Citrobacter koseri inhibits the growth of Staphylococcus epidermidis by suppressing iron utilization.

The human skin microbiome consists of many species of bacteria, including Staphylococcus aureus and S. epidermidis. Individuals with atopic dermatitis (AD) have an increased relative abundance of S. aureus, which exacerbates the inflammation of AD. Although S. epidermidis, a main component of healthy skin microbiota, inhibits the growth of S. aureus, the balance between S. epidermidis and S. aureus is disrupted in the skin of individuals with AD. In this study, we found that Citrobacter koseri isolated from patients with AD produces substances that inhibit the growth of S. epidermidis. Heat-treated culture supernatant (CS) of C. koseri inhibited the growth of S. epidermidis but not S. aureus. The genome of C. koseri has gene clusters related to siderophores and the heat-treated CS of C. koseri contained a high concentration of siderophores compared with the control medium. The inhibitory activity of C. koseri CS against the growth of S. epidermidis was decreased by the addition of iron, but not copper or zinc. Deferoxamine, an iron-chelating agent, also inhibited the growth of S. epidermidis, but not that of S. aureus. These findings suggest that C. koseri inhibits the growth of S. epidermidis by interfering with its iron utilization.

Citrobacter koseri related abortion and fetal septicemia in cattle.

A 31-month-old Holstein dairy cow aborted at 224 days of gestation with ejection of cheese-like lochia. Citrobacter koseri, which commonly exists in the normal flora of human and animal digestive tracts, was isolated from aborted fetal tissues (liver, spleen, kidney, heart, lung, cerebrum, and skeletal muscle) and fetal membranes. Histopathological examination revealed suppurative fibrinous meningoencephalitis of the cerebrum, cerebellum, and brainstem; suppurative bronchopneumonia; suppurative chorioamnionitis; and fibrous splenic serositis. Numerous gram-negative bacilli were detected in the cytoplasm of macrophages and/or neutrophils in these lesions. Bacteriological investigation and immunohistochemical staining identified the bacilli as C. koseri. This is the first report of cattle abortion caused by C. koseri infection in dairy cattle.

Citrobacter koseri Surgical Site Infection after Femoropopliteal Vein Bypass for Popliteal Artery Aneurysm Treated with a Graft Preserving Strategy.

Background: A 69-year-old man underwent ligation and evacuation of a popliteal artery aneurysm with a femoral-to-popliteal vein bypass. He had a history of Citrobacter koseri prostatitis two months prior to the surgery. One month postoperatively, he presented with extremity swelling, redness, and fluid collections around the graft. Methods: A graft preserving strategy was adopted. The patient underwent operative drainage, washing, and received long-term antibiotic therapy. Fluid culture grew Citrobacter koseri, previously not reported as cause of surgical site infection with infrainguinal graft involvement. Results: The infection was treated successfully, and the patient is remains symptom free 18 months post-operatively. Conclusions: This case highlights the importance of considering culturing the aneurysm content in the presence of infectious history.

Citrobacter koseri stimulates dendritic cells to induce IL-33 expression via abundant ATP production.

Introduction. Food allergies (FAs) occur due to intestinal immune dysfunction elicited by dysbiotic conditions. It was previously determined by us that Citrobacter species propagate in the faeces of mice with FAs and worsen allergic symptoms by inducing the allergenic cytokine IL-33. Dendritic cells can play important roles in regulation of FA responses.Hypothesis. Citrobacter species propagating in intestines of mice worsen allergic symptoms by stimulating dendritic cells to induce IL-33 expression.Aim. The aim of the present study was to analyse whether C. koseri stimulates dendritic cells to induce IL-33 expression.Methodology. IL-33 expression was evaluated in a DC2.4 mouse dendritic cell line stimulated by live or heat-inactivated C. koseri JCM1658, ATP, LPS extracted from C. koseri JCM1658 or other enterobacteria by real-time PCR. The ATP concentration and number of live bacteria in the culture supernatant were measured simultaneously.Results. Live C. koseri JCM1658 induced higher levels of IL-33 expression than other enterobacteria tested, but such a response was not elicited by heat-inactivated C. koseri JCM1658. LPS extracted from C. koseri JCM1658 did not induce IL-33 expression and suppressed live C. koseri JCM1658-induced IL-33 expression via the activation of Toll-like receptor 4 signalling. Furthermore, ATP produced by C. koseri JCM1658 stimulated dendritic cells to induce IL-33 expression by stimulating the P2X7 receptor, and LPS attenuated extracellular ATP-induced IL-33 expression. C. koseri JCM1658 was observed to proliferate more vigorously and produce more ATP than other enterobacteria.Conclusion. C. koseri acts as an allergenic bacterium through ATP production, stimulating dendritic cells to induce IL-33 expression, while LPS released from inactivated C. koseri JCM1658 attenuates this allergenicity.

