Acta Microbiologica et Immunologica Hungarica, 48 (3–4), pp. 359–391 (2001) * This paper was written to commemorate to the fiftieth anniversary of the foundation of the Hungarian Society for Microbiology. 1217-8950/2001/$ 5.00  2001 Akadémiai Kiadó, Budapest RESISTANCE TO β-LACTAMS AND GLYCOPEPTIDES IN STAPHYLOCOCCI AND STREPTOCOCCI (A REVIEW)* FERENC ROZGONYI, ESZTER OSTORHÁZI, CSABA L. MARÓDI AND ÁGOSTON GHIDÁN Institute of Medical Microbiology, Faculty of General Medicine, Semmelweis University P.O. Box 370, H-1445 Budapest, Hungary (Received: March 21, 2001; accepted: March 28, 2001) Molecular mechanisms of the action of β-lactam and glycopeptide antibiotics, as well as genetic background and phenotipical features of the resistance of staphylococci, streptococci and enterococci to these antibiotics are reviewed. Furthermore, susceptibility patterns concerning β-lactam and glycopeptide drugs of staphylococcal, streptococcal, as well as enterococcal strains isolated from clinical specimens at the Semmelweis University of Medicine, Budapest, Hungary between January 1997 and December 2000 are also presented. Keywords: β-lactam resistance, glycopeptide resistance, staphylococci, enterococci, streptococci Introduction Staphylococci, enterococci and streptococci are the most frequently isolated bacteria from extraintestinal clinical specimens. Staphylococcus aureus can cause both local, disseminated, disseminated generalized infections such as furuncle, abscess or postoperative wound infections and bacteriaemia, endocarditis, meningitis, sepsis and osteomyelitis. Exfoliative toxin producing strains can also cause scalded skin syndromes and toxic shock syndrome toxin-1 producing ones can induce toxic shock syndromes, too. Coagulase-negative staphylococci (CNS) and enterococci are common causes of any – mainly catheter associated-nosocomial infections in premature infants