Course Of Antimicrobial Therapy Research Articles

Local Phage Therapy During Surgical Treatment of Burn Wounds Reduces the Risk of Colonization of the Skin of the Periwound Area by Pathogens of the ESKAPE Group

Aim of study To study the effect of local phage therapy alone and in combination with systemic antibiotic therapy on the dynamics of microflora colonizing the skin of the periwound area during surgical treatment of infected burn wounds.Material and methods Scientific hypothesis: the use of local phage therapy in monotherapy in the treatment of burn wound infections reduces the risk of colonization of the skin of the periwound area by bacteria of the ESKAPE group. The experimental study analyzed the results of microbiological studies of washings from the skin surface of 40 animals with infected burn wounds, in the course of phage therapy in monotherapy and in combination with systemic antibiotic therapy.Results In the group of animals receiving phage therapy alone, the proportion of ESKAPE group bacteria colonizing the skin of the periwound area at the time of completion of the course of antimicrobial therapy was 9%, while in the group receiving phage therapy in combination with systemic antibiotic therapy it was 43% (p=0.011).Conclusion The use of local phage therapy in single mode during the surgical treatment of infected burn wounds reduces the risk of colonization of the skin of the peri-wound area by pathogens of the ESKAPE group. At the same time, systemic antibiotic therapy causes an imbalance of resident and transient skin microbiota in the periwound area and an increase in the frequency of its colonization by pathogens of the ESKAPE group.

Practical Guidance for Clinical Microbiology Laboratories: Microbiologic diagnosis of implant-associated infections.

SUMMARYImplant-associated infections (IAIs) pose serious threats to patients and can be associated with significant morbidity and mortality. These infections may be difficult to diagnose due, in part, to biofilm formation on device surfaces, and because even when microbes are found, their clinical significance may be unclear. Despite recent advances in laboratory testing, IAIs remain a diagnostic challenge. From a therapeutic standpoint, many IAIs currently require device removal and prolonged courses of antimicrobial therapy to effect a cure. Therefore, making an accurate diagnosis, defining both the presence of infection and the involved microorganisms, is paramount. The sensitivity of standard microbial culture for IAI diagnosis varies depending on the type of IAI, the specimen analyzed, and the culture technique(s) used. Although IAI-specific culture-based diagnostics have been described, the challenge of culture-negative IAIs remains. Given this, molecular assays, including both nucleic acid amplification tests and next-generation sequencing-based assays, have been used. In this review, an overview of these challenging infections is presented, as well as an approach to their diagnosis from a microbiologic perspective.

Compatible co-administration of BioThrax® vaccine and ciprofloxacin—Results of a randomized open-label drug-vaccine interaction trial

The recommended treatment for post-exposure prophylaxis (PEP) following known/suspected exposure to Bacillus anthracis involves immunization with anthrax vaccine adsorbed (AVA, i.e., BioThrax® vaccine) and a course of antimicrobial therapy. A drug-vaccine interaction clinical trial was conducted to determine whether this combined treatment might modify antimicrobial exposure or vaccine immunogenicity.A Phase 2, randomized, open-label, multi-center trial involving 154 healthy adult participants was completed to evaluate the effect of AVA immunization (three doses administered subcutaneously (SC) at weeks 0, 2 and 4) on the pharmacokinetics (PK) of ciprofloxacin, as well as the effect of ciprofloxacin administration (500 mg po bid) on the immunogenicity of AVA. PK parameters were derived using noncompartmental analysis of ciprofloxacin serum concentrations. Immunogenicity was assessed using a toxin neutralizing antibody (TNA) assay resulting in 50 % neutralization factor (NF50) values. Safety was assessed via reports of adverse events (AEs), clinically significant changes in laboratory parameters and vital signs, and collection of solicited local and systemic reactogenicity reactions.Statistical analyses of the steady state (SS) and single dose PK parameters Cmax and AUC0-–12h indicated that the AVA PEP regimen did not significantly modify ciprofloxacin exposure. Comparison of the geometric mean TNA NF50 values between participants receiving AVA + ciprofloxacin and those receiving AVA alone showed that the combined treatment was non-inferior to AVA alone. The trial met all prospectively defined success criteria for the primary PK endpoint and for the secondary PK and immunogenicity endpoints. There were no deaths, SAEs or AEs leading to drug discontinuation or study withdrawal during the trial.Overall, concomitant administration of ciprofloxacin and AVA produced no significant changes in the PK profile of ciprofloxacin nor in the immunogenicity of AVA. Furthermore, this trial demonstrated that the co-administration of ciprofloxacin and AVA was well tolerated in healthy adult participants.

