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PubMed2003

Comparative in vitro activity of faropenem and 11 other antimicrobial agents against 250 invasive Streptococcus pneumoniae isolates from France.

The aim of the study presented here was to evaluate the in vitro activity of faropenem, a new member of the penem class intended for oral administration, compared with 11 other antimicrobial agents against a large number of Streptococcus pneumoniae strains isolated from adults and children with bloodstream infections in France. The minimum inhibitory concentration of faropenem against 90% of the pediatric strains tested was generally one to two dilutions lower than the most potent beta-lactam agents (i.e., 0.5 micro g/ml for faropenem vs. 1 for amoxicillin, 1 for cefotaxime and 0.5 micro g/ml for ceftriaxone). Against the adult strains, only moxifloxacin had a MIC(90) value similar to faropenem (i.e., 0.25 micro g/ml for both agents). Faropenem seems to be a promising antimicrobial agent for the treatment of adult and pediatric Streptococcus pneumoniae infections.

Anti-Bacterial Agents↗
PubMed2004

Dissemination of emm28 erythromycin-, clindamycin- and bacitracin-resistant Streptococcus pyogenes in Spain.

Reported here is an unusual cluster of non-invasive infections caused by an emm28 Streptococcus pyogenes strain resistant to bacitracin, erythromycin and clindamycin detected in Santander, Spain. Since one of the characteristics of group A streptococci is their almost uniform susceptibility to bacitracin, this finding was unusual, and a search for bacitracin-resistant Streptococcus pyogenes strains was conducted in two other distant cities of Spain (Madrid and San Sebastián) where their presence was confirmed. These strains were frequently associated with erythromycin- and clindamycin-resistance, and most of them belonged to a unique emm28 T28, ST52 clone.

Bacitracin↗
PubMed2004

Laboratory detection of group B Streptococcus for prevention of perinatal disease.

Group B Streptococcus (GBS) or Streptococcus agalactiae emerged in the 1970s as the leading cause of neonatal morbidity and mortality. Today, GBS remains one of the leading causes of sepsis and meningitis in newborns despite important prevention efforts, including the issuance of recommendations for prevention of perinatal GBS disease by the American College of Obstetricians and Gynecologists, the Centers for Disease Control and Prevention, and the American Academy of Pediatrics in 1996/1997. The gastrointestinal tract is the natural human reservoir for GBS and is the likely source of vaginal colonization. GBS disease in newborns usually results from ascending spread of GBS into the amniotic fluid, which leads to neonatal colonization and to invasive disease in some infants. This review analyzes the various laboratory methods available for the detection of GBS from clinical samples collected from pregnant women and will discuss their impact in the prevention of neonatal GBS infections and in the rationalization of antibiotic use. The recent commercial availability of a rapid and highly sensitive real-time polymerase chain reaction assay suitable for the specific detection of GBS from vagino-rectal samples obtained from pregnant women during delivery, which is approved by the US Food and Drug Administration, provides improvements in the accuracy and rapidity of GBS colonization screening compared to the standard culture-based method using the recommended selective enrichment broth.

Anti-Bacterial Agents↗
PubMed2005

Ciprofloxacin treatment failure in a patient with resistant Streptococcus pneumoniae infection following prior ciprofloxacin therapy.

Reported here is the case of a patient with underlying chronic obstructive pulmonary disease (COPD) in whom ciprofloxacin treatment of a lower respiratory tract infection failed subsequent to ciprofloxacin treatment of an exacerbation of COPD several weeks earlier. During the second course of ciprofloxacin therapy, the patient's condition continued to deteriorate, and she was admitted to the intensive care unit. Bilateral pneumonia was diagnosed. Streptococcus pneumoniae, serotype 11A, resistant to ciprofloxacin was isolated from the sputum. Sequencing revealed a S79F mutation in parC and there was evidence of an efflux pump. The patient improved rapidly after administration of azithromycin and ampicillin/sulbactam. This report of treatment failure due to ciprofloxacin-resistant Streptococcus pneumoniae shows that fluoroquinolones should be avoided when treating patients who have recently received this class of antibiotics.

Aged↗
PubMed2005

Antimicrobial resistance of Streptococcus pneumoniae isolates in Athens, Greece.

