Infection Abscess Research Articles

Infectious brain abscesses and granulomas: analysis of 110 episodes in adults

Infectious brain abscesses and granulomas: analysis of 110 episodes in adults

Pattern of Rapidly growing Mycobacteria (RGM) species isolated from clinical samples: A 10-year retrospective study in a tertiary care hospital of Bangladesh.

Infections caused by rapidly growing mycobacteria (RGM) are increasing worldwide. The study was conducted in a microbiological laboratory of Bangladesh to determine the pattern of detection of RGM from clinical samples. All laboratory culture records of RGM from 2012 to 2022 were collected retrospectively and analyzed. A total 62 RGM infected patients with surgical site infection (74.1%), injection site and skin abscess (9.7%), septicemia (4.8%) and UTI (1.6%) were identified. The annual isolation frequency of RGM increased 4.8% to 29.1% in between year 2012 and 2022. RGM infected patients (14.5%) were mistakenly treated with first line anti tubercular drug before correct microbiological diagnosis (median, IQR; 3, 2-5 months). Out of 23 RGM isolates, 86.9% were M. abscessus and rest 13.1% were M. fortuitum. Most of them (≥95%) were sensitive to amikacin, linezolid, clarithromycin where as 27.1% to imipenem and ciprofloxacin, 40% to cefoxitin, 35.3% and 1.7% to doxycycline and co-trimoxazole respectively. Misdiagnosis or delay in diagnosis and erroneous treatment with first line anti tubercular drug may cause prolong morbidity and therapeutic failure to patients with RGM infection. So, early and appropriate diagnosis is crucial for successful outcome.

Association of gut microbiota imbalance with risk of postoperative infections in patients with left ventricular assist device

Abstract Background Infections are the most common complications following left ventricular assist device (LVAD) implantation and associated with adverse events. Gut microbial imbalance may predispose to mucosal colonization with pathogens, resulting in a risk of subsequent serious infections. However, it remains unclear whether gut microbiota imbalance is associated with postoperative infections in patients with LVAD. Purpose The aim of this study was to investigate whether gut microbiota imbalance was associated with postoperative infections in patients with LVAD. Methods We prospectively examined 22 consecutive LVAD patients who were admitted to a university hospital for routine check-ups and had stool cultures taken between March 2022 and December 2023. All patients had no signs of infection. The patients were divided into two groups according to positive (normal bacterial flora and other bacteria including Streptococcus viridans, Klebsiella, or Extended-spectrum β-lactamase Escherichia coli; n = 7) and negative (normal bacterial flora only; n = 15) for stool culture. The primary outcome was serious infection requiring hospitalisation treated with intravenous antimicrobial agents. Results Patients were predominantly male (68%) and the median age was 49 (interquartile range [IQR] 29-58) years. There were no significant differences in age, sex, primary aetiology of heart failure, type of LVAD devices, time on LVAD support, the history of infection, or antibiotics use within six months between the groups. During a median follow-up period of 316 days (IQR 242-559), the primary outcome occurred in seven patients (32%), including four hospitalisation for driveline infections, two pneumoniae and bacterial bloodstream infections, and one lung abscess and bacterial bloodstream infection. Kaplan–Meier analysis showed that the adverse events more frequently occurred in LVAD patients with positive for stool culture (P = 0.010) (Figure). A multivariable Cox regression analysis showed that positive for stool culture was independently associated with an increased subsequent risk of the primary outcome (hazard ratio 6.99, 95% confidence interval 1.17-41.7, P = 0.033), even after adjustments for age, male, body mass index, diabetes, INTERMACS profile, mechanical circulatory support, serum creatinine, serum albumin, and white blood cell count, which are known to be strong determinants of worse clinical outcomes in patients with LVAD. Conclusions In patients with LVAD, gut microbial imbalance was associated with subsequent serious infections. These findings suggest that the screening of stool culture might be useful for early identification of high-risk patients for infectious complication after LVAD implantation.

