Nontyphoid Salmonella gastroenteritis in pediatric patients from urban areas in the city of Mérida, Venezuela

Abstract

Background: Nontyphoid Salmonella (NTS) infections are a frequent cause of self-limited diarrhoeal illness in healthy children that do not usually require antibiotic treatment. This study was conducted by analyzing the phenotypic and genotypic traits of NTS strains from pediatric patients with acute gastroenteritis living in urban areas in the city of Mérida, Venezuela. Methodology: Thirty-seven Salmonella strains (18 S. Enteritidis; 14 S. Typhimurium; 2 S. Java; 2 S. Saintpaul; 1 S. Infantis) were isolated from 243 stool specimens. These strains were biochemically identified and serotyped. Antimicrobial susceptibility was determined by the disc-diffusion assay. Genetic characterization included plasmid profiling, PCR detection of the spv region and inv genes, and IS200 typing. Results: Thirty (81.0%) of the Salmonella isolates were resistant to the antimicrobial tested. Of these strains, 17 (56.7%) were resistant to at least one antibiotic. Five resistance patterns were observed, of which the most frequently found was the single type (tetracycline, streptomycin or ampicillin). All the S. Typhimurium harbored plasmids, but only three large plasmids (60, 72 and 84 kb) yielded amplicons with a spvR specific primers. All the Salmonella serotypes showed the presence of an inv region. Eight distinct IS200 profiles could be detected among the 37 Salmonella strains studied. Conclusions: Predominant Enteritidis and Typhimurium serotypes, as well as serotypes Java, Saintpaul and Infantis, are circulating in the city of Mérida, Venezuela. Most of these strains are susceptible to first-line antibiotics but active monitoring of isolates for antimicrobial resistance is necessary. IS200 typing, applied in association with conventional methods, allowed the characterization of all isolates and suggested the presence of different infection sources.

Antimicrobial resistance of Salmonella isolated from food animals: A review

“…These resistances are of great concern as these expanded-spectrum cephalosporins (ESCs) and quinolones have been recommended for the treatment of human Salmonella infections (Chen et al, 2004;Gebreyes & Thakur, 2005). In addition, antibiotic therapy using β-lactams is recommended for treating complicated cases of salmonellosis in children and the elderly Ahmed, Younis, et al, 2009;Araque, 2009;Chen et al, 2004). More than 50% of the isolates were resistant to β-lactams including ampicillin, piperacillin and ticarcillin.…”

“…The link between the use of antimicrobial drugs in livestock and the emergence of antimicrobial drug resistance in human pathogenic bacteria has been welldocumented Ahmed, Younis, Ishida, & Shimamoto, 2009;Araque, 2009;Martinez & Baquero, 2002). Thus, it is important to monitor resistance among bacteria found in animals and their food products.…”

“…The extensive use or misuse of antimicrobial agents, not only as treatment in humans and veterinary medicine but also as growthpromoting substances in livestock production, has greatly promoted the appearance of antimicrobial-resistant bacteria (Araque, 2009;Gousia, Economou, Sakkas, Leveidiotou, & Papadopoulou, 2011;Hur et al, 2010;Singh et al, 2010) which has become a major public health issue. Recently, the European Union (EU) initiated several actions including the removal of all antimicrobials used as growth-promoting substances in the livestock industry (Regulation EC 1831/2003) (García-Feliz et al, 2008) in an effort to decrease the appearance of antimicrobial-resistant bacteria.…”

Typing of Salmonella Typhi strains isolated from Egypt by RAPD PCR

“…Several typing methods for Salmonella have been described for epidemiological and phylogenetic purposes (Ruiz et al 2003; Lim et al 2005; Araque 2009; Nath et al 2010). The DNA-based typing methods are becoming increasingly useful for performing epidemiological surveys of pathogenic bacteria.…”

Antimicrobial resistance, presence of integrons and biofilm formation ofSalmonellaPullorum isolates from eastern China (1962–2010)

“…The increasing appearance of multidrug-resistant Salmonella has become a worldwide concern. The link between the use of antimicrobials in food animals and the emergence of antimicrobial resistance of human pathogenic bacteria is well documented (Martínez & Baquero, 2002;Ahmed et al, 2009;Araque, 2009). Integrons are capable of capturing and mobilizing antimicrobial resistance bacterial genes.…”