Abdominal abscess caused by Raoultella ornithinolytica secondary to postoperative gastric fistula: case report and review of literature

BACKGROUND

In recent years, Raoultella ornithinolytica (R. ornithinolytica) have attracted clinical attention as a new type of pathogen. A wide range of infections with these germs is reported, and commonly found in urinary tract infections, respiratory infections, and bacteremia.

CASE PRESENTATION

We report the case of an elderly woman with liver abscess, choledocholithiasis and cholangitis, who developed gastric fistula and abdominal abscess after underwent choledocholithotomy, and R. ornithinolytica were isolated from the abdominal drainage fluid. The patient was treated with meropenem and levofloxacin and had a good outcome.

CONCLUSIONS

To the best of our knowledge, case of isolating R. ornithinolytica from a patient with non-viscerally abdominal abscess was extremely rare. We share a case of a woman with non-viscerally abdominal abscess secondary to postoperative gastric fistula, R. ornithinolytica was isolated from the patient's pus, and the pathogenic bacteria may originate from the gastrointestinal tract. Based on this case, We should be cautious that invasive treatment may greatly increase the probability of infection with this pathogenic bacterium.

Human Amnion-Derived Mesenchymal Stromal Cells: A New Potential Treatment for Carbapenem-Resistant Enterobacterales in Decompensated Cirrhosis

BACKGROUND

Spontaneous bacterial peritonitis (SBP) is a severe and often fatal infection in patients with decompensated cirrhosis and ascites. The only cure for SBP is antibiotic therapy, but the emerging problem of bacterial resistance requires novel therapeutic strategies. Human amniotic mesenchymal stromal cells (hA-MSCs) possess immunomodulatory and anti-inflammatory properties that can be harnessed as a therapy in such a context.

METHODS

An in vitro applications of hA-MSCs in ascitic fluid (AF) of cirrhotic patients, subsequently infected with carbapenem-resistant Enterobacterales, was performed. We evaluated the effects of hA-MSCs on bacterial load, innate immunity factors, and macrophage phenotypic expression.

RESULTS

hA-MSCs added to AF significantly reduce the proliferation of both bacterial strains at 24 h and diversely affect M1 and M2 polarization, C3a complement protein, and ficolin 3 concentrations during the course of infection, in a bacterial strain-dependent fashion.

CONCLUSION

This study shows the potential usefulness of hA-MSC in treating ascites infected with carbapenem-resistant bacteria and lays the foundation to further investigate antibacterial and anti-inflammatory roles of hA-MSC in in vivo models.

λ-carrageenan exacerbates Citrobacter rodentium-induced infectious colitis in mice by targeting gut microbiota and intestinal barrier integrity

For nearly half a century, the scientific community has been unable to agree upon the safety profile of carrageenan (CGN), a ubiquitous food additive. Little is known about the mechanisms by which consumption of CGN aggravates the etiopathogenesis of murine colitis. However, analyses of gut microbiota and intestinal barrier integrity have provided a breakthrough in explaining the synergistic effect of CGN upon colitis. In Citrobacter rodentium-induced infectious murine colitis, inflammation and the clinical severity of gut tissue were aggravated in the presence of λ-CGN. Using fecal transplantation and germ-free mice experiments, we evaluated the role of intestinal microbiota on the pro-inflammatory effect of λ-CGN. Mice with high dietary λ-CGN consumption showed altered colonic microbiota composition that resulted in degradation of the colonic mucus layer, a raised fecal LPS level, and a decrease in the presence of bacterially derived short-chain fatty acids (SCFAs). Mucus layer defects and altered fecal LPS and SCFA levels could be reproduced in germ-free mice by fecal transplantation from CGN-H-fed mice, but not from germ-free CGN-H-fed mice. Our results confirm that λ-CGN may create an environment that favors inflammation by altering gut microbiota composition and gut bacterial metabolism. The present study provides evidence that the "gut microbiota-barrier axis" could be an alternative target for ameliorating the colitis promoting effect of λ-CGN.

Amino Acid-Based Diet Prevents Lethal Infectious Diarrhea by Maintaining Body Water Balance in a Murine Citrobacter rodentium Infection Model

Infectious diarrhea is one of the most important health problems worldwide. Although nutritional status influences the clinical manifestation of various enteric pathogen infections, the effect of diet on enteric infectious diseases remains unclear. Using a fatal infectious diarrheal model, we found that an amino acid-based diet (AD) protected susceptible mice infected with the enteric pathogen Citrobacter rodentium. While the mice fed other diets, including a regular diet, were highly susceptible to C. rodentium infection, AD-fed mice had an increased survival rate. An AD did not suppress C. rodentium colonization or intestinal damage; instead, it prevented diarrhea-induced dehydration by increasing water intake. An AD altered the plasma and fecal amino acid levels and changed the gut microbiota composition. Treatment with glutamate, whose level was increased in the plasma and feces of AD-fed mice, promoted water intake and improved the survival of C. rodentium-infected mice. Thus, an AD changes the systemic amino acid balance and protects against lethal infectious diarrhea by maintaining total body water content.

Colonization of the Caenorhabditis elegans gut with human enteric bacterial pathogens leads to proteostasis disruption that is rescued by butyrate

Protein conformational diseases are characterized by misfolding and toxic aggregation of metastable proteins, often culminating in neurodegeneration. Enteric bacteria influence the pathogenesis of neurodegenerative diseases; however, the complexity of the human microbiome hinders our understanding of how individual microbes influence these diseases. Disruption of host protein homeostasis, or proteostasis, affects the onset and progression of these diseases. To investigate the effect of bacteria on host proteostasis, we used Caenorhabditis elegans expressing tissue-specific polyglutamine reporters that detect changes in the protein folding environment. We found that colonization of the C. elegans gut with enteric bacterial pathogens disrupted proteostasis in the intestine, muscle, neurons, and the gonad, while the presence of bacteria that conditionally synthesize butyrate, a molecule previously shown to be beneficial in neurodegenerative disease models, suppressed aggregation and the associated proteotoxicity. Co-colonization with this butyrogenic strain suppressed bacteria-induced protein aggregation, emphasizing the importance of microbial interaction and its impact on host proteostasis. Further experiments demonstrated that the beneficial effect of butyrate depended on the bacteria that colonized the gut and that this protective effect required SKN-1/Nrf2 and DAF-16/FOXO transcription factors. We also found that bacteria-derived protein aggregates contribute to the observed disruption of host proteostasis. Together, these results reveal the significance of enteric infection and gut dysbiosis on the pathogenesis of protein conformational diseases and demonstrate the potential of using butyrate-producing microbes as a preventative and treatment strategy for neurodegenerative disease.

