Colonization Of Gastrointestinal Tract Research Articles

Comparison between Perianal Swab and Stool Specimens for Detecting Colonization with Extended-Spectrum Beta-Lactamase-Producing and Fluoroquinolone-Resistant Enterobacterales.

Stool specimens are frequently used to detect gastrointestinal tract colonization with antimicrobial-resistant enteric bacteria, but they cannot be rapidly collected. Perianal swab specimens can be collected more quickly and efficiently, but data evaluating their suitability as a specimen type for this purpose are sparse. We performed selective culture for extended-spectrum β-lactamase-producing Enterobacterales (ESBL-E) and fluoroquinolone-resistant Enterobacterales (FQRE) using paired perianal swab and stool specimens that were collected within 1 day of each other from hematopoietic cell transplant recipients and patients with acute leukemia. Nineteen (7.6%) of 251 stool specimens yielded ESBL-E and 64 (26%) of 246 stool specimens yielded FQRE. The positive percent agreement of perianal swab specimens compared to stool specimens was 95% (18/19; 95% confidence interval [CI], 74% to 100%) for detecting ESBL-E and 95% (61/64; 95% CI, 87% to 99%) for detecting FQRE. The concordance between specimen types was 98% (95% CI, 97% to 100%). Perianal swabs are a reliable specimen type for surveillance of the gastrointestinal tract for ESBL-E and FQRE.

Gastrointestinal tract Candida spp colonization shows mostly a monoclonal pattern: an intra-patient pilot study.

We genotyped C. albicans, C. parapsilosis, C. tropicalis, and C. glabrata isolates prospectively from rectal swabs to study the gastrointestinal colonization pattern in the patients. Gastrointestinal tract colonization is mostly monoclonal and commonly dominated by one genotype.

The Impact of Escherichia coli Probiotic Strain O83:K24:H31 on the Maturation of Dendritic Cells and Immunoregulatory Functions In Vitro and In Vivo.

Early postnatal events are important for the development of the neonatal immune system. Harboring the pioneering microorganisms forming the microbiota of the neonatal gastrointestinal tract is important for priming the immune system, as well as inducing appropriate tolerance to the relatively innocuous environmental antigens and compounds of normal healthy microbiota. Early postnatal supplementation of suitable, safe probiotics could accelerate this process. In the current study, the immunomodulatory capacity of the probiotic strain of Escherichia coli O83:K24:H31 (EcO83) was characterized in vitro and in vivo. We compared the capacity of EcO83 with and without hemolytic activity on selected immune characteristics in vitro as determined by flow cytometry and quantitative real-time PCR. Both strains with and without hemolytic activity exerted comparable capacity on the maturation of dendritic cells while preserving the induction of interleukin 10 (Il10) expression in dendritic cells and T cells cocultured with EcO83 primed dendritic cells. Early postnatal supplementation with EcO83 led to massive but transient colonization of the neonatal gastrointestinal tract, as detected by in vivo bioimaging. Early postnatal EcO83 administration promoted gut barrier function by increasing the expression of claudin and occludin and the expression of Il10. Early postnatal EcO83 application promotes maturation of the neonatal immune system and promotes immunoregulatory and gut barrier functions.

Preterm Infant with Respiratory Distress, Hypotonia, and Hypoglycemia.

Preterm Infant with Respiratory Distress, Hypotonia, and Hypoglycemia.

Development of an environmental contamination model to simulate the microbial bloom that occurs in commercial hatch cabinets

