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PubMed1977

[In vitro examination on antibacterial activity of ciclacillin (ACPC) against clinically isolated strains (author's transl)].

(1) The antibacterial acivity of ciclacillin (ACPC) with inoculum size of 10(6) cells/ml was four times less potent than that of ampicillin (ABPC) and 4 approximately 8 times less potent than that of AMPC, but was 4 approximately 8 times more potent than that of CEX against Streptococcus pyogenes. For Streptococcus pneumoniae, ACPC was 2 approximately 4 times less active than ABPC and AMPC, but 16 approximately 32 times more active than CEX. Staphylococcus aureus was 4 approximately 8 times less susceptible to ACPC than to ABPC and AMPC, but 1 approximately 2 times more susceptible than to CEX. Against E. coli, ACPC was as active as CEX, 2 approximately 4 times less active than ABPC, and 4 approximately 8 times less active than AMPC. (2) It was suposed that ACPC was more resistant to penicillinase and more antibacterial with inoculum size of 10(6) cells/ml cells/ml than with 10(6) cells/ml. ACPC was 4 approximately 8 times less active than ABPC, and AMPC against Staphylococcus aureus with 10(8) cells/ml, while with 10(6) cells/ml, it was 2 times less active than ABPC and AMPC. (3) ACPC-resistant strains (greater than or equal to 3.13 microng/ml) of Streptococcus pyogenes and Streptococcus pneumoniae were not found. (4) A difference was noted in MIC of three semi-synthetic penicillins, ACPC, ABPC and AMPC, against Staphylococcus aureus, and E. coli between the sources from which their strains were isolated. (5) There were many strains resistant to erythromycin (EM) and josamycin (JM) (greater than 60%, respectively to both antibiotics) in Stretpococcus pyogenes and pus-isolated Staphylococcus aureus. No strains of Streptococcus pyogenes, were found resistant to EM and JM.

Amoxicillin↗

PubMed2004

Evaluation of the Hyplex BloodScreen Multiplex PCR-Enzyme-linked immunosorbent assay system for direct identification of gram-positive cocci and gram-negative bacilli from positive blood cultures.

We evaluated the Hyplex BloodScreen PCR-enzyme-linked immunosorbent assay (ELISA) system (BAG, Lich, Germany), a new diagnostic test for the direct identification of gram-negative bacilli and gram-positive cocci from positive blood cultures, with 482 positive BACTEC 9240 blood culture bottles. The test involves amplification of the bacterial DNA by multiplex PCR and subsequent hybridization of the PCR product to specific oligonucleotide probes in an ELISA-based format. The available probes allow the separate detection of Escherichia coli, Pseudomonas aeruginosa, Enterobacter aerogenes, Klebsiella spp., Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis/Enterococcus faecium, Streptococcus pyogenes, and Streptococcus pneumoniae and the staphylococcal mecA gene. The Hyplex BloodScreen test showed an overall sensitivity of 100% for the identification of gram-negative bacilli and 96.6 to 100% for the identification of gram-positive cocci (S. aureus, 100%; S. epidermidis, 97.2%; Enterococcus faecalis/Enterococcus faecium, 96.6%; and Streptococcus pneumoniae, 100%). The specificities of the test modules ranged from 92.5 to 100% for gram-negative bacilli and 97.7 to 100% for gram-positive cocci (Escherichia coli, 92.5%; Pseudomonas aeruginosa, 98.5%; Klebsiella spp., 100%; Enterobacter aerogenes, 100%; S. aureus, 100%, S. epidermidis, 97.7%; Enterococcus faecalis/Enterococcus faecium, 99.6%; Streptococcus pyogenes, 100%; and Streptococcus pneumoniae, 99.3%). The result of the mecA gene detection module correlated with the result of the phenotypic oxacillin resistance testing in all 38 isolates of Staphylococcus aureus investigated. In conclusion, the Hyplex BloodScreen PCR-ELISA system is well suited for the direct and specific identification of the most common pathogenic bacteria and the direct detection of the mecA gene of Staphylococcus aureus in positive blood cultures.

Bacteremia↗

PubMed1981

Microbial flora of the lower genital tract of women in labour in Zaria, Nigeria.

