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PubMed1989

[Characterization of fatty acid composition in the cytoplasmic membrane of Streptococcus mutans].

The present study was performed to investigate the role of the fatty acid composition of cytoplasmic membranes in bacterial differentiation and the appearance of cariogenic properties of Streptococcus mutans. Bacterial fatty acid composition was effective for differentiation of Streptococcus mutans from the other oral streptococci. The composition obtained from the reference strains and the clinical isolates involved five groups and was useful as a rapid screening index for Streptococcus mutans. Compositional changes in membrane lipids played important roles in synthesis and secretion of extracellular glucosyltransferase for Streptococcus mutans. A characteristic property of Streptococcus mutans, resistance to 40% sucrose in the medium, is ascribable to compositional changes in membrane lipids, especially the glycolipids, of Streptococcus mutans.

Cell Membrane↗
PubMed1975

[Production of sera for determining group A Streptococcus using the precipitation in gel reaction].

The sera of rabbits immunized with the culture of streptococcus, group A, treated with pepsin were studied by the immunodiffusion methods. The sera intensively reacted with the polysaccharide of the streptococcus, group A, but not with the polysaccharide of the streptococcus of A-variant and with the proteins contained in the hyfrochloric extracts of group A. Some of the sera contained antibodies to polyglycerophosphate and antigen E4 which could be eliminated by sorption of the sera with the culture of the streptococcus of A-variant treated with pepsin. Despite the sorption, individual sera reacted with the hydrochloric extracts obtained from the streptococcus, group L, or the S. aureus. The sera reacting with the polysaccharide of group A could be used for the identification of streptococcus, group A, by the method of precipitation in gel. The advantages of the method consist in its simplicity and distinct result, which can be obtained in two hours.

Adsorption↗
PubMed1994

[3 different methods for evaluating Streptococcus mutans in the saliva].

Three different methods for detection and count of Streptococcus mutans in saliva have been compared with a microbiological method in order to estimate their efficacy and practicality. The study has been carried out on fifty children of six-eleven years old. The first method (stamp method) derives from that of Kohler and Bratthall, improved on the sampling, without saliva stimulation and, hence, more rapid. Furthermore, using a tongue depressor with a shovel-like extremity, we can either restrict the area where the grown colonies must be counted, avoiding any mistake, and stamp the spatula in the centre of the plate, not in the border, as the original method described, pressing it with the same force in every part, so that almost all the saliva collected can be plated on the Streptococcus mutans selective medium. As stated by this method, a tongue depressor is pressed first on the subject's tongue, then on a plate containing the medium. After incubation, the Streptococcus mutans colonies are counted on the plate's area limited by the stamp of the extremity of the spatula. According to Emilson we can also discriminate Streptococcus mutans and Streptococcus sobrinus colonies. The second method is a "strip mutans test" (Dentocult): saliva is stimulated making the subject chew a piece of paraffin and then it is collected passing a plastic spatula for ten times on the child's tongue. The spatula is introduced into a tube containing a liquid medium selective for Streptococcus mutans and then incubated.(ABSTRACT TRUNCATED AT 250 WORDS)

Bacteriological Techniques↗
PubMedDate not supplied

[Sensitivity of Streptococcus pneumoniae to antimicrobial drugs].

