Penicillin-resistant pneumococci in a Merseyside hospital

Antimicrobial resistance and serotype distribution of Streptococcus pneumoniae isolates from Crete, Greece

Susceptibility to 14 antibiotics was determined for 125 clinical isolates of Streptococcus pneumoniae collected over a 3-year period in Crete, Greece. Twenty-three isolates (18.4%) showed intermediate resistance and 15 (12%) high-level resistance to penicillin. Erythromycin, chloramphenicol, tetracycline, trimethoprim-sulphamethoxazole and sparfloxacin resistance rates were 16.8, 10.4, 19.2, 24.8 and 9.6%, respectively. Multiple resistance was observed in 22 strains. Vancomycin and levofloxacin were the most active agents tested. The most prevalent serotype among penicillin-susceptible pneumococci was 14, followed by 9, 7 and 1, while among penicillin-intermediate or -resistant strains serotype 23 was predominant followed by 19 and 9. These results show that as well as a high level of penicillin resistance in this region, some strains are also resistant to other antibiotics and may show multi-drug resistance.

Nosocomial transmission of penicillin-resistant Streptococcus pneumoniae

Two patients were found to harbor intermediate-level penicillin-resistant Streptococcus pneumoniae in a pediatric hospital setting. For the first patient, the bacterium was isolated from a tracheal aspirate, and for the second patient, a positive blood culture was found a short time after the index case. Two molecular typing techniques (enterobacterial repetitive intergenic consensus sequence polymerase chain reaction, and repetitive sequence-based polymerase chain reaction) demonstrated homology among these isolates, which suggests person-to-person spread. We propose the need for institution-based infection control precautions that will limit the spread of penicillin-resistant pneumococci.

Antibiotic resistance among clinically important gram-positive bacteria in the UK

The resistance of bacteria to antibiotics, particularly those used for first-line therapy, is an increasing cause for concern. In the UK, the prevalence of resistance to methicillin and mupirocin in Staphylococcus aureus, and to penicillin and macrolides in Streptococcus pneumoniae, appear to be increasing. There has also been an increase in the number of hospitals where glycopeptide-resistant enterococci are known to have been isolated. The increases in methicillin-resistant S. aureus and glycopeptide-resistant enterococci are due, in part, to the inter-hospital spread of epidemic strains. Although new quinolones and streptogramins with activity against Gram-positive bacteria (including strains resistant to currently available agents) are under development, there is no reason to believe that resistance to these agents will not emerge. The control of resistance in Gram-positive bacteria will require a multi-faceted approach, including continued and improved surveillance, a reduction in the unnecessary use of antibiotics, and the application of other strategies such as vaccination.

Prevalence of antibiotic resistance and serotypes in pneumococci in England and Wales: results of observational surveys in 1990 and 1995

OBJECTIVE

To assess the prevalence of antibiotic resistance and serotype distribution among pneumococci in England and Wales in 1990 and 1995.

DESIGN

Observational surveys in March 1990 and March 1995. During two weeks in each survey period all pneumococci isolated in public health laboratories in England and Wales were collected and assessed for sensitivity to antibiotics and the distribution of serogroups or serotypes.

SETTING

The network of public health laboratories throughout England and Wales.

SUBJECTS

1127 individual patient isolates of Streptococcus pneumoniae obtained during the two surveys.

MAIN OUTCOME MEASURES

Sensitivity or resistance to a range of antibiotics; serogroup or serotype.

RESULTS

The prevalence of intermediate or full resistance to penicillin increased from 1.5% in 1990 to 3.9% in 1995 and resistance to erythromycin increased from 2.8% to 8.6%. About 92% of isolates belonged to serogroups or serotypes included in the currently available pneumococcal vaccine.

CONCLUSION

Resistance to penicillin and erythromycin has increased among pneumococci in England and Wales. Continued surveillance to assess further increases in the prevalence of pneumococcal resistance to antibiotics is essential.

Trends in antimicrobial resistance of Streptococcus pneumoniae in Japan

A total of 184 isolates of Streptococcus pneumoniae were recovered from the sputa of patients over a 5-year period in the Nagasaki area and were examined. A total of 30 strains were resistant to penicillin (MIC, > or = 0.10 micrograms/ml), 13 of which belonged to serotype 19B. These strains showed decreased susceptibility to other antimicrobial agents. Vancomycin, cefpirome, and imipenem were the most active agents tested.

