Abscess Research Articles

Early sterile splenic abscess following vehicular trauma in a dog

Early sterile splenic abscess following vehicular trauma in a dog

A case series of melioidosis: An underdiagnosed entity in Kerala

Abstract Melioidosis is an emerging infection in India and is caused by a Gram-negative oxidase-positive bacilli, Burkholderia pseudomallei which is present in soil and surface water in the endemic region. Clinical manifestations are protean varying from asymptomatic infection, multiple skin abscesses, chronic pneumonia mimicking tuberculosis, and fulminant septic shock with abscesses in multiple internal organs. Isolation of bacilli from aspirated fluids remains the gold standard of diagnosis. Lack of microbiological services in many parts of the state, protean nature of clinical manifestations, lack of awareness among clinicians, and misidentification of the organism as Pseudomonas spp leads to delay in diagnosis and treatment. We have, retrospectively, analyzed 14 cases with culture-proven melioidosis diagnosed during 10 years. Case records of culture-positive patients were retrospectively analyzed for demographic data, clinical characteristics, management, complications, and clinical outcomes. Out of these, 13 cases were male. The most common age group affected was 50–59 years. The major occupation affected was manual laborer. Nonbacteremic melioidosis accounted for 12 cases. Concerning clinical presentations, intra-abdominal abscesses mainly in the liver and spleen accounted for seven cases. All the isolates were susceptible to ceftazidime, meropenem, and doxycycline, whereas 12 isolates were susceptible to chloramphenicol, 11 isolates were susceptible to trimethoprim–sulfamethoxazole combination, and 10 cases were susceptible to amoxicillin–clavulanic acid and ciprofloxacin. Ten cases recovered with ceftazidime administration along with surgical drainage of abscess and three cases recovered with meropenem administration and surgical drainage. One patient expired and was on piperacillin–tazobactam. Melioidosis is a disease of public health importance and early clinical and laboratory diagnosis is crucial in the effective management of melioidosis.

Development of amphipathic derivatives of thymol and carvacrol as potent broad-spectrum antibacterial agents

In the current study, to discover novel antibacterial agents, we designed and synthesized 72 carvacrol and thymol derivatives by biomimicking the structure and function of cationic antimicrobial peptides (AMPs). Many of the derivatives showed good antibacterial activity, and compound thy2I exhibited the most potent antibacterial activity with minimum inhibitory concentration (MIC) values ranging from 0.5 μg/mL to 8 μg/mL. Compound thy2I could kill both gram-positive and gram-negative bacteria via a membrane-targeting mechanism of action with a low frequency of resistance. In addition, thy2I had the advantages of good membrane selectivity, low toxicity in vitro and in vivo, and good plasma stability. The in vivo activity results revealed that thy2I exhibited a positive therapeutic effect in a mouse skin abscess model induced by Staphylococcus aureus ATCC29213. After thy2I treatment (10 mg/kg), the bacterial load of the S. aureus-infected abscesses was reduced by approximately 99.65 %. Our study suggests that thy2I may serve as an antibacterial lead for further clinical evaluation.

Antimicrobial Evaluation of Two Polycyclic Polyprenylated Acylphloroglucinol Compounds: PPAP23 and PPAP53.

Polycyclic polyprenylated acylphloroglucinols (PPAPs) comprise a large group of compounds of mostly plant origin. The best-known compound is hyperforin from St. John's wort with its antidepressant, antitumor and antimicrobial properties. The chemical synthesis of PPAP variants allows the generation of compounds with improved activity and compatibility. Here, we studied the antimicrobial activity of two synthetic PPAP-derivatives, the water-insoluble PPAP23 and the water-soluble sodium salt PPAP53. In vitro, both compounds exhibited good activity against methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus faecium. Both compounds had no adverse effects on Galleria mellonella wax moth larvae. However, they were unable to protect the larvae from infection with S. aureus because components of the larval coelom neutralized the antimicrobial activity; a similar effect was also seen with serum albumin. In silico docking studies with PPAP53 revealed that it binds to the F1 pocket of human serum albumin with a binding energy of -7.5 kcal/mol. In an infection model of septic arthritis, PPAP23 decreased the formation of abscesses and S. aureus load in kidneys; in a mouse skin abscess model, topical treatment with PPAP53 reduced S. aureus counts. Both PPAPs were active against anaerobic Gram-positive gut bacteria such as neurotransmitter-producing Clostridium, Enterococcus or Ruminococcus species. Based on these results, we foresee possible applications in the decolonization of pathogens.

