Pathogenic Bacterial Colonization Research Articles

A33 EOSINOPHILS PROMOTE SALMONELLA TYPHIMURIUM COLONIZATION IN THE MURINE SMALL INTESTINE

Abstract Background During inflammatory bowel disease (IBD) both the number of intestinal eosinophils and susceptibility to enteric bacterial infections can drastically increase. It is unknown, however, whether eosinophils recruited to the tissues lining the gastrointestinal (GI) tract during severe disease help to control pathogenic bacterial colonization or whether their presence promotes bacterial infection. No studies to date have examined the role of eosinophils during an acute bacterial infection in the small intestine. Aims Our research aims to uncover the role of eosinophils during an enteric Salmonella infection in mice and we hypothesize that eosinophils undergo phenotypic changes in the presence of Salmonella and aid in the clearance of this enteric bacterial pathogen. Methods To assess how the presence of Salmonella impacts the frequency and phenotype of eosinophils we performed flow cytometry on eosinophils isolated from mice 3-days post-oral infection with Salmonella enterica serovar Typhimurium and compared these findings to naïve BALB/c controls. To determine if eosinophils are essential for controlling Salmonella infection we quantified levels of Salmonella colonization along the GI tract, liver and spleen of wild-type and eosinophil-deficient (ΔdblGATA) littermate mice by plating homogenized tissues on LB agar. Results Following an oral Salmonella infection we found higher frequencies of eosinophils in the gut-draining mesenteric lymph nodes compared to uninfected mice. Intestinal lamina propria-resident eosinophils in the small intestine and colon displayed altered phenotypes following infection in an intestinal-region specific manner: during infection, in the small intestine eosinophils increased their expression of MHCII, and in the colon eosinophils displayed elevated granularity. When wild-type and ΔdblGATA mice were pre-treated with the antibiotic streptomycin 1-day prior to infection to confer robust Salmonella burdens in the small intestine we found a significant reduction in Salmonella colonization in the ileum of the small intestine in ΔdblGATA mice compared to their wild-type littermates. These data suggest eosinophils have a role in promoting colonization by this enteric bacterial pathogen. Conclusions Our data contribute to the growing evidence that microbes can influence the phenotype of intestinal eosinophils and demonstrate that the influence of and requirements for eosinophils during bacterial infection is highly context-dependent. We found that eosinophils are not essential for controlling an acute enteric Salmonella infection and instead they promote Salmonella colonization in the small intestine. Funding Agencies CIHRTRIANGLE

The potential impact of periodontitis on cerebral small vessel disease

AbstractCerebral small vessel disease (CSVD) is a term used to describe abnormalities in the intracranial microvasculature affecting small arteries, arterioles, capillaries, and venules. The etiology of these conditions is not fully understood but inflammation appears to play a significant role. Periodontal diseases have been associated with conditions such as stroke and dementia, which are clinical consequences of CSVD. Periodontitis is a highly prevalent chronic multifactorial inflammatory disease regulated by the host immune response against pathogenic bacterial colonization around the teeth. The inflammatory response and the microbial dysbiosis produce pro‐inflammatory cytokines that can reach the brain and promote local changes. This review will explore the potential association between periodontitis and CSVD by assessing the impact of periodontitis‐induced inflammation and periodontopathogenic bacteria on the underlying mechanisms leading to CSVD. Given the association of periodontitis with stroke and dementia, which are clinical features of CSVD, it may be possible to suggest a link with CSVD. Current evidence linking periodontitis with neuroimaging findings of CSVD enforces the possible link between these conditions.

Oral flora and functional dysbiosis of cleft lip and palate patients: A scoping review.

This scoping review aimed to conduct an assessment of the current literature on specific ecological changes in the oral microbiota of individuals living with cleft lip and/or palate. All studies that assess oral microbiota and ecological changes distinct of individuals living with cleft lip and/or palate were included. Ovid MEDLINE and EMBASE databases were used, using planned search keywords. Included articles were grouped into cohort, cross-sectional, case-control, and retrospective reviews. A total of 164 eligible title articles were recognized. Of these, 32 full-text studies were included in the present review. All the included articles were published between 1992 and 2022. These studies were two retrospective studies, two review studies, and the remaining (n=28) were observational studies. The oral flora of cleft lip and/or palate patients has been shown in scientific studies to have an increased frequency of potentially pathogenic fungal and bacterial colonization, particularly Candida species, Staphylococcus aureus, Lactobacili and Streptococci mutans. This may influence oral diseases and post-operative repair complications, potentially necessitating further surgical intervention.

