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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 ß-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.
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Antibacterianos/farmacologia , Listeria monocytogenes/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Argentina , Humanos , Listeriose/epidemiologia , Listeriose/microbiologiaRESUMO
INTRODUCTION: Streptococcus suis serotype 2 is an important swine pathogen and emerging zoonotic agent causing meningitis and septicemia/septic shock. Strains are usually virulent (Eurasia) or of intermediate/low virulence (North America). Very few data regarding human and swine isolates from South America are available. CASE PRESENTATION: Seventeen new human S. suis cases in Argentina (16 serotype 2 strains and a serotype 5 strain) are reported. Alongside, 14 isolates from pigs are analyzed: 12 from systemic disease, one from lungs and one from tonsils of a healthy animal. All human serotype 2 strains and most swine isolates are sequence type (ST) 1, as determined by multilocus sequence typing and present a mrp+/epf+/sly+ genotype typical of virulent Eurasian ST1 strains. The remaining two strains (recovered from swine lungs and tonsils) are ST28 and possess a mrp+/epf - /sly- genotype typical of low virulence North American strains. Representative human ST1 strains as well as one swine ST28 strain were analyzed by whole-genome sequencing and compared with genomes from GenBank. ST1 strains clustered together with three strains from Vietnam and this cluster is close to another one composed of 11 strains from the United Kingdom. CONCLUSION: Close contact with pigs/pork products, a good surveillance system, and the presence of potentially virulent Eurasian-like serotype 2 strains in Argentina may be an important factor contributing to the higher number of human cases observed. In fact, Argentina is now fifth among Western countries regarding the number of reported human cases after the Netherlands, France, the UK and Poland.
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Salmonella enterica serovar Heidelberg ranks among the most prevalent causes of human salmonellosis in the United States and Canada, although it has been infrequently reported in South American and European countries. Most Salmonella infections are self-limiting; however, some invasive infections require antimicrobial therapy. In this work we characterized an oxyimino-cephalosporin resistant S. Heidelberg isolate recovered from an inpatient in a Buenos Aires hospital. CMY-2 was responsible for the ß-lactam resistance profile. S. Heidelberg contained a 97kb plasmid belonging to the Inc N group harboring blaCMY-2. ISEcp1 was located upstream blaCMY-2 driving its expression and mobilization. The isolate belonged to sequence type 15 and virotyping revealed the presence of sopE gene. In this study we identified the first CMY-2 producing isolate of S. Heidelberg in Argentina and even in South America.
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Proteínas de Bactérias/genética , Fatores R/genética , Infecções por Salmonella/microbiologia , Salmonella enterica/genética , beta-Lactamases/genética , Adulto , Argentina , Elementos de DNA Transponíveis , Gastroenterite/complicações , Gastroenterite/microbiologia , Ordem dos Genes , Genes Bacterianos , Infecções por HIV/complicações , Humanos , Infecções por Salmonella/complicações , Infecções por Salmonella/epidemiologia , Salmonella enterica/classificação , Salmonella enterica/efeitos dos fármacos , Salmonella enterica/enzimologia , Sorotipagem , América do Sul/epidemiologiaRESUMO
Salmonellaenterica serovar Heidelberg es uno de los principales agentes causantes de salmonelosis en humanos en Estados Unidos y Canadá, sin embargo, resulta infrecuente en los países de Sudamérica y Europa. En este trabajo se caracterizó un aislamiento de S. Heidelberg resistente a oximino-cefalosporinas recuperado de un paciente internaen un hospital de la Ciudad de Buenos Aires. Se evidenció la presencia de un plásmido de 97 kbperteneciente al grupo de incompatibilidad IncN, portador del gen blaCMY-2. ISEcp1 fue localizado corriente arriba de blaCMY-2, promoviendo su expresión y movilización.El aislamiento de S. Heidelberg correspondió al secuenciotipo 15 y en la virotipifi cación se detectó el gen sopE. En este trabajo describimos por primera vez la producción de CMY-2 en una cepa de S. Heidelberg en nuestro país y América Latina