INTRODUCTION: Streptococcus pneumoniae is the leading cause of community acquired pneumonia and a frequent cause of otitis media, sinusitis and meningitis. Although most pneumococci remain susceptible to penicillin, relatively less susceptible and resistant strains have been recognized with increasing frequency throughout the world (1). The aim of this study was to determine whether and to what degree pneumococci isolated in our laboratory were resistant to penicillin and other frequently used antimicrobial agents. MATERIAL AND METHODS: During the period from 1991 to 1995 1139 Streptococcus pneumoniae strains isolated from patients with different pneumococcal infections were tested for their susceptibility to antimicrobial agents at the Department of Bacteriology and Parasitology of the Institute of Public Health in Novi Sad. Antimicrobial agents tested included: penicillin, ampicillin, cephalexin, erythromycin, sulfamethoxazole-trimethoprim and clindamycin. Susceptibility test was performed by using Kirby-Bauer disc diffusion technique on Mueller-Hinton agar supplemented with 5% defibrinated bovine blood (5). RESULTS: Susceptibility of Streptococcus pneumoniae to seven antimicrobial agents used in the study is shown in Table 2. There was a resistance to all antimicrobial agents tested. It was the lowest to erythromycin (1.6%) and the highest to sulfamethoxazole+ trimethoprim (67.3%). The rate of resistance of penicillin was 3.3%. In Table 3 and 4 we can also see that the lowest resistance was to erythromycin, and the highest to sulfamethoxazole+trimethoprim, both for isolates from nose and other sources. Strains of Streptococcus pneumoniae isolated from nasal swabs were more susceptible to penicillin than those isolated from blood, sputum and cerebrospinal fluid. DISCUSSION: For many years penicillin has been the mainstay of therapy for pneumococcal diseases. Clinical resistance to penicillin was first reported in 1960's. Since this early reported, penicillin resistance has been encountered with increasing frequency in strains of Streptococcus pneumoniae from around the world. In our study resistance to penicillin was low (3.3%). This is in accordance with the authors from Italy, Great Britain, USA and Germany (7, 8, 9, 10). Much higher prevalence of resistant pneumococci we found in the reports from Spain, France and Hungary (13, 14, 15, 17). Many of these strains have been resistant to multiple drugs and have been isolated from patients with invasive infections (meningitis, pneumonia, bacteremia). Percentage of penicillin resistant pneumococci isolated from blood, sputum and cerebrospinal fluid in our study was relatively low (7.7%), but it was higher than the percentage of resistant isolates from nasal swabs (2.0%). These findings are in accordance with other reports (20, 21). CONCLUSION: The increasing number of Streptococcus pneumoniae isolates resistant to penicillin and other antimicrobial agents indicates the need to perform susceptibility testing for every isolated strain in order to avoid possible therapeutic failure.

Anti-Bacterial Agents↗
PubMed1998

Flush resuscitation for group A streptococcus toxic shock: a possible role for continuous renal replacement therapy and plasmapheresis.

Group A streptococcus has emerged as a major cause of aggressive life-threatening deep-seated infections. In addition, toxic shock syndrome caused by Group A streptococcus was recognized in 1983. Group A streptococcus produces several potent exotoxins which explain the pathophysiology of these invasive infections. Other virulence factors such as M protein, which can impede phagocytosis, are associated with some Group A streptococcus. M protein and streptococcal pyrogenic exotoxins may act as super antigens. Host factors may influence the severity of infection. Blood purification techniques such as continuous renal replacement therapy and plasmapheresis can remove streptococcal exotoxins as well as inflammatory mediators. Replacement with fresh-frozen plasma corrects coagulopathy and may provide some antibody protection. Four patients with Group A streptococcus-toxic shock syndrome treated with continuous renal replacement therapy, plasmapheresis, or both showed dramatic, rapid improvement in cardiovascular dynamics and respiratory parameters. Two patients died. The mainstay of treatment for Group A streptococcus-toxic shock syndrome remains early diagnosis, aggressive surgical control of the infection, and appropriate antibiotics (i.e., penicillin and clindamycin). Flush resuscitation may rescue some patients from profound toxic shock. The mechanisms of action need to be delineated.

Anti-Bacterial Agents↗
PubMed1963

INTRASPECIES AND INTERSPECIES TRANSFORMATION REACTIONS IN PNEUMOCOCCUS AND STREPTOCOCCUS.

The efficiency of transformation of pneumococcus and a strain of viridans streptococcus (strain D) to streptomycin resistance is influenced by the species in which the mutation to resistance occurred, as well as by the species in which the mutated gene has been replicated. Pneumococcus and streptococcus strain D transform in higher frequency with DNA that has been replicated in bacteria of the same species than with DNA from the heterologous species. However, the difference between the frequencies of interspecific and intraspecific transformation is much greater with pneumococcus as receptor than with streptococcus. In addition pneumococcus transforms in higher frequency with wholly homologous (pneumococcal) DNA than with DNA from pneumococci that have replicated the streptococcal Sm(r) gene. Pneumococcus is transformed in lower frequency by wholly heterologous (streptococcal) DNA than by DNA from streptococci that have replicated the pneumococcal Sm(r) gene. Streptococcus behaves similarly in that wholly homologous (streptococcal) DNA transforms it more efficiently than when the transforming fragment contains a pneumococcal moiety. Streptococcus is transformed in the same or lower frequency by wholly heterologous (pneumococcal) DNA than by DNA from pneumococci that have replicated the streptococcal Sm(r) gene. When erythromycin resistance was used as genetic marker instead of streptomycin resistance, similar results were found.