Microbial blooms that emerge in commercial hatch cabinets consist of apathogenic and pathogenic microorganisms, including Escherichia coli, Enterococcus faecalis, and Aspergillus fumigatus. Objectives of the present study included the development of a multipathogen contamination model to mimic commercial conditions and optimization of sampling methods to quantify bacterial or fungal presence within the hatch cabinet. The pathogen challenge mix (PM) was recreated from select bacterial or fungal isolates recovered from an egg homogenate (EH) derived from the contents of infertile eggs and late embryonic mortalities. Isolates selected for PM included Enterococcus faecalis (∼108 CFU/egg), Staphylococcus aureus (∼107 CFU/egg), Staphylococcus chromogenes (∼107 CFU/egg), Aspergillus fumigatus (∼106 spores/egg), and 2 Escherichia coli (∼108 CFU/egg) isolates. Challenge (100 μL of PM or EH) was administered using a sterile loop to a 28 mm area on the blunt end of the eggshell at day 19 of embryogenesis (DOE). In 3 experiments, microbiological data were collected from environmental hatcher samples (open-agar plate method), fluff samples, postmortem whole-body chick rinse samples, and gastrointestinal tract (GIT) samples to evaluate select bacteria and fungi circulating within the hatch cabinet and colonization of GIT. Cumulative bacterial and fungal recovery from the PM hatching environment from DOE20 to hatch was higher than the nonchallenged group (NC) and EH group at ∼860 and ∼1,730 CFU, respectively. Bacterial recovery from GIT, fluff, and chick rinse samples were similar for the PM and EH group in Exp. 1. However, Aspergillus fumigatus recovery from fluff and chick rinse samples for the PM group was significantly (P < 0.001) higher than the NC and EH group. In Exp. 2 and 3, PM challenge significantly (P < 0.05) increased Gram-negative bacterial recovery from the GIT, fluff and chick rinse samples compared to both the NC and EH group. These data suggest this innovative multispecies environmental contamination model using PM could be utilized to evaluate strategies to mitigate microbial contamination in commercial hatch cabinets in a laboratory setting.

Isolation and Characterization of a Novel Temperate Escherichia coli Bacteriophage, Kapi1, Which Modifies the O-Antigen and Contributes to the Competitiveness of Its Host during Colonization of the Murine Gastrointestinal Tract.

ABSTRACTIn this study, we describe the isolation and characterization of novel bacteriophage vB_EcoP_Kapi1 (Kapi1) isolated from a strain of commensal Escherichia coli inhabiting the gastrointestinal tract of healthy mice. We show that Kapi1 is a temperate phage integrated into tRNA argW of strain MP1 and describe its genome annotation and structure. Kapi1 shows limited homology to other characterized prophages but is most similar to the seroconverting phages of Shigella flexneri and clusters taxonomically with P22-like phages. The receptor for Kapi1 is the lipopolysaccharide O-antigen, and we further show that Kapi1 alters the structure of its host’s O-antigen in multiple ways. Kapi1 displays unstable lysogeny, and we find that the lysogenic state is more stable during growth in simulated intestinal fluid. Furthermore, Kapi1 lysogens have a competitive advantage over their nonlysogenic counterparts both in vitro and in vivo, suggesting a role for Kapi1 during colonization. We thus report the use of MP1 and Kapi1 as a model system to explore the molecular mechanisms of mammalian colonization by E. coli to ask what the role(s) of prophages in this context might be.

P105 Treatment of the lower gastrointestinal tract Klebsiella infections by recombinant bacteriocin KvarIa

Abstract Background Hospital-acquired infections (HAI) are one of the leading worldwide health care issues. The most prevalent HAI are the Klebsiella species. K. quasipneumoniae strains tend to colonize the gastrointestinal tract (GI) and show high rates of resistance against antibiotics. Orally delivered recombinant bacteriocins, like klebicins, could be employed as oral antimicrobials to eradicate multidrug-resistant Klebsiella from the intestinal tract prior to/during hospitalization. Methods This study aimed to investigate the antimicrobial efficacy of orally delivered Eudragit - coated klebicin (KvarIa) in a murine lower gastrointestinal tract model of K. quasipneumoniae infection. Four study groups were used (3 animals/group) to test the antimicrobial efficacy of orally delivered klebicin KvarIa: vehicle-only group (control, phosphate-buffered saline), and other three groups with bacteria, antibiotic therapy, and 100 µg of uncoated Kvarla, 100 µg coated KvarIa, 1000 µg coated KvarIa. Faecal and tissue samples were used for Klebsiella haemolysin gene (khe) analysis using RT-PCR. Results The gastrointestinal K. quasipneumoniae colonization was achieved only in the antibiotic-treated mice groups ((i) penicillin, streptomycin or (ii) penicillin, streptomycin, and metronidazole) followed by the introduction of K. quasipneumoniae. Analysis of the antimicrobial efficacy of Kvarla showed that coated-KvarIa significantly reduced colonization of K. quasipneumoniae in both mice groups compared to the control group. The amounts of K. quasipneumoniae changed from 6.3 x 107 CFU/50mg on the 18th day to 3.9 x 105 CFU/50mg on the 22nd day (p = 0.01) in the Eudragit S100-coated KvarIa 100 µg group and from 4.0 x 107 CFU/50mg on the 18th day to 1.6 x 105 CFU/50mg on 22nd day (p = 0.009) in the Eudragit S100-coated KvarIa 1000 µg group. Conclusion Our study demonstrates that colonization of mice intestinal tract by K. quasipneumoniae can be achieved after eradication of resident gut microbiota with antibiotics. Furthermore, using this murine model, we showed that orally delivered encapsulated klebicins substantially reduce K. quasipneumoniae colonization in the lower gastrointestinal tract.