Salmonellaenterica serovar Heidelberg ranks among the most prevalent causes of human salmonellosis in the United States and Canada, although it has been infrequently reported in South American and European countries.Most Salmonella infections are self-limiting; however, some invasive infections require antimicrobial therapy. In this work we characterized an oxyimino-cephalosporin resistant S. Heidelberg isolate recovered from an inpatient in a Buenos Aires hospital. CMY-2 was responsible for the ß-lactam resistance profi le. S. Heidelberg contained a 97 kb plasmid belonging to the Inc N groupharboring blaCMY-2. ISEcp1 was located upstream blaCMY-2 driving its expression and mobilization.The isolate belonged to sequence type 15 and virotyping revealed the presence of sopE gene. In this study we identifi ed the fi rst CMY-2 producing isolate of S. Heidelberg in Argentina and even in South Americ
Assuntos
Humanos , Masculino , América do Sul/epidemiologia , beta-Lactamases/análise , Salmonella enterica/isolamento & purificação , Plasmídeos/análise , Salmonella enterica/patogenicidadeAssuntos
Infecções Estreptocócicas/microbiologia , Streptococcus suis/isolamento & purificação , Antibacterianos/uso terapêutico , Argentina , Humanos , Masculino , Pessoa de Meia-Idade , Peritonite/diagnóstico , Peritonite/tratamento farmacológico , Peritonite/microbiologia , Infecções Estreptocócicas/diagnóstico , Infecções Estreptocócicas/tratamento farmacológico , Streptococcus suis/classificação , Streptococcus suis/genética , Resultado do TratamentoRESUMO
Salmonella enterica serovar Heidelberg ranks among the most prevalent causes of human salmonellosis in the United States and Canada, although it has been infrequently reported in South American and European countries. Most Salmonella infections are self-limiting; however, some invasive infections require antimicrobial therapy. In this work we characterized an oxyimino-cephalosporin resistant S. Heidelberg isolate recovered from an inpatient in a Buenos Aires hospital. CMY-2 was responsible for the ß-lactam resistance profile. S. Heidelberg contained a 97kb plasmid belonging to the Inc N group harboring blaCMY-2. ISEcp1 was located upstream blaCMY-2 driving its expression and mobilization. The isolate belonged to sequence type 15 and virotyping revealed the presence of sopE gene. In this study we identified the first CMY-2 producing isolate of S. Heidelberg in Argentina and even in South America.
Assuntos
Proteínas de Bactérias/genética , Fatores R/genética , Infecções por Salmonella/microbiologia , Salmonella enterica/genética , beta-Lactamases/genética , Adulto , Argentina , Elementos de DNA Transponíveis , Gastroenterite/complicações , Gastroenterite/microbiologia , Ordem dos Genes , Genes Bacterianos , Infecções por HIV/complicações , Humanos , Infecções por Salmonella/complicações , Infecções por Salmonella/epidemiologia , Salmonella enterica/classificação , Salmonella enterica/efeitos dos fármacos , Salmonella enterica/enzimologia , Sorotipagem , América do Sul/epidemiologiaRESUMO
Kocuria rosea is an uncommon pathogen may cause opportunistic infections in immunocompromised patient. We report a HIV patient, who presented bacteremia caused by Kocuria rosea. He was successfully treated with vancomycin and by catheter removal.
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Síndrome da Imunodeficiência Adquirida/microbiologia , Bacteriemia/imunologia , Hospedeiro Imunocomprometido , Micrococcaceae/classificação , Micrococcaceae/isolamento & purificação , Humanos , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-IdadeRESUMO
Kocuria rosea is an uncommon pathogen may cause opportunistic infections in immunocompromised patient. We report a HIV patient, who presented bacteremia caused by Kocuria rosea. He was successfully treated with vancomycin and by catheter removal.