Profile of Antimicrobial Consumption in Patients Assisted by a Palliative Care Team During the COVID-19 Pandemic in Brazil.

This study aimed to evaluate the profile of antimicrobial consumption in patients assisted by a palliative care (PC) team during the COVID-19 pandemic. A retrospective observational study was conducted in a quaternary hospital. Patients assisted by the PC team in 2020 were selected. The clinical and demographic characteristics, as well as the outcomes, were assessed using electronic records. A total of 181 patients were included in the study, of whom 93.4% had used antimicrobials and 24.3% had had COVID-19. COVID-19 patients were more likely to receive at least one course of antimicrobial therapy. Patients who received polytherapy in the first course of treatment were more likely to die and to be still receiving antimicrobials at death. There was no significant difference in the length of hospital stay, new hospitalization in 12months, nor the time to death among patients who received monotherapy or polytherapy during the first course of antimicrobial therapy. There was a large amount of PC patients receiving antimicrobial therapy during the COVID-19 pandemic. SARS-CoV-2-positive patients were more likely to receive antimicrobial therapy.

Real-Life Experience of Continuously Infused Ceftolozane/Tazobactam in Patients with Bronchiectasis and Multidrug-Resistant Pseudomonas aeruginosa Infection in the Outpatient Setting.

(1) Background: Ceftolozane/tazobactam (C/T) is a novel β-lactam/β-lactamase inhibitor with excellent activity against the multidrug-resistant (MDR) P. aeruginosa. Continuous infusion (CI) dosing allows the optimization of pharmacokinetic and pharmacodynamic (PK/PD) properties of β-lactam antibiotics and may support patients' treatment as outpatients. (2) Methods: Adult patients receiving their entire course of C/T as a CI in the outpatient setting were retrospectively included in the study. The primary outcome evaluated was clinical resolution. The secondary outcomes evaluated were PK/PD target attainment (ƒT > 4 × MIC) and microbiologic clearance at the end of treatment. Therapeutic drug monitoring to assess C/T concentration was performed. (3) Results: Three patients were enrolled in the study and received 9 g of C/T in CI every 24 h. One patient received an additional course of antimicrobial therapy due to disease exacerbation six months after initial treatment, accounting for four evaluated treatments. The primary outcome was achieved in 3/4 treatments and the secondary outcome was achieved in 4/4 and 3/3, respectively. In all patients, free ceftolozane concentrations were >10 times higher than the EUCAST breakpoint (4 mg/L). (4) Conclusions: Elastomeric infusion of C/T delivered in CI can be an effective and convenient way to treat acute diseases caused by MDR-P. aeruginosa, avoid hospital admission, and contribute to infection control strategies. Despite the small number of enrolled patients, clinical and microbiological results support this strategy.

Effect of Antibiotic Therapy on the Sensitivity of Etiological Diagnostic Methods in Patients with Infective Endocarditis after Surgery