Antifungal Activity of Natural Compounds vs. Candida spp.: A Mixture of Cinnamaldehyde and Eugenol Shows Promising In Vitro Results.

Candida spp. are commensal organisms of the skin, mucous membranes, gastrointestinal tract, blood, and vagina of animals and humans. In recent decades, the incidence of human fungal infections has increased, with Candida spp. (mainly C. albicans) infections being the most frequent, and the treatment of fungal infections is still a clinical challenge. Colonization of the human gastrointestinal tract by Candida spp. is significant because infections (e.g., candidemia and vulvovaginal candidiasis) frequently arise from commensal microorganisms. The aim of this study was to test in vitro the antifungal activity and the eventual synergistic effect of five pure components of essential oils: cinnamaldehyde, α-pinene, limonene, eucalyptol, and eugenol. These compounds were tested on 18 Candida strains (15 C. albicans, 2 C. glabrata, and 1 C. lusitaniae) derived from a culture collection of vaginal clinical strains. Methods: Fungistatic activity was evaluated using the disk diffusion method. For fungicidal activity, microdilution and time–kill curve protocols were set up. The checkerboard method was chosen to evaluate a possible synergistic effect of these compounds when mixed. Results: Cinnamaldehyde and eugenol gave the best results, inhibiting all the Candida strains and showing a highly additive effect (FICI 0.625). The cinnamaldehyde inhibition zone (IZ), MIC, and MFC means were 69 mm, 50.05 mg/L, and 109.26 mg/L respectively. Cinnamaldehyde led to the total loss of viable Candida cells within 4 h. Eugenol IZ, MIC, and MFC means were 35.2 mm, 455.42 mg/L, and 690.09 mg/L, respectively. Eugenol led to the total loss of viable fungal cells within 1 h. Treatment with α-pinene inhibited 88.9% of Candida strains, with an IZ mean of 21.2 mm, a MIC mean of 195.41 mg/L, and a MFC mean of 251.27 mg/L; this compound led to the total loss of viable fungal cells only after 24 h. Limonene inhibited only 33.3% of the tested strains and eucalyptol did not produce an inhibition halo, so these compounds were not tested further. Conclusions: These characteristics, together with the well-known safety of cinnamaldehyde and eugenol for human use, make these two natural compounds the perfect candidates for the treatment of candidiasis. This was a pilot study, the purpose of which was to evaluate the best composition of a mixture to be used against intestinal and vulvovaginal candidiasis; in vivo studies are needed to confirm these very encouraging results.

Comparative Analysis of the Fitness of Candida albicans Strains During Colonization of the Mice Gastrointestinal Tract.

