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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.
The antibiotic susceptibility of 10 strains of non-enterococcal group-D streptococci was compared with that of 20 strains of viridans streptococci. The minimal inhibitory concentrations of penicillin, ampicillin, oxacillin, nafcillin, cephalothin, vancomycin, erythromycin and clindamycin for the two groups of streptococci were very similar in range and median values. Both groups of streptococci were resistant to the aminoglycosides. The effect of the combination of penicillin, ampicillin or vancomycin with streptomycin, kanamycin, gentamicin or tobramycin on the in-vitro killing of the two groups of streptococci was compared. For all the antibiotic combinations tested, synergism was demonstrated against all strains of non-enterococcal group-D streptococci after one or more of the time-intervals 6, 24 and 48 h. Some or all of the antibiotic combinations were synergistic against all strains of viridans streptococci after one or more of the same time-intervals. The other aminoglycosides (kanamycin, gentamicin and tobramycin) offered no advantage over streptomycin in synergism with penicillin, ampicillin or vancomycin against nonenterococcal group-D streptococci or viridans streptococci. These results suggest that non-enterococcal group-D streptococcal endocarditis may be treated by the same regimen as endocarditis caused by the viridans streptococci.
The incidence of oral alpha-streptococci with inhibitory activity against group A streptococci, as a defense mechanism against bacterial infection in the oral cavity, was investigated in 141 patients with streptococcal tonsillitis. The study population included both children (n = 79) and adults (n = 62). Infection by group A streptococci appeared to be more common in children than in adults, as the detection rates of inhibitory alpha-streptococci in healthy children (29.7%), as well as pediatric patients with tonsillitis (14.9%), were lower than those in adults (63.0%; p < .01). It is possible to consider oral alpha-streptococci with inhibitory activity to be among the indications for tonsillectomy in patients with streptococcal tonsillitis, since the detection rate of inhibitory alpha-streptococci in surgical cases (10.9%) was significantly lower than that in nonsurgical cases (31.1%; p < .01). The high detection rate of these strains during the postoperative state supported the observation that the incidence of group A streptococcal infection was decreased postoperatively. Accordingly, it is useful to investigate bacterial interference between oral alpha-streptococci and group A streptococci in patients scheduled for tonsillectomy.
Group A streptococci (S. pyogenes) are responsible for pharyngitis, impetigo and several more serious diseases. Emergence of toxic shock, and necrotizing fasciitis, associated with this pathogen over the past 10 years, has generated interest in development of a vaccine, which would prevent infections and potential serious complications. The highly conserved C5a peptidase that is expressed on the surface of group A streptococcus and other streptococcal species, associated with human infections, is a prime vaccine candidate. Here, we report construction of an inactive form of the peptidase and test its potential to induce protection in mice from intranasal challenge with either serotype M1 and M49 strains of streptococci. Mice were immunized by subcutaneous administration of recombinant proteins, mixed with Alum and monophosphoryl lipid A (MPL) adjuvants. Control mice were vaccinated with tetanus toxoid in the same adjuvants. Preparations of SCPA protein were highly immunogenic in mice. Antibody directed against protein from either group A (SCPAw) or group B (SCPBw) streptococci neutralized activity associated with both enzymes. Streptococci were cleared from the oral-nasal mucosa of mice immunized with vaccine protein more rapidly than those immunized with tetanus toxoid. Moreover, immunization with either protein enhanced clearance of group A streptococci from the lung. These results suggest that parenteral vaccination with SCPBw protein will provide protection against infection by either group A or B streptococci.
To understand the significance to the host of streptococci as part of the intestinal microflora, we first tried to investigate the distribution of human fecal streptococci on the species level. Of the selective media compared, KMN agar was more effective than the other media for the isolation of streptococci from human feces. We made an effort to improve streptococcal classification. Especially we used utilization of 1% pyruvate, 1% arginine, and 1% citrate for differentiation between Streptococcus faecalis and S. faecium. In a tellurite tolerance test, S. faecalis was distinguished more clearly from S. faecium in the medium containing 0.16 or 0.32% tellurite. We devised methods of presumptive identification of fecal streptococci from the results of the characteristics of 1,442 isolates. These methods enabled us to identify many strains rapidly. Different results in the distribution of species of streptococci between children and adults were observed. S. faecalis and S. faecium were isolated constantly from both groups. S. bovis and S. avium were isolated frequently from the feces of children. On the other hand, "viridans" streptococci, e.g. S. salivarius, S. mitis and S. MG-intermedius were present at a high frequency in, and no S. avium could be isolated from, the feces of adults.
