Background
Methods
Sample collection
Bacterial strains
PCR amplification and sequencing
Sequence analysis
Results
Different prominent species and biovars during three incidence stages
Strains | STa
| Time | Period | Stageb
| Species | Biovarc
|
---|---|---|---|---|---|---|
Bru001 | 8 | 1955 | 1950s | 1950-1960s |
B. melitensis
| 2 |
Bru002 | 8 | 1958 | 1950s | 1950-1960s |
B. melitensis
| 2 |
Bru003 | 8 | 1960 | 1960s | 1950-1960s |
B. melitensis
| 2 |
Bru004 | 34 | 1963 | 1960s | 1950-1960s |
B. melitensis
| 2 |
Bru005 | 8 | 1965 | 1960s | 1950-1960s |
B. melitensis
| 2 |
Bru006 | 34 | 1966 | 1960s | 1950-1960s |
B. melitensis
| 2 |
Bru007 | 8 | 1957 | 1950s | 1950-1960s |
B. melitensis
| 3 |
Bru008 | 8 | 1957 | 1950s | 1950-1960s |
B. melitensis
| 3 |
Bru009 | 8 | 1957 | 1950s | 1950-1960s |
B. melitensis
| 3 |
Bru010 | 8 | 1958 | 1950s | 1950-1960s |
B. melitensis
| 3 |
Bru011 | 8 | 1958 | 1950s | 1950-1960s |
B. melitensis
| 3 |
Bru012 | 8 | 1960 | 1960s | 1950-1960s |
B. melitensis
| 3 |
Bru013 | 8 | 1965 | 1960s | 1950-1960s |
B. melitensis
| 3 |
Bru014 | 2 | 1960 | 1960s | 1950-1960s |
B. abortus
| 1 |
Bru018 | 5 | 1956 | 1950s | 1950-1960s |
B. abortus
| 3 |
Bru019 | 2 | 1956 | 1950s | 1950-1960s |
B. abortus
| 3 |
Bru022 | 36 | 1957 | 1950s | 1950-1960s |
B. suis
| 1 |
Bru023 | 17 | 1963 | 1960s | 1950-1960s |
B. suis
| 3 |
Bru015 | 28 | 1972 | 1970s | 1970-1980s |
B. abortus
| 1 |
Bru016 | 1 | 1980 | 1980s | 1970-1980s |
B. abortus
| 1 |
Bru020 | 33 | 1979 | 1970s | 1970-1980s |
B. abortus
| 6 |
Bru021 | 31 | 1980 | 1980s | 1970-1980s |
B. abortus
| 6 |
Bru024 | 2 | 1988 | 1980s | 1970-1980s |
B. abortus
| 3 |
Bru025 | 2 | 1988 | 1980s | 1970-1980s |
B. abortus
| 3 |
Bru026 | 1 | 1988 | 1980s | 1970-1980s |
B. abortus
| 1 |
Bru027 | 29 | 1989 | 1980s | 1970-1980s |
B. abortus
| 3 |
Bru028 | 29 | 1985 | 1980s | 1970-1980s |
B. abortus
| 3 |
Bru029 | 32 | 1985 | 1980s | 1970-1980s |
B. abortus
| 3 |
Bru030 | 8 | 1985 | 1980s | 1970-1980s |
B. melitensis
| 1 |
Bru031 | 2 | 1985 | 1980s | 1970-1980s |
B. abortus
| 3 |
Bru032 | 30 | 1985 | 1980s | 1970-1980s |
B. abortus
| 1 |
Bru033 | 29 | 1988 | 1980s | 1970-1980s |
B. abortus
| 3 |
Bru034 | 2 | 1988 | 1980s | 1970-1980s |
