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Meningitis and endocarditis caused by group B streptococcus in a human immunodeficiency virus (HIV) infected patient.

We present a case of meningitis and endocarditis caused by Streptococcus agalactiae (group B streptococcus) in an adult patient with human immunodeficiency virus (HIV) infection. To our knowledge, only four other cases of meningitis, none of which had concomitant endocarditis, have been reported so far. A 45-year-old homosexual patient presented with fever, confusion, and signs of meningeal irritation. Streptococcus agalactiae was cultured from the blood, urine, and cerebrospinal fluid (CSF). Diagnosis of meningitis caused by streptococcus agalactiae was made. On day 35, a heart murmur was noticed, and patient developed cardiac decompensation. Echocardiography revealed vegetations on the mitral and aortic valve. After nine weeks of antibiotic treatment, the patient was discharged from the hospital in good general condition, with improved CSF and echocardiographic findings.

Endocarditis, Bacterial↗

A surveillance study on penicillin-resistant streptococcus pneumoniae in China.

OBJECTIVES: To find out whether there are also penicillin-resistant streptococcus pneumoniae and the resistant rate in China. METHODS: A surveillance study which is a part of the international surveillance on pneumococci resistance to penicillin and other antimicrobial agents was conducted in Beijing, China. More than 900 pediatric patients with respiratory tract infections aged from six months to three years selected from two pediatric units were enrolled in the study. Perthroat swabs were immediately streaked onto blood agar plates. Isolates were identified as pneumococci by their typical appearance, gram stain, confirmation tests. Antibiotic susceptibility was assessed by the disk diffusion method and minimal inhibition concentration (MIC) determination according to Protocol and National Committee for Clinical Laboratory Standards (NCCLS). RESULTS: Of the 51 streptococcus pneumoniae isolates, 5 strains had zones of inhibition indicative of penicillin resistance, of which two had penicillin MICs > or = 0.1 mg/L and were considered to be relatively or fully resistant to penicillin. The MICs of two penicillin resistant strains were 2 mg/L and 4 mg/L. Resistant rates to ceftriaxone and cefotaxime were 0% and 10% respectively. For the other ten antimicrobial agents, the resistant rates were as follows: ampicillin 12%, piperacillin 26%, furbenicillin 14%, cefuroxime 6%, erythromycin 54%, clarithromycin 52%, meleumycin 64%, roxithromycin 52%, chloramphenicol 35%, tetracycline 100%. CONCLUSIONS: The study suggested that penicillin resistant streptococcus pneumoniae strains existed in China and were also resistant to ampicillin, piperacillin, furbenicillin and cefuroxime. Moreover, the resistant rates of penicillin resistant streptococcus pneumoniae to macrolides and tetracycline were high.

Ampicillin Resistance↗

[Cloning and analyzing of the conserved protein gene in Streptococcus sanguinis ATCC10556].

OBJECTIVE: To clone and analyze the conserved protein gene in Streptococcus sanguinis(S.s) ATCC10556. METHODS: Southern blotting hybridization, molecular cloning techniques and dot blotting hybridization were employed to obtain the target clone which harbored the specific DNA fragment. The nucleotide sequence of the target clone was determined. The gene and its product were analyzed by Genework software and bioinformatics techniques. RESULTS: The conserved protein gene in Streptococcus sanguinis ATCC10556 was cloned for the first time and named as Streptococcus sanguinis conserved protein gene (Sscp gene). The Genbank accession number for Sscp gene is AY032739. The conserved protein gene in S.s ATCC10556 (named sscp163) was a transmembrane protein and contained two AAA domains. CONCLUSION: sscp163 protein might take part in the cell division in Streptococcus sanguinis; its function is similar to that of FtsK in E.coli.

Amino Acid Sequence↗

[A study on the pathogenesis of Streptococcus mitis exotoxin].

