A cross-sectional study was done to determine the seroprevalence of Mycoplasma penetrans in human immunodeficiency virus (HIV) type 1-seropositive and -seronegative persons recruited in France. The data were analyzed with respect to the sociodemographic, clinical, and biologic status of the patients. M. penetrans seropositivity was associated with HIV infection (18.2% of HIV-seropositive vs. 1.3% of HIV-seronegative persons were M. penetrans-seropositive; P < .001). M. penetrans infection was predominantly but not exclusively associated with homosexual practices in HIV-seropositive subjects and thus presumably sexually transmitted. M. penetrans seroprevalence increased with progression of HIV-associated disease. No association was found between M. penetrans and Kaposi's sarcoma. Thus, there is an unambiguous association between M. penetrans and HIV, particularly among homosexual persons, but its clinical significance remains to be investigated.

The nucleotide sequence of the 16s rRNA gene of Mycoplusmuflocculare was determined and was compared with the sequence of a related porcine mycoplasina, Mycoplusmu hyopneumoniae. While the overall level of DNA-DNA homology was approximately 11%, sequence alignment of the two 16s rRNA genes yielded .a homology value of more than 95%, emphasizing the highly conserved nature of the 16s rRNA gene. Multiple sequence alignments with other mollicutes indicated that M. flocculare, M. hyopneumoniue, and Mycoplusmu hyorhinis form a subcluster within the fermentans phylogroup, and this subcluster is distinct from the Mycoplasma pneumoniue phylogroup. Thus, the three mycoplasmas isolated from porcine respiratory systems exhibit phylogenetic similarities. The following three mycoplasmal species have been isolated from porcine respiratory systems: Mycoplasma hyo-pneumoniae (Mycoplasma suipneumoniae) , Mycoplasma flocculare, and Mycoplasma hyorhinis. Early work on the taxonomy of M. hyopneumoniae and M. jlocculare was reported by Rose et al. (14). M. hyopneumoniae is a recognized etiological agent of porcine mycoplasmal pneumonia, while M. hyorhinis is an agent of polyserositis and arthritis (15). M. jlocculare has not yet been implicated as an agent of naturally occurring diseases. However, antigenic cross-reactivity of M. jlocculare and M. hyopneumoniae has been recognized; there is a weaker and more variable reaction with M. hyorhinis (1). The results of DNA-DNA hybridiza-tion studies have also indicated that there is some related-ness between M. hyopneumoniae and M. flocculare (10 to 11%); in contrast, M. hyopneumoniae and M. jlocculare cross-hybridize with nonporcine mycoplasmas at levels of about 3% (17). Woese (21) and Weisburg et al. (20) have used analysis of 16s rRNA gene sequences to determine the phylogenetic and taxonomic relationships among Mollicutes genera and species, as well as between Mollicutes and bacteria. We determined the complete 16s rRNA nucleotide sequence of M. jlocculare and compared it with the previously published complete sequence of M. hyopneumoniae (19), as well as with partial sequences of several other Mollicutes, including M. hyorhinis, obtained from data banks. MATERIALS AND METHODS Culture. M. jlocculare Ms42 was obtained from M. Kobish and was propagated on Friis medium (2) to the first visible color change. Cells were harvested by centrifugation at 14,000 x g for 25 min, washed once, and either used immediately for DNA preparation or stored as a frozen pellet at-80°C until they were used. DNA was purified as described previously (5). M. jlocculare Ms42 (= ATCC 27716) was grown similarly, and its DNA was prepared. * Corresponding author. The authenticity of the strain obtained from M. Kobish was determined by comparing the DNA of this strain with DNA obtained from M. flocculare Ms42 (= ATCC 27716); identical restriction enzyme digests were observed with both EcoRI and HindIII. These patterns differed from those of M. hyopneumoniae and M. hyorhinis. Furthermore, identical banding patterns...