B. abortus
| 3 |
Bru035 | 2 | 1988 | 1980s | 1970-1980s |
B. abortus
| 3 |
Bru036 | 2 | 1988 | 1980s | 1970-1980s |
B. abortus
| 3 |
Bru037 | 29 | 1988 | 1980s | 1970-1980s |
B. abortus
| 3 |
Bru038 | 8 | 1988 | 1980s | 1970-1980s |
B. melitensis
| 1 |
Bru039 | 34 | 1989 | 1980s | 1970-1980s |
B. melitensis
| 1 |
Bru040 | 8 | 1989 | 1980s | 1970-1980s |
B. melitensis
| 1 |
Bru017 | 1 | 2006 | 2000s | 1990-2000s |
B. abortus
| 1 |
Bru041 | 34 | 1993 | 1990s | 1990-2000s |
B. melitensis
| 1 |
Bru042 | 8 | 1990 | 1990s | 1990-2000s |
B. melitensis
| 1 |
Bru043 | 34 | 2001 | 2000s | 1990-2000s |
B. melitensis
| 1 |
Bru044 | 8 | 1996 | 1990s | 1990-2000s |
B. melitensis
| 1 |
Bru045 | 8 | 1997 | 1990s | 1990-2000s |
B. melitensis
| 1 |
Bru046 | 8 | 1998 | 1990s | 1990-2000s |
B. melitensis
| 1 |
Bru047 | 8 | 1996 | 1990s | 1990-2000s |
B. melitensis
| 1 |
Bru048 | 8 | 1999 | 1990s | 1990-2000s |
B. melitensis
| 1 |
Bru049 | 34 | 2008 | 2000s | 1990-2000s |
B. melitensis
| 1 |
Bru050 | 8 | 1998 | 1990s | 1990-2000s |
B. melitensis
| 1 |
Bru051 | 8 | 2002 | 2000s | 1990-2000s |
B. melitensis
| 1 |
Bru052 | 34 | 2002 | 2000s | 1990-2000s |
B. melitensis
| 1 |
Bru053 | 35 | 1997 | 1990s | 1990-2000s |
B. melitensis
| 1 |
Bru054 | 34 | 2007 | 2000s | 1990-2000s |
B. melitensis
| 1 |
Bru055 | 34 | 1996 | 1990s | 1990-2000s |
B. melitensis
| 1 |
Bru056 | 8 | 2007 | 2000s | 1990-2000s |
B. melitensis
| 1 |
Bru057 | 8 | 2006 | 2000s | 1990-2000s |
B. melitensis
| 1 |
Bru058 | 2 | 1995 | 1990s | 1990-2000s |
B. abortus
| 3 |
Bru059 | 29 | 1996 | 1990s | 1990-2000s |
B. abortus
| 3 |
Bru060 | 2 | 1997 | 1990s | 1990-2000s |
B. abortus
| 3 |
Species/Biovars | Incidence stagea
| Total | |||
---|---|---|---|---|---|
Species | Biovars | 1950-1960s | 1970-1980s | 1990-2000s | |
B. melitensis
| 1 | 0 | 4 | 17 | 21 |
2 | 6 | 0 | 0 | 6 | |
3 | 7 | 0 | 0 | 7 | |
B. abortus
| 1 | 1 | 4 | 1 | 6 |
3 | 2 | 11 | 3 | 16 | |
6 | 0 | 2 | 0 | 2 | |
B. suis
| 1 | 1 | 0 | 0 | 1 |
3 | 1 | 0 | 0 | 1 | |
Total | 18 | 21 | 21 | 60 |
Different sequence type distributions among the three incidence stages
ST | Incidence stagea
| Total | ||
---|---|---|---|---|
1950-1960s | 1970-1980s | 1990-2000s | ||