Dietary Indole-3-Carbinol Alleviated Spleen Enlargement, Enhanced IgG Response in C3H/HeN Mice Infected with Citrobacter rodentium

Enteropathogenic and enterohemorrhagic Escherichia coli are important enteric pathogens that induce hemorrhagic colitis or even fatal hemolytic uremic syndrome. Emerging evidence shows that some bio-actives derived from fruits and vegetables may serve as alternatives to antibiotics for overcoming multidrug resistant E. coli infections. In this study, the Citrobacter rodentium (Cr) infection model was utilized to mimic E. coli-induced acute intestinal inflammation, and the effects of a cruciferous vegetable-derived cancer protective compound, indole-3-carbinol (I3C), on the immune responses of Cr-susceptible C3H/HeN mice were investigated. Dietary I3C significantly inhibited the loss of body weight and the increase in spleen size in Cr infected mice. In addition, I3C treatment reduced the inflammatory response to Cr infection by maintaining anti-inflammatory cytokine IL-22 mRNA levels while reducing expression of other pro-inflammatory cytokines including IL17A, IL6, IL1β, TNF-α, and IFN-γ. Moreover, the serum cytokine levels of IL17, TNF-α, IL12p70, and G-CSF also were down-regulated by I3C in Cr-infected mice. Additionally, dietary I3C specifically enhanced the Cr-specific IgG response to Cr infection. In general, dietary I3C reduced the Cr-induced pro-inflammatory response in susceptible C3H/HeN mice and alleviated the physiological changes and tissue damage induced by Cr infection but not Cr colonization.

Complete Genome Sequences of Leclercia sp. W6 and W17 Isolated from a Gastric Cancer Patient

Leclercia sp. W6 and W17, which belong to the Enterobacteriaceae, were isolated from a stomach sample from a 78-year-old female gastric cancer patient, and genomic sequencing and analysis were performed. The genome of Leclercia sp. W6 consists of one chromosome with a size of 4,945,486 bp, while that of Leclercia sp. W17 contains one chromosome and two plasmids with a total size of 5,125,645 bp. Average nucleotide identity (ANI) calculations indicated that strains W6 and W17 exhibited similarities < 91.0% to other strains within the Enterobacteriaceae, except for six Leclercia strains. Phylogenomic analysis based on core-genome showed that strains W6 and W17 belong to the genus Leclercia, and phylogenetic analysis based on ANI values revealed that strains W6 and W17 formed an independent clade from those six Leclercia strains. Furthermore, comparative genomic analysis revealed that strains W6 and W17 had 5086 orthologous clusters (OCs) in their pan-genomes, and 59 exclusive OCs which were absent in their closest relatives. Genomic annotations revealed that the genomes of strains W6 and W17 encoded genes related to multidrug resistance clusters, multiple antibiotic resistance loci, and multidrug efflux pumps and had an identical urease gene cluster and a dissimilatory nitrate reduction pathway. Bioinformatic analyses indicated that strains W6 and W17 represented a novel species within the genus Leclercia. Genomic annotations revealed that these strains encoded genes related to multidrug resistance, nitrate reduction, and urease activity, which contribute to gastric malignant transformation. This will broaden our knowledge of the genetic mechanisms of the Enterobacteriaceae and help improve the clinical conditions of gastric cancer patients.

Catfish Bite Case Report

Although catfish are found worldwide and commonly consumed in the southern United States, fatal infections from catfish are rare. Edwardsiella tarda is a bacterium known to cause gastrointestinal distress most commonly, but extraintestinal infections are a rarely considered danger for those acquiring, preparing, and consuming aquatic animals. Susceptible to all gram-negative active antibiotics, it is easily treated except in immunocompromised hosts, such as those with malignancy, diabetes, and hepatic dysfunction.

Risk factors for extended-spectrum beta-lactamase-producing Enterobacteriaceae infection causing septic shock in cancer patients with chemotherapy-induced febrile neutropenia

Patients with chemotherapy-induced febrile neutropenia (FN) are vulnerable to extended-spectrum b-lactamase-producing Enterobacteriaceae (ESBL-PE) infection. Early identification of patients suspected to have ESBL-PE infection for empirical carbapenem administration is crucial; nevertheless, risk factors for ESBL-PE causing septic shock remain unclear. We identify factors to predict ESBL-PE in septic shock patients with chemotherapy-induced FN. In this observational, prospectively collected registry-based study, consecutive adult chemotherapy-induced FN patients with septic shock who were admitted to the emergency department between June 2012 and June 2018 were enrolled. Clinical and laboratory data extracted from the septic shock registry were assessed to identify risk factors for ESBL-PE. Of 179 chemotherapy-induced FN septic shock patients, ESBL-PE is isolated in 23 (12.8%). ESBL-PE infection is frequently seen in patients with hepatobiliary cancer (17.4% vs. 4.5%, P = 0.037), leukemia (13.0% vs. 2.6%, P = 0.046), and those with profound neutropenia (defined as absolute neutrophil count < 100) (73.9% vs. 43.6%, P = 0.007) in contrast to those with lung cancer (0% vs. 14.7%, P = 0.048) and other solid cancer (0% vs. 19.2%, P = 0.016). Multivariate logistic regression reveals that profound neutropenia (adjusted OR 3.67; 95% CI 1.372-9.799; P = 0.010) is an independent risk factor for ESBL-PE infection after adjusting age, the presence of solid tumor, and the parameters of sepsis severity scores. ESBL-PE is rare (12.9%) in chemotherapy-induced FN patients with septic shock. Early empirical carbapenem therapy might be considered in chemotherapy-induced FN patients with profound neutropenia.

