Analysis of the prophages carried by human infecting isolates provides new insight into the evolution of Group B Streptococcus species

OBJECTIVES

Group B Streptococcus (GBS) emerged in the 1970s as a major cause of neonatal infections, and has been increasingly associated with infections in adults since the 1990s. Prophages have been suspected to have driven these epidemiological trends. We have characterized the prophages harboured by 275 human GBS isolates belonging to the major lineages.

METHODS

We applied whole genome sequencing (WGS) to 14 isolates representative of the diversity within GBS species, located and identified their prophages. Using prediction tools, we searched for prophage elements potentially involved with the ability of GBS to infect humans. Using the data obtained by WGS, we designed a PCR-based tool and studied the prophage content of 275 isolates.

RESULTS

WGS of the 14 isolates revealed 22 prophages (i) distributed into six groups (A-F), (ii) similar to phages and prophages from GBS and non-GBS streptococci recovered from livestock, and (iii) carrying genes encoding factors previously associated with host adaptation and virulence. PCR-based detection of prophages revealed the presence of at least one prophage in 72.4% of the 275 isolates and a significant association between neonatal infecting isolates and prophages C, and between adult infecting isolates and prophages A.

CONCLUSIONS

Our results suggest that prophages (possibly animal-associated) have conditioned bacterial adaptation and ability to cause infections in neonates and adults, and support a role of lysogeny with the emergence of GBS as a pathogen in human.

Blood Pressure Cuff as a Potential Vector of Pathogenic Microorganisms A Prospective Study in a Teaching Hospital

Objective.

To investigate the potential role of blood pressure (BP) cuffs in the spread of bacterial infections in hospitals.

Design.

A comprehensive, prospective study quantitatively and qualitatively evaluating the bacterial contamination on BP cuffs of 203 sphygmomanometers in use in 18 hospital units from January through March 2003.

Setting.

A university hospital with surgical, medical, and pediatric units.

Results.

A level of contamination reaching 100 or more colony-forming units per 25 cm2was observed on 92 (45%) of inner sides and 46 (23%) of outer sides of 203 cuffs. The highest rates of contamination occurred on the inner side of BP cuffs kept in intensive care units (ICUs) (20 [83%] of 24) or on nurses' trolleys (27 [77%] of 35). None of the 18 BP cuffs presumed to be clean (ie, those that had not been used since the last decontamination procedure) had a high level of contamination. Potentially pathogenic microorganisms were isolated from 27 (13%) of the 203 BP cuffs: 20 of these microorganisms wereStaphylococcus aureus, including 9 methicillin-resistant strains. The highest rates of contamination with potentially pathogenic microorganisms were observed on cuffs used in ICUs and those kept on nurses' trolleys. For 4 patients with a personal sphygmomanometer, a genetic link was found between the strains isolated from the BP cuffs and the strains isolated from the patients.

Conclusions.

The results of this survey highlight the importance of recognizing BP cuffs as potential vectors of pathogenic bacteria among patients and as a source of reinfection when dedicated to a single patient, emphasizing the urgent need for validated procedures for their use and maintenance.

[Microbiologic basis of diagnosis and treatment of pelvic inflammatory disease]

Pelvic inflammatory disease (PID) is caused by a large spectrum of micro-organisms. However, the microbiological cause is unknown in approximately half of cases according to varying series. In the context of sexually transmitted disease (STD), the most frequently identified microorganisms causing PID are Neisseria gonorrhoeae, Chlamydia trachomatis and Mycoplasma genitalium. In such cases, bacterial vaginosis and Trichomonas vaginalis are frequently associated. In case of complicated PID or when PID is the consequence of delivery, abortion, intra-uterine procedure, bacteria that come from vaginal carriage may be encountered: Enterobacteriacae, Staphylococcus spp., Streptococcus spp., anaerobes. Mycopslama hominis as well as Ureaplasma urealyticum may also be found in this context. The microbiological diagnosis may be performed on samples of vaginal liquid, endocervix or, when available, surgical specimens. The microbiological diagnostic procedures that are used to identify these microrgansims are reviewed. Vaginal sampling may help to identify N. gonorrhoeae, C. trachomatis and M. genitalium using nucleic acid amplification tests (NAAT), and is also of interest because of the epidemiological association of PID to bacterial vaginosis and trichomoniasis. Samples from the endocervix, and if available, from endometrial biopsy surgical procedures, should be processed to detect N. gonorrhoeae, C. trachomatis and M. genitalium using NAAT, and to search for the presence of Neisseria gonorrhoeae (antibiogram should be performed), facultative anaerobes, anaerobes and capnophilic bacteria. The antibiotic treatment should at least cover N. gonorrhoeae, C. trachomatis and M. genitalium, and for most of the authors, anaerobes. In case, microbiological studies demonstrate the role of other bacteria (e.g., Enterobacteriacae), theses should be treated according to the results of antibiogram.