Aim. Assessment of impact of the duration of preoperative antimicrobial therapy (AMT) on the sensitivity of microbiological examination and polymerase chain reaction (PCR) of blood/tissues of resected valves in operated patients with infective endocarditis (IE).Materials and methods. 52 operated patients with active IE were included prospectively (Duke criteria, 2015). All patients underwent microbiological examination of blood before admission to the cardiac surgery hospital, as well as parallel simultaneous microbiological examination and PCR of blood/tissues of excised valves, followed by Sanger sequencing. The duration of preoperative treatment was calculated from the first day of AMT according to IE diagnosis to the day of surgery.Results. The causative agent of IE was established in 84.6% (n=44) patients by means of complex etiological diagnosis. A significant decrease in the sensitivity of microbiological examination of venous blood was revealed when performed in the period before and after hospitalization to a surgical hospital (up 44.2% to 17.3%, p<0.05). When comparing microbiological examination of blood/tissues of resected valves and PCR of blood/tissues of resected valves, molecular biological methods demonstrated the greatest sensitivity, with a great advantage when examining the tissues of resected valves (17.3% and 19.2% vs. 38.5% and 75.0%, respectively; p<0.001). The microbiological examination of venous blood performed at an early date before admission to the cardiac surgery hospital was comparable in sensitivity to the PCR blood test performed at a later date after prolonged AMT, and significantly less sensitive in relation to the PCR of resected valve tissues [44.2% and 38.5% (p>0.05) vs. 75.0% (p<0.05)]. In course of AMT 1-28 days, there were comparable results of microbiological examination with PCR blood examination and significantly better results of PCR of resected valve tissues [31.0% and 34.5% and 41.4% (p>0.05) vs 72.4% (p<0.001), respectively], and with AMT ≥ 29 days, microbiological examination of any biological material was negative in all patients, and PCR of blood/tissues of resected valves retained high sensitivity (0% and 0% vs. 34.8% and 78.3%, respectively; p<0.01).Conclusion. Long-term preoperative AMT significantly reduced the sensitivity of microbiological examination of resected valve blood/tissue in operated patients with IE, whereas PCR of resected valve blood/tissue was highly sensitive even with preoperative AMT for more than 29 days.

The Short versus Long Antibiotic Course for Pleural Infection Management (SLIM) randomised controlled open-label trial.

Based on expert opinion, the length of antibiotic treatment for pleural infection in adults is typically recommended to be a minimum of 4 weeks. This clinical trial aimed to assess whether shorter antibiotic courses lead to more treatment failures than standard longer courses. In an open-label randomised controlled trial, adult patients with pleural infection who were medically treated and stabilised within 14 days of admission were randomised to either a short antibiotic course (total course 14-21 days) or a long antibiotic course (total course 28-42 days). Patients were excluded if their baseline RAPID score was >4 (high-risk category). The primary outcome was the incidence of treatment failure by 6 weeks post-admission. Secondary outcomes were total length of antibiotic treatment, proportion of patients who resumed normal activity levels within 6 weeks post-admission, time from discharge to resuming normal activity levels and incidence of antibiotic-related adverse reactions. Between September 2020 and October 2021, 50 patients (mean±sd age 46±13.7 years; 35 (70%) males) were recruited to the trial and randomly assigned to the short course group (n=25) or the long course group (n=25), with outcome data available for 24 patients in each study group. Treatment failure occurred in four (16.7%) patients in the short course group and three (12.5%) patients in the long course group. In the intention-to-treat analysis the OR for treatment failure in the long course group was 0.714 (95% CI 0.142-3.600; p=0.683). The median (interquartile range) duration of antibiotic treatment in the short course group was 20.5 (18-22.5) days compared with 34.5 (32-38) days in the long course group (p<0.001). There were no statistically significant differences in the other outcomes. In medically treated adult patients with pleural infection a long course of antimicrobial therapy did not lead to fewer treatment failures compared with a shorter course. These findings need to be confirmed in a larger multicentre trial.