CITROBACTER ENDOGENOUS ENDOPHTHALMITIS: A CASE REPORT AND REVIEW OF THE LITERATURE.

PURPOSE: We present a case of endogenous endophthalmitis because of an unusual bacterium, Citrobacter koseri. PATIENT: A 57-year-old woman without previous history of eye surgery or trauma presented with diabetic ketoacidosis and a painful right eye with the reduction of vision. C. koseri was identified in blood culture; thus, a diagnosis of right eye endogenous endophthalmitis was made. Intravenous and intravitreal antibiotics were both started, and vitreous culture further confirmed C. koseri as the causative organism. Computed tomography of the abdomen and pelvis revealed a right C-shaped perinephric abscess, which was drained under ultrasound guidance. RESULTS: Because of rapid progression to corneal melting, evisceration was performed. CONCLUSION: Cases of endogenous endophthalmitis caused by Citrobacter are very limited, and a review of all published cases in the English literature and the present case revealed that endogenous Citrobacter endophthalmitis arose almost entirely from Citrobacter renal infection. Early recognition and drainage of renal abscess may lower the chance of uncontrolled infection and endogenous spread to the eyes. Despite prompt and intensive treatment, the clinical outcome of Citrobacter endogenous endophthalmitis seems to be poor.

Unusual cranial infection caused by Citrobacter Koseri.

A 60-year-old female had a frontal bone intraosseous meningioma resected 10 years previously. On follow up CT head, an enlarging intraosseous frontal bone lesion was noted. This was thought to be a recurrent frontal meningioma. Intraooperatively, she was found to have an abscess deep to the cranioplasty.

The Effect of Ten Essential Oils on Several Cutaneous Drug-Resistant Microorganisms and Their Cyto/Genotoxic and Antioxidant Properties.

In this study, we determined the antimicrobial activity of ten essential oils (EOs)-oregano, thyme, clove, arborvitae, cassia, lemongrass, melaleuca, eucalyptus, lavender, and clary sage-against drug-resistant microorganisms previously isolated from patients with skin infections. The essential oil compositions were determined using gas chromatography coupled to mass spectrometry (GC/MS). The assayed bacteria included Pseudomonas aeruginosa, Proteus vulgaris, Citrobacter koseri, and Klebsiella pneumoniae. Two drug-resistant yeasts (Candida albicans and Candida parapsilosis) were also involved in our survey. Oregano, thyme, cassia, lemongrass and arborvitae showed very strong antibacterial and antifungal activity against all tested strains. These results show that these essential oils may be effective in preventing the growth of the drug-resistant microorganisms responsible for wound infections. In this study, the genotoxic effects of tested essential oils on healthy human keratinocytes HaCaT were evaluated using the comet assay for the first time. These results revealed that none of the essential oils induced significant DNA damage in vitro after 24 h. Moreover, the treatment of HaCaT cells with essential oils increased the total antioxidant status (TAS) level. The obtained results indicate that EOs could be used as a potential source of safe and potent natural antimicrobial and antioxidant agents in the pharmaceutical and food industries.

Liver abscess with Citrobacter koseri bacteremia.

Citrobacter koseri is a rare cause of liver abscess with two reported cases in diabetic patients. We report a rare case of C. koseri liver abscess with C. koseri bacteremia in an elderly male with chronic kidney disease. He presented vomiting and weakness without any other signs. He was diagnosed with liver abscess by ultrasound, and blood culture showed C. koseri growth. The patient was treated effectively with a course of antibiotics and drainage. When C. koseri is isolated in patients with comorbidity, such as chronic kidney disease, we should consider the possibility of abscess including liver abscess and utilize a combined treatment of drainage and course of antibiotics for mixed infection.

[FOUR CASES OF THE PROSTATIC ABSCESS IN WHICH DRAINAGE WAS EFFECTIVE].