Association between different dietary patterns and eating disorders and periodontal diseases.

Periodontal diseases is a highly prevalent chronic condition regulated by the host immune response to pathogenic bacterial colonization on the teeth surfaces. Nutrition is a critical component in the modulation of the immune system, hence the importance of a balanced diet. With the understanding of how dietary intake composition affects various health outcomes, nutrient diversity has been reported as a modifiable risk factor for periodontal disease. Eating disorders and different dietary patterns can be associated with periodontal diseases. In this sense, balanced and healthy nutrition plays a major role in maintaining the symbiosis between oral microbiota and periodontal health. Therefore, this review seeks to report the associations found in the literature between high- or low-fat/sodium/sugar, eating disorders and periodontal diseases. It was found that some dietary patterns such as high carbohydrate/sugar, high fat, and low fiber intake may be associated with periodontal disease. In addition, the presence of eating disorders can negatively impact patients' oral health and it is related to the development of several complications, including periodontal diseases. In both situations, nutritional and vitamin deficiencies can aggravate the periodontal condition. However, the relationship between periodontal disease, dietary patterns, and eating disorders still needs more scientific support to be well established, mainly in the sense of pointing out a protective relationship between both.

COLONIZATION OF PATHOGENIC AEROBIC BACTERIA IN THE EXTERNAL EAR AND EFFECTS OF CERUMEN TYPES, AGE, AND GENDER ON COLONIZATION

Aims: The study aimed to study the prevalence of pathogenic aerobic bacteria colonization in the outer ear and to determine the prevalence of cerumen types among different ages and sex of selected individuals in Sana'a city. Also determined the effects of cerumen types, age, and sex on the incidence of pathogenic aerobic bacterial colonization. Methods: The current study was carried out in the Department of Medical Microbiology and ENT Department, Faculty of Medicine and Health Sciences, Sana’a University. The study proposal was permitted by the ethics committee of the Faculty. Written informed consent was taken from the chosen participants. Families of the study sample members residing in the various sectors of Sana'a city were visited at home in which participants were randomly selected from all age groups and sexes. Households were reviewed on time and clinical examination of the ear was done and results were recorded and ear swab samples were collected. The rapid visual identification of cerumen was performed. The culture samples were collected and transferred to the laboratory then culture and bacterial growth was identified by standard bacteriological methods. Results: The study included 246 healthy persons, 33.3% of them male and 66.7% were females. The age ranged from 1 -80 years with mean age equal to 34.2±18.7 years, 96.3% of the study subjects have the wet type and only 3.7% have the dry type of cerumen, 2.03% had impacted cerumen. The most prevalent isolate from the outer ear was Staphylococcus aureus with 35 strains (14.2%), followed by Psedumonas aureginosa with 14 strains (5.7%). Klebsiella spp, Streptococcus pyogenes and Hemophilus influenzae isolates were less frequent with 7 (2.8%), 6 (2.4%) and 5 (2.03%) isolates, respectively. Positive growth for bacterial pathogens was significantly associated with males (OR=1.8, p=0.03), ≤15 years group (OR=2.5, p=0.01), and dry-type cerumen (OR=8.9, p=0.001). Conclusion: There are two distinct and specific types of cerumen, wet and dry, of which the wet type appears to be the most common in Yemen, and of the subspecies of the wet type, honey brown was dominant. The present study concluded that some pathogenic bacteria that can cause otitis externa are naturally present in the normal external auditory canal. The most prevalent isolate was Staphylococcus aureus, followed by Psedumonas aureginosa, Klebsiella spp, Streptococcus pyogenes, and Hemophilus influenzae. Hence clinicians must find a history of any predisposing factors before interpreting laboratory culture reports. Peer Review History: Received: 4 November 2022; Revised: 8 December; Accepted: 5 January 2023, Available online: 15 January 2023 Academic Editor: Ahmad Najib, Universitas Muslim Indonesia, Indonesia, ahmad.najib@umi.ac.id Received file: Reviewer's Comments: Average Peer review marks at initial stage: 6.0/10 Average Peer review marks at publication stage: 7.0/10 Reviewers: Dr. George Zhu, Tehran University of Medical Sciences, Tehran, Iran, sansan4240732@163.com Dr. A.A. Mgbahurike, University of Port Harcourt, Nigeria, amaka_mgbahurike@yahoo.com

