Pleisiomonas shigelloides bacteremia after catfish injury.

This case of Pleisimonas shigelloides bacteremia resulting after a catfish barb injury highlights an unusual presentation of a common condition that requires alternative therapy for successful treatment. An otherwise healthy male in his early 40s presented to the emergency department with sepsis and rapidly spreading cellulitis shortly after a catfish injury at a freshwater lake. His broad-spectrum antibiotics were narrowed to ciprofloxacin when P. shigelloides grew from his blood culture. The case presents a unique mode of bacteremia, as usually P. shigelloides bacteremia develops in immunocompromised hosts after bowel wall translocation. The venomous nature of catfish barbs also contributed to the severity and rapidity of his presentation secondary to the local tissue effects of envenomation. With proper antibiotics and supportive care, he made a full recovery.

Machine learning model for the prediction of gram-positive and gram-negative bacterial bloodstream infection based on routine laboratory parameters.

BACKGROUND: Bacterial bloodstream infection is responsible for the majority of cases of sepsis and septic shock. Early recognition of the causative pathogen is pivotal for administration of adequate empiric antibiotic therapy and for the survival of the patients. In this study, we developed a feasible machine learning (ML) model to predict gram-positive and gram-negative bacteremia based on routine laboratory parameters. METHODS: Data for 2118 patients with bacteremia were obtained from the Medical Information Mart for Intensive Care dataset. Patients were randomly split into the training set and test set by stratified sampling, and 374 routine laboratory blood test variables were retrieved. Variables with missing values in more than 40% of the patients were excluded. Pearson correlation test was employed to eliminate redundant features. Five ML algorithms were used to build the model based on the selected features. Additionally, 132 patients with bacteremia who were treated at Qilu Hospital of Shandong University were included in an independent test cohort to evaluate the model. RESULTS: After feature selection, 32 variables remained. All the five ML algorithms performed well in terms of discriminating between gram-positive and gram-negative bacteremia, but the performance of convolutional neural network (CNN) and random forest (RF) were better than other three algorithms. Consider of the interpretability of models, RF was chosen for further test (ROC-AUC = 0.768; 95%CI = 0.715-0.798, with a sensitivity of 75.20% and a specificity of 63.79%). To expand the application of the model, a decision tree (DT) was built utilizing the major variables, and it achieved an AUC of 0.679 (95%CI = 0.632-0.723), a sensitivity of 66%, and a specificity of 67.82% in the test cohort. When tested in the Qilu Hospital cohort, the ROC-AUC of the RF and DT models were 0.666 (95%CI = 0.579-0.746) and 0.615 (95%CI = 0.526-0.698), respectively. Finally, a software was developed to make the RF- and DT-based prediction models easily accessible. CONCLUSION: The present ML-based models could effectively discriminate between gram-positive and gram-negative bacteremia based on routine laboratory blood test results. This simple model would be beneficial in terms of guiding timely antibiotic selection and administration in critically ill patients with bacteremia before their pathogen test results are available.

[Efficacy and safefy of Polymyxin B treatment for neutropenic patients suffering from refractory Gram-negative bacterial bloodstream infection].

Objective: To assess the efficacy and safety of polymyxin B in neutropenic patients with hematologic disorders who had refractory gram-negative bacterial bloodstream infection. Methods: From August 2021 to July 2022, we retrospectively analyzed neutropenic patients with refractory gram-negative bacterial bloodstream infection who were treated with polymyxin B in the Department of Hematology of the First Affiliated Hospital of the Soochow University between August 2021 to July 2022. The cumulative response rate was then computed. Results: The study included 27 neutropenic patients with refractory gram-negative bacterial bloodstream infections. Polymyxin B therapy was effective in 22 of 27 patients. The median time between the onset of fever and the delivery of polymyxin B was 3 days [interquartile range (IQR) : 2-5]. The median duration of polymyxin B treatment was 7 days (IQR: 5-11). Polymyxin B therapy had a median antipyretic time of 37 h (IQR: 32-70). The incidence of acute renal dysfunction was 14.8% (four out of 27 cases), all classified as "injury" according to RIFLE criteria. The incidence of hyperpigmentation was 59.3%. Conclusion: Polymyxin B is a viable treatment option for granulocytopenia patients with refractory gram-negative bacterial bloodstream infections.

