Background: β-lactamase-producing Escherichia coli are a widely distributed source of antimicrobial resistance for animals and humans. Little is known about the susceptibility profile and genetic characteristics of E. coli strains isolated from domestic dogs in Latin America. Methods: We report on a cross-sectional study that evaluated E. coli strains isolated from fecal samples of domestic dogs in central Panama. The extended-spectrum β-lactamase (ESBL), AmpC genes, and plasmid-mediated quinolone resistance were investigated. Molecular typing using Pasteur’s multilocus sequence typing (MLST) was conducted. Results: A total of 40 E. coli isolates were obtained, of which 80% (32/40) were resistant to at least one of the antibiotics tested, while 20% (8/40) were sensitive to all antibiotics analyzed in this study (p < 0.001). Forty percent of the strains were resistant to three or more antibiotics. The most common resistance was to tetracycline (45%) and ampicillin (30%) while 2.5% showed an ESBL phenotype. Antibiotic resistance genes were detected for one β-lactamase (blaTEM-1) and two plasmid-mediated quinolone resistance (PMQR) enzymes (qnrS and qnrB). In addition, mutations in the chromosomal AmpC gene were observed at positions −35, −28, −18, −1, and +58. Fourteen different sequence types (STs) were identified; the most frequent were ST399 and ST425 (12% each). ST3 and ST88, which have been previously identified in human clinical isolates, were also evidenced. Three new STs were found for the first time: ST1015, ST1016 (carrier of the blaTEM-1 gene), and ST1017 (carrier of the blaTEM-1, qnrS, and qnrB genes). Conclusions: In the intestinal strains of E. coli isolated from domestic dogs, there was a high frequency of resistance to antibiotics. The presence of genes from plasmids and chromosomal mutations that conferred antibiotic resistance, the identification of isolates previously reported in humans, and the genetic diversity of STs (including three that were newly identified) confirmed the determinants of resistance to antibiotics in the domestic dogs from central Panama.

Growing lambs were evaluated for the effect of increasing dietary levels of beef tallow (BT) on performance, rumen fermentation, and carcass and meat characteristics. Twenty-one 5-month-old male Rambouillet lambs were assigned randomly to one of three diets with 0, 20, and 40 g BT/kg dry matter (DM) and similar energy and protein contents. Lambs were adapted to the diets for 15 days, followed by a 45-day evaluation trial. Data were analysed using a mixed model. Growth, feed intake and ruminal fermentation were not affected by the dietary level of BT. Daily metabolizable energy intake (MEI), carcass yield and degree of fatness, increased linearly as the BT level increased. Carcass classification and muscle conformation were not affected by BT. Most meat characteristics (texture, pH, myoglobin, protein content, colour, cathepsins, and chemical composition) five and eight days post-mortem were not affected, except for fat content in meat, which increased linearly as diet BT level increased. Fatty acid (FA) profiles of the meat from lambs fed the three diets were similar. In conclusion, addition of BT at 20 and 40 g/kg DM to diets for growing lambs allowed reduced grain usage and increased forage levels (from 0 to 270 g/kg DM), increasing energy intake, carcass yield and fatness, and intramuscular fat without causing harmful effects on growth, feed intake or ruminal fermentation characteristics. Keywords: dietary fat, fatty acids, meat colour, sheep

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Los hongos del suelo desempeñan funciones en los procesos de descomposición que mineralizan y reciclan nutrientes de plantas. En el suelo, los hongos interactúan con una compleja comunidad microbiana que incluye: bacterias, actinomicetos (actino bacterias) y pequeños invertebrados. Los hongos son una parte importante de la cadena alimenticia en el suelo, principalmente para la meso fauna que habita en el suelo (Bonkowski et al., 2000). Esta evaluación consistió en recolectar muestras de suelo, hojas y troncos en distintas áreas de la provincia de Los Santos, aislando hongos para el uso como control biológico contra microorganismos como Garrapatas de perro (Rhipicephalus sanguineus) y Gorgojos (Curculionidae), la mayor ocurrencia de aislamiento fue de Aspergillus spp con un 55%, siendo efectivos en 415 de infectividad sobre Rhiphicephalus sanguineus (garrapatas). Se concluye que hay una gran diversidad de hongos para control biológico.

Se adicionó Pseudomona aeruginosa y Pseudomona fluorescens a agua residual de procedencia urbana para determinar la capacidad de reducción de sólidos suspendidos mediante ensayo de laboratorio en tres tratamientos y tres repeticiones en la unidad de investigación microbiológica del CRU-Azuero en junio de 2017, se encontró que, P. aeruginosa disminuyó la concentración de sólidos disueltos de 1,24 g (control) a 0,03g, y la conductividad a 235 μS/cm, en mayor proporción que P. fluorescens y cultivo mixto, observado a través de los valores obtenidos en los 5 días de tratamiento. De esta manera se estima que P. aeruginosa resulta efectiva en la biorremediacion de aguas residuales.