De novo primary malignant lymphoma of the dura following recurrent episodes of subdural abscess presenting as chronic subdural hematoma: illustrative case.

Chronic inflammation of the thorax, as in tuberculosis-related pyothorax, can cause secondary malignant lymphomas. However, primary malignant lymphoma of the central nervous system, specifically of the dura mater, developing after intracranial infection or inflammation has rarely been reported. Herein, the authors describe a case of primary dural lymphoma that developed secondary to subdural empyema, with an initial presentation mimicking a chronic subdural hematoma. A 51-year-old man had undergone single burr hole drainage for subdural empyema 2 years prior. The patient subsequently underwent multiple craniotomy and drainage procedures, with successful remission of the subdural empyema. He was subsequently referred to the authors' hospital approximately a year after his initial treatment because of a recollection of subdural fluid, which was suspected to be recurrent empyema. After another single burr hole drainage, which revealed only a subdural hematoma, a histopathological diagnosis of B-cell lymphoma of the dural/subdural membrane was made. Subsequent radiation therapy was completed, with good local control and no recurrence of the subdural hematoma confirmed at 2 months posttreatment. Intracranial lymphoma triggered by chronic inflammation is rare but should be considered a differential diagnosis in subdural hematomas for which the background pathology is unclear. https://thejns.org/doi/10.3171/CASE24153.

Comparison of infection risk between enzalutamide and abiraterone in patients with prostate cancer.

Enzalutamide and abiraterone may differ in their immunomodulatory effects, and the prednisone coadministered with abiraterone can be immunosuppressive. This study aimed to compare the risk of different types of infection in patients with prostate cancer receiving enzalutamide or abiraterone in combination with androgen deprivation therapy. Patients with prostate cancer receiving enzalutamide or abiraterone in addition to androgen deprivation therapy in Hong Kong between December 1999 to March 2021 were identified in this retrospective cohort study and followed up until September 2021, death, or crossover. Outcomes, including any sepsis, pneumonia, urinary tract infection, cellulitis or skin abscess, central nervous system infections, and tuberculosis, were analyzed as both time-to-event outcomes (multivariable Fine-Gray regression, with mortality considered a competing event) and recurrent-event outcomes (multivariable negative binomial regression). Altogether, 1582 patients were analyzed (923 abiraterone users; 659 enzalutamide users) with a median follow-up of 10.6 months (interquartile range: 5.3-19.9 months). Compared to abiraterone users, enzalutamide users had lower cumulative incidences of sepsis (adjusted subhazard ratio [SHR] 0.70 [0.53-0.93], p=.014), pneumonia (adjusted SHR 0.76 [0.59-0.99], p=.040), and cellulitis or skin abscess (adjusted SHR 0.55 [0.39-0.79], p=.001), but not urinary tract infection (adjusted SHR 0.91 [0.62-1.35], p=.643). Associations between exposure and central nervous system infections and tuberculosis were not assessed because of low event rates. Analyzing the outcomes as recurrent events gave similar results. Enzalutamide use may be associated with a lower risk of urinary tract infection in patients with diabetes mellitus. Compared to abiraterone users, enzalutamide users have significantly lower risks of sepsis, pneumonia, cellulitis, or skin abscess.

Canadian emergency department best practices checklist for skin and soft tissue infections part 2: skin abscess.

Canadian emergency department best practices checklist for skin and soft tissue infections part 2: skin abscess.

