Early responses to nonconjugated polyribosylribitol phosphate challenge as evidence of immune memory after combined diphtheria-tetanus-pertussis-polio-Haemophilus influenzae type b primary vaccination

OBJECTIVES

A high risk of invasive Haemophilus influenzae type b (Hib) disease exists in the first few years of life. A reduction in anti-polyribosylribitol phosphate (PRP) antibody concentrations follows the administration of certain diphtheria-tetanus-acellular pertussis (DTPa)-based Hib conjugate combined vaccines. However, these combined vaccines prime the immune memory, which is an important factor in protection. As yet there is no direct evidence of the time scale involved in the development of the immune memory post-primary vaccination. In this report we investigated the presence of immune memory at 10 and 12 months of age, 4 and 6 months after primary vaccination of young infants with a pentavalent combination of DTPa, inactivated poliovirus vaccine (IPV) and Hib (DTPa-IPV/Hib) vaccine.

METHODS

In two trials (A and B) infants received DTPa-IPV combined with Hib-tetanus conjugate (PRP-T) vaccine at 2, 4 and 6 months of age. The presence of immune memory was assessed by measuring anti-PRP concentrations 7 to 10 days after a nonconjugated PRP challenge given at 10 months in Trial A and at 12 months in Trial B.

RESULTS

Administration of a nonconjugated PRP challenge 4 and 6 months after primary vaccination in Trials A and B, respectively, elicited an increase in anti-PRP geometric mean concentrations (4.5 and 5.8 microg/ml, respectively) within 7 to 10 days. These concentrations exceed those reported in the literature involving unprimed children who had received a single dose of nonconjugated PRP at the same age.

CONCLUSION

The results demonstrate the development of anti-PRP immune memory at an early age, 4 and 6 months after completion of a three dose primary vaccination course of combined DTPa-IPV/Hib vaccine. The ability of primed infants to mount a rapid response is an important observation given the high risk of Hib infection at this critical age.

Clinical relevance of lower Hib response in DTPa-based combination vaccines

Combination vaccines are essential to enable administration of all the required antigens in routine infant immunisation schedules at any single visit. Some combinations of diphtheria-tetanus-acellular pertussis (DTPa) with Haemophilus influenzae type b (Hib) conjugate vaccines have been shown to result in lower Hib titres than when Hib is administered separately. While confirming that a primary series with a DTPa-HBV-IPV/Hib combination gives lower antibody levels than separate Hib conjugates, we show that the nature (isotype and IgG subclasses) and function (avidity and opsonic activity) of the antibodies are the same, and immunologic memory is induced. It is likely therefore that the DTPa-HBV-IPV/Hib combination will be efficacious against Hib disease.

A new DTPa-HBV-IPV vaccine co-administered with Hib, compared to a commercially available DTPw-IPV/Hib vaccine co-administered with HBV, given at 6, 10 and 14 weeks following HBV at birth

Three hundred and twenty eligible infants were enrolled in an open randomized clinical trial and allocated to one of two groups to receive either separate concomitant injections of a candidate combined DTPa-HBV-IPV and commercial Hib vaccine (candidate administration: DTPa-HBV-IPV+Hib) or separate concomitant injections of licensed DTPw-IPV mixed in the same syringe with Hib and HBV vaccines (comparator administration: DTPw-IPV/Hib+HBV). Vaccines were administered at 6, 10 and 14 weeks of age preceded by a monovalent dose of HBV at birth. The candidate vaccine administration was shown to be at least as immunogenic (primary objective) as the candidate administration with respect to the diphtheria, tetanus, polio, HBs and PRP seroprotection rates (primary endpoints). Post vaccination, both vaccine administrations showed an equivalent level of seroprotection with nearly all subjects (>96%) acquiring seroprotective titers against diphtheria, tetanus, polioviruses, HBsAg and PRP antigens. A markedly higher anti-HBs response post dose 2 at week 14 in the group receiving the candidate vaccine, 98.6% of subjects had seroprotective titers (GMT of 505.7 mIU/ml) compared with only 88.7% (GMT of 107.5 mIU/ml) in the comparator group. There was a lower incidence of adverse events following the DTPa-based candidate administration compared with the DTPw-based comparator. Despite the early age and short interval between doses, both administrations were immunogenic, with the concomitant administration of DTPa-HBV-IPV and Hib vaccines showing an improved tolerability over the commercial vaccines DTPw-IPV/Hib and HBV.

Primary vaccination of infants with diphtheria-tetanus-acellular pertussis-hepatitis B virus- inactivated polio virus and Haemophilus influenzae type b vaccines given as either separate or mixed injections

OBJECTIVE

The aim of this open, multicenter, randomized trial was to evaluate the immunogenicity and reactogenicity of a candidate combined diphtheria-tetanus-acellular pertussis-hepatitis B virus-inactivated polio virus (DTaP-HBV-IPV) vaccine when given as either a mixed or as separate concomitant injections with Haemophilus influenzae type b (Hib) vaccine.

STUDY DESIGN

A total of 359 subjects were randomized to receive either DTaP-HBV-IPV/Hib (mixed administration - 180 subjects) or DTaP-HBV-IPV + Hib (separate administration in opposite limbs - 179 subjects) at 2, 3, and 4 months of age.

RESULTS

After vaccination, seroprotective antibody concentrations against diphtheria, tetanus, hepatitis B, and polio viruses and a high (> or = 97%) pertussis vaccine response were seen in almost all study participants. All subjects except one in the mixed administration group had postvaccination Hib anti-PRP antibody concentrations > or = 0.15 microg/mL. Of subjects in the mixed and separate group, 77.2% (geometric mean antibody concentration, 2. 62 microg/mL) and 88.6% (geometric mean antibody concentration, 4.45 microg/mL) had Hib anti-PRP concentrations > or = 1 microg/mL, respectively. The addition of the Hib component to the 5-component vaccine did not increase the incidence of local or general reactions.

CONCLUSION

Both administrations of the candidate vaccine were found to be safe, immunogenic, and well tolerated. Although anti-PRP geometric mean antibody concentrations and the percent of subjects achieving the 1 microg/mL seroprotective level were lower after the mixed administration, they were in the range seen with monovalent Hib vaccines or with other DTaP-based/Hib combinations licensed in some European countries. Therefore both administrations have the potential to simplify childhood immunization.

Acellular vaccines containing reduced quantities of pertussis antigens as a booster in adolescents

OBJECTIVE

To evaluate the immunogenicity and reactogenicity of an acellular pertussis vaccine (pa) either formulated with diphtheria and tetanus toxoids (dTpa) or administered consecutively with a licensed tetanus and diphtheria vaccine (Td) as a 5th dose in adolescents.

