Objective To study the types of subspecies of Francisella tularensis from China and to investigate the genetic relationships between F. tularensis strains from China and from other countries. Methods Ten strains of F....Objective To study the types of subspecies of Francisella tularensis from China and to investigate the genetic relationships between F. tularensis strains from China and from other countries. Methods Ten strains of F. tulorensis isolated from China were amplified by using typing primers Cl/C4 and RD1. On the basis of the lengths of the polymerase chain reaction （PCR） products, it was concluded that these strains of F. tularensis belonged to the same subspecies. At the same time, thefopA, tul4, and 16S rRNA genes of the I0 strains were amplified, and a three-gene based phylogenetic analysis was performed using the Molecular Evolutionary Genetics Analysis software version 4.0. Results The 10 strains of F. tularensis from China were all identified as belonging to subspecies holarctica （type B）. We found no direct relationship between the genotypes of F. tulurensis subsp. holarctica and the geographical area from where they were isolated. Conclusion The F. tularensis strains isolated from North China mainly belong to subspecies holorctica （type B）. The strains of F. tularensis subsp, holarctico from China may have evolved earlier than those from Europe and North America.展开更多
In 2013,a novel disease was detected in tilapia( Oreochromis niloticus × O.aureus) in Guangzhou,South China.To identify the causative pathogen,we conducted histological examination,bacteria isolation,and purifica...In 2013,a novel disease was detected in tilapia( Oreochromis niloticus × O.aureus) in Guangzhou,South China.To identify the causative pathogen,we conducted histological examination,bacteria isolation,and purification,and sequenced the 16 S rRNA gene of isolates.Infected fish had a large number of white granulomas in the kidney,liver,heart,and spleen.The head kidney and spleen were markedly swollen.A bacterium strain designated as gz201301 was recovered from the spleen of infected tilapia.The 16 S rRNA sequence of gz201301 revealed that it was highly similar to F.noatunensis subsp.orientalis.This is the first report of a Francisella-like infection in farmed tilapia in China.展开更多
基金supported by the National Technology Key Special Study Program of the Eleventh Five‐year Plan (No. 2008ZX10004‐010)
文摘Objective To study the types of subspecies of Francisella tularensis from China and to investigate the genetic relationships between F. tularensis strains from China and from other countries. Methods Ten strains of F. tulorensis isolated from China were amplified by using typing primers Cl/C4 and RD1. On the basis of the lengths of the polymerase chain reaction （PCR） products, it was concluded that these strains of F. tularensis belonged to the same subspecies. At the same time, thefopA, tul4, and 16S rRNA genes of the I0 strains were amplified, and a three-gene based phylogenetic analysis was performed using the Molecular Evolutionary Genetics Analysis software version 4.0. Results The 10 strains of F. tularensis from China were all identified as belonging to subspecies holarctica （type B）. We found no direct relationship between the genotypes of F. tulurensis subsp. holarctica and the geographical area from where they were isolated. Conclusion The F. tularensis strains isolated from North China mainly belong to subspecies holorctica （type B）. The strains of F. tularensis subsp, holarctico from China may have evolved earlier than those from Europe and North America.
基金Supported by the Pearl River Science&Technology Nova Program of Guangzhou City(No.2012J2200078)the Marine Fishery Science&Technology Promotion Project of Guangdong Provinces(No.A201301B06)
文摘In 2013,a novel disease was detected in tilapia( Oreochromis niloticus × O.aureus) in Guangzhou,South China.To identify the causative pathogen,we conducted histological examination,bacteria isolation,and purification,and sequenced the 16 S rRNA gene of isolates.Infected fish had a large number of white granulomas in the kidney,liver,heart,and spleen.The head kidney and spleen were markedly swollen.A bacterium strain designated as gz201301 was recovered from the spleen of infected tilapia.The 16 S rRNA sequence of gz201301 revealed that it was highly similar to F.noatunensis subsp.orientalis.This is the first report of a Francisella-like infection in farmed tilapia in China.