Raoultella planticola Bacteremia in a Patient with Early Gastric Cancer

The patient was an 81-year-old man who was found to have bacteremia due to Raoultella planticola, which might have entered the circulation through the bile duct during the passing of a gallbladder stone. In the present case, we screened for malignancies because most cases of R. planticola bacteremia occur after trauma, invasive procedures, or in patients with malignancy (70.6%). Early gastric cancer was detected. Although the association between R. planticola bacteremia and malignancy remains speculative in the present case, it may be useful to scrutinize similar cases involving low-virulence bacteremia for possible malignancies or immune conditions.

[Septic shock due to Citrobacter braakii following high-dose cytosine arabinoside therapy in a patient with acute myeloid leukemia]

Here, we report a case of a 67-year-old man who had septic shock due to Citrobacter braakii infection during the course of chemotherapy with high-dose cytosine arabinoside for acute myeloid leukemia. Treatment with cefepime rapidly improved his condition. The number of reported cases of sepsis due to Citrobacter braakii is limited. Further accumulation of cases is necessary to obtain accurate data such as the risk factors for Citrobacter braakii infections.

Bidirectional brain-gut interactions and chronic pathological changes after traumatic brain injury in mice

OBJECTIVES

Traumatic brain injury (TBI) has complex effects on the gastrointestinal tract that are associated with TBI-related morbidity and mortality. We examined changes in mucosal barrier properties and enteric glial cell response in the gut after experimental TBI in mice, as well as effects of the enteric pathogen Citrobacter rodentium (Cr) on both gut and brain after injury.

METHODS

Moderate-level TBI was induced in C57BL/6mice by controlled cortical impact (CCI). Mucosal barrier function was assessed by transepithelial resistance, fluorescent-labelled dextran flux, and quantification of tight junction proteins. Enteric glial cell number and activation were measured by Sox10 expression and GFAP reactivity, respectively. Separate groups of mice were challenged with Cr infection during the chronic phase of TBI, and host immune response, barrier integrity, enteric glial cell reactivity, and progression of brain injury and inflammation were assessed.

RESULTS

Chronic CCI induced changes in colon morphology, including increased mucosal depth and smooth muscle thickening. At day 28 post-CCI, increased paracellular permeability and decreased claudin-1 mRNA and protein expression were observed in the absence of inflammation in the colon. Colonic glial cell GFAP and Sox10 expression were significantly increased 28days after brain injury. Clearance of Cr and upregulation of Th1/Th17 cytokines in the colon were unaffected by CCI; however, colonic paracellular flux and enteric glial cell GFAP expression were significantly increased. Importantly, Cr infection in chronically-injured mice worsened the brain lesion injury and increased astrocyte- and microglial-mediated inflammation.

CONCLUSION

These experimental studies demonstrate chronic and bidirectional brain-gut interactions after TBI, which may negatively impact late outcomes after brain injury.

Augmented renal clearance is not a risk factor for mortality in Enterobacteriaceae bloodstream infections treated with appropriate empiric antimicrobials

The main objective of the study was to assess whether augmented renal clearance was a risk factor for mortality in a cohort of patients with Enterobacteriaceae sepsis, severe sepsis, or septic shock that all received appropriate antimicrobial therapy within 12 hours. Using a retrospective cohort from Barnes-Jewish Hospital, a 1,250-bed teaching hospital, we collected data on individuals with Enterobacteriaceae sepsis, severe sepsis, and septic shock who received appropriate initial antimicrobial therapy between June 2009 and December 2013. Clinical outcomes were compared according to renal clearance, as assessed by Modification of Diet in Renal Disease (MDRD) and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formulas, sepsis classification, demographics, severity of illness, and comorbidities. We identified 510 patients with Enterobacteriaceae bacteremia and sepsis, severe sepsis, or septic shock. Sixty-seven patients (13.1%) were nonsurvivors. Augmented renal clearance was uncommon (5.1% of patients by MDRD and 3.0% by CKD-EPI) and was not associated with increased mortality. Our results are limited by the absence of prospective determination of augmented renal clearance. However, in this small cohort, augmented renal clearance as assessed by MDRD and CKD-EPI does not seem to be a risk factor for mortality in patients with Enterobacteriaceae sepsis. Future studies should assess this finding prospectively.

Severely infected pneumoceles of the frontal sinus in patients with mental retardation and brain atrophy treated by endoscopic sinus surgery

We herein present three cases of abnormally expanded frontal sinuses (pneumoceles) with severe infection in patients with mental retardation and brain atrophy. Two patients previously underwent laryngotracheal separation surgery, and bacteriological examinations of purulent nasal discharge revealed infections caused by drug-resistant bacteria such as Pseudomonas aeruginosa and Acinetobacter baumannii. As conservative medical treatments were ineffective, all three patients were treated by computed tomography-guided endoscopic sinus surgery. This navigation system is useful for safer surgery in the area of anatomic deformity. The clinical findings, possible etiologies and surgical treatment of these cases are discussed.

Does antimicrobial usage before meningitis lead to a higher risk of adult postsurgical Acinetobacter baumannii meningitis than that of Enterobacteriaceae meningitis?

