Interspecies sequence differences in the Mip protein from the genus Legionella: implications for function and evolutionary relatedness

Abstract

SummaryThe nucleotide sequence of the mip genes and their inferred amino acid sequences were determined from 35 Legionella species and compared with the published sequences for L. pneumophila, L. micdadei and L. longbeachae. The sequences were 69-97% conserved at the nucleotide level and 82-99% at the amino acid level, with total conservation of amino acids determined to be associated with sites known to be involved in peptidyl prolyl cis-trans isomerase activity. No apparent difference could be determined in the arrangement of amino acids that would predict a functional difference in Mip from species associated with disease and Mip from species isolated only from the environment. Additionally, a phylogenetic comparison of the sequences with published 16S RNA sequences, using both genetic distance and maximum parsimony methods, was performed. Few relationships were apparent that were well supported by both data sets, the most robust being a clade comprising {[

Application of RNA Polymerase β-Subunit Gene ( rpoB ) Sequences for the Molecular Differentiation of Legionella Species

“…The mip gene encodes Mip, which has been reported to play a significant role in virulence (2). It has been shown that mip is useful for the discrimination of Legionella species (19,20). However, incongruences have been found between the phylogenies elucidated from the 16S rRNA gene and mip sequences (8,20).…”

“…Legionellosis is usually acquired in the community and accounts for 2 to 15% of all community-acquired pneumonia that requires hospitalization in the United States (27). So far, of the more than 40 Legionella species that have been characterized and classified by various methods (8,30), 21 have been reported to be pathogenic to humans (20,30) A classification scheme constructed by various methods can be efficiently used for the rapid and precise identification of clinical isolates in the diagnostic laboratory. One of these methods is the determination of molecular phylogenetic relationships or typing (18).…”

“…One of these methods is the determination of molecular phylogenetic relationships or typing (18). Legionella species have also been previously analyzed using 16S rRNA gene (1,6,8) and macrophage infectivity potentiator (mip) sequences (19,20). The 16S rRNA gene is by far the most widely used molecular marker to determine the phylogenetic relationships of bacteria (31).…”

Legionella drozanskii sp. nov., Legionella rowbothamii sp. nov. and Legionella fallonii sp. nov.: three unusual new Legionella species.

“…There is also serological evidence associating LLAPs with respiratory disease in humans (Rowbotham, 1993 ;Benson et al, 1995). The grouping together of members of the genus Legionella is based on phenotypic similarities and is supported by molecular techniques (Brenner et al, 1985 ; Brenner, 1986 ;Fry et al, 1991 ;Harrison & Saunders, 1994 ;Hookey, 1995 ;Benson et al, 1996 ;Hookey et al, 1996 ;Ratcliff et al, 1997Ratcliff et al, , 1998. There are few discriminatory phenotypic tests for the differentiation of Legionella species (Benson & Fields, 1998 ;Harrison & Saunders, 1994).…”

Real-Time PCR Assay Targets the 23S-5S Spacer for Direct Detection and Differentiation of Legionella spp. and Legionella pneumophila

“…(1, 7), 5S ribosomal DNA (7), 16S ribosomal DNA (11,12,14,16), and the 23S-5S spacer (15). While the mip gene was initially used as an L. pneumophila-specific marker (2), other legionellae were also found to harbor this gene (3,13). The 5S and 16S rRNA genes are such well-conserved regions that it is difficult to differentially detect L. pneumophila and other Legionella species on a real-time basis without subsequent tests (7,14) or that there is a risk of amplification of the DNAs of other than Legionella species (4).…”