CNS toxoplasmosis, a rare presentation in a patient with Myasthenia Gravis.

We report the case of a 78-year-old man with a past medical history of non-Hodgkin's lymphoma s/p chemotherapy and Myasthenia Gravis on chronic mycophenolate mofetil (MMF), who presented with altered mental status and was found to have ring enhancing brain lesions. A brain biopsy revealed organisms consistent with Toxoplasma gondii. Cerebral toxoplasmosis has been rarely reported in patients with hematologic malignancies or in those receiving immunosuppressive agents. There needs to be a high degree of suspicion for T. gondii in HIV-negative individuals who are on immunosuppressants drugs including MMF.

Hip periprosthetic joint infection due to Coxiella burnetii in an adult male.

Coxiella burnetii is an obligate intracellular Gram-negative bacterium. "Query fever" (Q fever) first described in 1939 is a disease caused by Coxiella burnetii. This bacterium infects animals including goats, sheep, and cattle, and has been recognized as a pathogen causing acute illness in humans. A patient living on a farm with a history of a right total hip arthroplasty presented with right hip pain. Arthrocentesis revealed a total nucleated count of 4288 (93% neutrophils), however his synovial fluid culture remained negative. His Q fever phase I IgG and phase II IgG were elevated at 1:4096 and 1:2048, respectively. He underwent incision and drainage with exchange of the femoral head and acetabular component, with retention of the femoral stem. PCR of tissue samples returned positive for Coxiella burnettii. He was diagnosed with a persistent localized prosthetic joint infection (PJI) of the right hip. Coxiella burnetii PJI is a rare but increasingly recognized form of persistent localized Q fever infection. Q fever should be considered in the differential diagnosis of culture-negative PJI, especially among patients with exposure to sheep, goats, or cattle. Initial screening for Coxiella burnetii includes serology, but tissue PCR and immunohistochemical staining may be obtained to confirm joint infection.

Effectiveness and acceptability of intranasal povidone-iodine decolonization among fracture fixation surgery patients to reduce Staphylococcus aureus nasal colonization.

We evaluated povidone-iodine (PVI) decolonization among 51 fracture-fixation surgery patients. PVI was applied twice on the day of surgery. Patients were tested for S. aureus nasal colonization and surveyed. Mean S. aureus concentrations decreased from 3.13 to 1.15 CFU/mL (P = .03). Also, 86% of patients stated that they felt neutral or positive about their PVI experience.

Effectiveness and Optimal Duration of Adjunctive Rifampin Treatment in the Management of Staphylococcus aureus Prosthetic Joint Infections After Debridement, Antibiotics, and Implant Retention.

Background: Rifampin is recommended as adjunctive therapy for patients with a Staphylococcus aureus prosthetic joint infection (PJI) managed with debridement, antibiotics, and implant retention (DAIR), with no solid consensus on the optimal duration of therapy. Our study assessed the effectiveness and optimal duration of rifampin for S aureus PJI using Veterans Health Administration (VHA) data. Methods: We conducted a retrospective cohort study of patients with S aureus PJI managed with DAIR between 2003 and 2019 in VHA hospitals. Patients who died within 14 days after DAIR were excluded. The primary outcome was a time to microbiological recurrence from 15 days up to 2 years after DAIR. Rifampin use was analyzed as a time-varying exposure, and time-dependent hazard ratios (HRs) for recurrence were calculated according to the duration of rifampin treatment. Results: Among 4624 patients, 842 (18.2%) received at least 1 dose of rifampin; 1785 (38.6%) experienced recurrence within 2 years. Rifampin treatment was associated with significantly lower HRs for recurrence during the first 90 days of treatment (HR, 0.60 [95% confidence interval {CI}, .45-.79]) and between days 91 and 180 (HR, 0.16 [95% CI, .04-.66]) but no statistically significant protective effect was observed with longer than 180 days (HR, 0.57 [95% CI, .18-1.81]). The benefit of rifampin was observed for subgroups including knee PJI, methicillin-susceptible or -resistant S aureus infection, and early or late PJI. Conclusions: This study supports current guidelines that recommend adjunctive rifampin use for up to 6 months among patients with S aureus PJI treated with DAIR.

Rates of Antimicrobial Resistance With Extended Oral Antibiotic Prophylaxis After Total Joint Arthroplasty.