Candida albicans populations present in the mammalian gastrointestinal tract are a major source of candidemia and subsequent severe invasive candidiasis in those individuals with acquired or congenital immune defects. Understanding the mechanisms used by this fungus to colonize this niche is, therefore, of primary importance to develop new therapeutic options that could lead to control its proliferation in the host. The recent popularization of models of commensalism in mice combined with the already powerful tools in C. albicans genetics allows to analyze the role of specific genes during colonization. Fitness can be analyzed for a specific C. albicans strain (test strain) by comparing its growth in vivo with an otherwise isogenic control strain via the analysis of the luminal content of the mouse gastrointestinal tract using flow cytometry, qPCR, or viable fungal cell counting. While all these procedures have limitations, they can be used to estimate the degree of adaptation of the test strain to the mammalian tract by determining its relative abundance with an internal control strain. By using specific genetically engineered C. albicans and mouse strains, antibiotic regimes, or even germ-free mice, this methodology allows to determine the role of the host immunological status, the bacterial microbiota, or individual fungal features (e.g., dimorphism) in the process of colonization of C. albicans of the mammalian gut.

Mango peel flour and potato peel flour as bioactive ingredients in the formulation of functional yogurt

In recent years, agro-industrial by-products derived from processing and consumption mainly of fruits have become an important source of bioactive products, as fiber with or without prebiotic potential, and polyphenols with antioxidant activity against free radicals. In this research the chemical composition, including dietary fiber, besides polyphenols and TEAC, mean growth rate and mean duplication time, and prebiotic activity score of mango peel flour and potato peel flour were determined to evaluate the feasibility as functional ingredient in yogurt. Yogurt formulated with mango peel flour presented lower syneresis and higher viscosity during storage, as compared to yogurts with potato peel flour or control yogurt. Higher titratable acidity and lower pH was the reflect of the prebiotic capacity of both peel flours, with no detrimental effect on consumer acceptance. Mango peel flour and potato peel flour, with a prebiotic capacity potential due their dietary fiber content and polyphenols content, can be employed as prebiotic to improve probiotics colonization of gastrointestinal tract, with a concomitantly effect on host health.

Targeted Development of Infant Microbiota on Formula Feeding: Modern Options

The review provides the analysis of recent publications covering the biological significance of infant microbiome and showing modern research technologies. Correlations of quantitative and qualitative characteristics of intestinal microbiota with delayed health issues were evaluated. Various concepts of newborn microbiome origin, timing, and stages of bacterial colonization of gastrointestinal tract were considered. Data on the role of delivery method on infant microbiota development is presented (including the significance of contamination with maternal vaginal flora where ontogenetic priority belongs to lactobacilli). It was revealed that Lactobacillus fermentum was the basis microflora providing the conditions for the subsequent successful colonization of the child’s intestines with obligate symbionts. The significance of breastfeeding in adequate microbiota development was confirmed. In case of mandatory formula feeding, it is necessary to enrich infant milk formulas with components that promote the selection of symbiotic microflora such as: long-chain polyunsaturated fatty acids, prebiotics, oligosaccharides, and probiotics of specific action. The innovative formula based on synbiotic/combiotic concept will be able to partially compensate impaired microbiota development in infant on mandatory formula feeding.

The Carbohydrate Metabolism of Lactiplantibacillus plantarum.

Lactiplantibacillus plantarum has a strong carbohydrate utilization ability. This characteristic plays an important role in its gastrointestinal tract colonization and probiotic effects. L. plantarum LP-F1 presents a high carbohydrate utilization capacity. The genome analysis of 165 L. plantarum strains indicated the species has a plenty of carbohydrate metabolism genes, presenting a strain specificity. Furthermore, two-component systems (TCSs) analysis revealed that the species has more TCSs than other lactic acid bacteria, and the distribution of TCS also shows the strain specificity. In order to clarify the sugar metabolism mechanism under different carbohydrate fermentation conditions, the expressions of 27 carbohydrate metabolism genes, catabolite control protein A (CcpA) gene ccpA, and TCSs genes were analyzed by quantitative real-time PCR technology. The correlation analysis between the expressions of regulatory genes and sugar metabolism genes showed that some regulatory genes were correlated with most of the sugar metabolism genes, suggesting that some TCSs might be involved in the regulation of sugar metabolism.

The Regulatory RNA ern0160 Confers a Potential Selective Advantage to Enterococcus faecium for Intestinal Colonization.

