Dimercaptosuccinic acid in combination with carbapenems against isogenic strains of Escherichia coli producing or not producing a metallo-ß-lactamase in vitro and in murine peritonitis.

BACKGROUND: Carbapenemase-producing Enterobacterales represent a major therapeutic challenge. MBLs, requiring zinc at their catalytic site, could be inhibited by meso-dimercaptosuccinic acid (DMSA), a heavy metal chelator already widely used for treating lead intoxication. OBJECTIVES: To evaluate the activity of carbapenems alone or combined with DMSA against MBL-producing Escherichia coli in a severe murine peritonitis model. METHODS: Isogenic strains of wild-type E. coli CFT073 producing the MBLs NDM-1, VIM-2 and IMP-1, and the control serine carbapenemases OXA-48 and KPC-3 were constructed. MIC determinations and time-kill assays were performed for imipenem, meropenem and ertapenem alone or in combination with DMSA. Infected mice were treated intraperitoneally for 24 h with imipenem, DMSA or their combination. Bacterial counts in peritoneal fluid and spleen were assessed at 24 h. RESULTS: DMSA in combination with each carbapenem caused a significant decrease in the MICs for all MBL-producing strains, in a concentration-dependent manner, but did not provide benefit against non-MBL strains. In mice infected with the NDM-1-producing strain, the combination of imipenem and DMSA significantly reduced bacterial counts in peritoneal fluid (P = 0.0006) and spleen (P < 0.0001), as compared with imipenem alone, with no benefit against the KPC-3-producing and CFT073 strains. DMSA concentrations in plasma of mice were comparable to those obtained in humans with a standard oral dose. CONCLUSIONS: DMSA restores the activity of carbapenems against MBL-producing strains, and its combination with carbapenems appears to be a promising strategy for the treatment of NDM-producing E. coli infections.

[Acute chest syndrome in adult sickle cell patients]. / Syndrome thoracique aigu chez les patients drépanocytaires adultes.

Sickle cell disease is a frequent genetic condition, due to a mutation of the ß-globin gene, leading to the production of an abnormal S hemoglobin and characterized by multiple vaso-occlusive events. The acute chest syndrome is a severe complication associated with a significant disability and mortality. It is defined by the association of one or more clinical respiratory manifestations and a new infiltrate on lung imaging. Its pathophysiology is complex and implies vaso-occlusive phenomena (pulmonary vascular thrombosis, fat embolism), infection, and alveolar hypoventilation. S/S or S/ß0-thalassemia genotype, a history of vaso-occlusive crisis or acute chest syndrome, a low F hemoglobin level (<5%), a high steady-state hemoglobin level (> 10 g/dL), or a high steady-state leukocytosis (>10 G/L) are the main risk factors. Febrile chest pain, dyspnea, sometimes cough with expectorations are its main clinical manifestations, and bi-basal crackles are found at auscultation. Inferior alveolar opacities with or without pleural effusions are identified on chest X-ray or CT-scan. Management of the acute chest syndrome should be prompt and implies, besides the recognition of severity signs, a multimodal analgesia, oxygen supplementation, sometimes a parenteral antibiotic treatment and the frequent use of blood transfusions especially in the most severe cases. Prevention is important and includes a regular monitoring of hospitalized patients and the use of incentive spirometry.

[Contribution and limits of "OSCE", "long-case" and "global end-of-placement marking" as end-of-rotation assessment methods. Experience from two internal medicine wards]. / Apport et limites des « ECOS ¼, « examen clinique au lit du malade ¼ et « appréciation globale de stage ¼ comme modalité d'évaluation de fin de stage. Expérience de deux services de médecine interne.

INTRODUCTION: During placements, there is an opportunity to learn clinical skills and to assess their application. However, it represents two different goals. The validity of an end-of-placement assessment is questionable, as the medical competency is contextual. We decided to evaluate the contribution and limits of different assessment modalities as an end-of-placement assessment. MATERIAL AND METHODS: Internal medicine clerks were assessed using the Mini-Cex grid by a structured objective clinical examination (OSCE), a long-case clinical examination (LCE) and a global end-of-placement marking (GEPM). Following these evaluations, students and teachers fulfilled an open questionnaire. RESULTS: In 2021, 41 students and 16 teachers participated in the study. Physical examination was evaluated in 0%, 97% et 76% of cases during OSCE, LCE and GEPM, respectively; teaching skills were assessed for 100, 42 et 49% of students in OSCE, LCE and GEPM, respectively. As compared to OSCE, there was a perceived superiority of LCE regarding its formative value (P=0.07 and P=0.03) and its summative value (P=0.0007 and P=0.02), for students and teachers, respectively. Qualitative analysis highlights the breadth of clinical skills that could be assessed during OSCE stations. Integration into a team was an additional skill that could specifically be assessed during GEPM. GEPM could also take into account the progress made during placement. CONCLUSION: Despite its subjectivity, LCE seemed to be the preferred modality for an end-of-rotation assessment.