Application of the French guidelines for preventing neonatal group B streptococcal disease in a university hospital

This study evaluated the application of the French guidelines for prevention of neonatal group B streptococcus (GBS) infections. The prevalence of GBS vaginal carriage by pregnant women during the study period was 6%. Less than 50% of pregnant women testing positive for GBS were treated with at least two doses of antibiotics during labour, and most received only one dose or no antibiotics. In addition, several neonates were colonised or infected by GBS although their mothers were GBS-negative. These results are consistent with vaginal screening having a poor sensitivity, as suggested by the low prevalence of GBS carriage.

Severe Relapsing Erysipelas Associated with ChronicStreptococcus agalactiaeVaginal Colonization

We report a case of severe recurrent erysipelas of the breast due to infection with Streptococcus agalactiae and demonstrate that strains isolated from the skin were closely related to strains isolated from the vagina, which is consistent with the claim that the vagina acts as a reservoir for S. agalactiae isolates that are responsible for erysipelas relapse. Hypervirulence of strains and persistence of a bacterial reservoir may explain why 5 months of prophylaxis with penicillin V (1 million U daily) was necessary to achieve permanent eradication of vaginal carriage and to prevent recurrence of erysipelas caused by S. agalactiae infection.

Non-touch fittings in hospitals: a procedure to eradicate Pseudomonas aeruginosa contamination

Non-touch taps, now common in hospitals, can easily be contaminated with Pseudomonas aeruginosa. We report our experience with 87 non-touch taps in a newly built wing of our teaching hospital contaminated with P. aeruginosa from the central pipe water system. Serotyping and genotyping of strains revealed genetic diversity of isolates, but also showed that major clones were able to persist for long periods of time in non-touch taps despite chlorination. It is notoriously difficult to decontaminate such taps with biocides and disinfectants. We describe an easy and economical procedure for the eradication of P. aeruginosa contamination from non-touch taps that does not require their removal.

Outbreak in France of Neisseria meningitidis B:15:P1.12 belonging to sequence type 1403

This report describes a meningococcal outbreak in France caused by Neisseria meningitidis B:15:P1.12 of sequence type 1403, which affected eight young patients, between November 2000 and February 2002. Epidemiological typing confirmed that a single strain was responsible. Favourable outcome, sequelae or death resulted in similar proportions as in other cases of meningococcal disease in France during the same period, but purpura was observed in all eight cases. The patients were aged between 14 and 28 years, whereas the median age of patients affected by other meningococcal strains during this period in the same area was 60.4 years.

Virulence and antibiotic susceptibility of Staphylococcus aureus strains isolated from various origins

We looked for links between the antibiotic susceptibility pattern of Staphylococcus aureus strains, their source and their virulence genes. Forty-four methicillin-sensitive and -resistant S. aureus strains from four antibiogroups were studied by SmaI macrorestriction and PCR detection of ea, eb, tst, lukS-PV and lukF-PV. Genes encoding virulence factors were most prevalent (i) in S. aureus strains originated from skin, (ii) in methicillin-sensitive, quinolone-resistant strains or in methicillin-sensitive multiresistant strains (EMSSA strains), and (iii) in strains with decreased susceptibility or resistance to fusidic acid. This is consistent with the hypothesis that S. aureus antibiotic resistance promoted by local antibiotic treatment also contributes to the emergence of virulence strains.

Prevention of Candida colonization prevents infection in a neonatal unit

This study represents a 1-year surveillance period using our epidemiology-based principles published and successfully followed since 1979: weekly culture for yeasts of oral and anal swabs, treatment with oral nystatin of all colonized newborns, and good hygiene/handwashing. Colonization was demonstrated in 23 out of 791 newborns admitted from October 1998 to September 1999. Twenty-two strains of Candida were identified: 16 C. albicans, 2 C. parapsilosis, 3 C. glabrata, and 1 C. tropicalis. Symptoms were erythema of the buttocks in 6 colonized newborns. No other culture positive for Candida could be found. Previous contamination was the main source (previous stay in an intensive care unit, rarely maternal origin). Contamination in the unit was unlikely. Eradication of Candida could be observed within 1 week. These good results, controversial in the literature, were obtained following epidemiological conclusions and support our guidelines.

Spread of Stenotrophomonas maltophilia colonization in a pediatric intensive care unit detected by monitoring tracheal bacterial carriage and molecular typing

In our pediatric intensive care unit in Tours (France), intubated and ventilated inpatients are systematically monitored for tracheal bacterial colonization twice a week. This led us to detect five patients colonized with Stenotrophomonas maltophilia over a 4-month period. Molecular typing of the isolates using random amplified polymorphism DNA (RAPD) and pulsed-field gel electrophoresis (PFGE) confirmed that four of the five isolates were genetically related. The strict isolation of carriers and improvements in hygiene measures stopped the spread. This systematic strategy prevented pulmonary nosocomial infections or allowed their early detection. Moreover, it has made it possible to assess the efficiency of care practices continuously.

