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PubMed2002

Genotypic diversity of clinical Actinomyces species: phenotype, source, and disease correlation among genospecies.

We determined the frequency distribution of Actinomyces spp. recovered in a routine clinical laboratory and investigated the clinical significance of accurate identification to the species level. We identified 92 clinical strains of Actinomyces, including 13 strains in the related Arcanobacterium-Actinobaculum taxon, by 16S rRNA gene sequence analysis and recorded their biotypes, sources, and disease associations. The clinical isolates clustered into 21 genogroups. Twelve genogroups (74 strains) correlated with a known species, and nine genogroups (17 strains) did not. The individual species had source and disease correlates. Actinomyces turicensis was the most frequently isolated species and was associated with genitourinary tract specimens, often with other organisms and rarely with inflammatory cells. Actinomyces radingae was most often associated with serious, chronic soft tissue abscesses of the breast, chest, and back. Actinomyces europaeus was associated with skin abscesses of the neck and genital areas. Actinomyces lingnae, Actinomyces gravenitzii, Actinomyces odontolyticus, and Actinomyces meyeri were isolated from respiratory specimens, while A. odontolyticus-like strains were isolated from diverse sources. Several of the species were commonly coisolated with a particular bacterium: Actinomyces israelii was the only Actinomyces spp. coisolated with Actinobacillus (Haemophilus) actinomycetemcomitans; Actinomyces meyeri was coisolated with Peptostreptococcus micros and was the only species other than A. israelii associated with sulfur granules in histological specimens. Most genogroups had consistent biotypes (as determined with the RapID ANA II system); however, strains were misidentified, and many codes were not in the database. One biotype was common to several genogroups, with all of these isolates being identified as A. meyeri. Despite the recent description of new Actinomyces spp., 19% of the isolates recovered in our routine laboratory belonged to novel genospecies. One novel group with three strains, Actinomyces houstonensis sp. nov., was phenotypically similar to A. meyeri and A. turicensis but was genotypically closest to Actinomyces neuii. A. houstonensis sp. nov. was associated with abscesses. Our data documented consistent site and disease associations for 21 genogroups of Actinomyces spp. that provide greater insights into appropriate treatments. However, we also demonstrated a complexity within the Actinomyces genus that compromises the biochemical identification of Actinomyces that can be performed in most clinical laboratories. It is our hope that this large group of well-defined strains will be used to find a simple and accurate biochemical test for differentiation of the species in routine laboratories.

Actinomyces↗
PubMed1983

New Actinomyces and Streptococcus coaggregation groups among human oral isolates from the same site.

The coaggregation properties of recent human oral streptococcal and actinomyces isolates from the same site were determined and compared with the coaggregation properties of well-characterized stock strains of these two kinds of bacteria. Streptococcus sanguis, Actinomyces viscosus, Actinomyces naeslundii, and phenotypically similar strains of actinomyces were isolated from subgingival samples from periodontally healthy older individuals, from persons participating in an experimental gingivitis study, and from young persons with localized (juvenile) and generalized (severe) periodontitis. All 34 of the actinomyces isolates coaggregated with reagent strains of S. sanguis that represented the four streptococcal coaggregation groups. Most of these actinomyces exhibited coaggregations identical to those of actinomyces stock strains. However, five isolates of an Actinomyces WVa-963 serovar exhibited a coaggregation pattern different from any previously described, which was used to define coaggregation group F. All coaggregations with members of this group were lactose inhibitable. Only 57% (8 of 14) of the recent S. sanguis isolates coaggregated with actinomyces reagent strains. But when the nonreactive streptococcal isolates were tested for their ability to coaggregate with actinomyces from the same patient, a new, highly specific coaggregation pattern (group 6) for S. sanguis was discovered. Coaggregation of these streptococci was observed only with certain isolates of A. naeslundii (members of coaggregation group D) from the same site, and none of these coaggregations were inhibited by lactose. Subsequent testing revealed that streptococci of group 6 coaggregated with group D actinomyces from other sources but not with actinomyces of other coaggregation groups. Only two strains of S. sanguis failed to coaggregate with any strain of actinomyces tested. These results indicate that nearly all fresh isolates of these species obtained from both diseased and healthy sites exhibit specific, nonrandom patterns of coaggregation and suggest the widespread occurrence of in vivo cell-to-cell recognition between oral actinomyces and streptococci.

