Cytomegalovirus strain diversity in seropositive women

Abstract

Infection and reinfection with multiple cytomegalovirus (CMV) strains have been shown to occur in immunocompromised individuals, sexually transmitted disease clinic attendees, and children attending day care centers. To characterize the CMV diversity in healthy seropositive individuals, 16 CMV PCR-positive specimens from 113 seropositive women were analyzed for glycoprotein gN and gB genotypes by cloning, followed by nucleotide sequencing of the plasmid DNA and/or restriction fragment length polymorphism (RFLP). The results showed that most (93.7%) of the PCR-positive specimens contained multiple gN and/or gB genomic variants, suggesting that the majority of women were infected with more than one virus strain. The results also showed that the RFLP technique might not be sufficiently sensitive to detect all of the genomic variants present in a sample.

FIG. 1.

Alignment of gN (UL73) nucleotide sequences with only part of the variable region shown. Dots indicate identity, and dashes indicate deletions. Strains are grouped by comparing the sequences of the recombinants with the prototypic gN genotypes previously described (11). The sequences are listed with the unique study subject identifiers. Prototypical laboratory-adapted strains are in parentheses. The nucleotide sequences were aligned with that of AD169 (gN1 prototype) with the Vector NTI Advance software package V.10 (Invitrogen, Carlsbad, CA) and displayed as a printable output by the BOXSHADE server (http://www.ch.embnet.org/software/BOX_form.html).

FIG. 2.

Alignment of representative gB (UL55) sequences with the prototypes (only part of the variable region of gB is shown). Dots indicate identity, and dashes indicate deletions. Strains are grouped by comparing the sequences of the recombinants with the prototypic gB genotypes previously described (9). The sequences are listed with the unique study subject identifiers. The nucleotide sequences were aligned with the gB1 prototype with the Vector NTI Advance software package V.10 (Invitrogen, Carlsbad, CA) and displayed as a printable output by the BOXSHADE server (http://www.ch.embnet.org/software/BOX_form.html).

FIG. 3.

Relative frequencies of CMV gN and gB genotypes in urine and blood samples from CMV-seropositive women.