Acinetobacter baumannii and Enterobacteriaceae are two pathogens responsible for postneurosurgical meningitis. The aim of this retrospective study was to evaluate the factors that influenced the outcomes in patients with postneurosurgical meningitis caused by A. baumannii and Enterobacteriaceae. Patients with post-surgical meningitis were identified from infection control committee charts between 2007 and 2015. Subjects over 16 years old who had positive cerebral spinal fluid cultures for A. baumannii or Enterobacteriaceae were enrolled in the study. Clinical and laboratory data for 30 patients with A. baumannii meningitis were compared with those of 12 patients with Enterobacteriaceae meningitis. The mean age of patients was 51.9 years and 57.1% were male. Eleven patients had comorbidities, the most common being diabetes mellitus. Most patients were due to intracranial haemorrhage (78.6%). The rate of the patients who received an appropriate antimicrobial therapy was 35.7%, and the crude mortality rate was 64.3%. In univariate analysis, previous antibiotic use, an infection before meningitis and mechanical ventilation had an increased risk of A. baumannii meningitis. Moreover, intrathecal antimicrobial use, inappropriate empirical antimicrobial use, antimicrobial resistance and alanine aminotransferase elevation were significantly higher in patients with A. baumannii meningitis than in those with Enterobacteriaceae meningitis. Antimicrobial use before meningitis (8.84 times) and mechanical ventilation (7.28 times) resulted in an increased risk of A. baumannii meningitis. None of the results affected 30-day mortality. Avoidance of unnecessarily prolonged antimicrobial usage may help to prevent a selection of A. baumannii.

Acute Infectious Gastroenteritis Potentiates a Crohn's Disease Pathobiont to Fuel Ongoing Inflammation in the Post-Infectious Period

Crohn’s disease (CD) is a chronic inflammatory condition of diverse etiology. Exposure to foodborne pathogens causing acute gastroenteritis produces a long-term risk of CD well into the post-infectious period but the mechanistic basis for this ongoing relationship to disease onset is unknown. We developed two novel models to study the comorbidity of acute gastroenteritis caused by Salmonella Typhimurium or Citrobacter rodentium in mice colonized with adherent-invasive Escherichia coli (AIEC), a bacterial pathobiont linked to CD. Here, we show that disease activity in the post-infectious period after gastroenteritis is driven by the tissue-associated expansion of the resident AIEC pathobiont, with an attendant increase in immunopathology, barrier defects, and delays in mucosal restitution following pathogen clearance. These features required AIEC resistance to host defense peptides and a fulminant inflammatory response to the enteric pathogen. Our results suggest that individuals colonized by AIEC at the time of acute infectious gastroenteritis may be at greater risk for CD onset. Importantly, our data identify AIEC as a tractable disease modifier, a finding that could be exploited in the development of therapeutic interventions following infectious gastroenteritis in at-risk individuals.

Western societies have a disproportionately high rate of inflammatory bowel disease (IBD), with growing incidence especially in the adolescent population. A large body of evidence supports the view that bacteria in the gut participate in the pathophysiology of human bowel diseases. The unifying concept is chronic inflammation that is driven by microbial stimulation of the mucosal immune system. However, the mechanisms by which pathogenic or commensal microbes work in concert with each other and with host responses to perpetuate this inflammation is not well known. Adherent-invasive E. coli (AIEC) are Crohn’s disease (CD)-associated bacteria that are implicated in disease pathology. AIEC are pro-inflammatory and may play a central role in maintaining chronic inflammation in response to other CD risk factors, such as acute infectious gastroenteritis. Here, we show that indeed, acute infectious gastroenteritis creates an inflammatory environment in the gut that drives AIEC expansion and worsens disease severity. The increase in disease severity strictly correlates with this AIEC bloom because blocking this bloom by sensitizing AIEC to host defenses also improves the health status of the host. The long time period between recovery from acute gastroenteritis and new onset CD may allow for targeted interventions to mitigate the risk of CD in AIEC-positive individuals.

Bacteremia due to carbapenem-resistant Enterobacteriaceae in neutropenic patients with hematologic malignancies

OBJECTIVES

To determine the prevalence, risk factors, treatments, and outcomes of bloodstream infections (BSIs) due to carbapenem-resistant Enterobacteriaceae (CRE) in adult neutropenic patients with hematologic malignancies.

METHODS

We reviewed all BSIs between 2008 and 2012 in this population at two New York City oncology centers. A case-control study was conducted to identify CRE BSI risk factors, using three controls of non-CRE BSIs per case.

RESULTS

CRE caused 43 (2.2%) of 1992 BSIs overall and 4.7% of Gram-negative bacteremias. Independent risk factors for CRE BSI were prior β-lactam/β-lactamase inhibitor (adjusted odds ratio [aOR] 3.2; P = 0.03) or carbapenem (aOR 3.0; P = 0.05) use, current trimethoprim-sulfamethoxazole (aOR 24; P = 0.001) or glucocorticoid (aOR 5.4, P = 0.004) use, and having a prior CRE culture (aOR 12; P = 0.03). Patients with CRE bacteremia had a median of 52 h from culture collection until receipt of active therapy. They had a 51% BSI-related mortality rate, with a median of 4 days from bacteremia onset until death. CRE-active empirical therapy was associated with a lower 30-day mortality rate (17% vs. 59%; P = 0.08).

CONCLUSIONS

CRE are lethal emerging causes of bacteremia in neutropenic patients. New strategies are needed to shorten the delay in administration of CRE-active agents and improve outcomes in this vulnerable population.

IL10-Deficiency in CD4⁺ T Cells Exacerbates the IFNγ and IL17 Response During Bacteria Induced Colitis

BACKGROUND/AIMS

IL10 is a key inhibitor of effector T cell activation and a mediator of intestinal homeostasis. In addition, IL10 has emerged as a key immunoregulator during infection with various pathogens, ameliorating the excessive T-cell responses that are responsible for much of the immunopathology associated with the infection. Because IL10 plays an important role in both intestinal homeostasis and infection, we studied the function of IL10 in infection-associated intestinal inflammation.