Nine genera of microbes isolated from the lower genital tract of 187 women in labour in Zaria have been identified. The work was undertaken to establish the nature of microorganisms in the lower genital tract of women in labour as a basis for further study. The isolates in order of prevalence were: Candida albicans (20.9%), Klebsiella sp (15.0%), Escherichia coli (9.1%), Streptococcus faecalis (6.4%), haemolytic streptococci (other than Streptococcus pyogenes (2.7%), Streptococcus viridans (2.1%), Staphylococcus aureus (2.1%), Aeromonas hydrophila (2.1%), Proteus mirabilis (1.1%), Peptostreptococcus putridus (1.1%), Streptococcus pyogenes (0.5%), and Streptococcus pneumoniae (0.5%). Neisseria gonorrhoeae, Haemophilus sp, Lactobacillus sp, and Clostridium sp were sought but not found. Chlamydia, viruses, and T-strains of mycoplasma and trichomonas were not sought. It appears from this study that the lower genital tract of most women in Zaria at the time of labour is heavily colonised by pathogens. For this reason alone prolonged labour and trauma to the genital tract at the time of delivery should be avoided.

Bacteria↗

PubMed1988

Plasma bactericidal activity after administration of erythromycin estolate and erythromycin ethylsuccinate to healthy volunteers.

In a crossover design study, we compared the plasma bactericidal activities of erythromycin estolate (500 mg) and erythromycin ethylsuccinate (600 mg) after administration of a single oral dose to 12 healthy volunteers. Both erythromycin esters displayed very good plasma bactericidal activities against Streptococcus pneumoniae. The median bactericidal titers produced in plasma against Streptococcus pyogenes and Streptococcus pneumoniae were significantly higher with erythromycin estolate than with the ethylsuccinate ester at both 2 and 8 h after dosing (P less than 0.05 by Student's t test). Both erythromycin esters showed rather weak bactericidal activity against Branhamella catarrhalis; a further look at these results indicated that erythromycin estolate presented 50% of the plasma samples at 2 h with bactericidal titers superior or equal to 1:8, versus 11% for the ethylsuccinate ester. Of the 60 plasma bactericidal activity tests performed against Staphylococcus aureus, only 6 (10%) and 3 (5%) exhibited titers of 1:8 or greater for erythromycin estolate and erythromycin ethylsuccinate, respectively. Clinical trials are warranted in which these products are compared in infections other than Streptococcus pyogenes pharyngitis, for which the clinical superiority of erythromycin estolate has been demonstrated.

Adult↗

PubMed2005

Generation of transposon insertion mutant libraries for Gram-positive bacteria by electroporation of phage Mu DNA transposition complexes.

Transposon mutagenesis is a powerful technique for generating collections of insertion mutants for genetic studies. This paper describes how phage Mu DNA transposition complexes, transpososomes, can be exploited for gene delivery to efficiently introduce selectable markers to genomes of Gram-positive bacteria. Mu transpososomes were assembled in vitro with custom-designed mini-Mu transposons, concentrated, and electroporated into cells of three Gram-positive bacterial species: Staphylococcus aureus, Streptococcus pyogenes and Streptococcus suis. Within cells, the complexes reproduced an authentic DNA transposition reaction and integrated the delivered transposons into the bacterial genomes, yielding single-copy insertions. The integration efficiency among different species and strains of Gram-positive bacteria ranged from 1x10(1) to 2x10(4) c.f.u. (mug introduced transposon DNA)(-1). The strategy should be applicable to a variety of other Gram-positive species after initial optimization of certain key factors affecting transposon delivery, such as the preparation method of competent cells and physical parameters of electroporation. This study extends the scope of the Mu transpososome delivery-based genomic DNA integration strategy to Gram-positive bacteria. Thus, a straightforward generation of sizeable mutant banks is feasible for these bacteria, potentiating several types of genomic-level approaches for studies of a variety of important bacterial processes, such as pathogenicity.

Bacteriophage mu↗

PubMed2000

Comparative in vitro activity of moxifloxacin against Gram-positive clinical isolates.