The aim of this study was to evaluate the role of the regulatory small RNA (sRNA) Ern0160 in gastrointestinal tract (GIT) colonization by Enterococcus faecium. For this purpose, four strains of E. faecium were used, Aus0004 (WT), an ern0160-deleted Aus0004 mutant (Δ0160), a trans-complemented Δ0160 strain overexpressing ern0160 (Δ0160_0160), and a strain Δ0160 with an empty pAT29 vector (Δ0160_pAT29). Strains were studied both in vitro and in vivo, alone and in competitive assays. In in vitro experiments, no difference was observed between WT and Δ0160 strains cultured single while Δ0160_0160 strain grew more slowly than Δ0160_pAT29. In competitive assays, the WT strain was predominant compared to the deleted strain Δ0160 at the end of the experiment. Then, in vivo experiments were performed using a GIT colonization mouse model. Several existing models of GIT colonization were compared while a novel one, combining ceftriaxone and amoxicillin, was developed. A GIT colonization was performed with each strain alone, and no significant difference was noticed. By contrast, significant results were obtained with co-colonization experiments. With WT + Δ0160 suspension, a significant advantage for the WT strain was observed from day 5 to the end of the protocol, suggesting the involvement of ern0160 in GIT colonization. With Δ0160_0160 + Δ0160_pAT29 suspension, the strain with the empty vector took the advantage from day 3 to the end of the protocol, suggesting a deleterious effect of ern0160 overexpression. Altogether, these findings demonstrate the potential implication of Ern0160 in GIT colonization of E. faecium. Further investigations are needed for the identification of sRNA target(s) in order to decipher underlying molecular mechanisms.

Incorporation of probiotic bacteria on larval culture of Macrobrachium amazonicum (Heller, 1862)

In this study, we evaluated the utilization of two probiotics incorporated into the water and in the diet in a larval culture system of Amazon River prawn. Autochthonous probiotic bacteria from the gut of wild juveniles of M. amazonicum juveniles and a commercial probiotic were tested and the following parameters were analyzed: survival, productivity, fresh weight, length, larval condition index (LCI) and larval stage index (LSI). The colonization of the larval gastrointestinal tract by probiotics took place when they were incorporated into diet, while probiotics in the water proved to be unsuccessful. The use of lactic acid bacteria had no significant effects (p&gt;0.05) on survival, productivity, length, fresh weight, LSI and LCI, showing similar results in relation to the control group. However, we recommend the inclusion of probiotics into diet in larval culture of Amazon prawn since this method allowed bacterial gut colonization, which is important to evaluate the resistance to disease in further studies.

ADHESION FACTORS OF LACTIC ACID BACTERIA AND BIFIDOBACTERIA

The review presents data on adhesive and biofilm-generating capacity of lactic acid bacteria and bifidobacteria, promoting microbial colonization of gastrointestinal tract and their application as constituents of probiotics. The structural elements &#x0D; involved in adhesion include pili-like formations, cell surface proteins (adhesins, S-layer proteins, moonlighting proteins), exopolysaccharides, lipoteichoic and teichoic acids. Methods of studying the adhesive properties of bacteria and the main &#x0D; environmental factors affecting the expression of genes engaged in the mechanism of adhesion have been considered.

Role of the WOR1 Promoter of Candida albicans in Opaque Commitment

ABSTRACTDuring induced differentiation, the process often involves a commitment event, after which induced cells, when returned to noninducing conditions, continue to differentiate. The commitment event is rarely identified. Candida albicans differentiates from the white to opaque phenotype, a prerequisite for mating and a process accompanying colonization of the lower gastrointestinal tract and skin. In analyses of white cell populations induced to synchronously differentiate from the white to opaque phenotype, opaque commitment occurs at approximately the same time as evagination and chitin ring formation in the process of daughter cell formation, several hours after the master switch gene WOR1 is upregulated. Mutational analyses of transcription factor binding regions P1, P2, P3, P4, and P6 of the WOR1 promoter reveal that individual deletion of any of the five transcription factor binding regions does not eliminate morphological differentiation to the opaque cell phenotype under opaque-inducing conditions, but individual deletion of P2, P3, or P4, blocks opaque commitment and maintenance of the opaque phenotype after transition to noninducing conditions. These results suggest that commitment occurs at the level of the WOR1 promoter and that morphological differentiation can be dissociated from phenotypic commitment.