Perry, Dennis (Northwestern University Medical School, Chicago, Ill.), and Hutton D. Slade. Effects of filtrates from transformable and nontransformable streptococci on the transformation of streptococci. J. Bacteriol. 91:2216-2222. 1966.-The nature of the transformation competence factor from a group H streptococcus was investigated. The activity of competence factor reached a maximum at the time that optimal competence was attained, the maxima of both occurring in the early log phase of growth. The decrease in competence factor was much more gradual than the decrease in number of competent cells. No inhibitor, however, was detected as being responsible for the decrease in either competent cells or competence factor activity. Efforts to induce transformation in other serological groups of streptococci with the use of group H competence factor were unsuccessful. The development of competence in group H when grown in the presence of nontransformable group A strains resulted in a significant increase in the number of transformants. Culture filtrates from early log phase group A cells also caused an increase in the number of transformants from the group H strain. The addition of 10(-4)m ethylenediaminetetraacetic acid to group A (or group H) culture filtrates caused significant increases in the number of transformants. These results thus indicate that group A streptococci, although nontransformable, produce low levels of "competence factor." Late culture filtrates from the group H streptococcus and several strains of group A streptococci possessed deoxyribonuclease-like activity which inhibited the transformation of the group H strain. This activity in the A filtrates, however, was not prevented by group A anti-deoxyribonuclease sera. Instead, these sera also inhibited transformation. Evidence indicates that the lack of transformation of group A streptococci is due to factors other than the production of deoxyribonuclease.
Samples of human dental plaque were obtained from sound tooth surfaces in the lower anterior and upper posterior areas of each of 11 subjects with various degrees of caries experience. Both types of plaque were compared for: (1) their pH-lowering potential [pH at 10 and 60 min after sugar addition and the pH drop between 0 and 10 min (delta pH)] with an in vitro method involving dispersed plaque suspensions and excess glucose supply; (2) the proportions of mutans streptococci; and (3) the distribution of the predominant non-mutans streptococci according to their final pH in glucose broth. Compared with plaque from the lower anterior area, plaque from the upper posterior area exhibited a significantly higher pH-lowering potential, i.e., a lower pH at 10 and 60 min and a greater delta pH and significantly higher levels of mutans streptococci. The final pH values for the non-mutans streptococci exhibited a wide range from about 4.4 to over 5.0. The proportions of such organisms designated as capable of acidogenesis at low pH (final pH less than 4.6), whether expressed as a percentage of the total non-mutans streptococci or of the total plaque flora, were significantly increased in plaque from the upper posterior area. The proportions of non-mutans streptococci capable of acidogenesis at low pH in plaque from the upper posterior area were also significantly increased, with decreasing pH values at 10 and 60 min.(ABSTRACT TRUNCATED AT 250 WORDS)
The results of typing all group A streptococci isolated in one laboratory in 5 years were reviewed to see if the collected information showed epidemiological patterns. The great majority of the 5858 streptococci typed came from patients seen in general practice: 72% from throat swabs and 11% from skin lesions. Eight types, M types 1, 2, 3, 4, 6, 12, 22 and type 28 R accounted for 65% of strains. These eight types had different patterns: types 2 and 6 caused small circumscribed outbreaks and were uncommon between epidemics; types 3, 4 and 12 caused larger, wider epidemics, whereas types 1, 22 and 28 R had a more stable pattern. Type 4 was more commonly resistant to tetracycline than most other types, a finding which affected the apparent incidence of tetracycline resistance in group A streptococci. Streptococci from superficial sites were more likely to have serum opacity factor and to lack a detectable M-antigen than strains isolated from the throat. Routine typing of streptococci helped to detect outbreaks of infection in special groups. It is concluded that regular streptococcal typing should be continued in some places.