Effect of propolis supplementation and breed on growth performance, immunity, blood parameters and cecal microbiota in growing rabbits.

ObjectiveThe present study was conducted to investigate the potential effects of dietary supplemented propolis in two growing rabbit breeds on growth performance, immune response, blood parameters, carcass characteristics, and cecal microflora composition.MethodsA total of 90 growing rabbits aged 6 weeks from two breeds (V-line and Jabali) were randomly allocated to 3 dietary propolis experimental treatments. The experimental treatments consisted of a 2×3 factorial arrangement with two rabbit breeds and three levels of dietary propolis supplementation (0, 250 mg/kg, and 500 mg/kg). Each sub-treatment has 15 rabbits. The experimental period lasted six weeks.ResultsThere were no significant differences in growth performance and carcass characteristics due to propolis administration. Propolis supplementation at a high level significantly increased (linear; p<0.05) cellular-mediated immunity compared with the unsupplemented group. Furthermore, the rabbits receiving propolis exhibited a significant increase (linear and quadratic; p<0.03) in IgM immunoglobulins compared to the control. The current study provides further evidence that the dietary inclusion of propolis can significantly reduce pathogenic bacterial colonization in growing rabbits. The total count of microflora, E. coli, and Salmonella spp. was significantly lower (linear; p<0.01) in supplemented rabbit groups compared to the control group according to the microbiological analysis of cecal digesta. Based on breed effect, the results indicated that Jabali rabbits (local) performed better than V-line rabbits (foreign) in the majority of the studied traits.ConclusionDietary propolis is promising for further investigation into improving intestinal health and enhancing immunity in growing rabbits.

Oropharyngeal Pathogenic Bacteria: Carriage, Antimicrobial Susceptibility Pattern and Associated Risk Factors among Febrile Patients

Background: Pharyngeal and respiratory infections due to bacteria are global concerns especially because of the emergence of multi-drug resistant strains. The Oropharynx is one of the regions of the human body that is heavily colonized by microbial flora. So, the Oropharyngeal carriage is a major risk factor for an invasion and developing the disease. Therefore, this study was aimed at determining the carriage rate of potential pathogenic Oropharyngeal bacteria, associated risk factors, and antimicrobial susceptibility patterns among febrile patients at AHMC. Methods: A Cross-sectional study was conducted from November 2018 to April 2019. A systematic random technique was implemented to collect Oropharyngeal samples from 253 selected febrile patients. Specimen collection and processing were done following standard bacteriological procedures in Adama Public Health, Research, and Referral Laboratory. Antimicrobial susceptibility testing was done using the disk diffusion method in accordance with the Clinical and Laboratory Standard Institutes guideline. Data were analyzed using SPSS version 20. Results: Overall oropharyngeal bacteria carriage rate was 75.1%. A total of 190 bacterial organisms were isolated with 96 Coagulase-Negative Staphylococci (CNS), 55 Streptococcus pyogenes, and 19 Staphylococcus aureus were dominant isolates among gram-positive. Klebsiella pneumoniae, Neisseria meningitides, Moraxella catarrhalis, and Escherichia coli were among gram-negative bacteria isolates. Living in urban, cigarette smoking, and poor oral hygiene was significantly associated with the Oropharyngeal bacterial carriage rate. The majority of CNS, S.aureus, and S. pyogenes were resistant to different classes of antibiotics. Conclusion: Potentially pathogenic Oropharyngeal bacterial colonization rate was high. Place of living and behavioral factors are risk factors that were associated with bacterial colonization of the oropharynx. Several bacterial isolates were resistant to frequently prescribed antibiotic classes. Therefore, determining the antimicrobial susceptibility pattern of the isolates is important to intervene and prevent the risk of infection and also the emergence of multiple drug-resistant strains and disease management.

