Bacterial Abscess Research Articles

Brain Abscess Causes Brain Damage With Long-Lasting Focal Cerebral Hypoactivity that Correlates With Abscess Size: A Cross-Sectional 18F-Fluoro-Deoxyglucose Positron Emission Tomography Study.

Bacterial brain abscesses may have long-term clinical consequences, eg, mental fatigue or epilepsy, but long-term structural consequences to the brain remain underexplored. We asked if brain abscesses damage brain activity long term, if the extent of such damage depends on the size of the abscess, and if the abscess capsule, which is often left in place during neurosurgery, remains a site of inflammation, which could explain long-lasting symptoms in patients with brain abscess. 2-[18F]-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (FDG-PET/CT), electroencephalography, and MRI were performed 2 days to 9 years after neurosurgery for bacterial brain abscess. FDG-PET/CT revealed hypometabolism in the neocortex or cerebellum overlying the previous bacterial abscess in 38 of 40 patients. The larger the abscess, the greater was the extent of the subsequent hypometabolism (r = 0.63; p = 3 × 10-5). In 9 patients, the extent of subsequent hypometabolism seemed to coincide with the extent of peri-abscess edema in the acute phase. Follow-up MRI after ≥1 year in 9 patients showed focal tissue loss and gliosis. In 13 patients with abnormal electroencephalography recordings, abnormalities extended beyond the cerebral lobe affected by the abscess, indicating damage to wider brain networks. The abscess capsule had an FDG signal indicating inflammation only during the first week after neurosurgical pus drainage. The bigger a brain abscess is allowed to grow, the more extensive is the long-term focal reduction in brain activity. This finding emphasizes the need for rapid neurosurgical intervention. The abscess capsule does not display long-lasting inflammation and probably does not explain long-term symptoms after brain abscess.

Detection of Gram-positive and Gram-negative bacteria in brain abscesses by 16S rRNA in situ hybridization.

In situ hybridization (ISH) staining of bacterial 16S ribosomal RNA (rRNA) is an alternative to standard histological stains (eg, Gram, Warthin-Starry), and may improve the diagnosis of bacterial brain abscesses. To evaluate the utility of 16S rRNA ISH, a 10-year retrospective cohort was assembled from a large academic medical center. Results of histological stains, cultures, and 16S rRNA sequencing were extracted from reports, and new Gram and 16S rRNA ISH stains were performed. Histologically identifiable bacteria were present in 40/63 (63%) cases and 38/57 (67%) were associated with positive cultures. Overall, 16S rRNA ISH was positive in 18/63 (29%) cases, including 16/37 (43%) with positive Gram stains, 12/38 (32%) positive by culture, and 4/8 (50%) positive by sequencing. 16S rRNA ISH highlighted bacteria in 14/40 (35%) cases with Gram-positive organisms and 9/17 (53%) with Gram-negative organisms (including 6 polymicrobial cases). Compared to a composite gold standard of Gram stain and culture, the sensitivity and specificity of 16S rRNA ISH were 35% and 93%, respectively. While sensitivity is relatively low, 16S rRNA ISH may be useful for distinguishing real organisms from artifacts and for identifying brain abscess cases suitable for 16S rRNA sequencing.

Preparation, in vitro and in vivo assessment of novel carvacrol@pro-phytomicelles for the treatment of Salmonella enteritidis infection in mice.