METHODS

A total of 510 healthy children 10 to 13 years of age were assigned randomly, using a single-blind design, to receive either the dTpa vaccine or the Td vaccine with the pa vaccine 1 month later. The quantities of 3 pertussis antigens (pertussis toxin, filamentous hemagglutinin, and pertactin) in the dTpa and the pa vaccines were one third of those of the Infanrix vaccine (SmithKline Beecham Biologicals, Rixensart, Beligium) licensed for use in infants. For enzyme-linked immunosorbent assay measurement of serum immunoglobulin G antibodies and proliferation assay of peripheral blood mononuclear cells, blood samples were obtained before and 1 month after immunization. Local and systemic reactions were recorded on diary cards for 15 days after immunization.

RESULTS

After immunization with dTpa or pa, significant and comparable rises in geometric mean values of antibodies (12- to 46-fold) and proliferations (8- to 18-fold) to each of the pertussis antigens were noted. After immunization with dTpa or Td, significant rises in geometric mean values of antidiphtheria and antitetanus antibodies (35- to 76-fold) were noted, and all subjects had values of these antibodies >/=.1 international units/mL. The dTpa and pa vaccines were at least as well tolerated as the licensed Td vaccine.

CONCLUSIONS

Booster immunization of adolescents with an acellular vaccine containing reduced quantities of pertussis antigens in addition to diphtheria and tetanus toxoids induces good responses in both arms of the immune system without an increase in adverse reactions.

Reactogenicity and immunogenicity of reduced antigen content diphtheria-tetanus-acellular pertussis vaccines as a booster in 4-7-year-old children primed with diphtheria-tetanus-whole cell pertussis vaccine before 2 years of age

BACKGROUND

The recent introduction of acellular pertussis vaccines (Pa) offers the possibility of booster doses in older children and adults. This can be conveniently accomplished by combining acellular pertussis antigens with diphtheria and tetanus toxoids. However the optimal dosage for the booster injection has not yet been determined.

OBJECTIVE

To compare the reactogenicity and immunogenicity of diphtheria-tetanus-acellular pertussis vaccines (DTPa) with lower antigen contents to a licensed DTPa vaccine when given at 4-7 years of age as a booster to DTPw-primed children.

METHODS

Two hundred and twenty-six children primed with four doses of DTPw before 2 years of age were enrolled and allocated to three groups to receive one dose of either DTPa (Infanrix, SmithKline Beecham, Biologicals), a reduced antigen formulation of this vaccine (dtpa, SmithKline Beecham Biologicals), or an experimental low dose formulation (dtpa-exp; d and t, Michigan Biologic Products Institute). Reactogenicity was assessed using diary cards for 15 days. Immunogenicity was determined as antibody responses against the vaccine components in pre- and 1 month postvaccination sera.

RESULTS

Of the 225 children who completed the study, 60.0-66.7% reported symptoms, with no significant differences in rates between groups. Local, systemic and unsolicited symptoms occurred with similar frequencies in all three groups, the vast majority (> 90%) being considered as mild or moderate. No serious adverse events related to vaccination were reported. After vaccination, all subjects displayed seroprotective concentrations against diphtheria and tetanus, and 98.7-100% had antibodies against the three pertussis component antigens. The group receiving the reduced dose of the licensed vaccine showed antibody concentrations comparable to those of the full dose group. However, the group receiving the experimental low dose formulation had statistically significantly lower antibody concentrations against both diphtheria and tetanus toxoids compared with the two other groups, as well as significantly lower anti FHA antibody concentrations.

CONCLUSIONS

Reducing the antigen content of dtpa had no deleterious effect on the immunogenicity of the vaccine when given as a fifth dose at 4-7 years of age in DTPw-primed children. The reactogenicity profile of both the reduced antigen dtpa vaccines and DTPa were acceptable, the vast majority of local and systemic reactions being considered as mild to moderate, with no vaccine-related serious adverse events reported. The use of lower antigen content dtpa vaccine as a booster in children aged 4-7 is safe and immunogenic.

Reactogenicity and immunogenicity of a new live attenuated combined measles, mumps and rubella vaccine in healthy children

OBJECTIVE

To compare the reactogenicity and immunogenicity of a novel live attenuated measles-mumps-rubella vaccine, SB MMR (Priorix; SmithKline Beecham Biologicals), with a widely used MMR vaccine, Merck MMR (M-M-R II; Merck & Co. Inc).

METHODS

A total of 4702 healthy children, ages 9 to 24 months, were enrolled in 8 single blind, randomized, controlled trials. Reactogenicity (local and general solicited symptoms and all unsolicited symptoms) was assessed for up to 42 days postvaccination. Immunogenicity [seroconversion rates and geometric mean titers (GMT)] was assessed at 42 or 60 days postvaccination in 1912 subjects in 7 studies. In two studies the persistence of the antibodies at Month 12 postvaccination was assessed in 201 subjects.

RESULTS

Local symptoms (pain on or immediately after injection; pain, redness and swelling within 4 days of injection) were reported less frequently after SB MMR than Merck MMR (P < 0.0001). General symptoms and all other events were similar between the two groups. Fever >39.5 degrees C was reported after 9.5 and 11.9% of the SB MMR and Merck MMR doses, respectively. At Days 42 to 60 postvaccination seroconversion rates for antimeasles antibodies were higher with SB MMR than with Merck MMR (98.7% vs. 96.9%, P < 0.031) but similar in both groups for anti-mumps and anti-rubella antibodies, GMTs being approximately 10% higher (P < 0.05) with Merck MMR than with SB MMR. At the Month 12 assessment the seropositivity rates and GMTs were similar in both groups.

CONCLUSION

When administered as primary vaccination in children in the second year of life, the new SB MMR vaccine has been shown to be superior to a comparator vaccine in terms of local reactogenicity, with equivalent immunogenicity.

Contiguous inflammation of the skin

Contiguous inflammation of the skin (CIS) is a condition comprising localized inflammatory skin reactions which are secondary to a source of infection originating in deeper anatomical structures (bacterial or sterile abscesses, neoplasm-associated inflammations, foreign bodies, osteomyelitis, sinusitis, etc.). The main clinical symptom of contiguous inflammation of the skin is an asymmetrical, localized and painful erythema in combination with different case-specific symptoms. Four patients are presented below, who developed CIS caused by an ethmoidal carcinoma with superinfection, a postoperative mediastinal abscess, an odontogenic staphylococcal abscess and a purulent sinusitis maxillaris. The purpose of this paper is to bring attention to this condition and to offer guidelines for a rapid diagnosis of its underlying, potentially life-threatening, causal inflammatory focus.

Does aggregation substance of Enterococcus faecalis contribute to development of endocarditis?

Aggregation substance (AS) of Enterococcus faecalis which is encoded by so-called sex pheromone plasmids enables the bacteria to bind to in vitro-cultured pig kidney tubular cells. It is reported that the presence of AS is not of pivotal importance for the ability of E. faecalis to cause infective endocarditis (EN). The lines of evidence for this are twofold: 1) sex pheromone plasmids and, therefore, the gene for AS were not present more often in epidemiologically unrelated strains of E. faecalis isolated from human cases of EN than in isolates from well-water (26 vs. 18%); 2) the presence of the adhesin did not correlate with the establishment of EN in an animal (rat) model. The data are discussed with respect to the specificity of interaction of AS with eukaryotic cells and the results of other studies.