1861. The Spectrum and Clinical Significance of Actinomyces Blood Stream Infection

Abstract Background Actinomyces species are Gram-positive anaerobic branching bacilli which are commensal of oropharynx, urogenital and gastrointestinal tracts that is associated with infrequent chronic granulomatous diseases including cervicofacial, intrabdominal and genital infections. Actinomyces Blood Stream Infections (BSIs) are usually rare but becoming more frequent with advanced modern diagnostic techniques. The presented study aims to evaluate the spectrum and clinical relevance of Actinomyces BSI at Hamad Medical Corporation (HMC), Qatar. Methods A retrospective observational study was conducted for all reported Actinomyces species BSI at HMC between January 2016 to November 2020. Isolates were identified using modern automated BD PhoenixTM and MALDI-TOF microbiological methods. Results Over the five years study period, 37 episodes of Actinomyces BSIs were recorded the majority of which identified as Actinomyces odontolyticus (40.5 %, 15/37). The mean age was 32 years (range 1 month – 81 years), 62.2 % were females (23/37), 64.8 % had chronic medical conditions while 78.4 % developed fever as presenting illness. Out of the total cases, cultures were considered significant in only 48.6 % of cases (18/37), in which primary source of infection was oropharyngeal (10) followed by genitourinary (4), gastrointestinal (2) and 2 infected diabetic foot. However, 86.5 % (32/37) received antimicrobial therapy mainly as βlactam antibiotics or cephalosporins ranging between 3 days to 6 months. Antimicrobial therapy was given for a short duration in 87.5% (28/32) of cases for less than 14 days with no long-term complications while only four cases received prolonged therapy. The remaining Five patients did not receive any antibiotics as the cultures were considered contaminants by the primary provider. Conclusion Actinomyces species blood stream infection is becoming more frequent with advanced diagnostic techniques affecting all age groups. Females and patients with chronic comorbidities are more commonly affected while A. odontolyticus is the predominant isolated species. Almost half of the cases were not clinically relevant, but most cases received short courses of antimicrobial therapy with no long-term complications. Disclosures All Authors: No reported disclosures.

Clinical Outcome in Children With Cancer With Two or More Microorganisms Isolated From Blood Cultures During Episodes of Fever and Neutropenia.

Bacterial bloodstream infections are a major cause of morbidity and mortality in children with cancer and episodes of fever and neutropenia (FN). The aim of this study was to evaluate the clinical outcome in children with cancer with 2 or more microorganisms isolated from blood cultures during their episodes of FN. Between 2016 and 2021, children presenting with high-risk FN, admitted to any of the 6 participating hospitals in Santiago, Chile, were included in this study if they have positive blood cultures. We compared the clinical outcome of children with 2 or more microorganisms versus those with single agent isolation. A total of 1074 episodes of high-risk FN were enrolled in the study period, of which 27% (298) had positive blood cultures and 3% (32) had 2 or more microorganisms isolated from blood cultures. The most frequent identified agents were Viridans group streptococci and Escherichia coli in 20%, followed by Coagulase negative staphylococci in 14%. Children with 2 or more microorganisms presented more days of fever (7 vs. 4 days, P = 0.02), needed longer courses of antimicrobial therapy (16 vs. 14 days, P = 0.04) and had higher mortality at day 30 (13% vs. 1%, P = 0.003). Children with cancer and FN with 2 or more microorganisms isolated from blood cultures had a worse clinical outcome than children with single agent isolation.

Short courses of antimicrobial therapy for bacterial vaginosis: the possibilities of modern pharmacology: A review

Bacterial vaginosis is associated with severe infectious and inflammatory diseases and reduces the quality of life in women of reproductive age. Its worldwide prevalence is up to 80%. Thus, the development of new effective and safe methods of antimicrobial therapy becomes an urgent problem.&#x0D; This article provides a review of current antimicrobial therapies for bacterial vaginosis and evaluates the safety and efficacy of short courses of antimicrobial therapy using combined agents for intravaginal use.

37-Year-Old Man With Headache and Nasal Congestion

37-Year-Old Man With Headache and Nasal Congestion

Expert clinical pharmacological advice may make an antimicrobial TDM program for emerging candidates more clinically useful in tailoring therapy of critically ill patients