In livestock and poultry farming, the use of antibiotics has been abused, which seriously endangers human health. Thus, antibiotic alternatives are urgently needed. The phytochemical carvacrol (CAR) has attracted attention as an antibiotic alternative due to its excellent antibacterial activity and anti-inflammatory activity. However, CAR has high volatility and low water solubility, which seriously affect its antibacterial activity. In this study, two plant-derived small-molecule phytochemicals-glycyrrhizin and rebaudioside A-were selected as nanocarriers for the preparation of a novel solid pro-phytomicelle formulation named as CAR@PP. Using a simple fabrication method, the encapsulation efficiency of CAR reached 98.74 ± 1.14 %. CAR@PP was found to rapidly dissolve in water, resulting in a transparent solution (named as CAR@M) and a 59-fold increase in solubility compared to CAR. CAR@M contained uniform nanoparticles with a particle size, polydispersity index, and zeta potential of 3.52 ± 0.93 nm, 0.17 ± 0.01, and -10.63 ± 0.45 mV, respectively. The in vitro antibacterial activity of CAR@M was evaluated, and the minimum inhibitory concentration for the tested strains was 125-250 μg/ml. The antibacterial mechanisms were found that CAR@M disrupted the bacterial wall and biomembranes and efficiently inhibited bacterial biofilm growth. To the in vivo activity evaluation, treatment with 50 mg/kg CAR@M could effectively improve bacterial liver abscesses, decrease the inflammatory cytokine levels in the liver and cecum, and reduce the bacterial load in the liver and feces in Salmonella enteritidis-infected mice. In conclusion, CAR@PP is a promising alternative to antibiotics in livestock and poultry farming warranting further research.

Fatigue and depression at 8 weeks and 1 year after bacterial brain abscess and their relationship with cognitive status

ABSTRACT A bacterial brain abscess (BA) is a focal brain infection with largely unknown long-term implications. This prospective study assessed the frequency of fatigue and symptoms of depression at 8 weeks and 1 year after BA and examined the relationship between fatigue, depressive symptoms, and cognitive status. Twenty BA-patients (age 17–73; 45% female) were assessed for fatigue, depression, memory, and executive functions. Fatigue rates were 40-65% at 8 weeks and 25-33% at 1 year on various fatigue questionnaires. Patient Health Questionnaire indicated symptoms of depression in 10% at the 8-week follow-up only. Relevant comorbidities and vocational outcomes were not associated with fatigue or symptoms of depression. Mean fatigue scores improved significantly between the two-time points. Greater fatigue was related to subjective problems with working memory, inhibition, self-monitoring, and emotional control and worse objective verbal memory performance. Symptoms of depression were associated with one out of two fatigue measures. We conclude that fatigue is common in the first year after BA, and higher levels of fatigue are related to more cognitive problems. Symptoms of clinical depression were rare. These findings underscore fatigue as an important consequence of BA and emphasize the necessity for targeted rehabilitation interventions.

A β-Lactamase Responsive Peptide Inhibits MRSA Infection through Self-Assembled Nanonet.

Gram-positive S. aureus is one of the leading pathogens for death associated with antimicrobial resistance. The β-lactamase (Bla) secreted by methicillin-resistant S. aureus (MRSA) hydrolyzes nearly all β-lactam antibiotics, leaving only a few antibiotics available for the clinical treatment of MRSA infections. Thereby, a Bla-responsive peptide (BLAP) is designed here with the capacity of inhibiting MRSA infection through mimicking the host defense mechanism of human defensin-6. The BLAP comprising a self-assembling peptide sequence can respond specifically to the secreted Bla and assemble in situ surrounding MRSA. The assembled nanofibrous network is able to trap MRSA, preventing its invasion into the host cells effectively. As a consequence, the intramuscular injection of BLAP significantly restricted bacterial infection and abscess formation in mice. The biomimetic BLAP holds great potential for the efficient treatment of drug-resistant gram-positive bacterial infections.

Increase of pyogenic bacterial infections after relaxation of social distancing measures linked to COVID-19 pandemic.

