Evaluation of Early Reading of Broth Microdilution Technique for Polymyxin B.

Delay in the results of standard phenotypic susceptibility tests is the main obstacle to adequate antibiotic treatment. For this reason, the European Committee for Antimicrobial Susceptibility Testing has proposed the Rapid Antimicrobial Susceptibility Testing for the disk diffusion method directly from blood culture. However, to date, there are no studies evaluating early readings of polymyxin B broth microdilution (BMD), the only standardized methodology for assessing susceptibility to polymyxins. This study aimed to evaluate modifications in the BMD technique for polymyxin B using fewer antibiotic dilutions and reading after an incubation time of 8-9 hr (early reading) in comparison to 16-20 hr of incubation (standard reading) for isolates of Enterobacterales, Acinetobacter baumannii complex, and Pseudomonas aeruginosa. A total of 192 isolates of gram-negative bacteria were evaluated and the minimum inhibitory concentrations were read after early and standard incubations. The early reading presented 93.2% of essential agreement and 97.9% of categorical agreement with the standard reading of BMD. Only three isolates (2.2%) presented major errors and only one (1.7%) presented a very major error. These results indicate a high agreement between the early and the standard reading times of BMD of polymyxin B.

Early Language and Reading Development of Bilingual Preschoolers From Low-Income Families.

Learning to read is a complex process and a number of factors affect a child's success in beginning reading. This complexity increases when a child's home language differs from that of the school and when the child comes from a home with limited economic resources. This article discusses factors that have been shown to contribute to children's success in early reading, namely-phonological awareness, letter-word identification, oral language, and the home literacy environment. Preliminary evidence suggests that bilingual children from low-income backgrounds initially perform poorly on phonological awareness and letter identification tasks, but appear to acquire these abilities quickly in kindergarten once these abilities are emphasized in early reading instruction. In addition, the findings show that bilingual preschoolers' receptive language abilities in English and Spanish positively impact their early letter-word identification abilities at the end of kindergarten. A positive relationship between bilingual preschoolers' home literacy environment and early reading outcomes has not been found to date. Educational implications for serving young, bilingual children from programs such as Head Start are discussed.