Predictor of gram-negative bacteremia in cirrhotic patients with skin and soft-tissue infections.

Cirrhosis always goes with profound immunity compromise, and makes those patients easily be the target of skin and soft-tissue infections (SSTIs). Cirrhotic patients with SSTIs have a dramatically increased mortality. To recognize the risk factors of gram-negative infections are critical for improving survival rate. A retrospective cohort study of hospitalized cirrhotic patients with SSTIs and gram-negative bacteremia (GNB) was conducted in 2 tertiary hospitals in southern Taiwan between March 2015 and January 2020. Another group were matched by controls with non-GNB based on time, demographics and immune status. Data such as infectious location, comorbidities, and laboratory findings were recorded and compared. Receiver operating curve and the area under the curve were used to evaluate its discriminating ability. A total of 186 patients were included, 62 in GNB group and 124 in non-GNB group. Comorbidities that were significant risk factors for gram-negative bacteremia included acute kidney injury. Significant risk factors evident in laboratory evaluations included higher model for end-stage liver disease score, higher serum lactate, higher C-reactive protein and higher creatinine level. This study found acute kidney injury, or those exhibiting hyperlactatemia (>16 mg/dL), high MELD score (>14), high CRP (>50 mg/dL), and high creatinine (>2.0 mg/dL) were risk factors associated with gram-negative bacteremia. Cirrhotic patients with SSTIs with aforementioned risk factors should pay more attention by clinicians due to higher mortality.

Oral colonization by gram-negative bacilli in patients with hematologic malignancies and solid tumors compared with healthy controls.

BACKGROUND: Colonization of the oropharynx with gram-negative bacilli (GNB) is considered a negative prognostic factor in immunocompromised individuals. Hemato-oncologic patients represent a high-risk group due to their immunodeficiencies and associated treatments. This study aimed to determine the rates of oral colonization by GNB, associated factors, and clinical outcomes in patients with hematologic malignancies and solid tumors compared with healthy subjects. METHODS: We conducted a comparative study of hemato-oncologic patients and healthy subjects from August to October 2022. Swabs were taken from the oral cavity; specimens with GNB were identified and tested for antimicrobial susceptibility. RESULTS: We included 206 participants (103 hemato-oncologic patients and 103 healthy subjects). Hemato-oncologic patients had higher rates of oral colonization by GNB (34% vs. 17%, P = 0.007) and GNB resistant to third-generation cephalosporins (11.6% vs. 0%, P < 0.001) compared to healthy subjects. Klebsiella spp. was the predominant genus in both groups. The factor associated with oral colonization by GNB was a Charlson index ≥ 3, while ≥ 3 dental visits per year were a protective factor. Regarding colonization by resistant GNB in oncology patients, antibiotic therapy and a Charlson index ≥ 5 were identified as associated factors, while better physical functionality (ECOG ≤ 2) was associated with less colonization. Hemato-oncologic patients colonized with GNB had more 30-day infectious complications (30.5% vs. 2.9%, P = 0.0001) than non-colonized patients. CONCLUSION: Oral colonization by GNB and resistant GNB are prevalent in cancer patients, especially those with higher scores on the severity scales. Infectious complications occurred more frequently in colonized patients. There is a knowledge gap about dental hygiene practices in hemato-oncologic patients colonized by GNB. Our results suggest that patients' hygienic-dietary habits, especially frequent dental visits, are a protective factor against colonization.

Effect of Purslane (Portulaca oleracea L.) on Intestinal Morphology, Digestion Activity and Microbiome of Chinese Pond Turtle (Mauremys reevesii) during Aeromonas hydrophila Infection.