Synergy of bacteriophage depolymerase with host immunity rescues sepsis mice infected with hypervirulent Klebsiella pneumoniae of capsule type K2

ABSTRACT The hypervirulent Klebsiella pneumoniae (hvKp) with K1 and K2 capsular types causes liver abscess, pneumonia, sepsis, and invasive infections with high lethality. The presence of capsular polysaccharide (CPS) resists phagocytic engulfment and contributes to excessive inflammatory responses. Bacteriophage depolymerases can specifically target bacterial CPS, neutralizing its defense. Based on our previous research, we expressed and purified a bacteriophage depolymerase (Dep1979) targeting hvKp with capsule type K2. Interestingly, although Dep1979 lacked direct bactericidal activity in vitro, it exhibited potent antibacterial activity in vivo. Low-dose Dep1979 (0.1 mg/kg) improved the 7-day survival of immunocompetent mice to 100%. Even at 0.01 mg/kg, mice achieved 100% survival at 5 days, although efficacy sharply declined at doses as low as 0.001 mg/kg. Following Dep1979 treatment, reduced expression of inflammatory factors and no apparent tissue damage were observed. However, therapeutic efficacy significantly diminished in immunosuppressed mice. These findings underscore the critical role of Dep1979 in disarming CPS, which synergizes with host immunity to enhance antibacterial activity against hvKp.

Metagenomic next-generation sequencing in diagnosing perinephric abscess infection caused by Trichomonas vaginalis.

Metagenomic next-generation sequencing in diagnosing perinephric abscess infection caused by Trichomonas vaginalis.

Versatile self-assembled near-infrared SERS nanoprobes for multidrug-resistant bacterial infection-specific surveillance and therapy

The rise of multidrug-resistant bacteria (MDRB) has made bacterial infection one of the biggest health threats, causing numerous antibiotics to fail. Real-time monitoring of bacterial disease treatment efficacy at the infection site is required. Herein, we report a versatile Raman tag 3,3′-diethylthiatricarbocyanine iodide (DTTC)-conjugated star-shaped Au-MoS2@hyaluronic acid (AMD@HA) nanocomposite as a surface-enhanced Raman scattering (SERS) nanoprobe for quick bacterial identification and in-situ eradication. Localized surface plasmon resonance (LSPR) from the hybrid metallic nanostructure makes AMD@HA highly responsive to the near-infrared laser, enabling it to demonstrate a photothermal (PTT) effect, increased SERS activity, and peroxidase-like catalytic reaction to release reactive oxygen species. The tail vein injection of AMD@HA nanoprobes is invasive, however SERS imaging for bacterial identification is non-invasive and sensitive, making it an efficient residual bacteria monitoring method. The detection limit for methicillin-resistant Staphylococcus aureus (MRSA) is as low as 102 CFU·mL-1, and the substrates allow for taking 120 s to acquire a Raman image of 1600 (40 × 40) pixels. In mouse models of MRSA-induced wound infection and skin abscess, the combination of AMD@HA-mediated PTT and catalytic therapy demonstrates a synergistic effect in promoting wound healing through rapid sterilization. This SERS-guided therapeutic approach exhibits little toxicity and does not cause considerable collateral damage, offering a highly promising intervention for treating diseases caused by MDRB. Statement of significanceThis research introduces a SERS nanoprobe, AMD@HA, for the rapid identification and eradication of multidrug-resistant bacteria (MDRB), a critical health threat. The nanoprobe leverages localized surface plasmon resonance for photothermal therapy and enhanced Raman signals, offering a sensitive, non-invasive diagnostic tool. With a low detection limit for MRSA and a synergistic therapeutic effect in mouse models, our approach holds significant promise for treating MDRB-driven infections with minimal toxicity, advancing the field of antimicrobial strategies.

Bismuth Tungstate-Based Nanoparticles Promoting Healing of Drug-Resistant Bacteria Infected Abscesses by Chemical/Low-Temperature Photothermal Therapy

Bismuth Tungstate-Based Nanoparticles Promoting Healing of Drug-Resistant Bacteria Infected Abscesses by Chemical/Low-Temperature Photothermal Therapy

TRPA1 Influences Staphylococcus aureus Skin Infection in Mice and Associates with HIF-1a and MAPK Pathway Modulation.