In order to determine the current antibiotic susceptibility of Streptococcus pneumoniae strains in Greece, the present study was performed on 282 clinical isolates collected from patients at the Sotiria Chest Hospital of Athens, Greece, during the years 1997-2003. Susceptibility testing revealed that 52 (18.4%) isolates were not susceptible to penicillin, with 13.1% demonstrating intermediate and 5.3% high-level resistance. One of the penicillin-non-susceptible isolates was also resistant to cefotaxime. Comparison with results of a previous study conducted at the same hospital during the period 1992-1993 showed that penicillin resistance had increased by 4.5%. The results of this study indicate the antimicrobial susceptibility of Streptococcus pneumoniae continues to change in Greece and continuous surveillance remains important for guiding empirical antibiotic therapy.

Anti-Bacterial Agents↗
PubMed2007

Complicating infectious foci in patients with Staphylococcus aureus or Streptococcus species bacteraemia.

Complicating infectious foci resulting from haematogenous or local spread of microorganisms are observed frequently in patients with Staphylococcus aureus bacteraemia (SAB) or Streptococcus species bacteraemia (SSB). The aim of this study was to compare the epidemiology of complicating infectious foci during SAB and SSB in a university hospital in The Netherlands. The charts of all adult patients diagnosed with SAB or SSB (except for Streptococcus pneumoniae bacteraemia) from July 2002 until December 2004 were reviewed retrospectively. Overall, 180 immunocompetent patients were identified, 127 with SAB and 53 with SSB. The percentage of patients with complicating infectious foci (39% of SAB patients, 25% of SSB patients) did not differ significantly between the groups. Endocarditis and cerebral involvement, however, were significantly more common in the SSB group. Of all complicating infectious foci, 32% lacked guiding signs or symptoms and 10% were detected only at autopsy. Factors associated with the development of complicating infectious foci were a delay in treatment for more than 48 h after the onset of symptoms, community acquisition, persistently positive blood cultures, congenital heart disease, and the presence of foreign bodies or prosthetic valves. Infection-related mortality was 18% in SAB patients and 11% in SSB patients and was significantly higher in patients with complicating infectious foci (29 vs. 9%). In conclusion, complicating infectious foci develop in approximately one-third of all patients with SAB and SSB. An active approach that entails searching for the complicating infectious foci is warranted in these patients, because only two-thirds of complicated infectious foci have guiding symptoms or signs, and infection-related mortality is significantly increased in patients with complicating infectious foci compared to patients without these infections.

Bacteremia↗
PubMed2000

Evaluation of the Vitek 2 system for susceptibility testing of Streptococcus pneumoniae isolates.

Vitek 2 (bioMérieux, France) is a new commercial system that allows rapid identification and rapid determination of the minimum inhibitory concentration (MIC) of Streptococcus pneumoniae by monitoring the growth kinetics of the organisms in microwells. The accuracy of the Vitek 2 system in susceptibility testing was evaluated by determining the MICs of 50 penicillin-susceptible and 150 intermediate or penicillin-resistant Streptococcus pneumoniae isolates and comparing the results with those obtained using the agar dilution method. The essential agreement between the Vitek 2 system and the reference method was 91% for penicillin, 93% for cefotaxime and ceftriaxone, and more than 94% for amoxicillin, erythromycin, ofloxacin, co-trimoxazole, tetracycline, and imipenem. One very major error (1.1%) and one major error (0.9%) were obtained for tetracycline. The minor error rate for penicillin of 19.3% was mainly due to intermediate category isolates (n = 29) being identified as resistant and susceptible isolates (n = 6) being identified as intermediate by the commercial system. The minor error rates for amoxicillin, cefotaxime, ceftriaxone, imipenem, and ofloxacin were 25.4%, 25.4%, 29.4%, 19.2%, and 31.5%, respectively. Vancomycin, tetracycline, co-trimoxazole, and erythromycin showed minor error rates of 0-6.1%. In conclusion, Vitek 2 shows good agreement with the reference method, as demonstrated by the low numbers of major errors, but it has a tendency to overestimate MICs, resulting in minor errors.

Anti-Bacterial Agents↗
PubMed1999

Low prevalence of the immunoglobulin-A-binding beta antigen of the C protein among Streptococcus agalactiae isolates causing neonatal sepsis.