Actinomyces↗
PubMed1999

Identification of oral Actinomyces species using DNA probes.

Oral Actinomyces comprise a major segment of both the supra- and subgingival microbiota; however, little is known about the distribution of individual species in different sites or clinical conditions. The purpose of the present investigation was to develop DNA probes for suggested species and genotypes of oral Actinomyces. Whole genomic DNA probes to 12 human oral species and/or serotypes were labeled with digoxigenin and used to seek cross-reactions among the taxa using the checkerboard DNA-DNA hybridization assay. The Actinomyces formed three distinct groups: 1) Actinomyces georgiae, Actinomyces meyeri and Actinomyces odontolyticus serotypes I and II; 2) Actinomyces viscosus and Actinomyces naeslundii serotypes I, II, III and WVA 963; and 3) Actinomyces gerencseriae and Actinomyces israelii. Cross-reactions among taxa were detected and minimized by increasing the temperature of the post-hybridization high-stringency wash to 80 degrees C. Despite the elevation in high stringency wash temperature, cross-reactions among strains of the A. naeslundii/A. viscosus group persisted. Probes for two of the three currently recognized genospecies in this group were prepared by removing the DNA in common between cross-reacting species using subtraction hybridization and polymerase chain reaction. Nine species and genospecies could be clearly separated by a combination of whole genomic and subtraction hybridization probes and by increasing the high-stringency wash temperature. A total of 195 fresh isolates of Actinomyces were grouped in a blind study using DNA probes and separately by SDS-PAGE protein profiles. Concordance between the two methods was 97.3%. The probes and hybridization conditions were tested for their ability to detect the Actinomyces species and genospecies in samples of supragingival and subgingival plaque from periodontitis subjects using checkerboard DNA-DNA hybridization. The probes detected the species in samples of supragingival and subgingival plaque. We concluded that whole genomic and subtraction hybridization DNA probes facilitate the detection and enumeration of species and genospecies of Actinomyces in plaque samples.

Actinomyces↗
PubMed2005

Antimicrobial susceptibility testing of Actinomyces species with 12 antimicrobial agents.

OBJECTIVE: This study was conducted to assess the susceptibility of human clinical isolates of Actinomyces species to 12 antimicrobial agents. METHODS: Human clinical isolates of Actinomyces spp. were collected from stored collections held at the Microbiology Department, Edinburgh University, Anaerobe Reference Laboratory, Cardiff, Glasgow Dental Hospital and Glasgow Royal Infirmary. Each isolate was identified by restriction analysis of amplified 16S ribosomal DNA. MICs of 12 antibiotics comprising benzyl penicillin, amoxicillin, ceftriaxone, linezolid, tetracycline, deoxycycline, clindamycin, erythromycin, clarithromycin, ciprofloxacin, meropenem and piperacillin/tazobactam for 87 strains of Actinomyces species were obtained by Etest methodology. RESULTS: The Actinomyces species identified for this study comprised: Actinomyces israelii, Actinomyces gerencseriae, Actinomyces turicensis, Actinomyces funkei, Actinomyces graevenitzii and Actinomyces europaeus. All isolates were susceptible to penicillin and amoxicillin. All but one strain of A. turicensis was susceptible to linezolid. A number of A. europaeus and A. graevenitzii isolates were resistant to ceftriaxone and piperacillin/tazobactam. A number of isolates of A. turicensis and A. europaeus also demonstrated resistance to erythromycin. All Actinomyces species tested appeared resistant to ciprofloxacin. CONCLUSIONS: Actinomyces species appear to be susceptible to a wide range of beta-lactam agents and these, when combined with beta-lactamase inhibitors, should be regarded as agents of first choice. Ciprofloxacin performed poorly. Tetracyclines also demonstrated poor performance. This is the first study of antimicrobial susceptibilities for a number of accurately identified clinical isolates of Actinomyces spp. There are a number of species differences in susceptibility profiles to the antimicrobials tested, suggesting that accurate identification and speciation may have an impact on clinical outcome.

Actinomyces↗
PubMed2001

Actinomyces suimastitidis sp. nov., isolated from pig mastitis.