[Hospital infection surveillance and multiresistance monitoring: role of an external quality control]

The "Relais Régional d'Hygiène Hospitalière du Centre" (RHC) promotes the hospital infection prevention at a regional level in France, including 80 healthcare institutions. The accuracy of antimicrobial susceptibility data submitted by laboratories to surveillance is essential. Since 2001, RHC imposed an external quality control to validate the accuracy of the data submitted by the laboratories that are involved in survey programs. Most laboratories are able to detect homogenous methicillin resistance in S. aureus, and high-level vancomycin resistance in E. faecalis. Nevertheless, the ability of laboratories to detect organisms with emerging antimicrobial resistance patterns is not optimal for (i) detection of heterogeneous methicillin resistance, (ii) reduced susceptibility to teicoplanin in a non-multiresistant S. aureus and (iii) detection of resistance to extended-spectrum cephalosporins. Educational program to optimize the testing methods has been programmed and perennially of quality control testing prior to accepting data from laboratory participating in surveillance system is decided.

Comparison of Fecal Flora following Administration of Two Antibiotic Protocols for Suspected Maternofetal Infection

Two protocols are used by French neonatologists for the treatment of suspected maternofetal infection (SMFI). Three groups of premature and term neonates were included to study the impact of antibiotics on fecal flora: 10 infants with SMFI treated with amoxicillin and netilmicin (group BI), 10 infants with SMFI treated with amoxicillin, cefotoxime and netilmicin (group TRI) and 10 infants without antibiotic therapy as controls (group C). Group BI samples were colonized with Klebsiella oxytoca and Escherichia coli resistant to amoxicillin and by Eneterococcus faecium and coagulase-negative staphylococci. In group TRI biodiversity of the intestinal flora was low, with rapid growth of staphyloccoci and occurrence of Candida spp. These modifications of the intestinal flora should encourage us to use antibiotic treatment as targeted as possible.

Pseudomonas aeruginosa and cystic fibrosis: correlation between exoenzyme production and patient's clinical state

In this study, we investigated the correlation between the production by Pseudomonas aeruginosa isolates of four exoenzymes (protease, elastase, neuraminidase, and phospholipase C (PLC)) and the clinical state of cystic fibrosis (CF) patients. We studied 212 P. aeruginosa isolates from 22 CF patients chronically infected with this bacterium. Patients were classified into three clinical groups according to a modified Shwachman-Kulczycki-Khaw (SKK) scoring system. The production of enzymes by isolates from patients in the three populations was analyzed and compared using four statistical tests: chi-square, Mann-Whitney U, principal component analysis, and discriminant analysis. Isolates from patients with excellent or good clinical status (group I, SKK score >/=71) had higher elastase and neuraminidase activities than isolates from the other patients. In contrast, PLC activity, a common characteristic of CF isolates, was higher in isolates from patients with poor or weak clinical status (group III, SKK score </=55). PLC also appeared to be the best parameter for differentiating between groups I and III. Enzyme production was highly variable in group II isolates (SKK score, 56-70). Our results suggest that P. aeruginosa isolates from patients with good clinical status produce large amounts of neuraminidase, and that PLC production may be involved in the decrease in pulmonary function.

Identification of new phages to type strains and comparison with a genotypic method

The aim of this study was to optimize the epidemiological monitoring of strains of Staphylococcus aureus, a major cause of hospital-acquired infections. From September to December 1998 47 S. aureus strains isolated from swabs taken from orthopaedic and trauma patients were in studied. Thirty-five isolates were sensitive to methicillin (MSSA) and 12 were methicillin-resistant (MRSA). Ten of the 47 isolates could not be phage-typed using the international set of typing phages: five of these isolates were MSSA and five were MRSA. These MRSA isolates, which were also not typeable by the phages currently recommended for phage-typing MRSA, were lysed by locally isolated experimental phages 584 and 1814. Phage 1814 lysed the gentamicin-resistant MRSA and phage 584 acted on the gentamicin-sensitive MRSA. Both new phages were inactive against the methicillin-sensitive isolates. Cloning of certain isolates was confirmed by macrorestriction genomic profiles obtained by pulsed-field gel electrophoresis analysis (PFGE). The results showed good discriminatory ability of antibiotic-resistance pattern phenotyping and phage-typing when the phages used were adapted to epidemic-associated MRSA strains.

Staphylococcus lugdunensis infections: high frequency of inguinal area carriage

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 beta-lactamase were homogeneous; six of the eight beta-lactamase-positive strains displayed the same pulsed-field gel electrophoresis pattern.

Viral and bacterial DNA in carotid atherosclerotic lesions

Atherosclerosis is a major health problem in industrialised countries. Several studies have suggested an association exists between certain microorganisms and the development of atherosclerosis. The aim of the study presented here was to assess the presence of viral or bacterial DNA in carotid atherosclerotic lesions. Nucleic acids were extracted from 18 carotid atherosclerotic lesions that had been collected surgically. Polymerase chain reaction was used to screen for specific genomic DNA from Chlamydia pneumoniae, cytomegalovirus and herpes simplex virus types 1 and 2. An original approach, based on the amplification by PCR of conserved bacterial 16S rDNA nucleotide sequences was also used to detect any bacterial species. The amplification product was identified by sequencing. Chlamydia pneumoniae, cytomegalovirus and herpes simplex 2 DNA were not detected in any of the samples. Herpes simplex 1 DNA was detected in 3 of the 18 samples. Genes encoding bacterial 16S rRNA were amplified and sequenced in eight atherosclerotic lesions. DNA sequences were identified by comparison with sequences registered in the GenBank database. These eight carotid atherosclerotic lesions were shown to contain several bacterial species belonging to human flora or the environment. The exact role of these microorganisms in the genesis or development of the atherosclerotic lesions remains unclear, but they may increase the inflammatory process or be an epiphenomenon.

