High-level penicillin G-resistant as well as multidrug-resistant Streptococcus pneumoniae isolates were first described in South Africa in 1977. The relationship between these original multidrug-resistant South African isolates and other resistant clones was investigated. Twenty-six representative isolates isolated from initial outbreaks in South Africa from 1977 to 1978 were characterized by m...

OBJECTIVE To determine the penicillin resistance and serotype distribution of Streptococcus pneumoniae strains and to identify clonal relationships of isolates resistant to penicillin by means of pulsed-field gel electrophoresis (PFGE). METHODS In total, 193 S. pneumoniae strains were isolated from clinical specimens between November 1997 and January 2000. Susceptibility testing was carried o...

A total of 125 non-penicillin-susceptible Streptococcus pneumoniae isolates were received at the Norwegian Institute of Public Health in the period from 1995 to 2001. The strains were tested for antimicrobial susceptibility, serotyped, and genotyped by multilocus sequence typing (MLST); and their penicillin-binding proteins (PBPs) were typed by restriction fragment length polymorphism analysis ...

Lobar pneumonia models were established in rats by intratracheal inoculation of either penicillin-susceptible (immunocompetent model) or penicillin-resistant (immunocompetent and neutropenic models) Streptococcus pneumoniae. Untreated animals maintained a relatively high bacterial load in the lungs but only occasionally developed bacteraemia or pleurisy. The infection was rarely fatal in immuno...

Erythromycin resistance rates among penicillin-susceptible Streptococcus pneumoniae were 38 and 92% among penicillin-intermediate and -resistant S. pneumoniae isolates from Hong Kong, respectively, and 27% (43 of 158) of the isolates showed the MLS(B) phenotype, and the majority carried the ermB gene; 73% (115 of 158) displayed the M phenotype, and all possessed the mef gene. The MLS(B) phenoty...

Reduced affinity of penicillin-binding proteins (PBPs) for binding penicillin has been proposed as a mechanism of beta-lactam antibiotic resistance in staphylococci. Penicillin binding by PBPs of three penicillin-susceptible and two penicillin-resistant strains of Staphylococcus aureus was studied in kinetic assays to determine rate constants, drug concentrations at which PBPs were bound and th...

During the isolation of penicillin resistant mutants of Brucella abortus, B. suis, or B. melitensis two effects of the antibiotic were observed: (1) rapid population changes involving the establishment of nonsmooth mutants during growth in increasing concentrations of penicillin; and (2) the occurrence of smooth, penicillin resistant cells whose phenotype differed depending on whether they grew...

Streptococcus pneumoniae is a major cause of pneumonia, meningitis, septicemia, acute otitis media, and other serious infections, severely affecting infants, young children, and the elderly. In the past, S. pneumoniae was uniformly susceptible to penicillin, which remained the drug of choice for serious infections. However, since the mid-1960s, resistance to penicillin, which was first reported...