OBJECTIVE: To study the isolation, purification and pathogenesis of Streptococcus mitis pyrogenic exotoxin causing toxic shock syndrome. METHODS: Streptococcus mitis isolated from patients' throat were shaking cultivated. After being centrifuged, the supernatant fluid of the culture was precipitated with 20%, 40%, 60%, 80% (NH(4))(2)SO(4) respectively and the fast protein liquid chromatography(FPLC) was used for the final step of purification. Rabbits receiving subcutaneous injection with respective purified proteins were monitored daily for fever. The ability of the purified proteins to enhance the susceptibility of the rabbits to lethal Escherichia coli endotoxin shock is recorded, when the endotoxin was injected intravenously 4 hours after administration of 10 microg Streptococcus mitis exotoxin. RESULTS: Only the protein precipitated by 20% (NH(4))(2)SO(4) (molecular weight is 34,000) from culture supernatant fluid was pyrogenic for rabbits (average temperature increase near 1 degrees C), and it can also cause the proliferation of rabbit splenocytes (mitogenicity). All the animals receiving subcutaneous injection of exotoxin containing purified proteins precipitated with higher concentrations of (NH(4))(2)SO(4) died within 16 approximately 29 hours after intravenous injection of the Escherichia coli endotoxin, demonstrating the enhanced susceptibility of the animals to lethal endotoxin shock. The control rabbits displayed none of these effects. CONCLUSION: Streptococcus mitis exotoxin is a novel streptococcal pyrogenic exotoxin.

Animals↗

[Population biology of Streptococcus pneumoniae carried by healthy children in Shanghai].

OBJECTIVE: To investigate the population biology of Streptococcus pneumoniae carried by healthy children. METHODS: Drug resistant patterns and serotypes of 222 strains were determined. PFGE, BOX PCR and pbp fingerprint techniques were used to analyze the homology among strains. RESULTS: Among 222 nasopharyngeal isolates from 5 day-care centers, there were 32 penicillin intermediate Streptococcus pneumoniae (PISP, MIC 0.125 approximately 1 mg/L), and no penicillin resistant Streptococcus pneumoniae (PRSP, MIC >/= 2 mg/L) was found. The main serotypes of all strains were 23F (25.7%), 6A (13.1%), 19F (10.8%), and 6B (8.1%). The serotypes of PISP were mainly 23F (50%), 19A (15.6%) and 19F (15.6%). Among the 32 PISP strains, 8 BOX PCR clusters and 7 PFGE types were identified. The resistance patterns, serotypes, BOX PCR and pbp fingerprints of PFGE type A strains were highly consistent. In day care center (DCC) SY, the penicillin resistant rate was 31.8%, being much higher than the average level. Twenty of the 21 PISP strains isolated from this DCC belonged to PFGE type A or B. CONCLUSIONS: The penicillin resistant rate of Streptococcus pneumoniae carried by healthy children in 5 DCCs of Shanghai was still low. However in one DCC, there could be a prevalence of some resistant clones which resulted in high penicillin resistant rate.

Anti-Bacterial Agents↗

[Preliminary study on the rules of streptococcus mutans reactive oxygen species metabolism].

OBJECTIVE: To study the rules of Streptococcus mutans reactive oxygen species metabolism and its enzymatic basis, and to investigate its significance intermediate to plaque microbial ecology. METHODS: Electron spin trapping method was used to measure reactive oxygen species produced by Streptococcus mutans in the different incubation conditions, and evaluate the efficicay of NADH to hypoxanthine-xanthine oxidase and Fe(2+)-H2O2 system. RESULTS: Electron spin resonance (ESR) spectrum of DMPO-O2- and DMPO-OH. and superoxide dismutase were obtained in Streptococcus mutans culture fluid, these spectrum were strengthened by exogenous sugar, and disappeared when methylene blue was added to culture fluid, but that spectrum was not significantly changed by NADH. ESR spectrum of hypoxanthine-xanthine oxidase and Fe(2+)-H2O2 system were significantly reduced or disappeared by NADH. CONCLUSION: These results suggest that there are O2- and OH in Streptococcus mutans metabolism, and they may come mainly from the reaction catalyzed by NADH oxidase.

Electron Spin Resonance Spectroscopy↗

[Partial gene clone and nif gene homologous sequence analysis of Streptococcus sanguis].

OBJECTIVE: To analyze the sequence of Streptococcus sanguis chromosome which contains one DNA fragment of 800 base pairs (bp) and discuss Streptococcus sanguis biological features of heredity. METHODS: Streptococcus DNA of 800-bp genetic fragment was cloned and analyzed by using eukaryotic expression vector. RESULTS: By Genbank database, it showed that the 800-bp genetic sequence was highly homologous with other bacterial nifS and nifU gene, and the highest homologous score was 114. CONCLUSION: This nif gene of ATCC 10556 strain may correlate with nutrient metabolism and peroxide hydrogen release of Streptococcus sanguis.

