identification, and then antimicrobial susceptibility testing by the disk diffusion method. A total of 191 stool samples from male and female in-patients within the range of 2-60 years were screened for the gastrointestinal colonization of Carbapenem Resistance Enterobacteriacea (CRE). Data were analysed using Statistical Package for Social Sciences (SPSS) windows version 21. The overall prevalence was 15.7% The prevalence rate was found exclusively in males. The highest prevalence was found within the age group of 30-40 years. Escherichia coli, Klebsiella species, Pseudomonas species and salmonella species were the bacteria isolated. The most predominant bacteria isolated were Escherichia coli, accounting for 85 (9.4%) resistant strains, Klebsiella species accounting for 50 (8%) resistant strain, Pseudomonas aeruginosa 21% and Salmonella species accounting for 42 (0%) no resistant strain isolated. The misuse of antibiotics is a major factor responsible for the high rate of bacterial resistance. Improvement on the management and personal hygiene, as well as the appropriate use of antibiotics would reduce the prevalence of Nosocomial Carbapenem Resistance (NCR) especially among prolonged hospitalized patients.

Effect of Alfalfa Hay and Starter Feeding Intervention on Gastrointestinal Microbial Community, Growth and Immune Performance of Yak Calves.

The present study aims to evaluate the effects of different early weaning paradigms, which supplied with extra alfalfa hay, or starter feeding, or both alfalfa hay and starter feeding, along with the milk replacer, on the gastrointestinal microbial community, growth, and immune performance of yak calves. Twenty 30-day-old male yak calves were randomly assigned to four groups, including the control (CON), alfalfa hay (A), starter feeding (S), and starter plus alfalfa hay (SA) groups. The gastrointestinal microbial colonization, the gastrointestinal development and function, and the growth and immune performance of all the yak calves were separately measured. Supplementation with alfalfa and starter feeding during the pre-weaning period significantly increased body weight, body height, body length, and chest girth. The significantly improved rumen fermentation and promoted intestinal digestion-absorption function in alfalfa and starter feeding groups, including the identified significantly increased concentrations of ruminal total volatile fatty acid (VFA); the significantly increased concentrations and proportions of acetate, butyrate, and isovalerate; the increased α-amylase activities in the duodenum, jejunum, and ileum; the increased papillae length and width of rumen epithelium and rumen wall thickness; and the increased villus height and crypt depth of the duodenum, jejunum, and ileum, could all contribute to promote the growth of calves. These significant improvements on rumen fermentation and intestinal digestion-absorption function could be further attributed to the increased proliferation of starch-decomposing, and cellulose- or hemicellulose-decomposing bacteria identified in the rumen, jejunum, and ileum. Furthermore, based on the expression of intestinal inflammatory cytokines and the rumen epithelial RNA sequencing results, alfalfa supplementation reduced the occurrence of ruminal and intestinal inflammation, whereas starter feeding supplementation was mainly beneficial to the differentiation of immune cells and the improved immune function. Meanwhile, the significantly altered relative abundances of genera in the SA group, including increased relative abundance of Limnobacter, Escherichia/Shigella, and Aquabacterium in the rumen and increased relative abundance of Coprococcus, Pseudobutyrivibrio, Flavonifractor, Synergistes, and Sutterella in jejunum, were able to reduce gastrointestinal inflammation and enhance the immune function, which enhanced the immune function of the yak calves fed with alfalfa and starter feeding. Overall, milk replacer supplemented with alfalfa and starter feeding during the pre-weaning period could alter gastrointestinal microbiota and then benefit the gastrointestinal development, digestion-absorption function, growth, and immune performance of the yak calves.

Determination of gastrointestinal tract colonization sites from feedlot cattle transiently shedding or super-shedding Escherichia coli O157:H7 at harvest.

