title: Evidence for recombination among the alleles encoding TEM and SHV beta-lactamases.
abstract: OBJECTIVE
  The objective of this research was to determine whether recombination occurs in class A beta-lactamases.
  
  
  METHODS
  We performed chi(2) analysis of the observed and expected numbers of times that beta-lactamases from the TEM, SHV and CTX-M groups co-occurred. Additionally, we performed phylogenetic analysis to detect independent occurrences of silent mutations in bla(TEM) and bla(SHV) variants.
  
  
  RESULTS
  We found that the distribution of co-occurring bla(TEM), bla(SHV) and bla(CTX-M) alleles in clinical microbial populations is consistent with the regular occurrence of recombination among alleles within the groups. We also found that the distribution of silent mutations in bla(TEM) and bla(SHV) alleles is inconsistent with spontaneous point mutations.
  
  
  CONCLUSIONS
  Our findings indicate that recombination has an important effect on the sequence evolution and population distribution of the alleles that encode class A beta-lactamases.
authors.affiliation: School of Natural Sciences, University of California, Merced, CA, USA. mbarlow@ucmerced.edu
authors.forename: Miriam
authors.initials: M
authors.lastname: Barlow
authors.forename: Javad
authors.initials: J
authors.lastname: Fatollahi
authors.forename: Merijn
authors.initials: M
authors.lastname: Salverda
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics*; D019143:Evolution, Molecular; D006090:Gram-Negative Bacteria / Q000201:enzymology* / Q000235:genetics* / Q000302:isolation & purification; D016905:Gram-Negative Bacterial Infections / Q000382:microbiology*; D006801:Humans; D010802:Phylogeny; D011995:Recombination, Genetic; D001618:beta-Lactamases / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; D001618:beta-Lactamases