Using time-series chest radiographs and laboratory data by machine learning for identifying pulmonary infection and colonization of Acinetobacter baumannii.

BACKGROUND: Accurately distinguishing between pulmonary infection and colonization in patients with Acinetobacter baumannii is of utmost importance to optimize treatment and prevent antibiotic abuse or inadequate therapy. An efficient automated sorting tool could prompt individualized interventions and enhance overall patient outcomes. This study aims to develop a robust machine learning classification model using a combination of time-series chest radiographs and laboratory data to accurately classify pulmonary status caused by Acinetobacter baumannii. METHODS: We proposed nested logistic regression models based on different time-series data to automatically classify the pulmonary status of patients with Acinetobacter baumannii. Advanced features were extracted from the time-series data of hospitalized patients, encompassing dynamic pneumonia indicators observed on chest radiographs and laboratory indicator values recorded at three specific time points. RESULTS: Data of 152 patients with Acinetobacter baumannii cultured from sputum or alveolar lavage fluid were retrospectively analyzed. Our model with multiple time-series data demonstrated a higher performance of AUC (0.850, with a 95% confidence interval of [0.638-0.873]), an accuracy of 0.761, a sensitivity of 0.833. The model, which only incorporated a single time point feature, achieved an AUC of 0.741. The influential model variables included difference in the chest radiograph pneumonia score. CONCLUSION: Dynamic assessment of time-series chest radiographs and laboratory data using machine learning allowed for accurate classification of colonization and infection with Acinetobacter baumannii. This demonstrates the potential to help clinicians provide individualized treatment through early detection.

A case report of intraventricular and intrathecal tigecycline infusions for an extensively drug-resistant intracranial Acinetobacter baumannii infection.

RATIONALE: The treatment of intracranial Acinetobacter baumannii infections is made difficult by multidrug-resistance poor drug penetration through the blood-brain barrier (BBB). Although tigecycline appears to be effective against A baumannii, it is only administered intravenously because it does not readily cross the BBB. The addition of intraventricular (IVT) or intrathecal infusions of tigecycline could revolutionize clinical therapy for intracranial A baumannii infections. However, there are few reports on the successful use of such treatments. PATIENT CONCERNS: We report the case of a 17-year-old male who presented with high fever and neck rigidity after intracranial drainage. DIAGNOSIS: Intracranial infection with extensively drug-resistant A baumannii after intracranial drainage. INTERVENTIONS: On the advice of a clinical pharmacist, the patient was administered intrathecal infusions of tigecycline after treatment failure with IVT tigecycline. OUTCOMES: The patient's body temperature returned to normal. Thereafter, the patient was in good clinical condition without signs of cerebrospinal fluid infection and tuberculosis. LESSONS: However, when central nervous system infections fail IVT tigecycline, clinicians should consider changing to intrathecal tigecycline infusions rather than raising the dose of IVT tigecycline. In addition, the co-administration of tigecycline with other drugs that can penetrate the BBB should not be ruled out.

Multidrug-Resistant Acinetobacter baumannii Ventriculostomy-Related Infection, Treated by a Colistin, Tigecycline, and Intraventricular Fibrinolysis.

BACKGROUND: Acinetobacter baumannii meningitis and ventriculitis are difficult issues, because of the low diffusion of antibiotics in the cerebrospinal fluid and bacterial multidrug resistance. The presence of an infected intraventricular hematoma, constituting an equivalent of undrained abscess, may promote biofilm formation and failure of medical treatment. CASE DESCRIPTION: In this case of ventriculostomy-related infection after ventricular hemorrhage, Acinetobacter baumannii was sensitive only to colistin and tigecycline. Despite a combination therapy involving intraventricular injections of colistin, we observed clinical and bacteriologic failure. Therefore, at day 4 of antibiotic therapy, we performed intraventricular fibrinolysis, which dissolved the clot, enabling sterilization of the cerebrospinal fluid after 48 hours. CONCLUSION: This clinical case suggests the usefulness of intraventricular fibrinolysis to lyse the clot and optimize the action of antibiotics.

Repair of ascending aortic pseudoaneurysm eroding through the sternum.

In reoperation for an ascending aortic pseudoaneurysm eroding through the sternum, a left ventricular vent allows careful unhurried sternal division under deep hypothermic circulatory arrest. We repaired ascending aortic pseudoaneurysms in 2 patients who had undergone aortic valve implantation 6 and 21 months earlier. A minithoracotomy was made in the left 5th intercostal space, and a vent was placed in the left ventricular apex. Repair was accomplished with a bovine pericardial patch reinforced with a Teflon felt strip. Both patients made an uneventful recovery with good functional status at discharge at the 8- and 18-month follow-up.