Cloning, Molecular↗

[Relationship between Streptococcus mutans, Lactobacillus spp. and lactate-producing level and nursing bottle caries].

OBJECTIVE: The study aimed to investigate the levels of Streptococcus mutans and Lactobacillus spp. as well as the relationship between lactate-productive and aciduric organisms and nursing bottle caries. METHODS: Totally, 30 children of 2- to 2.5-year-old were divided into two groups, including the group of nursing bottle caries and the group of caries-free. Streptococcus mutans and Lactobacillus spp. were isolated from dental plaque of all the children. The amount of lactate produced was measured with a microlitre plate reader. RESULTS: The isolation frequency of Streptococcus mutans and Lactobacillus spp. were both 100 percent in the children with nursing bottle caries, and that the composition of these bacteria from nursing bottle caries lesions was higher than that of caries-free dental surface. Lactate-producing level was higher in the caries group than that of the caries-free group. CONCLUSION: This study suggests Streptococcus mutans and Lactobacillus spp. may be the major pathogenic bacteria leading to nursing bottle caries.

Bottle Feeding↗

[Construction of eukaryotic expression plasmid pcDNA3-gtfB expressing glucosyltransferase B of Streptococcus mutans].

OBJECTIVE: Glucosyltransferase (GTF) of Streptococcus mutans is considered as a cariogenic virulence factor due to its ability to synthesize glucan, which facilitate sucrose-depended adherence and cell-to-cell accumulation of bacteria. In this study, gtfB, the target gene fragment which encodes multiple catalytic sites and antigen epitopes of GTF, was recombined into eukaryotic expression vector pcDNA3. The feasibility of the recombination plasmid pcDNA3-gtfB used as gene vaccine will be investigated in further study. METHODS: The target gene fragment gtfB (904-4578 bp) was obtained by standard PCR amplification while genome DNA of streptococcus mutans GS-5 was used as template. Then the PCR products were extracted and purified from low-melting temperature agarose. The gtfB and plasmid pcDNA3 were cut by Kpn I, Xho I, and the digested products were extracted and purified again for recombination. The purified gtfB and plasmid pcDNA3 were recombined by T4 DNA ligase, ligation products were transformed into competent cell, Escherichia coli JM109. Transformed colonies were screened by Ampr LB plate, then recombined plasmids were isolated and identified by restricted endonuclease cutting and Sanger dideoxy DNA sequencing. RESULTS: Identified by agarose gel electrophoresis, the target gene-gtfB obtained PCR amplification had the same molecular size (36 kb) as predicted. It was indicated that recombined plasmids contained inserted gtfB gene fragment by restricted endonuclease cut analysis, the sequencing data also indicated that inserted gtfB gene had correct DNA sequence and orientation according to DNA sequence of Streptococcus mutans GS-5 (gene bank M17361). CONCLUSION: Inserted gene-gtfB of recombined plasmid pcDNA3-gtfB encoded multiple catalytic sites and epitopes. It was proved that these epitopes had high immune antigenicity and that antiserum could significantly inhibit the synthesis of water-insoluble glucans and water-soluble glucan. In vitro adherence experiment also indicated that it could inhibit streptococcus mutans adherence to saliva-coated hydroxyapatite. Vector pcDNA3 was high expressing eukaryotic vector, and could stimulate antigen-representing cell. It was suggested that recombined plasmid pcDNA3-gtfB had high immune antigenicity and immune responsiveness, and this supported its use as gene vaccine candidates in the development of anti-caries vaccines.

Dental Caries↗

[A study of tarnish induced by Streptococcus sobrinus serotype g on Co-Cr, Ni-Cr and casting titanium alloys].