The in vitro activity of moxifloxacin was compared with that of 15 antibacterial agents against 513 Gram-positive microorganisms. The MIC(90) (mg/L) of moxifloxacin was 0.06 for quinolone-susceptible Staphylococcus aureus and Staphylococcus epidermidis, 0.12 for Streptococcus pyogenes and Streptococcus agalactiae; 0.25 for Streptococcus pneumoniae, Streptococcus mitis, Streptococcus bovis, Streptococcus anginosus and Actinomyces pyogenes; 0.5 for Streptococcus sanguis and Listeria monocytogenes, 2 for Corynebacterium jekeium and Bifidobacterium bivius. Over 50% of Enterococcus faecalis, Enterococcus faecium, quinolone-resistant staphylococci, Nocardia steroides and Clostridium difficile were susceptible to 2 mg/L moxifloxacin. Moxifloxacin and trovafloxacin demonstrated comparably high activity towards Gram-positive cocci; moxifloxacin and clinafloxacin were most active against Gram-positive bacilli.

Anti-Infective Agents↗

PubMed2004

Transcriptome analysis and gene expression profiles of early apoptosis-related genes in Streptococcus pyogenes-infected epithelial cells.

Epithelial cells are the initial sites of host invasion by group A Streptococcus pyogenes (GAS), and GAS infection of epithelial cells has been suggested to induce apoptosis. We previously reported that the induction of apoptosis is strongly associated with the protein F1-mediated invasion. We present here the gene expression profiles of the human epithelial HEp-2 cells during GAS-induced apoptosis, using serial gene analysis of expression (SAGE) analysis and macroarray analysis of apoptosis-related genes. Serial gene analysis of expression revealed the downregulation of voltage-dependent anion channels 1 and 2 genes and the upregulation of the cytochrome c oxidase and calcium binding protein genes (calpactin, calgizzarin and programmed cell death 6). Macroarray analysis and quantitative RT-PCR analysis also revealed that the genes for IL-1beta, IL-12 p35, IL12 p40, and GM-CSF are also markedly induced by GAS invasion. Furthermore, caspase-1, -9, and -14 genes are significantly upregulated during GAS invasion. These observations indicated that apoptosis associated with GAS invasion is mainly induced by mitochondrial dysfunction and calcium regulation as well as by stress, and that these transcriptional controls may regulate the cellular response to GAS invasion.

Apoptosis↗

PubMed2001

Cytochrome c-mediated caspase-9 activation triggers apoptosis in Streptococcus pyogenes-infected epithelial cells.

Epithelial cells are the initial sites of host invasion by group A Streptococcus pyogenes (GAS), and their infection of epithelial cells has been suggested to induce apoptosis. However, the mechanism responsible for bacteria-host interaction and the induction of apoptosis has not been clearly understood. We demonstrate here that human pharyngeal epithelial HEp-2 cells became apoptotic with DNA fragmentation by invasion of GAS strains JRS4 (M6+, F1+) and JRS145 (M6-, F1+ mutant of JRS4), whereas apoptotic cellular changes were not observed in SAM1 (M6+, F1- mutant) or SAM2 (M6-, F1- mutant) infected HEp-2 cells. Confocal microscopy revealed that Bax translocation to mitochondria and cytochrome c release occurred after 4 h of infection. Western blot analyses showed that the amounts of Bcl-2 and Bcl-xL were decreased in the mitochondria of infected cells. In addition, we demonstrated that the release of nuclear histone from infected cells was prevented by the addition of caspase-9 inhibitor (Ac-LEHD-CHO). We conclude that the internalization of GAS in epithelial cells is necessary and sufficient for the induction of apoptosis, which is initiated by mitochondrial dysfunction, and the mechanism of GAS-induced apoptosis is clearly different from that induced by other intracellular invasive bacteria, e.g. Shigella and Salmonella species.

Apoptosis↗

PubMed1985

Chemical properties and immunobiological activities of streptococcal lipoteichoic acids.

