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

Abstract

A total of 283 Salmonella Typhimurium strains isolated from cases of human infections and non human sources, were examined for antimicrobial susceptibility and the incidence of resistance was 38% and multiple resistance (to three or more antimicrobials) was 15%. All 43 multidrug-resistant strains (MDR) and 13 susceptible ones were characterized by phage typing and pulsed-field gel electrophoresis (PFGE). The strains encompassed 14 definitive phage types (DT), three were untypable (UT), and 18 atypicals or reaction does not conform (RDNC), which belonged to 21 PFGE patterns, A1-A21. The predominant phage types were DT49, DT193, and RDNC and two strains belonging to DT 104 and 104b were also identified. The most commum PFGE patterns were A1 and A8. Analysis by PFGE and phage typing demonstrated that the most of the MDR were multiclonal and association among multiresistance, phage typing, and PFGE patterns was not so significant. Key words: Salmonella Typhimurium -phage types -multidrug-resistantSalmonella is one of the most important causal agents of foodborne illness. It can be isolated from a variety of foodstuff such as raw meats, poultry and poultry products, milk and milk products (Gorman & Adley 2004). The zoonotic nature of Salmonella infections is well established and the observed increase in human cases has been associated with high levels of infections in animal husbandry, mainly in pigs and poultry (Seyfarth et al. 1997).The Salmonella genus comprises more than 2500 serotypes (Popoff 2001), most of which are considered potential human pathogens, but only a reduced number of them have been associated with human infections (Uzzau et al. 2000). In developed countries, outbreaks of nontyphoidal Salmonella infections have been caused mainly by serotypes Enteritidis and Typhimurium (Seyfarth et al. 1997, Davis et al. 1999, Kariuky et al. 1999.S. Typhimurium is a common cause of human salmonellosis in many countries , Leegaard et al. 2000, Esaki et al. 2004, Martinez-Urtaza et al. 2004, Gorman & Adley 2004. It represents the most common serotype isolated from humans and animals in the United States (Bender et al. 2001, Rabatsky et al. 2004) and the second in the United Kingdom (Martinez-Urtaza et al. 2004).Studies reported in the state of São Paulo, Brazil, have also indicated that S. Typhimurium is the second most common serotype isolated from human sources (Tavechio et al.1996) and one of the most frequent from non-human sources (Taunay et al. 1996). 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...

Genotypic diversity, pathogenic potential and the resistance profile of Salmonella Typhimurium strains isolated from humans and food from 1983 to 2013 in Brazil

“…Similar to our results, in Brazil, Ghilardi et al (2006) 2000-2001 and 2005-2006, in the study conducted by Hur et al (2011).…”

Antimicrobial susceptibility and MLVA analysis of S. Typhimurium strains isolated from human and poultry samples in Tunisia

“…In our study, 50% of the S. Typhimurium isolates showed a multiresistant phenotype, with a greater incidence during 2013-2015 as previously described [31][32][33] suggesting an increase in the use of antibiotics during this period. Hence, a better control to prevent S. Typhimurium food contamination is needed, but severe control is also needed to ensure a better usage of antimicrobials in animals and humans [34].…”

Avaliação epidemiológica de surtos de salmonelose ocorridos no período de 1999 a 2008 no Estado do Paraná, Brasil

“…Porém, muitos autores têm relatada a implicação da preparação de bolo nos surtos (CAMARGO, 2001;SILVA JUNIOR, 2001 (FERNANDES et al, 2006). Demonstrando que SE emergiu como um grande problema avícola e de saúde pública no Brasil a partir de 1993de (FERNANDES et al, 2003SILVA;DUARTE, 2002).…”

“…Informações na literatura sobre ocorrência, origem, fontes de contaminação e disseminação de SE PT9 são escassas. Estudos mostram que alguns fagotipos tendem a predominar em determinadas regiões geográficas por um período de tempo (KARIUKI et al, 1999) e que a tipagem destas cepas é fundamental para detectar as mudanças epidemiológicas (GHILARDI et al, 2006 Considerando as amostras de alimentos, os fagotipos PT4 e PT9 predominaram em produtos à base de ovo (Tabela 2), sugerindo uma possível veiculação destes produtos em surtos de salmonelose causadas por estes fagotipos. No entanto, quando se consideram categorias alimentícias individuais, verifica-se maior predominância do fagotipo PT9 em produtos designados como "outros", onde se incluem os mais diversos alimentos preparados e prontos para o consumo (farofas, macarronadas, macaxeira, arroz, entre outros) o que implica na possibilidade de manipulação ou conservação inadequada, ou até mesmo contaminação cruzada, fato este muito comum nas práticas domiciliares e industriais de preparo de alimentos.…”