Serratia marcescens, as a Gram-negative opportunistic pathogen, is a rare cause of peritonitis and has worse clinical outcomes than Gram-positive peritonitis. In this case report, we describe a case of Serratia marcescens associated peritonitis that was successfully cured without catheter removal. A 40-year-old male patient with peritoneal dialysis who worked in the catering industry was admitted to the hospital for 16 hours after the discovery of cloudy peritoneal dialysate and abdominal pain. Ceftazidime and cefazolin sodium were immediately given intravenously as an empirical antibiotic regimen. After detecting Serratia marcescens in the peritoneal diasate culture, the treatment was switched to ceftazidime and levofloxacin. The routine examination of peritoneal dialysate showed a significant decrease in white blood cells, the peritoneal dialysate became clear, and the peritoneal dialysis catheter was retained. The patient was treated for 2 weeks and treated with oral antibiotics for 1 week. It is necessary to further strengthen the hygiene of work environment to prevent Serratia marcescens infection in peritoneal dialysis patients. We recommend that patients with Serratia marcescens associated peritonitis should be treated with a combination of antibiotics as early as possible empirically, and at the same time, the peritoneal dialysis fluid culture should be improved, and the antibiotic regimen should be timely adjusted according to the drug sensitivity results. For patients with clinical symptoms for more than 3 days, considering the strong virulence of Serratia marcescens, whether to use meropenem directly or not can provide a reference for clinical decision-making. Further clinical studies are needed to achieve more precise anti-infective treatment.

Antibiotics have played a pivotal role in modern medicine, drastically reducing mortality rates associated with bacterial infections. Despite their significant contributions, the emergence of antibiotic resistance has become a formidable challenge, necessitating a re-evaluation of antibiotic use practices. The widespread belief in clinical practice that bactericidal antibiotics are inherently superior to bacteriostatic ones lacks consistent support from evidence in randomized controlled trials (RCTs). With the latest evidence, certain infections have demonstrated equal or even superior efficacy with bacteriostatic agents. Furthermore, within clinical practice, there is a tendency to indiscriminately order urine cultures for febrile patients, even in cases where alternative etiologies might be present. Consequently, upon obtaining a positive urine culture result, patients often receive antimicrobial prescriptions despite the absence of clinical indications warranting such treatment. Furthermore, it is a prevailing notion among physicians that extended durations of antibiotic therapy confer potential benefits and mitigate the emergence of antimicrobial resistance. Contrary to this belief, empirical evidence refutes such assertions. This article aims to address common myths and misconceptions within the field of infectious diseases.

To analyze the role played by the clinical pharmacist and its impact in antibiotic stewardship facing suspected allergy to beta-lactam antibiotics.
We performed 2 different independent bibliographic searches. A total of 35 articles were found, and the final number included in the study was 12. We analyzed the articles and collected variables of efficacy, safety, and applicability of evaluation tools applied to patients with suspected allergy to beta-lactams. Also, the variation in the consumption and prescription profile of alternative antibiotics was analyzed.
The selected studies analyzed questionnaires, allergy delabeling, intradermal tests, and oral challenge tests performed by pharmacists. Significant differences in the efficacy endpoint were found in 4 studies in favor of pharmaceutical intervention. In the study of Kwiatkowski et al., cefazolin use increased in surgical patients after pharmacist intervention (65% vs 28%; P < .01). In a quasi-experimental study, the mean defined daily dose of aztreonam and the mean days of therapy per 1000 patients/day decreased (21.23 vs 9.05, P <.01) and (8.79-4.24, P = .016), pre- and post-intervention, respectively, increasing antibiotic de-escalations (P = < .01). In another quasi-experimental study, the prescription of restricted use antibiotics decreased (42.5% vs 17.9%, P < .01)and the use of pre-surgical prophylactic antibiotics alternative to cefazolin (81.9% vs 55.9%, P < .01)in another study. Other study showed that the mean time per interview was 5.2 min per patient. No adverse events were reported in any study.
The pharmacist intervention in the evaluation of the patient with suspected allergy to beta-lactams is effective, safe, and feasible to implement on daily clinical practice. The standardization of protocols to clarify the history of allergies and development of evaluation tools represent simple screenings to perform delabeling or refer to the Immunoallergology service, improving penicilins use and reducing the need for second-line antibiotics. More studies are needed to standardize the desensitization tests made by pharmacists. However, despite these results, the involvement and leadership of the pharmacist in this area is limited and constitutes a future challenge for the profession.

