Multiple-Locus Variable-Number Tandem-Repeat Analysis Genotyping of Human Brucella Isolates from Turkey

Abstract

Brucellosis is the most common anthropozoonosis, with more than 500,000 cases annually. While the disease was eradicated in the vast majority of industrialized regions around the world, it remains a significant public health concern, mainly in the Mediterranean littoral, the Middle East, the Arabian Peninsula, the Indian subcontinent, Asia, Africa, and Central and South America (19,26).Turkey is a relatively large country in the eastern Mediterranean region, with a geographical surface of 783,562 km 2 , and comprises seven regions. It has a population of 72 million, 70% of which lives in cities and 30% in rural areas. Brucellosis is endemic, and approximately 10,000 human brucellosis cases are reported annually. The reported incidence is 150 cases per 1 million inhabitants (24). Its prevalence varies widely from region to region due to several factors, including food habits, milk processing methods, husbandry practices, nomadism, social customs, climatic conditions, socioeconomic status, and environmental conditions. A steady increase of reported human cases was observed from 1986 (3.03/100,000 population) until 2004 (25.65/100,000). Livestock vaccination, elimination of infected animals, control of animal movements, and education induced a decline in the number of annually reported human cases, from 18,563 cases in 2004 to 9,818 cases in 2008 (17).Rapid and accurate typing procedures are crucial for epidemiologic surveillance, investigation of outbreaks, and follow-up of a control program. Many molecular typing methods commonly used for the subtyping of isolates of other bacterial species are not appropriate for routine typing of Brucella strains, and none has proven to be fully satisfactory for epidemiological trace-back investigations of brucellosis (1,9,25). Recently, a selection of 16 variable-number tandem repeats has been proposed for fingerprinting Brucella isolates (7,14,25). This multiple-locus variable-number tandem-repeat analysis (MLVA) genotyping system, MLVA-16 Orsay , comprised eight minisatellite markers (panel 1, Bruce06, Bruce08, Bruce11, Bruce12, Bruce42, Bruce43, Bruce45, and Bruce55) for species identification and eight complementary microsatellite markers (panel 2A, Bruce18, Bruce19, and Bruce21; panel

MLVA Genotyping Characteristics of Human Brucella melitensis Isolated from Ulanqab of Inner Mongolia, China

“…These findings show that the genotypic variation of Ulanqab isolates was predominantly associated with the highly variable panel 2B loci and to a much lesser extent panel 2A (locus Bruce19 and 21) and panel 1 (loci Bruce 43) loci. In agreement with a previous report (Kilic et al, 2011), this may reflect microevolution through a stepwise mutational event of the most variable loci from a very limited number of ancestors. In addition, there was no clear relationship between biovar and genotype within this B. melitensis population.…”

“…Previous studies have confirmed that MLVA-16 genotyping results show good correlation with epidemiological data with epidemiologically related isolates displaying identical or very closely related genotypes (Al Dahouk et al, 2007; Nöckler et al, 2009; Kilic et al, 2011; Allen et al, 2015) The current study also confirms the occurrence of multipoint outbreak epidemics and intrafamilial brucellosis. The 11 shared genotypes observed during this analysis pertained to 33 Brucella strains obtained from the same area.…”

“…This source of infection also resulted in a higher incidence of brucellosis in other regions of China (Xiao et al, 2015; Ma et al, 2016). In accordance with the previous studies (Kilic et al, 2011), two isolates (genotype 7, ws049; genotype 16, ws050) with different MLVA-16 genotypes were obtained from members of the same family are likely to have resulted from either persistent circulating strains causing sporadic infections or mutation events during the course of the outbreak.…”

Imported human brucellosis in Belgium: Bio and molecular typing of bacterial isolates, 1996-2015

“…The East Mediterranean cluster contained the majority of the strains isolated in Belgium. Nine of them shared the same MLVA11 genotype (genotype 43) with dozens of strains coming from Turkey as previously described [17] [34]. Few strains with the same MLVA11 genotype come from Syria and Irak [17]; this genotype was also observed in strains coming from Lebanon [35].…”

“…Few strains with the same MLVA11 genotype come from Syria and Irak [17]; this genotype was also observed in strains coming from Lebanon [35]. Seven other strains isolated in Belgium shared the same genotype with a great panel of strains isolated in China [21] and Turkey [17][34] (genotype 42). Information about the genotypes present in countries geographically located between Turkey and China is missing but this genotype 42 seems to be highly represented in the Middle East [17][35] and has already been isolated in countries like Kazakhstan [17][36].…”