An unusual Actinomyces-like bacterium originating from a pig with mastitis was subjected to a polyphasic taxonomic investigation. The morphological and biochemical characteristics of the organism were consistent with its preliminary assignment to the genus Actinomyces but it did not appear to correspond to any recognized species. PAGE analysis of whole-cell proteins confirmed the phenotypic distinctiveness of the bacterium and 16S rRNA gene sequence analysis demonstrated that it represents a hitherto unknown sub-line amongst a cluster of Actinomyces species which embraces Actinomyces canis, Actinomyces georgiae, Actinomyces hyovaginalis, Actinomyces meyeri, Actinomyces odontolyticus, Actinomyces radingae and Actinomyces turicensis. Based on phylogenetic and phenotypic evidence, it is proposed that the unknown bacterium isolated from pig mastitis be classified as Actinomyces suimastitidis sp. nov. The type strain of Actinomyces suimastitidis is CCUG 39279T (= CIP 106779T).

Actinomyces↗
PubMed2000

Actinomyces canis sp. nov., isolated from dogs.

Three strains of a previously undescribed catalase-positive Actinomyces-like bacterium were isolated from dogs. Biochemical testing and PAGE analysis of whole-cell proteins indicated that the strains were phenotypically highly related to each other but different from previously described Actinomyces and Arcanobacterium species. Sequencing of 16S rRNA showed that the unknown bacterium represents a new subline within a cluster of species which includes Actinomyces hyovaginalis, Actinomyces georgiae, Actinomyces meyeri, Actinomyces odontolyticus, Actinomyces radingae and Actinomyces turicensis. On the basis of phenotypic evidence and 16S rRNA sequence divergence levels (greater than 5% with recognized Actinomyces species) it is proposed that the unknown strains from canine sources be classified as a new species with the name Actinomyces canis sp. nov. The type strain of Actinomyces canis is CCUG 41706T (= CIP 106351T).

Actinomyces↗
PubMed2005

Characterization of Actinomyces species isolated from failed dental implant fixtures.

In the oral cavity, Actinomyces form a fundamental component of the indigenous microflora, being among initial colonizers in polymicrobial biofilms. However, some differences may exist between different species in terms of their attachment not only to teeth but also to biomaterials. In this study we investigated the distribution of Actinomyces in 33 dental implant fixtures explanted from 17 patients. The identification was based on comprehensive biochemical testing and gas-liquid chromatography and when needed, 16S rRNA sequencing. Actinomyces was the most prevalent bacterial genus in these failed implants, colonizing 31/33 (94%) of the fixtures. Proportions of Actinomyces growth of the total bacterial growth in the Actinomyces-positive fixtures varied from 0.01% up to 75%. A. odontolyticus was the most common Actinomyces finding, present in 26/31 (84%) Actinomyces-positive fixtures. Actinomyces naeslundii and A. viscosus were both detected in 10/31 (32%) and A. israelii in 7/31 (23%) fixtures. Other Actinomyces species, including A. georgiae, A. gerencseriae and A. graevenitzii, were detected less frequently. Our results suggest that Actinomyces species are frequent colonizers on failed implant surfaces, where A. odontolyticus was the far most prominent Actinomyces species.

Journal Article↗
PubMed1997

Phylogenetic analysis of the genus Actinomyces based on 16S rRNA gene sequences: description of Arcanobacterium phocae sp. nov., Arcanobacterium bernardiae comb. nov., and Arcanobacterium pyogenes comb. nov.

A systematic phylogenetic analysis of the genus Actinomyces was performed. The 16S rRNA gene sequences of 13 Actinomyces species, an unnamed Actinomyces strain (ATCC 49338), and an Actinomyces-like isolate from sea mammals were determined. Comparative sequence analysis with closely related taxa revealed phylogenetic diversity and internal structure within the genus Actinomyces. In addition, some members of other genera (viz., the genera Arcanobacterium, Mobiluncus, and Rothia) were shown to be phylogenetically intermixed with the Actinomyces species. It was evident from both distance and tree topology considerations that the genus Actinomyces is in urgent need of taxonomic revision and requires subdivision into several genera. Based on the results of the present study it is proposed that Actinomyces bernardiae and Actinomyces pyogenes be assigned to the genus Arcanobacterium as Arcanobacterium bernardiae comb. nov. and Arcanobacterium pyogenes comb. nov., respectively. In addition, a new species, Arcanobacterium phocae, is proposed for Actinomyces-like bacteria isolated from seals.

Actinomycetaceae↗
PubMedDate not supplied

Actinomyces spp. in supragingival plaque of ethnic Chinese preschool children with and without active dental caries.

