Chronic Diarrhea Associated with Edwardsiella Tarda Gastroenteritis: A Case Report and Literature Review.

Edwardsiella tarda , a Gram-negative bacterium classified into the genus Enterobacteriaceae, causes self-limited gastroenteritis. Here, we report a case of E. tarda gastroenteritis in a previously healthy 12-year-old boy in whom inflammatory bowel disease was precluded by endoscopy and tissue biopsy due to 3-month history of diarrhea, abdominal pain and weight loss.

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.

First case report of acute cholangitis secondary to Cronobacter sakazakii.

INTRODUCTION: Cronobacter sakazakii is an opportunistic Gram-negative, rod-shaped bacterium which may be a causative agent of meningitis in premature infants and enterocolitis and bacteremia in neonates and adults. While there have been multiple cases of C. sakazakii infections, there have been no acute cholangitis cases reported in humans. CASE PRESENTATION: An 81-year-old male with a past medical history of basal cell carcinoma, alcoholic liver cirrhosis, transjugular intrahepatic portosystemic shunt procedure, complicated by staphylococcus bacteremia, pituitary tumor, glaucoma, and hypothyroidism presented to the emergency room with the complaint of diffuse and generalized 10/10 abdominal pain of 1 day's duration. There was a concern for pancreatitis, acute cholangitis, and possible cholecystitis, and the patient underwent a percutaneous cholecystostomy tube placement. Blood cultures from admission and biliary fluid cultures both grew C. sakazakii. The patient was treated with a carbapenem and clinically improved. CONCLUSIONS: The case study described a patient with multiple medical comorbidities that presented with C. sakazakii bacteremia and cholangitis. While this bacterium has been implicated in other infections, we believe this is the first time the bacteria is being documented to have caused acute cholangitis.

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.

Pyosalpinx due to Cronobacter sakazakii in an elderly woman.

BACKGROUND: Cronobacter sakazakii (C. sakazakii) is a bacterium known to cause severe neonatal infections in premature infants with the consumption of contaminated powdered milk formula. Adult infections are rare, and there have been no reports of pyosalpinx due to C. sakazakii to date. CASE PRESENTATION: We report a case of left pyosalpinx due to C. sakazakii in a sexually inactive postmenopausal woman. A 70-year-old woman presented to our hospital with left lower abdominal pain and fever. Abdominal computed tomography disclosed a cystic mass continuous with the left edge of the uterus. Urgent laparotomy revealed a ruptured left pyosalpinx with pus-like content. Left salpingo-oophorectomy, resection of the right tube, and washing of the abdominal cavity with saline were performed. Pathological examination of the left adnexa showed tubal tissue with acute inflammation and inflammatory exudate, which were compatible with pyosalpinx, and pus culture yielded C. sakazakii. CONCLUSIONS: This is the first case report of pyosalpinx due to C. sakazakii. Cronobacter sakazakii infections in adult women might occur in the elderly, whose immunity has weakened. Further accumulation of cases of C. sakazakii infection is needed to clarify the etiology and behavior of C. sakazakii in adults.

Cronobacter sakazakii Infection in Early Postnatal Rats Impaired Contextual-Associated Learning: a Putative Role of C5a-Mediated NF-κß and ASK1 Pathways.

This study was designed to test whether the Cronobacter sakazakii infection-impaired contextual learning and memory are mediated by the activation of the complement system; subsequent activation of inflammatory signals leads to alternations in serotonin transporter (SERT). To test this, rat pups (postnatal day, PND 15) were treated with either C. sakazakii (107 CFU) or Escherichia coli OP50 (107 CFU) or Luria bertani broth (100 µL) through oral gavage and allowed to stay with their mothers until PND 24. Experimental groups' rats were allowed to explore (PNDs 31-35) and then trained in contextual learning task (PNDs 36-43). Five days after training, individuals were tested for memory retention (PNDs 49-56). Observed behavioural data showed that C. sakazakii infection impaired contextual-associative learning and memory. Furthermore, our analysis showed that C. sakazakii infection activates complement system complement anaphylatoxin (C5a) (a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS1)) and mitogen-activated protein kinase kinase1 (MEKK1). Subsequently, MEKK1 induces pro-inflammatory signals possibly through apoptosis signal-regulating kinase-1 (ASK-1), c-Jun N-terminal kinase (JNK1/3) and protein kinase B gamma (AKT-3). In parallel, activated nuclear factor kappa-light-chain-enhancer B cells (NF-κB) induces interleukin-6 (IL-6) and IFNα-1, which may alter the level of serotonin transporter (SERT). Observed results suggest that impaired contextual learning and memory could be correlated with C5a-mediated NF-κß and ASK1 pathways.