Lipoteichoic acids (LTAs) were chromatographically purified from crude phenol-water extract of whole cells of some streptococcal species, which included Streptococcus pyogenes Sv, Streptococcus mutans 6715, and Streptococcus sanguis ATCC 10556. Among these, special attention was paid to S. pyogenes LTA for analyses of chemical composition and biological activities. All LTA preparations contained equimolar amounts of glycerol and phosphorus. Chemical analyses showed that S. pyogenes LTA contained glycerophosphate, alanine, glucose, and fatty acids (as palmitic acid) at molar ratio of 1 : 0.1 : 0.1 : 0.25. The crude phenol-water extract and isolated LTA from S. pyogenes Sv were found to be mitogenic for spleen cells of BALB/c and BALB/c (nu/nu) mice, but not for thymus cells of BALB/c mice. The mitogenicity of deacylated LTA (dLTA) was significantly lower than that of LTA. It was also found that various LTA preparations possessed polyclonal B cell activation ability and adjuvant activity both in vivo and in vitro, as demonstrated by using hemolytic plaque assay. LTA, but not dLTA, induced macrophage activation which resulted in tumor cytotoxicity in mice. Limulus lysate activity of S. pyogenes LTA was approximately 1,000 fold lower than that of Escherichia coli lipopolysaccharide. These results indicate that streptococcal LTA possesses various immunobiological activities that modulate lymphoreticular system in vivo and in vitro.

Animals↗

PubMed1985

Characterization of a glycophospholipid of Streptococcus pyogenes-derived L-form.

A glycophospholipid was detected as a major lipid in the L-form derived from Streptococcus pyogenes. The glycophospholipid was purified and chemically analyzed. From its phosphorus:glucose:glycerol molar ratio of 1:2:2 and mass spectrum, the deacylated glycophospholipid was identified as glycerophosphoryldiglucosylglycerol. This structural assignment was confirmed by thin layer chromatography of the lipid itself, which comigrated with known phosphatidyldiglucosyldiglyceride from S. faecalis. A possible mechanism for biosynthesis of the glycophospholipid in the L-form that invokes known biosynthetic processes involved in glycophospholipid metabolism in related bacteria is proposed.

Chromatography, Paper↗

PubMed2006

Use of CFSE staining of borreliae in studies on the interaction between borreliae and human neutrophils.

BACKGROUND: Species of the tick-transmitted spirochete group Borrelia burgdorferi sensu lato (B. burgdorferi) cause Lyme borreliosis. Acute borrelial infection of the skin has unusual characteristics with only a mild local inflammatory response suggesting that the interaction between borreliae and the cells of the first-line defence might differ from that of other bacteria. It has been reported that human neutrophils phagocytose motile borreliae through an unconventional mechanism (tube phagocytosis) which is not observed with non-motile borreliae. Therefore, it would be of great interest to visualise the bacteria by a method not affecting motility and viability of borreliae to be able to study their interaction with the cells of the innate immunity. Carboxyfluorescein diacetate, succinimidyl ester (CFSE) labelling has been previously used for studying the adhesion of labelled bacteria to host cells and the uptake of labelled substrates by various cells using flow cytometry. RESULTS: In this study, CFSE was shown to efficiently stain different genospecies of B. burgdorferi without affecting bacterial viability or motility. Use of CFSE staining allowed subsequent quantification of borreliae associated with human neutrophils with flow cytometry and confocal microscopy. As a result, no difference in association between different borrelial genospecies (Borrelia burgdorferi sensu stricto, Borrelia afzelii, Borrelia garinii), or between borreliae and the pyogenic bacterium Streptococcus pyogenes, with neutrophils could be detected. Borrelial virulence, on the other hand, affected association with neutrophils, with significantly higher association of a non-virulent mutant B. burgdorferi sensu stricto strain compared to the parental virulent wild type strain. CONCLUSION: These results suggest that the flow cytometric assay using CFSE labelled borreliae is a valuable tool in the analysis of the interaction between borreliae and human neutrophils. The results also indicate a clear difference in the association with neutrophils between virulent and non-virulent borrelial strains.

Borrelia↗

PubMed1998

Anhydrolide macrolides. 1. Synthesis and antibacterial activity of 2,3-anhydro-6-O-methyl 11,12-carbamate erythromycin A analogues.