To analyze the role played by the clinical pharmacist and its impact in antibiotic stewardship facing suspected allergy to beta-lactam antibiotics.
We performed two different independent bibliographic searches. A total of 35 articles were found, and the final number included in the study was 12. We analysed the articles and collected variables of efficacy, safety and applicability of evaluation tools applied to patients with suspected allergy to beta-lactams. Also, the variation in the consumption and prescription profile of alternative antibiotics was analyzed.
The selected studies analysed questionnaires, allergy delabeling, intradermal tests and oral challenge tests performed by pharmacists. Significant differences in the efficacy endpoint were found in 4 studies in favour of pharmaceutical intervention. In the study of Kwiatkowski et al, cefazolin use increased in surgical patients after pharmacist intervention (65 vs. 28%; p < 0.01). In a quasi-experimental study, the mean defined daily dose of aztreonam and the mean days of therapy per 1000 patients/day decreased (21.23 vs 9.05, p <0.01) and (8.79-4.24, p = 0.016), pre and post-intervention, respectively, increasing antibiotic de-escalations (p ≤ 0.01). In another quasi-experimental study, the prescription of restricted-use antibiotics decreased (42.5% vs. 17.9%, p < 0.01) and the use of pre-surgical prophylactic antibiotics alternative to cefazolin (81.9% vs 55.9%, p<0.01) in another study. Other study showed that the mean time per interview was 5.2 minutes per patient. No adverse events were reported in any study.
The pharmacist intervention in the evaluation of the patient with suspected allergy to beta-lactams is effective, safe and feasible to implement on daily clinical practice. The standardization of protocols to clarify the history of allergies and development of evaluation tools represent simple screenings to perform delabelling or refer to the Immunoallergology service, improving penicilins use and reducing the need for second line antibiotics. More studies are needed to standardize the desensitization tests made by pharmacists. However, despite these results, the involvement and leadership of the pharmacist in this area is limited and constitutes a future challenge for the profession.

Periprosthetic joint infections (PJI) following joint arthroplasty are now the leading cause of reoperation and are associated with serious morbidity to the patient, often requiring several staged operations and a prolonged course of parenteral antibiotics. Prophylactic administration of intravenous antibiotics before skin incision is arguably the most important measure to prevent PJI; however, the dose effectiveness of cefazolin in target tissue is not well known. We aimed to identify parameters affecting local tissue concentration (LTC) of cefazolin.
We performed a literature search using the following keywords: \"orthopaedics,\" \"orthopedic,\" \"arthroplasty\" and \"cefazolin.\" We included studies that measured LTC of cefazolin from samples obtained during either a total knee or total hip arthroplasty.
Of the 332 records screened, we included 10 studies that described LTC of cefazolin. The included studies evaluated dosing (n = 7), procedure type (n = 3), body mass index (n = 1) and tourniquet utilization (n = 1).
Few studies have measured LTC levels of antibiotics (or levels of cefazolin) to validate current recommendations for antibiotic prophylaxis in orthopedic surgery. With infection as the leading reason for early reoperation or revision surgery, the parameters affecting LTC during orthopedic procedures need to be further assessed.

To compare the efficacy of antimicrobial therapies used in the management of persistent methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia.
A literature search using the PubMed database (inception to December 2022) was conducted using the search terms \"Staphylococcus aureus bacteremia,\" \"methicillin-susceptible Staphylococcus aureus bacteremia,\" \"persistent methicillin-susceptible Staphylococcus aureus bacteremia,\" and \"refractory methicillin-susceptible Staphylococcus aureus bacteremia .\" In addition, therapeutic agents which could be used as treatment for MSSA including \"nafcillin,\" \"oxacillin,\" \"cefazolin,\" \"ceftaroline,\" \"gentamicin,\" \"rifampin,\" and \"daptomycin\" were also combined with the aforementioned search terms to capture data using these agents.
Clinical data were limited to those published in the English language. Articles and abstracts were considered for inclusion in addition to ongoing trials identified through ClinicalTrials.gov.
A total of 78 articles were reviewed including 17 in vitro or animal model studies and 39 studies including patient data. The remaining 22 articles included guidelines, review articles, and editorials. Recent data evaluating use of dual β-lactam regimens for persistent MSSA bacteremia were limited to 8 case reports or case series.
At present, there is little guidance on how to best manage patients with persistent MSSA bacteremia. This narrative review collates the available data to assist clinicians in selecting the best possible antimicrobial regimen when facing this clinical conundrum.
Modification of antimicrobial therapy, in conjunction with source control and infectious diseases consultation, may all be necessary to sterilize blood cultures in patients with persistent MSSA bacteremia.

