Lysotypes and plasmidial profile of Salmonella Serovar Typhimurium isolated from children with enteric processes in the cities of Rio de Janeiro, RJ, and Salvador, BA - Brazil

Abstract

The lysotypes, plasmidial profiles, and profiles of resistance to antimicrobial agents were determined in 111 Salmonella Typhimurium strains isolated from feces and blood of children treated in Rio de Janeiro and in Salvador. Six distinct lysotypes (19, 41, 97, 105, 120 and 193) were recognized, with a predominance of lysotype 193 (59.7%) in Rio de Janeiro and of phage type 105 (38.4) in Salvador. Approximately 86.7% of the lysotype 193 strains presented multiple resistance to more than six antimicrobial agents, whereas 93% of lysotype 105 strains were fully susceptible. More than 90% of the strains presented plasmids distributed into 36 different profiles in Rio de Janeiro and into 10 profiles in Salvador. A 40 MDa plasmid was the most frequent (47%) in the strains from Rio de Janeiro, whereas a 61 MDa plasmid predominated (14.5%) in Salvador. Combined analysis of plasmid profile and classification into lysotypes (especially those belonging to types 105 and 103, proved to be more discriminatory than the other methods applied).

Antimicrobial susceptibility, phage types, and pulsetypes of Salmonella Typhimurium, in São Paulo, Brazil

“…The extensive use of antimicrobials in human and veterinary medicine has led to an increase in multidrug resistance strains (MDR) (Threfall et al 1993, Glynn et al 1998, Davis et al 1999, Rabatsky et al 2004. Fernandes et al (1992) of S. Typhimurium strains isolated from humans presented high levels of resistance to antimicrobial agents (5-14 marks) and most were isolated in hospital environments, which have been considered the principal vehicle of epidemic MDR S. Typhimurium strains (Riley et al 1984, Fernandes et al 1992, Asensi et al 1995, Kariuky et al 1999.A MDR S. Typhimurium strain, with definitive phage type 104 (DT 104), has emerged and spread over the world since 1984 (Leegaard et al 2000, Liebana et al 2002, Van Duijkeren et al 2003. The dominant resistance type of these strains is ACSSuT, that is, they are resistant to ampicillin, chloramphenicol, streptomycin, sulfonamides, and tetracycline, and the resistance is encoded by chromosomally located genes (Davis et al 1999, Izumiya et al 2001.…”

Tracing lineage by phenotypic and genotypic markers in Salmonella enterica subsp. enterica serovar 1,4,[5],12:i:- and Salmonella Typhimurium isolated in state of São Paulo, Brazil

“…Another seven Salmonella Typhimurium strains [phage types AT 04-2406 (3), AT 04-6846, DT 49, DT 135 and DT 104b] displayed the pentaresistant pattern. Although streptomycin was not included in the study reported by Asensi et al (1995) in Brazil, they also found 47% of Salmonella Typhimurium isolates with the ACSSuT pattern.…”

“…A previous study on phage typing, antimicrobial resistance and plasmidial profiles of Salmonella Typhimurium isolated from children living in two Brazilian cities, Salvador and Rio de Janeiro, was described by Asensi et al (1995). They also detected the predominance of DT193 (47.7%) among six different phage types as well as a significant percentage (31%) of strains that could not be typed, with 2% considered to be RDNC.…”

“…In addition, the 60-MDa plasmid extracted from two Salmonella 1,4,[5],12:i:-and two Salmonella Typhimurium strains, which underwent plasmid restriction analysis with EcoRI and HindIII restriction enzymes, displayed the same restriction pattern. Asensi et al (1995) reported that 41% of all Salmonella Typhimurium isolates analysed harboured a 61-MDa plasmid in a total of 33 different profiles. Because the 60-MDa plasmid is known as the Salmonella Typhimurium serovar-associated plasmid (Helmuth et al 1985), which is dominant in Salmonella Typhimurium strains (Liebana et al 2002), our results suggest a close relationship between these monophasic strains and Salmonella Typhimurium.…”

Padrão de susceptibilidade a antimicrobianos e perfil plasmidial em Salmonella Muenster isoladas de suínos e do ambiente de abatedouros

“…Plasmídios de baixo peso molecular (2 a 12 Kb), em cepas resistentes a antimicrobianos, particularmente aos marcos Su, Sm e Tc, foram detectados por Holmberg et al (1984), Simmons et al (1988), Rivera et al (1991), Asensi et al (1995), Millemann et al (1995), Hampton et al (1995) e Shehabi (1995. Muito embora, amplamente disseminados entre as amostras resistentes, cumpre salientar que, na maioria das vezes a resistência a estes marcos foi associada a grandes plasmídios (Vinhas & Almeida 1984 Sant 'Ana & Chartone-de-Souza 1985, Platt et al 1987, Rivera et al 1991, Sant'Ana et al 1995, Bahrmand & Velayati 1997, Ling et al 1998.…”