OBJECTIVE: The objective of this study was to investigate the tarnish induced by Streptococcus sobrinus serotype g on Co-Cr, Ni-Cr and casting titanium alloys. METHODS: Co-Cr, Ni-Co and casting titanium alloys were respectively machined into a size of 10 mm x 10 mm x 1 mm in tablets, and totally 90 specimens with 30 of each were prepared for the test. The 30 specimens of each alloy were randomly and equally divided into three subgroups, including the blank control group, the media control group and the inoculated media group. Under the aerobic condition, the surfaces of the sucrose agar media were inoculated with Streptococcus sobrinus serotype g. The labeled sterile specimens were placed on the surface of the media for 10 weeks. The specimens were changed to a new sucrose media with bacteria each week. The specimens were removed after 10 weeks of incubation, immersed in 0.05% glutaraldehyde solution to eliminate AaY4, rinsed with distilled water. After 2 weeks, the specimens were removed and observed visually or examined by MINOLTA CR-100 color apparatus. RESULTS: Compared with the blank control, the control media without bacteria did not influence the alloy specimens (P > 0.05). Streptococcus sobrinus serotype g caused tarnish on specimens. There was significant difference between the control media group and the blank control group with inoculated media group on all the specimens (P < 0.05). CONCLUSION: Streptococcus sobrinus serotype g affects the color of Co-Cr, Ni-Cr and casting titanium alloys, but the color does not change from yellow-green range to red-yellow range.

Chromium Alloys↗

[Streptococcus suis bacteremia].

INTRODUCTION: Streptococcus suis infection is recognised despite it rareness as a zoonotic occupational disease in humans, and is often associated with meningitis, more rarely with bacteremia. OBSERVATION: A Streptococcus suis bacteremia occurred in a hunter and was complicated by septic shock with disseminated intravascular coagulation, rhabdomyolysis and purpura fulminans. Contamination had occurred through inoculation of a cut on the thumb when the hunter was slaughtering a wild boar. The blood cultures isolated Streptococcus suis. The patient died 36 hours after admission, despite intensive care and adapted antibiotic treatment with penicillin A and macrolide. CONCLUSION: Streptococcus suis bacteremia are uncommon but serious in humans. Despite adapted treatment, evolution may be fatal, so their conditions of occurrence must be well known by hunters and practitioners.

Anti-Bacterial Agents↗

[Two cases of severe community-acquired pleural pneumonia due to Streptococcus pyogenes].

INTRODUCTION: The microorganisms incriminated in severe community-acquired pneumonia hospitalized in intensive care unit are the following: Streptococcus pneumoniae, enterobacteria isolated in aspiration-related pneumonia and less frequently intracellular bacteria in so-called atypical pneumonia (Mycoplasma pneumoniae, Chlamydia pneumoniae, Legionella pneumophila). CASE REPORTS: We report two cases of severe community-acquired pneumonia admitted in intensive care unit and due to Lancefield Group A beta hemolytic streptococcus (Streptococcus pyogenes). Despite the increased incidence of invasive streptococcal infections, this microorganism still has a rare causative role in the pathogenesis of community-acquired pneumonia. The case reports concern two young patients without any significant medical history and with many clinical, radiological and microbiological similarities. However, the prognosis was not the same because of the way the initial management has been provided. DISCUSSION: Group A beta hemolytic streptococcus could be a causative microorganism of severe and possibly fulminating community-acquired pneumonia, even in young and healthy patients as is the case with pneumococcal infections. Medical history, clinical symptoms and radiological signs should be taken into account to evoke the diagnosis and to initiate antibiotherapy early, taking into account that this microorganism is sensitive to Penicillin G.

Abdominal Pain↗

Comparison of experimental models for Streptococcus suis infection of conventional pigs.

Four different experimental models for Streptococcus suis-induced disease were compared to find a model that closely mimics naturally occurring disease in conventional pigs. Fourteen, 2-week old pigs free of S. suis type 2 were used in 2 experiments. In experiment 1, 3 pigs were inoculated intravenously (IV) and 3 pigs intranasally (IN) with S. suis. Two out of 3 of the IV-inoculated pigs exhibited signs of severe central nervous system disease (CNS) and were euthanized. Streptococcus suis type 2 was isolated from whole blood, joints, and serosal surfaces of both pigs. No clinical signs and no growth of S. suis were detected in the IN-inoculated pigs. In experiment 2, 4 pigs were inoculated IV and another 4 were inoculated IN with the same isolate as in experiment 1. One hour before inoculation the IN-inoculated pigs were given 5 mL of 1% acetic acid intranasally (IN-AA). All the IV-inoculated pigs showed CNS disease and lameness, and 2 of the pigs became severely affected and were euthanized. All the IN-AA inoculated pigs exhibited roughened hair coats and 2 pigs developed severe CNS disease and were euthanized. Streptococcus suis was isolated from the joints and blood of 3 pigs in the IV-inoculated group. Streptococcus suis was isolated from blood of 2 pigs, meninges of 3 pigs, and joints of 1 pig in the IN-AA inoculated group. Natural exposure to S. suis most likely occurs by the intranasal route. The IN-AA model should serve as a good model for S. suis-induced disease, because the natural route of exposure is intranasal and the IN-AA model was effective in inducing disease that mimics what is observed in the field.

