Staphylococcus aureus nasal colonization and susceptibility profile to antimicrobials in hemodialysis patients using a protocol of seven collections.

BACKGROUND: Patients colonized with Staphylococcus aureus in their nasal passages have a higher risk of acquiring infection, especially if they are immunocompromised or have comorbidities such as chronic renal failure undergoing hemodialysis (HD). OBJECTIVE: This study aimed to report the prevalence of nasal carriage of S. aureus among HD patients utilizing a seven-week sampling protocol and to assess the susceptibility of these isolates to various antimicrobial agents. METHODS: Over seven consecutive weeks, nasal swab samples were collected from 47 HD patients, resulting in a total of 329 samples. The microorganisms were identified using biochemical methods and subjected to antimicrobial susceptibility testing via disk diffusion and microdilution techniques. RESULTS: Out of all the patients analyzed, 25 individuals (53.19%) were found to be colonized by S. aureus, with 21 of them displaying intermittent colonization. Additionally, 38% showed positive results for S. aureus in only the 6th or 7th week of sampling. Within the 58 isolates, 17.2% (n=10) exhibited methicillin (oxacillin)-resistance and 25.86% (n=15) displayed elevated vancomycin MIC values (2 µg/ml). Based on the results, daptomycin and gentamicin were found to be effective treatment options. However, 31% of the isolates (n=18) exhibited a MIC of 1 µg/ml for daptomycin. CONCLUSION: Over half of the patients were colonized by S. aureus, but mostly on an intermittent basis. The identification of oxacillin resistance and high vancomycin and daptomycin MICs serve as warnings for possible future complications in managing bacteremia caused by S. aureus in these patients.

The Joint Initiative for Teaching and Learning on Global Health Challenges and One Health experience on implementing an online collaborative course.

The "Joint Initiative for Teaching and Learning on Global Health Challenges and One Health" piloted the online course "Global Health Challenges and One Health in 2021. The present work documents this experience, lessons learned, and the future outlook of the course. A descriptive study was conducted based on the evaluations performed with the enrolled students and course coordinators. Of 30 enrolled students from graduate programs of six institutions from Brazil, Germany, Mozambique, and Kosovo, two unenrolled, and nine failed for not completing the activities. Therefore, 19 (63%) students completed the course. Some challenges identified were language and technology access barriers, difficulty scheduling group meetings due to different time zones, and high workload per credit in some institutions. Activities in groups conducted synchronously, such as debates, journal clubs, and case studies, were highlighted as those with higher impact in the learning process, having more participation of students when carried in small groups. Some students reported the establishment of research and work partnerships with other participants from partner institutions. The experience reinforces the importance of international exchange to improve collaboration between institutions and the impact of working in small interprofessional groups to develop technical, intercultural, and interdisciplinarity competencies necessary to human resources working with the One Health approach. The success of such international educational initiatives depends on overcoming barriers to implementation, which can be detected in institutional and course levels. Therefore, continuing evaluation of the course and improvements must be performed and involve all participants.

Low Serum Trough Concentrations and High Vancomycin Minimum Inhibitory Concentration in Methicillin-Sensitive Staphylococcus aureus From Hemodialysis Patients in Brazil.

BACKGROUND: The empiric antimicrobial therapy for bacteremia of long-term hemodialysis (HD) outpatients is currently based on the combination of vancomycin and gentamicin because of the high frequency of isolated Staphylococcus species. The vancomycin trough level range from 15 to 20 mcg/mL is expected for therapeutic success against methicillin-resistant Staphylococcus aureus with vancomycin minimum inhibitory concentration (MIC) ≥1.0 mcg/mL. Despite the availability of clinical practice guidelines for vancomycin therapeutic drug monitoring, these target serum concentrations are not reached in many patients. METHODS: In this study, the authors investigated the vancomycin trough levels in 20 HD patients with S. aureus bacteremia and the antimicrobial susceptibility pattern of 45 S. aureus strains isolated from 45 HD patients. The vancomycin serum concentration was determined by chemiluminescent assay. The MIC was determined by broth microdilution method. RESULTS: None of the HD patients included in this study had vancomycin trough concentrations within the therapeutic range. Also, the vancomycin MIC for most methicillin-sensitive S. aureus isolated from bacteremia was ≥1.0 mcg/mL. CONCLUSIONS: The therapeutic range of vancomycin was not achieved, and vancomycin MIC was surprisingly high in methicillin-sensitive S. aureus.