RESUMEN
Rhodococcus equi is a well-recognized Gram-positive intracellular facultative bacterium that is opportunistic in nature, which causes pyogranulomatous infections in humans and multiple host animals. The pathogenicity of the microorganism has been attributed to the presence of plasmid-encoded virulence-associated proteins (Vap). To date, three host-associated virulence plasmid types of R. equi have been identified as follows: the circular pVAPA and pVAPB, related, respectively, to equine and porcine isolates, and a recently described linear pVAPN plasmid associated with bovine strains, although these three types are found in human isolates. Recent phylogenomic studies support the evidence that human R. equi infection is zoonotically acquired. Nevertheless, data regarding distribution and prevalence of the host-adapted virulence plasmid types of R. equi isolated from meat animals are scarce or unnoticed. Here, the three host-associated virulence plasmid types (pVAPA, pVAPB, and pVAPN) were investigated in 154 R. equi isolates recovered from lymph nodes of cattle with lymphadenitis (n = 31), faeces of cattle without enteric signs (n = 49), as well as different clinical specimens from human patients (n = 74). The analysis of virulence profile of 74 R. equi from humans revealed six (8.1%) isolates pVAPB (type 8), two (2.7%) pVAPN, and one (1.3%) pVAPB (type 11), all of which were from lung samples from people living with HIV/AIDS. From the lymph node samples of cattle, 41.9% (13 of 31) isolates revealed pVAPN type, whereas all isolates from faecal samples were negative for three host-associated types. Here, recently described bovine-associated pVAPN type was detected in R. equi isolates recovered from the lungs of people living with HIV/AIDS and lymph nodes from slaughtered cattle intended for human consumption; a finding that represents a public health concern, mainly in countries where undercooked or raw meat are traditionally consumed.
Asunto(s)
Infecciones por Actinomycetales/veterinaria , Proteínas Bacterianas/genética , Enfermedades de los Bovinos/microbiología , Infecciones por VIH/microbiología , Enfermedades Pulmonares/microbiología , Ganglios Linfáticos/microbiología , Rhodococcus equi/aislamiento & purificación , Factores de Virulencia/genética , Infecciones por Actinomycetales/microbiología , Animales , Bovinos , ADN Bacteriano/genética , Heces , Humanos , Plásmidos/genética , Prevalencia , Rhodococcus equi/genéticaRESUMEN
UNLABELLED: The virulence-plasmid profile of Rhodococcus equi strains isolated from Suidae and humans is similar. Recent evidence suggests that the consumption of pork products contaminated with faeces might be a potential source of R. equi infections in humans, mainly to patients with rhodococcosis without history of contact with pigs or pig farms. This study investigated the virulence-associated genes (vapA and vapB) and plasmid profiles of R. equi among the 150 samples of small intestinal content obtained from slaughtered pigs. In addition, all samples were subjected to microbiological culture in conventional sheep blood agar and CAZ-NB, TCP and TVP selective media. A total of 40 (26·7%) of the samples recovered R. equi, with two samples recovering isolates harbouring the VapB type 8 plasmid. Among the 150 pigs sampled herein, CAZ-NB was considered the best selective medium for the isolation of R. equi from faeces. Our results provide evidence that the contamination of slaughtered pig carcasses with pathogenic R. equi might occur through faeces, representing a public health concern. Furthermore, this study is the first description of R. equi strains carrying the VapB plasmid in the gut of pigs. SIGNIFICANCE AND IMPACT OF THE STUDY: Intermediately virulent (VapB) is a common plasmid-type harboured by R. equi isolated from pigs and humans with AIDS. Curiously, humans with rhodococcosis usually have no history of contact with pigs or pig farms. Virulence-plasmid profile of 40 R. equi isolated among 150 small intestine content samples from pigs revelled two carrying isolates with the VapB type-8 plasmids. Moreover, comparison of three selective culture media shows that CAZ-NB was the best. Our results provide evidence that contamination of slaughtered pig carcasses with pathogenic R. equi might occur through faeces, representing a public health concern. Furthermore, R. equi carrying VapB type-8 plasmids types are described for the first time in the gut of the pig.