Administration, Intranasal↗

[The properties of cell wall hydrolysates of Streptococcus group A].

Products obtained from lysis in the cell wall of group A streptococcus have been studied in different growth phases: at the end of the exponential phase and in the stationary one. Endo-beta-N-acetylmuramidase extracted from the culture liquid of Streptomyces levoris 96 has been used for lysis of streptococcus. It is stated that streptococcus cell walls isolated at different growth stages differ in the protein and polysaccharide content. High content of protein in the cell wall of a young culture makes lower the initial rate of the walls' hydrolysis by endo-beta-N-acetylmuramidase. However, with the enzyme penetration into peptidoglycan the rate of hydrolysis of cell walls gets higher and after four-hour incubation the lysis degree of walls of the 16- and 8-hour cultures reaches the equal value (63%). Studies in the protein composition of lysates of the streptococcus cell walls have shown that they contain at least 12 proteins most of which are acid and neutral ones.

Cell Wall↗

[Nasopharyngeal colonization of Streptococcus pneumoniae in healthy children: percentage of carriers, serotypes distribution and antibiotic resistance].

AIM: The nasopharyngeal carriage of Streptococcus pneumoniae is an important risk factor for pneumococcal diseases. Data regarding prevalence and serotype distribution of this pathogen are lacking in our population. METHODS EXPERIMENTAL DESIGN: longitudinal observational cohort study. SETTING: healthy children aged 1-7 years attending day-care centers and schools of a district of a Southern Italy city. MEASURES: the nasopharyngeal colonization rate of Streptococcus pneumoniae as well as its antibiotic susceptibility was determined. RESULTS: Of 317 nasopharyngeal cultures obtained, 18.29% of the cultures were positive for Streptococcus pneumoniae; 60.34% of the isolates were serotypes 19A, 19F, 14, 6B, or 23F; 8.62% of the strains were intermediately resistant to penicillin. Erythromycin-resistance was observed in 65.51% of the micro-organisms isolated and particularly serotypes 19, 14, and 6 were more erythromycin-resistant than organisms of other serotypes. Co-trimoxazole resistance was detected in 17.24% of the strains. All the strains resulted uniformly susceptible to cefotaxime and ceftriaxone. CONCLUSION: The high rate of nasopharyngeal carriage of Streptococcus pneumoniae, along with the resistance to antibiotics widely used in the community, suggests the importance of an epidemiological surveillance as well as the application of new vaccine strategies.

Anti-Bacterial Agents↗

[Prevalence of serotypes and antimicrobial resistance of invasive strains of Streptococcus pneumoniae].