Investigation and control of an outbreak of methicillin-susceptible Staphylococcus aureus skin and soft tissue infections in a level IV NICU

Background: Neonatal intensive care units (NICU) outbreaks caused by methicillin-susceptible Staphylococcus aureus (MSSA) are less commonly reported than outbreaks caused by methicillin-resistant S. aureus. We report an unusual outbreak of MSSA skin and soft tissue infections (SSTIs) in a level IV NICU investigated by whole genome sequencing (WGS) and molecular typing. Methods: An investigation was initiated in a 56-single-bed NICU after four patients developed MSSA SSTIs in Week 1. Case-patients had positive MSSA cultures identified by clinical cultures or surveillance sampling (bilateral nares, axillae, umbilicus, and groin), and antibiotic susceptibility testing was performed. WGS and assessment of isolate relatedness through mutation event analysis and multi-locus sequence typing (MLST) was performed by the NYS DOH. Demographic and isolate characteristics were compared using Wilcoxon rank sum test, Fisher’s exact test and Pearson’s Chi-squared test, as appropriate. Results: From Week 2 to Week 32, 9 rounds of surveillance for MSSA colonization were conducted. In all, 30 case-patients had MSSA colonization and 16 infants developed infections including impetigo (n=7), pustules (n=5), staphylococcal scalded skin syndrome (SSSS, n=2), abscess (n=1), and bacteremia (n=1). All SSTI cases presented on infants’ faces, all of whom were on non-invasive respiratory support. MLST identified 4 distinct types including MLST 121 (n=12), MLST 398 (n=10), MLST 30 (n=6), and MLST 15 (n=6). Eight isolates were unrelated to other isolates. MLST 398 and MLST 30 included isolates not closely related (>9 mutation events). The 12 MLST 121 isolates were closely related (≤9 mutational events between all isolates), harbored the mupA gene, and were mupirocin-resistant (MIC>1024 ug/ml). Clinical infection and mupirocin resistance were associated with MLST 121 (Table 1). Multiple infection control measures were implemented, including increased availability of alcohol-based hand sanitizers, introducing bare-below-the-elbows practice for staff, contact precautions for case-patients, decolonization with mupirocin and chlorhexidine baths, environmental cleaning/disinfection, and removing excess equipment and supplies. No new cases of mupirocin-resistant or MLST 121 SSTIs occurred after Week 25. Conclusion: We report a MSSA outbreak associated with multiple MLST types and a predominant mupirocin-resistant strain. This report highlights the ability of molecular typing to characterize strains causing infections versus colonization and the potential loss of mupirocin as a control measure when outbreaks are caused by mupirocin-resistant strains. WGS analysis allows for increased discrimination of mutation events allowing for improved resolution of case relatedness compared to other typing methods. Successful control of this outbreak was achieved with a multitude of infection prevention and control.

Copper‐Cysteine Nanostructures for Synergetic Photothermal Therapy and Chemodynamic Therapy of Bacterial Skin Abscesses

AbstractSkin lesions, including skin bacterial abscesses, have become one of the most important health challenges and usually need systemic high‐dose antibiotics. Therefore, it is of particular importance to develop novel approaches for treating this ever‐growing challenge to human health. To address this challenge, herein a copper nanostructure is developed giving combined photothermal and chemodynamic therapies for focal infection treatment. The Cu‐based nanostructures with intrinsic catalytic properties are prepared by D‐L or L cysteine (Cys) as ligand and copper ions. It is shown that the multifunctional copper‐Cys (Cu‐Cys) nanostructures can produce reactive oxygen species (ROS) and they exhibit near infrared (NIR)‐enhanced catalytic activities to improve ROS production for highly efficient eradication of bacteria. Moreover, the results proved O2 evolution property of the Cu‐Cys nanoparticles (NPs). The nanostructures show shape‐dependent antibacterial activity where DL‐Cu‐Cys NPs show higher bactericidal performance than L‐Cu‐Cys NPs. In vitro results demonstrate that 2.5 and 1.25 µg mL−1 of DL‐Cu‐Cys NPs is enough to achieve rapid killing of Escherichia coli (E. coli) or Staphylococcus aureus (S. aureus) respectively under 808 nm light irradiation in 10 min. This work introduces a unique photoactive nanoagent to efficiently treat subcutaneous abscess by combining NIR light‐triggered photothermal effect and catalytic generation of ROS without using any antibiotic.

Unusual Presentation of Chromoblastomycosis Masquerading as Cutaneous Abscess on the Back: A Case Report

Chromoblastomycosis, a chronic cutaneous mycosis caused by pigmented fungi, is typically associated with trauma in the exposed parts of the body. We report a 68-year-old male farmer diagnosed with chromoblastomycosis clinically mimicking a cutaneous abscess on the back, an unusual location. Histopathological and mycological examination identified Fonsecaea pedrosoi. Treatment with itraconazole and cryotherapy showed improvement after 4 months. High suspicion index and biopsy are imperative for early diagnosis of chromoblastomycosis. This case adds to the limited cases reported in Korea, emphasizing the importance of considering chromoblastomycosis in diverse clinical presentations.