Safety and immunogenicity of a combined pentavalent diphtheria, tetanus, acellular pertussis, inactivated poliovirus and Haemophilus influenzae type b-tetanus conjugate vaccine in infants, compared with a whole cell pertussis pentavalent vaccine

BACKGROUND

We compared the safety and immunogenicity of two combined diphtheria-tetanus-pertussis-inactivated poliovirus vaccines containing either acellular (Pa, SmithKline Beecham Biologicals) or whole cell (Pw, Pasteur Merieux Connaught) pertussis components, mixed with a Haemophilus influenzae type b polysaccharide polyribosylribitol phosphate-tetanus conjugate vaccine in an open, randomized study in healthy infants.

DESIGN

The combined vaccines were given at 2, 4, 6 and 12 months of age, and serum samples were obtained at ages 2, 6, 7, 12 and 13 months. Adverse events were obtained by diary cards.

RESULTS

The Pa group (n = 101) had a clearly lower incidence of both local and systemic adverse events than the Pw group (n = 100). Immunogenicity was comparable for the diphtheria and tetanus components, but significantly superior for pertussis toxin, filamentous hemagglutinin, pertactin and polioviruses 1, 2 and 3 in the Pa group. Both groups had an appropriate response with regard to H. influenzae type b polysaccharide polyribosylribitol phosphate, but the dynamics of the response were significantly different: geometric mean concentrations (micrograms per ml) after the second, third and booster doses were 1.27, 5.06 and 23.12 in the Pa group and 2.72, 6.66 and 13.59 in the Pw group, respectively (P = 0.0002 after second dose; P = 0.0005 after booster).

CONCLUSION

The presently studied diphtheria, tetanus, acellular pertussis-H. influenzae b vaccine conjugated to tetanus toxoid combination was at least as immunogenic as the diphtheria, tetanus, whole cell pertussis-H. influenzae b vaccine conjugated to tetanus toxoid combination, with a significantly better safety profile. This is of obvious importance in countries where inactivated poliovirus vaccine is part of the routine infant immunization programs.

Evidence for induction of polysaccharide specific B-cell-memory in the 1st year of life: plain Haemophilus influenzae type b-PRP (Hib) boosters children primed with a tetanus-conjugate Hib-DTPa-HBV combined vaccine

The lack of an adequate immune response to the major polysaccharide of the Haemophilus influenzae type b (Hib) capsule (polyribosyl ribitol phosphate) (PRP) in very young infants (< 18 months) can be overcome by conjugating PRP to a T-cell dependent carrier protein. We studied whether administration of a tetanus-PRP conjugate vaccine reconstituted with a diphtheria-tetanus-acellular pertussis-hepatitis B (DTPa-HBV) vaccine as a three dose primary course at 3, 4 and 5 months of age induced PRP-specific immunological memory, by examining the anti-PRP response to a dose of unconjugated PRP given with the DTPa-HBV booster approximately 1 year later. The unconjugated PRP elicited protective anti-PRP antibody levels (> or = 0.15 microgram/ml) in all but 3 of the 369 vaccinees, including 13 infants who failed to demonstrate a measurable immune response after the primary course. In a sub-cohort of 54 subjects all had anti-PRP levels > or = 0.5 microgram/ml within 7-14 days of the booster showing a rapid anamnestic type response. Both primary and booster responses were predominantly IgGl indicating a T-cell dependent response. The DTPa-HBV components elicited protective anti-diphtheria, anti-tetanus and anti-HBs antibody levels in > or = 98.5% of vaccinees, and immune responses to each of the acellular pertussis vaccine components in 92.3%-97.3% of subjects.

CONCLUSION

The tetanus-PRP conjugate vaccine not only elicited a good primary humoral response, but also induced immunological memory so that the infants were able to mount a large and rapid immune response to subsequent exposure to plain PRP, indicating that protection against circulating wild-type Hib had been generated. Successful induction of immunological memory occurred even when there was no measurable humoral anti-PRP response to the primary course. Tetanus-PRP conjugate vaccine can be used in combination with DTPa-HBV vaccine, when administered separately or as a single injection in the same syringe, in primary immunisation schedules at 3, 4 and 5 months of age.

[Microbiologic cervix and amniotic fluid studies in early 2nd trimester: prognostic value for subsequent course of pregnancy?]

Our purpose was to determine the impact of cervical and amniotic fluid colonization in the early second trimester on the course of pregnancy. Cervical canal and amniotic fluid specimens were obtained from 167 patients without increased risk for prematurity. The specimens were examined for facultative-pathogenic bacteria (including mycoplasmas), fungi and Chlamydia trachomatis. The outcome of pregnancies was assessed in correlation with the microbiological findings. Of the patients studied 37% were cervically and 9% were intraamniotically colonized. Mycoplasmas dominated (cervix: 70%, amniotic fluid: 33%). In only two cases the same species was demonstrated at both sites. Women intra-amniotically colonized with microorganisms did not demonstrate a higher frequency of premature labor and premature rupture of membranes. Women with cervical detection of microorganisms demonstrate a tendency to higher frequencies of prematurity.

Different alleles of the fcrA/mrp gene of Streptococcus pyogenes encode M-related proteins exhibiting an identical immunoglobulin-binding pattern

The majority of group A streptococci (GAS, Streptococcus pyogenes) express immunoglobulin (Ig)-binding proteins. The genes encoding these proteins belong either to the emm or the emm-related (fcrA/mrp and enn) gene family and are located in close proximity on the GAS genome, where they form part of the vir regulon. In the present study analysis of sequence data of the 5' terminal portions of the fcrA/mrp genes from GAS isolates representing 37 different M serotypes led to a classification of six different types. Thus, although fcrA/mrp genes exhibit an allelic polymorphism, they do not display the high degree of N-terminal sequence diversity found among emm genes. The nucleotide sequences of the fcrA/mrp genes from 3 GAS isolates, belonging to serotypes M8, M9, and M13 and representing newly characterized fcrA/mrp gene types, are reported. Analysis of the Ig-binding properties of recombinant FcrA/Mrp8, 9, and 13 proteins, demonstrated a similar Ig-binding profile being reactive with human IgG subclasses 1, 2, and 4. This pattern is identical to that previously described for other recombinant fcrA/mrp4, 49, 64/14 and 76 gene products, indicating that this property is not affected by the N-terminal variability. Evidence for recombination between an fcrA/mrp and an mga gene was observed in an M-type 33 strain isolate providing further support for the concept of gene rearrangement contributing to the diversity of vir regulon gene products.