We encountered four prostatic abscess patients. Although antimicrobial therapies were ineffective, drainage was effective in all cases. Patient 1 had lung cancer and diabetes mellitus (DM), and patient 2 developed acute prostatitis after transrectal prostatic biopsy. Culture of the urine and blood revealed extended-spectrum beta lactamase (ESBL) -producing Escherichia coli (E.coli). Patient 3 had previously sustained spinal cord injury, and urinated by self-catheterization. Patient 4 had untreated, severe DM. Patient 1, 2 and 3 had been treated by transurethral resection of the prostate (TURP). Patient 2 complained of ejaculatory incompetence after the surgery, and the symptom caused mental distress. Patient 4 was a 43-year-old man who had undergone transperineal needle aspiration under ultrasound guidance to avoid ejaculatory incompetence. The prostatic abscess disappeared in all cases after drainage without recurrence.

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.

Efficacy and safety of 3 day versus 7 day cefditoren pivoxil regimens for acute uncomplicated cystitis: multicentre, randomized, open-label trial.

BACKGROUND: Fluoroquinolone-non-susceptible Escherichia coli isolated from patients with acute uncomplicated cystitis are a matter of increasing concern. Cefditoren pivoxil is an oral, ß-lactamase-stable, extended-spectrum cephalosporin that is effective against fluoroquinolone-non-susceptible bacteria. OBJECTIVES: To evaluate the clinical and microbiological efficacies of cefditoren pivoxil against acute uncomplicated cystitis and to determine the optimal duration of cefditoren pivoxil treatment. METHODS: We compared 3 and 7 day regimens of cefditoren pivoxil in a multicentre, randomized, open-label study. RESULTS: A total of 104 female patients with acute uncomplicated cystitis were enrolled and randomized into 3 day (n = 51) or 7 day (n = 53) treatment groups. At first visit, 94 bacterial strains were isolated from the 104 participants of which 81.7% (85/104) were E. coli. Clinical and microbiological efficacies were evaluated 5-9 days following administration of the final dose of cefditoren pivoxil. The clinical efficacies of the 3 and 7 day groups were 90.9% (40/44) and 93.2% (41/44), respectively (P = 1.000). The microbiological efficacies of the 3 and 7 day groups were 82.5% (33/40) and 90.2% (37/41), respectively (P = 0.349). There were no adverse events due to cefditoren pivoxil treatment, with the exception of a mild allergic reaction in one patient, after which the cefditoren pivoxil was exchanged for another antimicrobial. CONCLUSIONS: Cefditoren pivoxil is safe and effective for uncomplicated cystitis, with no significant differences in clinical and microbiological efficacies between 3 and 7 day regimens.

Musculoskeletal infections associated with Citrobacter koseri.

Introduction Citrobacter koseri is a well known cause of central nervous system infections in the paediatric setting. Musculoskeletal infections caused by C koseri are rare, with only 14 previously reported cases. We present the first recorded case of C koseri induced septic arthritis of the knee along with a review of the literature. Methods A search of the PubMed, Embase(®) and Google Scholar™ databases was undertaken. Only complete or near complete cases were reviewed. Findings Fourteen musculoskeletal infections were identified. Of these, five were associated with an operative procedure and five involved a septic joint. Surgical treatment was required in the majority of cases and cure was achieved in all cases following prolonged antibiotic use. Conclusions C koseri associated musculoskeletal infections may complicate primary orthopaedic procedures. The organism can present aggressively and can be difficult to identify microbiologically. It is sensitive to newer generation beta-lactams, cephalosporin-based antibiotics and timely surgery.

Presence of gas in left ventricle due to infective endocarditis.

Gas in myocardium is a rare manifestation of infective endocarditis caused by gas producing bacteria. We present a case of infective endocarditis caused by Citrobacter Koseri initially diagnosed by computed tomography and confirmed with transesophageal echocardiogram.

[Septic shock following platelet transfusion contaminated with Citrobacter koseri in a child with postchemotherapy febrile neutropenia]. / Choc septique après transfusion d'un concentré plaquettaire contaminé par Citrobacter koseri chez une patiente en aplasie fébrile post-chimiothérapie.

The bacterial transfusion risk is currently the greatest infectious risk of blood transfusion. We report the case of a child with postchemotherapy febrile neutropenia who presented septic shock following platelet transfusion contaminated with Citrobacter koseri. The life-threatening development could have been avoided by strict compliance with good clinical practice. The stability of mortality rates due to adverse effects of bacterial proliferation during platelet transfusions in France since 1994 calls for optimization of all preventive measures throughout the transfusion chain and perfect knowledge of transfusion rules by medical staff and care givers.