The objective of the study was to determine levels of Escherichia coli O157:H7 colonization in the gastrointestinal tract (GIT) of naturally shedding cattle shedding the pathogen at low- or super-shedder levels. Over 2years, feedlot cattle were sampled multiple times for faecal shedding of E. coli O157:H7. Just prior to harvest (1-2days), animals that were super-shedders (≥104 CFU per gram of faeces) were specifically identified, and based on the longer term screening data, pen cohorts that were low-shedders (years 1 and 2) or chronic-shedders (year 1) were also identified. At harvest, samples were collected from throughout the GIT, including the rectoanal junction (RAJ) for enumeration and enrichment of E. coli O157:H7. The mouth samples exhibited the greatest prevalence for the pathogen, and the abomasum and rumen exhibited the lowest prevalence (P<0·05). Super-shedders had significantly greater prevalence for all GIT locations except the mouth and abomasum compared to low-shedders, but the super-shedders were the only animals with positive abomasum samples. Samples from the super-shedders were enumerable for most GIT locations, and the rectum and RAJ locations were the only locations that were significantly greater than other locations (P<0·05). Across all animals naturally exposed to E. coli O157:H7, the risk of ingestion is high, but rumen and abomasum are potential barriers to passage. In super-shedders, the passage through the GIT was greater, allowing colonization in the rectum and at the RAJ. Escherichia coli O157:H7 low-shedding cattle had lower pathogen levels throughout the GIT, indicating intrinsic GIT factors to these cattle may reduce pathogen passage through the GIT, including the abomasum, and minimize risk of RAJ colonization.

Breastfeeding may have a long-term effect on oral microbiota: results from the Fin-HIT cohort

BackgroundBreastfeeding contributes to gastrointestinal microbiota colonization in early life, but its long-term impact is inconclusive. We aimed to evaluate whether the type of feeding during the first six months of life was associated with oral microbiota in adolescence.MethodsThis is a cross-sectional sub-study using baseline information of 423 adolescents from the Finnish Health in Teens (Fin-HIT) cohort. Type of feeding was recalled by parents and dichotomized as (i) No infant formula; (ii) Infant formula (breastmilk + formula or only formula). Saliva microbiota was analysed using 16S rRNA (V3–V4) sequencing. Alpha diversity and beta diversity were compared between feeding type groups using ANCOVA and PERMANOVA, respectively. Differential bacteria abundance was tested using appropriate general linear models.ResultsMean age and body mass index were 11.7 years and 18.0 kg/m2, respectively. The No formula group contained 41% of the participants. Firmicutes (51.0%), Bacteroidetes (19.1%), and Proteobacteria (16.3%) were the most abundant phyla among all participants. Alpha and beta diversity indices did not differ between the two feeding groups. Three Operational Taxonomic Units (OTUs) belonging to Eubacteria and Veillonella genera (phylum Firmicutes) were more abundant in the No formula than in the Infant formula group (log2fold changes/ p - values − 0.920/ < 0.001, − 0.328/ 0.001, − 0.577/ 0.004).ConclusionDifferences exist in abundances of some OTUs in adolescence according to feeding type during the first six months of life, but our findings do not support diversity and overall oral microbiota composition in adolescents being affected by early feeding type.

Gastrointestinal Tract Colonization Rate of Extended-Spectrum Beta-Lactamase- and Carbapenemase-Producing Enterobacteriaceae and Associated Factors Among Hospitalized Patients in Arba Minch General Hospital, Arba Minch, Ethiopia.

BackgroundThe incidence of hospital-acquired enterobacteria that produce extended-spectrum beta-lactamases (ESBLs) is on the rise worldwide. Colonization of gastrointestinal tract by extended-spectrum beta-lactamase Enterobacteriaceae, a prominent causative agent, results in life-threatening infections.ObjectiveTo determine the rate of gastrointestinal colonization by extended-spectrum beta-lactamase- and carbapenemase-producing Enterobacteriaceae and also to elucidate the antibiotic susceptibility profile and associated risk factors among hospitalized patients in Arba Minch General Hospital, Ethiopia.MethodologyA facility-based cross-sectional study was conducted in Arba Minch General Hospital from May 2018 to July 2019. Sociodemographic data and associated factors were collected using a pre-tested-structured questionnaire. Stool specimens were collected using sterile stool cups. Each sample was then inoculated onto MacConkey agar. Bacterial isolates were identified using various biochemical tests. Screening and confirmatory tests for extended-spectrum beta-lactamase- and carbapenemase-producing Enterobacteriaceae were performed using the modified Kirby–Bauer disc diffusion technique. Statistical package for Social Science was used to analyze the data. The P-value ≤0.05 was considered as statistically significant.ResultsA total of 421 hospitalized patients were enrolled in this study of which there were 240 (57%) females. The mean age of the study participants was 28.8 with SD of 15.7. Majority of participants were in the age range of 25–40 years 179 (42.5%). About 146 (34.7%) participants were found to be colonized by extended-spectrum beta-lactamase-producing Enterobacteriaceae. The predominant ESBL-producing isolates were Escherichia coli 62 (42.46%) followed by Klebsiella pneumoniae 60 (41.09%). Six (1.43%) carbapenemase-producing K. pneumoniae were isolated. ESBL-producing Enterobacteriaceae showed higher resistance against tetracycline (91.1%) and cotrimoxazole (93.84%). Colonization of the gastrointestinal tract by ESBL showed statistically significant association with regard to chronic diseases (p<0.001) and the administration of oral antibiotics after admission (p=0.020).ConclusionThe overall colonization rate of the gastrointestinal tract by extended-spectrum beta-lactamase-producing Enterobacteriaceae was prominent. The extended-spectrum beta-lactamase-producing isolates exhibited a higher level of resistance against the commonly used antibiotics which further needs greater attention.