[Obstetrical management of Streptococcus agalactiae]

S. agalactiae is the main cause of maternal and neonatal infections. Correct bacteriological explorations of pregnant women and neonates with risk factors may allow early and effective antibiotherapy. The screening of S. agalactiae vaginal carriage at 34-38 weeks of amenorrhea and the administration of penicillin at delivery is considered as the best strategy for preventing S. agalactiae infections for asymptomatic patients.

Genetic relationship between Escherichia coli strains isolated from the intestinal flora and those responsible for infectious diseases among patients hospitalized in intensive care units

The exact origin of strains of Escherichia coli responsible for infectious diseases in intensive care units (ICUs) remains partly unknown. Our aim was to determine the nature of the link between strains from the intestinal flora of hospital staff, strains from the intestinal flora of patients hospitalized in ICUs and strains isolated from ICU patients with invasive diseases. For this purpose, 77 strains of E. coli were genetically characterized by exploring their entire genomes by random amplified polymorphism of DNA (RAPD), and by determining their phylogenetic position in ECOR (E. coli reference) groups, the virulence factors harboured (pap, sfa, afa, hly, aer and cnf) and their ability to mutate. The strains isolated from the intestinal flora of hospital staff were found to constitute a genetically heterogeneous population compared with the strains isolated from ICU carriers, which were highly clustered. The latter strains harboured numerous virulence factors, and 80% belonged to the group ECOR B2. The strains isolated from infected patients harboured fewer virulence factors than those from the ICU carriers, and only half belonged to ECOR B2. Moreover, these strains were more genetically related to strains from hospital staff than to strains from ICU carriers. Thus, the exogenous origin of the E. coli strains is probably almost as important as translocation from intestinal flora in ICUs. Moreover, a strong mutator phenotype had a minor, or no, role in the rapid adaptation to modifications in the ecological environment.

Combined ribotyping and random multiprimer DNA analysis to probe the population structure of Listeria monocytogenes

To improve our understanding of the genetic links between strains originating from food and strains responsible for human diseases, we studied the genetic diversity and population structure of 130 epidemiologically unrelated Listeria monocytogenes strains. Strains were isolated from different sources and ecosystems in which the bacterium is commonly found. We used rRNA gene restriction fragment length polymorphism analysis with two endonucleases and random multiprimer DNA analysis with seven oligonucleotide primers to study multiple genetic features of each strain. We used three clustering methods to identify genetic links between individual strains and to determine the precise genetic structure of the population. The combined results confirmed that L. monocytogenes strains can be divided into two major phylogenetic divisions. The method used allowed us to demonstrate that the genetic structure and diversity of the two phylogenetic divisions differ. Division I is the most homogeneous and can easily be divided into subgroups with dissimilarity distances of less than 0.30. Each of these subgroups mainly, or exclusively, contains a single serotype (1/2b, 4b, 3b, or 4a). The serotype 4a lineage appears to form a branch that is highly divergent from the phylogenetic group containing serotypes 1/2b, 4b, and 3b. Division II contains strains of serotypes 1/2a, 1/2c, and 3a. It exhibits more genetic diversity with no peculiar clustering. The fact that division II is more heterogeneous than division I suggests that division II evolved from a common ancestor earlier than division I. A significant association was found between division I and human strains, suggesting that strains from division I are better adapted to human hosts.

Nocardia farcinica infection of a cochlear implant in an immunocompetent boy

The first case of an infection caused by Nocardia farcinica on a cochlear implant and its progression is described. As it is difficult to diagnose Nocardia spp., the identification was confirmed by phylogenetic analysis using 16S rDNA sequencing.

[Neonatal bacterial infection by maternal-fetal contamination: for a change in approach? 2. Uncertainties and proposals]

Based on a critical analysis of the literature, it is clear that even though mortality has decreased to 10-15%, the prevalence of neonatal bacterial infections remains dramatically stable. Precise risk factors can be identified in most cases of neonatal infection, but remain uncertain in many others: Streptococcus agalactiae is found in only 40% of the cases of sepsis; Escherichia coli, Haemophilus influenzae, Pneumococcus, and group A Streptococcus strains should also be considered for a real prophylactic strategy; context (prematurity), lack of a consensual attitude for intrapartum strategies; management schemes for asymptomatic neonates. Based on these observations, we make proposals for a realistic attitude for everyday practice based on risk factors, maternal and neonatal bacterial sampling procedures, and modalities for neonatal antibiotic therapy.

[Neonatal bacterial infection by maternal-fetal contamination: for a change in approach? 1. Detection of Streptococcus agalactiae infection: methods and evaluation of results]

Perinatal group B streptococcal infection has been the subject of numerous studies and despite guidelines established during the last decade remains a frequent disease with high mortality. The basic aim of the guidelines is to screen for Streptococcus agalactiae during the antepartum period in order to institute antibiotic therapy during delivery. A critical review of the literature highlights the real impact and adverse effect of these guidelines: difficult application (only two-thirds of all maternity units have a protocol and compliance is only 75%), maternal risks of antibiotic therapy (especially the emergence of resistant Gram negative bacteria), fetal risks (accentuation of neonatal sepsis with resistant strains, retarded neonatal infections, frequent use of antibiotics with a broader spectrum, higher frequency of nosocomial sepsis).