METHODS

Wildtype mice and mice deficient in CD4+ T cell-derived or regulatory T cells-derived IL10 were infected with the enteric pathogen Citrobacter (C.) rodentium and analyzed for the specific immune response and pathogloy in the colon.

RESULTS

We found that IL10 expression is upregulated in colonic tissue after infection with C. rodentium, especially in CD4+ T cells, macrophages and dendritic cells. Whereas the deletion of IL10 in regulatory T cells had no effect on C. rodentium induced colitis, infection of mice deficient in CD4+ T cell-derived IL10 exhibited faster clearance of the bacterial burden but worse colitis, crypt hyperplasia, and pathology than did WT mice. In addition, the depletion of CD4+ T cell-derived IL10 in infected animals was accompanied by an accelerated IFNγ and IL17 response in the colon.

CONCLUSION

Thus, we conclude that CD4+ T cell-derived IL10 is strongly involved in the control of C. rodentium-induced colitis. Interference with this network could have implications for the treatment of infection-associated intestinal inflammation.

Bacteremic Urinary Tract Infection Caused by Multidrug-Resistant Enterobacteriaceae Are Associated With Severe Sepsis at Admission: Implication for Empirical Therapy

The purpose of this study is to compare the clinical features and treatment outcomes among patients with bacteremic urinary tract infection (UTI) caused by multidrug-resistant (MDR) and non-MDR Enterobacteriaceae and to identify whether MDR pathogens were independently associated with severe sepsis or septic shock at presentation.The clinical data of adult patients visiting and being treated at Chia-Yi Christian Hospital due to bacteremic UTI caused by Enterobacteriaceae from January 2006 to August 2015 were retrospectively analyzed.A total of 585 patients were enrolled. Among them, 220 (37.6%) were caused by the MDR Enterobacteriaceae. A total of 206 patients (35.2%) developed severe sepsis or septic shock at presentation. Patients in the MDR group tend to be male and have a past history of gout, recurrent UTI, prior hospitalization, hydronephrosis, renal stone, ureteral stone, indwelling urinary catheter, newly development of renal dysfunction, severe sepsis or septic shock, intensive care unit (ICU) admission, receipt of ineffective empirical therapy, longer hospital stay, and higher in-hospital mortality (2.7% vs 1.9%, P = 0.569). Using multivariate logistic regression analysis, it is revealed that independent predictors associated with severe sepsis or septic shock at presentation were liver cirrhosis (OR 2.868; 95% CI 1.439-5.716; P = 0.003), indwelling urinary catheter (OR 1.936; 95% CI 1.238-3.027; P = 0.004), and MDR Enterobacteriaceae (OR 1.447; 95% CI 1.002-2.090; P = 0.049).Multidrug resistance was associated with the development of severe sepsis or septic shock upon presentation among patients with bacteremic UTI caused by Enterobacteriaceae. Therefore, empirical antibiotics therapy for patients with UTI presented with severe sepsis and/or septic shock should be more broad-spectrum to effectively cover MDR Enterobacteriaceae.

R-Spondins Are Expressed by the Intestinal Stroma and are Differentially Regulated during Citrobacter rodentium- and DSS-Induced Colitis in Mice

The R-spondin family of proteins has recently been described as secreted enhancers of β-catenin activation through the canonical Wnt signaling pathway. We previously reported that Rspo2 is a major determinant of susceptibility to Citrobacter rodentium-mediated colitis in mice and recent genome-wide association studies have revealed RSPO3 as a candidate Crohn's disease-specific inflammatory bowel disease susceptibility gene in humans. However, there is little information on the endogenous expression and cellular source of R-spondins in the colon at steady state and during intestinal inflammation. RNA sequencing and qRT-PCR were used to assess the expression of R-spondins at steady state and in two mouse models of colonic inflammation. The cellular source of R-spondins was assessed in specific colonic cell populations isolated by cell sorting. Data mining from publicly available datasets was used to assess the expression of R-spondins in the human colon. At steady state, colonic expression of R-spondins was found to be exclusive to non-epithelial CD45- lamina propria cells, and Rspo3/RSPO3 was the most highly expressed R-spondin in both mouse and human colon. R-spondin expression was found to be highly dynamic and differentially regulated during C. rodentium infection and dextran sodium sulfate (DSS) colitis, with notably high levels of Rspo3 expression during DSS colitis, and high levels of Rspo2 expression during C. rodentium infection, specifically in susceptible mice. Our data are consistent with the hypothesis that in the colon, R-spondins are expressed by subepithelial stromal cells, and that Rspo3/RSPO3 is the family member most implicated in colonic homeostasis. The differential regulation of the R-spondins in different models of intestinal inflammation indicate they respond to specific pathogenic and inflammatory signals that differ in the two models and provides further evidence that this family of proteins plays a key role in linking intestinal inflammation and homeostasis.

[Etiology of infection associated with neoplastic changes of organs in the head and neck in patients hospitalized in the Oncology Centre in Warsaw]

INTRODUCTIONS

According to clinical observations primary neoplastic lesions in the head and neck are often complicated by infection. The incidence of postoperative complications of cancer lesions of the head and neck, oral cavity, upper airways or larynx is from 19% up to 47% cases but in extensive and long-term operations can reach 80%.

METHODS

We retrospectively evaluated results of microbiological investigations of 312 clinical specimens collected from patients from Clinical Head and Neck Cancers of On- cology Center in Warsaw in the years 2008 -2012. All samples of clinical materials were plated on the suitable culture media and incubated according to the recommendations.

RESULTS

The study has shown that from all collected clinical specimens 491 strains have been isolated. Nearly half of the cultured bacteria were Gram-positive cocci (48.7%), mainly methicillin-sensitive Staphylococcus aureus. Most Gram-negative bacteria isolated from neoplastic lesions in the head and neck belong to Enterobacteriaceae (21%), 23,4% of cultured bacteria grown anaerobically and they were mainly Gram-negative rods.