BACKGROUND: An infected popliteal pseudoaneurysm has never been described in the pediatric population. Physicians need to be aware of its presentation and management, in order to diagnose and treat this medical condition adequately.
METHODS: We describe the case of a 14-year-old boy who developed myositis and cellulitis centered at the popliteal fossa after playing basketball. A treatment of intravenous cefazolin was started. 5 days later, he experienced a knee pain flare-up, which turned out to be a popliteal pyomyositis with a pseudoaneurysm of the popliteal artery. A saphenous vein graft bypass of the popliteal artery and an excision of the popliteal pseudoaneurysm were performed. Intravenous cefazolin was continued for 6 weeks and prophylactic acetylsalicylic acid for 6 months.
CONCLUSIONS: This case highlighted the importance of repeating radiologic investigations if a patient suffering from soft tissue infection has persistent pain after several days of appropriate antibiotics. A popliteal pseudoaneurysm can be diagnosed with ultrasound imaging and treated with a popliteal-popliteal bypass. Our patient needed a catheter-guided dilation of the anastomosis at the vein graft 6 months post-surgery, and then evolved favorably and went back to playing basketball 6 months post-dilation.

Infections of the central nervous system (CNS) are complex to treat and associated with significant morbidity and mortality. Historically, antistaphylococcal penicillins such as nafcillin were recommended for the treatment of methicillin-susceptible staphylococcal CNS infections. However, the use of antistaphylococcal penicillins presents challenges, such as frequent dosing administration and adverse events with protracted use. This narrative reviews available clinical and pharmacokinetic/pharmacodynamic (PK/PD) data for cefazolin in CNS infections and produces a recommendation for use. Based on the limited available evidence analyzed, dose optimized cefazolin is likely a safe and effective alternative to antistaphylococcal penicillins for a variety of CNS infections due to methicillin-susceptible Staphylococcus aureus. Given the site of infection and wide therapeutic index of cefazolin, practitioners may consider dosing cefazolin regimens of 2 g IV every 6 h or a continuous infusion of 8-10 g daily instead of 2 g IV every 8 h to optimize PK/PD properties.

Intraoperative anaphylaxis is a life threatening and multiorgan system hypersensitivity reaction that frequently leads to cessation of operations. Despite the incidence of Cefazolin allergy being on the rise, the cases of anaphylaxis to Cefazolin during surgeries and its management are seldom reported.
We present two patients with no known beta-lactam allergy and end stage kidney disease who received perioperative intravenous Cefazolin for planned deceased kidney transplant surgery at our academic medical center. Both patients developed anaphylaxes approximately three minutes following the administration of the antibiotic and experienced severe, refractory hypotension that required the use of vasopressors. The severity of the anaphylactic reactions resulted in the cessation of the transplant operation and multiple days of intensive care unit admission.
Peri-or intraoperative anaphylaxis to Cefazolin is on the rise and its consequences in transplant candidates are even more dire given the pre-existing end organ failure, financial burden for health care system, potential loss of donor organs, and emotional burden for recipients and their families. These are the first two cases of reported Cefazolin-induced anaphylaxis that actually resulted in aborting the kidney transplant operation. In addition, cases of previously reported Type 1 hypersensitivity to Cefazolin as prophylaxis for operations were reviewed and the allergy workups were discussed.

UNASSIGNED: Currently, antibiotic treatment is often a standard dosing regimen in bone and joint infections (BJI). However, it remains unknown if exposure at the target-site is adequate. The aim of this review is to gain more insight in the relationship between the target site concentration of antibiotic and the minimal inhibitory concentration to target the bacteria in bone and joint infections (BJI).
UNASSIGNED: A literature search was performed by Erasmus MC Medical library. Bone, bone tissue and synovial concentration of antibiotics were covered in humans. In addition, we reported number of patients, dose, sampling method, analytical method and tissue and plasma concentrations. We used the epidemiological cutoff value (ECOFF) values of the targeted micro-organisms. If more than 3 publications were available on the antibiotic, we graphically presented ECOFFS values against reported antibiotic concentrations.
UNASSIGNED: For most antibiotics, the literature is sparse. In addition, a lot of variable and total antibiotic concentrations are published. Ciprofloxacin, cefazolin, cefuroxime, vancomycin and linezolid seem to have adequate average exposure if correlating total concentration to ECOFF, when standard dosing is used. With regard to other antibiotics, results are inconclusive. More extensive pharmacokinetic/pharmacodynamic modeling in BJI is needed.