Pathogenicity and phenotypic sulfadiazine resistance of Toxoplasma gondii isolates obtained from livestock in northeastern Brazil

Toxoplasma gondii is the causative protozoan agent of toxoplasmosis, which is a common infection that is widely distributed worldwide. Studies revealed stronger clonal strains in North America and Europe and genetic diversity in South American strains. Our study aimed to differentiate the pathogenicity and sulfadiazine resistance of three T. gondii isolates obtained from livestock intended for human consumption. The cytopathic effects of the T. gondii isolates were evaluated. The pathogenicity was determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) using a CS3 marker and in a rodent model in vivo. Phenotypic sulfadiazine resistance was measured using a kinetic curve of drug activity in Swiss mice. IgM and IgG were measured by ELISA, and the dihydropteroate synthase (DHPS) gene sequence was analysed. The cytopathic effects and the PCR-RFLP profiles from chickens indicated a different infection source. The Ck3 isolate displayed more cytopathic effects in vitro than the Ck2 and ME49 strains. Additionally, the Ck2 isolate induced a differential humoral immune response compared to ME49. The Ck3 and Pg1 isolates, but not the Ck2 isolate, showed sulfadiazine resistance in the sensitivity assay. We did not find any DHPS gene polymorphisms in the mouse samples. These atypical pathogenicity and sulfadiazine resistance profiles were not previously reported and served as a warning to local health authorities.

Tracheostomy in Pediatric Intensive Care Unit: When and Where?

Background: Tracheostomy was first observed in Egyptian drawings in 3600 BC and performed frequently during the 1800’s diphtheria epidemic. Objectives: The aim of this study was to elucidate the indications, complications, mortality rate, and the effect of pediatric tracheostomy on length of PICU or hospital stay. Materials and Methods: Demographic characteristics, diagnosis at admission, duration of ventilation of 152 patients were analyzed retrospectively. Results: The most common tracheostomy indication was prolonged intubation. The mean duration of mechanical ventilation before tracheostomy was 23.8 days. Forty five percent of the tracheostomy procedures were performed at bedside. Neither the place nor the age had any effect on the development of complications (P = 0.701, P = 0.622). The procedure enabled 62% of the patients to be discharged from hospital. Conclusions: Tracheostomy facilitates discharge and weaning of mechanical ventilation. Although the timing of tracheostomy has to be determined for each individual patient, three weeks of ventilation seems to be a suitable period for tracheostomy. Tracheostomy can be performed at bedside safely but patient selection should be made carefully.