Capsular serotypes and antibiotic sensitivity of Streptococcus pneumoniae isolated from primary-school children

A total of 1049 primary-school children in 18 schools were screened for carriage of Streptococcus pneumoniae. Data on family size, antibiotic use, travel and hospital admissions were collected. Pneumococcal serotyping and sensitivity tests were performed. One third of children were found to be pneumococcal carriers. Ten of 344 isolates were penicillin-resistant (2.9%). Apart from resistance to trimethoprim and ciprofloxacin, resistance rates in penicillin-sensitive strains were low. Among penicillin-resistant strains (PRP), co-resistance to trimethoprim, chloramphenicol and tetracycline was common. Cefotaxime-resistance was seen in 90% of PRP. Although 24 serotypes were represented, groups 6, 19 and 23 accounted for 55% of strains. Serogroup 23 strains were significantly more likely to be penicillin-resistant than other groups/types. Clustering of strains by serotype and antibiotic resistance was seen in several schools. No association with foreign travel, family size or age of siblings was seen and penicillin resistance was not associated with prior antibiotic use. However, hospital admission was significantly associated with carriage of PRP. The implications of detecting PRP in the community are discussed.

Penicillin resistance among Streptococcus pneumoniae in Europe

Penicillin resistance in Streptococcus pneumoniae, which has been occasionally described in European isolates since the early 1970s, presently constitutes a general problem, although its rate may vary largely between countries and areas. Spain and Hungary show the highest rates of resistance and were probably the starting point for further dissemination to adjacent and distant countries. In Europe, resistant strains belong predominantly to serotypes 6, 9, 14, 19, and 23, and are isolated more frequently from pediatric than from adult patients, and from respiratory and CSF samples rather than blood. Although penicillin resistance in pneumococci is usually a well-recognized problem, some difficulties, mainly related to methodologic aspects of in vitro susceptibility testing, still subsist for its proper surveillance, but may be overcome through the adoption of adequate diagnostic protocols and tools.

Co-existent cross-infection with Streptococcus pneumoniae and group B streptococci on an adult oncology unit

An outbreak of respiratory infection in an adult oncology unit is described where there was evidence of co-existent cross-infection with Streptococcus pneumoniae serotype 14 and Lancefield group B streptococcus type Ia. The presumed route of transmission was droplet spread from patient to patient. No further cases arose after the ward had been closed to new admissions and all symptomatic patients were treated with erythromycin. We suggest that patients with pneumococcal pneumonia on units housing elderly debilitated patients should be isolated. Infection control teams should be aware of the ability of Lancefield group B streptococci to spread by cross-infection among adult patients.

Capsular types and susceptibility to penicillin of pneumococci isolated from cerebrospinal fluid or blood in Denmark, 1983-1988

By means of the capsular reaction test, we typed 2,294 pneumococcal strains isolated from blood or cerebrospinal fluid (CSF) in Denmark during 1983-88.91% of the strains belonged to types included in the 23-valent vaccine. Among 254 pneumococcal isolates from blood and CSF from Danish children, types 6A + 6B, 18C, 14, 7F, 1 and 19F, in that order of frequency, were the most common ones, accounting for 68%. Among 2,031 pneumococcal strains from adults, the most common isolates were types 1, 3, 14, 7F, 4, and 6A + 6B, accounting for 50% of all pneumococcal strains isolated from patients with invasive disease. Penicillin-resistant invasive strains of Streptococcus pneumoniae are rare in Denmark (< 1%).

Penicillin-resistant pneumococci

Penicillin-resistant pneumococci were first reported in Australia in 1967 and appeared in the UK in 1976. Their prevalence is increasing but varies greatly worldwide. The mechanism of resistance lies in the alteration of penicillin-binding proteins. Penicillin-resistant strains are often also resistant to a variety of non-beta-lactam antibiotics. Many different serotypes have been found to be penicillin resistant, type 23 being the most common resistant serotype in the UK. Use of oxacillin discs is recommended for penicillin sensitivity testing, otherwise resistant isolates may escape detection. Treatment of infected patients depends on several factors including the degree of resistance of the infecting strain, the sensitivity to alternative agents and the achievable concentration of antibiotic at the site of the infection. Carriage of penicillin-resistant pneumococci is more common in children, especially the recently hospitalized and those recently exposed to antibiotics. Outbreaks of infection have occurred and various control measures have been suggested in attempts to limit the spread of resistant strains.