BackgroundTherapeutic drug monitoring (TDM) may represent an invaluable tool for optimizing antimicrobial therapy in septic patients, but extensive use is burdened by barriers. The aim of this study was to assess the impact of a newly established expert clinical pharmacological advice (ECPA) program in improving the clinical usefulness of an already existing TDM program for emerging candidates in tailoring antimicrobial therapy among critically ill patients.MethodsThis retrospective observational study included an organizational phase (OP) and an assessment phase (AP). During the OP (January–June 2021), specific actions were organized by MD clinical pharmacologists together with bioanalytical experts, clinical engineers, and ICU clinicians. During the AP (July–December 2021), the impact of these actions in optimizing antimicrobial treatment of the critically ill patients was assessed. Four indicators of performance of the TDM-guided real-time ECPA program were identified [total TDM-guided ECPAs July–December 2021/total TDM results July–December 2020; total ECPA dosing adjustments/total delivered ECPAs both at first assessment and overall; and turnaround time (TAT) of ECPAs, defined as optimal (< 12 h), quasi-optimal (12–24 h), acceptable (24–48 h), suboptimal (> 48 h)].ResultsThe OP allowed to implement new organizational procedures, to create a dedicated pathway in the intranet system, to offer educational webinars on clinical pharmacology of antimicrobials, and to establish a multidisciplinary team at the morning bedside ICU meeting. In the AP, a total of 640 ECPAs were provided for optimizing 261 courses of antimicrobial therapy in 166 critically ill patients. ECPAs concerned mainly piperacillin–tazobactam (41.8%) and meropenem (24.9%), and also other antimicrobials had ≥ 10 ECPAs (ceftazidime, ciprofloxacin, fluconazole, ganciclovir, levofloxacin, and linezolid). Overall, the pre–post-increase in TDM activity was of 13.3-fold. TDM-guided dosing adjustments were recommended at first assessment in 61.7% of ECPAs (10.7% increases and 51.0% decreases), and overall in 45.0% of ECPAs (10.0% increases and 35.0% decreases). The overall median TAT was optimal (7.7 h) and that of each single agent was always optimal or quasi-optimal.ConclusionsMultidisciplinary approach and timely expert interpretation of TDM results by MD Clinical Pharmacologists could represent cornerstones in improving the cost-effectiveness of an antimicrobial TDM program for emerging TDM candidates.

The effects of oclacitinib treatment on antimicrobial usage in allergic dogs in primary practice: an Australia wide case-control study

BackgroundCanine allergic dermatitis is a common diagnosis in veterinary practices which can lead to secondary infections requiring treatment with antimicrobials. A previous study suggested that dogs treated with oclacitinib in an Australian referral hospital required fewer courses of antimicrobial therapy compared to dogs receiving other anti-pruritic treatments. This study aimed to quantify the effect of oclacitinib treatment on the use of antimicrobials and other therapies in general practice veterinary clinics across Australia. A retrospective case-controlled review of patient records was designed to investigate the number of courses of antimicrobials and other therapies in dogs that received oclacitinib (Apoquel®), compared with those who received an anti-pruritic treatment that was not oclacitinib.ResultsThe target population included canine patients with a presumptive diagnosis of allergic dermatitis presenting between 2008 and 2018 to general practices contributing to the VetCompass Australia database. Patient records of interest were identified using search terms relating to allergic dermatitis, resulting in over 700,000 observations. Multivariable logistic regression models were developed to determine whether cases were prescribed fewer antimicrobial courses than controls, after adjusting for the presence of concurrent skin infections or infectious agents in ears. Our results indicate that fewer antimicrobial courses were prescribed in the cases compared to the controls. After adjusting for the concurrent skin infections, there was a significant reduction in the use of cefovecin [OR:0.62(0.39–0.98), P = 0.043], chlorhexidine [OR:0.57(0.42–0.77), P < 0.001], neomycin [OR:0.4(0.28–0.56), P < 0.001] and amoxycillin clavulanic acid (AMC) [OR: 0.55(0.39–0.78), P = 0.001] in cases compared to controls.ConclusionThis study demonstrates a potential sparing effect of oclacitinib on the prescription of antimicrobials for the treatment of allergic skin diseases in dogs. This information may assist in the planning of treatment for canine allergic dermatitis, with consideration for antimicrobial stewardship.

