Carmen Aravena1, Bárbara Valencia2, Andrea Villegas2, Mauricio Ortega1, Alda Fernández R3, Pamela Araya R3, Aníbal Saavedra2, Rosa Del Campo4. 1. Escuela de Medicina, Universidad de Valparaíso, San Felipe, Chile. 2. Escuela de Tecnología Médica, Universidad de Valparaíso, San Felipe, Chile. 3. Laboratorio de Bacteriología, Instituto de Salud Pública de Chile, Santiago, Chile. 4. Laboratorio de Bacteriología, Instituto Ramón y Cajal de Investigación Sanitaria, Madrid, España.
Abstract
BACKGROUND: Salmonella Heidelberg (S. Heidelberg) causes gastroenteritis and sometimes bacteremia and endocarditis. In other countries, this serovar has multidrug resistance including extended-spectrum β-lactamases (ESBLs) and AmpC (β-lactamases (AmpC), associated with the blaCMY-2 gene. In Chile, an outbreak by S. Heidelberg occurred in 2011, the phenotypic and genetic characteristics of Chilean strains are unknown. AIM: To determine the antimicrobial susceptibility, presence of plasmids and virulence factor genes in S. Heidelberg strains isolated in Chile over the period 2006-2011. MATERIAL AND METHODS: In sixty-one S. Heidelberg clinical and environmental strains collected by the Public Health Institute in Chile during 2006-2011, antimicrobial susceptibility, plasmids and virulence factor genes (invA, sifA, pefA, agfA, lpfA and, stkD) were studied. RESULTS: S. Heidelberg had a high susceptibility to sulfamethoxazole-trimethoprim, gentamicin, ceftriaxone, ceftiofur, chloramphenicol, amoxicillin-clavulanic acid and ampicillin. However, 52% had decreased susceptibility to ciprofloxacin and 33% resistance to tetracycline. ESBLs were detected in three strains isolated from blood cultures, environment and human feces. The latter strain was positive for AmpC and blaCMY-2 gene. Fifty three of 61 strains showed one to seven plasmids of 0.8 to approximately 30 kb. Most plasmids were small with sizes between 0.8 and 2 kb. All isolates were positive for all genes except pefA. CONCLUSIONS: S. Heidelberg isolated from Chilean samples was susceptible to first-line antimicrobials, except tetracycline and ciprofloxacin. The emergence of strains with ESBLs and AmpC should be a warning. The strains were homogeneous for virulence genes, but heterogeneous in their plasmids.
BACKGROUND:Salmonella Heidelberg (S. Heidelberg) causes gastroenteritis and sometimes bacteremia and endocarditis. In other countries, this serovar has multidrug resistance including extended-spectrum β-lactamases (ESBLs) and AmpC (β-lactamases (AmpC), associated with the blaCMY-2 gene. In Chile, an outbreak by S. Heidelberg occurred in 2011, the phenotypic and genetic characteristics of Chilean strains are unknown. AIM: To determine the antimicrobial susceptibility, presence of plasmids and virulence factor genes in S. Heidelberg strains isolated in Chile over the period 2006-2011. MATERIAL AND METHODS: In sixty-one S. Heidelberg clinical and environmental strains collected by the Public Health Institute in Chile during 2006-2011, antimicrobial susceptibility, plasmids and virulence factor genes (invA, sifA, pefA, agfA, lpfA and, stkD) were studied. RESULTS:S. Heidelberg had a high susceptibility to sulfamethoxazole-trimethoprim, gentamicin, ceftriaxone, ceftiofur, chloramphenicol, amoxicillin-clavulanic acid and ampicillin. However, 52% had decreased susceptibility to ciprofloxacin and 33% resistance to tetracycline. ESBLs were detected in three strains isolated from blood cultures, environment and human feces. The latter strain was positive for AmpC and blaCMY-2 gene. Fifty three of 61 strains showed one to seven plasmids of 0.8 to approximately 30 kb. Most plasmids were small with sizes between 0.8 and 2 kb. All isolates were positive for all genes except pefA. CONCLUSIONS:S. Heidelberg isolated from Chilean samples was susceptible to first-line antimicrobials, except tetracycline and ciprofloxacin. The emergence of strains with ESBLs and AmpC should be a warning. The strains were homogeneous for virulence genes, but heterogeneous in their plasmids.
Authors: Diéssy Kipper; Andréa Karoline Mascitti; Silvia De Carli; Andressa Matos Carneiro; André Felipe Streck; André Salvador Kazantzi Fonseca; Nilo Ikuta; Vagner Ricardo Lunge Journal: Vet Sci Date: 2022-08-03
Authors: Roberta T Melo; Newton N Galvão; Micaela Guidotti-Takeuchi; Phelipe A B M Peres; Belchiolina B Fonseca; Rodrigo Profeta; Vasco A C Azevedo; Guilherme P Monteiro; Bertram Brenig; Daise A Rossi Journal: Front Microbiol Date: 2021-06-18 Impact factor: 5.640