CONCLUSIONS

The presence of diverse bacterial flora colonizing the mucous membranes of the mouth and throat may be the reason of difficulties in interpretation of microbiological investigation. It must be remembered that knowledge of colonizing and pathogenic flora of the area of head and neck enables appropriate preoperative prevention and empiric therapy.

Morganella morganii Peritonitis Associated with Continuous Ambulatory Peritoneal Dialysis (CAPD) after Colonoscopy

A 79-year-old man on continuous ambulatory peritoneal dialysis (CAPD) developed abdominal pain and cloudy peritoneal fluid two days after colonoscopy that revealed multiple diverticula. The white blood cell count was 9,000 cells/μL, C-reactive protein level was 6.86 mg/dL, and the white blood cell count of the peritoneal fluid was 7,800 cells/μL, suggesting acute peritonitis. Empiric therapy consisting of cefazolin and ceftazidime slowly improved the patient's symptoms. The initial microbiological examination of the peritoneal fluid demonstrated Morganella morganii. He was changed from CAPD to hemodialysis. It is important to consider M. morganii peritonitis in patients with colonic diverticula.

[LEVELS OF SERUM ANTIBODIES TO ENTEROBACTERIAL LIPOPOLYSACCHARIDES AND THEIR RELATIONSHIP WITH CONCENTRATION OF C-REACTIVE PROTEIN IN DIABETES MELLITUS PATIENTS]

We examined patients with type 1 (DM 1) and type 2 (DM 2) diabetes mellitus. The concentration of C-reactive protein (CRP) in the blood and levels of serum antibodies to different classes of enterobacterial lipopolysaccharides (LPS) were determined by ELISA. Using cluster analysis it was shown that in 40.8% DM-1 patients the increased concentration of CRP is associated with a decrease in the levels of serum anti-LPS-IgA, anti-LPS-IgM and anti-LPS-IgG. In 56.7% of DM-2 patients with increased concentration of CRP levels of serum anti-LPS-IgA and anti-LPS-IgM were not significantly different from the normal values, but the levels of serum anti-LPS-IgG were significantly increased. Activation of inflammation and increase of concentration of the CRP in the blood of DM-2 patients is accompanied by a significant increase in the levels of serum anti-LPS-A and anti-LPS-G, as well as the tendency to reduce the levels of anti-LPS-IgM. The results of this study suggest an association between low intensity inflammation and immune response to enterobacterial LPS in type 1 and 2 diabetes mellitus.

DESCENDING NECROTIZING MEDIASTINITIS SECONDARY TO RETROPHARYNGEAL ABSCESS

Descending necrotizing mediastinitis secondary to a nontraumatic retropharyngeal abscess is very rare. This form of mediastinitis in the era of potent antibiotics often ends up with lethal outcome. It usually occurs in immunocompromised patients and requires intensive multidisciplinary treatment approach. We report a case of nontraumatic retropharyngeal abscess complicated by descending necrotizing mediastinitis in a 70-year-old man with insulin dependent diabetes mellitus. The patient was admitted to our hospital after clinical and radiological diagnosis of retropharyngeal abscess. During treatment for retropharyngeal abscess with antibiotic therapy and transoral incision, the patient showed mild clinical improvement but his condition suddenly aggravated on day 4 of hospital stay. He had high fever, chest pain with tachypnea, tachycardia, hypotension, and showed signs of occasional disorientation. Emergency computed tomography (CT) scan of the neck and thorax showed inflammation in the retropharyngeal space, as well as thickening of the upper posterior mediastinum fascia with the presence of air. Emergency surgery including cervicotomy and drainage of the retropharyngeal space and posterior mediastinum was performed. The patient promptly recovered with improvement of the clinical status and laboratory findings. After 16 days of treatment he was discharged from the hospital in good condition. Descending necrotizing mediastinitis can be a serious and life threatening complication of deep neck infection if the diagnosis is not quickly established. Besides inevitable application of antimicrobial drugs, good drainage of the mediastinum is necessary. We believe that transcervical approach can achieve high-quality drainage of the upper mediastinum, especially if it is done timely as in this case. Its efficacy can be verified by intensive monitoring of the patient clinical condition, by CT scan of the thorax, and by laboratory tests. In the case of inefficacy of this type of drainage, subsequently some other, more aggressive transthoracic methods of drainage can be done.

Multidrug resistant Fusarium keratitis

CASE REPORT

We report a case of keratitis in a female contact lens wearer, who developed a deep corneal abscess. The culture of a corneal biopsy scraping was positive for multiresistant Fusarium solani. The patient has a complicated clinical course and failed to respond to local and systemic antifungal treatment, requiring eye enucleation.

CONCLUSION

Fusarium keratitis may progress to severe endophthalmitis. Clinical suspicion is paramount in order to start antifungal therapy without delay. Therapy is complex due to the high resistance of this organism to usual antifungal drugs.

Candidemia, and infections by Clostridium difficile and carbapenemase-producing Enterobacteriaceae: new enteropathogenetic opportunistic syndromes?

In this paper we analyze three enteropathogenetic opportunistic infections represented by Candida spp., C. difficile and carbapenemase-producing K. pneumoniae. The common pathogenetic pathway is based on an alteration of the intestinal flora, now mainly referred as the human microbiome, with secondary opportunism for infections caused by Candida, C. difficile and carbapenemase-producing Enterobacteriaceae ("CCC"). We highlight the epidemiology, risk factors, clinical syndromes associated with the pathogens and we propose some new issues related to the epidemiology and diagnosis of candidemia, also using hierarchical cluster analysis, definitions of levels of interventions in patients colonized or infected by carbapenemase-producing bacteria. The "enteropathogenetic" opportunistic syndromes are best prevented with antimicrobial stewardship programs aiming at increasing diagnostic specificity of infectious syndromes to reduce the antimicrobial use and costs. Appropriate guidelines for infection control should also be implemented to reduce the nosocomial spread of enteropathogenetic microbes.