Optimal Frequency for Changing Single-Use Enteral Delivery Sets in Infants after Congenital Heart Surgery: A Randomized Controlled Trial

Objective We aimed to assess the optimal frequency for changing single-use enteral delivery sets during postoperative enteral feeding in infants with congenital heart disease (CHD). Methods We enrolled 120 CHD infants who were fed using an enteral nutrition pump directly connected to a milk bottle with a single-use enteral delivery set in a four-arm randomized controlled trial (ChiCTR2000039544). Patients were randomized into four groups based on the replacement frequency of the enteral delivery set (6 h, 12 h, 18 h, and 24 h groups). The primary outcome was the percentage of contaminated enteral delivery sets (overgrowth of microbiota and colonization of pathogenic bacteria). Secondary outcomes included evidence of infection, gastrointestinal tolerance, intestinal microflora dysbiosis, and healthcare costs. Results The percentages of microbial overgrowth detected in the 6 h, 12 h, 18 h, and 24 h groups were 6.7%, 30.0%, 46.7%, and 80%, respectively (P < 0.001). Significant differences were observed between the 6 h and 18 h groups (P < 0.001), the 6 h and 24 h groups (P < 0.001), and the 18 h and 24 h groups (P = 0.007). Meanwhile, pathogenic bacterial colonization was detected in 0, 4, 6, and 11 delivery sets in the 6 h, 12 h, 18 h, and 24 h groups, respectively (P = 0.002). No difference in clinical symptoms was found among the four groups. The total cost per patient in the 12 h group and the 18 h group was 340.2 RMB and 226.8 RMB, respectively. Conclusion Taking into consideration both microbial overgrowth and cost-effectiveness, the results of this study indicate that for children receiving continuous enteral feeding following CHD surgery, the optimal frequency for changing the single-use enteral delivery set when formula reconstituted from powder is used is 18 hours.

Impaired host resistance to Salmonella during helminth co-infection is restored by anthelmintic treatment prior to bacterial challenge.

Intestinal helminth infection can impair host resistance to co-infection with enteric bacterial pathogens. However, it is not known whether helminth drug-clearance can restore host resistance to bacterial infection. Using a mouse helminth-Salmonella co-infection system, we show that anthelmintic treatment prior to Salmonella challenge is sufficient to restore host resistance to Salmonella. The presence of the small intestine-dwelling helminth Heligmosomoides polygyrus at the point of Salmonella infection supports the initial establishment of Salmonella in the small intestinal lumen. Interestingly, if helminth drug-clearance is delayed until Salmonella has already established in the small intestinal lumen, anthelmintic treatment does not result in complete clearance of Salmonella. This suggests that while the presence of helminths supports initial Salmonella colonization, helminths are dispensable for Salmonella persistence in the host small intestine. These data contribute to the mechanistic understanding of how an ongoing or prior helminth infection can affect pathogenic bacterial colonization and persistence in the mammalian intestine.

Value of pre-existent bacterial colonization in patients with advanced/relapsed ovarian neoplasms undergoing cytoreductive surgery: a multicenter observational study (BONSAI)

ObjectiveAs an increasing number of patients with advanced/relapsed ovarian cancer need extensive cytoreductive procedures, there is an increasing number of complex cases collected in accredited tertiary cancer centers. With nosocomial...

Early life bacterial airway colonization, local immune mediator response and risk of otitis media

Introduction. Acute otitis media (AOM) is the most common bacterial infection in early childhood, but the underlying mechanisms making some children more susceptible are poorly understood.Aim. To examine the associations between bacterial airway colonization in early life and the risk of AOM and tympanostomy tube insertion (TTI), and whether such associations are modulated by an insufficient local immune mediator response to bacterial colonization.Methodology. Bacterial cultures from hypopharyngeal samples were obtained at 1 week, 1 month and 3 months of age in the Copenhagen Prospective Studies on Asthma in Childhood 2010 (COPSAC2010) cohort comprising 700 children. Twenty immune mediators were quantified from airway mucosal lining fluid sampled at 1 month. AOM symptoms were registered in a daily diary until 3 years. Information on TTI in the first 3 years was obtained from national registers.Results. Children colonized with Streptococcus pneumoniae at 1 month of age had increased incidence of AOM [aIRR 2.43 (1.14-5.21)] and children colonized with Moraxella catarrhalis at 1 month or Haemophilus influenzae at 3 months had an increased risk of TTI [aHR 1.45 (1.00-2.10) and 1.73 (1.10-2.71)]. There were no associations between the local immune mediator response to colonization and risk of AOM or TTI.Conclusion. Pathogenic bacterial airway colonization in early life was found to be associated with an increased risk of otitis media, albeit not consistently. These associations were independent of the local immune response to colonization.