Epidemiological assessment of non-tuberculous mycobacterial cervicofacial lymphadenitis: A PHIS database study

ObjectiveCervicofacial lymphadenitis caused by non-tubercular mycobacterial (NTM) infections has the highest infection rate in children. Our objective was to assess patient demographics, treatment methods, and the impact of weather and geography on the incidence of disease in patients with NTM cervicofacial lymphadenitis. MethodsThe Pediatric Health Information System (PHIS) database was queried for data on all patients diagnosed with concurrent cervicofacial lymphadenopathy and NTM infection from 2004 to 2022. We assessed the association between weather patterns and NTM cervicofacial lymphadenitis by collecting monthly weather data from the NOAA National Center for Environmental Information. Incidence rates were calculated by dividing the number of cases by the total hospital discharges during the study period. ResultsAmong 47 PHIS hospitals, there were 992 diagnoses of NTM cervicofacial lymphadenitis. The average age at diagnosis was 2 [IQR, 2–4], with 59 % female. Drainage of skin abscesses or lesions was performed for 93 (9.4 %) patients, while 15 (1.5 %) had an excisional procedure of the CPT codes assessed. The most common antibiotics utilized were cephalosporins (28 %), macrolides (27 %), and rifampin (12 %). The most common treatment method was surgery with antibiotics (37 %) followed by no treatment at all (35 %), surgery alone (17 %), and antibiotics alone (10 %). Of the 28 states included in the analysis, Washington (IR: 3.5) and Nebraska (IR: 3.3) had the highest incidence rates (IR) of NTM cervical lymphadenitis. The cases were relatively equally distributed across the different weather seasons within each U.S. geographic region. However, the overall average wind speed was weakly associated with increasing the risk of diagnosis when utilizing a mixed effect zero-inflated negative binomial model (Incidence Ratio: 1.07, 95 % CI: (1.01–1.14), p = 0.035). ConclusionsOur results indicate that the most common treatment method utilized in patients within our cohort with NTM cervicofacial lymphadenitis was the concurrent use of surgery and antibiotics. Our results also indicate there may be variation in the incidence rate among different states, but additional studies are needed as our cohort only included approximately 50 % of states within the U.S.

Sweet syndrome in pregnancy: A narrative review.

The aim of this review is to increase obstetrician awareness of pregnancy-associated Sweet syndrome. Patients present with fever, leukocytosis, and skin eruption, which can mimic other infectious or inflammatory conditions, but do not respond to antibiotics. A search using PubMed, EMBASE, and Web of Science Core Collection was conducted to review all reported cases of pregnancy-associated Sweet syndrome, an acute febrile neutrophilic dermatosis occurring during pregnancy or postpartum. A total of 33 episodes among 30 patients were identified, with the majority (54.5% [18]) of cases occurringwithin the second trimester. Among the 30 patients, skin lesions most commonly affected the head and neck (73.3% [22]), with rare oral or ocular involvement. Leukocytosis was the most common laboratory finding, reported in 96.7% [29] of patients, with neutrophil predominance noted in 70.0% [21]. The diagnosis was confirmed for all patients with pathognomonic results of skin biopsies. Of the 27 cases detailing treatment, systemic corticosteroids were most frequently used (19 cases), followed by conservative management (seven cases), and dapsone (one case). The dapsone-treated patient and 15 of the 19 steroid-treated patients experienced resolution, but additional management strategies were required in the remaining four individuals. Spontaneous resolution occurred during pregnancy in six of the seven conservatively managed individuals, with one patient experiencing spontaneous abortion shortly after skin eruption at 10 weeks of gestation. No associated maternal deaths were reported. Obstetric complications of pregnancy-associated Sweet syndrome included endomyometritis, sterile placental abscesses, and abdominal wall necrosis. Delivery of healthy infants occurred in 24 of the 25 cases that presented fetal outcome, which included two infants who underwent medically indicated preterm deliveries.

Deep-learning-enabled antibiotic discovery through molecular de-extinction.

