Background: In view of the widespread use of penicillin for >50 years for the treatment of group A streptococcal infections, we examined the question of whether there has been a change in susceptibility to penicillin in group A streptococcal strains collected during a span of 80 years (1917 to 1997).
Methods: One hundred thirty-three group A streptococcal strains collected during 80 years were tested for changes in penicillin susceptibility. Three tests were used: (1) the microtiter broth minimal inhibitory concentration (MIC); (2) the minimal bactericidal concentration (MBC); and (3) the penicillin E strip MIC.
Results: The results indicate there has been no change in the susceptibility to penicillin in these group A streptococci during the past 80 years. The microtiter broth MIC90 for the oldest strains (0.032 microg/ml) was not significantly different from those collected most recently (0.032 microg/ml); there is no statistical difference between the raw MIC data for the four collection periods (P=0.468, analysis of variance on ranks).
Conclusions: There has been no change in the susceptibility of group A streptococci during this time in spite of well-documented cases of penicillin resistance in other Gram-positive organisms and despite recognized resistance of group A streptococci to other antibiotics.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1097/00006454-199805000-00006 | DOI Listing |
BMC Infect Dis
January 2025
Department of Respiratory Medicine, Anting Hospital of Jiading District, 1060 Hejing Road, Anting Town, Jiading District, Shanghai, 201805, China.
Background: Respiratory tract infections (RTIs) are one of the leading causes of morbidity and mortality worldwide. The increase in antimicrobial resistance in respiratory pathogens poses a major challenge to the effective management of these infections.
Objective: To investigate the distribution of major pathogens of RTIs and their antimicrobial resistance patterns in a tertiary care hospital and to develop a mathematical model to explore the relationship between pathogen distribution and antimicrobial resistance.
mSphere
January 2025
Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
Unlabelled: During infection, bacterial pathogens rely on secreted virulence factors to manipulate the host cell. However, in gram-positive bacteria, the molecular mechanisms underlying the folding and activity of these virulence factors after membrane translocation are not clear. Here, we solved the protein structures of two secreted parvulin and two secreted cyclophilin-like peptidyl-prolyl isomerase (PPIase) ATP-independent chaperones found in gram-positive streptococcal species.
View Article and Find Full Text PDFInfect Immun
January 2025
Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia, USA.
Streptococcal pyogenic exotoxins (Spe proteins) secreted by (group A , GAS) are responsible for scarlet fever and streptococcal toxic shock syndrome. Most Spes are superantigens that cause excessive inflammation by activating large numbers of T cells. However, Streptococcal pyogenic exotoxin B (SpeB) is an exception, which is pro-inflammatory through its protease activity.
View Article and Find Full Text PDFClin Microbiol Rev
January 2025
Department of Medicine, Division of Pulmonary/Allergy/Critical Care, The University of Alabama at Birmingham, Birmingham, Alabama, USA.
SUMMARY (the "pneumococcus") is a significant human pathogen. The key determinant of pneumococcal fitness and virulence is its ability to produce a protective polysaccharide (PS) capsule, and anti-capsule antibodies mediate serotype-specific opsonophagocytic killing of bacteria. Notably, immunization with pneumococcal conjugate vaccines (PCVs) has effectively reduced the burden of disease caused by serotypes included in vaccines but has also spurred a relative upsurge in the prevalence of non-vaccine serotypes.
View Article and Find Full Text PDFClin Oral Implants Res
January 2025
Etiology and Therapy of Periodontal and Periimplant Diseases (ETEP) Research Group, Faculty of Dentistry, Complutense University, Madrid, Spain.
Aim: To evaluate in vitro the antibacterial efficacy and cytocompatibility of different implant-decontamination methods, using both 2D and 3D peri-implant mucosa models.
Methods: Four decontamination methods [chlorhexidine (CHX), electrolytic treatment (GS), curcumin (CUR), xanthohumol (XN)] were compared in four independent experiments, three with a 2D peri-implant mucosa model on titanium surfaces and another on a 3D peri-implant mucosa model. These decontamination procedures were tested for their antibacterial effect using a multispecies biofilm model with Streptococcus oralis, Actinomyces naeslundii, Veillonella dispar, and Porphyromonas gingivalis for 24 h.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!