DNA↗
PubMed1964

GENETIC LINKAGE OF MUTATIONAL SITES AFFECTING SIMILAR CHARACTERS IN PNEUMOCOCCUS AND STREPTOCOCCUS.

Ravin, Arnold W. (University of Rochester, Rochester, N.Y.), and Joscelyn D. H. De Sa. Genetic linkage of mutational sites affecting similar characters in pneumococcus and streptococcus. J. Bacteriol. 87:86-96. 1964.-By interspecific transformation, deoxyribonucleic acid (DNA) determinants conferring resistance to high levels of streptomycin in pneumococcus were found to be allelic with DNA determinants conferring low levels of streptomycin resistance in the Challis and NBSI strains of streptococcus. The reciprocal transformation (low resistance pneumococcus x high resistance streptococcus) led to the same conclusion. In addition, determinants controlling resistance to erythromycin in pneumococcus and the Challis strain of streptococcus were found to become closely linked after interspecific transformation. Modifier genes influencing the phenotype conferred by mutations at the streptomycin-resistance locus differentiate species to a certain extent. The results demonstrate that transformations between pneumococcus and streptococcus are not due to episomes, but involve recombinational events in which genetic material of the host species is replaced by homologous material that performed a similar function in the donor species.

DNA↗
PubMed1995

Streptococci and actinomyces inhibit regrowth of Streptococcus mutans on gnotobiotic rat molar teeth after chlorhexidine varnish treatment.

Clinical studies suggest that the long-term suppression of mutans streptococci on tooth surfaces after intensive chlorhexidine therapy is mainly due to bacterial interference. Other streptococci and also Actinomyces naeslundii are proposed to inhibit regrowth of mutans streptococci after suppression by the agent. We have tested this hypothesis in gnotobiotic rats associated with Streptococcus mutans alone, or associated with S. mutans and strains of Streptococcus oralis, Streptococcus sanguis, Streptococcus gordonii, Streptococcus mitis biovar I, and A. naeslundii. Left lower jaws in these rats were treated with concentrated chlorhexidine varnish, and the return of S. mutans on the treated jaws monitored. In mono-associated rats, S. mutans regained the level of the untreated right lower jaw in approximately 1 week. In contrast, S. mutans remained suppressed for several weeks in rats multi-associated with other streptococci and actinomyces strains. The suppression was more pronounced in the rats fed on basal diet with little free sugars than in rats fed on a sucrose-containing diet. Counts of other streptococci recovered quickly from the intensive chlorhexidine treatment, but A. naeslundii remained suppressed for at least 1 week. The findings demonstrate the crucial importance of the oral microflora in controlling regrowth of mutans streptococci after chemotherapy.

Actinomyces↗
PubMed1987

A simplified diagnostic system for cultural detection and enumeration of Streptococcus mutans.

A simple dip-slide test (Cariescreen SM) based on MSB selective agar was devised for detection and quantitation of Streptococcus mutans in oral samples. For this test, a bacitracin tablet is dissolved in a vial containing buffered saline diluent. Paraffin-stimulated saliva is collected in this diluent vial. A dip slide which incorporates a modified MSB agar (minus bacitracin) is immersed briefly in the diluted saliva. After addition of a CO2-generating tablet, the screw-cap dip slide is closed tightly in the vial and incubated for two days at 37 degrees C and one day at room temperature. S. mutans populations in saliva are estimated by comparison with a colony density chart. Growth of reference strains of S. mutans was equivalent on Cariescreen SM dip slides and on MSB agar plates. Reference strains of Streptococcus sanguis, Streptococcus salivarius, Streptococcus mitis, and Streptococcus milleri did not grow on Cariescreen SM dip slides. Aliquots of saliva from 50 schoolchildren and 51 adults were tested by the dip-slide method and by conventional plating methods in MSB agar. Very good correlation (0.93) between the two methods was obtained. This simplified S. mutans detection system is suitable for use by clinical personnel in dental clinics or other non-laboratory settings for identification of subjects potentially at risk for caries.

