Streptococcus spp. isolated from bovine mastitis: Antimicrobial sensitivity studies and disagreement evaluation between routine phenotypic diagnosis and molecular identification.

Bovine mastitis poses a significant threat to global dairy production, resulting in substantial losses in milk production. Streptococcus bacteria, particularly Streptococcus uberis, Streptococcus agalactiae, and Streptococcus dysgalactiae, are commonly implicated in this condition. An accurate diagnosis is crucial for implementing effective treatment and minimizing its impact on production. This study examined 115 Streptococcus strains isolated from bovine mastitis cases in Uruguay using PCR for species identification. Additionally, the resistance to tetracycline, erythromycin, and penicillin was assessed in 81 of the bacterial strains under study. Significant disparities between phenotypic and genotypic detection were evident across all three species, with only 31% of strains identified phenotypically aligning with PCR results. Phenotypic prevalence indicated S. dysgalactiae as the most prevalent (44.35%), followed by S. uberis (24.34%) and S. agalactiae (6.09%). However, the genotypic identification revealed S. uberis as the most prevalent, followed by S. dysgalactiae, while S. agalactiae remained the least prevalent. The high sensitivity and speed of PCR suggest its potential routine implementation for diagnosing bovine mastitis caused by Streptococcus in any laboratory. Although, penicillin resistance was practically nonexistent, tetracycline and erythromycin exhibit higher resistance levels across all three species studied. In conclusion, the study underlines the importance of early diagnosis, highlights variations in bacterial prevalence, and proposes PCR as a valuable diagnostic tool for Streptococcus species responsible for bovine mastitis.

Adaptación marginal y ajuste interno en estructuras de zirconia-ytria elaboradas con los sistemas CAD/CAM Procera® y Cerec in-Lab® / Marginal adaptation and internal fit of zirconia-ytrya frameworks fabricated with Procera® and Cerec in-Lab® CAD/CAM systems

Introducción: el objetivo fue determinar ex vivo la adaptación marginal y ajuste interno en estructuras de zirconiaytria elaboradas con los sistemas CAD/CAM Procera® y Cerec In-lab®. Métodos: se tomaron 15 pilares protésicos prefabricados contorneados de implantes divididos en tres grupos. Se fabricaron estructuras en aleación noble Pd-Au (control), Procera AllZircon® y Cerec In-lab YZ cubes®. Para evaluar la adaptación marginal se tomaron ocho medidas en la circunferencia del pilar protésico, tomando la distancia entre el borde de la estructura y el pilar. Para determinar el ajuste interno se hicieron ocho medidas desde la superficie externa del pilar a la superficie interna de la restauración. Las mediciones fueron hechas por microscopia óptica (50X). Los datos obtenidos fueron analizados por medio del análisis de varianza de una vía, la t de Student y prueba de Dunnett. Resultados: el promedio de adaptación marginal del grupo control fue 18,24 μm ±4,81; el grupo Procera®21,62 μm ±12,15 y el grupo Cerec In-lab® de 47,34 μm ±17,72. El promedio de ajuste interno para las estructuras Pd-Au fue 34,60 μm ±16,16; Procera® 118,67 μm ±50,84 y el Cerec In-lab® 65,62 μm ±25,80. Conclusiones: los valores de adaptación marginal de las estructuras de aleación metálica y de zirconia-ytria elaboradas con los sistemas CAD/CAM Procera® y CerecIn-lab® están entre los valores clínicamente aceptables. Las medidas de ajuste interno obtenidos para los grupos aleación metálica y Cerec® se encuentran dentro del rango reportado en la literatura. Mientras que el promedio obtenido para el grupo Procera® 118,67 μm ±50,84, aunque se acercó al límite máximo de ajuste interno reportado en la literatura, no se evidenció diferencia estadísticamente significativa con el sistema Cerec In-lab®.

Introduction: the purpose of this in vitro study was to determine the marginal adaptation and internal fit in zirconia ytrya frameworks fabricated with Procera® and Cerec In-lab® CAD/CAM systems. Methods: fifteen prefabricated implant abutmentswere divided in three equally sized groups; noble metal alloy Pd-Au structures were then fabricated (control group), Procera® and Cerec In-lab YZ cubes® (n = 5). The marginal gap was determined by measuring 8 points around the abutment circumferencetaking the distance between the margin of the structure and the abutment. In order to determine internal fit, 8 measures were taken from the abutment´s external surface to the internal surface of the restoration. The measures were done with an opticalmicroscope (50X). The data was the statistically analyzed using 1-way ANOVA, Student’s paired t test and Dunnett´test. Results: marginal adaptation mean for the control group was 18.24±4.81μm and Procera® 21.62 μm ±12.15 μm, while the average for Cerec In-lab® was 47.34 μm ±17.72 μm. The internal fit for the control group was 34,60 μm ±16.16 μm and Procera® group was of 118.67 μm ±50.84 μm in average and Cerec In-lab® 65.62 μm ±25.80 μm. Conclusions: the metal alloy and zirconia ytrya frameworksfabricated with Procera® and Cerec In-lab® CAD/CAM systems showed clinically acceptable marginal gap values. The internal fit values for metal alloy and Cerec® frameworks are within the ranges reported in the literature. While the mean for the Procera®group was 118.67 μm ±50.84, which is close to the internal fit maximum limit reported in the literature, there was no statistically significant difference when compared with the Cerec-In-lab® system.