Evaluating the potential of kit-based 68Ga-ubiquicidin formulation in diagnosis of infection: a pilot study68Ga.

OBJECTIVE: The aim was to evaluate the diagnostic potential of Ga-ubiquicidin positron-emission tomography/computed tomography (PET/CT) in imaging patients with infection. MATERIALS AND METHODS: Ga-NOTA-ubiquicidin (Ga-UBI) was prepared by addition of freshly eluted Ga-chloride from Ge/Ga generator into the NOTA-ubiquicidin vial and incubated at room for 15 min at 90°C. After compounding of the radiopharmaceutical, quality control using instant thin-layer chromatography, culture and endotoxin estimation was performed. Patients with suspected infection associated with diabetic foot, cellulitis and fracture were selected for the pilot study investigation to evaluate the ability of the tracer Ga-UBI in localization at infection sites. The PET/CT findings were compared with other diagnosis like microbial culture reports and bone scintigraphy to evaluate true positives or negatives in the study. RESULTS: The current study demonstrated the potential of kit-based Ga-UBI in localization of infection sites in most of the patients proven positive for infection on culture tests and bone scintigraphy. The kit could offer radiolabeling yield more than 95% in 15 min incubation at 90°C. Quality control rendered the kit as a clinical grade preparation with endotoxin content less than 10 EU/ml and sterility up to 14 days of culture incubation. Eight of 10 patients underwent culture test and showed positive results. Two patients had undergone three-phase bone scan as an indirect sign of active infection. Ga-UBI PET/CT showed tracer localization in four of eight culture-positive patients. Tracer localization was observed in one of two patients whose culture reports were not available. Ga-UBI failed to identify infection in four patients with culture-positive results. CONCLUSION: The present study concluded that Ga-UBI prepared using NOTA-UBI kit is a potential agent in targeting infections associated with disease conditions including diabetic foot, cellulitis and fracture. The patient selection holds significance in accurate diagnosis using Ga-UBI PET/CT.

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.

Isolated cerebral aspergillosis in an immunocompetent woman on treatment for bacterial infected necrotizing pancreatitis: A case report.

RATIONALE: Cerebral aspergillosis (CA) is a rare manifestation of invasive aspergillosis. It usually affects seriously immunocompromised hosts. Pancreatic bacterial or/and fungal infection is common in patients with severe acute pancreatitis. PATIENT CONCERNS: We report the first case of an immunocompetent woman with infected necrotizing pancreatitis due to multidrug resistant Acinetobacter baumannii who, in the course of treatment, developed isolated CA. DIAGNOSES: Magnetic resonance imaging, rather than computed tomography, revealed latent homolateral sinus disease-the possible source of the Aspergillus infection. INTERVENTIONS: The pancreatic infection was controlled by open necrosectomy, and the CA was disappeared after neuronavigation-guided drainage and voriconazole antifungal therapy. OUTCOME: The patient was discharged without complications. Our report revealed that persistent hyperglycemia, sepsisassociated immunoparalysis, and prolonged antibiotic use could impair severe patient's immunocompetence, making them more susceptible to opportunistic cerebral Aspergillus infection; the risk may be especially high in patients with paranasal sinus diseases. LESSONS: Timely neurosurgical intervention combined with voriconazole antifungal therapy can provide a favorable outcome.

Case Report Serious pulmonary infection in a splenectomized patient with adult type 1 Gaucher disease.

A 49-year-old man with a history of Gaucher disease type 1, resulting in serious splenomegaly and eating disorder, was referred to our department and underwent a splenectomy under general anesthesia. Gaucher disease is very rare, and its first signs are unexplained splenomegaly and hypersplenism. On preoperative examination, the patient's platelet count was slightly low, and his other test results were normal. Surprisingly, on the first postoperative day, the patient developed a lung infection. This gradually progressed to acute respiratory distress syndrome with respiratory failure, requiring intubation and mechanical ventilation. The patient eventually recovered, and he was discharged after receiving antibiotics and other treatments to enhance immunity. However, his postoperative lung infection led to a significantly prolonged and expensive hospital stay. This case suggests that we must pay close attention to the immune dysfunction of patients with Gaucher disease type 1. Anesthesia and surgery with accompanying post-traumatic stress can weaken patients' immunity and cause susceptibility to severe lung infections. Pulmonary signs and functions should be monitored closely during the perioperative period, and, if necessary, gamma globulin and thymosin should be administered early in the preoperative or postoperative period to enhance immunity.

Mortality associated with Acinetobacter baumannii infections experienced by lung transplant recipients.