[Lethal, non-menstrual toxic shock syndrome associated with Staphylococcus aureus sepsis]

We report a rare case of non-menstrual toxic shock syndrome (TSS) in the course of Staphylococcus aureus sepsis in a 31-year-old primigravida who developed high fever and severe pulmonary and cardiovascular failure within a few hours at the end of the 29th week of a twin pregnancy. Mechanical ventilation was necessary due to signs of adult respiratory distress syndrome (ARDS) and catecholamines were needed to maintain a somewhat adequate blood pressure. A forceps delivery was performed immediately. Postoperatively, the patient was brought to the intensive care unit (ICU) due to the suspicion of severe septic shock. In addition to the extreme cardiovascular instability and massive disturbance of pulmonary gas exchange, the clinical picture was characterised by a disseminated intravascular coagulopathy (DIC) with marked petechial bleeding and ecchymoses on all extremities. Moreover, a confluent, spotty exanthem of the trunk and extremities could be seen. Despite all therapeutic efforts, the patient died within a few hours after admission to the ICU with signs of multiorgan failure. Post-mortem, multiple staphylococcal abscesses were found in the kidneys, liver, and uterus. Moreover, acute ulcerous endocarditis of the mitral valve and septic myocardial foci with myocarditis were seen. The Staph. aureus strain isolated from the blood cultures was shown to produce TSS toxin 1 (TSST-1) and enterotoxin B. In summary, the clinical picture can be interpreted as severe staphylococcal sepsis complicated by TSS. TSS is a specific type of infectious disease, occurring mainly in young women during the menstrual period (80%-90%), but it has also been reported in non-menstrual cases (10%-20%). It is characterised by sudden-onset high fever, hypotension, rash, mucosal hyperaemia, and various additional symptoms such as myalgia, vomiting, and diarrhoea. The clinical course depends on the extent of the organ failure due to decreased tissue perfusion during hypotension. Severe cases are accompanied by multiple organ-system failure including impaired renal function, which is reversible in nearly all cases. Respiratory failure ranges from interstitial and alveolar aedema to ARDS in 10% of cases; severe DIC is seen in 10%-15%. Another severe clinical complication is cardiac insufficiency. The etiology of TSS is based on a localized or, rarely, systemic infection with certain Staph. aureus strains that are capable of producing toxins, the most important one being TSST-1. Staph. aureus strains can also produce various other enterotoxins that may be involved in the pathogenesis of TSS. The pathogenetic importance of the toxins is supported by the antibody titers in TSS patients: more than 80% of healthy adults show high levels of antibody titers, whereas 90% of TSS patients exhibit low levels in the acute phase followed by a significant increase during convalescence. It is not clear whether the toxins cause TSS by a direct effect or by release of mediators due to their function as superantigens. The clinical characteristics of non-menstrual TSS are identical to those of menstrual TSS, but it can occur in many clinical settings in both sexes at any age. Severe clinical courses are more frequent in non-menstrual TSS: the mortality is about 8%-11% in non-menstrual TSS compared to 2%-5% in menstrual TSS. The diagnosis is based mainly on clinical signs and the isolation of toxin-producing Staph. aureus strains. Besides antibiotic therapy, treatment is primarily directed to the correction of hypotension and additional organ-system failure. Other therapeutic measures such as the elimination of toxins by plasma separation or the administration of antibodies or gamma-globulins are subjects of investigation with no general recommendations at this time.

Antimicrobial resistance and type distribution of Streptococcus pneumoniae isolates causing systemic infections in Germany, 1992-1994

A prospective study of pneumococcal infections was performed in cooperation with 40 clinical microbiology laboratories in Germany. Minimal inhibitory concentration (MIC) values for 844 strains of Streptococcus pneumoniae, isolated from patients with systemic infections, were determined in tests with penicillin, tetracycline, erythromycin, chloramphenicol, cefotaxime, and clindamycin by a standard broth microdilution method; 1.8% of pneumococcal isolates exhibited reduced susceptibility to penicillin (MIC, > or = 0.1 micrograms/mL). The Etest, which was used to confirm the level of resistance to penicillin, proved to be a reliable and easily performed method for determination of MICs. The rates of resistance to clindamycin, erythromycin, tetracycline, and chloramphenicol were 1.4%, 3.2%, 11.0%, and 1.9%, respectively. Resistance to cefotaxime was not observed. Typing of a randomly selected subgroup of all strains (n = 115) showed types 1 (9.6%), 14 (8.7%), 3 (7.8%), and 23F (7.8%) to be the most prevalent types in Germany. At least 86.1% of these pneumococcal strains belonged to capsular types included in the 23-valent vaccine.

Species identification and antibiotic susceptibility of enterococci isolated from clinical specimens of hospitalized patients

Over a 4-month period, a total of 315 enterococci were isolated from various clinical specimens of hospitalized patients. By applying an array of biochemical tests, all strains were accurately identified to the species level, and their susceptibilities to clinically relevant antibiotics were determined by a standardized agar dilution technique. E. faecalis and E. faecium accounted for 87.3% and 9.2% of isolates, respectively. E. avium (1%), E. gallinarum (1%), E. durans (0.6%), E. hirae (0.6%), and E. casseliflavus (0.3%) isolates were also identified. Eleven strains of E. faecium and 1 E. hirae isolate were resistant to ampicillin, but none of the isolates produced beta-lactamase. Twenty-three E. faecium and 3 E. faecalis strains as well as 1 E. hirae isolate revealed imipenem resistance. A total of 25.4% enterococci (60 E. faecalis and 19 E. faecium isolates, 1 E. hirae strain) were erythromycin-resistant. Twelve strains (11 E. faecium and 1 E. avium) exhibited ciprofloxacin resistance. High-level resistance to streptomycin was found in 58 (21.1%) E. faecalis, 9 (31%) E. faecium, and both E. hirae strains, whereas high-level gentamicin resistance (HLGR) was exclusively seen in the species E. faecalis (11.6% of isolates belonging to this species). A simple agar screening test containing 500 micrograms of gentamicin per ml proved to be highly reliable for detection of HLGR. The structural gene coding for HLGR was specifically amplified by the polymerase chain reaction in all isolates showing this resistance trait. Moreover, the gene was specifically detected by a nonradioactively labelled oligonucleotide probe in colony blot hybridization assays, indicating the potential application of these molecular approaches as a diagnostic tool.

Sister chromatid exchange-inducing DNA lesions and depression of activation markers on the surface of cultured peripheral blood mononuclear cells after the addition of streptococcal pyrogenic exotoxins A and C

Cultivation of peripheral blood mononuclear cells (PBMC) in the presence of streptococcal pyrogenic exotoxins (SPE) A and C resulted in a significant induction of sister chromatid exchange (SCE)-inducing DNA lesions. Concomitantly, the expression of interleukin-2 receptor alpha chain (IL-2R alpha chain), transferrin receptor (TfR), and major histocompatibility complex class II molecule HLA-DR on the surface of phytohemagglutinin-activated T cells from whole blood culture cells (WBCC) significantly decreased within 72 h, that is at least two cell cycles, whereas unstimulated T cells from WBCC did not express these markers but had lost their CD3 molecules, an effect reported to precede apoptosis as part of a T cell inactivation pathway. However, no apoptotic cells were observed within a cultivation period of 120 h. We observed clearcut differences in the responses towards SPE A in WBCC and isolated lymphocytes, since SPE A-treated lymphocytes showed an increase in the [3H]thymidine incorporation and did express IL-2R alpha chain and TfR on their cell surface. Regardless of the precise underlying mechanism, T cells from WBCC seem to be in a state of functional incompetence. The data presented here are the first to provide strong evidence that streptococcal toxins produce SCE-inducing DNA lesions in PBMC, an effect that might contribute to the process of immune cell lethality in streptococcal toxic shock-like syndrome and could be of pivotal importance in the pathogenesis of severe streptococcal disease.