A 5-year retrospective study of Actinomyces odontolyticus bacteremia in the state of Qatar, case series

Introduction and importanceManifestations of infection by A. odontolyticus include thoracic, abdominal, pelvic, and central nervous system disease. In the four decades following its isolation, more than 20 cases of invasive infections were reported in multiple geographic locations including the United States and Europe. As such, A. odontolyticus is an emerging bacterium and related research is encouraged for further characterization of its prevalence and clinical significance. Our case series represents the first case series about A. odontolyticus bacteremia in the state of Qatar. MethodsWe are reporting 15 cases with isolated A. odontolyticus positive blood cultures at Hamad Medical Corporation, State of Qatar from 1/Jan/2016 to 1/Nov/2020. Electronic health records (EHR) of patients who were identified to have positive blood cultures were accessed and the demographics and other clinically related data were collected and mentioned in this manuscript, after obtaining the appropriate approval from the Corporation Medical Research Council (MRC). OutcomesWe are reporting 15 cases with isolated A. odontolyticus positive blood cultures at Hamad Medical Corporation, State of Qatar from 1/Jan/2016 to 1/Nov/2020. Conclusion12 of the 15 reported cases were considered significant and received a complete course of antimicrobial therapy. The patients presented with a wide variety of clinical pictures and were of variable age.

Therapeutic Target Attainment of 3-Hour Extended Infusion of Meropenem in Patients With Septic Burns

PurposeThe aim of this prospective cohort study was to evaluate the therapeutic target attainment of 3-hour extended infusion of meropenem in patients with septic burns in the early and late periods of septic shock. MethodsMeropenem serum levels were determined by liquid chromatography from blood samples collected within 48 hours (early period) of therapy and 10 to 14 days afterward (late period). Pharmacokinetic properties were investigated by noncompartmental analysis, and the therapeutic target was defined as 100% of the time above the MIC (100%fT> MIC). FindingsFifteen patients with 90 measured meropenem concentrations were included. Throughout the entire course of antimicrobial therapy, the therapeutic target was attained against gram-negative pathogens with an MIC ≤ 2 mg/L. Pathogens with intermediate susceptibility to meropenem were only covered in the early phase of therapy. ImplicationsHigher-dose regimens or continuous infusions may be necessary to guarantee antimicrobial coverage of meropenem against less sensitive pathogens in patients with septic burns.

Splenic Abscess in the New Millennium: A Descriptive, Retrospective Case Series.

BackgroundSplenic abscess is a rare infection often resulting from hematogenous spread. Immunocompromised states are commonly comorbid, and the microbiology is heterogeneous.MethodsWe conducted a retrospective review of 33 cases identified by convenience sampling. Cases were treated in our institution’s hospital system between May 2012 and February 2021 and classified as proven or probable based on predetermined criteria.ResultsThe median age was 57 years, and 58% were men. Common underlying diseases included diabetes mellitus (30%), pancreatic disease (30%), and hematological malignancy (15%). The most common mechanism of pathogenesis was hematogenous spread (n = 13). Escherichia coli, enterococcal spp., and anaerobes were frequently implicated. One case was discovered at autopsy and excluded from subsequent analyses. The median duration of antimicrobial therapy (range) was 45 (5–525) days, and the median length of index hospitalization was 20 days. Percutaneous drainage by interventional radiology was common (17 of 32; 53%), and 6 patients underwent splenectomy. Treatment success was achieved in 14 of 32 cases (44%), with clinical stability in 3 of 32 cases (9%). Failures occurred in 13 of 32 (41%) cases, 2 of whom died from splenic abscesses. Two patients (2 of 32) were lost to follow-up.ConclusionsTo our knowledge, this is the largest North American series since the turn of the century and the first to distinguish between proven and probable cases. As reflected in our series, patients with splenic abscess may require prolonged hospitalizations and courses of antimicrobial therapy. Improvements in management are needed.