Large-scale mortality due to Aeromonas hydrophila (A. hydrophila) infection has considerably decreased the yield of the Chinese pond turtle (Mauremys reevesii). Purslane is a naturally active substance with a wide range of pharmacological functions, but its antibacterial effect on Chinese pond turtles infected by A. hydrophila infection is still unknown. In this study, we investigated the effect of purslane on intestinal morphology, digestion activity, and microbiome of Chinese pond turtles during A. hydrophila infection. The results showed that purslane promoted epidermal neogenesis of the limbs and increased the survival and feeding rates of Chinese pond turtles during A. hydrophila infection. Histopathological observation and enzyme activity assay indicated that purslane improved the intestinal morphology and digestive enzyme (α-amylase, lipase and pepsin) activities of Chinese pond turtle during A. hydrophila infection. Microbiome analysis revealed that purslane increased the diversity of intestinal microbiota with a significant decrease in the proportion of potentially pathogenic bacteria (such as Citrobacter freundii, Eimeria praecox, and Salmonella enterica) and an increase in the abundance of probiotics (such as uncultured Lactobacillus). In conclusion, our study uncovers that purslane improves intestinal health to protect Chinese pond turtles against A. hydrophila infection.

Prevalence of bacterial bloodstream infections and association between neutropenia and 30-day mortality among oncology inpatients at a university hospital in Saudi Arabia.

BACKGROUND: Cancer patients are highly prone to develop bacterial bloodstream infections (BSI) and are also at risk of neutropenia. Knowledge of the prevalence of these infections and whether neutropenia is associated with a change in mortality is important to more effective management and reducing mortality and morbidity. OBJECTIVES: Estimate the prevalence of bacterial BSI among oncology inpatients and assess the associations of 30-day mortality with Gram stain results and neutropenia. DESIGN: Retrospective cross-sectional SETTING: University hospital in Saudi Arabia. PATIENTS AND METHODS: We retrieved records of oncology inpatients at King Khalid University Hospital, excluding patients without malignancy and with non-bacterial BSI. The number of records included in the analysis was reduced based on a sample size calculation and systematic random sampling used to select patients to include in the study. MAIN OUTCOME MEASURES: Prevalence of bacterial BSI and association between neutropenia and 30-day mortality. SAMPLE SIZE: 423. RESULTS: The prevalence of bacterial bloodstream infections was 18.9% (n=80). Gram-negative bacteria were more prevalent (n=48, 60.0%) than gram-positive bacteria, with the most common being Escherichia coli (n=20, 25.0%). The 23 patients (28.8%) who died included 16 (69.6%) with gram-negative infections and 7 (30.4%) with gram-positive infections. There was no statistically significant association of bacterial BSI-related 30-day mortality with Gram stain (P=.32). Of 18 patients (22.5%) who were neutropenic, only one (5.6%) died. Sixty-two (77.5%) patients were non-neutropenic, of whom 22 (35.50%) died. We found a statistically significant association between the presence of neutropenia and bacterial BSI-related 30-day mortality (P=.016), with mortality being lower among neutropenic patients. CONCLUSIONS: Gram-negative bacteria are more prevalent in bacterial BSI than gram-positive bacteria. No statistically significant association of Gram stain result with mortality was found. However, the 30-day mortality rate was lower among neutropenic patients than among non-neutropenic patients. We recommend further investigation with a larger sample size in multiple regions to further unravel the association of neutropenia with bacterial bloodstream infection-related 30-day mortality. LIMITATIONS: Lack of regional data and sample size. CONFLICT OF INTEREST: None.

Risk factors for Gram-negative bacterial infection of cardiovascular implantable electronic devices: multicentre observational study (CarDINe Study).