After the relaxation of COVID-19 mitigation measures, we observed a dramatic increase in pyogenic infections. Based on this observation, we retrospectively analysed all cases of invasive bacterial infections of brain, lung and complicated ear-nose-throat (ENT) infections, in the period from 1 August to 31 March from the years 2018-2019 to 2022-2023. The study was conducted in two Paediatric Emergency Departments, at IRCCS 'Burlo Garofolo' of Trieste and at Treviso Hospital. Electronic medical records were searched for all cases with a definitive diagnosis at discharge of mastoiditis, suppurative cervical lymphadenitis, retropharyngeal, parapharyngeal and peritonsillar abscess (ENT group), bacterial brain abscesses, epidural empyema, subdural empyema (central nervous system group), thoracic empyema and necrotising pneumonia (lung group). In 2022-2023, we observed an increase in infections compared to the previous years. Total number of cases were 22, 29, 8, 27 and 63 in 2018-2019, 2019-2020, 2020-2021, 2021-2022 and 2022-2023, respectively. The greater increase occurred in thoracic empyema, with a peak incidence of +120% in 2022-2023 in respect of 2021-2022. We reported an important increase in paediatric bacterial complicated infections in two North East Italian regions, possibly correlated with the relaxation of COVID-19 social distancing measures.

Bacterial liver abscess successfully treated by trans-gastric endoscopic ultrasound aspiration in a critically ill patient

Bacterial liver abscess successfully treated by trans-gastric endoscopic ultrasound aspiration in a critically ill patient

Utilization of In Vivo Imaging System to Study Staphylococcal Sepsis and Septic Arthritis Progression in Mouse Model.

Staphylococcus aureus [S. aureus] is a leading cause of sepsis and septic arthritis, conditions that pose significant medical challenges due to their high mortality and morbidity. No studies have used an in vivo imaging system [IVIS] to monitor S. aureus sepsis and septic arthritis. Here, we employed a bioluminescent reporter strain of S. aureus, Newman AH5016, administered intravenously to induce sepsis and intra-articularly to induce local septic arthritis in mice. Disease progression was monitored using IVIS to capture bioluminescent signals from kidneys, joints, and whole mice. Cytokines in the blood and joints were measured. The efficacy of cloxacillin treatment was evaluated. In the sepsis model, bioluminescent signals from kidneys, but not from whole mice, were correlated with kidney bacterial load and abscess formation. Ex vivo kidney imaging detected increased bacterial load and abscess formation from day 3 to day 10. Antibiotic treatment significantly reduced kidney signals, correlating with decreased bacterial counts and IL-6 levels, indicating effective infection control. In the local infection model, early-phase bioluminescent signals from joints were correlated with macroscopic arthritis and bacterial burden. Thus, signal detection from kidneys using IVIS is useful for monitoring S. aureus sepsis and assessing antibiotic efficacy, though it may only be effective for early-phase monitoring of local septic arthritis.

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.

Severe bacterial corneal abscesses in children

Severe bacterial corneal abscesses in children

Clinical characteristics, effectiveness and cost of different treatment methods for invasive Klebsiella pneumoniae liver abscess syndrome.