Asunto(s)
Infecciones por Actinomycetales/microbiología , Proteínas Bacterianas/genética , Medios de Cultivo , Proteínas de Unión al ADN/genética , Microbiología de Alimentos , Glicoproteínas de Membrana/genética , Carne Roja/microbiología , Rhodococcus equi/aislamiento & purificación , Mataderos , Animales , Brasil , Heces/microbiología , Humanos , Intestino Delgado/microbiología , Plásmidos/genética , Plásmidos/aislamiento & purificación , Rhodococcus equi/genética , Porcinos , Enfermedades de los Porcinos/microbiología , Virulencia/genética , Factores de Virulencia/genéticaRESUMEN
The identification of pathogens of viral (Rotavirus, Coronavirus), parasitic (Toxocara spp.) and bacterial (Escherichia coli, Salmonella spp., Rhodococcus equi) origin shed in feces, and the virulence profile of R. equi and E. coli isolates were investigated in 200 samples of sand obtained from 40 parks, located in central region of state of Sao Paulo, Brazil, using different diagnostic methods. From 200 samples analyzed, 23 (11.5%) strains of R. equi were isolated. None of the R. equi isolates showed a virulent (vapA gene) or intermediately virulent (vapB gene) profiles. Sixty-three (31.5%) strains of E. coli were identified. The following genes encoding virulence factors were identified in E. coli: eae, bfp, saa, iucD, papGI, sfa and hly. Phylogenetic classification showed that 63 E. coli isolates belonged to groups B1 (52.4%), A (25.4%) and B2 (22.2%). No E. coli serotype O157:H7 was identified. Eggs of Toxocara sp. were found in three parks and genetic material of bovine Coronavirus was identified in one sample of one park. No Salmonella spp. and Rotavirus isolates were identified in the samples of sand. The presence of R. equi, Toxocara sp, bovine Coronavirus and virulent E. coli isolates in the environment of parks indicates that the sanitary conditions of the sand should be improved in order to reduce the risks of fecal transmission of pathogens of zoonotic potential to humans in these places.
Asunto(s)
Coronavirus Bovino/aislamiento & purificación , Escherichia coli/aislamiento & purificación , Rhodococcus equi/aislamiento & purificación , Microbiología del Suelo , Toxocara/aislamiento & purificación , Animales , Brasil , Escherichia coli/clasificación , Escherichia coli/genética , Humanos , Rhodococcus equi/genética , Factores de Virulencia/genéticaRESUMEN
The identification of pathogens of viral (Rotavirus, Coronavirus), parasitic (Toxocara spp.) and bacterial (Escherichia coli, Salmonella spp., Rhodococcus equi) origin shed in feces, and the virulence profile of R. equi and E. coli isolates were investigated in 200 samples of sand obtained from 40 parks, located in central region of state of Sao Paulo, Brazil, using different diagnostic methods. From 200 samples analyzed, 23 (11.5%) strains of R. equi were isolated. None of the R. equi isolates showed a virulent (vapA gene) or intermediately virulent (vapB gene) profiles. Sixty-three (31.5%) strains of E. coli were identified. The following genes encoding virulence factors were identified in E. coli: eae, bfp, saa, iucD, papGI, sfa and hly. Phylogenetic classification showed that 63 E. coli isolates belonged to groups B1 (52.4%), A (25.4%) and B2 (22.2%). No E. coli serotype O157:H7 was identified. Eggs of Toxocara sp. were found in three parks and genetic material of bovine Coronavirus was identified in one sample of one park. No Salmonella spp. and Rotavirus isolates were identified in the samples of sand. The presence of R. equi, Toxocara sp, bovine Coronavirus and virulent E. coli isolates in the environment of parks indicates that the sanitary conditions of the sand should be improved in order to reduce the risks of fecal transmission of pathogens of zoonotic potential to humans in these places.