Clinical outcomes and prognostic factors in bloodstream infections due to extended-spectrum ß-lactamase-producing Enterobacteriaceae among patients with malignancy: a meta-analysis.

BACKGROUND: The colonization of Extended-spectrum ß-lactamase-producing Enterobacteriaceae (ESBL-PE) in bloodstream infections (BSIs) has been increased dramatically worldwide, and it was associated with worse clinical outcomes in patients with malignancy. We performed the meta-analysis to investigate the prognosis and risk factors in BSIs caused by ESBL-PE in oncological patients. METHODS: PubMed, EMBASE, and Cochrane Library were searched for related studies. All-cause mortality was considered as the primary outcome. Subgroup analyses, meta-regression analyses, and sensitivity analysis were used to investigate heterogeneity and reliability in results. RESULTS: 6,729 patients from 25 studies were eligible. Six studies enrolled oncological patients with BSIs caused by ESBL-PE only, while 19 studies both enrolled ESBL-PE and non-ESBL-PE infections. The results showed that BSIs caused by ESBL-PE in patients with malignancy was associated with higher mortality than non-ESBL-PE infections (RR = 2.21, 95% CI: 1.60-3.06, P < 0.001), with a significant between-study heterogeneity (I2 =78.3%, P < 0.001). Subgroup analyses showed that children (RR = 2.80, 95% CI: 2.29-3.43, P < 0.001) and hematological malignancy (RR = 3.20, 95% CI: 2.54-4.03, P < 0.001) were associated with a higher mortality. Severe sepsis/ septic shock, pneumonia, and ICU admission were the most common predictors of mortality. CONCLUSIONS: Our study identified that BSIs caused by ESBL-PE in patients with malignancy were associated with worse clinical outcomes compared with non-ESBL-PE infections. Furthermore, children and hematological malignancy were associated with higher mortality. Severe sepsis/ septic shock, pneumonia, and ICU admission were the most common predictors of mortality.

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, IL1ß, 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.

STING controls intestinal homeostasis through promoting antimicrobial peptide expression in epithelial cells.

Stimulator of interferon genes (STING) has been shown to play a critical role in orchestrating immune responses to various pathogens through sensing cyclic dinucleotides. However, how STING regulates intestinal homeostasis is still not completely understood. In this study, we found that STING-/- mice were more susceptible to enteric infection with Citrobacter rodentium compared to wild-type (WT) mice evidenced by more severe intestinal inflammation and impaired bacterial clearance. STING-/- mice demonstrated lower expression of REG3γ but not ß-defensins and Cramp in IECs. Consistently, STING-/- IECs showed reduced capacity to inhibit bacterial growth. STING agonists, both 10-carboxymethyl-9-acridanone (CMA) and 5,6-dimethylxanthenone-4-acetic acid (DMXAA), promoted REG3γ expression IECs. Furthermore, STING agonists promoted WT but not REG3γ-deficient IEC bacterial killing. Mechanistically, STING agonists activated STAT3 and promoted glycolysis in IECs. Inhibition of STAT3 pathway and glycolysis suppressed STING-induced REG3γ production in IECs, and abrogated STING-mediated IEC killing of C. rodentium. Additionally, treatment with the STING ligand, 2,3-cGAMP, inhibited C. rodentium-induced colitis in vivo. Overall, STING promotes IEC REG3γ expression to inhibit enteric infection and intestinal inflammation, thus, maintaining the intestinal homeostasis.

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.

Mortality impact of empirical antimicrobial therapy in ESBL- and AmpC-producing Enterobacteriaceae bacteremia in an Australian tertiary hospital.