Bifidobacterium breve Exopolysaccharide Blocks Dendritic Cell Maturation and Activation of CD4+ T Cells.

Exopolysaccharide (EPS) is a bacterial extracellular carbohydrate moiety which has been associated with immunomodulatory activity and host protective effects of several gut commensal bacteria. Bifidobacterium breve are early colonizers of the human gastrointestinal tract (GIT) but the role of EPS in mediating their effects on the host has not been investigated for many strains. Here, we characterized EPS production by a panel of human B. breve isolates and investigated the effect of EPS status on host immune responses using human and murine cell culture-based assay systems. We report that B. breve EPS production is heterogenous across strains and that immune responses in human THP-1 monocytes are strain-specific, but not EPS status-specific. Using wild type and isogenic EPS deficient mutants of B. breve strains UCC2003 and JCM7017 we show that EPS had strain-specific divergent effects on cytokine responses from murine bone marrow derived macrophages (BMDMs) and dendritic cells (BMDCs). The B. breve UCC2003 EPS negative (EPS–) strain increased expression of cytokine genes (Tnfa, Il6, Il12a, and Il23a) relative to untreated BMDCs and BMDCs treated with wild type strain. B. breve UCC2003 and JCM7017 EPS– strains increased expression of dendritic cell (DC) activation and maturation marker genes (Cd80, Cd83, and Cd86) relative to untreated BMDCs. Consistent with this, BMDCs co-cultured with B. breve UCC2003 and JCM7017 EPS– strains engineered to express OVA antigen activated OVA-specific OT-II CD4+ T-cells in a co-culture antigen-presentation assay while EPS proficient strains did not. Collectively, these data indicate that B. breve EPS proficient strains use EPS to prevent maturation of DCs and activation of antigen specific CD4+ T cells responses to B. breve. This study identifies a new immunomodulatory role for B. breve EPS and suggests it may be important for immune evasion of adaptive immunity by B. breve and contribute to host-microbe mutualism.

109 Is the equine gut colonised in utero by amniotic bacteria?

Until very recently it was believed that the uterus was sterile, with microbial colonisation of the foal's gastrointestinal tract (GIT) commencing at birth. GIT colonisation is an integral developmental process, critical for an optimal functioning immune system and ongoing health of the foal. The in utero colonisation paradigm has now challenged this concept, indicating that the amniotic fluid (AF) composition contains non-pathogenic microbiota that potentially commence colonisation of the GIT during the process of fetal swallowing. In turn, preparing the foal for life outside the womb. This study examined the presence of microbiota in the AF of healthy pregnant mares, identifying microorganisms that have the potential to colonise the fetal GIT in utero. AF samples were obtained from 14 healthy mares in the second stage of parturition, before the rupture of the amnion. When the amnion was clearly visible, the surface was seared with a sterile spatula and AF extracted with a sterile needle and syringe. The sample had no contact with any other surface of the mare and was immediately snap-frozen and stored at −80°C for microbiota analysis. Genomic DNA was extracted and processed for 16S rRNA gene amplicon sequencing, followed by bioinformatic analysis of the results using QIIME2 and CalypsoV8.84 software packages. Microbiota was detected in all AF samples. Communities were of low diversity, as indicated by the α diversity parameters Chao1, Evenness, Richness and Simpson's Index. Operational Taxonomic Units (OTUs) of the top 20 taxa showed some host variation. The most abundant OTUs across the majority of samples were classified to the phyla Opisthokonta (100% of samples), Bacteroidetes (79%), Actinobacteria (57%) and Firmicutes (57%). At the family level, Staphylococcacea (79%) and Microbacteriaceae (71%) were the most abundant. These microbes have been previously detected across other locations of the equine microbiome, including the oral, esophageal, distal GIT and vaginal ecosystems. Our results have demonstrated the presence of a complex microbial ecosystem of low diversity in the AF of healthy equine pregnancies, likely of maternal origin. The environmental and gastrointestinal microbes detected in the AF displayed similarities to other equine ecosystems, suggesting microbial translocation from the mare to the AF. Further research would be required to determine if these AF microbes are being ingested by the fetus, thus commencing GIT colonisation in utero . Deciphering microbial colonisation of the foal's GIT has important implications for maternal management before parturition and could lead to the development of strategies to enhance foal health outcomes.