What human sperm RNA-Seq tells us about the microbiome.

The study was designed to assess the capacity of human sperm RNA-seq data to gauge the diversity of the associated microbiome within the ejaculate. Semen samples were collected, and semen parameters evaluated at time of collection. Sperm RNA was isolated and subjected to RNA-seq. Microbial composition was determined by aligning sequencing reads not mapped to the human genome to the NCBI RefSeq bacterial, viral and archaeal genomes following RNA-Seq. Analysis of microbial assignments utilized phyloseq and vegan. Microbial composition within each sample was characterized as a function of microbial associated RNAs. Bacteria known to be associated with the male reproductive tract were present at similar levels in all samples representing 11 genera from four phyla with one exception, an outlier. Shannon diversity index (p < 0.001) and beta diversity (unweighted UniFrac distances, p = 9.99e-4; beta dispersion, p = 0.006) indicated the outlier was significantly different from all other samples. The outlier sample exhibited a dramatic increase in Streptococcus. Multiple testing indicated two operational taxonomic units, S. agalactiae and S. dysgalactiae (p = 0.009), were present. These results provide a first look at the microbiome as a component of human sperm RNA sequencing that has sufficient sensitivity to identify contamination or potential pathogenic bacterial colonization at least among the known contributors.

Antibiotic Drug Resistance in HIV Seropositive Pregnant Women

Background: Vaginal infections are often associated with a significant risk of morbidity especially in pregnant women. These infections if left untreated often result in a long-term sequelae and poses a higher adverse pregnancy outcome especially in immunocompromised women. While HIV infection has been reported to be a high risk of pathogenic bacterial colonization, the misuse of antibiotics is high among women in developing countries. Methodology and results: A high vaginal swab was collected from the posterior fornix from each pregnant women by the attending physician using sterile bivalve speculum and a cotton- tipped applicator. Each sample was cultured and identified using standard bacterlogical methods. Selected pathogens were thereafter tested for their sensitivity to 23 commonly prescribed antibiotics using the Kirby-Bauer method. Altogether, 1,156 bacterial isolates were cultured from high vaginal swabs of both 114 HIV seropositive and 126 HIV seronegative pregnant women, averaging 4.81 bacterial per subject each for both cohorts. S. aureus was seen as the single predominant isolate recovered from both groups. In addition, of the 22 S. aureus recovered from HIV infected women, 10 isolates were Methicillin resistant S. aureus (MRSA) and 12 Methicillin sensitive S aureus (MSSA), while, of the 25 S. aureus recovered from HIV seronegative women, 13 isolates were Methicillin resistant S. aureus (MRSA) and 12 Methicillin sensitive S aureus (MSSA). Other gram negative pathogens associated with lower genital infections were also studied. Conclusion: The incidence of multiple antibiotic resistance was high among isolates recovered from both cohorts, which is probably due to uncontrollable ease of access to these antibiotics in the environment where antibiotics restriction/policy is lacking. There is an urgent need for continuous monitoring, health education, drug abuse awareness and implementation of interventions to restrict antibiotic abuse especially among immunocompromised individuals in the study environment.

Understanding the pathophysiology behind chairside diagnostics and genetic testing for IL-1 and IL-6.