Measuring resistance to phagocytosis of group A and G streptococci: comparison of direct bactericidal assay and flow cytometry

M protein is thought to contribute to the ability of non-opsonized group A and group G streptococci (GAS and GGS, respectively) to resist phagocytosis by polymorphonuclear leukocytes. In previous studies, correlation between M protein expression and phagocytosis was determined by incubating these pathogens in human blood and comparing colony-forming bacterial counts prior to and after exposure to blood (direct bactericidal assay; DBA). Here, we report the application of flow cytometry to measure GAS and GGS resistance to phagocytosis. The results of the assays were in complete agreement with those from DBAs. Nevertheless, flow cytometry was regarded as superior to DBA because of its speed and potential uses for quantitative studies. In addition, the use of anti-CD11b monoclonal antibody for granulocyte staining guaranteed a non-compromized granulocyte function. The optimized protocol for flow cytometry presented here could be utilized to directly measure the involvement of individual protein types in bacterial resistance to phagocytosis.

Randomized evaluation of benzathine penicillin V twice daily versus potassium penicillin V three times daily in the treatment of group A streptococcal pharyngitis. Pharyngitis Study Group

In a randomized, prospective, multicenter study the clinical and bacteriological efficacies of three dosage schedules with two different salts of oral penicillin V suspensions (regimen 1: potassium salt of penicillin V, 50,000 U/kg of body weight per day in three divided doses; regimen 2: benzathine salt of penicillin V, 50,000 U/kg of body weight per day in two divided doses; and regimen 3: benzathine salt of penicillin V, 100,000 U/kg of body weight in two divided doses) for the treatment of streptococcal pharyngitis were evaluated. Children with clinical signs of acute pharyngitis and a positive throat culture for group A beta-hemolytic streptococci (GABHS) were eligible. There was no difference between the treatment groups with respect to the overall clinical success rate. Eradication of the original serotype of GABHS from throat cultures was achieved in 87.1% (regimen 1), 85.5% (regimen 2) and 87.7% (regimen 3) of patients. The incidence of potential drug-related adverse events was significantly higher in patients treated with regimen 3. The results of this and earlier studies strongly suggest that oral penicillin given twice daily should be the recommended treatment for the initial treatment of pharyngitis due to GABHS. Doubling the total daily dose is not beneficial in the usual clinical setting. Because of its favorable pharmacokinetics, the benzathine salt of penicillin V appears to be well suited for a twice-a-day dosage schedule.

M or M-like protein gene polymorphisms in human group G streptococci

Many group G streptococci (GGS) isolated from infected humans (but not from animal sources) express M or M-like proteins with biological, immunochemical, and genetic features similar to those of group A streptococci (GAS). To further elucidate the recently proposed M-like protein gene (emmL gene) polymorphisms in GGS, Southern blots of genomic DNAs from 38 epidemiologically unrelated GGS strains isolated from human specimens and 12 GGS strains recovered from animal sources were hybridized with oligonucleotide probes designed to specifically detect GAS M class I and M class II M protein (emm) genes. All human-associated GGS strains showed DNA homology to the GAS M class I emm gene probe, whereas no hybridization was found with DNA from any of the animal-associated strains. The emmL genes from all human isolates were amplified by PCR, and the complete sequence of the emmL gene of the Rebecca Lancefield grouping strain D166B was determined. Again, this gene exhibited the structural features typical for emm genes of M class I GAS. The 5' regions of the PCR-amplified emmL genes of the remaining 37 human GGS strains were sequenced. This region showed a sequence diversity similar to that known for GAS emm genes. When strains whose N-terminal emmL gene sequences showed a homology of > 95% were defined as belonging to one genetic type, 30 strains were segregated into six distinct genetic types, whereas the remaining 8 strains each exhibited a unique emmL gene sequence. A high degree of homology between the N-terminal emmL gene segments of six GGS strains and the corresponding regions of either the emm12 or the emm57 gene of GAS was found, suggesting a horizontal gene transfer between strains of these species of beta-hemolytic streptococci. Besides a further understanding of the evolution of GGS emmL genes, the observed emmL gene polymorphisms in GGS could provide the basis for a molecular subspecies delineation of strains and offers the potential of typing GGS for epidemiological purposes.

Serum antibody responses to vaccination with 23-valent pneumococcal vaccine in splenectomized patients

Sixty-three patients that have been splenectomized for various disorders were vaccinated with Pneumovax 23, the currently available pneumococcal vaccine. Before and one month after splenectomy, IgG antibodies against 8 pneumococcal polysaccharide antigens (types 3, 4, 6B, 7F, 10A, 14, 19F, and 20) were determined by a highly reproducible and type-specific enzyme-linked immunosorbent assay (ELISA). In order to increase the specificity of the assay, this method involved the use of a capture antibody (F(ab')2-fragments of a type-specific rabbit antipneumococcal hyperimmune serum) to bind the pneumococcal antigens to the plastic surface of microtiter plates and the absorption of these sera with the cross-reacting C polysaccharide. Rates of patients showing a two-fold antibody increase were dependent on pneumococcal type, ranging from 12.7% to 33.3%. Antibody responses of single patients were not uniform for all pneumococcal serotypes investigated. Only one patient responded to all of the eight antigens tested. In spite of relatively low response rates, splenectomized patients should be routinely vaccinated with the pneumococcal vaccine, especially when the low rate of adverse reactions is taken into consideration. It is emphasised that the results of the present study and those reported in the literature have to be compared and interpreted with caution, because the available data on the antibody response to pneumococcal vaccination are based on assays that differ substantially in methodology.