Bacitracin↗
PubMed1985

Streptococcus faecalis sex pheromone (cAM373) also produced by Staphylococcus aureus and identification of a conjugative transposon (Tn918).

Streptococcus faecalis RC73 was found to harbor a conjugative plasmid (pAM373) which confers a mating response to a sex pheromone (cAM373) excreted by plasmid-free members of the same species. The pheromone was also detected in culture filtrates of all of 23 Staphylococcus aureus strains but in only 2 of 22 coagulase negative staphylococcus strains. Streptococcus sanguis Challis and G9B also produced the activity, but 10 other Streptococcus sanguis strains did not. The activity was also produced by Streptococcus faecium 9790. A tetracycline resistance (Tc) determinant present in S. faecalis RC73 was not associated with pAM373 but served as a useful marker in efforts to identify pAM373 among other plasmids present in the strain. Analyses of the Tc determinant showed that it was located on a conjugative transposon very similar to Tn916. Designated Tn918, the transposon could insert into pAM373 as well as into two other hemolysin plasmids. Whereas pAM373 derivatives transferred very well between strains of Streptococcus faecalis, the plasmid would not establish in Staphylococcus aureus or Streptococcus sanguis. However, a derivative of pAM373 carrying Tn918 proved to be a useful delivery vehicle for generating transposon insertions into multiple sites on the staphylococcal chromosome.

Animals↗
PubMed1990

Septic arthritis due to group C streptococcus: report and review of the literature.

A case of polyarticular septic arthritis due to Lancefield group C streptococcus is described and the clinical details of 9 reported cases of septic arthritis due to group C streptococcus reviewed. Several features of the presentation and course of these patients, including polyarticular involvement (4/10), bacteremia (5/10), clinically important dysfunction in other systems (4/10 patients: cardiac, 3; CNS, 2; pneumonia, 1; gastrointestinal, 1), fatal outcome (3/10 patients, 2 during the course of active infection) and poor functional outcome in affected joints (4/7 surviving patients), serve to place group C streptococcus septic arthritis as a syndrome distinct from that usually expected with streptococcal septic arthritis. Specific features of the bacteriology of group C streptococcus are reviewed (including confusion with group A streptococcus when analyzed using nonserologic methods, occasional zoonotic source, and frequency of tolerance to penicillin) in order to emphasize the importance of both the specific identification of this particular streptococcal strain and the initiation of aggressive antibiotic therapy when group C streptococcus is identified as the causative agent in a case of septic arthritis.

Aged↗
PubMed1995

Pentoxifylline ameliorates pulmonary damage caused by Streptococcus pneumoniae infection in mouse.

Streptococcus pneumoniae stimulated mouse peritoneal macrophage to release tumor necrosis factor-alpha (TNF alpha) in vitro. When penicillin was added into the medium with bacteria, TNF alpha release was accelerated. Pentoxifylline (PTX), a phosphodiesterase inhibitor, significantly attenuated TNF alpha release caused either by Streptococcus pneumoniae or by its lysates. In this experiment, 150 Kunming mice were infected with Streptococcus pneumoniae through inspiration. Dynamic changes of TNF alpha concentration in serum and bronchoalveolar lavage fluid were determined, and pulmonary pathological changes were also observed. It was found that PTX significantly attenuated TNF alpha activity in serum and bronchoalveolar lavage fluid, and inhibited white blood cell chemotaxis, emigration and infiltration. In conclusion, Streptococcus pneumoniae infection stimulates the release of TNF alpha which is probably the major mediater that causes tissue damage during Streptococcus pneumoniae infection. The mechanism is probably that Streptococcus pneumoniae and its lysates activate TNF alpha gene transcription. As penicillin accelerates TNF alpha release, treatment with penicillin alone may aggravate the tissue damage. Combined treatment with PTX may be more reasonable.

Animals↗
PubMed1989

Reliable five-minute test strip method for identification of Streptococcus pyogenes.