Low sensitivity of Listeria monocytogenes to quaternary ammonium compounds

Ninety-seven epidemiologically unrelated strains of Listeria monocytogenes were investigated for their sensitivities to quaternary ammonium compounds (benzalkonium chloride and cetrimide). The MICs for seven serogroup 1/2 strains were high. Three came from the environment and four came from food; none were isolated from human or animal samples. All 97 strains carried the mdrL gene, which encodes a multidrug efflux pump, and the orfA gene, a putative transcriptional repressor of mdrL. The absence of plasmids in four of the seven resistant strains and the conservation of resistance after plasmid curing suggested that the resistance genes are not plasmid borne. Moreover, PCR amplification and Southern blot hybridization experiments failed to find genes phylogenetically related to the qacA and smr genes, encoding multidrug efflux systems previously described for the genus Staphylococcus. The high association between nontypeability by phages and the loss of sensitivity to quaternary ammonium compounds are suggestive of an intrinsic resistance due to modifications in the cell wall.

Pelvic inflammatory disease: medical treatment

Pelvic inflammatory disease (PID) refers to infection of the uterus (endometritis), fallopian tubes (salpingitis) and adjacent pelvic structures (tubo-ovarain complex, pelvic peritonitis). PID causes major medical, social, and economic problems. Long-term sequelae, especially tubal factor infertility and extra uterine pregnancy are common and their management is extremely costly. Medical treatment of PID should be immediate because sequelae are more frequent if the treatment is delayed or inadequate.

Capnocytophaga ochracea: characterization of a plasmid-encoded extended-spectrum TEM-17 beta-lactamase in the phylum Flavobacter-bacteroides

A plasmid-encoded extended-spectrum TEM beta-lactamase with a pI of 5.5 was detected in a Capnocytophaga ochracea clinical isolate. The bla gene was associated with a strong TEM-2 promoter and was derived from bla(TEM-1a) with a single-amino-acid substitution: Glu(104)-->Lys, previously assigned to TEM-17, which is thus the first TEM beta-lactamase to be reported in the phylum Flavobacter-Bacteroides.

Genetic features of Streptococcus agalactiae strains causing severe neonatal infections, as revealed by pulsed-field gel electrophoresis and hylB gene analysis

A collection of 114 independent Streptococcus agalactiae strains, including 54 strains isolated from the cerebrospinal fluid (CSF) samples of neonates and 60 strains from asymptomatic patients, was characterized by pulsed-field gel electrophoresis (PFGE) of DNA restricted with SmaI and by PCR analysis of the hylB gene. All strains were previously studied by multilocus enzyme electrophoresis (MLEE) (R. Quentin, H. Huet, F.-S. Wang, P. Geslin, A. Goudeau, and R. K. Selander, J. Clin. Microbiol. 33:2576-2581, 1995). Among these 114 strains, there were 92 PFGE patterns. Eleven genetic groups (A to K) were identified with 38% divergence. A more homogeneous group (PFGE group A) was defined, consisting of 73% of the strains previously identified as belonging to a particular MLEE phylogenetic group. A 162-kb fragment was identified as a marker of strains that invaded the central nervous system of neonates. It was detected in 69% of the PFGE patterns obtained with CSF isolates and in only 1.8% of the PFGE patterns obtained with carrier strains. The hylB gene encoding hyaluronate lyase was amplified for all strains in our collection. Ten of 15 isolates belonging to an MLEE subgroup, previously described as being likely to cause invasive infection, had an insertion in the hylB gene (IS1548).

[The Pneumococcus Observatory of the Central Region, from June 1, 1997 to May 31, 1998]

714 pneumococcus were listed from 14 laboratories between the 1 June 1997 and the 31 May 1998. Data capture was done on Epi info software and concerned age, file number, consultation/hospitalization, sample type, susceptibility to oxacilline (5 micrograms), the results of the E-test for penicillin G, amoxicillin, cefotaxime and the results of the routine disk diffusion susceptibility method. Strains with reduced susceptibility to penicillin G (PRSP) were collected by the coordinating center to perform MICs by the reference method of agar dilution and serotyping. Over 714 strains, 45.7% of the samples originated from lungs, followed by 22% for blood samples, 14% for ear pus and 2.3% for CSF. 34% of the patients were female. 36.7% were children under 16 (57.8% PRSP) and 63.3% were adults (41% PRSP). 338 strains (47.3%) were determined as PRSP and 293 of them were studied by the coordinating center. 81 of the 293 PRSP (27.7%) were resistant et 212 (72.3%) were intermediate to penicillin G. 81% of the PRSP studied had a CMI value for penicillin G within +/- 1 log2 dilution. 20 strains of PRSP were resistant for amoxicillin (6.8% of the PRSP) and two (0.7% of the PRSP) for cefotaxime. 289 serotyping were done, most met serotypes were 23 (25%), 14 (23%). The least met was 15 (2.4%). These results let assess the epidemiology of pneumococcus in our region.