The Paralogous Transcription Factors Stp1 and Stp2 of Candida albicans Have Distinct Functions in Nutrient Acquisition and Host Interaction.

Nutrient acquisition is a central challenge for all organisms. For the fungal pathogen Candida albicans, utilization of amino acids has been shown to be critical for survival, immune evasion, and escape, while the importance of catabolism of host-derived proteins and peptides in vivo is less well understood. Stp1 and Stp2 are paralogous transcription factors (TFs) regulated by the Ssy1-Ptr3-Ssy5 (SPS) amino acid sensing system and have been proposed to have distinct, if uncertain, roles in protein and amino acid utilization. We show here that Stp1 is required for proper utilization of peptides but has no effect on amino acid catabolism. In contrast, Stp2 is critical for utilization of both carbon sources. Commensurate with this observation, we found that Stp1 controls a very limited set of genes, while Stp2 has a much more extensive regulon that is partly dependent on the Ssy1 amino acid sensor (amino acid uptake and catabolism) and partly Ssy1 independent (genes associated with filamentous growth, including the regulators UME6 and SFL2). The ssy1Δ/Δ and stp2Δ/Δ mutants showed reduced fitness in a gastrointestinal (GI) colonization model, yet induced greater damage to epithelial cells and macrophages in a manner that was highly dependent on the growth status of the fungal cells. Surprisingly, the stp1Δ/Δ mutant was better able to colonize the gut but the mutation had no effect on host cell damage. Thus, proper protein and amino acid utilization are both required for normal host interaction and are controlled by an interrelated network that includes Stp1 and Stp2.

Are Clostridioides difficile infections being overdiagnosed in hematopoietic stem cell transplant recipients?

Because both diarrhea due to other causes and gastrointestinal colonization with toxigenic Clostridioides difficile are common in HSCT, there is a possibility of false-positive diagnoses of Cdifficile infections (CDI). We estimated the probability of a patient being colonized by toxigenic Cdifficile by testing non-diarrheal surveillance stools from 223 HSCT recipients and the probability that a specimen submitted for Cdifficile testing was not CDI by determining the number of clinical tests that returned negative from this cohort. The number of expected false-positive CDI was estimated using these probabilities and compared with observed clinical test results. The expected false-positive and the observed numbers of positive clinical results were similar. The 20 patients diagnosed with CDI were also similar to 142 patients with diarrhea and Cdifficile-negative stools in number of stools on day of testing, associated symptoms, and the recorded number of days to formed stools. Cdifficile colonization was most commonly detected during the first week and CDI during the second. Retrospective analysis of 837 patients showed that 18 stools were submitted for each diagnosis of CDI. Ribotyping of the surveillance samples showed 17 ribotypes. Although several assumptions could impact the accuracy of our false-positive CDI estimates, it appears that many HSCT recipients diagnosed with CDI may actually represent colonized status and an alternative cause of diarrhea. Diagnostic stewardship, including limiting CDI diagnoses to patients with positive toxin and restricting stool submissions to patients with more severe symptoms, may decrease the number of false-positive diagnoses.