The fibronectin binding domain of the Sfb protein adhesin of Streptococcus pyogenes occurs in many group A streptococci and does not cross-react with heart myosin

Sfb protein, a fibronectin binding adhesin of Streptococcus pyogenes (Lancefield group A streptococcus), mediates streptococcal adherence to human epithelial cells via its fibronectin binding domain coded by a repetitive gene region named fnbr. In the present study, Southern blot analysis using the fnbr gene region as a probe to screen genomic DNA from 51 epidemiologically unrelated clinical isolates of S. pyogenes revealed that 70% carried a sequence homologous to the fnbr probe. Among ten other streptococcal strains belonging to serological groups B, C, and G, DNA from only two human S. equisimilis (group C) strains reacted with the probe. Further analysis by PCR-mediated amplification of the binding repeat coding sequences revealed that repeats of different S. pyogenes isolates were identical in size but varied in number, ranging from one to five. Most of the isolates were shown to carry multiple repeats. Presence of the probe-positive sequence correlated strongly with streptococcal binding to purified fibronectin and adherence to HEp2 human epithelial cells; of the 36 probe-positive isolates, 95% bound fibronectin and 89% adhered strongly to epithelial cells, whereas among the 15 probe-negative isolates only 27% had binding activities for fibronectin and 27% showed strong adherence to HEp2 cells. Antibodies raised against the fibronectin binding domain of Sfb protein recognized streptococcal fibronectin binding surface proteins in most of the clinical isolates but did not react with heart or skeletal muscle myosin in an enzyme immunoassay, as is the case with antibodies directed to M protein, another major surface protein of group A streptococci. The results of the present study suggest that Sfb protein could be a potential candidate for a streptococcal vaccine.

Genetic variability of the emm-related gene of the large vir regulon of group A streptococci: potential intra- and intergenomic recombination events

One of the most prevalent genetic lineages of group A streptococci (GAS) harbors a genomic locus termed the large vir regulon, which contains an emm gene encoding the antiphagocytic M protein, and structurally related fcrA and enn (emm-related) genes encoding immunoglobulin-binding proteins. In the present study more than 100 large vir regulons from 42 different GAS serotypes were analyzed by PCR and partial DNA sequencing. On comparing these data to published sequences, sites of mutational and putative recombinational events were identified and ordered with respect to their intra/intergenic or intra/intergenomic nature. The emm-related genes were found to display small intragenic deletions or insertions, were completely deleted from, or newly inserted into the genome, or were fused to adjacent genes. Intergenomic exchanges of complete emm-related genes, or segments thereof, between different vir regulons were detected. Most of these processes seem to involve short flanking direct repeats. Occasionally, the structural changes could be correlated with changes in the functions of the encoded proteins.

Rapid typing of group A streptococci by the use of DNA amplification and non-radioactive allele-specific oligonucleotide probes

Because of the allelic variations within the M protein gene (emm gene) of group A streptococci, reliable typing of this important human pathogen can be accomplished by the use of emm gene-specific oligonucleotide probes. Two technical modifications (a reverse dot blot and a reverse line blot hybridization assay) of a novel approach for the type-specific identification of emm genes have been developed. Both procedures involved amplification of an emm gene by polymerase chain reaction. The non-radioactively labeled amplicon was subsequently hybridized to a membrane carrying an array of immobilized emm gene-specific oligonucleotide probes, thus allowing the simultaneous analysis of the gene polymorphism in a single hybridization reaction. The feasibility of these rapid and easy to perform methods was shown for the unequivocal identification of reference strains and clinical isolates belonging to 16 different M serotypes.

Recurrent systemic pneumococcal infection in an immunocompromised patient

A case is reported of a splenectomized patient who experienced four episodes of systemic pneumococcal infection after receiving appropriate therapy in every instance. Serogrouping showed at least two different strains to be responsible for these infections. Immunological investigations showed a reduction in immunoglobulins, a decrease in in vitro immunoglobulin synthesis and a disorder of immunoregulatory T-cells, but immunological changes could not be readily explained by splenectomy alone.

[Puerperium after threatened premature labor--effects of infection screening in pregnancy]

Subclinical intrauterine infection is one of the causes of preterm birth. Adjuvant antibiotic treatment can improve the prolongative effects of tocolysis in patients with preterm labour. This study was conducted to evaluate the effectiveness of screening for infection and of antibiotic treatment in reducing postpartal infectious complications in patients with so called idiopathic preterm labour being treated with tocolysis intravenously. At the time of admission, we obtained cervical swabs of 138 patients for bacteriological investigation. 23 of the 37 patients with pathologic cervical colonisation were treated with antibiotics in addition to tocolysis. In women in preterm labour with pathologic cervical microbial colonisation, the frequencies of infectious complications in the puerperium were markedly increased compared to women without cervical colonisation. Adjuvant antibiotic therapy during pregnancy significantly reduced such complications. Additional antibiotic treatment of patients in idiopathic preterm labour with indicators of silent intrauterine infection seems beneficial not only for prolongation of gestation, but also for the reduction of postpartal infectious morbidity.

Chromosomally mediated high-level gentamicin resistance in Streptococcus mitis

Four blood culture isolates of Streptococcus mitis were found to be resistant to penicillin (MIC, 16 to 32 micrograms/ml) and gentamicin (MIC, 128 or 1,000 micrograms/ml), and the two antibiotics demonstrated a lack of in vitro synergy. As shown by polymerase chain reaction assays, the structural gene known to encode high-level gentamicin resistance in Enterococcus faecalis, Enterococcus faecium, and Streptococcus agalactiae was also present in all four S. mitis strains. Attempts to isolate plasmids were unsuccessful, but an oligonucleotide probe derived from the gentamicin resistance gene hybridized to distinct restriction fragments of genomic DNA, suggesting that the resistance genes in these strains are integrated into the bacterial chromosome.

[Toxic shock syndrome caused by Streptococcus pyogenes]

Four days after being bitten by an insect a 35-year-old woman without any serious underlying disease developed an extensive phlegmonous inflammation of the left eyelid which soon spread to the entire left half of her face. Streptococcus pyogenes serotype M1, which produced the erythrogenic toxin A in vitro, was isolated from two blood cultures. The course of the illness was characterized by high fever, diarrhoea, vomiting, circulatory failure, consumption coagulopathy, abnormal renal functions and a generalized exanthem with desquamation of the skin, exhibiting the full-blown picture of a toxic shock syndrome caused by S. pyogenes. She eventually recovered completely under intensive care involving administration of catecholamines, fresh frozen plasma and antithrombin III substitution, as well as antibiotic treatment with clindamycin (600 mg three times daily), ampicillin/sulbactam (4 g three times daily)--after 3 days replaced by imipenem (0.5 g four times daily)--and gentamycin (80 mg three times daily) for two weeks. Extensive necroses later required plastic surgery to the left eyelid, cheek and temporal region.

Ochrobactrum anthropi bacteremia: report of four cases and short review

Ochrobactrum anthropi, formerly "Achromobacter" CDC group Vd, is a nonfermentative, nonfastidious gram-negative bacillus, that only recently has been given attention as a potential human pathogen. Over a 2-year period, we observed four patients with multiple blood cultures that were positive for the organism. The patients had acute leukemia as underlying disease, and presented with clinical and microbiologic features consistent with catheter-related bacteremia. In three of the patients the infection initially appeared to be unrelated to chemotherapy-associated profound neutropenia and occurred early after, or was the reason for, hospital admission. The antimicrobial susceptibility of the isolates varied: unlike previously reported cases, resistance in some of our isolates included aminoglycosides, newer fluoroquinolones, and trimethoprim-sulfamethoxazole. Despite in vitro susceptibility to imipenem in initial isolates, treatment of two patients with this agent obviously failed to eradicate the organism, and the patients either relapsed with bacteremia shortly after discontinuation of treatment or remained persistently febrile and bacteremic. O. anthropi appears to be increasingly recognized as a human opportunist pathogen associated with intravascular catheters and unpredictable multiple antibiotic resistance.