In order for chairside diagnostic testing to make an impact on dental therapy, practitioners require a better understanding of genetic mutations contributing to the pathophysiology of periodontal disease. Commensal and pathogenic bacterial colonization in oral cavity tissues produces a cascade of proinflammatory signaling pathways ultimately detrimental to host tissues. Resolving inflammation is a multifactorial process involving the downregulation of proinflammatory cytokines while allowing commensal bacterial levels to return to normal. Because of the complicated nature of commensal bacteria and oral health homeostasis, the emphasis of dental therapy should place renewed focus on limiting destructive inflammation rather than solely eliminating bacteria. Salivary diagnostics are an easy, non-invasive way to assess inflammatory markers. Inflammatory cytokine levels can help determine the subclinical health of a patient, showing the transition from health to gingivitis, or periodontitis, prior to clinical presentation. Single nucleotide polymorphism mutations can aid in determining increased risk of developing periodontitis. Taken together, and alongside regular clinical evaluations, chairside diagnostics help individualize treatment plans to slow, or halt, the progression of disease-before tissue destruction can take place. While more studies are needed analyzing specific mutations across periodontal categories, chairside diagnostics present an exciting adjunct to improve patient care.

STATE OF INTESTINAL MICROBIOTA IN PREMATURE INFANTS WITH NECROTIZING ENTEROCOLITIS

Introduction.Despite the advances in neonatal intensive care over the last 20 years, the incidence of necrotizing enterocolitis (NEC) in preterm infants has not significantly changed. Additional factors in the development of the disease in children are considered immaturity of the child (&lt;32 weeks of pregnancy; &lt;1500 g); infectious diseases; pathogenic bacterial colonization (Clostridium perfringens / butiricum / difficile, Pseudomonas aeruginosa) medium intensive care unit (the risk of infection with pathogenic flora), etc. In premature newborns with VLBW, a violation of the formation of a healthy intestinal microbiote has been proved.The aims. Identify the features of the formation of intestinal microbioma in preterm infants in the early neonatal period to determine the type and role of microflora in the implementation of NEC.Materials and methods of research. The state of intestinal microflora in 178 preterm infants with necrotizing enterocolitis, bacterial infection (ВІ) and conditionally healthy children during the early neonatal period was еxamined.Results of the research. More significant changes in the intestinal microbiota were found in children of groups BI, NEC II and III stages. The dynamics of the development of clinical manifestations of NEC in preterm infants during the first week of life correlates with the frequency and nature of the intestinal microflora, confirms the literature data on the participation of conditionally pathogenic flora in the pathogenesis of the NEC against the functional immaturity of the protective barriers of the intestines in the preterm infant.Conclusions. The study confirmed the presence of violations of the formation of normal intestinal microbiotа in preterm infants with NEC and bacterial infection. Given the current international recommendations for newborns with perinatal pathology and risk factors for the formation of violations of normal microbiota, the use of probiotics from the first days of life has been shown.

The Role of Probiotics and Synbiotics in Preventing Postoperative Sepsis in Gastrointestinal Surgery

Sepsis is a potentially fatal condition, accounting for over 1 million hospitalizations annually in the United States, with mortality rates as high as 40%. Patients undergoing gastrointestinal (GI) surgery are especially susceptible to sepsis, due to bacterial translocation secondary to surgical trauma and the use of antibiotics. Probiotics and synbiotics, which have been hypothesized to counteract disturbances in the intestinal flora and reduce pathogenic bacterial colonization, have been proposed for the prevention and treatment of a variety of GI conditions, including sepsis. Recent randomized control trials and meta-analyses evaluating the use of probiotic/symbiotic supplementation in elective surgical patients have demonstrated a significant reduction in the risk of developing postoperative sepsis in patients with the use of probiotic/synbiotics. Coupled with the prevention of numerous other GI symptoms, such as diarrhea, probiotics should be considered in all elective surgical GI patients.

The Power of a Toothbrush

The Power of a Toothbrush

Epithelial Hes1 maintains gut homeostasis by preventing microbial dysbiosis.