Infections caused by methicillin-resistant Staphylococcus aureus (MRSA) are a major public health burden. Emerging antibiotic resistance has heightened the need for new treatment approaches for MRSA infection such as developing novel antimicrobial agents and enhancing the host's defense response. The thermo-ion channels Transient Receptor Potential (TRP-) A1 and V1 have been identified as modulators of S. aureus quorum sensing in cell culture models. However, their effects on in vivo infection control are unknown. In this study, we investigated the therapeutic effect of natural TRP ion channel inhibitors on MRSA skin infection in mice. While deletion of TRPV1 did not affect lesion size or inflammatory markers, TRPA1-/- mice demonstrated significantly reduced infection severity and abscess size. Treatment with natural inhibitors of TRPA1 with or without blockade of TRPV1 also reduced abscess size. Tissue transcriptomic data coupled with immunohistochemistry revealed that TRPA1 inhibition impacted heat shock protein expression (HSP), modulated the HIF-1a and MAPK pathways, and reduced IL4 expression. Additionally, metabolomics data showed an impact on purine and glycosaminoglycan pathways. Multi-omic integration of transcriptomic and metabolic data revealed that diacylglycerol metabolism was the likely bridge between metabolic and immunological impacts. Our findings suggest that TRPA1 antagonism could provide a promising and cost-effective therapeutic approach for reducing the severity of MRSA infection, and presents a novel underlying molecular mechanism.

Alginate-based injectable probiotic/squid ink composite hydrogels for accelerated wound healing of MRSA infected abscess through photothermally synergized probiotic therapy

Methicillin-resistant Staphylococcus aureus (MRSA) infections pose great challenges to skin wound care due to the severe drug resistance developed in the clinic. There is an urgent need to exploit next-generation bactericidal therapeutics that are both antibiotic-free and multifunctional for enhanced wound healing. Herein, we designed a Ca2+-crosslinked alginate hydrogel (EcNSIN@Alg) containing two naturally derived bioactive components, probiotics Escherichia coli Nissle1917 (EcN) and Squid ink nanoparticles (SIN), to treat MRSA-infected wounds. The injectable composite hydrogel displayed excellent biocompatibility, photothermal antibacterial activity, and reactive oxygen species (ROS) scavenging property. Importantly, the probiotic EcN can enhance the photothermal SIN to promote immune regulatory activities, shifting pro-inflammatory macrophages (M1) to anti-inflammatory macrophages (M2). In an MRSA-infected abscess model, EcNSIN@Alg can reduce the expression level of wound inflammatory factors and ROS, increase the number of anti-inflammatory macrophages, accelerate collagen deposition and promote wound healing. This work offers a new perspective on developing safe, antibiotic-free, multifunctional bactericides using fully bioderived materials, with potential applications in clinical practice.

Do Postoperative Surgeon Phone Calls Improve Outcomes Following Mandibular Fracture Repair?

Complications of open reduction and internal fixation (ORIF) of mandibular fractures are influenced by several patient factors. A postoperative surgeon phone call could modify these factors through education and reinforcement of instructions, but its effect has not been studied. The purpose of this study was to measure and compare the frequencies of postoperative inflammatory complications (POICs) following ORIF of mandibular fractures in patients who did and did not receive a postoperative surgeon phone call. The authors conducted an ambispective cohort study consisting of patients with mandibular fractures treated with ORIF at a large urban trauma hospital with the prospective cohort from January 1, 2021 to March 31, 2022 and a retrospective cohort from April 1, 2020 to December 31, 2020. Prisoners and patients with gunshot wounds were excluded. The primary predictor variable was the surgeon call group. After January 2021, a postoperative call was implemented 1-3days following fracture repair to review instructions, such as nonchew diet and oral hygiene, and provide education, such as reviewing expectations. Prior to January 2021, patients were not called. This resulted in 3 categories: Not Called, Called and Answered, and No Answer. The primary outcome variable was POICs, defined as the occurrence of exposed or infected hardware, abscess formation, recurrent swelling/pain, nonunion, osteomyelitis, or fistula formation. Demographic variables, injury-related variables, and treatment-related variables were also measured. Statistical analysis was performed using Fisher's exact and Wilcoxon rank-sum tests, as well as multivariable logistic regression. A P value was considered significant if<.05. Of the 178 patients in the study, 137 (77%) were male and the average age was 39.9±12.6years. Sixty-five patients (36.5%) were not called. Of the patients called, 79 (44.4%) answered and 34 (19.1%) did not answer. POICs occurred in 9.2% of the Not Called group and 8.9% of the Called and Answered group (P=.99). In the No Answer group, 29.4% had POICs, which was higher than the other 2 groups (P=.01). A surgeon phone call was not associated with complication rates; however, patients in the No Answer group were significantly more likely to experience a POIC.

Transumbilical laparoscopic-assisted appendectomy in children and adolescents: what have we learnt in more than 1200 cases?