Background: There is increased interest and utilization of extended oral antibiotic prophylaxis (EOAP) following primary and revision total hip arthroplasties (THAs) and total knee arthroplasties (TKAs). The purpose of this study was to look for potential associations between EOAP and differential rates of antimicrobial resistance or epidemiology of organisms causing periprosthetic joint infection (PJI) following primary and aseptic revision THAs/TKAs. Methods: Patients who developed PJI following a primary or aseptic revision TKA/THA at a single institution from 2009 to 2020 were retrospectively identified. Patients who received at least 7 days of EOAP following the surgery were noted. Rates of antimicrobial resistance were compared between standard antibiotic prophylaxis and EOAP cohorts using the Fisher's exact test. Results: One hundred twenty-eight cultures were obtained from 119 patients with PJI. Fourty-four cases (37%) developed PJI after EOAP. Staphylococcus aureus was the most frequently isolated organism (30% of all cultures; 78% were methicillin-sensitive). Rates of antimicrobial resistance were similar between standard antibiotic prophylaxis and EOAP cohorts in all but 2 instances: Increased resistance to erythromycin and trimethoprim-sulfamethoxazole was observed in coagulase-negative Staphylococci isolates in the EOAP cohort (89% vs 21%, P < .01; 44% vs 0%, P = .02). An increased frequency of gram-negative organisms was observed in the EOAP group (22% vs 8%, P = .03). Conclusions: Rates of antimicrobial resistance were not significantly different between EOAP and standard antibiotic prophylaxis cohorts except in coagulase-negative Staphylococci. The increased frequency of gram-negative infections was present in the EOAP cohort. Larger, multicenter studies are needed to better understand the impact of EOAP on antimicrobial resistance and PJI epidemiology. Level of Evidence: Level III; retrospective cohort study.

Prosthetic hip infection due to Campylobacter jejuni.

A woman in her 60s with a left hip prosthesis was presented with left hip pain and fever. She had an elevated white blood cell count and inflammatory markers. Synovial fluid Gram stain demonstrated curved Gram-negative rods identified as Campylobacter jejuni The patient initially refused surgery and after 3 months underwent one-stage exchange after which she was treated with 12 weeks of levofloxacin. Her inflammatory markers normalised and she was clinically doing well at her 6-month follow-up. C. jejuni is a rare cause of prosthetic joint infection and should be included in the differential diagnosis when a patient has risk factors even without significant preceding gastrointestinal symptoms. Per most recent Infectious Diseases Society of America guidelines, treatment after one-stage revision includes 4-6 weeks of intravenous antimicrobials followed by possible oral suppression therapy, while the European guidelines recommend 12 weeks of orally bioavailable antibiotics.

Recurrent Cutibacterium acnes prosthetic valve endocarditis.

A 29-year-old man with a history of congenital aortic stenosis and mechanical aortic valve replacement with previous Cutibacterium acnes prosthetic valve endocarditis (PVE) presented with a 2-week history of fevers and night sweats. Transoesophageal echocardiogram revealed a 0.6 cm×0.5 cm vegetation on the mechanical aortic valve. An anaerobic blood culture became positive for C. acnes 6 days after the blood cultures were obtained. He did not have any surgical intervention. He was successfully treated with 6 weeks of ceftriaxone, followed by chronic suppression with oral doxycycline. Despite its low virulence, a growing number of C. acnes PVE cases have been reported, owing to its biofilm production. When clinical suspicion is high, extending culture incubation duration beyond the standard 5 days might be helpful. Most cases are treated with surgical repair or replacement in conjunction with antibiotics, but medical therapy alone has been documented as being successful.

Prosthetic hip infection due to Salmonella enterica serovar Enteritidis.

Prosthetic joint infection (PJI) is a serious complication of prosthetic joint implantation with a prevalence of about 1-2 % of all prosthetic joint surgeries. While Staphylococcus spp. are the most common organisms isolated, Salmonella spp. are a rare cause of PJI (estimated prevalence < 0.3 %). We present a case of a 62-year-old patient with a history of previous joint trauma complicated by osteonecrosis, infection and chronic alcohol abuse with late hematogenous prosthetic hip infection due to Salmonella enterica serovar Enteritidis. PJI due to Salmonella spp. should be considered in the differential diagnosis when a patient has risk factors such as malignancy, hemoglobinopathies, diabetes mellitus, human immunodeficiency virus/acquired immunodeficiency syndrome, alcohol dependency or immunosuppressed state, even without significant preceding gastrointestinal symptoms. Our patient had a few of these risk factors and required surgical debridement in addition to antimicrobials for treatment of his PJI.

Native joint septic arthritis due to Kingella kingae in an adult.

A 65-year-old woman with chronic osteoarthritis of the knees presented with a one-week history of acutely worsening right knee pain and swelling. Arthrocentesis was performed and synovial fluid was indicative of septic arthritis with a negative Gram stain for bacteria. Magnetic Resonance Imaging (MRI) was obtained, revealing a large anterior periarticular abscess with concomitant septic arthritis. Orthopedic surgeons performed urgent incision and drainage of the abscess and washout of the joint. Synovial fluid culture grew Kingella kingae and the patient was treated with four weeks of ceftriaxone with improvement in both clinical symptoms and laboratory values. Kingella kingae is a common cause of pediatric bone and joint infection but remains an exceedingly rare cause of native joint septic arthritis among immunocompetent adults. Kingella spp are largely susceptible to beta-lactam antimicrobials.

Prosthetic Finger Joint Infection Due to Aspergillus terreus.

Fungal periprosthetic joint infections (PJIs) are rare but associated with significant mortality. We report a case of a finger PJI secondary to Aspergillus terreus in an immunocompetent patient with soil exposure, successfully treated with surgical debridement and voriconazole. Identification of A terreus is important because of intrinsic amphotericin B resistance.

