Mónica Prieto1, Claudia Martínez2, Lorena Aguerre2, María Florencia Rocca2, Lucía Cipolla2, Raquel Callejo2. 1. Servicio Bacteriología Especial, Departamento Bacteriología, Instituto Nacional de Enfermedades Infecciosas (INEI) - Administración Nacional de Laboratorios e Institutos de Salud (ANLIS) "Dr. Carlos G. Malbrán", Ciudad Autónoma de Buenos Aires, Argentina. Electronic address: mprieto@anlis.gov.ar. 2. Servicio Bacteriología Especial, Departamento Bacteriología, Instituto Nacional de Enfermedades Infecciosas (INEI) - Administración Nacional de Laboratorios e Institutos de Salud (ANLIS) "Dr. Carlos G. Malbrán", Ciudad Autónoma de Buenos Aires, Argentina.
Abstract
INTRODUCTION: Listeria monocytogenes is the causative agent of listeriosis, a food-borne disease that mainly affects pregnant women, the elderly, and immunocompromised patients. The primary treatment of choice of listeriosis is the combination of ampicillin or penicillin G, with an aminoglycoside, classically gentamicin. The second-choice therapy for patients allergic to β-lactams is the combination of trimethoprim with a sulfonamide (such as co-trimoxazole). The aim of this study was to analyze the antimicrobial susceptibility profile of strains isolated from human infections and food during the last two decades in Argentina. METHODS: The minimal inhibitory concentration (MIC) of 8 antimicrobial agents was determined for a set of 250 strains of L. monocytogenes isolated in Argentina during the period 1992-2012. Food-borne and human isolates were included in this study. The antibiotics tested were ampicillin, chloramphenicol, trimethoprim-sulfamethoxazole, erythromycin, gentamicin, penicillin G, tetracycline and rifampicin. Breakpoints for penicillin G, ampicillin and trimethoprim-sulfamethoxazole were those given in the CLSI for L. monocytogenes. CLSI criteria for staphylococci were applied to the other antimicrobial agents tested. Strains were serotyped by PCR, and confirmed by an agglutination method. RESULTS: Strains recovered from human listeriosis patients showed a prevalence of serotype 4b (71%), with the remaining 29% corresponding to serotype 1/2b. Serotypes among food isolates were distributed as 62% serotype 1/2b and 38% serotype 4b. All antimicrobial agents showed good activity. CONCLUSION: The strains of L. monocytogenes isolated in Argentina over a period of 20 years remain susceptible to antimicrobial agents, and that susceptibility pattern has not changed during this period.
INTRODUCTION:Listeria monocytogenes is the causative agent of listeriosis, a food-borne disease that mainly affects pregnant women, the elderly, and immunocompromised patients. The primary treatment of choice of listeriosis is the combination of ampicillin or penicillin G, with an aminoglycoside, classically gentamicin. The second-choice therapy for patientsallergic to β-lactams is the combination of trimethoprim with a sulfonamide (such as co-trimoxazole). The aim of this study was to analyze the antimicrobial susceptibility profile of strains isolated from humaninfections and food during the last two decades in Argentina. METHODS: The minimal inhibitory concentration (MIC) of 8 antimicrobial agents was determined for a set of 250 strains of L. monocytogenes isolated in Argentina during the period 1992-2012. Food-borne and human isolates were included in this study. The antibiotics tested were ampicillin, chloramphenicol, trimethoprim-sulfamethoxazole, erythromycin, gentamicin, penicillin G, tetracycline and rifampicin. Breakpoints for penicillin G, ampicillin and trimethoprim-sulfamethoxazole were those given in the CLSI for L. monocytogenes. CLSI criteria for staphylococci were applied to the other antimicrobial agents tested. Strains were serotyped by PCR, and confirmed by an agglutination method. RESULTS: Strains recovered from human listeriosis patients showed a prevalence of serotype 4b (71%), with the remaining 29% corresponding to serotype 1/2b. Serotypes among food isolates were distributed as 62% serotype 1/2b and 38% serotype 4b. All antimicrobial agents showed good activity. CONCLUSION: The strains of L. monocytogenes isolated in Argentina over a period of 20 years remain susceptible to antimicrobial agents, and that susceptibility pattern has not changed during this period.
Authors: Krzysztof Skowron; Ewa Wałecka-Zacharksa; Katarzyna Grudlewska; Natalia Wiktorczyk; Agnieszka Kaczmarek; Grzegorz Gryń; Joanna Kwiecińska-Piróg; Klaudia Juszczuk; Zbigniew Paluszak; Katarzyna Kosek-Paszkowska; Eugenia Gospodarek-Komkowska Journal: Pol J Microbiol Date: 2019-09-03