Very limited molecular epidemiological data are available on the role of Actinomyces spp. in the pathogenesis of caries in the primary dentition. Therefore, we investigated their distribution in supragingival plaque of ethnic Chinese preschool children from Singapore and Hong Kong, either with or without active caries. Plaque samples were taken from intact interproximal enamel areas using dental floss. Bacterial genomic DNA of each sample was extracted and variable regions of 16S ribosomal DNA amplified and labelled with digoxigenin. Oligonucleotide probes specific for Actinomyces bovis, Actinomyces gerencseriae, Actinomyces israelii, Actinomyces meyeri, Actinomyces odontolyticus, catalase-negative Actinomyces naeslundii (genospecies 1 and 2) and catalase-positive Actinomyces naeslundii genospecies 2 (previously Actinomyces viscosus serotype II) were used to detect these species using Southern hybridization with a Minislot and Miniblotter system. A. odontolyticus, A. gerencseriae and A. meyeri were detected with similar frequency in both Singapore and Hong Kong samples or in those with and without active caries. However, the prevalence of A. naeslundii was significantly different in the two locales (p<0.05). A. odontolyticus (88.7%), A. gerencseriae (56.6%) and A. naeslundii (50.9%) were detected in a majority of the samples and the positive hybridization signals of A. gerencseriae in the caries-active group were stronger than from the caries-free group. A. bovis and A. israelii were undetectable in any of the samples. These data imply that A. odontolyticus, A. naeslundii and A. gerencseriae may play an important role in supragingival plaque formation on primary teeth in ethnic Chinese, with others such as A. meyeri contributing.

Actinomyces↗
PubMed2005

Actinomyces in cervical smears of women using the intrauterine device in Singapore.

OBJECTIVES: Reproductive tract actinomyces have been associated with the use of intrauterine contraceptive device (IUCD). Thus, there is a need to evaluate the prevalence of colonization with Actinomyces israelii in a cohort of Singaporean women using an IUCD. Second, the occurrence of actinomycosis in colonized women and the clinical need to remove the IUCD and/or possibly the need to treat asymptomatic carriers with antibiotics were evaluated. METHODS: The study population consisted of 1,108 IUCD users attending the Fertility Control Clinic, National University Hospital, Singapore. RESULTS: In our study, the prevalence of actinomyces-positive cervical smears among IUCD users was 13.7%; the incidence of actinomyces-positive smears was similar with Copper T (34.2%), Multiload (32.9%) and Nova T (32.9%) IUCDs. We found no association with the duration of use of IUCD and actinomyces infection. In our study, 150 out of 152 (98.7%) IUCD users with actinomyces-positive smears were asymptomatic, and only 2 out of 152 (1.3%) who had actinomyces-positive cervical smears developed pelvic inflammatory disease at 6 months. CONCLUSIONS: Our study suggests that removal of the IUCD in asymptomatic women with actinomyces-positive cervical smear is not necessary. Moreover, we suggest that asymptomatic carriers of actinomyces do not require preemptive antibiotic treatment.

Actinomyces↗
PubMed2005

Actinomyces in infected osteoradionecrosis--underestimated?

Infected osteoradionecrosis (IORN) is a severe complication of radiation therapy for head and neck cancer. Infected osteoradionecrosis can lead to fracture and often requires subsequent jaw resection. It is known that irradiated bone is highly susceptible to infections, mainly with Candida species and cariogenic bacteria. Only very few data exist on Actinomyces in IORN. The study population consisted of 31 patients (7 female, 24 male; median age, 58.3 years). All patients exhibited clinical and radiological signs of IORN (infection, mucosa or skin fistula, and sequestrated bone). To detect Actinomyces colonies, histological examination was performed using several staining procedures (hematoxylin-eosin, Gram, Grocott, periodic acid-Schiff). In addition, a semi-nested polymerase chain reaction (PCR) approach was designed targeting the 16S ribosomal RNA gene. We found prominent Actinomyces colonies in 20 (64.5%) of 31 patients. Most of these lesions were localized in the mandible (16/20). Most interestingly, Actinomyces were almost exclusively found attached to the necrotic bone. PCR testing confirmed the presence of Actinomyces-specific DNA sequences (Actinomyces israelii). We show that Actinomyces is considerably more frequent in IORN than previously demonstrated. We suggest that these organisms are involved in the chronic, nonhealing inflammatory processes and the purulent discharge, which are known as characteristics of IORN. It remains to be investigated whether Actinomyces could be involved in the osteolytic mechanisms. From the histopathologic perspective, detection of Actinomyces is important because these bacteria have been shown to be associated with prolonged treatment duration.