CAPD peritonitis caused by co-infection with Cellulosimicrobium cellulans (Oerskovia xanthineolytica) and Enterobacter cloacae: a case report and literature review

A 50-year-old woman with end-stage renal disease on continuous ambulatory peritoneal dialysis was admitted with abdominal pain, fever and cloudy peritoneal fluid. The diagnosis was peritonitis, and the causative bacteria were Cellulosimicrobium cellulans and Enterobacter cloacae. She was subsequently treated with the administration of intraperitoneal antibiotics and removal of the infected indwelling catheter. We herein report a case of Cellulosimicrobium cellulans and Enterobacter cloacae co-infection in a patient with peritonitis and review the relevant literature.

Recovery of Bacteria and Fungi From a Leg Wound

Acute and chronic wound infections can both be encountered in the deployed setting. These wounds are often contaminated by bacteria and fungi derived from the external environment. In this article, we present the case of a wound infection simultaneously colonized by Enterobacter cloacae (a bacterial pathogen) and Trichosporon asahii (an unusual fungal pathogen). We describe the examination and treatment of the patient and review the distinguishing characteristics of each organism.

Crusted scabies of the scalp in a patient with systemic lupus erythematosus

BACKGROUND

Crusted scabies is a severe, hyperkeratotic, psoriasiform disorder associated with immune suppression. Affected individuals typically present with crusted hyperkeratotic lesions in a variety of locations. This condition can lead to severe complications: institutional outbreaks and secondary bacterial infections associated with sepsis and high mortality.

MAIN OBSERVATIONS

A 37-year-old woman with a 12-year history of systemic lupus erythematosus treated with prednisone, methotrexate, and plaquenil presented with a three-week history of a painful scalp rash with adherent yellow scale. Skin biopsy and tissue culture were consistent with a diagnosis of crusted scabies with superficial bacterial infection. The patient was treated with oral ivermectin and permethrin cream, as well as ciprofloxacin for the bacterial infection. At one-week follow-up, the scalp was no longer tender and hyperkeratotic plaques had significantly improved. At one-month follow-up, the affected scalp demonstrated further improvement with decreasing erythema and alopecia with follicular ostia.

CONCLUSIONS

Our case highlights the atypical presentation of crusted scabies with primary scalp involvement and need for vigilance in recognizing and appropriately treating this condition to prevent the consequences of longstanding infection. Combination treatment with ivermectin and permethrin is appropriate management for this condition.

Prevalence and impact of extended-spectrum β-lactamase production on clinical outcomes in cancer patients with Enterobacter species bacteremia

BACKGROUND/AIMS

We examined the prevalence of extended-spectrum β-lactamase (ESBL) production and the impact of ESBL on clinical outcomes in cancer patients with Enterobacter spp. bacteremia.

METHODS

Using prospective cohort data on Enterobacter bacteremia obtained between January 2005 and November 2008 from a tertiary care center, the prevalence and clinical impact of ESBL production were evaluated.

RESULTS

Two-hundred and three episodes of Enterobacter spp. bacteremia were identified. Thirty-one blood isolates (15.3%, 31/203) scored positive by the double-disk synergy test. Among 17 isolates in which ESBL genes were detected by polymerase chain reaction and sequencing, CTX-M (n = 12), SHV-12 (n = 11), and TEM (n = 4) were the most prevalent ESBL types. Prior usage of antimicrobial agents (77.4% vs. 54.0%, p = 0.02) and inappropriate empirical antimicrobial therapy (22.6% vs. 3.0%, p < 0.001) were more commonly encountered in the ESBL-positive group than in the extended-spectrum cephalosporin-susceptible ESBL-negative group, respectively. Clinical outcomes did not differ significantly between the two groups (30-day mortality rate, 19.4% vs. 17.0%, p = 0.76; median length of hospital stay, 24.0 days vs. 30.5 days, p = 0.97). Initial presentation of severe sepsis/septic shock, pneumonia, and intra-abdominal infection were independently associated with 30-day mortality.

CONCLUSIONS

The prevalence of ESBL-producing isolates was 15.3% in cancer patients with Enterobacter bacteremia. Although inappropriate empirical therapy was more common in the ESBL-positive group, ESBL production was not associated with poorer outcomes.

Leclercia adecarboxylata bacteraemia in an immunocompromised patient with metabolic syndrome

Leclercia adecarboxylata is being increasingly diagnosed as a causative agent of infection due to the availability of rapid molecular diagnostic techniques Few cases of bacteraemia in subjects with underlying medical conditions have been reported. We report a case of L. adecarboxylata bacteraemia in an immunocompromised patient with metabolic syndrome.

[Seven cases of port-a-cath contamination caused by Pantoea agglomerans in the Oncological Service of Iseo Hospital, Brescia (Italy)]

Pantoea agglomerans, a gram negative bacillus in the Enterobacteriaceae family, has been isolated from feculent material, plants and soil. Soft tissue and bone-joint infections due to P. agglomerans following penetrating trauma by vegetation and bacteraemia in association with intravenous fluid, total parenteral nutrition, blood products and anaesthetic agent contamination have been reported. Between October 2009 and January 2010 seven cases of port a cath contamination caused by P. agglomerans were observed in the Oncological Service of our hospital. All patients presented with septic fever after heparinization of the central venous catheter. 5/7 patients were female; mean age was 67 years (range 58-75). 6/7 patients were affected by colorectal adenocarcinoma, 1/7 by mammarian cancer. Mean time from CVC insertion was 23.8 months (range 13-42) at the time of fever. In three cases, port a cath was removed following the oncologist prescription. P. agglomerans was isolated from the catheter tip in one case and from CVC blood culture in 6-7 cases. In all cases peripheral blood cultures were negative. Patients were treated with ciprofloxacin lock therapy and systemic therapy (per os), obtaining negative cultures from port a cath. Notwithstanding the absence of isolation of Pantoea strains from environmental cultures, after educational intervention, which underlined some faulty procedures in CVC management, no further cases were observed.