Bacterial liver abscess is one of the common infectious diseases of the digestive system. Invasive Klebsiella pneumoniae liver abscess syndrome (IKLAS) refers to cases where, in addition to liver abscess, there are migratory infections foci or other invasive manifestations. The clinical characteristics and risk factors of IKLAS are not fully elucidated, and there is a lack of research on the effectiveness and cost-effectiveness of different treatment methods. This study aims to compare the clinical characteristics of patients with IKLAS and non-IKLAS, and explore effective and economical treatment methods. This retrospective study collected medical records of patients with Klebsiella pneumoniae liver abscess treated at Xiangya Hospital of Central South University from January 2010 to December 2023. A total of 201 patients were included, dividing into an IKLAS group (n=37) and a non-IKLAS group (n=164). Differences in demographics, symptoms and signs, laboratory indicators, imaging characteristics, comorbidities, treatment methods, treatment outcomes, and direct treatment costs between 2 groups were analyzed. The study also compared the effectiveness and costs of different treatment methods. Compared with the non-IKLAS group, the proportion of patients with diabetes, Quick Sequential Organ Failure Assessment (qSOFA)≥2, immune deficiency, anemia, and thrombocytopenia in the IKLAS group was higher, and the level of procalcitonin at the onset in the IKLAS group was also higher (all P<0.05). In terms of symptoms and signs, the IKLAS group had a higher proportion of visual abnormalities and a lower proportion of complaints of abdominal pain (both P<0.05). In terms of complications, the incidence of combined pleural effusion, pulmonary infection, acute renal failure, respiratory failure, and multiple organ failure was higher in the IKLAS group (all P<0.05). The IKLAS group had a higher proportion of patients treated with antibiotics alone (24.32% vs 11.59%), while the non-IKLAS group had a higher proportion of patients treated with antibiotics combined with puncture and drainage (86.59% vs 64.86%, both P<0.05). The overall effective rate of the IKLAS group (83.78%) was lower than that of the non-IKLAS group (95.73%), and the treatment and drug costs were higher (all P<0.05). The treatment method of antibiotics combined with surgical resection of infectious foci showed a 100% improvement rate, antibiotics combined with abscess puncture and drainage had an 84.9% improvement rate, and in antibiotics alone had an 82.1% improvement rate, with statistical differences among the 3 treatment methods (P<0.05). In terms of treatment costs, antibiotics alone were the most expensive (P<0.05). Patients with IKLAS have poorer prognosis and higher direct medical costs. The combination of abscess puncture and drainage or surgery has a higher improvement rate and lower hospitalization costs compared to antibiotics alone, suggesting that surgical intervention may reduce antibiotic costs and save medical expenses.

Supervening Abscess Resulting in Streptococcus pyogenes Toxic Shock Syndrome Complicated by a Recent MRSA Infection in an Active Duty Military Member.

An 18-year-old male active duty US Army service member presented to the emergency department with a lower leg abscess in the region of a previously debrided methicillin-resistant Staphylococcus aureus abscess. After initial presentation, the patient became hypotensive, exhibited signs of renal failure, and developed a diffuse erythematous rash. Streptococcus pyogenes was grown from intraoperative cultures, and he was diagnosed with Streptococcal toxic shock syndrome (STSS). The patient subsequently underwent multiple surgical debridements, intravenous immunoglobulin treatment, and intravenous antibiotic administration. Streptococcal toxic shock syndrome may have a rapid onset and cause a sharp decline in hemodynamic status requiring admission to the intensive care unit. Any source of virulent Streptococcal pyogenes infection can cause STSS, including lower extremity abscesses. Therefore, it is imperative for physicians to recognize systemic involvement of seemingly isolated extremity infections. We encourage a high index of suspicion in treating bacterial abscesses for possible complications, and close monitoring of patient status. This suspicion should be even higher during outbreaks of bacteria that can cause STSS, much like the patient presented here.

SUBTENON'S VANCOMYCIN INJECTION FOR SUBRETINAL ABSCESS SECONDARY TO METHICILLIN-RESISTANT STAPHYLOCOCCUS AUREUS ENDOGENOUS ENDOPHTHALMITIS: A CASE REPORT AND LITERATURE REVIEW.

To report the use of a subtenon's vancomycin injection for the treatment of subretinal abscess secondary to methicillin-resistant Staphylococcus aureus endogenous endophthalmitis. A 17-year-old man developed endogenous endophthalmitis with subretinal abscess in his right eye secondary to methicillin-resistant Staphylococcus aureus bacteremia from axillary necrotizing fasciitis. Despite prompt treatment with IV vancomycin and an intravitreal vancomycin injection, the patient displayed minimal improvement. The patient was subsequently treated with a subtenon's vancomycin injection. The injection technique is described in detail, as well as a review of the treatment options available for bacterial subretinal abscesses. On presentation, examination revealed minimal vitritis and a large yellow subretinal abscess superotemporally extending close to the macula with subretinal fluid inferotemporally involving the macula. Four days postintravitreal vancomycin injection, the abscess remained stable and the patient developed an exudative detachment temporally. Vancomycin was injected superotemporally in the subtenon's space with no complications during the procedure or during his postoperative recovery. At seven days postinjection, the subretinal abscess and exudative retinal detachment resolved completely with necrosis at the area of previous abscess. We present the first successful case of subtenon's vancomycin injection for the treatment of bacterial subretinal abscess. Our case demonstrates that subtenon's injection of antibiotics is a safe and effective nonsurgical management option for bacterial subretinal abscesses.