Molecular de-extinction aims at resurrecting molecules to solve antibiotic resistance and other present-day biological and biomedical problems. Here we show that deep learning can be used to mine the proteomes of all available extinct organisms for the discovery of antibiotic peptides. We trained ensembles of deep-learning models consisting of a peptide-sequence encoder coupled with neural networks for the prediction of antimicrobial activity and used it to mine 10,311,899 peptides. The models predicted 37,176 sequences with broad-spectrum antimicrobial activity, 11,035 of which were not found in extant organisms. We synthesized 69 peptides and experimentally confirmed their activity against bacterial pathogens. Most peptides killed bacteria by depolarizing their cytoplasmic membrane, contrary to known antimicrobial peptides, which tend to target the outer membrane. Notably, lead compounds (including mammuthusin-2 from the woolly mammoth, elephasin-2 from the straight-tusked elephant, hydrodamin-1 from the ancient sea cow, mylodonin-2 from the giant sloth and megalocerin-1 from the extinct giant elk) showed anti-infective activity in mice with skin abscess or thigh infections. Molecular de-extinction aided by deep learning may accelerate the discovery of therapeutic molecules.

Cost-effectiveness of drug consumption rooms in France: a modelling study

BackgroundPeople who inject drugs (PWID) experience many health problems which result in a heavy economic and public health burden. To tackle this issue, France opened two drug consumption rooms (DCRs) in Paris and Strasbourg in 2016. This study assessed their long-term health benefits, costs and cost-effectiveness.MethodsWe developed a model to simulate two fictive cohorts for each city (n=2,997 in Paris and n=2,971 in Strasbourg) i) PWID attending a DCR over the period 2016-2026, ii) PWID attending no DCR. The model accounted for HIV and HCV infections, skin abscesses and related infective endocarditis, drug overdoses and emergency department visits. We estimated the number of health events and associated costs over 2016-2026, the lifetime number of quality-adjusted life-years (QALYs) and costs, and the incremental cost-effectiveness ratio (ICER).ResultsThe numbers of abscesses and associated infective endocarditis, drug overdoses, and emergency department visits decreased significantly in PWID attending DCRs (-77%, -69%, and -65%, respectively) but the impact on HIV and HCV infections was modest (-11% and -6%, respectively). This resulted in savings of €6.6 (Paris) and €5.8 (Strasbourg) millions of medical costs. The ICER of DRCs was €30,600/QALY (Paris) and €9,200/QALY (Strasbourg). In scenario analysis where drug consumption spaces are implemented inside existing harm reduction structures, these ICERs decreased to €21,400/QALY and €2,500/QALY, respectively.ConclusionsOur findings show that DCRs are highly effective and efficient to prevent harms in PWID in France, and advocate extending this intervention to other cities by adding drug consumption spaces inside existing harm reduction centers.

Propylthiouracil-Induced Anti-Neutrophil Cytoplasmic Antibody (ANCA)-Associated Vasculitis Presenting with Multiple Sterile Abscesses, Mononeuritis Multiplex, and Splenic Vein Thrombosis: A Case Report and Literature Review

Propylthiouracil-Induced Anti-Neutrophil Cytoplasmic Antibody (ANCA)-Associated Vasculitis Presenting with Multiple Sterile Abscesses, Mononeuritis Multiplex, and Splenic Vein Thrombosis: A Case Report and Literature Review

Clinical presentation and treatment of 2 patients with infection caused by Chromobacterium violaceum in Vietnam

Chromobacterium violaceum is a rare but severe and often fatal cause of disease in humans. We present 2 clinical cases of sepsis and skin abscesses / cellulitis caused by C. violaceum seen in a referral hospital for infectious diseases in Vietnam. Both patients survived, but appropriate antibiotic treatment was only installed after culture of the organism. We reviewed and summarised the characteristics of C. violaceum infection and treatment.

Case of successful treatment of spinal infection in a patient with high comorbidity and septic manifestations

The study presents a clinical case of complex treatment of a patient with high comorbidity (Charlson comorbidity index = 6 points) who had severe sepsis (SOFA score = 8 points) with multiple foci of pyogenic infection (spinal epiduritis, paravertebral and subdural abscesses, purulent meningitis, bilateral lower lobe pneumonia). The syndrome-based approach with the use of minimally invasive approaches in the early stages (no later than 12 hours from the onset of clinical manifestations of the disease) ensured a favorable outcome. Based on the results of surgical treatment, a conclusion was made about the tactics of surgical treatment in patients with spinal infection against the background of sepsis.