A new use of Lactobacillus rhamnosus GG administration in the NICU: colonized vancomycin-resistant enterococcus eradication in the gastrointestinal system

Introduction Enterococci are microbiota microorganisms that normally have low virulence; however, under some conditions they may cause community-acquired urinary tract and even hospital-acquired serious infections. Vancomycin-resistant enterococci (VRE) can cause aggressive infections in immunosuppressive patients; especially in newborns in intensive care units. Asymptomatic gastrointestinal system carriers are important sources of VRE. Asymptomatic patients colonized by VRE can infect both other patients and the environment. Prevention of gastrointestinal colonization of VRE is an important issue to prevent VRE infection, and for rational use of hospital source. Method This study was carried out at Hacettepe University, Faculty of Medicine in Newborn Intensive Care Unit between November 2015 and March 2017. The newborn infants who were find as colonized by VRE during weekly surveillance VRE rectal stool culture screening were taken into the study. A single dose of one million colonies of Lactobacillus rhamnosus GG (LGG®) was given to the study group daily. The probiotic supplement continued until consecutive three negative cultures were detected or maximum 6 months. Control group received conventional treatment. Results In the study group, VRE eradication was successful in 21 patients out of 22 within 6 months and 1 patient was still VRE positive at 6 months. In the control group, VRE was eradicated in 12 patients out of 23 and 11 patients continued to be colonized by VRE at 6 months. There was a statistically significant difference between the groups (p <.05). Conclusion Lactobacillus rhamnosus GG use is associated with early clearance of vancomycin-resistant enterococcus in newborn patients.

Maternal and Perinatal Factors Associated with the Human Milk Microbiome.

ABSTRACTMicrobes are present in human milk regardless of the mother's health. The origins of the milk microbiota likely include the mother's skin, infant's mouth, and transfer from the maternal gastrointestinal (GI) tract. Prominent bacterial taxa in human milk are Staphylococcus and Streptococcus, but many other genera are also found including anaerobic Lactobacillus, Bifidobacterium, and Bacteroides. The milk microbiome is highly variable and potentially influenced by geographic location, delivery mode, time postpartum, feeding mode, social networks, environment, maternal diet, and milk composition. Mastitis alters the milk microbiome, and the intake of Lactobacilli has shown potential for mastitis treatment and prevention. Although milk and infant fecal microbiomes are different, their variations appear to be related – suggesting that milk is an important contributor of early GI colonization. Nonetheless, nothing is known regarding whether the milk microbiome influences infant health. Further research and clinical interventions are needed to determine if changes in the microbiomes of human milk and infant formula/food impact health.

Virulence assessment of six major pathogenic Candida species in the mouse model of invasive candidiasis caused by fungal translocation

Gastrointestinal colonization has been considered as the primary source of candidaemia; however, few established mouse models are available that mimic this infection route. We therefore developed a reproducible mouse model of invasive candidiasis initiated by fungal translocation and compared the virulence of six major pathogenic Candida species. The mice were fed a low-protein diet and then inoculated intragastrically with Candida cells. Oral antibiotics and cyclophosphamide were then administered to facilitate colonization and subsequent dissemination of Candida cells. Mice infected with Candida albicans and Candida tropicalis exhibited higher mortality than mice infected with the other four species. Among the less virulent species, stool titres of Candida glabrata and Candida parapsilosis were higher than those of Candida krusei and Candida guilliermondii. The fungal burdens of C. parapsilosis and C. krusei in the livers and kidneys were significantly greater than those of C. guilliermondii. Histopathologically, C. albicans demonstrated the highest pathogenicity to invade into gut mucosa and liver tissues causing marked necrosis. Overall, this model allowed analysis of the virulence traits of Candida strains in individual mice including colonization in the gut, penetration into intestinal mucosa, invasion into blood vessels, and the subsequent dissemination leading to lethal infections.

Anti-Saccharomyces cerevisiae IgG and IgA antibodies are associated with systemic inflammation and advanced disease in hidradenitis suppurativa

Anti-Saccharomyces cerevisiae IgG and IgA antibodies are associated with systemic inflammation and advanced disease in hidradenitis suppurativa

Self-reinoculation with fecal flora changes microbiota density and composition leading to an altered bile-acid profile in the mouse small intestine