Late prosthetic shoulder joint infection due to Actinomyces neuii in an adult man.

A 72-year-old man with a history of right reverse shoulder arthroplasty presented with a 1-month history of erythema, pain and drainage from the right shoulder. Arthrocentesis was performed and synovial fluid gram stain revealed gram-positive rods. Clinical diagnosis of prosthetic shoulder joint infection was made. Orthopaedic surgeons performed irrigation and debridement with resection of the right shoulder prothesis and implantation of an antimicrobial spacer. Operative cultures grew Actinomyces neuii The patient was treated with 6 weeks of ceftriaxone with improvement in both clinical symptoms and laboratory values. Actinomyces species remain a rare cause of late prosthetic joint infection (PJI) due to their slow growing and indolent course. While generalised actinomycosis is often treated with 6-12 months of antibiotics, the treatment course of Actinomyces PJI is not well characterised, with some sources suggesting a minimum of 6 weeks of antimicrobial therapy.

Disseminated histoplasmosis presenting as bilateral lower extremity paresis.

Histoplasmosis is the most common endemic mycosis in the United States and is caused by the organism Histoplasma capsulatum. Infection is often asymptomatic or self-limited, but when symptomatic it usually presents in the form of pulmonary histoplasmosis. In its most severe form, H. capsulatum can spread to extrapulmonary sites causing disseminated infection. Here we present a peculiar case of central nervous system (CNS) histoplasmosis wherein multiple focal spinal cord lesions were the only manifestation of CNS infection, causing bilateral lower extremity paresis and loss of sensation. Although uncommon, CNS histoplasmosis should be included in the differential diagnosis when a patient presents with meningitis, encephalitis, or isolated brain or spinal cord lesions in endemic areas.

Escherichia hermannii as the sole cause of osteomyelitis in a patient with an open tibial shaft fracture.

Escherichia hermannii is a rare monomicrobial cause of infection in humans. E. hermannii has never before been reported as the sole isolate from an infected open tibia fracture. We present a case of E. hermannii infection after a type III open tibia fracture. The patient was initially treated with irrigation and debridement, open reduction internal fixation and primary wound closure. However, after 8 weeks, he developed a draining wound and infection at the fracture site. He required a repeat debridement, hardware removal, external fixation and 6 weeks of intravenous ceftriaxone for treatment. At 2-year follow-up, he remains infection free, asymptomatic and continues to work with excellent functional outcomes. This case adds to the growing literature that evidences E. hermannii as an organism that can be pathogenic, virulent and cause monomicrobial infection.

Mixed Actinomyces israelii and Aggregatibacter actinomycetemcomitans infection causing empyema necessitatis and multiple skin abscesses in an immunocompetent patient.

A 45-year-old- man presented with left chest wall pain, swelling and cough. Over a 2-month period he developed abscesses in the right foot, right anterior thigh, left buttock and left chest. Incision and drainage of the soft tissue abscesses and video-assisted thoracoscopic surgery to drain the loculated empyema contiguous with the chest wall abscess were performed as surgical management. Gram stain showed beaded Gram-positive rods and the culture initially grew Aggregatibacter actinomycetemcomitans and Eikenella corrodens Pathological evaluation of the pleura showed sulfur granules and organisms consistent with Actinomyces spp. on Gomori methenamine silver stain; Actinomyces israelii was recovered in culture with extended incubation. The patient was treated for 3 weeks with ceftriaxone and oral metronidazole, followed by oral amoxicillin. Culture of A. actinomycetemcomitans with other findings consistent with actinomycosis warrants 6-12 months of antibiotic therapy.

Current Evidence on Oral Antibiotics for Infective Endocarditis: A Narrative Review.

Infective endocarditis (IE) continues to be associated with high morbidity and mortality, even when treated with optimal antibiotic regimens. The selection of treatment depends on the causative pathogen, its antibiotic susceptibility profile, local and systemic complications and the presence of prosthetic materials or devices. Standard therapy typically involves 4-6 weeks of intravenous (IV) bactericidal therapy. However, there are instances in which IV antibiotic administration may be challenging due to cost, complications of IV access, adverse side-effects of the medication or concerns for misuse of the IV line. Current clinical guidance from the American Heart Association and the European Society of Cardiology cite scenarios where oral antibiotics can be considered for treatment of IE, though these situations are relatively infrequent and data to show their non-inferiority limited. Recently, a well-designed randomized clinical study reported favorable outcomes for partial oral antimicrobial therapy regimens given to patients with staphylococcal, streptococcal and enterococcal IE deemed clinically stable and without complications such as perivalvular abscess. Oral antibiotics, usually given in combination, were selected by infectious disease providers for their favorable pharmacologic properties and predicted bactericidal activity. There was a careful selection of patients who were transitioned to oral regimens. Before recommending routine use of oral antibiotics in the care of patients with IE, additional studies that better define eligible patients and that use regimens available in the countries that adopt this practice should be performed. If further studies confirm non-inferior outcomes with partial oral antibiotics for the treatment of IE, medical treatment could be delivered in a simpler, more costeffective manner, and likely with lower rates of adverse side-effects.