61. Short- versus prolonged-courses of antimicrobial therapy for patients with uncomplicated Pseudomonas aeruginosa bloodstream infection

BackgroundThe optimal duration of antimicrobial therapy for uncomplicated Pseudomonas aeruginosa bloodstream infection (BSI) is unknown. We compared the outcomes of short and prolonged courses of antimicrobial therapy in adults with uncomplicated pseudomonal BSI.MethodsAll patients with uncomplicated P. aeruginosa BSI admitted at a tertiary-care hospital from May 2016 to September 2020 were included. We compared the rate of recurrent P. aeruginosa infection and 30-day mortality among patients who underwent short (7‒11 days) and prolonged (12‒21 days) courses of antimicrobial therapy using propensity score analysis with the inverse probability of treatment weighting (IPTW) method. ResultsWe evaluated 1,477 patients with uncomplicated P. aeruginosa BSI; of them, 290 met the eligibility criteria, including 97 (33%) who underwent short-course therapy (9 [interquartile range (IQR), 8‒11] days) and 193 (67%) who underwent prolonged-course therapy (15 [IQR, 14‒18] days). We found no significant difference in the risk of recurrence or 30-day mortality between the prolonged-course and short-course groups (n=10, 11% vs. n=32, 16%; IPTW-adjusted hazard ratio (HR) 0.61; 95% confidence interval (CI) 0.30−1.24; p=0.17). The recurrence of P. aeruginosa infection at any site within 180 days of completing therapy occurred significantly more in the prolonged-course group (n=10, 10% vs. n=38, 20%; IPTW-adjusted HR 0.48; 95% CI 0.24−0.96, p=0.04). The resistance acquisition in subsequent P. aeruginosa isolates was more frequent in the prolonged-course group, although the difference was not statistically significant (n=2, 20% vs. n=12, 32%; p=0.70). ConclusionShort-course antimicrobial therapy could be as effective as prolonged-course therapy for uncomplicated P. aeruginosa bloodstream infection.Disclosures All Authors: No reported disclosures

Neisseria meningitidis-induced discitis at L5-S1 mimicking lumbar disc herniation

A 23-year-old man presented to his general practitioner with a 2-week history of increasing lumbar back pain and left-sided radiation at S1, with progressive motoric loss of function of S1 on the right side but with intact sensibility. On lumbar MRI, a medial L5-S1 disc herniation was identified (figure) and oral corticosteroid therapy (prednisolone 100 mg daily for 5 days) was initiated. Because the back pain and radiculopathy did not regress and a progressive functional motoric loss of function of S1 (M3) was present, he underwent microdiscectomy 2 weeks after initial presentation. At admission, the laboratory results showed moderately increased serum C-reactive protein (50 mg/L) and leukocyte count (12 × 109 cells per L). Preoperative antimicrobial prophylaxis with intravenous cefuroxime (1·5 g as a one-off injection) was administered. Intraoperatively, pus was detected in the epidural space and disc niche, hence lavage of the disc space and collection of two disc tissue biopsies followed. Antibiotic treatment with intravenous co-amoxiclav (2·2 g every 6 h for 7 days) was initiated postoperatively. Histopathological examination showed focal lymphoplasmacytic, partly granulocytic inflammation, which was consistent with discitis. Cultures of intraoperatively sampled tissue biopsies remained without bacterial growth, but broad-spectrum PCR identified Neisseria meningitidis (subgroup W135) in both disc tissue specimens. Antimicrobial treatment was subsequently changed to targeted therapy with intravenous ceftriaxone (2 g once daily for 14 days). On postoperative day 8, the patient had an exacerbation of pain. Despite debridement of the abscess at the first intervention, persistent epidural abscess collection was visible in the ensuing obtained lumbar MRI, which resulted in a second-look surgery with extensive lavage and abscess evacuation on the same day. Intraoperative tissue biopsies remained culture-negative; however, N meningitidis was identified by PCR again in three of six specimens (four disc tissue specimens and two abscess fluid specimens) taken during the second surgery. Subsequently, pain subsided substantially with extended oral analgesic treatment consisting of oral diclofenac (75 mg twice daily), oral metamizol (500 mg four times daily), oral tapentadol (150 mg prolonged-release tablet every 12 h), and oral pregabalin (50 mg three times daily), which was adminstered for 28 days. The patient was discharged on postoperative day 12 after index surgery still having increased inflammatory markers (C-reactive protein 47 mg/L, leukocyte count 9·7 × 109 cells per L). After 9 days of intravenous ceftriaxone (2 g once daily), oral ciprofloxacin (750 mg twice daily) was administered to complete the 6-week course of antimicrobial therapy for bacterial spondylodiscitis. The patient regained complete motor function at 6 weeks after the first surgery. Inflammatory laboratory parameters were completely resolved at 3 months of follow-up, and back and leg pain resolved at 6 months of follow-up.