1 | 2 (9.52%) | 1 (4.76%) | 3 (5.00%) | |
2 | 2 (11.11%) | 6 (28.57%) | 2 (9.52%) | 10 (16.67%) |
5 | 1 (5.56%) | 1 (1.67%) | ||
8 | 11 (61.11%) | 3 (14.29%) | 10 (47.62%) | 24 (40.00%) |
17 | 1 (5.56%) | 1 (1.67%) | ||
28 | 1 (4.76%) | 1 (1.67%) | ||
29 | 4 (19.05%) | 1 (4.76%) | 5 (8.33%) | |
30 | 1 (4.76%) | 1 (1.67%) | ||
31 | 1 (4.76%) | 1 (1.67%) | ||
32 | 1 (4.76%) | 1 (1.67%) | ||
33 | 1 (4.76%) | 1 (1.67%) | ||
34 | 2 (11.11%) | 1 (4.76%) | 6 (28.57%) | 9 (15.00%) |
35 | 1 (4.76%) | 1 (1.67%) | ||
36 | 1 (5.56%) | 1 (1.67%) |
Sequence polymorphism and alleles changes of the nine loci for predominant species during the three incidence stages
Locus | Alleles | Polymorphic sites | Polymorphic sites percent | dN
| dS
| dN/dS
| Mean % GC |
---|---|---|---|---|---|---|---|
aroA
| 6 | 4 | 0.71% | 0.0026 | 0.0058 | 0.4422 | 61.77 |
cobQ
| 5 | 4 | 0.95% | 0.0044 | 0.0058 | 0.7678 | 59.43 |
dnak
| 2 | 1 | 0.21% | 0 | 0.009 | 0 | 60.53 |
gap
| 3 | 3 | 0.51% | 0.0015 | 0.0091 | 0.1668 | 58.35 |
glk
| 4 | 4 | 0.84% | 0.0029 | 0.0038 | 0.761 | 62.53 |
gyrB
| 5 | 3 | 0.64% | 0.0017 | 0.0102 | 0.1681 | 58.93 |
omp25
| 5 | 4 | 0.82% | 0 | 0.02 | 0 | 59.2 |
trpE
| 3 | 2 | 0.41% | 0.0018 | 0.0056 | 0.3239 | 58.44 |
Int-hyp
| 3 | 4 | 0.93% | - | - | - | 55.81 |
STa
| Species | Allele distributionb
| ||||||||
---|---|---|---|---|---|---|---|---|---|---|
aroA |
cobQ |
dnak |
gap |
glk |
gyrB |
omp25 |
trpE |
Int-
hyp
| ||
1 |
B. abortus
| 1 | 1 | 2 | 2 | 1 | 1 | 1 | 3 | 1 |
2 |
B. abortus
| 1 | 1 | 2 | 2 | 2 | 1 | 1 | 3 | 1 |
5 |
B. abortus
| 1 | 1 | 2 | 2 | 1 | 1 | 1 | 4 | 1 |
28 |
B. abortus
| 1 | 1 | 2 | 2 | 1 | 1 | 11 | 4 | 1 |
29 |
B. abortus
| 1 | 1 | 2 | 2 | 2 | 1 | 11 | 3 | 1 |
30 |
B. abortus
| 1 | 1 | 2 | 2 | 3 | 1 | 1 | 3 | 1 |
32 |
B. abortus
| 8 | 1 | 2 | 2 | 2 | 1 | 1 | 3 | 1 |
31 |
B. abortus
| 1 | 8 | 2 | 2 | 1 | 1 | 1 | 3 | 2 |
33 |
B. abortus
| 10 | 9 | 2 | 2 | 4 | 7 | 1 | 3 | 1 |
8 |
B. melitensis
| 2 | 3 | 2 | 3 | 3 | 1 | 8 | 5 | 2 |
34 |
B. melitensis
| 2 | 3 | 2 | 3 | 3 | 1 | 12 | 5 | 2 |
35 |
B. melitensis
| 2 | 3 | 2 | 3 | 3 | 8 | 12 | 5 | 2 |
17 |
B. suis
| 6 | 5 | 1 | 1 | 4 | 5 | 2 | 3 | 4 |
36 |
B. suis
| 9 | 5 | 1 | 1 | 4 | 4 | 2 | 3 | 1 |