A series of 3-descladinosyl-2,3-anhydro-6-O-methylerythromycin A 11, 12-carbamate analogues have been synthesized and evaluated for antibacterial activity. These compounds were found to be potent antibacterial agents against Gram-positive organisms in vitro, many having MIC values below 1 microg/mL for the macrolide-susceptible Staphylococcus aureus, Streptococcus pyogenes, and Streptococcus pneumoniae, as well as improved activity compared to erythromycin A against the inducibly MLS (macrolide, lincosamide, and streptogramin B)-resistant organisms. Structure-activity studies revealed that arylalkyl carbamates with two and four carbon atoms between the aromatic moiety and carbamate nitrogen have the best in vitro activity. All of the C-10 epi analogues evaluated were found to have substantially less activity than the corresponding natural C-10 isomer. Several analogues demonstrated moderate antibacterial activity against the constitutively resistant S.aureus A-5278, S. pneumoniae5979, and S.pyogenes 930. However, despite potent in vitro activity, these analogues showed only moderate in vivo activity in mouse protection studies.

Animals↗

PubMed1976

Effect of capsular polysaccharide of Klebsiella pneumoniae on host resistance to bacterial infections. I. Induction of increased susceptibility to infections in mice.

When Klebsiella pneumoniae capsular polysaccharide (CPS-K) from type 1, Kasuya strain, was injected intraperitoneally (i.p.) immediately before i.p. bacterial challenge, the survival time of mice infected with Salmonella enteritidis NUB 1 (virulent strain) was shortened and the mortality rate for mice infected with S. enteritidis NUB 31 (avirulent strain) was enhanced. The promotion of infection with S. enteritidis NUB 1 by CPS-K depended upon its dose, the effect of CPS-K being demonstrable up to as little as 0.2 mug per mouse. In the case of S. enteritidis NUB 31, the effect of CPS-K was detectable only when more than 20 mug per mouse was injected. As a result of enumeration of bacterial populations in the peritoneal washing, blood, liver and spleen, it was revealed that CPS-K promoted in vivo growth of S. enteritidis NUB 1 and NUB 31. In addition, CPS-K enhanced the mortality rate in mice infected with Streptococcus pyogenes or Streptococcus pneumoniae. The peak CPS-K effect on infection with S. enteritidis NUB 1 was seen when given immediately before bacterial challenge. The active substance responsible for the infection-promoting effect of CPS-K was neutral CPS-K, which is distinct from the O antigen and from acidic CPS-K (the type-specific capsular antigen). Preparations of neutral CPS-K isolated from the other three strains of K. pneumoniae exhibited a marked infection-promoting effect comparable with that of preparations from the Kasuya strain. Neutral CPS-K, with identical antigenicity to that from the Kasuya strain, has already been found to exert a strong adjuvant effect on antibody responses to various antigens in mice. No parallelism exists between infection-promoting activity and adjuvant activity of neutral CPS-K.

Adjuvants, Immunologic↗

PubMed2006

In vitro activities of DX-619 and comparison quinolones against gram-positive cocci.

The in vitro activity of the novel quinolone DX-619 was compared to those of currently available quinolones against U.S. clinical isolates of Staphylococcus aureus, coagulase-negative staphylococci, Enterococcus spp., Streptococcus pyogenes, and Streptococcus pneumoniae. DX-619 was the most potent quinolone overall, indicating possible utility as an anti-gram-positive quinolone.

Anti-Infective Agents↗

PubMed1992

Postantibiotic sub-MIC effects of vancomycin, roxithromycin, sparfloxacin, and amikacin.

The sub-MIC effects (SMEs) and the postantibiotic sub-MIC effects (PA SMEs) of vancomycin, roxithromycin, and sparfloxacin for Streptococcus pyogenes and Streptococcus pneumoniae and of amikacin for Escherichia coli and Pseudomonas aeruginosa were investigated. A postantibiotic effect was induced by exposing strains to 10x the MIC of the antibiotic for 2 h in vitro. After the induction, the exposed cultures were washed to eliminate the antibiotics. Unexposed controls were treated similarly. Thereafter, the exposed cultures (PA SME) and the controls (SME) were exposed to different subinhibitory concentrations (0.1, 0.2, and 0.3x the MIC) of the same drug and growth curves for a period of 24 h were compared. In general, the PA SMEs were much more pronounced than the SMEs. However, for amikacin and E. coli the SME of 0.2 and 0.3x the MIC also had an initial bactericidal effect. The longest PA SMEs were demonstrated for the combinations with the most pronounced killing during the induction and for the combinations which exhibited the longest PAEs.