BACKGROUND: Infections of cardiovascular implantable electronic devices (CIED) are mainly due to Gram-positive bacteria (GPB). Data about Gram-negative bacteria CIED (GNB-CIED) infections are limited. This study aimed to investigate risk factors, clinical and diagnostic characteristics, and outcome of patients with GNB-CIED. METHODS: A multicentre, international, retrospective, case-control-control study was performed on patients undergoing CIED implantation from 2015 to 2019 in 17 centres across Europe. For each patient diagnosed with GNB-CIED, one matching control with GPB-CIED infection and two matching controls without infection were selected. RESULTS: A total of 236 patients were enrolled: 59 with GNB-CIED infection, 59 with GPB-CIED infection and 118 without infection. No between-group differences were found regarding clinical presentation, diagnostic and therapeutic management. A trend toward a higher rate of fluorodeoxyglucose positron emission computed tomography (FDG PET/CT) positivity was observed among patients with GNB than in those with GPB-CIED infection (85.7% vs. 66.7%; P = 0.208). Risk factors for GNB-CIED infection were Charlson Comorbidity Index Score (relative risk reduction, RRR = 1.211; P = 0.011), obesity (RRR = 5.122; P = 0.008), ventricular-pacing ventricular-sensing inhibited-response pacemaker implantation (RRR = 3.027; P = 0.006) and right subclavian vein site of implantation (RRR = 5.014; P = 0.004). At 180-day survival analysis, GNB-CIED infection was associated with increased mortality risk (HR = 1.842; P = 0.067). CONCLUSIONS: Obesity, high number of comorbidities and right subclavian vein implantation site were associated with increased risk of GNB-CIED infection. A prompt therapeutic intervention that may be guided using FDG PET/CT is suggested in patients with GNB-CIED infection, considering the poorer outcome observed in this group.

Efficacy and safefy of Polymyxin B treatment for neutropenic patients suffering from refractory Gram-negative bacterial bloodstream infection / 中华血液学杂志

Objective: To assess the efficacy and safety of polymyxin B in neutropenic patients with hematologic disorders who had refractory gram-negative bacterial bloodstream infection. Methods: From August 2021 to July 2022, we retrospectively analyzed neutropenic patients with refractory gram-negative bacterial bloodstream infection who were treated with polymyxin B in the Department of Hematology of the First Affiliated Hospital of the Soochow University between August 2021 to July 2022. The cumulative response rate was then computed. Results: The study included 27 neutropenic patients with refractory gram-negative bacterial bloodstream infections. Polymyxin B therapy was effective in 22 of 27 patients. The median time between the onset of fever and the delivery of polymyxin B was 3 days [interquartile range (IQR) : 2-5]. The median duration of polymyxin B treatment was 7 days (IQR: 5-11). Polymyxin B therapy had a median antipyretic time of 37 h (IQR: 32-70). The incidence of acute renal dysfunction was 14.8% (four out of 27 cases), all classified as "injury" according to RIFLE criteria. The incidence of hyperpigmentation was 59.3%. Conclusion: Polymyxin B is a viable treatment option for granulocytopenia patients with refractory gram-negative bacterial bloodstream infections.

[Rare complication of a dog bite: Capnocytophaga species bacteremia followed by an hemolytic uremic syndrome]. / Cas clinique. Complication méconnue des morsures canines : syndrome hémolytique et urémique suite à une bactériémie à Capnocytophaga Canimorsus.

Dog bites are a frequent reason for medical consultation. These can be responsible for severe infectious complications. Bacteria of the genus Capnocytophaga species are Gram-negative bacilli commonly found in the oral cavity of certain animals such as dogs and cats. Following a dog bite or wound contamination with animal spit, these bacteria can cause local (cellulitis), systemic and invasive manifestations (bacteremia, endocarditis, meningitis) or lead to rare and dreadful complications such as thrombotic microangiopathies. The identification of Capnocytophaga is slow due to their specific characteristics and their culture conditions. The treatment of Capnocytophaga species infections is based on antibiotic therapy with amoxicillin - clavulanic acid as the first choice. Although different types of Capnocytophaga have been described, C. Canimorsus appears to be associated with a higher rate of atypical complications. Here is the description of an immunocompetent patient who presented with C. Canimorsus bacteremia complicated by hemolytic uremic syndrome following a dog bite.