Gastrointestinal Tract Colonization Rate of Extended-Spectrum Beta-Lactamase-Producing Gram-Negative Bacteria and Associated Factors Among Orthopaedic Patients in a Tertiary Hospital in Tanzania: Implications for Infection Prevention.

BackgroundThe dual burden of road traffic accidents and antimicrobial resistance in orthopaedic infections is challenging already strained health-care systems. Limited information exists in Tanzania on antimicrobial resistance surveillance to delineate the potential sources of multi-drug-resistant bacteria for specific mitigation strategies among orthopaedic patients.MethodsA longitudinal study was conducted at Bugando Medical Centre in Mwanza city between January and May 2020. It involved the collection of rectal swabs/stools, hand swabs, and environmental sampling to identify extended-spectrum beta-lactamase (ESBL)-producing gram-negative bacteria. Participants’ data were collected using a structured questionnaire and analysed to determine factors associated with ESBL colonization among index orthopaedic patients and correlates with other ESBL sources using OR (95% CI) and a cut-off p-value of ≤0.05.ResultsWe found that 47.2% (125/265) of index patients, 77.8% (14/18) of neighbouring patients, 8.3% (2/24) of health-care workers, 72.2% (13/18) of non-medical caregivers, and 31.4% (27/86) of samples taken from the hospital environment had ESBL producers. Escherichia coli and Klebsiella spp. predominated among participants and Acinetobacter spp. predominated in the environmental samples. Patients with open fractures had increased odds of being colonized with ESBL producers [OR (95% CI): 2.08 (1.16–3.75); p=0.015]. The floor below patients’ beds was commonly contaminated; however, the odds of environmental contamination decreased on the third round of sampling [OR (95% CI: 0.16 (0.04–0.67); p=0.012], apparently as a result of parallel infection prevention and control responsive measures against coronavirus disease 2019 (COVID-19).ConclusionWe found a high occurrence of ESBL colonization among participants and in the environmentat this tertiary hospital. The importance of routine ESBL surveillance among orthopaedic patients with open fractures on admission and strengthened decontamination of health-care premises is reiterated.

Gene-Phenotype Associations Involving Human-Residential Bifidobacteria (HRB) Reveal Significant Species- and Strain-Specificity in Carbohydrate Catabolism.

Bifidobacteria are among the first colonizers of the human gastrointestinal tract. Different bacterial species use different mechanisms for utilization of various carbon sources in order to establish themselves in the complex microbial ecosystem of the gut. However, these mechanisms still need to be explored. Here, a large gene–phenotype correlation analysis was carried out to explore the metabolic and genetic diversity of bifidobacterial carbohydrate utilization abilities. In this study, we used 21 different carbohydrates to determine the growth phenotypes, the distribution of glycoside hydrolases (GHs), and gene clusters related to the utilization of multiple carbon sources in six human-residential Bifidobacterium species. Five carbohydrates significantly stimulated growth of almost all strains, while the remaining sugars exhibited species- and strain-specificity. Correspondingly, different Bifidobacterium species also had specific GHs involved in fermentation of plant or host glycans. Moreover, we analyzed several carbohydrate utilization gene clusters, such as 2-fucosyllactose (2′FL), sialic acid (SA), and fructooligosaccharide (FOS). In summary, by using 217 bifidobacterial strains and a wide range of growth substrates, our research revealed inter- and intra-species differences in bifidobacterial in terms of carbohydrate utilization. The findings of this study are useful for the process of developing prebiotics for optimum growth of probiotics, especially Bifidobacterium species.