Cognitive and everyday functioning after bacterial brain abscess: a prospective study of functional recovery from 8 weeks to 1 year post-treatment

ABSTRACT Objective A bacterial brain abscess may damage surrounding brain tissue by mass effect, inflammatory processes, and bacterial toxins. The aim of this study was to examine cognitive and functional outcomes at 8 weeks and 1 year following acute treatment. Methods Prospective study of 20 patients with bacterial brain abscess (aged 17–73 years; 45% females) with neuropsychological assessment at 8 weeks and 1 year post-treatment. Behavior Rating Inventory of Executive Function-Adult Version (BRIEF-A) and Patient Competence Rating Scale (PCRS) were used to assess everyday functioning and administered to patients and informants. Results Cognitive impairment was found in 30% of patients at 8 weeks and 22% at 1 year. Significant improvements were seen on tests of perceptual reasoning, attention, verbal fluency, and motor abilities (p < 0.05). At 1 year, 45% had returned to full-time employment. Nevertheless, patients and their informants obtained scores within the normal range on measures of everyday functioning (PCRS and BRIEF-A) at 8 weeks and 1 year. No significant improvements on these measures emerged over time. Conclusion Residual long-term cognitive impairment and diminished work ability affected 22% and 45% of patients one year after BA. Persistent cognitive impairment emphasizes the importance of prompt acute treatment and cognitive rehabilitation.

Bacterial Brain Abscess with Paradoxical Reaction: Three Case Reports and Literature Review (P8-13.003)

Bacterial Brain Abscess with Paradoxical Reaction: Three Case Reports and Literature Review (P8-13.003)

The Effect of Contrast-enhanced Ultrasound via Vessels and Surgical Drains Guidance Percutaneous Catheter Drainage in the Treatment of Pyogenic Liver Abscess.

Pyogenic liver abscess (PLA) is a purulent disease caused by microbial contamination of liver parenchyma and includes amoebic liver abscess, fungal liver abscess, and the most common bacterial liver abscess. Explore the efficacy of contrast-enhanced ultrasound (CEUS) via vessels and surgical drain guidance percutaneous catheter drainage (PCD) in the treatment of pyogenic liver abscesses (PLA). A total of 86 PLA patients who underwent PCD treatment in our hospital from May 2018 to February 2023 were retrospectively selected. Of them, 41 patients were treated under intravenous CEUS guidance (Control group), and 45 patients were treated under CEUS via vessels and surgical drain guidance (study group). Perioperative characteristics, treatment effectiveness, and incidence of complications were analyzed and compared between groups. The duration of surgery, drainage, white blood cell recovery, body temperature recovery, and hospitalization in the study group were longer than those in the control group (P<0.05). The total effective rate of the study group (95.56%) was higher than that of the control group (80.49%) (P<0.05). The incidence of complications in the study group (4.44%) was lower than that in the control group (19.51%) (P<0.05). Compared with intravenous CEUS alone, treatment under CEUS via vessels and surgical drains-guided PCD was associated with shorter surgical time, faster recovery, better treatment effect, lower risk of complications, and ensured treatment safety in PLA patients.