[Monitoring and antibiotic resistance profile of tracheal aspirate microbiota in ICU children with severe craniocerebral trauma]

Nosocomial infections and their rational antibiotic treatment represent a major challenge for the healthcare nowadays. In this context, gramnegative bacteria including Pseudomonas aeruginosa, Acinetobacter baumanii and Enterobacteriaceae spp. are etiologically important and characterized by a significant level of antibiotic resistance. To examine dynamics of the respiratory tract colonization by hospital flora, tracheal aspirates obtained at three time points from 69 children with severe craniocerebral trauma during their stay in ICU were analysed. Colonization was observed on the 4th day of the ICU stay with predomination of K. pneumoniae (45%) and A. baumanii (27-37%). P. aeruginosa was detected after the 8th day of the ICU stay with the isolation rate of 33%. Substantial proportions of P. aeruginosa (61%), A. baumanii (78%) and K. pneumoniae (25%) were resistant to carbapenems. In 65 carbapemen resistant isolates, the presence of carbapenemases was examined using PCRs. OXA-48 carbapenemase was detected in 11 out of 14 (78%) K. pneumoniae isolates. Among the A. baumanii isolates, 30/31 (97%) carried OXA-40 and 1/31 (3%) had OXA-23 carbapenemases. None of the examined A. baumanii and K. pneumoniae isolates produced metallo-betalactamases (MBL). In contrast, all 20 carbapenem resistant P. aeruginosa isolates produced a MBL, and in 12 out of 20 (60%) of theme VIM-2 was detected. Thus, gramnegative nosocomial microflora rapidly colonizes ICU patients and has a high level of resistance to antibiotics, including carbapenems.

[T-cells immunity in oral lichen planus pathogenesis]

In this review the modern ideas of the cell-like immune pathogenesis mechanism of Lichen planus)LP) are described. The special attention is paid to molecular diagnostics methods ( immunohistochemical and others). Communication of emergence of oral LP with infectious diseases is shown.

Co-infection with Arsenophonus nasoniae and Orientia tsutsugamushi in a traveler

Here we report a case of co-infection with Orientia tsutsugamushi, the causative agent of scrub typhus, and Arsenophonus nasoniae in a woman with a rash and an eschar who returned from a trip to Southeast Asia. A. nasoniae was previously considered to be a secondary insect and tick endosymbiont of unknown pathogenicity in humans. We amplified both O. tsutsugamushi and A. nasoniae DNA from a skin eschar with qPCR, and a seroconversion for O. tsutsugamushi and A. nasoniae was observed with immunofluorescence assays and western blotting for this patient. And we used 2-D western blotting with an A. nasoniae antigen and polyclonal mouse anti-A. nasoniae antibodies produced in our laboratory to detect the specific antigenic A. nasoniae proteins.

Rac2-deficiency leads to exacerbated and protracted colitis in response to Citrobacter rodentium infection

Recent genetic-based studies have implicated a number of immune-related genes in the pathogenesis of inflammatory bowel disease (IBD). Our recent genetic studies showed that RAC2 is associated with human IBD; however, its role in disease pathogenesis is unclear. Given Rac2's importance in various fundamental immune cell processes, we investigated whether a defect in Rac2 may impair host immune responses in the intestine and promote disease in the context of an infection-based (Citrobacter rodentium) model of colitis. In response to infection, Rac2(-/-) mice showed i) worsened clinical symptoms (days 13-18), ii) increased crypt hyperplasia at days 11 and 22 (a time when crypt hyperplasia was largely resolved in wild-type mice; WT), and iii) marked mononuclear cell infiltration characterized by higher numbers of T (CD3(+)) cells (day 22), compared to WT-infected mice. Moreover, splenocytes harvested from infected Rac2(-/-) mice and stimulated in vitro with C. rodentium lysate produced considerably higher levels of interferon-γ and interleukin-17A. The augmented responses observed in Rac2(-/-) mice did not appear to stem from Rac2's role in NADPH oxidase-driven reactive oxygen species production as no differences in crypt hyperplasia, nor inflammation, were observed in infected NOX2(-/-) mice compared to WT. Collectively, our findings demonstrate that Rac2(-/-) mice develop more severe disease when subjected to a C. rodentium-induced model of infectious colitis, and suggest that impaired Rac2 function may promote the development of IBD in humans.

"Swimming in resistance": Co-colonization with carbapenem-resistant Enterobacteriaceae and Acinetobacter baumannii or Pseudomonas aeruginosa

BACKGROUND

Co-colonization of patients with carbapenem-resistant Enterobacteriaceae (CRE) and Acinetobacter baumannii (AB) or Pseudomonas aeruginosa (PA) is reported to be associated with increased antibiotic resistance and mortality.

METHODS

CREs isolated between September 2008 and September 2009 were analyzed at Detroit Medical Center. Patients who had an additional isolation of AB or PA during the period spanning 7 days before to 7 days after CRE isolation were considered co-colonized. Molecular typing was used to determine genetic similarity among CRE strains.

RESULTS

Eighty-six unique patient isolates of CREs were analyzed. Thirty-four patients (40%) were co-colonized, and 26 (79%) had AB or PA isolated on the same day as the CRE. High Charlson Comorbidity Index score was an independent predictor for co-colonization. Recent stay at a long-term acute-care facility and previous therapy with antimicrobials with activity only against gram-positive microorganisms also were associated with co-colonization, but did not remain significant independent predictors. Co-colonization was associated with higher levels of resistance to carbapenems among CREs and increased 90-day mortality. Molecular typing revealed CRE polyclonality in co-colonized patients.

CONCLUSIONS

Co-colonization is found in patients with the greatest disease burden in the hospital and occurs due to the dissemination of multiple CRE strains. This finding calls into question the practice of cohorting patients with CRE in close proximity to patients with AB or PA.