[Current data on the antibiotic sensitivity of Streptococcus pneumoniae (Pneumococcus). The significance of penicillin resistant isolates]

Antibiotic-resistant pneumococci, including strains resistant to penicillin, are being isolated with increasing frequency also in Europe. Therefore, we studied the antibiotic sensitivity to penicillin, erythromycin, chloramphenicol, tetracycline, ofloxacin, and ciprofloxacin in 131 strains of Streptococcus pneumoniae; most of them were isolated from patients with systemic infections. A reduced susceptibility to penicillin was found in 7.6% (n = 10) of the Streptococcus pneumoniae strains. For the first time in Germany, in the present investigation two pneumococcal strains highly resistant to penicillin were isolated (minimal inhibitory concentration [MIC] values > or = 2 mg/l). These strains exhibited high MIC values against various cephalosporins as well. 10.7% of all pneumococci were resistant to tetracycline, resistance to erythromycin was found in 3.8% of the isolates. The emergence of pneumococci in Germany with reduced susceptibility to penicillin underscores the importance to include alternative drugs in sensitivity testing of pneumococci involved in systemic infections. Depending on the localization of the infection, parenteral third generation cephalosporins, glycopeptides and quinolone derivatives are primarily adequate in the treatment of infections caused by penicillin-resistant pneumococci.

The microbiologic aspects, including diagnosis, of beta-hemolytic streptococcal and enterococcal infections

Basic principles concerning the collection, transport, and processing of clinical specimens for the detection of Streptococcaceae are given. Identification of beta-hemolytic streptococci (S. pyogenes, S. agalactiae, Lancefield group C and G streptococci, S. anginosus) and enterococci is based on the careful observation of colony morphology and hemolytic pattern on sheep blood agar plates; subsequent genus or species confirmation is achieved by rather simple biochemical or enzymatic tests and by detection of streptococcal cell wall carbohydrate antigens (Lancefield grouping). Rapid antigen tests for the detection of group A and B streptococci directly from pharyngeal and vaginal swabs, respectively, are highly specific, thus allowing an immediate antibiotic therapy in patients with a positive test result. The reported sensitivities of these nonculture tests are too low to exclude streptococcal colonization or infection, however. The elucidation of the genetics of some major virulence factors of group A and B streptococci has contributed to knowledge of their association with disease, and molecular techniques have supplemented the traditional (mostly culture and serologic) methods for an improved understanding of the epidemiology and pathogenesis of streptococcal infections. Recently employed examples include the M protein gene typing of group A streptococci by oligonucleotide probes and the use of PCR assays for the detection of the genes encoding for the pyrogenic exotoxins. Restriction enzyme endonuclease digestions of bacterial DNA in association with DNA fragment separation by conventional or PFGE have been applied successfully to several species of Streptococcaceae (e.g., S. pyogenes, S. agalactiae). Enterococci are important pathogens in the hospital setting, exhibiting high morbidity and mortality rates in bacteremic patients with severe underlying disease. Molecular typing methods have clearly confirmed their potential to be nosocomially transmitted. E. faecalis and E. faecium still account for the majority of human infections, but some of the newer enterococcal species (at present 19 species are recognized) have been encountered as well. The definitive species identification of enterococci requires the performance of an array of biochemical tests. The increasing antimicrobial resistance of enterococci, including high-level resistance to penicillins and aminoglycosides and occasionally also to glycopeptides, has hampered standard therapeutic regimens. All enterococci isolated from serious infections should be tested for high-level gentamicin and streptomycin resistance by one of several methods evaluated; beta-lactamase production (primarily found in E. faecalis) is reliably detected by the nitrocefin test.(ABSTRACT TRUNCATED AT 400 WORDS)

T cell activation and cytokine release in streptococcal toxic shock-like syndrome

A 5-year-old girl with streptococcal toxic shock-like syndrome during varicella infection had high levels of tumor necrosis factor alpha and interleukin-6 but no interleukin-1 or interleukin-2 in the serum. Intravenous administration of gamma-globulin coincided with clinical improvement and with reduction of the levels of tumor necrosis factor alpha and interleukin-6. The data suggest that streptococcal pyrogenic exotoxins trigger synthesis of tumor necrosis factor alpha and interleukin-6 in vivo; intravenously administered gamma-globulin may down-regulate the cytokine response.

Molecular investigation of clinical Enterococcus faecium isolates highly resistant to gentamicin

Over a 10-month period, 22 beta-lactamase negative E. faecium strains resistant to ampicillin were isolated from severely compromised hospitalized patients. Most isolates were clinically significant. Twenty of these strains were also resistant to extraordinarily high levels of gentamicin, a finding described rarely in E. faecium. By whole-cell DNA restriction endonuclease digestion, the 20 strains with both ampicillin and high-level gentamicin resistance segregated into only 3 different groups, suggesting introduction of limited clones into this population of patients. Plasmid DNA profiles and plasmid DNA restriction enzyme analysis supported this grouping for 18 of these 20 strains, the two remaining isolates had slightly different profiles. Both strains lacking high-level gentamicin resistance had clearly different molecular profiles. The results of hybridization experiments strongly suggested the presence of a similar genetic determinant of high-level gentamicin resistance in E. faecalis and E. faecium. High-level gentamicin resistance in E. faecium was shown to be transferable on conjugative plasmids, so that further dissemination of this resistance trait may be anticipated. Our data indicate that the use of a nucleic acid probe is a promising diagnostic tool for screening both E. faecium and E. faecalis for high-level gentamicin resistance.

[Infections by Streptococcus pyogenes: new aspects of diagnosis, epidemiology, clinical practice, and therapy]

Essential procedures for the cultural and serological laboratory diagnosis of Streptococcus pyogenes are described. A reliable and rapid species identification is achieved by serologic or biochemical tests. Direct antigen detection tests from throat swabs have broadened the diagnostic possibilities; however, they are often not satisfactory in terms of sensitivity. Typing of strains (either by classic serologic techniques or by molecular methods) is of high value for the study of clinical and therapeutic questions. In recent years, the epidemiology of the prevalent group A streptococcal strains has changed in Europe as well as in the U.S.: an increase of those M protein serotypes that are associated with higher virulence is being recognized. There is good evidence that the unexpected resurgence of rheumatic fever in the U.S. and the emerging number of life-threatening invasive and toxic manifestations of disease (including the toxic shock syndrome) in the U.S. and in Europe are related to the changing epidemiology. The existence of strains with rheumatogenic and nephritogenic potency has been established, but genetic host factors are a prerequisite for the sequelae as well. Although, based on experimental data, there are a lot of hypotheses concerning the nonsuppurative sequelae and the toxic shock syndrome, the exact pathogenesis of these diseases remains to be clarified. A thorough knowledge of the various clinical manifestations of group A streptococcal infections is necessary in order to apply the therapeutic and preventive measures in a rational and sophisticated manner. For most infections penicillins are considered the drug of choice, although no final conclusions regarding optimal dosages or the reasons for treatment failures can be made.(ABSTRACT TRUNCATED AT 250 WORDS)