Endogenous endophthalmitis caused by Citrobacter koseri originating from a renal abscess.

We present a rare case of endogenous endophthalmitis caused by Citrobacter koseri. A 69-year-old woman with a history of poorly controlled diabetes and a protracted urinary tract infection (UTI) presented with a painful swollen left eye. There was no history of eye surgery or trauma. Imaging revealed an abscess in the right kidney. Although endophthalmitis is very rare in healthy patient, it is more common in the immunocompromised. In this patient, several multiple system illnesses including poorly controlled diabetes appear to have worked synergistically to make endophthalmitis a realistic complication of an otherwise isolated and remote source of infection, in this case pyelonephritis. Endophthalmitis, in the absence of an obvious exogenous cause, should be investigated thoroughly to exclude metastatic microbial spread. In addition, chronic features of UTI in a patient with poorly controlled diabetes or who is otherwise immunosuppressed warrant the exclusion of an underlying renal abscess.

Citrobacter koseri: an unusual cause of pyogenic liver abscess.

Liver abscess is a common pathology in the Indian subcontinent and usually results from amoebic or bacterial infection. Pyogenic abscesses usually occur in those with underlying predisposing factors like intra-abdominal infections, biliary infections or comorbidities like malignancy, immunosuppression, diabetes mellitus and previous biliary surgery or interventional endoscopy. Citrobacter is an unusual cause of pyogenic liver abscess and may occur in the setting of underlying comorbidities. We report a 56-year-old man with diabetes (operated for periampullary carcinoma 20 years ago), who presented with a history of fever for 1 week and on evaluation was found to have Citrobacter koseri-related hepatic abscess. The patient was managed with parenteral antibiotics, repeated aspiration of liver abscess and pigtail drainage.

Iron induces bimodal population development by Escherichia coli.

Bacterial biofilm formation is a complex developmental process involving cellular differentiation and the formation of intricate 3D structures. Here we demonstrate that exposure to ferric chloride triggers rugose biofilm formation by the uropathogenic Escherichia coli strain UTI89 and by enteric bacteria Citrobacter koseri and Salmonella enterica serovar typhimurium. Two unique and separable cellular populations emerge in iron-triggered, rugose biofilms. Bacteria at the air-biofilm interface express high levels of the biofilm regulator csgD, the cellulose activator adrA, and the curli subunit operon csgBAC. Bacteria in the interior of rugose biofilms express low levels of csgD and undetectable levels of matrix components curli and cellulose. Iron activation of rugose biofilms is linked to oxidative stress. Superoxide generation, either through addition of phenazine methosulfate or by deletion of sodA and sodB, stimulates rugose biofilm formation in the absence of high iron. Additionally, overexpression of Mn-superoxide dismutase, which can mitigate iron-derived reactive oxygen stress, decreases biofilm formation in a WT strain upon iron exposure. Not only does reactive oxygen stress promote rugose biofilm formation, but bacteria in the rugose biofilms display increased resistance to H(2)O(2) toxicity. Altogether, we demonstrate that iron and superoxide stress trigger rugose biofilm formation in UTI89. Rugose biofilm development involves the elaboration of two distinct bacterial populations and increased resistance to oxidative stress.

Sepsis, meningitis and cerebral abscesses caused by Citrobacter koseri.

After a 36-week diamniotic dichorionic gestation, an infant was delivered by elective caesarean section due to growth restriction and altered diastolic flow in the umbilical artery. Birth weight was 2140 g. The patient was admitted for exclusive parenteral nutrition, with umbilical venous catheter placement. Sinus tachycardia and temperature instability with positive inflammatory markers occurred at 51 h. Penicillin and gentamicin were started, but 6 h later septic shock with disseminated intravascular coagulation was noted. Vancomycin and meropenem were started and penicillin suspended. Citrobacter koseri was isolated from blood culture. Generalised clonic convulsions occurred on day 4, and an electroencephalogram revealed severe encephalic dysfunction. Cerebrospinal fluid cytochemical analysis was suggestive of meningitis, although culture was negative. Cefotaxime was added to the drug regimen. Cranioencephalic MR showed a temporal abscess and diffuse hemispheric destruction, with no indications for neurosurgery. After 6 weeks of therapy, neuroimaging follow-up showed multiloculated cystic encephalomalacia. Currently, the patient is 14 months old with axial hypotonia and decreased movements. The source of infection has not been determined. Nosocomial infection cannot be excluded and vertical transmission is unlikely.