A novel and rapid method (Strep Strip, Lab M) for identification of Streptococcus pyogenes was evaluated. The method combines the established test for pyroglutamyl aminopeptidase (PYR) with a rapid chromogenic test for beta-glucosidase on a paper strip. The test was evaluated with 274 clinical isolates and 237 culture collection isolates of beta-haemolytic streptococci. Streptococcus pyogenes was identified with 100% specificity. Six isolates identified as Lancefield group A and which might therefore be assumed to be Streptococcus pyogenes were shown by the test strip method not to be this species. The beta-glucosidase test on the test strip allowed differentiation between enterococci and Streptococcus pyogenes (both PYR positive) in all cases. The test strip method represents an economical and accurate method for identification of Streptococcus pyogenes in clinical material.

Aminopeptidases↗
PubMed1975

Meningitis caused by Streptococcus in adults.

Meningitis caused by Streptococcus is uncommon in adults. Otitis media, mastoiditis, sinusitis, or trauma has antedated most cases reported in the past. Data on 10 recent cases suggest changes in the current pathogenesis of streptococcal meningitis in adults and emphasize the importance of accurate streptococcal speciation. Endocarditis was present in five cases; trauma played a role in two others. Brain abscess, corticosteroids, alcoholic cirrhosis, and peritonitis secondary to chronic peritoneal dialysis were etiologic factors in five patients. Otitis media, mastoiditis, and sinusitis were conspicuously absent. Streptococcus agalctiae accounted for purulent meningitis in two postmenopausal women. Both strains of group B Streptococcus were bacitracin-sensitive and were thus mislabeled group A. Recognition of Streptococcus bovis spared two patients unnecessary aminoglycoside adminstration. Nine of the 10 patients survived, including a women with prosthetic mitral valve endocarditis and a man with a ruptured brain abscess. Differentiation of these streptococci from Streptococcus pneumoniae was seldon possible on the basis of the spinal fluid gram stain alone.

Adult↗
PubMed1983

Purification and properties of pyruvate kinase from Streptococcus sanguis and activator specificity of pyruvate kinase from oral streptococci.

It was found that pyruvate kinases with two different regulatory characteristics were distributed among oral streptococci. The pyruvate kinases of Streptococcus mutans, Streptococcus salivarius, and Streptococcus bovis were activated by glucose 6-phosphate, whereas the enzymes of both Streptococcus sanguis and Streptococcus mitis were activated by fructose 1,6-bisphosphate. Pyruvate kinase (EC 2.7.1.40) from S. sanguis NCTC 10904 was purified, giving a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The enzyme had a molecular weight of 250,000 to 260,000 and consisted of four identical subunits. Whereas the pyruvate kinase from S. mutans was completely dependent on glucose 6-phosphate (K. Abbe and T. Yamada, J. Bacteriol. 149:299-305, 1982), the enzyme from S. sanguis was activated by fructose 1,6-bisphosphate. In the presence of 0.5 mM fructose 1,6-bisphosphate, the saturation curves for the substrates, phosphoenolpyruvate and ADP, were hyperbolic, and the Km values were 0.13 and 0.30 mM, respectively. Without fructose 1,6-bisphosphate, however, saturation curves for both substrates were sigmoidal. GDP, IDP, and UDP could replace ADP. Like the enzyme from S. mutans, the enzyme from S. sanguis required a divalent cation, Mg2+ or Mn2+, and a monovalent cation, K+ or NH4+, for activity, and it was strongly inhibited by Pi. When the concentration of Pi was increased, the half-saturating concentration and Hill coefficient for fructose 1,6-bisphosphate increased. The remarkable fluctuation of intracellular levels of fructose 1,6-bisphosphate and phosphoenolpyruvate observed in the cells growing under glucose limitation and nitrogen limitation implies that the intracellular concentration of fructose 1,6-bisphosphate, in cooperation with that of Pi, may regulate pyruvate kinase activity in S. sanguis in vivo.

Cations↗
PubMed2006

Antibiotic sensitivities of Streptococcus pneumoniae, viridans streptococci, and group A hemolytic streptococci isolated from the maxillary and ethmoid sinuses.