[The vir-regulon of Streptococcus pyogenes: coordinate expression of important virulence factors]

Streptococcus pyogenes (group A streptococci; GAS) expresses important virulence factors like the antiphagocytic M protein, the complement factor-inactivating C5a peptidase and the immunoglobulin-Fc-binding proteins on its surface. The corresponding emm, scpA, and emm-related (fcrA, ennX) genes are adjacently encoded on the genome. They are coordinately in trans regulated by the positive regulatory VirR factor. The responsible virR gene is also located within this segment of the genome which was called vir-regulon. There are at least three different types of organization of the vir-regulon. A frequently encountered type is the "Large vir-regulon". It comprises from 5' to 3' the following genes: virR, fcrA, a relatively small emm, ennX, and a 4.6 kb version of scpA. Another common type is the "Small vir-regulon", which contains a virR deviating in its 3'-region, a relatively large emm, and a 3.5 kb version of scpA. The "Unusual vir-regulon" is less frequently detected. It closely resembles the small one, but harbors an additional 3 to 4 kb DNA fragment between emm and scpA, occasionally encoding an emm-related gene. The type of vir-regulon encoded by a GAS strain correlates to its serotype, its M class, and its expression of serum opacity factor. The structural genes of the vir-regulon are expressed at a high level during growth in exponential phase, under anaerobiosis, and at body temperature. The sensor molecule which modulates VirR activity according to these environmental conditions has not yet been detected.(ABSTRACT TRUNCATED AT 250 WORDS)

Characterization of methicillin-susceptible and methicillin-resistant Staphylococcus aureus isolates by molecular typing methods

Two groups of clinical Staphylococcus aureus isolates were examined by molecular typing methods. Detailed protocols for the technical procedures are described. By means of plasmid DNA profiles, plasmid DNA restriction enzyme digestion, as well as whole-cell DNA endonuclease digestions subjected to conventional agarose gel electrophoresis and pulsed-field gel electrophoresis, eight methicillin-susceptible S. aureus strains from three patients segregated into three different groups. Consecutive isolates from the same patient revealed identical fingerprints. Generally, good agreement between different molecular typing methods also was achieved in the investigation of 28 methicillin-resistant isolates. However, compared to whole-cell DNA restriction endonuclease analysis, plasmid DNA profiling (all but one strain had detectable plasmid DNA) showed a somewhat greater discriminatory ability. The techniques evaluated were reproducible and relatively easy to perform and provided valuable tools for studying the epidemiology of S. aureus in hospitals.

M protein gene typing of Streptococcus pyogenes by nonradioactively labeled oligonucleotide probes

A new approach for the typing of Streptococcus pyogenes is described. Oligonucleotide probes of 30 nucleotides in length were derived from currently known sequences of the N-terminal regions of M protein genes (emm genes). The oligonucleotides were labeled with digoxigenin-dUTP and hybridized to dot-blotted genomic DNA from 116 group A streptococcal strains of serotypes M-1, M-2, M-3, M-5, M-6, M-12, M-18, M-19, M-24, and M-49. Hybridization reactions were visualized with a chemiluminescent substrate. In comparison with conventional serological typing of expressed M proteins, the binding of the probes to the corresponding emm genes exhibited 100% sensitivity and specificity. The results emphasize the high degree of type-specific conservation of the N-terminal regions of emm genes from reference strains and epidemiologically unrelated U.S. and European clinical isolates. The existence of two distinct genetic subgroups among eight investigated M-49 strains was unequivocally shown by hybridization assays and further confirmed by nucleotide sequence data obtained from four selected M-49 strains. Because oligonucleotide probes are relatively easy to prepare, easy to handle, and known to give consistent interlaboratory results, the "oligotyping" technique appears to offer potential advantages over conventional serological typing methods.

The group A streptococcal M-type 3 protein gene exhibits a C terminus typical for class I M proteins

The M protein gene (emm gene) from a reference group A streptococcal strain of serotype M3 was amplified by the polymerase chain reaction and partially sequenced. Hybridization assays using an oligonucleotide probe derived from the N-terminal sequence revealed that this gene segment is highly homologous among M-type 3 isolates. Of note, analysis of the nucleotide sequence data from the C terminus of the gene confirmed that the emm 3 gene exhibited all the features characteristic for group A streptococcal M-class I molecules. Recently published sequence data that were assigned to emm 3 resulted from a strain confusion and were shown to be the first one derived from an emm gene of an M-untypable isolate.

[The possible nephrotoxicity of a bituminous coal dermatologic agent]

Nephrotoxic effects are discussed as a possible risk of dermatological coal tar preparations. Therefore, we have performed a renal tolerance study with a modern coal tar preparation for the scalp, Berniter. 15 healthy volunteers, randomly subjected to 3 different modes of application, applied the preparation: twice weekly (mode I) or daily (mode II) for a period of 8 weeks. In both modes, application time was 15 min. In mode III, the preparation was used under occlusion for 30 min every second day for a period of 4 weeks. Before, during and after treatment, renal functions and urinary phenol levels were assayed. No pathological change or impairment of renal functions was detected. A relationship between urinary phenol content and the coal tar treatment was not observed, either. We conclude that the coal tar preparation investigated here has no nephrotoxic properties.

Bacteremia caused by Stomatococcus mucilaginosus: report of seven cases and review of the literature

During a three-year period eight patients with blood cultures positive for Stomatococcus mucilaginosus were identified at two university hospitals. One patient without any signs of infection had a central venous catheter that was colonized with this organism, two patients had transient bacteremia without definite relationship to underlying disease, whereas the remaining five patients suffered from clinically significant infections. Of these last five patients, one had undergone prior head and neck surgery and four had hematologic malignancy with mild to severe neutropenia; two of the latter patients developed the infection subsequent to dental surgery. Besides neutropenia and mucosal damage in the oropharynx, quinolone antibacterial prophylaxis may have been an additional risk factor for the development of S. mucilaginosus bacteremia in these patients. A thorough review of the literature revealed that in addition to our findings, endocarditis and foreign body infections are further typical clinical manifestations. Although the overall antibiotic susceptibility pattern of S. mucilaginosus resembles that of streptococci, it is suggested that penicillin G may not be the drug of choice for initial therapy of particularly severe infections. S. mucilaginosus can be easily differentiated from other gram-positive bacteria when certain key criteria (e.g. adherence to agar surfaces, poor growth on Mueller-Hinton agar, presence of a capsule) as well as an array of biochemical tests, including commercially available identification systems, are applied. Our own and published data emphasize that both microbiologists and clinicians should be increasingly aware of this opportunistic pathogen.