A Case Report of Disseminated Nocardiosis in a Patient with HIV Infection: Concurrent Liver, Pulmonary, and Brain Involvements

Introduction: Disseminated nocardiosis is a rare but life-threatening infectious disease that occurs most often in immunocompromised individuals. This report presents a human immunodeficiency virus (HIV)-infected patient with disseminated nocardiosis in the liver, lung, and brain. Case Presentation: A 38-year-old woman who had recently been diagnosed with HIV infection complained of fever, abdominal pain, productive coughs, and occasional headaches from 2 months ago. Imaging findings of her abdomen and lungs displayed evidence of pyogenic liver abscess and lobar pneumonia with abscess formation, respectively. The patient underwent percutaneous liver abscess drainage and bronchoalveolar lavage (BAL). Using reverse transcription-polymerase chain reaction (RT-PCR), the genome of Nocardia farcinica was detected in the specimens obtained from both procedures. Besides, she had seizures during hospitalization. Based on cerebrospinal fluid (CSF) analysis, the specimen was positive for N. farcinica. Brain imaging also revealed evidence of multiple bacterial abscess formation. She was diagnosed with disseminated nocardiosis and treated with intravenous imipenem, trimethoprim/sulfamethoxazole, and amikacin, followed by appropriate oral agents. After a 6-month follow-up, the patient had no symptoms. Additionally, the lesions improved on brain imaging. Conclusions: Patients who are HIV-positive are particularly prone to opportunistic infections. Health care providers should consider all pathogens, even rare ones, like Nocardia spp., to establish a diagnosis if they're present. Furthermore, in cases initially diagnosed with localized nocardiosis, other body organs should also be reviewed so that the disseminated form of the disease can be diagnosed and treated immediately.

Bacterial abscesses in whitespotted bamboo sharks (Chiloscyllium plagiosum) in managed care.

Sixteen whitespotted bamboo sharks (Chiloscyllium plagiosum) with histologically similar bacterial abscesses were submitted to Northwest ZooPath from nine zoo and aquarium institutions over a 17-year period. These abscesses were characterized by inflammatory cell infiltrates and necrosis with intralesional small, Gram-positive, acid-fast negative, cocci bacteria. The clinical presentation, histologic findings, and culture results indicate that Enterococcus faecalis is a relatively common cause of these lesions in whitespotted bamboo sharks. This organism also provides a treatment challenge due to its inherent antibiotic-resistant properties and ability to form biofilms, confounding the host's immune response. Enterococcus faecalis represents an important cause for abscess formation and cellulitis in captive whitespotted bamboo sharks.

Electron Lock Manipulates the Catalytic Selectivity of Nanozyme.

Nanomaterials with enzyme-mimicking functions, termed nanozymes, offer attractive opportunities for biocatalysis and biomedicine. However, manipulating nanozyme selectivity poses an insurmountable hurdle. Here, we propose the concept of an energy-governed electron lock that controls electron transfer between nanozyme and substrates to achieve selectivity manipulation of enzyme-like catalysis. An electron lock can be constructed and opened, via modulating the nanozyme's electron energy to match the energy barrier of enzymatic reactions. An iron-doped carbon dot (FeCD) nanozyme with easy-to-regulate electron energy is selected as a proof of concept. Through regulating the conduction band which dominates electron energy, activatable oxidase and selective peroxidase (POD) with substrate affinity 123-fold higher than that of natural horseradish peroxidase (HRP) is achieved. Furthermore, while maintaining selectivity, FeCDs exhibit catalytic kinetics comparable to that of HRP upon transforming photons into electrons. Superior selectivity, efficient catalysis, and undetectable biotoxicity energize FeCDs as potent targeted drugs on antibiotic-resistant bacterial abscesses. An electron lock provides a robust strategy to manipulate selectivity toward advanced nanozymes.

Recurrent bacterial abscess of the left liver lobe caused by a foreign body (fish bone)

The authors present minimally invasive surgical treatment of recurrent liver abscess caused by migration of fish bone from the upper gastrointestinal tract. Two-stage treatment implied small-caliber transparietal drainage of abscess with evacuation of purulent detritus at the first stage. At the second stage, primary percutaneous approach was transformed into access of sufficient diameter for flexible or rigid optics for visually controlled bone extraction. Foreign body removal through the drainage tube with endoscopic capture under visual control is preferable regarding safety compared to removal under ultrasound and/or X-ray control. Indeed, endoscopic approach is valuable for optimal positioning of the object and prevention of damage to liver parenchyma during extraction.