Actinomyces↗
PubMed1997

Transfection of Actinomyces spp. by genomic DNA of bacteriophages from human dental plaque.

Bacteriophages that produced turbid or clear zones of lysis in strains of Actinomyces were isolated from 22 of 124 samples of fresh human dental plaque. All human and nonhuman strains of Actinomyces viscosus or Actinomyces naeslundii tested in this study were sensitive to infection by one or more of these phages. In contrast, none of the Actinomyces odontolyticus, Actinomyces israelii, or Actinomyces bovis strains tested were susceptible. Results of restriction endonuclease analyses indicated that the genomes of these phages consisted of double-stranded DNA molecules ranging in size between 16 and 60 kbp. Sequence homology under hybridization conditions of high stringency was observed among a few of the isolated phages. A lysogenized isolate of A. viscosus MG-1 was obtained following infection with a temperate phage, designated phi 225. Results of Southern blot analyses indicated that phi 225 replicated as a plasmid in the lysogenized strain. Genomic DNA from several lytic phages was used to establish conditions for transfection by electroporation of strains of Actinomyces spp. Efficiencies of DNA transfer ranged from 10(2) to 10(5) plaque-forming units per microgram of DNA were obtained under optimal transfection conditions. The results of these studies demonstrate that transfer of genetic information in Actinomyces spp. can be achieved by transfection.

Actinomyces↗
PubMed1999

Actinomyces bowdenii sp. nov., isolated from canine and feline clinical specimens.

Four strains of a previously undescribed Actinomyces-like bacterium were isolated from canine and feline clinical specimens. Phenotypic studies indicated the strains were members of the genus Actinomyces, and most closely resembled Actinomyces viscosus serotype I and Actinomyces slackii. Comparative 16S rRNA gene sequencing studies demonstrated the unknown bacterium constitutes a new subline within a group of Actinomyces species, which includes Actinomyces bovis, the type species of the genus. Based on phylogenetic and phenotypic evidence it is proposed that the unknown bacterium be classified as Actinomyces bowdenii sp. nov. The type strain of Actinomyces bowdenii is CCUG 37421T.

Actinomyces↗
PubMed1985

Isolation of Actinomyces bacteriophage from human dental plaque.

Human dental plaque samples were screened for the presence of bacteriophage for Actinomyces viscosus and Streptococcus sanguis. None of the 336 samples yielded phage for S. sanguis, but 10 contained virulent actinomyces phage. A high host cell specificity was observed in that one phage isolate infected only A. viscosus T14V, eight phage isolates infected only A. viscosus MG-1, and one infected both strains. None was capable of productively infecting various other actinomyces strains that represented the six actinomyces coaggregation groups. Because phage-containing samples occurred randomly in this survey, no correlation between the individual collecting the samples, dental clinic, or type of patient and the presence of phage in the sample was noted. Examination of one of the samples that yielded phage for the presence of a natural host strain for that particular phage resulted in the isolation of two strains which were identified as A. viscosus serotype II and Actinomyces naeslundii serotype I. This is the first report of an A. naeslundii host strain and actinomyces bacteriophage of human dental plaque origin. The finding of both phage and host strains in the same dental plaque sample along with the observation of high host cell specificity by these phage provide indicators that support an active role for actinomyces bacteriophage in oral microbial ecology. The use of these freshly isolated phage as probes to study actinomyces coaggregation properties is discussed.

Actinomyces↗
PubMed1990

Cellular coaggregation of oral Streptococcus milleri with actinomyces.