Streptococcus agalactiae (Group B streptococcus, GBS) is the most important pathogen causing neonatal sepsis. The role of bacterial proteins contributing to pathogenicity in GBS infections has not yet been clearly determined, but the C protein complex has been suggested to be involved in both virulence and protective immunity. The aim of this study was to assess the prevalence of GBS strains bearing the gene encoding for the beta antigen of the C protein among clinical isolates from 68 neonates with sepsis, 45 newborns colonized without clinical signs of infection, and 50 isolates from pregnant women. The prevalence of the beta antigen gene in all three groups was low (24% vs. 19% vs. 22%) [corrected], and the differences between groups were not statistically significant. Clinical characteristics and cytokine plasma levels did not differ between septic patients with beta antigen-positive and -negative strains. The beta-antigen gene was not found among serotype III isolates, which accounted for roughly half of all the strains isolated. Thus, polymerase chain reaction (PCR) analysis based on the beta antigen gene seems not helpful for distinguishing invasive from colonizing GBS strains. A vaccine based on peptide antigens from the beta antigen of the C protein would most probably not provide protection against the majority of GBS isolates. When analyzing the PCR products of the C protein beta antigen gene by DNA sequencing, a genetic heterogeneity was observed, revealing small repetitive genetic elements within the amplified fragment, an observation that should be studied further.

Antigens, Bacterial↗
PubMed2000

Carriage of antibiotic-resistant Streptococcus pneumoniae in Greek infants and toddlers.

The prevalence, resistance patterns and serotypes of antibiotic-resistant Streptococcus pneumoniae strains recovered from Greek carriers under 24 months of age were studied. From February 1997 to April 1998, nasopharyngeal cultures were performed in 1,269 children (ages 2-23 months, median 11 months) living in various areas of central and southern Greece. Resistance (including both intermediate and resistant isolates) to one or more antimicrobial agents was found in 132 of the 421 (31%) Streptococcus pneumoniae isolates, as follows: penicillin, 9% intermediate, 7.6% resistant; cefotaxime, 5.2% intermediate, 0.5% resistant; erythromycin, 0.7% intermediate, 18.1% resistant; clindamycin, 0.2% intermediate, 12.4% resistant; tetracycline, 0.7% intermediate, 16.4% resistant; chloramphenicol, 12.4% resistant; and trimethoprim-sulfamethoxazole, 3.8% intermediate, 14.3% resistant. The MICs of penicillin for 66% of the penicillin-nonsusceptible pneumococci were 1-4 microg/ml. Multidrug resistance was found in 64% of penicillin-nonsusceptible and 37% of penicillin-susceptible strains. Sixty-two percent of the penicillin-susceptible, multidrug-resistant strains belonged to serotype 6B and were resistant to all five non-beta-lactam agents tested. This notable serotype 6B resistance pattern was described for the first time in a previous study performed from December 1995 to February 1996 in the city of Patras, southwestern Greece. Seventy-two percent of antibiotic-resistant isolates belonged to serotypes 6B, 9V, 14, 18C, 19F and 23F. These results document the spread of resistant pneumococcal strains in central and southern Greece, many of which are multidrug resistant.

Anti-Bacterial Agents↗
PubMed2004

Detection of penicillin-binding protein 2b gene alteration in Streptococcus mitis by polymerase chain reaction.

Three isolates of beta-lactam-resistant streptococci from the saliva of healthy adults were identified as Streptococcus mitis. Minimum inhibitory concentrations (MICs) were 2 to 4 micro g/ml for ampicillin (ABPC) and 64 to more than 128 micro g/ml for cefaclor (CCL). To determine the position of base alterations of the penicillin-binding protein 2b ( pbp2b) gene, upstream primers containing possible mutation points were designed, and used for polymerase chain reaction (PCR), together with a downstream primer. Alterations adjacent to the conserved motifs of the pbp2b gene were apparent. DNA sequencing data indicated replacements in deduced amino acid sequences in all resistant isolates: from threonine to alanine just after the serine-serine-asparagine (SSN) motif, and from alanine to glycine two residues downstream of the lysine-threonine-glycine (KTG) motif. These changes were the same as those in penicillin-resistant Streptococcus pneumoniae (PRSP), suggesting importance for the enzymatic activity of the protein. Thus, Beta-lactam susceptibility of S. mitis may be partially predicted by PCR using our primer set for pbp2b.