Asunto(s)
Animales , Humanos , Coronavirus Bovino/aislamiento & purificación , Escherichia coli/aislamiento & purificación , Rhodococcus equi/aislamiento & purificación , Microbiología del Suelo , Toxocara/aislamiento & purificación , Brasil , Escherichia coli/clasificación , Escherichia coli/genética , Rhodococcus equi/genética , Factores de Virulencia/genéticaRESUMEN
The identification of pathogens of viral (Rotavirus, Coronavirus), parasitic (Toxocara spp.) and bacterial (Escherichia coli, Salmonella spp., Rhodococcus equi) origin shed in feces, and the virulence profile of R. equi and E. coli isolates were investigated in 200 samples of sand obtained from 40 parks, located in central region of state of Sao Paulo, Brazil, using different diagnostic methods. From 200 samples analyzed, 23 (11.5%) strains of R. equi were isolated. None of the R. equi isolates showed a virulent (vapA gene) or intermediately virulent (vapB gene) profiles. Sixty-three (31.5%) strains of E. coli were identified. The following genes encoding virulence factors were identified in E. coli: eae, bfp, saa, iucD, papGI, sfa and hly. Phylogenetic classification showed that 63 E. coli isolates belonged to groups B1 (52.4%), A (25.4%) and B2 (22.2%). No E. coli serotype O157:H7 was identified. Eggs of Toxocara sp. were found in three parks and genetic material of bovine Coronavirus was identified in one sample of one park. No Salmonella spp. and Rotavirus isolates were identified in the samples of sand. The presence of R. equi, Toxocara sp, bovine Coronavirus and virulent E. coli isolates in the environment of parks indicates that the sanitary conditions of the sand should be improved in order to reduce the risks of fecal transmission of pathogens of zoonotic potential to humans in these places.(AU)
Asunto(s)
Rhodococcus , Humanos , Toxocara , Escherichia coli , Factores de VirulenciaRESUMEN
A 2-year-old intact male domestic shorthaired cat presented with a chronic, nodular, ulcerated, cutaneous lesion on the right thoracic limb. Histological and cytological examination revealed a pyogranulomatous inflammation with basophilic organisms in the macrophages. A virulent form of Rhodococcus equi containing an 87 kb type I (VapA) virulence plasmid was identified from cultures of biopsy samples. This report describes the clinicopathological features, plasmid profile and virulence of this case of R equi infection.
Asunto(s)
Infecciones por Actinomycetales/veterinaria , Enfermedades de los Gatos/microbiología , Rhodococcus equi , Infecciones por Actinomycetales/microbiología , Infecciones por Actinomycetales/patología , Animales , Enfermedades de los Gatos/patología , Gatos , ADN Bacteriano/análisis , Resultado Fatal , Masculino , Plásmidos/genética , Rhodococcus equi/genética , Rhodococcus equi/patogenicidad , Virulencia/genéticaRESUMEN
The distributions of the incubation periods for infectious and neoplastic diseases originating from point-source exposures, and for genetic diseases, follow a lognormal distribution (Sartwell's model). Conversely, incubation periods in propagated outbreaks and diseases with strong environmental components do not follow a lognormal distribution. In this study Sartwell's model was applied to the age at onset and age at death of foals with Rhodococcus equi pneumonia. The age at onset of clinical signs and age at death were compiled for 107 foals that had been diagnosed with R. equi pneumonia at breeding farms in Argentina and Japan. For each outcome (disease and death), these data followed a lognormal distribution. A group of 115 foals with colic from the University of California were used as a comparison group. The age at onset of clinical signs for these foals did not follow a lognormal distribution. These results were consistent with the hypothesis that foals are infected with R. equi during the 1st several days of life, similar to a point-source exposure.