RESUMEN
Human brucellosis is a neglected zoonotic disease and has widespread geographical distribution. Brucella melitensis has caused outbreaks and sporadic cases in Malaysia. Here, we present the whole-genome sequences of four B. melitensis strains isolated from brucellosis patients in Malaysia.
RESUMEN
BACKGROUND: Brucellosis is one of the most common zoonotic diseases worldwide. It can cause acute febrile illness in human and is a major health problem. Studies in human brucellosis in Malaysia is limited and so far no genotyping studies has been done on Brucella isolates. The aim of the study was to determine the genetic diversity among Brucella species isolated from human brucellosis, obtained over a 6-year period (2009-2014). METHODS: In this study, the genotypic characteristics of 43 human Brucella melitensis isolates were analysed using multiple-locus variable-number tandem-repeat analysis (MLVA) which consisted of eight minisatellite loci (panel 1) and eight microsatellite loci; panels 2A (3 microsatellite loci) and panel 2B (5 microsatellite loci). Two human Brucella suis isolates were also investigated using the MLVA assay. RESULTS: Using panel 1 (MLVA8), two genotypes namely genotype 43 and 44 were obtained from the 43 B. melitensis isolates. Using the combination of panels 1 and 2A loci (MLVA11), two genotypes were obtained while using the complete panels 1, 2A and 2B, nine genotypes were obtained. The polymorphisms in using the complete panels (MLVA16) were observed in three loci from panel 2B, which showed a diversity index higher than 0.17. All B. melitensis isolates were closely related to the East Mediterranean group. For B. suis isolates, only genotype 6 and genotype 33 were obtained using panel 1 and MLVA11 respectively. CONCLUSION: In conclusion, the results of the present study showed a low genetic diversity among B. melitensis and B. suis isolates from human patients. Based on the MLVA16 assay, B. melitensis belonging to the East Mediterranean group is responsible for the vast majority of Brucella infections in our Malaysian patients. To our knowledge, this is the first genotyping study of human Brucella isolates in Malaysia.
Asunto(s)
Brucella melitensis/genética , Brucella suis/genética , Brucelosis/diagnóstico , Brucella melitensis/aislamiento & purificación , Brucella suis/aislamiento & purificación , Brucelosis/genética , Brucelosis/microbiología , ADN Bacteriano/análisis , ADN Bacteriano/aislamiento & purificación , Sitios Genéticos , Variación Genética , Genotipo , Humanos , Malasia , Repeticiones de Microsatélite/genética , Repeticiones de Minisatélite/genética , Técnicas de Amplificación de Ácido Nucleico , Reacción en Cadena de la PolimerasaRESUMEN
Molecular approaches have been investigated to overcome difficulties in identification and differentiation of Brucella spp. using conventional phenotypic methods. In this study, high-resolution melt (HRM) analysis was used for rapid identification and differentiation of members of Brucella genus. A total of 41 Brucella spp. isolates from human brucellosis were subjected to HRM analysis using 4 sets of primers, which identified 40 isolates as Brucella melitensis and 1 as Brucella canis. The technique utilized low DNA concentration and was highly reproducible. The assay is shown to be a useful diagnostic tool, which can rapidly differentiate Brucella up to species level.
Asunto(s)
Brucella canis/clasificación , Brucella canis/aislamiento & purificación , Brucella melitensis/clasificación , Brucella melitensis/aislamiento & purificación , Brucelosis/microbiología , Técnicas de Diagnóstico Molecular/métodos , Brucella canis/genética , Brucella melitensis/genética , Cartilla de ADN/genética , ADN Bacteriano/genética , Humanos , Malasia , Reproducibilidad de los Resultados , Manejo de Especímenes/métodos , Temperatura de TransiciónRESUMEN
Brucellosis is a world-wide zoonotic disease with a major impact on the public health. Due to the high risk of laboratory acquired infection, limited laboratory investigations were performed on this organism, including detailed identification and susceptibility study. Brucella melitensis is the commonest aetiological agent for human brucellosis in this region. The in vitro susceptibility pattern against selected antimicrobial agents was assessed using E-test. All isolates were noted to be sensitive to all the antimicrobial agents tested except for rifampicin where elevated MIC > 1 µg/mL was noted in 30 out of 41 isolates tested.
