Following a change in surgical practice, we noted that the rate at which Staphylococcus lugdunensis was isolated from samples from the plastic surgery unit of our hospital increased considerably. We investigated the sources of these S. lugdunensis strains, and we found that in the case of drain colonization or surgical site infection, the strain was more likely to have come from the patient's skin bacteria when the pubic site had been shaved preoperatively. To test the hypothesis of pubic site colonization, we evaluated the prevalence of S. lugdunensis carriage among the cutaneous flora of the inguinal area. We found that 22% of 140 incoming patients carried S. lugdunensis in this area and that carriage at both inguinal folds was frequent (68% of carriers). A study of the genetic structure of the total population, including the clinical (n ‫؍‬ 18) and the commensal (n ‫؍‬ 53) strains, revealed that the diversity of the species was low and that the population was composed of two major groups that diverged at a distance of 35%. No particular characteristics made it possible to distinguish between clinical and commensal strains. Only isolates producing ␤-lactamase were homogeneous; six of the eight ␤-lactamase-positive strains displayed the same pulsed-field gel electrophoresis pattern.Staphylococcus lugdunensis is a coagulase-negative Staphylococcus (CoNS) that was first described by Freney et al. (9) in 1988 and that has the potential to be an opportunistic pathogen. S. lugdunensis is an unusually virulent CoNS and can cause many types of infection, ranging from superficial skin infections to life-threatening endocarditis. Most laboratory isolates are collected from colonized patients or patients with primary skin infections or minor postoperative wound infections. Nevertheless, S. lugdunensis has been shown to be associated with serious infections such as breast abscesses (18, 34), peritonitis (19, 28), infected joint prostheses (26, 35), osteomyelitis (22), discitis (2), septic arthritis (12), and pacemaker infections (1,3,16). Unlike S. epidermidis, which usually results in indolent subacute infections, S. lugdunensis results in acute infections, similar to S. aureus. S. lugdunensis infections typically resemble S. aureus infections in terms of the virulence of the organism and the clinical course of infection, which is often highly destructive (28, 31, 33).S. lugdunensis can act as an etiologic agent of infective endocarditis. It may infect both prosthetic and native valves (31). Patel et al. (24) found that S. lugdunensis accounted for 18% of CoNS strains causing infective endocarditis and 44% of CoNS strains causing native valve endocarditis. The mortality rate as a result of endocarditis caused by S. lugdunensis is high (7,15,31). Few studies have looked at the epidemiology and ecology of S. lugdunensis. Similar to other CoNS strains, S. lugdunensis is considered part of the resident flora of the entire surface of the human skin and mucous membranes (11). No detailed studies have been carried out on the d...

Streptococcus agalactiae UCN36 was resistant to lincomycin (MIC ‫؍‬ 16 g/ml) but susceptible to clindamycin (MIC ‫؍‬ 0.12 g/ml) and erythromycin (MIC ‫؍‬ 0.06 g/ml).

Group B streptococcus or Streptococcus agalactiae is a component of the normal flora of human mucosa and a well-known cause of invasive infection in neonates, pregnant women, and older individuals with underlying chronic illness (4, 11). Dissemination of mobile elements largely contributes to the increasing resistance to macrolides among streptococci. Mobilizable transposons are genetic elements that are smaller than conjugative transposons, can range in size from 4.7 kb (Tn5520) to 12.7 kb (Tn4555), and have been identified only in Bacteroides spp. and Clostridium spp. (2,14,16,17).In this report, we demonstrate that MTnSag1, a 1,724-bplong element that we previously identified in the clinical strain S. agalactiae UCN36 (accession number AY928180), is a new transposon that can be mobilized by the conjugative transposon Tn916 to S. agalactiae recipients (1).Sequence analysis of the MTnSag1 transposase gene. The MTnSag1 element contained two open reading frames in the same orientation, ORF1 and ORF2, with sizes of 1,038 and 495 bp, respectively. ORF2, called lnu(C), encoded a lincosamide O-nucleotidyltransferase conferring resistance to lincomycin (1). ORF1 encoded a putative protein related to the protein InsA of the insertion sequence IS1 (35% identity) and to several transposases described for Clostridium spp. (33 to 42% identity). MTnSag1 had a pair of 25-bp imperfect inverted repeats at its termini. A search for motifs and domains using the NCBI Blastp and EMBOSS helix-turn-helix programs (http://www.ncbi.nlm.nih.gov/ and http://www.bioweb.pasteur .fr) revealed the presence of potential zinc finger (ZF) and helix-Turn-helix (HTH) motifs in the N-terminal region of the MTnSag1 transposase that are characteristics of IS1 transposases (8, 15) (Fig. 1). The conserved C residues were at positions 52, 55, 75, and 78. Other conserved residues, including an aromatic amino acid (F at position 82 corresponding to W at position 39 for IS1A), were identified. A putative DDE motif was also evidenced in the C terminus of the MTnSag1 transposase. This DDE motif (D-67-D-92-E) was distantly related to the DDE motif of the IS1 members (D-56/80-D-21/ 24-E) but was in agreement with the consensus motif of known transposases and retroviral integrases (D-50/80-D33/138-E) (15). These results lead us to classify the MTnSag1 putative transposase in the IS1 family.Transferability of MTnSag1. The transferability of the MTnSag1 transposon was tested using filter mating with S. agalactiae BM132 (resistant to rifampin and fusidic acid) or BM134 (resistant to streptomycin), Enterococcus faecalis JH2-2, and Escherichia coli K-12 AG100A (1) as recipient strains. MTnSag1 was transferable from S. agalactiae UCN36 to S. agalactiae BM134 or BM132 at a frequency of (1.6 Ϯ 0.3) ϫ 10 Ϫ7 transconjugants per donor cell. No transfer to E. faecalis JH2-2 and E. coli K-12 AG100A was detected (Յ10 Ϫ9 transconjugants). Southern blot experiments revealed that six copies of MTnSag1 were present in S. agalactiae UCN36 but only one copy was present in three ...

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