Evidence for recombination among the alleles encoding TEM and SHV beta-lactamases.
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.
Barlow
Miriam
M
School of Natural Sciences, University of California, Merced, CA, USA. mbarlow@ucmerced.edu
Fatollahi
Javad
J
Salverda
Merijn
M
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*
D001426:Bacterial Proteins; D001618:beta-Lactamases