Recent advancements suggest that in addition to its roles in developmental processes, transcription repressor hairy and enhancer of split 1 (Hes1) also acts as a key regulator of inflammatory responses. A healthy gut microbiota ecology is critical for establishment of tissue homeostasis. However, the role of epithelial Hes1 in regulating intestinal microbiota ecology and intestinal homeostasis remains unexplored. Here we show that epithelial Hes1 deficiency leads to intestinal microbial dysbiosis and disturbed homeostasis. Both inducible Hes1 deletion and intestinal epithelial cell (IEC)-intrinsic Hes1 deletion resulted in loss of Bacteroidetes in ileum and increase of Escherichia coli and Akkermansia muciniphila in colon. Loss of Bacteroidetes closely correlated with decreased expression of commensal-dependent antimicrobial genes, leading to impaired resistance against pathogenic bacterial colonization. Moreover, Hes1 deficiency enhanced susceptibility to Dextran sodium sulphate-induced intestinal inflammation. Of note, transfer of Hes1-deficient-mouse-derived fecal microbiota promoted intestinal inflammation. The increase of A. muciniphila in colon was associated with Hes1-deficiency-induced unbalanced mucosal microhabitats. Thus, our results support that IEC-intrinsic Hes1 maintains gut homeostasis by preventing microbial dysbiosis partially through regulating mucosal microhabitats.

Gold-Decorated Porous Silicon Nanopillars for Targeted Hyperthermal Treatment of Bacterial Infections.

In order to address the issue of pathogenic bacterial colonization of diabetic wounds, a more direct and robust approach is required, which relies on a physical form of bacterial destruction in addition to the conventional biochemical approach (i.e., antibiotics). Targeted bacterial destruction through the use of photothermally active nanomaterials has recently come into the spotlight as a viable approach to solving the rising problem of antibiotic resistant microorganisms. Materials with high absorption coefficients in the near-infrared (NIR) region of the electromagnetic spectrum show promise as alternative antibacterial therapeutic agents, since they preclude the development of bacterial resistance and can be activated on demand. Here were report on a novel approach for the fabrication of gold nanoparticle decorated porous silicon nanopillars with tunable geometry that demonstrate excellent photothermal conversion properties when irradiated with a 808 nm laser. These photothermal antibacterial properties are demonstrated in vitro against the Gram-positive bacteria Staphylococcus aureus (S. aureus) and Gram-negative Escherichia coli (E. coli). Results show a reduction in bacterial viability of up to 99% after 10 min of laser irradiation. We also show an increase in antibacterial performance after modifying the nanopillars with S. aureus targeting antibodies causing up to a 10-fold increase in bactericidal efficiency compared to E. coli. In contrast, the nanomaterial resulted in minimal disruption of metabolic processes in human foreskin fibroblasts (HFF) after an equivalent period of irradiation.

Preoperatiove Airway Bacterial Colonization: the Missing Link between Non-small Cell Lung Cancer Following Lobectomy and Postoperative Pneumonia?

背景与目的外科手术是目前治疗肺癌的主要手段，肺癌患者围术期死亡的主要原因仍是术后肺炎。已有的研究结果显示致病性气道定植菌被认为是术后肺部并发症的一个独立危险因素，本研究旨在探讨术前致病性气道定植菌的存在与术后发生肺炎的关系及其危险因素。方法横断面调查2014年5月至2015年1月连续收治于成都市6家三级甲等医院胸外科行手术治疗的125例非小细胞肺癌患者，术前经纤维支气管镜取气管及支气管内液细菌学标本，并检测术前血清肺表面活性蛋白D（surfactant protein D, SP-D）水平，术后肺部相关并发症进行分析。结果肺癌患者术前合并致病性气道定植菌的发生率为15.2%（19/125），以革兰氏阴性菌为主（19/22, 86.36%）；肺癌患者术前合并致病性气道定植菌的高危因素为：高龄（≥75岁）和长期吸烟史（吸烟指数≥400支/年）；术后肺部相关并发症和术后肺炎发生率在肺癌合并致病性气道定植菌组（42.11%, 26.32%）均显著高于非合并组（16.04%, 6.60%）（P=0.021, P=0.019）。术前血清SP-D浓度在肺癌合并致病性气道定植菌（31.25±6.09）显著高于非合并组（28.17±5.23）（P=0.023）。并发术后肺炎患者中气道致病性定值菌发生率为41.67%（5/12），其发生率是无手术后肺炎患者的3.4倍（OR=3.363, 95%CI: 1.467-7.711）。结论肺癌患者合并致病性气道定植菌与术后肺炎发生密切相关，且高危险因素是高龄和长期吸烟史。