Capnocytophaga canimorsus is a bacterium commonly found in the oral cavities of cats and dogs. Infections are particularly common in immunocompromised patients who have been exposed to bites or come in contact with saliva from these animals. The manifestations of infection include bacteremia, fever, and, rarely, meningitis. Diagnosis is challenging given the bacteria has slow growth on culture media. The organism is susceptible to beta-lactam antibiotics, with higher-generation cephalosporins recommended for treating meningitis. We present a case of a 74-year-old woman with altered mental status and no signs of immunosuppression. She was diagnosed with meningitis caused by Capnocytophaga, with an intriguing finding of pneumocephalus, which is a rare occurrence as per literature review.

Paenochrobactrum pullorum is a gram-negative bacterium and is not usually considered a human pathogen. This is the first case report of P. pullorum, highlighting the importance of understanding its clinical significance. The author reports a case of P. pullorum bacteremia from bilateral lower extremity wound infection.

Ochrobactrum anthropi is a non-fermenting, Gram-negative bacillus and an emerging opportunistic pathogen. We have isolated this organism from the blood cultures of two patients, a 53-year-old immunocompetent male presenting with an episode of mild fever post craniotomy and an 85-year-old male with chronic obstructive pulmonary disease (COPD) and urinary retention on an indwelling catheter. The organism was identified using VITEK 2 (bioMérieux, France). Both the isolates were resistant to most of the β-lactams, including cephalosporins, and sensitive to quinolones, aminoglycosides, and carbapenems.

BACKGROUND: The mortality rate of afebrile bacteremia has been reported to be as high as 45%. This investigation focused on the risk factors and predictive performance of scoring systems for the clinical outcomes of afebrile patients with monomicrobial gram-negative bacteria (GNB) in the emergency department (ED).
METHODS: We conducted a retrospective analysis of afebrile adult ED patients with monomicrobial GNB bacteremia from January 2012 to December 2021. We dissected the demographics, clinical pictures, and laboratory investigations. We applied five scoring systems and three revised systems to predict the clinical outcomes.
RESULTS: There were 600 patients included (358 males and 242 females), with a mean age of 69.6 ± 15.4 years. The overall mortality rate was 50.17%, reaching 68.52% (74/108) in cirrhotic patients. Escherichia coli was the leading pathogen (42.83%). The non-survivors had higher scores of the original MEDS (p < 0.001), NEWS (p < 0.001), MEWS (p < 0.001), qSOFA (p < 0.001), and REMS (p = 0.030). In univariate logistic regression analyses, several risk factors had a higher odds ratio (OR) for mortality, including liver cirrhosis (OR 2.541, p < 0.001), malignancy (OR 2.259, p < 0.001), septic shock (OR 2.077, p = 0.002), and male gender (OR 0.535, p < 0.001). The MEDS demonstrated that the best predictive power with the maximum area under the curve (AUC) was measured at 0.773 at the cut-off point of 11. The AUCs of the original NEWS, MEWS, qSOFA, and REMS were 0.663, 0.584, 0.572, and 0.553, respectively. We revised the original MEDS, NEWS, and qSOFA by adding red cell distribution width, albumin, and lactate scores and found a better predictive power of the AUC of 0.797, 0.719, and 0.694 on the revised MEDS ≥11, revised qSOFA ≥ 3, and revised NEWS ≥ 6, respectively.
CONCLUSIONS: The original MEDS, revised MEDS, revised qSOFA, and revised NEWS were valuable tools for predicting the mortality risk in afebrile patients with monomicrobial GNB bacteremia. We suggested that clinicians should explore patients with the risk factors mentioned above for possible severe infection, even in the absence of fever and initiate hemodynamic support and early adequate antibiotic therapy in patients with higher scores of the original MEDS (≥11), revised MEDS (≥11), revised NEWS (≥6), and revised qSOFA (≥3).

A 70-year-old female, diagnosed with mitochondrial diabetes mellitus (MDM) showing previously a point mutation at mitochondrial DNA 3316G>A, noticed urinary tract infection and diabetic gangrene of the foot with Gram-negative Bacteroides fragilis bacteremia, followed by aggressive jaundice with high serum level of direct bilirubin. She died two months after the symptom onset. At autopsy, multiple foci of bacteremia-induced hemorrhagic infarction were observed in the congestive bilateral lungs, whereas the cholestatic liver revealed no overt gross cholangiectasis. Microscopic findings characteristically showed many bile thrombi in the biliary canaliculi of hepatic lobules without any evidence of severe shock liver. Finally, we diagnosed it exclusively as sepsis-associated cholestasis due to the marked elevation of Gram-negative bacteria-derived endotoxins and inflammatory cytokines. We propose that these unique liver features in our MDM case might be one of the new clues to unveil its enigmatic etiology.

