Resistance of Peptostreptococcus spp. to macrolides and lincosamides: inducible and constitutive phenotypes

Reig, Milagro; Moreno, A. Vives; Baquero, Fernando

doi:10.1128/aac.36.3.662

Cited by 22 publications

(14 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…There was large variation in the numbers of isolates collected in the participating countries and therefore no analyses were performed on differences of resistance rates in separate regions. Similar resistance rates of anaerobic cocci have been reported previously [10,11], although a higher prevalence of resistance in particular to clindamycin has been observed in some studies [12][13][14]. However, in contrast to the results of some earlier investigations, no isolates resistant to metronidazole were found [10,15,16].…”

Section: Discussionsupporting

confidence: 83%

European surveillance study on antimicrobial susceptibility of Gram-positive anaerobic cocci

Brazier

Chmelař

Dubreuil

et al. 2008

International Journal of Antimicrobial Agents

View full text Add to dashboard Cite

Section: Discussionsupporting

confidence: 83%

European surveillance study on antimicrobial susceptibility of Gram-positive anaerobic cocci

Brazier

Chmelař

Dubreuil

et al. 2008

International Journal of Antimicrobial Agents

View full text Add to dashboard Cite

“…Inducible macrolide-lincosamide-streptogramin resistance has recently been described in Bacteroides species and peptostreptococci (19,33,34). These strains are resistant to high levels of erythromycin but are susceptible to clindamycin until resistance is induced.…”

Section: Discussionmentioning

confidence: 99%

Effect of CO2 on susceptibilities of anaerobes to erythromycin, azithromycin, clarithromycin, and roxithromycin

Spangler

Jacobs

Appelbaum

1994

Antimicrob Agents Chemother

View full text Add to dashboard Cite

The Oxyrase agar dilution method (Oxyrase, Inc., Mansfield, Ohio), which provides an anaerobic environment without added C02, was compared with the reference agar dilution method recommended by the National Committee for Clinical Laboratory Standards (anaerobic chamber with 10%o C02) to test the susceptibilities of 302 gram-negative and gram-positive anaerobes to erythromycin, azithromycin, clarithromycin, and roxithromycin. For erythromycin, the overall MIC for 50%6 of isolates tested (MIC50) was 0.5 p,g/ml and the MIC90 was 8.0 ,ug/ml by the Oxyrase method, whereas they were 4.0 and 64.0 ,ug/ml, respectively, under standard anaerobic conditions with CO2. At a breakpoint of 4.0 ,ug/ml, 88% of strains were susceptible to erythromycin by the Oxyrase method, whereas 63% were susceptible in the chamber. The corresponding MIC50s and MIC90s of azithromycin, clarithromycin, and roxithromycin by the Oxyrase method were 0.5 and 8.0, 0.25 and 4.0, and 0.5 and 16.0 ,ug/ml, respectively, whereas in the chamber they were 4.0 and >64.0, 2.0 and 64.0, and 2.0 and 64.0 ug/ml, respectively. At a breakpoint of 8.0 ,ug/ml for these three drugs, 89, 92, and 85% of the isolates, respectively, were susceptible by the Oxyrase method, whereas 67%, 72, and 68% of the isolates, respectively, were susceptible in the chamber. Most strains resistant to all four compounds by both methods were Bacteroides distasonis, Fusobacterium mortiferum, Fusobacterium varium and non-Clostridium perfiringens Clostridium species. Results of the study may lead to a reappraisal of the role played by macrolides and azalides in the treatment of anaerobic infections.Susceptibility testing of macrolides and azalides in the presence of CO2 leads to elevated MICs because of a C02-dependent decrease in the pH of the medium (2,3,14,35,39). Because MICs for anaerobes are determined in an atmosphere of N2, H2, and CO2 in an anaerobic chamber or anaerobic jars, it has generally been assumed that these compounds have low levels of activity against this class of organisms. However, Retsema and coworkers (35), Nachnani and coworkers (22), and Barry and Fuchs (3) have demonstrated by microdilution MIC testing that the absence of CO2 from the incubation atmosphere when testing azithromycin and erythromycin leads to lower MICs for aerobic as well as anaerobic organisms. Recently, we have developed an agar dilution method using Oxyrase to remove 02 from atmospheric air, and have demonstrated that 94 gram-negative and -positive anaerobes have significantly increased susceptibilities to azithromycin and erythromycin (39).In the current study, the latter findings have been extended by comparing the susceptibilities to erythromycin, azithromycin, clarithromycin, and roxithromycin of 302 anaerobes (170 gram-negative, 132 gram-positive organisms) by the Oxyrase agar dilution technique and agar dilution inside a chamber with CO2. MATERIALS AND METHODSBacterial strains. The organisms-used in the present study (see Table 1) were all clinical strains isolated within 4 years of the stu...