BackgroundThe upper gastrointestinal tract plays a prominent role in human physiology as the primary site for enzymatic digestion and nutrient absorption, immune sampling, and drug uptake. Alterations to the small intestine microbiome have been implicated in various human diseases, such as non-alcoholic steatohepatitis and inflammatory bowel conditions. Yet, the physiological and functional roles of the small intestine microbiota in humans remain poorly characterized because of the complexities associated with its sampling. Rodent models are used extensively in microbiome research and enable the spatial, temporal, compositional, and functional interrogation of the gastrointestinal microbiota and its effects on the host physiology and disease phenotype. Classical, culture-based studies have documented that fecal microbial self-reinoculation (via coprophagy) affects the composition and abundance of microbes in the murine proximal gastrointestinal tract. This pervasive self-reinoculation behavior could be a particularly relevant study factor when investigating small intestine microbiota. Modern microbiome studies either do not take self-reinoculation into account, or assume that approaches such as single housing mice or housing on wire mesh floors eliminate it. These assumptions have not been rigorously tested with modern tools. Here, we used quantitative 16S rRNA gene amplicon sequencing, quantitative microbial functional gene content inference, and metabolomic analyses of bile acids to evaluate the effects of self-reinoculation on microbial loads, composition, and function in the murine upper gastrointestinal tract.ResultsIn coprophagic mice, continuous self-exposure to the fecal flora had substantial quantitative and qualitative effects on the upper gastrointestinal microbiome. These differences in microbial abundance and community composition were associated with an altered profile of the small intestine bile acid pool, and, importantly, could not be inferred from analyzing large intestine or stool samples. Overall, the patterns observed in the small intestine of non-coprophagic mice (reduced total microbial load, low abundance of anaerobic microbiota, and bile acids predominantly in the conjugated form) resemble those typically seen in the human small intestine.ConclusionsFuture studies need to take self-reinoculation into account when using mouse models to evaluate gastrointestinal microbial colonization and function in relation to xenobiotic transformation and pharmacokinetics or in the context of physiological states and diseases linked to small intestine microbiome and to small intestine dysbiosis.4XA-zWEeGyrQSh45UEwNDtVideo abstract.

EFG1 Mutations, Phenotypic Switching, and Colonization by Clinical a/α Strains of Candida albicans.

The transcription factor EFG1 functions as a suppressor of white-to-opaque and white-to-gray switching in a/α strains of Candida albicans In a collection of 27 clinical isolates, 4 of the 17 EFG1/EFG1 strains, 1 of the 2 EFG1/efg1 strains, and all 8 of the efg1/efg1 strains underwent white-to-opaque switching. The four EFG1/EFG1 strains, the one EFG1/efg1 strain, and one of the eight efg1/efg1 strains that underwent switching to opaque did not switch to gray and could not be complemented with a copy of EFG1 Competition experiments in a mouse model for gastrointestinal (GI) colonization confirmed that efg1/efg1 cells rapidly outcompete EFG1/EFG1 cells, and in plating experiments, formed colonies containing both gray and opaque cells. Direct microscopic analysis of live cells in the feces, however, revealed that the great majority of cells were opaque, suggesting opaque, not gray, may be the dominant phenotype at the site of colonization.IMPORTANCE Close to half of a collection of 27 clinical a/α isolates of Candida albicans underwent white-to-opaque switching. Complementation experiments revealed that while approximately half of the a/α switchers were due to EFG1 mutations, the remaining half were due to mutations in other genes. In addition, the results of competition experiments in a mouse GI tract colonization model support previous observations that efg1/efg1 cells rapidly outcompete EFG1/EFG1 strains, but direct microscopic analysis reveals that the major colonizing cells were opaque, not gray.

Host-Microbe-Pathogen Interactions: A Review of Vibrio cholerae Pathogenesis in Drosophila.

Most animals maintain mutually beneficial symbiotic relationships with their intestinal microbiota. Resident microbes in the gastrointestinal tract breakdown indigestible food, provide essential nutrients, and, act as a barrier against invading microbes, such as the enteric pathogen Vibrio cholerae. Over the last decades, our knowledge of V. cholerae pathogenesis, colonization, and transmission has increased tremendously. A number of animal models have been used to study how V. cholerae interacts with host-derived resources to support gastrointestinal colonization. Here, we review studies on host-microbe interactions and how infection with V. cholerae disrupts these interactions, with a focus on contributions from the Drosophila melanogaster model. We will discuss studies that highlight the connections between symbiont, host, and V. cholerae metabolism; crosstalk between V. cholerae and host microbes; and the impact of the host immune system on the lethality of V. cholerae infection. These studies suggest that V. cholerae modulates host immune-metabolic responses in the fly and improves Vibrio fitness through competition with intestinal microbes.

Impact of microbiome-based interventions on gastrointestinal pathogen colonization in the intensive care unit.