UNASSIGNED: Robust data are lacking regarding the optimal route, duration, and antibiotic choice for gram-negative bloodstream infection from a complicated urinary tract infection source (GN-BSI/cUTI).
UNASSIGNED: In this multicenter observational cohort study, we simulated a 4-arm registry trial using a causal inference method to compare effectiveness of the following regimens for GN-BSI/cUTI: complete course of an intravenous β-lactam (IVBL) or oral stepdown therapy within 7 days using fluoroquinolones (FQs), trimethoprim-sulfamethoxazole (TMP-SMX), or high-bioavailability β-lactams (HBBLs). Adults treated between January 2016 and December 2022 for Escherichia coli or Klebsiella species GN-BSI/cUTI were included. Propensity weighting was used to balance characteristics between groups. The 60-day recurrence was compared using a multinomial Cox proportional hazards model with probability of treatment weighting.
UNASSIGNED: Of 2571 patients screened, 759 (30%) were included. Characteristics were similar between groups. Compared with IVBLs, we did not observe a difference in effectiveness for FQs (adjusted hazard ratio, 1.09 [95% confidence interval, .49-2.43]) or TMP-SMX (1.44 [.54-3.87]), and the effectiveness of TMP-SMX/FQ appeared to be optimal at durations of >10 days. HBBLs were associated with nearly 4-fold higher risk of recurrence (adjusted hazard ratio, 3.83 [95% confidence interval, 1.76-8.33]), which was not mitigated by longer treatment durations. Most HBBLs (67%) were not optimally dosed for bacteremia. Results were robust to multiple sensitivity analyses.
UNASSIGNED: These real-world data suggest that oral stepdown therapy with FQs or TMP-SMX have similar effectiveness as IVBLs. HBBLs were associated with higher recurrence rates, but dosing was suboptimal. Further data are needed to define optimal dosing and duration to mitigate treatment failures.

The Pantoea genus of bacteria is a group of Gram-negative rod-shaped bacteria in the Enterobacteriaceae family. It is an uncommon cause of infection in humans except in specific settings, including hospital-acquired infections and in immunocompromised patients. In this report, we describe the case of a 12-year-old girl with sickle cell disease who presented with a picture of sepsis and was found to have Pantoea species in her blood culture which was treated with antibiotics with a good response. From our literature review, risk factors were identified in the reported cases, for which further exploration is highly recommended.

Non-typhoidal Salmonella typically presents with gastroenteritis. However, an invasive Salmonella infection, which may be typically seen in immunocompromised patients, has a propensity for aortic involvement, especially in patients with risk factors for atherosclerosis. Here we present a 60-year-old female with multiple comorbid conditions and currently on immunosuppressants for rheumatoid arthritis, who presented with nausea, vomiting, and fever of three weeks duration and was found to have Salmonella bacteremia. Blood cultures were positive for Salmonella enterica. Computed tomography (CT) abdomen with contrast was concerning for mycotic aortitis. The patient underwent endovascular repair of an aortic ulcer and was treated with a six-week course of ceftriaxone. Mycotic aneurysm is a rare but potentially fatal complication of invasive Salmonella infection. It occurs typically in older men with atherosclerotic risk factors. It mostly presents as fever, back pain, and/or abdominal pain. Our patient was a middle-aged female who presented with non-specific symptoms. CT angiogram is the diagnostic modality of choice and treatment may require surgical vascular repair and long-term antibiotics. A high level of suspicion is needed to diagnose Salmonella-related mycotic aneurysm/aortitis. Early diagnosis and treatment may improve the mortality.

UNASSIGNED: Fluoroquinolones (FQs) are effective for oral step-down therapy for gram-negative bloodstream infections but are associated with unfavorable toxic effects. Robust data are lacking for trimethoprim-sulfamethoxazole (TMP-SMX) and high-bioavailability β-lactams (HBBLs).
UNASSIGNED: In this multicenter observational cohort study, we simulated a 3-arm registry trial using causal inference methods to compare the effectiveness of FQs, TMP-SMX, or HBBLs for gram-negative bloodstream infections oral step-down therapy. The study included adults treated between January 2016 and December 2022 for uncomplicated Escherichia coli or Klebsiella species bacteremia of urinary tract origin who were who were transitioned to an oral regimen after ≤4 days of effective intravenous antibiotics. Propensity weighting was used to balance characteristics between groups. 60-day recurrence was compared using a multinomial Cox proportional hazards model with probability of treatment weighting.
UNASSIGNED: Of 2571 patients screened, 648 (25%) were included. Their median age (interquartile range) was 67 (45-78) years, and only 103 (16%) were male. Characteristics were well balanced between groups. Compared with FQs, TMP-SMX had similar effectiveness (adjusted hazard ratio, 0.91 [95% confidence interval, .30-2.78]), and HBBLs had a higher risk of recurrence (2.19 [.95-5.01]), although this difference was not statistically significant. Most HBBLs (70%) were not optimally dosed for bacteremia. A total antibiotic duration ≤8 days was associated with a higher recurrence rate in select patients with risk factors for failure.
UNASSIGNED: FQs and TMP-SMX had similar effectiveness in this real-world data set. HBBLs were associated with higher recurrence rates but suboptimal dosing may have contributed. Further studies are needed to define optimal BL dosing and duration to mitigate treatment failures.

Introduction Bloodstream infections caused by Gram-negative rods are a pressing concern for the aging global population, particularly in rural settings. This study investigates the prevalence and entry pathways of Gram-negative rod bloodstream infections in elderly patients at a rural Japanese hospital, aiming to clarify the frequency and associated factors of straightforward entry and bacterial translocation. Method In this cross-sectional study, we analyzed electronic medical records of patients over 18 years of age with symptomatic Gram-negative rod bloodstream infections at Unnan City Hospital, Japan, from September 2021 to August 2023. We used multivariate logistic regression to assess factors of age, sex, body mass index, care dependency, and comorbidities. Results Among the participants who met the inclusion criteria, significant differences were observed in age, sex, inpatient status, and prevalence of conditions like respiratory diseases and cancer between the straightforward entry and bacterial translocation groups. Escherichia coli was the most common pathogen identified. Conclusion The study emphasizes the need for tailored medical approaches for elderly patients with bloodstream infections, considering their unique health profiles and risks. It highlights the importance of age, inpatient status, and cancer in determining infection risks, pointing to areas for further research to enhance infection management and healthcare outcomes in older populations.