Genetic Polymorphism Characteristics of Brucella canis Isolated in China

Abstract

In China, brucellosis is an endemic disease typically caused by Brucella melitensis infection (biovars 1 and 3). Brucella canis infection in dogs has not traditionally recognized as a major problem. In recent years however, brucellosis resulting from Brucella canis infection has also been reported, suggesting that infections from this species may be increasing. Data concerning the epidemiology of brucellosis resulting from Brucella canis infection is limited. Therefore, the purpose of this study was to assess the diversity among Chinese Brucella canis strains for epidemiological purposes. First, we employed a 16-marker VNTR assay (Brucella MLVA-16) to assess the diversity and epidemiological relationship of 29 Brucella canis isolates from diverse locations throughout China with 38 isolates from other countries. MLVA-16 analysis separated the 67 Brucella canis isolates into 57 genotypes that grouped into five clusters with genetic similarity coefficients ranging from 67.73 to 100%. Moreover, this analysis revealed a new genotype (2-3-9-11-3-1-5-1:118), which was present in two isolates recovered from Guangxi in 1986 and 1987. Second, multiplex PCR and sequencing analysis were used to determine whether the 29 Chinese Brucella canis isolates had the characteristic BMEI1435 gene deletion. Only two isolates had this deletion. Third, amplification of the omp25 gene revealed that 26 isolates from China had a T545C mutation. Collectively, this study reveals that considerable diversity exists among Brucella canis isolates in China and provides resources for studying the genetic variation and microevolution of Brucella.

Retrospective and prospective perspectives on zoonotic brucellosis

“…In addition of displaying host preferences, the various Brucella species and strains also form genetic groups that relate with distinctive geographic origins (Le Flèche et al, 2006; Foster et al, 2012; Garofolo et al, 2013; Jiang et al, 2013; Di et al, 2014). This means that Brucella clones rapidly expand and transmit within domesticated groups of animals.…”

Brucella canis Is an Intracellular Pathogen That Induces a Lower Proinflammatory Response than Smooth Zoonotic Counterparts

“…In the last decade, there has been a rise in the detection of human infections due to B. canis (8,9). This is due to awareness of the disease in areas where it is endemic and improved diagnoses, as well as increased prevalence of the bacterium in kennel facilities and roaming dogs (10,14,15). Therefore, it may be that B. canis displays an infectivity similar to that of the other zoonotic brucellae but has the potential to produce no symptoms for prolonged periods (16,17) by using a stealth strategy.…”

Brucellosis outbreak in a Swedish kennel in 2013: Determination of genetic markers for source tracing

“…canis strain HSK A52141 was isolated in Korea in 2011 but shows 100% similarity with the AAE group in phage analysis. Based on a MLVA-16 genotyping assay, strain HSK A52141 clustered also with B. canis strains from Romania, US and Canada (Di et al, 2014). Based on the current analysis and the results of Di et al (2014) it is most likely that this strain was transported to Korea with an imported dog.…”

“…Based on a MLVA-16 genotyping assay, strain HSK A52141 clustered also with B. canis strains from Romania, US and Canada (Di et al, 2014). Based on the current analysis and the results of Di et al (2014) it is most likely that this strain was transported to Korea with an imported dog. The Asian strain BCB018 (Tables 3 and 4) of a R. Kaden et al / Veterinary Microbiology xxx (2014) xxx-xxx 4 human isolate of B. canis acquired 21 genes of 20 different phages while most genes that exist in the AAE group are missing.…”