Les morsures de chien représentent un motif fréquent de consultation. Celles-ci peuvent entraîner des complications infectieuses graves. Les bactéries du genre Capnocytophaga species sont des bacilles Gram négatif fréquemment retrouvés dans la cavité buccale de certains animaux comme les chiens et les chats. à la suite d'une morsure canine ou d'une contamination de plaie par de la salive animale, ces bactéries peuvent provoquer des manifestations locales (cellulite), systémiques et invasives (bactériémie, endocardite, méningite) ou entraîner des complications rares et redoutables comme les microangiopathies thrombotiques. L'identification des Capnocytophaga est lente de par leurs caractéristiques propres et leurs conditions de mise en culture. Le traitement des infections à Capnocytophaga species repose sur une antibiothérapie par amoxicilline-acide clavulanique en première intention. Bien que différents types de Capnocytophaga aient été décrits, C. Canimorsus semble associé à un taux plus élevé de complications atypiques. Nous décrivons ici le cas d'une patiente immunocompétente ayant présenté une bactériémie à C. Canimorsus compliquée d'un syndrome hémolytique et urémique dans les suites d'une morsure de chien.

Clinical associations with carriage of pulmonary Stenotrophomonas maltophilia.

BACKGROUND: Stenotrophomonas maltophilia causes opportunistic respiratory infections and is associated with declining lung function in patients with cystic fibrosis (CF). Risk factors for carrying S. maltophilia remain unclear. METHODS: We conducted a retrospective study of patients yielding ⩾1 respiratory S. maltophilia isolate at the Oxford University Hospitals Trust between 2014 and 2019 and a cohort study of S. maltophilia carriage in CF patients attending annual review in 2018. RESULTS: Seven hundred and forty isolates were identified from 238 patients (median 1.0 isolate/patient). Predisposing conditions included invasive ventilation (29.8%), CF (25.6%) and non-CF bronchiectasis (24.4%). The rates of Stenotrophomonas isolates and co-trimoxazole resistance were stable over time. About 10.8% of isolates were co-trimoxazole-resistant, with resistance more common in CF than in other diagnoses (29.5% vs 5.8%, p < 0.001). No clinical features were significantly associated with S. maltophilia carriage in the CF population. DISCUSSION: We present new insight into the epidemiology of Stenotrophomonas colonisation/infection and identify increased co-trimoxazole resistance in CF isolates.

Meningitis caused by Capnocytophaga canimorsus in a COVID-19 patient: a rare complication of dog bites.

Capnocytophaga canimorsus is a gram-negative rod that is part of the commensal microbiota of dogs' and cats' mouths. In this case, we report an 85-year-old man with COVID-19 who had his right arm bitten by a dog. His symptoms were impaired consciousness, agitation and aggressive behavior. Physical examination revealed neck stiffness and Brudzinski's sign. The cerebrospinal fluid culture was compatible with Capnocytophaga canimorsus. He required intensive care and received a 14-day prescription of meropenem. After 40 days of hospitalization, the patient was fully recovered and was discharged. This case highlights the importance of physician and microbiologist be awareness of this disease, mainly in patients with neurological symptoms after a dog or cat bite.

Capnocytophaga canimorsus meningitis in a 38-year-old immunocompetent woman from household pet exposure.

A 38-year-old otherwise healthy woman with no history of immunocompromise, recent travel, or concerning exposures presented to the ED with several days of nonspecific cold-like symptoms with associated generalized headache. After the patient was symptomatically treated and discharged, she returned several hours later with worsening of symptoms and new vomiting, confusion, and sensorineural hearing loss. Blood and cerebrospinal fluid cultures eventually returned positive for a Capnocytophaga canimorsus infection, a bacterial pathogen found in the saliva of dogs and cats. Only after that, the patient recalled being scratched and licked by her pets, two dogs and a cat. She was treated with a course of systemic steroids, antibiotics and discharged home.

Putative Novel Species of Genus Capnocytophaga, Capnocytophaga stomatis Bacteremia in a Patient with Multiple Myeloma after Direct Contact with a Cat.

Capnocytophaga species are among the typical zoonotic pathogens causing infections following direct contact with animals. Recently, a putative novel species of zoonotic Capnocytophaga, Capnocytophaga stomatis, was reported. We herein report the first case of bacteremia caused by C. stomatis. A woman in her 80s with multiple myeloma who was receiving bortezomib and dexamethasone therapy was admitted to our hospital with a 2-day history of a fever and right calf redness. She was often licked by her cat. On a blood culture, thin, Gram-negative rods were detected, which were identified as C. stomatis by whole-genome sequencing. The patient was successfully treated with ampicillin-sulbactam treatment. Our case highlights the pathogenic potential of the putative novel Capnocytophaga, C. stomatis, in immunocompromised hosts.

