ABSTRACT
Ribotyping, exotoxin A genotyping (EAGP), and restriction fragment length polymorphism (RFLP) analysis of total DNA with SalI (SalI RFLP) were compared for intraspecies discrimination of 93 Pseudomonas aeruginosa isolates. Type-ability of all methods was 100% and the results of typing with each method remained unchanged during laboratory manipulation. Clonal groups defined with each molecular method were largely coincident and, in those cases where inconsistencies were detected, isolates were analyzed by transverse alternating field gel electrophoresis (TAFE) and arbitrarily primed polymerase chain reaction (AP-PCR). SalI RFLP analysis was highly discriminative so as to distinguish unrelated isolates of close lineage. However, it was not a good method to identify isolates of unrelated lineage because SalI RFLP appeared to be subjected to convergent evolution. The index of discrimination suggested by Hunter and Gaston was determined to assess the discriminatory power of the molecular methods utilized either alone or in several combinations. Combined use of ribotyping and SalI RFLP analysis reached the highest index of discrimination (0.982) and proved to be a very valuable tool for epidemiological differentiation of P. aeruginosa isolates.
Subject(s)
Bacterial Typing Techniques , DNA, Ribosomal/analysis , Deoxyribonucleases, Type II Site-Specific/metabolism , Exotoxins/genetics , Pseudomonas aeruginosa/genetics , Blotting, Southern , Electrophoresis, Agar Gel , Genotype , Microbial Sensitivity Tests , Phylogeny , Polymorphism, Restriction Fragment LengthABSTRACT
The phenotypes of 295 stray cats seen in the capital area of Buenos Aires, Argentina, between March and December of 1989 were recorded. The corresponding mutant allele frequencies were as follows: O = 0.28, a = 0.83, Ta = 0.01; tb = 0.31; d = 0.45; I = 0.40; S = 0.28; W = 0.02. The allele frequencies calculated at the O locus were consistent with those expected for a randomly breeding population according to the formula for the Hardy-Weinberg equilibrium. The analysis of the genetic distances between Buenos Aires and several European cat populations revealed that the Spanish and, especially, those with a proven more ancestral genetic constitution, are the most closely related. When a similar analysis was carried out, including other Latin American cat populations, those of Spanish origin were found to show the highest degree of relatedness. These findings suggest that the Buenos Aires cat population was not genetically structured following the "two-stepping-stone" model and support the hypothesis that differential gene flows play a transcendental role in understanding the genetic composition of domestic cat populations.
Subject(s)
Cats/genetics , Animals , Argentina , Europe , Gene FrequencyABSTRACT
Se analizó el contenido plasmídico de 40 cepas de Neisseria gonorrhoeae aisladas de exudados uretrales, provenientes de un solo centro asistencial de Montevideo. Se correlacionó el contenido plasmídico con la resistencia in vitro a la Penicilina G y con la producción de beta-lactamasa. De las cepas estudiadas, el 100 por ciento contiene un plásmido de 2,6 MDaltons. El 50 por ciento de las cepas posee además otros dos plásmidos de 3,2 MDal y 24,5 MDal, son resistentes a la penicilina y producen beta-lactamasa
Subject(s)
Humans , beta-Lactam Resistance/genetics , Neisseria gonorrhoeae , Neisseriaceae Infections , Penicillin Resistance , Penicillinase , Plasmids , Uruguay , Drug Resistance, Microbial , PlasmidsABSTRACT
Se analizó el contenido plasmídico de 40 cepas de Neisseria gonorrhoeae aisladas de exudados uretrales, provenientes de un solo centro asistencial de Montevideo. Se correlacionó el contenido plasmídico con la resistencia in vitro a la Penicilina G y con la producción de beta-lactamasa. De las cepas estudiadas, el 100 por ciento contiene un plásmido de 2,6 MDaltons. El 50 por ciento de las cepas posee además otros dos plásmidos de 3,2 MDal y 24,5 MDal, son resistentes a la penicilina y producen beta-lactamasa (AU)