We investigated the relationships between a putative cofactor of HIV infection, Mycoplasma penetrans, and the evolution of HIV disease. The evolution of titers of anti-M. penetrans antibodies in 58 randomly selected HIV-seropositive adult homosexual men was investigated. The median length of follow-up was 38 months. Thirty-six individuals was investigated. The median length of follow-up was 38 months. Thirty-six individuals (62.1%) remained M. penetrans seronegative (group 0). Fourteen patients (24.1%) had consistently low antibody titers or low antibody titer(s) in at least one sample and negative test(s) in the other(s). This pattern was possibly associated with latent or earlier infection (group 1). Eight patients (13.8%) had moderate to high antibody titers for long periods, indicating an active and persistent M. penetrans infection (group 2); four patients in this group presented a serological reactivation and thus probably developed an acute infection during the study; two had a stable and moderate level of antibody throughout the study; in two patients the antibody titers decreased substantially. Interestingly, CD4 cell counts declined more rapidly in group 2 than in group 0 (medians of -4.5 versus -2.1 cells/mm3/month, p < 0.05 and -0.16 versus 0 cell percentage/month, p < 0.05), whereas there was no significant difference between groups 1 and 0 (medians of -2.0 versus -2.1 cells/mm3/month and -0.15 versus 0 cell percentage/month). In patients with serological reactivation, the viral load was higher in sera with higher M. penetrans antibody titers. These findings suggest an association between active M. penetrans infection and progression of HIV disease.

The prevalence of Mycoplasma fermentans, Mycoplasma pirum, Mycoplasma genitalium, Mycoplasma pneumoniae, Mycoplasma hominis, and Mycoplasma penetrans was investigated by using specific PCR assays with peripheral blood mononuclear cells from subjects infected or not infected with the human immunodeficiency virus (HIV). Only M. fermentans was detected in 5.8% of 154 HIV-seropositive and 11.1% of 90 HIV-seronegative subjects.

We report the cloning and characterization of the gyrA gene of the Mycoplasma hominis DNA gyrase, which was previously shown to be associated with quinolone resistance in this organism. The 2,733-bp gyrA gene encodes a protein of 911 amino acids with a calculated molecular mass of 102.5 kDa. As expected, M. hominis GyrA exhibits higher homology with the GyrA subunits of the gram-positive bacteria Clostridium acetobutylicum, Bacillus subtilis, Streptococcus pneumoniae, and Staphylococcus aureus than with its Escherichia coli counterpart. Knowing the entire sequence of the gyrA gene of M. hominis could be very useful for confirming the role of the GyrA subunit in fluoroquinolone resistance. Twenty-nine mutants of M. hominis were selected stepwise for resistance to trovafloxacin, a new potent fluoroquinolone, and their gyrA, gyrB, parC, and parE quinolone resistance-determining regions were characterized. Three rounds of selection yielded 3 first-step, 12 secondstep, and 14 third-step mutants. The first-step mutants harbored a single substitution, Glu4603Lys (E. coli coordinates), in ParE. GyrA changes, Ser833Leu, Glu873Lys, and Ala1193Glu or Val, were found only in the second round of selection. At the third step, additional substitutions, at ParC Ser80, Ser81, and Glu84 and ParE Leu440, associated with high-level resistance to fluoroquinolones, appeared. Thus, high-level resistance to trovafloxacin required three steps and was associated with alterations in both fluoroquinolone targets. According to these genetic data, in M. hominis, as in Staphylococcus aureus and Streptococcus pneumoniae, topoisomerase IV seems to be the primary target of trovafloxacin.The intracellular targets of fluoroquinolones in bacteria are considered to be the type II topoisomerases, DNA gyrase and topoisomerase IV (23). DNA gyrase is composed of two A and two B subunits, encoded by the gyrA and the gyrB genes, respectively. This tetrameric enzyme catalyzes ATP-dependent negative supercoiling of DNA. Topoisomerase IV, a C 2 E 2 tetramer encoded by the parC and parE genes, is essential for chromosome partitioning. Mutations in the quinolone resistance-determining regions (QRDRs) of GyrA and ParC mainly and GyrB and ParE less frequently have been described as the major mechanism for quinolone resistance (10,23).Mycoplasma hominis is a cause of urogenital tract infections and has been implicated in extragenital infections as well, especially in immunocompromised patients (46). We recently reported in vitro and in vivo fluoroquinolone-resistant mutants of M. hominis associated with alterations in GyrA, ParC, and ParE QRDRs (3, 5, 7). Furthermore, previous genetic studies showed that topoisomerase IV was the primary target of pefloxacin, ofloxacin, and ciprofloxacin, whereas DNA gyrase was the primary target of sparfloxacin (5,25).Concerning the target genes of fluoroquinolones in M. hominis, the gyrB, parC, and parE genes and only the QRDR sequence of gyrA have been cloned and sequenced (3, 4, 28). Here we report the cloning, sequencing, and...