RESUMEN
The aim of this surveillance was to study both Salmonella spp. shedding patterns and the time course of serological response in farrow-to-finish reared pigs from a subclinically infected farm. Antimicrobial resistance profile, molecular subtyping, and the relationship among the isolates were determined by pulsed-field gel electrophoresis (PFGE). A farrow-to-finish farm of 6000 sows, with a history of Salmonella Typhimurium septicemia, was selected. A longitudinal bacteriological and serological study was conducted in 25 sows before farrowing (M/S1) and in 50 offspring at 21 (M/S2), 35 (M/S3), 65 (M/S4), 86 (M/S5), 128 (M/S6), and 165 (M/S7) days of age. Serum antibodies were tested using Herdcheck((R)) Swine Salmonella antibody test kit (Idexx Laboratories, ME). Bacteria were isolated from pooled fecal samples. Suspected isolates were confirmed by conventional biochemical assays, and those identified as Salmonella spp. were serotyped. A variation between seropositive percentages and positive fecal samples was observed. Serologically positive pigs decreased from S1 to S4, and subsequently increased from S4 to S7. The percentages of fecal positive culture increased from M1 to M3, and then declined in M4, increased in M5, and were negative in M6 and M7. In the study three serovars, Salmonella 3,10:e,h:-, Salmonella Muenster, and Salmonella Bovismorbificans, were identified with low pathogenicity for swine. Three multidrug resistance strains (one belonged to Salmonella 3,10:e,h:- and two belonged to Salmonella Muenster) were found. PFGE results showed three different but closely related patterns among the 13 isolates of Salmonella Bovismorbificans, and two patterns for the three Salmonella Muenster and Salmonella 3,10:e,h:- isolates. This longitudinal study established critical points of Salmonella spp. infection in the farm and the production stages, where appropriate control measures must be taken. PFGE showed clonal relationships in each serovar. Antibiotic resistance profiles should be periodically included due to public health concerns.
Asunto(s)
Farmacorresistencia Bacteriana/genética , Salmonelosis Animal/microbiología , Salmonella enterica , Enfermedades de los Porcinos/microbiología , Envejecimiento , Crianza de Animales Domésticos/métodos , Animales , Argentina/epidemiología , Derrame de Bacterias , ADN Bacteriano/genética , ADN Bacteriano/aislamiento & purificación , Electroforesis en Gel de Campo Pulsado/veterinaria , Heces/microbiología , Femenino , Variación Genética , Estudios Longitudinales , Masculino , Filogenia , Recto/microbiología , Salmonelosis Animal/epidemiología , Salmonelosis Animal/prevención & control , Salmonella enterica/clasificación , Estudios Seroepidemiológicos , Serotipificación/veterinaria , Porcinos , Enfermedades de los Porcinos/epidemiología , Factores de TiempoRESUMEN
Two blue and gold macaw (Ara ararauna) chicks died of fatal salmonellosis in Buenos Aires Province, Argentina. The birds were histopathologically and microbiologically examined. Salmonella enterica subspecies enterica serovar Typhimurium was isolated from the liver, spleen, heart, lung, kidney, and intestine of both birds. All strains were susceptible to ampicillin, cephalothin, cefotaxime, enrofloxacin, nalidixic acid, gentamicin, streptomycin, chloramphenicol, fosfomycin, tetracycline, nitrofurantoin, and trimethoprim-sulfamethoxazole. The XbaI-PFGE profile of the Salmonella Typhimurium isolated from the two animals, which shared the same cage, was identical and showed a unique pattern compared with 301 isolates included in the PulseNet national database of Salmonella pulsed-field gel electrophoresis patterns. This is the first report that describes fatal cases of salmonellosis from blue and gold macaws.
Asunto(s)
Enfermedades de las Aves/microbiología , Loros/microbiología , Salmonelosis Animal/microbiología , Salmonella typhimurium/aislamiento & purificación , Animales , Enfermedades de las Aves/patología , Pulmón/patología , Enfermedades Pulmonares/microbiología , Enfermedades Pulmonares/veterinaria , Filogenia , Salmonelosis Animal/patología , Salmonella typhimurium/genéticaRESUMEN
Salmonella Typhi is the etiological agent of typhoid fever with 16 million annual cases estimated worldwide. In Colombia and Argentina it is a notifiable disease but many cases have only a clinical diagnosis. Molecular subtyping of S. Typhi is necessary to complement epidemiologic analysis of typhoid fever. The aims of this study were to determine the genetic relationships between the strains circulating in both countries and to evaluate possible variations in the distribution of 12 virulence genes. A total of 136 isolates were analyzed by pulsed-field gel electrophoresis (PFGE) with XbaI following PulseNet protocols and analysis guidelines. Eighty-three different PFGE patterns were identified, showing high diversity among the strains from both countries. Three outbreaks, two in Colombia and one in Argentina, were caused by strains of different PFGE types. In Colombia, two PFGE patterns were found predominantly, which included 36.6% of the isolates from that country. No association was found between the PFGE patterns and the year or place of isolation of the strains, the age of the patients or type of sample. However, several clusters were detected, which included isolates recovered predominantly either from Colombia or Argentina. Most of the strains (97%) exhibited a single virulence profile, suggesting that the pathogenicity markers analyzed are of limited value for strain discrimination and do not correlate with the origin of the isolates (intestinal vs. extra-intestinal). Since the creation of PulseNet Latin America, this was the first international study conducted in South America. The PFGE types identified were incorporated into the Regional S. Typhi PulseNet Database and are now available for comparison with those of strains isolated in other regions. This information will be used for active surveillance, future studies, and outbreak investigations.
Asunto(s)
ADN Bacteriano/análisis , Salmonella typhi/clasificación , Fiebre Tifoidea/epidemiología , Fiebre Tifoidea/microbiología , Argentina/epidemiología , Análisis por Conglomerados , Colombia/epidemiología , Bases de Datos Factuales , Notificación de Enfermedades , Electroforesis en Gel de Campo Pulsado/métodos , Humanos , Epidemiología Molecular , Filogenia , Salmonella typhi/aislamiento & purificación , Virulencia/genéticaRESUMEN
Five sequential Cryptococcus neoformans isolates recovered from an AIDS patient with recurrent meningitis were analyzed. Four isolates were fluconazole susceptible, while the fifth isolate developed fluconazole resistance. Analysis of the 14-alpha lanosterol demethylase gene (ERG11) showed a point mutation in the resistant strain responsible for the amino acid substitution G484S.