A membrane-targeting magnolol derivative for the treatment of methicillin-resistant Staphylococcus aureus infections.

Multidrug-resistant bacterial infections are a major global health challenge, especially the emergence and rapid spread of methicillin-resistant Staphylococcus aureus (MRSA) urgently require alternative treatment options. Our study has identified that a magnolol derivative 6i as a promising agent with significant antibacterial activity against S. aureus and clinical MRSA isolates (MIC = 2-8 μg/mL), showing high membrane selectivity. Unlike traditional antibiotics, 6i demonstrated rapid bactericidal efficiency and a lower propensity for inducing bacterial resistance. Compound 6i also could inhibit biofilm formation and eradicate bacteria within biofilms. Mechanistic studies further revealed that 6i could target bacterial cell membranes, disrupting the integrity of the cell membrane and leading to increased DNA leakage, resulting in potent antibacterial effects. Meanwhile, 6i also showed good plasma stability and excellent biosafety. Notably, 6i displayed good in vivo antibacterial activity in a mouse skin abscess model of MRSA-16 infection, which was comparable to the positive control vancomycin. These findings indicated that the magnolol derivative 6i possessed the potential to be a novel anti-MRSA infection agent.

Using host-mimicking conditions and a murine cutaneous abscess model to identify synergistic antibiotic combinations effective against Pseudomonas aeruginosa.

Antibiotic drug combination therapy is critical for the successful treatment of infections caused by multidrug resistant pathogens. We investigated the efficacy of β-lactam and β-lactam/β-lactamase inhibitor combinations with other antibiotics, against the hypervirulent, ceftazidime/avibactam resistant Pseudomonas aeruginosa Liverpool epidemic strain (LES) B58. Although minimum inhibitory concentrations in vitro differed by up to eighty-fold between standard and host-mimicking media, combinatorial effects only marginally changed between conditions for some combinations. Effective combinations in vitro were further tested in a chronic, high-density murine infection model. Colistin and azithromycin demonstrated combinatorial effects with ceftazidime and ceftazidime/avibactam both in vitro and in vivo. Conversely, while tobramycin and tigecycline exhibited strong synergy in vitro, this effect was not observed in vivo. Our approach of using host-mimicking conditions and a sophisticated animal model to evaluate drug synergy against bacterial pathogens represents a promising approach. This methodology may offer insights into the prediction of combination therapy outcomes and the identification of potential treatment failures.

Enhancing the stability and therapeutic potential of the antimicrobial peptide Feleucin-K3 against Multidrug-Resistant a. Baumannii through rational utilization of a D-amino acid substitution strategy

Antimicrobial peptides (AMPs), which have a low probability of developing resistance, are considered the most promising antimicrobial agents for combating antibiotic resistance. Feleucin-K3 is an amphiphilic cationic AMP that exhibits broad-spectrum antimicrobial activity. In our previous research, the first phenylalanine residue was identified as the critical position affecting its biological activity. Here, a series of Feleucin-K3 analogs containing hydrophobic D-amino acids were developed, leveraging the low sensitivity of proteases to unnatural amino acids and the regulatory effect of hydrophobicity on antimicrobial activity. Among them, K-1dF, which replaced the phenylalanine of Feleucin-K3 with its enantiomer (D-phenylalanine), exhibited potent antimicrobial activity with a therapeutic index of 46.97 and MICs between 4 to 8 μg/ml against both sensitive and multidrug-resistant Acinetobacter baumannii. The introduction of D-phenylalanine increased the salt tolerance and serum stability of Feleucin-K3. Moreover, K-1dF displayed a rapid bactericidal effect, a low propensity to develop resistance, and a synergistic effect when combined with antibiotics. More importantly, it exhibited considerable or superior efficacy to imipenem against pneumonia and skin abscess infection. In brief, the K-1dF obtained by simple and effective modification strategy has emerged as a promising candidate antimicrobial agent for tackling multidrug-resistant Acinetobacter baumannii infections.