Nucleotide sequences of genes coding for fimbrial proteins in a cryptic genospecies of Haemophilus spp. isolated from neonatal and genital tract infections

Nineteen isolates belonging to a cryptic genospecies of Haemophilus (referred to here as genital strains) isolated from genital tract infections (6 strains) and from neonatal infections (13 strains) were studied for fimbrial genes. Sixteen strains exhibit peritrichous fimbriae observed by electron microscopy. By PCR with primers corresponding to the extreme ends of the Haemophilus influenzae type b (Hib) hifA and hifD genes and Southern blotting, a hifA-like gene (named ghfA) and a hifD-like gene (named ghfD) were identified in 6 of the 19 strains. Five of these six strains were from the genital tracts of adults, and one was from a neonate. For each gene, the nucleotide sequence was identical for the six strains. A hifE-like gene (named ghfE) was amplified from only one of the 19 genital strains of Haemophilus, but the ghfE probe gave a signal in Southern hybridization with the five other strains positive for ghfA and ghfD. Therefore, these strains may carry a ghfE-like gene. The Hib fimbrial gene cluster is located between the purE and pepN genes as previously described. For the 13 genital Haemophilus strains that lack fimbrial genes, this region corresponds to a noncoding sequence. Another major fimbrial gene designated the fimbrin gene was previously identified in a nontypeable H. influenzae strain. A fimbrin-like gene was identified for all of our 19 genital strains. This gene is similar to the ompP5 gene of many Haemophilus strains. Therefore, other, unidentified genes may explain the piliation observed in electron microscopy on genital Haemophilus strains which do not possess LKP-like fimbrial genes. Fimbrial genes were significantly associated with strains isolated from the genital tract. They may confer on the strain the ability to survive in the genital tract.

[Pristinamycin versus oxacillin in the treatment of superficial pyoderma. A multicenter randomized study in 293 outpatients]

BACKGROUND

Superficial pyoderma occurs frequently. Generally, the benign infection is caused by Staphylococcus aureus and/or a group A streptococci. The subject is controversial, but treatment usually is based on narrow-spectrum antibiotics active against both germs.

PATIENTS AND METHODS

A multicentric, randomized, double-blind, double-placebo study was conducted to compare pristinamycin (1 g b.i.d.) with a reference antibiotic, oxacillin (1 g b.i.d.) for 10 days. Inclusion criteria were: both sexes, age 15-80 years, clinical diagnosis of superficial pyoderma (impetigo, wound infection within the last 15 days, furunculosis, carbuncle, perionyxis), informed consent. The general practitioner investigators (n = 52) were assisted by 9 dermatologist-coordinators. Clinical diagnosis was validated by a committee of experts at the end of the study after analyzes of the photos and bacteriological results obtained on samples taken at the practitioner's office on visit 1 (D0), visit 3 (D14 +/- 3) and visit 4 (D25 +/- 3). Successful treatment was defined by clinical, bacteriological and photographic efficacy at visit 3 (equivalence analysis: one-way 95 p. 100 confidence interval).

RESULTS

There were 293 included patients given pristinamycin (n = 151) or oxacillin (n = 142). Mean age of analyzed patients was 40 +/- 17 years. Diagnosis was confirmed in 255 patients in accordance with the protocol: furunculosis or carbuncle (n = 100), recently superinfected wound (n = 97), impetigo (n = 41), acute perionyxis (n = 17). Thirty-five patients (12 p. 100) were considered to have been wrongly included. The germs most often isolated were: Staphylococcus aureus (n = 126), group A streptococci (n = 13), group B streptococci (n = 5) and P. multocida (n = 3). At visit 3, the two treatments were found to be equivalent with a success rate of 86.7 p. 100 for pristinamycin and 89.8 p. 100 for oxacillin (CI [*9.97]). Tolerance was statistically comparable between the two treatments (27 to 32 percent minor side effects).

DISCUSSION

This study is the first performed in outpatients attended by general practitioners with diagnostic confirmation on both bacteriological and photographic evidence of superficial pyoderma. The results obtained demonstrate the good reliability of such studies although 12 p. 100 of the patients were wrongly included, a factor which should be taken into account for future studies. The efficacy and tolerance of pristinamycin were statistically equivalent to those of oxacillin for all the patients with superficial pyoderma. Nevertheless, the subgroup of patients with folliculitis gave rather heterogeneous bacteriology and therapeutic results.

Characterization of Streptococcus agalactiae strains by randomly amplified polymorphic DNA analysis

A collection of 54 unrelated Streptococcus agalactiae strains isolated from cerebrospinal fluid samples from neonates and 60 unrelated strains isolated from carriers that had been previously studied by multilocus enzyme electrophoresis (R. Quentin, H. Huet, F.-S. Wang, P. Geslin, A. Goudeau, and R. K. Selander, J. Clin. Microbiol. 33:2576-2581, 1995) were characterized by randomly amplified polymorphic DNA (RAPD) assay. Four primers, 5'AGGGGGTTCC3', 5'AACGCGCAAC3', 5'GCATCAATCT3', and 5'AGTCGGGTGG3', named OPS16, AP42, A4, and OPS11, respectively, were selected from 29 primers tested. This investigation identified 71 RAPD types. The three families of strains defined by multilocus enzyme electrophoresis analysis, which contain most of the cerebrospinal fluid isolates, were also identified by clustering analysis of RAPD data. Each of these three groups exhibits specific RAPD patterns or fragments. The discriminatory power of the RAPD typing method was also evaluated. The simplest typing scheme was obtained by the combination of RAPD typing done with primers AP42 and OPS11 and serotyping (index of discrimination, 0.97).