Aminoacyltransferases↗
PubMed2004

The role of the capsule of the Streptococcus milleri group in its pathogenicity.

Study of the pathogenicity of encapsulated strains of the Streptococcus milleri group (SMG) was performed by examination of the ability to cause subcutaneous abscesses in mice and by phagocytosis and phagocytic killing of human polymorphonuclear neutrophils (PMNs) against the organisms. All 3 encapsulated isolates from patients with pneumonia or lung abscess induced abscesses in the mice; however, only 2 of 20 unencapsulated isolates from patients with lung abscess or thoracic empyema did so. The 3 encapsulated strains inhibited more phagocytosis and phagocytic killing of PMNs than the unencapsulated strains. In addition, encapsular material separated from Streptococcus constellatus RZYK001 also inhibited phagocytosis and phagocytic killing in proportion to increasing concentrations of the capsular material. These results suggest that capsular material produced by SMG might be a pathogenic factor.

Abscess↗
PubMed2004

A 3-year prospective study of a urinary antigen-detection test for Streptococcus pneumoniae in community-acquired pneumonia: utility and clinical impact on the reported etiology.

To evaluate the efficacy of a rapid immunochromatographic membrane test (ICT) for the detection of Streptococcus pneumoniae urinary antigen for diagnosing S. pneumoniae pneumonia, ICT was performed with urine samples using the Binax NOW Streptococcus pneumoniae kit at the time of admission. The results were compared with those from conventional microbiological studies. Three hundred and forty-nine adult patients with CAP who were admitted to the hospital were studied prospectively between February 2001 and January 2004. The ICT test was positive in 115 (33.0%) of 349 patients enrolled into the study and in 63 (75.9%) of 83 patients with pneumococcal pneumonia confirmed by conventional methods. The test revealed a sensitivity of 75.9% and a specificity of 94.0% with conventional microbiological criteria used as the reference standard. The positive predictive value was 91.3%, and the negative predictive value was 82.6%. The clinical features of 53 patients in whom ICT was positive and no pathogen was identified showed no significant difference from those of 83 patients who had pneumococcal pneumonia identified by conventional methods. The diagnostic yield of pneumococcal pneumonia was increased up to 38.9% using ICT combined with conventional methods. The Binax NOW ICT to detect S. pneumoniae urinary antigen is therefore a rapid and useful method for diagnosing pneumococcal pneumonia. Induction of ICT will prove the predominance of S. pneumoniae in the etiology of CAP.

Adolescent↗
PubMed2005

Performance of the Fontan procedure using extra-cardiac direct anastomosis on patients treated for penicillin-resistant Streptococcus pneumoniae endocarditis.

Streptococcus pneumoniae is now a rare cause of endocarditis in humans. We report a patient with a double outlet right ventricle and mitral atresia, who underwent the Fontan procedure without prosthetic materials after treatment for penicillin-resistant Streptococcus pneumoniae endocarditis. Postoperative infectious endocarditis was not found. In patients with a history of infectious endocarditis, direct anastomosis of the main pulmonary artery and inferior vena cava would reduce the risk of recurrent infectious endocarditis.

Abnormalities, Multiple↗
PubMed1983

Antibody to type III group B Streptococcus in the rhesus monkey.

Susceptibility to infection due to intra-amniotic type III group B streptococcal infection was studied in 27 rhesus monkeys. Sera from mothers and their offspring were tested to determine the concentration of antibody to the native type III group B Streptococcus antigen. Among 17 controls there was a statistically significant association between the concentration of maternal antibody prior to infection and both the neonatal survival rate and survival time (P less than 0.05). Neonatal survival was decreased to less than or equal to 6 hours (P = 0.005) if the maternal antibody concentration was less than 0.5 micrograms/ml. Modified immune serum globulin was given intravenously to the mothers prior to intra-amniotic infection with (five animals) or without (five animals) neonatal modified immune serum globulin. Neither of the modified immune serum globulin groups demonstrated a significant reduction in the neonatal mortality rate; however, the addition of the modified immune serum globulin provided protection against rapid neonatal death among those animals born to mothers which had low or no detectable antibody. All maternal groups developed a significant increase in the concentration of antibody in postpartum sera. These results indicate that both naturally acquired and passive (modified immune serum globulin) antibodies to type III group B Streptococcus antigen are partially protective against intra-amniotic infection.