TULAA combines the laparoscopic and open technique and is considered to be a safe, fast and cost-effective procedure. On the other hand, preparation is limited due to the single instrument, especially in complicated appendicitis. In this study we analyze the outcome of our TULAA patients, focusing on conversion and complication rates. We performed a retrospective study including all patients treated with TULAA in our department between 2006 and 2016. We analyzed patient data, operative data, costs, complications, and conversion rate to standard laparoscopic or open appendectomy. 1275 children and adolescents were enrolled. Mean age was 10.2 years. TULAA was completed in 88% of cases. The overall mean operative time was 33min. The overall complication rate was 5.7%. The most common complications were wound infection (2.7%), seroma (1.7%) and wound abscess (1.4%). Both the conversion rate and the complication rate were significantly higher in complicated appendicitis. Furthermore, the conversion rate is higher in overweight or obese patients. TULAA is a safe, quick and cost-effective treatment option for acute appendicitis in children and adolescents. The complication rate and conversion rate are significantly correlated with the degree of appendiceal inflammation and comparable other surgical procedures.

Mining human microbiomes reveals an untapped source of peptide antibiotics

Drug-resistant bacteria are outpacing traditional antibiotic discovery efforts. Here, we computationally screened 444,054 previously reported putative small protein families from 1,773 human metagenomes for antimicrobial properties, identifying 323 candidates encoded in small open reading frames (smORFs). To test our computational predictions, 78 peptides were synthesized and screened for antimicrobial activity invitro, with 70.5% displaying antimicrobial activity. As these compounds were different compared with previously reported antimicrobial peptides, we termed them smORF-encoded peptides (SEPs). SEPs killed bacteria by targeting their membrane, synergizing with each other, and modulating gut commensals, indicating a potential role in reconfiguring microbiome communities in addition to counteracting pathogens. The lead candidates were anti-infective in both murine skin abscess and deep thigh infection models. Notably, prevotellin-2 from Prevotella copri presented activity comparable to the commonly used antibiotic polymyxin B. Our report supports the existence of hundreds of antimicrobials in the human microbiome amenable to clinical translation.

Effect of peritoneal drainage on the prognosis following appendectomy in pediatric patients with appendicitis: a retrospective study based on appendicitis grade.

This study aimed to assess the impact of peritoneal drainage and its type on prognosis, encompassing postoperative recovery and complications, in pediatric patients (≤ 16years old) following appendectomy based on the grade of appendicitis. In this retrospective study, we analyzed pediatric patients (≤ 16years old) with appendicitis who met the inclusion and exclusion criteria in our center from January 2017 to January 2024 and classified them into grade I-V based on the grade of appendicitis, with V representing the most serious cases. The patients were grouped according to drainage status and type. The main clinical outcomes included postoperative rehabilitation indexes such as time to resume a soft diet, time to remove the drain, duration of postoperative antibiotic use and length of hospitalization (LOH), as well as postoperative complications including intra-abdominal abscess (IAA), ileus and wound infection (WI), and readmission within 30days after surgery. A total of 385 pediatric patients with appendicitis were included in the study and divided into No-drainage (ND) group (n = 74), Passive drainage (PD) group (n = 246) and Active drainage (AD) group (n = 65) according to drainage status and type. Compared to the other two groups, the ND group had a significantly shorter time to resume a soft diet, duration of postoperative antibiotic use and LOH, and these differences were statistically significant. Similar findings were observed in grade I patients too (P < 0.05). In all cases examined here, the AD group had a significantly shorter time for drain removal compared to the PD group (3.04 [1-12] vs 2.74 [1-15], P = 0.049); this difference was also evident among grade I patients (2.80 [1-6] vs 2.47 [1-9], P = 0.019). Furthermore, within the same grade, only in grade IV did the AD group exhibit a shorter duration of postoperative antibiotic use compared to the PD group (4.75 [4-5] vs 8.33 [5-15], P = 0.009). Additionally, the LOH in the AD group was longer than that in the PD group (8.00 [4-13] vs 4.75 [4-5], P = 0.025). Among all cases, the ND group exhibited significantly lower incidences of overall complications and WI compared to the other two groups (P < 0.05). Additionally, the incidence of IAA in the ND group was significantly lower than that in the PD group (0% vs 5.3%, P = 0.008 < 0.0167). Furthermore, although there were no statistically significant differences in the incidence of overall complications, IAA, ileus, and WI between the PD and AD groups during grade ≥ II analysis (P > 0.05), a higher readmission rate within 30days was observed in the PD group compared to the AD group; however, these differences were not statistically significant (P > 0.05). Moreover, multivariate analysis revealed that a higher grade of appendicitis was associated with an increased risk of overall complications and IAA as well as a longer duration of postoperative antibiotic use and LOH. The appendicitis grade is a crucial indicator for predicting postoperative IAA and LOH. In patients with grade I appendicitis, peritoneal drainage, even if active drainage, is not recommended; For patients with grade ≥ II appendicitis, active drainage may be more effective than passive drainage in reducing the duration of postoperative antibiotic use and LOH.