Endocervical infection in a pregnant woman caused by Neisseria meningitidis: evidence of associated oropharyngeal colonization of the male partner

A case of premature birth associated with an endocervical infection caused by Neisseria meningitidis is reported. Treatment of the mother with amoxycillin eradicated the bacteria from the endocervix and avoided newborn colonization or infection. Epidemiological investigation identified meningococcal oropharyngeal colonization of the male partner. The two strains were of the same antigenic formula B:4:P1.14 and exhibited identical rDNA restriction fragment patterns and outer membrane protein profiles. This phenotypic and genomic identity of strains is the first clear evidence for cross-colonization between sexual partners.

Use of a DNA typing method to investigate a fatal perinatal infection due to Staphylococcus aureus

The aim of this study was to determine, by random amplified polymorphic DNA analysis, the origin of a fatal Staphylococcus aureus perinatal infection which occurred after multiple cervical examinations before induction of labor for patient convenience. This DNA typing method was able to demonstrate that this infection originated from S. aureus genital carriage and urinary tract infection of the mother, and was not acquired in the hospital. This observation argues for the systematic screening of genital flora for highly virulent strains before induction of labor for non medical reasons. In addition, the DNA typing method used demonstrates that one neonate was subsequently infected by the strain responsible for the chorioamnionitis. This shows that molecular typing methods can help determine hospital staff responsibility.

Genetic diversity of rRNA operons of unrelated Streptococcus agalactiae strains isolated from cerebrospinal fluid of neonates suffering from meningitis

The genetic diversity of a collection of 54 unrelated Streptococcus agalactiae strains isolated from the cerebrospinal fluid of neonates and of 60 unrelated carrier strains was evaluated by investigating the restriction fragment length polymorphism of the rRNA gene region. Three restriction enzymes were selected for use: PstI, HindIII, and CfoI. Clustering analysis revealed two phylogenetic groups of strains with 40% divergence. Group I contained two clusters, A and B, and group II contained three clusters, C, D, and E. Strains of serotype Ia were mostly distributed in cluster A, and strains of serotype Ib were mostly distributed in cluster E. Serotype III isolates did not cluster. Nevertheless, 37 of 39 isolates belonging to cluster B were serotype III. With HindIII, two rRNA gene banding patterns characterized 38 of the 39 strains of cluster B, which represents a high-virulence group. In addition, two rRNA gene banding patterns with each enzyme and/or a pair of CfoI fragments of 905 and 990 bp identified 81% of the invasive strains. On account of the genetic homogeneity of the cerebrospinal fluid strains, ribotyping is a powerful typing method for investigation of nosocomial or epidemic invasive infections only when all three enzymes are used or when PstI and HindIII or PstI and CfoI are combined with serotyping (index of discrimination, > 0.95).

Genetic identification of cryptic genospecies of Haemophilus causing urogenital and neonatal infections by PCR using specific primers targeting genes coding for 16S rRNA

Previous genetic analysis of Haemophilus influenzae strains isolated from genital and neonatal infections identified a group of biotype IV that constitutes a cryptic genospecies only distantly related to H. influenzae and H. Haemolyticus. Small-subunit rRNA genes of two representative strains of this genital Haemophilus genospecies (strains 16N and 2406) were sequenced. The analysis indicated that these strains form a monophyletic unit with H. haemolyticus and H. influenzae biogroups Influenzae and Aegyptius and are more closely related to H. haemolyticus than to H. influenzae biogroups Influenzae and Aegyptius. 16S rRNA gene sequences were used to formulate primers for PCR-based identification of cryptic genital Haemophilus organisms. A 242-bp fragment was amplified from strains belonging to the genital Haemophilus genospecies but not from strains of 12 other Haemophilus species, including strains of H. influenzae biotype IV sensu stricto.

Development of listeriosis during vancomycin therapy in a neutropenic patient

Vancomycin and aminoglycosides are widely used for fever in neutropenic patients. This combination of antibiotics has also been proposed for the treatment of Listeria monocytogenes bacteremia. We report a case of fatal listeriosis in a 33-year-old man during acute lymphoblastic leukemia induction therapy in a total protective environment despite him having been on vancomycin for 8 days for treatment of staphylococcus bacteremia. Vancomycin and aminoglycoside cannot be proposed for the treatment of L. monocytogenes bacteria in neutropenic patients. Neutropenia might be a risk factor for listeriosis in cancer patients.