Animals↗
PubMed1992

Preterm premature rupture of membranes: results of expectant management in patients with cervical cultures positive for group B streptococcus or Neisseria gonorrhoeae.

OBJECTIVE: The antepartum course and short-term neonatal outcome for patients with premature rupture of membranes between 26 and 33 weeks' gestation with positive cervical cultures for group B streptococcus or Neisseria gonorrhoeae were reviewed. STUDY DESIGN: A retrospective analysis of 182 patients managed expectantly over a 3-year period was done. Thirty-four patients had cervical cultures positive for group B streptococcus, 11 had positive cultures for Neisseria gonorrhoeae, and 137 had negative cultures. Prophylactic antibiotics were routinely given, and antibiotic therapy was continued in patients with positive cultures. RESULTS: There was no difference between groups in latent phase or maternal morbidity. The incidence of neonatal pneumonia was increased in those with positive cervical cultures (p = 0.009, odds ratio 6.9, 90% confidence interval 2.1 to 22.8), but there was no difference in neonatal sepsis, respiratory distress, or neonatal mortality. CONCLUSION: These data support the conservative or expectant management of premature rupture of membranes between 26 and 33 weeks in patients with positive cervical cultures who are given prophylactic antibiotic therapy.

Case-Control Studies↗
PubMed1985

Infectivity and natural transmission of the bacterium Streptococcus mutans in monkeys (Macaca fascicularis) at different ages.

Oral inoculation of adolescent monkeys with laboratory strains of Streptococcus mutans resulted in only sporadic implantation. Oral colonization of all strains, except possibly one, was not enhanced by dietary sucrose compared with glucose nor by precleaning of accessible tooth surfaces. Infant animals were more susceptible to implantation by laboratory-maintained strains of Strep. mutans than adolescent or adult animals. This difference was magnified when in-vivo maintained Strep. mutans strains were used. Strep. mutans was readily acquired by uninfected adolescent animals from infected cage mates. Strep. mutans-free adolescent monkeys exhibited significant-salivary IgA and serum-IgG response to Strep. mutans antigen, possibly representing a cross-reaction to indigenous Streptococcus sanguis. Uninfected infant animals showed no salivary or serum response to Strep. mutans. There was no change in salivary IgA antibody to Strep. mutans in adolescent animals after implantation or in recipient animals after acquisition of Strep. mutans.

Age Factors↗
PubMed1985

The relationship between the number of the bacterium Streptococcus mutans at discrete sites on the dentition of macaque monkeys (Macaca fascicularis) and the subsequent development of dental caries.

Sixteen consecutively-born monkeys were used in a longitudinal study to determine the changes occurring in the total number of bacteria in the palatal grooves of the upper left first deciduous molar teeth, following the introduction of a sucrose-based diet. The total number of bacteria recovered from the grooves increased significantly following the diet change. Twenty-nine days after the diet change, the number of Streptococcus mutans had increased from a median value of less than 10(2) to approx. 10(7) per groove, and the number of Streptococcus sanguis decreased. These changes in the number of Strep. mutans occurred prior to the detection of dental caries. Grooves that became carious harboured significantly more bacteria and more Strep. mutans than did grooves remaining caries-free six months after the diet change.

Animals↗
PubMed1987

Relative cariogenicity and in-vivo plaque-forming ability of the bacterium Streptococcus oralis in gnotobiotic WAG/RIJ rats.

The rats, fed a high sucrose diet, were mono-infected with seven strains of Streptococcus oralis. Moderate levels of caries were induced by four strains, and three others induced low levels. Approximal lesions were induced by two strains; no buccal/lingual lesions were produced. Scanning electron microscopy showed that all strains colonized the tooth fissures, some strains producing a moderately abundant and dense plaque. The most cariogenic strains (PB178, PB180 and PB186) induced similar levels of caries to Streptococcus milleri.

Animals↗