The present study was carried out to determine the surface hydrophobicity of group A streptococcal strains responsible for rheumatic fever (RF), "rheumatogenic" strains (RG strains) and strains causing glomerulonephritis, "nephritogenic" strains (NG strains) in relation to their adhesion to human pharyngeal cells. Scanning electronmicroscopic (SEM) studies were carried out to the difference, if any, in the adherence of group A streptococci (M type 5) to pharyngeal and buccal cells (PEC and BEC). By employing two techniques for hydrophobicity determination, salt aggregation titre (SAT) and n-hexadecane binding technique, it was observed that RG strains (M5, M1 and M6) were more hydrophobic than NG strain, M49. However, NG strain M12 was almost equally as hydrophobic as RG strains. The adherence of RG strains, except M1 and M24, to PEC was greater in number than that of NG strains. Although M1 strain was hydrophobic, its adherence to PEC was less. Pepsin and trypsin treatment with streptococci reduced the hydrophobicity and adherence of RG and NG strains to PEC. SEM studies revealed firmly adhered indigenous bacteria on PEC and BEC. Streptococci (M5) adhered more to PEC than to BEC. SEM studies also showed that PEC had a peculiar ultrastructural surface feature to which streptococci adhered. These findings suggest that streptococcal hydrophobicity alone does not determine their adhesion to PEC. The surface nature of PEC might be a characteristic feature of the epithelial cells that allows streptococci to adhere and colonize or it might be a consequence of streptococcal adhesion.
OBJECTIVE: To explore the possibility of detecting the distribution of Mutans Streptococci in human dental plaque by Monoclonal antibody (WC2E10c, WC3A6d) against SA I/II and SPAa of Mutans Streptococci, which was prepared in our lab. METHODS: 60 subjects were divided into the experimental group and the control group. The distributions of Mutans Streptococci (serotype c and d) in dental plaques were detected in 60 subjects by the clonal blot technique. Positive colonies were examined by bacterial morphology, serology, biochemistry and SDS-PAGE. RESULTS: Bacterial colony was significantly different between the experimental group and the control group with eye observation. Colonies of the experimental group were deep brown and easily differentiated, but colonies of control group were white. Brown colonies were proved to be Mutans Streptococci (serotype c and d) by using assay of bacterial morphology, serology, biochemistry and SDS-PAGE, but white colonies were not. CONCLUSION: McAbs (WC2E10c, WC3A6d) were shown high specificity in Mutans Streptococci (Serotype c and d) of human dental plaques.
Despite some similarities, L-streptococci could be clearly differentiated from A-streptococci. Formamide, autoclaved and nitrous acid extracts of all L-streptococcal cultures studied reacted only with their specific antisera and did not cross-react with any other group specific streptococcal antigens. All 33 L-streptococcal cultures, in contrast to A-streptococci, produced beta-D-glucuronidase and beta-D-galactosidase, hydrolyzed Na-hippurate, grew on 10% and 40% bile blood agar and were agglutinated by the lectin of Arachis hypogaea. Some differences between A- and L-streptococci were also observed in their sensitivity patterns to bacitracin and sulfamethoxazole-trimethoprim.
Previous evidence for the presence of an M or M-like protein on group G streptococci has been based on the ability of these strains to survive in human blood. In addition, cross-reactions between group A and group G streptococci have been demonstrated, but they have relied either on whole bacterial cell vaccine-induced polyclonal sera or crude protein extracts of these cells. In this study two monoclonal antibodies prepared against the purified, native group A streptococcal M6 protein demonstrated a high degree of cross-reactivity with group G streptococcal clinical isolates (9 and 19 of 22 strains examined, respectively). Ten of these strains exhibited resistance to phagocytosis when rotated in human blood. In addition, immunoblot analysis of crude mutanolysin extracts of group G streptococci with one of the M6 monoclonal antibodies illustrated a remarkable similarity in the protein pattern of these extracts as compared with those of group A streptococcal M protein. The immunoblots further demonstrated a variation in the relative molecular weights of the extracted proteins from strain to strain over a range of 57,000 to 77,000. In addition, a purified, pepsin-derived fragment (Mr, 43,000) from a group G strain was capable of eliciting rabbit antibodies that were opsonic for group G cells in a bactericidal assay. These functional and immunochemical data, in concert with DNA hybridization between group G streptococcal DNA and a group A M6 gene probe (J. R. Scott, W. M. Pulliam, S. K. Hollingshead, and V. A. Fischetti, Proc. Natl. Acad. Sci. USA 82:1822-1826, 1985), provide strong evidence for the presence of an M protein on these organisms and indicate its probable role as a virulence molecule on the surface of group G streptococci.
