Dr. Juana María Coha was a professor at the Universidad Nacional Mayor de San Marcos, recognized for her inner energy and intense personality, which could be perceived in her courses and in particular in conversations with her students. With a great desire to promote research and solve problems in the country, it became the guide of many promotions of microbiologists. Juana María Coha Gonzáles, was born on June 24, 1926 in the city of Huacho and died on July 22, 2017. These lines are written by her students and disciples that we continue what she forged in her lines of research.

Dr. Juana María Coha was a professor at the Universidad Nacional Mayor de San Marcos, recognized for her inner energy and intense personality, which could be perceived in her courses and in particular in conversations with her students. With a great desire to promote research and solve problems in the country, it became the guide of many promotions of microbiologists. Juana María Coha Gonzáles, was born on June 24, 1926 in the city of Huacho and died on July 22, 2017. These lines are written by her students and disciples that we continue what she forged in her lines of research.

The Lima coast is highly affected by anthropogenic effluents from wastewater from contaminated urban rivers that flow into the coast. The objective of this study was to investigate the resistance to mercury and antibiotics, and the transfer of resistance to mercury by conjugative plasmids in 55 strains of Escherichia coli isolated of surface seawater from coastal Lima, Peru. The Minimum Inhibitory Concentration (MIC) was determined for various antibiotics and for mercury in the isolated strains. To confirm the plasmid resistance to mercury, the curing was carried out with 10% sodium dodecyl sulfate (SDS). The plasmid transfer assay by conjugation was performed using the E. coli DH5α as recipient strain only with the strains that showed sensitivity to mercury after curing. The extraction of the resistance plasmids was carried out only in the transconjugant strains resistant to mercury. 4...

El objetivo de este estudio fue investigar la resistencia al mercurio y los antibióticos, y la transferencia de resistencia al mercurio por plásmidos conjugativos en 55 cepas de Escherichia coli aisladas de aguas superficiales del litoral de Lima, Perú. Se determinó la Concentración Mínima Inhibitoria (CMI) a diversos antibióticos y al mercurio en las cepas aisladas. Para confirmar la resistencia plasmídica al mercurio, se realizó la curación de estos con dodecil sulfato de sodio (SDS) 10%. El ensayo de transferencia de plásmidos por conjugación se realizó usando la cepa receptora E. coli DH5α sólo con las cepas que mostraron sensibilidad al mercurio después de la curación. La extracción de los plásmidos de resistencia fue realizada sólo en las cepas transconjugantes resistentes al mercurio. 41 (74.5%) cepas fueron resistentes al mercurio (HgR), presentando CMIs entre...

The objective of the work was to optimize duplex PCR for the detection of Mycoplasma gallisepticum (MG) and Mycoplasma synoviae (MS) in tracheal tissue samples in Gallus gallus in order to save time and economic resources in their diagnosis. The methodology consisted of carrying out an in silico evaluation of the ideal primers for their detection, the first tests such as primer concentration, sensitivity and specificity were carried out, followed by determining the prevalence in samples from different poultry houses at national level during a period of 4 years. Once the first tests were completed, the ideal primers (MG 3 and MS 2) were chosen for duplex PCR, achieving a sensitivity and specificity greater than 99%. This technique was put into practice and 669 samples of chicken tracheal tissue were analyzed, in which 45 samples were found to be positive for MG and/or MS. Finally, the pos...