BACKGROUND: Treatment of ESBL- and AmpC-producing Enterobacteriaceae bacteremia is often complicated by lack of appropriate antibiotics. We aimed to determine the predictors of mortality and impact of empirical antibiotics. METHODS: A retrospective observational study was performed on consecutive adult cases of ESBL and AmpC bacteremia at the Alfred Hospital from 2014 through April 2018. RESULTS: Among 110 patients with ESBL (88.2%) and AmpC (14.5%) bacteremia episodes, 96.4% had comorbidities such as hematological malignancy (30%). Approximately 45% were on immunosuppressive drugs, while 69% had recent antibiotic exposure. Over 84% of bacteremias were hospital acquired or healthcare associated. Urinary tract was the main source of infection (40%) with E. coli being the commonest organism (66.4%). The isolates were least resistant to gentamicin (21.8%), which was often appropriately used in empirical therapy. About 34% of patients presented with severe sepsis or shock. The 30-day mortality rate was 20% with no correlation with inappropriate empirical antibiotics (52%). There was no significant mortality difference between carbapenem use in empirical and definitive therapy. Respiratory source [OR 11.77, 95% CI 1.30-106.85; p = 0.03], severe sepsis or shock [OR 5.17, 95% CI 1.37-19.55; p = 0.02] and inappropriate definitive therapy [OR 27.93, 95%CI 3.69-211.35; p = 0.001] were independent predictors for mortality. CONCLUSION: The choice and appropriateness of empirical therapy were not associated with mortality in ESBL and AmpC bacteremia. Prudent use of carbapenem is reasonable with gentamicin as alternative. Emphasis should be on prompt resuscitation in severe sepsis and early detection of ESBL and AmpC to facilitate appropriate switch to definitive therapy.

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.

Pelvic cellulitis caused by Raoultella planticola in a neutropenic patient.

Raoultella planticola is a gram-negative, encapsulated, aerobic bacterium within the Enterobacteriaceae family. It has been primarily described as pathogen in cases with pneumonia and gastrointestinal infections. Here we describe a case of severe pelvic cellulitis in a patient with neutropenia following induction therapy for myeloid sarcoma. The patient experienced a septic shock and was treated successfully with antibiotic therapy. A literature review is provided to put this case in context with previous reports on R. planticola. This report highlights that awareness for uncommon pathogens is crucial in the clinical management of infections in neutropenic patients.

[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.

Fat necrosis and polymicrobial wound infection caused partly by Raoultella ornithinolytica after reduction mammoplasty.

Raoultella ornithinolytica is a rare opportunistic aerobic gram-negative bacillus that naturally exists in soil, water and plants. The pathogen has been described in association with diabetic foot infections, biliary infections, bacteraemia and native and prosthetic joint infections. Fat necrosis and wound infection following breast reduction surgery or other plastic surgeries caused by this pathogen have not been previously described. We present a case of bilateral fat necrosis, wound infection and dehiscence in a 24-year-old woman with no significant past medical problems. She initially had an uneventful early postoperative course but 3 weeks after surgery noticed pain and discharge from both nipple/areola area of both breasts which later developed into full-thickness fat necrosis and complete destruction of the nipple areolar complex. R. ornithinolytica, Escherichia coli and Enterococcus faecalis were identified from wound exudate cultures. She was treated with surgical debridement and 2 weeks of appropriate antibiotics with a favourable outcome.

CNF1-like deamidase domains: common Lego bricks among cancer-promoting immunomodulatory bacterial virulence factors.

Alterations of the cellular proteome over time due to spontaneous or toxin-mediated enzymatic deamidation of glutamine (Gln) and asparagine (Asn) residues contribute to bacterial infection and might represent a source of aging-related diseases. Here, we put into perspective what is known about the mode of action of the CNF1 toxin from pathogenic Escherichia coli, a paradigm of bacterial deamidases that activate Rho GTPases, to illustrate the importance of determining whether exposure to these factors are risk factors in the etiology age-related diseases, such as cancer. In particular, through in silico analysis of the distribution of the CNF1-like deamidase active site Gly-Cys-(Xaa)n-His sequence motif in bacterial genomes, we unveil the wide distribution of the super-family of CNF-like toxins and CNF-like deamidase domains among members of the Enterobacteriacae and in association with a large variety of toxin delivery systems. We extent our discussion with recent findings concerning cellular systems that control activated Rac1 GTPase stability and provide protection against cancer. These findings point to the urgency for developing holistic approaches toward personalized medicine that include monitoring for asymptomatic carriage of pathogenic toxin-producing bacteria and that ultimately might lead to improved public health and increased lifespans.