show abstract

“…The rates of the 158 erythromycin-resistant strains isolated in this period for which erythromycin MICs were 8, 16, 32, 64, 128, and Ͼ128 g/ml were 13.3, 7.6, 2.5, 3.2, 5.7, and 67.7%, respectively. In 1992, we showed that both inducible and constitutive macrolide-lincosamide-streptogramin B (MLS) resistance phenotypes occurred in Peptostreptoccus, thus indicating the involvement of an erm mediated mechanism (11). The fact that these phenotypes were found among different Peptostreptococcus species suggests that erm genes are not only common but also circulate among species of this bacterial genus.…”

mentioning

confidence: 90%

Macrolide Resistance in Peptostreptococcus spp. Mediated by ermTR : Possible Source of Macrolide-Lincosamide-Streptogramin B Resistance in Streptococcus pyogenes

Reig

Galán

Baquero

et al. 2001

Antimicrob Agents Chemother

View full text Add to dashboard Cite

Eighty percent (21 of 26) of macrolide-resistant Peptostreptococcus strains studied harbored the ermTR gene. This methyltransferase gene is also the most frequently found gene among macrolide-lincosamide-streptogramin B-resistant Streptococcus pyogenes strains. Transfer of the ermTR gene from Peptostreptococcus magnus to macrolide-susceptible S. pyogenes strains indicates that this resistance determinant may circulate among gram-positive aerobic and anaerobic species of the oropharyngeal bacterial flora.Resistance to macrolides in Peptostreptococcus species is not a rare event. In our hospital, susceptibility of clinical isolates has been routinely studied using the broth microdilution technique (8); the E-test (AB Biodisk, Solna, Sweden) was used in strains with inadequate growth in liquid medium. Our rates of erythromycin resistance (MIC Ն 8 g/ml) in the last 6 years (1994 to 1999) ranged from 30.3 to 61.0%. The rates of the 158 erythromycin-resistant strains isolated in this period for which erythromycin MICs were 8, 16, 32, 64, 128, and Ͼ128 g/ml were 13.3, 7.6, 2.5, 3.2, 5.7, and 67.7%, respectively. In 1992, we showed that both inducible and constitutive macrolide-lincosamide-streptogramin B (MLS) resistance phenotypes occurred in Peptostreptoccus, thus indicating the involvement of an erm mediated mechanism (11). The fact that these phenotypes were found among different Peptostreptococcus species suggests that erm genes are not only common but also circulate among species of this bacterial genus. In this work, we present evidence that MLS resistance in Peptostreptococcus is determined by erm genes, most frequently by ermTR, and that these genes can be conjugatively transferred. As the ermTR determinant is the erm gene most common among Streptococcus pyogenes isolates, we hypothesized that Peptostreptococcus could serve as a potential source of macrolide resistance in group A beta-hemolytic streptococci. Twenty-six high-level macrolide-resistant (erythromycin MIC of Ն32 g/ml) clinical strains of different species in the Peptostreptococcus genus (eight of Peptostreptococcus magnus, six of Peptostreptococcus asaccharolyticus, five of Peptostreptococcus spp., three of Peptostreptococcus anaerobius, three of Peptostreptococcus prevotii, and one of Peptostreptococcus tetradius) were studied. As deduced from their erythromycin and clindamycin MICs and the double-disk test (in situ induction of resistance on solid medium with erythromycin disks apposed to clindamycin disks) (14, 17), constitutive and inducible resistance phenotypes were found in 16 and 10 strains, respectively.

show abstract

Resistance of Peptostreptococcus spp. to macrolides and lincosamides: inducible and constitutive phenotypes

Cited by 22 publications

References 11 publications

European surveillance study on antimicrobial susceptibility of Gram-positive anaerobic cocci

European surveillance study on antimicrobial susceptibility of Gram-positive anaerobic cocci

Effect of CO2 on susceptibilities of anaerobes to erythromycin, azithromycin, clarithromycin, and roxithromycin

Macrolide Resistance in Peptostreptococcus spp. Mediated by ermTR : Possible Source of Macrolide-Lincosamide-Streptogramin B Resistance in Streptococcus pyogenes

Contact Info

Product

Resources

About