Characterization of Streptococcus agalactiae strains by multilocus enzyme genotype and serotype: identification of multiple virulent clone families that cause invasive neonatal disease

The chromosomal genotypes of 277 isolates of 16 serotypes of Streptococcus agalactiae were characterized by analysis of electrophoretically demonstrable allele profiles at 12 metabolic enzyme loci. The collection comprised the type strain and 276 strains recovered from French symptomatic and asymptomatic subjects. Sixty-one distinctive electrophoretic types (ETs), representing multilocus clonal genotypes, were identified. Cluster analysis of the ETs revealed two primary phylogenetic divisions separated by a genetic distance of 0.62, Division I contained 67 isolates which could be assigned to 13 ETs. Twenty-seven of these isolates were from samples of cerebrospinal fluid (CSF) from neonatal meningitis patients. Two ETs, separated by a genetic distance of 0.217, contained 26 of these 27 isolates. Division II contained 210 isolates, of which 27 were isolated from CSF. This division was more polymorphic and included 48 ETs. Spanning a genetic distance of 0.3, three clusters and one ET were identified within this group. Twenty-four of 27 strains isolated from CSF belonged to one cluster, and 19 of them belonged to two adjacent ETs with a genetic distance of 0.083. Fifty-five of the 68 serotype Ia strains and 24 of the 26 serotype Ib strains were each confined to one of the evolutionary lineages, and 85 of the 86 strains which carried protein antigen c belonged to phylogenetic division II. Most of the type III organisms were assigned to two clone families. The characteristics of this French population argue for the existence of particular groups of strains responsible for neonatal meningitis and demonstrate that serotyping can supply information about the genetic distribution of strains.

Genetic diversity of Pseudomonas aeruginosa strains isolated from patients with cystic fibrosis revealed by restriction fragment length polymorphism of the rRNA gene region

The restriction fragment length polymorphism patterns of rDNAs from Pseudomonas aeruginosa strains isolated from the respiratory tracts of patients suffering from cystic fibrosis were obtained to evaluate the genetic polymorphism of this population of strains. Eighty-seven P. aeruginosa strains isolated from 87 patients from diverse areas of France and the ATCC 10145 strain were examined. Four restriction enzymes were used: BamHI, ClaI, EcoRI, and PstI. Forty-nine strains (56%) were in the three most frequent ribotypes (ribotypes R1 to R3). In addition, hierarchical clustering analysis of the data showed that 71 of the 88 strains (81%) clustered at a distance of less than one-third of the greatest distance observed in the total population. This indicates that clinical isolates implicated in the pathology of cystic fibrosis present a low degree of heterogeneity of rRNA operons, in contrast to the heterogeneity of strains of P. aeruginosa isolated from patients with various other pathologies. This relative homogeneity of rRNA genes was observed independently of the clinical status of the patient and the colony morphology.

Adherence to human cells of a cryptic Haemophilus genospecies responsible for genital and neonatal infections

Haemophilus strains usually identified as Haemophilus influenzae biotype IV belonging to a cryptic genospecies are responsible for genital and neonatal infections. As a first approach to identifying the bacterial factors involved in the pathogenesis of these unusual diseases, we studied the piliation, adherence, and invasion properties of 17 strains assigned to this cryptic genospecies. Twelve strains spontaneously displayed abundant peritrichous piliation, and two strains expressed peritrichous pili after enrichment procedures. For virtually all strains, piliation correlated with adhesion to cultured HeLa cells of genital origin and to a lesser extent with adhesion to HEp-2 cells of laryngeal origin. A variation in the adherence properties of the various strains was observed: all piliated strains except one adhered to 50 to 100% of HeLa cells, with a mean number of bacteria per cell varying from 4 to 50. Adherence was not dependent on the state of growth for most strains, was more pronounced with HeLa cells than with HEp-2 cells for 10 of the 12 highly adherent strains, was time and inoculum dependent, and was not followed by significant invasion of cells. Most of the strains belonging to this unusual Haemophilus clone possess adhesins that do not recognize erythrocyte receptors, since agglutination of human erythrocytes was observed with only 3 of the 14 piliated strains.

Use of nonradioactive DNA probes to identify a Campylobacter jejuni strain causing abortion

A case of human abortion due to a Campylobacter infection is reported. Cultures revealed two morphologically different isolates with large and small colonies respectively. Using conventional methods of identification, the large colonies were identified as Campylobacter jejuni and the small colonies as Campylobacter coli. Dot blot hybridization and determination of rDNA restriction fragment patterns revealed that both colony types were the same strain of Campylobacter jejuni. This observation illustrates the need to use methods other than phenotypic methods when identifying strains of Campylobacter.

Ribotyping of Streptococcus agalactiae strains isolated from vaginas of asymptomatic women

One hundred and eleven strains of Streptococcus agalactiae isolated from vaginas of asymptomatic women were characterized by determination of restriction length polymorphism profiles of rDNA regions (rDNA RFLP patterns) and serotyping. Thirty-five different PstI rDNA RFLP patterns were identified. Half of the strains fell into only seven of these 35 groups. No correlation between serotypes and rDNA RFLP patterns was found. These results indicate that (i) the genetic diversity of the S. agalactiae species is relatively limited and (ii) determination of rDNA RFLP patterns can be used as a typing system only in conjunction with serotyping.