Association between the duration of diabetes and gram-negative bacterial infection in diabetic foot infections: a case-control study.

This retrospective case-control study was designed to explore the association between the duration of diabetes and gram-negative bacterial infection in diabetic foot infections (DFIs). All DFI patients hospitalized in the Department of Endocrinology in the Sixth Affiliated Hospital of Sun Yat-sen University between 2013 and 2019 with positive microbial culture results were included. Cases were defined as DFI patients whose microbial cultures grew gram-negative bacteria (including polymicrobial flora). Controls were defined as DFI patients whose positive microbial cultures did not grow gram-negative bacteria. Clinical data were extracted from the hospital information system. Stabilized inverse probability weighting was used to balance between-group differences at baseline. Confounders were selected using a directed acyclic graph. Missing data were imputed with the multiple imputation of chained equations method. Odds ratios (ORs) with 95% confidence intervals (CIs) and Ptrend for associations between the duration of diabetes and gram-negative bacterial infection were obtained using binomial logistic regression models. The weighted OR of gram-negative bacterial infection for DFI patients with a moderate duration of diabetes (8~19 years) compared with those with a short duration (0~7 years) was 3.87 (95% CI: 1.15 to 13.07), and the OR for those with a longer duration (20~30 + years) was 7.70 (95% CI: 1.45 to 41.00), and there was a dose-response trend with increasing duration of diabetes (weighted Ptrend = 0.007). The results demonstrated that a long duration of diabetes might be associated with an increased risk of gram-negative bacterial infection in type 2 diabetes patients with DFI.

Platelet phagocytosis by leukocytes in a patient with cerebral hemorrhage and thrombocytopenia caused by gram-negative bacterial infection.

Bacteria-induced thrombocytopenia is a common clinical disease that is often ignored by clinical and scientific research. Thus, exploring the mechanism and principle of bacteria-induced thrombocytopenia could facilitate the development of new diagnostic, preventative, and treatment modalities for thrombocytopenia. This case report describes a case of platelet phagocytosis by neutrophils and monocytes in a patient with cerebral hemorrhage and thrombocytopenia caused by gram-negative bacterial infection. After the infection was eradicated, platelet phagocytosis was alleviated, and his platelet count normalized. Cellular immunity may be an important cause of bacteria-induced thrombocytopenia in patients with cerebral hemorrhage.

Sphingomonas paucimobilis - a rare cause of splenic abscesses: A case report.

RATIONALE: Infections with Sphingomonas paucimobilis are rarely described in the literature and can be community-acquired or associated with healthcare, especially in patients with chronic conditions (e.g., diabetes mellitus), malignancies, or other causes of immunosuppression, except in people without comorbidities. We present the case of a patient with diabetes mellitus and hypertension diagnosed during a routine evaluation, with splenic abscess caused by S paucimobilis. Our literature search revealed no other case report of splenic abscess caused only by S paucimobilis. PATIENT CONCERNS: We present the case of a 55-year-old Caucasian man with type 2 diabetes mellitus and hypertension. DIAGNOSIS: Thoraco-abdominal computed tomography revealed splenomegaly of 20X16X18 cm, with a homogeneous subcapsular hypodense collection, with a mass effect on the left hemidiaphragm. INTERVENTIONS: The patient underwent surgical intervention and S paucimobilis was isolated on blood agar. OUTCOME: The patient received treatment with ciprofloxacin (500 mg twice daily) for 14 days, with favorable outcomes. LESSONS: S paucimobilis, a low-virulence bacterium, can cause community-acquired or nosocomial infections. Visceral localizations, usually symptomatic, can evolve rapidly, and the diagnosis is associated with complications or, as in our case, with careful investigation of some changes in laboratory investigations.