OBJECTIVES: To investigate antibiotic sensitivities of Streptococcus pneumoniae, viridans streptococci, and group A hemolytic streptococci isolated from the culture materials obtained from the sinuses of patients undergoing functional endoscopic sinus surgery due to chronic sinusitis. PATIENTS AND METHODS: We recruited 93 patients (63 males, 30 females; mean age 36+/-17.5; range 19 to 68 years) who underwent functional endoscopic sinus surgery due to chronic sinusitis. Before surgical intervention, in order to eliminate a possible contamination from the skin and neighboring structures, nasal mucosa was cleansed with povidone-iodine solution. Nasal smear samples were obtained from all the patients before and after applying povidone-iodine solution. Streptococcus pneumoniae, viridans streptococci and group A hemolytic streptococci that were isolated from the cultures were tested for antibiotic sensitivity. RESULTS: The number of anaerobic bacteria isolated from 58 patients (62.3%) before applying povidone-iodine was 72, following the application of povidone-iodine a total of 16 microorganisms were identified from 12 patients (12.9%). Microorganisms were isolated from 95.6% (89/93) of the samples obtained from the maxillary sinuses and 91.3% (85/93) of the samples obtained from the ethmoid sinuses. The most commonly identified microorganisms from both sinuses were coagulase negative staphylococcus followed by viridans streptococci, coagulase positive staphylococcus, Streptococcus pneumoniae and group A hemolytic streptococci. For viridans streptococcal strains that were isolated, 33.3% were resistant to tetracycline, 23.8% to chloramphenicol, and 19.04% to penicillin. Hemolytic streptococci strains were sensitive to penicillin, ofloxacin, ceftriaxone, and cefepime in all the groups; however, they had 50% resistance to erythromycin and chloramphenicol and 100% resistance to tetracycline. The resistance pattern of the isolated Streptococcus pneumoniae strains were as follows: 25% to penicillin, 66.6% to trimethoprim/sulfamethoxazole, 41.6% to erythromycin, 58.3% to tetracycline, 33.3% to chloramphenicol and 16.6% to rifampin. All of the isolated strains were sensitive to vancomycin. CONCLUSION: We suggest that identification of strains that are resistant to penicillin and other antibiotics is an important tool for choosing empirical treatment for Streptococcus pneumoniae, viridans streptococci, and group A hemolytic streptococci in clinical practice. Viridans streptococci which are frequently isolated from chronic sinusitis patients should be kept in mind.

Adult↗
PubMed2004

Identification of the anginosus group within the genus Streptococcus using polymerase chain reaction.

The aim of this study was to establish an identification method for the anginosus group within the genus Streptococcus by polymerase chain reaction (PCR). Using a primer pair based on the group-specific sequences of penicillin-binding protein 2B (pbp2b) gene, a 275-bp fragment was amplified from each species in the group but no size-matched products were obtained in other streptococci. Further identification in the species or subspecies level was possible by a multiplex PCR with primers for the 16S ribosomal RNA gene of Streptococcus anginosus, the hyaluronate lyase genes both of Streptococcus intermedius and Streptococcus constellatus subsp. constellatus, and the intermedilysin (ily) gene of S. intermedius. In the case ofStreptococcus constellatus subsp. pharyngis, the amplified fragment from the S. intermedius-type hyaluronate lyase gene was obtained, while that from the ily gene was not. These results also indicate that two different hyaluronate lyase genes are distributed among the anginosus group.

Aminoacyltransferases↗
PubMedDate not supplied

Influence of diabetes on group B Streptococcus colonization in the pregnant patient.

To compare the incidence of group B Streptococcus colonization in diabetic (n = 98) and nondiabetic (n = 10) patients, 199 pregnant women were cultured at the vaginal introitus using a standardised technique. Eight diabetic patients had positive findings for group B Streptococcus cultures, and three nondiabetic patients had positive cultures. No significant difference (P = .109) was found in the group B Streptococcus colonization rates between these two groups of patients. In addition, no significant difference was found in the group B Streptococcal colonization rates between gestational and pregestational diabetics (P = .498). A within-group comparison of diabetic patients revealed that ethnicity (Hispanics versus nonhispanics) did generate a significant difference in the rate of colonization (P = .033). The results of the present study suggest that there is no substantial evidence to consider diabetes mellitus as a higher risk criterion for group B Streptococcus screening. However, population differences and ethnicity should be noted as important contributing factors when considering the implementation of group B Streptococcus screening protocols for pregnant women.

Adult↗