Imaging diagnosis and main consideration of urachal cyst infection and urachal abscess.

Imaging diagnosis and main consideration of urachal cyst infection and urachal abscess.

Capturing anatomy in computed tomography scans for genital pathology.

In this cross-sectional study,we aimed to characterize how frequently the anatomy of interest (AOI) was excluded when evaluating genital pathology using the current CT pelvis protocol recommended by the American College of Radiology and evaluate how AOI exclusion affects patient management. We retrospectively reviewed medical records, using diagnosis and CPT codes, of patients admitted with genital pathology who obtained a CT scan at our institution from July 1, 2020-April 30, 2023. Baseline patient demographics were included. Data about each index CT scan (scan obtained at our institution) were recorded and assessed for exclusion of the AOI. Statistical analysis was performed to determine the rate of AOI exclusion and to compare patient management between patients with AOI excluded versus those without AOI exclusion. 113 presentations for genital pathology included an index CT scan and were included for analysis. Patients were primarily men (98%) with a mean age of 53.1 years (SD 13.9). The most common diagnoses were Fournier's gangrene (35%), scrotal abscess (22%) and unspecified infection (19%). 26/113 scans (23%) did not capture the entire AOI. When the AOI was missed during the index scan, there was a higher rate of obtaining additional scans (38% vs. 21%), but a similar rate of intervention (77% vs. 63%) when compared to index scans that captured the entire AOI.35 scans (31%) had protocol-extending instructions;index scans that captured the entire AOI were more likely to have specific protocol-extending instructions(38% vs. 8% p < 0.01). Creating a specific CT protocol for genital pathology could decrease the amount of inappropriate irradiation and improve AOI capture rates without relying on specific request for protocol deviation.

Medication for Opioid Use Disorder After Serious Injection-Related Infections in Massachusetts

Serious injection-related infections (SIRIs) cause significant morbidity and mortality. Medication for opioid use disorder (MOUD) improves outcomes but is underused. Understanding MOUD treatment after SIRIs could inform interventions to close this gap. To examine rehospitalization, death rates, and MOUD receipt for individuals with SIRIs and to assess characteristics associated with MOUD receipt. This retrospective cohort study used the Massachusetts Public Health Data Warehouse, which included all individuals with a claim in the All-Payer Claims Database and is linked to individual-level data from multiple government agencies, to assess individuals aged 18 to 64 years with opioid use disorder and hospitalization for endocarditis, osteomyelitis, epidural abscess, septic arthritis, or bloodstream infection (ie, SIRI) between July 1, 2014, and December 31, 2019. Data analysis was performed from November 2021 to May 2023. Demographic and clinical factors potentially associated with posthospitalization MOUD receipt. The main outcome was MOUD receipt measured weekly in the 12 months after hospitalization. We used zero-inflated negative binomial regression to examine characteristics associated with any MOUD receipt and rates of treatment in the 12 months after hospitalization. Secondary outcomes were receipt of any buprenorphine formulation, methadone, and extended-release naltrexone examined individually. Among 8769 individuals (mean [SD] age, 43.2 [12.0] years; 5066 [57.8%] male) who survived a SIRI hospitalization, 4305 (49.1%) received MOUD, 5919 (67.5%) were rehospitalized, and 973 (11.1%) died within 12 months. Of those treated with MOUD in the 12 months after hospitalization, the mean (SD) number of MOUD initiations during follow-up was 3.0 (1.7), with 956 of 4305 individuals (22.2%) receiving treatment at least 80% of the time. MOUD treatment after SIRI hospitalization was significantly associated with MOUD in the prior 6 months (buprenorphine: adjusted odds ratio [AOR], 16.51; 95% CI, 13.81-19.74; methadone: AOR, 28.46; 95% CI, 22.41-36.14; or naltrexone: AOR, 2.05; 95% CI, 1.56-2.69). Prior buprenorphine (incident rate ratio [IRR], 1.17; 95% CI, 1.11-1.24) or methadone (IRR, 1.89; 95% CI, 1.79-2.01) use was associated with higher treatment rates after hospitalization, and prior naltrexone use (IRR, 0.86; 95% CI, 0.77-0.95) was associated with lower rates. This study found that in the year after a SIRI hospitalization in Massachusetts, mortality and rehospitalization were common, and only half of patients received MOUD. Treatment with MOUD before a SIRI was associated with posthospitalization MOUD initiation and time receiving MOUD. Efforts are needed to initiate MOUD treatment during SIRI hospitalizations and subsequently retain patients in treatment.