OBJECTIVE: To determine the prevalence of serotypes and antimicrobial susceptibility of invasive strains of Streptococcus pneumoniae and to discuss the implications of these findings for vaccine formulation. METHODS: Strains of Streptococcus pneumoniae obtained from normally sterile fluids from patients admitted with invasive diseases were isolated and identified at the Hospital de Clínicas, Universidade Federal de Uberlândia, state of Minas Gerais, and forwarded to Instituto Adolfo Lutz, state of São Paulo, for further identification, serotyping and determination of antimicrobial susceptibility. RESULTS: From April 1999 to March 2003, 148 invasive strains of Streptococcus pneumoniae were obtained. The age of patients ranged from 1 day to 88.83 years (mean: 21.33+/-25.82 years; median: 4.42 years). Eighty-four (56.7%) patients were male. The most common diagnoses were pneumonia (91 cases; 61.4%), meningitis (32 cases; 21.6%) and occult bacteremia (15 cases; 10.1%). Strains were isolated mostly from blood (76 occasions; 51.3%), pleural fluid (39 occasions; 26.3%) and cerebrospinal fluid (30 occasions; 20.2%). There were 23 different serotypes, and the most common were 14, 3, 1, 5, 6A, 6B and 18C. Among 30 (20.2%) oxacillin-resistant strains, 23 (15.5%) were confirmed as resistant to penicillin (12.8% intermediate resistance and 2.7% full resistance). Oxacillin-resistant strains were restricted to serotypes 14, 23F, 19A and 6B. Resistance to penicillin varied with age, being more common in children under two years of age (p = 0.0008). We observed decreased sensibility to sulfamethoxazole-trimethoprim (92 isolates; 63.4%), to erythromycin (12 isolates; 8.3%), to clindamycin (12 isolates; 8.7%), to ofloxacin (one strain; 0.8%) and to cefotaxime (three strains; 2%; also resistant to penicillin). All isolates were susceptible to chloramphenicol, rifampin and vancomycin. CONCLUSIONS: The decreased susceptibility to penicillin, detected in 15.5% of the strains was predominant in children under two years of age. There were 23 different Streptococcus pneumoniae serotypes. The 23-valent polysaccharide vaccine covers 82.6% of the serotypes and 90.2% of the invasive strains isolated in this population. In addition, 46.7% of the serotypes and 63.6% of the strains isolated from children until five years of age are covered in the currently available 7-valent conjugated vaccine (PN CRM7).

Adolescent↗

[Antibiotics-resistance pattern and genetic type of Streptococcus pneumoniae isolated from children in Hangzhou].

OBJECTIVE: To investigate the antibiotics-resistance type and molecular epidemiology of Streptococcus pneumoniae isolated from children in Hangzhou. METHODS: The sensitivities of 323 strains of Streptococcus pneumoniae to 9 antibiotics were determined in vitro by Kirby-Bauer diffuse methods, and MICs of penicillin and cefotaxime were determined by E-test methods. RESULTS: Among all 323 strains isolated from children during the period from August 2001 to July 2002, 136 strains (42.1%) were sensitive to penicillin, while 57 strains (17.7%) were penicillin-resistant. Penicillin MICs ranged from 0.012 microg/ml to 4.0 microg/ml. All the strains were sensitive to cefotaxime and its MICs ranged from 0.012 microg/ml to 4.0 microg/ml. The most resistant antibiotic was erythromycin and it's resistant-rate was as high as 90.7%, followed by tetracycline (87.6%), trimethoprim-sulfamethoxazole (48.6%) and chloromycetin (14.9%). Totally 197 strains (61.0%) were multi-drug-resistant pneumococci and most of them were resistant to trimethoprim-sulfamethoxazole, erythromycin and tetracycline at the same time. Two strains (0.6%) were resistant to rifampin and none was resistant to vancomycin and ofloxacin. BOX PCR typing was carried out and no overwhelming fingerprinting pattern was found among penicillin resistant Streptococcus pneumoniae strains which were isolated from patients, while the banding patterns were always similar or identical among the strains isolated from the same specimen or from the same patient at different time, respectively. CONCLUSION: The antibiotics-resistant rate of pneumococci was high in Hangzhou, but the third-generation cephalosporins were still the best antibiotics against Streptococcus pneumoniae. One child could be infected or colonized by more than one pneumococci clone at the same or different time.

Anti-Bacterial Agents↗

[Effect of para-aminobenzonic acid (PABA) on cell-surface hydrophobicity of Streptococcus mutans].

OBJECTIVE: To study the effect of Para-aminobenzonic acid on cell-surface hydrophobicity of Streptococcus mutans. METHODS: Microbial adhesion to hydrocarbons (MATH) was used to measure the cell-surface hydrophobicity of Streptococcus mutans which grew in modified Carlsson medium with different dilutions of PABA. RESULTS: The cell-surface hydrophobicity of Streptococcus mutans increased when Carlsson medium contained low dilution of PABA. But following the increase of PABA, the cell-surface hydrophobicity decreased. CONCLUSION: Para-aminobenzonic acid could inhibit the adherence of Streptococcus mutans through changing its cell-surface hydrophobicity.

4-Aminobenzoic Acid↗