Bloodstream infections with rapidly growing nontuberculous mycobacteria

BackgroundBloodstream infections (BSI) with rapidly growing mycobacteria (RGM) resulted in recent nosocomial outbreaks predominantly in immunocompromised patients. A little is known about the clinical implications of RGM BSI with different species. MethodsWe conducted a multicenter retrospective cohort study of patients with RGM BSI from November 2011 to December 2020. Demographic data, clinical presentation, laboratory and radiographic findings and microbiological characteristics were used to tabulate descriptive statistics. We performed a comparative analysis of patients with BSI due to Mycobacterium abscessus complex (MABC) vs. other RGM. ResultsWe identified 32 patients with positive blood cultures for RGM, 4/32 (12.5%) were considered to have unclear significance. The most common source for RGM BSI was intravascular catheters (14/28, 50%). Compared to other sources, patients with catheter-related bloodstream infection (CRBSI) received a shorter course of antimicrobial therapy (median [IQR]: one month [0.37–2.25] vs. six months [2–12]), (P = 0.01). The most common species isolated were MABC (12/28, 42.9%), followed by Mycobacterium fortuitum group (6/28, 21.4%) and Mycobacterium chelonae (6/28, 21.4%). Compared to other RGM, MABC BSI was more likely to be secondary to skin and soft tissue infection, associated with longer hospital stay (P = 0.04) and higher death rates despite a higher number of antimicrobial agents used for empirical and directed therapy per patient. ConclusionMABC BSI is associated with an overall more resistant profile, longer hospital stay, and higher death rate despite a more aggressive therapy approach.

Short versus prolonged courses of antimicrobial therapy for patients with uncomplicated Pseudomonas aeruginosa bloodstream infection: a retrospective study.

The optimal duration of antimicrobial therapy for uncomplicated Pseudomonas aeruginosa bloodstream infection (BSI) is unknown. We compared the outcomes of short and prolonged courses of antimicrobial therapy in adults with uncomplicated pseudomonal BSI. All patients with uncomplicated P. aeruginosa BSI admitted at a tertiary-care hospital from April 2010 to April 2020 were included. We compared the primary outcome (a composite of the rate of recurrent P. aeruginosa infection and mortality within 30 days after discontinuing antimicrobial therapy) among patients who underwent short (7‒11 days) and prolonged (12‒21 days) courses of antimicrobial therapy using propensity score analysis with the inverse probability of treatment weighting (IPTW) method. We evaluated 1477 patients with P. aeruginosa BSI; of them, 290 met the eligibility criteria who received antimicrobial agents with in vitro activity, including 97 (33%) who underwent short-course therapy [median of 9 (IQR = 8‒11) days] and 193 (67%) who underwent prolonged-course therapy [median of 15 (IQR = 14‒18) days]. We found no significant difference in the risk of recurrence or 30 day mortality between the prolonged-course and short-course groups [n = 30 (16%) versus n = 11 (11%); IPTW-adjusted HR = 0.68, 95% CI = 0.34 - 1.36, P = 0.28]. The prolonged-course therapy did not significantly reduce the risk of the recurrence of P. aeruginosa infection within 180 days compared with short-course therapy [n = 37 (19%) versus n = 12 (12%); IPTW-adjusted HR = 0.57, 95% CI = 0.29 - 1.10, P = 0.09]. Short-course antimicrobial therapy could be as effective as prolonged-course therapy for uncomplicated P. aeruginosa BSI.