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.

Diabetic myonecrosis complicated by emphysematous pyomyositis and abscess caused by Escherichia coli: a case report

BackgroundNecrotizing myopathies and muscle necrosis can be caused by immune-mediated mechanisms, drugs, ischemia, and infections, and differential diagnosis may be challenging.Case presentationWe describe a case of diabetic myonecrosis complicated by pyomyositis and abscess caused by Escherichia coli. A white woman in her late forties was admitted to the hospital with a 1.5 week history of bilateral swelling, weakness, and mild pain of the lower extremities and inability to walk. She had a history of type 1 diabetes complicated by diabetic retinopathy, neuropathy, nephropathy, and end-stage renal disease. C-reactive protein was 203 mg/l, while creatinine kinase was only mildly elevated to 700 IU/l. Magnetic resonance imaging of her lower limb muscles showed extensive edema, and muscle biopsy was suggestive of necrotizing myopathy with mild inflammation. No myositis-associated or myositis-specific antibodies were detected. Initially, she was suspected to have seronegative immune-mediated necrotizing myopathy, but later her condition was considered to be explained better by diabetic myonecrosis with multifocal involvement. Her symptoms alleviated without any immunosuppressive treatment. After a month, she developed new-onset and more severe symptoms in her right posterior thigh. She was diagnosed with emphysematous urinary tract infection and emphysematous myositis and abscess of the right hamstring muscle. Bacterial cultures of drained pus from abscess and urine were positive for Escherichia coli. In addition to abscess drainage, she received two 3–4-week courses of intravenous antibiotics. In the discussion, we compare the symptoms and findings typically found in pyomyositis, immune-mediated necrotizing myopathy, and diabetic myonecrosis (spontaneous ischemic necrosis of skeletal muscle among people with diabetes). All of these diseases may cause muscle weakness and pain, muscle edema in imaging, and muscle necrosis. However, many differences exist in their clinical presentation, imaging, histology, and extramuscular symptoms, which can be useful in determining diagnosis. As pyomyositis often occurs in muscles with pre-existing pathologies, the ischemic muscle has likely served as a favorable breeding ground for the E. coli in our case.ConclusionsIdentifying the etiology of necrotizing myopathy is a diagnostic challenge and often requires a multidisciplinary assessment of internists, pathologists, and radiologists. Moreover, the presence of two rare conditions concomitantly is possible in cases with atypical features.

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.

Ultrasound biomicroscopic imaging parameters associated with outcome in equine infectious ulcerative keratitis and stromal abscesses.

To determine the predictive value of corneal ultrasound biomicroscopy (UBM) findings for the outcome of equine corneal disease. 46 horses with a clinical diagnosis of either infectious ulcerative keratitis or stromal abscess. Corneal UBM (VevoMD; UHF70; VisualSonics) of horses with infectious corneal disease presenting to the North Carolina State University Equine Ophthalmology Service from 2019 to 2023 were evaluated. Size and depth of lesion, presence of Descemet membrane disruption (DMD), corneal thickness, and aqueous humor cell counts (AHCC) were assessed. Comparisons of UBM and clinical exam findings, presence of infectious organisms, and outcome (healed or enucleated) were performed. The UBMs from 46 horses were evaluated. Increased AHCC was significantly associated with increased size and depth of corneal lesions on UBM but not with DMD. Deep lesions and DMD were significantly associated with an enucleation outcome. Horses treated with systemic antibiotics had significantly lower AHCC on UBM, but there were no differences in AHCC with the use of other systemic or topical medications. There was no significant correlation between infectious disease results, clinical findings (aqueous flare or cells), outcome, and UBM AHCC. Parameters on UBM, such as depth of lesion, DMD, and AHCC, may be useful diagnostic and prognostic tools to augment the ophthalmic exam of horses with corneal disease. The UBM findings of deep corneal lesions and DMD suggest a poor prognosis and warrant aggressive surgical intervention.