Lung transplantation (LTX) requires continual systemic immunosuppression, which can result in infections that may compromise recipient survival. A recent outbreak of Acinetobacter baumannii at our institution resulted in infections experienced in both LTX recipients and nontransplant patients. A retrospective review was conducted of patients who had A. baumannii recovered from blood, other normally sterile body fluids, and/or respiratory secretions and who had clinical follow-up extending to 1 year postinfection. A. baumannii was considered "multidrug-resistant" when its growth was not inhibited by minimum inhibitory concentrations of multiple antibiotics. Despite the resistance profile, patients were treated with a combination of antibiotics, which included tigecycline, colistimethate, and when susceptible, imipenem. Once infection was diagnosed, immunosuppression was reduced in all LTX recipients. Six LTX recipients became infected with A. baumannii and were contrasted to infections identified in 14 non-LTX, nonimmunosuppressed patients. A. baumannii was persistently recovered in 4 of 6 LTX recipients (66.7%) compared with only 1 of 14 (7.1%) non-LTX patients (χ(2) = 9.9, p = 0.005). LTX recipients received antibiotic therapy for an average of 76 ± 18.4 days compared with 16.0 ± 6.8 days for the non-LTX patients (p = 0.025, Mann-Whitney U test). All 4 of the 6 (66.7%) LTX recipients died as a consequence of their infection compared with 1 of 14 (7.1%) of the non-LTX patients (χ(2) = 9.9, p = 0.005). Despite receiving more antibiotic therapy, LTX recipients who were infected with multidrug-resistant A. baumannii were less likely to clear their infection and experienced greater mortality compared with non-LTX patients.

Acinetobacter endocarditis presenting as a large right atrial mass: an atypical presentation.

This paper discusses a 26-year-old woman with end-stage renal disease on hemodialysis and Acinetobacter calcoaceticus-baumannii complex endocarditis. The patient had an indwelling right internal jugular catheter that was probably the nidus of infection. Transthoracic echocardiogram revealed an atypical presentation of the endocarditis as a large intracardiac mass, measuring in centimeters and occupying more than 50% of the right atrial cavity. The mass was attached to the lateral wall of the right atrium without valvular involvement. The patient was treated with prompt removal of the indwelling catheter, intravenous antibiotics, and surgical resection of the mass with an uneventful recovery. A literature search for cases of "Acinetobacter endocarditis" reveals this as the first case reported of Acinetobacter endocarditis presenting in this manner.

Endophthalmitis caused by Acinetobacter baumannii: report of two cases.

Acinetobacter baumannii is most often responsible for hospital-acquired infections and is occasionally associated with community-acquired infections. We report two cases of A. baumannii endophthalmitis, one with endogenous endophthalmitis and the other with postkeratoplasty endophthalmitis. Although endophthalmitis is rare, ophthalmologists should be alert to the possibility of patients having endophthalmitis caused by A. baumannii.

Prosthetic valve endocarditis caused by Acinetobacter lwoffi: a case report and review.

We are reporting a case of recurrent prosthetic-valve endocarditis (PVE) caused by an unusual pathogen. The patient suffered 2 consecutive relapses of Acinetobacter lwoffi bacteremia, although he had completed a full course of treatment with antibiotics to which the microorganism was susceptible. He was finally successfully operated with replacement of the infected aortic valve. Acinetobacter spp are relatively low-grade but potentially virulent pathogens, and endocarditis caused by these species can be fulminant, accompanied by septic complications, and fatal. Although some patients with relapsed PVE may respond to a second course of antibiotics and medical treatment rather than early valve replacement is suggested in A lwoffi PVE, combined antibiotic treatment and early surgical intervention may be considered as the first option in these patients. There are only a few cases of Acinetobacter endocarditis in the literature, and it is the first case reported in Greece to our knowledge.

Infective endocarditis following implantation of amplatzer atrial septal occluder.

Infective endocarditis is a rare but serious complication following device closure of atrial septal defect. Surgical removal of the device is mandatory in such cases. We report a rare case of polymicrobial endocarditis following implantation of Amplatzer septal occluder in an eight-year-old child.

[Community-acquired Acinetobacter baumannii pneumonia]. / Neumonía de la comunidad por Acinetobacter baumannii.

OBJECTIVES: Description of two cases of community-acquired Acinetobacter baumannii pneumonia. PATIENTS AND METHODS: Two patients, one with a history of diabetes mellitus type 2 and pulmonary thromboembolism 2 years earlier and the second without known risk factors except for the age, were admitted to hospital because of community-acquired A. baumannii pneumonia with cavitation and with favorable final evolution. CONCLUSION: A. baumannii is an infrequent cause of community-acquired pneumonia, although it should be suspected in patients with debilitating illness and in patients who do not evolve favorably on the first days of the admission with conventional treatment.