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Humanos , Masculino , Pessoa de Meia-Idade , Síndrome da Imunodeficiência Adquirida/microbiologia , Bacteriemia/imunologia , Hospedeiro Imunocomprometido , Micrococcaceae/classificação , Micrococcaceae/isolamento & purificação , Testes de Sensibilidade MicrobianaRESUMO
Objetivo. Evaluar la capacidad de 17 laboratorios nacionales de referencia que participan en el Programa Latinoamericano de Control de Calidad en Bacteriología y Resistencia a los Antimicrobianos (LA-EQAS) para detectar mecanismos de resistencia emergentes, a saber: resistencia de enterobacterias a carbapenemes por presencia de Klebsiella pneumoniae carbapenemasa (KPC); resistencia de enterobacterias a carbapenemes por presencia de metalobetalactamasas (MBL) tipo IMP, y resistencia intermedia a vancomicina de aislamientos de Staphylococcus aureus (VISA). Métodos. Se enviaron los siguientes tres aislamientos a los 17 laboratorios participantes del LA-EQAS: Klebsiella pneumoniae OPS-161 productor de KPC, Enterobacter cloacae OPS-166 productor de IMP y S. aureus OPS-165 con resistencia intermedia a vancomicina. Se evaluó la interpretación de las pruebas de sensibilidad y detección del mecanismo de resistencia y el tamaño de los halos de inhibición (método de difusión por discos) o valor de la concentración inhibitoria mínima (CIM). Resultados. La concordancia en la detección de los mecanismos de resistencia fue de 76,4%, 73,3% y 66,7% con respecto a la cepas K. pneumoniae OPS-161, E. cloacae OPS-166 y S. aureus OPS-165, respectivamente. La concordancia entre las zonas de inhibición obtenidas por los laboratorios participantes y los rangos establecidos por el laboratorio coordinador fue aceptable en los tres aislamientos, ya que alcanzó 90,8%, 92,8% y 88,9%, respectivamente, para cada cepa. Conclusiones. La concordancia global en la detección de los mecanismos de resistencia KPC, MBL y VISA fue de 72,1%. Consideramos que los laboratorios nacionales de referencia de América Latina son capaces de reconocer estos mecanismos de resistencia emergentes y se espera que en el futuro la concordancia alcance su nivel máximo.
Objective. To evaluate the capability of 17 national reference laboratories participating in the Latin American Quality Control Program in Bacteriology and Antibiotic Resistance (LA-EQAS) to detect emerging resistance mechanisms namely: resistance of enterobacteria to carbapenems due to the presence of Klebsiella pneumoniae carbapenemase (KPC) and metallo-beta-lactamase (MBL) type IMP, and intermediate resistance of Staphylococcus aureus isolates to vancomycin (vancomycinintermediate resistant S. aureusVISA). Methods. The following three isolates were sent to the 17 participating LA-EQAS laboratories: KPC-producing Klebsiella pneumoniae PAHO-161, IMP-producing Enterobacter cloacae PAHO-166, and S. aureus PAHO-165 with intermediate resistance to vancomycin. Performance of each of the following operations was evaluated: interpretation of sensitivity tests, detection of the resistance mechanism, and assessment of either inhibition halo size (disk diffusion method) or minimum inhibitory concentration (MIC). Results. Concordance in the detection of resistance mechanisms was 76.4%, 73.3%, and 66.7% for the K. pneumoniae PAHO-161, E. cloacae PAHO-166, and S. aureus PAHO- 165 strains, respectively. Concordance between the inhibition areas observed by the participating laboratories and the ranges established by the coordinating laboratory was acceptable for all three isolates, at 90.8%, 92.8%, and 88.9%, respectively. Conclusions. Overall concordance in on the detection of KPC, MBL, and VISA resistance mechanisms was 72.1%. We consider the national reference laboratories in Latin America capable of recognizing these emerging resistance mechanisms and expect that maximum levels of concordance will be reached in the future.