Plasmid-mediated resistance to erythromycin and chloramphenicol was successfully transferred from group A, B and H streptococci to group N streptococci by a process akin to conjugation. The results showed that plasmids from streptococcal groups other than N were able to replicate in lactic streptococci as well. The transfer experiments were carried out by using a membrane filter mating technique. Four of the five plasmids used (pSM15346, pSM10419, pIP501, and pEL1) were transferred at frequencies ranging from 10(-1) to 10(-8) transconjugants per donor colony-forming unit. The highest transfer frequencies were obtained when S. pyogenes strain 15346 (pSM15346) served as the donor strain. The identy of transconjugants was verified by testing for the presence of unselected markers of the recipient strains, and both transduction and transformation were ruled out as the mechanisms of transfer.
The aim of this study, performed in Bangkok, was to study whether a particular salivary immunoglobulin A (IgA) antibody profile against mutans streptococci could be related to the absence or presence of caries. A group of 12-year-old individuals representing various combinations of mutans streptococci levels and caries experience was selected. Whole saliva stimulated by paraffin-chewing was collected, and the children were investigated for decayed, missing and filled surfaces (DMFS) and teeth (DMFT), following WHO criteria and methods, at baseline and after 2 years. The total amount of salivary IgA was determined by an immunobead enzyme-linked immunosorbent assay, and SDS-PAGE and Western blot analysis was performed using sonicated antigens of Streptococcus mutans and Streptococcus sobrinus strains and, as a control, a Streptococcus parasanguis strain. The results showed that Thai children with low caries prevalence had more distinct immunoblot bands to antigens from mutans streptococci than did the high-caries children. A similar picture was not seen for S. parasanguis. On the whole, the Thai children also showed fewer bands than usual Swedish saliva samples from comparable age groups. The complexity of the relationship between dental caries and IgA in saliva is highlighted.
The immunoglobulin G (IgG)-binding capacity of 54 group G streptococci of human and bovine origin was investigated. Of 20 human strains, 17 carried a surface component which could combine with human IgG and bovine IgG1 and IgG2. Inhibition experiments with unlabeled human IgG and with a panel of animal sera revealed that the same surface component was involved in the binding of human as well as bovine immunoglobulins. Of 16 beta-hemolytic bovine group G streptococci, 13 reacted with human IgG but not with bovine IgG1 or IgG2. This binding structure was different from the type III Fc reactivity found in human group G streptococci. All human strains, including the three IgG Fc-nonreactive strains, fermented trehalose, in contrast to all bovine beta-hemolytic strains, which were negative. Immunoglobulin Fc reactivity is thus a feature not only of human strains but also of some bovine strains.
Twenty-nine lots of Bacti-Lab streptococci culture plates containing nalidixic acid, neomycin, and amphotericin B were inoculated with 25 strains of group A, B, C, F, and G strepotocci, 13 strains of nonstrepotcoccal organisms representative of the throat flora, and 198 fresh clinical thorat specimens to determine the accuracy of the plates in identifying group A streptococci. With the Bacti-Lab test plates 98.87% of the beta-hemolytic streptococcal strains tested produced growth 95.51% yielding more than 50 colonies. Of the nonstreptococcal beta-hemolytic and non-beta-hemolytic organism tested, 79.54% were inhibited by the selective media. When bacitracin disks were used for presumptive identification group A streptococci from clinical thorat specimens, 12.00% false positive and 0.00% false negative results were obtained as measured by the direct flourescent-antibody and Lancefield grouping methods.
Using the technique of phagocytic chemiluminescence, we have shown that serotypes Ib and II of group B streptococci are resistant to opsonophagocytosis. The resistant strains became susceptible to opsonophagocytosis by trypsin treatment, but neuraminidase had no effect. Several studies have failed to define a significant role for the alternative pathway of complement in opsonisation of group B streptococci. By simple chelation and heat inactivation studies, we have shown that the alternative pathway of complement is activated by serotype III of group B streptococci.