In the intensive care unit (ICU), colonization of the gastrointestinal tract by potentially pathogenic bacteria is common and often precedes clinical infection. Though effective in the short term, traditional antibiotic-based decolonization methods may contribute to rising resistance in the long term. Novel therapies instead focus on restoring gut microbiome equilibrium to achieve pathogen colonization resistance. This review summarizes the existing data regarding microbiome-based approaches to gastrointestinal pathogen colonization in ICU patients with a focus on prebiotics, probiotics, and synbiotics.

Reduced environmental bacterial load during early development and gut colonisation has detrimental health consequences in Japanese quail

Gastrointestinal colonisation by commensal microbiota is essential for the health and well-being of the host. We aimed to evaluate the influence of a reduced bacterial load environment on microbiota development and maturation, and the possibility of targeted colonisation via at-hatch administration of a selected bacterial strain. Japanese quail (Coturnix japonica) were inoculated within 1 h of hatch with a freshly grown culture of a Lactobacillus agilis isolate derived from a healthy adult quail. Hatchlings were kept in a mouse isolator for one week and then housed between one and four weeks of age, with a flock of normally grown adult quail to expose the bacteria-restricted birds to normal commensal quail bacteria. The bacterial isolate used to inoculate the birds was found to completely dominate the microbiota of the intestine of L.agilis at-hatch inoculated birds. Despite 3 weeks of co-housing of the test birds with an adult flock harbouring normal rich gut microbiota, neither the Lactobacillus inoculated nor PBS inoculated birds reached the level of bacterial diversity seen in birds raised under normal conditions. Neither PBS nor Lactobacillus inoculated birds were able to adopt normal quail microbiota after one week of restricted exposure to bacteria, indicating that contact with diverse microbiota during the early days of gut development in birds is critical for the establishment of healthy intestinal community. Very early intervention in the form of a suitable bacterial probiotic inoculant immediately post-hatch protected birds grown in extreme hygiene conditions from developing anomalous gut microbiota and intestinal damage. Our data shows that it is possible to induce dominance of desired strain using simple timed manipulation.

Carbapenemase-producing Enterobacteriaceae - once positive always positive?

This review provides an overview of gastrointestinal tract colonization with carbapenemase-producing Enterobacteriaceae (CPE), including risk factors for colonization, determinants for duration of colonization, and whether patients can decolonize, either spontaneously or via targeted interventions. CPE colonization is disseminating globally with increasing numbers of carbapenemases being identified in increasing patient cohorts. Numerous risk factors including repeated healthcare contact, patient co-morbidities and international travel have all been linked to increased rates of colonization. Duration of colonization has been investigated in various healthcare settings and ranges many months or even years. Although new methods for expediting decolonization are being investigated, including faecal microbiota transplantation, high quality evidence of impact is lacking. Current evidence indicates that CPE colonization usually persists throughout the duration of most hospital admissions, although the majority of patients will subsequently spontaneously decolonize. Difficulties remain in determining the point at which patients can be considered decolonized because of the lack acceptable criteria for defining eradication. This has significance implications for infection prevention and control measures during the initial and subsequent hospital admissions. Strategies to reduce the healthcare burden of CPE colonization continue to rely predominantly on preventing acquisition, whereas decolonization efforts remain a focus of research.

Incidence of genes encoding vanA/vanB vancomycin resistance in rectal swabs of patients with diagnosed cancer, on the day of admission to hospital, in a non-epidemic period.

IntroductionRapid diagnosis is important for preventing infections due to vancomycin-resistant enterococci.AimTo evaluate the status of gastrointestinal colonisation with strains containing vanA/vanB genes in oncological patients.Material and methodsA total of 167 samples of rectal swabs taken from 161 patients (mean age: 63, range: 29–93 years) were examined, including 113 patients from surgical wards (70.2%) and 48 patients from non-surgical wards (29.8%), with diagnosed cancer. The tests were carried out within 24 h of admitting the patient to the department, using the Cepheid Xpert vanA/vanB test, with a CE marked GeneXpert® Instrument Systems analyser. Samples with positive vanB gene results were additionally seeded on chromogenic media.ResultsThe presence of the vanA gene was found in 2.7% and 6.3% of the examined patients, respectively, from the surgical and non-surgical departments, which accounted for 3.7% of all the patients examined. The presence of the vanB gene was detected in 21.1% of the patients, but in no case was there any growth of vancomycin-resistant enterococci on the chromogenic medium.ConclusionsPatients admitted to non-surgical wards were more often colonised with vanA/vanB genes than were patients admitted to surgical wards, but the differences were not statistically significant.