Oral isolates of Streptococcus milleri were examined for their ability to coaggregate with actinomyces. Of the 68 S. milleri strains tested, including 3 reference strains, 40 strains coaggregated with Actinomyces naeslundii WVU45 (actinomyces coaggregation group B) and 36 strains coaggregated with Actinomyces viscosus T14V (actinomyces coaggregation group A). All S. milleri strains of serotypes b (4 strains), e (2 strains), and f (24 strains) coaggregated with both of the actinomyces. The coaggregation reactions between the S. milleri cells and A. naeslundii WVU45 cells were optimal at about pH 7.0 and were Ca2+ or Mg2+ dependent, but they were not inhibited by the presence of simple sugars or amino sugars, including lactose (up to 0.5 M). Treatment of the S. milleri cells with heat (100 degrees C, 3 min) or proteases (trypsin, 1.0 mg/ml; pronase, 0.25 mg/ml; 37 degrees C; 3 h) and of the actinomyces cells with periodate (0.01 M, 4 degrees C, 16 h) destroyed their coaggregating abilities. The coaggregations between cells of the S. milleri strains, we well as cells of the Streptococcus sanguis H1 (reference strain for streptococcus coaggregation group 2) and the actinomyces strains (WVU45 and T14V), were inhibited by AFH1 (a carbohydrate receptor on T14V cells for a lectin on H1 cells). These interactions were also inhibited by anti-AFH1 immunoglobulin G (IgG) and by anti-b, anti-e, and anti-f S. milleri IgG or anti-f IgG Fab fragments. These results suggest that S. milleri, at least strains of serotypes b, e, and f, belongs to streptococcus coaggregation group 2.

Actinomyces↗
PubMed2004

[Effect of metabolic substances of oral Actinomyces on Candida albicans].

Actinomyces naeslundii, Actinomyces viscosus and Candida albicans are associated with root cavity. The aim of this study was to determine, in vitro, the effect produced by the metabolic substances elaborated by Actinomyces naeslundii and Actinomyces viscosus on Candida albicans. The strains were isolated of saliva. There were used the double plaque diffusion method (DPDM) and the method of radial diffusion (MRD). The effect of the time of incubation and of different concentrations of metabolic substances elaborated by Actinomyces naeslundii and Actinomyces viscosus on the kinetics of growth of C. albicans were studied. Later, the nature of the substances produced by the two strains of Actinomyces was determined. It was found that there was no inhibition of the growth of C. albicans by A. naeslundii and A. viscosus in the DPDM and the MRD. There was stimulation of the growth of C. albicans by the two strains of Actinomyces when the DPDM was used. In the MRD the results were negative. Metabolic substances produced by both species stimulated the growth of C. albicans in low concentrations but at high concentrations inhibition was observed. The best concentration of the stimulating factor, a protein substance stable to 70 degrees C, corresponds to a dilution of 1/80. The inhibition of the growth of C. albicans was produced by the decrease of the pH, the higher effect being obtained with the dilution 1/5. The metabolic substances produced by A. naeslundii and A. viscosus can have both inhibitory and stimulant effects on C. albicans, according to their concentration. These metabolic interactions would condition the proportion of C. albicans in the oral microbial ecosystems.

Actinomyces↗
PubMed2001

Actinomyces funkei sp. nov., isolated from human clinical specimens.

Three strains of a previously undescribed Actinomyces-like bacterium were isolated from human clinical specimens. Phenotypic studies indicated that the strains were members of the genus Actinomyces and were presumptively identified as Actinomyces turicensis. Comparative 16S rRNA gene sequencing studies showed that although the bacterium is phylogenetically closely related to Actinomyces turicensis, it nevertheless constitutes a new sub-line within the genus Actinomyces. Based on phenotypic and molecular chemical and molecular genetic evidence, it is proposed that the unknown Actinomyces-like bacterium from human clinical specimens be classified as Actinomyces funkei sp. nov. The type strain of Actinomyces funkei is CCUG 42773T (= CIP 106713T).

Actinomycetales↗
PubMed1983

Factors associated with actinomyces-like organisms on Papanicolaou smear in users of intrauterine contraceptive devices.

To determine the factors associated with the presence of actinomyces-like organisms on cervicovaginal Papanicolaou smears in users of the intrauterine contraceptive device (IUD), we carried out a case-control study. Among about 80,000 Papanicolaou smears examined in one year in a large cytology laboratory, actinomyces-like organisms were identified on 107 smears; all but three smears were from IUD users. Compared with IUD users who did not have actinomyces-like organisms on Papanicolaou smears, those with actinomyces-like organisms had used the IUD for more years. An increased risk of actinomyces-like organisms on Papanicolaou smear was not apparent until 7 years of IUD use, however. No significant association of actinomyces-like organisms with the type of IUD was found after controlling for differences in duration of use between users of various IUDs. The percentage of women reporting gynecologic symptoms (vaginal discharge, pelvic pain, abnormal bleeding) also did not differ significantly between IUD users with and without actinomyces-like organisms on Papanicolaou smear (p = 0.5).

Actinomyces↗