Amikacin↗

PubMed1990

Regulation of human monocyte/macrophage function by extracellular matrix. Adherence of monocytes to collagen matrices enhances phagocytosis of opsonized bacteria by activation of complement receptors and enhancement of Fc receptor function.

In inflammation monocytes emigrate from the peripheral circulation into an extravascular area rich in extracellular matrix proteins. In this milieu, phagocytes ingest and kill invading pathogens. In the present studies, we found that monocytes adhered to type I collagen gels phagocytized 2.5-12-fold more opsonized Escherichia coli, Staphylococcus aureus, Streptococcus pyogenes, and Streptococcus pneumoniae than plastic-adherent monocytes. The rate of phagocytosis and the number of bacteria ingested by collagen-adherent monocytes was equal to, or greater than, the number of bacteria ingested by 7-d cultured macrophages (M phi). Although both collagen- and plastic-adherent monocytes were bactericidal for E. coli and S. aureus, more bacteria were killed by collagen-adherent monocytes by virtue of their enhanced phagocytic capacity. Cultured M phi only were bacteriostatic. Adherence of monocytes to collagen gels activated C receptors (CR) types 1 and 3 for phagocytosis, and enhanced Fc receptor (FcR)-mediated phagocytosis. Collagen- and plastic-adherent monocytes produced equivalent amounts of superoxide anion in response to phorbol myristate acetate and opsonized zymosan. Thus, the enhanced phagocytosis and killing of opsonized bacteria by collagen-adherent monocytes appear to be by regulation of the function of membrane CR and FcR, without apparent enhancement of the respiratory burst. These data suggest that adherence of monocytes to the extracellular matrix during inflammation may rapidly activate these cells for enhanced phagocytic bactericidal activity.

Blood Bactericidal Activity↗

PubMed1992

Antibiotic susceptibility of upper respiratory tract pathogens in Sweden: a seven year follow-up study including loracarbef. Swedish Respiratory Tract Study Group.

The antibiotic susceptibility of Haemophilus influenzae, Moraxella catarrhalis, Streptococcus pyogenes and Streptococcus pneumoniae was investigated in five different geographical areas of Sweden in 1990 and compared with results from similar investigations performed in 1983 and 1986. Tests on 100 isolates per species and laboratory were performed by the disk diffusion method, and 10% of the strains plus all resistant ones were sent to the central laboratory for determination of MICs of ampicillin, phenoxymethylpenicillin, cefaclor, loracarbef, erythromycin, tetracycline and trimethoprim/sulfamethoxazole. Beta-lactamase production was found in 7% of H. influenzae and 71% of M. catarrhalis, and reduced susceptibility to penicillin in 3% of S. pneumoniae. Low frequencies (1-3%) of tetracycline resistance were found in H. influenzae and in the 2 streptococcal species, in which also less than 1% of the strains were resistant to erythromycin. Resistance to trimethoprim/sulfamethoxazole occurred in 7% (range 3-14%) of H. influenzae and in 3% of S. pneumoniae. Cefaclor was active against all streptococci except against S. pneumoniae with reduced susceptibility to penicillin. It was active against beta-lactamase negative strains of M. catarrhalis but had, according to the SIR-system, intermediate activity against H. influenzae. Loracarbef was twice as active as cefaclor against H. influenzae but equally active against the 3 other species tested.

Cephalosporins↗

PubMed2005

[Sore throat, streptococcal etiology? Use of etiological screening and antimicrobial prescription in two university pediatric centers].

The diagnosis and treatment of sore throat in pediatric patients attending one of two facilities at a university hospital: pediatric ambulatory facility (PAF) and emergency unit (EU) in a period of 14 months are described. There were 421 patients at the PAF and 289 at the EU, of whom 65% and 76% were studied for Streptococcus pyogenes respectively. Streptococcus were detected in both centers in 37% of cases, with a peak detection of 50% at ages 6 to 10 years. There were 217 patients without any bacteriological study, of whom 162 (75%) received antibiotics. The importance of bacteriological confirmation prior to antibiotic prescription in this disease is emphasized.

Acute Disease↗